Factors Influencing Copulation Duration in Dastarcus helophoroides (Fairmaire) (Coleoptera: Bothrideridae)

The gregarious ectoparasitic beetle Dastarcus helophoroides (Fairmaire) is considered a primary biocontrol agent for controlling several cerambycid pests in East Asian countries. A thorough study of reproductive behavior is a prerequisite for the mass production of natural insect predators. Nonetheless, little attention has been given to this ectoparasitic beetle. We performed a series of trials to assess whether the adult copulation duration, a key behavioral trait, is differentially influenced by physiological and ecological factors, including body size, mating history, kinship, sex ratio, mating sequence, feeding status, ambient temperature, photoperiod, and time of day. Additionally, the effect of the copulation duration on the reproductive output of this beetle was also investigated. The results indicated that the copulation duration varied considerably, ranging from 1.12 min to 16.40 min and lasting for an average of 9.11 ± 0.12 min. Females with longer copulations laid more eggs and had a greater proportion of eggs hatched. Medium-sized individuals copulated significantly longer than small- and large-sized individuals. The copulation durations were significantly longer when both sexes experienced an asymmetric mating history than when both sexes experienced a symmetric mating history. Inbred couples copulated significantly longer than outbred couples. In terms of the adult sex ratio, increasing the density of females (polygamous group) or males (polyandrous group) led to significantly longer copulation durations than those in the monogamous group. The copulation durations gradually decreased with increasing the mating sequence and temperature. Food-absence couples copulated significantly longer than food-presence couples. The mean copulation duration of the scotophase was significantly longer than that of the photophase. These results demonstrate that all of the analyzed factors emerge as important factors influencing the copulation duration, ultimately affecting the reproductive outputs in this ectoparasitic beetle.

Predicting Risk of Bullying Victimization among Primary and Secondary School Students: Based on a Machine Learning Model

School bullying among primary and secondary school students has received increasing attention, and identifying relevant factors is a crucial way to reduce the risk of bullying victimization. Machine learning methods can help researchers predict and identify individual risk behaviors. Through a machine learning approach (i.e., the gradient boosting decision tree model, GBDT), the present longitudinal study aims to systematically examine individual, family, and school environment factors that can predict the risk of bullying victimization among primary and secondary school students a year later. A total of 2767 participants (2065 secondary school students, 702 primary school students, 55.20% female students, mean age at T1 was 12.22) completed measures of 24 predictors at the first wave, including individual factors (e.g., self-control, gender, grade), family factors (family cohesion, parental control, parenting style), peer factor (peer relationship), and school factors (teacher-student relationship, learning capacity). A year later (i.e., T2), they completed the Olweus Bullying Questionnaire. The GBDT model predicted whether primary and secondary school students would be exposed to school bullying after one year by training a series of base learners and outputting the importance ranking of predictors. The GBDT model performed well. The GBDT model yielded the top 6 predictors: teacher-student relationship, peer relationship, family cohesion, negative affect, anxiety, and denying parenting style. The protective factors (i.e., teacher-student relationship, peer relationship, and family cohesion) and risk factors (i.e., negative affect, anxiety, and denying parenting style) associated with the risk of bullying victimization a year later among primary and secondary school students are identified by using a machine learning approach. The GBDT model can be used as a tool to predict the future risk of bullying victimization for children and adolescents and to help improve the effectiveness of school bullying interventions.

The asymmetry in the sagitta of four mugilid species obtained from Köyceğiz Lagoon, Aegean Sea, Turkey

Otolith features such as size and weight were analysed in 656 fish specimens of Chelon auratus, Chelon labrosus, Chelon saliens and Mugil cephalus collected from the Köyceğiz Lagoon System, Aegean Sea, southwest Turkey. The aim was to calculate the asymmetry value of the otolith length (OL), otolith width (OW) and otolith weight (OWe). The asymmetry value of OL was greater than that of OW and OWe. The asymmetry value of the three otolith parameters increased with an increase in the fish's length. The probable cause of asymmetry in the otolith parameters investigated has been determined relative to the variability in growth prompted by ecological impact linked with the disparity in water temperature, salinity, depth and contaminants existing in the Köyceğiz Lagoon System.

Integrated Land Suitability Assessment for Depots Siting in a Sustainable Biomass Supply Chain

A sustainable biomass supply chain would require not only an effective and fluid transportation system with a reduced carbon footprint and costs, but also good soil characteristics ensuring durable biomass feedstock presence. Unlike existing approaches that fail to account for ecological factors, this work integrates ecological as well as economic factors for developing sustainable supply chain development. For feedstock to be sustainably supplied, it necessitates adequate environmental conditions, which need to be captured in supply chain analysis. Using geospatial data and heuristics, we present an integrated framework that models biomass production suitability, capturing the economic aspect via transportation network analysis and the environmental aspect via ecological indicators. Production suitability is estimated using scores, considering both ecological factors and road transportation networks. These factors include land cover/crop rotation, slope, soil properties (productivity, soil texture, and erodibility factor) and water availability. This scoring determines the spatial distribution of depots with priority to fields scoring the highest. Two methods for depot selection are presented using graph theory and a clustering algorithm to benefit from contextualized insights from both and potentially gain a more comprehensive understanding of biomass supply chain designs. Graph theory, via the clustering coefficient, helps determine dense areas in the network and indicate the most appropriate location for a depot. Clustering algorithm, via K-means, helps form clusters and determine the depot location at the center of these clusters. An application of this innovative concept is performed on a case study in the US South Atlantic, in the Piedmont region, determining distance traveled and depot locations, with implications on supply chain design. The findings from this study show that a more decentralized depot-based supply chain design with 3depots, obtained using the graph theory method, can be more economical and environmentally friendly compared to a design obtained from the clustering algorithm method with 2 depots. In the former, the distance from fields to depots totals 801,031,476 miles, while in the latter, it adds up to 1,037,606,072 miles, which represents about 30% more distance covered for feedstock transportation.

Gradual genome size evolution and polyploidy in Allium from the Qinghai-Tibetan Plateau

BACKGROUND AND AIMS

Genome size is an important plant trait, with substantial interspecies variation. The mechanisms and selective pressures underlying genome size evolution are important topics in evolutionary biology. There is considerable diversity in Allium from the Qinghai-Tibetan Plateau, where genome size variation and related evolutionary mechanisms are poorly understood.

METHODS

We reconstructed the Allium phylogeny using DNA sequences from 71 species. We also estimated genome sizes of 62 species, and determined chromosome numbers in 65 species. We examined the phylogenetic signal associated with genome size variation, and tested how well the data fit different evolutionary models. Correlations between genome size variations and seed mass, altitude and 19 bioclimatic factors were determined.

KEY RESULTS

Allium genome sizes differed substantially between species and within diploids, triploids, tetraploids, hexaploids and octaploids. Size per monoploid genome (1Cx) tended to decrease with increasing ploidy levels. Allium polyploids tended to grow at a higher altitude than diploids. The phylogenetic tree was divided into three evolutionary branches. The genomes in Clade I were mostly close to the ancestral genome (18.781 pg) while those in Clades II and III tended to expand and contract, respectively. A weak phylogenetic signal was detected for Allium genome size. Furthermore, significant positive correlations were detected between genome size and seed mass, as well as between genome size and altitude. However, genome size was not correlated with 19 bioclimatic variables.

