Earth

As plastic debris weathers in aquatic environments, it can shed tiny nanoplastics. Although scientists have a good understanding of how these particles form, they still don't have a good grasp of where all the fragments end up. Now, researchers reporting in ACS' Environmental Science & Technology have shown experimentally that most nanoplastics in estuarine waters can clump, forming larger clusters that either settle or stick to solid objects, instead of floating on into the ocean.

There is a huge discrepancy between the millions of tons of plastic waste entering rivers and streams and the amount researchers have found in the oceans. As large pieces of plastic break apart into successively smaller fragments on their transit to the sea, some eventually wear down to nano-sized particles. Previous studies have shown that these nanoplastics congregate in well-mixed, stagnant salty water. Yet, these results do not apply when the particles encounter dynamic changes in salt content, such as estuaries, where rivers carrying freshwater meet tidal saltwater. So, Hervé Tabuteau, Julien Gigault and colleagues wanted to perform laboratory experiments with micro-sized chambers mimicking the conditions measured in an estuary to show how nanoplastics interact and aggregate in this type of environment.

To determine how nanoplastics move in estuarine waters, the team developed a lab-on-a-chip device. They introduced crushed 400-nm-wide polystyrene beads and freshwater into one side of the device, while injecting saltwater through another inlet. At the opposite end of the 1.7-cm-long device, the researchers collected the output. The team tested different flow rates, replicating the salt gradient and water movement they measured in an estuary on the French Caribbean island of Guadeloupe. Nanoplastic aggregates up to 10-μm wide were detected within the zone of highest salt concentration in the flow chamber, regardless of how fast the water was moving. At the highest flow rate, only 12% of the nanoplastics were collected in the outlets; the remaining particles either clumped together and sank in the flow chamber or formed floating aggregates that stuck to the chamber's sides. The researchers say their results show estuaries and other coastal environments may filter out nanoplastics before they can enter the ocean.

Since its introduction, the emerald ash borer (EAB) has become the most devastating invasive forest insect in the United States, killing hundreds of millions of ash trees at a cost of hundreds of millions of dollars.

Now, new research from the University of Minnesota's Minnesota Invasive Terrestrial Plants and Pests Center (MITPPC) shows a possible path forward in controlling the invasive pest that threatens Minnesota's nearly one billion ash trees.

In a recent study published in Fungal Biology, MITPPC researchers identified various fungi living in EAB-infested trees -- a critical first step in finding fungi that may be harnessed to control the spread of EAB, and ultimately, prevent ash tree death.

"We discovered that several different species of fungi attack EAB and other insects, and they can now be further tested for their potential for biocontrol," said Robert Blanchette, the study's project leader and professor in the College of Food, Agricultural and Natural Resource Sciences. "This is a very important first step in the search for a biocontrol for emerald ash borer."

Larval EAB feed just beneath the bark, leaving behind tunnel galleries that can stretch up to 20 inches long. Beneath the surface, fungi -- some of which may be capable of parasitizing the EAB -- may be carried by the larvae as they develop, or may enter the tree through the tunnel galleries. Some of these fungi also seriously affect urban trees, causing rapid wood decay which result in hazardous tree situations.

From Rochester to Duluth, researchers gathered samples where ash is affected by EAB. Through DNA sequencing, scientists identified fungal isolates and revealed a diverse assemblage of fungi. This included entomopathogenic fungi that attack insects, as well as other fungi that cause cankers -- which help EAB kill trees -- and some that cause wood decay.

"Before now, we simply haven't been sure what fungi are associated with EAB infestations in Minnesota. This project identified those species and, in doing so, opened up new possibilities for managing one of our state's most devastating tree pests," said Ben Held, the study's lead author and researcher in the College of Food, Agricultural and Natural Resource Sciences.

As research continues, the scientists will build on the work from this study to determine if any of the fungi can be used to kill the emerald ash borer. Results will also be of value in helping control the insect in other parts of North America where EAB is found.

"Ash trees are vitally important to Minnesota," said Rob Venette, MITPPC director. "They reduce air pollution, storm water runoff, and cooling costs, all while increasing property values in local communities. It's critical we work to protect them from this invasive pest."

An international research team led by NUST MISIS has developed a new iron-cobalt-nickel nanocomposite with tunable magnetic properties. The nanocomposite could be used to protect money and securities from counterfeiting. The study was published in Nanomaterials.

Presently, research on magnetic nanomaterials with controlled magnetic characteristics is one of the most promising fields. Due to their small size, as well as their excellent magnetic and electric properties these materials have a broad range of potential applications from mobile devices to space technologies.

The new iron-cobalt-nickel nanocomposite was obtained by chemical precipitation, followed by a reduction process.

"This method is simple and, most importantly, it allows the properties of the product to be controlled at each stage of its production, and chemically pure nanopowders to be produced with a given composition, shape, and dispersion", noted Yuri Konyukhov, Deputy Head of the Department of Functional Nanosystems and High-Temperature Materials at NUST MISIS.

