Severity Levels (severity + level)

Distribution by Scientific Domains


Selected Abstracts


Clinical efficacy of Kampo medicine (Japanese traditional herbal medicine) in the treatment of primary dysmenorrhea

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 5 2008
Atsuko Oya
Abstract Objective:, We intended to evaluate the clinical efficacy of Kampo medicine, a Japanese traditional herbal medicine, for primary dysmenorrhea which was prescribed according to the Kampo diagnosis, with classification of its severity. Method:, A retrospective evaluation of Kampo treatment in 176 subjects with dysmenorrhea during the previous 12 years was performed. In order to minimize the subjective discretion of the severity of symptoms, classification of the severity level of abdominal pain during menstruation was applied by considering the requirement for non-steroidal anti-inflammatory drugs (NSAIDs) and disturbance of daily activities. The following severity levels were used: no abdominal pain (level 0), abdominal pain with no requirement of NSAIDs (level 1), abdominal pain with no daily activity disturbances with use of NSAIDs (level 2), and painful menstruation which required absenteeism even with use of NSAIDs (level 3). Results:, Severity levels before and after Kampo treatment were defined in 108 subjects. Distribution of the severity levels in 108 subjects was significantly changed by Kampo treatment; the numbers of cases in levels 0, 1, 2, and 3 changed from 0 (0%), 0 (0%), 47 (43.5%), and 61 (56.5%) to 5 (4.6%), 42 (38.9%), 51 (47.2%), and 10 (9.3%), respectively. (P < 0.0001) There were 25 kinds of Kampo formulae prescribed in effective cases. Conclusion:, Kampo medicine prescribed according to Kampo diagnosis reduced the severity of primary dysmenorrhea and is therefore suggested to be beneficial in improving quality of life. [source]


Investigating Driver Injury Severity in Traffic Accidents Using Fuzzy ARTMAP

COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 6 2002
Hassan T. Abdelwahab
This paper applies fuzzy adaptive resonance theory MAP (fuzzy ARTMAP) neural networks to analyze and predict injury severity for drivers involved in traffic accidents. The paper presents a modified version of fuzzy ARTMAP in which the training patterns are ordered using the K,means algorithm before being presented to the neural network. The paper presents three applications of fuzzy ARTMAP for analyzing driver injury severity for drivers involved in accidents on highways, signalized intersections, and toll plazas. The analysis is based on central Florida's traffic accident database. Results showed that the ordered fuzzy ARTMAP proved to reduce the network size and improved the performance. To facilitate the application of fuzzy ARTMAP, a series of simulation experiments to extract knowledge from the models were suggested. Results of the fuzzy ARTMAP neural network showed that female drivers experience higher severity levels than male drivers. Vehicle speed at the time of an accident increases the likelihood of high injury severity. Wearing a seat belt decreases the chance of having severe injuries. Drivers in passenger cars are more likely to experience a higher injury severity level than those in vans or pickup trucks. Point of impact, area type, driving under the influence, and driver age were also among the factors that influence the severity level. [source]


Clinical and Economic Factors Associated with Ambulance Use to the Emergency Department

