Numerical modeling of the dynamic tensile behavior of irregular fibers

Most fibers are irregular, and they are often subjected to rapid straining during mechanical processing and end-use applications. In this paper, the effect of fiber dimensional irregularities on the dynamic tensile behavior of irregular fibers is examined, using the finite element method (FEM). Fiber dimensional irregularities are simulated with sine waves of different magnitude (10%, 30% and 50% level of diameter variation). The tensile behavior of irregular fibers is examined at different strain rates (333%/sec, 3,333%/sec and 30,000%/sec). The breaking load and breaking extension of irregular fibers at different strain rates are then calculated from the finite element model. The results indicate that strain rate has a significant effect on the dynamic tensile behavior of an irregular fiber, and that the position of the thinnest segment along the fiber affects the simulation results markedly. Under dynamic conditions, an irregular fiber does not necessarily break at the thinnest segment, which is different from the quasi-static results.<br /

Watershed science: Coupling hydrological science and water resources management

While there have been advancements in hydrological science and water resources management, the world continues to face a water-supply crisis. In light of studies that report the missing links to be (i) effective collaborations between researchers and practitioners and (ii) interdisciplinary working, we promote the benefits of Watershed Science to address these gaps. Watershed Science incorporates basin hydrology, determines water resource thresholds, promotes water governance that forms partnerships between institutions, and enacts participatory decision making in water resources management. However, such partnerships must recognize the differential power and interests of different actors to ensure that outcomes are not skewed in favour of particular interests. It adds value to existing water management programs and has great potential for bringing disciplines and decision making together to address the global water crisis

Increased EMRSA-15 health-care worker colonization demonstrated in retrospective review of EMRSA hospital outbreaks

Background:Health care worker (HCW) colonization with methicillin resistant Staphylococcus aureus (MRSA) is a documented cause of hospital outbreaks and contributes to ongoing transmission. At Royal Perth Hospital (RPH) it had been anecdotally noted that the increasing prevalence of EMRSA-15 appeared to be associated with increased HCW colonization compared with Aus2/3-EMRSA. Hence we compared HCW colonization rates during outbreaks of EMRSA-15 and Aus2/3-EMRSA at a single institution.Methods:We performed a retrospective review of EMRSA-15 and Aus2/3-EMRSA outbreaks from 2000 –2009 at RPH, a quaternary hospital in Western Australia. Outbreak files were reviewed and relevant data extracted. Results:Ten EMRSA-15 outbreaks were compared with seven Aus2/3 outbreaks. The number of patients colonized was similar between EMRSA-15 and Aus2/ 3-EMRSA outbreaks (median 7 [range 3 – 20] and 11 [5 – 26], respectively; P = 0.07) but the number of HCWs colonized was significantl y higher in EMRSA-15 outbreaks compared to Aus2/3-EMRSA outbreaks (median 4 [range 0 – 15] and 2 [1-3], respectively; P = 0.013). The percentage of HCWs colonized was also higher in EMRSA-15 outbreaks versus Aus2/3-EMRSA outbreaks (median 3.4% [range 0 – 5.5%] and 0.81% [0.56 – 2.2%], respectively; P= 0.013).Conclusions:This study demonstrates a higher level of HCW colonization during EMRSA-15 outbreaks compared with Aus2/3-EMRSA outbreaks. This finding suggests that MRSA vary in their ability to colonize HCWs and contribute to outbreaks. MRSA type should be determined during outbreaks and future research should investigate the mechanisms by which EMRSA-15 contributes to increased HCW colonization

The Impact of Recombination on dN/dS within Recently Emerged Bacterial Clones

The development of next-generation sequencing platforms is set to reveal an unprecedented level of detail on short-term molecular evolutionary processes in bacteria. Here we re-analyse genome-wide single nucleotide polymorphism (SNP) datasets for recently emerged clones of methicillin resistant Staphylococcus aureus (MRSA) and Clostridium difficile. We note a highly significant enrichment of synonymous SNPs in those genes which have been affected by recombination, i.e. those genes on mobile elements designated “non-core” (in the case of S. aureus), or those core genes which have been affected by homologous replacements (S. aureus and C. difficile). This observation suggests that the previously documented decrease in dN/dS over time in bacteria applies not only to genomes of differing levels of divergence overall, but also to horizontally acquired genes of differing levels of divergence within a single genome. We also consider the role of increased drift acting on recently emerged, highly specialised clones, and the impact of recombination on selection at linked sites. This work has implications for a wide range of genomic analyses

Synthesizing attractors of Hindmarsh-Rose neuronal systems

In this paper a periodic parameter switching scheme is applied to the Hindmarsh-Rose neuronal system to synthesize certain attractors. Results show numerically, via computer graphic simulations, that the obtained synthesized attractor belongs to the class of all admissible attractors for the Hindmarsh-Rose neuronal system and matches the averaged attractor obtained with the control parameter replaced with the averaged switched parameter values. This feature allows us to imagine that living beings are able to maintain vital behavior while the control parameter switches so that their dynamical behavior is suitable for the given environment.Comment: published in Nonlinear Dynamic

