bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transcriptomic response of Daphnia magna to nitrogen‐ or phosphorus‐limited diet
Authors: Xu Zhimeng , Li Yingdong , Li Meng , Liu Hongbin 
Published: July 2021

Abstract

Effects of nutrient‐imbalanced diet on the growth and fitness of zooplankton were widely reported as key issues to aquatic ecology. However, little is known about the molecular mechanisms driving the physiological changes of zooplankton under nutrient stress.

In this study, we investigated the physiological fitness and transcriptomic response of Daphnia magna when exposed to nitrogen (N)‐limited or phosphorus (P)‐limited algal diet (Chlamydomonas reinhardtii) compared to regular algae (N and P saturated).

D. magna showed higher ingestion rates and overexpression of genes encoding digestive enzymes when fed with either N‐limited or P‐limited algae, reflecting the compensatory feeding. Under P‐limitation, both growth rate and reproduction rate of D. magna were greatly reduced, which could be attributed to the downregulated genes within the pathways of cell cycle and DNA replication. Growth rate of D. magna under N‐limitation was similar to normal group, which could be explained by the high methylation level (by degradation of methionine) supporting the body development.

Phenotypic changes of D. magna under nutrient stress were explained by gene and pathway regulations from transcriptome data. Generally, D. magna invested more on growth under N‐limitation but kept maintenance (e.g., cell structure and defense to external stress) in priority under P‐limitation. Post‐translational modifications (e.g., methylation and protein folding) were important for D. magna to deal with nutrient constrains.

This study reveals the fundamental mechanisms of zooplankton in dealing with elemental imbalanced diet and sheds light on the transfer of energy and nutrient in aquatic ecosystems.
Comparing spiraling‐ and transport‐based approaches to estimate in‐stream nutrient uptake length from pulse additions
Authors: Finkler Nícolas Reinaldo , Gücker Björn , Boëchat Iola Gonçalves , Tromboni Flavia , Thomas Steven Arnold , Mendes Ludmilson Abritta , Lima Daniel Moura Fontes , Covino Tim , Emanuelson Karin , Ponce de León Claudia , Fernandes Cunha Davi Gasparini 
Published: July 2021

AbstractThe distance that a nutrient travels as a solute before its removal from the stream water column is known as the uptake length (SW), which is a functional indicator of environmental quality and integrity. Among nutrient enrichment methods, instantaneous nutrient addition (e.g., slug or pulse) have been proposed as an alternative to plateau and labeled nutrient approaches. Two approaches have been commonly used to estimate SW and its associated metrics (i.e., areal uptake rate, U; and uptake velocity, Vf) from pulse additions: the spiraling approach, based on the longitudinal variation in nutrient concentrations, and the transport modeling approach, based on the advective and dispersive transport of solutes. However, little is known in how the choice of such analytical methods impacts the estimation of stream uptake parameters and the conclusions we draw from them. Here, we estimated the SW and Vf of ammonium‐nitrogen (NH4‐N) and soluble reactive phosphorus (SRP) from 16 pulsed additions conducted in four low‐order streams in southeastern Brazil. We compared metrics estimated by the Tracer Additions for Spiraling Curve Characterization (TASCC) and the One‐Dimensional Transport with Inflow and Storage (OTIS) methods, based on the spiraling‐ and transport‐based approaches, respectively. The TASCC:OTIS SW ratio averaged 0.71 for NH4‐N and 1.01 for SRP, whereas the mean of TASCC:OTIS Vf ratio was 2.04 for NH4‐N and 1.03 for SRP. The results showed that both SW and Vf estimates differed significantly between methods for NH4‐N, but no statistical differences were observed in SRP estimates. In our study, we highlighted the significant effects of transient storage and variable nutrient concentration on pulsed enrichments. Such information should be considered when choosing which method is appropriate to use for a particular site. Differences between modeling approaches must be addressed when comparing methods to expand our knowledge on broad temporal and spatial patterns of in‐stream nutrient uptake.
Space use and interactions of two introduced mesopredators, European red fox and feral cat, in an arid landscape
Authors: Roshier David A. , Carter Andrew 
Published: July 2021

