281 research outputs found

    Professional and Home-Made Face Masks Reduce Exposure to Respiratory Infections among the General Population

    Get PDF
    Governments are preparing for a potential influenza pandemic. Therefore they need data to assess the possible impact of interventions. Face-masks worn by the general population could be an accessible and affordable intervention, if effective when worn under routine circumstances.We assessed transmission reduction potential provided by personal respirators, surgical masks and home-made masks when worn during a variety of activities by healthy volunteers and a simulated patient.All types of masks reduced aerosol exposure, relatively stable over time, unaffected by duration of wear or type of activity, but with a high degree of individual variation. Personal respirators were more efficient than surgical masks, which were more efficient than home-made masks. Regardless of mask type, children were less well protected. Outward protection (mask wearing by a mechanical head) was less effective than inward protection (mask wearing by healthy volunteers).Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence, personal respirators providing most protection. Masks worn by patients may not offer as great a degree of protection against aerosol transmission

    Coupled Contagion Dynamics of Fear and Disease: Mathematical and Computational Explorations

    Get PDF
    Background: In classical mathematical epidemiology, individuals do not adapt their contact behavior during epidemics. They do not endogenously engage, for example, in social distancing based on fear. Yet, adaptive behavior is welldocumented in true epidemics. We explore the effect of including such behavior in models of epidemic dynamics. Methodology/Principal Findings: Using both nonlinear dynamical systems and agent-based computation, we model two interacting contagion processes: one of disease and one of fear of the disease. Individuals can ‘‘contract’ ’ fear through contact with individuals who are infected with the disease (the sick), infected with fear only (the scared), and infected with both fear and disease (the sick and scared). Scared individuals–whether sick or not–may remove themselves from circulation with some probability, which affects the contact dynamic, and thus the disease epidemic proper. If we allow individuals to recover from fear and return to circulation, the coupled dynamics become quite rich, and can include multiple waves of infection. We also study flight as a behavioral response. Conclusions/Significance: In a spatially extended setting, even relatively small levels of fear-inspired flight can have a dramatic impact on spatio-temporal epidemic dynamics. Self-isolation and spatial flight are only two of many possible actions that fear-infected individuals may take. Our main point is that behavioral adaptation of some sort must b

    Sirtuin 6 Activation Rescues the Age-Related Decline in DNA Damage Repair in Primary Human Chondrocytes

    Get PDF
    While advanced age is widely recognized as the greatest risk factor for osteoarthritis (OA), the biological mechanisms behind this connection remain unclear. Previous work has demonstrated that chondrocytes from older cadaveric donors have elevated levels of DNA damage as compared to chondrocytes from younger donors. The purpose of this study was to determine whether a decline in DNA repair efficiency is one explanation for the accumulation of DNA damage with age, and to quantify the improvement in repair with activation of Sirtuin 6 (SIRT6). After acute damage with irradiation, DNA repair was shown to be more efficient in chondrocytes from young (≤45 years old) as compared to middle-aged (50-65 years old) or older (\u3e70 years old) cadaveric donors. Activation of SIRT6 with MDL-800 improved the repair efficiency, while inhibition with EX-527 reduced the rate of repair and increased the percentage of cells that retain high levels of damage. In addition to affecting repair after acute damage, treating chondrocytes from older donors with MDL-800 for 48 hours significantly reduced the amount of baseline DNA damage. Chondrocytes isolated from the knees of mice between 4 months and 22 months of age revealed both an increase in DNA damage with aging, and a decrease in DNA damage following MDL-800 treatment. Lastly, treating murine cartilage explants with MDL-800 lowered the percentage of chondrocytes with high p16 promoter activity, which supports the concept that using SIRT6 activation to maintain low levels of DNA damage may prevent the initiation of senescence

    Secondary students' values and perceptions of science-related careers: responses to vignette-based scenarios

    Get PDF
    There has been concern about the attractiveness of science-based careers to many adolescent learners, and it has been suggested that school science may not always recognise or engage personal values that are important to young people in making life choices. The present study discusses interview comments made by upper secondary level students in England when 15 young people were asked to give their personal responses to brief vignettes describing scientific careers. Using an interview-about-scenarios approach, the students were asked about whether they would feel comfortable working in the scientific careers represented. The career areas were purposefully selected because they might be considered to potentially raise issues in relation to personal values or commitments that some students might hold. A range of student perceptions relating to the mooted careers were elicited (positive, negative and indifferent), but all of the participants raised issues that impacted on the acceptability or attractiveness of at least one of the mooted scientific careers, in terms of aspects of their own personal beliefs and values systems. It is recommended that teachers and career advisors should be aware of the range of value-related considerations that influence student views of science-related careers and should consider exploring aspects of science-based careers that link to values commonly shared by young people. This exploratory study also offers indications for directions for further research exploring how learners' value systems impact upon their perceptions of science and scientific work

    Identification of calcium-binding proteins associated with the human sperm plasma membrane

