200 research outputs found

    Isometric embedding via strongly symmetric positive systems

    Full text link
    We give a new proof for the local existence of a smooth isometric embedding of a smooth 33-dimensional Riemannian manifold with nonzero Riemannian curvature tensor into 66-dimensional Euclidean space. Our proof avoids the sophisticated arguments via microlocal analysis used in earlier proofs. In Part 1, we introduce a new type of system of partial differential equations, which is not one of the standard types (elliptic, hyperbolic, parabolic) but satisfies a property called strong symmetric positivity. Such a PDE system is a generalization of and has properties similar to a system of ordinary differential equations with a regular singular point. A local existence theorem is then established by using a novel local-to-global-to-local approach. In Part 2, we apply this theorem to prove the local existence result for isometric embeddings.Comment: 39 page

    Use of parent report to screen for feeding difficulties in young children

    Get PDF
    AimsThis study aimed to collect data on Australian children with regard to feeding difficulties using a standardised questionnaire, compare these data to international data collected using the same tool, assess the short-term reliability of this tool and determine the sensitivity and specificity of this tool in detecting feeding difficulties

    Fostering gender equality in research institutions through Transformational-Gender Action Plans

    Full text link
    "This paper draws upon baseline evidence compiled for the FP7 Project 'INstitutional Transformation for Effecting Gender Equality in Research' (INTEGER) in three very different research and higher education institutions. Despite institutional commitments towards gender equality, there is an under-representation of women at full professorship (Grade A) and equivalent positions. Furthermore, women and men are unequally represented on key committees and other decision-making bodies. INTEGER's task is to address these and other imbalances through the adoption of Transformational Gender Action Plans (T-GAPs). These T-GAPs involve: increasing the visibility and leadership potential of women academics/researchers; monitoring and gender proofing of recruitment/retention and promotion policies and practices; ensuring gender balance on decision-making bodies/committees; providing mentoring programmes and training in gender awareness to overcome unconscious bias at all levels of the institution; setting targets for high level appointments; and promoting gender equality as a core value contributing to research excellence. The T-GAP process is informed by international good practice through peer mentoring with research institutions in the UK/EU and USA and alignment with the Athena SWAN Charter and equivalent award holders. In addition, an external evaluation team assesses progress and impacts of the T-GAPs in each organisation. The paper presents common and different approaches of designing institutional transformation, strategies for building alliances in the institution for effective implementation of the T-GAPs and how the processes can be evaluated." (author's abstract

    Implementing the WHO caregivers skills training program with caregivers of autistic children via telehealth in rural communities

    Get PDF
    Background: For families with autistic children living in rural areas, limited access to services partly results from a shortage of providers and extensive travel time. Telehealth brings the possibility of implementing alternative delivery modalities of Parent Mediated Interventions (PMIs) with the potential to decrease barriers to accessing services. This study aimed to evaluate the feasibility and acceptability of implementing the World Health Organization-Caregivers Skills Training program (WHO-CST) via an online, synchronous group format in rural Missouri. Methods: We used a mixed methods design to collect qualitative and quantitative data from caregivers and program facilitators at baseline and the end of the program, following the last home visit. Caregivers of 14 autistic children (3-7 years), residents of rural Missouri, completed nine virtual sessions and four virtual home visits. Results: Four main themes emerged from the focus groups: changes resulting from the WHO-CST, beneficial aspects of the program, advantages and disadvantages of the online format, and challenges to implementing the WHO-CST via telehealth. The most liked activity was the demonstration (36%), and the least liked was the practice with other caregivers. From baseline to week 12, communication skills improved in both frequency (p \u3c 0.05) and impact (p \u3c 0.01), while atypical behaviors decreased (p \u3c 0.01). For caregivers\u27 outcomes, only confidence in skills (p \u3c 0.05) and parental sense of competence (p \u3c 0.05) showed a positive change. Conclusion: Our results support the feasibility of implementing the WHO-CST program via telehealth in a US rural setting. Caregivers found strategies easy to follow, incorporated the program into their family routines, and valued the group meetings that allowed them to connect with other families. A PMI such as the WHO-CST, with cultural and linguistic adaptations and greater accessibility via telehealth-plays an essential role in closing the treatment gap and empowering caregivers of autistic children

