1,924 research outputs found

    A revised parameterization for gaseous dry deposition in air-quality models

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    International audienceA parameterization scheme for calculating gaseous dry deposition velocities in air-quality models is revised based on recent study results on non-stomatal uptake of O3 and SO2 over 5 different vegetation types. Non-stomatal resistance, which includes in-canopy aerodynamic resistance, soil resistance and cuticle resistance, for SO2 and O3 is parameterized as a function of friction velocity, relative humidity, leaf area index, and canopy wetness. Non-stomatal resistance for all other species is scaled to those of SO2 and O3 based on their chemical and physical characteristics. Stomatal resistance is calculated using a leaf-stomatal-resistance model for all gaseous species of interest. The improvements in the present model compared to its earlier version include a newly developed non-stomatal resistance formulation, a realistic treatment of cuticle and ground resistance in winter and the handling of seasonally-dependent input parameters. Model evaluation shows that the revised parameterization can provide more realistic deposition velocities for both O3 and SO2, especially for wet canopies. Example model output shows that the parameterization provides reasonable estimates of dry deposition velocities for different gaseous species, land types and diurnal and seasonal variations. Maximum deposition velocities from model output are close to reported measurement values for different land types. The current parameterization can be easily adopted into different air-quality models that require inclusion of dry deposition processes

    Evidence for a dynamical ground state in the frustrated pyrohafnate Tb2Hf2O7

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    We report the physical properties of Tb2Hf2O7 based on ac magnetic susceptibility \chi_ac(T), dc magnetic susceptibility \chi(T), isothermal magnetization M(H), and heat capacity C_p(T) measurements combined with muon spin relaxation (\muSR) and neutron powder diffraction measurements. No evidence for long-range magnetic order is found down to 0.1 K. However, \chi_ac(T) data present a frequency-dependent broad peak (near 0.9 K at 16 Hz) indicating slow spin dynamics. The slow spin dynamics is further evidenced from the \muSR data (characterized by a stretched exponential behavior) which show persistent spin fluctuations down to 0.3 K. The neutron powder diffraction data collected at 0.1 K show a broad peak of magnetic origin (diffuse scattering) but no magnetic Bragg peaks. The analysis of the diffuse scattering data reveals a dominant antiferromagnetic interaction in agreement with the negative Weiss temperature. The absence of long-range magnetic order and the presence of slow spin dynamics and persistent spin fluctuations together reflect a dynamical ground state in Tb2Hf2O7.Comment: 11 pages and 8 figure

    Estimating the number needed to treat from continuous outcomes in randomised controlled trials: methodological challenges and worked example using data from the UK Back Pain Exercise and Manipulation (BEAM) trial

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    Background Reporting numbers needed to treat (NNT) improves interpretability of trial results. It is unusual that continuous outcomes are converted to numbers of individual responders to treatment (i.e., those who reach a particular threshold of change); and deteriorations prevented are only rarely considered. We consider how numbers needed to treat can be derived from continuous outcomes; illustrated with a worked example showing the methods and challenges. Methods We used data from the UK BEAM trial (n = 1, 334) of physical treatments for back pain; originally reported as showing, at best, small to moderate benefits. Participants were randomised to receive 'best care' in general practice, the comparator treatment, or one of three manual and/or exercise treatments: 'best care' plus manipulation, exercise, or manipulation followed by exercise. We used established consensus thresholds for improvement in Roland-Morris disability questionnaire scores at three and twelve months to derive NNTs for improvements and for benefits (improvements gained+deteriorations prevented). Results At three months, NNT estimates ranged from 5.1 (95% CI 3.4 to 10.7) to 9.0 (5.0 to 45.5) for exercise, 5.0 (3.4 to 9.8) to 5.4 (3.8 to 9.9) for manipulation, and 3.3 (2.5 to 4.9) to 4.8 (3.5 to 7.8) for manipulation followed by exercise. Corresponding between-group mean differences in the Roland-Morris disability questionnaire were 1.6 (0.8 to 2.3), 1.4 (0.6 to 2.1), and 1.9 (1.2 to 2.6) points. Conclusion In contrast to small mean differences originally reported, NNTs were small and could be attractive to clinicians, patients, and purchasers. NNTs can aid the interpretation of results of trials using continuous outcomes. Where possible, these should be reported alongside mean differences. Challenges remain in calculating NNTs for some continuous outcomes

    Comparison of diff erent lactation curve models in Sahiwal cows

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    Abstract: Th e present investigation was carried out on 12,859 fortnightly test-day milk yield records of fi rst lactation pertaining to 643 Sahiwal cows spread over a period of 49 years ), maintained at the National Dairy Research Institute, Karnal, India. Th e comparison of 3 lactation curve models, i.e. the quadratic model, gamma-type function, and mixed log function, was done using fortnightly test-day milk yield records. Th e mixed log function was the best fi t, with the highest (88.75%) coeffi cient of determination (R2 value) and the lowest (0.08 kg) root mean square error (RMSE) value, whereas the lowest (56.93%) R2 value was observed in the quadratic model with maximum (0.15 kg) RMSE value. Th e closeness of fi t of the mixed log function and gamma-type function with the observed lactation curve was almost of the same order. However, the gamma-type function gave a low peak yield, and therefore it is recommended that this function can give the best fi t for low-yielding cows

