bluuebunny/crossref_metadata_2025_split huggingface dataset:
Needle morphological evidence of the homoploid hybrid origin of Pinus densata based on analysis of artificial hybrids and the putative parents, Pinus tabuliformis and Pinus yunnanensis
Authors: Xing Fangqian , Mao Jian‐Feng , Meng Jingxiang , Dai Jianfeng , Zhao Wei , Liu Hao , Xing Zhen , Zhang Hua , Wang Xiao‐Ru , Li Yue 
Published: April 2014

AbstractGenetic analyses indicate that Pinus densata is a natural homoploid hybrid originating from Pinus tabuliformis and Pinus yunnanensis. Needle morphological and anatomical features show relative species stability and can be used to identify coniferous species. Comparative analyses of these needle characteristics and phenotypic differences between the artificial hybrids, P. densata, and parental species can be used to determine the genetic and phenotypic evolutionary consequences of natural hybridization. Twelve artificial hybrid families, the two parental species, and P. densata were seeded in a high‐altitude habitat in Linzhi, Tibet. The needles of artificial hybrids and the three pine species were collected, and 24 needle morphological and anatomical traits were analyzed. Based on these results, variations in 10 needle traits among artificial hybrid families and 22 traits among species and artificial hybrids were predicted and found to be under moderate genetic control. Nineteen needle traits in artificial hybrids were similar to those in P. densata and between the two parental species, P. tabuliformis and P. yunnanensis. The ratio of plants with three needle clusters in artificial hybrids was 22.92%, which was very similar to P. densata. The eight needle traits (needle length, the mean number of stomata in sections 2 mm in length of the convex and flat sides of the needle, mean stomatal density, mesophyll/vascular bundle area ratio, mesophyll/resin canal area ratio, mesophyll/(resin canals and vascular bundles) area ratio, vascular bundle/resin canal area ratio) relative to physiological adaptability were similar to the artificial hybrids and P. densata. The similar needle features between the artificial hybrids and P. densata could be used to verify the homoploid hybrid origin of P. densata and helps to better understand of the hybridization roles in adaptation and speciation in plants.
A hidden Markov model to identify and adjust for selection bias: an example involving mixed migration strategies
Authors: Fieberg John R. , Conn Paul B. 
Published: April 2014

AbstractAn important assumption in observational studies is that sampled individuals are representative of some larger study population. Yet, this assumption is often unrealistic. Notable examples include online public‐opinion polls, publication biases associated with statistically significant results, and in ecology, telemetry studies with significant habitat‐induced probabilities of missed locations. This problem can be overcome by modeling selection probabilities simultaneously with other predictor–response relationships or by weighting observations by inverse selection probabilities. We illustrate the problem and a solution when modeling mixed migration strategies of northern white‐tailed deer (Odocoileus virginianus). Captures occur on winter yards where deer migrate in response to changing environmental conditions. Yet, not all deer migrate in all years, and captures during mild years are more likely to target deer that migrate every year (i.e., obligate migrators). Characterizing deer as conditional or obligate migrators is also challenging unless deer are observed for many years and under a variety of winter conditions. We developed a hidden Markov model where the probability of capture depends on each individual's migration strategy (conditional versus obligate migrator), a partially latent variable that depends on winter severity in the year of capture. In a 15‐year study, involving 168 white‐tailed deer, the estimated probability of migrating for conditional migrators increased nonlinearly with an index of winter severity. We estimated a higher proportion of obligates in the study cohort than in the population, except during a span of 3 years surrounding back‐to‐back severe winters. These results support the hypothesis that selection biases occur as a result of capturing deer on winter yards, with the magnitude of bias depending on the severity of winter weather. Hidden Markov models offer an attractive framework for addressing selection biases due to their ability to incorporate latent variables and model direct and indirect links between state variables and capture probabilities.
Geographic variation in seed traits within and among forty‐two species of Rhododendron (Ericaceae) on the Tibetan plateau: relationships with altitude, habitat, plant height, and phylogeny
Authors: Wang Yongji , Wang Jianjian , Lai Liming , Jiang Lianhe , Zhuang Ping , Zhang Lehua , Zheng Yuanrun , Baskin Jerry M. , Baskin Carol C. 
Published: April 2014