    Molecular techniques reveal cryptic life history and demographic processes of a critically endangered marine turtle

    Get PDF
    The concept of ‘effective population size’ (Ne), which quantifies how quickly a population will lose genetic variability, is one of the most important contributions of theoretical evolutionary biology to practical conservation management. Ne is often much lower than actual population size: how much so depends on key life history and demographic parameters, such as mating systems and population connectivity, that often remain unknown for species of conservation concern. Molecular techniques allow the indirect study of these parameters, as well as the estimation of current and historical Ne. Here, we use genotyping to assess the genetic health of an important population of the critically endangered hawksbill turtle (Eretmochelys imbricata), a slow-to-mature, difficult-to-observe species with a long history of severe overhunting. Our results were surprisingly positive: we found that the study population, located in the Republic of Seychelles, Indian Ocean, has a relatively large Ne, estimated to exceed 1000, and showed no evidence of a recent reduction in Ne (i.e. no genetic bottleneck). Furthermore, molecular inferences suggest the species' mating system is conducive to maintaining a large Ne, with a relatively large and widely distributed male population promoting considerable gene flow amongst nesting sites across the Seychelles area. This may also be reinforced by the movement of females between nesting sites. Our study underlines how molecular techniques can help to inform conservation biology. In this case our results suggest that this important hawksbill population is starting from a relatively strong position as it faces new challenges, such as global climate change

    The immunogenicity and safety of a reduced PRP-content DTPw-HBV/Hib vaccine when administered according to the accelerated EPI schedule

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Combination vaccines improve coverage, compliance and effectively introduce new antigens to mass vaccination programmes. This was a phase III, observer-blind, randomized study of GSK Biologicals diphtheria-tetanus-whole cell pertussis vaccine combined with hepatitis B and <it>Haemophilus influenzae </it>type b vaccines, containing a reduced amount of polyribosyl-ribitol-phosphate (PRP) and a DTPw component manufactured at a different site (DTPw-HBV/Hib<sub>2.5 </sub>[Kft]). The primary aim of this study was to demonstrate that DTPw-HBV/Hib<sub>2.5 </sub>[Kft] was not inferior to the licensed DTPw-HBV/Hib (<it>Tritanrix</it>(tm)-HepB/<it>Hiberix</it>(tm)) vaccine or the DTPw-HBV/Hib<sub>2.5 </sub>vaccine, also containing a reduced amount of PRP, with respect to the immune response to the PRP antigen, when administered to healthy infants, according to the Expanded Programme for Immunization (EPI) schedule at 6, 10 and 14 weeks of age.</p> <p>Methods</p> <p>299 healthy infants were randomised to receive either DTPw-HBV/Hib<sub>2.5 </sub>[Kft] DTPw-HBV/Hib<sub>2.5 </sub>or DTPw-HBV/Hib according to the 6-10-14 week EPI schedule. Blood samples were analysed prior to the first dose of study vaccine and one month after the third vaccine dose for the analysis of immune responses. Solicited local and general symptoms such as pain, redness and swelling at the injection site and drowsiness and fever, unsolicited symptoms (defined as any additional adverse event) and serious adverse events (SAEs) were recorded up to 20 weeks of age.</p> <p>Results</p> <p>One month after the third vaccine dose, 100% of subjects receiving DTPw-HBV/Hib<sub>2.5 </sub>[Kft] or DTPw-HBV/Hib and 98.8% of subjects receiving DTPw-HBV/Hib<sub>2.5 </sub>vaccine had seroprotective levels of anti-PRP antibodies (defined as anti-PRP antibody concentration ≥0.15 μg/ml). Seroprotective antibody concentrations were attained in over 98.9% of subjects for diphtheria, tetanus and hepatitis B. The vaccine response rate to pertussis antigen was at least 97.8% in each group. Overall, the DTPw-HBV/Hib<sub>2.5 </sub>[Kft] vaccine was well tolerated in healthy infants; no SAEs were reported in any group.</p> <p>Conclusions</p> <p>The DTPw-HBV/Hib<sub>2.5 </sub>[Kft] vaccine was immunogenic and well-tolerated when administered according to the EPI schedule to Indian infants.</p> <p>Trial registration</p> <p><url>http://www.clinicaltrials.gov</url> NCT00473668</p

