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Phosphorus and calcium deficiency in horses represents an important factor responsible for the low equine production in Brazil. The basic mechanisms of P and Ca metabolism differ substantially among species. Regulation of P and Ca metabolism is less well understood in horses than in others species. With the use of the isotopic dilution technique is possible to evaluate the metabolism for this mineral. The aim of the present experiment was to study the effect of different Ca levels in the diet on P and Ca metabolism in horses.
The phenolic compounds are substances which reduce feed intake, protein digestibility and reduce ruminal activity in sheep and goats. To reduce the effects of tannins a lot of synthetic materials, for example PEG (polyethylene glycol) is tested as tannin-binding agent, and let protein free for the digestibility. The aim of this work was to test the effect of tannins in the rumen microbial growth using the in vitro 32P incorporation technique.
Cooperia punctata is the most prevalent parasitic intestinal nematode in Brazil and its site of fixation is duodenum and jejunum that are also the sites of greatest dietary phosphorus (P) absorption. Studies of phosphorus metabolism often involves balance trials and use of isotopes. When combined with mathematical modeling, calculation of flows between several pools becomes a possibility. The objective of the study on calves employing isotope and balance techniques was to apply and compare two models of P metabolism for resolving data generated by these techniques.
In vitro and in situ techniques for research on ruminants are currently much in focus. Since they have good correlations with in vivo data, they are feasible alternatives to predict the nutrition rates of feeds and may be applied in equine research on in vivo apparent digestibility. On the other hand, the disadvantage of these methods is due to the fact that fistulated animals are required to obtain the inoculum. Theodorou et al., (1994) developed an extremely promising gas production technique to assess feeds for ruminants, but still require rumen inoculum obtained from operated animals. Faecal microorganisms function similarly to those in the rumen and in the large intestine of equines. The objective this experiment was to compare rumen liquor and equine faeces as inoculum to determine in vitro digestibility of equine feeds.
Some herbaceous browses have shown a dry tolerance and had been used as animal feed. However, some of those plants have anti nutritional compounds such as tannins that can interfere on intake and digestibility. Tannins are polyphenolic compounds originated from the secondary metabolism of the plant as protection against insects, birds and as a result of drought, temperature or soil fertility. The objectives of this work were to evaluate the level and variation of tannins in important browses from the semi-arid of Brazil and to investigate the effects of different treatments (oven-, shade- and sun-drying and treatment with urea) on phenolics compounds.
Parasitic intestinal infections can affect the health of calves inducing symptoms like loss of appetite, diarrhoea, nutritional deficiency, loss of protein, and reduced weight gain. Cooperia punctata is the most prevalent parasitic intestinal nematode in Brazil (Lima, 1998) and its site of fixation is the upper part of the small intestine, i.e., duodenum and jejunum (Bailey, 1949) that are also the sites of greatest dietary phosphorus absorption (Schröder et al., 1995). Thus, the damage caused by the parasite when it penetrates the intestinal epithelium can interfere with phosphorus metabolism. The objective of this experiment was to evaluate the true phosphorus absorption by calves submitted to an acute infection with C. punctata using the 32P isotopic dilution technique.
In tropical countries, especially in Brazil, ruminants commonly are fed forage diets which are adequate in calcium but deficient in phosphorus, giving an inadequate Ca: P ratio. Thus, it is important to understand the effects of Ca level on phosphorus homeostasis control and to obtain more information on phosphorus utilization. The objective of this study is to provide information which may be useful to improve the understanding of the P homeostasis control in sheep fed various Ca levels, and to obtain more information on dietary Ca level effect on P utilization.
The Dark Energy Survey is undertaking an observational programme imaging 1/4 of the southern hemisphere sky with unprecedented photometric accuracy. In the process of observing millions of faint stars and galaxies to constrain the parameters of the dark energy equation of state, the Dark Energy Survey will obtain pre-discovery images of the regions surrounding an estimated 100 gamma-ray bursts over 5 yr. Once gamma-ray bursts are detected by, e.g., the Swift satellite, the DES data will be extremely useful for follow-up observations by the transient astronomy community. We describe a recently-commissioned suite of software that listens continuously for automated notices of gamma-ray burst activity, collates information from archival DES data, and disseminates relevant data products back to the community in near-real-time. Of particular importance are the opportunities that non-public DES data provide for relative photometry of the optical counterparts of gamma-ray bursts, as well as for identifying key characteristics (e.g., photometric redshifts) of potential gamma-ray burst host galaxies. We provide the functional details of the DESAlert software, and its data products, and we show sample results from the application of DESAlert to numerous previously detected gamma-ray bursts, including the possible identification of several heretofore unknown gamma-ray burst hosts.
