bluuebunny/crossref_metadata_2025_split huggingface dataset:
Long‐term environmental enrichment reduces microglia morphological diversity of the molecular layer of dentate gyrus
Authors: de Oliveira Thaís Cristina Galdino , Carvalho‐Paulo Dario , de Lima Camila Mendes , de Oliveira Roseane Borner , Santos Filho Carlos , Diniz Daniel Guerreiro , Bento Torres Neto João , Picanço‐Diniz Cristovam Wanderley 
Published: July 2020

AbstractWe investigated long‐term environmental influences on morphology of microglia from the outer and middle thirds of molecular layer of the dentate gyrus (MolDG), and on microglia from dorsal and ventral dentate gyrus molecular layer. We also estimated the total number of MolDG microglia using stereology. For this purpose, microglia of the molecular layer of the dentate gyrus of 20‐month‐old female Swiss albino mice, housed from 21st postnatal day onwards, in the impoverished environment of the standard laboratory cages (SEA), or in a cage with an enriched environment (EEA), were reconstructed microscopically in three dimensions and compared with each other and with microglia of 6‐month‐old female Swiss albino mice, also housed from weaning onwards in an enriched cage (EEY). All mice had their brains sectioned and processed for immunolabeling for IBA‐1, a selective microglia marker. Random and systematic microglia samples were reconstructed in three dimensions and classified morphologically using hierarchical cluster analysis, followed by discriminant function analysis. SEA and EEY showed two morphological phenotypes of microglia in both the outer and middle thirds of MolDG. EEA mice showed such a reduction in the morphological diversity of microglia that essentially a single morphotype was found. EEA mouse microglia showed an intermediate morphological complexity between types I and II SE microglia. We suggest that type I and type II microglia in SE mice may have different physiological roles and that long‐term EE may be associated with adaptive responses of microglial phenotypes to somatomotor and cognitive stimuli.
The neural mechanisms of audiotactile binding depend on asynchrony
Authors: Zumer Johanna M. , White Thomas P. , Noppeney Uta 
Published: July 2020

AbstractAsynchrony is a critical cue informing the brain whether sensory signals are caused by a common source and should be integrated or segregated. This psychophysics–electroencephalography (EEG) study investigated the influence of asynchrony on how the brain binds audiotactile (AT) signals to enable faster responses in a redundant target paradigm. Human participants actively responded (psychophysics) or passively attended (EEG) to noise bursts, “taps‐to‐the‐face” and their AT combinations at seven AT asynchronies: 0, ±20, ±70 and ±500 ms. Behaviourally, observers were faster at detecting AT than unisensory stimuli within a temporal integration window: the redundant target effect was maximal for synchronous stimuli and declined within a ≤70 ms AT asynchrony. EEG revealed a cascade of AT interactions that relied on different neural mechanisms depending on AT asynchrony. At small (≤20 ms) asynchronies, AT interactions arose for evoked response potentials (ERPs) at 110 ms and ~400 ms post‐stimulus. Selectively at ±70 ms asynchronies, AT interactions were observed for the P200 ERP, theta‐band inter‐trial coherence (ITC) and power at ~200 ms post‐stimulus. In conclusion, AT binding was mediated by distinct neural mechanisms depending on the asynchrony of the AT signals. Early AT interactions in ERPs and theta‐band ITC and power were critical for the behavioural response facilitation within a ≤±70 ms temporal integration window.
Insider trading in rumored takeover targets
Authors: Davis Frederick , Khadivar Hamed , Pukthuanthong Kuntara , Walker Thomas J. 
Published: July 2020

AbstractWe examine insider trading surrounding takeover rumors in a sample of 1,642 publicly traded US firms. Using difference‐in‐differences regressions, we find that insider net purchases increase within the year prior to the first publication of a takeover rumor, particularly when rumor articles are either accurate (lead to a takeover announcement) or informative (provide substantial justification for the rumor's publication). Moreover, we find abnormal insider trading to be a significant predictor of takeover announcements occurring within the following year. Finally, passive net purchasing (i.e., selling less rather than buying more) is more pronounced among managing insiders than among non‐managing insiders.
Changing spring snow cover dynamics and early season forage availability affect the behavior of a large carnivore
Authors: Rickbeil Gregory J. M. , Coops Nicholas C. , Berman Ethan E. , McClelland Cameron J. R. , Bolton Douglas K. , Stenhouse Gordon B. 
Published: July 2020

