Culture

Researchers from Indiana University and Miami University-Ohio published a new paper in the Journal of Marketing that examines how power distance belief affects consumers' price sensitivity.

The study forthcoming in the Journal of Marketing is titled "Price No Object!: The Impact of Power Distance Belief on Consumers' Price Sensitivity" and is authored by Hyejin Lee, Ashok Lalwani, and Jessie Wang.

Most marketers dream of being able to charge high prices for their products. However, few can do so without spending vast sums to enhance perceptions of value (e.g., by improving product benefits). Consequently, marketers continuously strive to identify and target consumer segments that are less price-sensitive because these consumers are more likely to find price increases palatable.

A new study in the Journal of Marketing identifies a cultural variable, namely power distance belief (PDB)--the extent to which people accept and endorse hierarchy--as an important determinant of consumers' price sensitivity. Across multiple studies, the researchers find that consumers high (vs. low) in PDB are less price-sensitive. Lee explains that "These consumers have a higher need for closure (NFC), which increases their tendency to 'seize and freeze' on a current offer and reduces their likelihood of searching for better priced options, thereby reducing price sensitivity."

Study 1a provides evidence of the negative relationship between PDB and price sensitivity using A.C. Nielsen scanner panel data.

Study 1b provides convergent evidence for external validity using a consequential measure to assess consumers' actual purchasing behavior driven by their price sensitivity.

Study 1c provides evidence of the relationship via a field study at a small local grocery store.

Study 2a directly assesses the mediating role of the need for closure and rules out other cultural variables and all alternative explanations.

Study 2b provides evidence for serial mediation through need for closure (mediator 1) and price search tendency (mediator 2) using four different established measures of price sensitivity.

The last study reveals that a high social density reduces the price sensitivity of low (but not high) PDB consumers. The effect is independent of numerous psychological (e.g., risk aversion, perceptions of self-efficacy, sacrifice mindset, need for status, self-regulation), cultural (e.g., uncertainty avoidance, long-term orientation, masculinity, interdependence), and demographic (income, occupation, education, household size, type of residence) variables.

Thus, low PDB consumers are identified as the roadblocks for marketers who seek to raise prices. To meet this challenge, the study offers several strategies, including: (1) targeting consumer segments high (vs. low) in PDB, (2) activating a high PDB via ads, slogans, or POP material, (3) heightening the need for closure using contextual cues, and (4) increasing social density in stores.

Scientists at St. Jude Children's Research Hospital are advancing understanding of a potential Alzheimer's disease treatment. The work focuses on LC3-associated endocytosis (LANDO) and its role in neuroinflammation. The results appeared as an advance online publication today in Science Advances.

The researchers previously discovered the LANDO pathway in microglial cells, the primary immune cells of the brain and central nervous system. Scientists found that when genes required for this pathway are deleted, Alzheimer's disease progression accelerates in a mouse model. The investigators also showed that LANDO protects against neuroinflammation, one of the hallmarks of Alzheimer's disease.

While continuing to investigate LANDO, the researchers identified a novel function of the protein ATG16L. This protein is critical for autophagy, the normal process by which a cell recycles its components during periods of stress or energy deprivation. While ATG16L is important for autophagy, it can also play a role in LANDO. The investigators found that if a region of ATG16L called the WD domain is deleted, LANDO is inhibited while autophagy continues.

"We learned about this pathway in the context of brain tumor research, but it has major implications for neuroinflammatory and neurodegenerative disease," said senior author Douglas Green, Ph.D., chair of the St. Jude Immunology Department. "We've shown that deficiency in LANDO, combined with aging, can lead to Alzheimer's disease in a unique mouse model, and there is evidence suggesting that this could also be the case in humans."

A model for Alzheimer's disease research

Most mouse models used in Alzheimer's disease research rely on making genetic changes to recreate the disease. For this work, researchers used a new model with a specific deficiency of just the WD domain of ATG16L. This means the model carries out autophagy normally but lacks the LANDO pathway. By the time the mice are 2 years old, they exhibit symptoms and pathology that mimic human Alzheimer's disease. This spontaneous age-associated model of Alzheimer's disease is the first created by deleting a single protein domain (WD on ATG16L), not previously associated with Alzheimer's disease.

The researchers also analyzed human Alzheimer's disease tissue samples, looking at the expression of proteins that regulate LANDO, including ATG16L. Expression of these proteins is decreased by more than 50% in people with Alzheimer's disease. This finding shows a correlation between how deficiency in LANDO combined with aging may lead to Alzheimer's disease in the mouse model and in humans.

A strategy for treatment emerges

Reducing neuroinflammation has been proposed as a potential way to treat Alzheimer's disease. To treat their new mouse model, researchers used a compound that inhibits the inflammasome - a complex of proteins that activates pro-inflammatory immune reactions. The scientists targeted the inflammasome responsible for neuroinflammation in people with Alzheimer's disease. Researchers profiled the model's behavior and found evidence of improved cognition and memory in addition to a decrease in neuroinflammation.

"This work solidifies LC3-associated endocytosis as a pathway that prevents inflammation and inflammatory cytokine production in the central nervous system," said first author Bradlee Heckmann, Ph.D., of St. Jude Immunology. "While much of the data on LANDO suggests a significant role in neuroinflammatory and neurodegenerative diseases, there is also a strong possibility that it could be targeted as a therapy against cancer or even infectious diseases that rely on similar processes for survival."

COVID-19 patients with cardiovascular comorbidities or risk factors are more likely to develop cardiovascular complications while hospitalized, and more likely to die from COVID-19 infection, according to a new study published August 14, 2020 in the open-access journal PLOS ONE by Jolanda Sabatino of Universita degli Studi Magna Graecia di Catanzaro, Italy, and colleagues.

For most people, the Novel Coronavirus Disease 2019 (COVID-19) causes mild illness, however it can generate severe pneumonia and lead to death in others. It is crucial for clinicians working with cardiovascular patients to understand the clinical presentation and risk factors for COVID-19 infection in this group.