ACADEMIC EMERGENCY MEDICINE, Issue 8 2006
Jennifer Prah Ruger PhD
Background: Concern about ambulance diversion and emergency department (ED) overcrowding has increased scrutiny of ambulance use. Knowledge is limited, however, about clinical and economic factors associated with ambulance use compared to other arrival methods. Objectives: To compare clinical and economic factors associated with different arrival methods at a large, urban, academic hospital ED. Methods: This was a retrospective, cross-sectional study of all patients seen during 2001 (N= 80,209) at an urban academic hospital ED. Data were obtained from hospital clinical and financial records. Outcomes included acuity and severity level, primary complaint, medical diagnosis, disposition, payment, length of stay, costs, and mode of arrival (bus, car, air-medical transport, walk-in, or ambulance). Multivariate logistic regression identified independent factors associated with ambulance use. Results: In multivariate analysis, factors associated with ambulance use included: triage acuity A (resuscitation) (adjusted odds ratio [OR], 51.3; 95% confidence interval [CI] = 33.1 to 79.6) or B (emergent) (OR, 9.2; 95% CI = 6.1 to 13.7), Diagnosis Related Group severity level 4 (most severe) (OR, 1.4; 95% CI = 1.2 to 1.8), died (OR, 3.8; 95% CI = 1.5 to 9.0), hospital intensive care unit/operating room admission (OR, 1.9; 95% CI = 1.6 to 2.1), motor vehicle crash (OR, 7.1; 95% CI = 6.4 to 7.9), gunshot/stab wound (OR, 2.1; 95% CI = 1.5 to 2.8), fell 0,10 ft (OR, 2.0; 95% CI = 1.8 to 2.3). Medicaid Traditional (OR, 2.0; 95% CI = 1.4 to 2.4), Medicare Traditional (OR, 1.8; 95% CI = 1.7 to 2.1), arrived weekday midnight,8 AM (OR, 2.0; 95% CI = 1.8 to 2.1), and age ,65 years (OR, 1.3; 95% CI = 1.2 to 1.5). Conclusions: Ambulance use was related to severity of injury or illness, age, arrival time, and payer status. Patients arriving by ambulance were more likely to be acutely sick and severely injured and had longer ED length of stay and higher average costs, but they were less likely to have private managed care or to leave the ED against medical advice, compared to patients arriving by independent means. [source]


Clinical efficacy of Kampo medicine (Japanese traditional herbal medicine) in the treatment of primary dysmenorrhea

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 5 2008
Atsuko Oya
Abstract Objective:, We intended to evaluate the clinical efficacy of Kampo medicine, a Japanese traditional herbal medicine, for primary dysmenorrhea which was prescribed according to the Kampo diagnosis, with classification of its severity. Method:, A retrospective evaluation of Kampo treatment in 176 subjects with dysmenorrhea during the previous 12 years was performed. In order to minimize the subjective discretion of the severity of symptoms, classification of the severity level of abdominal pain during menstruation was applied by considering the requirement for non-steroidal anti-inflammatory drugs (NSAIDs) and disturbance of daily activities. The following severity levels were used: no abdominal pain (level 0), abdominal pain with no requirement of NSAIDs (level 1), abdominal pain with no daily activity disturbances with use of NSAIDs (level 2), and painful menstruation which required absenteeism even with use of NSAIDs (level 3). Results:, Severity levels before and after Kampo treatment were defined in 108 subjects. Distribution of the severity levels in 108 subjects was significantly changed by Kampo treatment; the numbers of cases in levels 0, 1, 2, and 3 changed from 0 (0%), 0 (0%), 47 (43.5%), and 61 (56.5%) to 5 (4.6%), 42 (38.9%), 51 (47.2%), and 10 (9.3%), respectively. (P < 0.0001) There were 25 kinds of Kampo formulae prescribed in effective cases. Conclusion:, Kampo medicine prescribed according to Kampo diagnosis reduced the severity of primary dysmenorrhea and is therefore suggested to be beneficial in improving quality of life. [source]


Corticosteroids for acute chest syndrome in children with sickle cell disease: Variation in use and association with length of stay and readmission,