AbstractSeed mass and morphology are plant life history traits that influence seed dispersal ability, seeding establishment success, and population distribution pattern. Southeastern Tibet is a diversity center for Rhododendron species, which are distributed from a few hundred meters to 5500 m above sea level. We examined intra‐ and interspecific variation in seed mass and morphology in relation to altitude, habitat, plant height, and phylogeny. Seed mass decreased significantly with the increasing altitude and increased significantly with increasing plant height among populations of the same species. Seed mass differed significantly among species and subsections, but not among sections and subgenera. Seed length, width, surface area, and wing length were significantly negative correlated with altitude and significantly positive correlated with plant height. Further, these traits differed significantly among habitats and varied among species and subsection, but not among sections and subgenera. Species at low elevation had larger seeds with larger wings, and seeds became smaller and the wings of seeds tended to be smaller with the increasing altitude. Morphology of the seed varied from flat round to long cylindrical with increasing altitude. We suggest that seed mass and morphology have evolved as a result of both long‐term adaptation and constraints of the taxonomic group over their long evolutionary history.
A multiscale analysis of gene flow for the New England cottontail, an imperiled habitat specialist in a fragmented landscape
Authors: Fenderson Lindsey E. , Kovach Adrienne I. , Litvaitis John A. , O'Brien Kathleen M. , Boland Kelly M. , Jakubas Walter J. 
Published: April 2014

AbstractLandscape features of anthropogenic or natural origin can influence organisms' dispersal patterns and the connectivity of populations. Understanding these relationships is of broad interest in ecology and evolutionary biology and provides key insights for habitat conservation planning at the landscape scale. This knowledge is germane to restoration efforts for the New England cottontail (Sylvilagus transitionalis), an early successional habitat specialist of conservation concern. We evaluated local population structure and measures of genetic diversity of a geographically isolated population of cottontails in the northeastern United States. We also conducted a multiscale landscape genetic analysis, in which we assessed genetic discontinuities relative to the landscape and developed several resistance models to test hypotheses about landscape features that promote or inhibit cottontail dispersal within and across the local populations. Bayesian clustering identified four genetically distinct populations, with very little migration among them, and additional substructure within one of those populations. These populations had private alleles, low genetic diversity, critically low effective population sizes (3.2–36.7), and evidence of recent genetic bottlenecks. Major highways and a river were found to limit cottontail dispersal and to separate populations. The habitat along roadsides, railroad beds, and utility corridors, on the other hand, was found to facilitate cottontail movement among patches. The relative importance of dispersal barriers and facilitators on gene flow varied among populations in relation to landscape composition, demonstrating the complexity and context dependency of factors influencing gene flow and highlighting the importance of replication and scale in landscape genetic studies. Our findings provide information for the design of restoration landscapes for the New England cottontail and also highlight the dual influence of roads, as both barriers and facilitators of dispersal for an early successional habitat specialist in a fragmented landscape.
The causal pie model: an epidemiological method applied to evolutionary biology and ecology
Authors: Wensink Maarten , Westendorp Rudi G. J. , Baudisch Annette 
Published: April 2014

AbstractA general concept for thinking about causality facilitates swift comprehension of results, and the vocabulary that belongs to the concept is instrumental in cross‐disciplinary communication. The causal pie model has fulfilled this role in epidemiology and could be of similar value in evolutionary biology and ecology. In the causal pie model, outcomes result from sufficient causes. Each sufficient cause is made up of a “causal pie” of “component causes”. Several different causal pies may exist for the same outcome. If and only if all component causes of a sufficient cause are present, that is, a causal pie is complete, does the outcome occur. The effect of a component cause hence depends on the presence of the other component causes that constitute some causal pie. Because all component causes are equally and fully causative for the outcome, the sum of causes for some outcome exceeds 100%. The causal pie model provides a way of thinking that maps into a number of recurrent themes in evolutionary biology and ecology: It charts when component causes have an effect and are subject to natural selection, and how component causes affect selection on other component causes; which partitions of outcomes with respect to causes are feasible and useful; and how to view the composition of a(n apparently homogeneous) population. The diversity of specific results that is directly understood from the causal pie model is a test for both the validity and the applicability of the model. The causal pie model provides a common language in which results across disciplines can be communicated and serves as a template along which future causal analyses can be made.
Untangling the relationships among regional occupancy, species traits, and niche characteristics in stream invertebrates
Authors: Heino Jani , Grönroos Mira 
Published: April 2014

AbstractThe regional occupancy and local abundance of species are affected by various species traits, but their relative effects are poorly understood. We studied the relationships between species traits and occupancy (i.e., proportion of sites occupied) or abundance (i.e., mean local abundance at occupied sites) of stream invertebrates using small‐grained data (i.e., local stream sites) across a large spatial extent (i.e., three drainage basins). We found a significant, yet rather weak, linear relationship between occupancy and abundance. However, occupancy was strongly related to niche position (NP), but it showed a weaker relationship with niche breadth (NB). Abundance was at best weakly related to these explanatory niche‐based variables. Biological traits, including feeding modes, habit traits, dispersal modes and body size classes, were generally less important in accounting for variation in occupancy and abundance. Our findings showed that the regional occupancy of stream invertebrate species is mostly related to niche characteristics, in particular, NP. However, the effects of NB on occupancy were affected by the measure itself. We conclude that niche characteristics determine the regional occupancy of species at relatively large spatial extents, suggesting that species distributions are determined by environmental variation among sites.
Effect of cooking conditions on cholesterol oxidation and astaxanthin in dried salted shrimp
Authors: Hernández‐Becerra Josafat A. , Ochoa‐Flores Angélica A. , Soto‐Rodriguez Ida , Rodriguez‐Estrada Maria T. , García Hugo S. 
Published: April 2014