Konyukhov also stressed that the new composite was observed to possess high value of coercivity, which makes the technology applicable e.g. to magnetic rubbers and different magnetically coupled devices. Another potential application is protecting money and securities from counterfeiting.

"The efforts of the scientific community have been recently focused on protecting humans and electronic devices from electromagnetic radiation. The development of thin, flexible and relatively transparent metal-polymer composites for EMI shielding is a promising research direction. The use of the new nanocomposite with controlled magnetic properties as the magnetic filler could lead to a breakthrough in EMI protection", added Yuri Konyukhov.

Effective, specific, with a reversible and non-harmful action: the identikit of the perfect biomaterial seems to correspond to graphene flakes, the subject of a new study carried out by SISSA - International School for Advanced Studies of Trieste, Catalan Institute of Nanoscience and Nanotechnology (ICN2) of Barcelona and the National Graphene Institute of the University of Manchester, in the framework of the European Graphene Flagship project. This nanomaterial has demonstrated the ability to interact with the functions of the nervous system in vertebrates in a very specific manner, interrupting the building up of a pathological process that leads to anxiety related behaviour.

"We previously showed that when graphene flakes are delivered to neurons they interfere spontaneously with excitatory synapses by transiently preventing glutamate release from presynaptic terminals" says Laura Ballerini of SISSA, the leader of the team that carried out the research study 'Graphene oxide prevents lateral amygdala dysfunctional synaptic plasticity and reverts long lasting anxiety behavior in rats', recently published in Biomaterials, co-authored by Audrey Franceschi Biagioni, Giada Cellot, Elisa Pati, Neus Lozano, Belén Ballesteros, Raffaele Casani, Norberto Cysne Coimbra, Kostas Kostarelos.

"We investigated whether such a reduction in synaptic activity was sufficient to modify related behaviours, in particular the pathological ones that develop due to a transient and localised hyper-function of excitatory synapses". This approach would fortify the strategy of selective and transient targeting of synapses to prevent the development of brain pathologies by using the so-called precise medicine treatments.

To test this hypothesis, the team focused on post-traumatic stress disorder (PTSD) and carried out the experiments in two phases, in vivo and in vitro.

"We analysed defensive behaviours caused in rats by the presence of a predator, using the exposure to cat odour, to induce an aversive memory" explains Audrey Franceschi Biagioni of SISSA, the first author of the study. "If exposed to the predator odour, the rat has a defensive response, holing up, and this experience is so well-imprinted in the memory, that when the animal is placed in the same context even six days later, the animal remembers the odour of the predator and acts the same protective behaviour. This is a well-known and consolidated model, that we used to reproduce a stress behaviour. Exposure to the predator can modify neuronal connections - a phenomenon that is technically known as plasticity - and increases synaptic activity in a specific area of the amygdala that therefore represented the target of our study to test the effects of the nanomaterial".

Laura Ballerini adds: "We hypothesised that graphene flakes that we showed to temporarily inhibit excitatory synapses (without causing inflammation, damage to neurons or other side effects) could be injected in the lateral amygdala when the plasticity associated with memory was consolidated. If the nanomaterial was efficient in blocking excitatory synapses, it should inhibit plasticity and decrease the anxiety related response. And this is what happened: the animals that were administered with graphene flakes, after six days, "forgot" the anxiety related responses, rescuing their behaviour".

The second part of the research was performed in vitro. "In vivo we could observe only behavioural changes and could not evaluate the impact of the graphene flakes on synapses," explains Giada Cellot, researcher at SISSA and first author of the study together with Audrey Franceschi Biagioni. "In vitro experiments allowed to work on a simplified model, to get insight about the mechanisms through which the graphene flakes can interact with neurons. We used neuronal cultures obtained from the amygdala, the region of the brain where the stress response occurs, and we observed that the effects of nanomaterials were specific for the excitatory synapses and a short exposure to graphene flakes could prevent the pathological plasticity of the synapses".

Thanks to these findings, graphene flakes have shown their potential as nanotools (biomedical tools composed of nanomaterials) that could act in a specific and reversible way on synaptic activity to interrupt a pathological process and therefore they might be used also to transport drugs or for other applications in the field of precision medicine.

Associations between strong predictors of suicidal behaviors over the life course, such as adverse childhood events (ACEs), remain understudied among youth of color. Although not previously considered high risk, suicide attempts among Black youth increased 73% between 1991 and 2017.

Published in the Children and Youth Services Review, University of Minnesota researchers pulled data from the 2016 Minnesota Student Survey (MSS) to examine associations between ACEs, school connectedness and suicide ideation and attempts among Somali, Latino, Hmong and Non-Hispanic white (NH-white) adolescents from grades 8, 9 and 11.

