A simple model of price formation

A simple Ising spin model which can describe the mechanism of price formation in financial markets is proposed. In contrast to other agent-based models, the influence does not flow inward from the surrounding neighbors to the center site, but spreads outward from the center to the neighbors. The model thus describes the spread of opinions among traders. It is shown via standard Monte Carlo simulations that very simple rules lead to dynamics that duplicate those of asset prices.Comment: Version 2: 4 pages, 4 figures; added more stringent statistical analysis; to appear in Int. J. Modern Physics C, Vol. 13, No. 1 (2002

Open shells in reduced-density-matrix-functional theory

Reduced-density-matrix-functional theory is applied to open-shell systems. We introduce a spin-restricted formulation by appropriately expressing approximate correlation-energy functionals in terms of spin-dependent occupation numbers and spin-independent natural orbitals. We demonstrate that the additional constraint of total-spin conservation is indispensable for the proper treatment of open-shell systems. The formalism is applied to the first-row open-shell atoms. The obtained ground-state energies are in very good agreement with the exact values as well as other state of the art quantum chemistry calculationsComment: 4 pages, 2 figures, corrected typo

N-glycans of human amniotic fluid transferrin stimulate progesterone production in human first trimester trophoblast cells in vitro

Aims: During pregnancy, the placenta produces a variety of steroid hormones and proteins. Several of these substances have been shown to exert immunomodulatory effects. Progesterone is thought to mediate some of these effects by regulating uterine responsiveness. The aim of this study was to clarify the effect of amniotic fluid transferrin and its N-glycans on the release of progesterone by first trimester trophoblast cells in vitro. Methods: Cytotrophoblast cells were prepared from human first trimester placentae by trypsin-DNAse dispersion of villous tissue followed by a percoll gradient centrifugation and depletion of CD45 positive cells by magnetic cell sorting. Trophoblasts were incubated with varying concentrations (50-300 mug/ml) of transferrin from human amniotic fluid and serum as well as with N-glycans obtained from amniotic fluid transferrin. Culture supernatants were assayed for progesterone by enzyme-immunometric methods. Results: The release of progesterone increased in amniotic fluid transferrin- and N-glycan-treated trophoblast cell cultures compared to untreated trophoblast cells. There was no stimulating effect of serum transferrin on the progesterone production of trophoblast cells. Conclusions: The results suggest that amnion-transferrin and especially its N-glycans modulate the endocrine function of trophoblasts in culture by up regulating progesterone secretion

Competing spin transfer and dissipation at Co/Cu(001) interfaces on femtosecond timescales

By combining interface-sensitive non-linear magneto-optical experiments with femtosecond time resolution and ab-initio time-dependent density functional theory, we show that optically excited spin dynamics at Co/Cu(001) interfaces proceeds via spin-dependent charge transfer and backtransfer between Co and Cu. This ultrafast spin transfer competes with dissipation of spin angular momentum mediated by spin-orbit coupling already on sub 100 fs timescales. We thereby identify the fundamental microscopic processes during laser-induced spin transfer at a model interface for technologically relevant ferromagnetic heterostructures.Comment: 5 pages, 4 figure

Polarization operator approach to electron-positron pair production in combined laser and Coulomb fields

The optical theorem is applied to the process of electron-positron pair creation in the superposition of a nuclear Coulomb and a strong laser field. We derive new representations for the total production rate as two-fold integrals, both for circular laser polarization and for the general case of elliptic polarization, which has not been treated before. Our approach allows us to obtain by analytical means the asymptotic behaviour of the pair creation rate for various limits of interest. In particular, we consider pair production by two-photon absorption and show that, close to the energetic threshold of this process, the rate obeys a power law in the laser frequency with different exponents for linear and circular laser polarization. With the help of the upcoming x-ray laser sources our results could be tested experimentally.Comment: 10 pages, 3 figure

Evaluating and expanding the European Union's protected-area network toward potential post-2020 coverage targets

