Analysis of survival curves in seasonally mated pastoral goat herds in northern Kenya using logistic regression techniques

2002 ◽  
Vol 50 (4) ◽  
pp. 621-640 ◽  
Author(s):  
Ingo Hary
Keyword(s):  
Logistic Regression ◽  
Survival Curves ◽  
Northern Kenya ◽  
Regression Techniques

Predicting the Occurrence of Downy Brome (Bromus tectorum) in Central Oregon

2012 ◽  
Vol 5 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Sara C. P. Lovtang ◽  
Gregg M. Riegel
Keyword(s):  
Logistic Regression ◽  
Great Basin ◽  
Fire Regimes ◽  
National Forest ◽  
Downy Brome ◽  
Department Of Agriculture ◽  
Association Group ◽  
Average Probability ◽  
Regression Techniques ◽  
Successional Pathways

AbstractWhere the nonnative annual grass downy brome proliferates, it has changed ecosystem processes, such as nutrient, energy, and water cycles; successional pathways; and fire regimes. The objective of this study was to develop a model that predicts the presence of downy brome in Central Oregon and to test whether high presence correlates with greater cover. Understory data from the U.S. Department of Agriculture (USDA) Forest Service's Current Vegetation Survey (CVS) database for the Deschutes National Forest, the Ochoco National Forest, and the Crooked River National Grassland were compiled, and the presence of downy brome was determined for 1,092 systematically located plots. Logistic regression techniques were used to develop models for predicting downy brome populations. For the landscape including the eastside of the Cascade Mountains to the northwestern edge of the Great Basin, the following were selected as the best predictors of downy brome: low average March precipitation, warm minimum May temperature, few total trees per acre, many western junipers per acre, and a short distance to nearest road. The concordance index = 0.92. Using the equation from logistic regression, a probability for downy brome infestation was calculated for each CVS plot. The plots were assigned to a plant association group (PAG), and the average probability was calculated for the PAGs in which the CVS plots were located. This method could be duplicated in other areas where vegetation inventories take place.

scholarly journals Modeling of Combined Processing Steps for ReducingEscherichia coli O157:H7 Populations in Apple Cider

2001 ◽  
Vol 67 (1) ◽  
pp. 133-141 ◽  
Author(s):  
Heidi E. Uljas ◽  
Donald W. Schaffner ◽  
Siobain Duffy ◽  
Lihui Zhao ◽  
Steven C. Ingham
Keyword(s):  
Logistic Regression ◽  
Probabilistic Models ◽  
Storage Temperature ◽  
Potassium Sorbate ◽  
Data Set ◽  
Apple Cider ◽  
Multiple Treatment ◽  
Pathogen Control ◽  
Regression Techniques ◽  
Unit Reduction

ABSTRACT Probabilistic models were used as a systematic approach to describe the response of Escherichia coli O157:H7 populations to combinations of commonly used preservation methods in unpasteurized apple cider. Using a complete factorial experimental design, the effect of pH (3.1 to 4.3), storage temperature and time (5 to 35°C for 0 to 6 h or 12 h), preservatives (0, 0.05, or 0.1% potassium sorbate or sodium benzoate), and freeze-thaw (F-T; −20°C, 48 h and 4°C, 4 h) treatment combinations (a total of 1,600 treatments) on the probability of achieving a 5-log10-unit reduction in a three-strain E. coli O157:H7 mixture in cider was determined. Using logistic regression techniques, pH, temperature, time, and concentration were modeled in separate segments of the data set, resulting in prediction equations for: (i) no preservatives, before F-T; (ii) no preservatives, after F-T; (iii) sorbate, before F-T; (iv) sorbate, after F-T; (v) benzoate, before F-T; and (vi) benzoate, after F-T. Statistical analysis revealed a highly significant (P < 0.0001) effect of all four variables, with cider pH being the most important, followed by temperature and time, and finally by preservative concentration. All models predicted 92 to 99% of the responses correctly. To ensure safety, use of the models is most appropriate at a 0.9 probability level, where the percentage of false positives, i.e., falsely predicting a 5-log10-unit reduction, is the lowest (0 to 4.4%). The present study demonstrates the applicability of logistic regression approaches to describing the effectiveness of multiple treatment combinations in pathogen control in cider making. The resulting models can serve as valuable tools in designing safe apple cider processes.

scholarly journals Faktor-faktor yang Memengaruhi Preferensi Nasabah terhadap Produk Rahn: Studi Kasus PT. BPRS Amanah Ummah

Al-Muzara ah ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 1-16
Author(s):  
Lisda Qotrunnada Nabila Putri ◽  
Jaenal Effendi
Keyword(s):  
Logistic Regression ◽  
Public Interest ◽  
Education Level ◽  
Customer Preferences ◽  
Savings And Loan ◽  
Regression Techniques ◽  
Knowledge Promotion

Rahn is financing for the community to borrow money using personal items as collateral. Public interest in rahn is still small, even though rahn knew as savings and loan services for property that is guaranteed by customers. The savings and loan services are paid every month along with the loan installments and do not use the interest system, only determining the nominal value of the rupiah determined by the pawning party. Thus, this study aims to determine the factors that influence customer preferences in choosing rahn products. The total of 120 respondents are taken, with a proportion of 60 as respondents representing rahn product respondents and 60 other respondents. The collected data is processed using logistic regression techniques. The results of the study show the factors that influence customer preferences for rahn products are factors of knowledge, promotion, service, education level, employment, income, expenditure and the number of dependents significantly influence customer decisions in choosing rahn products.

scholarly journals Effects of Diabetes on The Output of Farmer and Its Policy Implications

2020 ◽  
Vol 15 (1) ◽  
pp. 1
Author(s):  
Syed Asif Ali Naqvi ◽  
Bilal Hussain ◽  
Syed Ale Raza Shah ◽  
Muhammad Sohail Amjad Makhdum
Keyword(s):  
Logistic Regression ◽  
Marital Status ◽  
Work Performance ◽  
Negative Influence ◽  
Policy Implications ◽  
Cross Sectional ◽  
Farming Communities ◽  
Regression Techniques ◽  
The Impact ◽  
Working Efficiency

This study investigated the impact of diabetes on work performance of different farming communities from Punjab, Pakistan. This study was based on cross-sectional data. A representative sample of 374 farmers was collected from five selected districts. Three types of respondents were analyzed in the study e.g.,laborer, small and large growers. Poisson and logistic regression techniques were used for the sake of analysis. According to the investigated results for thelabor category, respondents with more age, less qualification, low earning per month (Rupees), and having positive record of family diabetes, would havemore leave per month. In the same way, findings for small farmers revealed that education, family size, family with diabetic records, marital status and availability at farm (hour/day) were significant. In case of third category, study outcome highlighted that age, education, marital status, having positive record offamily diabetes and number of hours spent at farm would be positively correlated with the reduction in working efficiency at farm due to diabetes. It can beconcluded that diabetes have negative influence on the work performance of selected farming groups.

scholarly journals “Male effect” and “temporary weaning” in synchronization of post-partum ovarian activity in Pelibuey ewes

1970 ◽  
Vol 48 (4) ◽  
pp. 734-750
Author(s):  
J.A. Hernández-Marín ◽  
C. Cortez-Romero ◽  
C.A. Herrera-Corredor ◽  
P. Pérez-Hernández ◽  
A. Pro-Martínez ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Post Partum ◽  
Rate Of Return ◽  
Control Group ◽  
Ovarian Activity ◽  
Survival Curves ◽  
Male Effect ◽  
Two Factors ◽  
Lambing Rate

