Magnetic domain formation in itinerant metamagnets

We examine the effects of long-range dipolar forces on metamagnetic transitions and generalize the theory of Condon domains to the case of an itinerant electron system undergoing a first-order metamagnetic transition. We demonstrate that within a finite range of the applied field, dipolar interactions induce a spatial modulation of the magnetization in the form of stripes or bubbles. Our findings are consistent with recent observations in the bilayer ruthenate Sr$_3$Ru$_2$O$_7$.Comment: 4 pages, 3 figures, minor changes, references adde

Hair cortisol concentrations in different breeds of cows: Comparison of hair from unshorn and previously shorn areas and from various regions of the body

The goals of this study were to investigate hair cortisol concentration (HCC) in seven different breeds of cows, to establish reference intervals for HCC in Brown Swiss cows and to compare cortisol concentrations of hair collected from four different areas of the body. Three groups of cows were used. Group 1 comprised 70 healthy cows representing four dairy breeds (Brown Swiss, Swiss Fleckvieh, Holstein Friesian, Water Buffalo) and three beef breeds (Raetian Grey, Limousin, Highland). Group 2 consisted of 60 healthy Brown Swiss cows in which two different hair samples were collected from the thoracic region to establish reference intervals; A samples consisted of hair that had grown for one month in a pre-clipped area, and B samples consisted of hair from a previously unshorn area. Group 3 comprised 21 healthy Brown Swiss cows, in which HCCs were measured in A and B samples from four different body regions (neck, shoulder, thorax, rump). Liquid chromatography tandem mass-spectrometry was used for cortisol measurement. In group 1, the highest HCCs were measured in Holstein Friesian cows at 1,75 pg/mg, which was significantly higher than those of the Brown Swiss, the Swiss Fleckvieh and the Water Buffalo cows. Hair cortisol concentration and daily milk yield of the 40 dairy cows were highly correlated (r = 0,57, P < 0,01). In group 2, the HCCs of 77 % of the A samples and 85 % of the B samp-les were below the laboratory's limit of quantification (LOQ) of 0,50 pg/mg and the results were expressed semiquantitatively as

Hair cortisol concentrations in bovine neonates born to healthy and ill cows

The goal of this study was to investigate the hair cortisol concentration (HCC) in healthy and ill cows and their newborn calves. A total of 40 cows and their 42 newborn calves were divided into two groups: group 1 consisted of 19 clinically healthy cows and their 20 newborn calves, and group 2 comprised 21 cows that had had a chronic illness in the third trimester of gestation and their 22 newborn calves. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) system was used to measure the HCC in hair samples that were collected from the cows and calves on the day the calves were born. In both groups, the mean HCCs of the calves was significantly higher than that of the cows (group 1, 31,0 vs. 0,6 pg/mg; group 2, 19,4 vs. 0,8 pg/mg; P

Relationship between periparturient diseases, metabolic markers and the dynamics of hair cortisol concentrations in dairy cows

Hair cortisol concentration (HCC) might represent a promising marker for retrospective welfare assessment of dairy cows. The objective of the study was to explore the dynamics of HCC in diseased and healthy cows from eight-week ante partum (AP) to eight-week post partum (PP). Twenty-four pregnant cows were followed from drying off to week eight PP. Tail hair was used to measure cortisol at five different time points. The occurrence of peripartum diseases, lameness and the body condition score (BCS) were monitored on a weekly basis. Blood β-hydroxybutyric acid, non-esterified fatty acids, calcium and insulin-like growth factor-1 (IGF-1) concentrations were measured. The temperature-humidity index (THI) was continuously recorded. The median values of HCC in all cows were 0.4, 0.3, 0.6, 0.8 and 0.5 pg/mg at weeks eight, four AP, calving, weeks four, eight PP, respectively. There was no association between HCC and the occurrence of peripartum diseases (P ≥ 0.05). A positive correlation between HCC and BCS loss (P < 0.01) and THI (P < 0.05) was observed. The occurrence of peripartum diseases was associated with low IGF-1 during the study period but no relationship was found between cortisol and IGF-1 levels (P ≥ 0.05). Brown Swiss cows showed higher HCC (P < 0.01) at weeks eight, four AP, and week four PP and lower average milk yield (P < 0.05) than Holstein–Friesian cows. In conclusion, HCC was not a suitable marker for peripartum diseases but it could reflect a stress response, which is linked to BCS loss, heat stress and breed

Collective fields in the functional renormalization group for fermions, Ward identities, and the exact solution of the Tomonaga-Luttinger model

We develop a new formulation of the functional renormalization group (RG) for interacting fermions. Our approach unifies the purely fermionic formulation based on the Grassmannian functional integral, which has been used in recent years by many authors, with the traditional Wilsonian RG approach to quantum systems pioneered by Hertz [Phys. Rev. B 14, 1165 (1976)], which attempts to describe the infrared behavior of the system in terms of an effective bosonic theory associated with the soft modes of the underlying fermionic problem. In our approach, we decouple the interaction by means of a suitable Hubbard-Stratonovich transformation (following the Hertz-approach), but do not eliminate the fermions; instead, we derive an exact hierarchy of RG flow equations for the irreducible vertices of the resulting coupled field theory involving both fermionic and bosonic fields. The freedom of choosing a momentum transfer cutoff for the bosonic soft modes in addition to the usual band cutoff for the fermions opens the possibility of new RG schemes. In particular, we show how the exact solution of the Tomonaga-Luttinger model emerges from the functional RG if one works with a momentum transfer cutoff. Then the Ward identities associated with the local particle conservation at each Fermi point are valid at every stage of the RG flow and provide a solution of an infinite hierarchy of flow equations for the irreducible vertices. The RG flow equation for the irreducible single-particle self-energy can then be closed and can be reduced to a linear integro-differential equation, the solution of which yields the result familiar from bosonization. We suggest new truncation schemes of the exact hierarchy of flow equations, which might be useful even outside the weak coupling regime.Comment: 27 pages, 15 figures; published version, some typos correcte

