bluuebunny/crossref_metadata_2025_split huggingface dataset:
Body size and food plants drive local extinction risk in butterflies
Authors: Palash Anwar , Paul Shatabdi , Resha Sabrina Karim , Khan Md Kawsar 
Published: August 2020

AbstractLepidoptera, butterflies and moths, are significant pollinators and ecosystem health indicators. Therefore, monitoring their diversity, distribution, and extinction risks are of critical importance. We aim to understand the drivers of the local extinction risks of the butterflies in Bangladesh. We conducted a systematic review to extract the diversity, distribution and local extinction risks of the butterflies of Bangladesh, and possible drivers of their extinction, e.g., body size, host plants and nectar plants. We updated the current checklist, which now consists of 463 species. We provided distribution and extinctions risk atlas showing both the diversity and extinction risks were highest in the eastern region of Bangladesh. We tested whether body size and host plants contribute to the local extinction risks of butterflies. We predicted butterflies with larger body size and fewer host plants and nectar plants would be in greater extinction risk. Accordingly, we showed that extinction risk was higher in larger butterflies than smaller butterflies, and in butterflies with a fewer number of host plants and nectar plants than the butterflies with higher number host plants. Our study highlights the contribution of body size and host plants as potential drivers of the local extinction risks of butterflies.
Extreme ecological specialization in a rainforest mammal, the Bornean tufted ground squirrel,Rheithrosciurus macrotis
Authors: Marshall Andrew J. , Meijaard Erik , Leighton Mark 
Published: August 2020

AbstractThe endemic Bornean tufted ground squirrel,Rheithrosciurus macrotis, has attracted great interest among biologists and the public recently. Nevertheless, we lack information on the most basic aspects of its biology. Here we present the first empirical data on the feeding ecology of tufted ground squirrels, and use data from 81 sympatric mammalian and avian vertebrates to place it within a broad comparative context.R. macrotisis a dedicated seed predator and shows much more extreme ecological specialization than any other vertebrate, feeding on a far smaller subset of available plant foods and demonstrating a greater reliance on a single plant species–Canarium decumanum–than any other vertebrate taxon. Our results suggest thatR. macrotisplays an important, previously unknown role in the ecology of Bornean lowland forests, and highlight how much we have yet to learn about the fauna inhabiting some of the most diverse, and most severely threatened, ecosystems on the planet.
Reconciling fish and farms: Methods for managing California rice fields as salmon habitat
Authors: Holmes Eric J. , Saffarinia Parsa , Rypel Andrew L. , Bell-Tilcock Miranda N. , Katz Jacob V. , Jeffres Carson A. 
Published: August 2020

AbstractThe rearing habitat for juvenile Chinook Salmon (Oncorhynchus tshawytscha) in California, the southernmost portion of their range, has drastically declined throughout the past century. Recently, through cooperative agreements with diverse stakeholders, winter-flooded agricultural rice fields in California’s Central Valley have emerged as promising habitat for rearing juvenile Chinook Salmon. From 2013 to 2016, we conducted a series of experiments examining methods for rearing fall-run Chinook Salmon on winter-flooded rice fields in the Yolo Bypass, a modified floodplain of the Sacramento River in California. These included: 1) influence of field substrate differences from previous season rice harvest; 2) effects of depth refugia from avian predators (trenches); 3) field drainage methods to promote efficient egress of fish; and 4) in-field salmon survivorship over time. Zooplankton (fish food) in the winter-flooded rice fields were 53-150x more abundant when directly compared to the adjacent Sacramento River. Correspondingly, somatic growth rates of juvenile hatchery-sourced fall-run Chinook Salmon stocked in rice fields were two to five times greater versus fish in the adjacent Sacramento River. Post-harvest field substrate treatments had little effect on the lower trophic food web and had an insignificant effect on growth rates of in-field salmon. Though depth refugia did not directly increase survival, it buffered maximum water temperatures in the trenches and facilitated outmigration from fields during draining. Rapid field drainage methods yielded the highest survival and were preferable to drawn-out drainage methods. High initial mortality immediately after stocking was observed in the survival over time experiment with stable and high survival after the first week. In-field survival ranged 7.4–61.6% and increased over the course of the experiments. Despite coinciding with the most extreme drought in California’s recorded history, which elevated water temperatures and reduced the regional extent of adjacent flooded habitats which concentrated avian predators, the adaptive research framework enabled incremental improvements in design to increase survival. The abundance of food resources and exceptionally high growth rates observed during these experiments illustrate the benefits associated with reconciling off-season agricultural land use with fish conservation practices. Without any detriment to flood control or agricultural yield, there is great promise for reconciliation ecology between agricultural floodplains and endangered fish conservation where minor alterations to farm management practices could greatly enhance the effectiveness of fish conservation outcomes.
Antidiabetic drug therapy alleviates type 1 diabetes in mice by promoting pancreatic α-cell transdifferentiation
Authors: Sarnobat Dipak , Moffett Charlotte R , Tanday Neil , Reimann Frank , Gribble Fiona M , Flatt Peter R , Tarasov Andrei I 
Published: August 2020

