Femtosecond Laser Deposition of Germanium Selenide onto Silicon Platform at Different Substrate Temperatures.

Germanium selenide (GeSe) thin films were fabricated by employing femtosecond pulsed-laser deposition (fs-PLD) on silicon (100) substrates at various substrate temperatures, ranging from 25 °C to 600 °C. The thin films' surface morphology qualities and optical properties were studied by utilising transmission electron microscopy (TEM) and X-ray diffraction (XRD). The X-ray diffraction result signifies that the thin films deposited on the silicon at a substrate temperature below 400 °C were amorphous Ge-Se. In contrast, those grown at 400 °C and above exhibited crystallised peaks of Ge-Se orthorhombic and tetragonal structures. The deposition growth rate of the thin films was also found to decrease substantially with increasing substrate temperature. These results show that the fs-PLD process has great potential for fabricating good quality Ge-Se thin film. This technique could enable the manufacture of modern optoelectronic devices for applications in optical communication, sensing, and ovonic threshold switching for the high-density crossbar memory array.

Two new records of flies causing myiasis from Saudi Arabia with a survey of flies parasitizing goats and sheep in Jazan Region.

Despite the medical, veterinary and forensic relevance of myiasis-causing flies, knowledge of their diversity in Saudi Arabia is limited especially in the southern region. Therefore, a survey of myiasis-causing flies in the Jazan region was carried out using Red Top Fly Catcher traps baited with either decomposing beef liver or a lure composed primarily from fishmeal during the period April 2013-March 2014. Twelve known species were identified and recorded in this study, seven species of them belonging to Calliphoridae (Chrysomya, Lucilia, and Hemipyrella) and five species belonging to Sarcophagidae (Sarcophaga). Two of these species were recorded for the first time for Saudi Arabia, namely Hemipyrella pulchra (Wiedemann, 1830) and Sarcophaga (Liosarcophaga) exuberans Pandellé, 1896. Images of the species recorded are also provided for the first time. The results expand the knowledge of geographical distribution, fauna, and habitat of the myiasis-causing flies in Saudi Arabia. Biological information and world-wide geographical distribution of these species are included together with some taxonomic remarks.

Two new records of flies causing myiasis from Saudi Arabia with a survey of flies parasitizing goats and sheep in Jazan Region

@#Despite the medical, veterinary and forensic relevance of myiasis-causing flies, knowledge of their diversity in Saudi Arabia is limited especially in the southern region. Therefore, a survey of myiasis-causing flies in the Jazan region was carried out using Red Top Fly Catcher traps baited with either decomposing beef liver or a lure composed primarily from fishmeal during the period April 2013-March 2014. Twelve known species were identified and recorded in this study, seven species of them belonging to Calliphoridae (Chrysomya, Lucilia, and Hemipyrella) and five species belonging to Sarcophagidae (Sarcophaga). Two of these species were recorded for the first time for Saudi Arabia, namely Hemipyrella pulchra (Wiedemann, 1830) and Sarcophaga (Liosarcophaga) exuberans Pandellé, 1896. Images of the species recorded are also provided for the first time. The results expand the knowledge of geographical distribution, fauna, and habitat of the myiasis-causing flies in Saudi Arabia. Biological information and world-wide geographical distribution of these species are included together with some taxonomic remarks.

Multilocus sequence typing of Carnobacterium maltaromaticum strains associated with fish disease and dairy products.

AIMS: Carnobacterium maltaromaticum is a lactic acid bacterium of technological interest in the field of dairy ripening and food bioprotection and is generally recognized as safe in the United States. As it is associated with fish infections, the European Food Safety Agency did not include this species in the qualified presumption safety list of micro-organisms. This implies that the risk assessment for the species has to be performed at the strain level. METHODS AND RESULTS: Multilocus sequence typing (MLST) is a tool that (i) potentially allows to discriminate strains isolated from diseased fish from apathogenic strains and (ii) to assess the genetic relatedness between both groups of strains. In this study, we characterized by MLST 21 C. maltaromaticum strains including 16 strains isolated from diseased fish and 5 apathogenic dairy strains isolated from cheese. The resulting population structure was investigated by integrating these new data to the previously published population structure (available at http://pubmlst.org), which represents an overall of 71 strains. CONCLUSIONS: This analysis revealed that none of the strains isolated from diseased fish is assigned to a clonal complex containing cheese isolates, and that 11 strains exhibit singleton genotypes suggesting that the population of diseased fish isolates is not clonal. SIGNIFICANCE AND IMPACT OF THE STUDY: This study thus provides a population structure of C. maltaromaticum that could serve in the future as a reference that could contribute to the risk assessment of C. maltaromaticum strains intended to be used in the food chain.

Spatial distribution modeling of Stegomyia aegypti and Culex tritaeniorhynchus (Diptera: Culicidae) in Al-bahah Province, Kingdom of Saudi Arabia.

