13,037 research outputs found
Effects of population mixing on the spread of SIR epidemics
We study dynamics of spread of epidemics of SIR type in a realistic
spatially-explicit geographical region, Southern and Central Ontario, using
census data obtained from Statistics Canada, and examine the role of population
mixing in epidemic processes. Our model incorporates the random nature of
disease transmission, the discreteness and heterogeneity of distribution of
host population. We find that introduction of a long-range interaction destroys
spatial correlations very easily if neighbourhood sizes are homogeneous. For
inhomogeneous neighbourhoods, very strong long-range coupling is required to
achieve a similar effect. Our work applies to the spread of in influenza during
a single season and our model is applicable to other geographic regions, if
suitable data is available
Contact-line pinning controls how quickly colloidal particles equilibrate with liquid interfaces
Previous experiments have shown that spherical colloidal particles relax to
equilibrium slowly after they adsorb to a liquid-liquid interface, despite the
large interfacial energy gradient driving the adsorption. The slow relaxation
has been explained in terms of transient pinning and depinning of the contact
line on the surface of the particles. However, the nature of the pinning sites
has not been investigated in detail. We use digital holographic microscopy to
track a variety of colloidal spheres---inorganic and organic, charge-stabilized
and sterically stabilized, aqueous and non-aqueous---as they breach liquid
interfaces. We find that nearly all of these particles relax logarithmically in
time over timescales much larger than those expected from viscous dissipation
alone. By comparing our results to theoretical models of the pinning dynamics,
we infer the area per defect to be on the order of a few square nanometers for
each of the colloids we examine, whereas the energy per defect can vary from a
few for non-aqueous and inorganic spheres to tens of for aqueous
polymer particles. The results suggest that the likely pinning sites are
topographical features inherent to colloidal particles---surface roughness in
the case of silica particles and grafted polymer "hairs" in the case of polymer
particles. We conclude that the slow relaxation must be taken into account in
experiments and applications, such as Pickering emulsions, that involve
colloids attaching to interfaces. The effect is particularly important for
aqueous polymer particles, which pin the contact line strongly.Comment: 26 pages, 7 figure
Structure and evolution of chlorate reduction composite transposons.
UnlabelledThe genes for chlorate reduction in six bacterial strains were analyzed in order to gain insight into the metabolism. A newly isolated chlorate-reducing bacterium (Shewanella algae ACDC) and three previously isolated strains (Ideonella dechloratans, Pseudomonas sp. strain PK, and Dechloromarinus chlorophilus NSS) were genome sequenced and compared to published sequences (Alicycliphilus denitrificans BC plasmid pALIDE01 and Pseudomonas chloritidismutans AW-1). De novo assembly of genomes failed to join regions adjacent to genes involved in chlorate reduction, suggesting the presence of repeat regions. Using a bioinformatics approach and finishing PCRs to connect fragmented contigs, we discovered that chlorate reduction genes are flanked by insertion sequences, forming composite transposons in all four newly sequenced strains. These insertion sequences delineate regions with the potential to move horizontally and define a set of genes that may be important for chlorate reduction. In addition to core metabolic components, we have highlighted several such genes through comparative analysis and visualization. Phylogenetic analysis places chlorate reductase within a functionally diverse clade of type II dimethyl sulfoxide (DMSO) reductases, part of a larger family of enzymes with reactivity toward chlorate. Nucleotide-level forensics of regions surrounding chlorite dismutase (cld), as well as its phylogenetic clustering in a betaproteobacterial Cld clade, indicate that cld has been mobilized at least once from a perchlorate reducer to build chlorate respiration.ImportanceGenome sequencing has identified, for the first time, chlorate reduction composite transposons. These transposons are constructed with flanking insertion sequences that differ in type and orientation between organisms, indicating that this mobile element has formed multiple times and is important for dissemination. Apart from core metabolic enzymes, very little is known about the genetic factors involved in chlorate reduction. Comparative analysis has identified several genes that may also be important, but the relative absence of accessory genes suggests that this mobile metabolism relies on host systems for electron transport, regulation, and cofactor synthesis. Phylogenetic analysis of Cld and ClrA provides support for the hypothesis that chlorate reduction was built multiple times from type II dimethyl sulfoxide (DMSO) reductases and cld. In at least one case, cld has been coopted from a perchlorate reduction island for this purpose. This work is a significant step toward understanding the genetics and evolution of chlorate reduction
Sibling health, schooling and longer-term developmental outcomes
We explore the extent to which starting primary school earlier by up to one year can help shield children from the detrimental, long-term developmental consequences of having an ill or disabled sibling. Using data from the Longitudinal Study of Australian Children, we employ a Regression Discontinuity Design based on birthday eligibility cut-offs. We find that Australian children who have a sibling in poor health persistently lag behind other children in their cognitive development - but only for the children who start school later. In contrast, for the children who commence school earlier, we do not find any cognitive developmental gaps. The results are strongest when the ill-health in the sibling is of a temporary rather than longer-term nature. We hypothesise that an early school start achieves this by lessening the importance of resource-access inequalities within the family home. However, we find mixed impacts on the gaps in non-cognitive development
Physiological and genetic description of dissimilatory perchlorate reduction by the novel marine bacterium Arcobacter sp. strain CAB.
A novel dissimilatory perchlorate-reducing bacterium (DPRB), Arcobacter sp. strain CAB, was isolated from a marina in Berkeley, CA. Phylogenetically, this halophile was most closely related to Arcobacter defluvii strain SW30-2 and Arcobacter ellisii. With acetate as the electron donor, strain CAB completely reduced perchlorate (ClO4(-)) or chlorate (ClO3(-)) [collectively designated (per)chlorate] to innocuous chloride (Cl(-)), likely using the perchlorate reductase (Pcr) and chlorite dismutase (Cld) enzymes. When grown with perchlorate, optimum growth was observed at 25 to 30°C, pH 7, and 3% NaCl. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) preparations were dominated by free-swimming straight rods with 1 to 2 polar flagella per cell. Strain CAB utilized a variety of organic acids, fructose, and hydrogen as electron donors coupled to (per)chlorate reduction. Further, under anoxic growth conditions strain CAB utilized the biogenic oxygen produced as a result of chlorite dismutation to oxidize catechol via the meta-cleavage pathway of aerobic catechol degradation and the catechol 2,3-dioxygenase enzyme. In addition to (per)chlorate, oxygen and nitrate were alternatively used as electron acceptors. The 3.48-Mb draft genome encoded a distinct perchlorate reduction island (PRI) containing several transposases. The genome lacks the pcrC gene, which was previously thought to be essential for (per)chlorate reduction, and appears to use an unrelated Arcobacter c-type cytochrome to perform the same function. IMPORTANCE The study of dissimilatory perchlorate-reducing bacteria (DPRB) has largely focused on freshwater, mesophilic, neutral-pH environments. This study identifies a novel marine DPRB in the genus Arcobacter that represents the first description of a DPRB associated with the Campylobacteraceae. Strain CAB is currently the only epsilonproteobacterial DPRB in pure culture. The genome of strain CAB lacks the pcrC gene found in all other DPRB tested, demonstrating a new variation on the (per)chlorate reduction pathway. The ability of strain CAB to oxidize catechol via the oxygenase-dependent meta-cleavage pathway in the absence of external oxygen by using the biogenic oxygen produced from the dismutation of chlorite provides a valuable model for understanding the anaerobic degradation of a broad diversity of xenobiotics which are recalcitrant to anaerobic metabolism but labile to oxygenase-dependent mechanisms
