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Saliva plays an important role in the fluidity and buffering capacity of the rumen contents, with the parotid saliva accounting for a high proportion of the total buffering saliva. Feeding behaviour is one of the main factors influencing the amount of saliva produced and this in turn varies with the structure of the diet (Duric et al. 1994) and animal species (Domingue et al 1991). The objective of this study was to measure parotid salivation along with the feeding behaviour (eating, resting, ruminating) in sheep and goats fed either chopped or pelleted alfalfa.
The use of natural clays for the removal of dyes from wastewater, an important part of environmental remediation, is desirable due, not least, to their low cost. Palygorskite (PAL), a rigid-structure clay, is a good candidate for use in the elimination of industrial effluents, based on its exceptional adsorptive properties. Recently, a new palygorskite deposit has been discovered in Cuba and its use in the adsorption of dyes has not yet been explored in detail. In the present study, the use of unmodified natural Cuban palygorskite as a host for dyes was evaluated. Congo red (CR) and methylene blue (MB) were the anionic and cationic dyes tested, respectively, because of their wide use and toxicity to the environment. Several physical-chemical parameters were studied in order to establish the best experimental conditions under which to achieve the greatest dye load per gram of clay. Natural mixtures with different percentages of montmorillonite were also tested to evaluate their effect on the adsorption of the dyes. The results indicated that at pH values of ~7–9 and an initial dye concentration of 0.1 mg mL–1, the process was efficient. X-ray diffraction (XRD) analysis proved the surface adsorption of both dyes on the clays. The main interactions involved in the clay-dye system were electrostatic forces and H-bonds. Adsorption of CR seemed to be controlled fundamentally by the palygorskite phase. Such results support the use of this natural clay as an efficient host for the removal of MB and CR from wastewater.
Quantitative expressions of the kinetics of digestion are needed to estimate more precisely the quantity and composition of nutrients digested from feeds and their subsequent efficiency of utilization by the animal (Mertens, 1993). Degradation kinetic parameters are estimated by fitting appropriate models to data resulting from the measurement of either the undigested residue or the fermentation end-products after exposure of the feed to digestion. Kinetic data can be collected using either in vitro or in situ procedures. The in situ porous synthetic fibre bag technique has been extensively used to describe the kinetics of feeds degradation in the rumen. Several in vitro gas production methods have been developed to assess fermentation kinetics. The aim of this work was to study the relationship between rumen degradation parameters of forages determined either by the in situ procedure or by the gas production technique and to evaluate the potential of gas production measurements to assess the extent of dry matter degradation in the rumen.
In the last few years there has been an increasing concern regarding the use of antibiotics in ruminant feeding and the potential for selection of antibiotic-resistant pathogen micro-organisms. Some authors (Martin and Streeter, 1995; Callaway and Martin, 1996) suggested that organic acids (aspartate, fumarate, malate) potentially provide an alternative to currently used antimicrobial compounds. Several in vitro studies (Martin and Streeter, 1995; Callaway and Martin, 1996) showed that incorporation of DL-malate into fermentations with both Selenomonas ruminantium HD4 and with mixed ruminal micro-organisms resulted in changes in final pH, methane and volatile fatty acids (VFA) that are analogous to ionophore effects. Nisbet and Martin (1993) hypothesized that malate acted as an electron sink for hydrogen. However, the mechanism of action is not well known. Malate is a key intermediate in the succinate-propionate pathway and therefore could stimulate propionate production. The objective of this study was to study the effects of DL-malate and propionate on the in vitro rumen fermentation of a 50:50 foragexoncentrate diet.
The study was carried out using the rumen simulation technique (RUSITEC) following the general incubation procedure described by Czerkawski and Breckenridge (1977). The complete unit consisted of eight vessels with an effective volume of 700 ml each. The vessels inocula (solid and liquid) were obtained from three ruminally fistulated ewes given a diet consisting of 700 g alfalfa hay and 300 g concentrate per kg dry matter (DM) (Table 1) and transferred to the RUSITEC system within 30 min of the 1st day of the experiment. The flow through the vessels was maintained by continuous infusion of artificial saliva at a rate of 533 ml/day. Each vessel received daily a nylon bag containing 7 g alfalfa hay, 7 g concentrate and 0·10 g vitaminsminerals mix. From the 1st day of incubation three vessels received daily 5·62 mmol DL-malate (disodium salt; Sigma-Aldrich Quimica, S.A., Spain), three vessels received 5·62 mmol of propionate (monosodium salt; Sigma-Aldrich Quimica, S.A., Spain) and two vessels received no addition (control). DL-malate and propionate were weighed into the nylon bags and carefully mixed with the food.