AMERICAN JOURNAL OF HEMATOLOGY, Issue 1 2010
Amy Sobota
Acute chest syndrome (ACS) causes significant morbidity and mortality in sickle cell disease. The role of corticosteroids is unclear. The objectives of our study were to examine the variation between hospitals in their use of corticosteroids for ACS, describe characteristics associated with corticosteroids, and investigate the association between corticosteroids, length of stay, and readmission. We performed a retrospective examination of 5,247 hospitalizations for ACS between January 1, 2004, and June 30, 2008, at 32 hospitals in the Pediatric Health Information System database. We used multivariate regression to examine the variability in the use of corticosteroids adjusting for hospital case mix, identify factors associated with corticosteroid use, and evaluate the association of corticosteroids with length of stay and 3-day readmission rates controlling for propensity score. Corticosteroid use varied greatly by hospital (10,86% among all patients, 18,92% in patients with asthma). Treatment with corticosteroids was associated with comorbid asthma (OR 3.9, 95% CI: 3.2,4.8), inhaled steroids (OR 1.4, 95% CI: 1.1,1.7), bronchodilators (OR 3.2, 95% CI: 2.5,4.2), nitric oxide (OR 2.4, 95% CI: 1.2,5.0), oxygen (OR 2.3, 95% CI: 1.8,2.9), ICU (OR 1.7, 95% CI: 1.3,2.3), ventilation (OR 2.0, 95% CI: 1.4,2.8), APR-DRG severity level (OR 1.4, 95% CI: 1.2,1.6), and discharge year (OR 0.86, 95% CI: 0.80,0.92). Corticosteroids were associated with an increased length of stay (25%, 95% CI: 14,38%) and a higher 3-day readmission rate (OR 2.3, 95% CI: 1.6,3.4), adjusted for confounding. Hospitals vary greatly in the use of corticosteroids for ACS, even in patients with asthma. Clear evidence of the efficacy and toxicity of corticosteroid treatment in ACS may reduce variation in care. Am. J. Hematol. 2010. 2009 Wiley-Liss, Inc. [source]


Effect of Nasal Surgery on Sleep-Related Breathing Disorders

THE LARYNGOSCOPE, Issue 1 2002
Thomas Verse MD
Abstract Objective/Hypothesis Single cases of patients who have experienced obstructive sleep apnea (OSA) and who recovered completely after nasal surgery have been described in various studies. The purpose of this study was to evaluate the efficacy of only nasal surgery 1) in a group of patients with obstructive sleep apnea and 2) in simple snorers. Study Design A prospective, controlled study with 26 adult patients who underwent nasal surgery as single treatment of their sleep-related breathing disorders. The cases were evaluated based on the severity level of their preoperative Apnea Hypopnea Index (AHI). Material and Methods Between August 1996 and July 2000, 26 patients who snored and had impaired nasal breathing underwent attended polysomnography in the sleep laboratory as single treatment nasal surgery was performed. Postoperative polysomnographic findings and complications were reviewed. Results Nineteen of 26 patients (73.1%) were diagnosed as having OSA. Seven patients were simple snorers with an AHI below 10. The surgical response rates, defined as greater than or equal to 50% reduction in the postoperative AHI and a postoperative AHI of less than 20, was 15.8% in the apneics. For the whole group, the AHI decreased postoperatively from 31.6 to 28.9. However, daytime sleepiness improved significantly and arousals decreased significantly in both apneics and simple snorers after nasal surgery. Conclusions We conclude that nasal surgery has a limited efficacy in the treatment of adult patients with sleep apnea. Nevertheless, nasal surgery significantly improves sleep quality and daytime sleepiness independent of the severity of obstructive sleep-related breathing disorders. [source]


EFFECTS OF A CHILD'S DISABILITY ON AFFECTED FEMALE'S LABOUR SUPPLY IN AUSTRALIA

AUSTRALIAN ECONOMIC PAPERS, Issue 3 2010
ZENG-HUA LU
Australia has experienced a growing rate of child disability, with the rate of 3.7 per cent in 1998 increasing to 4.3 per cent in 2003 for children aged under four years and from 9.5 per cent to 10 per cent for children aged five to 14 years in the same period. However, surprisingly no study has examined the economic effects of child disability in the Australian context. This paper attempts to quantify the link between a child's disability and the work behaviour of the female in the affected family. Our findings provide empirical justifications for the current policy linking the severity level of child disability to the assessment of eligibility for Carer Payment (Child). We also found that child disability has different impacts on the labour market activities of married women and non-married women. It appears that child disability imposes a greater hardship on non-married women than on married women in terms of work choice decision. Once non-married women manage to enter the labour force, they may have to stay on to work as usual even if they have a disabled child, because they may not have other family members to turn to for help as married women do. [source]