Dried salted shrimp is a product made from raw shrimps, which are usually cooked and dried under direct sunlight. Brine cooking is an important step during the production of dried salted shrimp as it promotes changes that affect the product's end quality. The aim of this study was to evaluate the effect of brine concentration and boiling time on cholesterol oxidation products (COPs) formation and the concomitant changes in astaxanthin content and fatty acid profile in shrimp during cooking, sun drying, and storage. Boiling conditions did not affect COPs formation in shrimp after cooking. However, increased brine concentration and boiling time promoted high astaxanthin retention in cooked shrimp. During the first 24 h of sun drying, COPs formation in dried salted shrimp was influenced by the interaction between brine concentration and boiling time; in fact, the lowest COPs levels were observed in samples boiled at low brine concentration and short cooking times, as well as those boiled in brine with high salt concentration and long cooking times. Most astaxanthin (ca. 78%) present in cooked shrimp was degraded during solar drying. During storage, PUFA decreased, and a concomitant astaxanthin degradation and COPs formation in dried salted shrimp were observed. Neither boiling time nor storage at dark of dried salted shrimp prevented these changes.Practical applications: The content of oxysterols in cooked dried shrimps can be minimized by optimizing the processing conditions to minimize the oxidation. This is useful for processors and consumers to reduce the intake of these toxic forms of cholesterol.COPs and astaxanthin in dried shrimp were analysed during cooking, solar drying and storage. The COPs content in dried shrimp showed a dramatic increase after solar drying. During the ﬁrst 24 h of sun drying, COPs formation in dried salted shrimp was inﬂuenced by the brine concentration and boiling time.
Mitigating pesticide pollution in China requires law enforcement, farmer training, and technological innovation
Authors: Li Huizhen , Zeng Eddy Y. , You Jing 
Published: April 2014

Abstract

To feed an ever-growing population, it is necessary to take all measures to increase crop yields, including the use of pesticides. It has long been a difficult task to boost agricultural production and simultaneously minimize the impact of pesticide application on the environment, particularly in China, a developing country with more than 1.3 billion people. China has recently become the world's leading producer and consumer of pesticides, with production and consumption reaching 265 tons and 179 tons, respectively, in 2011, and a national average pesticide application dosage of more than 14 kg/ha. The large quantities of pesticides applied in agricultural fields have resulted in serious environmental deterioration. Organochlorine pesticides, such as dichloro-diphenyl-trichloroethane and hexachlorohexane, have become ubiquitous in the environment of China, with spatial distributions in soils and aquatic systems similar to their historic application patterns in different geographic regions: southeast &gt; central &gt; northwest. Pollution by current-use pesticides, for example, organophosphates and pyrethroids, has also been of great concern. To mitigate pesticide pollution in China, a significant reduction in pesticide inputs into the environment is mandatory. This can be accomplished only with joint efforts by the government, professionals, and citizens in combination with rigorous enforcement of laws and regulations, training of farmers in pesticide knowledge and environmental awareness, and technological innovation for producing low-risk pesticides and developing efficient application approaches. Restoring contaminated sites is also an urgent task. Finally, food security and environmental pollution are not problems for a sole country, and international cooperation and communication are necessary. Environ Toxicol Chem 2014;33:963–971. © 2014 SETAC
Lanthanum ions intervened in enzymatic production and elimination of reactive oxygen species in leaves of rice seedlings under cadmium stress
Authors: Wang Cheng-Run , Wang Qin-Ying , Tian Yuan , Zhang Ji-Feng , Li Zhi-Xiao , Cao Peng , Zhu Mei , Li Ting-Ting 
Published: April 2014

Abstract

Rare earth elements at proper concentrations were observed to alleviate heavy metal stress. However, the potential mechanisms of alleviation are not clear. Thus, the present study focused on the mechanisms of lanthanum (La) ions on the generation and elimination of reactive oxygen species (ROS) production in leaves of rice seedlings hydroponically cultivated in 30 µM cadmium chloride (CdCl2) for 2 d. Results showed that the decline of superoxide (O2 · −) or hydrogen peroxide (H2O2) was attributed not only to the decreased expressions of nicotinamide adenine dinucleotide phosphate oxidases-related gene, protein synthesis, and isozymes, but also to the decrease of xanthine oxidase, diamine oxidase, and guaiacol peroxidases isozymes and activities. Genes and isozymes related to superoxide dismutase, catalase, and ascorbate peroxidase were also differentially upregulated to control ROS accumulation when proper concentrations of La were combined with 30 µM Cd. Based on the results, one may conclude that La at proper concentrations not only limited the generation of O2 · − and H2O2 from the enzymatic sources but also promoted the elimination of O2 · − and H2O2 via the upregulating expressions of antioxidant enzyme–related genes and activities in the rice seedling's leaves under Cd stress. Environ Toxicol Chem 2014;33:1656–1664. © 2014 SETAC
Rapid settling of nanoparticles due to heteroaggregation with suspended sediment
Authors: Velzeboer Ilona , Quik Joris T.K. , van de Meent Dik , Koelmans Albert A. 
Published: April 2014

