bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of durum wheat lines derived from interspecific crosses under drought and heat stress
Authors: Aberkane Hafid , Amri Ahmed , Belkadi Bouchra , Filali‐Maltouf Abdelkarim , Kehel Zakaria , Tahir Izzat S. A. , Meheesi Sara , Tsivelikas Athanasios 
Published: August 2020

AbstractThe productivity of durum wheat [Triticum turgidum subsp. durum (Desf.) van Slageren] is affected by drought and/or high temperatures, challenges to be amplified by climate change. Pre‐breeding using wild relatives can supply useful traits for durum wheat improvement to adapt to major abiotic and biotic stresses. Sixty‐seven lines issued from backcrosses of Cham5 and Haurani durum wheat varieties with accessions of Triticum aegilopoides (Link) Bal. ex Koern., T. dicoccoides Koern. ex Schweinf., T. urartu Thumanian ex Gandilyan, and Aegilops speltoides Tausch were evaluated for drought and heat tolerance. The trials were conducted during two seasons (2016−2017 and 2017–2018) at Tessaout, Morocco, under full irrigation (optimal conditions) and rainfed conditions (drought stressed) and at Wed Medani, Sudan, under full irrigation combined with heat stress. The recurrent parents, along with eight best cultivars and elite breeding lines, were used as checks. Drought reduced the grain yield by 62%. Grain yield and drought tolerance index were used to identify lines to be used by breeding programs to enhance drought and heat tolerance. The derivatives lines 142014 (Cham5*3/T. aegilopoides), 142074 (Cham5*3/T. dicoccoides), and 142015 along with the checks Icarachaz and Gidara 2 ranked among the best under heat stress. Under drought stress, the lines 141972 (Haurani*2/T. urartu) and 141973 (Cham5*2/T. dicoccoides) yielded 196 and 142% of their recurrent parents’ yield, respectively. High variation was found for agronomic and phenology traits, with heading time explaining 16% of grain yield under drought, while thousand kernel weight accounted for 18% of the yield under heat. We conclude that gene introgression from wild relatives pays off and can increase wheat resilience to cope with climate change effects.
Phase I safety, tolerability, and pharmacokinetic studies of tetramethylpyrazine nitrone in healthy Chinese volunteers
Authors: Zhao Caiyun , Lv Yuan , Cui Hong , Zhu Yan , Wei Minji , Xia Yahong , Tian Jihong , Ma Yan , Liu Yan , Zhang Pu , Wang Xi , Wu Jing , Wang Yatai 
Published: August 2020

AbstractBackgroundThe purpose of this study was to investigate the safety, tolerability and pharmacokinetics of tetramethylpyrazine nitrone (TBN) in healthy Chinese volunteers.MethodsA single‐ascending‐dose (SAD) study where 68 subjects were randomized to a single dose of placebo or TBN (50, 100, 200, 400, 700, 1,000, 1,400, or 1,800 mg) through IV infusion over 30 min. A multiple‐ascending‐dose (MAD) study where 24 subjects received TBN twice daily (with 12 hr interval) for total 6.5 days at doses of either 700 or 1,400 mg. Adverse events were recorded and pharmacokinetic samples were collected during the whole study period.ResultsNo serious adverse events were found in the study. All of the observed adverse events, including increased white blood cell (4.4% subjects) and neutrophil counts (4.4% subjects), and decreased hemoglobin levels (4.2% subjects), were laboratory test abnormalities. All the adverse events were mild and tolerable, and returned to normal without any intervention. In the SAD study, linear Cmax values were observed in the dose interval of 50–1,800 mg. In the MAD study, the average steady‐state concentrations (Cavg.ss) of TBN in the 700 and 1,400 mg dose group were 2,407 and 5,837 ng/ml, respectively. No drug accumulation was observed in this study.ConclusionsTBN is well tolerated in healthy volunteers. Linear Cmax values were observed in the interval of 50–1,800 mg, and target exposures of TBN were achieved without accumulation after twice daily administration to subjects. (This study has been registered at ChiCTR.org.cn. Identifier: ChiCTR1800016225 and ChiCTR1800019627.)
Type II interferon signaling in the brain during a viral infection with age‐dependent pathogenesis
Authors: Creisher Patrick S. , Chandwani Manisha N. , Kamte Yashika S. , Covvey Jordan R. , Ganesan Priya , O'Donnell Lauren A. 
Published: August 2020

