The indicator of risk of water contamination by nitrate-nitrogen

2007 ◽  
Vol 87 (Special Issue) ◽  
pp. 179-188 ◽  
Author(s):  
R. De Jong ◽  
J Y Yang ◽  
C F Drury ◽  
E C Huffman ◽  
V. Kirkwood ◽  
...  
Keyword(s):  
High Risk ◽  
Prince Edward Island ◽  
Water Contamination ◽  
Nitrate Nitrogen ◽  
Soil Conditions ◽  
Agricultural System ◽  
Residual Soil ◽  
Risk Class ◽  
Production Practices ◽  
Drinking Water Guideline

Drriven by changes in agricultural production practices, nitrogen (N) inputs have increased steadily on Canadian farms. An agro-environmental indicator was developed to monitor potential water pollution by N: indicator risk of water contamination by nitrate-nitrogen (IROWC-N). The indicator links the residual soil nitrogen (RSN) indicator to climate and soil conditions to assess the likelihood of N moving through the soil and out of the agricultural system. The results are assessed in terms of Nlost via leached water (Nlost) and its concentration in the leached water (Nconc), with the IROWC-N risk classes based on Nlost and Nconc criteria. The estimated amount of Nlost in Canada ranged from 5.1 kg N ha-1 in 1991 to 6.4 kg N ha-1 in 2001. Nconc values remained fairly constant during the 1981 to 1996 census years (ranging from 3.7 to 4.5 mg N L-1), but increased sharply (27%) to 5.7 mg N L-1 in 2001 as compared with 1996. During the 1981 to 2001 period, close to 80% of the Canadian farmland area remained in the very low and low IROWC-N risk classes, but over the years 18% shifted to a higher risk class. In 2001, large areas (> 1 million ha) in the high risk IROWC-N class were found in Manitoba, southern and eastern Ontario and in Quebec. Provincial averages of Nlost over 5 census years (1981, 1986, 1991, 1996 and 2001) varied from less than 5 kg N ha-1 in Alberta and Saskatchewan to more than 20 kg N ha-1 in Ontario, Quebec and the Atlantic provinces. With the exception of Manitoba, provincial Nconc values did not exceed the Canadian drinking water guideline of 10 mg NO3-N L-1. In each of the census years, British Columbia, Alberta and Saskatchewan had more than 70% of the farmland area in the very low and low risk classes for IROWC-N. In Ontario and Quebec, most of the farmland area was either in the low or in the high risk class. More than 50% of the farmland area in New Brunswick, Nova Scotia and Newfoundland was in the very low, low and moderate risk classes, whereas in Manitoba and Prince Edward Island, more than 60% of the farmland was in the moderate and higher level risk classes for IROWC-N. Overall, the 20-yr trend in risk of water contamination by N was worsening. Key words: Water contamination by nitrogen, nitrate, water quality, Soil Landscapes of Canada, Census of Agriculture

scholarly journals Health-risk behaviors among Iranian university students, 2019: a web-based survey

2020 ◽  
Vol 78 (1) ◽  
Author(s):  
Farhad Shekari ◽  
Peyman Habibi ◽  
Haidar Nadrian ◽  
Asghar Mohammadpoorasl
Keyword(s):  
Substance Abuse ◽  
High Risk ◽  
Cigarette Smoking ◽  
Risk Behaviors ◽  
Online Survey ◽  
Latent Class ◽  
Risky Behaviors ◽  
High Risk Behaviors ◽  
Web Based ◽  
Risk Class

