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Boulder, Colo., USA: GSA's dynamic online journal, Geosphere, posts articles online regularly. Locations and topics studied this month include the Moine thrust zone in northwestern Scotland; the Eastern California shear zone; implementation of "OpenTopography"; the finite evolution of "mole tracks"; the southern central Andes; the work of International Ocean Discovery Program (IODP) Expedition 351; and the Fairweather fault, Alaska, USA. You can find these articles at https://geosphere.geoscienceworld.org/content/early/recent.

Detrital-zircon analyses, provenance, and late Paleozoic sediment dispersal in the context of tectonic evolution of the Ouachita orogen
William A. Thomas; George E. Gehrels; Kurt E. Sundell; Mariah C. Romero

Abstract: New analyses for U-Pb ages and εHft values, along with previously published U-Pb ages, from Mississippian-Permian sandstones in synorogenic clastic wedges of the Ouachita foreland and nearby intracratonic basins support new interpretations of provenance and sediment dispersal along the southern Midcontinent of North America. Recently published U-Pb and Hf data from the Marathon foreland confirm a provenance in the accreted Coahuila terrane, which has distinctive Amazonia/Gondwana characteristics. Data from Pennsylvanian-Permian sandstones in the Fort Worth basin, along the southern arm of the Ouachita thrust belt, are nearly identical to those from the Marathon foreland, strongly indicating the same or a similar provenance. The accreted Sabine terrane, which is documented by geophysical data, is in close proximity to the Coahuila terrane, suggesting the two are parts of an originally larger Gondwanan terrane. The available data suggest that the Sabine terrane is a Gondwanan terrane that was the provenance of the detritus in the Fort Worth basin. Detrital-zircon data from Permian sandstones in the intracratonic Anadarko basin are very similar to those from the Fort Worth basin and Marathon foreland, indicating sediment dispersal from the Coahuila and/or Sabine terranes within the Ouachita orogen cratonward from the immediate forelands onto the southern craton. Similar, previously published data from the Permian basin suggest widespread distribution from the Ouachita orogen. In contrast to the other basins along the Ouachita-Marathon foreland, the Mississippian-Pennsylvanian sandstones in the Arkoma basin contain a more diverse distribution of detrital-zircon ages, indicating mixed dispersal pathways of sediment from multiple provenances. Some of the Arkoma sandstones have U-Pb age dis¬tributions like those of the Fort Worth and Marathon forelands. In contrast, other sandstones, especially those with paleocurrent and paleogeographic indicators of southward progradation of deposi¬tional systems onto the northern distal shelf of the Arkoma basin, have U-Pb age distributions and εHft values like those of the "Appalachian signature." The combined data suggest a mixture of detritus from the proximal Sabine terrane/Ouachita orogenic belt with detritus routed through the Appalachian basin via the southern Illinois basin to the distal Arkoma basin. The Arkoma basin evidently marks the southwestern extent of Appalachian-derived detritus along the Ouachita-Marathon foreland and the transition southwestward to overfilled basins that spread detritus onto the southern craton from the Ouachita-Marathon orogen, including accreted Gondwanan terranes.

View article: https://pubs.geoscienceworld.org/gsa/geosphere/article-abstract/doi/10.1130/GES02288.1/598714/Detrital-zircon-analyses-provenance-and-late

Structural, petrological, and tectonic constraints on the Loch Borralan and Loch Ailsh alkaline intrusions, Moine thrust zone, northwestern Scotland
Robert Fox; Michael P. Searle

Abstract: During the Caledonian orogeny, the Moine thrust zone in northwestern Scotland (UK) emplaced Neoproterozoic Moine Supergroup rocks, metamorphosed during the Ordovician (Grampian) and Silurian (Scandian) orogenic periods, westward over the Laurentian passive margin in the northern highlands of Scotland. The Laurentian margin comprises Archean-Paleoproterozoic granulite and amphibolite facies basement (Scourian and Laxfordian complexes, Lewisian gneiss), Proterozoic sedimentary rocks (Stoer and Torridon Groups), and Cambrian-Ordovician passive-margin sediments. Four major thrusts, the Moine, Ben More, Glencoul, and Sole thrusts, are well exposed in the Assynt window. Two highly alkaline syenite intrusions crop out within the Moine thrust zone in the southern Assynt window. The Loch Ailsh and Loch Borralan intrusions range from ultramafic melanite-biotite pyroxenite and pseudoleucite-bearing biotite nepheline syenite (borolanite) to alkali-feldspar-bearing and quartz-bearing syenites. Within the thrust zone, syenites intrude up to the Ordovician Durness Group limestones and dolomites, forming a high-temperature contact metamorphic aureole with diopside-forsterite-phlogopite-brucite marbles exposed at Ledbeg quarry. Controversy remains as to whether the Loch Ailsh and Loch Borralan syenites were intruded prior to thrusting or intruded syn- or post-thrusting. Borolanites contain large white leucite crystals pseudomorphed by alkali feldspar, muscovite, and nepheline (pseudoleucite) that have been flattened and elongated during ductile shearing. The minerals pseudomorphing leucites show signs of ductile deformation indicating that high-temperature (~500 °C) deformation acted upon pseudomorphed leucite crystals that had previously undergone subsolidus breakdown. New detailed field mapping and structural and petrological observations are used to constrain the geological evolution of both the Loch Ailsh and the Loch Borralan intrusions and the chronology of the Moine thrust zone. The data supports the interpretation that both syenite bodies were intruded immediately prior to thrusting along the Moine, Ben More, and Borralan thrusts.

View article: https://pubs.geoscienceworld.org/gsa/geosphere/article-abstract/doi/10.1130/GES02330.1/598715/Structural-petrological-and-tectonic-constraints

Tectonostratigraphic record of late Miocene-early Pliocene transtensional faulting in the Eastern California shear zone, southwestern USA
Rebecca J. Dorsey; Brennan O'Connell; Kevin K. Gardner; Mindy B. Homan; Scott E.K. Bennett ...

Abstract: The Eastern California shear zone (ECSZ; southwestern USA) accommodates ~20%-25% of Pacific-North America relative plate motion east of the San Andreas fault, yet little is known about its early tectonic evolution. This paper presents a detailed stratigraphic and structural analysis of the uppermost Miocene to lower Pliocene Bouse Formation in the southern Blythe Basin, lower Colorado River valley, where gently dipping and faulted strata provide a record of deformation in the paleo-ECSZ. In the western Trigo Mountains, splaying strands of the Lost Trigo fault zone include a west-dipping normal fault that cuts the Bouse Formation and a steeply NE-dipping oblique dextral-normal fault where an anomalously thick (~140 m) section of Bouse Formation siliciclastic deposits filled a local fault-controlled depocenter. Systematic basinward thickening and stratal wedge geometries in the western Trigo and southeastern Palo Verde Mountains, on opposite sides of the Colorado River valley, record basinward tilting during deposition of the Bouse Formation. We conclude that the southern Blythe Basin formed as a broad transtensional sag basin in a diffuse releasing stepover between the dextral Laguna fault system in the south and the Cibola and Big Maria fault zones in the north. A palinspastic reconstruction at 5 Ma shows that the southern Blythe Basin was part of a diffuse regional network of linked right-step¬ping dextral, normal, and oblique-slip faults related to Pacific-North America plate boundary dextral shear. Diffuse transtensional strain linked northward to the Stateline fault system, eastern Garlock fault, and Walker Lane, and southward to the Gulf of California shear zone, which initiated ca. 7-9 Ma, implying a similar age of inception for the paleo-ECSZ.

View article: https://pubs.geoscienceworld.org/gsa/geosphere/article-abstract/doi/10.1130/GES02337.1/598716/Tectonostratigraphic-record-of-late-Miocene-early

Intra-oceanic submarine arc evolution recorded in an ~1-km-thick rear-arc succession of distal volcaniclastic lobe deposits
Kyle Johnson; Kathleen M. Marsaglia; Philipp A. Brandl; Andrew P. Barth; Ryan Waldman ...

