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3,121 results for “Resources”
Data from: Convergence in resource use efficiency across trees with differing hydraulic strategies in response to ecosystem precipitation manipulation
1. Plants are expected to respond to drought by maximizing the efficiency of the most limiting resource, the water use efficiency (WUE), at the expense of nitrogen and carbon use efficiencies (NUE and CUE). Therefore, plants resource use efficiencies are viewed as indicators of species drought tolerance. 2. We tested these predictions by measuring leaf-level intrinsic WUE (WUEi, the ratio of net assimilation to stomatal conductance), photosynthetic NUE (PNUE, the ratio of daily maximum net assimilation to leaf nitrogen content) and leaf-scale CUE (approached by the ratio of nighttime respiration to daytime net assimilation, Rd/An) in piñon pine and juniper, two tree species that differ in drought tolerance and vulnerability to drought-induced mortality. Variations in resource use efficiency in the two species were measured in response to seasonal drought and in response to an ecosystem-scale precipitation manipulation experiment comprising three precipitation treatments: ambient, irrigation (+30%) and partial rainfall exclusion (-45%). 3. Increasing water limitation, either seasonally or across treatments, resulted in increased WUE and decreased PNUE and CUE in both species. WUE, PNUE and CUE varied more strongly in response to water limitation than across species and converged to the same relationships against precipitation for piñon and juniper. 4. Plasticity in WUE, PNUE and CUE in response to water limitation was associated, in both species, with low carbon acquisition during drought. Our results exhibited a convergence in resource use efficiency across piñon and juniper which contradicts the paradigm that resource use efficiencies are indicators of species drought tolerance and ecological strategy.
Data from: Phenology of farmland floral resources reveals seasonal gaps in nectar availability for bumblebees
Floral resources are known to be important in regulating wild pollinator populations and are therefore an important component of agri‐environment and restoration schemes which aim to support pollinators and their associated services. However, the phenology of floral resources is often overlooked in these schemes – a factor which may be limiting their success. Our study characterises and quantifies the phenology of nectar resources at the whole‐farm scale on replicate farms in Southwestern UK throughout the flowering season. We quantify the corresponding nectar demands of a subset of common wild pollinators (bumblebees) to compare nectar supply and pollinator demand throughout the year, thereby identifying periods of supply‐demand deficit. We record strong seasonal fluctuations in farmland nectar supplies, with two main peaks of nectar production (May and July) and a considerable 'June Gap' in‐between. March and August/September are also periods of low nectar availability. Comparing the phenology of nectar supply with the phenology of bumblebee nectar demand reveals 'hunger gaps' during March and much of August/September when supply is unlikely to meet demand. Permanent pasture and woodland produced the greatest share of farmland nectar because of their large area, however linear features such as hedgerows and field margins provided the greatest nectar per unit area. 50% of total nectar was supplied by just three species (Allium ursinum, Cirsium arvense and Trifolium repens), but some less productive species (e.g. Hedera helix and Taraxacum agg.) were important in ensuring phenological continuity of nectar supply. Synthesis and applications. By comparing the phenology of farmland nectar supply with the phenology of pollinator demand, we demonstrate that the timing of nectar supply may be as important as total nectar production in limiting farmland pollinator populations. Considering phenology in the design of agri‐environment or restoration schemes is therefore likely to improve their suitability for pollinators. Plant species which flower during periods of resource deficit (early spring and late summer) should be prioritised in schemes which aim to conserve or restore pollinator populations. Maintaining a range of semi‐natural habitats with complementary flowering phenologies (e.g. woodland, hedgerows and field‐margins) will ensure a more continuous supply of nectar on farmland, thereby supporting pollinators for their entire flight season.
Data from: Competing for blood: the ecology of parasite resource competition in human malaria-helminth co-infections
Ecological theory suggests that co-infecting parasite species can interact within hosts directly, via host immunity and/or via resource competition. In mice, competition for red blood cells (RBCs) between malaria and bloodsucking helminths can regulate malaria population dynamics, but the importance of RBC competition in human hosts was unknown. We analyzed infection density (i.e. the concentration of parasites in infected hosts), from a 2-year deworming study of over 4,000 human subjects. After accounting for resource-use differences among parasites, we find evidence of resource competition, priority effects, and a competitive hierarchy within co-infected individuals. For example, reducing competition via deworming increased Plasmodium vivax densities 2.8-fold, and this effect is limited to bloodsucking hookworms. Our ecological, resource-based perspective sheds new light into decades of conflicting outcomes of malaria-helminth co-infection studies with significant health and transmission consequences. Beyond blood, investigating within-human resource competition may bring new insights for improving human health.