    Primary and booster vaccination in Latin American children with a DTPw-HBV/Hib combination: a randomized controlled trial

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Diphtheria-tetanus-whole-cell pertussis (DTPw)-based combination vaccines are an attractive option to rapidly achieve high coverage and protection against other important pathogens, such as hepatitis B virus (HBV) and <it>Haemophilus influenzae </it>type B (Hib). To ensure adequate antigen supply, GlaxoSmithKline Biologicals has introduced a new DTPw antigen source and developed a new DTPw-HBV/Hib combination vaccine containing a reduced amount of Hib polyribosylribitol phosphate (PRP). This study was undertaken to compare the immunogenicity and reactogenicity of this new DTPw-HBV/Hib vaccine with a licensed DTPw-HBV/Hib vaccine (<it>Tritanrix</it>™-HBV/Hib).</p> <p>Methods</p> <p>This was a randomized, partially-blind, multicenter study in three countries in Latin America (Argentina, Chile and Nicaragua). Healthy children received either the new DTPw-HBV/Hib vaccine (1 of 3 lots; n = 439; double-blind) or Tritanrix™-HBV/Hib (n = 146; single-blind) co-administered with oral poliovirus vaccine (OPV) at 2, 4 and 6 months, with a booster dose at 18-24 months.</p> <p>Results</p> <p>One month after the end of the 3-dose primary vaccination course, the new DTPw-HBV/Hib vaccine was non-inferior to Tritanrix™-HBV/Hib in terms of seroprotection/vaccine response rates for all component antigens; ≥97.3% and ≥93.9% of subjects in the two groups, respectively, had seroprotective levels of antibodies against diphtheria, tetanus, hepatitis B and Hib and a vaccine response to the pertussis component. Persistence of antibodies against all vaccine antigens was comparable between groups, with marked increases in all antibody concentrations after booster administration in both groups. Both vaccines were generally well-tolerated as primary and booster doses.</p> <p>Conclusions</p> <p>Results confirm the suitability of this new DTPw-HBV/Hib vaccine comprising antigens from a new source and a reduced PRP content for inclusion into routine childhood vaccination programs.</p> <p>Trial registration</p> <p><url>http://www.clinicaltrials.gov</url> NCT00332566</p

    Lipopolysaccharide Diversity Evolving in Helicobacter pylori Communities through Genetic Modifications in Fucosyltransferases

    Get PDF
    Helicobacter pylori persistently colonizes the gastric mucosa of half the human population. It is one of the most genetically diverse bacterial organisms and subvariants are continuously emerging within an H. pylori population. In this study we characterized a number of single-colony isolates from H. pylori communities in various environmental settings, namely persistent human gastric infection, in vitro bacterial subcultures on agar medium, and experimental in vivo infection in mice. The lipopolysaccharide (LPS) O-antigen chain revealed considerable phenotypic diversity between individual cells in the studied bacterial communities, as demonstrated by size variable O-antigen chains and different levels of Lewis glycosylation. Absence of high-molecular-weight O-antigen chains was notable in a number of experimentally passaged isolates in vitro and in vivo. This phenotype was not evident in bacteria obtained from a human gastric biopsy, where all cells expressed high-molecular-weight O-antigen chains, which thus may be the preferred phenotype for H. pylori colonizing human gastric mucosa. Genotypic variability was monitored in the two genes encoding Îą1,3-fucosyltransferases, futA and futB, that are involved in Lewis antigen expression. Genetic modifications that could be attributable to recombination events within and between the two genes were commonly detected and created a diversity, which together with phase variation, contributed to divergent LPS expression. Our data suggest that the surrounding environment imposes a selective pressure on H. pylori to express certain LPS phenotypes. Thus, the milieu in a host will select for bacterial variants with particular characteristics that facilitate adaptation and survival in the gastric mucosa of that individual, and will shape the bacterial community structure
    • …
    corecore