bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic diversity and evolutionary patterns of Taraxacum kok‐saghyz Rodin
Authors: Zhang Yan , Ren Hailong , Zhang Xuechao , Wang Li , Gao Qiang , Abudurezike Abudukeyoumu , Yan Qingqing , Lu Zifeng , Wang Yonggang , Nie Qiuhai , Xu Lin , Zhang Zhibin 
Published: May 2021

AbstractTaraxacum kok‐saghyz Rodin (TKS) is an important potential alternative source of natural inulin and rubber production, which has great significance for the production of industrial products. In this study, we sequenced 58 wild TKS individuals collected from four different geography regions worldwide to elucidate the population structure, genetic diversity, and the patterns of evolution. Also, the first flowering time, crown diameter, morphological characteristics of leaf, and scape of all TKS individuals were measured and evaluated statistically. Phylogenetic analysis based on SNPs and cluster analysis based on agronomic traits showed that all 58 TKS individuals could be roughly divided into three distinct groups: (a) Zhaosu County in Xinjiang (population AB, including a few individuals from population C and D); (b) Tekes County in Xinjiang (population C); and (c) Tuzkol lake in Kazakhstan (population D). Population D exhibited a closer genetic relationship with population C compared with population AB. Genetic diversity analysis further revealed that population expansion from C and D to AB occurred, as well as gene flow between them. Additionally, some natural selection regions were identified in AB population. Function annotation of candidate genes identified in these regions revealed that they mainly participated in biological regulation processes, such as transporter activity, structural molecule activity, and molecular function regulator. We speculated that the genes identified in selective sweep regions may contribute to TKS adaptation to the Yili River Valley of Xinjiang. In general, this study provides new insights in clarifying population structure and genetic diversity analysis of TKS using SNP molecular markers and agronomic traits.
Thermal ecology and baseline energetic requirements of a large‐bodied ectotherm suggest resilience to climate change
Authors: Crowell Hayley L. , King Katherine C. , Whelan James M. , Harmel Mallory V. , Garcia Gennesee , Gonzales Sebastian G. , Maier Paul H. , Neldner Heather , Nhu Thomas , Nolan John T. , Taylor Emily N. 
Published: May 2021

Abstract

Most studies on how rising temperatures will impact terrestrial ectotherms have focused on single populations or multiple sympatric species. Addressing the thermal and energetic implications of climatic variation on multiple allopatric populations of a species will help us better understand how a species may be impacted by altered climates.

We used eight years of thermal and behavioral data collected from four populations of Pacific rattlesnakes (Crotalus oreganus) living in climatically distinct habitat types (inland and coastal) to determine the field‐active and laboratory‐preferred body temperatures, thermoregulatory metrics, and maintenance energetic requirements of snakes from each population.

Physical models showed that thermal quality was best at coastal sites, but inland snakes thermoregulated more accurately despite being in more thermally constrained environments. Projected increases of 1 and 2°C in ambient temperature result in an increase in overall thermal quality at both coastal and inland sites.

Population differences in modeled standard metabolic rate estimates were driven by body size and not field‐active body temperature, with inland snakes requiring 1.6× more food annually than coastal snakes.

All snakes thermoregulated with high accuracy, suggesting that small increases in ambient temperature are unlikely to impact the maintenance energetic requirements of individual snakes and that some species of large‐bodied reptiles may be robust to modest thermal perturbations under conservative climate change predictions.

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Determinants of trophic cascade strength in freshwater ecosystems: a global analysis
Authors: Su Haojie , Feng Yuhao , Chen Jianfeng , Chen Jun , Ma Suhui , Fang Jingyun , Xie Ping 
Published: May 2021