Data from: Network analyses support the role of prey preferences in shaping resource use patterns within five animal populations
Individual variation is an inherent aspect of animal populations and understanding the mechanisms shaping resource use patterns within populations is crucial to comprehend how individuals partition resources. Theory predicts that differences in prey preferences among consumers and/or differences in the likelihood of adding new resources to their diets are key mechanisms underlying intrapopulation variation in resource use. We developed network models based on optimal diet theory that simulate how individuals consume resources under varying scenarios of individual variation in prey preferences and in the willingness of consuming alternate resources. We then investigated how the structure of individual–resource networks generated under each model compared to the structure of observed networks representing five classical examples of individual diet variation. Our results support the notion that, for the studied populations, individual variation in prey preferences is the major factor explaining patterns in individual–resource networks. In contrast, variation in the willingness of adding prey does not seem to play an important role in shaping patterns of resource use. Individual differences in prey preferences in the studied populations may be generated by complex behavioral rules related to cognitive constraints and experience. Our approach provides a pathway for mapping foraging models into network patterns, which may allow determining the possible mechanisms leading to variation in resource use within populations.
Data from: Extended phenotypes and foraging restrictions: ant nest entrances and resource ingress in leaf-cutting ants
Several factors may restrict the acquisition of food to below the levels predicted by the optimization theory. However, how the design of structures that animals build for foraging restrict the entry of food are less known. Using scaling relationships we determined whether the design of the entrances of leaf-cutting ant nests restricts resource input into the colony. We measured nests and foraging parameters in 25 nests of Atta cephalotes in a tropical rain forest. Ant flux was reduced to up to 60% at nest entrances. The width of all entrances per nest increased at similar rates as nest size, but the width of nest entrances increased with the width of its associated trail at rates below those expected by isometry. The fact that entrance widths grow slower than trail widths suggests that the enlargement of entrance holes does not reach the dimensions needed to avoid delays when foraging rates are high and loads are big. The enlargement of nest entrances appears to be restricted by the digging effort required to enlarge nest tunnels, and by increments in the risk of inundation, predator/parasitoid attacks, and microclimate imbalances inside the nest. The design of the extended phenotypes can also restrict the ingress of food into the organisms, offering additional evidence to better understand eventual controversies between empirical data and the foraging theory.
Data from: Sex-specific winter distribution in a sexually dimorphic shorebird is explained by resource partitioning
Sexual size dimorphism (SSD) implies correlated differences in energetic requirements and feeding opportunities, such that sexes will face different trade-offs in habitat selection. In seasonal migrants, this could result in a differential spatial distribution across the wintering range. To identify the ecological causes of sexual spatial segregation, we studied a sexually dimorphic shorebird, the bar-tailed godwit Limosa lapponica, in which females have a larger body and a longer bill than males. With respect to the trade-offs that these migratory shorebirds experience in their choice of wintering area, northern and colder wintering sites have the benefit of being closer to the Arctic breeding grounds. According to Bergmann's rule, the larger females should incur lower energetic costs per unit of body mass over males, helping them to winter in the cold. However, as the sexes have rather different bill lengths, differences in sex-specific wintering sites could also be due to the vertical distribution of their buried prey, that is, resource partitioning. Here, in a comparison between six main intertidal wintering areas across the entire winter range of the lapponica subspecies in northwest Europe, we show that the percentage of females between sites was not correlated with the cost of wintering, but was positively correlated with the biomass in the bottom layer and negatively with the biomass in the top layer. We conclude that resource partitioning, rather than relative expenditure advantages, best explains the differential spatial distribution of male and female bar-tailed godwits across northwest Europe.
