567 research outputs found

    CONTINUOUS HYDROLOGIC MODELING FOR ANALYZING THE EFFECTS OF DROUGHT ON THE LOWER COLORADO RIVER IN TEXAS

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    A physically based hydrologic model, the HEC-Hydrologic Modeling System (HMS), developed by the U.S. Army Corps of Engineers, has been parameterized using the Soil Moisture Accounting (SMA) algorithm, calibrated, and validated for the Lake Travis and Lake Lyndon B. Johnson (LBJ) contributing basins in central Texas. The basins are divided into a total of 15 sub-basins, and HEC-HMS with the SMA algorithm represents each sub-basin with five water storage layers involving twelve parameters--surface depression storage, canopy interception storage, upper zone soil storage, tension zone soil storage, infiltration rate, and soil percolation rate, along with storage depths, storage coefficients and percolation rates for one shallow and one deep groundwater layer. The first six parameters and the percolation rate for the interflow were estimated objectively using a combination of the National Land Cover Database 2011 (NLCD 2011) and Soil Survey Geographic Database (SSURGO). The next four parameters were estimated based on analysis of historical streamflow records, and the last parameter was determined through model calibration. The parameter analysis shows that the tension zone storage, interflow storage coefficient and the baseflow percolation rate are the most sensitive parameters for this watershed model. Comparison of simulated and observed streamflows showed that the estimated parameters can be used with meteorological data to simulate flows into the Highland Lakes system in central Texas. The results of the statistical analysis indicate that the simulated flows and observed flows are reasonably well correlated. The model performance is rated as good to very good for all the metrics. The PBIAS coefficient is 9.6 and the Nash-Sutcliffe efficiency value is 0.71 for the entire simulation period, 2004-2016. The model performance can potentially be improved through further calibration and by using the hourly climatic input data instead of daily data. xi In future work, the validated HEC-HMS model can be employed with seasonal climate forecasts and under long-range land-use and climate projections. In addition, radar-based precipitation data can be used to represent the climatic variability on a grid-based scale

    Can Advanced Physiological Testing Bridge the Gap Between Chest Pain and Nonobstructive Coronary Atherosclerosis?∗

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    Full-Thickness Rectal Prolapse in children: Sclerotherapy versus Lockhart Mummery Rectopexy

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    Introduction: Rectal prolapse is a relatively common disorder in childhood. In this phenomenon, the whole layers of the rectum protrude throughout the anus. Self-limiting cases of rectal prolapse are more common in children below four years old, and overall prevalence is higher in the first year of life, with a predominance of male children. Formerly, the therapeutic efforts insisted on surgery. Nowadays, noninvasive methods like Sclerotherapy have entered the arena. Materials and Methods: This study aimed to compare the efficacy and postoperative complications of 56 children suffering from full-thickness rectal prolapse retrospectively randomized in two groups of conventional surgery and Sclerotherapy referring to the Mofid children's hospital from 2017 to 2020. The authors have used Lockhart mummery rectopexy and Sclerotherapy methods with hypertonic dextrose 50%. Results: Our results revealed a statistically significant difference in mean hospital stay (P-value <0.0001) and follow-up time (P-value=0.009) in the sclerotherapy group compared to other group, but surgical complications (P-value=0.58) and recurrence rate (P-value= 0.62) were statistically non-significant in both groups. Conclusion: careful selection of patients based on symptoms has a vital role in the success of the chosen method for treating rectal prolapse in children. &nbsp

    A Rare Case of Squamous Cell Carcinoma of the Bladder Presenting as a Metastatic Right Ventricular Mass

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    A 74-year-old woman presented with bilateral lower extremity swelling, worsening dyspnea on exertion, and mild hemoptysis. An echocardiogram at time of admission showed a mass in the right ventricle. The pathology of a sample obtained via transvenous biopsy was consistent with squamous cell carcinoma; no primary source could initially be identified. Severe thrombocytopenia, likely consumptive, precluded surgical intervention, so the patient underwent palliative radiation. Unfortunately, she developed fatal respiratory failure. Upon autopsy, the bladder was found to contain polyps of invasive squamous cell carcinoma, similar in morphology to the tumor mass in the heart. Her lungs contained multiple tumor emboli at different stages, which was likely the final cause of her death. Squamous cell carcinoma metastases to the endocardium are extremely rare and without defined treatment. Surgery can improve prognosis in those with primary tumors that are benign or without metastases. In those with symptomatic metastatic tumors, palliative debulking can done although generally will not improve prognosis. It is currently unknown whether radiation improves survival. In this case, irradiation did destroy a portion of the tumor as the final pathology showed extensive necrosis of the tumor; unfortunately, it did not change her symptoms and did not change the final outcome

