Wideband Characteristic Basis Functions in Radiation Problems

In this paper, the use of characteristic basis function (CBF) method, augmented by the application of asymptotic waveform evaluation (AWE) technique is analyzed in the context of the application to radiation problems. Both conventional and wideband CBFs are applied to the analysis of wire and planar antennas

Quantifying tropical peatland dissolved organic carbon (DOC) using UV-visible spectroscopy

UV–visible spectroscopy has been shown to be a useful technique for determining dissolved organic carbon (DOC) concentrations. However, at present we are unaware of any studies in the literature that have investigated the suitability of this approach for tropical DOC water samples from any tropical peatlands, although some work has been performed in other tropical environments. We used water samples from two oil palm estates in Sarawak, Malaysia to: i) investigate the suitability of both single and two-wavelength proxies for tropical DOC determination; ii) develop a calibration dataset and set of parameters to calculate DOC concentrations indirectly; iii) provide tropical researchers with guidance on the best spectrophotometric approaches to use in future analyses of DOC. Both single and two-wavelength model approaches performed well with no one model significantly outperforming the other. The predictive ability of the models suggests that UV–visible spectroscopy is both a viable and low cost method for rapidly analyzing DOC in water samples immediately post-collection, which can be important when working at remote field sites with access to only basic laboratory facilities

International medical graduates in family medicine in the United States of America: an exploration of professional characteristics and attitudes

BACKGROUND: The number of international medical graduates (IMGs) entering family medicine in the United States of America has steadily increased since 1997. Previous research has examined practice locations of these IMGs and their role in providing care to underserved populations. To our knowledge, research does not exist comparing professional profiles, credentials and attitudes among IMG and United States medical graduate (USMG) family physicians in the United States. The objective of this study is to determine, at the time when a large influx of IMGs into family medicine began, whether differences existed between USMG and IMG family physicians in regard to personal and professional characteristics and attitudes that may have implications for the health care system resulting from the increasing numbers of IMGs in family medicine in the United States. METHODS: This is a secondary data analysis of the 1996–1997 Community Tracking Study (CTS) Physician Survey comparing 2360 United States medical graduates and 366 international medical graduates who were nonfederal allopathic or osteopathic family physicians providing direct patient care for at least 20 hours per week. RESULTS: Compared to USMGs, IMGs were older (p < 0.001) and practised in smaller (p = 0.0072) and younger practices (p < 0.001). Significantly more IMGs practised in metropolitan areas versus rural areas (p = 0.0454). More IMG practices were open to all new Medicaid (p = 0.018) and Medicare (p = 0.0451) patients, and a greater percentage of their revenue was derived from these patients (p = 0.0020 and p = 0.0310). Fewer IMGs were board-certified (p < 0.001). More IMGs were dissatisfied with their overall careers (p = 0.0190). IMGs and USMGs did not differ in terms of self-rated ability to deliver high-quality care to their patients (p = 0.4626). For several of the clinical vignettes, IMGs were more likely to order tests, refer patients to specialists or require office visits than USMGs. CONCLUSION: There are significant differences between IMG and USMG family physicians' professional profiles and attitudes. These differences from 1997 merit further exploration and possible follow-up, given the increased proportion of family physicians who are IMGs in the United States

Application of Satellite-Based Precipitation Estimates to Rainfall-Runoff Modelling in a Data-Scarce Semi-Arid Catchment

Rainfall-runoff modelling is a useful tool for water resources management. This study presents a simple daily rainfall-runoff model, based on the water balance equation, which we apply to the 11,630 km2 Lesser Zab catchment in northeast Iraq. The model was forced by either observed daily rain gauge data from four stations in the catchment or satellite-derived rainfall estimates from two TRMM Multi-satellite Precipitation Analysis (TMPA) data products (TMPA-3B42 and 3B42RT) based on the Tropical Rainfall Measuring Mission (TRMM) from 2003 to 2014. As well as using raw TMPA data, we used a bias-correction method to adjust TMPA values based on rain gauge data. The uncorrected TMPA data products underestimated observed mean catchment rainfall by −10.1% and −10.7%. Corrected data also slightly underestimated gauged rainfall by −0.7% and −1.6%, respectively. Nash-Sutcliffe Efficiency (NSE) and Pearson’s Correlation Coefficient (r) for the model fit with the observed hydrograph were 0.75 and 0.87, respectively, for a calibration period (2010–2011) using gauged rainfall data. Model validation performance (2012–2014) was best (highest NSE and r; lowest RMSE and bias) using the corrected 3B42 data product and poorest when driven by uncorrected 3B42RT data. Uncertainty and equifinality were also explored. Our results suggest that TRMM data can be used to drive rainfall-runoff modelling in semi-arid catchments, particularly when corrected using rain gauge data

