Finite Element Modelling for Fracture of Multilayer Fibrous Networks

Tissue engineering involves three-dimensional scaffolds to support cell culture activities and provide mechanical support. One of the potential scaffolds used in tissue engineering is an electrospun scaffold consisting fibres ranging from nano- to micrometer scales deposited on layer stack. The finite element models have been used to study the in-plane deformation of two-dimensional single layer fibrous networks and without considers out-of-plane deformation. While the existing study focuses on two-dimensional study, the out-of-plane deformation of layer structured of electrospun scaffolds through the scaffolds thickness has not been studied. In this study, three-dimensional finite element model was constructed to investigate the fracture of multilayer fibrous networks. The three-dimensional results were compared with the fracture on two-dimensional single layer fibrous network. The result shows that these two models had identical fracture behaviour and similar deformation at the crack-tip region, where the fibres are rearranged and reoriented with similar stress distribution. The work here concludes that two-dimensional single layer fibrous network model is a simple yet effective model for the study of homogeneous fibrous networks

Phylogeography of the smooth-coated otter (Lutrogale perspicillata): distinct evolutionary lineages and hybridization with the Asian small clawed otter (Aonyx cinereus)

We investigated the phylogeography of the smooth-coated otter (Lutrogale perspicillata) to determine its spatial genetic structure for aiding an adaptive conservation management of the species. Fifty eight modern and 11 archival (dated 1882–1970) otters sampled from Iraq to Malaysian Borneo were genotyped (mtDNA Cytochrome-b, 10 microsatellite DNA loci). Moreover, 16 Aonyx cinereus (Asian small-clawed otter) and seven Lutra lutra (Eurasian otter) were sequenced to increase information available for phylogenetic reconstructions. As reported in previous studies, we found that L. perspicillata, A. cinereus and A. capensis (African clawless otter) grouped in a clade sister to the genus Lutra, with L. perspicillata and A. cinereus being reciprocally monophyletic. Within L. perspicillata, we uncovered three Evolutionarily Significant Units and proved that L. p. maxwelli is not only endemic to Iraq but also the most recent subspecies. We suggest a revision of the distribution range limits of easternmost L. perspicillata subspecies. We show that smooth-coated otters in Singapore are L. perspicillata x A. cinereus hybrids with A. cinereus mtDNA, the first reported case of hybridization in the wild among otters. This result also provides evidence supporting the inclusion of L. perspicillata and A. cinereus in the genus Amblonyx, thus avoiding the paraphyly of the genus Aonyx

Molecular phylogeography of the smooth-­‐coated otter (Lutrogale perspicillata, Mustelidae) for its conservation in the Mesopotamian marshes of Iraq

The smooth-coated otter (Lutrogale perspicillata) (SCO) includes perspicillata (SE Asia), sindica (SE Pakistan, W India) and endemic-to-Iraq maxwelli morphological subspecies. Classified as vulnerable by IUCN, the SCO is threatened by habitat transformation, illegal trade and poaching. Non-invasively collected samples in Iraq (10), central and E Asia (nine countries, 46) were sequenced at the entire mtDNA Cytochrome-b gene and genotyped (ongoing) at the microsatellite DNA. We also obtained 307 bp-long gene fragments from 16 SCOs resident to US and European museums. We used 19 Lutrinae GenBank entries. In Iraq, we provided genetic evidence for endemicity of maxwelli to Mesopotamia (private haplotype, mostly from Al-Hawizeh Marsh, S Iraq), while we could not confirm the occurrence of the SCO in N Iraq (Kurdistan).We found reciprocally monophyletic mtDNA lineages across the SCO range each corresponding to a subspecies. Preliminary microsatellite DNA results confirmed this mtDNA picture, overall pointing to three Evolutionarily Significant Units. Looking-like SCOs from Singapore showed oriental small-clawed otter (Aonyx cinerea) mtDNA. We will investigate A. cinerea-mtDNA introgressed SCOs at the microsatellite DNA to assess if they are descendant of L. perspicillata x A. cinerea otters (i.e., first hybrid record in the wild for Lutrinae). Several museum specimens were genetically identified as other than the SCO (even an African otter),indicating that morphology can be not sufficient to reliably catalogue otter study skins. In Iraq, genetic and fieldwork (not shown) data will help establishing a National Single Species Action Plan for the SCO. [National Geographic Society Conservation