To evaluate the response of the “male effect” and “temporary weaning” on the synchronization of post-partum ovarian activity in Pelibuey ewes, an experiment was carried out using 78 Pelibuey ewes with suckling lambs. The ewes were separated from their offspring for 48 hours and randomly assigned to one of four treatments derived from the arrangement of two factors, “male effect” and “temporary weaning”, each at two levels. Treatments were: T1 (n = 20) control ewes, without “male effect” and without “temporary weaning”); T2 (n = 19) ewes without “male effect” and with “temporary weaning”; T3 (n = 20) ewes with “male effect” and without “temporary weaning”; and T4 (n = 19), ewes with “male effect” and with “temporary weaning”. The response to oestrus, return to oestrus, gestation rate and lambing rate were analysed using logistic regression. The onset of oestrus was analysed using survival curves. No significant differences were found for lambing rate and prolificacy among treatments. “Temporary weaning” (T2) and “male effect” (T3) did not influence the response to oestrus, rate and duration of return to oestrus, or gestation rate and fertility, and was similar to the control group (T1). The interaction of “male effect” with “temporary weaning” (T4) increased the response to oestrus, reduced the rate and duration of return to oestrus, and the gestation rate, but increased fertility. Synchronizing post-partum ovarian activity with “male effect” and “temporary weaning” reduces the onset of oestrus and the rate of return to oestrus, but increases the response to oestrus and fecundity in Pelibuey ewes.Keywords: Biostimulation, progestogens, prolificacy, prostaglandins, suckling

U.S. Statement of Demonstrated Ability Aeromedical Waivers

2019 ◽  
Vol 90 (12) ◽  
pp. 1034-1040
Author(s):  
William D. Mills ◽  
Joshua T. Davis
Keyword(s):  
Logistic Regression ◽  
Odds Ratio ◽  
Visual Fields ◽  
Transportation Safety ◽  
Medical Certification ◽  
Regression Techniques ◽  
National Transportation Safety Board

INTRODUCTION: The Statement of Demonstrated Ability (SODA) is a type of U.S. aeromedical waiver used for disqualifying conditions that are not expected to change. About 21,000 (2%) U.S. pilots possess a SODA waiver.METHODS: We matched all pilot medical exams from the FAA’s medical certification database from 2002 through 2011 to their respective accidents in the National Transportation Safety Board accident database. The association of SODA waivers and SODA conditions with the odds of an accident were explored using logistic regression techniques.RESULTS: For 3rd class flight exams, the presence of a SODA waiver was not associated with the odds of an accident. For the 1st and 2nd class exams, the accident odds ratio (OR = 1.45) was statistically significant. Crop dusting operations accounted for 17 of the 40 accidents where SODAs were present and returned a significant accident OR = 1.68. SODAs were not associated with the odds of accidents during other commercial operations. Six SODA conditions (amputation, internal eye, external eye, visual fields, bone and joint, and miscellaneous) were also found to have elevated ORs but were based on very small accident counts. NTSB investigators and the authors reviewed all accidents and none thought the SODA condition to be contributory.DISCUSSION: SODA waivers were not associated with increased accident odds except for crop dusting operations. Six specific SODA conditions also had elevated odds of an accident, but there was no evidence they contributed to the accidents. Overall, U.S. pilots with SODA waivers appear to have a satisfactory safety record.Mills WD, Davis JT. U.S. Statement of Demonstrated Ability aeromedical waivers. Aerosp Med Hum Perform. 2019; 90(12):1034–1040.

scholarly journals Importance, Causes, and Management Responses to Farm Risks: Evidence From Florida and Alabama

1985 ◽  
Vol 17 (2) ◽  
pp. 105-116 ◽  
Author(s):  
William G. Boggess ◽  
Kwabena A. Anaman ◽  
Gregory D. Hanson
Keyword(s):  
Risk Management ◽  
Logistic Regression ◽  
Management Practices ◽  
Summary Statistics ◽  
Relative Importance ◽  
Risk And Uncertainty ◽  
Chi Square ◽  
Perceptions Of Risk ◽  
Regression Techniques ◽  
Random Survey

AbstractDespite the contention that risk and uncertainty play an important role in agriculture in North Florida and South Alabama, very little is known about producers' perceptions of risk. This paper describes the procedures used and the results obtained from a statistically random survey of farmers' perceptions of the importance of various sources of risk and alternative risk management practices. Initially, farmers were asked to define risk and then to rank various sources of risk and management responses to risk based on the relative importance of each to their operation. Summary statistics, Chi-square analyses, and logistic regression techniques were used to analyze the data.