The research found that:

over 40% of students reported at least one ACE, and more girls compared to boys reported four or more ACEs;

Latinas (9.6%) experienced more ACEs compared to Latino boys (4.7%), Somali boys (4.4%) and Hmong boys (2.9%);

there was a similar trend in suicide behaviors, with all girls reporting more suicide behaviors compared to boys;

each additional ACE significantly increased the odds of suicide behaviors for all youth, but there were notable differences;

for Hmong, NH-white girls and Latinas, odds of a suicide attempt increased 60-69% but 109% for Somali girls;

for Latino and NH-White boys, odds of a suicide attempt increased 70% and 80% for Somali and Hmong boys respectively;

school connectedness only buffered the association between ACEs and suicidality for NH-white youth and Latinas. However, at higher levels, school connectedness was associated with a higher probability of suicide behaviors among Latinas.

"Suicides are preventable with timely evidence-based interventions. However, to develop effective programs, we need adequate data to identify protective and risk factors for possible intervention," said Eunice Areba, a clinical assistant professor in the School of Nursing. "Prevention programming should be multisectoral and multigenerational to mitigate intergenerational transmission of the effects of ACEs and trauma along the life course."

Areba also noted that researchers should examine findings on suicide aggregated into broad categories -- such as Black/African American, Latino/Hispanic, or Asian -- with caution. Such designations, and the dearth of research on ethnic minority youth can mask a significant rise in suicide that may go unrecognized and unaddressed.

She recommends that schools facilitate connectedness by ensuring learning is meaningful and relevant to adolescents' lives and struggles (normalize their experiences), teachers' pedagogy and curricula should align with students ' lived experiences, and provide clear and consistent expectations for discipline and performance. Additionally, access to multicultural and multilingual teachers and counselors, and supports that affirm adolescents' ethnic and cultural heritage and identity development can reduce stigma around mental illness, and encourage help-seeking among vulnerable adolescents.

Obtaining a precise understanding of magnetic structures is one of the main objectives of solid-state physics. Significant research is currently being undertaken in this field, the aim being to develop future data processing applications that use tiny magnetic structures as information carriers. Physicists at Johannes Gutenberg University Mainz (JGU) and the Helmholtz Institute Mainz (HIM) recently presented a new method for investigating magnetic structures combining two different techniques. This allows to measure and map the magnetization as well as the magnetic fields of the sample. Involved in the project were atomic physicists from the work group led by Professor Dmitry Budker and the team of experimental solid-state physicists led by Professor Mathias Kläui. The findings have been published in "Physical Review Applied".

"In this project we combined two quantum sensing techniques which never before had been used together to analyze a sample," explained Till Lenz, first author of the article and a doctoral candidate in Budker's group. One well-known method employed in solid-state physics uses the magneto-optic Kerr effect (MOKE) in order to detect magnetic fields and magnetization. "But this gives us only a limited amount of information," said Lenz. For this reason, the researchers decided to combine the Kerr effect with magnetometry methods that utilize so-called diamond color centers in order to also enable the mapping of magnetic fields. "We hope that this will lead to new insights when it comes to solid-state physics and ferromagnetic structures," stated Georgios Chatzidrosos, also a doctoral student in the Budker group. Professor Mathias Kläui is excited about the new measuring capabilities: "The use of diamond probes provides a sensitivity that opens up entirely new options with regard to measurement potentials."

New combined measurement methods can be used in a wide range of different ambient conditions

Diamond is not only a precious stone but is also used to make cutting and grinding tools. Specific defects in the diamond crystal lattice result in properties that can be used to examine magnetic structures. These color centers, also known as nitrogen-vacancy centers, are point defects in the carbon lattice structure of diamond. The research group led by Professor Dmitry Budker uses these color centers in diamond as probes to measure magnetic phenomena.

Diamond-based magnetometers can function at very low temperatures as well at temperatures above room temperature, while the distances required between sample and probe can be miniscule, in the range of just a few nanometers. "We have a thin layer of nitrogen defects in a diamond crystal and with this we can map magnetic structures and take photos of magnetic fields," explained Dr. Arne Wickenbrock from the Budker group. And co-author Dr. Lykourgos Bougas added: "By mapping all the components of a magnetic field, we can complement and extend the possibilities offered by magneto-optic measurements."

Support for the JGU Dynamics and Topology (TopDyn) Top-level Research Area

"The probe that functions with the help of diamond color centers is much more sensitive than conventional tools and provides us with extremely good results. We are able to access some fascinating samples, which results in unique opportunities for cooperation," emphasized Professor Mathias Kläui, describing the advantage of the collaboration between the two research groups. "Combining our complementary measurement techniques enables the complete reconstruction of the magnetic properties of our samples." The recently published article is the product of teamwork within the Dynamics and Topology (TopDyn) Top-level Research Area at JGU, which is funded by the state of Rhineland-Palatinate. In addition, the work was also undertaken under the umbrella of the 3D MAGiC project, which was launched in collaboration with Forschungszentrum Jülich and Radboud University Nijmegen in the Netherlands and has been awarded an ERC Synergy Grant.

