Community differentiation of bacterioplankton in the epipelagic layer in the South China Sea

The South China Sea (SCS) is the largest marginal sea in the western tropical Pacific Ocean and is characterized by complex physicochemical environments. To date, the biogeographic patterns of the microbial communities have rarely been reported at a basin scale in the SCS. In this study, the bacterial assemblages inhabiting the epipelagic zone across 110°E to 119°E along 14°N latitude were uncovered. The vertical stratification of both bacterial taxa and their potential functions were revealed. These results suggest that the water depth‐specific environment is a driver of the vertical bacterioplankton distribution. Moreover, the bacterial communities were different between the eastern stations and the western stations, where the environmental conditions were distinct. However, the mesoscale eddy did not show an obvious effect on the bacterial community due to the large distance between the sampling site and the center of the eddy. In addition to the water depth and longitudinal location of the samples, the heterogeneity of the phosphate and salinity concentrations also significantly contributed to the variance in the epipelagic bacterial community in the SCS. To the best of our knowledge, this study is the first to report that the variability in epipelagic bacterioplankton is driven by the physicochemical environment at the basin scale in the SCS. Our results emphasize that the ecological significance of bacterioplankton can be better understood by considering the relationship between the biogeographic distribution of bacteria and the oceanic dynamics processes.     

太浦河水体叶绿素a纵向演变特征及主要影响因子

叶绿素a作为重要的水质指标,可直观的描述水体的营养状态。在随水流输送过程中,受沿程环境条件的影响,水体叶绿素a浓度会发生相应改变。2017年11月-2018年10月,在东太湖及太浦河沿线设置了固定采样站点,开展了水体叶绿素a的月际取样调研与分析。结果表明：从东太湖至太浦河沿线叶绿素a浓度发生了明显的纵向演变,在东太湖叶绿素a浓度年平均为（15.341±2.329）μg/L,经过多个站点,到达金泽水文站时,浓度为（11.002±1.004）μg/L,整体上呈显著下降态势（P<0.05）,但不同站点两两之间的对比特征存在差异,而且在不同月份其纵向演变特征也有所不同。聚类及非度量多维尺度分析也表明其在空间和时间上分布的差异性。非线性回归分析表明,在时间和空间上与叶绿素a浓度相关性最高的环境因子为水下0.5 m处的光照强度（P<0.01）;在2018年10月,水体叶绿素a浓度与溶解氧也呈显著相关（P<0.05）。综合现有研究,水体叶绿素a的纵向演变受水质等多种因素的影响。未来需采用系统分析手段,探讨水质、降水、水力停留时间、流速和流量等多种因子对叶绿素a时空分布特征的综合作用,以期为水源地水质安全保障提供科学依据。     

Responses of an Australian freshwater turtle to drought‐flood cycles along a natural to urban gradient

Urban areas provide habitat for numerous native species, but life in towns and cities presents many challenges. The effect of climate on the ecology and the behaviour of non‐volant vertebrates inhabiting urban habitats have received little attention. In this study, we investigated demography, growth rates, movements and reproduction of a semi‐aquatic freshwater turtle, Chelodina longicollis, along a natural to urban gradient during a period of relatively high rainfall (2011–2014) and compared this to a previous study in the same system during drought (2006–2007). In addition to changes in rainfall, urbanization increased considerably over the same time period and a pest‐exclusion fence was constructed to mitigate against urban hazards encroaching on the adjacent reserve. Turtles grew at similar rates, had similar abundances and sex ratios and had similar reproductive output across the gradient from urban to non‐urban sites during the wet period. Despite increasing urbanization, recruitment occurred at all sites and survivorship estimates were similar among sites. Turtles moved among wetlands at high rates and over long distances (6 km), underscoring the importance of movements in urban landscapes. Our results contrast with those for the same system during drought, when turtles were less abundant and grew slower in the nature reserve compared with the urban environment. Our results underscore the strong influence climate can have on population dynamics and resilience of species to changes brought about by urbanization. Further monitoring is required to understand the long‐term population responses of long‐lived species to drought cycles.     

Detection and modelling of time-dependent QTL in animal populations

A longitudinal approach is proposed to map QTL affecting function-valued traits and to estimate their effect over time. The method is based on fitting mixed random regression models. The QTL allelic effects are modelled with random coefficient parametric curves and using a gametic relationship matrix. A simulation study was conducted in order to assess the ability of the approach to fit different patterns of QTL over time. It was found that this longitudinal approach was able to adequately fit the simulated variance functions and considerably improved the power of detection of time-varying QTL effects compared to the traditional univariate model. This was confirmed by an analysis of protein yield data in dairy cattle, where the model was able to detect QTL with high effect either at the beginning or the end of the lactation, that were not detected with a simple 305 day model.     

