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This study compared the physical properties and mechanical strength development of PCBAs with water, sealed, standard, and open ambient air curing over 28 days to find a suitable curing method for the production of phosphogypsum-based cold-bonded aggregates. The types and relative amounts of hydration products, microstructural morphology and pore structure parameters were characterized utilizing XRD, TGA, FTIR, SEM and nitrogen adsorption methods. According to the results, water curing leads to rapid increases in single aggregate strength, reaching 5.26 MPa at 7 d. The standard curing condition improved the 28 d mechanical strength of the aggregates by 19.3% over others by promoting the generation of hydration products and the transformation of the C-S-H gel to a higher degree of polymerization and by optimizing the pore structure. Further, PCBAs achieved an excellent solidification of phosphorus impurities under all four curing conditions. This work provides significant guidance for selecting an optimized PCBA curing method for industrial production. [ABSTRACT FROM AUTHOR]

The Wright–Fisher model predicts that the ratio of effective population size ( N e ) to actual population size ( N ) is <1.0 due to inbreeding and random drifts under constant population sizes. However, social structure may prevent inbreeding and result in outbreeding through coancestry, causing the N e / N ratio to exceed 1.0. We integrated three years of data on seasonal population fluctuations and population genetics of group-living Daurian pikas (Ochotona dauurica) to test the prediction of >1.0 N e / N ratio for social small mammals. We estimated biweekly pika population sizes using capture–recapture data from May 2010 to October 2012. We genotyped all captured pikas in each of the three years with 11 microsatellite markers. We estimated pika effective population sizes for 2010–2011, 2011–2012, and 2010–2012, respectively, using the temporal methods with the program MLNe. Pika populations underwent a 75% decline in the summer of 2010 and exhibited relatively constant seasonal fluctuations from 2011 to 2012. Bayesian clustering with program STRUCTURE identified two distinct genetic clusters for the pikas of 2010 and 2011–2012, respectively. The N e / N ratios of the pikas were 0.46, 1.13, and 0 54 for 2010–2011, 2011–2012, and 2010–2012, respectively. Our findings partially support our hypothesis with the N e / N ratio being >1.0 from 2011 to 2012. The dramatic population decline in the summer of 2010 probably disrupted the social structure of pikas, which subsequently increased the rate of genetic diversity losses. Re-establishments of the social structure during 2011 and 2012 probably restored the outbreeding of pikas like in other social mammals. [ABSTRACT FROM AUTHOR]

Globally, the majority of habitat loss is irreversible, and most species will never recover their former ranges. We have learned a great deal about what leads to population decline and extinction, but less about recovery. The recently downlisted giant panda provides a unique opportunity to understand the mechanisms of species recovery. In our study, we estimate giant panda suitable habitats, population density, and gene flow across landscapes to fully investigate the direct and indirect ecological mechanisms underlying bold conservation strategies. We found that the Giant Panda National Survey has modestly but systematically underestimated population size. China's effort to mitigate anthropogenic disturbances was associated with increased panda population density through improving habitat quality and reducing habitat fragmentation. Enhanced landscape connectivity reduced inbreeding via gene flow but indirectly increased inbreeding temporarily due to high local panda density. Although the panda's recovery has been geographically uneven, we provide evidence for improving connectivity and gene flow resulting from conservation efforts. If these processes can be sustained and improved, the panda's path to recovery will be less encumbered by loss of genetic diversity, fostering hope that the present rate of recovery will not be stalled. Findings from this study will not only help guide future giant panda conservation management but also provide a model for how a more mechanistic examination of the genetic processes underlying species recovery can foster the development of more effective strategies for endangered species recovery. [Display omitted] • China's Giant Panda National Survey modestly underestimated population size • China's effort to mitigate human disturbance has increased pandas and their habitat • Conservation-driven landscape connectivity directly reduced inbreeding via gene flow Wang et al. integrate multiple data to understand giant panda recovery. They find that the national survey has systematically underestimated population size. Reduced human disturbance enhances habitat quality and reduces fragmentation, thereby increasing density. Landscape connectivity improves gene flow and generally reduces inbreeding. [ABSTRACT FROM AUTHOR]

Resource utilization strategies of avian migrants are a major concern for conservation and management. Understanding seasonal habitat selection by migratory birds helps us explain the ongoing continental declines of migratory bird populations. Our objective was to compare the second-order and third-order habitat selection by the American White Pelican (Pelecanus erythrorhynchos; hereafter pelican) between the breeding and non-breeding grounds. We tested the Lack hypothesis that habitat selection by migratory birds is stronger on the breeding grounds than on the non-breeding grounds. We used random-effect Dirichlet-multinomial models to estimate the second-order habitat selection between the seasons with the GPS locations of 32 tracked pelicans. We used Gaussian Markov random field models to estimate the third-order habitat selection by pelicans at the breeding and non-breeding grounds, accounting for spatial autocorrelation. Pelicans strongly selected waterbodies and wetlands at both non-breeding and breeding grounds, tracking their foraging habitats between the seasons at the home range level. However, pelicans exhibited seasonal differences in the strength of the third-order selection of wetlands and waterbodies with foraging habitat selection being stronger at the breeding grounds than at the non-breeding grounds, supporting the Lack hypothesis. [ABSTRACT FROM AUTHOR]

Genetic diversity plays an important role in the evolution and adaptation of organisms. Losses of genetic diversity make organisms more vulnerable to climate changes and diseases, reducing the viability of small populations. In addition to natural selection, genetic drift, dispersal, inbreeding, and population bottleneck, the social systems of animals may also affect the genetic diversity of populations. We aimed to test the hypothesis that the delayed dispersal of group-living small mammals would reduce genetic diversity through attenuated gene flow but enhance genetic relatedness. We used microsatellite analysis to estimate genetic diversity and the Queller and Goodnight relatedness coefficients of Daurian pikas (Ochotona dauurica) and Mongolian gerbils (Meriones unguiculatus), two socially monogamous small mammals living in social groups in Inner Mongolia, China. The average genetic relatedness of social groups was inversely related to the average genetic diversity of social groups in Daurian pikas but not in Mongolian gerbils, partially supporting our hypothesis. Dispersal following frequent local extinctions resulted in the recolonization of burrow systems by individuals with different genetic makeups, increasing genetic diversity and reducing the genetic relatedness of the social groups of Daurian pikas. On the other hand, delayed short-distance dispersal was sufficient to maintain the high genetic diversity and high genetic relatedness of gerbil social groups independently. [ABSTRACT FROM AUTHOR]

Avian migrants are challenged by seasonal adverse climatic conditions and energetic costs of long‐distance flying. Migratory birds may track or switch seasonal climatic niche between the breeding and non‐breeding grounds. Satellite tracking enables avian ecologists to investigate seasonal climatic niche and circannual movement patterns of migratory birds. The Double‐crested Cormorant (Nannopterum auritum, hereafter cormorant) wintering in the Gulf of Mexico (GOM) migrates to the Northern Great Plains and Great Lakes and is of economic importance because of its impacts on aquaculture. We tested the climatic niche switching hypothesis that cormorants would switch climatic niche between summer and winter because of substantial differences in climate between the non‐breeding grounds in the subtropical region and breeding grounds in the northern temperate region. The ordination analysis of climatic niche overlap indicated that cormorants had separate seasonal climatic niche consisting of seasonal mean monthly minimum and maximum temperature, seasonal mean monthly precipitation, and seasonal mean wind speed. Despite non‐overlapping summer and winter climatic niches, cormorants appeared to be subjected to similar wind speed between winter and summer habitats and were consistent with similar hourly flying speed between winter and summer. Therefore, substantial differences in temperature and precipitation may lead to the climatic niche switching of fish‐eating cormorants, a dietary specialist, between the breeding and non‐breeding grounds. [ABSTRACT FROM AUTHOR]

