4,095 research outputs found

    Defining critical factors in multi-country studies of assisted reproductive technologies (ART): data from the US and UK health systems

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    As the worldwide use of assisted reproductive technologies (ART) continues to grow, there is a critical need to assess the safety of these treatment parameters and the potential adverse health effects of their use in adults and their offspring. While key elements remain similar across nations, geographic variations both in treatments and populations make generalizability challenging. We describe and compare the demographic factors between the USA and the UK related to ART use and discuss implications for research. The USA and the UK share some common elements of ART practice and in how data are collected regarding long-term outcomes. However, the monitoring of ART in these two countries each brings strengths that complement each other’s limitations

    Is the even distribution of insecticide-treated cattle essential for tsetse control? Modelling the impact of baits in heterogeneous environments

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    Background: Eliminating Rhodesian sleeping sickness, the zoonotic form of Human African Trypanosomiasis, can be achieved only through interventions against the vectors, species of tsetse (Glossina). The use of insecticide-treated cattle is the most cost-effective method of controlling tsetse but its impact might be compromised by the patchy distribution of livestock. A deterministic simulation model was used to analyse the effects of spatial heterogeneities in habitat and baits (insecticide-treated cattle and targets) on the distribution and abundance of tsetse. Methodology/Principal Findings: The simulated area comprised an operational block extending 32 km from an area of good habitat from which tsetse might invade. Within the operational block, habitat comprised good areas mixed with poor ones where survival probabilities and population densities were lower. In good habitat, the natural daily mortalities of adults averaged 6.14% for males and 3.07% for females; the population grew 8.46in a year following a 90% reduction in densities of adults and pupae, but expired when the population density of males was reduced to <0.1/km2; daily movement of adults averaged 249 m for males and 367 m for females. Baits were placed throughout the operational area, or patchily to simulate uneven distributions of cattle and targets. Gaps of 2–3 km between baits were inconsequential provided the average imposed mortality per km2 across the entire operational area was maintained. Leaving gaps 5–7 km wide inside an area where baits killed 10% per day delayed effective control by 4–11 years. Corrective measures that put a few baits within the gaps were more effective than deploying extra baits on the edges. Conclusions/Significance: The uneven distribution of cattle within settled areas is unlikely to compromise the impact of insecticide-treated cattle on tsetse. However, where areas of >3 km wide are cattle-free then insecticide-treated targets should be deployed to compensate for the lack of cattle

    Influence of a knot on the strength of a polymer strand

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    Many experiments have been done to determine the relative strength of different knots, and these show that the break in a knotted rope almost invariably occurs at a point just outside the `entrance' to the knot. The influence of knots on the properties of polymers has become of great interest, in part because of their effect on mechanical properties. Knot theory applied to the topology of macromolecules indicates that the simple trefoil or `overhand' knot is likely to be present with high probability in any long polymer strand. Fragments of DNA have been observed to contain such knots in experiments and computer simulations. Here we use {\it ab initio} computational methods to investigate the effect of a trefoil knot on the breaking strength of a polymer strand. We find that the knot weakens the strand significantly, and that, like a knotted rope, it breaks under tension at the entrance to the knot.Comment: 3 pages, 4 figure

    High burden of viral respiratory co-infections in a cohort of children with suspected pulmonary tuberculosis

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    Background The presentation of pulmonary tuberculosis (PTB) in young children is often clinically indistinguishable from other common respiratory illnesses, which are frequently infections of viral aetiology. As little is known about the role of viruses in children with PTB, we investigated the prevalence of respiratory viruses in children with suspected PTB at presentation and follow-up. Methods In an observational cohort study, children < 13 years were routinely investigated for suspected PTB in Cape Town, South Africa between December 2015 and September 2017 and followed up for 24 weeks. Nasopharyngeal aspirates (NPAs) were tested for respiratory viruses using multiplex PCR at enrolment, week 4 and 8. Results Seventy-three children were enrolled [median age 22.0 months; (interquartile range 10.0–48.0); 56.2% male and 17.8% HIV-infected. Anti-tuberculosis treatment was initiated in 54.8%; of these 50.0% had bacteriologically confirmed TB. At enrolment, ≥1 virus were detected in 95.9% (70/73) children; most commonly human rhinovirus (HRV) (74.0%). HRV was more frequently detected in TB cases (85%) compared to ill controls (60.6%) (p = 0.02). Multiple viruses were detected in 71.2% of all children; 80% of TB cases and 60.6% of ill controls (p = 0.07). At follow-up, ≥1 respiratory virus was detected in 92.2% (47/51) at week 4, and 94.2% (49/52) at week 8. Conclusions We found a high prevalence of viral respiratory co-infections in children investigated for PTB, irrespective of final PTB diagnosis, which remained high during follow up. Future work should include investigating the whole respiratory ecosystem in combination with pathogen- specific immune responses

