8,545 research outputs found

    Observing plasticity of the auditory system: Volumetric decreases along with increased functional connectivity in aspiring professional musicians

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    Playing music relies on several sensory systems and the motor system, and poses strong demands on control processes, hence, offering an excellent model to study how experience can mold brain structure and function. Although most studies on neural correlates of music expertise rely on cross-sectional comparisons, here we compared within-person changes over time in aspiring professionals intensely preparing for an entrance exam at a University of the Arts to skilled amateur musicians not preparing for a music exam. In the group of aspiring professionals, we observed gray-matter volume decrements in left planum polare, posterior insula, and left inferior frontal orbital gyrus over a period of about 6 months that were absent among the amateur musicians. At the same time, the left planum polare, the largest cluster of structural change, showed increasing functional connectivity with left and right auditory cortex, left precentral gyrus, left supplementary motor cortex, left and right postcentral gyrus, and left cingulate cortex, all regions previously identified to relate to music expertise. In line with the expansion–renormalization pattern of brain plasticity (Wenger et al., 2017a. Expansion and renormalization of human brain structure during skill acquisition. Trends Cogn Sci. 21:930–939.), the aspiring professionals might have been in the selection and refinement period of plastic change

    Evaluation of Herbage Intake Estimation Methods for Dairy Cattle Grazing on Semi-Extensive Pastures

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    Available empirical and mechanistic models to estimate total dry matter intake (DMI) and pasture dry matter intake (PDMI) of grazing lactating dairy cows have mainly been developed under intensive grazing conditions. The objective was to evaluate the adequacy of such existent models for use under semi-extensive grazing conditions, characterised by semi-natural grassland and less intensive resource use. Feed intake of lactating cows was measured on three commercial organic dairy farms in South Germany during one or two 6-d-periods/farm in 2019. Each period, DMI was determined in 10 or 20 cows per farm from their daily faecal output measured using titanium dioxide as marker and the apparent total tract digestibility of ingested organic matter derived from faecal crude protein concentration. PDMI was then calculated by subtracting weighed DMI of supplement feeds from total DMI. Further, individual milk yield and body weight were recorded, and samples of milk, pasture forage, supplement feed, and faeces were taken. For further analysis, means of observed values per farm and period (n = 7) were used, resulting in a diverse dataset of grazing systems differing in supplement feeding, daily pasture allocation, cow breed, and PDMI. Two semi-mechanistic PDMI models and six empirical and two semi-mechanistic models to predict total DMI were evaluated by their Mean Squared Error of Prediction, Relative Prediction Error (RPE) and Concordance Correlation Coefficient. One PDMI model produced acceptable (RPE \u3c 20% of mean observed PDMI), and four total DMI models yielded satisfactory (RPE \u3c 10%) prediction accuracy, however yet at a moderate precision (greatest Pearson correlation coefficient = 0.73). To further specify the grazing conditions under which the models reach both, satisfactory precision and accuracy, and due to the low number of observations, data of the present study will be complemented with data gathered on more farms in Southwest Germany in 2020

    Seasonality and Grazing Management Effect on Growth and Nutritional Composition of Herbage on Semi-Natural Grasslands Grazed by Dairy Cows in Southwest Germany

