7,365 research outputs found
Blue Nile Runoff Sensitivity to Climate Change
This study describes implementation of hydrological climate change impact assessment tool utilising a combination of statistical spatiotemporal downscaling and an operational hydrological model known as the Nile Forecasting System. A spatial rainfall generator was used to produce high-resolution (daily, 20km) gridded rainfall data required by the distributed hydrological model from monthly GCM outputs. The combined system was used to assess the sensitivity of upper Blue Nile flows at Diem flow gauging station to changes in future rainfall during the June-September rainy season based on output from three GCMs. The assessment also incorporated future evapotranspiration changes over the basin. The climate change scenarios derived in this study were broadly in line with other studies, with the majority of scenarios indicating wetter conditions in the future. Translating the impacts into runoff in the basin showed increased future mean flows, although these would be offset to some degree by rising evapotranspiration. Impacts on extreme runoff indicated the possibility of more severe floods in future. These are likely to be exacerbated by land-use changes including overgrazing, deforestation, and improper farming practices. Blue Nile basin flood managers therefore need to continue to prepare for the possibility of more frequent floods by adopting a range of measures to minimise loss of life and guard against other flood damage
Demographic performance of local sheep and goat breeds in two agro-ecological zones in Egypt
Small breeders in Egypt raise locally adapted sheep and goats breeds, which have the ability to produce and reproduce under the prevailing harsh conditions. Improving resilience of their production system is a major challenge to support socioeconomic development. However, little is known about the productive abilities of these breeds in small farming systems. The present work is an attempt to assess the performance of local breeds in small farming systems, and their capacity to cope with feed scarcity and harsh climatic conditions. In 2018, a retrospective survey was conducted over 12 month period to assess demographic rates of 25 local Barki sheep and goat flocks in the rain-fed area of Coastal Zone of Western Desert (CZWD) and 28 local Saidi sheep and goat flocks under the hot intensive agriculture system in Upper Egypt (UE). Flocks are larger, reproductive performance and offtake rates are higher (and mortality lower) in the CZWD, a region specialized in small ruminant breeding whereas it remains a secondary activity in Upper Egypt. The marketing season is mainly during Korban Eid festival. Their main challenges are frequent incidence of drought in the CZWD and high prices of feed stuffs in both sites. Our study suggests breeders have different strategies in UE and the CZWD when confronted with feed shortage. Breeders in the CZWD purchase feed to maintain high herd productivity whereas in UE small ruminant breeding is a minor activity with less productive animals that are resilient to feed shortage
A pilot comparative study of fissurectomy/diltiazem and fissurectomy/botulinum toxin in the treatment of chronic anal fissure
Background: Treatment of chronic anal fissure (CAF) by fissurectomy with botulinum toxin A (BTA) injection results in a healing rate of greater than 90%. BTA injection, however, can cause incontinence and perianal sepsis. The decrease in sphincter pressure following topical treatment with 2% diltiazem cream (DTC) is comparable to that following BTA injection but with potentially fewer complications and at less cost. We report the shortterm results of a pilot study comparing fissurectomy with BTA and fissurectomy followed by DTC for the treatment of CAF. Methods: The recorded outcomes of CAF following treatment with the two methods were analysed retrospectively. Patients underwent either fissurectomy followed by injection of 40 U BTA into the internal sphincter (group A) or fissurectomy followed by the perianal application of DTC twice daily for 8 weeks (group B). Symptom resolution and treatment side effects at the initial follow-up were compared. Results: Demographics, fissure characteristics and the number of multiparous women between the two groups were comparable. At a median follow-up of 12 weeks (range 8-20 weeks), the two groups had similar rates of complete symptom resolution (group A, 25/28, 89.3%; group B, 19/23, 82.6%; p=0.7739), with minor side effects. Conclusions: In this small pilot study fissurectomy combined with chemical sphincterotomy resulted in high short-term fissure healing rates. The study also suggested that fissurectomy followed by 8 weeks of topical DTC may be as good as fissurectomy with BTA injection in the treatment of CAF. A prospective study, adequately powered to determine the significance of differences is neede
Vertical Muscle Transposition with Augmentation for Treatment of Exotropia Caused by Iatrogenic Lost Medial Rectus Muscle
Purpose: To evaluate the results of vertical muscle transposition with augmentation in cases of exotropia caused by iatrogenic lost medial rectus muscle.
Methods: This is a retrospective review of 5 cases of lost medial rectus with exotropia and marked limitation of adduction that underwent surgery. All cases had a history of strabismus surgery on the medial rectus and failed attempt at retrieval of the lost muscle.
Results: Five patients fulfilled the criteria. Full tendon vertical muscle transposition with augmentation sutures was done for all cases. Surgery led to a significant reduction of the angle of exotropia 25.8±13.6 ?D (P=0.027) and improvement in adduction of 7.5±3.8 degrees (P=0.034). There were no complications.
Conclusions: Isolated vertical muscle transposition with augmentation is a useful option to improve the exotropia and adduction deficit in patients with iatrogenic lost medial rectus muscle
Anti-Microbial Dendrimers against Multidrug-Resistant P. aeruginosa Enhance the Angiogenic Effect of Biological Burn-wound Bandages.
