bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative effect of orally administered sodium butyrate before or after weaning on growth and several indices of gastrointestinal biology of piglets
Authors: Le Gall Maud , Gallois Mélanie , Sève Bernard , Louveau Isabelle , Holst Jens J. , Oswald Isabelle P. , Lallès Jean-Paul , Guilloteau Paul 
Published: June 2009

Sodium butyrate (SB) provided orally favours body growth and maturation of the gastrointestinal tract (GIT) in milk-fed pigs. In weaned pigs, conflicting results have been obtained. Therefore, we hypothesised that the effects of SB (3 g/kg DM intake) depend on the period (before v. after weaning) of its oral administration. From the age of 5 d, thirty-two pigs, blocked in quadruplicates within litters, were assigned to one of four treatments: no SB (control), SB before (for 24 d), or after (for 11–12 d) weaning and SB before and after weaning (for 35–36 d). Growth performance, feed intake and various end-point indices of GIT anatomy and physiology were investigated at slaughter. The pigs supplemented with SB before weaning grew faster after weaning than the controls (P < 0·05). The feed intake was higher in pigs supplemented with SB before or after weaning (P < 0·05). SB provided before weaning improved post-weaning faecal digestibility (P < 0·05) while SB after weaning decreased ileal and faecal digestibilities (P < 0·05). Gastric digesta retention was higher when SB was provided before weaning (P < 0·05). Post-weaning administration of SB decreased the activity of three pancreatic enzymes and five intestinal enzymes (P < 0·05). IL-18 gene expression tended to be lower in the mid-jejunum in SB-supplemented pigs. The small-intestinal mucosa was thinner and jejunal villous height lower in all SB groups (P < 0·05). In conclusion, the pre-weaning SB supplementation was the most efficient to stimulate body growth and feed intake after weaning, by reducing gastric emptying and intestinal mucosa weight and by increasing feed digestibility.
Adaptation of a non-ruminant nutrient-based growth model to rainbow trout (Oncorhynchus mykiss Walbaum)
Authors: HUA K. , BIRKETT S. , DE LANGE C. F. M. , BUREAU D. P. 
Published: June 2009

SUMMARYModels that accurately describe and predict growth and nutrient utilization of fish can be useful in developing strategies to improve the economic and environmental sustainability of aquaculture operations. Current bioenergetics models are not sufficiently flexible to be applied to the wide range of conditions encountered in aquaculture. There is a need to move from bioenergetics approaches to more mechanistic approaches based on nutrient utilization by fish. A non-ruminant nutrient-based growth model has been successfully used in pig production. The model explicitly describes the utilization of energy-yielding nutrients and metabolites for body protein deposition (Pd) and body lipid deposition (Ld) at the whole animal level. Partitioning of intake of energy-yielding nutrients between Pd and Ld is governed by a minimum ratio (minLP) of the body lipid mass (L) to protein mass (P), a maximum daily rate of Pd (PdMax), or maximum efficiency of using intake of the first limiting dietary essential amino acid (AA) for body Pd. The growth model was adapted to rainbow trout (Oncorhynchus mykiss (Walbaum 1792)) through parameterization and various modifications consistent with its framework. The fish nutrient-based model was evaluated by comparing model simulations with data from various experiments carried out with rainbow trout. Significant discrepancies between model predictions and experimental observations were observed. The model predicted energy retention well but did not always accurately predict growth rate, nor Pd and Ld. Overall, the model underestimated growth rate (expressed as thermal-unit growth coefficient (TGC)) by 37% and Pd by 15% and overestimated Ld by 13%. These discrepancies are probably attributable to differences in nutrient utilization and partitioning mechanisms between fish and pigs. The development of more reliable models requires better understanding of the nutritional and endogenous determinants of fish growth.
The changing role of agriculture in Dutch society
Authors: MEERBURG B. G. , KOREVAAR H. , HAUBENHOFER D. K. , BLOM-ZANDSTRA M. , VAN KEULEN H. 
Published: June 2009

