983 research outputs found

    Genetic fat – bullet proofing the Merino ewe

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    Merino ewes are the backbone of the Australian sheep industry and this is likely to be the case for some time. Stocking rate will remain a key profit driver in Merino enterprises and to maintain or improve profitability producers will need to continually adapt their production systems to deal with even larger changes in feed supply between seasons and years. The reproductive performance of the Merino ewe also needs to improve, largely through improving the survival of twin born lambs, to rebuild flock numbers and meet market demand for lamb and sheep meat. Increasing both stocking rates and reproductive performance need to be achieved in the context of producers wanting to run more sheep per person with less intervention and increased consumer demand for welfare friendly products. Improving genetics and matching sheep genotype to the production and management system will inevitably become more important. We believe this will include defining traits to more easily identify Merino sheep that are more robust, that lose less liveweight when faced with sub-optimum nutrition and that produce more progeny with higher survival rates both pre- and post-weaning. Increasing genetic fat is the prime candidate for increasing the robustness of Merino ewes and their progeny as the storage and mobilisation of fat is an important mechanism for all animals to cope with fluctuating environments. Fat is stored during favourable times and then mobilised to provide energy for fundamental functions when requirements exceed supply, such as during periods of limited nutrition or during late pregnancy and lactation. The amount of fat stored in fat depots in sheep can be increased by selection for higher subcutaneous fat depth, using Australian Sheep Breeding Values (ASBVs) from MERINOSELECT. However, from a genetic perspective, reducing the fatness of lamb to improve its appeal to the consumer has resulted in a general focus on selection for less fat in Australian sheep breeds. Merino sheep have also become leaner as a result of selection for higher fleece weights and the genetic association between higher fleece weight and reduced fatness (Huisman and Brown 2009). Defining the true value of fat requires an understanding of the effect it has on the value of lamb carcasses as well as its effects on the productivity of the sheep production system in different environments. In this paper we have reviewed published papers and our own unpublished work to test the hypothesis that Merino sheep that are genetically fatter will have improved performance especially under more restricted nutritional conditions

    Assessment of patients knowledge and attitude towards diabetes and its relationship with glycemic control: a cross-sectional study in a Nigerian tertiary hospital

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    Background: It is postulated that increased knowledge of patients about diabetes as well as a positive attitude will lead to improved glycaemic control and better outcome. The aim of this study was to determine the knowledge and attitude of diabetic patients in a tertiary hospital in Enugu and the relationship with their glycaemic control.Methods: A cross-sectional study was done using a structured questionnaire to obtain socio-demographic data and assess knowledge and attitude to diabetes on consecutive patients attending the outpatient clinic in a tertiary hospital. Responses were scored with equal weighting. The fasting blood glucose of the patients was measured and recorded.Result: There were 51(60.7%) females and 33 (39.3%) males, with majority (63.1%) in the age range 41 -64 years and 32(38.1%) had only primary education. The mean knowledge score was 6.19 ± 2.08 and 33(39.3%) demonstrated good knowledge. Knowledge did not differ between males and females (p=0.34), but was highest in those with tertiary education (p = 0.02). Positive attitude to the condition was recorded in 63(75%) subjects. There was poor correlation between knowledge and attitude (r = -0.161, p= 0.14). Those with good knowledge scores were 2 times more likely to have good glycaemic control compared with those with poor knowledge; OR = 2.015, p = 0.02. There was no significant difference between the glycemic control of those with good attitude and those with poor attitude (p= 0.08).Conclusion: Although overall knowledge was poor, patients had a good attitude to their illness. Knowledge, but not attitude was significantly positively associated with glycemic control.Keywords: Diabetes mellitus, Knowledge, Attitude, Glycaemic contro

    Model Flames in the Boussinesq Limit: The Effects of Feedback

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    We have studied the fully nonlinear behavior of pre-mixed flames in a gravitationally stratified medium, subject to the Boussinesq approximation. Key results include the establishment of criterion for when such flames propagate as simple planar flames; elucidation of scaling laws for the effective flame speed; and a study of the stability properties of these flames. The simplicity of some of our scalings results suggests that analytical work may further advance our understandings of buoyant flames.Comment: 11 pages, 14 figures, RevTex, gzipped tar fil