To quote the paper published in "Physical Review Applied": "Our concept represents a novel platform for wide-field imaging of the magnetization and resultant magnetic fields of magnetic structures using engineered diamond magnetic sensors and an optical setup that allows for both measurement modalities." In addition to the two JGU and HIM work groups, also involved was Professor Yannick Dumeige of Université de Rennes 1 in France, who as a recipient of a Friedrich Wilhelm Bessel Research Award of the Alexander von Humboldt Foundation in 2018 also worked with the Budker group. Professor Kai-Mei Fu, physicist at the University of Washington, also participated in the project as a HIM Distinguished Visitor.

Looking to the future, the cooperation partners plan to employ the new technique to analyze various multidisciplinary aspects that are of particular interest to the respective groups. These include investigating two-dimensional magnetic materials, the magnetic effects of molecular chirality, and high-temperature superconductivity.

For ice, so-called "surface melting" was postulated as early as the 19th century by Michael Faraday: Already below the actual melting point, i.e. 0 °C, a thin liquid film forms on the free surface because oft he interface between ice and air. Scientists led by Markus Mezger, group leader at the Max Planck Institute for Polymer Research (department of Hans-Jürgen Butt) and professor at the University of Vienna, have now studied this phenomenon in more detail at interfaces between ice and clay minerals.

In nature, this effect is particularly interesting in permafrost soils - i.e. soils that are permanently frozen. About a quarter of the land area in the northern hemisphere is covered by permafrost. These are composed of a mixture of ice and other materials. Microscopically thin platelets were formed over geological time by the weathering of clay minerals. Similar to a sponge, a lot of water can enter the narrow slit pores between the thin platelets, be stored there, and freeze. Therefore, there is a lot of contact area between ice and clay minerals. For every gram of clay mineral, there are about 10 square meters of surface area! This causes a comparatively high proportion of liquid water in the interfacially induced melt layer already below 0 °C.

The researchers have now investigated how fast the water molecules move in the thin melt layer at the boundary between ice and clay mineral. This value, known as "self-diffusion," is directly linked to the viscosity of the water. For three different minerals, it has been shown that the viscosity of water in the interface-induced melt layer is sometimes significantly higher than that of ordinary water - i.e., the molecules are limited in their ability to move because the layer is more viscous. These results may help to better understand various phenomena in the future, such as the mechanical stability of permafrost, the transport of plant nutrients and pollutants, and geochemical reactions such as ion exchange processes at ice/mineral interfaces.

For their measurements, the Mainz scientists collaborated with partners at the research reactors of the TU Munich and the Institut Laue-Langevin in Grenoble, France. The neutrons generated in the reactors there strike the sample at a certain speed. Similar to a ball bouncing back from a vehicle moving toward it at a higher speed, velocity measurements of the neutrons scattered from the sample allow conclusions to be drawn about the motion of the water molecules in the interface-induced premelting layer.

Light microscopes have revolutionized our understanding of the microcosmos, but their resolution is limited to about 100 nanometers. To see how molecules bond, break, or change their structure, we need at least 1000 times better resolution.

Laser induced electron diffraction (LIED) is a technique which allows to pinpoint the individual atoms inside a single molecule, and to see where each atom moves when the molecule undergoes a reaction. This technique proved to be an amazing tool for the imaging molecules, such as water, carbonyl sulfide or carbon disulfide. However, using a strong laser field to generate the electron diffraction presented challenges in retrieving the exact structure, since the structural resolution depended on exact knowledge of the laser field itself.

In a study recently published in Nature Communications, ICFO researchers Aurelien Sanchez, Kasra Amini, Tobias Steinle, Xinyao Liu, led by ICREA Prof. at ICFO Jens Biegert, in collaboration with researchers from Kansas State University, Max-Planck-Institut für Kernphysik, Physikalisch-Technische Bundesanstalt, and Friedrich-Schiller-Universität Jena, have reported on an alternative and novel approach that retrieves accurate and precise information about the atomic structure without exact knowledge over the laser field. They successfully applied the method to imaging gas-phased molecule Carbonyl Sulfide (OCS), in particular on the bond lengths between the constituent atoms, showing a significant bent and asymmetrically stretched configuration of the ionized OCS+ structure.

Determining the atomic bonds of Carbonyl Sulfide

In their experiment, the scientists took a gas mixture of 1% OCS in helium and expanded it supersonically to create a molecular beam of the gas with a temperature below 90K. They then took a 3.2?m laser and exposed the molecule to the strong laser field. The interaction between the laser and the molecule produced an accelerated electron, which was released from the molecule, accelerated into the laser field and returned back to the target ion by the electric field of the laser; the re-collision of the electron with the ion structure generated a molecular imprint of the structure and, by extracting this information from the electron interference pattern and the scattering angle analysis, the scientists were capable of determining the proper structure of the molecule.