SUMMARYDutch agriculture has undergone significant changes in the past century, similar to many countries in the European Union. Due to economies of scale and in order to remain economically profitable, it became necessary for farmers to increase farm size, efficiency and external inputs, while minimizing labour use per hectare. The latter has resulted in fewer people working in the agricultural sector. Consequently, Dutch society gradually lost its connection to agricultural production. This divergence resulted in a poor image for the agricultural sector, because of environmental pollution, homogenization of the landscape, outbreaks of contagious animal diseases and reduced animal welfare. Although the general attitude towards agriculture seems to have improved slightly in recent years, there is still a long way to go in regaining this trust.In order to keep the Dutch countryside viable, farmers are considered indispensable. However, their methods of production should match the demands of society in terms of sustainability. This applies both to farming systems that are used in a monofunctional way (production only) and to multifunctional farming systems. For researchers involved in development of these farming systems, this requires new capabilities; contrary to the situation in the past, citizens and stakeholder groups now demand involvement in the design of farming systems. In the current paper, it is suggested that, besides traditional mainstream agriculture, other alternative farming systems should be developed and implemented. Hence, Dutch agricultural research should remain focused on the cutting edge of economy and society. Despite all efforts, not all of these newly developed systems will acquire a position within the agricultural spectrum. However, some of the successful ones may prove extremely valuable.
Magnetohydrodynamic stability of plasmas with ideal and relaxed regions
Authors: MILLS R. L. , HOLE M. J. , DEWAR R. L. 
Published: June 2009

AbstractA unified energy principle approach is presented for analysing the magnetohydrodynamic (MHD) stability of plasmas consisting of multiple ideal and relaxed regions. The gauge a = ξ × B for the vector potential, a, of linearized perturbations is used, with the equilibrium magnetic field B obeying a Beltrami equation, ∇ × B = αB, in relaxed regions. In a region with such a force-free equilibrium Beltrami field we show that ξ obeys the same Euler–Lagrange equation whether ideal or relaxed MHD is used for perturbations, except in the neighbourhood of the magnetic surfaces where B · ∇ is singular. The difference at singular surfaces is analysed in cylindrical geometry: in ideal MHD only Newcomb's small solutions are allowed, whereas in relaxed MHD only the odd-parity large solution and even-parity small solution are allowed. A procedure for constructing global multi-region solutions in cylindrical geometry is presented. Focusing on the limit where the two interfaces approach each other arbitrarily closely, it is shown that the singular-limit problem encountered previously by Hole et al. in multi-region relaxed MHD is stabilized if the relaxed-MHD region between the coalescing interfaces is replaced by an ideal-MHD region. We then present a stable (k, pressure) phase-space plot, which allows us to determine the form a stable pressure and field profile must take in the region between the interfaces. From this knowledge, we conclude that there exists a class of single-interface plasmas that were found to be stable by Kaiser and Uecker, but are shown to be unstable when the interface is resolved.
A length-scale formula for confined quasi-two-dimensional plasmas
Authors: ANDERSEN TIMOTHY D. , LIM CHJAN C. 
Published: June 2009

AbstractTypically a magnetohydrodynamical model for neutral plasmas must take into account both the ionic and the electron fluids and their interaction. However, at short time scales, the ionic fluid appears to be stationary compared to the electron fluid. On these scales, we need consider only the electron motion and associated field dynamics, and a single fluid model called the electron magnetohydrodynamical model which treats the ionic fluid as a uniform neutralizing background applies. Using Maxwell's equations, the vorticity of the electron fluid and the magnetic field can be combined to give a generalized vorticity field, and one can show that Euler's equations govern its behavior. When the vorticity is concentrated into slender, periodic, and nearly parallel (but slightly three-dimensional) filaments, one can also show that Euler's equations simplify into a Hamiltonian system and treat the system in statistical equilibrium, where the filaments act as interacting particles. In this paper, we show that, under a mean-field approximation, as the number of filaments becomes infinite (with appropriate scaling to keep the vorticity constant) and given that angular momentum is conserved, the statistical length scale, R, of this system in the Gibbs canonical ensemble follows an explicit formula, which we derive. This formula shows how the most critical statistic of an electron plasma of this type, its size, varies with angular momentum, kinetic energy, and filament elasticity (a measure of the interior structure of each filament) and in particular it shows how three-dimensional effects cause significant increases in the system size from a perfectly parallel, two-dimensional, one-component Coulomb gas.
Streptococcus pyogenes emmand T types within a decade, 1996–2005: implications for epidemiology and future vaccines
Authors: NIR-PAZ R. , KORENMAN Z. , RON M. , MICHAEL-GAYEGO A. , COHEN-PORADOSU R. , VALINSKY L. , BEALL B. , MOSES A. E. 
Published: June 2009