CONCLUSIONS

Allium genome size shows gradual evolution, followed by subsequent adaptive radiation. The three well-supported Allium clades are consistent with previous studies. The evolutionary patterns in different Allium clades revealed genome contraction, expansion and relative stasis. The Allium species in Clade II may follow adaptive radiation. The genome contraction in Clade III may be due to DNA loss after polyploidization. Allium genome size might be influenced by selective pressure due to the conditions on the Qinghai-Tibetan Plateau (low temperature, high UV irradiation and abundant phosphate in the soil).

Exploring Help-Seeking Predictors Among Colombian Victims of Intimate Partner Violence in Different Age Groups

This study examined the extent, source, and individual, microsystem, exosystem, and macrosystem-level (Heise's Ecological Model) predictors of help-seeking behaviors among women of different age groups in Colombia. Data on 12,915 married or cohabitating women who had experienced diverse forms of intimate partner violence (IPV) were obtained from the Colombia Demographic Health Survey 2015. More than half of the Colombian women who reported some form of IPV experience did not seek any help. Women aged 25-39 were less likely to seek help. Type of violence and experience of IPV and education were the strongest predictors of help-seeking among women in all age groups. Implications for research and programming are discussed.

What Ecological Factors Favor Parthenogenesis over Sexual Reproduction? A Study on the Facultatively Parthenogenetic Mayfly Alainites muticus in Natural Populations

AbstractDifferent reproductive modes are characterized by costs and benefits that depend on ecological contexts. For example, sex can provide benefits under complex biotic interactions, while its costs increase under mate limitation. Furthermore, ecological contexts often vary along abiotic gradients. Here, we study how these factors simultaneously influence the frequency of sex in the facultatively parthenogenetic mayfly Alainites muticus. We first verified that parthenogenesis translates into female-biased population sex ratios. We then measured the density of individuals (a proxy for mate limitation) and community diversity (biotic interaction complexity) for 159 A. muticus populations covering a broad altitudinal gradient and used structural equation modeling to investigate their direct and indirect influences on sex ratios. We found no effect of community diversity or altitude on sex ratios. Furthermore, even when females can reproduce parthenogenetically, they generally reproduce sexually, indicating that the benefits of sex exceed its costs in most situations. Sex ratios become female-biased only under low population densities, as expected if mate limitation was the main factor selecting for parthenogenesis. Mate limitation might be widespread in mayflies because of their short adult life span and limited dispersal, which can generate strong selection for reproductive assurance and may provide a stepping stone toward obligate parthenogenesis.

Determining Effective Environmental Factors in the Distribution of Endangered Endemic Medicinal Plant Species Using the BMLR Model: The Example of Wild Celery (Kelussia odoratissima Mozaff., Apiaceae) in Zagros (Iran)

Kelussia odoratissima Mozaff. is a medicinal species native to Iran. The goal of this research was to determine the environmental factors important for the distribution of K. doratissima in Iran using BMLR modeling. Six random transects were established throughout the species’ habitat, and 220 quadrats with an area of 4 m2 were plotted. The canopy cover percentages of K. doratissima were estimated in each quadrat. Topographic factors, including elevation, slope, and aspect maps, were generated by creating DEM images. Land use, land evaluation, evaporation, temperature, and precipitation maps of the area were created accordingly. The data collected from the experiments were analyzed using the Minitab and R statistical packages. To determine the effect of the studied factors in the distribution of K. doratissima, we ran a set of backward multiple linear regressions. The results showed that the effects of evaporation, elevation, and slope were significant in the species’ distribution, with elevation having a positive effect and evaporation and slope showing negative effects. Further, elevation had the highest effect on distribution (greatest absolute value of beta at 9.660). The next most significant factors in the plant’s distribution were evaporation (beta = 8.282) and slope (beta = 0.807), respectively.

[DNA methylation diversity analysis of Lycium barbarum samples from different cultivation areas based on MSAP]

Obvious epigenetic differentiation occurred on Lycium barbarum in different cultivation areas in China. To investigate the difference and change rule of DNA methylation level and pattern of L. barbarum from different cultivation areas in China, the present study employed fluorescence-assisted methylation-sensitive amplified polymorphism(MSAP) to analyze the methylation level and polymorphism of 53 genomic DNA samples from Yinchuan Plain in Ningxia, Bayannur city in Inner Mongolia, Jingyuan county and Yumen city in Gansu, Delingha city in Qinghai, and Jinghe county in Xinjiang. The MSAP technical system suitable for the methylation analysis of L. barbarum genomic DNA was established and ten pairs of selective primers were selected. Among amplified 5'-CCGG-3' methylated sites, there were 35.85% full-methylated sites and 39.88% hemi-methylated sites, showing a high degree of epigenetic differentiation. Stoichiometric analysis showed that the ecological environment was the main factor affecting the epigenetic characteristics of L. barbarum, followed by cultivated varieties. Precipitation, air temperature, and soil pH were the main ecological factors affecting DNA methylation in different areas. This study provided a theoretical basis for the analysis of the epigenetic mechanism of L. barbarum to adapt to the diffe-rent ecological environments and research ideas for the introduction, cultivation, and germplasm traceability of L. barbarum.

A Narrative Case Study of Chinese Senior High School English Teachers' Emotions: An Ecological Perspective

Teacher emotion research is of great significance to teachers’ teaching effectiveness, professional development, and physical and mental health. Taken from an ecological perspective, this narrative case study used purposeful sampling to select two Chinese senior high school English teachers as research participants. Various data collection methods were used, including narrative framework, teacher interview and teacher reflection log, to describe the emotional episodes of Chinese senior high school English teachers before and after collective lesson presentation, trial teaching, and formal teaching in a teaching improvement project. The purpose of this collection of data was to explore the dynamic emotional development process and characteristics of Chinese senior high school English teachers in the interaction with ecological systems and those ecological factors that may influence their emotional development. Results indicated that the two participants developed 68 emotions: 39 positive and 29 negative emotions. At exosystem, they developed the most emotions (28 emotions). Teacher emotion changed with time quite obviously. They evolved from positive to negative and, finally, predominantly positive. Personal antecedents, contextual antecedents, and teachers’ emotional capacity are the main ecological factors that may influence the development of teacher emotion. Based on the research findings, implications for teachers’ professional development and teacher education were also provided.

Environmental and anthropogenic effects on the nesting patterns of Nigeria-Cameroon chimpanzees in North-West Cameroon

Environmental conditions and human activity influence the selection of nest sites by chimpanzees and may have serious conservation implications. We examined the characteristics of nesting trees preferred by chimpanzees, investigated the effect of vegetation composition and topography on nest site locations and seasonality on nesting heights of chimpanzees, and verified the effect of predator occurrence and human activity on the nesting behavior of the Nigeria-Cameroon chimpanzee (Pan troglodytes ellioti) in Kom-Wum Forest Reserve (KWFR) and surrounding unprotected forest in Cameroon. We recorded 923 nests, 502 signs of human activity, and 646 nesting trees along line transects and recces (reconnaissance) for two seasons. We found that chimpanzees constructed more arboreal nests on tall primary trees with high lowest branch height and large diameter at breast height. Moreover, they oriented their nests within trees in the slope direction when the nesting trees were located on slopes. Additionally, the occurrence of chimpanzee nests was positively related to increasing elevation and slope and decreased with distance to primary forest. In contrast, the number of nests increased with distance to secondary forest, open land, and villages, and nesting height was not influenced by seasons. While we recorded no signs of large nocturnal chimpanzee predators at nesting trees, we found signs of hunting activity at nesting locations. Nesting high in trees is likely a way of avoiding hunting, while nest orientation within trees in slope direction shortens escape routes from human hunters. Our findings suggest that chimpanzees select safe trees (tall trees with high lowest branch height) located in nesting areas (primary forest, high elevation, and steep slopes) that are not easily accessible by humans. Therefore, conservation efforts should focus on protecting primary forests at high elevation and steep slopes and reducing human impact.

