155 research outputs found

    Generalized Confidence Intervals and Fiducial Intervals for Some Epidemiological Measures.

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    For binary outcome data from epidemiological studies, this article investigates the interval estimation of several measures of interest in the absence or presence of categorical covariates. When covariates are present, the logistic regression model as well as the log-binomial model are investigated. The measures considered include the common odds ratio (OR) from several studies, the number needed to treat (NNT), and the prevalence ratio. For each parameter, confidence intervals are constructed using the concepts of generalized pivotal quantities and fiducial quantities. Numerical results show that the confidence intervals so obtained exhibit satisfactory performance in terms of maintaining the coverage probabilities even when the sample sizes are not large. An appealing feature of the proposed solutions is that they are not based on maximization of the likelihood, and hence are free from convergence issues associated with the numerical calculation of the maximum likelihood estimators, especially in the context of the log-binomial model. The results are illustrated with a number of examples. The overall conclusion is that the proposed methodologies based on generalized pivotal quantities and fiducial quantities provide an accurate and unified approach for the interval estimation of the various epidemiological measures in the context of binary outcome data with or without covariates

    Channel and terminal description of the ACTS mobile terminal

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    The Advanced Communications Technology Satellite (ACTS) Mobile Terminal (AMT) is a proof-of-concept K/Ka-band mobile satellite communications terminal under development by NASA at JPL. Currently the AMT is undergoing system integration and test in preparation for a July 1993 ACTS launch and the subsequent commencement of mobile experiments in the fall of 1993. The AMT objectives are presented followed by a discussion of the AMT communications channel and mobile terminal design and performance

    Medical Encounter Characteristics of HIV Seroconverters in the US Army and Air Force, 2000–2004

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    BACKGROUND AND METHODS: Active duty US Army and Air Force military personnel undergo mandatory biennial HIV antibody screening. We compared pre- and post-HIV seroconversion health status by conducting a case-control study, which evaluated all medical encounters and sociodemographic factors among incident HIV seroconverters and HIV-negative controls from June 2000 through February 2004. RESULTS: A total of 274 HIV seroconverters and 6205 HIV-negative personnel were included. In multivariate analysis restricted to male personnel (cases = 261, controls = 5801), single marital status (adjusted odds ratio [AOR] = 14.37), clinical indicators or symptoms within four years of HIV diagnosis (AOR = 6.22), black race (AOR = 5.88), nonindicator clinical syndromes within 2 years of HIV diagnosis (AOR = 3.31), any mental disorder within 4 years of HIV diagnosis (AOR = 3.04), increasing service-connected time (AOR = 1.69), and older age (AOR = 1.12) were associated with HIV diagnosis among males. A prior history of a sexually transmitted infection (STI) was associated with post-HIV seroconversion STI (OR(M-H) = 4.10). Similarly, a prior history of mental disorder was associated with post-HIV seroconversion mental disorder (OR(M-H) = 4.98). Forty-seven (18%) male cases were hospitalized at least once after HIV diagnosis; infectious diseases, and mental disorders made up 53% of initial admissions. CONCLUSIONS: HIV seroconversion was associated with increased health care-seeking behavior, STIs, and mental disorders, some of which may be amenable to screening. The higher STI rate after HIV diagnosis may partially be a consequence of monitoring, but secondary transmission of STI and possibly HIV require further definition and subsequent tailored preventive interventions

    Trend and Causes of Maternal Mortality in a Nigerian Tertiary Hospital: A 5-year Retrospective Study (2010-2014) at the University of Calabar Teaching Hospital, Calabar, Nigeria