AbstractIntroduced mammalian predators are drivers of species decline and extinction globally. The successful management and control of introduced mammalian predators is dependent on some knowledge of space use and movements in order to target a population and monitor outcomes. In Australia, these tasks are made complex as there is more than one significant introduced mammalian predator, namely the European red fox Vulpes vulpes and feral cat Felis catus, the landscapes are vast, and individual‐level interactions between predators are little studied. The impact of these two introduced predators is large and a significant factor in the extinction of many of the country’s small‐ to medium‐sized mammals, either regionally or globally. In a three‐year study, we used high‐frequency location data, the deployment of the latest GPS tracking technologies, and recent advances in statistical modeling to examine how these two species distributed themselves in space, the degree to which individual distributions overlapped, intra‐ and interspecific interactions, and temporal patterns of activity in an arid landscape. In the absence of an apex predator, the two introduced mesopredators showed large differences in how they distribute themselves across the landscape and interact with conspecifics. The red fox mostly occupies defined territories, while most feral cats roam apparently independent of each other with occasional periods of frequent interaction with conspecifics of either sex. Intraspecific attraction was strongest in cats, while interspecific avoidance was observed in both directions. The home ranges of feral cats that were range‐resident were 3–3.5 times larger than foxes in the same landscape. Notably, we observed long‐distance movements in feral cats and some were displaced up to 164 km from their point of release. A greater portion of the feral cat population were non‐sedentary and therefore likely less amenable to local control efforts than foxes. Given the different patterns of distribution in time and space, the reliable monitoring of population trends or estimates of abundance will necessarily differ in extent, intensity, or duration for the same level of precision and/or require a different method for monitoring each population.
Site‐specific impacts of a major hurricane on alpha and beta diversity in tropical forest seedling communities
Authors: Worthy Samantha J. , Rubio Vanessa E. , Staiger Kirstin , Ngouajio Boris , Yang Jie , Swenson Nathan G. 
Published: July 2021

AbstractLarge scale disturbances are known to impact the alpha and beta diversity of communities. However, whether these disturbances increase or decrease diversity is often debated. The goal of this study was to quantify how the diversity of the seedling community was impacted within and across elevation in the El Yunque forest of Puerto Rico following a major hurricane. We tested two alternative hypotheses, that hurricanes are relatively more homogenizing or non‐homogenizing forces, by quantifying changes in alpha and beta diversity of the seedling community post‐hurricane. This approach highlights whether ecological mechanisms associated with community homogenization (species‐specific survival, successional processes, and reduced environmental heterogeneity) or non‐homogenization (resource release, increased environmental heterogeneity, and stochastic processes) structure the seedling community post‐hurricane. We compared species richness, Fisher’s α, Simpson’s evenness, and multiple aspects of beta diversity within and among 25 seedling plots at 300, 400, and 500 m in elevation pre‐ and post‐hurricane. We found that species richness, diversity, and evenness were higher post‐hurricane, but abundance decreased 19%. Increases in alpha diversity suggest that hurricanes are non‐homogenizing forces potentially linked with increases in light levels promoting colonization of early‐successional species and resource release for other light‐demanding species. The beta diversity results varied in their support for hurricanes as homogenizing depending upon the spatial scale of the analysis, potentially due to a combination of mechanisms including species‐specific survival and site‐specific differences. To fully grasp how the seedling community responds and recovers from disturbance, additional long‐term monitoring will be needed to allow insight into the future of species richness, abundance, and spatial and temporal changes in community composition.
Ecological and environmental context shape the differential effects of a facilitator in its native and invaded ranges
Authors: Hesketh Amelia V. , Schwindt Evangelina , Harley Christopher D. G. 
Published: July 2021

