Evaluation of a mass distribution programme for fine-mesh impregnated bednets against visceral leishmaniasis in eastern Sudan.

During an epidemic of visceral leishmaniasis (VL) in eastern Sudan, Médecins Sans Frontières distributed 357,000 insecticide-treated bednets (ITN) to 155 affected villages between May 1999 and March 2001. To estimate the protective effect of the ITN, we evaluated coverage and use of ITN, and analysed VL incidence by village from March 1996 to June 2002. We provided ITN to 94% of the individuals >5 years old. Two years later, 44% (95% CI 39-48%) of nets were reasonably intact. Because ITN were mainly used as protection against nuisance mosquitoes, bednet use during the VL transmission season ranged from <10% during the hot dry months to 55% during the beginning of the rainy season. ITN were put up from 9 to 11 p.m., leaving children unprotected during a significant period of sandfly-biting hours after sunset. Regression analysis of incidence data from 114 villages demonstrated a significant reduction of VL by village and month following ITN provision. The greatest effect was 17-20 months post-intervention, with VL cases reduced by 59% (95% CI: 25-78%). An estimated 1060 VL cases were prevented between June 1999 and January 2001, a mean protective effect of 27%. Although results need to be interpreted with caution, this analysis indicates a potentially strong reduction in VL incidence following a community distribution of ITN. The effectiveness of ITN depends on behavioural factors, which differ between communities

Aquifer investigations in north Qatar

A thesis submitted to the Faculty of Science, Technology and Design, Department of Environment, Geography and Geology, University of Luton, UK in partial fulfillment ofthe requirements for the degree of Master of PhilosophyThe purpose of this study was to investigate the levels and quality of groundwater in a farming area to the north of Doha, the capital of the State of Qatar. Two rows of about five wells were selected, the lines being more or less parallel to each other, about 30 km apart, running for 45 km inland from the east coast. Vertical electrical sounding surveys were undertaken and groundwater samples were taken from these wells in winter and in summer. The water was chemically analysed, and the results formed the basis for a hydrogeochemical modelling exercise. The results of the geophysical and geochemical surveys indicate that there is a seasonal vertical and lateral migration of the fresh water/salt water interface in winter before the rainfall replenishes the groundwater aquifers. The geochemistry of the groundwater indicate that there is a gradual decrease of cations and anions, particularly Na+, cr, S04, and HC03-, together with a decrease in conductivity CEC), total dissolved solids (TDS) and sodium absorption ratio (SAR) from the coast inland. There is an upconing which brings the saline water to the surface near the middle of the southern profile in both seasons. In both profiles the fresh water/salt water interface migrates inland due to the excessive extraction of fresh water from the wells

David Roediger Interview

Jennifer Thomson, assistant professor of History at Bucknell University and Mohammed Elnaiem, student at Bucknell University, interview David Roediger, professor of American Studies at the University of Kansas. Thomson and Roediger discuss self-emancipation of enslaved peoples as a catalyst for liberation movements in the United States. Elnaiem draws parallels between the 19th century activism inspired by emancipation and the social movements inspired by the Civil Rights and Black Lives Matter movements. Thomson asks Roediger about his next book and the discussion centers around the American middle class, class consciousness, and the rhetoric used by politicians to appeal to the middle class

ANTIFUNGAL AND AUXIN-LIKE ACTIVITY OF CARBENDAZIM IN MICROPROPAGATION AND ESSENTIAL OIL COMPOSITION OF EUCALYPTUS CAMALDULENSIS DEHNH