The current paper aims to determine regional impacts of climate change on Irish farms examining the variation in farm responses. A set of crop growth models were used to determine crop and grass yields under a baseline scenario and a future climate scenario. These crop and grass yields were used along with farm-level data taken from the Irish National Farm Survey in an optimizing farm-level (farm-level linear programming) model, which maximizes farm profits under limiting resources. A change in farm net margins under the climate change scenario compared to the baseline scenario was taken as a measure to determine the effect of climate change on farms. The growth models suggested a decrease in cereal crop yields (up to 9%) but substantial increase in yields of forage maize (up to 97%) and grass (up to 56%) in all regions. Farms in the border, midlands and south-east regions suffered, whereas farms in all other regions generally fared better under the climate change scenario used in the current study. The results suggest that there is a regional variability between farms in their responses to the climate change scenario. Although substituting concentrate feed with grass feeds is the main adaptation on all livestock farms, the extent of such substitution differs between farms in different regions. For example, large dairy farms in the south-east region adopted total substitution of concentrate feed while similar dairy farms in the south-west region opted to replace only 0·30 of concentrate feed. Farms in most of the regions benefitted from increasing stocking rate, except for sheep farms in the border and dairy farms in the south-east regions. The tillage farms in the mid-east region responded to the climate change scenario by shifting arable production to beef production on farms.
Spectroscopic redshift surveys are an incredibly valuable tool in cosmology, allowing us to trace the distribution of galaxies as a function of distance and, thus, trace the evolution of structure formation in the Universe. However, estimating the redshifts from spectra with low signal-to-noise is difficult, and such data are often either discarded or require human classification of spectral lines to obtain the galaxy redshift. Darth Fader offers an automated method for estimating the redshifts of galaxies in the low signal-to-noise regime. Using a sophisticated, wavelet-based technique, galaxy spectra can be separated into continuum, line and noise components, and the lines can then be cross-correlated with template spectra in order to estimate the redshifts. Cross-matching of the identified lines then allows for a cleaning of the resulting catalogue, effectively removing the vast majority of erroneous redshift estimates and resulting in a highly pure, highly accurate redshift catalogue. Darth Fader allows us to effectively use low signal-to-noise galaxy spectra, and dramatically reduces the number of human hours required to do this, allowing spectroscopic surveys to probe deeper into the formation history of the Universe.
The problem of supernova photometric identification is still an open issue faced by large photometric surveys. In a previous investigation, we showed how combining Kernel Principal Component Analysis and Nearest Neighbour algorithms enable us to photometrically classify supernovae with a high rate of success. In the present work, we demonstrate that the introduction of Gaussian Process Regression (GPR) in determining each light curve highly improves the efficiency and purity rates. We present detailed comparison with results from the literature, based on the same simulated data set. The method proved to be satisfactorily efficient, providing high purity (⩽ 96%) rates when compared with standard algorithms, without demanding any information on astrophysical properties of the local environment, host galaxy or redshift.
A design of low mutual coupling between two microstrip patch antennas for multi input multi output antenna is presented. The two antenna elements operate at 5.8 GHz for wireless applications. The reduction of mutual coupling between the antenna elements is achieved by using a defected ground structure (DGS). The DGS is inserted between the microstrip patch antenna elements to limit the surface waves between them. The separation between the edges of the two elements has been achieved to be only 0.058λ0. The analysis of the correlation coefficient, diversity gain and total active reflection coefficient is presented to validate the performance of the multiple-input–multiple-output (MIMO) antenna. The isolation of the proposed MIMO antenna is 28 dB at 5.8 GHz and the envelope correlation equals 0.003. Owing to these good performances each antenna can operate almost independently. A good agreement is achieved between the simulated and the measured results.
Ofer Lahav, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK,
Filipe B. Abdalla, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK,
Manda Banerji, Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
Oxidative stress is a physiological condition that is associated with atherosclerosis, and it can be influenced by diet. Our objective was to group fifty-seven individuals with dyslipidaemia controlled by statins according to four oxidative biomarkers, and to evaluate the diet pattern and blood biochemistry differences between these groups. Blood samples were collected and the following parameters were evaluated: diet intake; plasma fatty acids; lipoprotein concentration; glucose; oxidised LDL (oxLDL); malondialdehyde (MDA); total antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing ability power assays. Individuals were separated into five groups by cluster analysis. All groups showed a difference with respect to at least one of the four oxidative stress biomarkers. The separation of individuals in the first axis was based upon their total antioxidant activity. Clusters located on the right side showed higher total antioxidant activity, higher myristic fatty acid and lower arachidonic fatty acid proportions than clusters located on the left side. A negative correlation was observed between DPPH and the peroxidability index. The second axis showed differences in oxidation status as measured by MDA and oxLDL concentrations. Clusters located on the upper side showed higher oxidative status and lower HDL cholesterol concentration than clusters located on the lower side. There were no differences in diet among the five clusters. Therefore, fatty acid synthesis and HDL cholesterol concentration seem to exert a more significant effect on the oxidative conditions of the individuals with dyslipidaemia controlled by statins than does their food intake.
Researches worldwide have been studying ruminal methane production in vitro and the in vitro gas production technique has demonstrated an ability to predict the in vivo enteric methane production from ruminants (Getachew et al., 2005; Tavendale et al., 2005). Studies of rumen microbial ecology in animals fed with tannin rich plants have demonstrated that tannins can affect rumen ecology. The objective of this study was to measure methane (CH4) production of Brazilian tannin rich plants incubated in vitro.
Calcium is needed for bone formation, muscle contraction, nerve transmission and a variety of other functions in the organism. Experiments has been carried out to study phosphorus metabolism in sheep and cattle, by using isotope dilution techniques however, there is very little information on Ca metabolism in sheep. The objective of this experiment was to study the effects of various Ca sources on the Ca flows in sheep by two models.