SUMMARYStreptococcus pyogenesgroup A (GAS) is a primary human pathogen. We performed geneticemmsequence and serological T-antigen typing of 819 mostly invasive GAS isolates recovered in Israel during 1996–2005. Of the 72emmtypes found, the six most prevalent types (1, 81, 89, 14, 28, 5) comprised 30·2% of all isolates, andemm-type changes were observed over the years. The predicted coverage of the 26-valentS. pyogenesvaccine formulated for usage in the USA was predicted to be only ~60%. On the basis of differentemm–T antigen type associations, some Israeli strains are probably different clonal types than those found in USA. About 2% of GAS hademmtypes that were originally associated withS. dysgalactiaesubsp.equisimilis emmgenes. Therefore, routineemmtyping allows meaningful GAS strain surveillance, and provides data relevant to better vaccine coverage.
Characterization and epidemiological relationships of SpanishBrachyspira hyodysenteriaefield isolates
Authors: HIDALGO Á. , CARVAJAL A. , PRINGLE M. , RUBIO P. , FELLSTRÖM C. 
Published: June 2009

SUMMARYThis research aimed to describe the genetic and phenotypic diversity of 74 SpanishBrachyspira hyodysenteriaefield isolates, to establish epidemiological relationships between the isolates and to confirm the presence of tiamulin-resistant isolates in Spain. For these purposes, we performed biochemical tests in combination with diagnostic PCR analysis for the identification ofBrachyspiraspp. and for detection of thesmpA/smpBgene. We also used antimicrobial susceptibility tests, random amplified polymorphic DNA (RAPD) and a new pulsed-field gel electrophoresis (PFGE) protocol. The combination of RAPD and PFGE allowed the study of epidemiological relationships. Both indole-negative and tiamulin-resistant isolates ofB. hyodysenteriaeare reported in Spain for the first time. The genetic analyses indicated a relationship between these Spanish isolates and indole-negative isolates previously obtained from Germany and Belgium.
Critical parameters for modelling the spread of foot-and-mouth disease in wildlife
Authors: HIGHFIELD L. D. , WARD M. P. , LAFFAN S. W. , NORBY B. , WAGNER G. G. 
Published: June 2009

SUMMARYA series of simulation experiments was conducted to determine how estimates of the latent and infectious periods, number of neighbours (contacts) and population size impact on the predicted magnitude and distribution of foot-and-mouth disease (FMD) outbreaks in white-tailed deer in southern Texas. Outbreaks were simulated using a previously developed and applied susceptible–latent–infected–recovered geographic automata model. There were substantial differences in the estimated predicted number of deer and locations infected, based on the model parameters used (3779–119 879 deer infected and 227–6526 locations affected). There were also substantial differences in the spatial risk of infection based on the model parameters used. The predicted spread of FMD was found to be most sensitive to the assumed latent period and the assumed number of contacts. How these parameters are estimated is likely to be critical in studies on the impact of FMD spread in situations in which wildlife reservoirs might potentially exist.
Coxiella burnetii(Q fever) seroprevalence in cattle
Authors: McCAUGHEY C. , MURRAY L. J. , McKENNA J. P. , MENZIES F. D. , McCULLOUGH S. J. , O'NEILL H. J. , WYATT D. E. , CARDWELL C. R. , COYLE P. V. 
Published: June 2009

SUMMARYHuman cases of Q fever appear to be common in Northern Ireland compared to the rest of the British Isles. The purpose of this study was to describe the seroepidemiology ofCoxiella burnetiiinfection in cattle in Northern Ireland in terms of seroprevalence and determinants of infection. A total of 5182 animals (from a stratified systematic random sample of 273 herds) were tested with a commercialC. burnetiiphase 2 IgG ELISA. A total of 6·2% of animals and 48·4% of herds tested positively. Results from a multilevel logistic regression model indicated that the odds of cattle being infected with Q fever increased with age, Friesian breed, being from large herds and from dairy herds. Large dairy herd animal prevalence was 12·5% compared to 2·1% for small beef herds. Preliminary seroprevalence in sheep (12·3%), goats (9·3%), pigs (0%) rats (9·7%) and mice (3·2%) using indirect immunofluorescence is reported.
Cytomegalovirus seroprevalence and ‘cytomegalovirus-safe’ seropositive blood donors
Authors: BADAMI K. G. , McQUILKAN-BICKERSTAFFE S. , WELLS J. E. , PARATA M. 
Published: June 2009