    Systematic and computer assisted design of measurement systems

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    In this paper, a new approach is presented for the user guided automatised design of measurement systems. Two concepts are presented: an adapted concept for describing a measurement system and a new concept for the design of a measurement system. For the design concept, a heterarchical implementation is proposed. The applicability of our approach is illustrated with an example from practice

    Development of learning objectives for neurology in a veterinary curriculum: Part II: Postgraduates

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    Background: Specialization in veterinary medicine in Europe is organized through the Colleges of the European Board of Veterinary Specialization. To inform updating of the curriculum for residents of the European College of Veterinary Neurology (ECVN) job analysis was used. Defining job competencies of diploma holders in veterinary neurology can be used as references for curriculum design of resident training. With the support of the diplomates of the ECVN and the members of the European Society of Veterinary Neurology (ESVN) a mixed-method research, including a qualitative search of objectives and quantitative ranking with 149 Likert scale questions and 48 free text questions in 9 categories in a survey was conducted. In addition, opinions of different groups were subjected to statistical analysis and the result compared. Results: A return rate of 62% (n = 213/341) was achieved. Of the competencies identified by the Delphi process, 75% objectives were expected to attain expert level; 24% attain advanced level; 1% entry level. In addition, the exercise described the 11 highly ranked competencies, the 3 most frequently seen diseases of the central and peripheral nervous systems and the most frequently used immunosuppressive, antiepileptic and chemotherapeutic drugs. Conclusion: The outcomes of this “Delphi job analysis” provide a powerful tool to align the curriculum for ECVN resident training and can be adapted to the required job competencies, based on expectations. The expectation is that for majority of these competencies diplomates should attain an expert level. Besides knowledge and clinical skills, residents and diplomates are expected to demonstrate high standards in teaching and communication. The results of this study will help to create a European curriculum for postgraduate education in veterinary neurology

    Occurrence of Eimeria species parasites on small-scale commercial chicken farms in Africa and indication of economic profitability.

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    Small-scale commercial poultry production is emerging as an important form of livestock production in Africa, providing sources of income and animal protein to many poor households, yet the occurrence and impact of coccidiosis on this relatively new production system remains unknown. The primary objective of this study was to examine Eimeria parasite occurrence on small-scale commercial poultry farms in Ghana, Tanzania and Zambia. Additionally, farm economic viability was measured by calculating the farm gross margin and enterprise budget. Using these economic measures as global assessments of farm productivity, encompassing the diversity present in regional husbandry systems with a measure of fundamental local relevance, we investigated the detection of specific Eimeria species as indicators of farm profitability. Faecal samples and data on production parameters were collected from small-scale (less than 2,000 birds per batch) intensive broiler and layer farms in peri-urban Ghana, Tanzania and Zambia. All seven Eimeria species recognised to infect the chicken were detected in each country. Furthermore, two of the three genetic variants (operational taxonomic units) identified previously in Australia have been described outside of Australia for the first time. Detection of the most pathogenic Eimeria species associated with decreased farm profitability and may be considered as an indicator of likely farm performance. While a causal link remains to be demonstrated, the presence of highly pathogenic enteric parasites may pose a threat to profitable, sustainable small-scale poultry enterprises in Africa

    Морфологічне дослідження впливу мелатоніну на стан слизової оболонки шлунка щурів в умовах експериментальної гастральної виразки

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    Введение серотонина вызывает в слизистой оболочке желудка животных острые деструктивные изменения преимущественно в виде эрозий и язв различного размера и численности, которые сопровождаются уменьшением содержания нейтральных мукополисахаридов в цитоплазме клеток поверхностно-ямочного эпителия. Введение мелатонина при гастральной язве уменьшает деструктивные изменения в слизистой оболочке желудка и восстанавливает состояние защитного слизистого барьера.Введение серотонина вызывает в слизистой оболочке желудка животных острые деструктивные изменения преимущественно в виде эрозий и язв различного размера и численности, которые сопровождаются уменьшением содержания нейтральных мукополисахаридов в цитоплазме клеток поверхностно-ямочного эпителия. Введение мелатонина при гастральной язве уменьшает деструктивные изменения в слизистой оболочке желудка и восстанавливает состояние защитного слизистого барьера.The introduction of serotonin is in the gastric mucosa of animals’ acute destructive changes mainly in the form of erosions and ulcers of various sizes and numbers, which are accompanied by a decrease in the amount of neutral mucopolysaccharides in the cytoplasm of the cell surface patching of the epithelium. The administration of melatonin in the gastric ulcer reduces the destructive changes in the gastric mucosa and restores the state of the protective mucus barrier

    “Четвертий поділ” Польщі і встановлення радянського тоталітарного режиму в Західній Україні

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    The present article was based on the unknown documents of the Branch state archive of Security service of Ukraine and showed the first phase so called “sovietizashion” (establishment of Soviet regim) of Western Ukraine after being joined to the USSR in the September 1939. The author investigeted the measures used to arrange the 800-meter borderland between the USSR and Third Reich
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