[Effects of ecological factors on shape and ginsenoside of Panax ginseng]

The ecological environment is closely related to the growth and quality of authentic medicinal materials. Ginseng is very strict with its natural environment and grows mostly in the damp valleys of forests, and the appearance and chemical composition of ginseng under different growth environments are very different. This article reviews the effects of different ecological factors(including light, temperature, altitude, moisture, soil factors, etc.)on the appearance and chemical composition(mainly ginsenosides) of ginseng. Through systematic review, it is found that soil physical factors are the most important ecological factors that affect the appea-rance of ginseng, and soil bulk density plays a key role; temperature affects ginsenosides in ginseng medicinal materials The dominant ecological factors for the accumulation of chemical ingredents; strong light, high altitude, high soil moisture, low soil nutrient and strong acid soil can influence the accumulation of secondary metabolites in ginseng. Environmental stress can also stimulate the formation and accumulation of secondary metabolites in medicinal plants. Appropriate low temperature stress, high or low water stress, acid or alkali stress can also promote the accumulation of ginsenosides. This article systematically reviews the ecological factors that affect the appearance and chemical composition of ginseng, and clarifies the dominant ecological factors and limiting factors for the formation of ginseng's appearance and quality, as well as beneficial environmental stress factors, in order to provide a theoretical basis for ginseng ecological planting and ginseng quality improvement.

The quality of wild Salvia miltiorrhiza from Dao Di area in China and its correlation with soil parameters and climate factors

INTRODUCTION

Salvia miltiorrhiza is a frequently used herb in traditional Chinese medicine, and tanshinone IIA (Tan IIA) and salvianolic acid B (Sal Acid B) are two major extracts obtained from its dried root. The quality of herbal ingredients can be affected by environmental factors.

OBJECTIVE

To evaluate the quality of wild S. miltiorrhiza and investigate the influence of soil constituents and parameters as well as climatic conditions and factors on the content of Tan IIA and Sal Acid B.

METHODOLOGY

We collected samples in 12 natural locations in the Dao Di area in China, the area in which S. miltiorrhiza grows, that results in a distinctive higher quality of medicinal materials from the harvested plant. The concentrations of Tan IIA and Sal Acid B were measured by high-performance liquid chromatography (HPLC). Soil total carbon, total nitrogen, available nitrogen, available phosphorus, available potassium, and particle size distribution were determined. We also collected climate data using ArcGIS from the WorldClim database, and correlation tests, redundancy, and regression analyses were conducted to analyse the relationship and cluster the samples according to their chemical profile.

RESULTS

The content of Tan IIA and Sal Acid B in most of the samples was significantly different (P < 0.05). Soil available phosphorus was considered as a key factor that influenced the quality of wild S. miltiorrhiza, and we found a significant negative association between the concentration of Tan IIA in roots and soil available phosphorus. Moreover, the accumulation of Tan IIA in S. miltiorrhiza was also significantly associated with precipitation in April, May, and October, maximum temperature in January, and standard deviation of temperature seasonality. There was no significant correlation between the content of Sal Acid B and ecological factors. In addition, samples collected from Mengshan, Hexian, and Lushi locations were rich in Tan IIA and tended to cluster together, whereas samples collected from Longquan and Huoshan locations tended to cluster and were poor in Tan IIA.

CONCLUSION

The Tan IIA content in samples collected from southern Anhui was significantly lower than that in other Dao Di locations. The content of Tan IIA was related more to the soil than the temperature. Compared with Tan IIA, Sal Acid B was less influenced by soil and climate factors. The findings of this study may provide helpful references for quality control of medicinal plants that exert pharmacological effects in humans.

Exploration of population ecological factors related to the spatial heterogeneity of dengue fever cases diagnosed through a national network of laboratories in India, 2017

Background & objectives:

Dengue virus (DENV) transmission is known to be influenced by the environmental conditions. During 2017, the Viral Research and Diagnostic Laboratories (VRDLs) tested 78,744 suspected dengue fever (DF) patients, of whom, 21,260 were laboratory confirmed. The objectives of the study were to evaluate the hypothesis that spatial heterogeneity existed for DF patients and to identify significant determinants of DENV transmission in various districts across the Indian States during 2017.

Methods:

Laboratory confirmed DF cases were analysed from 402 districts spread across the Indian States. The determinants for DF transmission included in the model were population density, proportion of population living in rural areas, proportion of forest cover area to the total geographical area, proportion of persons not able to read and write and who were aged greater than seven years; the climatic variables considered were minimum, maximum and average temperature, precipitation and cumulative rainfall. The spatial heterogeneity was assessed using spatial regression analysis.

Results:

DF cases showed strong spatial dependency, with Moran's I=4.44 (P<0.001). The robust measure for spatial lag (6.55; P=0.01) was found to be the best model fit for the data set. Minimum temperature and cumulative rainfall were significant predictors.

Interpretation & conclusions:

A significant increase in the number of dengue cases has occurred when the minimum temperature was 23.0-25.8°C and the cumulative rainfall 118.14-611.64 mm across the Indian districts. Further in-depth investigations incorporating more number of demographic, ecological and socio-economic factors would be needed for robust conclusions.

Environmental and ecological factors of stomach cancer incidence and mortality: a systematic review study on ecological studies

OBJECTIVES

Stomach cancer (SC) is one of the most common and deadly types of cancer. It is the third leading cause of cancer deaths worldwide. The effect of environmental and ecological factors in SC have been assessed in some studies. Thus, we aimed to synthesize the environmental and ecological factors of SC incidence and mortality.

CONTENT

In this systematic review study, the scientific databases, including Web of Science, Scopus and PubMed, were searched from inception to November 2019 for all primary articles written in English by using relevant Medical Subject Heading (Mesh) terms. Two independent authors conducted the screening process to decide on the eligibility and inclusion of the articles in the study. The third author acted as an arbiter to resolve any disagreements.

SUMMARY AND OUTLOOK

A total of 157 potentially relevant articles were identified from the initial search 38 of which met the eligibility criteria; finally, 34 articles were included in the systematic review. The results revealed that soil arsenic exposure, coal and other opencast mining installations, living near incinerators and installations for the recovery or disposal of hazardous waste, installations for the production of cement, lime, plaster, and magnesium oxide, proximity to a metal industry sources, dietary iron, ingested asbestos, farming, arsenic in soil, altitude, organochlorines and environmental exposure to cadmium and lead have positive associations with SC incidence or death. Most of the ecological and environmental factors such as living near the mineral industries, the disposal of hazardous waste, metal industry sources and environmental exposure to cadmium and lead are positively related to SC mortality and incidence. However, solar UV-B, heat index and dietary zinc can be taken into account as protective factors against SC mortality and incidence.