Novelty of the approach

Named ZCP-LIED, the novelty of this approach resides in the fact that the scientists came up with a very clever way to retrieve the atomic information by using the full 2D electron scattering information, mainly the energy and scattering angle spectra of the electron in the laboratory frame instead of the laser frame, which drastically improved the statistics of the results. Alongside to using 2D data instead of 1D information, they also identified a distinctive feature in spectra related to what they called the zero crossing point (ZCP) positions (where the interference signal showed a null value). By carrying out the analysis over these critical points, the scientists were able to obtain from a much smaller data set more precise information on the bond lengths of the atoms that make up the molecule, reducing quite considerably the calculation time.

For validation of their approach, they used various methods, compared them to quantum chemistry theoretical simulations and prove that their ZCP-LIED technique could obtain inter-nuclear distances with a much higher precision, could measure bond distances of similar length (something rather impossible to do with previous methods), that it avoided converting frames of reference, and was able to determine the molecular structure in environments where the background noise could be considerable. Taking all this into account, they reported obtaining the molecular information of 10-atom molecules, and in particular, for the carbonyl sulfide, where they saw that the molecule OCS+ had a significantly bent and asymmetrically stretched structure, different to what previous studies had determined for this molecule.

The results obtained by this study have demonstrated that the ZCP-LIED technique could be a very powerful tool to determine the molecular structure of large and more complex molecules. It could also be extended to ultrafast electron diffraction (UED) and even ultrafast X-ray diffraction (UXD) to track the geometric structure molecules in a transient phase.

Researchers at Charité - Universitätsmedizin Berlin and TU Berlin as well as the University of Oslo have developed a new tissue-section analysis system for diagnosing breast cancer based on artificial intelligence (AI). Two further developments make this system unique: For the first time, morphological, molecular and histological data are integrated in a single analysis. Secondly, the system provides a clarification of the AI decision process in the form of heatmaps. Pixel by pixel, these heatmaps show which visual information influenced the AI decision process and to what extent, thus enabling doctors to understand and assess the plausibility of the results of the AI analysis. This represents a decisive and essential step forward for the future regular use of AI systems in hospitals. The results of this research have now been published in Nature Machine Intelligence*.

Cancer treatment is increasingly concerned with the molecular characterization of tumor tissue samples. Studies are conducted to determine whether and/or how the DNA has changed in the tumor tissue as well as the gene and protein expression in the tissue sample. At the same time, researchers are becoming increasingly aware that cancer progression is closely related to intercellular cross-talk and the interaction of neoplastic cells with the surrounding tissue - including the immune system.

Although microscopic techniques enable biological processes to be studied with high spatial detail, they only permit a limited measurement of molecular markers. These are rather determined using proteins or DNA taken from tissue. As a result, spatial detail is not possible and the relationship between these markers and the microscopic structures is typically unclear. "We know that in the case of breast cancer, the number of immigrated immune cells, known as lymphocytes, in tumor tissue has an influence on the patient's prognosis. There are also discussions as to whether this number has a predictive value - in other words if it enables us to say how effective a particular therapy is," says Prof. Dr. Frederick Klauschen of Charité's Institute of Pathology.

"The problem we have is the following: We have good and reliable molecular data and we have good histological data with high spatial detail. What we don't have as yet is the decisive link between imaging data and high-dimensional molecular data," adds Prof. Dr. Klaus-Robert Müller, professor of machine learning at TU Berlin. Both researchers have been working together for a number of years now at the national AI center of excellence the Berlin Institute for the Foundations of Learning and Data (BIFOLD) located at TU Berlin.

It is precisely this symbiosis which the newly published approach makes possible. "Our system facilitates the detection of pathological alterations in microscopic images. Parallel to this, we are able to provide precise heatmap visualizations showing which pixel in the microscopic image contributed to the diagnostic algorithm and to what extent," explains Prof. Müller. The research team has also succeeded in significantly further developing this process: "Our analysis system has been trained using machine learning processes so that it can also predict various molecular characteristics, including the condition of the DNA, the gene expression as well as the protein expression in specific areas of the tissue, on the basis of the histological images.

Next on the agenda are certification and further clinical validations - including tests in tumor routine diagnostics. However, Prof. Klauschen is already convinced of the value of the research: "The methods we have developed will make it possible in the future to make histopathological tumor diagnostics more precise, more standardized and qualitatively better."

In light of the United Nations (UN) declaration that 2021-2030 is the UN Decade on Ecosystem Restoration, a group of scientists voice concerns about restoration in heavily fragmented landscapes under a hotter and drier future scenario.

Poor recovery of small fragments will end up costing management and wider society later down the line. Millions are invested in setting aside patches, but management is then weak and costly.

Rainforests turn into oil palm plantations

The past 40 years in Southeast Asia have seen about 50% of lowland rainforests converted to oil palm and other plantations, and much of the remaining forest heavily logged.