Evaluation of a state law on opioid-prescribing behaviour and the void affecting codeine-containing antitussive syrup

2020 ◽  
pp. emermed-2019-209008
Author(s):  
Warren M. Perry ◽  
Chris B. Agala ◽  
Erika M. Agala
Keyword(s):  
North Carolina ◽  
Logistic Regression ◽  
Acute Pain ◽  
Opioid Misuse ◽  
Opioid Prescription ◽  
Opioid Medication ◽  
The North ◽  
Prescribing Behaviour ◽  
Regression Techniques ◽  
The Difference

BackgroundGovernment opioid policies—such as the North Carolina Strengthen Opioid Misuse Prevention (STOP) Act—have aided in lowering the days’ supply of opioid prescriptions. However, what effect do these laws have on codeine-containing antitussive syrup? We aimed to assess the effect of the North Carolina STOP Act on ED opioid prescriptions written for >5 days for acute pain/non-pain diagnoses and whether it had an effect on the prescribing of codeine-containing antitussive syrup.MethodsA retrospective study of two emergency departments, with an average annual census of 70 000 and 22 000 patients, from January to August of 2017 and 2018. We applied logistic regression techniques to calculate the odds of an opioid prescription for >5 days. Opioid medication categories were formed to determine relational proportions. Two-tailed z-tests were used to test the difference in proportions.ResultsOur study included 5366 verifiable opioid prescriptions. The percentage of an opioid prescription for >5 days decreased by 3.3% (95% CI −1.8% to −4.7%, p<0.05) after the North Carolina STOP Act (9.8% to 6.5%; 95% CI 5.5% to 7.5%, p<0.05). There was no statistically significant change in the prescribing of codeine syrup for >5 days pre-STOP and post- STOP Act, respectively (91.5% and 90.4%; difference=−1.1%, p=0.83).ConclusionThe North Carolina STOP Act was associated with a reduction in the overall percentage of opioid prescriptions for >5 days for acute pain/non-pain diagnoses. However, there was no statistically significant effect on the prescribing of codeine-containing antitussive syrup.

Stalking Recidivism: A Comparison of Operational Definitions

2020 ◽  
pp. 088626052097585
Author(s):  
Martyna Bendlin ◽  
Lorraine Sheridan ◽  
Andrew Johnson
Keyword(s):  
Logistic Regression ◽  
Predictor Variables ◽  
Prior History ◽  
Survival Curves ◽  
Criminal Offense ◽  
Criminal Charge ◽  
Offender Characteristics ◽  
History Of ◽  
Criminal Charges ◽  
Incident Reports

The criminal offense of stalking is somewhat different to other offenses due to the repetitive, innocuous, and often multifaceted nature of the crime. Given that stalking constitutes a number of different behaviors, such as violence and threats, research on stalking recidivism becomes difficult as recidivism can be defined in a number of ways. This study utilized a dataset of Western Australia Police Force incident reports, comprising a sample of 404 stalking offenders. Survival curves and a binomial logistic regression were used to determine time to recidivism and predictors of recidivism, using four different definitions of recidivism. Predictor variables included age of the offender, prior history of criminal charges, and offender ethnicity. The four definitions ranged from narrow (a new stalking charge) to broad (any new criminal charge). The results of the study show that stalkers reoffend quickly, however our understanding of how fast and which offender characteristics predict recidivism, is dependent on how we define recidivism. This highlights the importance of considering how stalking recidivism is defined in future works and may explain current differences in stalking recidivism findings.

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