The Convention on Biological Diversity's (CBD) strategic plan will expire in 2020, but biodiversity loss is ongoing. Scientists call for more ambitious targets in the next agreement. The nature-needs-half movement, for example, has advocated conserving half of Earth to solve the biodiversity crisis, which has been translated to protecting 50 of each ecoregion. We evaluated current protection levels of ecoregions in the territory of one of the CBD's signatories, the European Union (EU). We also explored the possible enlargement of the Natura 2000 network to implement 30 or 50 ecoregion coverage in the EU member states’ protected area (PA) network. Based on the most recent land-use data, we examined whether ecoregions have enough natural area left to reach such high coverage targets. We used a spatially explicit mixed integer programing model to estimate the least-cost expansion of the PA network based on 3 scenarios that put different emphasis on total conservation cost, ecological representation of ecosystems, or emphasize an equal share of the burden among member states. To realize 30 and 50 ecoregion coverage, the EU would need to add 6.6 and 24.2, respectively, of its terrestrial area to its PA network. For all 3 scenarios, the EU would need to designate most recommended new PAs in seminatural forests and other semi- or natural ecosystems. Because 15 ecoregions did not have enough natural area left to implement the ecoregion-coverage targets, some member states would also need to establish new PAs on productive land, allocating the largest share to arable land. Thirty percent ecoregion coverage was met by protecting remaining natural areas in all ecoregions except 3, where productive land would also need to be included. Our results support discussions of higher ecoregions protection targets for post-2020 biodiversity frameworks. © 2020 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology

Community pharmacy-based intervention to improve self-monitoring of blood glucose in type 2 diabetic patients

Self-monitoring of blood glucose (SMBG) is clearly correlated with increased life expectancy and quality of life in type 2 diabetic patients. Objective: The objective of our study was to record and assess the errors patients make in preparing, performing, and processing self-monitoring of blood glucose (SMBG). Furthermore, the study aimed to determine to what extent a single standardized SMBG instruction session in a community pharmacy might reduce the number of patients making errors or the number of errors per patient. Methods: Between May and October 2005, SMBG of 462 randomly selected patients with type 2 diabetes was monitored in 32 pharmacies specialized in diabetes care. The patients performed blood glucose self-tests using their own blood glucose meters. Self-testing was monitored using a standardized documentation sheet on which any error made during the performance of the test was recorded. If necessary, patients were instructed in the accurate operation of their meter and the use of the necessary equipment. Additionally, patients obtained written instructions. Six weeks later, assessment of the quality of patient’s SMBG was repeated.Results: During the first observation, 383 patients (83%) made at least one mistake performing SMBG. By the time of the second observation, this frequency had fallen to 189 (41%) (p<0.001). The average number of mistakes fell from 3.1 to 0.8 per patient. Mistakes that may potentially have led to inaccurate readings were initially recorded for 283 (61%) and at study end for 110 (24%) patients (p<0.001). Conclusion: It is important to periodically instruct type 2 diabetic patients in the proper SMBG technique in order to ensure accurate measurements. In this study it was shown that community pharmacies specialized in diabetes care can provide this service effectively

Leistungen und Entwicklung von Öko- Milchviehbetrieben mit geringem Kraftfuttereinsatz in Baden-Württemberg

The aim of this study was the analysis of dairy farms in Baden-Württemberg producing milk without or with only a little amount of concentrate. 12 biological managed farms have been visited and consulted by questionnaire in 2010. Also the results of milk yield testing have been examined. Economic calculations were run for a comparison to conventionally working dairy farms. In 2015 the results were for 10 of these farms updated. Since 2010 the structure of the farms remained almost unchanged (number of cows, milk yield, cultivated area). The proportion of pasture from grassland increased from 45 to 53%. The ecological-low input drived production system leads to better conditions for profitable milk production compared to conventional dairy farms

The Alzheimer variant of Lewy body disease: A pathologically confirmed case-control study

The objective of the study was to identify clinical features that distinguish patients with dementia with Lewy bodies (DLB), who were classified as Alzheimer's disease ( AD) patients, from patients with AD. We examined a group of 27 patients from our memory clinic, originally diagnosed with AD, of whom 6 were postmortem found to have DLB. For the present study, we compared cognitive, noncognitive and neurological symptoms between the two groups. We found that there were no differences on ratings of dementia and scales for activities of daily living. Patients with DLB performed better on the MMSE and the memory subtest of the CAMCOG, but there was no difference in any other cognitive domain. Furthermore, genetic risk factors, including family history of dementia or allele frequency of the apolipoprotein epsilon 4, did not discriminate between the two groups, and there were no differences on CCT scans. Taken together, our findings suggest that Lewy body pathology may be present in patients who do not show the typical clinical features which distinguish DLB from AD. Copyright (C) 2005 S. Karger AG, Basel

Back-to-back correlations of high p_T hadrons in relativistic heavy ion collisions

We investigate the suppression factor and the azimuthal correlation function for high $p_T$ hadrons in central Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV by using a dynamical model in which hydrodynamics is combined with explicitly traveling jets. We study the effects of parton energy loss in a hot medium, intrinsic $k_T$ of partons in a nucleus, and $p_{\perp}$ broadening of jets on the back-to-back correlations of high $p_T$ hadrons. Parton energy loss is found to be a dominant effect on the reduction of the away-side peaks in the correlation function.Comment: 4 pages, 4 figures; version to appear in Phys. Rev. Let