The present study was designed to describe the effects of early feed restriction of Merino lambs on feed efficiency during the fattening period by examining ruminal microbiota and fermentation parameters, gastrointestinal morphology, digestibility or liver proteome. In total, 24 male Merino lambs were randomly assigned to two experimental treatments (n=12 per treatment). Lambs of the first group (ad libitum (ADL)) were kept permanently with the dams, whereas the other 12 lambs (restricted (RES)) were milk restricted. When lambs reached a live BW (LBW) of 15 kg, all the animals were offered the same complete pelleted diet (35 g dry matter/kg LBW per day) until slaughter at a LBW of 27 kg. The RES lambs showed poorer feed efficiency during the fattening period when compared with the ADL group (feed to gain ratio, 3.69 v. 3.05, P<0.001). No differences were observed in ruminal microbiota, fermentation parameters or apparent digestibility. However, the proportion of the small intestine and the length of ileal villi were reduced in the RES lambs. In total, 26 spots/proteins were identified in the liver proteomic profile, with significant differences (P<0.05) between experimental treatments, suggesting a higher catabolism of proteins and a reduction in β-oxidation of fatty acids in RES lambs when compared with the ADL animals. In conclusion, early feed restriction of Merino lambs during the suckling period promotes long-term effects on the small intestine and the proteomic profile of the liver, which may influence the metabolic use of nutrients, thus negatively affecting feed efficiency during the fattening phase.
In north-west of Spain dairy sheep are fed high amounts of concentrate, which are usually offered at milking time. This pattern of feeding often affects negatively the rumen fermentation (Mould et al., 1983). One alternative to reduce these negative effects could be the use of complete diets. The objective of this study was to obtain information on rumen fermentation in sheep receiving complete diets with different forage:concentrate ratio.
The inoculum represents one of the greatest sources of uncontrolled variation in digestibility estimates via in vitro rumen fermentation methods (Marten and Barnes 1980). Microbial activity of rumen inoculum may be influenced by animal and diet factors. The objective of this work was to evaluate the effects of the level of inclusion of concentrate in the diet of the donor animal on the measurement of the in vitro digestibility of hay.
The aim of this work is to calibrate and validate an empirical approach to predict the date of occurrence of the grapevine phenology (budburst, flowering and veraison) temporally and spatially at the within-field scale. It is based on the collaboration between a classical model of phenology based on climate data and a spatial model calibrated with ancillary data of phenology observations. This approach was tested and validated on a field of cv Cabernet Sauvignon. Results showed that the spatial component improved the fit of the climatic model, allowing the generation of maps of the grapevine phenology with errors lower than 5 days of prediction. Spatio-temporal model errors were mainly associated with the temporal component of the model.
Early prediction of the final size of any epidemic and in particular for Zika disease outbreaks can be useful for health authorities in order to plan the response to the outbreak. The Richards model is often been used to estimate epidemiological parameters for arboviral diseases based on the reported cumulative cases in single- and multi-wave outbreaks. However, other non-linear models can also fit the data as well. Typically, one follows the so called post selection estimation procedure, i.e., selects the best fitting model out of the set of candidate models and ignores the model uncertainty in both estimation and inference since these procedures are based on a single model. In this paper we focus on the estimation of the final size and the turning point of the epidemic and conduct a real-time prediction for the final size of the outbreak using several non-linear models in which these parameters are estimated via model averaging. The proposed method is applied to Zika outbreak data in four cities from Colombia, during the outbreak ocurred in 2015–2016.
This paper proposes a methodology aiming at using historical yield data to improve yield sampling and yield estimation. The sampling method is based on a collaboration between historical data (at least three years) and yield measurements of the year performed on some sites within the field. It assumes a temporal stability of within field yield spatial patterns over the years. The first factor of a principal component analysis (PCA) is used to summarize the stable temporal patterns of within field yield data and it represents a large part of the variability of the different years assuming yield temporal stability and a high positive correlation between this factor and the yield. This main factor is then used to choose the best sites to sample (target sampling). Yield measurements are then used to calibrate a model that relates yield values to coordinates on the first factor of the PCA. This sampling method was tested on three vine fields (Vitis vinifera L.) in Chile and France with different varieties (Chardonnay, Cabernet Sauvignon and Syrah). For each of these fields, yield data of several years were available at the within field level. After temporal stability of yield patterns was verified for almost all the fields, the proposed sampling method was applied. Results were compared to those of a classical random sampling method showing that the use of historical yield data allows sampling sites selection to be optimized. Errors in yield estimations were reduced by more than 10% in all the cases, except when yield stable patterns are affected by specific events, i.e. early frost occurring on Chardonnay field.