An investigation on Eucalyptus camaldulensis Dehnh. was carried out using samples from matured field grown trees in Malaysia. Surface sterilization and callus induction protocols have been described intended for in vitro plant regeneration using leaf and stem explants. A multi-option surface sterilization protocol has been established using three common sterilizing agents such as Mercuric Chloride (HgCl2), Sodium Hypochlorite (NaOCl) and ethanol which were tested by varying their combinations and their time of exposure. Combined treatments with two and three of sterilizing agents proved efficient in getting higher rates of clean, especially, when 70% alcohol was included. Using of 2.63% NaOCl for 10 min, 0.1% HgCl2 for 2.0 min and 70% ethanol for 1.0 min was the most effective sterilizing method for E. camaldulensis leaf explants and could obtain low contamination and damage rates, which can be applied to other plants with the same rigidity. Callus induction was successfully obtained on MS medium from leaf and stem explants using different auxins and cytokinins i.e. 6-Benzylaminopurine (BA), Kinetin (Kn), 2,4-Dichlorophenoxyacetic acid (2,4-D), Indole-3-acetic acid (IAA), Indole-3-butyric acid (IBA) and 1-naphthaleneacetic acid (NAA) in the concentration range of 0.5 - 3.0 mg/l. IBA and 2, 4-D were shown to be the best hormones for callus induction in leaves and stems, respectively. Combination of BA and NAA showed a better callus induction response, than individual hormones. Embryogenic callus was produced in leaf explants using IBA and the globular and heart stages were observed. The effects of the potent fungicide Carbendazim (MBC) were evaluated in in vitro cultures of E. camaldulensis. It showed significant reduction in fungal contamination, especially at ≥25 mg/l and low phytotoxic effects. Callus induced by NAA and BA from leaf and stem explants were not highly sensitive to MBC at low and moderate concentrations (≤15 and <50 mg/l, respectively). At higher MBC concentrations, callus iv induction and organogenesis were decreased. The highest MBC concentrations (200 and 300 mg/l), inhibited callus induction in leaf and callus development in stem. In addition to its cytokinin-like effect, the compound showed auxin-like effect by enhancement of callus induction in stem explants. The remarkable callus induction increment was observed when 3 mg/l MBC was combined with 3 mg/l 2,4-D or 0.1 mg/l BA and 3.0 mg/l NAA. Stem callus derived from MBC grown cultures could be efficient, regenerated into complete plants and established in field conditions. Direct shoot formation using plant nodal segments was also not sensitive to the fungicide concentrations (≥50 mg/l). Increasing concentrations of MBC in media caused some ultrastructural and anatomical alterations. Thus, these findings may have significance towards the understanding of the roles of the fungicide in plants. The essential oils compositions of E. camaldulensis various organs were investigated. Fifteen (15) is major compounds were identified represented 98.8, 97.5 and 99.5% of the compounds in the leaves, stems and immature flowers, respectively. Monoterpenes hydrocarbons were predominant in the three oil samples. The flower oil had the highest oxygenated monoterpenes content (19.6%). The most abundant compound in the three essential oils was γ-terpinene, as a principal oil component (57.4–72.5%) followed by o-cymene (14.6–26.3%) and terpinen-4-ol (6.6–16.2%). The regenerated plants from callus induced in stem using 3.0 mg/l NAA and 0.1 mg/l BA and 3.0 mg/l MBC, rooted on MS half strength medium fortified with 1.0 mg/l IBA and successively established under the field environment. They showed the same essential oil major components as those of the field-grown plants. In addition, E. camaldulensis leaf oils demonstrated cytotoxic effects in four cell lines; WEHI-3, HT-29, HL-60 and RAW 264.7 with WEHI-3 was the most sensitive to the essential oils with IC50 16.1

A possible role for Phlebotomus (Anaphlebotomus) rodhaini (Parrot, 1930) in transmission of Leishmania donovani

<p>Abstract</p> <p>Background</p> <p>Visceral leishmaniasis (VL, kala azar), caused by <it>Leishmania donovani </it>is a major health problem in Sudan and other East African countries. In this region the only proven vectors of <it>L. donovani </it>are <it>Phlebotomus orientalis </it>in eastern Sudan, Ethiopia and Upper Nile areas of Southern Sudan and <it>Phlebotomus martini </it>in Ethiopia, Kenya and Southern Sudan. In this report, we present the first evidence that <it>Phlebotomus rodhaini </it>may also play a role in maintaining transmission of <it>L. donovani </it>between animal reservoir hosts in eastern Sudan. The study was conducted in a zoonotic focus of visceral leishmaniasis in Dinder National Park, eastern Sudan, where previous work showed high infection rates of <it>L. donovani </it>in <it>P. orientalis</it>. Sand flies, captured by CDC traps were dissected and examined for infection with <it>Leishmania </it>parasites. Parasite isolates were subjected to <it>L. donovani </it>specific PCR. Field experiments were also carried out to compare efficiency of rodent baited and un-baited CDC traps in collection of <it>P. rodhaini </it>and determine its man-biting rate.</p> <p>Results</p> <p>Three female <it>P. rodhain</it>i were found infected with <it>Leishmania </it>parasites in an astonishingly small number of flies captured in three separate field trips. Two of these isolates were typed by molecular methods as <it>L. donovani</it>, while the third isolate was inoculated into a hamster that was subsequently lost. Although <it>P. rodhaini is </it>generally considered a rare species, results obtained in this study indicate that it can readily be captured by rodent-baited traps. Results of human landing collection showed that it rarely bites humans in the area.</p> <p>Conclusion</p> <p>It is concluded that <it>P. rodhaini </it>is a possible vector of <it>L. donovani </it>between animal reservoir hosts but is not responsible for infecting humans. It is suggested that the role of <it>P</it>. <it>rodhaini </it>in transmission of <it>L. donovani </it>in other zoonotic foci of visceral leishmaniasis in Africa should be re-examined.</p

Effects of Mixing Some Wood and Non-Wood Lignocellulosic Materials on the Properties of Cement and Resin- Bonded Particleboard.