AbstractViral infections of the central nervous system (CNS) often cause disease in an age‐dependent manner, with greater neuropathology during the fetal and neonatal periods. Transgenic CD46+ mice model these age‐dependent outcomes through a measles virus infection of CNS neurons. Adult CD46+ mice control viral spread and survive the infection in an interferon gamma (IFNγ)‐dependent manner, whereas neonatal CD46+ mice succumb despite similar IFNγ expression in the brain. Thus, we hypothesized that IFNγ signaling in the adult brain may be more robust, potentially due to greater basal expression of IFNγ signaling proteins. To test this hypothesis, we evaluated the expression of canonical IFNγ signaling proteins in the neonatal and adult brain, including the IFNγ receptor, Janus kinase (JAK) 1/2, and signal transducer and activator of transcription‐1 (STAT1) in the absence of infection. We also analyzed the expression and activation of STAT1 and IFNγ‐stimulated genes during MV infection. We found that neonatal brains have equivalent or greater JAK/STAT1 expression in the hippocampus and the cerebellum than adults. IFNγ receptor expression varied by cell type in the brain but was widely expressed on neuronal and glial cells. During MV infection, increased STAT1 expression and activation correlated with viral load in the hippocampus regardless of age, but not in the cerebellum where viral load was consistently undetectable in adults. These results suggest the neonatal brain is capable of initiating IFNγ signaling during a viral infection, but that downstream STAT1 activation is insufficient to limit viral spread.
Development of the lamprey velum and implications for the evolution of the vertebrate jaw
Authors: Yokoyama Hiromasa , Yoshimura Miho , Suzuki Daichi G. , Higashiyama Hiroki , Wada Hiroshi 
Published: August 2020

AbstractBackgroundThe vertebrate jaw is thought to have evolved through developmental modification of the mandibular arch. An extant jawless vertebrate, the lamprey, possesses a structure called “velum”—a mandibular arch derivative—in addition to the oral apparatus. This leads us to assess the velum's possible contribution to the evolution of jaws.ResultsThe velar muscles develop from progenitor cells distinct from those from which the oral muscles develop. In addition, the oral and velar regions originate from the different sub‐population of the trigeminal neural crest cells (NCCs): the former region receives NCCs from the midbrain, whereas the latter region receives NCCs from the anterior hindbrain. The expression of patterning genes (eg,DlxAandMsxA) is activated at a later developmental stage in the velum compared to the oral region,and more importantly, in different cells from those in the oral region.ConclusionThe lamprey mandibular arch consists of two developmental units: the anterior oral unit and the posterior velar unit. Because structural elements of the lamprey velum may be homologous to the jaw, the evolution of vertebrate jaws may have occurred by the velum being released from its functional roles in feeding or respiration in jawless vertebrates.
Springs ecosystem classification
Authors: Stevens Lawrence E. , Schenk Edward R. , Springer Abraham E. 
Published: August 2020

AbstractSprings ecosystems are globally abundant, geomorphologically diverse, and bio‐culturally productive, but are highly imperiled by anthropogenic activities. More than a century of scientific discussion about the wide array of ecohydrological factors influencing springs has been informative, but has yielded little agreement on their classification. This lack of agreement has contributed to the global neglect and degradation of springs ecosystems by the public, scientific, and management communities. Here we review the historical literature on springs classification variables, concluding that site‐specific source geomorphology remains the most diagnostic approach. We present a conceptual springs ecosystem model that clarifies the central role of geomorphology in springs ecosystem development, function, and typology. We present an illustrated dichotomous key to terrestrial (non‐marine) springs ecosystem types and subtypes, and describe those types. We identify representative reference sites, although data limitations presently preclude selection of continentally or globally representative reference springs of each type. We tested the classification key using data from 244 randomly selected springs of 13 types that were inventoried in western North America. The dichotomous key correctly identified springs type in 87.5% of the cases, with discrepancies primarily due to differentiation of primary vs. secondary typology, and insufficient inventory team training. Using that information, we identified sources of confusion and clarified the key. Among the types that required more detailed explanation were hypocrenes, springs in which groundwater is expressed through phreatophytic vegetation. Overall, springs biodiversity and ecosystem complexity are due, in part, to the co‐occurrence of multiple intra‐springs microhabitats. We describe microhabitats that are commonly associated with different springs types, reporting at least 13 microhabitats, each of which can support discrete biotic assemblages. Interdisciplinary agreement on basic classification is needed to enhance scientific understanding and stewardship of springs ecosystems, the loss and degradation of which constitute a global conservation crisis.
Incorporating capture heterogeneity in the estimation of autoregressive coefficients of animal population dynamics using capture–recapture data
Authors: Nicolau Pedro G. , Sørbye Sigrunn H. , Yoccoz Nigel G. 
Published: August 2020