Abstract Background High-risk behaviors are among the most serious threats for the physical and mental health of adolescents and young adults. Our aims in this study were to investigate the subgroups of students based on risky behaviors and to identify the prevalence rate of these subgroups. Methods This cross-sectional web-based survey was conducted from July to August 2019 in Tabriz, Iran. We performed proportional sampling in all nine universities of the city, according to the number of students in each university. Applying an online survey questionnaire, the data were collected from 3649 students and analyzed using Latent Class Analysis. Results For total sample, standardized prevalence rates of cigarette smoking, hookah use, alcohol consumption, substance abuse and unsafe sex were 18.5 (Confidence Interval (CI) 95%: 17.3–19.8), 9.1 (CI 95%: 8.2–10.1), 9.2 (CI 95%: 8.3–10.2), 8.3 (CI 95%: 7.4–9.3) and 14.5 (CI 95%: 13.3–15.7), respectively. Three latent classes of risky behaviors were determined among students: a) low risk b) smoking and c) high risk. About 18% of boys and 1.5% of girls were in the high risk class. Cigarette smoking (18.5%, CI 95%: 17.3–19.8) and substance abuse (8.3%, CI 95%: 7.4–9.3) were the most and the least common risky behaviors among the students. Conclusion In this we-based survey, a considerable number of students, particularly boys (18%), was at high-risk class, stressing the need for preventive interventions for this group of youth. Our findings are beneficial for planning and development of risky-behavior preventive strategies to prevent high-risk behaviors among college students.

Microsite and litter cover effects on soil conditions and seedling recruitment in a saline agricultural system

2011 ◽  
Vol 348 (1-2) ◽  
pp. 397-409 ◽  
Author(s):  
Claire Farrell ◽  
Christopher Szota ◽  
Richard J. Hobbs ◽  
Timothy D. Colmer
Keyword(s):  
Seedling Recruitment ◽  
Soil Conditions ◽  
Agricultural System ◽  
Litter Cover

scholarly journals Aspects of nitrogen use efficiency of cauliflower I. A simulation modelling based analysis of nitrogen availability under field conditions

2003 ◽  
Vol 141 (1) ◽  
pp. 1-16 ◽  
Author(s):  
H. KAGE ◽  
C. ALT ◽  
H. STÜTZEL
Keyword(s):  
Root Growth ◽  
Soil Water ◽  
Nitrogen Availability ◽  
Simulation Modelling ◽  
Activity Period ◽  
Nitrate Transport ◽  
Soil Conditions ◽  
Residual Soil ◽  
Soil Nitrate ◽  
N Supply

Data from several field experiments (eight crops grown under a widely varying nitrogen supply on a loess loam soil) were used for a simulation modelling based analysis of nitrogen availability of cauliflower. The model was built out of components describing root growth, nitrate transport to the roots and the vertical nitrate transport within the soil.Root observations obtained over 2 years indicated an increased fraction of dry matter allocated to the fine roots under N deficiency. An adopted version of a root growth model for cauliflower described the rooting data with an R2=0·75. Based upon an acceptable description of the soil water budget, vertical nitrate movement during the growth period of cauliflower was accurately described. The magnitude of this movement, however, was limited to soil depths of about 60 cm even after periods of high rainfall, because of a high soil water holding capacity. An analysis of the factors determining nitrate availability indicated that apparent mass flow was only of high importance for conditions of extremely high N supply where high amounts of nitrate nitrogen remain in the soil up to the end of the growing season. Otherwise, the dominating fraction of nitrate has to be transported to the roots by diffusion. Single root model based calculations of maximum nitrate transport to roots overestimated N availability as indicated by estimates of critical soil nitrate N that were too low. The introduction of a restricted uptake activity period of the roots was used to bridge the gap between theoretical calculations and empirical results. Scenario calculations were carried out to obtain functional relationships between N supply and residual soil nitrate levels for different soil conditions and management practices.