Data from: Multi-objective optimization for plant germplasm collection conservation of genetic resources based on molecular variability
Germplasm collections play a significant role among strategies for conservation of diversity. It is common to select a core collection to represent the genetic diversity of a germplasm collection, in order to minimize the cost of conservation, while ensuring the maximization of genetic variation. We aimed to solve two main problems: (1) to select a set of individuals, from an in situ data set, that is genetically complementary to an existing germplasm collection, and (2) to define a core collection for a germplasm collection. We proposed a new multi-objective optimization (MOO) approach based on principles of systematic conservation planning (SCP) incorporating heterozygosity information; therefore, optimization takes genotypic diversity and variability patterns into account as well. As a case study, we used Dipteryx alata microsatellite loci information from two sources, an ex situ germplasm collection located at the Agronomy School of the Federal University of Goiás (UFG-AS), and an in situ data set composed of 642 sampled individual trees. We were able to identify within a population of several individuals, the exact accessions/samples that should be chosen in order to preserve the species diversity. We found that material from nine in situ individual trees are enough to complement the UFG-AS germplasm collection as it is, and that it is possible to define a core collection of 20 individual trees representing all studied genetic diversity. Moreover, we defined a method (a protocol) to deal with large amounts of accessions in the context of MOO. The proposed approach can be used to help constructing collections with maximal allelic richness and can also be extended to the in situ conservation. As far as we know, this is the first time that principles of SCP and the MOO approach are applied to the problem of complementing a germplasm collection and of finding a core collection for a germplasm collection.
Data from: Resource levels and prey state influence antipredator behavior and the strength of nonconsumptive predator effects
The risk of predation can drive trophic cascades by causing prey to engage in antipredator behavior (e.g. reduced feeding), but these behaviors can be energetically costly for prey. The effects of predation risk on prey (nonconsumptive effects, NCEs) and emergent indirect effects on basal resources should therefore depend on the ecological context (e.g. resource abundance, prey state) in which prey manage growth/predation risk tradeoffs. Despite an abundance of behavioral research and theory examining state-dependent responses to risk, there is a lack of empirical data on state-dependent NCEs and their impact on community-level processes. We used a rocky intertidal food chain to test model predictions for how resources levels and prey state (age/size) shape the magnitude of NCEs. Risk cues from predatory crabs (Carcinus maenas) caused juvenile and sub-adult snails (Nucella lapillus) to increase their use of refuge habitats and decrease their growth and per capita foraging rates on barnacles (Semibalanus balanoides). Increasing resource levels (high barnacle density) and prey state (sub-adults) enhanced the strength of NCEs. Our results support predictions that NCEs will be stronger in resource-rich systems that enhance prey state and suggest that the demographic composition of prey populations will influence the role of NCEs in trophic cascades. Contrary to theory, however, we found that resources and prey state had little to no effect on snails in the presence of predation risk. Rather, increases in NCE strength arose because of the strong positive effects of resources and prey state on prey foraging rates in the absence of risk. Hence, a common approach to estimating NCE strength – integrating measurements of prey traits with and without predation risk into a single metric – may mask the underlying mechanisms driving variation in the strength and relative importance of NCEs in ecological communities.
Data from: Differential resource consumption in leaf litter mixtures by native and non-native amphipods
Leaf litter processing is an essential ecosystem function in freshwater systems, since much of the carbon and nutrients moving through freshwater food webs come from the surrounding terrestrial ecosystems. Thus, it is important to understand how the species performing this function differ, especially because many native species are being replaced by non-native species in aquatic ecosystems. We used a field experiment to examine leaf consumption rates of two common shredding macroinvertebrates (the native Gammarus fossarum and the non-native Gammarus roeselii). Leaves from three species, varying in resource quality, were added both in leaf monocultures and as a three-species mixture. Biomass-adjusted daily consumption rates were similar between the two amphipod species, and each consumed nitrogen-rich alder leaves faster than oak or beech leaves. However, because adult G. roeselii are approximately twice the size of G. fossarum, this led to systematic, though nonsignificant, differences in consumption rates at the per-capita or population level. Furthermore, we found nuanced effects of decomposer identity on leaf decomposition in mixtures. Only G. roeselii showeding increased consumption of the preferred resource (alder) in the mixture, while G. fossarum consumed all leaves at the same proportional rates as in monocultures. This is an important distinction, as most measures of macroinvertebrate leaf shredding are made in the laboratory with only a single leaf resource available. Our results, based on a field experiment which could control the presence of dominant macroinvertebrates while still providing natural, biologically realistic context, suggests that even functionally-similar species may subtly shift ecosystem processes.