In the new study, researchers analyzed data from 21 published observational studies on a total of 77,317 hospitalized COVID-19 patients in Asia, Europe and the United States. At the time they were admitted to the hospital, 12.89% (95% CI 8.24-18.32) of the patients had cardiovascular comorbidities, 36.08% (95% CI 20.25-53.64) had hypertension and 19.45% (95% CI 12.55-27.45) had diabetes.

Cardiovascular complications were documented during the hospital stay of 14.09% (95% CI 10.26-20.23) of the COVID-19 patients. The most common of these complications were arrhythmias or palpitations; significant numbers of patients also had myocardial injury. When the researchers analyzed the data, they found that pre-existing cardiovascular comorbidities or risk factors were significant predictors of cardiovascular complications (p=0.019), but age (p=0.197) and gender (p=0.173) were not. Both age and pre-existing cardiovascular comorbidities or risk factors were significant predictors of death.

The authors add: "Cardiovascular complications are frequent among COVID-19 patients and might contribute to adverse clinical events and mortality."

You have just enjoyed a delicious summer BBQ. After approximately eight hours, food molecules reach your small intestine, where specialized lymph capillaries, called lacteals, absorb fat nutrients. Lacteals are different from other lymphatics, as they continue to regenerate during adulthood, with a slow, but steady pace. Their unique renewal capacity is still poorly understood.

A team of scientists led by KOH Gou Young at the Center for Vascular Research, within the Institute for Basic Science (IBS, South Korea) have identified new subsets of gut connective cells, which are crucial for lymphatic growth. Their new findings have been reported in the journal Nature Communications.

The walls of the small intestine are covered with fingerlike projections, called villi. Lining these villi, heterogeneous populations of epithelial, immune, vascular, connective and even neural cells co-exist and help the digestive process. Lacteals and blood capillaries run inside the villi and take in different food molecules. The gut environment needs to cope with water secretion and reabsorption (osmotic stress), as well as the repetitive muscular activity that moves food through the intestine. How all these complex mechanisms are harmonized is still a mystery.

The research team was able to place a new piece towards completing this mysterious puzzle. The researchers found that the regulatory proteins YAP/TAZ in villi's connective cells, the intestinal stromal cells, play a role in the growth of nearby lacteals. In mice with an abnormal hyperactivation of YAP/TAZ, the team observed atypical sprouting of lacteals and impaired dietary fat uptake.

"The lacteals in these mice looked like tridents, which is very intriguing, since we did not manipulate the lacteals themselves, but the surrounding cells," says HONG Seon Pyo, first co-author of this study.

The researchers took a step further and discovered that intestinal stromal cells belong to several subtypes, with distinct gene expression and localizations within the villi. Among these subsets, three newly identified populations secrete VEGF-C - an essential molecule for lymphatic growth - upon YAP/TAZ activation. YANG Myung Jin, first co-author of this study, explains, "We were very surprised to see such heterogeneity in a cell population that was considered homogeneous."

Lastly, researchers showed that mechanical force and osmotic stress regulate YAP/TAZ activity in stromal cells. In summary, mechanical stimulation activates YAP/TAZ in the intestinal stromal cells, which in turn release VEGF-C and can account for lacteal growth. CHO Hyunsoo, first co-author of this study notes, "This result implies a crucial link between the physiology of intestinal environment and biological interactions between cell types."

"We are interested in investigating how each newly identified cell type works in healthy and diseased conditions," adds Koh.

Researchers at the University of Maryland (UMD) have discovered an entirely new role for a well-known plant molecule called ACC, providing the first clear example of ACC acting on its own as a likely plant hormone. Just like in humans and animals, hormones in plants carry messages to signal and trigger essential processes for plant health and functionality, from reproduction to defense. Without these processes, crops can't reproduce and thrive to provide the food we need to feed a growing global population. In a new publication in Nature Communications, researchers show that ACC has a critical role in pollination and seed production by activating proteins similar to those involved in nervous system responses in humans and animals. These findings could not only change textbooks that have previously attributed plant responses to the hormone ethylene instead of ACC, but could also open the door for new research to improve plant health and crop yield.

"There are several novel things about this paper," explains Caren Chang, UMD. "But the main impact is that it introduces a new plant growth regulator or plant hormone, alongside a small handful of other publications. It isn't a newly identified molecule, but it has never been thought of before as a plant hormone, only as the precursor to ethylene."

Chang, a professor in Cell Biology & Molecular Genetics and affiliate professor of Plant Science & Landscape Architecture supported by the Maryland Agricultural Experiment Station (MAES), explains that ethylene is one of the five major plant hormones and has been studied for over a century. It is important for many processes that are vital to plant health and crop production, including fruit ripening, stress responses to flooding and drought, plant disease defenses, germination, and flowering.

"In much of the research, ACC has been used in place of ethylene, knowing that it's a precursor that plants convert into ethylene. This is because ACC is easy to work with in powder form and can even be sprayed on the plant, but working with ethylene is very difficult because it is a gas. So researchers have used ACC for decades in place of ethylene, and the literature would interpret the observed responses as ethylene responses. What our paper shows is that an ACC response is not necessarily an ethylene response. While ethylene is an important plant hormone with its own set of functions, some of these responses that have been attributed to ethylene through ACC may actually be separate ACC responses, acting as a growth regulator or hormone itself."

This finding opens the door for many papers across decades of research, as well as textbooks and future education on plant hormone responses, to be revised in the event that ACC is actually triggering important plant processes previously attributed to ethylene.

According to Chang, the paper also presents advances in plant reproduction. "In the plant reproduction field, there are many steps that are critical in pollination, and one of these steps requires the pollen to reach the ovules to actually produce a seed," says Chang. "Our paper shows that ACC signaling in the ovule is involved in getting the pollen tube to turn and effectively deliver the pollen, which makes it essential for seed production. It's probably the first example showing how the maternal ovule tissue actually helps attract the pollen tube." And this isn't a small effect, Chang stresses. "The seed number pretty much doubles in the presence of ACC. There is potential here to improve the seed number, which can increase food production in certain crops and have an impact on food security long-term."