Endogenous (e.g., age and sex) and exogenous (e.g., climate and resource availability) factors influence avian migration phenology. However, little is known regarding the migration ecology of birds at the non-breeding grounds, including the American white pelican (Pelecanus erythrorhynchos). We used Global Positioning System transmitters to track the movements and migration of 51 pelicans from 2002 to 2012. We used the Kaplan–Meier model to estimate pelican spring migration probabilities to quantify partial migration with 94 spring migration events and used the Cox proportional hazards model to evaluate the effects of the North Atlantic Oscillation index (NAOI), Southern Oscillation Index (SOI), and spring daily precipitation on the propensity of pelican spring migration departures. Increases in the NAOI and SOI enhanced the propensity of pelican spring departure. The propensity of spring departure was also positively related to daily precipitation. Male pelicans have greater spring migration probabilities than female pelicans. Spring migration departure probabilities of adult pelicans are greater than those of immature pelicans. Therefore, both large-scale and local climatic conditions affect pelican spring departure probabilities. Advanced migratory phenology of pelicans caused by climate changes with warming temperature and increased precipitation may result in the mismatch of pelican spring arrival with food resource availability of breeding grounds and subsequent pelican population declines. [ABSTRACT FROM AUTHOR]

Species distribution modeling often involves high‐dimensional environmental data. Large amounts of data and multicollinearity among covariates impose challenges to statistical models in variable selection for reliable inferences of the effects of environmental factors on the spatial distribution of species. Few studies have evaluated and compared the performance of multiple machine learning (ML) models in handling multicollinearity. Here, we assessed the effectiveness of removal of correlated covariates and regularization to cope with multicollinearity in ML models for habitat suitability. Three machine learning algorithms maximum entropy (MaxEnt), random forests (RFs), and support vector machines (SVMs) were applied to the original data (OD) of 27 landscape variables, reduced data (RD) with 14 highly correlated covariates being removed, and 15 principal components (PC) of the OD accounting for 90% of the original variability. The performance of the three ML models was measured with the area under the curve and continuous Boyce index. We collected 663 nonduplicated presence locations of Eastern wild turkeys (Meleagris gallopavo silvestris) across the state of Mississippi, United States. Of the total locations, 453 locations separated by a distance of ≥2 km were used to train the three ML algorithms on the OD, RD, and PC data, respectively. The remaining 210 locations were used to validate the trained ML models to measure ML performance. Three ML models had excellent performance on the RD and PC data. MaxEnt and SVMs had good performance on the OD data, indicating the adequacy of regularization of the default setting for multicollinearity. Weak learning of RFs through bagging appeared to alleviate multicollinearity and resulted in excellent performance on the OD data. Regularization of ML algorithms may help exploratory studies of the effects of environmental factors on the spatial distribution and habitat suitability of wildlife. [ABSTRACT FROM AUTHOR]

Spatial and temporal heterogeneity are fundamental mechanisms structuring home ranges. Under optimality, an individual should structure their space use economically to maximize fitness. We evaluated support for three hypotheses related to range optimality in American black bears (Ursus americanus), predicting (a) range location on a landscape will correspond with high vegetation productivity, (b) increasing forest fragmentation will result in larger ranges, and (c) increasing proportion of forest and/or mean vegetation productivity will result in smaller ranges. We used black bear radio telemetry data from Michigan (2009–2015), Missouri (2010–2016), and Mississippi (2008–2017), USA. Annual space use excluded winter, and we separated seasonal space use into spring, summer, and fall. We collected data from 143 bears (80 females, 63 males), resulting in 97 annual and 538 seasonal ranges. We used generalized linear mixed models to evaluate productivity (estimated through Normalized Difference Vegetation Index [NDVI]) selection, and range size (km2) variation between individuals. At the annual scale, black bears consistently selected areas with greater vegetation productivity than the surrounding landscape; yet selection weakened and was more variable seasonally. Opposite to our prediction, we found that increasing fragmentation consistently resulted in smaller ranges; non‐forested land covers and forest edges might provide greater abundance or more diverse foods for bears. Ranges with a greater proportion of forest were smaller, likely reflecting an increase in food and cover which could reduce movements, yet there was no support for more productive ranges also being smaller as expected from an area minimizing strategy. Black bears displayed a scale‐dependent space use strategy: at larger spatial and temporal scales, productivity acted as the strongest limiting factor and energy maximizing was the dominant strategy, while an area minimizing strategy was exhibited seasonally. We revealed consistent, scale‐dependent responses by black bears to environmental conditions, demonstrating the intrinsic plasticity of this adaptable omnivore. Spatial and temporal heterogeneity are fundamental mechanisms structuring home ranges. American black bears display a scale‐dependent space use strategy: at larger spatial and temporal scales, productivity acted as the strongest limiting factor and energy maximizing was the dominant strategy, while an area minimizing strategy was exhibited seasonally, demonstrating the intrinsic plasticity of this adaptable omnivore. [ABSTRACT FROM AUTHOR]

Mammalian mesocarnivores play critical roles in ecosystems via trophic interactions. The fluctuation of mesocarnivore abundance may cause trophic cascading throughout the ecosystems. However, little was known about density dependence and spatiotemporal dynamics of mesocarnivore populations. Northern raccoon Procyon lotor is a common mammalian mesocarnivore in North America, and is the host of many human infectious diseases. Few studies have investigated density dependence and hierarchical spatiotemporal dynamics of raccoon populations. We used 23‐year time series of raccoon relative abundance from 14 wildlife management areas in Mississippi, USA, to test for spatial synchrony of raccoon populations with nonparametric correlation functions. We developed non‐Gaussian state space models to detect density dependence of raccoon populations, and also used dynamic factor analysis (DFA) to determine the structure of the spatiotemporal dynamics of raccoon populations. The 14 raccoon populations lacked common trends, and were not synchronized. Strength of density dependence varied among raccoon populations, but was not related to the amount of hardwood forests. Differences in the structure of density dependence probably prevented populations from being synchronize by climatic variability. The raccoon populations exhibited greater local or idiosyncratic variability than regional variability in Mississippi. Northern raccoons have plastic life history traits permitting their population dynamics to closely track local variations in resource availability. [ABSTRACT FROM AUTHOR]

