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- Noormahomed, Emilia Virginia, et al.
(author)
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A cross-sectional serological study of cysticercosis, schistosomiasis, toxocariasis and echinococcosis in HIV-1 infected people in Beira, Mozambique
- 2014
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In: PLoS Neglected Tropical Diseases. - : Public Library of Science (PLoS). - 1935-2727 .- 1935-2735. ; 8:9
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Journal article (peer-reviewed)abstract
- BackgroundHelminthic infections are highly endemic in Mozambique, due to limited access to healthcare and resources for disease prevention. Data on the subclinical prevalence of these diseases are scarce due to the fact that an immunological and imaging diagnosis is not often available in endemic areas. We conducted a cross-sectional study on HIV1+ patients from Beira city in order to determine the seroprevalence of cysticercosis, schistosomiasis, toxocariasis and echinoccocosis and its possible interaction with HIV infection.Methodology/Principal FindingsPatients (601) were voluntarily recruited at the Ponta Gea Health Center and their demographic and clinical data were recorded (including CD4+ cell count and antiretroviral regimen). Mean age was 39.7 years, 378 (62.9%) were women and 223 (37.1%) were men. Four hundred seventy-five (475) patients (79%) were already on highly active antiretroviral therapy (HAART), and 90 started therapy after being enrolled in the study. For serological testing we used a Multiplex Western Blot IgG from LDBIO Diagnostics. The overall seroprevalence was 10.2% for cysticercosis, 23% for schistosomiasis, 7.3% for toxocariasis and 17.3% for echinococcosis.Conclusions/SignificanceNeither age nor the CD4+ count were significantly associated with the seroprevalence of the helminths studied. However, patients with CD4+ between 200–500/µl had a higher seroprevalence to all helminths than those with less than 200/µl cells/and those with more than 500 cells/µl. Female gender was significantly associated with cysticercosis and schistosomiasis, and being in HAART with toxocariasis. Headache was significantly associated with cysticercosis and toxocariasis. There was no association between epilepsy and seropositivity to any of the parasites. The study concluded that a clear understanding of the prevalence and manifestations of these coinfections, how best to diagnose subclinical cases, and how to manage diseases with concomitant antiretroviral therapy is needed.
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| 2. |
- Pfeffer, M. A., et al.
(author)
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SO 2 emission rates and incorporation into the air pollution dispersion forecast during the 2021 eruption of Fagradalsfjall, Iceland
- 2024
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In: Journal of Volcanology and Geothermal Research. - 0377-0273. ; 449
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Journal article (peer-reviewed)abstract
- During the low-effusion rate Fagradalsfjall eruption (19 March – 18 September 2021), the emission of sulfur dioxide (SO2) was frequently measured using ground-based UV spectrometers. The total SO2 emitted during the entire eruption was 970 ± 540 kt, which is only about 6% of the SO2 emitted during the similar length Holuhraun eruption (2014–2015). The eruption was divided into five phases based on visual observations, including the number of active vents and the occurrence of lava fountaining. The SO2 emission rate ranged from 44 ± 19 kg/s in Phase 2 to 85 ± 29 kg/s in Phase 5, with an average of 64 ± 34 kg/s for the entire eruption. There was notable variability in SO2 on short timescales, with measurements on 11 August 2021 ranging from 17 to 78 kg/s. SO2 flux measurements were made using scanning DOAS instruments located at different distances from and orientations relative to the eruption site augmented by traverses. Four hundred and forty-four scan and traverse measurements met quality criteria and were used, along with plume height and meteorological data, to calculate SO2 fluxes while accounting for wind-related uncertainties. A tendency for stronger SO2 flux concurrent with higher amplitude seismic tremor and the occurrence of lava fountaining was observed during Phases 4 and 5 which were characterized by intermittent crater activity including observable effusion of lava and gas release interspersed with long repose times. This tendency was used to refine the calculation of the amount of SO2 emitted during variably vigorous activity. The continuous seismic tremor time series was used to quantify how long during these eruption phases strong/weak activity was exhibited to improve the calculated SO2 flux during these Phases. The total SO2 emissions derived from field measurements align closely with results obtained by combining melt inclusion and groundmass glass analyses with lava effusion rate measurements (910 ± 230 kt SO2). Specifically, utilizing the maximum S content found in evolved melt inclusions and the least remaining S content in accompanying quenched groundmasses provides an identical result between field measurements and the petrological calculations. This suggests that the maximum SO2 release calculated from petrological estimates should be preferentially used to initialize gas dispersion models for basaltic eruptions when other measurements are lacking. During the eruption, the CALPUFF dispersion model was used to forecast ground-level exposure to SO2. The SO2 emission rates measured by DOAS were used as input for the dispersion model, with updates made when a significant change was measured. A detailed analysis of one mid-distance station over the entire eruption shows that the model performed very well at predicting the presence of volcanic SO2 when it was measured. However, it frequently predicted the presence of SO2 that was not measured and the concentrations forecasted had no correlation with the concentrations measured. Various approaches to improve the model forecast were tested, including updating plume height and SO2 flux source terms based on measurements. These approaches did not unambiguously improve the model performance but suggest that improvements might be achieved in more-polluted conditions.
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| 3. |
- Shimchenko, Marina, et al.
(author)
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Analysing software prefetching opportunities in hardware transactional memory
- 2022
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In: Journal of Supercomputing. - : Springer Nature. - 0920-8542 .- 1573-0484. ; 78:1, s. 919-944
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Journal article (peer-reviewed)abstract
- Hardware transactional memory emerged to make parallel programming more accessible. However, the performance pitfall of this technique is squashing speculatively executed instructions and re-executing them in case of aborts, ultimately resorting to serialization in case of repeated conflicts. A significant fraction of aborts occurs due to conflicts (concurrent reads and writes to the same memory location performed by different threads). Our proposal aims to reduce conflict aborts by reducing the window of time during which transactional regions can suffer conflicts. We achieve this by using software prefetching instructions inserted automatically at compile-time. Through these prefetch instructions, we intend to bring the necessary data for each transaction from the main memory to the cache before the transaction itself starts to execute, thus converting the otherwise long latency cache misses into hits during the execution of the transaction. The obtained results show that our approach decreases the number of aborts by 30% on average and improves performance by up to 19% and 10% for two out of the eight evaluated benchmarks. We provide insights into when our technique is beneficial given certain characteristics of the transactional regions, the advantages and disadvantages of our approach, and finally, discuss potential solutions to overcome some of its limitations.
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