Landscape scale effects of disturbance on riparian vegetation

1. Differing responses in riparian species richness and composition to disturbance have been reported as a possible explanation for the differences along and between rivers. This paper explores the role of physical disturbance in shaping landscape‐scale patterns of species distribution in riparian vegetation along a free‐flowing river in northern Sweden. 2. To test whether sensitivity to disturbance varies across large landscapes, we experimentally disturbed riparian vegetation along an entire, free‐flowing river by scouring the soil and the vegetation turf, cutting vegetation, applying waterborne plant litter, and after a period of recovery we measured vegetation responses. The experiment was repeated for two consecutive years. 3. We found no significant effect of disturbance on species composition, but all three forms of disturbance significantly reduced species richness. There was no downstream variation in community responses to disturbance but morphological groups of species responded differently to different kinds of disturbance. Graminoids were most resistant, suppressed only by litter burial. All forms of disturbance except cutting reduced the density of herbaceous species, and species density of trees + shrubs and dwarf shrubs was negatively affected by both scouring and cutting. We also evaluated the effects of disturbance in relation to varying levels of species richness. In nearly all cases, responses were significantly negatively correlated with control plot species richness, and relative responses indicated that species‐rich plots were less resistant to scouring and cutting. 4. Our results suggest that although all disturbance treatments had an effect on species richness, variation in sensitivity to disturbance is not the most important factor shaping landscape‐scale patterns of riparian plant species richness along rivers.     

Inflammation-associated enterotypes,host genotype,cage and inter-individual effects drive gut microbiota variation in common laboratory mice

Background

Murine models are a crucial component of gut microbiome research. Unfortunately, a multitude of genetic backgrounds and experimental setups, together with inter-individual variation, complicates cross-study comparisons and a global understanding of the mouse microbiota landscape. Here, we investigate the variability of the healthy mouse microbiota of five common lab mouse strains using 16S rDNA pyrosequencing.

Results

We find initial evidence for richness-driven, strain-independent murine enterotypes that show a striking resemblance to those in human, and which associate with calprotectin levels, a marker for intestinal inflammation. After enterotype stratification, we find that genetic, caging and inter-individual variation contribute on average 19%, 31.7% and 45.5%, respectively, to the variance in the murine gut microbiota composition. Genetic distance correlates positively to microbiota distance, so that genetically similar strains have more similar microbiota than genetically distant ones. Specific mouse strains are enriched for specific operational taxonomic units and taxonomic groups, while the ''cage effect'' can occur across mouse strain boundaries and is mainly driven by Helicobacter infections.

Conclusions

The detection of enterotypes suggests a common ecological cause, possibly low-grade inflammation that might drive differences among gut microbiota composition in mammals. Furthermore, the observed environmental and genetic effects have important consequences for experimental design in mouse microbiome research.     

Fate of fluoroquinolone antibiotics in Vietnamese coastal wetland ecosystem

Vietnamese coastal wetlands have traditionally been used for shrimp farming, but with the expansion of commercial shrimp farming and the associated clearance of mangroves, these valuable ecosystems have been rapidly degraded. The application of veterinary antibiotics in shrimp culture is one of the major threats to Vietnamese mangroves. These antibiotics are released into the environment through wastewater streams from shrimp ponds and cause environmental problems as well as the occurrence of antibiotic resistant bacteria. However, there is only a limited amount of information available on the occurrence and fate of antibiotics in Vietnamese mangroves. Ciprofloxacin and norfloxacin are two of most commonly fluoroquinolones used in shrimp culture. Laboratory experiments were therefore carried out using saline shrimp pond water to investigate the fate of both antibiotics in a coastal wetland ecosystem. Furthermore, two wetland plant species (Ceratophyllum demersum and Chrysopogon zizanioides), were used for studying phytoremediation of both antibiotics through a hydroponic experiment. Both ciprofloxacin and norfloxacin were photodegradable but at a slow rate, whereas the biodegradation seemed to be insignificant. If given at an initial concentration of 5 or 10?mg/L, a higher removal of antibiotics was achieved using C. demersum: 40?% for norfloxacin and 44?C39?% for ciprofloxacin, respectively. With C. zizanioides, ciprofloxacin and norfloxacin were reduced by 40?C38 and 36?C34?%, respectively. These results indicated that phytoremediation could be effective in the removal of both antibiotics.     

Exposure to conflicts and the continuum of maternal healthcare: Analyses of pooled cross-sectional data for 452,192 women across 49 countries and 82 surveys