Data from: Impact of past climatic changes and resource availability on the population demography of three food-specialist bees
Past climate change is known to have strongly impacted current patterns of genetic variation of animals and plants in Europe. However, ecological factors also have the potential to influence demographic history, and thus patterns of genetic variation. In this study, we investigated the impact of past climate, and also the potential impact of host plant species abundance, on intraspecific genetic variation in three co-distributed and related specialized solitary bees of the genus Melitta with very similar life history traits and dispersal capacities. We sequenced five independent loci in samples collected from the three species. Our analyses revealed that the species associated with the most abundant host plant species (Melitta leporina) displays unusually high genetic variation, to an extent that is seldom reported in phylogeographic studies of animals and plants. This suggests a potential role of food resource abundance in determining current patterns of genetic variation in specialized herbivorous insects. Patterns of genetic variation in the two other species indicated lower overall levels of diversity, and that M. nigricans could have experienced a recent range expansion. Ecological niche modelling of the three Melitta species and their main host plant species suggested a strong reduction in range size during the last glacial maximum. Comparing observed sequence data with data simulated using spatially explicit models of coalescence suggests that M. leporina recovered a range and population size close to their current levels at the end of the last glaciation, and confirms recent range expansion as the most likely scenario for M. nigricans. Overall, this study illustrates that both demographic history and ecological factors may have contributed to shape current phylogeographic patterns.
Data from: Hummingbirds budget energy flexibly in response to changing resources
1. Managing energy stores in response to variable resource availability is a key component to individual fitness, yet because directly measuring energy budgets is difficult, daily energy management is rarely measured. 2. Hummingbirds' energy management is relatively simple to model compared to other endotherms because they have high mass-specific metabolic rates and store little fat. 3. We determined which aspects of the hummingbird daily energy budget (i.e. thermoregulation, daytime activity costs, nighttime costs) change at the individual level in response to environmental variation. 4. We found that daily energy expenditure varied three-fold in two populations of broad-billed hummingbirds (Cynanthus latirostris). 5. Our model indicated the energy budget was distributed in the following proportions: daytime activity, 59% (range 22-84%); thermoregulation, 23% (11 – 32%), basal metabolism, 7% (3 – 16%), and nighttime energy 17% (6 – 37%). Activity costs were higher at the hotter, homogeneous site and during the early-wet season at both sites. 6. Increased daily energy expenditure was related to decreased nectar availability, and not significantly related to temperature or bird mass. With climate change, the indirect energetic costs of shifting resources could have greater impacts on endotherm energy budgets than direct costs such as thermoregulation. Increased foraging and activity costs could decrease the energy available to birds for somatic repair and reproduction, potentially causing differential fitness across seasons and sites.
Data from: "Polar bear (Ursus maritimus) transcriptome assembly and SNP discovery" in Genomic Resources Notes accepted 1 August 2013-30 September 2013
Polar bears (Ursus maritimus) in the Western Hudson Bay subpopulation have been declining in size and body condition for decades, as climate change causes earlier sea ice breakup, reduced hunting time on the ice, and an increasingly long fasting season. As Western Hudson Bay females have decreased in size, rates of litter production and average litter size have also decreased, while cub mortality and average time to independence have increased. Although these changes have potential evolutionary consequences, little is yet known about the adaptive genetic variation in body size or fat accumulation that would have to underlie any such change. In this study, we used high-throughput Illumina sequencing to develop SNPs from pooled blood and fat transcriptomes, using samples from five adult female polar bears and five (unrelated) dependent cubs. In total, we generated 371,258 transcripts of which 36,755 were deemed to be "full length" (i.e., covered more than 90% of their best BLAST hit), and we identified 63,020 SNPs. Since this study was conducted, we have used a subset of these SNPs to develop an Illumina BeadArray for quantitative genetics research in Western Hudson Bay.