Investigating Driver Injury Severity in Traffic Accidents Using Fuzzy ARTMAP

COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 6 2002
Hassan T. Abdelwahab
This paper applies fuzzy adaptive resonance theory MAP (fuzzy ARTMAP) neural networks to analyze and predict injury severity for drivers involved in traffic accidents. The paper presents a modified version of fuzzy ARTMAP in which the training patterns are ordered using the K,means algorithm before being presented to the neural network. The paper presents three applications of fuzzy ARTMAP for analyzing driver injury severity for drivers involved in accidents on highways, signalized intersections, and toll plazas. The analysis is based on central Florida's traffic accident database. Results showed that the ordered fuzzy ARTMAP proved to reduce the network size and improved the performance. To facilitate the application of fuzzy ARTMAP, a series of simulation experiments to extract knowledge from the models were suggested. Results of the fuzzy ARTMAP neural network showed that female drivers experience higher severity levels than male drivers. Vehicle speed at the time of an accident increases the likelihood of high injury severity. Wearing a seat belt decreases the chance of having severe injuries. Drivers in passenger cars are more likely to experience a higher injury severity level than those in vans or pickup trucks. Point of impact, area type, driving under the influence, and driver age were also among the factors that influence the severity level. [source]


Randomized controlled trial of physiotherapy in 56 children with cerebral palsy followed for 18 months

DEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 1 2001
E Bower PhD MCSP Senior Research Fellow
This study aimed to determine whether motor function and performance is better enhanced by intensive physiotherapy or collaborative goal-setting in children with cerebral palsy (CP). Participants were a convenience sample of 56 children with bilateral CP classified at level III or below on the Gross Motor Function Classification System (GMFCS), aged between 3 and 12 years. A 2 2 factorial design was used to compare the effects of routine amounts of physiotherapy with intensive amounts, and to compare the use of generalized aims set by the child's physiotherapist with the use of specific, measurable goals negotiated by the child's physiotherapist with each child, carer, and teacher. Following the six-month treatment period there was a further six-month period of observation. Changes in motor function and performance were assessed by a masked assessor using the Gross Motor Function Measure (GMFM) and the Gross Motor Performance Measure (GMPM) at three-month intervals. There was no statistically significant difference in the scores achieved between intensive and routine amounts of therapy or between aim-directed and goal-directed therapy in either function or performance. Inclusion of additional covariates of age and severity levels showed a trend towards a statistically significant difference in children receiving intensive therapy during the treatment period. This advantage declined over the subsequent six months during which therapy had reverted to its usual amount. Differences in goal-setting procedures did not produce any detectable effect on the acquisition of gross motor function or performance. [source]


Medical Error Identification, Disclosure, and Reporting: Do Emergency Medicine Provider Groups Differ?

ACADEMIC EMERGENCY MEDICINE, Issue 4 2006
Cherri Hobgood MD
Abstract Objectives: To determine if the three types of emergency medicine providers,physicians, nurses, and out-of-hospital providers (emergency medical technicians [EMTs]),differ in their identification, disclosure, and reporting of medical error. Methods: A convenience sample of providers in an academic emergency department evaluated ten case vignettes that represented two error types (medication and cognitive) and three severity levels. For each vignette, providers were asked the following: 1) Is this an error? 2) Would you tell the patient? 3) Would you report this to a hospital committee? To assess differences in identification, disclosure, and reporting by provider type, error type, and error severity, the authors constructed three-way tables with the nonparametric Somers' D clustered on participant. To assess the contribution of disclosure instruction and environmental variables, fixed-effects regression stratified by provider type was used. Results: Of the 116 providers who were eligible, 103 (40 physicians, 26 nurses, and 35 EMTs) had complete data. Physicians were more likely to classify an event as an error (78%) than nurses (71%; p = 0.04) or EMTs (68%; p < 0.01). Nurses were less likely to disclose an error to the patient (59%) than physicians (71%; p = 0.04). Physicians were the least likely to report the error (54%) compared with nurses (68%; p = 0.02) or EMTs (78%; p < 0.01). For all provider and error types, identification, disclosure, and reporting increased with increasing severity. Conclusions: Improving patient safety hinges on the ability of health care providers to accurately identify, disclose, and report medical errors. Interventions must account for differences in error identification, disclosure, and reporting by provider type. [source]


Do biotic interactions shape both sides of the humped-back model of species richness in plant communities?