Impact of various ecological parameters on the life-history characteristics of Bufotes viridis sitibundus from Turkey

In this study, we used the skeletochronology method to estimate various growth parameters, such as age structure, minimum and maximum life span, age of sexual maturity, and the relationship between body size and weight of eight different populations of the variable toad, Bufotes viridis sitibundus, in Turkey. Further, we determined the relationship between these parameters and ecologic factors using the partial Mantel test. A significant difference was found among the populations with respect to age, body size, and body weight in both males and females. On average, the maximum life span was recorded as 10 years for males and 11 years for females. In the studied populations, the average age of sexual maturity ranged between 2 and 4 years for both sexes. Sexual dimorphism in terms of snout-vent length (SVL) was not observed between males and females in all the populations. Toads from the higher altitudes tended to be significantly larger, older, and heavier than those from lower altitudes. We concluded that altitude and temperature have an impact on the growth rate, body size, and body mass.

Effect of ecological factors on fine-scale patterns of social structure in African lions

Environmental variations can influence the extent to which individuals interact with other individuals by changing the value of grouping. It is well known that many species can form and disband groups, often in response to the distribution and abundance of resources. While previous studies showed that resources influence the broad-scale structure of animal groups, knowledge gaps remain on whether they affect fine-scale patterns of association among individuals within groups. We quantify association patterns in African lions while simultaneously monitoring the abundance and distribution of prey. We test how social and ecological factors, including individual trait (age, sex, reproductive state) similarity and prey availability (prey abundance, dispersion, herd size and body size) affect within-pride social structure in African lions. We found that individual decisions about associates depended on resource availability with individuals associating equally across all members of the pride when prey herds were scarce, aggregated or large bodied, and associating more exclusively (in subgroups of preferred associates) when prey herds were abundant, dispersed or small bodied. Individuals within lion prides seemed to be buffering against changes in prey availability by modulating their strength and density of connections with conspecifics when prides split into subgroups. The strength and density of connections among individuals within subgroups was greater when prey herds were large and lower when prey herds were dispersed or are large bodied. Our findings suggest that individual lions are making social decisions at both the subgroup level and the pride level, with decisions representing putatively fitness-enhancing strategies. Individuals were typically shifting between having few strong connections and having many weaker connections depending on prevailing ecological conditions, with prey abundance, dispersion and body size having the greatest impact on decisions about splitting into subgroups. The maintenance of connections within prides and subgroups in the face of ecological change suggests that the fission-fusion nature of lion prides might be essential for the long-term maintenance of social connections even when short-term conditions do not allow them. More broadly, our study reveals how fission-fusion dynamics and ecological factors can simultaneously have an effect on animals across multiple levels of sociality.

Changes in Metabolome and Nutritional Quality of Lycium barbarum Fruits from Three Typical Growing Areas of China as Revealed by Widely Targeted Metabolomics

This study aimed at assessing the climatic factors influencing the wolfberry fruit morphology, and the composition of its nutritious metabolites. The cultivar Ningqi1, widely grown in Northwest China was collected from three typical ecological growing counties with contrasting climatic conditions: Ningxia Zhongning (NF), Xinjiang Jinghe (XF) and Qinghai Nomuhong (QF). During the ripening period, 45 fruits from different plantations at each location were sampled. A total of 393 metabolites were detected in all samples through the widely targeted metabolomics approach and grouped into 19 known classes. Fruits from QF were the biggest followed by those from XF and NF. The altitude, relative humidity and light intensity had negative and strong correlations with most of the metabolites, suggesting that growing wolfberry in very high altitudes and under high light intensity is detrimental for the fruit nutritional quality. Soil moisture content is highly and negatively correlated with vitamins, organic acids and carbohydrates while moderately and positively correlated with other classes of metabolites. In contrast, air and soil temperatures exhibited positive correlation with majority of the metabolites. Overall, our results suggest high soil and air temperatures, low altitude and light intensity and moderate soil moisture, as the suitable conditions to produce Lycium fruits with high content of nutritious metabolites.

Polyphenols of Leaf, Litter and Soil of Pinus bungeana across China and Their Responses to Ecological Factors

The importance of phenolic compounds for responding to various environmental conditions has been widely emphasized. However, the role of interactions between polyphenols and ecological factors, especially C, N, and P stoichiometry was little studied. Here, 15 sites across five provinces of Pinus bungeana in temperate regions of China were studied. The results showed that the higher values of total phenolic contents (TPC) of leaf and litter were distributed among the north distribution area of P. bungeana, lower values were in the south, whereas soil TPC were contrary to leaf and litter TPC. The stepwise regression, path analysis and decision index of path analysis for leaf TPC and ecological factors showed that altitude had the most direct impact on leaf TPC. Moreover, the principal determinants of leaf, litter and soil TPC were soil C/P ratios, longitude, and soil N/P ratios, respectively. In addition, the leaf, litter and soil TPC of P. bungeana were limited by soil C/N ratios, mean annual temperature, and soil P, respectively. Overall, our study provided evidence that ecological factors affected strongly the leaf, litter and soil TPC of P. bungeana.

Environmental factors affect the distribution of two Epichloë fungal endophyte species inhabiting a common host grove bluegrass (Poa alsodes)

AIM

The endophyte Epichloë alsodes, with known insecticidal properties, is found in a majority of Poa alsodes populations across a latitudinal gradient from North Carolina to New York. A second endophyte, E. schardlii var. pennsylvanica, with known insect-deterring effects, is limited to a few populations in Pennsylvania. We explored whether such disparate differences in distributions could be explained by selection from biotic and abiotic environmental factors.

LOCATION

Along the Appalachian Mountains from North Carolina to New York, USA.

TAXON

Fungi.

METHODS

Studied correlations of infection frequencies with abiotic and biotic environmental factors. Checked endophyte vertical transmission rates and effects on overwintering survival. With artificial inoculations for two host populations with two isolates per endophyte species, tested endophyte-host compatibility. Studied effects of isolates on host performances in greenhouse experiment with four water-nutrients treatments.

RESULTS

Correlation analysis revealed positive associations of E. alsodes frequency with July Max temperatures, July precipitation, and soil nitrogen and phosphorous and negative associations with insect damage and soil magnesium and potassium. Plants infected with E. alsodes had increased overwintering survival compared to plants infected with E. schardlii or uninfected (E-) plants. Artificial inoculations indicated that E. alsodes had better compatibility with a variety of host genotypes than did E. schardlii. The experiment with reciprocally inoculated plants grown under different treatments revealed a complexity of interactions among hosts, endophyte species, isolate within species, host plant origin, and environmental factors. Neither of the endophyte species increased plant biomass, but some of the isolates within each species had other effects on plant growth such as increased root:shoot ratio, number of tillers, and changes in plant height that might affect host fitness.

MAIN CONCLUSION

In the absence of clear and consistent effects of the endophytes on host growth, the differences in endophyte-mediated protection against herbivores may be the key factor determining distribution differences of the two endophyte species.