Data from: Distribution and drift dispersal dynamics of a caddisfly grazer in response to resource abundance and its ontogeny
Stream grazers have a major impact on food web structure and the productivity of stream ecosystems; however, studies on the longitudinal (upstream versus downstream) and temporal changes in their drift dynamics and resulting distributions remain limited. Here, we investigated the longitudinal and temporal distributions and drift propensity of a trichopteran grazer, the caddisfly, Micrasema quadriloba, during its life cycle in a Japanese stream. The distribution of larvae significantly shifted downstream during the fifth instar larval stage during late winter; with periphyton abundance (i.e. their food source) showing similar shifts downstream. Therefore, our results show that the drift dispersal the caddisfly occurs in response to decline in available food resources (i.e. food-resource scarcity) and an increase in food requirements by growing individuals. Furthermore, our results show that this observed longitudinal shift in larval distribution varies through their life cycle, because the drift dispersal of fifth instar larvae was greater than that of immature larvae. The correlation between periphyton abundance and drift propensity of fourth instar larvae was not statistically significant, whereas that of fifth instar larvae was significantly negative. In conclusion, we detected an ontogenetic shift in drift propensity, which might explain the longitudinal and temporal distributions of this species.
Data from: Amount or pattern? Grassland responses to the heterogeneity and availability of two key resources
Patterns of resource availability and heterogeneity shape the composition, productivity, and dynamics of plant assemblages in a wide variety of terrestrial ecosystems. Despite this, the responses of plant assemblages to simultaneous changes in the availability and heterogeneity of more than a single resource are virtually unknown. To fill this gap, microcosms consisting of assemblages formed by Lolium perenne, Plantago lanceolata, Anthoxantum odoratum, Holcus lanatus, and Trifolium repens were grown in a factorial experiment with the following treatments: nutrient availability (NA), water availability (WA), spatial nutrient heterogeneity (NH), and temporal water heterogeneity (WH). Assemblages exhibited precise root foraging patterns in response to nutrient heterogeneity, which were modified by NA and WA. A series of two- and three-way interactions involving the four factors evaluated determined biomass production, the belowground : aboveground biomass ratio, the patterns of root biomass allocation with depth, and the relative contribution to aboveground biomass of Lolium and Anthoxanthum. In all cases, these interactions explained significant amounts of the variation found in the data. Our study demonstrates that considering the interactions between resource availability and heterogeneity allows for a refinement of predictions that can detectably reduce the error associated with extrapolating from single factor analyses.
Data from: Genetic resources of teak (Tectona grandis Linn. f.) – strong genetic structure among natural populations
Twenty-nine provenances of teak (Tectona grandis Linn. f.) representing the full natural distribution range of the species were genotyped with microsatellite DNA markers to analyse genetic diversity and population genetic structure. Provenances originating from the semi-moist east coast of India had the highest genetic diversity while provenances from Laos showed the lowest. In the eastern part of the natural distribution area, comprising Myanmar, Thailand and Laos, there was a strong clinal decrease in genetic diversity the further east the provenance was located. Overall, the pattern of genetic diversity supports the hypothesis that teak has its centre of origin in India, from where it spread eastwards. The analysis of molecular variance (AMOVA) gave an overall highly significant F st value of 0.227—population pairwise F st values were in the range 0.01–0.48. Applying the G″st differentiation parameter, the estimated overall differentiation was 0.632, implying a strong genetic structure among populations. A neighbour-joining (NJ) tree, using the pairwise population matrix of G″st values as input, contained three distinct groups: (1) the eight provenances from Thailand and Laos, (2) the Indian provenances from the dry interior and the moist west coast and (3) the provenances from northern Myanmar. The provenances from southern Myanmar were placed close to the root of the tree together with the three provenances from the semi-moist east coast of India. A Bayesian cluster analysis using the STRUCTURE software gave very similar results, with three main clusters, each containing two sub-clusters, while Bayesian cluster analysis in the Geneland software, exploiting the spatial coordinates of the provenances, resulted in five clusters in accordance with the former results. The implications of the findings for conservation and use of genetic resources of the species are discussed.