SUMMARYCytomegalovirus (CMV) seroprevalence was determined in 9343 first-time New Zealand blood donors between 2003 and 2006. Of 39 960 current seropositive donors the proportion testing seropositive more than 12 months previously was calculated. Overall, seroprevalence declined from 66·1% [95% confidence interval (CI) 64·1–68·1] in 2003 to 60·6% (95% CI 58·5–62·6) in 2006. Nevertheless, these rates are significantly higher than the 47% overall seroprevalence found in a 1988 study. Seroprevalence was higher in females than males and in older than in younger age groups in all four years examined. Ethnicity appeared to be related to seroprevalence with the highest rates found in Pacific Islanders (93·2%) and the lowest in Caucasians (54·8%). At least 38 242/39 960 (95·7%) seropositive donors were found to have seroconverted more than 12 months previously. Recent evidence suggests that such ‘remote’ seroconverters may pose a much lower risk of transfusion-transmitted CMV infection than recently infected seroconverting, but seronegative, blood donors.
Household clustering of gastroenteritis
Authors: LEDER K. , SINCLAIR M. , FORBES A. , WAIN D. 
Published: June 2009

SUMMARYSurveillance for gastroenteritis rarely detects small, intra-familial outbreaks. This study examined intra-household transmission of gastroenteritis using prospectively collected data from 2811 participants (600 households) in a community-based study. There were 258 household clusters of gastroenteritis during the 15 months of observation involving 774 residents (28% of total). Age <6 years and attendance at a day care/kindergarten were associated with increased likelihood of inclusion in a cluster. The reach of illness into the household was extensive, with 63% of household members affected by symptoms during clusters. Simultaneous and secondary transmission of gastroenteritis appeared equally common. In only 20% of clusters did more than one member submit a faecal specimen. Of clusters where two or more specimens were submitted, concordance in laboratory confirmation of pathogens was 18·8%. Our results show that clustering of gastrointestinal symptoms within households occurs commonly, but reliance on pathogen notification data will substantially underestimate the true frequency of gastroenteritis clusters.
On Colourings of Hypergraphs Without Monochromatic Fano Planes
Authors: LEFMANN HANNO , PERSON YURY , RÖDL VOJTĚCH , SCHACHT MATHIAS 
Published: June 2009

For k-uniform hypergraphs F and H and an integer r, let cr,F(H) denote the number of r-colourings of the set of hyperedges of H with no monochromatic copy of F, and let $c_{r,F}(n)=\max_{H\in\ccHn} c_{r,F}(H)$, where the maximum runs over all k-uniform hypergraphs on n vertices. Moreover, let ex(n,F) be the usual extremal or Turán function, i.e., the maximum number of hyperedges of an n-vertex k-uniform hypergraph which contains no copy of F.For complete graphs F = Kℓ and r = 2, Erdős and Rothschild conjectured that c2,Kℓ(n) = 2ex(n,Kℓ). This conjecture was proved by Yuster for ℓ = 3 and by Alon, Balogh, Keevash and Sudakov for arbitrary ℓ. In this paper, we consider the question for hypergraphs and show that, in the special case when F is the Fano plane and r = 2 or 3, then cr,F(n) = rex(n,F), while cr,F(n) ≫ rex(n,F) for r ≥ 4.
The age of the Galaxy's thick disk
Authors: Feltzing Sofia , Bensby Thomas 
Published: June 2009

AbstractWe discuss the age of the stellar disks in the solar neighborhood. After reviewing the various methods for age dating, we discuss current estimates of the ages of both the thin- and the thick disks. We present preliminary results for kinematically-selected stars that belong to the thin- as well as the thick disk. All of these dwarf and sub-giant stars have been studied spectroscopically and we have derived both elemental abundances as well as ages for them. A general conclusion is that in the solar neighborhood, on average, the thick disk is older than the thin disk. However, we caution that the exclusion of stars with effective temperatures around 6500 K might result in a biased view of the full age distribution for the stars in the thick disk.
Signatures of heating processes in the Galactic thin disk
Authors: Nordström Birgitta 
Published: June 2009