Evaluating and adapting new technologies in a high-risk agricultural system—Niger

1993 ◽  
Vol 42 (1-2) ◽  
pp. 153-171 ◽  
Author(s):  
B.I. Shapiro ◽  
J.H. Sanders ◽  
K.C. Reddy ◽  
T.G. Baker
Keyword(s):  
High Risk ◽  
New Technologies ◽  
Agricultural System

scholarly journals Analytical validity of DecisionDx-SCC, a gene expression profile test to identify risk of metastasis in cutaneous squamous cell carcinoma (SCC) patients

2021 ◽  
Author(s):  
Sherri Borman ◽  
Jeff Wilkinson ◽  
Lauren Meldi-Sholl ◽  
Clare Johnson ◽  
Kelsey Carter ◽  
...  
Keyword(s):  
Gene Expression ◽  
Squamous Cell Carcinoma ◽  
High Risk ◽  
Cell Carcinoma ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
Squamous Cell ◽  
Cutaneous Squamous Cell Carcinoma ◽  
Risk Class ◽  
Class 1

Abstract Background To improve identification of patients with cutaneous squamous cell carcinoma (SCC) at high risk for metastatic disease, the DecisionDx-SCC assay, a prognostic 40-gene expression profile (40-GEP) test, was developed and validated. The 40-GEP assay utilizes RT-PCR gene expression analysis on primary tumor biopsy tissue to evaluate the expression of 34 signature gene targets and 6 normalization genes. The test provides classifications of low risk (Class 1), moderate risk (Class 2A), and high risk (Class 2B) of metastasis within 3 years of diagnosis. The primary objective of this study was to validate the analytical performance of the 40 gene expression signature. Methods The repeatability and reproducibility of the 40-GEP test was evaluated by performance of inter-assay, intra-assay, and inter-operator precision experiments along with monitoring the reliability of sample and reagent stability for class call concordance. The technical performance of clinical orders from September 2020 through July 2021 for the 40-GEP test was assessed. Results Patient hematoxylin and eosin (H&E) stained slides were reviewed by a board-certified pathologist to assess minimum acceptable tumor content. Class specific controls (Class 1 and Class 2B) were evaluated with Levey Jennings analysis and demonstrated consistent and reproducible results. Inter-assay, inter-operator and intra-assay concordance were all ≥90%, with short-term and long-term RNA stability also meeting minimum concordance requirements. Of the 2,446 orders received, 93.4% remained eligible for testing, with 96.8% of all tested samples that completed the assay demonstrating actionable class call results. Conclusion DecisionDx-SCC demonstrates a high degree of analytical precision, yielding high concordance rates across multiple performance experiments, along with exhibiting robust technical reliability on clinical samples.

scholarly journals Shear Wave Elastography and Thyroid Imaging Reporting and Data System (TIRADS) for the Risk Stratification of Thyroid Nodules—Results of a Prospective Study

Diagnostics ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 109
Author(s):  
Manuela Petersen ◽  
Simone A. Schenke ◽  
Jonas Firla ◽  
Roland S. Croner ◽  
Michael C. Kreissl
Keyword(s):  
High Risk ◽  
Risk Stratification ◽  
Prospective Study ◽  
Thyroid Nodules ◽  
Shear Wave Elastography ◽  
Low Risk ◽  
Intermediate Risk ◽  
Risk Class ◽  
Benign Nodules ◽  
A Prospective Study

Purpose: To compare the diagnostic performance of thyroid imaging reporting and data system (TIRADS) in combination with shear wave elastography (SWE) for the assessment of thyroid nodules. Methods: A prospective study was conducted with the following inclusion criteria: preoperative B-mode ultrasound (US) including TIRADS classification (Kwak-TIRADS, EU-TIRADS), quantitative SWE and available histological results. Results: Out of 43 patients, 61 thyroid nodules were detected; 10 nodules were found to be thyroid cancer (7 PTC, 1 FTC, 2 HüCC) and 51 were benign. According to Kwak-TIRADS the majority of benign nodules (47 out of 51, 92.2%) were classified in the low-risk- and intermediate-risk class, four nodules were classified as high-risk (7.8%). When using EU-TIRADS, the benign nodules were distributed almost equally across all risk classes, 21 (41.2%) nodules were classified in the low-risk class, 16 (31.4%) in the intermediate-risk class and 14 (27.4%) in the high-risk class. In contrast, most of the malignant nodules (eight out of ten) were classified as high-risk on EU-TIRADS. One carcinoma was classified as low-risk and one as intermediate-risk nodule. For SWE, ROC analysis showed an optimal cutoff of 18.5 kPa to distinguish malignant and benign nodules (sensitivity 80.0%, specificity 49.0%, PPV 23.5% and NPV 92.6%). The addition of elastography resulted in an increase of accuracy from 65.6% to 82.0% when using Kwak-TIRADS and from 49.2% to 72.1% when using EU-TIRADS. Conclusion: Our data demonstrate that the combination of TIRADS and SWE seems to be superior for the risk stratification of thyroid nodules than each method by itself. However, verification of these results in a larger patient population is mandatory.

