Influence of environmental conditions on extracellular and intracellular antibiotic resistance genes in manure-amended soil: A microcosm study

Extracellular and intracellular antibiotic resistance genes (eARGs and iARGs) possess significant differences with respect to their mobility and availability to bacteria, thus it is important to understand their partitioning, persistence, and fate in the environment. The objectives of this study were to: (i) modify the protocol of a commercial DNA extraction kit to sequentially extract extracellular and intracellular DNA (eDNA and iDNA) from the same soil sample; and (ii) determine the effect of temperature (5, 20, and 35C), water holding capacity (25, 50, and 75% of WHCmax), and freeze-thaw (-20/20C) on the abundance of two ARGs [sul1 and tet(M)], class 1 integron-integrase gene (intI1), and 16S rRNA gene in soils treated with dairy manure. To assess the efficiency of the eDNA/iDNA method, we performed spiking and recovery experiments with a gene that codes for a green fluorescent protein (gfp). When soils were spiked with a whole-cell preparation of gfp-containing E. coli, the recovery of the gfp gene was on average 0.2% and 1.2% for eDNA and iDNA, respectively. Soils were also spiked with the gfp gene itself, which showed that nearly 80% of the DNA could not be recovered. Results from the microcosm experiments indicate that extracellular and intracellular sul1, tet(X), intI1, and 16S rRNA genes are resilient and not readily affected by temperature, WHC, or freeze-thaw cycles. The intracellular gene levels decreased only slightly during the 56-day incubation period. The extracellular gene levels (when detectable) decreased dramatically by day 7, then leveled off thereafter, which may have been caused by adsorption to soil particles and/or degradation. Absolute gene abundances (per g of dry soil) were one to two orders of magnitude higher in iDNA than in eDNA fractions, but were similar when normalized to the 16S rRNA gene throughout the incubation period, indicating that enrichment of eARGs and iARGs did not occur. It is important for the scientific community to standardize total, as well as, extracellular/intracellular DNA extractions in order to readily compare results between laboratories

Elastic-to-plastic crossover below the peak effect in the vortex solid of YBa2Cu3O7 single crystals

We report on transport and ac susceptibility studies below the peak effect in twinned YBa2Cu3O7 single crystals. We find that disorder generated at the peak effect can be partially inhibited by forcing vortices to move with an ac driving current. The vortex system can be additionally ordered below a well-defined temperature where elastic interactions between vortices overcome pinning-generated stress and a plastic to elastic crossover seems to occur. The combined effect of these two processes results in vortex structures with different mobilities that give place to history effects.Comment: 4 pages, 4 figures. Published in PRB Rapid Comm., February 1, 200

Migrating Songbirds on Stopover Prepare for, and Recover from, Oxidative Challenges Posed by Long-Distance Flight

Managing oxidative stress is an important physiological function for all aerobic organisms, particularly during periods of prolonged high metabolic activity, such as long-distance migration across ecological barriers. However, no previous study has investigated the oxidative status of birds at different stages of migration and whether that oxidative status depends on the condition of the birds. In this study, we compared (1) energy stores and circulating oxidative status measures in (a) two species of Neotropical migrants with differing migration strategies that were sampled at an autumn stopover site before an ecological barrier; and (b) a species of trans-Saharan migrant sampled at a spring stopover site after crossing an ecological barrier; and (2) circulating oxidative measures and indicators of fat metabolism in a trans-Saharan migrant after stopovers of varying duration (0–8 nights), based on recapture records. We found fat stores to be positively correlated with circulating antioxidant capacity in Blackpoll Warblers and Red-eyed Vireos preparing for fall migration on Block Island, USA, but uncorrelated in Garden Warblers on the island of Ponza, Italy, after a spring crossing of the Sahara Desert and Mediterranean Sea. In all circumstances, fat stores were positively correlated with circulating lipid oxidation levels. Among Garden Warblers on the island of Ponza, fat anabolism increased with stopover duration while oxidative damage levels decreased. Our study provides evidence that birds build antioxidant capacity as they build fat stores at stopover sites before long flights, but does not support the idea that antioxidant stores remain elevated in birds with high fuel levels after an ecological barrier. Our results further suggest that lipid oxidation may be an inescapable hazard of using fats as the primary fuel for flight. Yet, we also show that birds on stopover are capable of recovering from the oxidative damage they have accrued during migration, as lipid oxidation levels decrease with time on stopover. Thus, the physiological strategy of migrating songbirds may be to build prophylactic antioxidant capacity in concert with fuel stores at stopover sites before a long-distance flight, and then repair oxidative damage while refueling at stopover sites after long-distance flight

