258 research outputs found
Experiences with the KOALA co-allocating scheduler in multiclusters
In multicluster systems, and more generally, in grids, jobs may require co-allocation, i.e., the simultaneous allocation of resources such as processors and input files in multiple clusters. While such jobs may have reduced runtimes because they have access to more resources, waiting for processors in multiple clusters and for the input files to become available in the right locations, may introduce inefficiencies. Moreover, as single jobs now have to rely on multiple resource managers, co-allocation introduces reliability problems. In this paper, we present two additions to the original design of our KOALA co-allocating scheduler (different priority levels of jobs and incrementally claiming processors), and we report on our experiences with KOALA in our multicluster testbed while it was unstable
Communication-aware job placement policies for the KOALA grid scheduler
In multicluster systems, and more generally, in grids, parallel applications may require co-allocation, i.e., the simultaneous allocation of resources such as processors in multiple clusters. Although co-allocation enables the allocation of more processors than available on a single cluster, depending on the applicationsÿ¿ communication characteristics, it has the potential disadvantage of increased execution times due to relatively slow wide-area communication. In this paper, we present two job placement policies, the Cluster Minimization and the Flexible Cluster Minimization policies which take into account the wide-area communication overhead when co-allocating applications across the clusters. We have implemented these policies in our grid scheduler called KOALA in order to serve different job request types. To assess the performance of the policies, we perform experiments in a real multicluster testbed using communication-intensive parallel applications
Biochar: The Black Diamond for Soil Sustainability, Contamination Control and Agricultural Production
Production of biochars from agricultural wastes reduces significantly the volume and weight of the wastes, and hence, it can be considered as a promising means for managing the agricultural wastes. Biochar has received great interest during the last few years, due to its beneficial role to mitigate CO2 emission through enhancing the long-term carbon sequestration. The effects of biochar on soil properties vary widely, depending on the characteristics of soil and the biochar. Most types of biochars are of alkaline nature and of high C content. Addition of biochar to the soil can improve the cation exchange capacity enrich soil with the nutrients and enhance the microbial growth, and improve some soil physical properties such as water retention and aggregation. For contamination control, biochars have proven to be a suitable tool for controlling the contaminants in the environment. The high surface area, porous structure, alkaline nature, and the presence of functional groups characterized the biochar as alternative option for the remediation of heavy metal contaminated waters and soils. However, there is a lack of knowledge regarding the effects of biochar in the presence of mineral and/or organic fertilizers on the plant growth and nutrient transformation in soils. In addition, biochar is successfully used for treating the acid soils; therefore, future studies are needed to investigate the neutralization of alkaline performance of biochar to be used safely in alkaline soils
Comorbidities Schizophrenia-Addiction to Cannabis and Tobacco in Madagascar in 2022
The use of psychoactive substances is frequent in schizophrenic patients. The main objective was to determine the prevalence of schizophrenia-addiction comorbidity and to characterize its evolution.This is an observational, cross-sectional, descriptive and bicentric study carried out in the Psychiatry Department of the Professor Zafisaona Gabriel University Hospital Center and at the Toby Peniela in Antanimasaja over a period of 4 months from February to May 2022.All schizophrenics meeting DSM-V criteria were included. It was collected 60 patients. The average age was 30.60 years, a sex ratio of 2.15; Joblessness was found in 45%. The prevalence of active drug taking was 91.66%, including cannabis in 60% and tobacco in 40%. Non-deficient schizophrenia predominated in 53.33% of cases and 66.67% of them were cannabis users and 61.11% of these cannabis patients had grown up in a “non-biparental” situation. The age of onset of drug intake was 17.5 years and the time between drug intake and psychiatric disorders was 3.25 years. The begining of the disease for addicted patients was at 22.52 years and for those non-addicted one at 30.6 years. Cannabis addiction was found in 51.61%.Strengthening the fight against drug addiction, increasing sensitization of psychiatric pathologies and supporting single-parent families could reduce the prevalence of drug addiction and improve their care
Host range, damage and seasonality of fruit flies in Sennar State, Sudan
Fruit flies (Diptera: Tephritidae) are one of the most economically important groups of insects in the afrotropical region because they cause damage to fruits and vegetables. Integrated fruit fly (FF) control program requires accurate data about taxonomy, incidence, distribution and seasonality of the members of this pest. Surveys and collection missions were carried out in Sennar State during January 2006- January 2008. Yellow sticky traps were used for adult collection. Trapped fruit flies were labeled, identified and counted monthly to estimate their abundance throughout the year. In addition, infested fruits of mango, guava, grapefruit, orange, banana, melons, pumpkin, watermelon, and the wild magad (Cucurbitaceae) were collected monthly from the surveyed areas. Larvae were reared till the adult stage and identified. Field infestation rate of FF species was determined on mango and guava at Singa area. Percentage of FF infestation on mango Baladi cultivar was 10% in March, 15% in April and 20% in May. During the period from June to August, Abu Samaka cultivar was the only mango cultivar available, and accordingly, was subjected to a heavy attack by the FF. The infestation reached 30% in June and 50% in July. The FF moved to guava, during the period from October to December. The rate of FF infestation on guava was very high during this period and ranged from 80% to 90%. Mango fruits in Singa area were infested by Bactrocera invadens (Drew, Tsuruta and White) (80%), C. cosyra (19.8%) and Dacus longistylus (Wiedemann) (0.2%) of the total emerged adults. This was the first record for the latter species in a host other than Calotropis procera (Apocynaceae). Guava fruits were infested by B. invadens (84.5%), C. cosyra (15.3%), and C. quinaria (Bezzi) (0.2%) of the total emerged adults. B. invadens seemed to out-compete and replace the indigenous species. Cucurbit fruits hosted D. ciliatus (Leow) only. The wild magad fruits hosted B. invadens and B. cucurbitae (Coquillet). The highest population of B.invadenss was observed during July and December (254 and 253 adults/trap, respectively). March and April showed the lowest population due to higher temperatures and low relative humidity.