AbstractTop‐down cascade effects are among the most important mechanisms underlying community structure and abundance dynamics in aquatic and terrestrial ecosystems worldwide. A current challenge is understanding the factors controlling trophic cascade strength under global environmental changes. Here, we synthesized 161 global sites to analyze how multiple factors influence consumer‐resource interactions with fish in freshwater ecosystems. Fish have a profound negative effect on zooplankton and water clarity but positive effects on primary producers and water nutrients. Furthermore, fish trophic levels can modify the strength of trophic cascades, but an even number of food chain length does not have a negative effect on primary producers in real ecosystems. Eutrophication, warming, and predator abundance strengthen the trophic cascade effects on phytoplankton, suggesting that top‐down control will be increasingly important under future global environmental changes. We found no influence or even an increasing trophic cascade strength (e.g., phytoplankton) with increasing latitude, which does not support the widespread view that the trophic cascade strength increases closer to the equator. With increasing temporal and spatial scales, the experimental duration has an accumulative effect, whereas the experimental size is not associated with the trophic cascade strength. Taken together, eutrophication, warming, temporal scale, and predator trophic level and abundance are pivotal to understanding the impacts of multiple environmental factors on the trophic cascade strength. Future studies should stress the possible synergistic effect of multiple factors on the food web structure and dynamics.
A novel downstream process for highly pure 1,3‐propanediol from an efficient fed‐batch fermentation of raw glycerol by Clostridium pasteurianum
Authors: Zhang Chijian , Sharma Shubhang , Wang Wei , Zeng An‐Ping 
Published: May 2021

AbstractAn efficient downstream process without prior desalination was developed for recovering 1,3‐propanediol (1,3‐PDO) with high purity and yield from broth of a highly productive fed‐batch fermentation of raw glycerol by Clostridium pasteurianum. After removal of biomass and proteins by ultrafiltration, and concentration by water evaporation, 1,3‐PDO was directly recovered from the broth by vacuum distillation with continuous addition and regeneration of glycerol as a supporting agent. Inorganic salts in the fermentation broth were crystallized but well suspended by a continuous flow of glycerol during the distillation process, which prevented salt precipitation and decline of heat transfer. On the other hand, ammonium salt of organic acids were liberated as ammonia gas and free organic acids under vacuum heating. The latter ones formed four types of 1,3‐PDO esters of acetic acid and butyric acid, which resulted in yield losses and low purity of 1,3‐PDO (< 80%). In order to improve the efficiency of final 1,3‐PDO rectification, we examined alkaline hydrolysis to eliminate the ester impurities. By the use of 20% (w/w) water and 2% (w/w) sodium hydroxide, > 99% reduction of 1,3‐PDO esters was achieved. This step conveniently provided free 1,3‐PDO and the sodium salt of organic acids from the corresponding esters, which increased the 1,3‐PDO yield by 7% and prevented a renewed formation of esters. After a single stage distillation from the hydrolyzed broth and a followed active carbon treatment, 1,3‐PDO with a purity of 99.63% and an overall recovery yield of 76% was obtained. No wastewater with high‐salt content was produced during the whole downstream process. The results demonstrated that the monitoring and complete elimination of 1,3‐PDO esters are crucial for the efficient separation of highly pure 1,3‐PDO with acceptable yield from fermentation broth of raw glycerol.
Survival and Contaminants in Imperiled and Common Riverine Fishes Assessed with an In Situ Bioassay Approach
Authors: Grieshaber Casey A. , Cope W. Gregory , Kwak Thomas J. , Penland Tiffany N. , Heise Ryan J. , Mac Law J. 
Published: May 2021