How soil granulometry, temperature, and water predict genetic differentiation in Namibian spiders (Ariadna: Segestriidae) and explain their behavior

The Namib Desert is a biodiversity hotspot for many invertebrates, including spiders. Tube-dwelling spiders belonging to the Ariadna genus are widespread in gravel plains. These sit-and-wait predators share a particular behavior, as they spend their life in tunnels in the soil, surrounding the entrance of their burrow with stone rings. We investigated five spider populations taking into account environmental parameters, functional traits, and molecular data. We have chosen the temperature at the soil surface and at the bottom of the burrow, the air humidity, and the soil granulometry to define the environment. The chosen functional traits were the diameter and depth of the burrows, the ratio between weight and length, the thermal properties of their silks, and the number of ring elements. The molecular branch lengths and the evolutionary distance emerging from cytochrome oxidase I gene sequences summarized the molecular analysis. Our study highlights a strong coherence between the resulting evolutionary lineages and the respective geographical distribution. Multivariate analyses of both environmental and molecular data provide the same phylogenetic interpretation. Low intrapopulation sequence divergence and the high values between population sequence divergence (between 4.9% and 26.1%) might even suggest novel taxa which deserve further investigation. We conclude that both the Kimura distance and the branch lengths are strengthening the environmental clustering of these peculiar sites in Namibia.

[Analysis on ecological factors and active components content of wild Dipsacus asper in Chongqing Wulong district]

An HPLC method was developed for the determination of iridoid glycosides (loganin acid, loganin, sweroside) and saponins (asperosaponin Ⅵ) in the wild Dipsacus asper. A total of 108 samples consecutive growing 12 month were collected in 9 plots in Wulong district of Chongqing. Subsequent analysis of the content of loganin acid, loganin, sweroside and asperosaponin Ⅵ was performed by HPLC to evaluate the quality. In addition, 20 climate data provided by the world climate database (http://www.worldclim.org/) was analyzed to deduce the correlation between the growing environment factors and the active ingredient content accumulation of D. asperoides and choose the apposite growing environment for D. asper. The range of active ingredient content in wild D. asper were 0.01%-3.80%(loganin acid), 0.08%-0.62%(loganin), 0.12%-0.78%(sweroside), 0.64%-5.26%(asperosaponin Ⅵ). The highest content of these active ingredients was concentrated from February to April, with 2.64% of loganin acid, 0.36% of loganin), 0.57% of sweroside, and 3.09% of asperosaponin Ⅵ. The method used for determination of the active ingredient content in D. asper was simple and convenient with accurate result. The selection of the quadrats is scientific and reasonable and can be used for the analysis of the contents of the wild D. asper, thus provide a reference for quality evaluation of D. asper and protection of D. asper resources.

[Potential distribution of Rhodiola crenulata in Tibetan Plateau based on Maxent model]

Wildlife tending and artificial cultivation is an important way to protect the wild resources of Rhodiola crenulata. It is a study hotspot at present. The distribution information of R. crenulata was collected by query data and field survey, the ecological suitability regionalization was conducted based on maximum entropy model combine with ecological factors, including climate, soil and altitude. To provide the reference for production layout, suitable planting area and the selection of artificial planting base by studying the ecological suitability regionalization of R. crenulata. The potential distribution areas mainly concentrated in the easen Tibet, western Sichuan, southern Qinghai, and Gansu Gannan Tibetan Autonomous Prefecture, Yunnan Diqing Tibetan Autonomous Prefecture. There were 5 major environmental factors to have obvious influence on ecology suitability distributions of R. crenulata, including altitude (contribution rate of 61.8%), precipitation of warmest quarter (contribution rate of 19%), the coefficient of variation of precipitation seasonality (contribution rate of 4.7%), the SD of temperature seasonality (contribution rate of 4%), mean temperature of driest quarter (contribution rate of 2.5%). The AUCs of ROC curve were both above 0.9, indicating that the predictive results with the Maxent model were highly precise. The study of the ecological suitability regionalization of R. crenulata based on Maxent can provide a scientific basis for the selection of artificial planting base.

Residential Area Life Expectancy: Association With Outcomes and Processes of Care for Patients With ESRD in the United States

BACKGROUND

The effects of underlying noncodified risks are unclear on the prognosis of patients with end-stage renal disease (ESRD). We aimed to evaluate the association of residential area life expectancy with outcomes and processes of care for patients with ESRD in the United States.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Adult patients with incident ESRD between 2006 and 2013 recorded in the US Renal Data System (n=606,046).

PREDICTOR

The primary exposure was life expectancy in the patient's residential county estimated by the Institute for Health Metrics and Evaluation.

OUTCOMES

Death, placement on the kidney transplant wait list, living and deceased donor kidney transplantation, and posttransplantation graft loss.

RESULTS

Median life expectancies of patients' residences were 75.6 (males) and 80.4 years (females). Compared to the highest life expectancy quintile and adjusted for demographic factors, disease cause, and multiple comorbid conditions, the lowest quintile had adjusted HRs for mortality of 1.20 (95% CI, 1.18-1.22); placement onto the waiting list, 0.68 (95% CI, 0.67-0.70); living donor transplantation, 0.53 (95% CI, 0.51-0.56); posttransplantation graft loss, 1.35 (95% CI, 1.27-1.43); and posttransplantation mortality, 1.29 (95% CI, 1.19-1.39). Patients living in areas with lower life expectancy were less likely to be informed about transplantation, be under the care of a nephrologist, or receive an arteriovenous fistula as the initial dialysis access. Results remained consistent with additional adjustment for zip code-level median income, population size, and urban-rural locality.

LIMITATIONS

Potential residual confounding and attribution of effects to individuals based on residential area-level data.

CONCLUSIONS

Residential area life expectancy, a proxy for socioeconomic, environmental, genetic, and behavioral factors, was independently associated with mortality and process-of-care measures for patients with ESRD. These results emphasize the underlying effect on health outcomes of the environment in which patients live, independent of patient-level factors. These findings may have implications for provider assessments.

[Predictive distribution and planting GAP of Cyathula officinalis in China based on 3S technology and MaxEnt modelling]

Research on predictive distribution and planting GAP of Cyathula officinalis in China is helpful to provide scientific basis for its protection and planting popularization. According to the data in 63 distribution sites and 49 ecological variables, using MaxEnt ecological niche model and 3S technology, we performed a quantitative analysis of suitable distribution and planting GAP of C. officinalis in China. Our results show that: ① the area of suitable distribution of C. officinalis is about 634 385.80 km² in total, and mainly in Northeastern and Southeastern Sichuan, Northern and Southeastern Yunnan, Western and Southwestern Guizhou, Southwestern and Northeastern Chongqing, Southwestern Shaanxi, Southeastern Gansu, Western Guangxi, Southeastern Tibet. ② The main ecological factors determining the potential distribution are precipitation, altitude, minimum temperature of coldest month, soil type, monthly mean temperature. ③ The planting GAP region are mainly in Guangyuan, Mianyang, Ya'an, Leshan, Liangshan, Panzhihua of Sichuan province, Hanzhong of Shaanxi province, Dali, Nujiang, Chuxiong, Baoshan, Qujing, Wenshan of Yunnan province, southwestern autonomous prefecture in Guizhou province. The results are of great significance for realizing the growth environment, predicting the potential distribution and promoting planting popularization for C. officinalis.

