2,945 research outputs found

    Occupational Health and Safety Prevention Plan in Water Treatment Plant

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    The research was carried out at the "El Guarumo" drinking water plant located in Santa Ana, province of Manabí, Ecuador. The objective of the investigation was the proposal of a plan of prevention of occupational risks that allows the management of the labor risks in said plant. The main tools used were: survey, interview, checklist, LEST questionnaire for the diagnosis of the current situation in terms of working conditions, the risk identification matrix and the binary method of risk assessment. The main results obtained were the identification of the risks in their different categories, observing that the critical risk factors are related to the physical overexertion, the uncomfortable postures and the manual lifting of the load. Among the important risks are falling objects, skin contact with toxic substances and mental overwork, closely related to work pressures and job security? It was possible to carry out the proposal of preventive and corrective measures in order to properly manage the risks and contribute to the safety and health of the workers

    Intracellular trafficking and cellular uptake mechanism of PHBV nanoparticles for targeted delivery in epithelial cell lines

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    Indexación: Web of Science; Scopus; Scielo.Background: Nanotechnology is a science that involves imaging, measurement, modeling and a manipulation of matter at the nanometric scale. One application of this technology is drug delivery systems based on nanoparticles obtained from natural or synthetic sources. An example of these systems is synthetized from poly(3-hydroxybutyrate-co-3-hydroxyvalerate), which is a biodegradable, biocompatible and a low production cost polymer. The aim of this work was to investigate the uptake mechanism of PHBV nanoparticles in two different epithelial cell lines (HeLa and SKOV-3). Results: As a first step, we characterized size, shape and surface charge of nanoparticles using dynamic light scattering and transmission electron microscopy. Intracellular incorporation was evaluated through flow cytometry and fluorescence microscopy using intracellular markers. We concluded that cellular uptake mechanism is carried out in a time, concentration and energy dependent way. Our results showed that nanoparticle uptake displays a cell-specific pattern, since we have observed different colocalization in two different cell lines. In HeLa (Cervical cancer cells) this process may occur via classical endocytosis pathway and some internalization via caveolin-dependent was also observed, whereas in SKOV-3 (Ovarian cancer cells) these patterns were not observed. Rearrangement of actin filaments showed differential nanoparticle internalization patterns for HeLa and SKOV-3. Additionally, final fate of nanoparticles was also determined, showing that in both cell lines, nanoparticles ended up in lysosomes but at different times, where they are finally degraded, thereby releasing their contents. Conclusions: Our results, provide novel insight about PHBV nanoparticles internalization suggesting that for develop a proper drug delivery system is critical understand the uptake mechanism.https://jnanobiotechnology.biomedcentral.com/articles/10.1186/s12951-016-0241-

    Growth patterns and reproductive performance of grazing Brahman cows in a tropical environment

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    Two experiments were conducted in the neotropical savannas of Carimagua, Colombia to test the hypothesis that Brahman females subjected to sustained grazing undernutrition as heifers can attain high reproductive performance as mature cows if allowed to make compensatory gains. Experiment 1 subjected weaned heifers to three distinct, but modest, rates of weight gain (H, M, and L) on a poor quality tropical pasture until reaching mating weight at 270 kg. Each group was then subdivided and grazed on pastures that allowed high (h) or low (l) weights gains. Experiment 2 allowed heifers of the same type to achieve continuous high weight gains and served as a control. Regardless of earlier treatment, all h cows in Experiment 1 achieved mature body size and reproductive performance comparable to those of the well-fed animals of Experiment 2. It is concluded that the potential exists for a wide range of grazing management of Brahman heifers in the tropics, and it is possible to achieve levels of performance that represent a substantial improvement over current standards at a modest management cost

    Experimental study of the mechanical transmission of rabbit hemorrhagic disease virus (RHDV2/b) by Aedes Albopictus (Diptera: Clicidae) and Phlebotomus papatasi (diptera: psychodidae); 34447999

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    Rabbit hemorrhagic disease (RHD) is caused by a lagovirus mainly affecting European rabbits (Oryctolagus cuniculus), although other European and North American lagomorph species are also susceptible to fatal infection by the new viral variant RHDV2/b. In the present work, direct mechanical transmission of the rabbit hemorrhagic disease virus (RHDV2/b variant) by the hematophagous Diptera Aedes albopictus (Skuse) (Diptera: Culicidae) and the sand fly Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae) was tested. For each species, six and three laboratory rabbits were exposed to bites of dipterous females partially fed on RHDV2/b viral suspension 2 h and 24 h prior to exposure, respectively. The rabbits were then monitored for clinical changes and mortality for 35 d, and seroconversion was assessed by indirect ELISA. No rabbit died or showed clinical signs of disease, and seroconversion was recorded in two rabbits challenged with P. papatasi females fed the viral suspension 2 h prior to exposure. The number of RHDV2/b RNA copies/female was higher in Ae. albopictus than in P. papatasi but the decrease over time of RNA load in Ae. albopictus was greater than that in P. papatasi. The results of this study suggest the inability of Ae. albopictus to serve as a direct mechanical vector of RHDV2/b, but sand flies could play a role in the local transmission of RHD. © The Author(s) 2021. Published by Oxford University Press on behalf of Entomological Society of America

    Ergonomic Risk Assessment for Forced Posture

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    Applying the ergonomic method "rapid assessment of the whole body" (REBA), a way of evaluation and diagnosis of the jobs immersed within the direction of Human Talent of the Provincial Government of Manabí (GPM) is demonstrated. To the prevention of future diseases by studying techniques that can improve the health of the personnel involved. A diagnosis of the risk factors present in the workplace was carried out. The field evaluation was carried out and the descriptive procedure was applied by collecting data from a population in association with the following techniques: observation, survey, matrix, As a result, a rest break system should be implemented so that people can recover their energies in order to improve their work performance and that they develop training, talks, and workshops that help to improve knowledge about ergonomics and their risk factors