Abstract
An in situ bioassay approach was used to determine whether aquatic contaminant stressors in a large Atlantic river ecosystem affect the survival of 3 fish species: the largemouth bass (Micropterus salmoides, juveniles), the fathead minnow (Pimephales promelas, adults), and the robust redhorse (Moxostoma robustum, juveniles). Hatchery-propagated fish were placed into cages to assess site-specific survival in the Yadkin-Pee Dee River of North Carolina and South Carolina, USA. Contaminants were measured in caged fish and sediment and surface water at each site. No apparent longitudinal trends in fish survival were detected, and contaminant concentrations varied among sites. Juvenile largemouth bass and robust redhorse did not survive past 13 and 23 d, with corresponding Kaplan-Meier median survival estimates of 9.7 and 12.1 d, respectively. Survival of adult fathead minnows deployed in cages alongside the juvenile fish averaged 43% at the end of the 28-d exposure, with a 22-d median survival estimate. The intersex condition, an indicator of endocrine disruption, was not observed in any adult fathead minnow. Contaminant accumulation in surviving fathead minnows was apparent, with highest accumulated concentrations of polychlorinated biphenyls (34.6–93.4 ng/g dry wt), organochlorine pesticides (19.9–66.1 ng/g dry wt), and mercury (0.17–0.63 μg/g dry wt). Contaminants and other water quality stressors in this river system appear to detrimentally impact juvenile fish survival, with presumed effects at the fish assemblage and community levels. Environ Toxicol Chem 2021;40:2206–2219. © 2021 SETAC
Abstract
An in situ bioassay approach was implemented to determine if aquatic contaminant stressors in a river ecosystem affect the survival of juvenile imperiled and common fishes. PCB = polychlorinated biphenyl.
Overexpression of PIF4 affects plant morphology and accelerates reproductive phase transitions in soybean
Authors: Arya Hina , Singh Mohan B. , Bhalla Prem L. 
Published: May 2021

AbstractPhytochrome‐interacting factor 4 acts as a signalling hub for integrating multiple environmental cues like light and temperature. While the function of PIF4 in the model plant Arabidopsis has been studied, there is limited knowledge regarding the role of PIF4 in agronomically important legume crop soybean. Here, we employed a constitutive overexpression approach to functionally characterise a soybean PIF4 homolog, GmPIF4b in a determinate short‐day cultivar, Bragg. Multiple sequence alignment of seven soybean PIF4 homologs (GmPIF4a‐g) with Arabidopsis PIF4 revealed the presence of an active phytochrome‐binding (APB) domain in the N‐terminal region of six soybean PIF4 homologs. Cis‐elements related to plant hormone biosynthesis, stress response, meristem and endosperm gene expression were located in the promoter region of soybean PIF4s. Interestingly, transgenic soybean plants carrying 35s::GmPIF4b::polyA construct showed reduced plant height, reduced leaf surface area, decreased branching, early flowering and faster transition from full‐bloom flowering stage to full maturity stage without any decline in yield. Further, pod colour of transgenic soybean plants changed to dark brown, whereas wild‐type plants showed tan or light brown pod colour. Clear hilum was observed in seeds obtained from transgenic plants as opposed to the dark or black hilum of wild‐type seeds. Transcripts of soybean florigens GmFT2a and GmFT5a were also elevated in transgenic plants. Collectively, our results suggest that GmPIF4b overexpression could affect phenotypes related to plant morphology and reproductive stages in soybean, and can be used as a gene target for soybean improvement programmes to ensure future food security.
Gene‐based mapping of trehalose biosynthetic pathway genes reveals association with source‐ and sink‐related yield traits in a spring wheat panel
Authors: Lyra Danilo H. , Griffiths Cara A. , Watson Amy , Joynson Ryan , Molero Gemma , Igna Alina‐Andrada , Hassani‐Pak Keywan , Reynolds Matthew P. , Hall Anthony , Paul Matthew J. 
Published: May 2021

AbstractTrehalose 6‐phosphate (T6P) signalling regulates carbon use and allocation and is a target to improve crop yields. However, the specific contributions of trehalose phosphate synthase (TPS) and trehalose phosphate phosphatase (TPP) genes to source‐ and sink‐related traits remain largely unknown. We used enrichment capture sequencing on TPS and TPP genes to estimate and partition the genetic variation of yield‐related traits in a spring wheat (Triticum aestivum) breeding panel specifically built to capture the diversity across the 75,000 CIMMYT wheat cultivar collection. Twelve phenotypes were correlated to variation in TPS and TPP genes including plant height and biomass (source), spikelets per spike, spike growth and grain filling traits (sink) which showed indications of both positive and negative gene selection. Individual genes explained proportions of heritability for biomass and grain‐related traits. Three TPS1 homologues were particularly significant for trait variation. Epistatic interactions were found within and between the TPS and TPP gene families for both plant height and grain‐related traits. Gene‐based prediction improved predictive ability for grain weight when gene effects were combined with the whole‐genome markers. Our study has generated a wealth of information on natural variation of TPS and TPP genes related to yield potential which confirms the role for T6P in resource allocation and in affecting traits such as grain number and size confirming other studies which now opens up the possibility of harnessing natural genetic variation more widely to better understand the contribution of native genes to yield traits for incorporation into breeding programmes.
Fractional cointegration in bitcoin spot and futures markets
Authors: Wu Jinghong , Xu Ke , Zheng Xinwei , Chen Jian 
Published: May 2021