Dengue hemorrhagic fever and Rift Valley fever are the most important mosquitoborne diseases in the Kingdom of Saudi Arabia. The characteristic habitat requirements of Stegomyia aegypti and Culex tritaeniorhynchus, the two mosquito vectors will help in the identification of "high risk" areas in their development. Species distribution modelling was assessed by using MaxEnt software combined with geographical information systems (GIS) to predict suitable larval habitats for these two vectors and develop potential risk maps that can be used for their targeted control. Climate and topographical data layers from Worldclim and larval occurrence records were used to model these two vectors. The results showed that suitable habitats of St. aegypti are widely distributed only in the central region and Cx. tritaeniorhynchus were in the central and southwestern parts of Al-Bahah Province. The highest predictive power was shown by topographical variables in St. aegypti modeling and the minor contributions were shown by precipitation and temperature related variables. The maximum contribution was shown by temperature related variables and minor contribution was shown by topographical and precipitation related variables in Cx. tritaeniorhynchus modeling. Linear regression model indicates non significant correlation between TDS/pH and species abundance of these two mosquitoes.

Spatial distribution modeling of Stegomyia aegypti and Culex tritaeniorhynchus (Diptera: Culicidae) in Al-bahah Province, Kingdom of Saudi Arabia

Dengue hemorrhagic fever and Rift Valley fever are the most important mosquitoborne diseases in the Kingdom of Saudi Arabia. The characteristic habitat requirements of Stegomyia aegypti and Culex tritaeniorhynchus, the two mosquito vectors will help in the identification of “high risk” areas in their development. Species distribution modelling was assessed by using MaxEnt software combined with geographical information systems (GIS) to predict suitable larval habitats for these two vectors and develop potential risk maps that can be used for their targeted control. Climate and topographical data layers from Worldclim and larval occurrence records were used to model these two vectors. The results showed that suitable habitats of St. aegypti are widely distributed only in the central region and Cx. tritaeniorhynchus were in the central and southwestern parts of Al-Bahah Province. The highest predictive power was shown by topographical variables in St. aegypti modeling and the minor contributions were shown by precipitation and temperature related variables. The maximum contribution was shown by temperature related variables and minor contribution was shown by topographical and precipitation related variables in Cx. tritaeniorhynchus modeling. Linear regression model indicates non significant correlation between TDS/pH and species abundance of these two mosquitoes.

Breeding habitats characterization of Anopheles mosquito (Diptera: Culicidae) in Najran Province, Saudi Arabia.

An ecological study on mosquito larval breeding habitats was conducted in Najran Region, Saudi Arabia during 2005-2006 to study the breeding habitats determinants for Anopheles mosquito in two ecological types (cities and villages). The increased rate of developmental activities promotes man-made mosquito breeding habitats, which regulate Anopheles mosquito abundance or absence. The linear regression analysis revealed that An. gambiae s.l. abundance or absence is regulated by the presence of natural water habitats, which has the highest rate (79%) in villages. Other ecological, biological and physiochemical predictors for Anopheles mosquito larvae abundance or absence in the two ecological types were discussed.

Distribution and seasonal activity of mosquitoes in al Madinah Al Munwwrah, Saudi Arabia.

In this study, 2654 adults and mosquito larvae, which belong to 18 species and 4 genera, were collected: Aedes (2 spp.), Anopheles (7 spp.), Culex (8 spp.) and Culiseta (1 sp.). They were Aedes caspius, Ae. aegypti, Anopheles. azaniae, An. d'thali, An. multicolor, An. rhodesiensis, An. stephensi, An. Sub-pictus, An. turkhudi, Culex laticinctus, Cx. perexiguus, Cx. pipiens, Cx. quin-quefasciatus, Cx. simpsoni, Cx. theileri, Cx. tritaeniorhynchus, Cx. univittatus and Culiseta longiareolata. A total of 2270 mosquito larvae were collected, and Culex spp. were the most abundant, where 1629 (71.76%) larvae were collected, followed by 499 (21.98%) Anopheles spp., 94 (4.14%) Aedes spp. and 48 (2.12%) Culiseta longiareolata. Of, 384 adult mosquitoes collected Culex spp. were the most abundant and 328 (85.42%) were collected, followed by 22 (5.73%) Aedes spp., 19 (4.94%) Anopheles spp. and 15 (3.91%) Culiseta longiareolata. The physical properties of the water in the breeding sites of mosquito larvae showed that pH of water varied between 6.9 & 9.9, the total dissolved salts (TDS) varied between 378-9504 ppm and water temperature varied between 8.7 degrees C in winter to 29.9 degrees C in summer. There was no correlation between pH & TDS of water in breeding site and distribution of larvae. The population density started to increase in March, with a peak in August when temperature was 36 degress C. The activity started to decrease in October, and minimum activity was in January, when temperature was below 5 degrees C. The seasonal abundance of adult mosquitoes was not affected by rainfall. A. aegypti, vector of Dengue fever virus, Cx. tritaeniorhynchus, vector of Rift Valley fever and Cx. univittatus, vector of sindbis virus were reported for the first time in Al Madinah Al Munawwrah Region. These vectors constituted a major health problem, and every effort should be made for feasible control.