AbstractInvasive species often exhibit disproportionately strong negative effects in their introduced range compared to their native range, and much research has been devoted to understanding the role of shared evolutionary history, or lack thereof, in driving these differences. Less studied is whether introduced species, particularly those that are important as facilitators in their native range, have persistent positive effects in their invaded range despite a lack of a shared evolutionary history with the invaded community. Here, we manipulated the density of a habitat‐forming facilitator, the high intertidal acorn barnacle Balanus glandula, factorially with herbivore density in its native range (Bluestone Point, British Columbia, Canada) and invaded range (Punta Ameghino, Chubut Province, Argentina) to determine how this facilitator differentially affects associated species at these two locations. Given that high intertidal species at Punta Ameghino (PA) are evolutionarily naïve to barnacles, we predicted that the positive effects of B. glandula at PA would be absent or weak compared to those at Bluestone Point (BP). However, we found that B. glandula had an equally positive effect on herbivore biomass at PA compared to BP, possibly because the moisture‐retaining properties of barnacle bed habitats are particularly important in seasonally dry Patagonia. Barnacle presence indirectly decreased ephemeral algal cover at BP by increasing grazer pressure, but barnacles instead facilitated ephemeral algae at PA. In contrast, B. glandula increased perennial algal cover at BP, but generally decreased perennial algal cover at PA, likely due to differences in dominant algal morphology. Though our experiment was limited to one location on each continent, our results suggest that shared evolutionary history may not be a prerequisite for strong facilitation to occur, but rather that the nature and strength of novel species interactions are determined by the traits of associated species and the environment in which they occur.
Parental investment in the Columbian ground squirrel: empirical tests of sex allocation models
Authors: Barra Thibaut , Viblanc Vincent A. , Saraux Claire , Murie Jan O. , Dobson F. Stephen 
Published: July 2021

AbstractParental allocation of resources into male or female offspring and differences in the balance of offspring sexes in natural populations are central research topics in evolutionary ecology. Fisher (Fisher, R. A. 1930. The genetical theory of natural selection, Clarendon Press, Oxford, UK) identified frequency‐dependent selection as the mechanism responsible for an equal investment in the sexes of offspring at the end of parental care. Three main theories have been proposed for explaining departures from Fisherian sex ratios in light of variation in environmental (social) and individual (maternal condition) characteristics. The Trivers–Willard model (Trivers, R., and D. Willard. 1973. Natural selection of parental ability to vary the sex ratio of offspring. Science 179:90–92) of male‐biased sex allocation by mothers in the best body condition is based on the competitive ability of male offspring for future access to mates and thus superior reproduction. The local resource competition model is based on competitive interactions in matrilines, as occur in many mammal species, where producing sons reduces future intrasexual competition with daughters. A final model invokes advantages of maintaining matrilines for philopatric females, despite any increased competition among females. We used 29 yr of pedigree and demographic data to evaluate these hypotheses in the Colombian ground squirrel (Urocitellus columbianus), a semisocial species characterized by strong female philopatry. Overall, male offspring were heavier than female offspring at birth and at weaning, suggesting a higher production cost. With more local kin present, mothers in the best condition biased their offspring sex ratio in favor of males, and mothers in poor condition biased offspring sex ratio in favor of females. Without co‐breeding close kin, the pattern was reversed, with mothers in the best condition producing more daughters, and mothers in poor condition producing more sons. Our results do not provide strong support for any of the single‐factor models of allocation to the sexes of offspring, but rather suggest combined influences of relative maternal condition and matriline dominance on offspring sex ratio.
Association of estimated glucose disposal rate and chronic diabetic complications in patients with type 1 diabetes
Authors: Lam‐Chung César Ernesto , Martínez Zavala Néstor , Ibarra‐Salce Raúl , Pozos Varela Francisco Javier , Mena Ureta Tania S. , Berumen Hermosillo Francisco , Campos Muñoz Alejandro , Janka Zires Marcela , Almeda‐Valdes Paloma 
Published: July 2021