Abstract: International Ocean Discovery Program (IODP) Expedition 351 drilled a rear-arc sedimentary succession ~50 km west of the Kyushu-Palau Ridge, an arc remnant formed by rifting during formation of the Shikoku Basin and the Izu-Bonin-Mariana arc. The ~1-km-thick Eocene to Oligocene deep-marine volcaniclastic succession recovered at Site U1438 provides a unique opportunity to study a nearly complete record of intra-oceanic arc development, from a rear-arc perspective on crust created during subduction initiation rather than supra-subduction seafloor spreading. Detailed facies analysis and definition of depositional units allow for broader stratigraphic analysis and definition of lobe elements. Patterns in gravity-flow deposit types and subunits appear to define a series of stacked lobe systems that accumulated in a rear-arc basin. The lobe subdivisions, in many cases, are a combination of a turbidite-dominated subunit and an overlying debris-flow subunit. Debris flow-rich lobe-channel sequences are grouped into four, 1.6-2 m.y. episodes, each roughly the age range of an arc volcano. Three of the episodes contain overlapping lobe facies that may have resulted from minor channel switching or input from a different source. The progressive up-section coarsening of episodes and the increasing channel-facies thicknesses within each episode suggest progressively prograding facies from a maturing magmatic arc. Submarine geomorphology of the modern Mariana arc and West Mariana Ridge provide present-day examples that can be used to interpret the morphology and evolution of the channel (or channels) that fed sediment to Site U1438, forming the sequences interpreted as depositional lobes. The abrupt change from very thick and massive debris flows to fine-grained turbidites at the unit III to unit II boundary reflects arc rifting and progressive waning of turbidity current and ash inputs. This interpretation is consistent with the geochemical record from melt inclusions and detrital zircons. Thus, Site U1438 provides a unique record of the life span of an intra-oceanic arc, from inception through maturation to its demise by intra-arc rifting and stranding of the remnant arc ridge.

View article: https://pubs.geoscienceworld.org/gsa/geosphere/article-abstract/doi/10.1130/GES02321.1/598717/Intra-oceanic-submarine-arc-evolution-recorded-in

Measuring change at Earth's surface: On-demand vertical and three-dimensional topographic differencing implemented in OpenTopography
Chelsea Scott; Minh Phan; Viswanath Nandigam; Christopher Crosby; J Ramon Arrowsmith

Abstract: Topographic differencing measures landscape change by comparing multitemporal high-resolution topography data sets. Here, we focused on two types of topographic differencing: (1) Vertical differencing is the subtraction of digital elevation models (DEMs) that span an event of interest. (2) Three-dimensional (3-D) differencing measures surface change by registering point clouds with a rigid deformation. We recently released topographic differencing in OpenTopography where users perform on-demand vertical and 3-D differencing via an online interface. OpenTopography is a U.S. National Science Foundation-funded facility that provides access to topographic data and processing tools. While topographic differencing has been applied in numerous research studies, the lack of standardization, particularly of 3-D differencing, requires the customization of processing for individ¬ual data sets and hinders the community's ability to efficiently perform differencing on the growing archive of topography data. Our paper focuses on streamlined techniques with which to efficiently difference data sets with varying spatial resolution and sensor type (i.e., optical vs. light detection and ranging [lidar]) and over variable landscapes. To optimize on-demand differencing, we considered algorithm choice and displacement resolution. The optimal resolution is controlled by point density, landscape characteristics (e.g., leaf-on vs. leaf-off), and data set quality. We provide processing options derived from metadata that allow users to produce optimal high-quality results, while experienced users can fine tune the parameters to suit their needs. We anticipate that the differencing tool will expand access to this state-of-the-art technology, will be a valuable educational tool, and will serve as a template for differencing the growing number of multitemporal topography data sets.

View article: https://pubs.geoscienceworld.org/gsa/geosphere/article-abstract/doi/10.1130/GES02259.1/598718/Measuring-change-at-Earth-s-surface-On-demand

Coseismic deformation of the ground during large-slip strike-slip ruptures: Finite evolution of "mole tracks"
T.A. Little; P. Morris; M.P. Hill; J. Kearse; R.J. Van Dissen ...

Abstract: To evaluate ground deformation resulting from large (~10 m) coseismic strike-slip displacements, we focus on deformation of the Kekerengu fault during the November 2016 Mw 7.8 Kaik?ura earthquake in New Zealand. Combining post-earthquake field observations with analysis of high-resolution aerial photography and topographic models, we describe the structural geology and geomorphology of the rupture zone. During the earthquake, fissured pressure bulges ("mole tracks") initiated at stepovers between synthetic Riedel (R) faults. As slip accumulated, near-surface "rafts" of cohesive clay-rich sediment, bounded by R faults and capped by grassy turf, rotated about a vertical axis and were internally shortened, thus amplifying the bulges. The bulges are flanked by low-angle contractional faults that emplace the shortened mass of detached sediment outward over less-deformed ground. As slip accrued, turf rafts fragmented into blocks bounded by short secondary fractures striking at a high angle to the main fault trace that we interpret to have originated as antithetic Riedel (R¢) faults. Eventually these blocks were dispersed into strongly sheared earth and variably rotated. Along the fault, clockwise rotation of these turf rafts within the rupture zone averaged ~20°-30°, accommodat¬ing a finite shear strain of 1.0-1.5 and a distributed strike slip of ~3-4 m. On strike-slip parts of the fault, internal shortening of the rafts averaged 1-2 m parallel to the R faults and ~1 m perpendicular to the main fault trace. Driven by distortional rotation, this contraction of the rafts exceeds the magnitude of fault heave. Turf rafts on slightly transtensional segments of the fault were also bulged and shortened--relationships that can be explained by a kinematic model involving "deformable slats." In a paleoseismic trench cut perpendicular the fault, one would observe fissures, low-angle thrusts, and steeply dipping strike-slip faults--some cross-cutting one another--yet all may have formed during a single earthquake featuring a large strike-slip displacement.

View article: https://pubs.geoscienceworld.org/gsa/geosphere/article-abstract/doi/10.1130/GES02336.1/598719/Coseismic-deformation-of-the-ground-during-large

Detrital zircon record of Phanerozoic magmatism in the southern Central Andes
T.N. Capaldi; N.R. McKenzie; B.K. Horton; C. Mackaman-Lofland; C.L. Colleps ...

Abstract: The spatial and temporal distribution of arc magmatism and associated isotopic variations provide insights into the Phanerozoic history of the western margin of South America during major shifts in Andean and pre-Andean plate interactions. We integrated detrital zircon U-Th-Pb and Hf isotopic results across continental magmatic arc systems of Chile and western Argentina (28°S-33°S) with igneous bedrock geochronologic and zircon Hf isotope results to define isotopic signatures linked to changes in continental margin processes. Key tectonic phases included: Paleozoic terrane accretion and Carboniferous subduction initiation during Gondwanide orogenesis, Permian-Triassic extensional collapse, Jurassic-Paleogene continental arc magmatism, and Neogene flat slab subduction during Andean shortening. The ~550 m.y. record of magmatic activity records spatial trends in magma composition associated with terrane boundaries. East of 69°W, radiogenic isotopic signatures indicate reworked continental lithosphere with enriched (evolved) εHf values and low (0.7) zircon Th/U values consistent with increased asthenospheric contributions during lithospheric thinning. Spatial constraints on Mesozoic to Cenozoic arc width provide a rough approximation of relative subduction angle, such that an increase in arc width reflects shallower slab dip. Comparisons among slab dip calculations with time-averaged εHf and Th/U zircon results exhibit a clear trend of decreasing (enriched) magma compositions with increasing arc width and decreasing slab dip. Collectively, these data sets demonstrate the influence of subduction angle on the position of upper-plate magmatism (including inboard arc advance and outboard arc retreat), changes in isotopic signatures, and overall composition of crustal and mantle material along the western edge of South America.

View article: https://pubs.geoscienceworld.org/gsa/geosphere/article-abstract/doi/10.1130/GES02346.1/596772/Detrital-zircon-record-of-Phanerozoic-magmatism-in

Prehistoric earthquakes on the Banning strand of the San Andreas fault, North Palm Springs, California
Bryan A. Castillo; Sally F. McGill; Katherine M. Scharer; Doug Yule; Devin McPhillips ...

Abstract: We studied a paleoseismic trench excavated in 2017 across the Banning strand of the San Andreas fault and herein provide the first detailed record of ground-breaking earthquakes on this important fault in Southern California. The trench exposed an ~40-m-wide fault zone cutting through alluvial sand, gravel, silt, and clay deposits. We evaluated the paleoseismic record using a new metric that combines event indicator quality and stratigraphic uncertainty. The most recent paleoearthquake occurred between 950 and 730 calibrated years B.P. (cal yr B.P.), potentially contemporaneous with the last rupture of the San Gorgonio Pass fault zone. We interpret five surface-rupturing earthquakes since 3.3-2.5 ka and eight earthquakes since 7.1-5.7 ka. It is possible that additional events have occurred but were not recognized, especially in the deeper (older) section of the stratigraphy, which was not fully exposed across the fault zone. We calculated an average recurrence interval of 380-640 yr based on four complete earthquake cycles between earthquakes 1 and 5. The average recurrence interval is thus slightly less than the elapsed time since the most recent event on the Banning strand. The average recurrence interval on the Banning strand is thus intermediate between longer intervals published for the San Gorgonio Pass fault zone (~1600 yr) and shorter intervals on both the Mission Creek strand of the San Andreas fault (~215 yr) and the Coachella section (~125 yr) of the San Andreas fault.