    The occurrence and characterization of Campylobacter jejuni and C. coli in organic pigs and their outdoor environment

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    The occurrence and species distribution of thermophilic Campylobacter was investigated in organic outdoor pigs. An increased exposure of outdoor pigs to C. jejuni from the environment may cause a shift from a normal dominance of C. coli to more C. jejuni, which may imply a concern of reduced food safety. Bacteriological methods for determination of Campylobacter excretion level were combined with colony-blot hybridization and real-time PCR for specific detection of C. jejuni in pigs. Campylobacter was isolated from pigs (n = 47), paddock environment (n = 126) and wildlife (n = 44), identified to species by real-time PCR and sub-typed by serotyping (Penner) and pulse-field gel electrophorsis (PFGE) genotyping. All pigs excreted Campylobacter (103–107 CFU g1 faeces) from the age of 8–13-weeks old. C. jejuni was found in 29% of pigs in three consecutive trials and always in minority to C. coli (0.3–46%). C. jejuni and C. coli were isolated from 10% and 29% of the environmental samples, respectively, while crow-birds and rats harboured C. jejuni. Individual pigs hosted several strains (up to nine serotypes). The paddock environment was contaminated with C. coli serotypes similar to pig isolates, while most of the C. jejuni serotypes differed. C. jejuni isolates of different origin comprised few similar serotypes, just one identical genotype was common between pigs, environment and birds. In conclusion, the occurrence of C. jejuni varied considerably between the three groups of outdoor pigs. Furthermore, transfer of C. jejuni to the outdoor pigs from the nearby environment was not predominant according to the subtype dissimilarities of the obtained isolates

    Ultraviolet Spectrophotometric Method for Determination of Gelatin Crosslinking in the Presence of Amino Groups

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    The study was carried out to develop procedure for determining concentration of formaldehyde to be used for crosslinking of gelatin in the presence of drugs having amino groups. Gentamicin sulfate was used as a drug candidate due to its high content of amino acids. Gelatin crosslinking is accelerated by aldehyde-containing compounds and inhibited by amino group-containing compounds. The major modifications from already existing procedures are that the trinitrobenzenesulphonic acid (TNBS) reaction is used to detect e-amino groups of Type A gelatin in the presence of formaldehyde and further it is supported with colorimetric analysis of free formaldehyde content using a chromotropic acid regent. Since formaldehyde crosslinks amino groups, the TNBS assay can be effectively utilized for determination of complete crosslinking of gelatin with analysis of free amino acid content in crosslinked formulation. The effect of the presence of amino groups on gelatin crosslinking was estimated in the presence of gentamicin sulfate. The ε-amino content of uncrosslinked Type A gelatin was found to be 28.6 mol/gelatin molecule of 1000 residues and in case of crosslinked gelatin it varies with varying concentration of formaldehyde. The procedure stated here should be applicable to a broad range of drugs containing amino groups which are used along with gelatin or other proteinaceous materials which are applicable after crosslinking with formaldehyde

    Addendum to: Capillary floating and the billiard ball problem

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    We compare the results of our earlier paper on the floating in neutral equilibrium at arbitrary orientation in the sense of Finn-Young with the literature on its counterpart in the sense of Archimedes. We add a few remarks of personal and social-historical character.Comment: This is an addendum to my article Capillary floating and the billiard ball problem, Journal of Mathematical Fluid Mechanics 14 (2012), 363 -- 38

    Extended T-systems

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    We use the theory of q-characters to establish a number of short exact sequences in the category of finite-dimensional representations of the quantum affine groups of types A and B. That allows us to introduce a set of 3-term recurrence relations which contains the celebrated T-system as a special case.Comment: 36 pages, latex; v2: version to appear in Selecta Mathematic