Led by José Feijó, another professor in Cell Biology & Molecular Genetics and affiliate professor of Plant Science & Landscape Architecture, another major finding of this paper shows clear connections between human, animal, and plant hormone signaling pathways by identifying a potential receptor for ACC activity.

"The most interesting parallel is cell-cell communication," explains Feijó. "Animal glutamate receptors are proteins which are needed for information to jump from one neuron to the next, either through an electric impulse or through calcium signaling, which is essential for things like memory. Problems in the processes mediated by glutamate receptors are known to be related to neurodegeneration and depression."

Chang adds, "These receptors have been found in the human nervous system, and neuroscientists have been studying them for drug development to treat nervous system issues like depression. They found that ACC can actually affect the nervous system in humans. So we decided to look for the same receptors, named glutamate-like receptors (GLRs) in plants, to see if they respond to ACC in plants. We found that ACC can actually affect GLRs in plants as well."

This finding opens an entirely new avenue of research in plant biology and points to similarities in plants and humans that are currently not well understood. "In plants, GLRs all seem to convey functions related to communication, either to bring male and female genes into an egg, or in pathogen or stress alert systems and defenses," says Feijó.

"Emerging trends suggest that GLRs underlie long distance electric signaling through the plant vascular system, where injury to tissues in one leaf inform the whole plant to create nasty substances to deter insects. All these lines seem to point into the existence of electric communication within plant tissues and organs, and that these functions involve GLRs. This is an interesting parallel evolution of a function for glutamate receptors as they evolved to be associated with the animal nervous systems to perform similar functions."

With ACC as a new candidate activating GLRs and all the newly discovered roles it is playing as a plant hormone, Chang and the team are excited about the directions this work can go. "There is still a lot of research to be done to see how this is all happening and can be used in different crops, but all that new research can happen now."

Molecular and computational biologists from Peter the Great St. Petersburg Polytechnic University (SPbPU), St. Petersburg State University and Federal Centre for Bast Fiber Crops teamed up to sequence and assemble genome of Fusarium oxysporum f.sp. lini, a highly destructive fungal parasite infecting flax. The results of the study were published in the Molecular Plant-Microbe Interactions.

Fusarium wilt is a nasty but common disease affecting economically important crops such as banana, cotton, flax, canola, melons, onions, potato and tomato. The release of the complete genome sequence is a milestone in comparative genomics studies of fungal parasites; it contributes to the global efforts aimed at elimination of plant disease outbreaks by aiding in engineering of new resistant crops varieties.

Fusarium wilt is a plant disease caused by various species of Fusarium fungi. Botanists and plant scientists are aware of approximately 120 species of the parasite, capable of infecting a wide spectrum of crops, such as tomatoes, cucumbers, melons, cabbages, peas, corn, barley, wheat, and many other plants. This study focuses on detailed characterization of F. oxysporum f.sp. lini which infects flax, a major source of textile fibre, seed and flaxseed (linseed) oil in Russia.

"The pathogen has a remarkable resistance to chemical agents and its spores may persist quite comfortably in soil for years. It is a widely accepted opinion in modern crop science that the most promising approach to fight the infection is to breed new resistant varieties,' says Anastasia Samsonova, Professor at the Centre for Genome Bioinformatics at St Petersburg University. "The host and parasite are engaged in an endless "arms race" to survive. Sooner or later, the flax varieties that are currently commercially cultivated may lose their resistance, succumb to the disease completely and become unprofitable to grow. Naturally, this creates a demand for breeding new resistant crops."

The whole genome chromosome-level assembly of the Fusarium oxysporum f.sp. lini was completed in a joint research effort by scientists from St. Petersburg University, Peter the Great St. Petersburg Polytechnic University, and the Centre for Bast Fiber Crops in Torzhok. "The parasite's genome consists of two components; the stable one, which is almost identical in different Fusariums, and the variable part which is mainly responsible for amazing adaptation of the fungus to various plants." says Alexander Kanapin, Professor at the Centre for Genome Bioinformatics at St Petersburg University. "The chromosome-level assembly of the genome is a significant step towards understanding the parasite evolution and adaptation to a particular host."

"Thanks to recent advances in omics technologies and computational biology, and to our fantastic collaborators at the Centre for Bast Fiber Crops, we generated a high quality data resource for comparative studies of Fusarium pathogenic diversity and molecular mechanisms of interaction between the fungus and the host. This will undoubtedly increase the power of integrative systems genetics analyses and thus contribute to the global efforts aimed at elimination of plant disease outbreaks by aiding in engineering of new resistant crops varieties.", explains Maria Samsonova, Head of the Laboratory for Mathematical Biology and Bioinformatics at Peter the Great St Petersburg Polytechnic University.

Further research will address many important questions left unanswered; the team will try to find a genetic determinants of the fungus "taste". In other words, why certain species "enjoys" melons, while the other one "fancies" tomatoes. Knowing parasite's preferences will help to elucidate specific mechanisms of Fusarium adaptation to different hosts and find genes responsible.

When Anthropologist Caroline Arcini and her colleagues at the Swedish Natural Historical Museum discovered small calcifications in the extremely well preserved lungs of Bishop Peder Winstrup, they knew more investigation was needed. "We suspected these were remnants of a past lung infection," says Arcini, "and tuberculosis was at the top of our list of candidates. DNA analysis was the best way to prove it."

Up to one quarter of the world's population is suspected to have been exposed to bacteria of the Mycobacterium tuberculosis complex, which cause tuberculosis (TB). Bishop Winstrup would have been one of many to fall ill during the onset of the so-called "White Plague" TB pandemic that ravaged post-medieval Europe. Today, TB is among the most prevalent diseases, accounting for the highest worldwide mortality from a bacterial infection.