View article: https://pubs.geoscienceworld.org/gsa/geosphere/article-abstract/doi/10.1130/GES02237.1/596773/Prehistoric-earthquakes-on-the-Banning-strand-of

Geomorphic expression and slip rate of the Fairweather fault, southeast Alaska, and evidence for predecessors of the 1958 rupture
Robert C. Witter; Adrian M. Bender; Katherine M. Scharer; Christopher B. DuRoss; Peter J. Haeussler ...

Abstract: Active traces of the southern Fairweather fault were revealed by light detection and ranging (lidar) and show evidence for transpressional deformation between North America and the Yakutat block in southeast Alaska. We map the Holocene geomorphic expression of tectonic deformation along the southern 30 km of the Fairweather fault, which ruptured in the 1958 moment magnitude 7.8 earthquake. Digital maps of surficial geology, geomorphology, and active faults illustrate both strike-slip and dip-slip deformation styles within a 10°-30° double restraining bend where the southern Fairweather fault steps offshore to the Queen Charlotte fault. We measure offset landforms along the fault and calibrate legacy 14C data to reassess the rate of Holocene strike-slip motion (?49 mm/yr), which corroborates published estimates that place most of the plate boundary motion on the Fairweather fault. Our slip-rate estimates allow a component of oblique-reverse motion to be accommodated by contractional structures west of the Fairweather fault consistent with geodetic block models. Stratigraphic and structural relations in hand-dug excavations across two active fault strands provide an incomplete paleoseismic record including evidence for up to six surface ruptures in the past 5600 years, and at least two to four events in the past 810 years. The incomplete record suggests an earthquake recurrence interval of ?270 years--much longer than intervals View article: https://pubs.geoscienceworld.org/gsa/geosphere/article-abstract/doi/10.1130/GES02299.1/596774/Geomorphic-expression-and-slip-rate-of-the

RIVERSIDE, Calif. -- As its name suggests, dark matter -- material which makes up about 85% of the mass in the universe -- emits no light, eluding easy detection. Its properties, too, remain fairly obscure.

Now, a theoretical particle physicist at the University of California, Riverside, and colleagues have published a research paper in the Journal of High Energy Physics that shows how theories positing the existence a new type of force could help explain dark matter's properties.

"We live in an ocean of dark matter, yet we know very little about what it could be," said Flip Tanedo, an assistant professor of physics and astronomy and the paper's senior author. "It is one of the most vexing known unknowns in nature. We know it exists, but we do not know how to look for it or why it hasn't shown up where we expected it."

Physicists have used telescopes, gigantic underground experiments, and colliders to learn more about dark matter for the last 30 years, though no positive evidence has materialized. The negative evidence, however, has forced theoretical physicists like Tanedo to think more creatively about what dark matter could be.

The new research, which proposes the existence of an extra dimension in space-time to search for dark matter, is part of an ongoing research program at UC Riverside led by Tanedo. According to this theory, some of the dark matter particles don't behave like particles. In effect, invisible particles interact with even more invisible particles in such a way that the latter cease to behave like particles.

"The goal of my research program for the past two years is to extend the idea of dark matter 'talking' to dark forces," Tanedo said. "Over the past decade, physicists have come to appreciate that, in addition to dark matter, hidden dark forces may govern dark matter's interactions. These could completely rewrite the rules for how one ought to look for dark matter."

If two particles of dark matter are attracted to, or repelled by, each other, then dark forces are operating. Tanedo explained that dark forces are described mathematically by a theory with extra dimensions and appear as a continuum of particles that could address puzzles seen in small galaxies.

"Our ongoing research program at UCR is a further generalization of the dark force proposal," he said. "Our observed universe has three dimensions of space. We propose that there may be a fourth dimension that only the dark forces know about. The extra dimension can explain why dark matter has hidden so well from our attempts to study it in a lab."

Tanedo explained that although extra dimensions may sound like an exotic idea, they are actually a mathematical trick to describe "conformal field theories" -- ordinary three-dimensional theories that are highly quantum mechanical. These types of theories are mathematically rich, but do not contain conventional particles and so are typically not considered to be relevant for describing nature. The mathematical equivalence between these challenging three-dimensional theories and a more tractable extra dimensional theory is known as the holographic principle.

"Since these conformal field theories were both intractable and unusual, they hadn't really been systematically applied to dark matter," Tanedo added. "Instead of using that language, we work with the holographic extra-dimensional theory."

The key feature of the extra-dimensional theory is that the force between dark matter particles is described by an infinite number of different particles with different masses called a continuum. In contrast, ordinary forces are described by a single type of particle with a fixed mass. This class of continuum-dark sectors is exciting to Tanedo because it does something "fresh and different."

According to Tanedo, past work on dark sectors focuses primarily on theories that mimic the behavior of visible particles. His research program is exploring the more extreme types of theories that most particle physicists found less interesting, perhaps because no analogs exist in the real world.

In Tanedo's theory, the force between dark matter particles is surprisingly different from the forces felt by ordinary matter.

"For the gravitational force or electric force that I teach in my introductory physics course, when you double the distance between two particles you reduce the force by a factor of four. A continuum force, on the other hand, is reduced by a factor of up to eight."

What implications does this extra dimensional dark force have? Since ordinary matter may not interact with this dark force, Tanedo turned to the idea of self-interacting dark matter, an idea pioneered by Hai-Bo Yu, an associate professor of physics and astronomy at UCR who is not a coauthor on the paper. Yu showed that even in the absence of any interactions with normal matter, the effects of these dark forces could be observed indirectly in dwarf spheroidal galaxies. Tanedo's team found the continuum force can reproduce the observed stellar motions.

"Our model goes further and makes it easier than the self-interacting dark matter model to explain the cosmic origin of dark matter," Tanedo said.

Next, Tanedo's team will explore a continuum version of the "dark photon" model.

"It's a more realistic picture for a dark force," Tanedo said. "Dark photons have been studied in great detail, but our extra-dimensional framework has a few surprises. We will also look into the cosmology of dark forces and the physics of black holes."

Tanedo has been working diligently on identifying "blind spots" in his team's search for dark matter.

"My research program targets one of the assumptions we make about particle physics: that the interaction of particles is well-described by the exchange of more particles," he said. "While that is true for ordinary matter, there's no reason to assume that for dark matter. Their interactions could be described by a continuum of exchanged particles rather than just exchanging a single type of force particle."

It's long been known that people living with HIV experience a loss of white matter in their brains. As opposed to "gray matter," which is composed of the cell bodies of neurons, white matter is made up of a fatty substance called myelin that coats neurons, offering protection and helping them transmit signals quickly and efficiently. A reduction in white matter is associated with motor and cognitive impairment.

Earlier work by a team from the University of Pennsylvania and Children's Hospital of Philadelphia (CHOP) found that antiretroviral therapy (ART)--the lifesaving suite of drugs that many people with HIV use daily--can reduce white matter, but it wasn't clear how the virus itself contributed to this loss.

In a new study using both human and rodent cells, the team has hammered out a detailed mechanism, revealing how HIV prevents the myelin-making brain cells called oligodendrocytes from maturing, thus putting a wrench in white matter production. When the researchers applied a compound blocking this process, the cells were once again able to mature.

The work is published in the journal Glia.

"Even when people with HIV have their disease well-controlled by antiretrovirals, they still have the virus present in their bodies, so this study came out of our interest in understanding how HIV infection itself affects white matter," says Kelly Jordan-Sciutto, a professor in Penn's School of Dental Medicine and co-senior author on the study. "By understanding those mechanisms, we can take the next step to protect people with HIV infection from these impacts."

"When people think about the brain, they think of neurons, but they often don't think about white matter, as important as it is," says Judith Grinspan, a research scientist at CHOP and the study's other co-senior author. "But it's clear that myelination is playing key roles in various stages of life: in infancy, in adolescence, and likely during learning in adulthood too. The more we find out about this biology, the more we can do to prevent white matter loss and the harms that can cause."

