bluuebunny/crossref_metadata_2025_split huggingface dataset:
Urbanization is associated with modifications in DNA methylation in a small passerine bird
Authors: Watson Hannah , Powell Daniel , Salmón Pablo , Jacobs Arne , Isaksson Caroline 
Published: October 2020

AbstractUrbanization represents a fierce driver of phenotypic change, yet the molecular mechanisms underlying observed phenotypic patterns are poorly understood. Epigenetic changes are expected to facilitate more rapid adaption to changing or novel environments, such as our towns and cities, compared with slow changes in gene sequence. A comparison of liver and blood tissue from great tits Parus major originating from an urban and a forest site demonstrated that urbanization is associated with variation in genome‐wide patterns of DNA methylation. Combining reduced representation bisulphite sequencing with transcriptome data, we revealed habitat differences in DNA methylation patterns that suggest a regulated and coordinated response to the urban environment. In the liver, genomic sites that were differentially methylated between urban‐ and forest‐dwelling birds were over‐represented in regulatory regions of the genome and more likely to occur in expressed genes. DNA methylation levels were also inversely correlated with gene expression at transcription start sites. Furthermore, differentially methylated CpG sites, in liver, were over‐represented in pathways involved in (i) steroid biosynthesis, (ii) superoxide metabolism, (iii) secondary alcohol metabolism, (iv) chylomicron remodelling, (v) cholesterol transport, (vi) reactive oxygen species (ROS) metabolic process and (vii) epithelial cell proliferation. This corresponds with earlier studies identifying diet and exposure to ROS as two of the main drivers of divergence between organisms in urban and nonurban environments. Conversely, in blood, sites that were differentially methylated between urban‐ and forest‐dwelling birds were under‐represented in regulatory regions, more likely to occur in nonexpressed genes and not over‐represented in specific biological pathways. It remains to be determined whether diverging patterns of DNA methylation represent adaptive evolutionary responses and whether the conclusions can be more widely attributed to urbanization.
Up in the air: Threats to Afromontane biodiversity from climate change and habitat loss revealed by genetic monitoring of the Ethiopian Highlands bat
Authors: Razgour Orly , Kasso Mohammed , Santos Helena , Juste Javier 
Published: October 2020

AbstractWhile climate change is recognized as a major future threat to biodiversity, most species are currently threatened by extensive human‐induced habitat loss, fragmentation and degradation. Tropical high‐altitude alpine and montane forest ecosystems and their biodiversity are particularly sensitive to temperature increases under climate change, but they are also subject to accelerated pressures from land conversion and degradation due to a growing human population. We studied the combined effects of anthropogenic land‐use change, past and future climate changes and mountain range isolation on the endemic Ethiopian Highlands long‐eared bat, Plecotus balensis, an understudied bat that is restricted to the remnant natural high‐altitude Afroalpine and Afromontane habitats. We integrated ecological niche modelling, landscape genetics and model‐based inference to assess the genetic, geographic and demographic impacts of past and recent environmental changes. We show that mountain range isolation and historic climates shaped population structure and patterns of genetic variation, but recent anthropogenic land‐use change and habitat degradation are associated with a severe population decline and loss of genetic diversity. Models predict that the suitable niche of this bat has been progressively shrinking since the last glaciation period. This study highlights threats to Afroalpine and Afromontane biodiversity, squeezed to higher altitudes under climate change while losing genetic diversity and suffering population declines due to anthropogenic land‐use change. We conclude that the conservation of tropical montane biodiversity requires a holistic approach, using genetic, ecological and geographic information to understand the effects of environmental changes across temporal scales and simultaneously addressing the impacts of multiple threats.
A review of oestrus suppression techniques in mares
Authors: Crabtree J. R. 
Published: October 2020

SummaryMany fillies and mares are accused of behaving badly by their owners or trainers, and their reproductive hormones and ovaries are commonly blamed for this. Overt oestrus behaviour, however natural, is undesirable when a horse is being ridden, trained and competed. More subtle behaviours may be attributed to the reproductive cycle and presented as the cause of poor performance in the elite competition mare. Sometimes behaviours are complex, perhaps at odds with what one expects for normal reproductive behaviour and in many cases may not be associated with the reproductive cycle at all, rather associated with pain of musculoskeletal or soft tissue origin. The situation represents a diagnostic dilemma to positively associate undesirable behaviours with the ovarian hormones or ovarian pain, before an attempt can be made to modify the behaviour through the suppression of oestrus. This article will review the reasons for presentation, the behavioural patterns of the reproductive cycle and the diagnosis of reproductive behavioural problems. The range of techniques for oestrus suppression will be reviewed along with their clinical application and any known current regulatory issues associated with their use.
Fatigue analysis and fracture toughness of graphene reinforced carbon fibre polymer composites
Authors: Tareq Md Sarower , Jony Bodiuzzaman , Zainuddin Shaik , Al Ahsan Mohammad , Hosur Mahesh V. 
Published: October 2020

