45 research outputs found

    The utility of complex soil reflectance image properties for soil mapping

    Get PDF
    This investigation is concerned with the application of complex quantitative analysis to remotely sensed data for mapping soils. The major aim of this thesis is to examine, by means of illustrative examples, the utility of complex image metrics in the detection, differentiation, and partitioning of satellite images of soil landscapes. Satellite images have been widely used for soil mapping. In order to realise the maximum potential of satellite imagery, improvements are needed both in visual presentation of such images, and in their automatic classification, in order to reveal the complex properties of soil landscape. A Landsat TM image of the Al-Ahsa area of Saudi Arabia was used in the investigation. It presents an ideal region for remote sensing studies due to the absence of vegetation cover and the existence of different type of landforms in a region of low topography. Three techniques for modelling complex elements of images were used and evaluated; Fast Fourier Transform (FFT), Artificial Neural Network Analysis (ANN), Fractal and Multifractal Analysis. The FFT technique developed in this thesis isolates spatial frequency components in specific wavebands. The inverse FFT images are enhanced to (i) display optimised zoning of the image, and (ii) to display specific features. This technique partitions images into major zones that are different zones from the standard soil maps. The ANN technique developed is a non-linear measure of image texture. It shows difference within an image. The texture model is trained on areas selected on the basis of the existing soil map. Substitution analysis of training areas allows an assessment of image zones and boundaries. The texture image is displayed by linear contrast stretch. Zonation does not correspond with published maps or with FFT zonation. The fractal method is based on the local fractal dimension that is used as a texture measure based on a moving pre-set size filter over the entire image. The resulting images do not give zones but shows clear patterns of complexity such as spatial transitions. It is possible to derive areas of similar patterns of transition in complexity. There are implications of these results for soil mapping at the theoretical and practical levels. The implications of the theoretical level are about the existences of soil units defined following the classical approach. In the practical level, the classical approach would be abandoned. There is at present nowhere near the same support of the ideas to complement the traditional mapping approach and raise awareness that soils are inherently complex. The study has important implications for classical theory and practice of soil mapping

    The Epidemiology and Outcome of Biliary Atresia: Saudi Arabian National Study (2000–2018)

    Get PDF
    BackgroundThe epidemiology and outcomes of biliary atresia (BA) have been well-documented in national cohorts from two main ethnicities, namely, the Asian Orientals and Caucasians, with incidence ranging from 1 in 5,000 to 1 in 9,000 live births in East Asia and 1 in 15,000 to 19,000 live births in Europe and North America.ObjectiveWe report the first nationwide BA study outside North America, Europe, and East Asia to describe the epidemiology and outcomes of BA in Saudi Arabia.MethodsA national database of BA cases diagnosed between 2000 and 2018 was analyzed. We assessed clearance of jaundice (bilirubin <20 μmol/L) in all cases that underwent Kasai portoenterostomy (KPE). We then estimated survival using the Kaplan–Meier method with endpoints of liver transplantation (LT), death, or survival with native liver (SNL).ResultsBA was diagnosed in 204 infants (106 females; 10% pre-term). The incidence of BA was 1 in 44,365, or 2.254 in 100,000 live births (range, 0.5–4 in 100,000). Polysplenia was diagnosed in 22 cases (11%). The median age at referral was 65 days. A total of 146 children (71.5%) underwent KPE at a median age of 70 days. Clearance of jaundice was achieved in 66 of the 146 (45%) infants. The 10-year SNL after KPE was 25.5%, and the overall 10-year estimated survival was 72.5%. The Kaplan–Meier survival curves for patients undergoing KPE at the age of <60, 61–90, and >90 days showed a SNL rate at 51.6, 33, and 12.5%, respectively, at 5 years (P < 0.001). The 2-, 5-, and 10-year post-LT survival rates were 92.5, 90.6, and 90%, respectively. Undergoing an initial KPE did not impact negatively on the overall LT survival rate when compared to BA cases that underwent primary LT (P = 0.88).ConclusionThe incidence rate of BA in Saudi Arabia is lower than the incidence reported elsewhere. Late referral of BA cases remains a problem in Saudi Arabia; as a result, the SNL rate was lower than reported by other national registries. Hence, national policies devoted to timely referral and earlier age at KPE are needed