Mosquito fauna (Diptera: Culicidae) and seasonal activity in Makka Al Mukarramah Region, Saudi Arabia.

From March 2004 to February 2006, a mosquito survey was conducted in Makka Al Mukarrama Region, in the western part of Saudi Arabia, and 19 species which belong to 4 genera, were collected: Aedes (2 species), Anopheles (8 species), Culex (8 species) and Culiseta (1 species). The mosquitoes were Aedes caspius, Ae. aegypti, Anopheles d'thali, An. gambiae, An. multicolor, An. rhodesiensis, An. sergenti, An. stephensi, An. subpictus, An. turkhudi, Culex arbieeni, Cx. laticinctus, Cx. pipiens, Cx. quinquefasciatus, Cx. sinaiticus, Cx. tigripes, Cx. tritaeniorhynchus, Cx. univittatus and Culiseta longiareolata. Cx. arbieeni was reported for the first time in Saudi Arabia from Al Taif District. The physical properties of water of mosquito's larval breeding sites showed the total dissolved salts (TDS) varied between 70-15552 ppm, pH ranged between 5.4-11.2 and water temperature varied between 15 degrees C in winter to 40.7 degrees C in summer. There was no correlation between these physical properties and the distribution of mosquito larvae. Light traps collected 1858 mosquitoes, and adult Culex were the most prevalent as 1658 (89.24%) were collected, followed by 121 (6.51%) Aedes, 68 (3.66%) Anopheles and 11 (0.59%) Culiseta. The effects of temperature and rainfall on seasonal abundance of mosquitoes in the study area are discussed.

Efficacy of flumethrin and coumaphos against the camel tick Hyalomma dromedarii L. (Acari: Ixodidae).

The efficacy of Flumethrin pour on and Coumaphos 50% WP was tested against different stages of Hyalomma dromedarii. With contact method, LC50 values for larvae and adults were 0.04, 0.03 ug/cm2 and 0.05, 1.06 ug/cm2 respectively. The LC50 for coumaphos against the larvae, adults and eggs using dipping method were 44, 63, and 62 ppm respectively. Flumethrin caused significant reduction in oviposition and hatchability in female ticks that survived sublethal concentrations, while sublethal doses of coumaphos had no effect on the reproductive potential of the tick. The results showed that flumethrin was 8 times more toxic than coumaphos.

Camel (Camelus dromedarius) contagious ecthyma in the Sudan. A case report.

The clinical and pathological features of the contagious ecthyma in camel calves in the Sudan were investigated. The animals were inappetant, emaciated and slightly anaemic. The disease was characterized by skin lesions around the lips and nostrils with occasional involvement of mucocutaneous junctions. The pathology includes vaculoar changes of the epithelial layers. Affected areas were ulcerated, haemorrhagic and with frequent secondary bacterial surinfection. Negative contrast electron microscopy has proven to be an extremely useful procedure for quick differential diagnosis.

Occurrence of runting and stunting syndrome in broiler chickens in the Sudan.

The first outbreak of reovirus infection in broiler chickens was observed in the Sudan in the largest poultry industry of the country. The disease was characterized clinically by growth retardation, lameness, poor feathering, shank depigmentation and occasionally retraction of the head. Grossly there was enlargement of the proventriculus, atrophy of the pancreas and bone abnormalities. Histopathologic changes included hepatitis, nephritis, myocarditis, pericarditis, catarrhal enteritis, pancreatic necrosis, encephalomalacia and ricketic changes. Details were described. Reovirus was isolated from affected birds and reisolated from experimentally infected chicks. Infection was confirmed by immunoelectrophoresis and agar gel precipitation tests.

Prognostic significance of DNA aneuploidy in stage I cutaneous melanoma.