ECOLOGY LETTERS, Issue 7 2006
Richard Michalet
Abstract A humped-back relationship between species richness and community biomass has frequently been observed in plant communities, at both local and regional scales, although often improperly called a productivity,diversity relationship. Explanations for this relationship have emphasized the role of competitive exclusion, probably because at the time when the relationship was first examined, competition was considered to be the significant biotic filter structuring plant communities. However, over the last 15 years there has been a renewed interest in facilitation and this research has shown a clear link between the role of facilitation in structuring communities and both community biomass and the severity of the environment. Although facilitation may enlarge the realized niche of species and increase community richness in stressful environments, there has only been one previous attempt to revisit the humped-back model of species richness and to include facilitative processes. However, to date, no model has explored whether biotic interactions can potentially shape both sides of the humped-back model for species richness commonly detected in plant communities. Here, we propose a revision of Grime's original model that incorporates a new understanding of the role of facilitative interactions in plant communities. In this revised model, facilitation promotes diversity at medium to high environmental severity levels, by expanding the realized niche of stress-intolerant competitive species into harsh physical conditions. However, when environmental conditions become extremely severe the positive effects of the benefactors wane (as supported by recent research on facilitative interactions in extremely severe environments) and diversity is reduced. Conversely, with decreasing stress along the biomass gradient, facilitation decreases because stress-intolerant species become able to exist away from the canopy of the stress-tolerant species (as proposed by facilitation theory). At the same time competition increases for stress-tolerant species, reducing diversity in the most benign conditions (as proposed by models of competition theory). In this way our inclusion of facilitation into the classic model of plant species diversity and community biomass generates a more powerful and richer predictive framework for understanding the role of plant interactions in changing diversity. We then use our revised model to explain both the observed discrepancies between natural patterns of species richness and community biomass and the results of experimental studies of the impact of biodiversity on the productivity of herbaceous communities. It is clear that explicit consideration of concurrent changes in stress-tolerant and competitive species enhances our capacity to explain and interpret patterns in plant community diversity with respect to environmental severity. [source]


Neuroimaging predictors for depressive symptoms in cerebral small vessel disease

INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 10 2010
Jian Hui Fu
Abstract Objective Although cerebral small vessel disease (SVD) is closely associated with late life depression, patients with even severe SVD may have no depressive symptoms. We postulate that concurrent brain atrophy may also involve in the pathogenesis of depressive symptoms in SVD. We aimed to investigate the relevance of brain atrophy in predicting depressive symptoms among patients with severe SVD. Methods We recruited 45 lacunar stroke patients who had diffuse white matter lesion (WML) and varying severity levels of depressive symptoms. We used a quantitative hybrid warping method to determine the volume of 99 brain regions for each patient. We assessed severity of depressive symptoms using the depression score of the hospital anxiety and depression scale (HADS-D). We first performed correlation analysis of each brain variable with the depression score. Significant variables were then entered separately into linear regression analysis to explore predictors of HADS-D, with adjustment of relevant clinical variables. Results The mean age (SD) of the 45 participants was 74.6 (8.3) years. The mean HADS-D score was 3.5, with score ranging from 0 to15. Variables that had a significant correlation coefficient with HADS-D were gender, hypertension, Oxford handicap scale, left inferior frontal gyrus, right subthalamic nucleus, left posterior limb of internal capsule, and right cerebellum. Regression analyses showed that only left inferior frontal gyrus atrophy (,,=,,0.354, p,=,0.017) predicted HADS-D score after adjusted for other relevant clinical variables. Conclusion Concurrent atrophy of left inferior frontal gyrus is associated with depressive symptoms in elderly patients with severe SVD. Copyright 2009 John Wiley & Sons, Ltd. [source]


Clinical efficacy of Kampo medicine (Japanese traditional herbal medicine) in the treatment of primary dysmenorrhea