Little is known about how fragmentation influences recovery and whether climate change will hamper restoration.

"Here, we use repeat airborne LiDAR surveys spanning the hot and dry 2015-16 El Niño Southern Oscillation (ENSO) event to measure canopy height growth across 3,300 ha of regenerating tropical forests spanning a logging intensity gradient in Malaysian Borneo", says postdoctoral researcher Matheus Nunes from the University of Helsinki, lead author of the paper recently published in Nature Communications.

Repeat high-density airborne LiDAR across the human-modified forests of Borneo provided a unique perspective on the regrowth of forests during the 2015-2016 ENSO and the environmental controls on the canopy. Regeneration of logged forests was still positive during the hot and dry ENSO in Borneo when the highest temperatures and the highest VPD exceeded 2.1 °C and 140% the local long-term average during non-El Niño years. The results demonstrate that regenerating logged forests in this landscape - which contain a high abundance of pioneer tree species with acquisitive traits - continued to grow, despite the high temperatures and water demand in these logged forests.

However, the predictions revealed in the paper show that environmental controls were key to modulating regrowth at the landscape level.

Fragmentation effects increased exponentially with proximity to oil palm plantations, which is consistent with the long-term fragmentation effects that lead to tree mortality and lower productivity.

"Additionally, we demonstrate that the position of fragmented forests across the landscape was also a predictor of forest growth, with valleys and riparian forests showing higher canopy growth compared to those on hilltops during the El Niño", says Nunes.

Suggestions to the Roundtable for Sustainable Oil Palm

Oil palm companies that have joined the Roundtable for Sustainable Oil Palm are committed to the protection of high conservation value forests along rivers and on steep slopes within their estates.

"Our results suggest buffers have to be wide (at least 40 m on each side of the river) to ensure the interior of the strip retains a stable canopy height during droughts", says Nunes.

This is twice the width of what is currently required by law in Sabah, Malaysia. If designed and protected appropriately, riparian reserves in oil palm estates support regrowth with potential positive consequences for the global carbon cycle and for ecosystem function.

The results also demonstrate that small, fragmented patches of regenerating logged forests left on hilltops will be slow to recover due to lower water availability, particularly as El Niño events are becoming more frequent as a result of climate change. Fragmentation in these regenerating logged forests leads to consistent canopy loss within 110 m from oil palm plantations. These results suggest that small patches of logged forests on hilltops will not recover, reflecting the intertwined effects of fragmentation and climate.

Gas and liquid separation processes in the chemical industry could be made more efficient and environmentally friendly by using substances known as intrinsically porous materials (IPMs). KAUST researchers review the prospects for IPMs in the journal Accounts of Chemical Research.

Niveen Khashab and her team are currently heavily involved in IPM research. "We focus on making materials that will have an impact on the chemical and petrochemical industries in Saudi Arabia and the world," says Niveen Khashab, the corresponding author of the review.

IPM materials can separate gases and liquids without using traditional high-temperature methods like heat-driven distillation.

"Through the review, we identified some IPMs with impressive performance," says Gengwu Zhang, a postdoc in Niveen Khashab's team. He explains that these IPMs, like other porous materials being developed, could save 70 to 90 percent of the energy costs of existing technologies, with consequent environmental advantages.

A key advantage of IPMs over many other porous materials is their stability and ability to maintain their porous properties in the solid, liquid, gas or solution states. They can also be readily processed and modified when in solution, unlike many alternatives.

"They can be easily prepared on a large scale by using cheap starting materials," says Zhang, "Some of them are even commercially available products."

IPMs have diverse chemical structures, but they share the property of being permeated with pores that have sizes and chemical natures that make them suitable for separating and purifying different molecules. The structure of the pores determines which chemicals they can selectively adsorb, block or allow to pass through.

The KAUST authors reviewed the state of research into several IPMs, ranging from large individual molecules with internal pores to giant assemblies of molecules held together by weak multimolecular interactions.

The most promising IPMs identified in the review include the chemicals cyclodextrin, cucurbiturils, pillararenes, trianglamines and porous organic cages (POCs). These are all carbon-based or "organic" compounds. Cyclodextrins are ring-like carbohydrate structures produced from natural starch. The other compounds are specialized products of synthetic organic chemistry. The potential of these materials has been demonstrated by their performance in separating common industrial gases and liquid derivatives of the central industrial chemical benzene.

Khashab explains that the KAUST team are now addressing the challenge of scaling up their own work on IPMs, saying: "We have started discussions with Aramco for a pilot plan for liquid separations that should begin this year."

Researchers have demonstrated that a slimy, yet tough, type of biofilm that certain bacteria make for protection and to help them move around can also be used to separate water and oil. The material may be useful for applications such as cleaning contaminated waters.

In the journal Langmuir, North Carolina State University researchers reported the findings of an experiment in which they used a material produced by the bacteria Gluconacetobacter hansenii as a filter to separate water from an oil mixture.

