1,026 research outputs found
A Configuration System Architecture Supporting Bit-Stream Compression for FPGAs
This paper presents an investigation and design of an enhanced on-chip configuration memory system that can reduce the time to (re)configure an FPGA. The proposed system accepts configuration data in a compressed form and performs decompression internally, The resulting FPCA can be (re)configured in time proportional to the size of the compressed bit-stream. The compression technique exploits the redundancy present in typical configuration data. An analysis of configurations corresponding to a set of benchmark circuits reveals that data that controls the same types of configurable elements have a common byte that occurs at a significantly higher frequency. This common byte is simply broadcast to all instances of that element. This step is followed by byte updates if required. The new configuration system has modest hardware requirements and was observed to reduce reconfiguration time for the benchmark set by two-thirds on average
evaluating the performance of a rotary vane expander for small scale organic rankine cycles using cfd tools
Abstract This work proposes a focus on the simulation of a rotative volumetric expander via a CFD code. A customized application of OpenFOAMOR has been developed to handle the particular motion of the calculation grid. In particular, a prescribed shape of the stator has been defined in order to adapt the motion of the vanes along the whole cycle. The model uses a mesh to mesh interpolation technique, switching from a calculation grid to the new one on the basis of dynamic mesh quality considerations. This particular approach allows to account for the presence of leakages occurring between the stator and vane tips and also occurring at the top and bottom of the vanes. The fluid considered is the refrigerant R245fa, whose particular properties have been determined resorting to the NIST database. Experimental data, measured at different conditions of mass flow and fluid temperature, are compared to calculation results. Moreover, the CFD analysis has allowed the estimation of the influence of the leakage mass flow occurring at the tip of the vanes on the overall machine performances
The sticky resting box, a new tool for studying resting behaviour of Afrotropical malaria vectors
Background:
Monitoring densities of adult mosquito populations is a major challenge in efforts to evaluate the epidemiology of mosquito-borne diseases, and their response to vector control interventions. In the case of malaria, collection of outdoor-resting Anophelines is rarely incorporated into surveillance and control, partially due to the lack of standardized collection tools. Such an approach, however, is increasingly important to investigate possible changes in mosquito behaviour in response to the scale up of Insecticide Treated Nets and Indoor Residual Spraying. In this study we evaluated the Sticky Resting Box (SRB) - i.e. a sticky variant of previously investigated mosquito Resting Box, which allows passive collection of mosquitoes entering the box – and compared its performance against traditional methods for indoor and outdoor resting mosquito sampling.<p></p>
Methods:
Daily collections were carried out in two neighbouring villages of Burkina Faso during rainy season 2011 and dry season 2012 by SRB located indoors and outdoors, and by Back-Pack aspiration inside houses (BP) and in ad hoc built outdoor pit-shelters (PIT).<p></p>
Results:
Overall, almost 20,000 Culicidae specimens belonging to 16 species were collected and morphologically identified. Malaria vectors included Anopheles coluzzii (53%), An. arabiensis (12%), An. gambiae s.s. (2.0%) and An. funestus (4.5%). The diversity of species collected in the two villages was similar for SRB and PIT collections outdoors, and significantly higher for SRB than for BP indoors. The population dynamics of An. gambiae s.l. mosquitoes, as obtained by SRB-collections was significantly correlated with those obtained by the traditional methods. The predicted mean estimates of An. gambiae s.l. specimens/sampling-unit/night-of-collections was 6- and 5-times lower for SRB than for BP indoors and PIT outdoors, respectively.<p></p>
Conclusions:
Overall, the daily performance of SRB in terms of number of malaria vectors/trap was lower than that of traditionally used approaches for in- and outdoor collections. However, unlike these methods, SRB could be set up to collect mosquitoes passively over at least a week. This makes SRB a promising tool for passively monitoring anopheline resting populations, with data presented here providing guidance for how to set up SRB-based collections to acquire information comparable to those obtained with other methods.<p></p>
7th Biannual ECOtoxicology MEeting (BECOME 2016) - Managing aquatic and terrestrial environments: An ecotoxicological perspective
Adaptive potential of hybridization among malaria vectors: Introgression at the immune locus TEP1 between Anopheles coluzzii and A. gambiae in 'Far-West' Africa
“Far-West” Africa is known to be a secondary contact zone between the two major malaria vectors Anopheles coluzzii and A. gambiae.We investigated gene-flow and potentially adaptive introgression between these species along a west-to-east transect in Guinea Bissau, the putative core of this hybrid zone. To evaluate the extent and direction of gene flow, we genotyped site 702 in Intron-1 of the para Voltage-Gated SodiumChannel gene, a species-diagnostic nucleotide position throughout most of A. coluzzii and A. gambiae sympatric range. We also analyzed polymorphismin the thioester-binding domain (TED) of the innate immunity-linked thioester-containing protein 1 (TEP1) to investigate whether elevated hybridization might facilitate the exchange of variants linked to adaptive immunity and Plasmodium refractoriness. Our results confirm asymmetric introgression of genetic material from A. coluzzii to A. gambiae and disruption of linkage between the centromeric "genomic islands" of inter-specific divergence. We report that A. gambiae from the Guinean hybrid zone possesses an introgressed TEP1 resistant allelic class, found exclusively in A. coluzzii elsewhere and apparently swept to fixation inWest Africa (i.e. Mali and Burkina Faso). However, no detectable fixation of this allele was found in Guinea Bissau, which may suggest that ecological pressures driving segregation between the two species in larval habitats in this region may be different from those experienced in northern and more arid parts of the species’ range. Finally, our results also suggest a genetic subdivision between coastal and inland A. gambiae Guinean populations and provide clues on the importance of ecological factors in intra-specific differentiation processes