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 5 2008
Atsuko Oya
Abstract Objective:, We intended to evaluate the clinical efficacy of Kampo medicine, a Japanese traditional herbal medicine, for primary dysmenorrhea which was prescribed according to the Kampo diagnosis, with classification of its severity. Method:, A retrospective evaluation of Kampo treatment in 176 subjects with dysmenorrhea during the previous 12 years was performed. In order to minimize the subjective discretion of the severity of symptoms, classification of the severity level of abdominal pain during menstruation was applied by considering the requirement for non-steroidal anti-inflammatory drugs (NSAIDs) and disturbance of daily activities. The following severity levels were used: no abdominal pain (level 0), abdominal pain with no requirement of NSAIDs (level 1), abdominal pain with no daily activity disturbances with use of NSAIDs (level 2), and painful menstruation which required absenteeism even with use of NSAIDs (level 3). Results:, Severity levels before and after Kampo treatment were defined in 108 subjects. Distribution of the severity levels in 108 subjects was significantly changed by Kampo treatment; the numbers of cases in levels 0, 1, 2, and 3 changed from 0 (0%), 0 (0%), 47 (43.5%), and 61 (56.5%) to 5 (4.6%), 42 (38.9%), 51 (47.2%), and 10 (9.3%), respectively. (P < 0.0001) There were 25 kinds of Kampo formulae prescribed in effective cases. Conclusion:, Kampo medicine prescribed according to Kampo diagnosis reduced the severity of primary dysmenorrhea and is therefore suggested to be beneficial in improving quality of life. [source]


Elaboration and Validation of a Diagrammatic Scale for Epidemiological Studies of Cercospora Leaf Spot of Castor Bean

JOURNAL OF PHYTOPATHOLOGY, Issue 6 2010
Wellington Freire Dos Santos
Abstract The castor bean cercospora leaf spot (Cercospora ricinella Sacc. & Berl.) is a common disease in castor bean crop (Ricinus communis L.), causing defoliation and losses. In spite of this, the evaluation of disease severity is an important decision support for adoption of strategies and tactics for disease control. Therefore the objective of this work was to elaborate and to validate a diagrammatic to evaluate cercospora leaf spot severity in the castor bean. The scale was developed based on six treatments with different irrigation depths plus the control treatment without irrigation. Based on disease incidence analysis, it was possible to select different severity levels per treatment, which were used to define the percentage intervals of foliar diseased area of the diagrammatic scale. In view of the inexistence of standardized methods for the quantification of cercospora leaf spot in the field, the levels of 0%, 0.1 to 1%, 1.1 to 10%, 10.1 to 20% and 20.1 to 45% of lesioned foliar area were established, pointing out the observation that in the interval of 20 to 45% leaf fall started to occur. The scale was tested according its accuracy, precision and reproducibility. For that, 40 leaves with different disease severity levels were appraised by 10 users, without and with the scale, with an interval of seven days between evaluations of the same users. The appraisers obtained better results under utilization of the scale. The scale proposed in this work presented appropriate applicability for cercospora leaf spot evaluation in castor bean. Higher disease intensity was observed in the control and in treatments with higher irrigation depth and lower irrigation frequency. [source]


ICF-CY: A Universal Tool for Documentation of Disability

JOURNAL OF POLICY AND PRACTICE IN INTELLECTUAL DISABILITIES, Issue 2 2009
Rune J. Simeonsson
Abstract The International Classification of Functioning, Disability and Health,ICF (ICF-CY) conceptual framework offers a new paradigm and taxonomy of human functioning disability, which can be used to guide holistic and interdisciplinary approaches to assessment and intervention. In settings serving children, youth, or adults with disabilities, the ICF-CY can provide comprehensive documentation of its involvement in special education and rehabilitation. Implementation of the ICF-CY in early intervention, special education, and habilitation settings should build on the adoption of the dimensional framework for practice and corresponding applications in assessment and intervention practices. An important priority in such applications is the identification and development of instruments and assessment tools that can provide evidence for assigning severity levels to ICF-CY codes. [source]


PTSD symptoms, substance use, and vipassana meditation among incarcerated individuals