Jordan-Sciutto and Grinspan have been collaborating for several years to elucidate how ART and HIV affect the brain, and specifically oligodendrocytes, a focus of Grinspan's research. Their previous work on antiretrovirals had shown that commonly used drugs disrupted the function of oligodendrocytes, reducing myelin formation.

In the current study, they aimed to isolate the effect of HIV on this process. Led by Lindsay Roth, who recently earned her doctoral degree within the Biomedical Graduate Studies group at Penn and completed a postdoctoral fellowship working with Jordan-Sciutto and Grinspan, the investigation began by looking at human macrophages, one of the major cell types that HIV infects.

Scientists had hypothesized that HIV's impact on the brain arose indirectly through the activity of these immune cells since the virus doesn't infect neurons or oligodendrocytes. To learn more about how this might affect white matter specifically, the researchers took the fluid in which macrophages infected with HIV were growing and applied it to rat oligodendrocyte precursor cells, which mature into oligodendrocytes. While this treatment didn't kill the precursor cells, it did block them from maturing into oligodendrocytes. Myelin production was subsequently also reduced.

"Immune cells that are infected with the virus secrete harmful substances, which normally target invading organisms, but can can also kill nearby cells, such as neurons, or stop them from differentiating," Grinspan says. "So the next step was to figure out what was being secreted to cause this effect on the oligodendrocytes."

The researchers had a clue to go on: Glutamate, a neurotransmitter, is known to have neurotoxic effects when it reaches high levels. "If you have too much glutamate, you're in big trouble," says Grinspan. Sure enough, when the researchers applied a compound that blunts glutamate levels to HIV-infected macrophages before the transfer of the growth medium to oligodendrocyte precursors, the cells were able to mature into oligodendrocytes. The result suggests that glutamate secreted by the infected macrophages was the culprit behind the precursor cells getting "stuck" in their immature form.

There was another mechanism, however, that the researchers suspected might be involved: the integrated stress response. This response integrates signals from four different signaling pathways, resulting in changes in gene expression that serve to protect the cell from stress or to prompt the cell to die, if the stress is overwhelming. Earlier findings from Jordan-Sciutto's lab had found the integrated stress response was activated in other types of brain cells in patients who had cognitive impairment associated with HIV infection, so the team looked for its involvement in oligodendrocytes as well.

Indeed, they found evidence that the integrated stress response was activated in cultures of oligodendrocyte precursor cells.

Taking this information with what they had found out about glutamate, "Lindsay was able to tie these two things together," Jordan-Sciutto says. She demonstrated that HIV-infected macrophages secreted glutamate, which activated the integrated stress response by turning on a pathway governed by an enzyme called PERK. "If you blocked glutamate, you prevented the activation of the integrated stress response," Jordan-Sciutto says.

To take these findings further, and potentially test out new drug targets to address HIV-related cognitive impairments, the team hopes to use a well-characterized rat model of HIV infection.

"HIV is a human disease, so it's a hard one to model," says Grinspan. "We want to find out if this model recapitulates human disease more accurately than others we've used in the past."

By tracking white matter in this animal model and comparing it to imaging studies done on patients with HIV, they hope to get at a better understanding of what factors shape white matter loss. They're particularly interested in looking at a cohort of adolescents being treated at CHOP, as teens are a group in whom HIV infection rates are climbing.

Ultimately, the researchers want to discern the effects of the virus from the drugs used to treat it in order to better evaluate the risks of each.

"When we put people on ART, especially kids or adolescents, it's important to understand the implications of doing that," says Jordan-Sciutto. "Antiretrovirals may prevent the establishment of a viral reservoir in the central nervous system, which would be wonderful, but we also know that the drugs can cause harm, particularly to white matter.

"And then of course we can't forget the 37 million HIV-infected individuals who live outside the United States and may not have access to antiretrovrials like the patients here," she says. "We want to know how we can help them too."

There is a long-held belief that having your pet sleep on the bed is a bad idea. Aside from taking up space, noisy scratching, or triggering allergies, the most common assertion averred that your furry companion would disrupt your sleep.

A new study published in the journal Sleep Health tells a different story. Researchers at Concordia's Pediatric Public Health Psychology Lab (PPHP) found that the sleep quality of the surprisingly high number of children who share a bed with their pets is indistinguishable from those who sleep alone.

"Sleeping with your pet does not appear to be disruptive," says the paper's lead author, PhD student Hillary Rowe. "In fact, children who frequently slept with their pet endorsed having higher sleep quality."

Rowe co-wrote the paper with fellow PPHP researchers Denise Jarrin, Neressa Noel, Joanne Ramil and Jennifer McGrath, professor of psychology and the laboratory's director.

Serendipitous findings

The data the researchers used was found amid the findings of the larger Healthy Heart Project, a longitudinal study funded by the Canadian Institutes of Health Research, which explores the links between childhood stress, sleep and circadian timing.

Children and parents answered questionnaires about bedtime routines and sleep hygiene: keeping a consistent bedtime, having a relaxing pre-sleep routine and sleeping in a quiet comfortable space. For two weeks, children wore wearables (wrist actigraphy) and filled out daily logs to track their sleep. Children were also fitted with a specialized home polysomnography device for one night to allow the researchers to record their brain waves (EEG signals) while they were sleeping.

"One of the sleep hygiene questions asked if they shared their bed with a pet," McGrath says. "We were startled to find that one in three children answered yes!"

Following this discovery, they looked to see what the existing literature said about the subject of bed-sharing with animals. They found a few studies with adults, but almost nothing with youth.

"Co-sleeping with a pet is something many children are doing, and we don't know how it influences their sleep," Rowe adds. "So, from a sleep science perspective, we felt this was something important we should look into."

Shining a better light on sleep measurement

The researchers categorized the children into one of three groups based on how often they sleep with their pet: never, sometimes or frequent. They then compared the three groups across a diverse range of sleep variables to see if there were any significant differences between them.

"Given the larger goals of the Healthy Heart Project, we were able to not only look at bedtimes and amount of time sleeping (duration), but also how long it took to fall asleep (latency), nighttime awakenings (disruptions) and sleep quality," McGrath says. They found that the three groups were generally similar across all sleep dimensions.

"The findings suggest that the presence of a pet had no negative impact on sleep," Rowe notes. "Indeed, we found that children who slept with their pets most often reported higher perceived sleep quality, especially among adolescents."

She hypothesizes that the children are more likely to consider pets as their friends and derive comfort from sleeping with them.

"These findings also sharpen our thinking about how to improve technology to measure sleep," McGrath adds.

"Many wearables like Apple Watch and Fitbit or even smartphones themselves have accelerometers that detect movement to decode one's sleep. Given the number of people who share their bed with their partner, or their pet, it may be sensible to develop a setting for co-sleeping to tweak the algorithm used to define sleep intrusions or awakenings, which would make for a much more accurate sleep assessment."

Do firms respond to tougher competition by searching for completely new technological solutions (exploration), or do they work to defend their position by improving current technologies (exploitation)?

Competition from increased import penetration generally results in tight profit margins, low prices, and strong efficiency pressures, immediately affecting firms' bottom lines in the form of reduced profits and increased bankruptcy risk.

A firm's R&D strategy is one of the fundamental determinants of success or failure when responding to competitive threats. To ensure both short-term performance and long-term survival, firms have two basic R&D options: explore new knowledge or exploit existing knowledge bases.

A new study published in the Strategic Management Journal (SMJ) examines how firms change the knowledge sources used in their R&D efforts in response to substantial increases in import penetration in their domestic market. The study was conducted by Raffale Morandi Stagni, Universidad Carlos III de Madrid, Spain, Andrea Fosfuri, Bocconi University, Milan, Italy and Juan Santaló, IE University, Madrid, Spain. They studied a sample of U.S. manufacturing firms over the years 1989-2006.

"Our focus on technology reflects both its increasing importance for firm survival and competitive advantage," write the authors. "Specifically, we study competition created by import penetration, which has increased steadily in recent years to become a central concern for companies, for example, dealing with imports from China.

"We find that in the years that immediately follow an increase in import penetration, firms tend to rely more on familiar knowledge in the development of innovations and less on knowledge sources that were not previously used. This switch in R&D strategy also appears to be temporary (reversed in later years), and it is positively associated with an increased likelihood of survival."

The researchers argue that while exploration is riskier and costlier than exploitation, it also requires a longer time horizon to produce results due to its slower learning pattern.