A rapid development of the wood–based panel industry has been reported in recent literature. Major growth opportunities are expected to continue in particleboard market. The supply for wood which is so far the main raw material for particleboard has become problematic. Particleboard industry is intensifying efforts to find suitable substitutes for wood. In recent years effective utilization of thinning produce, wood and agricultural residues has gained increasing importance. Several attempts were made to mix different types of raw materials for making particleboard. Particleboard production is directly linked to some of the key issues of our times, namely; resources conservation, housing and the environment. This study investigated the effect of some conventional treatments on compatibility of cement and some wood and non-wood lignocellulosic materials. It also examined the effect of blending different proportions of the lignocellulosic materials on the properties of particleboards made using cement (inorganic binder) and Urea formaldehyde (organic binder). The three lignocellulosic materials used were Acacia nilotica sawdust, bagasse and cotton stalks. They are waste materials of widely cultivated species in Sudan. They were collected from EL Suki sawmill, EL Gunied sugar factory and the Fields of EL Kamlin state. Four experiments were carried out. The first was conducted to investigate the effect of six treatments {control (untreated material), control +3%CaCl2, hot water extraction, Hot water extraction +3%CaCl2,1%NaOH extraction, and 1%NaOH extraction +3%CaCl2} on the hydration characteristics of the three lignocellulosic materials with cement. Two Dewar flasks and a digital thermocouple were used. The maximum hydration temperature, time to reach maximum temperature and rise in temperature above the ambient were determined for each lignocellulosic material. The most suitable treatment common to all materials was the 1%NaOH+3%CaCl2 .The average maximum hydration temperatures were 63.87 °C, for bagasse, 67.87 °C for cotton stalks and 67.9 °C for sunt sawdust. Bagasse was the least responsive material to the treatments used, followed by cotton stalks and then sunt sawdust. In the second experiment, extractive contents, lignin content, hot water and weak alkali solubility of the three lignocellulosic materials were determined. The results of the above mentioned tests revaled that bagasse attained the highest results of hot water and 1% NaOH extraction. The results were therefore consistent with the hydration characteristics observed. In the third experiment different mixtures and ratios were used to manufacture laboratory size cement bonded particle boards. Analysis of variance and Duncan Multiple Range Test were used to study the significance of the variations, if any. Reasonable panel properties were obtained from the three lignocellulosic materials either pure or mixed using different cement/wood ratios (3:1, 3.5:1 and 4: 1). In the fourth experiment ten different mixtures of the three lignocellulosic materials (Nine homogenous, One layered) of urea formaldehyde resin bonded particleboards were manufactured under the laboratory conditions. The minimum property requirements of commercial particleboard standards EN 312:2003 for MOR,MOE were met or exceeded at 10% resin content level except for pure cotton stalks boards. Addition of bagasse particles to sunt sawdust or cotton stalks or to their mixtures improved the properties of boards made of their respective blend

Optical properties of annealed As30Te67Ga3 thin films grown by thermal evaporation

Chalcogenide glasses have received lots of attention because of their superior optical properties. To optimize these properties and expand areas of applications, more studies are required to establish the extent to which the parameters can be tuned over a wide range of annealing temperatures and heating rates. To do this, bulk and thin ∼150 nm As30Te67Ga3 films were prepared by melt-quenching and thermal evaporation techniques, respectively. The phase transition was investigated using differential scanning calorimeter (DSC) while the crystal structures were studied by X-ray diffraction (XRD). Characteristic temperatures such as the glass transition, crystallization and melting temperature of the bulk glass were found to depend on the heating rate. The activation energy of glass transition was 167.29 kJ/mol while the energy of crystallization was 103.98 kJ/mol. XRD results indicated that the annealed films showed more crystallinity, larger average crystallite size, lower dislocation density and lower strain as annealing temperature increased. According to the Avrami exponent, a combination of two and three-dimensional crystal growth with heterogeneous nucleation are possible mechanisms for the crystallization process. Moreover, optical constants such as the optical band gap, refractive index, extinction coefficient, high-frequency dielectric constants, real and imaginary parts of dielectric constants were found to strongly depend on the annealing temperature. The optical energy gap decreased from 1.1 to 0.89 eV as the annealing temperature increased from 373 to 433 K. These results indicate that thermal annealing is a major factor that can be used to tune the crystal structure, and hence the optical properties of As30Te67Ga3 system