Energy and time expenditures are determinants of bird migration strategies. Soaring birds have developed migration strategies to minimize these costs, optimizing the use of all the available resources to facilitate their displacement. We analysed the effects of different wind factors (tailwind, turbulence, vertical updrafts) on the migratory flying strategies adopted by 24 satellite-tracked American white pelicans (Pelecanus erythrorhynchos) throughout spring and autumn in North America. We hypothesize that different wind conditions encountered along migration routes between spring and autumn induce pelicans to adopt different flying strategies and use of these wind resources. Using quantile regression and fine-scale atmospheric data, we found that the pelicans optimized the use of available wind resources, flying faster and more direct routes in spring than in autumn. They actively selected tailwinds in both spring and autumn displacements but relied on available updrafts predominantly in their spring migration, when they needed to arrive at the breeding regions. These effects varied depending on the flying speed of the pelicans. We found significant directional correlations between the pelican migration flights and wind direction. In light of our results, we suggest plasticity of migratory flight strategies by pelicans is likely to enhance their ability to cope with the effects of ongoing climate change and the alteration of wind regimes. Here, we also demonstrate the usefulness and applicability of quantile regression techniques to investigate complex ecological processes such as variable effects of atmospheric conditions on soaring migration. [ABSTRACT FROM AUTHOR]

Global biodiversity conservation has recently focused on the roles of land management strategies of land sharing vs. land sparing. However, few studies have evaluated the roles of social and ecological interactions in modifying the effectiveness of land management for top predator conservation. Using a 65-year dataset from northeastern China, we evaluated the roles of government social policies in resolving human-wildlife conflicts and improving human livelihood. From 1998 to 2015, both big cat populations and their habitats have increased. Concurrently, regional human population density decreased by 59.6%, forest volume logged was reduced by 62.6%. Consequently, increases of key prey species were observed during the same periods. Although populations remained small, the annual finite rate of increase was 1.04 for the Amur tiger population and 1.08 for Amur leopards from 1999 to 2015. Habitat areas occupied by big cats increased significantly. Overexploitation of forest resources and big cat declines under previous unsustainable land use are progressively being reversed under land sparing. Large economic investment and intense human-relocation projects coupled with efforts to reduce poaching and illegal hunting and trapping demonstrate a complex social and ecological synergy in big cat conservation in China. [ABSTRACT FROM AUTHOR]

Physiological states and foraging behaviors may shape movement patterns of animals. Optimal foraging theory and what we term the deliberate movement hypothesis predict that, to reduce predation risk, central place foragers should move faster with smaller turning angles the further they are from their central place. The complementary bimodal foraging trip hypothesis predicts that the distribution of foraging distances exhibited by central place foragers should be bimodal due to a trade-off between provisioning offspring and self-feeding. We used radio-telemetry to test these hypotheses for American beavers (Castor canadensis) in northern Alabama, United States. American beavers moved faster with increasing distance from lodges in wetland land cover but not in terrestrial land covers, partially supporting the deliberate movement hypothesis. Hourly distances moved from lodges were distributed bimodally during the breeding season, which supports the bimodal foraging trip hypothesis. Therefore, central place foraging may be a determinant of movement characteristics of American beavers. [ABSTRACT FROM AUTHOR]

Deterministic feedbacks within populations interact with extrinsic, stochastic processes to generate complex patterns of animal abundance over time and space. Animals inherently differ in their responses to fluctuating environments due to differences in body sizes and life history traits. However, controversy remains about the relative importance of deterministic and stochastic forces in shaping population dynamics of large and small mammals. We hypothesized that effects of environmental stochasticity and density dependence are stronger in small mammal populations relative to their effects in large mammal populations and thus differentiate the patterns of population dynamics between them. We conducted an extensive, comparative analysis of population dynamics in large and small mammals to test our hypothesis, using seven population parameters to describe general dynamic patterns for 23 (14 species) time series of observations of abundance of large mammals and 38 (21 species) time series for small mammals. We used state-space models to estimate the strength of direct and delayed density dependence as well as the strength of environmental stochasticity. We further used phylogenetic comparative analysis to detect differences in population dynamic patterns and individual population parameters, respectively, between large and small mammals. General population dynamic patterns differed between large and small mammals. However, the strength of direct and delayed density dependence was comparable between large and small mammals. Moreover, the variances of population growth rates and environmental stochasticity were greater in small mammals than in large mammals. Therefore, differences in population response to stochastic forces and strength of environmental stochasticity are the primary factor that differentiates population dynamic patterns between large and small mammal species. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, effect of water–binder ratio and fly ash on the homogeneity of concrete are investigated. The image analysis, segregation degree, compressive strength and microhardness are used as the evaluation of homogeneity. The results demonstrate that the image analysis method can effectively describe the homogeneity of concrete. Meanwhile, the segregation degree exhibits a linear relationship to the reduction ratio of compressive strength of concrete. It also can be concluded that the lower water–binder ratio and the addition of fly ash can effectively improve the homogeneity in ITZ of concrete. On the other hand, microhardness testing indicates that the top of aggregate has the highest microhardness and the narrowest width of ITZ, and the interior of concrete performs better than the surface. The reason is that both the segregation at macro-level and the asymmetrical distribution of the water content around the single aggregate particle lead to the obviously difference in the formation of hydration products and the compactness in ITZ of hardened concrete, which can be illustrated by SEM analysis. Thus, the homogeneity of concrete can be evaluated by the combination of image analysis, segregation degree, compressive strength and microhardness. [Copyright &y& Elsevier]

Animal populations interact with their environments in a scale-dependent manner and exhibit scale-dependent dynamics. Animals may adjust reproductive frequency and fecundity in response to fluctuating environments to maximize reproductive success. We hypothesize that populations of insectivorous small mammals undergo seasonal variations owing to predictable shortages of winter food and short breeding periods, whereas populations of herbivorous small mammals may exhibit multi-year fluctuations owing to food-induced variability in the length of the breeding period among years. We predict that omnivorous Peromyscus and Reithrodontomys species would have population dynamics patterns similar to insectivorous small mammals, if the omnivorous rodents rely on insects as winter food. Using the wavelet transform, we re-analyzed nine long-term monthly population time series of Blarina brevicauda, Microtus ochrogaster, Microtus pennsylvanicus, Peromyscus leucopus, Peromyscus maniculatus, Reithrodontomys megalotis, and Sigmodon hispidus from Illinois, Kansas, and Pennsylvania, United States to test our hypothesis. Populations of B. brevicauda in Illinois, P. leucopus in Pennsylvania, and S. hispidus and R. megalotis in Kansas resonated with climate change at an annual scale (8–16 months), whereas Microtus populations in Illinois and Kansas and P. leucopus, P. maniculatus, and S. hispidus populations in Kansas exhibited the greatest variability at a scale of 32 months. Our Kansas M. ochrogaster population cycled every 2–3 years from 1984 to 1994. Therefore, small mammal populations form a continuum of slow–fast dynamics. Variation in small mammal population abundances is related to climate dynamics only at annual scales. However, it is unlikely that long-term dynamics of local climate directly result in long-term variation in small mammal population abundances, including population cycles. Our findings demonstrate the importance of scale-specific effects of exogenous factors in the dynamics of animal populations and offer a new interpretation of complex effects of climate on population dynamics. [Copyright &y& Elsevier]

As an important tool for environment management, eco-efficiency has been widely applied, but eco-effectiveness has only made progress on eco-design and life cycle management in recent years. Few have attempted to integrate eco-efficiency and eco-effectiveness into sustainable industrial systems. In a new framework integrating eco-efficiency and eco-effectiveness, both concepts can find unique roles and complement each other in industrial ecosystems to dissolve conflicts between industry and the environment. This article provides a case study of China in which eco-efficiency indicators (energy, water and waste utilisation intensity) have demonstrated great progress in China, but eco-efficiency cannot stop the increasing release of pollutants and their accumulating impact on ecological life-support systems. China must integrate eco-effectiveness and eco-efficiency into concrete sustainable development strategies, questioning whether limited resources are being used correctly. Both eco-efficiency and eco-effectiveness are identified as important indicators in the development of sustainable industrial systems. In the framework of sustainable industrial systems, eco-effectiveness must begin to play a more important role. [ABSTRACT FROM AUTHOR]