    Boron removal from produce water through adsorption

    Get PDF
    Boron (B) is essential for the development and functioning of organisms, involving their growth, health, and development of plants, animals, and humans. Nevertheless, the increasing use of boron in various applications has led to environmental problems and health issues. Several separation technologies have been employed to remove boron, and adsorption is one such technology that utilizes adsorbents to address solutions containing extremely low levels of boron. This finding investigates the residual boron from a synthesized solution through adsorption, using CRB05 as the adsorbent. The impact of adsorbent dosage, contact time, boron concentration, and pH on residual boron was examined. The findings indicate that the pH plays a substantial role impact on the residual boron efficiency from all adsorbents. The highest residual of boron was achieved at pH 4.5, adsorbent dosage 1125 mg/L, time 255 minutes, and concentration 1150 mg/L with 98% removal. Adsorption of boron using CRB05 proved to be an effective method for recovering boron from the synthesis solution. The findings of this study enhance our comprehension of the adsorption behavior of CRB05 and provide insights into the optimal operating conditions for efficient boron removal

    Ovarian germ cell tumors with rhabdomyosarcomatous components and later development of growing teratoma syndrome: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>Development of a sarcomatous component in a germ cell tumor is an uncommon phenomenon. Most cases reported have a grim prognosis. Growing teratoma syndrome is also an uncommon phenomenon and occurs in approximately 2% to 7% of non seminomatous germ cell tumors and should be treated surgically.</p> <p>Case presentation</p> <p>We report the case of a 12-year-old Asian girl with an ovarian mixed germ cell tumor containing a rhabdomyosarcomatous component. She was treated with a germ cell tumor chemotherapy regimen and rhabdomyosarcoma-specific chemotherapy. Towards the end of her treatment, she developed a retroperitoneal mass that was increasing in size. It was completely resected, revealing a mature teratoma, consistent with growing teratoma syndrome. She is still in complete remission approximately three years after presentation.</p> <p>Conclusion</p> <p>The presence of rhabdomyosarcoma in a germ cell tumor should be treated by a combined chemotherapy regimen (for germ cell tumor and rhabdomyosarcoma). In addition, development of a mass during or after therapy with normal serum markers should raise the possibility of growing teratoma syndrome that should be treated surgically.</p

    Clinical, biochemical, cellular and molecular characterization of mitochondrial DNA depletion syndrome due to novel mutations in the MPV17 gene

    Get PDF
    Mitochondrial DNA (mtDNA) depletion syndromes (MDS) are severe autosomal recessive disorders associated with decreased mtDNA copy number in clinically affected tissues. The hepatocerebral form (mtDNA depletion in liver and brain) has been associated with mutations in the POLG, PEO1 (Twinkle), DGUOK and MPV17 genes, the latter encoding a mitochondrial inner membrane protein of unknown function. The aims of this study were to clarify further the clinical, biochemical, cellular and molecular genetic features associated with MDS due to MPV17 gene mutations. We identified 12 pathogenic mutations in the MPV17 gene, of which 11 are novel, in 17 patients from 12 families. All patients manifested liver disease. Poor feeding, hypoglycaemia, raised serum lactate, hypotonia and faltering growth were common presenting features. mtDNA depletion in liver was demonstrated in all seven cases where liver tissue was available. Mosaic mtDNA depletion was found in primary fibroblasts by PicoGreen staining. These results confirm that MPV17 mutations are an important cause of hepatocerebral mtDNA depletion syndrome, and provide the first demonstration of mosaic mtDNA depletion in human MPV17 mutant fibroblast cultures. We found that a severe clinical phenotype was associated with profound tissue-specific mtDNA depletion in liver, and, in some cases, mosaic mtDNA depletion in fibroblasts