Selective inhibition of phosphodiesterases 4, 5 and 9 induces HSP20 phosphorylation and attenuates amyloid beta 1-42 mediated cytotoxicity
Phosphodiesterase (PDE) inhibitors are currently under evaluation as agents that may facilitate the improvement of cognitive impairment associated with Alzheimer's disease. Our aim was to determine whether inhibitors of PDEs 4,5 and 9 could alleviate the cytotoxic effects of amyloid beta 1–42 (Aβ1-42) via a mechanism involving the small heatshock protein HSP20. We show that inhibition of PDEs 4,5 and 9 but not 3 induces the phosphorylation of HSP20 which, in turn, increases the co-localisation between the chaperone and Aβ1-42 to significantly decrease the toxic effect of the peptide. We conclude that inhibition of PDE9 is most effective to combat Aβ1-42 cytotoxicity in our cell model
Evaluating the prevalence of potentially inappropriate prescribing in older adults in intermediate care facilities: a cross-sectional observational study
Background: Potentially inappropriate prescribing (PIP) [encompassing potentially inappropriate medicines (PIMs) and potential prescribing omissions (PPOs)], is prevalent amongst older adults in primary and secondary care. However, PIP prevalence in intermediate care (IC) is unknown. Objective To determine the prevalence of PIMs/PPOs and associated patient factors. Setting Three IC facilities in Northern Ireland. Method: The Screening Tool of Older People's Prescriptions and the Screening Tool to Alert doctors to Right Treatment were used to identify PIP over 8 weeks. Wilcoxon signed-rank tests were performed to compare the prevalence of PIMs/PPOs at admission and discharge. Spearman's correlation coefficients were calculated to determine factors associated with PIMs/PPOs (p < 0.05 considered significant). Main outcome measure Prevalence of PIMs/PPOs. Results: 74 patients [mean age 83.5(±7.4) years] were included. Discharge medication data were available for 30 (40.5%) patients. 53 (71.6%) and 22 (73.3%) patients had ≥1 PIM at admission and discharge, respectively. 45 (60.8%) and 15 (50.0%) patients had ≥1 PPO at admission and discharge, respectively. No significant difference was found in PIM/PPO prevalence at admission compared to discharge (Z = -0.36, p = 0.72; Z = -1.63, p = 0.10). Increasing comorbidity and medication regimen complexity were associated with PIMs at admission (r = 0.265, p = 0.023; r = 0.338 p = 0.003). The number of medicines was correlated with PIMs at admission (r = 0.391, p = 0.001) and discharge (r = 0.515, p = 0.004). Conclusion: Whilst IC represents an ideal setting in which to review prescribing, this study found PIP to be highly prevalent in older adults in IC, with no detectably significant change in prevalence between admission to and discharge from this setting
The Burqa Ban: Legal Precursors for Denmark, American Experiences and Experiments, and Philosophical and Critical Examinations
As the title of the article suggests, “The Burqa Ban”: Legal Precursors for Denmark, American Experiences and Experiments, and Philosophical and Critical Examinations, the authors embark on a factually investigative as well as a reflective response. More precisely, they use The 2018 Danish “Burqa Ban”: Joining a European Trend and Sending a National Message (published as a concurrent but separate article in this issue of INTERNATIONAL STUDIES JOURNAL) as a platform for further analysis and discussion of different perspectives. These include case-law at the international level while focusing attention on recent rulings and judicial reasoning by the ECtHR and the ECJ; critical thought-experiments in religion, morality, human rights, and the democratic public space; a contextualized account of burqa-wearing interventions by federal and state governments and, moreover, various courts in the United States; and philosophical commentary and, in some instances, criticism of the Danish and/or European (French, etc.) approach. The different contributions have different aims. The section on case-law at the international level reports on those central judgments that, in effect, helped to pave the path for the Kingdom of Denmark’s burqa ban. Concerning the concurring judges at the ECtHR, the opinions served to uphold a preexisting ban and to grant a wide margin of appreciation to the national authorities, thereby limiting the Court’s own review.