Small mammal populations fluctuate erratically and exhibit seasonal and multi-annual variations in abundance. The decomposition of population dynamics into seasonal fluctuations, stochastic trends, and residuals helps to quantify environmental stochasticity of population dynamics. We used basic structural model (BSM), a state-space time series model, to decompose and de-trend 25 years of monthly live-trapping data for Microtus ochrogaster, M. pennsylvanicus, and Blarina brevicauda in east-central Illinois, USA. We further used Bayesian state-space models (BSSM) to determine the structure of within-year and between-year density dependent feedbacks in the stationarized residuals from the BSM for the three species. The BSM and spectral analysis identified significant seasonal fluctuations for the B. brevicauda populations. All populations of the three species exhibited strong stochastic fluctuations, but those of M. ochrogaster and B. brevicauda displayed greater environmental stochasticity than that of M. pennsylvanicus. The BSSM analysis indicates that M. pennsylvanicus was subject to density-dependence with a 4-month time lag, whereas the M. ochrogaster and B. brevicauda populations displayed 18-and 10-month delayed density-dependence, respectively. Moreover, spectral analysis suggests that none of the species exhibited multi-annual cyclic population fluctuations. Thus, both environmental stochasticity and density-dependence appeared to play significant roles in the population dynamics. State-space models are a promising tool for analyzing long-term monthly population time series. [Copyright &y& Elsevier]

Abstract: Nonlinear state-space models have been increasingly applied to study population dynamics and data assimilation in environmental sciences. State-space models can account for process error and measurement error simultaneously to correct for the bias in the estimates of system state and model parameters. However, few studies have compared the performance of different nonlinear state-space models for reconstructing the state of population dynamics from noisy time series. This study compared the performance of the extended Kalman filter (EKF), unscented Kalman filter (UKF) and Bayesian nonlinear state-space models (BNSSM) through simulations. Synthetic population time series were generated using the theta logistic model with known parameters, and normally distributed process and measurement errors were introduced using the Monte Carlo simulations. At higher levels of nonlinearity, the UKF and BNSSM had lower root mean square error (RMSE) than the EKF. The BNSSM performed reliably across all levels of nonlinearity, whereas increased levels of nonlinearity resulted in higher RMSE of the EKF. The Metropolis–Hastings algorithm within the Gibbs algorithm was used to fit the theta logistic model to synthetic time series to estimate model parameters. The estimated posterior distribution of the parameter θ indicated that the 95% credible intervals included the true values of θ (=0.5 and 1.5), but did not include 1.0 and 0.0. Future studies need to incorporate the adaptive Metropolis algorithm to estimate unknown model parameters for broad applications of Bayesian nonlinear state-space models in ecological studies. [Copyright &y& Elsevier]

We studied the roles of soil moisture contents and vegetation structure in the spatial distribution of small mammals in the typical steppes of Inner Mongolia, China, using logistic and linear regressions of a data set collected in a 6-year study. Our results indicated that soil moisture contents remained in the most parsimonious models for Spermophilus dauricus, Cricetulus barabensis, Microtus maximowiczii, M. gregalis, and Ochotona daurica. The relative abundance of C. barabensis, M. maximowiczii, and O. daurica was inversely related to soil moisture contents, while that of M. gregalis and S. dauricus was positively related to soil moisture contents in logistic regressions. Linear regression analyses showed that soil moisture contents and the number of small mammal species were inversely related. The negative effects of wet soil were consistent at both small mammal population and community levels in the semi-arid steppes. Above-ground plant biomass and plant coverage also affected the spatial distribution of small mammals in the typical steppe of Inner Mongolia. [Copyright &y& Elsevier]

Through realisation of ecological opportunities, populations and species can experience relaxed selection pressures, facilitating ecological release and leading to rapid speciation and morphological diversification. Behavioural plasticity in response to environmental change contributes to diversification by exposing individuals to novel conditions through their interactions with resources or dispersal to new areas. Despite strong theoretical support, demonstrations of this evolutionary process are rare.The family Ursidae is the product of one or more adaptive radiations following the Miocene–Pliocene transition. Denning behaviour associated with over‐winter seclusion, fasting, and parturition coinciding with seasonally decreased food availability appears to be paraphyletic in Ursidae phylogenies. However, female bears of all species undergo varying degrees of seclusion and fasting during parturition and early post‐natal care, which is not consistent with periods of seasonally decreased food availability. As denning behaviour is tightly linked to fitness through energetics and reproduction, these behaviours are suspected to be under strong selection. Mechanisms responsible for the observed variability among species, populations, and individuals have not been explored.In this review, we detail the evolutionary history of extinct and extant Ursidae regarding expression of denning behaviour and as a function of realised ecological opportunities. We compare behaviours across Ursidae and contextualise our results within extant species ecology.We demonstrate the role of relaxed extrinsic and intrinsic factors in the expression of metabolic suppression among Ursidae species, and across populations and reproductive groups, through the realisation of ecological opportunities. In doing so, we propose a more refined consideration of and perspective on this behaviour and provide a mechanism for the adaptive radiation in Ursidae. [ABSTRACT FROM AUTHOR]

Background: Semiaquatic mammals require both aquatic and terrestrial habitats, particularly interfaces between the two habitats. As ecosystem engineers, American beaver (Castor canadensis) consume and fell a great amount of deciduous trees. We tested the prediction that open water and amounts of food resources, including hardwood forests (i.e., deciduous trees as the dominant form of vegetation), herbaceous and woody wetlands, and shrubs, would influence the second-order habitat selection (i.e., placing home ranges on the landscape) by American beaver, whereas the third-order habitat selection of American beaver would be associated with woody wetland and shrub edges. We investigated hierarchical habitat selection by American beaver using location data from very high frequency telemetry. Dirichlet-multinomial models were used to determine the second-order habitat selection at landscape scales. Bayesian spatial resource selection function was used to assess the third-order habitat selection within home ranges. Results: Second-order habitat selection by American beaver was associated with herbaceous wetland, shrubs, hardwood forest, grassland, and woody wetland more than open water bodies at landscape scales. At the third-order scale, American beaver selected herbaceous wetlands as well as the edges of shrubs and woody wetland within established home ranges. Conclusions: Spatial distributions of food resources affected both the second- and third-order habitat selection by American beaver. Herbaceous wetlands were more important habitat components than water bodies in the second- and third-order habitat selection by American beaver. Dirichlet-multinomial distribution models for the second-order habitat selection and Bayesian spatial resource selection functions for the third-order habitat selection do not need pseudo-absence locations, providing alternative approaches to the presence–absence methods for habitat selection by animals. [ABSTRACT FROM AUTHOR]

• The abnormally high expression of Tspan5 mRNA in the tubal may be related to TP. • The expression level of Tspan5 mRNA may reflect degree of endometrial decidualization. [ABSTRACT FROM AUTHOR]