AbstractThree‐point flexural fatigue behaviour and mode I interlaminar fracture toughness of the carbon fibre reinforced polymer composites (CFRPCs) modified by the addition of graphene nanoplatelet (GnP) were investigated. CFRPCs without any addition of nanoparticles were also tested as control samples. Fatigue life was characterized by the two parameter Weibull distribution function and predicted using the combined Weibull and Sigmoidal model. It was found that incorporation of very small amount (0.1%) of GnP in the epoxy polymer matrix improved mean and predicted fatigue life up to 155% and 190% (0.5 failure probability), respectively. The critical mode I interlaminar fracture toughness of the GnP reinforced composites was found up to 40% higher than the control samples. The improvement achieved by incorporating GnP is discussed in terms of crack deflection mechanism by nanoparticles and scanning electron micrograph images of the fracture specimens that revealed strong interfacial bonding in the nanoreinforced specimens.
A nonrandom walk down Hollywood boulevard: Celebrity deaths and investor sentiment
Authors: Lepori Gabriele M. 
Published: October 2020

AbstractMotivated by psychological evidence that shows the public experiences emotional distress in response to the deaths of popular figures, I employ the deaths of 1,391 Hollywood Walk of Fame celebrities as natural experiments to identify exogenous public mood changes over the period 1926–2009. Consistent with the psychological theories which maintain that sadness encourages individuals to favor high‐risk/high‐reward investments, I find that U.S. stock returns are abnormally high immediately after the death of a major celebrity. This effect is particularly large during periods of high market‐level uncertainty (+0.40%) and for stocks headquartered in the city where the celebrity died (+0.26%).
Much stronger tundra methane emissions during autumn freeze than spring thaw
Authors: Bao Tao , Xu Xiyan , Jia Gensuo , Billesbach David P. , Sullivan Ryan C. 
Published: October 2020

AbstractWarming in the Arctic has been more apparent in the non‐growing season than in the typical growing season. In this context, methane (CH4) emissions in the non‐growing season, particularly in the shoulder seasons, account for a substantial proportion of the annual budget. However, CH4 emissions in spring and autumn shoulders are often underestimated by land models and measurements due to limited data availability and unknown mechanisms. This study investigates CH4 emissions during spring thaw and autumn freeze using eddy covariance CH4 measurements from three Arctic sites with multi‐year observations. We find that the shoulder seasons contribute to about a quarter (25.6 ± 2.3%, mean ± SD) of annual total CH4 emissions. Our study highlights the three to four times higher contribution of autumn freeze CH4 emission to total annual emission than that of spring thaw. Autumn freeze exhibits significantly higher CH4 flux (0.88 ± 0.03 mg m−2 hr−1) than spring thaw (0.48 ± 0.04 mg m−2 hr−1). The mean duration of autumn freeze (58.94 ± 26.39 days) is significantly longer than that of spring thaw (20.94 ± 7.79 days), which predominates the much higher cumulative CH4 emission during autumn freeze (1,212.31 ± 280.39 mg m−2 year−1) than that during spring thaw (307.39 ± 46.11 mg m−2 year−1). Near‐surface soil temperatures cannot completely reflect the freeze–thaw processes in deeper soil layers and appears to have a hysteresis effect on CH4 emissions from early spring thaw to late autumn freeze. Therefore, it is necessary to consider commonalities and differences in CH4 emissions during spring thaw versus autumn freeze to accurately estimate CH4 source from tundra ecosystems for evaluating carbon‐climate feedback in Arctic.
Method to Estimate Thermal Conductivity of Subsurface Media
Authors: Karimi Askarani Kayvan , Gallo Sam , Kirkman Andrew J. , Sale Tom C. 
Published: October 2020