They also tested the effects of import penetration according to the type of competition and the type of industry affected. They separated imports from low-technology countries from imports from high-technology countries.

"If technological competition has a different effect on search strategies than price-based competition, we might expect the results to differ," write the researchers. "Instead, the effects of the two types of import penetration are qualitatively similar.

"We also performed a sample split of industries in which the primary customers are other businesses (B2B) or those in which the primary customers are final consumers (B2C). Consistent with the intuition that import penetration issues a greater threat to firm survival in B2B industries, we find that the effect of import penetration on technological exploration and exploitation is stronger for that group than for B2C industries."

The final variable they researched was whether technology search strategies are moderated by factors that might alleviate or increase concerns about firm survival.

"The findings show that the negative relationship between competition and exploration is magnified for firms that are relatively more vulnerable, because they have greater degrees of operating leverage and lower degrees of product diversification," the researchers write.

A new study by a team of University of Rochester psychologists and other researchers in the Collaborative Initiative on Fetal Alcohol Spectrum Disorders (CIFASD) finds that partners of mothers-to-be can directly influence a pregnant woman's likelihood of drinking alcohol and feeling depressed, which affects their babies' development.

The study, which appeared in Alcoholism: Clinical & Experimental Research, highlights the importance of engaging partners in intervention and prevention efforts to help pregnant women avoid drinking alcohol. A baby's prenatal alcohol exposure carries the risk of potential lifelong problems, including premature birth, delayed infant development, and fetal alcohol spectrum disorders (FASD).

"The findings emphasize how many factors influence alcohol use during pregnancy," says lead author Carson Kautz-Turnbull, a third-year graduate student in the Rochester Department of Psychology whose interests lie in FASD intervention work and reaching underserved populations, including racial minorities, rural populations, and low-income groups. "The more we learn about these factors, the more we can reduce stigma around drinking during pregnancy and help in a way that's empowering and meaningful," Kautz-Turnbull says.

The team followed 246 pregnant women at two sites in western Ukraine over time as part of CIFASD, an international consortium of researchers that researchers at the University's Mt. Hope Family Center are members of, which is funded by the NIH's National Institute of Alcohol Abuse and Alcoholism.

The team found that higher use of alcohol and tobacco by partners as well as pregnant women's lower relationship satisfaction increased the likelihood of their babies' prenatal alcohol exposure. Conversely, women who felt supported by their partners reported lower rates of depressive symptoms and were less likely to drink during pregnancy.

All study participants had a partner; most were married. In their first trimesters, the women reported on their relationship satisfaction, including frequency of quarreling, happiness with the relationship, and the ease of talking to their partners, their partners' substance use, and their socioeconomic status. In the third trimester, the participants were surveyed about their own drinking habits and depressive symptoms. Subsequently, the researchers assessed the infants' mental and psychomotor development around the age of six months.

According to the team's analysis, pregnant women's depressive symptoms and drinking directly correlated with their relationships with their partners and to their partners' substance use. (The researchers asked about alcohol and tobacco use only.) Positive partner influences resulted in women's lower alcohol use in late pregnancy and fewer depressive symptoms. The findings applied even when socioeconomic status, which is generally linked to depression and drinking, was taken into account. Higher prenatal alcohol exposure resulted in poorer mental and psychomotor development in the infants, though a mother's prenatal depression did not affect babies the way drinking did.

That's why maternal health and pregnancy interventions are likely to be more effective when partners are included, with benefits for both mothers and babies, the team concludes. Interventions addressing the partners' substance use may help reduce pregnant women's substance use, too, while improving their relationship satisfaction, protecting against depression, and boosting infant development.

Besides Kautz-Turnbull, the study was coauthored by Rochester's Christie Petrenko and Elizabeth Handley, Emory University's Claire Coles and Julie Kable, University of South Alabama's Wladimir Wertelecki, Lyubov Yevtushok of Omni-Net Centers in Ukraine, Natalya Zymak-Zakutnya of the OMNI-Net for Children International Charitable Fund in Ukraine, Christina Chambers of the University of California, San Diego, and CIFASD.

A new study from North Carolina State University found that certain types of messages could influence how people perceive information about the spread of diseases from wildlife to humans.

The researchers say the findings, published in the journal Frontiers in Communication, could help scientists, policymakers and others more effectively communicate with diverse audiences about zoonotic diseases and the role of wildlife management in preventing them from spreading to people. Zoonotic diseases are diseases that originate in wildlife and become infectious to people.

"If we want to prevent and mitigate the next giant zoonotic disease, we need people to recognize these diseases can emerge from their interactions with wildlife," said study co-author Nils Peterson, professor of forestry and environmental resources at NC State. "We have to do better with how we interact with wildlife. We also have to do better in terms of our communication, so people recognize the root of the problem. We need to learn how to communicate with people about zoonotic diseases and wildlife trade across partisan divides."

In the study, researchers surveyed 1,554 people across the United States to understand whether they would see greater acceptance of scientific information about zoonotic diseases - specifically in regard to the potential role of wildlife trade in the origin and spread of the virus that causes COVID-19 - depending on how they structured their messaging. Scientists from the World Health Organization concluded in a report earlier this year that evidence points to a likely animal origin. One group of scientists has recently called for more clarity.

In the experiment, study participants were asked to read one of three articles. One article used a "technocratic" frame that emphasized the use of technology and human ingenuity to address diseases from wildlife, such as using monitoring and culling of animals with diseases. This frame was designed to appeal to people with an "individualistic" worldview. A second article had a "regulatory frame" that emphasized using land conservation to create wildlife refuges as a solution. This frame was designed to appeal to people with a "communitarian" view. The third article was designed as a control, and was intended to be neutral.

Researchers then asked all of the participants to read part of an article that researchers wrote about COVID-19 and the potential role of wildlife trade in its origin and spread, and asked them about their perceived validity of the information. Researchers also surveyed participants about their trust in science overall, and belief in COVID-19's wildlife origin.

"Past research suggests people process and filter information through their cultural lens, or based on how they think the society should function," said the study's lead author Justin Beall, a graduate student in parks, recreation and tourism management at NC State. "We wanted to know, in the domain of zoonotic disease management, what are the solutions for managing diseases that might align with different cultural values in the United States? Would using those perspectives impact how people accepted scientific information about the wildlife origin of COVID-19?"

Researchers found that people who identified as liberal reported higher perceived risk on average from COVID-19. They were also more likely to accept evidence for the wildlife origin of COVID-19 and support restrictions on wildlife trade.

When researchers considered the link between message frames and participants' acceptance of the information about COVID-19 and the potential role of wildlife trade in its origin and spread, they found liberals who received the technocratic framing were significantly less likely to find the information valid, while conservatives were slightly more likely to find it valid. They didn't see any statistically significant relationship between the "regulatory" framing and participants' acceptance of the information.

"The findings show us that cultural views are relevant for communicating about wildlife disease," Beall said. "We found that the technocratic viewpoint might be more polarizing."

That suggests that for communicating to a diverse public audience about zoonotic disease and wildlife trade, communicators should avoid using the technocratic frame. However, when communicators are speaking to a conservative audience, they could consider using the technocratic frame to increase acceptance.

Researchers underscored the importance of the findings for conveying the idea that the health of humans, wildlife and the environment are connected.

"We all exist in this giant ecosystem, and disease is part of it," said study co-author Lincoln Larson, associate professor of parks, recreation and tourism management at NC State. "If we're talking about the health of humans, we're talking about the health of wildlife and ecosystems simultaneously. It's critical to develop effective communication strategies that resonate with ideologically diverse audiences and lead to bipartisan support and action."

"Improving communication and framing around zoonotic disease could help to prevent the next global pandemic, and that's a message everyone can get behind," he added.

A new global review has found that receiving Opioid Agonist Therapy (OAT) is associated with lower risk of multiple causes of death among people with opioid dependence.

The review found that people with opioid dependence were less likely to experience overdose-related, suicide, alcohol-related, cancer, and cardiovascular-related mortality while receiving OAT.

Researchers from the National Drug and Alcohol Research Centre (NDARC) at UNSW Sydney, University of Bristol and several other global institutions reviewed the relationship between OAT and mortality across type of drug, setting and participant groups from over 700,000 participants, which is six times the number of any other previous review.

The review found that mortality risk was lower for those receiving either buprenorphine or methadone treatment, the two most common forms of OAT for people with opioid dependence.

Lead author, Thomas Santo Jr, PhD candidate at NDARC, said, "People with opioid dependence who receive OAT are not only at lower risk of overdose than those who do not, but also at lower risk of suicide and several other common causes of death."