AbstractChanging climates are altering wildlife habitats and wildlife behavior in complex ways. Here, we examine how changing spring snow cover dynamics and early season forage availability are altering grizzly bear (Ursus arctos) behavior postden emergence. Telemetry data were used to identify spring activity dates for 48 individuals in the Yellowhead region of Alberta, Canada. Spring activity date was related to snow cover dynamics using a daily percent snow cover dataset. Snow melt end date, melt rate, and melt consistency explained 45% of the variation in spring activity date. We applied this activity date model across the entire Yellowhead region from 2000 to 2016 using simulated grizzly bear home ranges. Predicted spring activity date was then compared with a daily spring forage availability date dataset, resulting in “wait time” estimates for four key early season forage species. Temporal changes in both spring activity date and early season forage “wait times” were assessed using non‐parametric regression. Grizzly bear activity date was found to have either remained constant (95%) or become earlier (5%) across the study area; virtually no areas with significantly later spring activity dates were detected. Similarly, the majority of “wait times” did not change (85%); however, the majority of significant changes in “wait times” for the four early season forage species indicated that “wait times” were lessening where changes were detected. Our results show that spring activity date is largely dictated by snow melt characteristics and that changing snow melt conditions may result in earlier spring activity. However, early season food stress conditions are likely to remain unchanged or improve as vegetation phenology also becomes earlier. Our findings extend the recent work examining animal movement in response to changing phenology from migratory birds and ungulates to an apex predator, further demonstrating the potential effects of changing climates on wildlife species.
The vertical distribution and control of microbial necromass carbon in forest soils
Authors: Ni Xiangyin , Liao Shu , Tan Siyi , Peng Yan , Wang Dingyi , Yue Kai , Wu Fuzhong , Yang Yusheng 
Published: July 2020

AbstractAimForest soils contain large amounts of terrestrial organic carbon (C), but the formation pathway of soil organic C (SOC) remains unclear. Recent evidence suggests that microbial necromass is a significant source of SOC, yet a global quantitative assessment across the whole soil profile is lacking. We aimed to assess the vertical distribution and control of microbial‐derived SOC in forest soils.LocationGlobal forests.Time period1996–2019.Major taxa studiedSoil microbial necromass carbon.MethodsWe evaluated the proportions of fungal and bacterial necromass C in total SOC in the litter layer, O horizon soil, and various depths of mineral soil in forests using microbial biomarker (glucosamine and muramic acid) data.ResultsThe total microbial necromass C increased significantly with soil depth, ranging from 30% of SOC in O horizon soil to 62% of SOC in mineral soils below 50 cm. However, only bacterial necromass C followed this increasing trend with soil depth; fungal necromass C showed little variation across the whole soil profile. Higher fungal and bacterial necromass C was observed in soils with lower C/N ratios and smaller aggregate sizes. Soil C/N ratio and microbial biomass C dominantly determined microbial necromass C in surface soil (above 20 cm), but soil clay content was the primary factor in subsoil (below 20 cm).Main conclusionsMicrobial necromass C accounted for high percentages of the total SOC in forest soils (particularly at depths >20 cm), but its long‐term stabilization may be governed by different mechanisms at different soil horizons. Substrate quality regulates microbial activity and then controls biomass turnover in surface soil, while aggregate occlusion facilitates mineral protection of microbial necromass C in subsoil. These differential controls of microbial‐derived organic C could be applied in Earth system studies for predicting soil organic C dynamics in forests.
Bile duct adenoma may be a precursor lesion of small duct type intrahepatic cholangiocarcinoma
Authors: Sasaki Motoko , Sato Yasunori , Nakanuma Yasuni 
Published: July 2020