AbstractThermal conductivity is an essential parameter in heat transfer models including soil‐water systems. Herein, an Internet of Things (IoT) tool and a computational method are advanced for vertically resolving in situ thermal conductivity values in soil‐groundwater systems. A demonstrative application of this approach at a former petroleum refinery is presented. A line heat source is co‐located with a vertical string of in situ temperature sensors. Five‐minute multiple level temperature data were collected before, during, and after a 100‐min long heating period. Vertically distributed temperature data are transformed into vertically discretized thermal conductivity values using an analytical solution. Results fall in the range of thermal conductivity values reported in the literature. Specifically, estimated thermal conductivity values from 0.3 to 7.3 m below ground surface range between 0.7 and 5.4 (W/m/C) with the highest values occurring in media with greater water content. Overall, the advanced method in this study provides a pragmatic approach for vertically resolving subsurface thermal conductivity values applicable for many scientific disciplines.
Processing of MAX phases: From synthesis to applications
Authors: Gonzalez‐Julian Jesus 
Published: October 2020

AbstractMAX phases are a large family of materials with more than 150 different compositions that have been extensively investigated during the last 25 years. They present a layered structure and a unique combination of properties, bridging the gap between metallic and ceramic properties. However, despite their excellent response of some compositions at high temperature—excellent oxidation resistance up to 1400°C under corrosive environment, good damage and radiation tolerance, thermal shock resistance, and self‐crack healing—their transfer to applications has been limited by three main factors: i) complexity of this large family of materials, ii) unavailability of highly pure commercial powders, and iii) extensive time to license products in strategic fields such as nuclear or aviation. In this article, the main properties and synthesis routes are reviewed, including solid state reaction methods, physical vapor deposition (PVD) techniques and molten salt processes. Emphasis is given to processing routes for developing different structures such as dense bulk samples, ceramic matrix composites, foams with different porosity, coatings by PVD and thermal spray technologies, and near net shaping by slip casting, injection molding, and additive manufacturing. Well‐known and novel potential applications are described such as structural materials for high temperature applications, protective coatings and bond‐coats for gas turbines, accident tolerant fuel cladding in nuclear power plants, solar receiver in concentrated solar power systems, electrical contacts, catalyst, and joining material. Finally, high impact investigations and future challenges are listed in order to facilitate the transfer of MAX phases to the market.
Androgen receptor suppresses vasculogenic mimicry in hepatocellular carcinoma via circRNA7/miRNA7‐5p/VE‐cadherin/Notch4 signalling
Authors: Bao Shixiang , Jin Shuai , Wang Chunhua , Tu Peipei , Hu Kongwang , Lu Jingtao 
Published: October 2020

AbstractAndrogen receptor (AR) can suppress hepatocellular carcinoma (HCC) invasion and metastasis at an advanced stage. Vasculogenic mimicry (VM), a new vascularization pattern by which tumour tissues nourish themselves, is correlated with tumour progression and metastasis. Here, we investigated the effect of AR on the formation of VM and its mechanism in HCC. The results suggested that AR could down‐regulate circular RNA (circRNA) 7, up‐regulate micro RNA (miRNA) 7‐5p, and suppress the formation of VM in HCC Small hairpin circR7 (ShcircR7) could reverse the impact on VM and expression of VE‐cadherin and Notch4 increased by small interfering AR (shAR) in HCC, while inhibition of miR‐7‐5p blocked the formation of VM and expression of VE‐cadherin and Notch4 decreased by AR overexpression (oeAR) in HCC. Mechanism dissection demonstrated that AR could directly target the circR7 host gene promoter to suppress circR7, and miR‐7‐5p might directly target the VE‐cadherin and Notch4 3′UTR to suppress their expression in HCC. In addition, knockdown of Notch4 and/or VE‐cadherin revealed that shVE‐cadherin or shNotch4 alone could partially reverse the formation of HCC VM, while shVE‐cadherin and shNotch4 together could completely suppress the formation of HCC VM. Those results indicate that AR could suppress the formation of HCC VM by down‐regulating circRNA7/miRNA7‐5p/VE‐Cadherin/Notch4 signals in HCC, which will help in the design of novel therapies against HCC.
Alterations in the phosphodiesterase type 5 pathway and oxidative stress correlate with erectile function in spontaneously hypertensive rats
Authors: He Weixiang , Liu Jianmin , Liu Daoquan , Hu Jundong , Jiang Ye , Li Mingzhou , Wang Qian , Chen Ping , Zeng Guang , Xu Deqiang , Wang Xinghuan , DiSanto Michael E. , Zhang Xinhua 
Published: October 2020