The global distribution of TB has led to the prevailing assumption that the pathogen evolved early in human history and reached its global distribution via the hallmark Out of Africa human migrations tens of thousands of years ago, but recent work on ancient TB genomes has stirred up controversy over when this host-pathogen relationship began. In 2014, a team led by scientists from the University of Tübingen and Arizona State University reconstructed three ancient TB genomes from pre-contact South America - not only were the ancient strains unexpectedly related to those circulating in present-day seals, but comparison against a large number of human strains suggested that TB emerged within the last 6000 years. Understandably, skepticism surrounded this new estimate since it was based entirely on ancient genomes that are not representative of the TB strains associated with humans today.

"Discovery of the Bishop's lung calcification gave us the opportunity to revisit the question of tuberculosis emergence with data from an ancient European," comments Kirsten Bos, group leader for Molecular Paleopathology at the Max Planck Institute for the Science of Human History (MPI-SHH), who co-led the study. "If we could reconstruct a TB genome from Bishop Winstrup, where we know his date of death to the day, it would give a secure and independent calibration for our estimates of how old TB, as we know it, actually is."

The highest quality ancient TB genome to date

In a new study published this week in Genome Biology, Susanna Sabin of MPI-SHH and colleagues reconstruct a tuberculosis genome from the calcified nodule discovered in Bishop Winstrup's remains.

"The genome is of incredible quality - preservation on this scale is extremely rare in ancient DNA," comments Bos.

Together with a handful of tuberculosis genomes from other work, the researchers revisit the question of the age of the Mycobacterium tuberculosis complex, with the year of the Bishop's death as a fine-tuned calibration point. Using multiple molecular dating models, all angles indeed point to a relatively young age of the Mycobacterium tuberculosis complex.

"A more recent emergence of the tuberculosis pathogen complex is now supported by genetic evidence from multiple geographic regions and time periods," comments Sabin, first author of the study. "It's the strongest evidence available to date for this emergence having been a Neolithic phenomenon."

This most recent shift in the narrative for when bacteria in the Mycobacterium tuberculosis complex became highly infectious to humans raises further questions about the context of its emergence, as it appears to have coincided with the rise of pastoralism and sedentary lifestyles.

"The Neolithic transition seems to have played an important role for the emergence of a number of human pathogens," comments Denise Kühnert, group leader for disease transmission research at MPI-SHH who co-led the investigation.

"For TB in particular, stronger evidence could only come from an older genome, though these deeper time periods are unlikely to yield preservation on the scale of what we've seen for Bishop Winstrup," adds Bos.

"Moving forward," Sabin further comments, "the hope is we will find adequately preserved DNA from time periods close to the emergence of the complex, or perhaps from its ancestor."

An international team led by the chemist Heinz Langhals of LMU Munich succeeded in molecular deflection of light radiation by means of Diamantane. Novel applications such as efficient light collectors or broadband light absorbers are promising.

Diamantane, the second smallest and thus molecular diamond, is a highly fascinating material for chemists. It can be applied as rigid spacer and stiff pillar in molecular architectures so that optically functional units can be three-dimensionally arranged in well-defined larger assemblies. Noteworthy is: The diamond allows the vibration-mediated transmission of optical energy in light-collecting systems in spite of his firmness; this proceeds according to a mechanism that was recently discovered by an international group of researchers led by the chemist Heinz Langhals of LMU Munich, in which slow molecular bending vibrations play the key role.

The work refers to an international co-operation. Researchers at the University of Stanford isolated the preparatively only laboriously accessible Diamantane efficiently from crude oil. Chemists in Taipei were responsible for the targeted functionalization. The researchers at the LMU Munich constructed the optical functional unit from adapted components. The newly found mechanism of energy transfer in such units causes consequences in physics because it requires a correction and extension of the theory of FRET where the familiar dipole interaction for the energy transfer is disproved as the exclusive mechanism and slow molecular vibronic processes have to be considered. On the other hand, this allows a 90° deflection of light simulating a 45° oriented molecular mirror useful for optical devices such as solar light-collecting systems where the high stability and rigidity of diamondoid spacers mean a special advantage for the construction of well-defined complex molecular structures.

Researchers in South Africa's Border Cave, a well-known archaeological site perched on a cliff between eSwatini (Swaziland) and KwaZulu-Natal in South Africa, have found evidence that people have been using grass bedding to create comfortable areas for sleeping and working on at least 200 000 years ago.

These beds, consisting of sheaves of grass of the broad-leafed Panicoideae subfamily were placed near the back of the cave on ash layers. The layers of ash was used to protect the people against crawling insects while sleeping. Today, the bedding layers are visually ephemeral traces of silicified grass, but they can be identified using high magnification and chemical characterisation.

The Border Cave study was conducted by a multidisciplinary team from the University of the Witwatersrand, South Africa, the CNRS (University of Bordeaux), and Université Côte d'Azur, France, the Instituto Superior de Estudios Sociales, Tucumán, Argentina, and the Royal Institute for Cultural Heritage, Belgium. The research was published in the high impact journal Science.

"We speculate that laying grass bedding on ash was a deliberate strategy, not only to create a dirt-free, insulated base for the bedding, but also to repel crawling insects," says Professor Lyn Wadley, principal researcher and lead author.

"Sometimes the ashy foundation of the bedding was a remnant of older grass bedding that had been burned to clean the cave and destroy pests. On other occasions, wood ash from fireplaces was also used as the clean surface for a new bedding layer."

Several cultures have used ash as an insect repellent because insects cannot easily move through fine powder. Ash blocks insects' breathing and biting apparatus, and eventually dehydrates them. Tarchonanthus (camphor bush) remains were identified on the top of the grass from the oldest bedding in the cave. This plant is still used to deter insects in rural parts of East Africa.

"We know that people worked as well as slept on the grass surface because the debris from stone tool manufacture is mixed with the grass remains. Also, many tiny, rounded grains of red and orange ochre were found in the bedding where they may have rubbed off human skin or coloured objects," says Wadley.