Background/aimsPrecursor lesions of small duct type intrahepatic cholangiocarcinoma (small duct iCCA) have not been clarified so far. We hypothesised that precursor lesions may be frequently distributed in the background liver of small duct iCCA.Methods and resultsWe determined by histology the presence of bile duct adenomas and von Meyenburg complexes as candidate precursor lesions in the background liver of small duct iCCA, with other primary liver carcinomas as control. Subjects included 28 patients with small duct iCCA, 29 with large duct iCCAs, 60 with combined hepatocellular–cholangiocarcinoma (Comb) and 40 with hepatocellular carcinoma (HCC). The prevalence of bile duct adenomas in the background liver was significantly higher in small duct iCCA (35.7%) compared to other primary liver carcinomas (Comb, 4.9%; 10%, HCC) (P < 0.01). The prevalence of bile duct adenomas was significantly associated with the presence of von Meyenburg complexes and ductal plate malformation‐like patterns in small duct iCCAs and Combs. Von Meyenburg complexes were detected in 11 small duct iCCA (39.3%), five large duct iCCAs (17.2%), 10 Comb (16.4%) and 13 HCC (33.3%), respectively (P > 0.05). Small duct iCCAs showed altered expression of ARID1A (46.4%), p53 (39.3%), PBRM1 (14.3%), IMP3 (85.7%) and EZH2 (82.1%), whereas these markers were negative in bile duct adenomas.ConclusionBile duct adenomas may be precursor lesions of small duct iCCAs. Alteration of ARID1A, p53 or PBRM1 may be involved in the carcinogenesis of small duct iCCAs.
Climate change in Alaska: Social workers’ attitudes, beliefs, and experiences
Authors: Allen Mary Dallas 
Published: July 2020

The average temperature in Alaska and the North American Arctic has risen at twice the rate of the global average due to climate change, causing changes to the natural environment that affect the physical, social, and emotional well‐being of people and communities. Social workers must be prepared to respond. Using a non‐probability, convenience sample, this study surveyed 159 social workers in Alaska to assess their attitudes and their perceptions of the effects of climate change on their clients and constituents. Results indicate that social workers in Alaska believe that climate change is happening, that human activities are responsible, and that it is a large threat to people in Alaska. Over 75% believe that climate change is dangerous for their clients now or will be dangerous in 10 years. Social workers report that in the past year their clients or constituents have experienced multiple climate change‐related problems with community infrastructure, health, and mental health.
From scenarios to conditional scenarios in two‐stage stochastic MILP problems
Authors: Beltran‐Royo C. 
Published: July 2020

AbstractThe conditional scenario (CS) approach was introduced as an effective approximation to the two‐stage stochastic mixed‐integer linear programming problem. Although the original definition of CS is general, in practice it is basically suitable for the multivariate normal distribution. In this paper, we propose a new definition of CS that is suitable for approximating any multivariate distribution (continuous or discrete). This definition allows the approximation of a potentially large set of scenarios using a small set of CSs, unlike the previous definition. In the computational study, dedicated to solving the portfolio optimization problem with hard real‐world constraints, the CS approach has clearly outperformed the sample average approximation approach in terms of solution time.
Soret coefficient of a sodium germanate glass melt: Experiment, theory, and molecular dynamics simulation
Authors: Nakashima Kento , Shimizu Masahiro , Matsuoka Jun , Fukuyo Tsubasa , Kato Hiroshi , Nishi Masayuki , Shimotsuma Yasuhiko , Miura Kiyotaka 
Published: July 2020

AbstractThe Soret effect is a diffusion phenomenon driven by a temperature gradient in a multicomponent system. This effect in condensed systems is not fully understood. Previously, we reported a theoretical model called “adjusted Kempers model” to predict the Soret coefficient in glass melts, and compared the experimental value to the theoretical value for 11Na2O‐89B2O3 (mol%) melts. Here, molecular dynamics calculations, as well as theoretical and experimental values, are quantitatively compared in 10Na2O‐90GeO2 melts. We used a vertical tubular furnace to cause a temperature gradient and heated the sample from top side to reduce the natural convection. We measured the composition of 10Na2O‐90GeO2 glass samples after 45, 90, and 180 hours of heat treatment under a temperature gradient, and estimated the steady‐state Soret coefficient near 1373 K to be 1.09 × 10−3 K−1. In addition, we calculated Soret coefficients to be 3.65 × 10−3 K−1 and 1.85 × 10−3 K−1 in theory and molecular dynamics calculation, respectively. The ratios between the experimental and theoretical Soret coefficients were 1.2 and 3.3 for 11Na2O‐89B2O3 melts and 10Na2O‐90GeO2 melts, respectively. The difference in ratios may be attributed to the mass and size of diffusion species in the glass melts.
Phase development and pore stability of yttria‐ and ytterbia‐stabilized zirconia aerogels
Authors: Hurwitz Frances I. , Rogers Richard B. , Guo Haiquan , Garg Anita , Olson Nathaniel S. , Phan David , Cashman Jessica L. 
Published: July 2020