Data from: Selfish mothers indeed! Resource-dependent conflict over extended parental care in free-ranging dogs
Parent–offspring conflict (POC) theory provides an interesting premise for understanding social dynamics in facultatively social species. In free-ranging dogs, mothers increase conflict over extended parental care with their pups beyond the weaning stage. In this study, we investigated whether resource quality affects POC in the dogs that typically live in a highly competitive environment as scavengers. We built a theoretical model to predict the alternative options available to the mother in the context of food sharing with her pups when protein-rich food (meat) is provided, as compared to carbohydrate-rich food (biscuits). We fit the mothers' response from experimental data to the model and show that the mothers choose a selfish strategy, which can in turn ensure higher lifetime reproductive success, while depriving the current litter access to better resources. These results have interesting implications for understanding the social dynamics of the dogs, and the emergence of facultative sociality in a species that evolved from strongly social ancestors. We speculate that the tendency of increased conflict in resource-rich conditions might have driven the process of domestication in the ancestors of dogs which defected from their groups in favour of richer resources around human settlements.
Data from: Resource selection and landscape change reveal mechanisms suppressing population recovery for the world's most endangered antelope
Understanding how bottom-up and top-down forces affect resource selection can inform restoration efforts. With a global population size of <500 individuals, the hirola Beatragus hunteri is the world's most endangered antelope, with a declining population since the 1970s. While the underlying mechanisms are unclear, some combination of habitat loss and predation are thought to be responsible for low abundances of contemporary populations. Efforts to conserve hirola are hindered by a lack of understanding as to why population density remains low, despite eradication of the viral disease, rinderpest. To elucidate factors underlying chronically low numbers, we examined resource selection and landscape change within the hirola's native range. Because hirola are grazers, we hypothesized that the availability of open areas would be linked both to forage and safety from predators. We quantified: (1) changes in tree cover across the hirola's historical range in eastern Kenya over the past 27 years; (2) how tree cover has influenced resource selection by hirola; and (3) interactions between tree cover and predation. Between 1985 and 2012, tree cover increased by 251% across the historical range of hirola. Tree encroachment was associated with a 98% decline of hirola and elephant Loxodonta africana populations, a 74% decline in cattle Bos indicus, an increase in browsing livestock by 327%, and a reduction in rainfall. Although hirola avoided tree cover, we found no evidence that predation on hirola increased with increasing tree cover. Synthesis and applications. Hirola may qualify as a refugee species, in which contemporary populations are restricted to suboptimal habitat and exhibit low survival, reproduction, or both. The extinction of hirola would be the first of a mammalian genus on the African continent in modern history. We conclude that contemporary low numbers of hirola are due at least partly to habitat loss via tree encroachment, triggered by some combination of elephant extirpation, overgrazing, drought, and perhaps fire suppression. We recommend a combination of rangeland restoration efforts (including conservation of elephants, manual clearing of trees, and grass seeding), increased enforcement of an existing protected area (Arawale National Reserve), and reintroductions to enhance recovery for this endangered species. These efforts will rely on enhanced support from the international conservation community and the cooperation of pastoralist communities with which the hirola coexist.
Data from: Complex genetic effects on early vegetative development shape resource allocation differences between Arabidopsis lyrata populations
Costs of reproduction due to resource allocation trade-offs have long been recognized as key forces in life history evolution, but little is known about their functional or genetic basis. Arabidopsis lyrata, a perennial relative of the annual model plant A. thaliana with a wide climatic distribution, has populations that are strongly diverged in resource allocation. In this study, we evaluated the genetic and functional basis for variation in resource allocation in a reciprocal transplant experiment, using four A. lyrata populations and F2 progeny from a cross between North Carolina (USA) and Norway parents, which had the most divergent resource allocation patterns. Local alleles at quantitative trait loci (QTL) at a North Carolina field site increased reproductive output while reducing vegetative growth. These QTL had little overlap with flowering date QTL. Structural equation models incorporating QTL genotypes and traits indicated that resource allocation differences result primarily from QTL effects on early vegetative growth patterns, with cascading effects on later vegetative and reproductive development. At a Norway field site, North Carolina alleles at some of the same QTL regions reduced survival and reproductive output components, but these effects were not associated with resource allocation trade-offs in the Norway environment. Our results indicate that resource allocation in perennial plants may involve important adaptive mechanisms largely independent of flowering time. Moreover, the contributions of resource allocation QTL to local adaptation appear to result from their effects on developmental timing and its interaction with environmental constraints, and not from simple models of reproductive costs.
