1,190 research outputs found

    A Note on the Reliability Tests of Estimates from ARMS Data

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    USDA uses the concept of "publish-ability" rather than statistical reliability of an estimate for quality validation of USDA estimates, which is solely based on the sample size and the coefficient of variation (CV). We demonstrate conceptually how the reliability of the sample mean can be tested by estimating the upper and lower bounds of the confidence interval for an unknown population mean using the CV. However, the reliability test for the sample mean can be made only under the normality assumption. USDA multiple-way Agricultural Resource Management Survey (ARMS) estimates are used to illustrate the relative measure of precision for sample-based estimators.Research Methods/ Statistical Methods,

    Evaluation of the knowledge and application of diagnostic imaging modalities among veterinary surgeons in Nigerian veterinary medical schools

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    The awareness, theoretical and practical knowledge of radiography, ultrasonography, magnetic resonance imaging (MRI), computed tomography (CT), nuclear medical imaging (NMI) and thermography were accessed among veterinary surgeons teaching in veterinary schools in Nigeria, using a structured questionnaire. Respondents were grouped into five depending on their years of experience post-graduation. These were Group A (0-5 years), Group B (6-10 years), Group C (11-15 years) Group D (16-20 years) and Group E (> 20 years). The result of the awareness of radiography as a diagnostic imaging modality in veterinary practice was not dependent on the years of research experience. A 100 % of respondents in Group A were aware that ultrasonography is indicated in veterinary practice; while only 96.67 % were aware that radiography is so indicated. There was a gradual decline in the awareness of CT compared to radiography and ultrasonography. There was low awareness of the application of MRI, NMI and thermography in veterinary practice by all respondents irrespective of their years of experience. There was a decline in the degree of theoretical knowledge with advancement in the technique. The variation in the mere observation of the practical demonstration of radiography was related to years of research experience, with the exception of Group D. Group E recorded the highest positive response to practical knowledge of all the diagnostic imaging modalities. There was a remarkable drop in the practical knowledge of CT, MRI, NMI and thermography, compared to radiography and ultrasonography in each of the study groups. Only 1 veterinary school had a CT scanning machine, and none had an MRI unit, a gamma camera or a thermographic camera. Only 4 veterinary schools taught MRI. No veterinary school taught NMI and thermography. Appropriate recommendations were made. Keywords: CT, MRI, NMI, Radiography, Thermography, Ultrasonograph

    On the non-existence of a projective (75, 4,12, 5) set in PG(3, 7)

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    We show by a combination of theoretical argument and computer search that if a projective (75, 4, 12, 5) set in PG(3, 7) exists then its automorphism group must be trivial. This corresponds to the smallest open case of a coding problem posed by H. Ward in 1998, concerning the possible existence of an infinite family of projective two-weight codes meeting the Griesmer bound

    Field based reliability and validity of the Bioharness multivariable monitoring device

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    The BioharnessTM device is designed for monitoring physiological variables in free-living situations but has only been proven to be reliable and valid in a laboratory environment. Therefore, this study aimed to determine the reliability and validity of the BioharnessTM using a field based protocol. Twenty healthy males participated. Heart rate (HR), breathing frequency (BF) and accelerometry (ACC) were assessed by simultaneous measurement of two BioharnessTM devices and a test-retest of a discontinuous incremental walk-jog-run protocol (4 – 11 km·h-1) completed in a sports hall. Adopted precision of measurement devices were; HR: Polar T31 (Polar Electro), BF: Spirometer (Cortex Metalyser), ACC: Oxygen expenditure (Cortex Metalyser). For all data, precision of measurement reported good relationships (r = 0.61 to 0.67, p \u3c 0.01) and large Limits of Agreement for HR (\u3e79.2 b·min-1) and BF (\u3e54.7 br·min-1). ACC presented excellent precision (r = 0.94, p \u3c 0.01). Results for HR (r= ~0.91, p \u3c 0.01: CV \u3c7.6) and ACC (r \u3e 0.97, p \u3c 0.01; CV \u3c14.7) suggested these variables are reliable. BF presented more variable data (r = 0.46-0.61, p \u3c 0.01; CV \u3c 23.7). As velocity of movement increased (\u3e8 km·h-1) data became more erroneous. A data cleaning protocol removed gross errors in the data analysis and subsequent reliability and validity statistics improved across all variables. In conclusion, the BioharnessTM HR and ACC variables have demonstrated reliability and validity in a field setting, though data collected at higher velocities should be treated with caution. Measuring human physiological responses in a field based environment allows for more ecologically valid data to be collected and devices such as the BioharnessTM could be used by exercise professionals to begin to further investigate this area

    Field based reliability and validity of the Bioharness multivariable monitoring device