AbstractTo explore how alterations in the phosphodiesterase type 5 (PDE5) signalling pathway and oxidative stress correlate with changes in the expression of relaxation and contraction molecules and erectile dysfunction (ED) in the corpus cavernosum smooth muscle (CCSM) of spontaneously hypertensive rats (SHR). In this study, SHR and Wistar‐Kyoto (WKY) rats were used. Erectile function was determined by apomorphine test and electrical stimulation (ES) of cavernous nerve. Masson's trichrome staining and confocal microscopy were performed. Nitric oxide synthase (NOS), PDE5, phosphorylated‐PDE5 and α1‐adrenergic receptor (α1AR) were determined by RT‐PCR and Western blotting while oxidative stress in CC was determined by colorimetric analysis. SHR exhibited obvious ED. CC of SHR showed less SM but more collagen fibres. The expression of NOS isoforms in SHR was significantly decreased while all α1AR isoforms were increased. In addition, PDE5 and phosphorylated‐PDE5 were down‐regulated and its activity attenuated in the hypertensive rats. Meanwhile, the SHR group suffered oxidative stress, which may be modulated by endoplasmic reticulum stress and NADPH oxidase up‐regulation. Dysregulation of NOS and α1AR, histological changes and oxidative stress in CC may be associated with the pathophysiology of hypertension‐induced ED. In addition, PDE5 down‐regulation may lead to the decreased efficacy of PDE5 inhibitors in some hypertensive ED patients and treatment of oxidative stress could be used as a new therapeutic target for this type of ED.
Convergence in sympatry: Evolution of blue‐banded wing pattern in Morpho butterflies
Authors: Llaurens Violaine , Le Poul Yann , Puissant Agathe , Blandin Patrick , Debat Vincent 
Published: October 2020

AbstractSpecies interactions such as mimicry can promote trait convergence but disentangling this effect from those of shared ecology, evolutionary history, and niche conservatism is often challenging. Here by focusing on wing colour pattern variation within and between three butterfly species living in sympatry in a large proportion of their range, we tested the effect of species interactions on trait diversification. These butterflies display a conspicuous iridescent blue coloration on the dorsal side of their wings and a cryptic brownish colour on the ventral side. Combined with an erratic and fast flight, these colour patterns increase the difficulty of capture by predators and contribute to the high escape abilities of these butterflies. We hypothesize that, beyond their direct contribution to predator escape, these wing patterns can be used as signals of escape abilities by predators, resulting in positive frequency‐dependent selection favouring convergence in wing pattern in sympatry. To test this hypothesis, we quantified dorsal wing pattern variations of 723 butterflies from the three species sampled throughout their distribution, including sympatric and allopatric situations and compared the phenotypic distances between species, sex and localities. We detected a significant effect of localities on colour pattern, and higher inter‐specific resemblance in sympatry as compared to allopatry, consistent with the hypothesis of local convergence of wing patterns. Our results provide support to the existence of escape mimicry in the wild and stress the importance of estimating trait variation within species to understand trait variation between species, and to a larger extent, trait diversification at the macro‐evolutionary scale.
Lysophosphatidic acid induces thrombospondin‐1 production in primary cultured rat cortical astrocytes
Authors: Hisaoka‐Nakashima Kazue , Yokoe Toshiki , Watanabe Shintaro , Nakamura Yoki , Kajitani Naoto , Okada‐Tsuchioka Mami , Takebayashi Minoru , Nakata Yoshihiro , Morioka Norimitsu 
Published: October 2020