Sustained virological response after ten days of triple anti-hepatitis C virus (HCV) therapy with telaprevir plus pegylated interferon and ribavirin in an HIV/HCV co-infected cirrhotic woman
The introduction of first-generation protease inhibitors for the treatment of chronic hepatitis C in subjects infected with hepatitis C virus (HCV) genotype 1 has significantly improved the sustained virological response (SVR) rate. As liver cirrhosis reduces the probability of achieving SVR, current guidelines discourage response-guided therapy in cirrhotic patients. We report the first case of a cirrhotic woman with chronic HCV and HIV co-infection achieving virological response after an ultra-short course of therapy. A 40-year-old HIV/HCV co-infected woman with compensated liver cirrhosis was treated with anti-HCV triple therapy containing telaprevir plus pegylated interferon and ribavirin. Baseline plasma HCV RNA was 3.6 log IU/ml and transaminases were within the normal range. She harboured IL28B rs12979860 C/C alleles. Ten days after starting therapy, the patient stopped treatment because of mild anorexia and nausea. Virological response was detected at treatment discontinuation and was maintained up to 24 weeks. This case describes an unexpected SVR after a 10-day course of antiviral therapy in a cirrhotic HIV/HCV co-infected woman presenting positive predictive factors for a response (low viral load, IL28B genotype). Nonetheless, there is no evidence to suggest a shorter duration of treatment in this subset of patients
Evaluation of a protocol for remote identification of mosquito vector species reveals BG-Sentinel trap as an efficient tool for Anopheles gambiae outdoor collection in Burkina Faso
Chromosomal plasticity and evolutionary potential in the malaria vector Anopheles gambiae sensu stricto: insights from three decades of rare paracentric inversions
Background: In the Anopheles gambiae complex, paracentric chromosomal inversions are nonrandomly distributed along the complement: 18/31 (58%) of common polymorphic inversions are on chromosome arm 2R, which represents only ~30% of the complement. Moreover, in An.gambiae sensu stricto, 6/7 common polymorphic inversions occur on 2R. Most of these inversions are considered markers of ecological adaptation that increase the fitness of the carriers of alternative karyotypes in contrasting habitats. However, little is known about the evolutionary forces responsible for their origin and subsequent establishment in field populations. Results: Here, we present data on 82 previously undescribed rare chromosomal inversions (RCIs) recorded during extensive field sampling in 16 African countries over a 30 year period, which may shed light on the dynamics of chromosomal plasticity in An. gambiae. We analyzed breakpoint distribution, length, and geographic distribution of RCIs, and compared these measures to those of the common inversions. We found that RCIs, like common inversions, are disproportionately clustered on 2R, which may indicate that this arm is especially prone to breakages. However, contrasting patterns were observed between the geographic distribution of common inversions and RCIs. RCIs were equally frequent across biomes and on both sides of the Great Rift Valley (GRV), whereas common inversions predominated in arid ecological settings and west of the GRV. Moreover, the distribution of RCI lengths followed a random pattern while common inversions were significantly less frequent at shorter lengths. Conclusion: Because 17/82 (21%) RCIs were found repeatedly at very low frequencies – at the same sampling location in different years and/or in different sampling locations – we suggest that BMC Evolutionary Biology 2008, 8:309 http://www.biomedcentral.com/1471-2148/8/309 RCIs are subject mainly to drift under unperturbed ecological conditions. Nevertheless, RCIs may represent an important reservoir of genetic variation for An. gambiae in response to environmental changes, further testifying to the considerable evolutionary potential hidden within this pan-African malaria vector
Novel genotyping approaches to easily detect genomic admixture between the major Afrotropical malaria vector species, Anopheles coluzzii and An. gambiae
The two most efficient and most recently radiated Afrotropical vectors of human malaria - Anopheles coluzzii and An.gambiae - are identified by single-locus diagnostic PCR assays based on species-specific markers in a 4Mb region on chromosome-X centromere. Inherently, these diagnostic assays cannot detect interspecific autosomal admixture shown to be extensive at the westernmost and easternmost extremes of the species range. The main aim of this study was to develop novel, easy-to-implement tools for genotyping An.coluzzii and An.gambiae-specific ancestral informative markers (AIMs) identified from the Anopheles gambiae 1000 genomes (Ag1000G) project. First, we took advantage of this large set of data in order to develop a multilocus approach to genotype 26 AIMs on all chromosome arms valid across the species range. Second, we tested the multilocus assay on samples from Guinea Bissau, The Gambia and Senegal, three countries spanning the westernmost hybridization zone, where conventional species diagnostic is problematic due to the putative presence of a novel "hybrid form". The multilocus assay was able to capture patterns of admixture reflecting those revealed by the whole set of AIMs and provided new original data on interspecific admixture in the region. Third, we developed an easy-to-use, cost-effective PCR approach for genotyping two AIMs on chromosome-3 among those included in the multilocus approach, opening the possibility for advanced identification of species and of admixed specimens during routine large scale entomological surveys, particularly, but not exclusively, at the extremes of the range, where WGS data highlighted unexpected autosomal admixture
First evidence of resistance to pyrethroid insecticides in Italian Aedes albopictus populations after 26 years since invasion
Aedes albopictus has spread during the last decades all over the world. This has increased significantly the risk of exotic arbovirus transmission (e.g. Chikungunya, Dengue, and Zika) also in temperate areas, as testified by the Chikungunya 2007- and 2017-outbreaks in north-east and central Italy. Insecticides represent a main tool for limiting the circulation of these mosquito-borne viruses. The aim of the present study is to start filling the current gap of knowledge on pyrethroid insecticide resistance of European Ae. albopictus populations focusing on populations from Italy, Albania and Greece
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