scholarly journals MO245OUTCOME OF DIFFERENT INDUCTION REGIMENS IN ANCA-ASSOCIATED GLOMERULONEPHRITIS ACCORDING TO THE HISTOPATHOLOGICAL CHARACTERISTICS: THE REASSESS STUDY*

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Martina Uzzo ◽  
Jennifer Scott ◽  
Alice Guerini ◽  
Jennifer O'brien ◽  
Anna Ricchiuto ◽  
...  
Keyword(s):  
High Risk ◽  
Regression Model ◽  
Cox Regression ◽  
Renal Involvement ◽  
Free Survival ◽  
Risk Class ◽  
Cox Regression Analysis ◽  
Multicenter Survey ◽  
Induction Regimen ◽  
Renal Relapse

Abstract Background and Aims Renal involvement in ANCA-associated vasculitis (AAV) impacts significantly on patients’ prognosis. The role of different induction regimens on remission rates and long-term renal outcomes according to renal histological characteristics has not been explored yet. Method AAV patients with biopsy-proven renal involvement were collected retrospectively from eleven centers and stratified according to the induction regimen employed: Rituximab (RTX), Cyclophosphamide (CYC) or both (RTX-CYC). Kidney biopsies were classified according to the Berden and Brix classifications. Renal remission rate was assessed 6 months after the induction regimen and defined as a renal Birmingham Vasculitis Activity Score (BVAS) of 0. Among patients who achieved remission at 6 months, renal relapse was defined as a renal-BVAS>0 associated with an increase in immunosuppressive treatment. ESRD was defined as an eGFR<15 ml/min/1,73m2, need for dialysis or renal transplant. Results 323 patients were identified and followed-up for a median time of 36 months (IQR 18-72). The cohort included 38% patients with GPA and 62% with MPA, 53% patients were MPO-ANCA and 41% PR3-ANCA positive. The median baseline eGFR in the overall cohort was 19 ml/min/1,73m2 (IQR 12- 34). 58% of patients were treated with CYC, 24% with RTX-CYC and 18% with RTX. According to the Berden classification, 24% biopsies were classified as Focal, 31% as Crescentic, 33% as Mixed and 12% as Sclerotic. The Brix score was assessable in 270/323 (84%) patients: 17%, 52% and 31% were respectively in the Low, Medium and High-risk class. The overall renal remission at 6 months was 90%; according to the Berden classification, 94% patients achieved remission in the Focal, 88% in the Crescentic, 91% in the Mixed and 86% in the Sclerotic class. According to the Brix risk score, 88% patients achieved remission in the High risk, 91% in the Medium and 96% in the Low-risk class. According to induction regimen employed, 91%, 90% and 90% patients achieved remission in the RTX, CYC and RTX plus CYC group respectively. In a logistic regression model adjusted for sex, age, ANCA type, AAV diagnosis, creatinine and proteinuria at onset, the induction regimen employed was not predictive of renal remission at 6 months, neither in Berden Focal plus Crescentic and Mixed plus Sclerotic classes, nor in Brix High and Low plus Medium risk classes. Of the 185 patients with at least 6 months of follow-up available after remission, 25% experienced a renal relapse. In a Cox regression model adjusted for sex, age, ANCA type, AAV diagnosis, creatinine and proteinuria at onset, the induction regimen or histological score were not predictive of renal relapse. In the unadjusted survival analysis with the Kaplan-Maier curve, patients in the Crescentic group treated with RTX had a shorter ESRD-free survival compared to the CYC group (p=0.033) and the RTX-CYC group (p=0.044); figure 1: This was confirmed also with a Cox regression analysis adjusted for sex, age, ANCA type, AAV diagnosis, creatinine and proteinuria when comparing the RTX group with the CYC one (HR 8.30 [95% CI 1.64 to 42.01], p=0.011); figure 2: While the eGFR changes over time in the Focal plus Crescentic and Mixed plus Sclerotic classes showed a similar trend between treatment groups, in the Crescentic class the median eGFR values in the RTX group tended to be lower compared to the CYC and the RTX-CYC ones; figure 3: The rate of severe infections in the RTX, CYC and RTX-CYC group was respectively 6.3, 8.5 and 8.8 per 100 patient-years during the first 12 months. Conclusion in a retrospective multicenter survey, response rates and relapse risk after different induction regimens in AAV patients with renal involvement were comparable in the overall cohort and in the different histopathological subgroups. Although in a small subset of patients, the ESRD-free survival in the Crescentic class was shorter in the RTX group compared to the CYC one.