AbstractGut incretins, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), enhance secretion of insulin in a glucose-dependent manner, predominantly by elevating cytosolic levels of cAMP in pancreatic β-cells. Successful targeting of the incretin pathway by several drugs, however, suggests the antidiabetic mechanism is likely to span beyond the acute effect on hormone secretion and include, for instance, stimulation of β-cell growth and/or proliferation. Likewise, the antidiabetic action of kidney sodium-glucose linked transporter-2 (SGLT-2) inhibitors exceeds simple increase glucose excretion. Potential reasons for these ‘added benefits’ may lie in the long-term effects of these signals on developmental aspects of pancreatic islet cells. In this work, we explored if the incretin mimetics or SGLT-2 inhibitors can affect the size of the islet α- or β-cell compartments, under the condition of β-cell stress.To that end, we utilised mice expressing YFP specifically in pancreatic α-cells, in which we modelled type 1 diabetes by injecting streptozotocin, followed by a 10-day administration of liraglutide, sitagliptin or dapagliflozin.We observed an onset of diabetic phenotype, which was partially reversed by the administration of the antidiabetic drugs. The mechanism for the reversal included induction of β-cell proliferation, due to a decrease in β-cell apoptosis and, for the incretin mimetics, transdifferentiation of α-cells into β-cells.Our data therefore emphasize the role of chronic incretin signalling in induction of α-/β-cell transdifferentiation. We conclude that incretin peptides may act directly on islet cells, making use of the endogenous local sites of ‘ectopic’ expression, whereas SGLT-2 inhibitors work via protecting β-cells from chronic hyperglycaemia.Graphical abstract
Esrrbis a cell cycle dependent XEN priming factor balancing between pluripotency and differentiation
Authors: Levi Sapir Herchcovici , Feldman Sharon , Arnon Lee , Lahav Shlomtzion , Awawdy Muhammad , Alajem Adi , Bavli Danny , Sun Xue , Buganim Yosef , Ram Oren 
Published: August 2020