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    BACKGROUND: Maternal mortality ratios (MMR) are still unacceptably high in many low-income countries especially in sub-Saharan Africa. MMR had been reported to have improved from an initial 3,026 per 100,000 live births in 1999 to 941 in 2009, at the University of Calabar Teaching Hospital (UCTH), Calabar, a tertiary health facility in Nigeria. Post-partum haemorrhage and hypertensive diseases of pregnancy have been the common causes of maternal deaths in the facility.AIM: This study was aimed at determining the trend in maternal mortality in the same facility, following institution of some facility-based intervention measures.METHODOLOGY: A retrospective study design was utilised with extraction and review of medical records of pregnancy-related deaths in UCTH, Calabar, from January 2010 to December 2014. The beginning of the review period coincided with the period the “Woman Intervention Trial†was set up to reduce maternal mortality in the facility. This trial consists of the use of Tranexamic acid for prevention of post-partum haemorrhage, as well as more proactive attendance to parturition.RESULTS: There were 13,605 live births and sixty-one (61) pregnancy-related deaths in UCTH during the study period. This yielded a facility Maternal Mortality Ratio of 448 per 100,000 live births. In the previous 11-year period of review, there was sustained the decline in MMR by 72.9% in the initial four years (from 793 in 2010 to 215 in 2013), with the onset of resurgence to 366 in the last year (2014). Mean age at maternal death was 27 ± 6.5 years, with most subjects (45, 73.8%) being within 20-34 years age group. Forty-eight (78.7%) were married, 26 (42.6%) were unemployed, and 33 (55.7%) had at least secondary level of education. Septic abortion (13, 21.3%) and hypertensive diseases of pregnancy (10, 16.4%) were the leading causes of death. Over three quarters (47, 77.0%) had not received care from any health facility. Most deaths (46, 75.5%) occurred between 24 and 97 hours of admission.CONCLUSION: Compared with previous trends, there has been a significant improvement in maternal mortality ratio in the study setting. There is also a significant change in the leading cause of maternal deaths, with septic abortion and hypertensive disease of pregnancy now replacing post-partum haemorrhage and puerperal sepsis that was previously reported. This success may be attributable to the institution of the Woman trial intervention which is still ongoing in other parts of the world. There is, however, need to sustain effort at a further reduction in MMR towards the attainment of set sustainable development goals (SDGs), through improvement in the provision of maternal health services in low-income countries

    Using nanogap in label-free impedance based electrical biosensors to overcome electrical double layer effect

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    Point-of-care biosensor applications require low-cost and low-power solutions. They offer being easily accessible at home site. They are usable without any complex sample handling or any kind of special expertise. Impedance spectroscopy has been utilized for point-of-care biosensor applications; however, electrical double layer formed due to ions in the solution of interest has been a challenge, due to shielding of the electric field used for sensing the target molecules. Here in this study, we demonstrate a nanogap based biosensor structure with a relatively low frequency (1–100 kHz) measurement technique, which not only eliminates the undesired shielding effect of electrical double layer but also helps in minimizing the measurement volume and enabling low concentration (µ molar level) detection of target molecules (streptavidin). Repeatability and sensitivity tests proved stable and reliable operation of the sensors. These biosensors might offer attributes such as low-cost label-free detection, fast measurement and monolithic chip integrability. © 2015, Springer-Verlag Berlin Heidelberg

    Students' Economic Status and Access to Technology in Relation to Their Academic Stress on Online Learning at the University of Bohol

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    Socioeconomic status refers to the family's social and economic standing in society. It is measured by combining an individual or group's economic and social position, which is often based on income, education, and occupation. It significantly affects academic performance and even one's health status. The pandemic changed the educational system, causing a huge transition from traditional learning methods to online learning. This shift resulted in confusion, burden, and difficulty among students from different walks of life. This study was conducted to determine the academic stress on online learning among nursing students in relation to their economic status and their ability to access technology. The study utilized a quantitative-correlational method aided by a standard questionnaire. Two hundred thirty-six University of Bohol nursing students enrolled in the second semester of SY 2021–2022 were included in the study by random selection. Data revealed a significant correlation between economic status and the level of stress related to academic expectations and a significant correlation between economic status and access to technology after being subjected to the Spearman rho test of correlation. However, no significant correlation was found between access to technology and the respondents' level of academic stress

    Global patterns in endemicity and vulnerability of soil fungi

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    Fungi are highly diverse organisms, which provide multiple ecosystem services. However, compared with charismatic animals and plants, the distribution patterns and conservation needs of fungi have been little explored. Here, we examined endemicity patterns, global change vulnerability and conservation priority areas for functional groups of soil fungi based on six global surveys using a high-resolution, long-read metabarcoding approach. We found that the endemicity of all fungi and most functional groups peaks in tropical habitats, including Amazonia, Yucatan, West-Central Africa, Sri Lanka, and New Caledonia, with a negligible island effect compared with plants and animals. We also found that fungi are predominantly vulnerable to drought, heat and land-cover change, particularly in dry tropical regions with high human population density. Fungal conservation areas of highest priority include herbaceous wetlands, tropical forests, and woodlands. We stress that more attention should be focused on the conservation of fungi, especially root symbiotic arbuscular mycorrhizal and ectomycorrhizal fungi in tropical regions as well as unicellular early-diverging groups and macrofungi in general. Given the low overlap between the endemicity of fungi and macroorganisms, but high conservation needs in both groups, detailed analyses on distribution and conservation requirements are warranted for other microorganisms and soil organisms
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