The prognostic significance of DNA aneuploidy was studied restrospectively in 177 Stage I cutaneous melanomas. DNA content was determined by flow cytometry of propidium iodide-stained nuclei recovered from formalin-fixed, paraffin-embedded material. Of 162 evaluable histograms, 124 were diploid, 35 aneuploid, and 3 tetraploid. Aneuploidy strongly correlated with established predictors of unfavorable prognosis, namely, thickness p less than .005, level p less than 0.005, ulceration p less than 0.005, and presence of vertical growth phase p less than 0.02. Overall, aneuploidy was strongly correlated with recurrence (p less than 0.005) and shorter disease-free survival (p less than 0.0001). Aneuploidy was an independent predictor of recurrence for tumors less than 1.5 mm thick (p less than 0.0001) and greater than or equal to 3 mm thick (p = 0.031). For melanomas 1.5-2.9 mm thick, aneuploid tumors had a 27% higher recurrence rate than diploid tumors (63% vs. 36%). This was not statistically significant (p = 0.247). In a multivariate analysis of common predictors stratified by thickness, DNA aneuploidy was the most significant independent parameter (p less than 0.002). DNA content appears to be an important stratification parameter for Stage I cutaneous melanoma.

Histologic variation in the skin lesions of the glucagonoma syndrome.

Three cases of glucagonoma syndrome were seen in 1 year. Study of the skin biopsies from the first two cases led to a correct diagnosis from skin biopsy of the third case, although it was not suggested clinically. In each case serum glucagon levels were high and a pancreatic tumor was found, with complete remission of symptoms in cases 1 and 3 after resection; case 2 refused surgery and has died. A total of nine skin biopsies from the three patients showed a variety of findings: epidermal necrosis; subcorneal pustules, either isolated or associated with necrosis of the epidermis; confluent parakeratosis, epidermal hyperplasia, and marked papillary dermal angioplasia; and suppurative folliculitis. The clinical lesions in this syndrome vary from bright red macules to annular superficial erosions and flaccid pustules. Similarly, several histopathologic features of the disease can occur, which may represent the progression of the disease. No single histologic feature was specific for the disease, but a combination of the features is probably diagnostic. Therefore, multiple skin biopsies are recommended when this diagnosis is suspected.

Significance of DNA abnormalities in primary malignant melanoma and nevi, a retrospective flow cytometric study.

DNA ploidy of melanocytic skin tumors from 87 patients (53 primary melanomas, 34 nevi) was determined by flow cytometry from routinely prepared paraffin blocks. Ploidy data correlated strongly with conventional morphological parameters. Only 1 of 34 nevi, but 13 of 53 melanomas were aneuploid. Among the melanomas, none of 21 levels I-III melanomas was aneuploid, but 13 of 32 levels IV and V melanomas were aneuploid. There was also a significant correlation between increasing Breslow thickness and the presence of DNA aneuploidy. For 33 melanoma patients with over 2 yr of follow-up (average, 7.1 yr), only 4 of 23 diploid tumors have recurred, but 9 of 10 aneuploid tumors have recurred. We conclude that the biological potential of melanocytic skin tumors is strongly linked to DNA aneuploidy. Since this parameter can be conveniently determined from paraffin blocks, determination of ploidy abnormalities in these tumors may be clinically useful.

Tsetse and trypanosomiasis survey of Southern Darfur province, Sudan. II. Entomological aspects.

Atsetse survey of Southern Darfur province, Sudan showed that the distribution of the only species present, Glossina morsitans submorsitans, had not appreciably altered over 10 years. Fly populations are most dense south of the Wadi Umbelasha but light infestations are found in the woodlands north of this riverine system to a latitude of about 10 degrees 15' N. Data are given on host availability which is thought to be the major factor determining tsetse distribution. The relative importance of tsetse and of tabanids as transmitters of bovine trypanosomiasis in the province is discussed. The evidence indicates that tsetse are very much more important and that cattle are most at risk of contracting infections during their dry season southerly migrations to the tsetse belts especially during their "Rushash" migration at first rains. Possibilities of tsetse control are discussed but in the short term trypanosomiasis control is most likely best achieved by chemical prophylaxis/therapy of cattle at risk.

Paraganglioma of the duodenum in association with congenital neurofibromatosis. Possible relationship.

A case of a duodenal paraganglioma in a patient with von Recklinghausen's disease is presented, along with a review of the common clinical features of the 26 cases of duodenal paraganglioma and related neurogenic tumors reported in the literature. There was no reported evidence of recurrence or metastasis. Local excision was the most commonly employed method of treatment. It is proposed that duodenal paraganglioma with its admixed components and variable histologic features may represent hamartomatous hyperplasia of the paraganglia and the supporting neuroid tissue in this area. This would explain the benign behavior of these tumors as compared with carcinoids. Its association, in this case, with neurofibromatosis supports the neural crest origin of duodenal paragangliomas.

Recurrent Spitz's nevus.

A recurrence of a spindle- and epithelioid-cell nevus following partial removal is described. Clinical and histologic photographs of the original and recurrent lesion and an immunohistochemical stain (S-100) which highlights melanocytic cells and their pattern of growth are included. This nodular recurrence of a Spitz's nevus is contrasted with macular recurrence of ordinary melanocytic nevi that may follow partial removal by shaves. It is presented in order to promote recognition and prevent misdiagnosis of such a recurrence as a malignant melanoma.