As regards to the ECJ, the legality of company rules that contain a policy of neutrality for the workplace was examined, with a similar outcome. The authors who discuss religion, morality, human rights and the democratic public space are endeavoring to, respectively, appeal to ethics as a testing stone for law and to both challenge and address several forms of “expressivist worry” in connection with face veils. In doing so, the authors ask a number of thought-provoking questions that hopefully will inspire public policymakers to careful analysis. While the section that is devoted to American perspectives highlights a comprehensive survey of political and legal responses to, in particular, full-face veils like the burqa, the relevant author also incorporates public perceptions and, in the course of examining these, draws a parallel to “the fate” of the hoodie. The constitutionality of burqa-wearing in America, so it also appears, is partially an open question, but differentiating between religious, political, or personal reasons is a de jure premise. Given that the Danish legislators who drafted law L 219 to ban burqa-wearing in public places rely on a reference to political Islam, they relegate religious and personal reasons to the private domain, thereby also adopting secularism as a premise. This is explored in the last author response of the article, more precisely, in an account of the underlying materialism that, in turn, is applied to Muslim women. If policymakers and legislators engaged in Thinking Things Through exercises, they could, as a minimum, avoid law-making strategies that are not in the spirit of the theory they themselves invoke, albeit tacitly. While the aim of, as it were, arresting culturally self-contradicting legislators is unique for the section in question, all the authors who contribute to the joint research project have one end-goal in common, namely to inform about important perspectives while at the same time opening up for parameters for (more) fruitful, constructive and (if need be) critical debate in the future. With this in mind, four recommendations are presented by the research director for the project. Legally, politically, socially and culturally, conflict-resolution should not translate the relationship between rulers and the ruled into a separation ideology, an instance of controllers versus the controlled. All things being equal, that is the objective limit for a democratic society
Eliminating Barriers: Connecting Seniors to Services in Chittenden County
Introduction. Physical activity programs for older adults help to improve physical, social, and emotional health and reduce impairments in activities of daily living1. In Chittenden county, less than 1⁄3 of older adults participate in programs, while 48% report that they would like to exercise more. Our aim was to identify barriers to participation in physical activity programs by older adults in Chittenden county, such as accessibility, transportation, health, affordability, and social isolation, and to identify strategies to overcome these barriers.
Methods. 144 paper and electronic surveys were administered in Chittenden County, Vermont to assess use of group programs among older adults aged ≥ 50 years including transportation, motivation, preferences, advertisement, and barriers to access. A focus group explored aspects of ideal group activities for seniors.
Results. 87.9% of respondents were active for two or more hours each week, while 46.5% had participated in group programming in the past 6 months. Group par- ticipation was significantly higher among physically active respondents (p=0.020). Motivators for participation in group activity included health benefits, social aspects, and physical activity, while the most cited barrier to attendance was timing conflicts. Respondents received information about programming via word of mouth, email, and online resources.
Discussion. Overall, our findings indicate that the majority of respondents are highly active, however, they frequently experience barriers that prevent them from participating in group programming. We recommend offering flexible scheduling, advertising programming via word of mouth and email, and emphasizing program health benefits.https://scholarworks.uvm.edu/comphp_gallery/1260/thumbnail.jp
Buckeyes for Buckeyes: Increasing the Tree Canopy on The Ohio State University's Main Campus
Course Code: ENR/AEDE 4567This report seeks to assist The Ohio State University with its goal of doubling the tree canopy by 2025. This report suggests either the revision or reworking of the goal due to issues with feasibility. It also suggests a new tree care policy based on case studies of similar universities which has stricter penalties for damage and encourages a campus culture of tree preservation, especially with regards to mature trees. A cost-benefit analysis for two possible planting scenarios was performed, and the non-monetary ecosystem and aesthetic benefits were far greater than the costs in each. A map of possible planting areas was also generated. Overall, this report provides Ohio State with both recommendations and a general framework for increasing the tree canopy on campus.Academic Major: Environment, Economy, Development, and Sustainabilit
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