Data from: Predation risk, resource quality, and reef structural complexity shape territoriality in a coral reef herbivore
For many species securing territories is important for feeding and reproduction. Factors such as competition, habitat availability, and male characteristics can influence an individual's ability to establish and maintain a territory. The risk of predation can have an important influence on feeding and reproduction; however, few have studied its effect on territoriality. We investigated territoriality in a haremic, polygynous species of coral reef herbivore, Sparisoma aurofrenatum (redband parrotfish), across eight reefs in the Florida Keys National Marine Sanctuary that were either protected or unprotected from fishing of piscivorous fishes. We examined how territory size and quality varied with reef protection status, competition, predation risk, and male size. We then determined how territory size and quality influenced harem size and female size to understand the effect of territoriality on reproductive potential. We found that protected reefs trended towards having more large predatory fishes and that territories there were smaller but had greater algal nutritional quality relative to unprotected reefs. Our data suggest that even though males in protected sites have smaller territories, which support fewer females, they may improve their reproductive potential by choosing nutritionally rich areas, which support larger females. Thus, reef protection appears to shape the trade-off that herbivorous fishes make between territory size and quality. Furthermore, we provide evidence that males in unprotected sites, which are generally less complex than protected sites, choose territories with higher structural complexity, suggesting the importance of this type of habitat for feeding and reproduction in S. aurofrenatum. Our work argues that the loss of corals and the resulting decline in structural complexity, as well as management efforts to protect reefs, could alter the territory dynamics and reproductive potential of important herbivorous fish species.
Data from: Small volume plasma exchange for Guillain-Barré syndrome in resource-limited settings: a phase II safety and feasibility study
OBJECTIVE: To assess the safety and feasibility of small volume plasma exchange (SVPE) as an alternative to standard plasma exchange (PE) or intravenous immunoglobulin (IVIg) for Guillain-Barré syndrome (GBS) patients. DESIGN: Non-randomized, single arm, interventional trial. SETTING: National Institute of Neurosciences and Hospital, Dhaka, Bangladesh. PARTICIPANTS: Twenty adult (>18 years) patients with GBS presented within 2 weeks of onset of weakness who were unable to walk unaided for more than 10 meters. INTERVENTIONS: SVPE involves blood cell sedimentation in a blood bag and removal of supernatant plasma after blood cells are re-transfused. This procedure was repeated three to six times a day, for eight consecutive days. OUTCOME MEASURES: Serious adverse events (SAE) were defined as severe sepsis and deep venous thrombosis related to the central vein catheter (CVC) used during SVPE. SVPE was considered safe if less than 5/20 patients experienced a SAE, and feasible if 8 L plasma could be removed within 8 days in at least 15/20 patients. RESULTS Median patient age 33 years (IQR 23-46; range 18-55); 13 (65%) were male. Median MRC sum score was 20 (IQR 0-29; range 0-36); three (15%) patients required mechanical ventilation. One patient developed SAE (severe sepsis, possibly related to CVC). Minor adverse effects were transient hypotension in 10 (50%) patients; CVC-associated bleeding in 10 (50%); transfusion reaction to fresh frozen plasma in 4 (20%); and hypo-albuminemia, anaemia or electrolyte imbalance in 4 (20%). Removal of 8 L plasma was possible in 15 (75%) patients. GBS disability score improved by at least one grade in 14 (70%) patients four weeks after SVPE started. No patients died. CONCLUSION: SVPE seems a safe and feasible alternative treatment to standard PE or IVIg for GBS; further studies of clinical efficacy in low-resource developing countries are warranted. TRIAL REGISTRATION: Clinicaltrials.gov NCT02780570 on May 23, 2016. Strength and limitations of the study: 1. The strength of this study underlies the novel and simple technique of SVPE, which is much less expensive than conventional immunotherapies (plasma exchange and intravenous immunoglobulin). 2. SVPE is corroborated as safe and feasible for the first time in a prospective and standardized cohort of patients with Guillain-Barré syndrome (GBS). 3. The intrinsic limitations of this study are its non-randomized, single arm nature, which is conducted in a single center with a limited sample size of GBS patients. 4. Clinical efficacy of SVPE on patients with GBS was a secondary end-point assessment and therefore deserves a randomized controlled trial in future to assess the clinical efficacy of SVPE for the patients with GBS.
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.