JOURNAL OF TRAUMATIC STRESS, Issue 3 2007
T. L. Simpson
The present study evaluated whether Posttraumatic Stress Disorder (PTSD) symptom severity was associated with participation and treatment outcomes comparing a Vipassana meditation course to treatment as usual in an incarcerated sample. This study utilizes secondary data. The original study demonstrated that Vipassana meditation is associated with reductions in substance use. The present study found that PTSD symptom severity did not differ significantly between those who did and did not volunteer to take the course. Participation in the Vipassana course was associated with significantly greater reductions in substance use than treatment as usual, regardless of PTSD symptom severity levels. These results suggest that Vipassana meditation is worthy of further study for those with comorbid PTSD and substance use problems. [source]


Comparison of three diagrammatic keys for the quantification of late blight in tomato leaves

PLANT PATHOLOGY, Issue 6 2009
F. M. Corra
Three diagrammatic grading keys were designed for the assessment of the severity of late blight (caused by Phytophthora infestans) in tomato leaves. Simplified and broad keys considered, respectively, six (3, 12, 22, 40, 60 and 77%) and eight (3, 6, 12, 22, 40, 60, 77 and 90%) levels of disease severity, whilst a modified key based on a previous proposal for potato late blight considered six levels (1, 5, 10, 16, 32 and 50%). The keys were validated by 24 evaluators who assessed digital images of tomato leaves exhibiting different areas with lesions. Evaluator errors were compared using a mixed model in which evaluators were considered as random effects and the keys and evaluations as fixed effects. The accuracy and precision of the evaluators were compared by simple linear regression between the estimated and actual values of disease severity. The repeatability of evaluators was assessed using Pearson's correlation coefficient. There was significant (P , 0001) variability amongst the errors made by evaluators, although the precision of each of the three keys was high with a coefficient of determination (R2) of 096, 093 and 083 for the simplified, broad and modified key, respectively. Repeatability of estimations amongst the evaluators was adequate (correlation coefficients of 091, 091 and 090 for the three keys, respectively). The simplified and broad keys resulted in higher precision and accuracy for the estimation of severity than did the modified key. Since the simplified key considers a smaller number of disease severity levels, its use is recommended in the assessment of late blight in tomato leaves. [source]


Relationship between incidence and severity of cashew gummosis in semiarid north-eastern Brazil

PLANT PATHOLOGY, Issue 3 2004
J. E. Cardoso
The incidence,severity relationship for cashew gummosis, caused by Lasiodiplodia theobromae, was studied to determine the feasibility of using disease incidence to estimate indirectly disease severity in order to establish the potential damage caused by this disease in semiarid north-eastern Brazil. Epidemics were monitored in two cashew orchards, from 1995 to 1998 in an experimental field composed of 28 dwarf clones, and from 2000 to 2002 in a commercial orchard of a single clone. The two sites were located 10 km from each other. Logarithmic transformation achieved the best linear adjustment of incidence and severity data as determined by coefficients of determination for place, age and pooled data. A very high correlation between incidence and severity was found in both fields, with different disease pressures, different cashew genotypes, different ages and at several epidemic stages. Thus, the easily assessed gummosis incidence could be used to estimate gummosis severity levels. [source]


Risk-Group-Specific Dose Finding Based on an Average Toxicity Score

BIOMETRICS, Issue 2 2010
B. Nebiyou Bekele
Summary We propose a Bayesian dose-finding design that accounts for two important factors, the severity of toxicity and heterogeneity in patients' susceptibility to toxicity. We consider toxicity outcomes with various levels of severity and define appropriate scores for these severity levels. We then use a multinomial-likelihood function and a Dirichlet prior to model the probabilities of these toxicity scores at each dose, and characterize the overall toxicity using an average toxicity score (ATS) parameter. To address the issue of heterogeneity in patients' susceptibility to toxicity, we categorize patients into different risk groups based on their susceptibility. A Bayesian isotonic transformation is applied to induce an order-restricted posterior inference on the ATS. We demonstrate the performance of the proposed dose-finding design using simulations based on a clinical trial in multiple myeloma. [source]