[Research on suitable distribution of Paris yunnanensis based on remote sensing and GIS]

Paris yunnanensis is a kind of rare medicinal herb, having a very high medicinal value. Studying its suitable ecological condition can provide a basis for its rational exploitation, artificial cultivation, and sustainable utilization. A practicable method in this paper has been proposed to research the suitable regional distribution of P. yunnanensis in Sichuan province. By the case study of P. yunnanensis in Sichuan province, and according to related literatures, the suitable ecological condition of P. yunnanensis such as altitude, mean annual temperature (MAT), annual precipitation, regional slope, slope ranges, vegetative cover, and soil types was analyzed following remote sensing (RS) and GIS.The appropriate distribution regionof P. yunnanensis and its area were extracted based on RS and GIS technology,combing with the information of the field validation data. The results showed that the concentrated distribution regions in counties of Sichuan province were, Liangshan prefecture, Aba prefecture, Sertar county of Ganzi prefecture, Panzhihua city, Ya'an city, Chengdu city, Meishan city, Leshan city, Yibin city, Neijiang city, Luzhou city, Bazhong city, Nanchong city, Guangyuan city and other cities and counties area.The suitable distribution area in Sichuan is about 7 338 km², accounting for 3.02% of the total study regional area. The analysis result has high consistency with the filed validation data, and the research method for P. yunnanensis distribution region based onspatial overlay analysis and the extracted the information of land usage and ecological factors following the RS and GIS is reliable.

Moderate climate signature in cranial anatomy of late holocene human populations from Southern South America

OBJECTIVE

The aim of this study is to analyze the association between cranial variation and climate in order to discuss their role during the diversification of southern South American populations. Therefore, the specific objectives are: (1) to explore the spatial pattern of cranial variation with regard to the climatic diversity of the region, and (2) to evaluate the differential impact that the climatic factors may have had on the shape and size of the diverse cranial structures studied.

MATERIALS AND METHODS

The variation in shape and size of 361 crania was studied, registering 62 3D landmarks that capture shape and size variation in the face, cranial vault, and base. Mean, minimum, and maximum annual temperature, as well as mean annual precipitation, but also diet and altitude, were matched for each population sample. A PCA, as well as spatial statistical techniques, including kriging, regression, and multimodel inference were employed.

RESULTS

The facial skeleton size presents a latitudinal pattern which is partially associated with temperature diversity. Both diet and altitude are the variables that mainly explain the skull shape variation, although mean annual temperature also plays a role. The association between climate factors and cranial variation is low to moderate, mean annual temperature explains almost 40% of the entire skull, facial skeleton and cranial vault shape variation, while annual precipitation and minimum annual temperature only contribute to the morphological variation when considered together with maximum annual temperature. The cranial base is the structure less associated with climate diversity.

CONCLUSION

These results suggest that climate factors may have had a partial impact on the facial and vault shape, and therefore contributed moderately to the diversification of southern South American populations, while diet and altitude might have had a stronger impact. Therefore, cranial variation at the southern cone has been shaped both by random and nonrandom factors. Particularly, the influence of climate on skull shape has probably been the result of directional selection. This study supports that, although cranial vault is the cranial structure more associated to mean annual temperature, the impact of climate signature on morphology decreases when populations from extreme cold environments are excluded from the analysis. Additionally, it shows that the extent of the geographical scales analyzed, as well as differential sampling may lead to different results regarding the role of ecological factors and evolutionary processes on cranial morphology.

[Production regionalization study of Lycii Fructus]

The distribution information of Lycii Fructus was collected by interview investigation and field survey, and 46 related environmental factors were collected, some kinds of functional chemical constituents the of Lycii Fructus were analyzed. Integrated climate, topography and other related ecological factors, the habitat suitability study was conducted based on Arc geographic information system(ArcGIS),and maximum entropy model. The AUC of ROC curve was both above 0.95, indicating that the predictive results with the maximum model were highly precise. The results showed that 5 major ecological factors had obvious influence on ecology suitability distributions of Lycii Fructus, including soil pH, soil subclass, vegetation type and in August the average temperature et al. It is suitable for the living habits of the Lycii Fructus, dry, cool weather, more hardy, drought-resistant, alkali soil, which is suitable for distribution in the northern temperate plains. In addition, the ecological suitability regionalization based on the chemical constituents of Lycii Fructus also provides a new suitable distribution area other than the traditional distribution area, which provides a scientific basis for the reasonable introduction of Lycii Fructus.

Is xenodontine snake reproduction shaped by ancestry, more than by ecology?

One of the current challenges of evolutionary ecology is to understand the effects of phylogenetic history (PH) and/or ecological factors (EF) on the life-history traits of the species. Here, the effects of environment and phylogeny are tested for the first time on the reproductive biology of South American xenodontine snakes. We studied 60% of the tribes of this endemic and most representative clade in a temperate region of South America. A comparative method (canonical phylogenetic ordination-CPO) was used to find the relative contributions of EF and PH upon life-history aspects of snakes, comparing the reproductive mode, mean fecundity, reproductive potential, and frequency of nearly 1,000 specimens. CPO analysis showed that PH or ancestry explained most of the variation in reproduction, whereas EF explained little of this variation. The reproductive traits under study are suggested to have a strong phylogenetic signal in this clade, the ancestry playing a big role in reproduction. The EF also influenced the reproduction of South American xenodontines, although to a lesser extent. Our finding provides new evidence of how the evolutionary history is embodied in the traits of living species.

The dependence of Hyalomma aegyptium on its tortoise host Testudo graeca in Algeria

Hyalomma aegyptium (Linnaeus, 1758) (Ixodida: Ixodidae) has recently been confirmed as a carrier of numerous pathogenic, including zoonotic, agents. Four environmentally distinct regions of Algeria, located between the humid coastal zone and the arid Saharan Atlas range, were selected in order to compare differences in tick abundance among localities, and the correlations between tick abundance and host population characteristics and other environmental conditions. Sampling was carried out during May and early June in 2010-2012. A total of 1832 H. aegyptium were removed from 201 tortoises. Adult ticks accounted for 52% of the collection. In the pre-adult stages, larvae were dominant. Data on prevalence, intensity (mean ± standard deviation, range) and abundance of tick infestation were calculated for each locality. Locally, prevalences reached 100%. The sex ratio was biased in favour of males (4.2). Intensities of infestation differed significantly among the localities studied for all developmental stages of the tick. The intensity of infestation by adult ticks was positively correlated to the size of the tortoise and with tortoise population density in the habitat. However, findings for immature tick stages were independent of both variables. No significant correlations between infestation intensities and the climatic parameters tested were found. Immature ticks were observed to prefer the front parts of their tortoise hosts, whereas the majority of adults were attached to the rear parts.

[Oxygen consumption rate of Sepia pharaonis embryos.]