AbstractHigh‐porosity yttria‐ and ytterbia‐stabilized zirconia aerogels offer the potential of extremely low thermal conductivity materials for high‐temperature applications. Yttria‐ and ytterbia‐doped zirconia aerogels were synthesized using a sol‐gel approach over the dopant range of 0‐20 atomic percent. Surface area, pore volume, and morphology of the as‐dried aerogels and materials thermally exposed for short periods of time to temperatures up to 1200°C were characterized by nitrogen physisorption, scanning and transmission electron microscopy, and X‐ray diffraction. The aerogels as supercritically dried all were X‐ray amorphous. At a 5% dopant level, a tetragonal structure with a smaller monoclinic phase developed on thermal exposure. Mixed tetragonal and cubic phases or predominantly cubic materials were observed at higher dopant levels, depending on the dopant level, temperature and exposure time. The formation of crystalline phases was accompanied by loss of surface area and pore volume, although some mesoporous structure was maintained on short‐term exposure to 1000°C. Incorporation of the smaller Yb atom into the lattice structure resulted in smaller lattice dimensions on crystallization than was seen with Y doping and favored a more highly equiaxed structure. Aerogels synthesized with 15% Y maintained the smallest particle size without evidence of sintering at 1100°C. Largest shrinkage and loss of pore volume occurred on crystallization from the amorphous phase, with further loss of pores at temperatures above 1000°C attributable to changes in lattice parameters.
Novel scheelite‐type [Ca0.55(Nd1‐xBix)0.3]MoO4 (0.2 ≤ x ≤ 0.95) microwave dielectric ceramics with low sintering temperature
Authors: Hao Shu‐Zhao , Zhou Di , Hussain Fayaz , Su Jin‐Zhan , Liu Wen‐Feng , Wang Da‐Wei , Wang Qiu‐Ping , Qi Ze‐Ming 
Published: July 2020

AbstractNovel scheelite‐type [Ca0.55(Nd1‐xBix)0.3]MoO4 (0.2 ≤ x ≤ 0.95) ceramics were prepared using the solid‐state reaction method. According to the X‐ray diffraction data, a solid solution was formed in 0.2 ≤ x ≤ 0.95 and all the samples belong to pure scheelite phase with the tetragonal structure. As revealed by Raman spectroscopy, the number of vibrational modes decreased with the increase in x value, which further indicated that Bi3+ ions occupied A‐site of scheelite structure. As the x value increased, the sintering temperature decreased from 740°C to 660°C; the permittivity increased from 12.6 to 20.3; the Qf value first decreased slightly and gradually remained stable. Based on the infrared reflectivity spectrum analysis, the calculated permittivity derived from the fitted data shared the same trend with the measured value. The [Ca0.55(Nd0.05Bi0.95)0.3]MoO4 ceramic sintered at 660 °C attained a near‐zero value temperature coefficient ~τf (−7.1 ppm/°C) and showed excellent microwave dielectric properties with a ɛr ~ 20.3 and a Qf ~ 33 860 GHz, making this system a promising candidate in the ultralow temperature cofired ceramic (ULTCC) technology.
Direct and indirect selection on mate choice during pollen competition: Effects of male and female sexual traits on offspring performance following two‐donor crosses
Authors: Madjidian Josefin A. , Smith Henrik G. , Andersson Stefan , Lankinen Åsa 
Published: July 2020

