2,010 research outputs found
Open forest successional stages and landscape heterogeneity promote wild bee diversity in temperate forests
Recent studies have emphasized forests as crucial habitat for wild bees. In
Europe, most forests are managed following the principles of close-to-nature
silviculture, which combine timber production and nature conservation. How-
ever, open late and early successional stages within these forests are largely
missing, which could be important for wild bees. This highlights that close-to-
nature silviculture alone might not be sufficient to conserve bees within tem-
perate forests. Open structures such as canopy gaps and road verges in forests
could improve habitat for bees. To provide management recommendations for
wild bee conservation in temperate forests, we analyzed how components of
bee beta diversity varied between forest management types and tested how
open structures, namely clear-cuts, canopy gaps, and forest road verges influ-
enced bee abundance, richness, and diversity. In addition, we analyzed the
abundance and percent of red-listed bee species at different scales. Bees were
sampled using 90 pan traps on 45 (1 ha) plots in 2019 and 2020 in the Black
Forest, Germany. Plots were selected in 15 triplets each consisting of three
management types related to different successional stages: unmanaged, close-
to-nature, and small clear-cut. Beta diversity was not consistently nested
highlighting the importance of different management and successional stages
within the landscape to support bees in forests. Abundance, species richness,
and Shannon diversity of bees were highest on clear-cuts, compared to
unmanaged- and close-to-nature plots. At landscape scale, wild bee abundance
increased with canopy openness while wild bee diversity increased with land-
scape heterogeneity. Abundance- and percent of red-listed bee species
increased with the length of forest road verges. We advocate creating habitats
at local scales which offer flowering and nesting resources by providing canopy
gaps. At landscape scale, heterogeneity created through different forest succes-
sional stages is needed to conserve the entire community of wild bees
Non-relativistic limit of Randall-Sundrum model: solutions, applications and constraints
In the Randall-Sundrum model with one brane, we found the approximate and
exact solutions for gravitational potentials and accelerations of test bodies
in these potentials for different geometrical configurations. We applied these
formulas for calculation of the gravitational interaction between two spheres
and found the approximate and exact expressions for the relative force
corrections to the Newton's gravitational force. We demonstrated that the
difference between relative force corrections for the approximate and exact
cases increases with the parameter (for the fixed distance between
centers of the spheres). On the other hand, this difference increases with
decreasing of the distance between the centers of the spheres (for the fixed
curvature scale parameter ). We got the upper limit for the curvature scale
parameter m. For these values of , the difference
between the approximate and exact solutions is negligible.Comment: LaTex 11 pages, 3 figure
Designing forest biodiversity experiments : general considerations illustrated by a new large experiment in subtropical China
Funded by German Research Foundation. Grant Number: DFG FOR 891/1 and 2 National Natural Science Foundation of China. Grant Numbers: NSFC 30710103907, 30930005, 31170457 , 31210103910 Swiss National Science Foundation (SNSF) Sino-German Centre for Research Promotion in BeijingPeer reviewedPublisher PD
Depletion of Foxp3(+) regulatory T cells is accompanied by an increase in the relative abundance of Firmicutes in the murine gut microbiome
A reciprocal interaction exists between the gut microbiota and the immune system. Regulatory T (Treg) cells are important for controlling immune responses and for maintaining the intestinal homeostasis but their precise influence on the gut microbiota is unclear. We studied the effects of Treg cell depletion on inflammation of the intestinal mucosa and analysed the gut microbiota before and after depletion of Treg cells using the DEpletion of REGulatory T cells (DEREG) mouse model. DNA was extracted from stool samples of DEREG mice and wild‐type littermates at different time‐points before and after diphtheria toxin application to deplete Treg cells in DEREG mice. The V3/V4 region of the 16S rRNA gene was used for studying the gut microbiota with Illumina MiSeq paired ends sequencing. Multidimensional scaling separated the majority of gut microbiota samples from late time‐points after Treg cell depletion in DEREG mice from samples of early time‐points before Treg cell depletion in these mice and from gut microbiota samples of wild‐type mice. Treg cell depletion in DEREG mice was accompanied by an increase in the relative abundance of the phylum Firmicutes and by intestinal inflammation in DEREG mice 20 days after Treg cell depletion, indicating that Treg cells influence the gut microbiota composition. In addition, the variables cage, breeding and experiment number were associated with differences in the gut microbiota composition and these variables should be respected in murine studies
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Developing European conservation and mitigation tools for pollination services: approaches of the STEP (Status and Trends of European Pollinators) project