    Awareness and utilization of HIV testing and prevention services among female sex workers in Dnipro, Ukraine: implications for prevention program strengthening from the dynamics study

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    INTRODUCTION: Approximately 240,000 people live with HIV in Ukraine, concentrated among key populations, including sex workers. Non-governmental organizations (NGOs) play an important role in the funding and delivery of HIV testing and prevention services in Ukraine. These services are set within the context of national healthcare reforms as well as ongoing armed conflict. This study seeks to describe and understand the usage of HIV testing and prevention services among sex workers in the eastern Ukrainian city of Dnipro. METHODS: A cross-sectional bio-behavioral survey was administered in September 2017-March 2018 among 560 sex workers working in Dnipro. Descriptive analyses of survey data are presented alongside multivariable logistic regression models identifying factors associated with NGO awareness and HIV testing in the past 12 months; adjusted odds ratios (AOR) and 95% confidence intervals (95% CI) are reported. RESULTS: Sixty-two percent of respondents were aware of NGOs offering HIV services. Sixty-eight percent had tested for HIV in the past 12 months, and 51% of those who reported the location of their most recent test were tested at an NGO. Those with 5-9 years in sex work had greater odds of being aware of NGOs (AOR = 5.5, 95%CI: 3.2-9.7) and testing for HIV (AOR = 3.4, 95%CI: 2.0-6.0) compared to those new to the profession. Contact with outreach workers was strongly associated with increased odds of testing (AOR = 13.0, 95%CI: 7.0-24.0). Sex workers in "offices" (brothel-like venues) reported higher odds of testing than all other workplaces, while those in entertainment venues (AOR = 0.3, 95%CI: 0.2-0.5) and public places (AOR = 0.2, 95%CI: 0.1-0.3) reported lower rates. Receiving prevention services, such as free condoms, was associated with increased testing (AOR = 16.9, 95%CI: 9.7-29.3). DISCUSSION: NGOs in Dnipro, Ukraine play an important role in HIV testing and prevention for women involved in sex work. However, focused efforts should be placed on supporting access to these services for women that are newer to sex work, and those working in entertainment venues or public places. Outreach workers appear to support access to HIV prevention information and supplies and facilitate linkages to HIV testing for sex workers

    The Application of Electromagnetic Waves in Monitoring Water Infiltration on Concrete Flat Roof: The Case of Malaysia

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    Roof leakages of high-rise buildings involving concrete flat roof design in tropical countries continue to be a serious problem. Currently, exiting methods of detecting potential leaks are mostly destructive to the building material. Although the method of detecting a defect using non-destructive measurement exists, current methods such as infrared thermography, metal detector and humidity meter have varying constraints in their application. This paper describes the potential use of microwave technology as an effective non-destructive tool to monitor and investigate leakage of concrete flat roof due to failure of membrane layer. This study was performed experimentally on flat room structures built for laboratory use and according to Malaysian flat roof concrete proportions standards. Experiments performed utilized a sensor equipped with essential parameters that enable control to sensor angle, temperature and distance between object and sensor structure and designed to enable numerous measurements in real time. The study determined that microwave technology can be used to identify moisture content in concrete flat roof by analysing properties of the concrete roof and water. This proves to be an effective non-destructive method of determining leakage problems in concrete flat roof in real time before the defects become critical

    Comparative analysis of Middle Stone Age artifacts in Africa (CoMSAfrica).

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    Spatial and temporal variation among African Middle Stone Age (MSA) archeological assemblages provide essential cultural and behavioral data for understanding the origin, evolution, diversification, and dispersal of Homo sapiens—and, possibly, interactions with other hominin taxa. However, incorporating archeological data into a robust framework suited to replicable, quantitative analyses that can be integrated with observations drawn from studies of the human genome, hominin morphology, and paleoenvironmental contexts requires the development of a unified comparative approach and shared units of analysis. The CoMSAfrica workshop presented here, has the ambition to build bridges between researchers and research regions in Africa on these paramount topics

    Overcoming barriers to engaging socio-economically disadvantaged populations in CHD primary prevention: a qualitative study