    Prevalence and Characteristics of Developmental Dental Anomalies in Iranian Orofacial Cleft Patients

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    Statement of the Problem: Individuals with oral clefts exhibit considerably more dental anomalies than individuals without clefts. These problems could initially be among the symptoms of their disease and/or they may be the side effect of their treatments. Pushback palatoplasty could cause some interference during the development of teeth and result in tooth defects. Purpose: The study was performed to assess the prevalence and characteristics of developmental dental anomalies in orofacial cleft patients who attended Shiraz Orthodontics Research Center-Cleft Lip and Palate Clinic. We managed to compare dental anomaly traits based on gender and cleft side. Materials and Method: Eighty out of 121 cleft patients were included in this cross-sectional study. All the patients used pushback palatoplasty in their palate closure surgeries. Intraoral photographs, panoramic and intraoral radiographs, cone-beam computed tomography (CBCT) and dental and medical histories were examined and recorded by two observers. Data were analyzed using SPSS PC version 20.0. The differences in the side of cleft and dental anomalies were compared using the Mann-Whitney test. Results: The mean age of patients was 14.27 years (SD=5.06). The most frequent cleft type was unilateral cleft lip and palate (50%) followed by bilateral cleft lip and palate (43.75%), cleft palate (2.5%) and cleft lip (1.25%). Male predominance (70%) was observed. 92.5 percent had at least one developmental dental anomaly. The most prevalent anomalies were hypodontia (71.25%) followed by microdontia (30%), root dilacerations (21.25%) and supernumerary teeth (15%). Conclusion: The most prevalent cleft types were unilateral and bilateral cleft lip and palate with male and left side predominance. Hypodontia, microdontia, dilacerations and supernumerary teeth were the most prevalent developmental dental anomalies among Iranian southwestern cleft patients. The surgical technique used to repair their cleft palate may have played a role in developmental dental defects

    Semi-Automatic Reconstruction of Patient-Specific Stented Coronaries based on Data Assimilation and Computer Aided Design

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    Purpose The interplay between geometry and hemodynamics is a significant factor in the development of cardiovascular diseases. This is particularly true for stented coronary arteries. To elucidate this factor, an accurate patient-specific analysis requires the reconstruction of the geometry following the stent deployment for a computational fluid dynamics (CFD) investigation. The image-based reconstruction is troublesome for the different possible positions of the stent struts in the lumen and the coronary wall. However, the accurate inclusion of the stent footprint in the hemodynamic analysis is critical for detecting abnormal stress conditions and flow disturbances, particularly for thick struts like in bioresorbable scaffolds. Here, we present a novel reconstruction methodology that relies on Data Assimilation and Computer Aided Design. Methods The combination of the geometrical model of the undeployed stent and image-based data assimilated by a variational approach allows the highly automated reconstruction of the skeleton of the stent. A novel approach based on computational mechanics defines the map between the intravascular frame of reference (called L-view) and the 3D geometry retrieved from angiographies. Finally, the volumetric expansion of the stent skeleton needs to be self-intersection free for the successive CFD studies; this is obtained by using implicit representations based on the definition of Nef-polyhedra. Results We assessed our approach on a vessel phantom, with less than 10% difference (properly measured) vs. a customized manual (and longer) procedure previously published, yet with a significant higher level of automation and a shorter turnaround time. Computational hemodynamics results were even closer. We tested the approach on two patient-specific cases as well. Conclusions The method presented here has a high level of automation and excellent accuracy performances, so it can be used for larger studies involving patient-specific geometries

    Programa de auditoría ambiental para prevenir los efectos contaminantes generados por los procesos productivos en el Molino San Fernando S.R.L

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    La presente tesis surgió con la iniciativa de identificar en cuales de los procesos productivos del Molino San Fernando S.R.L se genera mayor contaminación con el fin de mejorar la prevención de los efectos contaminantes; para lo cual se utilizaron métodos teóricos como el descriptivo, inductivo- deductivo, analítico-sintético e histórico lógico; y se aplicaron técnicas empíricas como la encuesta y la entrevista a la población objeto de estudio, que estuvo compuesta por auditores externos, funcionarios administrativos y jefe de planta. Con ello se elaboró el programa de auditoría ambiental en el que se establecieron procedimientos para el diagnóstico de la situación ambiental, proceso productivo, riesgos, sustancias y efectos de contaminación los cuales permiten mejorar la prevención de los efectos contaminantes generados por los procesos productivos. Actualmente el Molino San Fernando S.R.L. no aplica medidas de prevención para mitigar los efectos contaminantes generados de sus procesos productivos; por lo que resulta necesario aplicar de manera periódica el programa de auditoría ambiental para determinar la situación actual de la relación que tiene la entidad con el entorno
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