AbstractPopulation dynamic models combine density dependence and environmental effects. Ignoring sampling uncertainty might lead to biased estimation of the strength of density dependence. This is typically addressed using state‐space model approaches, which integrate sampling error and population process estimates. Such models seldom include an explicit link between the sampling procedures and the true abundance, which is common in capture–recapture settings. However, many of the models proposed to estimate abundance in the presence of capture heterogeneity lead to incomplete likelihood functions and cannot be straightforwardly included in state‐space models. We assessed the importance of estimating sampling error explicitly by taking an intermediate approach between ignoring uncertainty in abundance estimates and fully specified state‐space models for density‐dependence estimation based on autoregressive processes. First, we estimated individual capture probabilities based on a heterogeneity model for a closed population, using a conditional multinomial likelihood, followed by a Horvitz–Thompson estimate for abundance. Second, we estimated coefficients of autoregressive models for the log abundance. Inference was performed using the methodology of integrated nested Laplace approximation (INLA). We performed an extensive simulation study to compare our approach with estimates disregarding capture history information, and using R‐package VGAM, for different parameter specifications. The methods were then applied to a real data set of gray‐sided volesMyodes rufocanusfrom Northern Norway. We found that density‐dependence estimation was improved when explicitly modeling sampling error in scenarios with low process variances, in which differences in coverage reached up to 8% in estimating the coefficients of the autoregressive processes. In this case, the bias also increased assuming a Poisson distribution in the observational model. For high process variances, the differences between methods were small and it appeared less important to model heterogeneity.
Resource selection of apex raptors: implications for siting energy development in sagebrush and prairie ecosystems
Authors: Squires John R. , Olson Lucretia E. , Wallace Zachary P. , Oakleaf Robert J. , Kennedy Patricia L. 
Published: August 2020

AbstractThere is an urgent need to understand ecological responses of avian species to the rapidly expanding human footprint of conventional and renewable energy development in sagebrush and prairie ecosystems. The ferruginous hawk (Buteo regalis) and golden eagle (Aquila chrysaetos) are two sympatric raptors of conservation concern that occupy and flourish in the most intact sagebrush steppe region remaining in North America. To understand these species’ use of habitat relative to energy development, we built resource selection functions using a spatially representative sample of occupied nesting territories collected in 2010–2011 and remotely sensed environmental variables across an extensive study area (186,693 km2). We used the resulting predicted resource selection maps to evaluate spatial overlap between the nesting habitats of these sympatric raptor species, as well as overlap of predicted habitat with potential development of oil/gas and wind energy resources. Remotely sensed variables were very effective in modeling patterns of nest‐site selection based on fivefold cross‐validation (>0.93 Spearman‐rank correlation) and validation with an independent dataset of historical nests collected from 2000 to 2009. Topographic roughness and intermediate levels of spring precipitation were the strongest drivers of differences in habitat use between ferruginous hawks and golden eagles. We did not detect a strong signal of avoidance of energy infrastructure by either species at current levels of development and both nested closer than expected to gravel/dirt roads associated with oil and gas infrastructure. However, extensive overlap of nesting habitat more selected by ferruginous hawks and golden eagles with areas of actual and potential energy development suggests both species are at risk from future habitat fragmentation. Given that 80% of nests are> 1 km from oil/gas wells, we believe the density of energy‐related disturbance present during our study was insufficient to drive patterns of resource selection for ferruginous hawks when considered at broad spatial scales. However, it was beyond the scope of our study to predict long‐term, population‐level responses. We suggest rigorous monitoring of long‐term trends in occupancy, productivity, and distribution is warranted for populations of ferruginous hawk and golden eagle in sagebrush and prairie ecosystems exposed to increased energy development.
Generalized mycorrhizal interactions and fungal enemy release drive range expansion of orchids in southern Florida
Authors: Downing Jason L. , Liu Hong , McCormick Melissa K. , Arce Jay , Alonso Dailen , Lopez‐Perez Jorge 
Published: August 2020