"This review provides further justification for expanding access to OAT to help lower the risk of mortality among people with opioid dependence," said Mr Santo.

"Importantly, the benefits of OAT were consistent across region, age, sex, and comorbidity status. The few studies that examined the impact of OAT after release from prison, found that time in OAT lowered risk of mortality."

The review confirmed that there was a greater risk of death in the first month after OAT is stopped. For patients on methadone, there was a greater risk of mortality at the beginning of treatment which was not seen for patients on buprenorphine.

"The first four weeks that follow treatment cessation are associated with particularly high rates of suicide and overdose-related mortality," said Mr. Santo.

"These findings emphasise the importance of retention in treatment for those with opioid dependence who start treatment on OAT. There is also a need for more detailed investigation and intervention development to minimise mortality risk during induction onto OAT."

The review shows that randomised controlled trials (RCTs) of OAT are underpowered (do not have a large enough sample size) to examine mortality risk.

"We looked at trial evidence but so few studies were powered to examine mortality, which is why we need to rely on cohort studies of people in treatment around the world," said Mr Santo.

Professor Matt Hickman, at the NIHR Health Protection Research Unit in Behavioural Science and Evaluation at University of Bristol, said, "The research evidence is clear - OAT reduces mortality risk - but the population benefits of OAT may not be realised if treatment periods in the community are too short and prisoners with opioid use disorders are not released on OAT after leaving prison. Countries - like the UK - with ongoing public health crises in drug related deaths - need to review both access to OAT and the way it is delivered to ensure the greatest number of deaths are averted.

"A clinical decision support system, stratifying clients' risk of dropout in real time, may facilitate the identification of those in need of service enhancements to increase engagement and prevent dropout.

"Work to scale up access and retention could have important population-level benefits."

A team of Colorado State University scientists, led by veterinary postdoctoral fellow Dr. Anna Fagre, has detected Zika virus RNA in free-ranging African bats. RNA, or ribonucleic acid, is a molecule that plays a central role in the function of genes.

According to Fagre, the new research is a first-ever in science. It also marks the first time scientists have published a study on the detection of Zika virus RNA in any free-ranging bat.

The findings have ecological implications and raise questions about how bats are exposed to Zika virus in nature. The study was recently published in Scientific Reports, a journal published by Nature Research.

Fagre, a researcher at CSU's Center for Vector-Borne Infectious Diseases, said while other studies have shown that bats are susceptible to Zika virus in controlled experimental settings, detection of nucleic acid in bats in the wild indicates that they are naturally infected or exposed through the bite of infected mosquitoes.

"This provides more information about the ecology of flaviviruses and suggests that there is still a lot left to learn surrounding the host range of flaviviruses, like Zika virus," she said. Flaviviruses include viruses such as West Nile and dengue and cause several diseases in humans.

CSU Assistant Professor Rebekah Kading, senior author of the study, said she, Fagre and the research team aimed to learn more about potential reservoirs of Zika virus through the project.

The team used 198 samples from bats gathered in the Zika Forest and surrounding areas in Uganda and confirmed Zika virus in four bats representing three species. Samples used in the study date back to 2009 from different parts of Uganda, years prior to the large outbreaks of Zika virus in 2015 to 2017 in North and South Americas.

"We knew that flaviviruses were circulating in bats, and we had serological evidence for that," said Kading. "We wondered: Were bats exposed to the virus or could they have some involvement in transmission of Zika virus?"

The virus detected by the team in the bats was most closely related to the Asian lineage Zika virus, the strain that caused the epidemic in the Americas following outbreaks in Micronesia and French Polynesia. The first detection of the Asian lineage Zika virus in Africa was in late 2016 in Angola and Cape Verde.

"Our positive samples, which are most closely related to the Asian lineage Zika virus, came from bats sampled from 2009 to 2013," said Fagre. "This could mean that the Asian lineage strain of the virus has been present on the African continent longer than we originally thought, or it could mean that there was a fair amount of viral evolution and genomic changes that occurred in African lineage Zika virus that we were not previously aware of."

Fagre said the relatively low prevalence of Zika virus in the bat samples indicates that bats may be incidental hosts of Zika virus infection, rather than amplifying hosts or reservoir hosts.

"Given that these results are from a single cross-sectional study, it would be risky and premature to draw any conclusions about the ecology and epidemiology of this pathogen, based on our study," she said. "Studies like this only tell one part of the story."

The research team also created a unique assay for the study, focusing on a specific molecular component that flaviviruses possess called subgenomic flavivirus RNA, sfRNA. Most scientists that search for evidence of Zika virus infection in humans or animals use PCR, polymerase chain reaction, to identify bits of genomic RNA, the nucleic acid that results in the production of protein, said Fagre.

Kading said her team will continue their research to try and learn more about how long these RNA fragments persist in tissues, which will allow them to approximate when these bats were infected with Zika virus.

"There is always a concern about zoonotic viruses," she said. "The potential for another outbreak is there and it could go quiet for a while. We know that in the Zika forest, where the virus was first found, the virus is in non-human primates. There are still some questions with that as well. I don't think Zika virus has gone away forever."

URBANA, Ill. -When pigs get hit with significant illnesses during key stages of pregnancy, their immune response may negatively affect developing piglets, making them less productive on the farm. New research from the University of Illinois shows that when those piglets - especially males - experience a second stressor in early life, they are at higher risk of neurodevelopmental and other neurological anomalies, putting them at an even greater disadvantage in production settings.

"With more information about maternal illness, what we call maternal immune activation, we can make better decisions about how to handle these types of immune challenges within animal production settings," says Marissa Keever-Keigher, doctoral student in the Department of Animal Sciences at Illinois and lead researcher on the study.

Studying brain development in the domestic pig is relevant on the farm, of course, but pig studies can also inform human neurodevelopmental research. That's because the pig's development, genetics, brain structure, and more are very similar to our own.

In previous pig studies looking at the effects of maternal immune activation, Keever-Keigher and her colleagues showed important genetic changes occur in the piglet amygdala, a brain structure that plays an important role in learning, social behavior, and stress response in both humans and pigs.

The researchers also knew from primate and rodent studies that a second immune challenge, known as a double hit, can further disrupt typical brain development in young animals. To test the double hit hypothesis in pigs, the team chose weaning as the second challenge.

"While weaning is not itself an immune challenge, it is an extremely stressful time during a piglet's life and can elicit an immune response," says Haley Rymut, doctoral student in animal sciences and co-author on the study. "Piglets have to deal with a broad array of stressors, including physical stressors from being handled and moved, and emotional stressors from being taken away from the mom and placed with their peers. Any of those physical or emotional stressors can kick off an immune response."

The researchers looked at a combination of factors for piglets in the study: whether or not their moms were infected with porcine reproductive and respiratory syndrome virus (PRRSV) during gestation, and whether or not they were weaned at 21 days of age, the typical age in production settings. They also noted the sex of the piglets, as their earlier research indicated male piglets showed more changes in the amygdala as a result of maternal illness.

"Using high throughput sequencing technologies, we were able to monitor the levels of more than 16,000 genes in the pigs. We uncovered more than 100 genes and molecular pathways affected by either maternal immune activation, weaning, sex, or a combination of factors in the amygdala on day 22 for all piglets. The effect of pre- and postnatal stressors on neuropeptide genes confirms the plasticity of the infant brain during development to respond and adapt to challenges," says Sandra Rodriguez-Zas, professor in animal sciences and faculty advisor to Keever-Keigher and Rymut. Rodriguez-Zas is principal investigator of the U.S. Department of Agriculture-funded study.

Many of the genes expressed at higher or lower-than-typical rates in weaned piglets from virus-infected mothers have been associated with autism spectrum disorder (ASD) and schizophrenia spectrum disorder (SSD) in previous studies. But genes relevant to other neurological disorders were affected too.

"We also found changes in expression of genes associated with neurodegenerative diseases like Huntington's and Alzheimer's disease," Keever-Keigher says.

As in the scientists' previous work, the double hit affected male piglets more than females, with greater dysregulation of genes in the amygdala. The researchers found evidence of more protective pathways in female brains, giving them an advantage in handling stressful events.

The study provides valuable clues for researchers studying ASD, SSD, and neurodegenerative disorders in humans, even though some aspects might not translate directly.

Rymut says, "For most children, weaning isn't nearly as stressful as it is for pigs in a production setting. But many other traumatic events early in childhood could set up that double hit."