Multi-drug resistant Pseudomonas aeruginosa has increased progressively and impedes further regression in mortality in burn patients. Such wound infections serve as bacterial reservoir for nosocomial infections and are associated with significant morbidity and costs. Anti-microbial polycationic dendrimers G3KL and G3RL, able to kill multi-drug resistant P. aeruginosa, have been previously developed. The combination of these dendrimers with a class of biological bandages made of progenitor skin cells, which secrete growth factors, could positively impact wound-healing processes. However, polycations are known to be used as anti-angiogenic agents for tumor suppression. Since, neovascularization is pivotal in the healing of deep burn-wounds, the use of anti-microbial dendrimers may thus hinder the healing processes. Surprisingly, we have seen in this study that G3KL and G3RL dendrimers can have angiogenic effects. Moreover, we have shown that a dendrimer concentration ranging between 50 and 100 μg/mL in combination with the biological bandages can suppress bacterial growth without altering cell viability up to 5 days. These results show that antimicrobial dendrimers can be used in combination with biological bandages and could potentially improve the healing process with an enhanced angiogenesis
Role of hydrogen in volatile behaviour of defects in SiO2-based electronic devices
Charge capture and emission by point defects in gate oxides of metal–oxide–semiconductor field-effect transistors (MOSFETs) strongly affect reliability and performance of electronic devices. Recent advances in experimental techniques used for probing defect properties have led to new insights into their characteristics. In particular, these experimental data show a repeated dis- and reappearance (the so-called volatility) of the defect-related signals. We use multiscale modelling to explain the charge capture and emission as well as defect volatility in amorphous SiO2 gate dielectrics. We first briefly discuss the recent experimental results and use a multiphonon charge capture model to describe the charge-trapping behaviour of defects in silicon-based MOSFETs. We then link this model to ab initio calculations that investigate the three most promising defect candidates. Statistical distributions of defect characteristics obtained from ab initio calculations in amorphous SiO2 are compared with the experimentally measured statistical properties of charge traps. This allows us to suggest an atomistic mechanism to explain the experimentally observed volatile behaviour of defects. We conclude that the hydroxyl-E′ centre is a promising candidate to explain all the observed features, including defect volatility
Modelling dependency networks to inform data structures in BIM and smart cities
The pervasive deployment of "smart city" and "smart building" projects in cities world-wide is driving innovation on many fronts including; technology, telematics, engineering and entrepreneurship. This paper focuses on the technical and engineering perspectives of BIM and smart cities, by extending building and urban morphology studies as to respond to the challenges posed by Big Data, and smart infrastructure. The proposed framework incorporates theoretical and modelling descriptions to verify how network-based models can act as the backbone skeletal representation of both building and urban complexity, and yet relate to environmental performance and smart infrastructure. The paper provides some empirical basis to support data information models through building dependency networks as to represent the relationships between different existing and smart infrastructure components. These dependency networks are thought to inform decisions on how to represent building and urban data sets in response to different social and environmental performance requirements, feeding that into void and solid descriptions of data maturity models. It is concluded that network-based models are fundamental to comprehend and represent the complexity of cities and inform urban design and public policy practices, in the design and operation phases of infrastructure projects
Schur functions and their realizations in the slice hyperholomorphic setting
we start the study of Schur analysis in the quaternionic setting using the
theory of slice hyperholomorphic functions. The novelty of our approach is that
slice hyperholomorphic functions allows to write realizations in terms of a
suitable resolvent, the so called S-resolvent operator and to extend several
results that hold in the complex case to the quaternionic case. We discuss
reproducing kernels, positive definite functions in this setting and we show
how they can be obtained in our setting using the extension operator and the
slice regular product. We define Schur multipliers, and find their co-isometric
realization in terms of the associated de Branges-Rovnyak space
Orally active antischistosomal early leads identified from the open access malaria box.
BACKGROUND: Worldwide hundreds of millions of schistosomiasis patients rely on treatment with a single drug, praziquantel. Therapeutic limitations and the threat of praziquantel resistance underline the need to discover and develop next generation drugs. METHODOLOGY: We studied the antischistosomal properties of the Medicines for Malaria Venture (MMV) malaria box containing 200 diverse drug-like and 200 probe-like compounds with confirmed in vitro activity against Plasmodium falciparum. Compounds were tested against schistosomula and adult Schistosoma mansoni in vitro. Based on in vitro performance, available pharmacokinetic profiles and toxicity data, selected compounds were investigated in vivo. PRINCIPAL FINDINGS: Promising antischistosomal activity (IC50: 1.4-9.5 µM) was observed for 34 compounds against schistosomula. Three compounds presented IC50 values between 0.8 and 1.3 µM against adult S. mansoni. Two promising early leads were identified, namely a N,N'-diarylurea and a 2,3-dianilinoquinoxaline. Treatment of S. mansoni infected mice with a single oral 400 mg/kg dose of these drugs resulted in significant worm burden reductions of 52.5% and 40.8%, respectively. CONCLUSIONS/SIGNIFICANCE: The two candidates identified by investigating the MMV malaria box are characterized by good pharmacokinetic profiles, low cytotoxic potential and easy chemistry and therefore offer an excellent starting point for antischistosomal drug discovery and development
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