"It's really remarkable to think that these little bugs can make this stuff that is so perfect in many ways," said Lucian Lucia, the study's corresponding author and an associate professor of forest biomaterials and chemistry at NC State.

The biofilm the bacteria make and release into their environment is made of cellulose, which is the same material that gives plants a sturdy structure in their cell walls. However, when bacteria make cellulose, it has a tightly packed, crystalline structure, researchers said.

"It's one of the purest, if not the purest, forms of cellulose out there," Lucia said. "It's very well structured. It's very water loving, and it's got a very high crystallinity, so it packs very beautifully. Once you strip out the bacteria, you have this amazingly tough material that has a real robustness, or toughness."

The bacteria make the film to protect themselves, the researchers said.

"If you leave something like an unwashed dish out, it can turn all slimy and gross - that's a biofilm," said study co-author Wendy Krause, associate professor of textile engineering, chemistry and science at NC State. "Different bacteria make different biofilms. The bacterial film that we're studying is made of cellulose. The bacteria are making it because they live on it and in it. They're making their home."

In the experiment, researchers used the bacteria as factories of cellulose nano-fibers. They then removed the bacteria and their non-cellulose residue. Finally, the researchers used the cellulose membrane to see if it could separate water from a solution containing both oil and water.

They found the material was effective at removing water, and it was sturdy.

"The oil doesn't want to go through the membrane; it has a repulsive effect to it," Lucia said. "It's super fat-hating."

"If the oil and water were highly mixed, it doesn't matter," Krause added. "You could put an immersion blender into the solution, and the membrane will still separate the water and oil."

Researchers see a variety of potential applications for the material in situations where you need to recover water from an oily mixture - whether it be to clean water contaminated with a textile dye or for environmental remediation. In future work, the researchers want to explore how they can tailor the membrane by chemically modifying it for certain applications.

The study, "Bacterial Superoleophobic Fibrous Matrices: A Naturally Occurring Liquid-Infused System for Oil-Water Separation," was published online in the journal Langmuir on Feb. 19.

Scientists have used modern genetic techniques to prove age-old assumptions about what sizes of fish to leave in the sea to preserve the future of local fisheries.

"We've known for decades that bigger fish produce exponentially more eggs," said the lead author of the new study, Charles Lavin, who is a research fellow from James Cook University (JCU) and Nord University in Norway.

"However, we also found while these big fish contributed significantly to keeping the population going--they are also rare."

Co-author Dr Hugo Harrison from the ARC Centre of Excellence for Coral Reef Studies at JCU said as fish grow older, they become more fertile and their chances of having babies increase.

"This is an age-old assumption of fisheries management--and with the help of modern genetics, we can show that this assumption is correct."

"But the smaller fish are just as important to keeping populations going. They may have fewer babies, but they also are more abundant."

The study used genetic parentage analysis to identify which adult coral groupers (Plectropomus maculatus) contribute to replenishing fished populations in the Great Barrier Reef Marine Park (GBRMP).

The authors found that large coral groupers are important because they are more likely to replenish the fish stocks removed from the fishery. However, smaller fish are still making a meaningful contribution.

"We show that minimum size-limits on catches are effective at protecting the reproductively mature coral grouper," Mr Lavin said. "This ensures all fish have the opportunity to reproduce at least once prior to being caught."

The authors said all fisheries must ensure there are enough fish reproducing to replace the portion of the population that are caught.

"We're fortunate in the GBRMP to have measures in place that protect both the small and larger fish," Dr Harrison said.

"These ensure our fisheries remain sustainable and can bounce back quickly after a disturbance."

In the GBRMP, catches of coral grouper are limited by size and catch limits, as well as seasonal closures to ensure the fishery is productive and sustainable.

"It's encouraging that these measures are effective," Mr Lavin said.

"But it's important that we also protect the bigger, rarer fish inside no-take marine reserves because they are super-productive," he said.

"For the fisher, this means there will always be fish to catch."

Polymer scientists from the University of Groningen and NHL Stenden University of Applied Sciences, both in the Netherlands, have developed a polymer membrane from biobased malic acid. It is a superamphiphilic vitrimer epoxy resin membrane that can be used to separate water and oil. This membrane is fully recyclable. When the pores are blocked by foulants, it can be depolymerized, cleaned and subsequently pressed into a new membrane. A paper describing the creation of this membrane was published in the journal Advanced Materials on 7 March 2021.

How do you clean up an oil spill in water? This is quite a challenge. Superamphiphilic membranes, that 'love' both oil and water, are a promising solution but not yet a very practical one. These membranes are often not robust enough for use outside the laboratory environment and the membrane pores can clog up as a result of fouling by algae and sand. Chongnan Ye and Katja Loos from the University of Groningen and Vincent Voet and Rudy Folkersma from NHL Stenden used a relatively new type of polymer to create a membrane that is both strong and easy to recycle.