How do road traffic noise and residential greenness correlate with noise annoyance and long-term stress? Protocol and pilot study for a large field survey with a cross-sectional design

Urban areas are continuously growing, and densification is a frequent strategy to limit urban expansion. This generally entails a loss of green spaces (GSs) and an increase in noise pollution, which has negative effects on health. Within the research project RESTORE (Restorative potential of green spaces in noise-polluted environments), an extended cross-sectional field study in the city of Zurich, Switzerland, is conducted. The aim is to assess the relationship between noise annoyance and stress (self-perceived and physiological) as well as their association with road traffic noise and GSs. A representative stratified sample of participants from more than 5000 inhabitants will be contacted to complete an online survey. In addition to the self-reported stress identified by the questionnaire, hair cortisol and cortisone probes from a subsample of participants will be obtained to determine physiological stress. Participants are selected according to their dwelling location using a spatial analysis to determine exposure to different road traffic noise levels and access to GSs. Further, characteristics of individuals as well as acoustical and non-acoustical attributes of GSs are accounted for. This paper presents the study protocol and reports the first results of a pilot study to test the feasibility of the protocol

Exact integral equation for the renormalized Fermi surface

The true Fermi surface of a fermionic many-body system can be viewed as a fixed point manifold of the renormalization group (RG). Within the framework of the exact functional RG we show that the fixed point condition implies an exact integral equation for the counterterm which is needed for a self-consistent calculation of the Fermi surface. In the simplest approximation, our integral equation reduces to the self-consistent Hartree-Fock equation for the counterterm.Comment: 5 pages, 1 figur

Duplication of clostridial binding domains for enhanced macromolecular delivery into neurons

Neurological diseases constitute a quarter of global disease burden and are expected to rise worldwide with the ageing of human populations. There is an increasing need to develop new molecular systems which can deliver drugs specifically into neurons, non-dividing cells meant to last a human lifetime. Neuronal drug delivery must rely on agents which can recognise neurons with high specificity and affinity. Here we used a recently introduced ‘stapling’ system to prepare macromolecules carrying duplicated binding domains from the clostridial family of neurotoxins. We engineered individual parts of clostridial neurotoxins separately and combined them using a strong alpha-helical bundle. We show that combining two identical binding domains of tetanus and botulinum type D neurotoxins, in a sterically defined way by protein stapling, allows enhanced intracellular delivery of molecules into neurons. We also engineered a botulinum neurotoxin type C variant with a duplicated binding domain which increased enzymatic delivery compared to the native type C toxin. We conclude that duplication of the binding parts of tetanus or botulinum neurotoxins will allow production of high avidity agents which could deliver imaging reagents and large therapeutic enzymes into neurons with superior efficiency

Loss of AP-3 function affects spontaneous and evoked release at hippocampal mossy fiber synapses

Synaptic vesicle (SV) exocytosis mediating neurotransmitter release occurs spontaneously at low intraterminal calcium concentrations and is stimulated by a rise in intracellular calcium. Exocytosis is compensated for by the reformation of vesicles at plasma membrane and endosomes. Although the adaptor complex AP-3 was proposed to be involved in the formation of SVs from endosomes, whether its function has an indirect effect on exocytosis remains unknown. Using mocha mice, which are deficient in functional AP-3, we identify an AP-3-dependent tetanus neurotoxin-resistant asynchronous release that can be evoked at hippocampal mossy fiber (MF) synapses. Presynaptic targeting of the tetanus neurotoxin-resistant vesicle soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) tetanus neurotoxin-insensitive vesicle-associated membrane protein (TI-VAMP) is lost in mocha hippocampal MF terminals, whereas the localization of synaptobrevin 2 is unaffected. In addition, quantal release in mocha cultures is more frequent and more sensitive to sucrose. We conclude that lack of AP-3 results in more constitutive secretion and loss of an asynchronous evoked release component, suggesting an important function of AP-3 in regulating SV exocytosis at MF terminals

Strong Longitudinal Magnetic Fluctuations near Critical End Point in UCoAl: A ^59Co-NMR Study

We report ^59Co-NMR measurements in UCoAl where a metamagnetism occurs due to enhancement of ferromagnetism by magnetic field. The metamagnetic transition from a paramagnetic (PM) state to a ferromagnetic state is a first order transition at low temperatures, but it changes to a crossover at high temperatures on crossing the critical end pint (CEP) at T_CEP ~ 12 K. The contrasting behavior between the relaxation rates 1/T_1 and 1/T_2 suggests that the longitudinal magnetic fluctuation of U moment is strongly enhanced especially near the CEP. A wide diffusion of the fluctuation from the CEP can be confirmed even in the PM state where the magnetic transition does not occur.Comment: 5pages, 6 figures, to be published in J. Phys. Soc. Jp