    Performance and carcass characteristics of steers fed with two levels of metabolizable energy intake during summer and winter season

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    Climate change is producing an increase on extreme weather events around the world such as flooding, drought and extreme ambient temperatures impacting animal production and animal welfare. At present, there is a lack of studies addressing the effects of climatic conditions associated with energy intake in finishing cattle in South American feed yards. Therefore, two experiments were conducted to assess the effects of environmental variables and level of metabolizable energy intake above maintenance requirements (MEI) on performance and carcass quality of steers. In each experiment (winter and summer), steers were fed with 1.85 or 2.72 times of their requirements of metabolizable energy of maintenance. A total of 24 crossbred steers per experiment were used and located in four pens (26.25 m2/head) equipped with a Calan Broadbent Feeding System. Animals were fed with the same diet within each season, varying the amount offered to adjust the MEI treatments. Mud depth, mud scores, tympanic temperature (TT), environmental variables, average daily gain, respiration rates and carcass characteristics plus three thermal comfort indices were collected. Data analysis considered a factorial arrangement (Season and MEI). In addition, a repeated measures analysis was performed for TT and respiration rate. Mean values of ambient temperature, solar radiation and comfort thermal indices were greater in the summer experiment as expected (P\u3c 0.005). The mean values of TT were higher in steers fed with higher MEI and also in the summer season. The average daily gain was greater during summer v. winter (1.10 ± 0.11 v. 0.36 ± 0.06) kg/day, also when steers were fed 2.72 v. 1.85 MEI level (0.89 ± 0.12 v. 0.57 ± 0.10) kg/day. In summer, respiration rate increased in 41.2% in the afternoon. In winter, muddy conditions increased with time of feeding, whereas wind speed and rainfall had significant effects on TT and average daily gain. We conclude that MEI and environmental variables have direct effects on the physiology and performance of steers, including TT and average daily gain, particularly during the winter. In addition, carcass characteristics were affected by season but not by the level of MEI. Finally, due to the high variability of data as well as the small number of animals assessed in these experiments, more studies on carcass characteristics under similar conditions are required

    Racial disparity and survival outcomes between African-American and Caucasian American men with penile cancer

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    Objective: To determine whether there is a survival difference for African-American men (AAM) versus Caucasian American men (CM) with penile squamous cell carcinoma (pSCC), particularly in locally advanced and metastatic cases where disease mortality is highest. Patients and Methods: Using the Florida Cancer Data System, we identified men with pSCC from 2005 to 2013. We compared age, follow-up, stage, race, and treatment type between AAM and CM. We performed Kaplan\u2013Meier analysis for overall survival (OS) between AAM and CM for all stages, and for those with locally advanced and metastatic disease. A multivariable model was developed to determine significant predictors of OS. Results: In all, 653 men (94 AAM and 559 CM) had pSCC and 198 (30%) had locally advanced and/or metastatic disease. A higher proportion of AAM had locally advanced and/or metastatic disease compared to CM (38 [40%] vs 160 [29%], P = 0.03). The median (interquartile range) follow-up for the entire cohort was 12.6 (5.4\u201332.0) months. For all stages, AAM had a significantly lower median OS compared to CM (26 vs 36\ua0months, P = 0.03). For locally advanced and metastatic disease, there was a consistent trend toward disparity in median OS between AAM and CM (17 vs 22\ua0months, P = 0.06). After adjusting for age, stage, grade, and treatment type, AAM with pSCC had a greater likelihood of death compared to CM (hazard ratio 1.64, P = 0.014). Conclusions: AAM have worse OS compared to CM with pSCC and this may partly be due to advanced stage at presentation. Treatment disparity may also contribute to lessened survival in AAM, but we were unable to demonstrate a significant difference in treatment utilisation between the groups

    Microbial fuel cells: a green and alternative source for bioenergy production

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    Microbial fuel cell (MFC) represents one of the green technologies for the production of bioenergy. MFCs using microalgae produce bioenergy by converting solar energy into electrical energy as a function of metabolic and anabolic pathways of the cells. In the MFCs with bacteria, bioenergy is generated as a result of the organic substrate oxidation. MFCs have received high attention from researchers in the last years due to the simplicity of the process, the absence in toxic by-products, and low requirements for the algae growth. Many studies have been conducted on MFC and investigated the factors affecting the MFC performance. In the current chapter, the performance of MFC in producing bioenergy as well as the factors which influence the efficacy of MFCs is discussed. It appears that the main factors affecting MFC’s performance include bacterial and algae species, pH, temperature, salinity, substrate, mechanism of electron transfer in an anodic chamber, electrodes materials, surface area, and electron acceptor in a cathodic chamber. These factors are becoming more influential and might lead to overproduction of bioenergy when they are optimized using response surface methodology (RSM)

    Perturbations in the relaxation mechanism for a large cosmological constant

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    Recently, a mechanism for relaxing a large cosmological constant (CC) has been proposed [arxiv:0902.2215], which permits solutions with low Hubble rates at late times without fine-tuning. The setup is implemented in the LXCDM framework, and we found a reasonable cosmological background evolution similar to the LCDM model with a fine-tuned CC. In this work we analyse analytically the perturbations in this relaxation model, and we show that their evolution is also similar to the LCDM model, especially in the matter era. Some tracking properties of the vacuum energy are discussed, too.Comment: 18 pages, LaTeX; discussion improved, accepted by CQ
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