Dynamic network

In recent years, the researchers from both institutes have joined forces to investigate vitrimer plastics, polymer materials that have the mechanical properties and chemical resistance of a thermoset plastic. However, vitrimer plastics can also behave like a thermoplastic, since they can be depolymerized and reused. This means that a vitrimer plastic has all the qualities to make a good membrane for oil spill remediation. 'Furthermore, it was made from malic acid, a natural monomer,' adds Loos.

'The polymers in the vitrimer are crosslinked in a reversible manner,' explains Voet. 'They form a dynamic network, which enables recycling of the membrane.' The vitrimer is produced through base-catalysed ring-opening polymerization between pristine and epoxy-modified biobased malic acid. The polymers are ground into a powder by ball milling and turned into a porous membrane through the process of sintering.

Pores

Both water and oil will spread out on the resulting superamphiphilic membrane. In an oil spill, much more water is present than oil, which means that the membrane is covered by water that can then pass through the pores. Voet: 'The water film on the membrane's surface keeps the oil out of the pores so that it is separated from the water.'

The membrane is firm enough to filter oil from the water. When sand and algae clog up the pores, the membrane can be depolymerized and recreated from the building blocks after removal of the pollutants. 'We have tested this on a laboratory scale of a few square centimetres,' says Loos. 'And we are confident that our methods are scalable, both for the polymer synthesis and for the production and recycling of the membrane.' The scientists are hoping that an industrial partner will take up further development.

Applications

Creating this new membrane for oil spill remediation shows the power of cooperation between a research university and an applied university. 'A while ago, we decided that the polymer groups at the two institutes should become one, by sharing students, staff and facilities. We recently started the first hybrid research group in the Netherlands,' explains Loos. This makes it easier to find applications for newly designed materials. Voet: 'Polymer chemists strive to link molecular structures to material properties and applications. Our hybrid research team has the experience to do just that.'

Non-Small Cell Lung Cancer (NSCLC) is the most prevalent form of lung cancer, accounting for more than 80 percent of all lung cancer cases. Despite the aggressive nature of NSCLC, circulating tumor cells that lead to metastases often go undetected in the blood compared to breast, prostate, colorectal, and other cancers. 

Now, scientists have developed a novel method to better detect the circulating tumor cells (CTCs) that are a telltale sign of metastases. The research was published in the journal Proceedings of the National Academy of Sciences (PNAS). 

ISB and a collaborative team of researchers looked at hexokinase-2, or HK2, a key enzyme in glucose metabolism. "A set of previous reports from our collaborator Dr. Herschman (co-author of the paper) and others revealed that cancer cells often rely on HK2 to elevate glucose metabolism to fuel their uncontrolled growth, making this enzyme a desirable target for testing," said ISB Assistant Professor Dr. Wei Wei, the lead corresponding author of the paper. 

Conventional CTC detection methods, as exemplified by the FDA-cleared CellSearch system, normally rely on the use of a family of proteins called cytokeratins (CKs) that are typically found in epithelial tissues. As roughly 90 percent of human cancers arise in epithelial tissues and express CKs, these methods work very well in many major cancer types. However, their performance in NSCLC is suboptimal, despite the highly aggressive nature of NSCLC, which represents a long-standing puzzle in this field.

The researchers addressed this challenge to achieve a greater spectrum for CTC detection through exploiting a common feature of a wide range of cancer cells - elevated glucose consumption driven by the high level of HK2. The use of HK2 as a biomarker allowed them to develop metabolic activity-based methods for the identification of a novel CTC population without CK expression that was normally overlooked by conventional methods. This CK-negative CTC population was a prevalent subtype in 50 percent of NSCLC patients analyzed and was the only subtype in one-third of them, although all these patients were bearing CK-positive primary tumors, indicating that these tumor cells transitioned to CK-negative after detaching from the primary sites and shedding into the bloodstream in these NSCLC patients. 

Sequencing analysis revealed metastasis and drug-resistance molecular signatures associated with CK-negative CTCs. Consistently, patients with prevalent CK-negative CTCs in blood were having poorer therapy response, shorter progression-free survival, and a higher chance for metastasis. Interestingly, the researchers found that patients with the EGFRL858R mutation - a common mutation of NSCLC treated by EGFR inhibitors - are more likely to have CK-negative CTCs circulating in their blood, which partially explains a long-standing clinical observation, namely the suboptimal therapeutic efficacy of first-line EGFR inhibitors in EGFRL858R-mutant tumors.

"The use of HK2 as a tumor cell marker permits us to reveal a novel circulating tumor cell population which is not accessible with and is normally overlooked by current epithelial marker-based CTC detection methods," Wei said. "Moreover, this approach can be exploited to anticipate NSCLC patient therapy response before they undergo cancer therapy, and more generally, it will be useful in identifying CTCs from patients with a wide variety of cancers, independent of epithelial traits."