This research was conducted to unravel the variation of oxygen consumption rate during different developmental stages and the effects of different ecological factors on embryonic oxygen consumption rate of Sepia pharaonis. The oxygen consumption rates were measured at twelve deve-lopmental stages by the sealed volumetric flasks, and four embryonic developmental periods (oosperm, gastrula, the formation of organization, endoskeleton) were selected under various ecological conditions, such as salinity (21, 24, 27, 30, 33), water temperature (18, 21, 24, 27, 30 ℃) and pH (7.0, 7.5, 8.0, 8.5, 9.0). The results showed that the oxygen consumption rate rose along with the developmental progress, and distinctly differed from each other. The oxygen consumption rate was 0.082 mg·(100 eggs)^-1·h^-1 during oosperm period, and rose to 0.279 mg·(100 eggs)^-1·h^-1 during gastrula period, which was significantly higher than that of blastula period. Finally, the oxygen consumption rate rose to 1.367 mg·(100 eggs)^-1·h^-1 during hatching period. The salinity showed a significant effect on oxygen consumption rate during the formation of organization and endoskeleton formation stage (P<0.05), but no significant effect during oosperm and gastrula periods (P>0.05). The oxygen consumption rates of four studied embryonic stages all rose and then declined along with the increase of salinity, and reached the highest values [0.082, 0.200, 0.768 and 1.301 mg·(100 eggs)^-1·h^-1, respectively] at salinity 30. The water temperature had a significant effect on the embryo oxygen consumption rates of gastrula, and the formation of organization and endoskeleton formation stage (P<0.05), with the exception of oosperm (P>0.05). The oxygen consumption rates of four studied embryonic stages all rose and then declined along with the increase of temperature, and reached the highest values at 27 ℃ [0.082, 0.286, 0.806 and 1.338 mg·(100 eggs)^-1·h^-1, respectively]. The pH had no significant effect on the oxygen consumption rates of four embryonic stages (P>0.05). The oxygen consumption rates of four studied embryonic stages all rose and then declined along with the increase of pH. The oxygen consumption rates of gastrula, the formation of organization, endoskeleton reached the according highest values [0.281, 0.799 and 1.130 mg·(100 eggs)^-1·h^-1] at pH 8.5, but that during oosperm period occurred at pH 8.0 [0.116 mg·(100 eggs)^-1·h^-1].

Spatial-Temporal Epidemiology of Tuberculosis in Mainland China: An Analysis Based on Bayesian Theory

OBJECTIVE

To explore the spatial-temporal interaction effect within a Bayesian framework and to probe the ecological influential factors for tuberculosis.

METHODS

Six different statistical models containing parameters of time, space, spatial-temporal interaction and their combination were constructed based on a Bayesian framework. The optimum model was selected according to the deviance information criterion (DIC) value. Coefficients of climate variables were then estimated using the best fitting model.

RESULTS

The model containing spatial-temporal interaction parameter was the best fitting one, with the smallest DIC value (-4,508,660). Ecological analysis results showed the relative risks (RRs) of average temperature, rainfall, wind speed, humidity, and air pressure were 1.00324 (95% CI, 1.00150-1.00550), 1.01010 (95% CI, 1.01007-1.01013), 0.83518 (95% CI, 0.93732-0.96138), 0.97496 (95% CI, 0.97181-1.01386), and 1.01007 (95% CI, 1.01003-1.01011), respectively.

CONCLUSIONS

The spatial-temporal interaction was statistically meaningful and the prevalence of tuberculosis was influenced by the time and space interaction effect. Average temperature, rainfall, wind speed, and air pressure influenced tuberculosis. Average humidity had no influence on tuberculosis.

The Chemical and Genetic Characteristics of Szechuan Pepper (Zanthoxylum bungeanum and Z. armatum) Cultivars and Their Suitable Habitat

Szechuan peppers, famous for their unique sensation and flavor, are widely used as a food additive and traditional herbal medicine. Zanthoxylum bungeanum and Z. armatum are both commonly recognized as Szechuan peppers, but they have different tastes and effects. The chemical components, genetic characteristics, and suitable habitat of six cultivars were analyzed in this study. The results indicated that Z. armatum contained a larger proportion of volatile oil, whereas Z. bungeanum produced a more non-volatile ether extraction. The average content of volatile oil and non-volatile ether extract of Z. armatum were 11.84 and 11.63%, respectively, and the average content of volatile oil and non-volatile ether extract of Z. bungeanum were 6.46 and 14.23%, respectively. Combined with an internal transcribed spacer 2 (ITS2) sequence characters and chemical PCA results, six cultivars were classified into their own groups, for the two species in particular. The temperature in January and July were the most significant ecological factors influencing the contents of the Z. armatum volatile oil. However, annual precipitation, temperature in January and relevant humidity had a significant positive correlation with the content of non-volatile ether extract in Z. bungeanum. Thus, the most suitable areas for producing Z. bungeanum cultivars ranged from the Hengduan Mountains to the Ta-pa Mountains, and the regions suitable for Z. armatum cultivars were found to be in the Sichuan Basin and Dalou-Wu mountains. The predicted suitable habitat could be used as a preliminary test area for Szechuan pepper cultivar production.

Chromatic Dimensions Earthy, Watery, Airy, and Fiery

In our study, for a small number of antonyms, we investigate whether they are cross-modally or ideaesthetically related to the space of colors. We analyze the affinities of seven antonyms (cold-hot, dull-radiant, dead-vivid, soft-hard, transparent-chalky, dry-wet, and acid-treacly) and their intermediate connotations (cool-warm, matt-shiny, numb-lively, mellow-firm, semi-transparent-opaque, semi-dry-moist, and sour-sweet) as a function of color. We find that some antonyms relate to chromatic dimensions, others to achromatic ones. The cold-hot antonym proves to be the most salient dimension. The dry-wet dimension coincides with the cold-hot dimension, with dry corresponding to hot and wet to cold. The acid-treacly dimension proves to be transversal to the cold-hot dimension; hence, the pairs mutually span the chromatic domain. The cold-hot and acid-treacly antonyms perhaps recall Hering's opponent color system. The dull-radiant, transparent-chalky, and dead-vivid pairs depend little upon chromaticity. Of all seven antonyms, only the soft-hard one turns out to be independent of the chromatic structure.

Observations on changes in abundance of questing Ixodes ricinus, castor bean tick, over a 35-year period in the eastern part of its range (Russia, Tula region)

Ixodes ricinus (Acari: Ixodidae) L. transmit a wide variety of pathogens to vertebrates including viruses, bacteria and protozoa. Understanding of the epidemiology of tick-borne infections requires basic knowledge of the regional and local factors influencing tick population dynamics. The present study describes the results of monitoring of a questing I. ricinus population, conducted over 35 years (1977-2011) in the eastern, poorly studied part of its range (Russia, Tula region). We have found that the multiannual average abundance of ticks is small and varies depending on the biotope and degree of urban transformation. Tick abundance for the first 14 years of observations (1977-1990) was at the lower limit of the sensitivity of our methods throughout the study area (0.1-0.9 specimens per 1-km transect). In the following 21 years (1991-2011), a manifold increase in abundance was observed, which reached 18.1 ± 1.8 individuals per 1-km transect in moist floodplain terraces, and 4.8 ± 0.9 in xerophylic hill woods. Long-term growth of tick abundance occurred in spite of a relatively constant abundance of small mammals and only minor fluctuations in the abundance of large wild animals. Climate and anthropogenic changes appear to be the main contributors to increased abundance of the tick.

