64 research outputs found
Effects of a single transdermal administration of flunixin meglumine in early postpartum Holstein Friesian dairy cows: Part 2. Milk yield, culling risk, and reproductive performance
This study was conducted to assess the effects of a single transdermal administration of flunixin meglumine (FM) in early postpartum Holstein Friesian dairy cows on milk yield, culling risk, and reproductive performance. We hypothesized that FM treatment would reduce systemic inflammation, leading to higher milk yield, reduced culling risk, and better reproductive performance in the subsequent lactation. Holstein Friesian dairy cows [n = 500, 153 primiparous (PRIM), 347 multiparous (MULT)] from 3 farms in northeast Germany were enrolled in a prospective, randomized controlled clinical trial. Farms at risk for cows with excessive postpartum inflammation were identified in a preliminary trial by measuring serum haptoglobin concentrations in their fresh lactating cows. Only cows that had a eutocic birth and delivered a singleton calf alive, with no signs of milk fever or retained fetal membranes and rectal temperature ≤40°C at first clinical examination, were included within 24 to 36 h postpartum. Treatment included a single transdermal administration of either FM (3.33 mg/kg) or a placebo as control (CON). Milk production, milk solids, urea, and somatic cell count were recorded monthly for 8 mo after calving. Culling risk, first-service conception risk, and days open were retrieved from the farms' herd management software. Separate models for PRIM and MULT cows were built for most parameters because of significant effects of parity and parity × treatment interaction. Energy-corrected milk yield from 8 monthly Dairy Herd Improvement-equivalent tests was slightly greater in PRIM cows treated with FM (29.51 and 30.73 ± 1.35 kg, CON vs. FM), whereas it was reduced in treated MULT cows (38.23 and 37.47 ± 1.17 kg, CON vs. FM) compared with CON. Milk fat and protein yields were greater in FM-treated PRIM cows and lower in treated MULT cows compared with CON. Milk urea and somatic cell count were not affected by treatment. No differences in culling risk, first-service conception risk, or days open were observed. We conclude that a single transdermal administration of FM in early postpartum dairy cows on farms at risk for excessive postpartum inflammation slightly increased milk, milk fat, and milk protein yields in PRIM cows and decreased these variables in MULT cows. Neither culling risk nor fertility was affected by treatment in this study
Part 1. Inflammatory and metabolic markers, uterine health, and indicators of pain
The objectives of this study were to assess the effects of a single transdermal administration of flunixin meglumine (FM) in early postpartum Holstein Friesian dairy cows on serum concentrations of inflammatory and metabolic markers, uterine health, and indicators of pain. The hypothesis was that the anti-inflammatory, antipyretic, and analgetic effects of the pharmaceutic agent would reduce systemic inflammation, resulting in improved metabolic and inflammatory profile, diminished incidence of metritis, and reduced expression of pain. A total of 500 cows (153 primiparous, 347 multiparous) from 3 different commercial dairy farms in the northeast of Germany were included in a randomized controlled clinical trial. Farms were preselected based on high haptoglobin concentrations in their fresh lactating cows. Cows were excluded if they had experienced dystocia, stillbirth, or twin birth, or if they showed any signs of milk fever, retained fetal membranes, or fever (>40°C). The cows were treated once with either FM (3.33 mg/kg) or a placebo as control (CON) through transdermal administration between 24 to 36 h postpartum (d 2). General health examinations were performed (daily from d 2–8 and additionally on d 15 postpartum), vaginal discharge was assessed using the Metricheck device (d 8 and 15 postpartum) and serum samples were analyzed for inflammatory and metabolic markers (d 2, 4, and 6 postpartum). Effects of treatment, parity, sampling day, and their interactions were evaluated using mixed effects models. Primiparous cows treated with FM showed lower serum haptoglobin concentrations (0.90 ± 0.08 vs. 1.17 ± 0.07 g/L; ± standard error of the mean) and higher serum albumin concentrations (35.5 ± 0.31 vs. 34.8 ± 0.31 g/L) on d 6 postpartum. They also had a lower risk for purulent vaginal discharge with or without a fever compared with CON cows on d 15 postpartum (odds ratio for CON vs. FM: 1.63, 95% CI: 1.26–2.00), and body temperature was lower throughout the first 15 d in milk (39.1 ± 0.11 vs. 39.2 ± 0.11°C). Multiparous cows treated with FM had lower serum β-hydroxybutyrate concentrations on d 4 postpartum (0.71 ± 0.05 vs. 0.78 ± 0.05 mmol/L) and d 6 postpartum (0.74 ± 0.05 vs. 0.80 ± 0.05 mmol/L). Regardless of parity, FM-treated cows were significantly less likely to abduct their tail from their body (14.3 vs. 23.6%) and show an arched back (27.9 vs. 39.7%) on the day after treatment compared with CON cows. It can be concluded that FM treatment slightly reduced inflammation and diminished the risk for metritis in primiparous cows, improved metabolic profile in multiparous cows, and reduced expressions of pain in all cows