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    &lt;p&gt;&lt;b&gt;Background:&lt;/b&gt; Preventative medicine has become increasingly important in efforts to reduce the burden of chronic disease in industrialised countries. However, interventions that fail to recruit socio-economically representative samples may widen existing health inequalities. This paper explores the barriers and facilitators to engaging a socio-economically disadvantaged (SED) population in primary prevention for coronary heart disease (CHD).&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods:&lt;/b&gt; The primary prevention element of Have a Heart Paisley (HaHP) offered risk screening to all eligible individuals. The programme employed two approaches to engaging with the community: a) a social marketing campaign and b) a community development project adopting primarily face-to-face canvassing. Individuals living in areas of SED were under-recruited via the social marketing approach, but successfully recruited via face-to-face canvassing. This paper reports on focus group discussions with participants, exploring their perceptions about and experiences of both approaches.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Results:&lt;/b&gt; Various reasons were identified for low uptake of risk screening amongst individuals living in areas of high SED in response to the social marketing campaign and a number of ways in which the face-to-face canvassing approach overcame these barriers were identified. These have been categorised into four main themes: (1) processes of engagement; (2) issues of understanding; (3) design of the screening service and (4) the priority accorded to screening. The most immediate barriers to recruitment were the invitation letter, which often failed to reach its target, and the general distrust of postal correspondence. In contrast, participants were positive about the face-to-face canvassing approach. Participants expressed a lack of knowledge and understanding about CHD and their risk of developing it and felt there was a lack of clarity in the information provided in the mailing in terms of the process and value of screening. In contrast, direct face-to-face contact meant that outreach workers could explain what to expect. Participants felt that the procedure for uptake of screening was demanding and inflexible, but that the drop-in sessions employed by the community development project had a major impact on recruitment and retention.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusion:&lt;/b&gt; Socio-economically disadvantaged individuals can be hard-to-reach; engagement requires strategies tailored to the needs of the target population rather than a population-wide approach.&lt;/p&gt

    Satisfaction with the Use of Different Technologies for Insulin Delivery and Glucose Monitoring Among Adults with Long-Standing Type 1 Diabetes and Problematic Hypoglycemia: 2-Year Follow-Up in the HypoCOMPaSS Randomized Clinical Trial

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    Background In the HypoCOMPaSS trial, adults with long-standing type 1 diabetes and problematic hypoglycaemia were randomised to compare insulin pump (CSII) vs multiple daily injections (MDI) and real-time continuous glucose monitoring (RT-CGM) vs conventional self-monitoring (SMBG). Our aim was to investigate participants\u27 satisfaction with these technologies at 6-month RCT endpoint and at 2-year follow-up. Methods Participants completed the Insulin Treatment Satisfaction Questionnaire (ITSQ) subscales \u27device delivery\u27 and \u27hypoglycaemia control\u27; and Glucose Monitoring Experience Questionnaire (GME-Q), assessing \u27convenience\u27, \u27effectiveness\u27, \u27intrusiveness\u27 and \u27total satisfaction\u27. We assessed change over time and between group differences by insulin and monitoring modalities. Results Participants (N=96) were: 64% women, aged 49\ub112 years, diabetes duration 29\ub112 years. At 6 months, participants reported improvements compared to baseline (all p&lt;0.001) in satisfaction with insulin \u27delivery device\u27 (r=0.39) and \u27hypoglycaemia control\u27 (r=0.52), and trends towards significance in perceived \u27effectiveness\u27 (r=0.42) and \u27intrusiveness\u27 (r=0.27) of monitoring device (but not \u27convenience\u27, p=0.139). All improvements were sustained at 2 years. At 6 months, the only difference between arms was that greater satisfaction with insulin \u27delivery device\u27 was reported in the CSII group compared to MDI (p&lt;0.001, r=0.40). No between-group differences were observed at 2 years. Conclusions Overall, significant improvements in participant satisfaction with diabetes technologies were observed over the 6-month RCT, in all domains except \u27convenience\u27, maintained at 2 years. While HypoCOMPaSS demonstrated non-inferiority of SMBG versus CGM, and MDI versus CSII in terms of biomedical outcomes, detailed assessments confirm participants\u27 satisfaction with delivery device was greater in those allocated to CSII than MDI

    A novel adaptor protein orchestrates receptor patterning and cytoskeletal polarity in T-cell contacts.

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    Recognition of antigen by T cells requires the formation of a specialized junction between the T cell and the antigen-presenting cell. This junction is generated by the recruitment and the exclusion of specific proteins from the contact area. The mechanisms that regulate these events are unknown. Here we demonstrate that ligand engagement of the adhesion molecule, CD2, initiates a process of protein segregation, CD2 clustering, and cytoskeletal polarization. Although protein segregation was not dependent on the cytoplasmic domain of CD2, CD2 clustering and cytoskeletal polarization required an interaction of the CD2 cytoplasmic domain with a novel SH3-containing protein. This novel protein, called CD2AP, is likely to facilitate receptor patterning in the contact area by linking specific adhesion receptors to the cytoskeleton
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