Peculiar from-Edge-to-Interior Spin Freezing in a Magnetic Dipolar Cube

By molecular dynamics simulation, we have investigated classical Heisenberg spins, which are arrayed on a finite simple cubic lattice and interact with each other only by the dipole-dipole interaction, and have found its peculiar it from-Edge-to-interior freezing process. As the temperature is decreased, spins on each edge predominantly start to freeze in a ferromagnetic alignment parallel to the edge around the corresponding bulk transition temperature, then from each edges grow domains with short-range orders similar to the corresponding bulk orders, and the system ends up with a unique multi-domain ground state at the lowest temperature. We interpret this freezing characteristics is attributed to the anisotropic and long-range nature of the dipole-dipole interaction combined with a finite-size effect.Comment: 11 pages 5 figure

Magnetic Properties of 2-Dimensional Dipolar Squares: Boundary Geometry Dependence

By means of the molecular dynamics simulation on gradual cooling processes, we investigate magnetic properties of classical spin systems only with the magnetic dipole-dipole interaction, which we call dipolar systems. Focusing on their finite-size effect, particularly their boundary geometry dependence, we study two finite dipolar squares cut out from a square lattice with $\Phi=0$ and $\pi/4$, where $\Phi$ is an angle between the direction of the lattice axis and that of the square boundary. Distinctly different results are obtained in the two dipolar squares. In the $\Phi=0$ square, the ``from-edge-to-interior freezing'' of spins is observed. Its ground state has a multi-domain structure whose domains consist of the two among infinitely (continuously) degenerated Luttinger-Tisza (LT) ground-state orders on a bulk square lattice, i.e., the two antiferromagnetically aligned ferromagnetic chains (af-FMC) orders directed in parallel to the two lattice axes. In the $\Phi=\pi/4$ square, on the other hand, the freezing starts from the interior of the square, and its ground state is nearly in a single domain with one of the two af-FMC orders. These geometry effects are argued to originate from the anisotropic nature of the dipole-dipole interaction which depends on the relative direction of sites in a real space of the interacting spins.Comment: 21 pages, 13 figures, submitted to Journal of Physical Society Japa

Tapasztalatok es motiváltság: magyar középiskolások véleménye az egészségvédő programokról.

INTRODUCTION: Health-related attitudes can be encouraged most effectively at young ages. Young generations would require more interactive methods in programs engaged in health promotion. AIM: The aim of the authors was to get an insight into the attitudes, experience and motivation of youngsters in connection with health promotion programs and the community service work. METHOD: The questionnaires were filled in by high school students studying in Budapest and in the countryside (N = 898). RESULTS: 44.4% of the students did not have lessons or extracurricular activities dealing with health promotion. Concerning health promotion programs, youngsters in Budapest had more positive experience, while female students showed a more adoptive attitude. CONCLUSIONS: It was concluded that in one of the most susceptible life stages, many youngsters either do not participate in programs dealing with health promotion, or participate in programs that are within the framework of school subjects or extracurricular activities building on traditional teaching methods. Orv. Hetil., 2016, 157(2), 65-69

Listeria pathogenesis and molecular virulence determinants

The gram-positive bacterium Listeria monocytogenes is the causative agent of listeriosis, a highly fatal opportunistic foodborne infection. Pregnant women, neonates, the elderly, and debilitated or immunocompromised patients in general are predominantly affected, although the disease can also develop in normal individuals. Clinical manifestations of invasive listeriosis are usually severe and include abortion, sepsis, and meningoencephalitis. Listeriosis can also manifest as a febrile gastroenteritis syndrome. In addition to humans, L. monocytogenes affects many vertebrate species, including birds. Listeria ivanovii, a second pathogenic species of the genus, is specific for ruminants. Our current view of the pathophysiology of listeriosis derives largely from studies with the mouse infection model. Pathogenic listeriae enter the host primarily through the intestine. The liver is thought to be their first target organ after intestinal translocation. In the liver, listeriae actively multiply until the infection is controlled by a cell-mediated immune response. This initial, subclinical step of listeriosis is thought to be common due to the frequent presence of pathogenic L. monocytogenes in food. In normal indivuals, the continual exposure to listerial antigens probably contributes to the maintenance of anti-Listeria memory T cells. However, in debilitated and immunocompromised patients, the unrestricted proliferation of listeriae in the liver may result in prolonged low-level bacteremia, leading to invasion of the preferred secondary target organs (the brain and the gravid uterus) and to overt clinical disease. L. monocytogenes and L. ivanovii are facultative intracellular parasites able to survive in macrophages and to invade a variety of normally nonphagocytic cells, such as epithelial cells, hepatocytes, and endothelial cells. In all these cell types, pathogenic listeriae go through an intracellular life cycle involving early escape from the phagocytic vacuole, rapid intracytoplasmic multiplication, bacterially induced actin-based motility, and direct spread to neighboring cells, in which they reinitiate the cycle. In this way, listeriae disseminate in host tissues sheltered from the humoral arm of the immune system. Over the last 15 years, a number of virulence factors involved in key steps of this intracellular life cycle have been identified. This review describes in detail the molecular determinants of Listeria virulence and their mechanism of action and summarizes the current knowledge on the pathophysiology of listeriosis and the cell biology and host cell responses to Listeria infection. This article provides an updated perspective of the development of our understanding of Listeria pathogenesis from the first molecular genetic analyses of virulence mechanisms reported in 1985 until the start of the genomic era of Listeria research