On the growth of perturbations in interacting dark energy and dark matter fluids

The covariant generalizations of the background dark sector coupling suggested in G. Mangano, G. Miele and V. Pettorino, Mod. Phys. Lett. A 18, 831 (2003) are considered. The evolution of perturbations is studied with detailed attention to interaction rate that is proportional to the product of dark matter and dark energy densities. It is shown that some classes of models with coupling of this type do not suffer from early time instabilities in strong coupling regime.Comment: 11 pages, 2 figures. v3: minor changes, typos fixe

Final report on project SP1210: Lowland peatland systems in England and Wales – evaluating greenhouse gas fluxes and carbon balances

Lowland peatlands represent one of the most carbon-rich ecosystems in the UK. As a result of widespread habitat modification and drainage to support agriculture and peat extraction, they have been converted from natural carbon sinks into major carbon sources, and are now amongst the largest sources of greenhouse gas (GHG) emissions from the UK land-use sector. Despite this, they have previously received relatively little policy attention, and measures to reduce GHG emissions either through re-wetting and restoration or improved management of agricultural land remain at a relatively early stage. In part, this has stemmed from a lack of reliable measurements on the carbon and GHG balance of UK lowland peatlands. This project aimed to address this evidence gap via an unprecedented programme of consistent, multi year field measurements at a total of 15 lowland peatland sites in England and Wales, ranging from conservation managed ‘near-natural’ ecosystems to intensively managed agricultural and extraction sites. The use of standardised measurement and data analysis protocols allowed the magnitude of GHG emissions and removals by peatlands to be quantified across this heterogeneous data set, and for controlling factors to be identified. The network of seven flux towers established during the project is believed to be unique on peatlands globally, and has provided new insights into the processes the control GHG fluxes in lowland peatlands. The work undertaken is intended to support the future development and implementation of agricultural management and restoration measures aimed at reducing the contribution of these important ecosystems to UK GHG emissions

RISK FACTORS OF SURGICAL SITE INFECTION AT THE REGIONAL AND TEACHING HOSPITAL CENTER OF BORGOU (BENIN)

Introduction: The reduction of the SSI rate requires knowledge of its risk factors. Objective: To analyze the risk factors of SSI occurrence at CHD-B Methods: Prospective, descriptive and analytical study involving 603 patients undergoing general surgery (218) and obstetrics and gynecology (385) from 1st&nbsp;January to 31st&nbsp;July 2013. Results: 44 patients have developed SSI (7.3%). The SSI frequency was 12.8% in general surgery and 4.2% in gynecology-obstetrics (p significant). The mean age of patients developing SSI was 30.7 ± 15.8 years with a minimum and maximum 5 months and 70 years, respectively; and for general surgery patients, there were 23 men and 5 women (p not significant). The presence of preoperative infectious spot at admission (P = 0.003), the preoperative shaving of the site to be incised (p = 0.000), the ASA score (p = 0.000), the surgery contamination class (p = 0.000), and the NNIS score (p = 0.000) were all significantly related to SSI occurrence. Considering all these factors, the NNIS score ≥2 remained the predictive tool by multiplying by 3.4 the risk of SSI occurrence. Conclusion: NNIS score is the best SSI prediction tool at CHD-B. KEYWORDS: Surgical site infection; Risk factor; NNIS score

RISK FACTORS OF SURGICAL SITE INFECTION AT THE REGIONAL AND TEACHING HOSPITAL CENTER OF BORGOU (BENIN)

Introduction: The reduction of the SSI rate requires knowledge of its risk factors. Objective: To analyze the risk factors of SSI occurrence at CHD-B Methods: Prospective, descriptive and analytical study involving 603 patients undergoing general surgery (218) and obstetrics and gynecology (385) from 1st&nbsp;January to 31st&nbsp;July 2013. Results: 44 patients have developed SSI (7.3%). The SSI frequency was 12.8% in general surgery and 4.2% in gynecology-obstetrics (p significant). The mean age of patients developing SSI was 30.7 ± 15.8 years with a minimum and maximum 5 months and 70 years, respectively; and for general surgery patients, there were 23 men and 5 women (p not significant). The presence of preoperative infectious spot at admission (P = 0.003), the preoperative shaving of the site to be incised (p = 0.000), the ASA score (p = 0.000), the surgery contamination class (p = 0.000), and the NNIS score (p = 0.000) were all significantly related to SSI occurrence. Considering all these factors, the NNIS score ≥2 remained the predictive tool by multiplying by 3.4 the risk of SSI occurrence. Conclusion: NNIS score is the best SSI prediction tool at CHD-B. KEYWORDS: Surgical site infection; Risk factor; NNIS score