AbstractA species’ ability to establish and spread is influenced by different types of biotic interactions encountered in a new range. Species with high dependency on biotic interactions, such as orchids, are believed to have low ability to expand ranges. Using a comparative approach, we addressed the role of below‐ground biotic interactions in the naturalization and spread of two introduced orchids. Using fungus‐specific DNA primers and symbiotic germination trials, we identified the types of fungal taxa associated with Cyrtopodium flavum and Eulophia graminea, two invasive orchids in southern Florida, with that of two native congeners, C. punctatum and E. alta. We quantified the degrees of mycorrhizal specificity as well as associations with pathogenic fungi. We identified a total of 57 distinct fungal taxa, collected from a total of 104 root samples (67 adults and 37 seedlings), and 111 protocorms derived from fungal baits in southern Florida and southwest China. We found that invasive orchids were capable of associating with a broader range of mycorrhizal fungi than co‐occurring native congeners (i.e., generalist strategy). Concurrently, invasive orchid species were less likely to harbor pathogenic fungal groups (Ascomycete) than native congeners, suggesting enemy release played a role as well in these orchids’ naturalization and spread. These findings provided insights into the complex roles of mycorrhizal symbioses in range expansions.
Feeding specialists on fatty acid‐rich prey have higher gonad weights: Pay‐off in Baltic perch?
Authors: Scharnweber Kristin , Gårdmark Anna 
Published: August 2020

AbstractIndividual specialization is a common phenomenon throughout the animal kingdom. Many studies have identified intraspecific competition as one of the main drivers for individual feeding specialization. These studies have mainly considered the quantity of resources, commonly overlooking qualitative aspects of the diet. For example, highly unsaturated fatty acids of the ω‐3 class (ω‐3 HUFAs) are related to optimal health and growth in consumers. However, little is known on direct fitness consequences for consumers of natural populations that specialize on high‐quality resources, such as those rich in ω‐3 HUFAs. Despite being such an important qualitative aspect of the diet, it is still unknown whether natural populations show among‐individual variation in their choice on prey items that are either rich or poor in HUFAs, and how it affects individual performances. In this study, we investigated whether there is individual feeding specialization and whether it is related to fitness benefits, in a population of perch (Perca fluviatilis) in the Baltic Sea. The contribution of pelagic planktivorous fish to the diet varied from 17% to 61% among perch individuals, as depicted by stable isotope mixing models. This variation in diet was also qualitative, as the ω‐3 HUFA content differed among prey types. Specialization on the high‐quality resource pelagic planktivorous fish was associated with the proportions of ω‐3 HUFA in the individuals’ muscles and individuals among those with the highest proportions of ω‐3 HUFAs had the greatest relative gonad weight (gonadosomatic index, GSI), a proxy for reproductive investment. Thus, our results highlight the function of food quality for individual specialization and its potential to have direct fitness benefits, playing a major role in shaping ecological interactions.
Soil precipitation legacies influence intraspecific plant–soil feedback
Authors: Crawford Kerri M. , Hawkes Christine V. 
Published: August 2020