AbstractMate choice in plants is poorly understood, in particular its indirect genetic benefits, but also the direct benefits of avoiding harmful matings. In the herbCollinsia heterophylla, delayed stigma receptivity has been suggested to enhance pollen competition, potentially functioning as a female mate choice trait. Previous studies show that this trait can mitigate the cost of early fertilization caused by pollen, thus providing a direct benefit. We performed two‐donor pollinations during successive floral stages to assess how this stigma receptivity trait and two pollen traits known to affect siring success influence indirect benefits in terms of offspring performance. We also investigated differential resource allocation by studying the influence of sibling performance in the same capsule. Offspring performance in terms of flower number was mainly affected by parental identities and differential resource allocation. Offspring seed production showed some influence of resource allocation, but was also affected by pollen donor identity and varied positively with late stigma receptivity. However, the effect of late stigma receptivity on offspring seed production was weakened in matings with pollen that advanced stigma receptivity. In conclusion, delayed stigma receptivity may be selected through both direct and indirect fitness effects inC. heterophylla, where pollen‐based delay on stigma receptivity might act as a cue for mate choice. However, selection may also be counteracted by antagonistic selection on pollen to advance stigma receptivity. Our results highlight the challenges of studying indirect genetic benefits and other factors that influence mate choice in plants.
Arms as areas for larval development of migratory fish species in a Neotropical reservoir and the influence of rainfall over abundances
Authors: Sanches Paulo Vanderlei , Gogola Tatiane Mary , Silva Rafael Olimpio , Topan Dhyego Amilton , dos Santos Picapedra Pablo Henrique , Piana Pitágoras Augusto 
Published: July 2020

AbstractThe aim of the present study was to verify the use of the arms of the Itaipu Reservoir as areas of initial development for migratory fish species and to assess the relationship between rainfall and the spawning of migratory fish. Accordingly, fish larvae were collected from five arms of the reservoir from 2009 to 2016 using 0.5 mm plankton nets. Density was standardized as the number of larvae per 10 m3filtered water, and the captured larval and juvenile specimens were identified at the lowest‐possible taxonomic level. The larvae were also classified according to the degree of development and notochord flexion stage: larval vitelline, pre‐flexion, flexion and post‐flexion. To evaluate the distribution of larval abundance and the developmental stage along the longitudinal gradients of the arms, the data were evaluated using a set of nested linear models, following the AIC and Bayesian information criteria. In addition, an analysis of covariance was performed to investigate the influence of rainfall on the larval abundance of migratory species. During sampling, several species of economic and conservation interest such asSalminus brasiliensisandPseudoplatystoma corruscanswere collected.The larvae of the migratory fish taxa were captured from all sampled arms, which indicate them as areas of initial development. Nevertheless, it was observed that larval density increases from fluvial towards lacustrine zones inside the arms. Also, the present study verified that species, even in lentic environments, respond positively to rainfall stimuli in a manner similar to that exhibited by conspecifics in lotic environments. Such results reinforce the necessity of the protection of arms aiming at the conservation of this main group of species impaired by the construction of dams.
Maturation of female common snook Centropomus undecimalis: implications for managing protandrous fishes
Authors: Young Joy M. , Yeiser Beau G. , Whittington James A. , Dutka‐Gianelli Jynessa 
Published: July 2020

AbstractThe assumption for hermaphroditic fish species that mature individuals of the terminal sex arise directly from mature individuals of the primary sex has led to the use of sex ratios as a proxy for age at maturity (A50). The timing of transition and deficient energy reserves, however, can result in a delay between transition and spawning. To test the assumption of female maturity and investigate the relationship between maturation and energy reserves, common snook, Centropomus undecimalis, a protandrous hermaphrodite, were collected from rivers, estuaries, inlets and offshore habitats on the east coast of Florida during 2010–2015. Immature females were observed every month, with lowest proportions during the peak spawning months of July and August. When calculated based on sex ratio, A50 (8.1 years) overestimated the age at which 50% of the female population was, in fact, mature (4.1–4.9 years). Best‐fit models indicate that mesenteric fat index (IF) and hepato‐somatic index (IH) were significantly affected by gonad phase, month and size and weakly by habitat. In post hoc analysis, immature female IF did not differ significantly from developing and regenerating females, but immature female IH was significantly lower than that for all mature phases except animals in the regressing phase. Although immature females may have sufficient energy in terms of fat, it appears that energy is not allocated to reproductive processes, as evidenced by lower IH. Nonetheless, approximately 95% of females were spawning‐capable during peak spawning months, suggesting that the energy threshold at which immature females reach maturity is met by most females each spawning cycle.