    The effect of a diet with fructan-rich chicory roots on intestinal helminths and microbiota with special focus on Bifidobacteria and Campylobacter in piglets around weaning

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    The restrictions on the use of antibiotic and anthelmintic treatments in organic pig farming necessitate alternative non-medical control strategies. Therefore, the antibiotic and parasite-reducing effect of a fructan-rich (prebiotic) diet of dried chicory was investigated in free-ranging piglets. Approximately half of 67 piglets from 9 litters were experimentally infected with Ascaris suum and Trichuris suis in the suckling period (1 to 7 weeks of age) and 58 of the piglets were challenged daily with E. coli O138:F8 for 9 days after weaning to induce weaning diarrhoea. The litters were fed either chicory (30% DM) or a control diet. The effect of chicory on intestinal helminths, intestinal microbiota, especially Bifidobacteria and Campylobacter spp., and E. coli post-weaning diarrhoea was assessed. The weight gain of the piglets was not impaired significantly by chicory. The intestinal A. suum worm burden was reduced by 64% (P=0.034) in the chicory-fed piglets, whereas these same piglets had 63% more T. suis worms (P=0.016). Feeding with chicory elicited no changes among the main bacterial groups in ileum according to terminal restriction fragment length polymorphism (T-RFLP) analysis. However, the terminal-restriction fragment (T-RF) 208 bp, which may belong to Lachnospiraceae, was stimulated by the chicory feed (P=0.03), and T-RF 370 bp that matches Enterobacter belonging to the Enterobacteria was reduced (P=0.004). Additionally, chicory increased the level of Bifidobacteria (P=0.001) and the faecal Campylobacter excretion level was transitorily reduced in chicory-fed piglets at 7 weeks of age (P=0.029). Unfortunately, it was not possible to assess the effect of chicory on post-weaning diarrhoea as it did not develop. In conclusion, feeding piglets chicory around the time of weaning caused complex changes of the microbiota and parasite communities within the intestinal tract, and feeding piglets chicory may therefore serve as an animal-friendly strategy to control pathogens

    Signal and System Approximation from General Measurements

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    In this paper we analyze the behavior of system approximation processes for stable linear time-invariant (LTI) systems and signals in the Paley-Wiener space PW_\pi^1. We consider approximation processes, where the input signal is not directly used to generate the system output, but instead a sequence of numbers is used that is generated from the input signal by measurement functionals. We consider classical sampling which corresponds to a pointwise evaluation of the signal, as well as several more general measurement functionals. We show that a stable system approximation is not possible for pointwise sampling, because there exist signals and systems such that the approximation process diverges. This remains true even with oversampling. However, if more general measurement functionals are considered, a stable approximation is possible if oversampling is used. Further, we show that without oversampling we have divergence for a large class of practically relevant measurement procedures.Comment: This paper will be published as part of the book "New Perspectives on Approximation and Sampling Theory - Festschrift in honor of Paul Butzer's 85th birthday" in the Applied and Numerical Harmonic Analysis Series, Birkhauser (Springer-Verlag). Parts of this work have been presented at the IEEE International Conference on Acoustics, Speech, and Signal Processing 2014 (ICASSP 2014

    Nonpropagation of massive mode on AdS2 in topologically massive gravity

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    Making use of Achucarro-Ortiz (AO) type of dimensional reduction, we study the topologically massive gravity with a negative cosmological constant on AdS2 spacetimes. For a constant dilaton, this two-dimensional model also admits three AdS2 vacuum solutions, which are related to two AdS3 and warped AdS3 backgrounds with an identification upon uplifting three dimensions. We carry out the perturbation analysis around these backgrounds to find what is a physically propagating field. However, it turns out that there is no propagating massive mode on AdS2 background, in contrast to the Kaluza-Klein (KK) type of dimensional reduction. We note that two dimensionally reduced actions are different and thus, the non-equivalence of their on-shell amplitudes is obtained.Comment: 19 pages, version to appear in EPJ
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