The Wildlife Services—National Wildlife Research Center Mississippi Field Station, working in conjunction with Mississippi State University, conducted a study to evaluate the effectiveness of several non-lethal, commercial, physical bird deterrents. Deterrents were available on the open market to reduce double-crested cormorant (Nannopterum auritus) (DCCO) roosting time on floating oyster cages. We hypothesized that reducing bird loafing time on floating oyster cages would reduce the potential for bird defecation. Double-crested cormorant defecation can increase coliform counts in both the water and oysters, which could result in oyster farm closure. Shellfish farms often differ from one another due to environmental factors and farm locations. Six deterrent devices were selected as options for farmers, and the amount of time DCCOs occupied floats with deterrents was compared to the time they occupied those without deterrents (i.e., on a control pond). All deterrents except the Scarem Kite significantly reduced or halted DCCO use of floats compared to the control. Of note, the Scarem Kite is the only deterrent that requires consistent wind to operate effectively. The research facility is open-air, but we did not have sufficient wind for proper Scarem Kite function. Thus, it is possible that all deterrents would have produced significant reductions in DCCO use. Our results are encouraging and show that minimal deterrent applications to oyster cage floats can help farms achieve their operational plans' goals and reduce the potential for pathogen transfer by birds. The data presented here should be considered a starting point for developing an efficient deterrent plan that meets state and federal standards. [ABSTRACT FROM AUTHOR]

Spring migration phenology of birds has advanced under warming climate. Migration timing of short-distance migrants is believed to be responsive to environmental changes primarily under exogenous control. However, understanding the ecological causes of the advancement in avian spring migration phenology is still a challenge due to the lack of long-term precise location data. We used 11 years of Global Positioning System relocation data to determine four different migration dates of the annual migration cycle of the American white pelican (Pelecanus erythrorhynchos), a short-distance migrant. We also tested the hypothesis that increases in winter temperature and precipitation on the wintering grounds would advance pelican spring migration. Pelican spring departures and arrivals advanced steadily from 2002 to 2011. Spring departure timing exhibited high repeatability at the upper end of migration timing repeatability reported in literature. However, individual spring departure and arrival dates were not related to winter daily temperature, total winter precipitation, and detrended vegetation green-up dates indexed by the normalized difference vegetation index. Despite high repeatability, the observed between-year variation of spring departure dates was still sufficient for the advancement of spring departure timing. [ABSTRACT FROM AUTHOR]

Weather has been recognized as a density independent factor influencing the abundance, distribution, and behavior of vertebrates. Male wild turkeys' (Meleagris gallopavo) breeding behavior includes vocalizations and courtship displays to attract females, the phenology of which can vary with latitude. State biologists design spring turkey-hunting season frameworks centered on annual vocalization patterns to maximize hunter engagement. The Mississippi Department of Wildlife, Fisheries, and Parks has traditionally instituted a statewide, 7-week, spring harvest season. However, hunters routinely argue that different peaks in gobbling activity across the state exist. The objective of this study was to determine whether differences in peak gobbling activity existed across a latitudinal gradient of Mississippi and assess the effect of weather on gobbling. During 2008 and 2009, we conducted a statewide gobbling survey. We used generalized additive mixed models to describe the probability and frequency of gobbling activity within northern and southern regions of the state. We also investigated the effect of daily weather conditions on gobbling activity. Our results revealed an approximate 10–14-day difference in peak gobbling activity between southern and northern Mississippi. The majority of all gobbling activity occurred within the current spring harvest framework. Perhaps more importantly, gobbling activity was more prevalent on days of regionally dry conditions (i.e., less humid) according to the Spatial Synoptic Classification. Our results provide information on gobbling activity phenology relative to hunting-season dates and weather-response information. Our approach may be particularly applicable in states with relatively shorter seasons or highly variable daily weather conditions that moderate gobbling frequency. [ABSTRACT FROM AUTHOR]

Reforestation practices have intensified in the Mississippi Alluvial Valley (MAV) of the United States of America with the aid of Farm Bill programs during the past three decades. Increases in reforested land also enhance possibilities to restore once-abundant but currently sparse species, such as eastern wild turkeys (Meleagris gallopavo silvestris) in the MAV. However, it is unknown whether <20-year-old hardwood regeneration provides a suitable habitat for re-establishing wild turkey populations in the MAV. We translocated wild turkeys to two study sites in reforested areas of the MAV. We monitored 74 wild turkeys' habitat use and resource selection using radio telemetry from February 2009 to June 2010. We developed land use and land cover maps for the resource selection analysis of translocated wild turkeys. We found that turkey habitat use varied by site, sex, season, land cover type, and distance to mature hardwoods. Habitat use by wild turkeys decreased as distance to mature hardwood forest increased. Female wild turkeys used more hardwood regeneration during nesting and post-nesting seasons than during pre-nesting seasons. Although wild turkeys did not use regenerating and mature hardwood forests to the same extent, management of these forests appears critical to restoring wild turkeys in the MAV. [ABSTRACT FROM AUTHOR]

Highlights • The effect of MK based materials on the steam cured high performance concrete is investigated. • The XRD and TG analysis were applied to quantify the content of CH and AFt after curing. • The MK based admixtures remarkably refines the ITZ and optimize the pore structure of concrete after heat treatment. Abstract High performance pipe piles are widely used in precast industry. In order to improve the production efficiency and performances of the products, steam curing and mineral admixtures are usually applied. This paper evaluates the performances of HPC pipe piles produced with metakaolin-based admixtures. Quantitative phase composition analysis shows that the addition of 10 wt% metakaolin reduces the portlandite content by up to 57.1%, while increases the content of ettringite to some extent. The addition of metakaolin or metakaolin-slag/limestone blends improves the mechanical properties, especially the hybrid usage of metakaolin and limestone filler. Pore structure and microscope analyze confirm the remarkably-refined pore characteristics caused by the addition of metakaolin-based admixtures, in which case the gel pores accounts up to 85% of the total pores. Those remarkably improved properties caused by the addition of metakaolin-based admixtures indicate a promising future for their applications in producing high performance pipe piles with further modified properties. [ABSTRACT FROM AUTHOR]

Migratory soaring birds exhibit spatiotemporal variation in their circannual movements. Nevertheless, it remains uncertain how different winter environments affect the circannual movement patterns of migratory soaring birds. Here, we investigated annual movement strategies of American white pelicans Pelecanus erythrorhynchos (hereafter, pelican) from two geographically distinct wintering grounds in the Southern and Northern Gulf of Mexico (GOM). We hypothesized that hourly movement distance and home range size of a soaring bird would differ between different geographic regions because of different thermals and wind conditions and resource availability. We calculated average and maximum hourly movement distances and seasonal home ranges of GPS-tracking pelicans. We then evaluated the effects of hour of the day, seasons, two wintering regions in the Southern and Northern GOM, human footprint index, and relative pelican abundance from Christmas Bird Count data on pelican hourly movement distances and seasonal home ranges using linear mixed models and generalized linear mixed models. American white pelicans moved at greatest hourly distance near 1200 h at breeding grounds and during spring and autumn migrations. Both wintering populations in the Northern and Southern GOM exhibited similar hourly movement distances and seasonal home ranges at the shared breeding grounds and during spring and autumn migrations. However, pelicans wintering in the Southern GOM showed shorter hourly movement distances and smaller seasonal home ranges than those in the Northern GOM. Hourly movement distances and home ranges of pelicans increased with increasing human footprint index. Winter hourly movements and home ranges of pelicans differed between the Northern and Southern GOM; however, the winter difference in pelican movements did not carry over to the shared breeding grounds during summers. Therefore, exogenous factors may be the primary drivers to shape the flying patterns of migratory soaring birds. [ABSTRACT FROM AUTHOR]