    Therapeutic applications of octreotide in pediatric patients

    No full text
    Background/Aim: We report our experience with the use of octreotide as primary or adjunctive therapy in children with various gastrointestinal disorders. Patients and Methods: A pharmacy database identified patients who received octreotide for gastrointestinal diseases. Indications for octreotide use, dosing, effectiveness, and adverse events were evaluated by chart review. Results: A total of 21 patients (12 males), aged 1 month to 13 years, were evaluated. Eleven received octreotide for massive gastrointestinal bleeding caused by portal hypertension-induced lesions (n=7), typhlitis (1), Meckel′s diverticulum (1), and indefinite source (2). Blood transfusion requirements were reduced from 23±9 mL/kg (mean±SD) to 8±15 mL/kg (P<0.01). Four patients with pancreatic pseudocyst and/or ascites received octreotide over 14.0±5.7 days in 2 patients. In 3 children, pancreatic pseudocyst resolved in 12±2 days and pancreatic ascites resolved in 7 days in 2. Three patients with chylothorax received octreotide for 14±7 days with complete resolution in each. Two infants with chronic diarrhea received octreotide over 11±4.2 months. Stool output decreased from 85±21 mL/kg/day to 28±18 mL/kg/day, 3 months after initiation of octreotide. The child with dumping syndrome responded to octreotide in a week. Adverse events developed in 4 patients: Q-T interval prolongation and ventricular fibrillation, hyperglycemia, growth hormone deficiency, and hypertension. Conclusion: Octreotide provides a valuable addition to the therapeutic armamentum of the pediatric gastroenterologist for a wide variety of disorders. Serious adverse events may occur and patients must be closely monitored

    Herpes Simplex Ulcerative Esophagitis in Healthy Children

    No full text
    Herpes simplex virus is a common cause of ulcerative esophagitis in the immunocompromised or debilitated host. Despite a high prevalence of primary and recurrent Herpes simplex virus infection in the general population, Herpes simplex virus esophagitis (HSVE) appears to be rare in the immunocompetent host. We report three cases of endoscopically-diagnosed HSVE in apparently immunocompetent children; the presentation was characterized by acute onset of fever, odynophagia, and dysphagia. In two cases, the diagnosis was confirmed histologically by identification of herpes viral inclusions and culture of the virus in the presence of inflammation. The third case was considered to have probable HSVE based on the presence of typical cold sore on his lip, typical endoscopic finding, histopathological evidence of inflammation in esophageal biopsies and positive serologic evidence of acute Herpes simplex virus infection. Two cases received an intravenous course of acyclovir and one had self-limited recovery. All three cases had normal immunological workup and excellent health on long-term follow-up

    Eosinophilic Esophagitis in a Developing Country: Is It Different from Developed Countries?

    Get PDF
    Background and Objective. Despite the extensive reporting of eosinophilic esophagitis (EoE) from industrialized developed countries, reports from developing countries are rare. The aim of our study was to determine the epidemiological, clinical, and endoscopic features of EoE and response to therapy in children and adults from a developing country, Saudi Arabia. Methods. We identified patients diagnosed with EoE in our center from 2004 to 2011. EoE was defined as esophageal mucosal infiltration with a peak eosinophil count ≥15 eosinophils/high-powered field. Results. Forty-five patients were diagnosed with EoE (37 children and 8 adults; 36 males; median age 10.5 years, range from 1–37 years). Feeding difficulty, vomiting/regurgitation, and failure to thrive predominated in young children, whereas dysphagia and food impactions predominated in older children and adults. Allergy testing revealed food sensitization in 12 of 15 patients (80%); 3 responded to elemental formula, while 8 failed to respond to dietary manipulation after the allergy testing. Thirty-nine patients achieved remission by swallowed inhaled fluticasone. The majority of patients experienced a recurrence of symptoms upon the discontinuation of fluticasone. Conclusion. Our data indicate that EoE is increasingly recognized in Saudi Arabia and show many similarities to data from North America and Europe
    corecore