AbstractIntroductionThe role of insulin resistance in diabetic chronic complications among individuals with type 1 diabetes (T1D) has not been clearly defined. The aim of this study was to examine the performance of insulin resistance, evaluated using the estimated glucose disposal rate (eGDR) for the identification of metabolic syndrome (MS) and diabetic chronic complications.MethodsCross‐sectional study in a tertiary care centre. We included patients of 18 years and older, with at least 6 months of T1D duration. Anthropometric, clinical and biochemical data were collected.ResultsSeventy patients, 41 (58.6%) women, with a median age of 36.6 years (range 18–65). Mean age of onset and duration of diabetes was 13.5 ± 6.5 and 23.6 ± 12.2 years, respectively. Twenty‐one (30%) patients met the metabolic syndrome (MS) criteria. Patients with MS had lower eGDR compared to patients without (5.17 [3.10–8.65] vs. 8.86 [6.82–9.85] mg/kg/min, respectively, p = .003). Median eGDR in patients with nephropathy, retinopathy and neuropathy compared with those without was 6.75 (4.60–8.20) versus 9.53 (8.57–10.3); p < .001, 6.45 (4.60–7.09) versus 9.50 (8.60–10.14); p < .001, 5.56 (4.51–6.81) versus 9.49 [8.19–10.26] mg/kg/min; p < .001, respectively. The eGDR showed an area under the curve of 0.909, 0.879, 0.897 and 0.836 for the discrimination of MS, retinopathy, neuropathy and nephropathy, respectively.ConclusionsPatients with T1D diabetic complications have higher insulin resistance. The eGDR discriminates patients with chronic diabetic complications and MS. While more ethnic‐specific studies are required, this study suggests the possibility to incorporate eGDR into routine diabetes care.
The inhibitory receptor CD300a is essential for neutrophil‐mediated clearance of urinary tract infection in mice
Authors: Isaacson Batya , Baron Maya , Yamin Rachel , Bachrach Gilad , Levi‐Schaffer Francesca , Granot Zvi , Mandelboim Ofer 
Published: July 2021

AbstractNeutrophils play a crucial role in immune defense against and clearance of uropathogenic Escherichia coli (UPEC)‐mediated urinary tract infection, the most common bacterial infection in healthy humans. CD300a is an inhibitory receptor that binds phosphatidylserine and phosphatidylethanolamine, presented on the membranes of apoptotic cells. CD300a binding to phosphatidylserine and phosphatidylethanolamine, also known as the “eat me” signal, mediates immune tolerance to dying cells. Here, we demonstrate for the first time that CD300a plays an important role in the neutrophil‐mediated immune response to UPEC‐induced urinary tract infection. We show that CD300a‐deficient neutrophils have impaired phagocytic abilities and despite their increased accumulation at the site of infection, they are unable to reduce bacterial burden in the bladder, which results in significant exacerbation of infection and worse host outcome. Finally, we demonstrate that UPEC's pore forming toxin α‐hemolysin induces upregulation of the CD300a ligand on infected bladder epithelial cells, signaling to neutrophils to be cleared.
Switching between laser‐induced thermophoresis and thermal convection of liquid suspension in a microgap with variable dimension
Authors: Tsuji Tetsuro , Taguchi Satoshi , Takamatsu Hiroki 
Published: July 2021

AbstractPhoretic motion of particles along a temperature gradient formed in a fluid, known as thermophoresis, often takes place under the influence of bulk motion caused by thermal convection. In this paper, using a laser heating method, the significance of two competing effects, that is, thermophoresis and thermal convection, for the particle transport in a liquid phase confined in a microgap is investigated experimentally by changing the gap size as a control parameter. It is found that there is a threshold of the gap size, above which the particles tend to accumulate around the heated spot, forming a ring‐like particle distribution. On the contrary, if the gap size is below the threshold, the particles are depleted from the heated spot. Switching between these accumulation and depletion modes is expected to develop novel manipulation techniques.
Antiepileptogenesis and disease modification: Clinical and regulatory issues
Authors: French Jacqueline A. , Bebin Martina , Dichter Marc A. , Engel Jerome , Hartman Adam L. , Jóźwiak Sergiusz , Klein Pavel , McNamara James , Twyman Roy , Vespa Paul 
Published: July 2021