AbstractLysophosphatidic acid (LPA), a brain membrane‐derived lipid mediator, plays important roles including neural development, function, and behavior. In the present study, the effects of LPA on astrocyte‐derived synaptogenesis factor thrombospondins (TSPs) production were examined by real‐time PCR and western blotting, and the mechanism underlying this event was examined by pharmacological approaches in primary cultured rat cortical astrocytes. Treatment of astrocytes with LPA increased TSP‐1 mRNA, and TSP‐2 mRNA, but not TSP‐4 mRNA expression. TSP‐1 protein expression and release were also increased by LPA. LPA‐induced TSP‐1 production were inhibited by AM966 a LPA1 receptor antagonist, and Ki16425, LPA1/3 receptors antagonist, but not by H2L5146303, LPA2 receptor antagonist. Pertussis toxin, Gi/o inhibitor, but not YM‐254890, Gq inhibitor, and NF499, Gs inhibitor, inhibited LPA‐induced TSP‐1 production, indicating that LPA increases TSP‐1 production through Gi/o‐coupled LPA1 and LPA3 receptors. LPA treatment increased phosphorylation of extracellular signal‐regulated kinase (ERK), p38 mitogen‐activated protein kinase (MAPK), and c‐Jun N‐terminal kinase (JNK). LPA‐induced TSP‐1 mRNA expression was inhibited by U0126, MAPK/ERK kinase (MEK) inhibitor, but not SB202190, p38 MAPK inhibitor, or SP600125, JNK inhibitor. However, LPA‐induced TSP‐1 protein expression was diminished with inhibition of all three MAPKs, indicating that these signaling molecules are involved in TSP‐1 protein production. Treatment with antidepressants, which bind to astrocytic LPA1 receptors, increased TSP‐1 mRNA and protein production. The current findings show that LPA/LPA1/3 receptors signaling increases TSP‐1 production in astrocytes, which could be important in the pathogenesis of affective disorders and could potentially be a target for the treatment of affective disorders.
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24S‐hydroxycholesterol: Cellular effects and variations in brain diseases
Authors: Sodero Alejandro O. 
Published: October 2020

AbstractThe adult brain exhibits a characteristic cholesterol homeostasis, with low synthesis rate and active catabolism. Brain cholesterol turnover is possible thanks to the action of the enzyme cytochrome P450 46A1 (CYP46A1) or 24‐cholesterol hydroxylase, that transforms cholesterol into 24S‐hydroxycholesterol (24S‐HC). But before crossing the blood–brain barrier (BBB), this oxysterol, that is the most abundant in the brain, can act locally, affecting the functioning of neurons, astrocytes, oligodendrocytes, and vascular cells. The first part of this review addresses different aspects of 24S‐HC production and elimination from the brain. The second part concentrates in the effects of 24S‐HC at the cellular level, describing how this oxysterol affects cell viability, amyloid β production, neurotransmission, and transcriptional activity. Finally, the role of 24S‐HC in Alzheimer, Huntington and Parkinson diseases, multiple sclerosis and amyotrophic lateral sclerosis, as well as the possibility of using this oxysterol as predictive and/or evolution biomarker in different brain disorders is discussed.
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Infarct Growth despite Endovascular Thrombectomy Recanalization in Large Vessel Occlusive Stroke
Authors: Regenhardt Robert W. , Etherton Mark R. , Das Alvin S. , Schirmer Markus D. , Hirsch Joshua A. , Stapleton Christopher J. , Patel Aman B. , Leslie‐Mazwi Thabele M. , Rost Natalia S. 
Published: October 2020

ABSTRACTBACKGROUND AND PURPOSEEndovascular thrombectomy (EVT) has revolutionized large vessel occlusion stroke care. However, not all patients with good endovascular results achieve good outcomes. We sought to understand the clinical significance of magnetic resonance imaging defined infarct growth despite adequate reperfusion and identify associated clinical and radiographic variables.METHODSHistory, presentation, treatments, and outcomes for consecutive EVT patients at a referral center were collected. Adequate reperfusion was defined as thrombolysis in cerebral infarction (TICI) score 2b‐3. Region‐specific infarct volumes in white matter, cortex, and basal ganglia were determined on diffusion‐weighted imaging. Infarct growth was defined as post‐EVT minus pre‐EVT volume. Good outcome was defined as 90‐day modified Rankin Scale ≤2.RESULTSForty‐four patients with adequate reperfusion were identified with median age 72 years; 64% were women. Each region showed infarct growth: white matter (median pre‐EVT 7 cubic centimeters [cc], post‐EVT 16 cc), cortex (4 cc, 15 cc), basal ganglia (2 cc, 4 cc), total (20 cc, 39 cc). In multivariable regression, total infarct growth independently decreased the odds of good outcome (odds ratio = .946, 95% CI = .897, .998). Further multivariable analyses for determinants of infarct growth identified female sex was associated with less total growth (β = −.294, P = .042), TICI 3 was associated with less white matter growth (β = −.277, P = .048) and cortical growth (β = −.335, P = .017), and both female sex (β = −.332, P = .015) and coronary disease (β = −.337, P = .015) were associated with less cortical growth.CONCLUSIONSInfarct growth occurred despite adequate reperfusion, disproportionately in the cortex, and independently decreased the odds of good outcome. Infarct growth occurred while patients were hospitalized and may represent a therapeutic target. Potential determinants of region‐specific infarct growth were identified that require confirmation in larger studies.