Advances in radiocarbon dating by accelerator mass spectrometry (AMS) have made it possible to date prehistoric cave paintings by sampling the pigment itself instead of relying on dates derived from miscellaneous prehistoric remains recovered in the vicinity of the paintings. The work at the Laboratoire des Sciences du Climat et de l'Environnement (LSCE) concentrated on prehistoric charcoal cave paintings from southern France and northern Spain. In most caves, pigment samples were collected from several paintings, and in some instances the sample size allowed for multiple independent measurements on the same figure, so that the coherence of the calculated dates could be tested. Before being dated, each specimen was subjected to a thermal treatment preceded by an acid and basic treatment of intensity commensurate with the sample size.
Nine bison drawings from three caves in the Cantabrian region of Spain—two from Covaciella, three from Altamira, and four from El Castillo—were sampled and dated. The 27 dates fell between 13,000 and 14,500 BP, allowing us to attribute the drawings to the Magdalenian period. The 24 dates for 13 drawings in the Cosquer cave indicated two distinct periods of painting activity—one around 28,000 BP and the other around 19,000 BP. The Chauvet cave paintings turned out to be the oldest recorded to date, as five dates fell between 32,000 and 31,000 BP. After discussing the sample preparation protocol in more detail, we will discuss the ages obtained and compare them with other chronological data.
Recently, new views of the current status of δ Scuti stars have been developed by Rodríguez & Breger (2001) who carried out an excellent review, listing 8 pre-main-sequence (PMS) δ Scuti candidates and examined the possibility of the existence of PMS δ Scuti variable stars. Here we discuss the nature of 4 stars from their list: 2 said to be members of NGC 2264 and 2 of NGC 6823.
Thirty-two lambs (n = 8 per treatment) were fed a total mixed ration (TMR) formulated either with palm oil (CTRL; 34 g palm oil/kg TMR) or flaxseed (FS) (85 g FS/kg TMR) alone or enriched with quercetin (QCT, 34 g palm oil plus 2 g QCT/kg TMR; FS-QCT, 85 g FS plus 2 g QCT/kg TMR). The animals were slaughtered after being fed for at least 5 weeks with the experimental diets and samples of ruminal contents and ruminal liquid were collected for quantitative real-time polymerase chain reaction analyses of ruminal microbial species and fatty acid profile or in vitro fermentation, respectively. Results demonstrated that Butyrivibrio vaccenic acid (VA) and Butyrivibrio stearic acid (SA) producing bacteria copy numbers were decreased when FS was added to the diet of fattening lambs, which seemed to be in agreement with numerically (but not significantly) lower values for gas production, methane production and butyric acid during in vitro incubation. Ciliate protozoa were significantly enhanced by QCT, which was in accordance with numerically (but not significantly) higher values for in vitro methane production. Moreover, the modifications observed in ruminal microbial populations (Butyrivibrio and ciliate protozoa) when FS and QCT were included together (but not separately) in the diet of fattening lambs were probably related to a trend towards significantly higher values of rumenic acid (RA) in ruminal content. In conclusion, when FS and QCT were administered together in the diet of fattening lambs quantitative changes in the ruminal microbiota were observed, which might have promoted an increment of RA concentration in ruminal contents.
Structural brain magnetic resonance imaging (MRI) traits share part of their genetic variance with cognitive traits. Here, we use genetic association results from large meta-analytic studies of genome-wide association (GWA) for brain infarcts (BI), white matter hyperintensities, intracranial, hippocampal, and total brain volumes to estimate polygenic scores for these traits in three Scottish samples: Generation Scotland: Scottish Family Health Study (GS:SFHS), and the Lothian Birth Cohorts of 1936 (LBC1936) and 1921 (LBC1921). These five brain MRI trait polygenic scores were then used to: (1) predict corresponding MRI traits in the LBC1936 (numbers ranged 573 to 630 across traits), and (2) predict cognitive traits in all three cohorts (in 8,115–8,250 persons). In the LBC1936, all MRI phenotypic traits were correlated with at least one cognitive measure, and polygenic prediction of MRI traits was observed for intracranial volume. Meta-analysis of the correlations between MRI polygenic scores and cognitive traits revealed a significant negative correlation (maximal r = 0.08) between the HV polygenic score and measures of global cognitive ability collected in childhood and in old age in the Lothian Birth Cohorts. The lack of association to a related general cognitive measure when including the GS:SFHS points to either type 1 error or the importance of using prediction samples that closely match the demographics of the GWA samples from which prediction is based. Ideally, these analyses should be repeated in larger samples with data on both MRI and cognition, and using MRI GWA results from even larger meta-analysis studies.
