2,981 research outputs found

    Inclusion of Secale cereale and Pentosanases in the Ration of Laying Hens: Exploring its Effect on Egg Production and Concentrate Intake and Searching the Optimal Combination in a Diet

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    Background and Objective: Antinutritional factors are usually found in cereals, these correspond to molecular complexes structured by carbohydrates present in the grains, which increase the viscosity of the food bolus, resulting in diminished organic matter digestibility, food intake and egg production. These polymers are known as soluble non-starch polysaccharides (NSPs). The objective of this experiment was to assess the effect of incorporating Secale cereale (SEc) and pentosanases (EEp) in the diets of laying hens (Lohmann LSL hybrid) on their egg production (EP) and concentrate consumption (CC), optimal combination between the main factors was estimated for EP and CC. Materials and Methods: The trial was carried out on a commercial egg-producing poultry farm (Valparaíso Region, Chile). A completely randomized experimental design was used, with a 4×5 factorial arrangement of two factors (four levels for SEc and five levels for EEp). Ten repetitions were used per treatment, where each experimental unit corresponded to one cage with five hens. A contour curvature analysis was carried out to determine the optimal level of inclusion of SEc with EEp. The experimental period lasted 84 days. Results: There was an interaction effect of SEc and EEp on EP and CC. The optimum level of inclusion for EP was 200 g kg–1 SEc and 1 g kg–1 EEp, with average production of 396 units, for CC, the optimum value observed corresponded to 200 g kg–1 SEc with 0.5 g kg–1 EEp (47.56 kg). The lowest EP and CC responses, regardless of the EEp level in the diet, was observed with the inclusion of 600 g kg–1 SEc. The contour area curvature analysis for EP gave a high response curve zone between 130-390 g kg–1 SEc and 0.38-1.57 g kg–1 EEp, the highest response levels for CC were 120-350 g kg–1 SEc and 0.43-1.75 g kg–1 EEp. Conclusion: In this research it was possible to establish that high level of SEc inclusion in the diet affects negatively eggs production and concentrate intake. However, when pentosanases are included in the diet improve these variables. These results suggest possible antinutritional factors of SEc that could have caused negative effects on the hens' physiological response

    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

    Anatomical and molecular properties of long descending propriospinal neurons in mice

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    Long descending propriospinal neurons (LDPNs) are interneurons that form direct connections between cervical and lumbar spinal circuits. LDPNs are involved in interlimb coordination and are important mediators of functional recovery after spinal cord injury (SCI). Much of what we know about LDPNs comes from a range of species, however, the increased use of transgenic mouse lines to better define neuronal populations calls for a more complete characterisation of LDPNs in mice. In this study, we examined the cell body location, inhibitory neurotransmitter phenotype, developmental provenance, morphology and synaptic inputs of mouse LDPNs throughout the cervical and upper thoracic spinal cord. LDPNs were retrogradely labelled from the lumbar spinal cord to map cell body locations throughout the cervical and upper thoracic segments. Ipsilateral LDPNs were distributed throughout the dorsal, intermediate and ventral grey matter as well as the lateral spinal nucleus and lateral cervical nucleus. In contrast, contralateral LDPNs were more densely concentrated in the ventromedial grey matter. Retrograde labelling in GlyT2GFP and GAD67GFP mice showed the majority of inhibitory LDPNs project either ipsilaterally or adjacent to the midline. Additionally, we used several transgenic mouse lines to define the developmental provenance of LDPNs and found that V2b positive neurons form a subset of ipsilaterally projecting LDPNs. Finally, a population of Neurobiotin (NB) labelled LDPNs were assessed in detail to examine morphology and plot the spatial distribution of contacts from a variety of neurochemically distinct axon terminals. These results provide important baseline data in mice for future work on their role in locomotion and recovery from SCI

    Spatially resolved CO2 carbon stable isotope analyses at the microscale using Raman spectroscopy

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    Measuring the carbon stable isotope ratio (13C/12C, expressed as δ13CCO2) in geogenic CO2 fluids is a crucial geochemical tool for studying Earth's degassing. Carbon stable isotope analysis is traditionally performed by bulk mass spectrometry. Although Raman spectroscopy distinguishes 12CO2 and 13CO2 isotopologue bands in spectra, using this technique to determine CO2 isotopic signature has been challenging. Here, we report on in-situ non-destructive analyses of the C stable isotopic composition of CO2, applying a novel high-resolution Raman configuration on 42 high-density CO2 fluid inclusions in mantle rocks from the Lake Tana region (Ethiopia) and El Hierro (Canary Islands). We collected two sets of three spectra with different acquisition times at high spectral resolution in each fluid inclusion. Among the 84 sets of spectra, 58 were characterised by integrated 13CO2/12CO2 band area ratios with reproducibility better than 4‰. Our results demonstrate the determination of δ13CCO2 by Raman spectroscopy in individual fluid inclusions with an error better than 2.5 ‰, which satisfactorily matches bulk mass spectrometry analyses in the same rock samples, supporting the accuracy of the measurements. We thus show that Raman Spectroscopy can provide a fundamental methodology for non-destructive, site-specific, and spatially resolved carbon isotope labelling at the microscale

    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

    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

    Managerial Work in a Practice-Embodying Institution - The role of calling, the virtue of constancy

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    What can be learned from a small scale study of managerial work in a highly marginal and under-researched working community? This paper uses the ‘goods-virtues-practices-institutions’ framework to examine the managerial work of owner-directors of traditional circuses. Inspired by MacIntyre’s arguments for the necessity of a narrative understanding of the virtues, interviews explored how British and Irish circus directors accounted for their working lives. A purposive sample was used to select subjects who had owned and managed traditional touring circuses for at least 15 years, a period in which the economic and reputational fortunes of traditional circuses have suffered badly. This sample enabled the research to examine the self-understanding of people who had, at least on the face of it, exhibited the virtue of constancy. The research contributes to our understanding of the role of the virtues in organizations by presenting evidence of an intimate relationship between the virtue of constancy and a ‘calling’ work orientation. This enhances our understanding of the virtues that are required if management is exercised as a domain-related practice

    Galactic Indigestion: Numerical Simulations of the Milky Way's Closest Neighbor

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    Are dwarf spheroidal galaxies dark matter dominated? We present N-body simulations of the interaction between the Milky Way and its closest companion, the Sagittarius dwarf spheroidal galaxy, constrained by new kinematic, distance and surface density observations detailed in a companion paper. It is shown that there is no possible self-consistent solution to the present existence of the Sagittarius dwarf if its distribution of luminous matter traces the underlying distribution of mass. The luminous component of the dwarf galaxy must therefore be shielded within a small dark matter halo. Though at present we are unable to construct a fully self-consistent model that includes both the stellar and dark matter components, it is shown numerically that it is possible that a pure dark matter model, approximating the dark matter halo deduced for the Sagittarius dwarf from analytical arguments, may indeed survive the Galactic tides. The orbit of the Sagittarius dwarf galaxy around the Milky Way is considered, taking into account the perturbative effects of the Magellanic Clouds. It is shown that at the present time, the orbital period must be short, ~ 0.7 Gyr; the initial orbital period for a 10^9 Solar mass model will have been ~ 1 Gyr. It is found that a close encounter with the Magellanic Clouds may have occured, though the chances of such an interaction affecting the orbit of the Sagittarius dwarf galaxy is negligible.Comment: To appear in Ap
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