Modern hunter-gatherer camps have fires as focal points; people regularly sleep alongside them and perform domestic tasks in social contexts. People at Border Cave also lit fires regularly, as seen by stacked fireplaces throughout the sequence dated between about 200 000 and 38 000 years ago.

"Our research shows that before 200 000 years ago, close to the origin of our species, people could produce fire at will, and they used fire, ash, and medicinal plants to maintain clean, pest-free camps. Such strategies would have had health benefits that advantaged these early communities."

Although hunter-gatherers tend to be mobile and seldom stay in one place for more than a few weeks, cleansing camps had the potential to extend potential occupancy.

Crop scientists, molecular and computational biologists from two leading St. Petersburg Universities and Federal Centre for Bast Fiber Crops teamed up to sequence and assemble genome of Fusarium oxysporum f.sp. lini, a highly destructive fungal parasite infecting flax.

Fusarium wilt is a plant disease caused by various species of Fusarium fungi. Botanists and plant scientists are aware of approximately 120 species of the parasite, capable of infecting a wide spectrum of crops, such as tomatoes, cucumbers, melons, cabbages, peas, corn, barley, wheat, and many other plants. This study focuses on detailed characterization of F. oxysporum f.sp. lini which infects flax, a major source of textile fibre, seed and flaxseed (linseed) oil in Russia.

"The pathogen has a remarkable resistance to chemical agents and its spores may persist quite comfortably in soil for years. It is a widely accepted opinion in modern crop science that the most promising approach to fight the infection is to breed new resistant varieties,' says Anastasia Samsonova, Professor at the Centre for Genome Bioinformatics at St Petersburg University. "The host and parasite are engaged in an endless "arms race" to survive. Sooner or later, the flax varieties that are currently commercially cultivated may lose their resistance, succumb to the disease completely and become unprofitable to grow. Naturally, this creates a demand for breeding new resistant crops."

The whole genome chromosome-level assembly of the Fusarium oxysporum f.sp. lini was completed in a joint research effort by scientists from St. Petersburg University, Peter the Great St. Petersburg Polytechnic University, and the Centre for Bast Fiber Crops in Torzhok. "The parasite's genome consists of two components; the stable one, which is almost identical in different Fusariums, and the variable part which is mainly responsible for amazing adaptation of the fungus to various plants." says Alexander Kanapin, Professor at the Centre for Genome Bioinformatics at St Petersburg University. "The chromosome-level assembly of the genome is a significant step towards understanding the parasite evolution and adaptation to a particular host."

"Thanks to recent advances in omics technologies and computational biology, and to our fantastic collaborators at the Centre for Bast Fiber Crops, we generated a high quality data resource for comparative studies of Fusarium pathogenic diversity and molecular mechanisms of interaction between the fungus and the host. This will undoubtedly increase the power of integrative systems genetics analyses and thus contribute to the global efforts aimed at elimination of plant disease outbreaks by aiding in engineering of new resistant crops varieties.", explains Maria Samsonova, Head of the Laboratory for Mathematical Biology and Bioinformatics at Peter the Great St Petersburg Polytechnic University.

Further research will address many important questions left unanswered; the team will try to find a genetic determinants of the fungus "taste". In other words, why certain species "enjoys" melons, while the other one "fancies" tomatoes. Knowing parasite's preferences will help to elucidate specific mechanisms of Fusarium adaptation to different hosts and find genes responsible.

To get a better look at the world around them, animals constantly are in motion. Primates and people use complex eye movements to focus their vision (as humans do when reading, for instance); birds, insects, and rodents do the same by moving their heads, and can even estimate distances that way. Yet how these movements play out in the elaborate circuitry of neurons that the brain uses to "see" is largely unknown. And it could be a potential problem area as scientists create artificial neural networks that mimic how vision works in self-driving cars.

To better understand the relationship between movement and vision, a team of Harvard researchers looked at what happens in one of the brain's primary regions for analyzing imagery when animals are free to roam naturally. The results of the study, published Tuesday in the journal Neuron, suggest that image-processing circuits in the primary visual cortex not only are more active when animals move, but that they receive signals from a movement-controlling region of the brain that is independent from the region that processes what the animal is looking at. In fact, the researchers describe two sets of movement-related patterns in the visual cortex that are based on head motion and whether an animal is in the light or the dark.

The movement-related findings were unexpected, since vision tends to be thought of as a feed-forward computation system in which visual information enters through the retina and travels on neural circuits that operate on a one-way path, processing the information piece by piece. What the researchers saw here is more evidence that the visual system has many more feedback components where information can travel in opposite directions than had been thought.

These results offer a nuanced glimpse into how neural activity works in a sensory region of the brain, and add to a growing body of research that is rewriting the textbook model of vision in the brain.

"It was really surprising to see this type of [movement-related] information in the visual cortex because traditionally people have thought of the visual cortex as something that only processes images," said Grigori Guitchounts, a postdoctoral researcher in the Neurobiology Department at Harvard Medical School and the study's lead author. "It was mysterious, at first, why this sensory region would have this representation of the specific types of movements the animal was making."

While the scientists weren't able to definitively say why this happens, they believe it has to do with how the brain perceives what's around it.

"The model explanation for this is that the brain somehow needs to coordinate perception and action," Guitchounts said. "You need to know when a sensory input is caused by your own action as opposed to when it's caused by something out there in the world."

For the study, Guitchounts teamed up with former Department of Molecular and Cellular Biology Professor David Cox, alumnus Javier Masis, M.A. '15, Ph.D. '18, and postdoctoral researcher Steffen B.E. Wolff. The work started in 2017 and wrapped up in 2019 while Guitchounts was a graduate researcher in Cox's lab. A preprint version of the paper published in January.