Litter size and body size of animals may coevolve under the concomitant pressures of sexual selection, fecundity selection, and viability selection. Studies have demonstrated the positive relationship between body size and litter size, consistent with Darwin's fecundity advantage of large body size. However, the counterbalancing selection hypothesis predicts fecundity selection would result in a positive correlation between litter size and body size initially, whereas the opposite pressure by viability selection would decrease litter size with further increasing body size beyond a threshold size. Moreover, the reproduction senescence hypothesis predicts that litter size of old, large females would decline with deteriorating body conditions. In this study, we tested the predictions of the counterbalancing selection hypothesis and the reproduction senescence hypothesis concerning the quadratic relationship between body size and litter size in Daurian ground squirrels ( Spermophilus dauricus ). Litter size increased initially with increasing carcass weight of females, and then decreased with further increases in carcass weight, supporting the prediction of the counterbalancing hypothesis. However, litter size was not related to body condition index of females, and body conditions improved with increasing body weight, suggesting that the reproduction senescence hypothesis alone cannot explain the observed quadratic relationship between litter size and carcass weight of female S. dauricus . [ABSTRACT FROM AUTHOR]

The Amur leopard ( Panthera pardus orientalis ) is highly elusive, rare species, critically threatened with extinction worldwide. In this study, we conducted camera-trap surveys of an Amur leopard population in Jilin Province, northeast China. We estimated population abundance and density distribution, and explored the effects of prey population densities and biomass of prey, habitat and anthropogenic factors on the spatial distribution of Amur leopard density. Our results suggested that Amur leopard density was 0.62 individuals/100 km 2 and 16.58 individuals might live within the study area. The spatial distribution of Amur leopard density exhibited different responses to the population densities of different prey species. We found that two ecological thresholds existed in maximum responses of Amur leopard distribution to elevation and prey biomass. Vegetation and anthropogenic factors also showed significant effects on leopard population distribution. In general, there was a combination of habitat factors including, not only prey assembly and biomass, but also vegetation, anthropogenic and geographical factors driving the spatial distribution of Amur leopard population. These insights informed us that comprehensive adaptive landscape and prey conservation strategies should be conducted for saving this critically endangered predator. [ABSTRACT FROM AUTHOR]

ABSTRACT Since the early 20th century, wildlife managers have deployed artificial nesting structures for wood ducks ( Aix sponsa) to increase availability of nest sites and local reproduction of the species. However, knowledge is lacking of the effects of nest structure size (i.e., large vs. small; Stephens et al. 1998) and reproductive data (e.g., clutch size, hatch date, duckling survival) on recruitment of wood ducks. We used stochastic simulation analyses to predict recruitment of wood ducks into late summer by analyzing data from a 6-year study of box-nesting wood ducks, and 4-year (Mississippi) and 2-year (Alabama) studies of radio-marked female wood ducks and their ducklings. Our index of recruitment was the number of radio-marked ducklings per nest box that survived until 1 September. Ducklings hatched after 1 June exhibited a 30-day survival probability of 0.29, which was nearly 3 times greater than those hatched before 1 June. In east-central Mississippi, 68% and 65% of total wood duck recruits from large and small boxes, respectively, were hatched and reared from June to August. In western Mississippi, 91% of recruits from each box size also were hatched and reared from June to August. Mean number of wood duck recruits produced from large boxes was greater than small boxes at each study site; each large box in western Mississippi produced approximately 4 recruits on average, whereas small boxes in east-central Mississippi produced approximately 1 recruit. Wood duck recruits in our study resulted primarily from late spring and summer hatched birds in contrast to most Nearctic ducks with adaptive, early nesting to promote recruitment. In Mississippi and similar southern environments, we recommend use of large boxes and cleaning boxes around 1 May after completion of initial nests, and emphasize the importance of late spring and summer duckling production to wood duck recruitment. © 2015 The Wildlife Society. [ABSTRACT FROM AUTHOR]

Abstract: Winter survival is an important fitness component of non-hibernating small mammals in northern latitudes. Body sizes are related to many life history traits influencing the fitness of animals. Counterbalancing selective forces of survival selection may optimize autumn body weight to maximize winter survival of non-hibernating small mammals. Brandt's voles (Lasiopodomys brandtii) are non-hibernating and live in groups year round. We live trapped Brandt's voles in an enclosure and estimated weekly survival probabilities and daily proportional body weight growth rates of the voles from September 2003 to March 2004. Autumn body weight as an individual covariate explained about 43% of variation in autumn–spring survival of the voles. Survival of females and males peaked at body weight of about 33 g and 51 g, respectively, supporting stabilizing survival selection on body sizes of Brandt's voles. However, breeding selection may reduce the optimal body size of female voles. Brandt's voles did not lose body weight during the autumn and winter probably to enhance winter survival. Therefore, Brandt's voles adapt to the energetically demanding winter environments with optimal body size and maximized winter survival. [Copyright &y& Elsevier]

Abstract: The double-crested cormorant is a native North American waterbird that recently underwent a dramatic population expansion. Population control efforts in the USA and Canada attempt to mitigate cormorant damages to natural resources and aquaculture. However, there is currently no coordination among the various stakeholders involved in management activities as well as no attempt to optimize population control efficiency. In this paper, we present for the first time a spatially explicit stage-structured metapopulation model parameterized for the cormorant. We developed simulation tools to get insights into the efficiency gain that can be expected from a better planning of management activities in both space and time. A case study is presented, in which we randomized where (on which colonies) and when (which years) a pre-determined amount of management activities would occur on 4 or 8 of 16 active colonies arranged on a 4×4 or 2×8 spatial grid over a period of 8 years, including 2 or 4 management years. We calculated two indices measuring the location of management activities, namely the average date of management years and the average degree of peripherality of colonies undertaking management, together with two indices measuring the resulting correlation of management activities, i.e., the degree of clustering of management activities both in space and time. Different spatio-temporal configurations of management activities generally yielded different metapopulation trajectories. Room for improving management efficiency increased with the intensity of management activities. However, the greatest efficiency gains are to be expected when colonies are far from carrying capacity, while the majority of management operations are undertaken when colonies are near or at carrying capacity. Locations of management activities in space and time appeared more important than resulting spatio-temporal correlations to explain the dispersion of metapopulation trajectories. When colonies were far from their individual carrying capacity, management was more efficient when applied earlier (a consequence of delayed reproductive maturity) and to more central colonies (due to greater immigration). The situation was more complex when colonies were closer to or at carrying capacity. Our modelling framework is flexible enough to allow more complex scenarios to be investigated in the future. [Copyright &y& Elsevier]