Stress, illness, and the social environment: depressive symptoms among first generation mandarin speaking Chinese in greater Los Angeles

This study documents the indirect effects of social and environmental variables as mediated by immigrant stress and physical health. Using data from a large dual frame sample of first generation mandarin speaking Chinese immigrants in metropolitan Los Angeles counties with the largest groups of Chinese immigrants, this study uses a path analytic approach to trace how predictors are related to depressive symptoms and to measure direct and indirect influences of variables. Although bivariate analyses suggested that many predictors were associated with depressive symptoms, multivariate path analysis revealed a more complex structure of mediated associations. In the multivariate path analysis only reports of physical health and immigrant stress were directly related to depressive symptoms (P < 0.05), while acculturation, time in the US, income, US citizenship, and distance of persons on whom one could rely were related to stress (but not to physical health status) and only to depressive symptoms as mediated by stress. Age and educational attainment were related to health status (and to stress as mediated by physical health) and to depressive symptoms as mediated by both health and stress. These variables were also unrelated directly to health status and to depressive symptoms. Associations were evaluated using statistical significance, P < 0.05. This study demonstrates the significance of stress and health as mediators of variables in the larger context of the physical environment and suggests that the mechanisms linking ecological characteristics of immigrants to depressive symptoms may be stress and physical health among immigrants.

Seed dormancy distribution: explanatory ecological factors

BACKGROUND AND AIMS

Knowledge of those traits that vary with latitude should be helpful in predicting how they may evolve locally under climate change. In the sea beet Beta vulgaris ssp. maritima, seed dormancy largely controls the timing of germination, is highly heritable and varies geographically; it is therefore thought to be selected by climate. The aim here was to characterize the variation in seed dormancy among sea beet populations across the French distribution area, as well as the ecological factors in situ that are correlated with and that could therefore select for seed dormancy. The relative importance of genetic inheritance vs. non-genetic variation is also evaluated.

METHODS

The proportions of dormant seeds from 85 natural populations encompassing different climates over the whole French distribution area were measured under controlled conditions. Germination phenology was observed in a common garden experiment. Dormancy variation of seeds collected in situ was compared with that of seeds collected on plants grown in the greenhouse.

KEY RESULTS

The proportions of dormant seeds in the greenhouse were highly variable, covering almost the entire range from 0 to 1, and followed a geographical pattern from lower dormancy at high latitudes to high dormancy at low latitudes. The distribution of dormancy was positively correlated with yearly temperatures, especially summer temperatures. Minimum temperatures in winter did not significantly explain the trait variation. The genetic component of the total variation was significant and is probably completed by an important adjustment to the local conditions brought about by maternal adaptive phenotypic plasticity.

CONCLUSIONS

Dormancy in sea beet could be interpreted as a way to limit summer germination and spread germination over the first autumn and spring or following autumns. This highly heritable trait has the potential to evolve in the relatively near future because of climate change.

Reef fish hybridization: lessons learnt from butterflyfishes (genus Chaetodon)

Natural hybridization is widespread among coral reef fishes. However, the ecological promoters and evolutionary consequences of reef fish hybridization have not been thoroughly evaluated. Butterflyfishes form a high number of hybrids and represent an appropriate group to investigate hybridization in reef fishes. This study provides a rare test of terrestrially derived hybridization theory in the marine environment by examining hybridization between Chaetodon trifasciatus and C. lunulatus at Christmas Island. Overlapping spatial and dietary ecologies enable heterospecific encounters. Nonassortative mating and local rarity of both parent species appear to permit heterospecific breeding pair formation. Microsatellite loci and mtDNA confirmed the status of hybrids, which displayed the lowest genetic diversity in the sample and used a reduced suite of resources, suggesting decreased adaptability. Maternal contribution to hybridization was unidirectional, and no introgression was detected, suggesting limited, localized evolutionary consequences of hybridization.

Comparisons to other reef fish hybridization studies revealed that different evolutionary consequences emerge, despite being promoted by similar factors, possibly due to the magnitude of genetic distance between hybridizing species. This study highlights the need for further enquiry aimed at evaluating the importance and long-term consequences of reef fish hybridization.

Poverty, life events and the risk for depression in Uganda

BACKGROUND

Understanding the determinants of major depression in sub-Saharan Africa is important for planning effective intervention strategies.

OBJECTIVE

To investigate the social and life-event determinants of major depressive disorder in the African sociocultural context of rural Uganda.

METHODS

A cross-section survey was carried out in 14 districts in Uganda from 1 June 2003 to 30 October 2004. 4,660 randomly selected respondents (15 years and above) were interviewed. The primary outcome was the presence of 'probable major depressive disorder' (PMDD) as assessed by the Hopkins symptom checklist.

RESULTS

The prevalence of PMDD was 29.3% (95% confidence interval, 28.0-30.6%). Factors independently associated with depression in both genders included: the ecological factor, district; age (increase with each age category after 35 years); indices of poverty and deprivation (no formal education, having no employment, broken family, and socioeconomic classes III-V). Only a few adverse life events, notably those suggestive of a disrupted family background (death of a father in females and death of a mother in males) were associated with increased risk.

CONCLUSION

Socioeconomic and sociodemographic factors, operating at both ecological and the individual level are the strongest independent determinants of depression. Adverse life events were less strongly associated with depression in this sample.

Ecological differences in weight, length, and weight for length of Mexican American children in the WIC program

PURPOSE

Examine factors common in the environments of children who obtain services from a WIC program to determine if differences in ecological/environmental factors can be found in the children who differ in weight, length, and weight for length.

DESIGN AND METHODS

Cross-sectional study of 300 children, 100 each who were stunted, normal weight for length, or overweight. Instruments used were NCATS, ARSMA II, 24-hr diet recall, and Baecke Activity Questionnaire.

RESULTS

Significant differences were present in children's diet, parents' BMI, parents' generation in United States, parents' activity levels, and maternal-child relationship.

PRACTICE IMPLICATIONS

Encourage parents to adopt family approaches to encourage normal body size in children.

Ecological and historical filters constraining spatial caddisfly distribution in Mediterranean rivers

1. Contemporary species distributions are determined by a mixture of ecological and historical filters acting on several spatial and temporal scales. Mediterranean climate areas are one of the world's biodiversity hotspots with a high level of endemicity, which is linked to complex ecological and historical factors. 2. This paper explores the ecological and historical factors constraining the distribution of caddisfly species on a large regional scale. A total of 69 taxa were collected from 140 sampling sites in 10 Iberian Mediterranean river basins. Approximately 74% of taxa can be considered rare, with the southern basins (the Baetic-Riffian region) having greater endemicity. The greatest richness, involving a mixture of northern and southern species, was found in the transitional area between the Baetic-Riffian region and the Hesperic Massif. 3. The historical processes occurring during the Tertiary (i.e. the junction of the Eurasian and African plates) explained 3.1% of species distribution, whereas ecological factors accounted for 20.7%. Only 0.3% was explained by the interaction of history and ecology. A set of multi-scale ecological variables (i.e. basin, reach and bedform characteristics) defined five river types with specific caddisfly assemblages. The commonest caddisfly species accounted for the regional distribution pattern, while rare taxa contributed to the explanation of subtle patterns not shown by common species. 4. Despite the importance of historical factors for biogeography and the large scale used in our study, ecological variables better explained caddisfly distribution. This may be explained by the length of time since the historical process we are considering, the high dispersion and colonisation capacity of many caddisfly species, and the strong environmental gradient in the area. Because of the historical and environmental complexity of Mediterranean areas, rare taxa should be included in ecological studies so that the singularity of these ecosystems is not missed.