Estimating daily reference evapotranspiration in a semi-arid region using remote sensing data

Estimating daily evapotranspiration is challenging when ground observation data are not available or scarce. Remote sensing can be used to estimate the meteorological data necessary for calculating reference evapotranspiration ETₒ. Here, we assessed the accuracy of daily ETₒ estimates derived from remote sensing (ETₒ-RS) compared with those derived from four ground-based stations (ETₒ-G) in Kurdistan (Iraq) over the period 2010–2014. Near surface air temperature, relative humidity and cloud cover fraction were derived from the Atmospheric Infrared Sounder/Advanced Microwave Sounding Unit (AIRS/AMSU), and wind speed at 10 m height from MERRA (Modern-Era Retrospective Analysis for Research and Application). Four methods were used to estimate ETₒ: Hargreaves–Samani (HS), Jensen–Haise (JH), McGuinness–Bordne (MB) and the FAO Penman Monteith equation (PM). ETₒ-G (PM) was adopted as the main benchmark. HS underestimated ETₒ by 2%–3% (R2 = 0.86 to 0.90; RMSE = 0.95 to 1.2 mm day−1 at different stations). JH and MB overestimated ETₒ by 8% to 40% (R2= 0.85 to 0.92; RMSE from 1.18 to 2.18 mm day−1). The annual average values of ETₒ estimated using RS data and ground-based data were similar to one another reflecting low bias in daily estimates. They ranged between 1153 and 1893 mm year−1 for ETₒ-G and between 1176 and 1859 mm year−1 for ETₒ-RS for the different stations. Our results suggest that ETₒ-RS (HS) can yield accurate and unbiased ETₒ estimates for semi-arid regions which can be usefully employed in water resources management

Improved skin test for differential diagnosis of bovine tuberculosis by the addition of Rv3020c-derived peptides

A peptide cocktail derived from the mycobacterial antigens ESAT-6, CFP-10, and Rv3615c allowed differentiation between Mycobacterium bovis-infected and M. bovis bacillus Calmette-Guérin (BCG)-vaccinated cattle when used as a skin test reagent for a “DIVA” test (i.e., a test capable of differentiating infected and uninfected vaccinated animals). Addition of the antigen Rv3020c improves the diagnostic sensitivity without compromising specificity in the face of BCG or Johne's disease vaccination

Ammonia Removal in Free-Surface Constructed Wetlands Employing Synthetic Floating Islands: Employing synthetic floating islands