AbstractThis is a summary report of clinical and regulatory issues discussed at the 2018 NINDS workshop, entitled “Accelerating Therapies for Antiepileptogenesis and Disease Modification.” The intent of the workshop was to optimize and accelerate development of therapies for antiepileptogenesis (AEG) and disease modification in the epilepsies. The working group discussed nomenclature for antiepileptogenic therapies, subdividing them into “antiepileptogenic therapies” and “disease modifying therapies,” both of which are urgently needed. We use the example of traumatic brain injury to explain issues and complexities in designing a trial for disease‐preventing antiepileptogenic therapies, including identifying timing of intervention, selecting the appropriate dose, and the need for biomarkers. We discuss the recent trials of vigabatrin to prevent onset and modify epilepsy outcome in children with tuberous sclerosis (Epistop and PreVeNT). We describe a potential approach to a disease modification trial in adults, using patients with temporal lobe epilepsy. Finally, we discuss regulatory hurdles for antiepileptogenesis and disease‐modifying trials.
Zu den geomechanischen Parametern von Nürnberger Keupersandstein für den kreuzungsfreien Ausbau des Frankenschnellwegs Nürnberg (Abschnitt Mitte)
Authors: Hu Yifeng , Bayer Manfred , Sieler Ulrich 
Published: July 2021

AbstractIm Zuge des kreuzungsfreien Ausbaus des Frankenschnellwegs in Nürnberg ist im Abschnitt Mitte ein Tunnel mit tiefer Gradiente in Spritzbetonbauweise geplant. Der Tunnel wird überwiegend im Nürnberger Keupersandstein (Blasensandstein der Kategorie mürb bis mittelhart) aufgefahren. Hierbei werden mehrere kreuzende Bahnlinien mit dem geplanten Tunnel unterfahren. Zur Gewährleistung der Betriebssicherheit stellt die Deutsche Bahn hohe Anforderungen an die Begrenzung der Verformungen bzw. Setzungen der Eisenbahndämme durch den Tunnelvortrieb bei einer Überdeckungshöhe bis ca. 18 m. Zur realitätsnahen Prognose des Verformungs‐ bzw. Setzungsverhaltens durch Tunnelvortrieb wurden zahlreiche Triaxialversuche an Prüfproben der mürben, mittelharten und harten Sandsteine durchgeführt. Dabei wurden insbesondere die Einflüsse des Seitendrucks und der Ent‐ bzw. Wiederbelastungsschleifen auf Steifigkeiten untersucht. Der Auswertung der Versuchsergebnisse wurde das Stoffmodell Hardening Soil Model (HSM) zugrunde gelegt. Davon ausgehend wurde die Anwendbarkeit des Stoffmodells HSM für die Nürnberger Keupersandsteine je nach der Kategorie bzw. Druckfestigkeit überprüft, die entsprechenden geomechanischen Parameter ermittelt und zur Bemessung empfohlen. In diesem Aufsatz werden die wesentlichen Ergebnisse dargestellt.
Longitudinal white matter changes associated with cognitive training
Authors: Nichols Emily Sophia , Erez Jonathan , Stojanoski Bobby , Lyons Kathleen Michelle , Witt Suzanne Theisen , Mace Charlotte Anna , Khalid Sameera , Owen Adrian Mark 
Published: July 2021

AbstractImprovements in behavior are known to be accompanied by both structural and functional changes in the brain. However, whether those changes lead to more general improvements, beyond the behavior being trained, remains a contentious issue. We investigated whether training on one of two cognitive tasks would lead to either near transfer (that is, improvements on a quantifiably similar task) or far transfer (that is, improvements on a quantifiably different task), and furthermore, if such changes did occur, what the underlying neural mechanisms might be. Healthy adults (n = 16, 15 females) trained on either a verbal inhibitory control task or a visuospatial working memory task for 4 weeks, over the course of which they received five diffusion tensor imaging scans. Two additional tasks served as measures of near and far transfer. Behaviorally, participants improved on the task that they trained on, but did not improve on cognitively similar tests (near transfer), nor cognitively dissimilar tests (far transfer). Extensive changes to white matter microstructure were observed, with verbal inhibitory control training leading to changes in a left‐lateralized network of frontotemporal and occipitofrontal tracts, and visuospatial working memory training leading to changes in right‐lateralized frontoparietal tracts. Very little overlap was observed in changes between the two training groups. On the basis of these results, we suggest that near and far transfer were not observed because the changes in white matter tracts associated with training on each task are almost entirely nonoverlapping with, and therefore afford no advantages for, the untrained tasks.