On the farm, pigs from virus-infected mothers often show anti-social behaviors. Because pigs are typically group-housed and fed via communal feeders, pigs that don't like being around their peers are often last to feed and generally more stressed, leading to slower growth rates and lower overall body condition scores.

"The lesson for swine producers, I think, is to be really mindful of stressful conditions in the production cycle, and try to mitigate those as much as we can in order to create the most productive and healthy livestock animals and benefit producers' bottom lines," Keever-Keigher says.

Rymut adds, "Also, knowing how the different sexes respond could help producers manage animals that are less likely to be productive as a result of maternal immune activation."

In a new study, University of Maine researchers found that culture helps humans adapt to their environment and overcome challenges better and faster than genetics.

After conducting an extensive review of the literature and evidence of long-term human evolution, scientists Tim Waring and Zach Wood concluded that humans are experiencing a "special evolutionary transition" in which the importance of culture, such as learned knowledge, practices and skills, is surpassing the value of genes as the primary driver of human evolution.

Culture is an under-appreciated factor in human evolution, Waring says. Like genes, culture helps people adjust to their environment and meet the challenges of survival and reproduction. Culture, however, does so more effectively than genes because the transfer of knowledge is faster and more flexible than the inheritance of genes, according to Waring and Wood.

Culture is a stronger mechanism of adaptation for a couple of reasons, Waring says. It's faster: gene transfer occurs only once a generation, while cultural practices can be rapidly learned and frequently updated. Culture is also more flexible than genes: gene transfer is rigid and limited to the genetic information of two parents, while cultural transmission is based on flexible human learning and effectively unlimited with the ability to make use of information from peers and experts far beyond parents. As a result, cultural evolution is a stronger type of adaptation than old genetics.

Waring, an associate professor of social-ecological systems modeling, and Wood, a postdoctoral research associate with the School of Biology and Ecology, have just published their findings in a literature review in the Proceedings of the Royal Society B, the flagship biological research journal of The Royal Society in London.

"This research explains why humans are such a unique species. We evolve both genetically and culturally over time, but we are slowly becoming ever more cultural and ever less genetic," Waring says.

Culture has influenced how humans survive and evolve for millenia. According to Waring and Wood, the combination of both culture and genes has fueled several key adaptations in humans such as reduced aggression, cooperative inclinations, collaborative abilities and the capacity for social learning. Increasingly, the researchers suggest, human adaptations are steered by culture, and require genes to accommodate.

Waring and Wood say culture is also special in one important way: it is strongly group-oriented. Factors like conformity, social identity and shared norms and institutions -- factors that have no genetic equivalent -- make cultural evolution very group-oriented, according to researchers. Therefore, competition between culturally organized groups propels adaptations such as new cooperative norms and social systems that help groups survive better together.

According to researchers, "culturally organized groups appear to solve adaptive problems more readily than individuals, through the compounding value of social learning and cultural transmission in groups." Cultural adaptations may also occur faster in larger groups than in small ones.

With groups primarily driving culture and culture now fueling human evolution more than genetics, Waring and Wood found that evolution itself has become more group-oriented.

"In the very long term, we suggest that humans are evolving from individual genetic organisms to cultural groups which function as superorganisms, similar to ant colonies and beehives," Waring says. "The 'society as organism' metaphor is not so metaphorical after all. This insight can help society better understand how individuals can fit into a well-organized and mutually beneficial system. Take the coronavirus pandemic, for example. An effective national epidemic response program is truly a national immune system, and we can therefore learn directly from how immune systems work to improve our COVID response."

People of color are more than twice as likely to die after a traumatic brain injury as white people, according to a new retrospective review from Oregon Health & Science University.

The study published today in the journal Frontiers in Surgery.

In the report, "Racial and Ethnic Inequities in Mortality During Hospitalization for Traumatic Brain Injury: A Call to Action," the researchers analyzed more than a decade of data related to the health outcomes and demographics of thousands of patients treated for traumatic head injuries at OHSU Hospital, one of two Level 1 trauma centers in the state.

They found a clear delineation of worse outcomes for people of color.

"We have a societal and professional duty to recognize and accept that the effects of structural racism have taken hold of our patients' health long before they arrive in our trauma bays, ICU beds, and operating tables," they write. "These disparities permeate our society and contribute to inequitable health outcomes, and we must take action to identify the factors which perpetuate this disproportionate suffering."

The researchers found no bias in the treatment patients received while in the hospital. Measurements including the number of days spent in intensive care and charges for hospital services were similar between groups.

Rather, they say the findings highlight underlying disparities in health that disproportionately affect people of color.

"If you ran the same analysis with patients with pneumonia, you might find the same results," said senior author Ahmed M. Raslan, M.D., FAANS, associate professor of neurological surgery in the OHSU School of Medicine. "Our findings point to the problem in a more robust and clear way. The problem is rooted in social determinants of health, including factors such as diet, lifestyle, occupations and access to health care."

The study is the first to review racial and ethnic disparities in the field of neurosurgical trauma.

Researchers reviewed outcomes for 6,352 patients treated for traumatic brain injuries between 2006 and 2017. The overall mortality rate was 9.9% among all patients. Among the 1,504 patients who identified as racial or ethnic minorities, 14.6% died.

Weighted for severity of injury, age and other factors, researchers calculated an in-hospital mortality hazard ratio of 2.21 for minority patients compared to white patients.

"Dr. Raslan's research is incredibly important in highlighting disparities in health outcomes experienced by people of color," said Nathan Selden, M.D., Ph.D., professor and chair of neurological surgery in the OHSU School of Medicine. "Together with our department's efforts to improve the care of traumatic brain injuries, and more broadly to improve diversity in medicine, I am confident OHSU can really make a difference."

Hydrogels are commonly used inside the body to help in tissue regeneration and drug delivery. However, once inside, they can be challenging to control for optimal use. A team of researchers in the Department of Biomedical Engineering at Texas A&M University is developing a new way to manipulate the gel -- by using light.

Graduate student Patrick Lee and Dr. Akhilesh Gaharwar, associate professor, are developing a new class of hydrogels that can leverage light in a multitude of ways. Light is a particularly attractive source of energy as it can be confined to a predefined area as well as be finetuned by the time or intensity of light exposure. Their work was recently published in the journal Advanced Materials.

Light?responsive hydrogels are an emerging class of materials used for developing noninvasive, noncontact, precise and controllable medical devices in a wide range of biomedical applications, including photothermal therapy, photodynamic therapy, drug delivery and regenerative medicine.

Lee said light-responsive biomaterials are often used in biomedical applications; however, current light sources, such as ultraviolet light and visible light, cannot sufficiently penetrate the tissue to interact with the hydrogel. Instead, the team is researching near-infrared (NIR) light, which has a higher penetration depth.

The team is using a new class of two-dimensional nanomaterials known as molybdenum disulfide (MoS2), which has shown negligible toxicity to cells and superior NIR absorption. These nanosheets with high photothermal conversion efficiency can absorb and convert NIR light to heat, which can be developed to control thermoresponsive materials.

In the group's previous study published in Advanced Materials, certain polymers react with MoS2 nanosheets to form hydrogels. Building on this discovery, the team further utilizes MoS2 nanosheets and thermoresponsive polymers to control the hydrogel under NIR light by photothermal effect.

"This work leverages light to activate the dynamic polymer-nanomaterials interactions," Gaharwar said. "Upon NIR exposure, MoS2 acts as a crosslink epicenter by connecting with multiple polymeric chains via defect?driven click chemistry, which is unique."

NIR light allows internal formation of therapeutic hydrogels in the body for precise drug delivery. For cancer therapy, most of the drugs can be retained within the tumor, which will ease the side effects of chemotherapy. Moreover, NIR light can generate heat inside the tumors to ablate cancer cells, known as photothermal therapy. Therefore, a synergetic combination of photothermal therapy and chemotherapy has shown a higher efficacy in destroying cancer cells.

The Permian Basin, located in western Texas and southeastern New Mexico, is the largest oil- and gas-producing region in the U.S. The oilfield operations emit methane, but quantifying the greenhouse gas is difficult because of the large area and the fact that many sources are intermittent emitters. Now, researchers reporting in ACS' Environmental Science & Technology Letters have conducted an extensive airborne campaign with imaging spectrometers and identified large methane sources across this area.