AbstractThis paper adopts the fractional cointegrated vector autoregressive (FCVAR) model to examine high‐frequency price discovery of bitcoin spot and futures prices from December 18, 2017 to July 31, 2020. We find that bitcoin spot and futures prices exhibit long memory properties and they are fractionally cointegrated. The result shows that the bitcoin futures market dominates the price discovery process. Interestingly, during the Covid‐19 pandemic, the bitcoin price discovery leadership has switched to the spot market. Moreover, we find that the bitcoin futures market follows a long‐run contango. The nonfractional CVAR model overestimates the price discovery of the futures market.
Disentangling age‐ and disease‐related alterations in schizophrenia brain network using structural equation modeling: A graph theoretical study based on minimum spanning tree
Authors: Liu Xinyu , Yang Hang , Becker Benjamin , Huang Xiaoqi , Luo Cheng , Meng Chun , Biswal Bharat 
Published: May 2021

AbstractFunctional brain networks have been shown to undergo fundamental changes associated with aging or schizophrenia. However, the mechanism of how these factors exert influences jointly or interactively on brain networks remains elusive. A unified recognition of connectomic alteration patterns was also hampered by heterogeneities in network construction and thresholding methods. Recently, an unbiased network representation method regardless of network thresholding, so called minimal spanning tree algorithm, has been applied to study the critical skeleton of the brain network. In this study, we aimed to use minimum spanning tree (MST) as an unbiased network reconstruction and employed structural equation modeling (SEM) to unravel intertwined relationships among multiple phenotypic and connectomic variables in schizophrenia. First, we examined global and local brain network properties in 40 healthy subjects and 40 schizophrenic patients aged 21–55 using resting‐state functional magnetic resonance imaging (rs‐fMRI). Global network alterations are measured by graph theoretical metrics of MSTs and a connectivity‐transitivity two‐dimensional approach was proposed to characterize nodal roles. We found that networks of schizophrenic patients exhibited a more star‐like global structure compared to controls, indicating excessive integration, and a loss of regional transitivity in the dorsal frontal cortex (correctedp<.05). Regional analysis of MST network topology revealed that schizophrenia patients had more network hubs in frontal regions, which may be linked to the “overloading” hypothesis. Furthermore, using SEM, we found that the level of MST integration mediated the influence of age on negative symptom severity (indirect effect 95% CI [0.026, 0.449]). These findings highlighted an altered network skeleton in schizophrenia and suggested that aging‐related enhancement of network integration may undermine functional specialization of distinct neural systems and result in aggravated schizophrenic symptoms.
Functional connectivity of the human hypothalamus during wakefulness and nonrapid eye movement sleep
Authors: Jiang Jun , Zou Guangyuan , Liu Jiayi , Zhou Shuqin , Xu Jing , Sun Hongqiang , Zou Qihong , Gao Jia‐Hong 
Published: May 2021