Pollinating insects form a key component of European biodiversity, and provide a vital ecosystem service to crops and wild plants. There is growing evidence of declines in both wild and domesticated pollinators, and parallel declines in plants relying upon them. The STEP project (Status and Trends of European Pollinators, 2010-2015, www.stepproject.net) is documenting critical elements in the nature and extent of these declines, examining key functional traits associated with pollination deficits, and developing a Red List for some European pollinator groups. Together these activities are laying the groundwork for future pollinator monitoring programmes. STEP is also assessing the relative importance of potential drivers of pollinator declines, including climate change, habitat loss and fragmentation, agrochemicals, pathogens, alien species, light pollution, and their interactions. We are measuring the ecological and economic impacts of declining pollinator services and floral resources, including effects on wild plant populations, crop production and human nutrition. STEP is reviewing existing and potential mitigation options, and providing novel tests of their effectiveness across Europe. Our work is building upon existing and newly developed datasets and models, complemented by spatially-replicated campaigns of field research to fill gaps in current knowledge. Findings are being integrated into a policy-relevant framework to create evidence-based decision support tools. STEP is establishing communication links to a wide range of stakeholders across Europe and beyond, including policy makers, beekeepers, farmers, academics and the general public. Taken together, the STEP research programme aims to improve our understanding of the nature, causes, consequences and potential mitigation of declines in pollination services at local, national, continental and global scales
Detection of pneumonia associated pathogens using a prototype multiplexed pneumonia test in hospitalized patients with severe pneumonia
Severe pneumonia remains an important cause of morbidity and mortality. Polymerase chain reaction (PCR) has been shown to be more sensitive than current standard microbiological methods--particularly in patients with prior antibiotic treatment--and therefore, may improve the accuracy of microbiological diagnosis for hospitalized patients with pneumonia. Conventional detection techniques and multiplex PCR for 14 typical bacterial pneumonia-associated pathogens were performed on respiratory samples collected from adult hospitalized patients enrolled in a prospective multi-center study. Patients were enrolled from March until September 2012. A total of 739 fresh, native samples were eligible for analysis, of which 75 were sputa, 421 aspirates, and 234 bronchial lavages. 276 pathogens were detected by microbiology for which a valid PCR result was generated (positive or negative detection result by Curetis prototype system). Among these, 120 were identified by the prototype assay, 50 pathogens were not detected. Overall performance of the prototype for pathogen identification was 70.6% sensitivity (95% confidence interval (CI) lower bound: 63.3%, upper bound: 76.9%) and 95.2% specificity (95% CI lower bound: 94.6%, upper bound: 95.7%). Based on the study results, device cut-off settings were adjusted for future series production. The overall performance with the settings of the CE series production devices was 78.7% sensitivity (95% CI lower bound: 72.1%) and 96.6% specificity (95% CI lower bound: 96.1%). Time to result was 5.2 hours (median) for the prototype test and 43.5 h for standard-of-care. The Pneumonia Application provides a rapid and moderately sensitive assay for the detection of pneumonia-causing pathogens with minimal hands-on time
Histomorphometry of the Sural Nerve for Use as a CFNG in Facial Reanimation Procedures
Facial palsy (FP) is a debilitating nerve pathology. Cross Face Nerve Grafting (CFNG) describes a surgical technique that uses nerve grafts to reanimate the paralyzed face. The sural nerve has been shown to be a reliable nerve graft with little donor side morbidity. Therefore, we aimed to investigate the microanatomy of the sural nerve. Biopsies were obtained from 15 FP patients who underwent CFNG using sural nerve grafts. Histological cross-sections were fixated, stained with PPD, and digitized. Histomorphometry and a validated software-based axon quantification were conducted. The median age of the operated patients was 37 years (5–62 years). There was a significant difference in axonal capacity decrease towards the periphery when comparing proximal vs. distal biopsies (p = 0.047), while the side of nerve harvest showed no significant differences in nerve caliber (proximal p = 0.253, distal p = 0.506) and axonal capacity for proximal and distal biopsies (proximal p = 0.414, distal p = 0.922). Age did not correlate with axonal capacity (proximal: R = −0.201, p = 0.603; distal: R = 0.317, p = 0.292). These novel insights into the microanatomy of the sural nerve may help refine CFNG techniques and individualize FP patient treatment plans, ultimately improving overall patient outcomes
Resource Heterogeneity Moderates the Biodiversity-Function Relationship in Real World Ecosystems
Numerous recent studies have tested the effects of plant, pollinator, and predator diversity on primary productivity, pollination, and consumption, respectively. Many have shown a positive relationship, particularly in controlled experiments, but variability in results has emphasized the context-dependency of these relationships. Complementary resource use may lead to a positive relationship between diversity and these processes, but only when a diverse array of niches is available to be partitioned among species. Therefore, the slope of the diversity-function relationship may change across differing levels of heterogeneity, but empirical evaluations of this pattern are lacking. Here we examine three important functions/properties in different real world (i.e., nonexperimental) ecosystems: plant biomass in German grasslands, parasitism rates across five habitat types in coastal Ecuador, and coffee pollination in agroforestry systems in Indonesia. We use general linear and structural equation modeling to demonstrate that the effect of diversity on these processes is context dependent, such that the slope of this relationship increases in environments where limiting resources (soil nutrients, host insects, and coffee flowers, respectively) are spatially heterogeneous. These real world patterns, combined with previous experiments, suggest that biodiversity may have its greatest impact on the functioning of diverse, naturally heterogeneous ecosystems
Tribute to Professor David Bruck
A tribute to Professor David I. Bruck, who served on the faculty of the Washington and Lee University School of Law from 2004 to 2020. Bruck directed W&L\u27s death penalty defense clinic, the Virginia Capital Case Clearinghouse, also known as VC3 . He became Professor of Law, Emeritus in 2020
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