Inelastic light scattering by intrasubband spin-density excitations in GaAs-AlGaAs quantum wells with balanced Bychkov-Rashba and Dresselhaus spin-orbit interaction: Quantitative determination of the spin-orbit field
Inelastic light scattering experiments on low-energy intrasubband spin-density excitations (SDEs) are performed in (001)-grown modulation-doped GaAs-AlGaAs single quantum wells in in-plane external magnetic fields. The investigated samples possess balanced linear Bychkov-Rashba (alpha) and Dresselhaus (beta) spin-orbit strengths in two different configurations, alpha = beta and alpha = -beta Both configurations lead to an extreme anisotropy of the spin splitting of the conduction band, where the in-plane directions of maximum spin splitting for both configurations are perpendicular to each other. The spin splitting asymmetry can be directly detected via the SDE by breaking of the time-reversal symmetry due to transfer of a momentum q in the quantum-well plane. In addition, the application of an in-plane magnetic field B-ext perpendicular to q allows us to modulate the effective magnetic field. Via a numerical line-shape analysis of the experimental SDE spectra, we determine the relevant parameters of the samples. We find that the linear spin-orbit strength vertical bar alpha vertical bar = beta is comparable for both samples, while the electron g factors are markedly different. Furthermore, we experimentally quantify the values of the maximum internal spin-orbit fields, which are as high as B-so similar to 18 T for both samples
Application of a bacteriological on-farm test to reduce antimicrobial usage in dairy cows with purulent vaginal discharge
The objective of this study was to assess the effect of a selective antibiotic treatment strategy based on a quick bacteriological on-farm test (Petrifilm, 3M Corp., St. Paul, MN) compared with the conventional antibiotic treatment of all cows having clinical endometritis (CE) defined by the presence of purulent vaginal discharge on both clinical cure rate and reproductive performance. The study was simultaneously conducted with dairy cows reared under a highly supplemented rotational grazing system in Argentina and in a freestall system in Slovakia. Cows having an abnormal vaginal discharge (VD, indicative of clinical endometritis) on 21 to 35 d in milk (DIM) were randomly allocated to 1 of 2 study groups: selective treatment (ST) or conventional treatment (CT). All cows in the CT group (n = 174) received a single intrauterine administration of 500 mg of cephapirin. In the ST group (n = 178), treatment decision was made according to the results of the bacteriological on-farm test. For this test, we collected intrauterine samples with the cytobrush technique and stroke the brushes onto 2 different Petrifilm plates, one for aerobic count and another for Enterobacteriaceae count, incubated the plates, and counted the number of colonies after 24 h. Positive cows (≥5 colonies in one or both plates) received a single intrauterine treatment with 500 mg of cephapirin, whereas negative cows (<5 colonies) remained untreated. Clinical cure rate was assessed by direct vaginal inspection at 14 d after treatment (VD-0). The odds for conception at first artificial insemination, artificial insemination by 80 DIM, pregnancy by 100 DIM, and for nonpregnancy by 200 DIM were estimated with mixed logistic regression models. The hazard of conception was also assessed with proportional hazard regression model. The selective antibiotic treatment strategy based on the outcome of Petrifilm test reduced the number of required treatments (57%) and maintained similar efficacy in terms of clinical cure and reproductive performance as the conventional antibiotic treatment of all endometritic cows.Facultad de Ciencias Veterinaria
The absence of finite-temperature phase transitions in low-dimensional many-body models: a survey and new results
After a brief discussion of the Bogoliubov inequality and possible
generalizations thereof, we present a complete review of results concerning the
Mermin-Wagner theorem for various many-body systems, geometries and order
parameters. We extend the method to cover magnetic phase transitions in the
periodic Anderson Model as well as certain superconducting pairing mechanisms
for Hubbard films. The relevance of the Mermin-Wagner theorem to approximations
in many-body physics is discussed on a conceptual level.Comment: 33 pages; accepted for publication as a Topical Review in Journal of
Physics: Condensed Matte
Ferromagnetic Kondo-Lattice Model
We present a many-body approach to the electronic and magnetic properties of
the (multiband) Kondo-lattice model with ferromagnetic interband exchange. The
coupling between itinerant conduction electrons and localized magnetic moments
leads, on the one hand, to a distinct temperature-dependence of the electronic
quasiparticle spectrum and, on the other hand, to magnetic properties, as
e.~g.the Curie temperature T_C or the magnon dispersion, which are strongly
influenced by the band electron selfenergy and therewith in particular by the
carrier density. We present results for the single-band Kondo-lattice model in
terms of quasiparticle densities of states and quasiparticle band structures
and demonstrate the density-dependence of the self-consistently derived Curie
temperature. The transition from weak-coupling (RKKY) to strong-coupling
(double exchange) behaviour is worked out.