We investigated how individual strategies combine with demographic and ecological factors to determine local and migratory movements in the double-crested cormorants (Phalacrocorax auritus). One hundred and forty-five cormorants were captured from 14 nesting colonies across the Great Lakes area and fitted with satellite transmitters. We first tested the hypotheses that sexual segregation, density-dependent effects, and the intensity of management operations influenced home range size during the breeding season. The influence of these factors appeared to be limited in part due to random variability in foraging and dispersal decisions at individual and colony levels. We also designed a statistical framework to investigate the degree and determinants of migratory connectivity. Our analyses revealed a significant migratory connectivity in cormorants, although we also observed a nonnegligible amount of individual variability and flexibility. Our data were most consistent with the existence of a migratory divide across the Great Lakes, with western populations using mainly the Mississippi Flyway and eastern populations the Atlantic Flyway. Previous and current studies suggest that the divide cannot be explained by past divergence in isolation, a way to diminish travel cost, or the Appalachians constituting an ecological barrier per se but is rather the consequence of the distribution of suitable stopover and nonbreeding areas. However, a parallel migration system and no migratory divide could not be entirely ruled out with present data. [ABSTRACT FROM PUBLISHER]

Although spatial variation in climate can directly affect the survival and reproduction of forest insects and the tree species compositions of forests, little is known about the indirect effects of climate on outbreaks of forest insects through its effects on forest composition. In this study, we use structural equation modeling to examine the direct and indirect effects of climate, water capacity of the soil, host tree density, and non-host density on the spatial extent of Lymantria dispar outbreaks in the Eastern USA over a period of 44 years (1975–2018). Host species were subdivided into four taxonomic and ecologically distinct groups: red oaks (Lobatae), white oaks (Lepidobalanus), other preferred hosts, and intermediate (less preferred) hosts. We found that mean annual temperature had stronger effects than mean annual precipitation on the spatial extent of outbreaks, and that indirect effects of temperature (via its effects on oak density) on defoliation were stronger than direct effects. The density of non-host trees increased with increasing precipitation and, consistent with the 'associational resistance hypothesis', defoliation decreased with increasing density of non-host trees. This study offers quantitative evidence that geographic variation in climate can indirectly affect outbreaks of a forest insect through its effects on tree species composition. [ABSTRACT FROM AUTHOR]

Mechanical vibrations have a significant impact on the performance of cement-based materials in engineering. In this study, the particle distribution characteristics and hydration mechanism of cement-based paste during mechanical vibrations were clarified, including examination of hardened properties and thermodynamic modeling. X-ray fluorescence was used to determine the distribution of raw material particles. Differential thermal analysis was employed to characterize the in situ hydration process of paste. Thermodynamic modeling determines the dependency between raw material distribution and the corresponding hydration process. The results indicated that low-frequency vibrations extend the setting time and induce lower flexural strength of cement paste during early ages. Mechanical vibrations result in significant inhomogeneous distribution of element content, which was attributed to the difference in raw material composition. The hydration degree after mechanical vibrations decreased the pore-size distribution of hardened paste. The calculated particle distributions were inconsistent with the obtained hydration process and porosity development. [ABSTRACT FROM AUTHOR]

Examines the effect of juvenile recruitment, growth rates, survival and timing of sexual maturation among gray-tailed voles on the densities of each sex adult. Impact of stress due to anxiety, fear and crowding; Measurement of survival rates and population sizes; Average proportions of adult females that were reproductively active.

• The crystallinity of coal-series and water-washed kaolin are investigated. • The coal-series kaolin with poor crystallinity presents a lower pozzolanic activity. • The increase of amount of AlV and AlVI results in a higher pozzolanic activity. In this paper, we investigated the pozzolanic activity of thermal-activated coal-series kaolin and two types of water-washed kaolin, which were calcined at temperatures ranging from 600 to 700 °C for 3 h. Chapelle test and strength activity index were used to evaluate the pozzolanic activity of thermal-treated kaolin. Results indicated that thermal-activated water-washed kaolin presented a higher pozzolanic activity when calcined at same temperature, which is due to its well-defined morphology, relatively high specific surface area, and high amounts of active aluminum. The incorporation of 10 wt% of calcined kaolin significantly increased the amount of hydrate water and promoted strength development at 7 and 28 days. Moreover, the crystallinity of kaolinite showed obvious impacts on the dehydroxylation temperature and aluminum structure. The optimum dehydroxylation temperature is mainly dependent on the crystallinity of the kaolinite; in addition, the aluminium structure is closely related to the kaolinite crystallinity. Well-crystallized kaolin showed higher pozzolanic activity than poorly crystallized kaolin at the same calcination condition. [ABSTRACT FROM AUTHOR]

Spatial distribution and habitat selection are integral to the study of animal ecology. Habitat selection may optimize the fitness of individuals. Hutchinsonian niche theory posits the fundamental niche of species would support the persistence or growth of populations. Although niche‐based species distribution models (SDMs) and habitat suitability models (HSMs) such as maximum entropy (Maxent) have demonstrated fair to excellent predictive power, few studies have linked the prediction of HSMs to demographic rates. We aimed to test the prediction of Hutchinsonian niche theory that habitat suitability (i.e., likelihood of occurrence) would be positively related to survival of American beaver (Castor canadensis), a North American semi‐aquatic, herbivorous, habitat generalist. We also tested the prediction of ideal free distribution that animal fitness, or its surrogate, is independent of habitat suitability at the equilibrium. We estimated beaver monthly survival probability using the Barker model and radio telemetry data collected in northern Alabama, United States from January 2011 to April 2012. A habitat suitability map was generated with Maxent for the entire study site using landscape variables derived from the 2011 National Land Cover Database (30‐m resolution). We found an inverse relationship between habitat suitability index and beaver survival, contradicting the predictions of niche theory and ideal free distribution. Furthermore, four landscape variables selected by American beaver did not predict survival. The beaver population on our study site has been established for 20 or more years and, subsequently, may be approaching or have reached the carrying capacity. Maxent‐predicted increases in habitat use and subsequent intraspecific competition may have reduced beaver survival. Habitat suitability‐fitness relationships may be complex and, in part, contingent upon local animal abundance. Future studies of mechanistic SDMs incorporating local abundance and demographic rates are needed. [ABSTRACT FROM AUTHOR]

The aim of this study is to compare sinking beads (SB) with fly ash (FA) and metakaolin (MK) with regard to their ability to improve the performance of concretes. The workability, compressive strength, free shrinkage and chloride resistance of concretes with and without the above mineral admixtures are investigated. To explicate the differences of above results, the pore structure and pore solution chemistry were also studied. Besides, the Chapelle test was adopted to compare the pozzolanic activity of the mineral admixtures. The water-to-binder ratio of concretes and pastes was 0.35 by mass. The incorporation level of MK was 5 and 10 wt%, while that of FA and SB was 10, 20 and 30 wt%. A systematic improvement in flowability, compressive strength, chloride resistance, free shrinkage is observed for SB concretes compared with FA concretes due to the smaller particle size, more round particle shape and higher pozzolanic activity of SB. MK shows the overwhelming ability to improve compressive strength and chloride resistance ability of concretes compared with SB and FA for the same replacement level, but comparable compressive strength and chloride resistance for SB concretes can be obtained by increasing the content of SB. In addition, inclusion of 20 wt% SB demonstrates remarkable potential to reduce free shrinkage to 25% less than concretes with 10 wt% MK. It may be ascribed to the dense structure of SB, which brings less volume reduction or even some increase during pozzolanic reaction. [ABSTRACT FROM AUTHOR]