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    The Bioharness™ device is designed for monitoring physiological variables in free-living situations but has only been proven to be reliable and valid in a laboratory environment. Therefore, this study aimed to determine the reliability and validity of the Bioharness™ using a field based protocol. Twenty healthy males participated. Heart rate (HR), breathing frequency (BF) and accelerometry (ACC) were assessed by simultaneous measurement of two Bioharness™ devices and a test-retest of a discontinuous incremental walk-jog-run protocol (4 - 11 km·h-1) completed in a sports hall. Adopted precision of measurement devices were; HR: Polar T31 (Polar Electro), BF: Spirometer (Cortex Metalyser), ACC: Oxygen expenditure (Cortex Metalyser). For all data, precision of measurement reported good relationships (r = 0.61 to 0.67, p 79.2 b·min-1) and BF (>54.7 br·min-1). ACC presented excellent precision (r = 0.94, p 0.97, p 8 km·h-1) data became more erroneous. A data cleaning protocol removed gross errors in the data analysis and subsequent reliability and validity statistics improved across all variables. In conclusion, the Bioharness™ HR and ACC variables have demonstrated reliability and validity in a field setting, though data collected at higher velocities should be treated with caution. Measuring human physiological responses in a field based environment allows for more ecologically valid data to be collected and devices such as the Bioharness™ could be used by exercise professionals to begin to further investigate this area

    CHO genome mining for synthetic promoter design

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    Synthetic promoters are an attractive alternative for use in mammalian hosts such as CHO cells as they can be designed de novo with user-defined functionalities. In this study, we describe and validate a method for bioprocess-directed design of synthetic promoters utilizing CHO genomic sequence information. We designed promoters with two objective features, (i) constitutive high-level recombinant gene transcription, and (ii) upregulated transcription under mild hypothermia or late-stage culture. CHO genes varying in transcriptional activity were selected based on a comparative analysis of RNA-Seq transcript levels in normal and biphasic cultures in combination with estimates of mRNA half-life from published genome scale datasets. Discrete transcription factor regulatory elements (TFREs) upstream of these genes were informatically identified and functionally screened in vitro to identify a subset of TFREs with the potential to support high activity recombinant gene transcription during biphasic cell culture processes. Two libraries of heterotypic synthetic promoters with varying TFRE combinations were then designed in silico that exhibited a maximal 2.5-fold increase in transcriptional strength over the CMV-IE promoter after transient transfection into host CHO-K1 cells. A subset of synthetic promoters was then used to create stable transfectant pools using CHO-K1 cells under glutamine synthetase selection. Whilst not achieving the maximal 2.5-fold increase in productivity over stable pools harboring the CMV promoter, all stably transfected cells utilizing synthetic promoters exhibited increased reporter production - up to 1.6-fold that of cells employing CMV, both in the presence or absence of intron A immediately downstream of the promoter. The increased productivity of stably transfected cells harboring synthetic promoters was maintained during fed-batch culture, with or without a transition to mild hypothermia at the onset of stationary phase. Our data exemplify that it is important to consider both host cell and intended bioprocess contexts as design criteria in the de novo construction of synthetic genetic parts for mammalian cell engineering

    Light and Life: Exotic Photosynthesis in Binary Star Systems

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    The potential for hosting photosynthetic life on Earth-like planets within binary/multiple stellar systems was evaluated by modelling the levels of photosynthetically active radiation (PAR) such planets receive. Combinations of M and G stars in: (i) close-binary systems; (ii) wide-binary systems and (iii) three-star systems were investigated and a range of stable radiation environments found to be possible. These environmental conditions allow for the possibility of familiar, but also more exotic forms of photosynthetic life, such as infrared photosynthesisers and organisms specialised for specific spectral niches.Comment: Accepted for publication in: Astrobiolog

    The Environmental Impacts of International Finance Corporation Lending and Proposals for Reform: A Case Study of Conservation and Oil Development in the Guatemalan Petén

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    This Article presents a case study of lending by the International Finance Corporation (IFC), the private-sector lending arm of the World Bank Group, in the oil and gas sector in Guatemala. The case study emphasizes the need for additional environmental reform at IFC. With two separate loans in 1994 and 1996, IFC supported the activities of a small international oil company that was operating within a national park in the northern Guatemalan Petdn, an area of rich tropical forests and globally important wetlands. The company\u27s operations had been grandfathered in to the park upon its creation in 1990. Funding from IFC was used to construct a pipeline from the oil field in the park to a refinery outside of the park. The crux of the authors\u27 findings is that the pipeline should have been constructed to follow the path of an existing road, rather than along the chosen route that crosses significant stretches of primary tropical forest and that opened a new right-of-way into a park already facing continued pressure from colonization. The authors conclude that a stronger set of IFC lending policies, combined with a better environmental impact assessment and more extensive public consultation, would have led to a less environmentally damaging outcome. Although the authors acknowledge the complex questions about the role of governments, development agencies, the private sector, conservation organizations, and local communities raised by this issue, they focus on the narrow subject of IFC\u27s role in this matter, stressing the need for a reform agenda at that institution
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