199 research outputs found
Medical and Psychological Risk Factors for Incident Hypertension in Type 1 Diabetic African-Americans
Objective. To determine risk factors for the development of hypertension among African-Americans living with type 1 diabetes.
Methods. African-Americans with type 1 diabetes (n = 483)
participated in a 6-year followup. At both baseline and followup blood pressure was measured twice in both sitting and standing positions using a standard protocol. Patients had a structured clinical interview, ocular examination, retinal photographs, and blood and urine assays and completed the Hostility and Direction of Hostility Questionnaire (HDHQ) and the Beck Depression Inventory (BDI).
Results. Of the 280 diabetic patients with no hypertension at baseline, 82 (29.3%) subsequently developed hypertension over the 6-year followup. Baseline older age, longer duration of diabetes, family history of hypertension, greater mean arterial blood pressure, overt proteinuria, increasing retinopathy severity, peripheral neuropathy, smoking, and higher hostility scores were significantly associated with the development of hypertension. Multivariate analyses showed that higher hostility scores and overt proteinuria were significantly and independently associated with the development of hypertension in this population.
Conclusions. The development of hypertension in African-Americans living with type 1 diabetes appears to be multifactorial and includes both medical (overt proteinuria) as well as psychological (high hostility) risk factors
Risks to biodiversity and coastal livelihoods from artisanal elasmobranch fisheries in a Least Developed Country: The Gambia (West Africa)
Developing nations in tropical regions harbour rich biological resources on which humans depend for food, income and employment, yet data to aid their management is often lacking. In West Africa, the diversity and fisheries of elasmobranchs are poorly documented, despite them being known to be economically important and vulnerable to overexploitation. Rapid qualitative surveys of fish processing and landing sites in The Gambia from 2010-2018 revealed valuable new data on species composition, biology, relative abundance, fisheries and utilisation by humans. Diversity and abundance was dominated by batoids, with a major component comprising a large guitarfish (Glaucostegus cemiculus) that was apparently targeted, and a small whipray (Fontitrygon margaritella). Nearly all taxa recorded are classified by the IUCN Red List as Critically Endangered (angel sharks Squatina spp.), Endangered, Data Deficient, or Not Evaluated; several were endemic, of exceptional evolutionary distinctness, cryptic, possibly undescribed, and rare (including stingray Hypanus rudis not apparently recorded since description in 1870). Significant threats to biodiversity, coastal livelihoods and possibly food security are identified based on the apparent importance of elasmobranch fisheries and processing; the known inability of key taxa to withstand intensive fisheries; ‘fishing down the food web’ by intensive utilisation of F. margaritella; and the absence or rarity of previously common elasmobranch species that may be severely depleted in the region. This study provides data that may act as a starting point to aid sustainability accreditation of local fin-fisheries, and demonstrates the value of inexpensive and low-resolution data collection in developing countries
Quantitative Verification with Neural Networks
We present a data-driven approach to the quantitative verification of
probabilistic programs and stochastic dynamical models. Our approach leverages
neural networks to compute tight and sound bounds for the probability that a
stochastic process hits a target condition within finite time. This problem
subsumes a variety of quantitative verification questions, from the
reachability and safety analysis of discrete-time stochastic dynamical models,
to the study of assertion-violation and termination analysis of probabilistic
programs. We rely on neural networks to represent supermartingale certificates
that yield such probability bounds, which we compute using a
counterexample-guided inductive synthesis loop: we train the neural certificate
while tightening the probability bound over samples of the state space using
stochastic optimisation, and then we formally check the certificate's validity
over every possible state using satisfiability modulo theories; if we receive a
counterexample, we add it to our set of samples and repeat the loop until
validity is confirmed. We demonstrate on a diverse set of benchmarks that,
thanks to the expressive power of neural networks, our method yields smaller or
comparable probability bounds than existing symbolic methods in all cases, and
that our approach succeeds on models that are entirely beyond the reach of such
alternative techniques.Comment: The conference version of this manuscript appeared at CONCUR 202
MEMS Gate Structures for Electric Propulsion Applications
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76598/1/AIAA-2006-5011-327.pd
Designing a brief behaviour change intervention to reduce sexually transmitted infections: a discrete choice experiment
Objectives: To understand whether people attending sexual health (SH) clinics are willing to participate in a brief behavioural change intervention (BBCI) to reduce the likelihood of future sexually transmitted infections (STIs) and to understand their preferences for different service designs.
Methods: A discrete choice experiment (DCE) with young heterosexual adults (aged 16-25 years), and men who have sex with men (MSM) aged 16 or above, attending SH clinics in England.
Results: Data from 368 participants showed that people particularly valued BBCIs that involved talking (OR 1.45; 95%CI 1.35, 1.57 compared with an ‘email or text’ based BBCI), preferably with a health care professional rather than a peer. Findings also showed that 26% of respondents preferred ‘email / texts’ to all other options; the remaining 14% preferred not to participate in any of the offered BBCIs.