Genetic and Environmental Influences on the Tracking of Body Size from Birth to Early Adulthood

Objective: This study identified genetic and environmental influences on the tracking of body size from birth to 16 to 18.5 years of age. Research Methods and Procedures: Longitudinal information was collected from a nationally representative sample of Finnish twin adolescents (birth cohorts 1975 to 1979) and their parents through questionnaires mailed when the twins were ages 16 and 18.5 years old. The sample included 702 monozygotic, 724 same‐sex dizygotic, and 762 opposite‐sex dizygotic sets of twins. The measures used were length, weight, ponderal index (kilograms per cubic meters), and gestational age at birth, and height, weight, and body mass index (kilograms per square meters) at 16 to 18.5 years of age. The changes in genetic and environmental influences on body size from birth to early adulthood were analyzed by quantitative genetic modeling. Results: The twins who had a higher weight or ponderal index at birth were taller and heavier in early adulthood, whereas those who were longer at birth were taller, but not heavier, later in life. Adult height was affected more by the birth size than body mass index. In the genetic modeling analyses, the genetic factors accounting for the variation of body size became more apparent with age, and both genetic and environmental influences on stature had a sizable carry‐over effect from birth to late adolescence, whereas for relative weight, the influences were more age‐specific. Discussion: The genetic and environmental architecture of body size changes from birth to adulthood. Even in monozygotic twins who share their genetic background, the initially larger twin tended to remain larger, demonstrating the long‐lasting effects of fetal environment on final body size.     

Longitudinal study on growth in height in Polish boys and girls

Physical growth and development of children, determined by endogenous factors (genetic and paragenetic) is modified by numerous exogenic ones. This affects differentiation of ways of growth in individual children. In order to estimate the individual growth patterns and changes in growth rate as well as differences in growth of boys and girls, one must observe the process of growth of the same children and over a period of many years (longitudinal study). Such longitudinal study is the only way to provide information about the variability of growth and growth velocity at each age.     

Role of mef2ca in developmental buffering of the zebrafish larval hyoid dermal skeleton

Phenotypic robustness requires a process of developmental buffering that is largely not understood, but which can be disrupted by mutations. Here we show that in mef2ca^b1086 loss of function mutant embryos and early larvae, development of craniofacial hyoid bones, the opercle (Op) and branchiostegal ray (BR), becomes remarkably unstable; the large magnitude of the instability serves as a positive attribute to learn about features of this developmental buffering. The OpBR mutant phenotype variably includes bone expansion and fusion, Op duplication, and BR homeosis. Formation of a novel bone strut, or a bone bridge connecting the Op and BR together occurs frequently. We find no evidence that the phenotypic stability in the wild type is provided by redundancy between mef2ca and its co-ortholog mef2cb, or that it is related to the selector (homeotic) gene function of mef2ca. Changes in dorsal–ventral patterning of the hyoid arch also might not contribute to phenotypic instability in mutants. However, subsequent development of the bone lineage itself, including osteoblast differentiation and morphogenetic outgrowth, shows marked variation. Hence, steps along the developmental trajectory appear differentially sensitive to the loss of buffering, providing focus for the future study.     

Multi-segment foot kinematics and ground reaction forces during gait of individuals with plantar fasciitis

Background

Clinically, plantar fasciitis (PF) is believed to be a result and/or prolonged by overpronation and excessive loading, but there is little biomechanical data to support this assertion. The purpose of this study was to determine the differences between healthy individuals and those with PF in (1) rearfoot motion, (2) medial forefoot motion, (3) first metatarsal phalangeal joint (FMPJ) motion, and (4) ground reaction forces (GRF).

Methods

We recruited healthy (n=22) and chronic PF individuals (n=22, symptomatic over three months) of similar age, height, weight, and foot shape (p>0.05). Retro-reflective skin markers were fixed according to a multi-segment foot and shank model. Ground reaction forces and three dimensional kinematics of the shank, rearfoot, medial forefoot, and hallux segment were captured as individuals walked at 1.35 ms⁻¹.

Results

Despite similarities in foot anthropometrics, when compared to healthy individuals, individuals with PF exhibited significantly (p<0.05) (1) greater total rearfoot eversion, (2) greater forefoot plantar flexion at initial contact, (3) greater total sagittal plane forefoot motion, (4) greater maximum FMPJ dorsiflexion, and (5) decreased vertical GRF during propulsion.

Conclusion

These data suggest that compared to healthy individuals, individuals with PF exhibit significant differences in foot kinematics and kinetics. Consistent with the theoretical injury mechanisms of PF, we found these individuals to have greater total rearfoot eversion and peak FMPJ dorsiflexion, which may put undue loads on the plantar fascia. Meanwhile, increased medial forefoot plantar flexion at initial contact and decreased propulsive GRF are suggestive of compensatory responses, perhaps to manage pain.