Objective: To compare postoperative outcomes between the perineal inverted-U and the vertical midline incision approaches of the urethroplasty and clarify them via gross anatomy.Patients and methods: A total of 461 male patients, from Jan. 2006 to Jun. 2014, who underwent the urethroplasty via perineal midline vertical or inverted-U incision approach were recruited retrospectively. By match pairing for etiology and stricture length, 410 patients from two groups (205 for each group) were selected. Anatomy experiments were also performed. Outcome measurements and statistical analysis: the Chi-square, Student’s t and binary logistic regression analyses were performed to compare the operative and postoperative data on the two groups.Results: With regard to patients with bulbar urethral stricture, the rate of surgical site infection (SSI) in perineal inverted-U group was 18.6% while 1.9% in the midline vertical group (p < 0.001). As for patients with posterior urethral stricture, the rate of SSI in the perineal inverted-U group was 16.4% while 3.1% in the midline vertical group (p = 0.001). Mean hospital stay between both groups were 15.8 ± 9.0 vs. 12.7 ± 3.8 days (p < 0.001). Anatomy experiments showed the number of damaged vessels and nerves involved in the inverted-U incision were approximately 1.6 to 2.0 folds more than the vertical midline, but the visual operation fields are similar between two approaches.Conclusions: The perineal midline vertical incision is a safer approach with fewer SSI and shorter hospital stay than the perineal inverted-U incision for bulbar and posterior urethroplasty. [ABSTRACT FROM AUTHOR]

The aim of this study was to improve the pozzolanic activity of metakaolin used as mineral additive in concrete by urea intercalation technique. A precursor, urea-kaolin (U-kaolin) with the intercalation degree of 92%, was prepared by evaporating the solvent from suspension containing original kaolin (O-kaolin) and urea. Two series of metakaolin were obtained by calcining the O-kaolin and U-kaolin at nine different temperatures from 550 °C–950 °C for 2 h. The pozzolanic activity of the two series of metakaolin were evaluated and compared by Fixation of Calcium Hydroxide (FCH) and mortar strength as well. In addition, X-ray diffraction, Fourier Transform Infrared Spectroscopy, Thermogravity-Differntial Scanning Calormetry, Brunauer-Emmett-Teller method and Scanning Electron Microscopy were also applied to study the microstructure of the precursor and mechanisms for the pozzolanic activity improvement. The results show that the pozzolanic activity of metakaolin calcined by U-kaolin is 15% higher in the FCH test and 20% higher in cement mortar strength test than the normal one when the calcination temperature is 800 °C. U-kaolin presents lower dehydroxylation temperature due to the weakened interlayer attractive force, and forms less inert component at high temperature due to the looser structure of calcined products. The joint effects of intercalated urea molecules in making precursor and calcination process result in looser structure and higher specific surface to improve of the pozzolanic activity. [ABSTRACT FROM AUTHOR]

Maternal and early-life influences may affect life-long individual phenotype, potentially influencing reproductive success. However, some individuals may compensate for a poor start to life, which may improve longevity and reproductive success later in life. We developed four models to assess whether maternal characteristics (age, body mass and previous year cumulative lactation demand) and/or birth date influenced a long-lived mammal's phenotype to maturity. We used a directional separation analysis to assess the relative influence of each maternal characteristic and birth date on captive male white-tailed deer ( Odocoileus virginianus) body mass and antler size. We found that birth date was the only characteristic that persistently influenced male body mass. Depending on when offspring were born, they used alternative tactics to increase their body mass. Birth date positively influenced body mass at 1, 2 and 3 years of age-indicating males displayed faster growth and compensated for late birth (hare tactic). However, early-, heavy-born males were heavy juveniles, and juvenile body mass positively influenced mature body mass (slow but steady growth; tortoise tactic). Our findings provide a first evidence that a long-lived ungulate can display alternative tactics to achieve heavy body mass; individuals are either born early and heavy and are heavy throughout life (tortoise), or light, late-born individuals compensate for a poor start in life by growing at a faster rate to equal or surpass the body mass of early-born individuals (hare). Either tactic may be viable if it influences reproductive success as body mass positively influences access to mates in ungulates. [ABSTRACT FROM AUTHOR]

In this research, the feasibility of using coral filler in Calcium sulfoaluminate (CSA) cements based materials is investigated, targeting at reducing transportation cost for the marine construction. Properties including setting time, mechanical properties and hydration kinetics are investigated. Two blended materials groups with and without anhydrite are tested. Then, their properties are compared with the plain CSA cement clinker samples (with and without quartz filler). The obtained results indicate that coral filler decreases the hydration heat and generates hemicarbonate instead of monosulfate. Moreover, the replacement of CSA cement clinker by coral filler can slightly decrease the setting time and improve the strength development of sulpho-aluminous cement based materials with limited anhydrite. However, the activity of coral filler decreases with the addition of anhydrite. In the group with sufficient anhydrite, the replacement of CSA cement clinker by coral filler has limited effect on the CSA cement hydration, and can decline the long-term mechanical properties of CSA cement based materials. [ABSTRACT FROM AUTHOR]

In this article, the T15M (belonging to a kind of high speed steel powder) composite coating with different Ti content was prepared by laser cladding technology (LCT). The microstructure and properties of the samples were investigated by scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), automatic micro hardness tester and multifunctional friction and wear testing machine. The results show that the microstructure of the T15M composite coating is mainly composed of martensite, austenite and carbides which mainly distribute on the original austenite grain boundaries. With the increase of titanium element, the shape of carbides become more spherical and the carbides on the grain boundaries change from continuous to discontinuous which attributes to the destruction of carbon concentration balance at the interface. In contrast to the T15M composite coating without adding titanium, the carbides distribution in the coating are more uniform relying on preferential homogeneous nucleation of titanium compounds in solidification. By hardness test, it can be discovered that the addition of titanium to T15M composite coating has no significant effect on the average hardness, but the fluctuation range of the microhardness value decreases. After the sliding wear test, both the coefficient of friction and the mass loss after wear are reduced with the addition of titanium. [ABSTRACT FROM AUTHOR]

• Less than 10% of PG could extend the setting time of AAS pastes. • Multiple tests were conducted to monitor the hydration process. • Ettringite could be generated in AAS samples with more gypsum. • PG made a retardation on the micro development of hardened structure. Effects of phosphogypsum (PG) on hydration process and microstructure of the alkali activated slag (AAS) pastes were discussed in this study, taking the natural gypsum (NG) as a reference. Hydration process was monitored by several kinds of measurements including the isothermal calorimetry, the electrical resistivity, the autogenous shrinkage and the 1H nuclear magnetic resonance. Hydration product assemblages were analyzed by the XRD, NMR, SEM and the mercury intrusion porosimetry (MIP)test. Results showed that less than 10 % of gypsums could retard the setting process of AAS pastes. PG could enhance the late strength although the early strength was decreased, but the addition of NG would reduce the strength at all ages. Induction period and the autogenous shrinkage were both reduced by gypsum gradually. Additionally, PG conducts to the higher MCL and higher polymerization degree of CASH gels than NG. And the addition of PG would refine the pore structure and produce a lower porosity than NG. Furthermore, the comprehensive analysis showed that the setting behavior happened at the initial dissolution period. And PG would delay the acceleration period, indicating the slower development of microstructure. [ABSTRACT FROM AUTHOR]