 
Polycarbonate microchannel network with carpet of Gold NanoWires as SERS-active device
A polycarbonate (PC) microchannel network supporting gold nanowires was developed to be a SERSactive microchip. Observations of large increases in a Raman cross-section, allowed us to collect vibrational signatures which are not easily detectable by Raman techniques due to the high fluorescence level of bare PC. Compared to other SERS experiments, this study relies on the use of dielectric polymer/metal surfaces which are well defined at microscale and nanoscale levels. This device seems a promising tool for sensing the adsorption of biomolecules
Radio Location of Partial Discharge Sources: A Support Vector Regression Approach
Partial discharge (PD) can provide a useful forewarning of asset failure in electricity substations. A significant proportion of assets are susceptible to PD due to incipient weakness in their dielectrics. This paper examines a low cost approach for uninterrupted monitoring of PD using a network of inexpensive radio sensors to sample the spatial patterns of PD received signal strength. Machine learning techniques are proposed for localisation of PD sources. Specifically, two models based on Support Vector Machines (SVMs) are developed: Support Vector Regression (SVR) and Least-Squares Support Vector Regression (LSSVR). These models construct an explicit regression surface in a high dimensional feature space for function estimation. Their performance is compared to that of artificial neural network (ANN) models. The results show that both SVR and LSSVR methods are superior to ANNs in accuracy. LSSVR approach is particularly recommended as practical alternative for PD source localisation due to it low complexity
Hidrogel berasaskan pektin kulit buah naga (Hylocereus polyrhizus) sebagai pembawa ubat melalui sistem penghantar oral
Kajian ini memfokuskan kepada aplikasi hidrogel berasaskan ekstrak pektin daripada kulit buah naga (Hylocereus polyrhizus) yang digunakan sebagai biobahan pembawa ubat. Sebanyak 5 sampel telah disediakan dengan peratus komposisi pektin yang berbeza (0%, 0.5%, 1.0%, 1.5%, 2.0%). Keputusan menunjukkan hidrogel dengan 1.0% pektin telah mengembang secara maksimum pada pH 7. Imej daripada mikroskop elektron pengimbas (SEM) mendapati saiz keporosan hidrogel meningkat dengan penambahan pektin. Potensi hidrogel sebagai agen pembawa ubat telah dilakukan dengan melihat kecekapan muatan ubat, ujian perlepasan ubat dan ujian biodegradasi di dalam saluran pencernaan menggunakan medium simulasi perut (SGF), usus (SIF) dan kolon (SCF) secara in-vitro secara tanpa/kehadiran enzim. Hasil ujian ketoksikan menggunakan kaedah embrio ikan kuda belang (Danio rerio) telah memberikan keputusan yang negatif terhadap hidrogel yang diuji
Epidemiological impact of prioritising SARS-CoV-2 vaccination by antibody status: Mathematical modelling analyses
Background Vaccines against SARS-CoV-2 have been developed, but their availability falls far short of global needs. This study aimed to investigate the impact of prioritising available doses on the basis of recipient antibody status, that is by exposure status, using Qatar as an example. Methods Vaccination impact (defined as the reduction in infection incidence and the number of vaccinations needed to avert one infection or one adverse disease outcome) was assessed under different scale-up scenarios using a deterministic meta-population mathematical model describing SARS-CoV-2 transmission and disease progression in the presence of vaccination. Results For a vaccine that protects against infection with an efficacy of 95%, half as many vaccinations were needed to avert one infection, disease outcome or death by prioritising antibody-negative individuals for vaccination. Prioritisation by antibody status reduced incidence at a faster rate and led to faster elimination of infection and return to normalcy. Further prioritisation by age group amplified the gains of prioritisation by antibody status. Gains from prioritisation by antibody status were largest in settings where the proportion of the population already infected at the commencement of vaccination was 30%-60%. For a vaccine that only protects against disease and not infection, vaccine impact was reduced by half, whether this impact was measured in terms of averted infections or disease outcomes, but the relative gains from using antibody status to prioritise vaccination recipients were similar. Conclusions Major health and economic gains can be achieved more quickly by prioritizing those who are antibody-negative while doses of the vaccine remain in short supply.This study received support from the Biomedical
Research Program, and the Biostatistics, Epidemiology, and
Biomathematics Research Core, all at Weill Cornell MedicineQatar, as well as support provided by the Ministry of Public
Health and Hamad Medical Corporation. The developed
mathematical models were made possible by NPRP grant number
9-040-3-008 (principal investigator: LJA-R) and NPRP grant
number 12S-0216-190094 (principal investigator: LJA-R) from the
Qatar National Research Fund (a member of Qatar Foundation;
https://www.qnrf.org)
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