Abstract

Sedimentation of engineered nanoparticles (ENPs) has been studied mainly in artificial media and stagnant systems mimicking natural waters. This neglects the role of turbulence and heteroaggregation with sediment. The authors studied the apparent sedimentation rates of selected ENPs (cerium dioxide [CeO2], polyvinylpyrrolidone-capped silver [PVP-Ag], and silica-coated silver [SiO2-Ag]) in agitated sediment–water systems resembling fresh, estuarine, and marine waters. Experiments were designed to mimic low energy and periodically resuspended sediment water systems (14 d), followed by a long-term aging, resuspension, and settling phase (6 months), as would occur in receiving shallow lakes. The ENPs in systems with periodical resuspension of sediment were removed with sedimentation rates between 0.14 m/d and 0.50 m/d. The sedimentation rates did not vary much among ENP type, salinity, and aging time, which is attributed to the capture of ENPs in sediment flocks. The sedimentation rates were 1 to 2 orders of magnitude higher than those reported for aggregation–sedimentation in stagnant systems without suspended sediment. Heteroaggregation rates were estimated and ranged between 0.151 L/mg/d and 0.547 L/mg/d, which is up to 29 times higher than those reported for natural colloids under quiescent settling conditions. The authors conclude that rapid scavenging and sedimentation drives removal of ENPs from the water column. Environ Toxicol Chem 2014;33:1766–1773. © 2014 SETAC
Shape analysis, a field in need of careful validation
Authors: Gao Yi , Riklin‐Raviv Tammy , Bouix Sylvain 
Published: April 2014

AbstractIn the last two decades, the statistical analysis of shape has become an actively studied field and finds applications in a wide range of areas. In addition to algorithmic development, many researchers have distributed end‐user orientated toolboxes, which further enable the utilization of the algorithms in an “off the shelf” fashion. However, there is little work on the evaluation and validation of these techniques, which poses a rather serious challenge when interpreting their results. To address this lack of validation, we design a validation framework and then use it to test some of the most widely used toolboxes. Our initial results show inconsistencies and disagreement among four different methods. We believe this type of analysis to be critical not only for the community of algorithm designers but also perhaps more importantly to researchers who use these tools without knowing the algorithm details and seek objective criteria for tool selection. Hum Brain Mapp 35:4965–4978, 2014. © 2014 Wiley Periodicals, Inc.
The influence of group membership and individual differences in psychopathy and perspective taking on neural responses when punishing and rewarding others
Authors: Molenberghs Pascal , Bosworth Rebecca , Nott Zoie , Louis Winnifred R. , Smith Joanne R. , Amiot Catherine E. , Vohs Kathleen D. , Decety Jean 
Published: April 2014

AbstractUnderstanding how neural processes involved in punishing and rewarding others are altered by group membership and personality traits is critical in order to gain a better understanding of how socially important phenomena such as racial and group biases develop. Participants in an fMRI study (n = 48) gave rewards (money) or punishments (electroshocks) to in‐group or out‐group members. The results show that when participants rewarded others, greater activation was found in regions typically associated with receiving rewards such as the striatum and medial orbitofrontal cortex, bilaterally. Activation in those regions increased when participants rewarded in‐group compared to out‐group members. Punishment led to increased activation in regions typically associated with Theory of Mind including the medial prefrontal cortex and posterior superior temporal sulcus, as well as regions typically associated with perceiving others in pain such as the dorsal anterior cingulate cortex, anterior insula and lateral orbitofrontal cortex. Interestingly, in contrast to the findings regarding reward, activity in these regions was not moderated by whether the target of the punishment was an in‐ or out‐group member. Additional regression analysis revealed that participants who have low perspective taking skills and higher levels of psychopathy showed less activation in the brain regions identified when punishing others, especially when they were out‐group members. In sum, when an individual is personally responsible for delivering rewards and punishments to others, in‐group bias is stronger for reward allocation than punishments, marking the first neuroscientific evidence of this dissociation. Hum Brain Mapp 35:4989–4999, 2014. © 2014 Wiley Periodicals, Inc.