  تعتبر أنظمة الأراضي الرطبة ذات الجريان السطحي أحد أنظمة المعالجة التقليدية المستخدمة في معالجة ملوثات المياه على الرغم من محدودية كفائتها جراء النسبة الحجمية العالية للسعة المائية الى المساحة السطحية المهيئة للنشاط الميكروبي في تحليل الملوثات البيئة. تمتاز أنظمة المعالجة العائمة (بما تتضمنه من أنظمة طافية فوق سطح الماء) بالقدرة على زيادة المساحة السطحية الضرورية لنشوء وتنامي المجتمعات الميكروبية المحللة على إختلاف أنواعها فضلاً عن إعتبارها منصة عائمة لنمو النباتات فوق سطح الماء وبالتالي زيادة معدلات العمليات البيئية المحللة للملوثات المختلفة. يهدف هذا البحث الى تقييم فاعلية أنظمة المعالجة العائمة في إزالة تراكيز الأمونيا الكلية من مياه الصرف الصحي المصنع  بإستخدام أنظمة تجريبية تعمل بطريقة الدفق المستمر-الثابت مؤلفة من 10 معاملات مكررة وبتصاميم تشغيلية مختلفة تتضمن إختبار مستويات مختلفة لعمود لماء و مساحات سطحية مختلفة للأظمة الطاقية فوق الماء و بإستخدام وفرة نباتية بكثافة مختلفة فضلاً عن معاملات اليسطرة لمقارنة النتائج). بالإضافة الى ذلك, تم إستحداث وتسخير نموذج رياضي لتطوير فهم ميكانيكي متقدم لديناميكيات النتروجين في النظام التجريبي. تمت معايرة النموذج الرياضي بإستخدام بيانات أحد المعاملات ومن ثم التحقق من دقة الموديل من خلال تطبيقه على بقية المعاملات. أستند أداء الموديل الرياضي على فرضية أن ثوابت معدلات عمليات النترتة والتطاير للأمونيا تتناسب عكسياً مع عمق الماء إلا أنها تتناسب طردياً مع المساحة السطحية. أظهر التحليل المعتمد على النموذج الرياضي إمكانية تقدير نسبة مساهمة بعض ميكانيكيات التحليل الى الأداء الكلي في إزالة الأمونيا من الوسط. أثبت الموديل الرياضي دقة عالية في وصف وتوقع ديناميكيات تراكيز الأمونيا والأطوار المؤكسدة للنتروجين في المعاملات التجريبية المختلفة (التحليل الإحصائي لإداء الموديل الخاص بسلوك الأمونيا هو RMSE = 0.88 and 0.40 mg N L-1 وللأطوار المؤكسدة هو RMSE = 0.63 and 1.75 mg N L-1 ). دلت النتائج الى أن إزالة الأمونيا بواسطة عملية النترتة كانت هي السائدة بالمقارنة مع بقية العمليات الأخرى وأن الخصائص التصميمية للنظام و المتمثلة بالعمق المنخفض لعمود الماء مقترناً مع زيادة المساحة السطحية للنظام الطافي تمثل النظام التصميم الأكفاء في إزالة الأمونيا الكلي من الوسط المائي. تؤكد النتائج التي تم الحصول عليها على قدرة الأنظمة المعالجة الطافية على تحسين كفاءة أداء أنظمة الأراضي الرطبة ذات الجريان السطحي في إزالة الأمونيا كما وتظهر أهمية إستخدام الموديلات الرياضية في بناء وتطوير المفاهيم الميكانيكية لديناميكيات النتروجين ومدى مساهمة العمليات البايوجيوكيميائية المختلفة في مصير الأمونيا في ظل تأثير عدد من الخصائص التصميمية والتشغيلية.Free water surface constructed wetlands (FSCWs) can be used to complement conventional waste water treatment but removal efficiencies are often limited by a high ratio of water volume to biofilm surface area (i.e. high water depth). Floating treatment wetlands (FTWs) consist of floating matrices which can enhance the surface area available for the development of fixed microbial biofilms and provide a platform for plant growth (which can remove pollutants by uptake).  In this study the potential of FTWs for ammoniacal nitrogen (AN) removal was evaluated using experimental mesocosms operated under steady-state flow conditions with ten different treatments (two water depths, two levels of FTW mat coverage, two different plant densities and a control, all replicated three times). A simple model was constructed as a framework for understanding N dynamics in each treatment.  The model was calibrated using data obtained from one treatment and validated independently for the other treatments. Specifically, we hypothesized that the nitrification and volatilization rate constants are inversely proportional to water depth and proportional to mat surface area. This allowed the relative magnitude of different removal mechanisms to be estimated.  The model was able to predict steady-state concentrations of AN and total oxidized nitrogen (TON) across the different treatments well (values for correlation in the regression between measured and predicted steady-state concentrations and RMSE were 0.88 and 0.40 mg N L-1 for AN, and 0.63 and 1.75 mg N L-1 for TON).  The results confirm that nitrification is the principal AN removal process, with maximum removal occurring in shallow systems with high matrix cover (i.e. a high ratio of biofilm surface area to water volume). Plant uptake was a relatively minor loss process compared to nitrification. Integrated experimental and model-based approach was found to be a useful tool to improve mechanistic understanding AN dynamics in FSCWs and system performance.

The flux of dissolved nitrogen from the UK: evaluating the role of soils and land use

Fluvial dissolved nitrogen (dissolved organic nitrogen [DON], nitrate and ammonium) fluxes from the terrestrial biosphere of the UK to surrounding oceans are explained on the basis of combined predictions of soil to water transfer and in-stream loss. The flux of different nitrogen species from land to surface waters is estimated using an export coefficient model employing catchment soil, land use and hydroclimatic characteristics, fitted to flux estimates derived from the Harmonised Monitoring Scheme between 2001 and 2007 for 169 UK catchments. In-stream losses of DON, nitrate and ammonium were estimated using a transit time filter in the fluvial network. Comparisons of modelled land to water N flux (2125 ktonnes N yr− 1) with estimates of N fluxes to estuarine and ocean systems at the tidal limit (791 ktonnes N yr− 1) suggest that significant in-channel N losses occur. These in transit losses are equivalent to up to 55 kg N ha− 1 yr− 1