AbstractCell cycle and differentiation decisions are tightly linked; however, the underlying principles that drive these decisions are not fully understood. Here, we combined cell-cycle reporter system and single-cell RNA-seq profiling to study the transcriptomes of mouse embryonic stem cells (ESCs) in the context of cell cycle states and differentiation. By applying retinoic acid, a multi-linage differentiation assay, on G1 and G2/M pre-sorted ESCs, we show that only G2/M ESCs were capable of differentiating into extraembryonic endoderm cells (XENs), whereas cells in the G1 phase predominantly produce Epiblast Stem Cells. We identified ESRRB, a key pluripotency factor that is upregulated during G2/M phase, as a central driver of XEN differentiation. Furthermore, enhancer chromatin states based on WT andEsrrb-KO ESCs show association of ESRRB with XEN poised enhancers. Cells engineered to overexpress Esrrb during G1 allow ESCs to produce XENs, while ESRRB-KO ESCs lost their potential to differentiate into XEN. In addition, Embryonic bodies (EBs) are not affected by deletion of ESRRB but trigger apoptosis upon attempts to apply direct XEN differentiation. Taken together, this study reveals an important functional link between Esrrb and cell-cycle states during the exit from pluripotency. Finally, the experimental scheme of single cell RNA-seq in the context of cell cycle can be further expanded into other cellular systems to better understand differentiation decisions and cancer models.
Non-canonical, potassium-driven cerebrospinal fluid clearance
Authors: Xu Huixin , Fame Ryann M , Sadegh Cameron , Sutin Jason , Naranjo Christopher , Syau Della , Cui Jin , Shipley Frederick B , Vernon Amanda , Gao Fan , Zhang Yong , Holtzman Michael J. , Heiman Myriam , Warf Benjamin C , Lin Pei-Yi , Lehtinen Maria K 
Published: August 2020

ABSTRACTCerebrospinal fluid (CSF) provides vital support for the brain. Abnormal CSF accumulation is deleterious for perinatal neurodevelopment, but how CSF leaves the brain during this critical period is unknown. We found in mice a postnatal neurodevelopmental transition phase featuring precipitous CSF K+clearance, accompanied by water, through the choroid plexus (ChP). The period corresponds to a human fetal stage when canonical CSF clearance pathways have yet to form and congenital hydrocephalus begins to manifest. Unbiased ChP metabolic and ribosomal profiling highlighted this transition phase with increased ATP yield and activated energy-dependent K+transporters, in particular the Na+-K+-Cl−and water cotransporter NKCC1. ChP-targeted NKCC1 overexpression enhanced K+-driven CSF clearance and enabled more permissive cerebral hydrodynamics. Moreover, ventriculomegaly in an obstructive hydrocephalus model was improved by ChP-targeted NKCC1 overexpression. Collectively, we identified K+-driven CSF clearance through ChP during a transient but critical neurodevelopmental phase, with translational value for pathologic conditions.
Structural and functional microbial community response to short-term impact of switching between tillage and no-tillage at soil aggregate level
Authors: Frene Juan Pablo , Gabbarini Luciano Andrés , Wall Luis Gabriel 
Published: August 2020

AbstractAn understanding of the distribution of soil microorganisms and enzyme activities at different soil aggregate level could help to understand the mechanisms operating behind different tillage management on soil structure and function. Our objective was to determine if the microbial community structure and soil enzymes activity (EA) associated with different aggregate fractions changed within the transition at switching between no-till and conventional tillage at 30 months after the switch of management on a base line field of 27 years long were no-till (NT) and conventional tillage (CT) were side by side compared. Part of NT plot was turned into new CT (n-CT) while part of CT plot was turned into new NT (n-NT). Aggregate fractions of 2000-250, 250-63, 63-20, 20-2 and 2-0.1μm were obtained from soil samples taken at 30 months after the switch. Specific microbial abundances, measured by qPCR, and EAs were greatest on 2-0.1μm following by 20-2and 2000-250μm. The EAs showed the highest activities in the CT (β-Glucosidase and β-D-cellobiosidase) and in the nCT (Phosphatase and N-acetyl-β-Glucosaminidase) in 2000-250μm. In contrast, in the intermediate fractions (250-63μm and 63-20μm), the highest activities were observed in NT soil. Microbial communities were significantly different among different aggregates. In the 20-2μm fraction, fungi were able to differentiate between current treatments, and bacteria and archaea showed similar trends. In 2000-250μm, the treatments were associated by their historical management, and the abundances in CT samples were superior to those of the NT. In contrast, in the fractions 250-63 and 63-20μm, the NT samples showed greater abundances to those of the CT and the new treatment samples have suffered differences from historical treatments. In conclusion, tillage systems influenced the spatial distribution of soil enzymes as well as the abundances of microbial communities in the different soil aggregate size fractions.HighlightsSoil microbial structure and functional activity showed a heterogeneous distribution within aggregate soil fraction.Distribution of functions and microbial structure is shaped by tillage soil managementThe greater values of microbial abundance and soil activity appeared at smaller aggregates.Fungi abundance significantly enhanced under NT than the CT at 20-2 μm.
Photosynthetic resistance and resilience under drought and rewatering in maize plants
Authors: Qi Miao , Liu Xiaodi , Li Yibo , Song He , Zhang Feng , Xu Zhenzhu , Zhou Guangsheng 
Published: August 2020