Implications: These results suggest that most people attending SH clinics in England are likely to participate in a BBCI if offered, but the type / format of the BBCI is likely to be the single important determinant of uptake rather than characteristics such as the length and the number of sessions. Moreover, participants generally favoured ‘talking’ based options rather than digital alternatives, which are likely to require the most resources to implement
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Single Molecule Imaging of Transcription Factor Binding to DNA in Live Mammalian Cells
Imaging single fluorescent proteins in living mammalian cells is challenged by out-of-focus fluorescence excitation. To reduce out-of-focus fluorescence we developed reflected light-sheet microscopy (RLSM), a fluorescence microscopy method allowing selective plane illumination throughout the nuclei of living mammalian cells. A thin light sheet parallel to the imaging plane and close to the sample surface is generated by reflecting an elliptical laser beam incident from the top by 90° with a small mirror. The thin light sheet allows for an increased signal-to-background ratio superior to that in previous illumination schemes and enables imaging of single fluorescent proteins with up to 100-Hz time resolution. We demonstrated the single-molecule sensitivity of RLSM by measuring the DNA-bound fraction of glucocorticoid receptor (GR) and determining the residence times on DNA of various oligomerization states and mutants of GR and estrogen receptor-α (ER), which permitted us to resolve different modes of DNA binding of GR. We demonstrated two-color single-molecule imaging by observing the spatiotemporal colocalization of two different protein pairs. Our single-molecule measurements and statistical analysis revealed dynamic properties of transcription factors.The Classic
Use of Boron Nitride for Field Effect Electron Emission
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76687/1/AIAA-2007-5253-734.pd
Healthcare provider and service user perspectives on STI risk reduction interventions for young people and MSM in the UK
Objective
Behavioural interventions have been shown to reduce sexual behaviours associated with increased risk of sexually transmitted infections in young people (<25 years) and men who have sex with men (MSM) internationally, but evidence from England is limited. We aimed to explore service provider and user experiences and perspectives on behavioural interventions to reduce sexual behaviour risks, and the use of automated methods to triage individuals to these services.
Methods
We conducted a sequential mixed methods study with sexual health service providers and users in 2015/2016. Qualitative interviews with providers and service users (heterosexual young people and MSM) in London and Brighton allowed us to explore a range of experiences and expectations. A subsequent national web-survey of service providers measured the feasibility of delivery within existing resources and preferences for intervention attributes.
Results
We conducted 35 service user (15 heterosexual young people; 20 MSM), and 26 provider interviews, and had 100 web-survey responses. We found considerable heterogeneity in prevention services offered. Service users and providers were broadly supportive of tailoring interventions offered, but service users raised concerns about automated, data-driven triage, particularly around equity and fairness of service delivery. Digital technologies, including social media or apps, were appealing to providers, being less resource intensive. However, one-to-one talking interventions remained popular with both service users and providers, being familiar, trust-worthy, and personal. Key tensions between desirability of interventions and availability of resources to deliver them was acknowledged/recognised by providers and users.
Conclusion
Overall, behavioural interventions to reduce sexual behaviour risks were viewed favourably by service providers and users, with key considerations including: privacy, personalisation and convenience. However, introducing desirable targeted interventions within heterogeneous sexual health settings will require resources to adapt interventions and research to fully understand the barriers and facilitators to use within routine services
Seagrass ecosystem contributions to people's quality of life in the Pacific Island Countries and Territories
Seagrass ecosystems provide critical contributions (goods and perceived benefits or detriments) for the livelihoods
and wellbeing of Pacific Islander peoples. Through in-depth examination of the contributions provided by
seagrass ecosystems across the Pacific Island Countries and Territories (PICTs), we find a greater quantity in the
Near Oceania (New Guinea, the Bismarck Archipelago and the Solomon Islands) and western Micronesian (Palau
and Northern Marianas) regions; indicating a stronger coupling between human society and seagrass ecosystems.
We also find many non-material contributions historically have been overlooked and under-appreciated by
decision-makers. Closer cultural connections likely motivate guardianship of seagrass ecosystems by Pacific
communities to mitigate local anthropogenic pressures. Regional comparisons also shed light on general and
specific aspects of the importance of seagrass ecosystems to Pacific Islanders, which are critical for forming
evidence-based policy and management to ensure the long-term resilience of seagrass ecosystems and the contributions
they provide
Seagrass ecosystems of the Pacific Island countries and territories: a global bright spot
Seagrass ecosystems exist throughout Pacific Island Countries and Territories (PICTs). Despite this area covering nearly 8% of the global ocean, information on seagrass distribution, biogeography, and status remains largely absent from the scientific literature. We confirm 16 seagrass species occur across 17 of the 22 PICTs with the highest number in Melanesia, followed by Micronesia and Polynesia respectively. The greatest diversity of seagrass occurs in Papua New Guinea (13 species), and attenuates eastward across the Pacific to two species in French Polynesia. We conservatively estimate seagrass extent to be 1446.2 km2, with the greatest extent (84%) in Melanesia. We find seagrass condition in 65% of PICTs increasing or displaying no discernible trend since records began. Marine conservation across the region overwhelmingly focuses on coral reefs, with seagrass ecosystems marginalised in conservation legislation and policy. Traditional knowledge is playing a greater role in managing local seagrass resources and these approaches are having greater success than contemporary conservation approaches. In a world where the future of seagrass ecosystems is looking progressively dire, the Pacific Islands appears as a global bright spot, where pressures remain relatively low and seagrass more resilient
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