Shellfish reef restoration pilots: Voordelta The Netherlands

Once, shellfish reefs - mainly flat oysters - covered about 20% of the North Sea floor, but diseases, pollution and overfishing have led to a significant decline. As part of the Haringvliet Dream Fund Project (www.haringvliet.nu), ARKNature and World Wildlife Fund Netherlands are working on shellfish reef restoration. Shellfish, such as mussels and flat oysters, are keystone species for marine biodiversity, since they filter the water, provide shelter and nursery grounds for many marine animals, serve as attachment substrate for plants and range of animals, including birds. They also play an important role in natural coastal protection. Therefore, mussel and flat oyster reef restoration is attempted within the Haringvliet coastal zone (the so-called Voordelta).This project is co-funded by the ministry for Economic Affairs, the ministry for and Environment, province of South Holland, Port of Rotterdam, National Postcode Lottery and LIFE. ARK Nature leads this project. The North Sea Flat (a cooperation of Wageningen Marine Research, Bureau Waardenburg and Sas Consultancy) is responsible for the execution of the current two pilots: maintenance, monitoring, analysis of monitoring results and reporting

Musicians’ perceptions and experiences of using simulation training to develop performance skills

Simulation has been applied as a tool for learning and training in sports, psychology and medicine for some time, but its current use and potential for training musicians is less well understood. The aim of this study was to explore musicians’ perceptions and experiences of using simulated performance environments. Nine conservatory students performed in two simulations, each with interactive virtual elements and vivid environmental cues: a recital with a virtual audience and an audition with virtual judges. Qualitative data were collected through a focus group interview and written reflective commentaries. Thematic analysis highlighted the musicians’ experiences in terms of (1) their anticipation of using the simulations, (2) the process of performing in the simulations, (3) the usefulness of simulation as a tool for developing performance skills and (4) ways of improving simulation training. The results show that while simulation was new to the musicians and individual levels of immersion differed, the musicians saw benefits in the approach for developing, experimenting with and enhancing their performance skills. Specifically, the musicians emphasised the importance of framing the simulation experience with plausible procedures leading to and following on from the performance, and they recognised the potential for combining simulation with complementary training techniques

Exposure to Traffic Pollution and Increased Risk of Rheumatoid Arthritis

Background: Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease that affects approximately 1% of the adult population, and to date, genetic factors explain < 50% of the risk. Particulate air pollution, especially of traffic origin, has been linked to systemic inflammation in many studies. Objectives: We examined the association of distance to road, a marker of traffic pollution exposure, and incidence of RA in a prospective cohort study.Methods We studied 90,297 U.S. women in the Nurses’ Health Study. We used a geographic information system to determine distance to road at the residence in 2000 as a measure of traffic exposure. Using Cox proportional hazard models, we examined the association of distance to road and incident RA (1976–2004) with adjustment for a large number of potential confounders. Results: In models adjusted for age, calendar year, race, cigarette smoking, parity, lactation, menopausal status and hormone use, oral contraceptive use, body mass index, physical activity, and census-tract-level median income and house value, we observed an elevated risk of RA [hazard ratio (HR) = 1.31; 95% confidence interval (CI), 0.98–1.74] in women living within 50 m of a road, compared with those women living 200 m or farther away. We also observed this association in analyses among nonsmokers (HR = 1.62; 95% CI, 1.04–2.52), nonsmokers with rheumatoid factor (RF)-negative RA (HR = 1.77; 95% CI, 0.93–3.38), and nonsmokers with RF-positive RA (HR = 1.51; 95% CI, 0.82–2.77). We saw no elevations in risk in women living 50–200 m from the road. Conclusions: The observed association between exposure to traffic pollution and RA suggests that pollution from traffic in adulthood may be a newly identified environmental risk factor for RA