The typical setup of past experiments on vision worked like this: Animals, like mice or monkeys, were sedated, restrained so their heads were in fixed positions, and then given visual stimuli, like photographs, so researchers could see which neurons in the brain reacted. The approach was pioneered by Harvard scientists David H. Hubel and Torsten N. Wiesel in the 1960s, and in 1981 they won a Nobel Prize in medicine for their efforts. Many experiments since then have followed their model, but it did not illuminate how movement affects the neurons that analyze.

Researchers in this latest experiment wanted to explore that, so they watched 10 rats going about their days and nights. The scientists placed each rat in an enclosure, which doubled as its home, and continuously recorded their head movements. Using implanted electrodes, they measured the brain activity in the primary visual cortex as the rats moved.

Half of the recordings were taken with the lights on. The other half were recorded in total darkness. The researchers wanted to compare what the visual cortex was doing when there was visual input versus when there wasn't. To be sure the room was pitch black, they taped shut any crevice that could let in light, since rats have notoriously good vision at night.

The data showed that on average, neurons in the rats' visual cortices were more active when the animals moved than when they rested, even in the dark. That caught the researchers off guard: In a pitch-black room, there is no visual data to process. This meant that the activity was coming from the motor cortex, not an external image.

The team also noticed that the neural patterns in the visual cortex that were firing during movement differed in the dark and light, meaning they weren't directly connected. Some neurons that were ready to activate in the dark were in a kind of sleep mode in the light.

Using a machine-learning algorithm, the researchers encoded both patterns. That let them not only tell which way a rat was moving its head by just looking at the neural activity in its visual cortex, but also predict the movement several hundred milliseconds before the rat made it.

The researchers confirmed that the movement signals came from the motor area of the brain by focusing on the secondary motor cortex. They surgically destroyed it in several rats, then ran the experiments again. The rats in which this area of the brain was lesioned no longer gave off signals in the visual cortex. However, the researchers were not able to determine if the signal originates in the secondary motor cortex. It could be only where it passes through, they said.

Furthermore, the scientists pointed out some limitations in their findings. For instance, they only measured the movement of the head, and did not measure eye movement. The study is also based on rodents, which are nocturnal. Their visual systems share similarities with humans and primates, but differ in complexity. Still, the paper adds to new lines of research and the findings could potentially be applied to neural networks that control machine vision, like those in autonomous vehicles.

"It's all to better understand how vision actually works," Guitchounts said. "Neuroscience is entering into a new era where we understand that perception and action are intertwined loops. ... There's no action without perception and no perception without action. We have the technology now to measure this."

UNIVERSITY PARK, Pa. -- Fungal spores responsible for bitter rot disease, a common and devastating infection in fruit, do not encounter their host plants by chance. Turns out, they have a symbiotic association with the plant, often living inside its leaves.

The new way of looking at the fungal pathogen, Colletotrichum fioriniae, as a leaf endophyte -- bacterial or fungal microorganisms that colonize healthy plant tissue -- was the outcome of a two-year study conducted by researchers in Penn State's College of Agricultural Sciences.

According to Phillip Martin, a doctoral candidate in plant pathology, the findings, which were published recently in the journal Phytopathology, have important implications for the management of the pathogen in fruit trees.

Colletotrichum fioriniae causes diseases, often called anthracnoses, in more than 100 fruit and vegetable plants, including apple, peach, pear and strawberry. The fungus infects the fruit under warm and wet conditions and causes brown, sunken lesions; occasionally, orange spores will be seen on the surface.

The disease is of concern to the Pennsylvania apple industry, which produces 400 million to 500 million pounds of apples per year. The state ranks fourth in the nation for apple production, per statistics from the U.S. Department of Agriculture.

"The research was based on the idea that if we can determine where the spores are coming from, then maybe we can eliminate the source and break the bitter rot disease cycle," said Martin, who carried out the study under the guidance of Kari Peter, associate research professor of tree-fruit pathology. "Unfortunately, from this perspective, many of the spores come from leaves, including apple leaves, and from trees and shrubs that are everywhere in Pennsylvania."

Previously, the spores in question were thought to originate mostly from diseased fruits and twigs. However, even when infected fruits and twigs were removed from a tree, the disease, while reduced, often still was present, a circumstance that puzzled scientists.

The research, which took place in 2018 and 2019, focused on apples and involved the placement of rain-splash spore traps in orchards at Penn State's Fruit Research and Extension Center, at Hollabaugh Bros. Inc. fruit and vegetable farm, and at a satellite location in Arendtsville, all of which are located in Adams County. Traps also were placed in two forested areas -- comprised mostly of deciduous trees -- near the orchards.

Based on previous research that indicated that Colletotrichum fioriniae could survive on leaves, the team collected more than 1,000 leaves of apple and of 24 forest plant species. The leaves were disinfected to kill fungi on the leaf surface, frozen to kill the leaves and incubated to allow the fungi inside of the leaves to grow out and sporulate.

This test found Colletotrichum fioriniae in more than 30% of leaves sampled, with most spores coming from the forest samples. In orchards that were managed with fungicides, up to 8% of apple leaves were infected with the fungus. In the untreated orchard, Martin said, the spores were abundant, meaning they were found in 15-80% of the leaves. The infections did not seem to be causing any leaf diseases, however.

"While unexpected, these findings did explain why growers struggle with bitter rot even when they remove all diseased fruits and twigs -- the fungus was living in the leaves during the season," Martin said. "The fungus was present in all the tested orchards and could not be traced to infection from a nursery, which makes sense since the initial infections likely are coming from surrounding forests and fence rows."

Since the fungus is abundant in the forest canopy, eradication from nearby areas would be impractical, Martin added. However, the spatial limitations of rain-splash dispersal mean that forests are not regular sources of fungus spread; they likely serve only as primary introduction sources during extreme rain and wind events, after which the fungus becomes established in agricultural areas.

"Our study changes how we think about this fungus," Martin said. "While it may not supply quick fixes, it provides the basis for further research aimed at developing better management techniques, such as selecting resistant cultivars and breeding for genetic resistance."