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    Natural and semi-natural grasslands represent an attractive forage source for cows in organic dairy farming. Throughout the grazing season, however, diverse factors such as climatic conditions, botanical composition, as well as grazing and herd management, can influence growth and nutritive value of forage on grasslands. We aimed at investigating the influence of seasonality and grazing management in forage growth and nutritional quality in seven commercial organic dairy cattle farms during the grazing season 2019 in South Germany. Therefore, forty exclusion cages (1 m2) were installed on pastures, which were under three different grazing systems: rotational, short-grass, and continuous grazing. Pasture herbage within and outside the cages was harvested every 4-6 weeks. The botanical composition of the pasture vegetation was estimated by visual observation, its sward height measured by a rising plate meter, and the aboveground biomass accumulation determined gravimetrically. Besides, air temperature and relative humidity were monitored by climate logger. Pasture samples inside and outside the cages were measured for dry matter (DM) according to the Association of German Agricultural Analytic and Research Institutes (VDLUFA) methods. Crude protein (CP), neutral-detergent (NDF), and acid-detergent (ADF) fibre of the samples were determined by near-infrared spectroscopy (NIRS). The forage biomass yield reached the growth peak in the second sampling (30.4 dt DM/ha) after 52 days. The CP concentrations outside the cages were greatest in late summer (166 g/ kg DM). While the ADF content outside the cages were greatest at the beginning of the grazing season (274 g/ kg DM). Besides, the CP content of the pastures was greatest under the short-grass system (193 g/kg DM) compared to the others systems. In conclusion, the seasonality influences the nutritional characteristics of the herbage, as well as the grazing management. However, the grazing management is influenced by other factors that are difficult to statistically measure

    Adiabatic dynamics of a quantum critical system coupled to an environment: Scaling and kinetic equation approaches

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    We study the dynamics of open quantum many-body systems driven across a critical point by quenching an Hamiltonian parameter at a certain velocity. General scaling laws are derived for the density of excitations and energy produced during the quench as a function of quench velocity and bath temperature. The scaling laws and their regimes of validity are verified for the XY spin chain locally coupled to bosonic baths. A detailed derivation and analysis of the kinetic equation of the problem is presented.Comment: 15 pages, 13 figure

    Linking Dynamical and Thermal Models of Ultrarelativistic Nuclear Scattering

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    To analyse ultrarelativistic nuclear interactions, usually either dynamical models like the string model are employed, or a thermal treatment based on hadrons or quarks is applied. String models encounter problems due to high string densities, thermal approaches are too simplistic considering only average distributions, ignoring fluctuations. We propose a completely new approach, providing a link between the two treatments, and avoiding their main shortcomings: based on the string model, connected regions of high energy density are identified for single events, such regions referred to as quark matter droplets. Each individual droplet hadronizes instantaneously according to the available n-body phase space. Due to the huge number of possible hadron configurations, special Monte Carlo techniques have been developed to calculate this disintegration.Comment: Complete paper enclosed as postscript file (uuencoded

    Deep Chandra observation and numerical studies of the nearest cluster cold front in the sky

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    We present the results of a very deep (500 ks) Chandra observation, along with tailored numerical simulations, of the nearest, best resolved cluster cold front in the sky, which lies 90 kpc (19 arcmin) to the north-west of M 87. The northern part of the front appears the sharpest, with a width smaller than 2.5 kpc (1.5 Coulomb mean free paths; at 99 per cent confidence). Everywhere along the front, the temperature discontinuity is narrower than 4–8 kpc and the metallicity gradient is narrower than 6 kpc, indicating that diffusion, conduction and mixing are suppressed across the interface. Such transport processes can be naturally suppressed by magnetic fields aligned with the cold front. Interestingly, comparison to magnetohydrodynamic simulations indicates that in order to maintain the observed sharp density and temperature discontinuities, conduction must also be suppressed along the magnetic field lines. However, the northwestern part of the cold front is observed to have a non-zero width. While other explanations are possible, the broadening is consistent with the presence of Kelvin–Helmholtz instabilities (KHI) on length-scales of a few kpc. Based on comparison with simulations, the presence of KHI would imply that the effective viscosity of the intracluster medium is suppressed by more than an order of magnitude with respect to the isotropic Spitzer-like temperature dependent viscosity. Underneath the cold front, we observe quasi-linear features that are ∼10 per cent brighter than the surrounding gas and are separated by ∼15 kpc from each other in projection. Comparison to tailored numerical simulations suggests that the observed phenomena may be due to the amplification of magnetic fields by gas sloshing in wide layers below the cold front, where the magnetic pressure reaches ∼5–10 per cent of the thermal pressure, reducing the gas density between the bright features