Design concepts for a supermirror V cavity based combined beam polarizer and compressor system for the upgraded neutron time of flight spectrometer NEAT

Here we present several design concepts for polarization of incoming neutrons based on the use of supermirror optical devices for application in time of flight neutron spectroscopy. The polarization systems, designed for time of flight spectrometer NEAT [], are using so called V cavity approach and due to the conditions imposed by instrument layout are to polarize and compress the neutron beam. The polarizers design secures high values of both polarization and transmittance of neutron beam intensity, corresponding to recent state of the arts performances. The results are supported by analytical calculations and simulations by VITESS software

Polarized beam option for the time of flight spectrometer NEAT

We present the basic design of the incoming neutron beam polarizer system recently installed at the TOF spectrometer NEAT at HZB and first experimental test results. The recent upgrade of the instrument resulted in beam flux on the sample, which is one of the highest worldwide for this class of instruments. The very substantial intensity gain obtained in the upgrade provides good conditions for polarized neutron experiments, considering the inherent cuts of neutron intensity by polarizing the beam. The neutron beam polarizer is placed inside a 3.3 m long neutron guide changer , which allows us to move into the beam delivery guide one of 3 alternative straight neutron guide sections mounted in parallel on a linear translation stage. The new transmission polarizer takes up the inside volume of a 1.33 m long, 60 mm x 125 mm cross section guide portion. The focusing of the beam after the polarizer to the 30 mm x 50 mm sample area happens over a total length of 3.5 m, of which 2.92 cm is a converging guide section with m 4 supermirror coating and parabolic end. This guide section leaves 58 cm space between guide exit and sample axis for sample environment equipment, in particular for high field cryomagnets. The transmission polarizer contains 8 V cavity channels with non polarizing supermirror coated, opaque side walls and m 3 polarizing supermirror coated neutron transparent Si cavity plates, coated on both sides [1]. The nominal operational wavelength band width of the polarizer is 2.5 8 , with measured polarization efficiency between 92 and 96 . The beam transmission efficiency for the preferred neutron spin state is about 65 . The polarization guide field between the exit of the polarizer and the end of the converging guide in front of the sample contains a wavelength tunable single coil Mezei flipper coil with guide field with flipping efficiency gt; 99 . The rest of the guide field is provided by solenoids around the guide. The supermirror coating in the polarized neutron section of the guide has been manufactured using a non magnetic Ni alloy, the guide exchanger housing and mechanical parts inside are made of non magnetic alloys, primarily stainless steel. The polarized beam delivery system is by now operational and it is available for polarized neutron beam experiments on samples in a magnetic field and a 14 T maximal vertical field cryomagnet is available at the HZB Sample Environment Group for use on NEAT. The NEAT sample chamber has been designed and built with non magnetic or weakly magnetic materials to allow both for polarized neutron beam experiments and polarization analysis wor

A Study of Factors Influencing Burnout in Teachers in Western Hungary

It is obvious to professionals employed in teaching and education that over the course of their work they continuously need to face a multitude of emotional reactions from children and adults, and need to address the reasons and effects of such. Thus, it is important for them to be knowledgeable of the factors that render easier or more difficult the education process itself, their work, and the conscious ways of combating these difficulties; this, while staying psychologically and emotionally functional both in their work and in their private life. In their helping profession, their most important tool is obviously their own personality. It is important for them to be able to help others, but it is equally important to be able to take care of themselves, these being the two sides of the same process. A person’s emotional life affects others – therefore it is not simply a private issue – whereas others, their circumstances, and their way of life affect the state of their inner self. This study set the goal of examining the factors influencing burnout in teachers. It therefore focuses on certain elements of choosing a profession, interests, needs, the relationship between the individual and the environment, parental upbringing attitudes, career patterns in the family, and satisfaction about career choice. Through the question of work and mental health, the author examines the degree to which professional, financial, and moral recognition influence burnout, the impact of the relationship with colleagues and the manager on the risk of burnout, and the connection between symptoms of physical health (days off work / sick leave) and mental health. The author further refines the issue studied along factors of sex, years spent in the profession, and manager / employee status