To determine the effect of pterygopalatine fossa injection with xylocaine and adrenaline on: surgical field bleeding and blood loss during functional endoscopic sinus surgery for chronic rhinosinusitis, and the duration of the procedure.
A prospective, single-blinded, controlled trial was performed in a tertiary care academic centre. A total of 45 patients undergoing functional endoscopic sinus surgery for chronic rhinosinusitis, whose disease was symmetrical based on computed tomography grading, were included. A unilateral pterygopalatine fossa injection with 1 per cent xylocaine and 1:100 000 adrenaline was performed after the induction of anaesthesia. The contralateral side served as the control. The operating surgeon, who was blinded to the injected side, assessed the surgical field using a validated six-item grading system. Blood loss, blood pressure, heart rate and end-tidal carbon dioxide were recorded every 15 minutes for each side separately, and duration of surgery was noted.
There was no statistically significant difference in the surgical field grade between the injected and non-injected sides (p = 0.161). There were no differences in blood loss or duration of surgery.
Pterygopalatine fossa injection prior to functional endoscopic sinus surgery did not decrease intra-operative surgical field bleeding, blood loss or duration of surgery.
To evaluate the outcomes (using validated outcome tools) and cost benefits of functional endoscopic sinus surgery in a population of severely asthmatic patients with chronic rhinosinusitis.
A prospective cohort study was conducted. The study comprised consecutive patients diagnosed with asthma and chronic rhinosinusitis for whom medical treatment had failed and who were scheduled for functional endoscopic sinus surgery. General health and disease-specific outcome questionnaires were completed pre- and post-operatively. Costs associated with both functional endoscopic sinus surgery and out-patient visits to a comprehensive asthma clinic were calculated.
A total of 47 patients completed the surveys. The average improvement in Chronic Sinusitis Survey scores following functional endoscopic sinus surgery was 17 per cent. The average reduction in out-patient asthma clinic visits was 50 per cent, which translates to an average cost saving of $1035 Canadian dollars per patient per year.
Functional endoscopic sinus surgery is a cost-effective treatment modality for asthmatic patients with chronic rhinosinusitis. This information is important for: the distribution and planning of resources, prioritising health programmes, and establishing practice guidelines.
In this work, it was used a Johnson-Cook elastic-plastic model to represent the behavior in the friction welding process of 6063 aluminum. Temperature and strain rate dependent laws were used to determine the behavior of the material. The results determined that the amount of heat transferred into the material dictates the quality and the microstructure of the welding and the mechanical strength of the welded joint in an ideal process.
This article presents an analysis of the heat generated by welding two different metals by friction. The welded samples were a DP600 steel and aluminum 6063. To perform this analysis it study the heat conducted in this system using Fourier’s Law and respective specific heat of each metal. We analyzed the integral equations that make up the model and the heat flow analysis to predict the optimal combination of alloys, in an ideal process.
In this study the influence of heat input (HI) and heat treatment on submerged arc welded duplex SAF 2205 steel joints has been evaluated. In particular, multi-pass welding operations have been performed on 18 mm thick plates using four different heat inputs; a post-weld solubilizing heat treatment has been carried out in order to reduce the microstructural effects on the structure of the heat affected zone (HAZ). Instrumented impact strength tests have been performed on Charpy samples machined from the welded joints; the total absorbed energy and the two complementary contributions of initiation and propagation energies have been evaluated and correlated to the percentages of ferrite and austenite. The microstructures and the fracture profiles have been observed using an optical microscope (OM) and quantitatively analyzed by means of an image analyzer. A scanning electron microscope (SEM) equipped by energy dispersive X-ray spectroscopy (EDS) has been used to study the fractured surfaces. Hardness profiles have been performed across the joints in order to verify the hardness variations. A total absence of secondary phases has been found on the joints due to the performing of a suitable solubilizing heat treatment after the welding process. The results have shown that the impact properties of the samples have been mostly affected by the different heat inputs; in some cases a partial welding penetration has been found.