    All Teleportation and Dense Coding Schemes

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    We establish a one-to-one correspondence between (1) quantum teleportation schemes, (2) dense coding schemes, (3) orthonormal bases of maximally entangled vectors, (4) orthonormal bases of unitary operators with respect to the Hilbert-Schmidt scalar product, and (5) depolarizing operations, whose Kraus operators can be chosen to be unitary. The teleportation and dense coding schemes are assumed to be ``tight'' in the sense that all Hilbert spaces involved have the same finite dimension d, and the classical channel involved distinguishes d^2 signals. A general construction procedure for orthonormal bases of unitaries, involving Latin Squares and complex Hadamard Matrices is also presented.Comment: 21 pages, LaTe

    Psychopathological Course Typology in Schizophrenia Spectrum Disorders: A Heuristic Approach in a Sample of 100 Patients

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    Background: Despite several previous attempts at subtyping schizophrenia, a typology that reflects neurobiological knowledge and reliably predicts course and outcome is lacking. We applied the system-specific concept of the Bern Psychopathology Scale (BPS) to generate a course typology based on three domains: language, affectivity, and motor behaviour. Sampling and Methods: A cohort of 100 patients with schizophrenia or schizoaffective disorders according to DSM-IV criteria underwent psychopathological assessment, and all their available medical records were retrospectively analysed on the basis of the BPS. Results: Overall, 39% of the patients showed dominant abnormalities in only one domain, 37% in two domains, and 24% in all three domains. The motor domain was affected in the majority of patients (76%), followed by affectivity (63%) and language (46%). Eighty-six percent of patients showed a bipolar course pattern in at least one domain. Conclusions: In a retrospective analysis of 100 patient records we described system-specific course patterns of schizophrenia by using a neurobiologically informed psychopathological assessment. The results showed a surprisingly high proportion of bipolar courses and a pattern of pure and mixed subtypes, which speaks for an overlap of domains with regards to psychopathological symptoms. A limitation of this heuristic and retrospective approach is that it was largely based on clinical judgement. Prospective studies with more rigorous threshold definitions are needed to clarify the neurobiological and clinical implications of the proposed reorganization of psychotic disorders. (C) 2016 S. Karger AG, Base

    What did we learn from the extraction experiments with bent crystals at the CERN SPS?

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    The feasibility and properties of particle extraction from an accelerator by means of a bent crystal were studied extensively at the CERN SPS. The main results of the experiments are presented. This includes the evidence for multipass extraction of heavy ions. These results are compared with theoretical expectations and computer simulations

    Technical Report Scintigraphic Evaluation of Bone Formation in Göttingen Minipigs

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    In experiments and processes requiring the application of nuclear tracers in large animals, statutory provisions  and safety standards as well as a variety of techniques have to be regarded and employed. In order to sufficiently analyze questions pertaining to osseointegration as well as the possibility of ectopic  bone formation in Göttingen minipigs, we decided to use scintigraphic examinations using 99mTc-HDP  (Technetium - hydroxymethane diphosphonate). In this study, metallic implants coated in different forms  with rhBMP-2 (recombinant human bone morphogenetic protein-2) were surgically introduced into the  pigs’ femora. A total of 26 adult female minipigs (Ellegard, Dalmose, Denmark) averaging 40 months in  age were post-surgically evaluated through the application of a radionuclide and its subsequent distribution  using a scintillation camera. Each animal received approximately 10 MBq/kg BW (mega Becquerel per  kilogram bodyweight). This paper describes the procedures of anaesthesia, the quite challenging transvaginal- urethral catheterization,  the application of a catheter in the jugular vein, the radionuclide injection and the disposal of the  sacrificed animals under statutory provisions and safety standards. The technical report reveals that the scintigraphic evaluation in large animal experiments is a practicable  – yet sophisticated – method of examination and also strives to encourage further research groups to implement  this elegant procedure.
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