AbstractThe term “heating” is used loosely to refer to a range of processes that result in an increase in velocity dispersion with age for subgroups of disk stars. We briefly summarise the observational basis for studies of disk heating and show that qualitative differences exist between the evolution of the in-plane and vertical motions. Ways to discriminate between various heating scenarios are discussed; the most recent galaxy merger simulations may in fact suggest that discrimination on purely kinematic grounds might be unfeasible, even with large samples of stars with excellent ages.
The timescales of chemical enrichment in the Galaxy
Authors: Pipino Antonio , Matteucci Francesca 
Published: June 2009

AbstractThe time-scales of chemical enrichment are fundamental to understand the evolution of abundances and abundance ratios in galaxies. In particular, the time-scales for the enrichment by SNe II and SNe Ia are crucial in interpreting the evolution of abundance ratios such as [α/Fe]. In fact, the α-elements are produced mainly by SNe II on time-scales of the order of 3 to 30 Myr, whereas the Fe is mainly produced by SNe Ia on a larger range of time-scales, going from 30 Myr to a Hubble time. This produces differences in the [α/Fe] ratios at high and low redshift and it is known as “time-delay” model. In this talk we review the most common progenitor models for SNe Ia and the derived rates together with the effect of the star formation history on the [α/Fe] versus [Fe/H] diagram in the Galaxy. From these diagrams we can derive the timescale for the formation of the inner halo (roughly 2 Gyr), the timescale for the formation of the local disk (roughly 7-8 Gyr) as well the time-scales for the formation of the whole disk. These are functions of the galactocentric distance and vary from 2-3 Gyr in the inner disk up to a Hubble time in the outer disk (inside-out formation). Finally, the timescale for the formation of the bulge is found to be no longer than 0.3 Gyr, similar to the timescale for the formation of larger spheroids such as elliptical galaxies. We show the time-delay model applied to galaxies of different morphological type, identified by different star formation histories, and how it constrains differing galaxy formation models.
The star formation history of the Magellanic Clouds
Authors: Gallart Carme , Meschin Ingrid , Noël Noelia E. D. , Aparicio Antonio , Hidalgo Sebastián L. , Stetson Peter B. 
Published: June 2009

AbstractThe star formation history of the Magellanic Clouds, including the old and intermediate-age star formation events, can be studied reliably and in detail through color-magnitude diagrams reaching the oldest main sequence turnoffs. This paper reviews our current understanding of the Magellanic Clouds' star formation histories and discusses the impact of this information on general studies of galaxy formation and evolution.
Star formation histories of resolved galaxies
Authors: Tosi Monica 
Published: June 2009

AbstractThe colour-magnitude diagrams of resolved stellar populations are the best tool to study the star formation histories of the host galactic regions. In this review the method to derive star formation histories by means of synthetic colour-magnitude diagrams is briefly outlined, and the results of its application to resolved galaxies of various morphological types are summarized. It is shown that all the galaxies studied so far were already forming stars at the lookback time reached by the observational data, independently of morphological type and metallicity. Early-type galaxies have formed stars predominantly, but in several cases not exclusively, at the earliest epochs. All the other galaxies appear to have experienced rather continuous star formation activities throughout their lifetimes, although with significant rate variations and, sometimes, short quiescent phases.
The ACS LCID project: Variable stars as tracers of population gradients
Authors: Bernard Edouard J. ,   for the LCID Team
Published: June 2009

AbstractWe present a few highlights concerning the search for short-period variable stars in four galaxies, namely IC 1613, LGS3, Cetus and Tucana, based on very deep, multi-epoch HST/ACS photometry. These are discussed in the context of the star formation histories obtained from our very deep color-magnitude diagrams. In particular, we show how the pulsational properties of the RR Lyrae stars, which represent the vast majority of the observed variables, can trace subtle differences in the age and metallicity of the old population. For example, in the dwarf spheroidal galaxy Tucana we find that the fainter RR Lyrae stars, having a shorter period, are more centrally concentrated than the more luminous, longer period RR Lyrae variables. Through comparison with the predictions of theoretical models of stellar evolution and stellar pulsation, we interpret the fainter RR Lyrae stars as a more metal-rich subsample. In addition, we show that they must be older than about 10 Gyr, indicating that the metallicity gradient must have appeared very early on in the history of this galaxy. We also compare the populations of Cepheids in the galaxies of our sample based on their period-Wesenheit diagram. We tentatively classify them as classical short-period Cepheids in the two gas-rich galaxies (IC 1613 & LGS3), and as anomalous Cepheids in the dwarf spheroidals.