Peter agreed. "Although it's exciting to understand that Colletotrichum fiorinae's niche in the environment is more sophisticated than we had appreciated, it does make managing bitter rot in apple orchards less straightforward," she said. "As researchers, we can view this is an opportunity to think outside the box and to be creative in figuring out a sustainable bitter rot management strategy."

In the meantime, Martin noted, disease-management tactics stay the same. "We don't believe most spores are overwintering in the leaves," he said. "Growers should continue to remove the infected fruits and twigs to help reduce disease spread season to season."

A special type of aurora, draped east-west across the night sky like a glowing pearl necklace, is helping scientists better understand the science of auroras and their powerful drivers out in space. Known as auroral beads, these lights often show up just before large auroral displays, which are caused by electrical storms in space called substorms. Previously, scientists weren't sure if auroral beads are somehow connected to other auroral displays as a phenomenon in space that precedes substorms, or if they are caused by disturbances closer to Earth's atmosphere.

But powerful new computer models combined with observations from NASA's Time History of Events and Macroscale Interactions during Substorms - THEMIS - mission have provided the first strong evidence of the events in space that lead to the appearance of these beads, and demonstrated the important role they play in our near space environment.

"Now we know for certain that the formation of these beads is part of a process that precedes the triggering of a substorm in space," said Vassilis Angelopoulos, principal investigator of THEMIS at the University of California, Los Angeles. "This is an important new piece of the puzzle."

By providing a broader picture than can be seen with the three THEMIS spacecraft or ground observations alone, the new models have shown that auroral beads are caused by turbulence in the plasma - a fourth state of matter, made up of gaseous and highly conductive charged particles - surrounding Earth. The results, recently published in the journals Geophysical Research Letters and Journal of Geophysical Research: Space Physics, will ultimately help scientists better understand the full range of swirling structures seen in the auroras.

"THEMIS observations have now revealed turbulences in space that cause flows seen lighting up the sky as of single pearls in the glowing auroral necklace," said Evgeny Panov, lead author on one of the new papers and THEMIS scientist at the Space Research Institute of the Austrian Academy of Sciences. "These turbulences in space are initially caused by lighter and more agile electrons, moving with the weight of particles 2000 times heavier, and which theoretically may develop to full-scale auroral substorms."

Mysteries of Auroral Beads Formation

Auroras are created when charged particles from the Sun are trapped in Earth's magnetic environment - the magnetosphere - and are funneled into Earth's upper atmosphere, where collisions cause hydrogen, oxygen, and nitrogen atoms and molecules to glow. By modelling the near-Earth environment on scales from tens of miles to 1.2 million miles, the THEMIS scientists were able to show the details of how auroral beads form.

As streaming clouds of plasma belched by the Sun pass Earth, their interaction with the Earth's magnetic field creates buoyant bubbles of plasma behind Earth. Like a lava lamp, imbalances in the buoyancy between the bubbles and heavier plasma in the magnetosphere creates fingers of plasma 2,500 miles wide that stretch down towards Earth. Signatures of these fingers create the distinct bead-shaped structure in the aurora.

"There's been a realization that, all summed up, these relatively little transient events that happen around the magnetosphere are somehow important," said David Sibeck, THEMIS project scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "We have only recently gotten to the point where computing power is good enough to capture the basic physics in these systems."

Now that scientists understand the auroral beads precede substorms, they want to figure out how, why and when the beads might trigger full-blown substorm. At least in theory, the fingers may tangle magnetic field lines and cause an explosive event known as magnetic reconnection, which is well known to create full-scale substorms and auroras that fill the nightside sky.

New Models Open New Doors

Since its launch in 2007, THEMIS has been taking detailed measurements as it passes through the magnetosphere in order to understand the causes of the substorms that lead to auroras. In its prime mission, THEMIS was able to show that magnetic reconnection is a primary driver of substorms. The new results highlight the importance of structures and phenomenon on smaller scales - those hundreds and thousands of miles across as compared to ones spanning millions of miles.

"In order to understand these features in the aurora, you really need to resolve both global and smaller, local scales. That's why it was so challenging up to now," said Slava Merkin, co-author on one of the new papers and scientist at NASA's Center for Geospace Storms headquartered at Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. "It requires very sophisticated algorithms and very big supercomputers."

The new computer simulations almost perfectly match THEMIS and ground observations. After the initial success of the new computer models, THEMIS scientists are eager to apply them to other unexplained auroral phenomena. Particularly in explaining small-scale structures, computer models are essential as they can help interpret what happens in between the spaces where the three THEMIS spacecraft pass.

"There's lots of very dynamic, very small-scale structures that people see in the auroras which are hard to connect to the larger picture in space since they happen very quickly and on very small scales," said Kareem Sorathia, lead author on one of the new papers and scientist at NASA's Center for Geospace Storms headquartered at Johns Hopkins Applied Physics Laboratory. "Now that we can use global models to characterize and investigate them, that opens up a lot of new doors."

BOZEMAN -- A Montana State University researcher contributed to a novel project with scientists from around the country and world that sheds light on one of Earth's most important reptile species.

Chris Organ, an assistant teaching professor in the Department of Earth Sciences in MSU's College of Letters and Science, worked with a team from 10 countries and six U.S. states along with Washington D.C.'s Smithsonian Institution to sequence the genome of the tuatara, a reptile Organ refers to as a "living fossil."

"The tuatara isn't a lizard, even though it looks like one. They evolved early among their group of amniotes, animals like lizards, birds and mammals," said Organ. "The group never really diversified much, so the tuatara is very similar anatomically to fossils that we see that go back 200 million years. The question that remains is, if the anatomy of the animal hasn't evolved very much, what about the genome?"

The project marks the first time the tuatara genome, which is roughly twice the size of a human genome, has ever been sequenced, which illuminates not only how the unique species evolved, but also offers some insights into human genetic lineage as well. Organ brought a paleontological perspective to the international team, helping to compare the genome of the animals living today to their prehistoric ancestors. The paper, "The tuatara genome reveals ancient features of amniote evolution," appeared in the scientific journal Nature on Aug. 5.