Seed production from the mixed mating system of Chesapeake Bay (USA) eelgrass (Zostera marina; Zosteraceae)

In monoecious plants, gametes can be exchanged in three ways: among unrelated genets (outbreeding), with close relatives (inbreeding), or within individuals (geitonogamous selling). These different mating systems may have consequences for population demography and fitness. The experiment presented herein used artificial crosses to examine the mating system of Chesapeake Bay, Virginia, USA eelgrass (Zostera marina L; Zosteraceae), a bisexual submerged aquatic plant that can outbreed, inbreed, and self. Genetic data indicate severe heterozygosity deficiencies and patchy genotype distribution in these beds, suggesting that plants therein reproduce primarily by vegetative propagation, autogamy, or geitonogamy. To clarify eelgrass reproductive strategies, flowers from three genetically and geographically distinct beds were hand-pollinated in outbred, inbred, and selfed matings. Fertilization success and seed production, life history stages which contribute greatly to the numeric maintenance of populations, were monitored. We found no evidence that inbreeding had negative consequences for seed production. On the contrary, selfed matings produced seeds significantly more frequently than outcrossed matings and produced significantly larger numbers of seeds than either inbred or outbred matings. These results contrast with patterns for eelgrass in other regions but might be expected for similar populations in which pollen limitation or a short reproductive season renders selfing advantageous

Slow relaxations and history dependence of the transport properties of layered superconductors

We study numerically the time evolution of the transport properties of layered superconductors after different preparations. We show that, in accordance with recent experiments in BSCCO performed in the second peak region of the phase diagram (Portier et al, 2001), the relaxation strongly depends on the initial conditions and is extremely slow. We investigate the dependence on the pinning center density and the perturbation applied. We compare the measurements to recent findings in tapped granular matter and we interpret our results with a rather simple picture.Comment: 4 pages, 4 fig

Mapping on slope seepage problem using Electrical Resistivity Imaging (ERI)

The stability of slope may influenced by several factors such as its geomaterial properties, geometry and environmental factors. Problematic slope due to seepage phenomenon will influenced the slope strength thus promoting to its failure. In the past, slope seepage mapping suffer from several limitation due to cost, time and data coverage. Conventional engineering tools to detect or mapped the seepage on slope experienced those problems involving large and high elevation of slope design. As a result, this study introduced geophysical tools for slope seepage mapping based on electrical resistivity method. Two spread lines of electrical resistivity imaging were performed on the slope crest using ABEM SAS 4000 equipment. Data acquisition configuration was based on long and short arrangement, schlumberger array and 2.5 m of equal electrode spacing interval. Raw data obtained from data acquisition was analyzed using RES2DINV software. Both of the resistivity results show that the slope studied consists of three different anomalies representing top soil (200 – 1000 Ωm), perched water (10 – 100 Ωm) and hard/dry layer (> 200 Ωm). It was found that seepage problem on slope studied was derived from perched water zones with electrical resistivity value of 10 – 100 Ωm. Perched water zone has been detected at 6 m depth from the ground level with varying thickness at 5 m and over. Resistivity results have shown some good similarity output with reference to borehole data, geological map and site observation thus verified the resistivity results interpretation. Hence, this study has shown that the electrical resistivity imaging was applicable in slope seepage mapping which consider efficient in term of cost, time, data coverage and sustainability

Communitarian perspectives on social enterprise

Concepts of social enterprise have been debated repeatedly, and continue to cause confusion. In this paper, a meta-theoretical framework is developed through discussion of individualist and communitarian philosophy. Philosophers from both traditions build social theories that emphasise either consensus (a unitarist outlook) or diversity (a pluralist outlook). The various discourses in corporate governance reflect these assumptions and create four distinct approaches that impact on the relationship between capital and labour. In rejecting the traditional discourse of private enterprise, social enterprises have adopted other approaches to tackle social exclusion, each derived from different underlying beliefs about the purpose of enterprise and the nature of governance. The theoretical framework offers a way to understand the diversity found within the sector, including the newly constituted Community Interest Company (CIC).</p