294 research outputs found

    Ingested insecticide to control Aedes aegypti: developing a novel dried attractive toxic sugar bait device for intra-domiciliary control

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    © 2020 The Author(s). Background: Illnesses transmitted by Aedes aegypti (Linnaeus, 1762) such as dengue, chikungunya and Zika comprise a considerable global burden; mosquito control is the primary public health tool to reduce disease transmission. Current interventions are inadequate and insecticide resistance threatens the effectiveness of these options. Dried attractive bait stations (DABS) are a novel mechanism to deliver insecticide to Ae. aegypti. The DABS are a high-contrast 28 inch2 surface coated with dried sugar-boric acid solution. Aedes aegypti are attracted to DABS by visual cues only, and the dried sugar solution elicits an ingestion response from Ae. aegypti landing on the surface. The study presents the development of the DABS and tests of their impact on Ae. aegypti mortality in the laboratory and a series of semi-field trials. Methods: We conducted multiple series of laboratory and semi-field trials to assess the survivability of Ae. aegypti mosquitoes exposed to the DABS. In the laboratory experiments, we assessed the lethality, the killing mechanism, and the shelf life of the device through controlled experiments. In the semi-field trials, we released laboratory-reared female Ae. aegypti into experimental houses typical of peri-urban tropical communities in South America in three trial series with six replicates each. Laboratory experiments were conducted in Quito, Ecuador, and semi-field experiments were conducted in Machala, Ecuador, an area with abundant wild populations of Ae. aegypti and endemic arboviral transmission. Results: In the laboratory, complete lethality was observed after 48 hours regardless of physiological status of the mosquito. The killing mechanism was determined to be through ingestion, as the boric acid disrupted the gut of the mosquito. In experimental houses, total mosquito mortality was greater in the treatment house for all series of experiments (P \u3c 0.0001). Conclusions: The DABS devices were effective at killing female Ae. aegypti under a variety of laboratory and semi-field conditions. DABS are a promising intervention for interdomiciliary control of Ae. aegypti and arboviral disease prevention.[Figure not available: see fulltext.

    Q-switched mode locking noise-like pulse generation from a thulium-doped all-fiber laser based on nonlinear polarization rotation

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    Q-switched mode locking (QML) noise-like pulse (NLP) emission from an all-fiber thulium-doped laser based on the nonlinear polarization rotation effect is reported. The QML emission is obtained in a cavity with net anomalous dispersion in a pump power interval in between the CW laser threshold and the threshold of the NLP regime. Highest-energy QML pulses were observed with a repetition rate of 812 kHz with a pump power of 520 mW at the optical wavelength of 1881.09 nm. A maximum overall energy of 460 nJ at an average output power of 6.4 mW was reached, which corresponds to a burst of mode-locked noise-like sub-pulses with 8.7 ns of pulse duration within a QML envelope of 11 μs. These results demonstrate unconventional pulse operation regime of NLPs and provide insights into the dynamics of mode-locked fiber lasers

    Gene discovery for facioscapulohumeral muscular dystrophy by machine learning techniques

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    Facioscapulohumeral muscular dystrophy (FSHD) is a neuromuscular disorder that shows a preference for the facial, shoulder and upper arm muscles. FSHD affects about one in 20-400,000 people, and no effective therapeutic strategies are known to halt disease progression or reverse muscle weakness or atrophy. Many genes may be incorrectly regulated in affected muscle tissue, but the mechanisms responsible for the progressive muscle weakness remain largely unknown. Although machine learning (ML) has made significant inroads in biomedical disciplines such as cancer research, no reports have yet addressed FSHD analysis using ML techniques. This study explores a specific FSHD data set from a ML perspective. We report results showing a very promising small group of genes that clearly separates FSHD samples from healthy samples. In addition to numerical prediction figures, we show data visualizations and biological evidence illustrating the potential usefulness of these results.Peer ReviewedPostprint (published version

    Validación de la nasa hondureña para el fortalecimiento de la pesca artesanal

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    El presente trabajo es el resultado de un proceso articulado de investigación e innovación en el que se vincula la Universidad Simón Bolívar, el Sector Productivo a través de asociaciones de pescadores del departamento del Atlántico, y el Estado a través del Ministerio de Agricultura. Se fundamentó en la imperiosa necesidad del sector pesquero de diversificar su actividad y fortalecer sus procesos internos en aras de hacerse más competitivo y sostenible. En este sentido, se soportó en la generación de nuevo conocimiento, la transferencia de tecnologías, la capacitación, la asistencia técnica y la validación técnica y económica de un arte de pesca nuevo en la región como estrategias de fortalecimiento empresarial de organizaciones del sector primario.This work is a result from a research and innovation process jointly developed by the Universidad Simón Bolívar, the productive sector through fishermen partnerships of department Atlántico and the State with the Agriculture Ministry. It supported on the imperative need of the fishing industry to diversify its business and strengthen its internal processes in order to become more competitive and sustainable. In this sense, it endured in new knowledge creation, technology transfer, training, technical assistance and technical and economic validation of a new fishing art in the region as business strategies to strengthen communities in the economy primary sector

    A novel rhein-huprine hybrid ameliorates disease-modifying properties in preclinical mice model of Alzheimer's disease exacerbated with high fat diet