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The precise composition of the human sperm plasma membrane, the molecular interactions that define domain specific functions, and the regulation of membrane associated proteins during the capacitation process, still remain to be fully understood. Here, we investigated the repertoire of calcium-regulated proteins associated with the human sperm plasma membrane.</p> <p>Methods</p> <p>Surface specific radioiodination was combined with two-dimensional gel electrophoresis, a 45Ca-overlay assay, computer assisted image analysis and mass spectrometry to identify calcium-binding proteins exposed on the human sperm surface.</p> <p>Results</p> <p>Nine acidic 45Ca-binding sperm proteins were excised from stained preparative 2D gels and identified by mass spectrometry. Five of the calcium binding proteins; HSPA2 (HSP70-1), HSPA5 (Bip), HYOU1 (ORP150), serum amyloid P-component (SAP) and protein kinase C substrate 80K-H (80K-H) were found to be accessible to Iodo-Bead catalyzed 125I-labelling on the surface of intact human sperm. Agglutination and immunofluorescence analysis confirmed that SAP is situated on the plasma membrane of intact, motile sperm as well as permeabilized cells. Western blot analysis showed increased phosphorylation of human sperm 80K-H protein following in vitro capacitation. This is the first demonstration of the 80K-H protein in a mammalian sperm.</p> <p>Conclusion</p> <p>The presence of SAP on the surface of mature sperm implies that SAP has a physiological role in reproduction, which is thought to be in the removal of spermatozoa from the female genital tract via phagocytosis. Since 80K-H is a Ca2+-sensor recently implicated in the regulation of both inositol 1,4,5-trisphosphate receptor and transient receptor potential (TRP) cation channel activities, its detection in sperm represents the first direct signaling link between PKC and store-operated calcium channels identified in human sperm.</p

    Psychological correlates of self-reported functional limitation in patients with ankylosing spondylitis

    Get PDF
    Abstract Introduction Functional status is an integral component of health-related quality of life in patients with ankylosing spondylitis (AS). The purpose of this study was to investigate the role of psychological variables in self-reported functional limitation in patients with AS, while controlling for demographic and medical variables. Methods 294 AS patients meeting modified New York Criteria completed psychological measures evaluating depression, resilience, active and passive coping, internality and helplessness at the baseline visit. Demographic, clinical, and radiologic data were also collected. Univariate and multivariate analyses were completed to determine the strength of correlation of psychological variables with functional limitation, as measured by the Bath AS Functional Index (BASFI). Results In the multivariate regression analysis, the psychological variables contributed significantly to the variance in BASFI scores, adding an additional 24% to the overall R-square beyond that accounted by demographic and medical variables (R-square 32%), resulting in a final R-square of 56%. Specifically, arthritis helplessness, depression and passive coping beside age, ESR and the Bath AS Radiograph Index accounted for a significant portion of the variance in BASFI scores in the final model. Conclusions Arthritis helplessness, depression, and passive coping accounted for significant variability in self-reported functional limitation beyond demographic and clinical variables in patients with AS. Psychological health should be examined and accounted for when assessing functional status in the AS patients

    Gender Socialization in Chinese Kindergartens: Teachers’ Contributions

    Get PDF
    Teacher-child interactions and peer exchanges were observed once a week for 10 months in four kindergartens in Hong Kong, China. A total of 206 anecdotes/scenes considered representative of the gender-related experiences of 109 4-year-old Chinese children in these kindergartens were analyzed. Descriptive codes, generated iteratively were clustered, categorized, integrated, recoded and recategorized and led to the identification of two major themes related to the socialization practices of teachers: Gendered Kindergarten Routines and Perpetuation of Gender Stereotypes. Findings indicated that these early years’ educational contexts were not gender neutral. Teachers interacted with boys significantly more than girls. They also subtly conveyed traditional Chinese gender values through their repeated use of gendered routines in the kindergartens and their behaviors reflected gender stereotypes

    Guidelines for diagnosis and management of the cobalamin-related remethylation disorders cblC, cblD, cblE, cblF, cblG, cblJ and MTHFR deficiency

    Get PDF
    BACKGROUND: Remethylation defects are rare inherited disorders in which impaired remethylation of homocysteine to methionine leads to accumulation of homocysteine and perturbation of numerous methylation reactions. OBJECTIVE: To summarise clinical and biochemical characteristics of these severe disorders and to provide guidelines on diagnosis and management. DATA SOURCES: Review, evaluation and discussion of the medical literature (Medline, Cochrane databases) by a panel of experts on these rare diseases following the GRADE approach. KEY RECOMMENDATIONS: We strongly recommend measuring plasma total homocysteine in any patient presenting with the combination of neurological and/or visual and/or haematological symptoms, subacute spinal cord degeneration, atypical haemolytic uraemic syndrome or unexplained vascular thrombosis. We strongly recommend to initiate treatment with parenteral hydroxocobalamin without delay in any suspected remethylation disorder; it significantly improves survival and incidence of severe complications. We strongly recommend betaine treatment in individuals with MTHFR deficiency; it improves the outcome and prevents disease when given early
    corecore