AbstractFeedbacks between plants and soil microbial communities can play an important role in structuring plant communities. However, little is known about how soil legacies caused by environmental disturbances such as drought and extreme precipitation events may affect plant–soil feedback or whether plant–soil feedback operates within species as it does between species. If soil legacies alter plant–soil feedback among genotypes within a plant species, then soil legacies may alter the diversity within plant populations. We conducted a fully factorial pairwise plant–soil feedback experiment to test how precipitation legacies influenced intraspecific plant–soil feedbacks among three genotypes of a dominant grass species, Panicum virgatum. Panicum virgatum experienced negative intraspecific plant–soil feedback, i.e., genotypes generally performed worse on soil from the same genotype than different genotypes. Soil precipitation legacies reversed the rank order of the strength of negative feedback among the genotypes. Feedback is often positively correlated with plant relative abundance. Therefore, our results suggest that soil precipitation legacies may alter the genotypic composition of P. virgatum populations, favoring genotypes that develop less negative feedback. Changes in intraspecific diversity will likely further affect community structure and ecosystem functioning, and may constrain the ability of populations to respond to future changes in climate.
Serum potassium in the PARADIGM‐HF trial
Authors: Ferreira João Pedro , Mogensen Ulrik M. , Jhund Pardeep S. , Desai Akshay S. , Rouleau Jean‐Lucien , Zile Michael R. , Rossignol Patrick , Zannad Faiez , Packer Milton , Solomon Scott D. , McMurray John J.V. 
Published: August 2020

AbstractAimsThe associations between potassium level and outcomes, the effect of sacubitril–valsartan on potassium level, and whether potassium level modified the effect of sacubitril–valsartan in patients with heart failure and a reduced ejection fraction were studied in PARADIGM‐HF. Several outcomes, including cardiovascular death, sudden death, pump failure death, non‐cardiovascular death and heart failure hospitalization, were examined.Methods and resultsA total of 8399 patients were randomized to either enalapril or sacubitril–valsartan. Potassium level at randomization and follow‐up was examined as a continuous and categorical variable (≤3.5, 3.6–4.0, 4.1–4.9, 5.0–5.4 and ≥5.5 mmol/L) in various statistical models. Hyperkalaemia was defined as K+ ≥5.5 mmol/L and hypokalaemia as K+ ≤3.5 mmol/L. Compared with potassium 4.1–4.9 mmol/L, both hypokalaemia [hazard ratio (HR) 2.40, 95% confidence interval (CI) 1.84–3.14] and hyperkalaemia (HR 1.42, 95% CI 1.10–1.83) were associated with a higher risk for cardiovascular death. However, potassium abnormalities were similarly associated with sudden death and pump failure death, as well as non‐cardiovascular death and heart failure hospitalization. Sacubitril–valsartan had no effect on potassium overall. The benefit of sacubitril–valsartan over enalapril was consistent across the range of baseline potassium levels.ConclusionsAlthough both higher and lower potassium levels were independent predictors of cardiovascular death, potassium abnormalities may mainly be markers rather than mediators of risk for death.
The effectiveness of parental distraction during children’s acute pain: The moderating effect of socioeconomic status
Authors: Moore Shannon V. , Lecarie Emma K. , Davis Mary C. , Lemery‐Chalfant Kathryn 
Published: August 2020

AbstractBackgroundParental responses to children's pain shape how children interpret and cope with pain symptoms through parental modelling and operant conditioning. Evidence suggests that parental distraction is effective in reducing children's acute pain responses, but findings are inconsistent across pain tolerance, intensity and unpleasantness, and are limited to samples of primarily middle and upper‐middle class families. Although socioeconomically disadvantaged families may have fewer psychological resources to cope with pain, no studies have examined whether the utility of parent distraction varies by family socioeconomic status (SES). The current study tested the hypothesis that relations between parental distraction and acute pain responses in children vary by family SES, with children from higher versus lower SES families experiencing more substantial benefits.MethodsChildren's pain symptoms and parents’ use of verbal distraction during a cold pressor task were examined in a community sample of 530 twin children aged 7–12 years old and their primary caregivers.ResultsParental distraction was positively associated with children‘s pain tolerance and unrelated to intensity and unpleasantness, but these associations are qualified by significant moderation. In families with higher SES, parental distraction was an effective technique in children's pain management, associated with more pain tolerance and less pain intensity and unpleasantness. However, for families with lower SES, these same benefits were not present.ConclusionsFindings suggest that the effectiveness of parental distraction for children's acute pain may depend on family SES.SignificanceStudy findings suggest that the effects of parental distraction on children's responses to an acute pain task vary by family SES. Although parental distraction may be effective for higher SES children, further research is needed to identify whether and why distraction may not be beneficial for lower SES families.