BackgroundViolent conflicts are observed in many parts of the world and have profound impacts on the lives of exposed individuals. The limited evidence available from specific country or region contexts suggest that conflict exposure may reduce health service utilization and have adverse affects on health. This study focused on identifying the association between conflict exposure and continuum of care (CoC) services that are crucial for achieving improvements in reproductive, maternal, newborn, and child health and nutrition (RMNCHN).Methods and findingsWe combined data from 2 sources, the Demographic Health Surveys (DHS) and the Uppsala Conflict Data Program’s (UCDP) Georeferenced Event Dataset, for a sample of 452,192 women across 49 countries observed over the period 1997 to 2018. We utilized 2 consistent measures of conflict—incidence and intensity—and analyzed their association with maternal CoC in 4 key components: (i) at least 1 antenatal care (ANC) visit; (ii) 4 or more ANC visits; (iii) 4 or more ANC visits and institutional delivery; and (iv) 4 or more ANC visits, institutional delivery, and receipt of postnatal care (PNC) either for the mother or the child within 48 hours after birth. To identify the association between conflict exposure and components of CoC, we estimated binary logistic regressions, controlling for a large set of individual and household-level characteristics and year-of-survey and country/province fixed-effects. This empirical setup allows us to draw comparisons among observationally similar women residing in the same locality, thereby mitigating the concerns over unobserved heterogeneity. Around 39.6% (95% CI: 39.5% to 39.7%) of the sample was exposed to some form of violent conflict at the time of their pregnancy during the study period (2003 to 2018). Although access to services decreased for each additional component of CoC in maternal healthcare for all women, the dropout rate was significantly higher among women who have been exposed to conflict, relative to those who have not had such exposure. From logistic regression estimates, we observed that relative to those without exposure to conflict, the odds of utilization of each of the components of CoC was lower among those women who were exposed to at least 1 violent conflict. We estimated odds ratios of 0.86 (95% CI: 0.82 to 0.91, p < 0.001) for at least 1 ANC; 0.95 (95% CI: 0.91 to 0.98, p < 0.005) for 4 or more ANC; and 0.92 (95% CI: 0.89 to 0.96, p < 0.001) for 4 or more ANC and institutional delivery. We showed that both the incidence of exposure to conflict as well as its intensity have profound negative implications for CoC. Study limitations include the following: (1) We could not extend the CoC scale beyond PNC due to inconsistent definitions and the lack of availability of data for all 49 countries across time. (2) The measure of conflict intensity used in this study is based on the number of deaths due to the absence of information on other types of conflict-related harms.ConclusionsThis study showed that conflict exposure is statistically significantly and negatively associated with utilization of maternal CoC services, in each component of the CoC scale. These findings have highlighted the challenges in achieving the Sustainable Development Goal 3 in conflict settings, and the need for more concerted efforts in ensuring CoC, to mitigate its negative implications on maternal and child health.

Anu Rammohan and co-workers study associations between exposure to violent conflicts and take-up of maternal health care services across countries.     

Comparison of Aerodynamic Forces and Moments Calculated by Three-dimensional Unsteady Blade Element Theory and Computational Fluid Dynamics

In previous work,we modified blade element theory by implementing three-dimensional wing kinematics and modeled the unsteady aerodynamic effects by adding the added mass and rotational forces.This method is referred to as Unsteady Blade Element Theory (UBET).A comparison between UBET and Computational Fluid Dynamics (CFD) for flapping wings with high flapping frequencies (＞30 Hz) could not be found in literature survey.In this paper,UBET that considers the movement of pressure center in pitching-moment estimation was validated using the CFD method.We investigated three three-dimensional (3D) wing kinematics that produce negative,zero,and positive aerodynamic pitching moments.For all cases,the instantaneous aerodynamic forces and pitching moments estimated via UBET and CFD showed similar trends.The differences in average vertical forces and pitching moments about the center of gravity were about 10％ and 12％,respectively.Therefore,UBET is proven to reasonably estimate the aerodynamic forces and pitching moment for flight dynamic study of FW-MAV.However,the differences in average wing drags and pitching moments about the feather axis were more than 20％.Since study of aerodynamic power requires reasonable estimation of wing drag and pitching moment about the feather axis,UBET needs further improvement for higher accuracy.     

Non-standard O(2) consumption-temperature curves during rest and isometric exercise in human skeletal muscle

The present work was aimed at measuring intramuscular oxygen consumption (O(2)) as a function of temperature (T), in human forearm, during rest and aerobic isometric exercise (4% of the maximal voluntary contraction, MVC). Based upon results from in vitro experiments performed on isolated mitochondria of animal species, it was hypothesised that, during isometric exercise, the O(2)-T curve should display a maximum for some 'optimal' T. Intramuscular T and measurements were performed using a combined deep body temperature/near infrared probe during muscle cooling. At rest, O(2) increased non-linearly and monotonically as a function of T (n=8). O(2) increased approximately 2 times when going from 26 to 36 degrees C. A log(O(2))-T plot or a log(O(2))-1/T did not linearise the data. During isometric contraction, O(2) values at 26.8+/-0.6, 28.6+/-0.9, 31.9+/-0.9 and 35.9+/-0.9 degrees C were 3.04+/-1.26, 7.60+/-1.64, 4.43+/-1.95, and 6.64+/-1.37 micromol 100 g(-1) min(-1), respectively (n=6). The O(2) value at 28.6 degrees C was significantly higher (P<0.05) than that at 26.8 and 31.9 degrees C. The 'sudden' O(2) change at 28.6 degrees C is compatible with the phenomenon observed at the mitochondrial level.     

Identification of Thai isolates assigned to the genus Gluconobacter based on 16S-23S rDNA ITS restriction analysis

Forty-four Thai isolates phenotypically assigned to the genus Gluconobacter were examined for 16S-23S rDNA ITS restriction analysis by MboII and SduI (=Bsp1286I) digestions. The Thai isolates tested were divided into seven groups: Group I for fourteen isolates, Group IX for one isolate, Group X for two isolates, Group V-2 for four isolates, Group XI for three isolates, Group IV for one isolate, and Group III for nineteen isolates. There were no isolates of either Group II or Group V-1 that were identified as G. cerinus. The isolates of Group III, Group IV, and Group XI were subjected to an additional 16S-23S rDNA ITS restriction analysis by AvaII, TaqI, BsoBI, and BstNI digestions. The isolates of Group III were divided into three groups and two subgroups: Group III-2 for five isolates, Group III-6 for two isolates, and Group III-4, which was divided into two subgroups, Subgroup III-4a for four isolates and Subgroup III-4b for eight isolates. The fourteen isolates of Group I were identified as G. oxydans, and the two isolates of Group X were temporarily identified as G. oxydans. The five isolates of Group III-2 and the one isolate of Group IV were identified as G. frateurii. The remaining twenty-two isolates of Group V-2, Group III-4, Group III-6, Group IX, and Group XI were not identified but are candidates for several new species.