AbstractAbnormally altered precipitation patterns induced by climate change have profound global effects on crop production. However, the plant functional responses to various precipitation regimes remain unclear. Here, greenhouse and field experiments were conducted to determine how maize plant functional traits respond to drought, flooding, and rewatering. Drought and flooding hampered photosynthetic capacity, particularly when severe and/or prolonged. Most photosynthetic traits recovered after rewatering, with few compensatory responses. Rewatering often elicited high photosynthetic resilience in plants exposed to severe drought at the end of plant development, with the response strongly depending on the drought severity/duration and plant growth stage. The associations of chlorophyll concentrations with photosynthetically functional activities were stronger during post-tasselling than pre-tasselling, implying an involvement of leaf age/senescence in responses to episodic drought and subsequent rewatering. Coordinated changes in chlorophyll content, gas exchange, fluorescence parameters (PSII quantum efficiency and photochemical/non-photochemical radiative energy dissipation) possibly contributed to the enhanced drought resistance and resilience and suggested a possible regulative trade-off. These findings provide fundamental insights into how plants regulate their functional traits to deal with sporadic alterations in precipitation. Breeding and management of plants with high resistance and resilience traits could help crop production under future climate change.
TheArabidopsis thalianaNIP2;1 Lactic Acid Channel promotes Plant Survival Under Low Oxygen Stress
Authors: Beamer Zachary , Routray Pratyush , Choi Won-Gyu , Spangler Margaret K. , Lokdarshi Ansul , Roberts Daniel M. 
Published: August 2020

AbstractUnder anaerobic stressArabidopsis thalianainduces the expression of a collection of core hypoxia genes that encode proteins associated with an adaptive response. Included in these core hypoxia genes isNIP2;1, which encodes a member of the “Nodulin-like Intrinsic Protein” (NIP) subgroup of the aquaporin superfamily of membrane channel proteins. Under normal growth,NIP2;1expression is limited to the “anoxia core” region of the root stele, but shows substantial induction in response to low oxygen stress (as high as 1000-fold by 2-4 hr of hypoxia challenge), and accumulates in all root tissues. During hypoxia,NIP2;1-GFP, accumulates on the cell surface by 2 hr and then is distributed between the cell surface and internal membranes during sustained hypoxia, and remains elevated in root tissues through 4 hrs of reoxygenation recovery. T-DNA insertional mutantnip2;1plants show elevation of lactic acid within root tissues, and a reduced efflux of lactic acid and acidification of the external medium. Together with previous biochemical evidence demonstrating that NIP2;1 has lactic acid permease activity, the present work supports the hypothesis that the protein facilitates the release of cellular lactate to the rhizosphere to prevent lactic acid toxicity. In support of this,nip2;1plants show poorer survival to argon-induced hypoxia stress.Nip2;1mutant plants also show elevated expression of ethanolic fermentation transcripts, as well as reduced expression the lactate metabolic enzyme GOX3, suggesting that the altered efflux of lactate through NIP2;1 regulates other pyruvate and lactate metabolism pathways.One-sentence SummaryThe NIP2;1 lactic acid permease is necessary for an optimum response to low oxygen stress through the release of lactate from roots during hypoxia stress.
E-scape: consumer specific landscapes of energetic resources derived from stable isotope analysis and remote sensing
Authors: James W. Ryan , Santos Rolando O. , Rehage Jennifer S. , Doerr Jennifer C. , Nelson James A. 
Published: August 2020