The multiband model is combined with a tight-binding-LMTO bandstructure
calculation to describe real magnetic materials. As an example we present
results for the archetypal ferromagnetic local-moment systems EuO and EuS. The
proposed method avoids the double counting of relevant interactions and takes
into account the correct symmetry of atomic orbitals.Comment: 15 pages, 10 figure
Kondo-lattice model: Application to the temperature-dependent electronic structure of EuO(100) films
We present calculations for the temperature-dependent electronic structure
and magnetic properties of thin ferromagnetic EuO films. The treatment is based
on a combination of a multiband-Kondo lattice model with first-principles
TB-LMTO band structure calculations. The method avoids the problem of
double-counting of relevant interactions and takes into account the correct
symmetry of the atomic orbitals. We discuss the temperature-dependent
electronic structures of EuO(100) films in terms of quasiparticle densities of
states and quasiparticle band structures. The Curie temperature T_C of the EuO
films turns out to be strongly thickness-dependent, starting from a very low
value = 15K for the monolayer and reaching the bulk value at about 25 layers
Application of a bacteriological on-farm test to reduce antimicrobial usage in dairy cows with purulent vaginal discharge
The objective of this study was to assess the effect of a selective antibiotic treatment strategy based on a quick bacteriological on-farm test (Petrifilm, 3M Corp., St. Paul, MN) compared with the conventional antibiotic treatment of all cows having clinical endometritis (CE) defined by the presence of purulent vaginal discharge on both clinical cure rate and reproductive performance. The study was simultaneously conducted with dairy cows reared under a highly supplemented rotational grazing system in Argentina and in a freestall system in Slovakia. Cows having an abnormal vaginal discharge (VD, indicative of clinical endometritis) on 21 to 35 d in milk (DIM) were randomly allocated to 1 of 2 study groups: selective treatment (ST) or conventional treatment (CT). All cows in the CT group (n = 174) received a single intrauterine administration of 500 mg of cephapirin. In the ST group (n = 178), treatment decision was made according to the results of the bacteriological on-farm test. For this test, we collected intrauterine samples with the cytobrush technique and stroke the brushes onto 2 different Petrifilm plates, one for aerobic count and another for Enterobacteriaceae count, incubated the plates, and counted the number of colonies after 24 h. Positive cows (≥5 colonies in one or both plates) received a single intrauterine treatment with 500 mg of cephapirin, whereas negative cows (<5 colonies) remained untreated. Clinical cure rate was assessed by direct vaginal inspection at 14 d after treatment (VD-0). The odds for conception at first artificial insemination, artificial insemination by 80 DIM, pregnancy by 100 DIM, and for nonpregnancy by 200 DIM were estimated with mixed logistic regression models. The hazard of conception was also assessed with proportional hazard regression model. The selective antibiotic treatment strategy based on the outcome of Petrifilm test reduced the number of required treatments (57%) and maintained similar efficacy in terms of clinical cure and reproductive performance as the conventional antibiotic treatment of all endometritic cows.Facultad de Ciencias Veterinaria
Thermodynamic formalism for contracting Lorenz flows
We study the expansion properties of the contracting Lorenz flow introduced
by Rovella via thermodynamic formalism. Specifically, we prove the existence of
an equilibrium state for the natural potential for the contracting Lorenz flow and for in an interval
containing . We also analyse the Lyapunov spectrum of the flow in terms
of the pressure
The Philosopher's Medicine of the Mind: Kant's Account of Mental Illness and the Normativity of Thinking
Kant’s conception of mental illness is unlikely to satisfy contemporary readers. His classifications of mental illness are often fluid and ambiguous, and he seems to attribute to human beings at least some responsibility for preventing mental illness. In spite of these apparent disadvantages, I argue that Kant’s account of mental illness can be illuminating to his views about the normative dimensions of human cognition. In contrast to current understandings of mental illness, Kant’s account is what I refer to as “non-pathological.” That is, most mental illnesses are for Kant continuous with normally functioning cognition. Someone with a healthy reason can easily fall into mental illness and someone with mental illness can (perhaps not as easily) re-establish healthy reason. By accepting a non-pathological definition of mental illness, it follows for Kant that humans have more agency and responsibility regarding their mental health than current views allow, which explains why several of his writings aim to prescribe a “diet of the mind” (2:271). Contrary to popular readings of Kant as a champion of reason’s power, Kant’s conception of mental illness shows that he recognizes how fragile human reason can be
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