Lead author Neil Gemmell from the University of Otago in New Zealand said sequencing the genome allows scientists to learn just where the tuatara fits in the tree of life.

"If we consider a tree, with species diverging over time and splitting off into groups such as reptiles, birds and mammals, we can finally see with some certainty where the tuatara sits," Gemmell said. The sequencing of the tuatara genome places it on the same branch of the tree of life as snakes and lizards up until about 250 million years ago, when the tuatara's branch, the genus Sphenodon, split from the class branch squamata, the branch that includes snakes and lizards. The tuatara has been genetically unique ever since.

Tuatara are native only to the islands of New Zealand, and because of that they have experienced very little habitat change during their long evolutionary existence, said Organ. Rodents, as a counterexample, exist all over the world. They have adapted over time to survive in a multitude of habitats with varying weather, predators, threats and food sources. Tuatara have been exposed to very few such speciation events, meaning they have seen a remarkably slow pace of evolutionary change.

Coupled with a long lifespan -- a tuatara can live for more than 100 years -- this consistent habitat means tuatara have seen very slow evolutionary rates.

Tuatara predate modern snakes and lizards by around 100 million years, said Organ. They also do not use genetic sex chromosomes to determine the sex of offspring, instead determining sex based on the temperature of their surroundings. This makes them particularly sensitive to changing habitats or a warming climate, which could unbalance the male-to-female ratio and lead to significant declines in population.

The tuatara is also a culturally significant animal to the Maori native people of New Zealand, said Gemmell. The research team worked closely with indigenous communities in New Zealand as well as the New Zealand Institute for Plant and Food Research, the Ngatiwai Trust Board and the New Zealand Department of Conservation to explore how these novel insights into the tuatara could aid in its preservation in New Zealand.

In addition to having an unusually large genome for an amniote, the tuatara also bears unique, never-before-identified genetic elements discovered through this research. Through narrowing down what makes the tuatara unique, the team hopes to discover the root of the species' longevity and to identify the best way to preserve this unique reptile.

"Sequencing a genome is like piecing together a page of text using only sentence fragments," said Organ. "But because the tuatara genome is so large and has changed over time, it's like trying to piece together 'War and Peace,' and in a different dialect. Since the tuatara is so distantly related to anything that's alive today, we have genomic 'sentences' that don't overlap clearly, and that makes compiling this genome something new and exciting."

If you want to enhance a locust to be used as a bomb-sniffing bug, there are a few technical challenges that need solving before sending it into the field.

Is there some way to direct the locust -- to tell it where to go to do its sniffing? And because the locusts can't speak (yet), is there a way to read the brain of these cyborg bugs to know what they're smelling?

For that matter, can locusts even smell explosives?

Yes and yes to the first two questions. Previous research from Washington University in St. Louis has demonstrated both the ability to control the locusts and the ability to read their brains, so to speak, to discern what it is they are smelling. And now, thanks to new research from the McKelvey School of Engineering, the third question has been settled.

The answer, again: 'yes.'

In a pre-proof published online Aug. 6 in the journal Biosensors and Bioelectronics: X, researchers showed how they were able to hijack a locust's olfactory system to both detect and discriminate between different explosive scents -- all within a few hundred milliseconds of exposure.

They were also able to optimize a previously developed biorobotic sensing system that could detect the locusts' firing neurons and convey that information in a way that told researchers about the smells the locusts were sensing.

"We didn't know if they'd be able to smell or pinpoint the explosives because they don't have any meaningful ecological significance," said Barani Raman, professor of biomedical engineering. "It was possible that they didn't care about any of the cues that were meaningful to us in this particular case."

Previous work in Raman's lab led to the discovery that the locust olfactory system could be decoded as an 'or-of-ands' logical operation. This allowed researchers to determine what a locust was smelling in different contexts.

With this knowledge, the researchers were able to look for similar patterns when they exposed locusts to vapors from TNT, DNT, RDX, PETN and ammonium nitrate -- a chemically diverse set of explosives. "Most surprisingly," Raman said, "we could clearly see the neurons responded differently to TNT and DNT, as well as these other explosive chemical vapors."

With that crucial piece of data, Raman said, "We were ready to get to work. We were optimized."

Now they knew that the locusts could detect and discriminate between different explosives, but in order to seek out a bomb, a locust would have to know from which direction the odor emanated. Enter the "odor box and locust mobile."

"You know when you're close to the coffee shop, the coffee smell is stronger, and when you're farther away, you smell it less? That's what we were looking at," Raman said. The explosive vapors were injected via a hole in the box where the locust sat in a tiny vehicle. As the locust was driven around and sniffed different concentrations of vapors, researchers studied its odor-related brain activity.

The signals in the bugs' brains reflected those differences in vapor concentration.

The next step was to optimize the system for transmitting the locusts' brain activity. The team, which included Shantanu Chakrabartty, the Clifford W. Murphy Professor in the Preston M. Green Department of Electrical & Systems Engineering, and Srikanth Singamaneni, the Lilyan & E. Lisle Hughes Professor in the Department of Mechanical Engineering & Materials Science, focused the breadth of their expertise on the tiny locust.

In order to do the least harm to the locusts, and to keep them stable in order to accurately record their neural activity, the team came up with a new surgical procedure to attach electrodes that didn't hinder the locusts' movement. With their new instrumentation in place, the neuronal activity of a locust exposed to an explosive smell was resolved into a discernible odor-specific pattern within 500 milliseconds.

"Now we can implant the electrodes, seal the locust and transport them to mobile environments," Raman said. One day, that environment might be one in which Homeland Security is searching for explosives.

The idea isn't as strange as it might first sound, Raman said.

"This is not that different from in the old days, when coal miners used canaries," he said. "People use pigs for finding truffles. It's a similar approach -- using a biological organism -- this is just a bit more sophisticated."