scholarly journals Application of The Hierarchical Multicriteria Analysis Method to The Study of Water Erosion (South of Azilal, Morocco)

2021 ◽  
Vol 2 (1) ◽  
pp. 12-22
Author(s):  
Abdelouhed Farah ◽  
Ahmed Algouti ◽  
Abdellah Algouti ◽  
Mohamed Ifkirne
Keyword(s):  
Information System ◽  
Geographic Information System ◽  
High Risk ◽  
Multicriteria Analysis ◽  
Water Erosion ◽  
Soil Conditions ◽  
Analysis Method ◽  
Erosion Risk ◽  
Risk Zones ◽  
Sensitivity Map

This study aims to apply the process of the analytical hierarchy in geographic information system to the study of water erosion in the southern part of the Azilal region, Morocco. This method is an important tool to be used in the planning and management of natural risks; it has allowed us to obtain a multi-factorial sensitivity map to water erosion. This sensitivity map of erosive soil conditions in the study area shows that 6% of the area is (less) exposed to erosion risk while 85% of the mapped area is moderately exposed to erosion risk and only 8% of the mapped area is highly exposed to water weathering factors.  Visually, the high-risk zones correspond to the area around ‘’Oued Lakhdar’’ and its tributaries.

Classification of cutaneous leishmaniasis patients based on its risk factors using latent class analysis

2020 ◽  
pp. 004947552097159
Author(s):  
Mojtaba Salimi ◽  
Ebrahim Shakiba ◽  
Eslam Moradi-Asl ◽  
Abbas Abbasi-Ghahramanloo ◽  
Keyvan Khassi
Keyword(s):  
Risk Factors ◽  
High Risk ◽  
Latent Class Analysis ◽  
Cutaneous Leishmaniasis ◽  
Latent Class ◽  
Preventive Intervention ◽  
Class Analysis ◽  
Risk Class ◽  
Very High

Cutaneous leishmaniasis is one of the main health-economic problems around the world. Data were collected from all patients with cutaneous leishmaniasis referred to the health centres of Kermanshah province between 2013 and 2019. Latent class analysis was conducted by PROC LCA in SAS 9.2 and a significant level was set at 0.05. Four latent classes were identified: low (33.8%), moderate (9.8%), high (22.4%) and very high risk (34.0%). The probability of having a travel history was high in the third class. Our study indicated that having history of an eschar has no role in the classification of patients. On the other hand, a positive smear test is important in classifying subjects. Our results indicate that more than half of all patients fell under high risk or very high-risk class. This emphasises the importance of planning preventive intervention by considering different risk factors of cutaneous leishmaniasis simultaneously.

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