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    Background: Alzheimer's disease (AD) is characterized by a polyetiological origin. Despite the global burden of AD and the advances made in AD drug research and development, the cure of the disease remains elusive, since any developed drug has demonstrated effectiveness to cure AD. Strikingly, an increasing number of studies indicate a linkage between AD and type 2 diabetes mellitus (T2DM), as both diseases share some common pathophysiological features. In fact, β-secretase (BACE1) and acetylcholinesterase (AChE), two enzymes involved in both conditions, have been considered promising targets for both pathologies. In this regard, due to the multifactorial origin of these diseases, current research efforts are focusing on the development of multi-target drugs as a very promising option to derive effective treatments for both conditions. In the present study, we evaluated the effect of rhein-huprine hybrid (RHE-HUP), a synthesized BACE1 and AChE inhibitor, both considered key factors not only in AD but also in metabolic pathologies. Thus, the aim of this study is to evaluate the effects of this compound in APP/PS1 female mice, a well-established familial AD mouse model, challenged by high-fat diet (HFD) consumption to concomitantly simulate a T2DM-like condition. Results: Intraperitoneal treatment with RHE-HUP in APP/PS1 mice for 4 weeks reduced the main hallmarks of AD, including Tau hyperphosphorylation, Aβ42 peptide levels and plaque formation. Moreover, we found a decreased inflammatory response together with an increase in different synaptic proteins, such as drebrin 1 (DBN1) or synaptophysin, and in neurotrophic factors, especially in BDNF levels, correlated with a recovery in the number of dendritic spines, which resulted in memory improvement. Notably, the improvement observed in this model can be attributed directly to a protein regulation at central level, since no peripheral modification of those alterations induced by HFD consumption was observed. Conclusions: Our results suggest that RHE-HUP could be a new candidate for the treatment of AD, even for individuals with high risk due to peripheral metabolic disturbances, given its multi-target profile which allows for the improvement of some of the most important hallmarks of the disease

    Ingested insecticide to control Aedes aegypti : developing a novel dried attractive toxic sugar bait device for intra-domiciliary control

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    Laboratory work was Funded by Pontificia Universidad Católica del Ecuadorʼs Internal Research Grant L13234, awarded to MN. Semi-field work was funded by a seed grant from the Syracuse University, awarded to DL.Background: Illnesses transmitted by Aedes aegypti (Linnaeus, 1762) such as dengue, chikungunya and Zika comprise a considerable global burden; mosquito control is the primary public health tool to reduce disease transmission. Current interventions are inadequate and insecticide resistance threatens the effectiveness of these options. Dried attractive bait stations (DABS) are a novel mechanism to deliver insecticide to Ae. aegypti. The DABS are a high-contrast 28 inch2 surface coated with dried sugar-boric acid solution. Aedes aegypti are attracted to DABS by visual cues only, and the dried sugar solution elicits an ingestion response from Ae. aegypti landing on the surface. The study presents the development of the DABS and tests of their impact on Ae. aegypti mortality in the laboratory and a series of semi-field trials. Methods: We conducted multiple series of laboratory and semi-field trials to assess the survivability of Ae. aegypti mosquitoes exposed to the DABS. In the laboratory experiments, we assessed the lethality, the killing mechanism, and the shelf life of the device through controlled experiments. In the semi-field trials, we released laboratory-reared female Ae. aegypti into experimental houses typical of peri-urban tropical communities in South America in three trial series with six replicates each. Laboratory experiments were conducted in Quito, Ecuador, and semi-field experiments were conducted in Machala, Ecuador, an area with abundant wild populations of Ae. aegypti and endemic arboviral transmission. Results: In the laboratory, complete lethality was observed after 48 hours regardless of physiological status of the mosquito. The killing mechanism was determined to be through ingestion, as the boric acid disrupted the gut of the mosquito. In experimental houses, total mosquito mortality was greater in the treatment house for all series of experiments (P < 0.0001). Conclusions: The DABS devices were effective at killing female Ae. aegypti under a variety of laboratory and semi-field conditions. DABS are a promising intervention for interdomiciliary control of Ae. aegypti and arboviral disease prevention.Publisher PDFPeer reviewe

    ESTUDO DA CONTRIBUIÇÃO INERCIAL E DE AMORTECIMENTO DE LINHAS DE ANCORAGEM NO MOVIMENTO DE MONOBOIAS

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    In offshore oil production activities, monobuoys comprise oceanic terminals used by offloading ships to control the oil transference to the coast. They are relatively small structures, with accentuated dynamic responses when submitted to wave forces. Due to their lower inertia when compared with other types of floating systems, their mooring lines and risers lines may contribute directly with its static and dynamic behavior, evidencing a structural and hydrodynamic coupling between monobuoy and lines. In the search of an&nbsp;analysis methodology that may take advantage on both coupled and uncoupled formulations, this work presents procedures to evaluate, based on coupled simulations, the inertial and damping contribution of the mooring lines and risers into the monobuoy’s responses. These values may be inserted as input parameters into a calibrated uncoupled simulation to obtain dynamic responses with higher accuracy and lower computational cost. This work will present a case study of a standard monobuoy, with 9 mooring lines, located into a 90 meter water depth, comparing the motions provided by coupled and uncoupled simulations, with and without the proposed calibration procedure, and assessing the computational costs
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