According to the U.S. Energy Information Administration, 38% of the nation's total oil and 17% of natural gas production took place in the Permian Basin in 2020. Therefore, quantifying emissions from these operations, which continue to expand rapidly, is of great interest to environmental scientists. Previous studies have tried to estimate methane leakage in the Permian Basin through satellite images or mobile field studies, but either the spatial resolution was too coarse to quantify methane coming from individual sources, or the studies were limited to small areas or timeframes. So Daniel Cusworth and colleagues from the NASA Jet Propulsion Laboratory, the University of Arizona and Arizona State University formed a collaboration. They wanted to quantify strong methane point source emissions (greater than 22-44 pounds of methane per hour) in the Permian Basin using airborne imaging spectrometry, a technology that would allow high-resolution mapping of those sources across large areas and multiple overflights.

From September to November 2019, the researchers conducted repeated flights in airplanes carrying imaging spectrometers, covering about 21,000 square miles and 60,000 active wells in the Permian Basin. The spectrometers detected 1,100 unique large methane point sources that were sampled at least three times. Most of these sources were highly intermittent (detected 25% or fewer of the times sampled). However, sources that were routinely persistent (detected 50-100% of the time) comprised 11% of the methane emitters but 29% of the total detected emissions, possibly indicating leaking equipment that needs repair. Half of the detected methane came from oil and gas production wells, 38% from pipelines and other equipment used to collect and transport oil and gas, and 12% from processing plants. These results show that frequent, high-resolution monitoring is necessary to understand intermittent methane emitters across large areas and to pinpoint persistent leaks for mitigation, the researchers say.

Jack Tseng loves bone-crunching animals -- hyenas are his favorite -- so when paleontologist Joseph Peterson discovered fossilized dinosaur bones that had teeth marks from a juvenile Tyrannosaurus rex, Tseng decided to try to replicate the bite marks and measure how hard those kids could actually chomp down.

Last year, he and Peterson made a metal replica of a scimitar-shaped tooth of a 13-year-old juvie T. rex, mounted it on a mechanical testing frame commonly used in engineering and materials science, and tried to crack a cow legbone with it.

Based on 17 successful attempts to match the depth and shape of the bite marks on the fossils -- he had to toss out some trials because the fresh bone slid around too much -- he determined that a juvenile could have exerted up to 5,641 newtons of force, somewhere between the jaw forces exerted by a hyena and a crocodile.

Compare that to the bite force of an adult T. rex -- about 35,000 newtons -- or to the puny biting power of humans: 300 newtons.

Previous bite force estimates for juvenile T. rexes -- based on reconstruction of the jaw muscles or from mathematically scaling down the bite force of adult T. rexes -- were considerably less, about 4,000 newtons.

Why does it matter? Bite force measurements can help paleontologists understand the ecosystem in which dinosaurs -- or any extinct animal -- lived, which predators were powerful enough to eat which prey, and what other predators they competed with.

"If you are up to almost 6,000 newtons of bite force, that places them in a slightly different weight class," said Tseng, UC Berkeley assistant professor of integrative biology. "By really refining our estimates of juvenile bite force, we can more succinctly place them in a part of the food web and think about how they may have played the role of a different kind of predator from their larger, adult parents."

The study reveals that juvenile T. rexes, while not yet able to crush bones like their 30- or 40-year-old parents, were developing their biting techniques and strengthening their jaw muscles to be able do so once their adult teeth came in.

"This actually gives us a little bit of a metric to help us gauge how quickly the bite force is changing from juvenile to adulthood, and something to compare with how the body is changing during that same period of time," said Peterson, a professor at the University of Wisconsin in Oshkosh and a paleopathologist -- a specialist on the injuries and deformities visible in fossil skeletons. "Are they already crushing bone? No, but they are puncturing it. It allows us to get a better idea of how they are feeding, what they are eating. It is just adding more to that full picture of how animals like tyrannosaurs lived and grew and the roles that they played in that ecosystem."

Tseng, Peterson and graduate student Shannon Brink of East Carolina University in Greenville, North Carolina, will publish their findings this week in the journal PeerJ.

Teeth marks galore, but who was the biter?

Experiments using metal casts of dinosaur teeth to match observed bite marks are rare, not because bite marks on dinosaur fossils are rare, but because the identity of the biter is seldom clear.

Two dinosaur fossils that Peterson excavated years earlier from the Hell Creek Formation of eastern Montana, however, proved ideal for such an experiment. One, the skull of a juvenile T. rex, had a healed bite mark on its face. "What, other than another T. rex, would be able to chomp another T. rex and puncture its skull?" he reasoned. Tyrannosaurs, like crocodiles today, played rough, and the wound was likely from a fight over food or territory.

In addition, the puncture holes in the skull, which had healed, were the size and shape of juvenile T. rex teeth, and the spacing fit a juvenile's tooth gap. Juvenile T. rexes have teeth that are oval in cross section: more knife-like, presumably to cut and tear flesh. Adult T. rexes have teeth with round cross sections: more like posts, to crush bone. Both juveniles and adults could replace lost or broken teeth from spares buried in the jaw that emerged once the socket was empty.

Because skull bone is harder than other bone, Peterson said, matching these holes with punctures made by the metal tooth in a cow bone provided an upper limit to the bite force.

The other fossil was a tail vertebra from a plant-eating, duckbilled dinosaur, an Edmontosaurus. It had two puncture marks from teeth that matched those of a juvenile T. rex. Peterson said that T. rex was the only predator around at that time -- the late Cretaceous Period, more than 66 million years ago -- that could have bitten that hard on the tailbone of a duckbill. The juvenile likely punctured the bone when chomping down on a meaty part of the tail of the already dead animal.

Because vertebrae are softer, experimentally creating similar punctures in a cow bone gave the researchers a lower limit on bite force.

Tseng employed a testing technique that was used in 2010 by researchers who measured the bite force of a much older and smaller dinosaur from the early Cretaceous: a Deinonychus, made famous under a different name -- Velociraptor -- in the 1993 movie Jurassic Park. Its bite force was between 4,000 and 8,000 newtons.

Tseng, then at the University at Buffalo in New York, and Peterson made a replica of a juvenile T. rex tooth from the middle of the jaw using a dental-grade cobalt chromium alloy, which is much harder than dinosaur tooth enamel, Tseng said.

They then mounted the metal tooth in a mechanical testing frame and pushed it slowly, at a millimeter per second, into a fresh-frozen and thawed humerus of a cow. Bones are easier to fracture at low speed than with a rapid chomp. Because the middle of the humerus has a thicker cortex than the bone near the joint ends, the middle was used to replicate the facial punctures. The ends were used to simulate the vertebra punctures.

"What we did, an actualistic study, is to say, 'Let's actually stab the thing with a tooth and see what it does,'" Peterson said. "What we are finding is that our estimates are slightly different than other models, but they are within a close enough range -- we are on the same page."

Tseng emphasized that there is no one number describing the bite force of any animal: it depends on how the creature bites and adjusts the prey in its mouth for the best leverage.

"They probably were not just chomping down. If you look at modern predators, even reptilian predators, sometimes there is adjustment. Maybe they are finding the most mechanically advantageous place, or the strongest tooth to make their bite," said Tseng, who is a 2004 graduate of UC Berkeley's Department of Integrative Biology and an assistant curator in the University of California Museum of Paleontology. "Presumably, there is some tuning involved before they make that bite, so they can literally take the best bite forward to make that kill or to damage whatever they are trying to get into."

Nevertheless, the measurements are a start in charting the increase in tyrannosaurs' bite force as they mature, similar to how paleontologists have charted T. rex size and weight with age.

"Just as you can do a growth curve for such an organism, you can also do a strength curve for their bite force -- what was their bite force at 12 or 13 years old, what was it at 30, 35 or 40 years old. And what does that potentially mean about the role that those animals played in that ecosystem at the time?" Peterson said. "What's cool about finding bite marks in bone from a juvenile tyrannosaur is that it is tells us that at 13 years old, they weren't capable of crushing bone yet, but they were already trying, they were puncturing bone, pretty deep. They are probably building up their strength as they get older."

Tseng, whose primary interest is mammals, is eager to resume studies interrupted by the pandemic to measure the bite force of various living and extinct animals in order to infer the ecosystem niches of predators no longer alive. For those creatures, fossils are all that paleontologists have, in order to "interpret behavior and breathe some life into these extinct animals," said Peterson.

"I use a biomechanical lens when I look at everything, living or extinct," Tseng added. "Ecologists today studying food webs and ecosystems don't rely much on bones; they have physical animals and plants. It is really the paleontologists who are interested in this approach, because the majority of what we have to study are bones and bite marks."