AbstractEnergy and habitat distribution are inherently linked. Energy is a major driver of the distribution of consumers, but estimating how much specific habitats contribute to the energetic needs of a consumer can be problematic. We present a new approach that combines remote sensing information and stable isotope ecology to produce maps of energetic resources (E-scapes).E-scapes project species specific resource use information onto the landscape to classify areas based on energetic importance and successfully predict the biomass and energy density of a consumer in salt marsh habitats in coastal Louisiana, USA. OurE-scape maps can be used alone or in combination with existing models to improve habitat management and restoration practices and have potential to be used to test fundamental movement theory.
Plant carbohydrate depletion impairs water relations and spreads via ectomycorrhizal networks
Authors: Sapes Gerard , Demaree Patrick , Lekberg Ylva , Sala Anna 
Published: August 2020

AbstractCarbon and water relations are fundamental to plant life and strongly interact. Under drought, the ability of plants to assimilate carbon is reduced, which increases their consumption of stored labile carbon in the form of non-structural carbohydrates (NSC). Stored NSC depletion may impair plant water relations, but mechanisms are not clear, and we do not know if its effects are independent of water deficit. If so, carbon costs of fungal symbionts could also indirectly influence plant drought tolerance through stored NSC depletion. We connected well-wateredPinus ponderosaseedling pairs via ectomycorrhizal (EM) networks where one seedling was shaded and the other experienced full light and compared responses to seedling pairs in the light. We measured plant water relations and traced carbon movements using13CO2to explore the mechanisms linking stored NSC to water relations, and to identify potential tradeoffs between the ability to endure low water potentials and maintaining EM fungi under carbon-limiting conditions. Even in the absence of drought, mild NSC depletion impaired osmoregulation capacity and turgor maintenance, a critical strategy to tolerate drought. This demonstrates that NSC storage influences plant water relations independently of plant water status. We also found that EM networks propagated NSC depletion and its negative effects on water relations from carbon stressed hosts to non-stressed hosts. These results highlight carbon allocation tradeoffs between supporting fungal symbionts and retaining water via stored NSC and have implications for biotic interactions and forest drought responses.Significance StatementThe potential effects of future drought on global carbon cycles, vegetation-climate feedbacks, species distributions and their ecological impacts, urgently call for a clear understanding of factors influencing vegetation tolerance to drought. Key to this is the understanding of mechanisms and processes by which plants tolerate drought and how prevalent plant-fungal interactions may influence these processes.We demonstrate that even mild depletion of plant non-structural carbohydrate (NSC) storage readily decreases plant water retention capacity, therefore decreasing tolerance to drought. Because plant-fungal interactions depend on NSC exchange, plants face carbon-allocation tradeoffs between maintaining drought tolerance and feeding fungal symbionts. The impacts of these tradeoffs extend across plants connected via ectomycorrhizal networks as fungi propagate NSC depletion from NSC-limited plants to non-stressed individuals.
EEG signals index a global signature of arousal embedded in neuronal population recordings
Authors: Johnston Richard , Snyder Adam C. , Schibler Rachel S. , Smith Matthew A. 
Published: August 2020

AbstractElectroencephalography (EEG) has long been used to index brain states, from early studies describing activity during visual stimulation to modern work employing complex perceptual tasks. These studies shed light on brain-wide signals but lacked explanatory power at the single neuron level. Similarly, single neuron studies can suffer from inability to measure brain-wide signals. Here, we combined these techniques while monkeys performed a change detection task and discovered a link between EEG and a signal embedded in spiking responses. This ‘slow drift’ was associated with arousal: decreases in pre-stimulus α power/increases in P1 amplitude were accompanied by :1) increases in pupil size, false alarm rate and saccade velocity; and 2) decreases in microsaccade rate and reaction time. These results show that brain-wide EEG signals can be used to index modes of activity acquired from direct neural recordings, that in turn reflect global changes in brain state that influence perception and behavior.