AbstractAnimal experiments indicate that the hypothalamus plays an essential role in regulating the sleep–wake cycle. A recent neuroimaging study conducted under resting wakefulness conditions suggested the presence of a wake‐promoting region and a sleep‐promoting region in the human posterior hypothalamus and anterior hypothalamus, respectively, and interpreted their anticorrelated organization in resting‐state functional networks as evidence for their opposing roles in sleep–wake regulation. However, whether and how the functional networks of the two hypothalamic regions reorganize according to their wake‐ or sleep‐promoting roles during sleep are unclear. Here, we constructed functional networks of the posterior and anterior hypothalamus during wakefulness and nonrapid eye movement (NREM) sleep using simultaneous electroencephalography and functional magnetic resonance imaging data collected from 62 healthy participants. The functional networks of the posterior and anterior hypothalamus exhibited inversely correlated organizations during both wakefulness and NREM sleep. The connectivity strength of the posterior hypothalamic functional network was stronger during wakefulness than during stable sleep. From wakefulness to sleep, the anterior cingulate gyrus, paracingulate gyrus, insular cortex, and fontal operculum cortex showed decreased positive connectivity, while the precentral gyrus and postcentral gyrus showed decreased negative connectivity with the posterior hypothalamus. Additionally, the insular cortex and frontal operculum cortex showed negative connectivity during wakefulness and positive connectivity during sleep with the anterior hypothalamus, exhibiting an increasing trend. These findings provide insights into the correspondence between the functional network organizations and hypothalamic sleep–wake regulation in humans.
Predicting survival in head and neck cancer: External validation and update of the prognostic model OncologIQ in 2189 patients
Authors: Hoesseini Arta , van Leeuwen Nikki , Offerman Marinella P. J. , Zhang Jang , Dronkers Emilie A. C. , Sewnaik Aniel , Lingsma Hester F. , Baatenburg de Jong Robert Jan 
Published: May 2021

AbstractBackgroundDisclosing prognostic information is necessary to enable patients to make well‐informed treatment decisions. OncologIQ is a prognostic model that predicts the overall survival (OS) probability in patients with head and neck squamous cell carcinoma (HNSCC). We aimed to externally validate and update the model with new prognostic factors and translate it to a clinically useful tool.MethodsA consecutive retrospective sample of 2189 patients eligible for curative treatment of a primary HNSCC were selected. Discriminative performance was determined using the C‐statistic.ResultsExternal validation showed systematic underestimation of OS in the new population, and reasonable discrimination (C‐statistic 0.67). Adding smoking, pack years, BMI, weight loss, WHO performance, socioeconomic status, and p16 positivity to the recalibrated multivariable model, improved the internally validated C‐statistic to 0.71. The model showed minor optimism and was translated in an online tool (www.oncologiq.nl).ConclusionsThe updated model enables personalized patient counseling during treatment decision consultations.
NRSF deficiency leads to abnormal postnatal development of dentate gyrus and impairment of progenitors in subgranular zone of hippocampus
Authors: Wang Yan‐Cong , Liu Pu , Yue Ling‐Yun , Huang Fang , Xu Yu‐Xia , Zhu Cui‐Qing 
Published: May 2021

AbstractNeuron‐restrictive silencing factor (NRSF) is a zinc‐finger transcription factor that regulates expression of a diverse set of genes. However, NRSF function in brain development still remains elusive. In the present study, we generated NRSF‐conditional knockout (NRSF‐cKO) mice by hGFAP‐Cre/loxp system to study the effect of NRSF deficiency on brain development. Results showed that NRSF conditional knockout caused a smaller hippocampus and a thinner granule cell layer (GCL) in mice. Moreover, the reduction and disarrangement of GFAP+ cells in subgranular zone (SGZ) of NRSF‐cKO mice was accompanied with the decreased number of premature neurons, neural stem cells (NSCs) and neural progenitor cells (NPCs), as well as compromising the majority of mitotically active cells. The analysis of postnatal development of hippocampus indicated the existence of an abnormality at postnatal day (P) 8, rather than at P1, in NRSF‐cKO mice, although the densities of Ki67+ cells with mitotic ability in dentate gyrus were relatively unaffected at P1 and P8. Meanwhile, NRSF deficiency led to abnormal organization of SGZ at P8 during postnatal development. RNA‐Seq analysis revealed 79 deregulated genes in hippocampus of NRSF‐cKO mice at P8, which were involved in p53 signal transduction, neuron migration and negative regulation of cell proliferation, etc. The deregulation of p53 pathway in NRSF‐cKO mice at P1 and P8 was evidenced, of which p21/Cdkn1a was accumulated in a portion of NSCs and NPCs in hippocampus during postnatal development. Together, these results, for the first time, revealed that NRSF could significantly influence the postnatal development of hippocampus, especially the formation of SGZ.