Filtration and Breakdown of Clay Clusters during Resin Transfer Molding of Nanoclay/Glass/Epoxy Composites

Dispersion of nanoclay clusters during resin transfer molding of nanoclay/glass/epoxy disks is investigated. In addition to a center-gated disk containing only 14% glass fibers, three nanocomposite disks are fabricated with the addition of 2, 5 or 10 wt% Cloisite® 25A nanoclay. The spatial distribution of nanoclay clusters along the radial axis of the nanocomposite disks are characterized at two length scales. Clusters larger than 1.5 μm are characterized by performing image analysis on the SEM micrographs whereas smaller nanoclay clusters are identified by wavelength dispersive spectrometry. Results obtained from image analysis indicate that nanoclay clusters are filtered out by as much as 50% in the flow direction by the glass fiber preforms. In addition, increasing nanoclay content led to higher filtration, suggesting that cluster formation is more prominent at higher nanoclay loadings. Cluster size distribution analyses revealed that the outer edges of the disks, on average, contain finer nanoclay particles. For instance, the outer edge of the nanocomposite with 2% clay contains 22% more small nanoclay clusters compared to center of the disk. Glass transition temperature, Tg, of four specimens obtained from each molded disks is characterized under oscillatory shear. Glass transition temperature of the samples are shown to increase with the nanoclay content, yielding a 40% higher Tg at 10% nanoclay loading compared to glass/epoxy composite without clay. Increasing glass transition temperature with increasing nanoclay content may be an indication of intercalation of nanoclay within the epoxy matrix.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Are interventions to increase the uptake of screening for cardiovascular disease risk factors effective? a systematic review and meta-analysis

Background: Cardiovascular disease (CVD) is the leading cause of death globally. However many individuals are unaware of their CVD risk factors. The objective of this systematic review is to determine the effectiveness of existing intervention strategies to increase uptake of CVD risk factors screening. Methods: A systematic search was conducted through Pubmed, CINAHL, EMBASE and Cochrane Central Register of Controlled Trials. Additional articles were located through cross-checking of the references list and bibliography citations of the included studies and previous review papers. We included intervention studies with controlled or baseline comparison groups that were conducted in primary care practices or the community, targeted at adult populations (randomized controlled trials, non-randomized trials with controlled groups and pre- and post-intervention studies). The interventions were targeted either at individuals, communities, health care professionals or the health-care system. The main outcome of interest was the relative risk (RR) of screening up take rates due to the intervention. Results: We included 21 studies in the meta-analysis. The risk of bias for randomization was low to medium in the randomized controlled trials, except for one, and high in the non-randomized trials. Two analyses were performed; optimistic (using the highest effect sizes) and pessimistic (using the lowest effect sizes). Overall, interventions were shown to increase the uptake of screening for CVD risk factors (RR 1.443; 95% CI 1.264 to 1.648 for pessimistic analysis and RR 1.680; 95% CI 1.420 to 1.988 for optimistic analysis). Effective interventions that increased screening participation included: use of physician reminders (RR ranged between 1.392; 95% CI 1.192 to 1.625, and 1.471; 95% CI 1.304 to 1.660), use of dedicated personnel (RR ranged between 1.510; 95% CI 1.014 to 2.247, and 2.536; 95% CI 1.297 to 4.960) and provision of financial incentives for screening (RR 1.462; 95% CI 1.068 to 2.000). Meta-regression analysis showed that the effect of CVD risk factors screening uptake was not associated with study design, types of population or types of interventions. Conclusions: Interventions using physician reminders, using dedicated personnel to deliver screening, and provision of financial incentives were found to be effective in increasing CVD risk factors screening uptake