380 research outputs found

    Phase stability analysis in Fe-Pt and Co-Pt alloy systems: An augmented space study

    Full text link
    We have studied the problem of phase stability in Fe-Pt and Co-Pt alloy systems. We have used the orbital peeling technique in the conjunction of augmented space recursion based on the tight binding linear orbital method as the method for the calculation of pair interaction energies. In particular, we have generalized our earlier technique to take into account of magnetic effects for the cases where the magnetic transition is higher than the order disorder chemical transition temperature as in the case of Co3_3Pt. Our theoretical results obtained within this framework successfully reproduce the experimentally observed trends.Comment: 17 pages, 9 Figures. Accepted for publication in Journal of Physics : Condensed Matte

    State-dependent signatures of anti-N-methyl-d-aspartate receptor encephalitis

    Get PDF
    Traditional static functional connectivity analyses have shown distinct functional network alterations in patients with anti-N-methyl-d-aspartate receptor encephalitis. Here, we use a dynamic functional connectivity approach that increases the temporal resolution of connectivity analyses from minutes to seconds. We hereby explore the spatiotemporal variability of large-scale brain network activity in anti-N-methyl-d-aspartate receptor encephalitis and assess the discriminatory power of functional brain states in a supervised classification approach. We included resting-state functional magnetic resonance imaging data from 57 patients and 61 controls to extract four discrete connectivity states and assess state-wise group differences in functional connectivity, dwell time, transition frequency, fraction time and occurrence rate. Additionally, for each state, logistic regression models with embedded feature selection were trained to predict group status in a leave-one-out cross-validation scheme. Compared to controls, patients exhibited diverging dynamic functional connectivity patterns in three out of four states mainly encompassing the default-mode network and frontal areas. This was accompanied by a characteristic shift in the dwell time pattern and higher volatility of state transitions in patients. Moreover, dynamic functional connectivity measures were associated with disease severity and positive and negative schizophrenia-like symptoms. Predictive power was highest in dynamic functional connectivity models and outperformed static analyses, reaching up to 78.6% classification accuracy. By applying time-resolved analyses, we disentangle state-specific functional connectivity impairments and characteristic changes in temporal dynamics not detected in static analyses, offering new perspectives on the functional reorganization underlying anti-N-methyl-d-aspartate receptor encephalitis. Finally, the correlation of dynamic functional connectivity measures with disease symptoms and severity demonstrates a clinical relevance of spatiotemporal connectivity dynamics in anti-N-methyl-d-aspartate receptor encephalitis

    A Precision Measurement of pp Elastic Scattering Cross Sections at Intermediate Energies

    Get PDF
    We have measured differential cross sections for \pp elastic scattering with internal fiber targets in the recirculating beam of the proton synchrotron COSY. Measurements were made continuously during acceleration for projectile kinetic energies between 0.23 and 2.59 GeV in the angular range 30≤θc.m.≤9030 \leq \theta_{c.m.} \leq 90 deg. Details of the apparatus and the data analysis are given and the resulting excitation functions and angular distributions presented. The precision of each data point is typically better than 4%, and a relative normalization uncertainty of only 2.5% within an excitation function has been reached. The impact on phase shift analysis as well as upper bounds on possible resonant contributions in lower partial waves are discussed.Comment: 23 pages 29 figure

    From Teamchef Arminius to Hermann Junior: glocalised discourse about a national foundation myth

    Get PDF
    If for much of the nineteenth and twentieth centuries, the ‘Battle of the Teutoburg Forest’, fought in 9 CE between Roman armies and Germanic tribes, was predominantly a reference point for nationalist and chauvinist discourses in Germany, the first decade of the twenty-first century has seen attempts to link public remembrance with local/regional identities on the one hand and international/intercultural contact on the other. In the run up to and during the ‘anniversary year’ of 2009, German media, sports institutions and various other official institutions articulating tourist, economic and political interests attempted to create a new ‘glocalised’ version of the public memory of the Teutoburg battle. Combining methods of Cognitive Linguistics and Critical Discourse Analysis, the paper analyses the narrative and argumentative topoi employed in this re-orientation of public memory, with a special emphasis on hybrid, post-national identity-construction. Das zweitausendjährige Gedenkjahr der „Schlacht im Teutoburger Wald“ im Jahr 2009 bot eine günstige Gelegenheit, die bis in die zweite Hälfte des 20. Jahrhunderts dominante Tradition nationalistisch–chauvinistischer Deutungen des Sieges von germanischen Stämmen über drei römische Legionen zu korrigieren und zu überwinden. Der Aufsatz analysiert mit Hilfe diskurslinguistischer Methoden die Anstrengungen regionaler Institutionen und Medien, die nationale Vereinnahmung des historischen Gedenkens kritisch zu thematisieren sowie neue, zum eine lokal situierte, zum andern international orientierte Identifikationsangebote anzubieten. Die Analyse zeigt, dass solche „de-nationalisierten“ Identifikationsangebote zwar teilweise auch früher verwendet wurden, aber heutzutage rekontextualisiert und auf innovative Weise in den Vordergrund gestellt werden

    Acute maternal infection and risk of pre-eclampsia: a population-based case-control study.

    Get PDF
    BACKGROUND: Infection in pregnancy may be involved in the aetiology of pre-eclampsia. However, a clear association between acute maternal infection and pre-eclampsia has not been established. We assessed whether acute urinary tract infection, respiratory tract infection, and antibiotic drug prescriptions in pregnancy (a likely proxy for maternal infection) are associated with an increased risk of pre-eclampsia. METHODS AND FINDINGS: We used a matched nested case-control design and data from the UK General Practice Research Database to examine the association between maternal infection and pre-eclampsia. Primiparous women aged at least 13 years and registered with a participating practice between January 1987 and October 2007 were eligible for inclusion. We selected all cases of pre-eclampsia and a random sample of primiparous women without pre-eclampsia (controls). Cases (n=1533) were individually matched with up to ten controls (n=14236) on practice and year of delivery. We calculated odds ratios and 95% confidence intervals for pre-eclampsia comparing women exposed and unexposed to infection using multivariable conditional logistic regression. After adjusting for maternal age, pre-gestational hypertension, diabetes, renal disease and multifetal gestation, the odds of pre-eclampsia were increased in women prescribed antibiotic drugs (adjusted odds ratio 1.28;1.14-1.44) and in women with urinary tract infection (adjusted odds ratio 1.22;1.03-1.45). We found no association with maternal respiratory tract infection (adjusted odds ratio 0.91;0.72-1.16). Further adjustment for maternal smoking and pre-pregnancy body mass index made no difference to our findings. CONCLUSIONS: Women who acquire a urinary infection during pregnancy, but not those who have a respiratory infection, are at an increased risk of pre-eclampsia. Maternal antibiotic prescriptions are also associated with an increased risk. Further research is required to elucidate the underlying mechanism of this association and to determine whether, among women who acquire infections in pregnancy, prompt treatment or prophylaxis against infection might reduce the risk of pre-eclampsia

    Long-Range Magnetic Interactions Induced by the Lattice Distortions and the Origin of the E-type Antiferromagnetic Phase in the Undoped Orthorhombic Manganites

    Full text link
    With the increase of the lattice distortion, the orthorhombic manganites RRMnO3_3 (RR== La, Pr, Nd, Tb, and Ho) are known to undergo the phase transition from the layered A-type antiferromagnetic (AFM) state to the zigzag E-type AFM state. We consider the microscopic origin of this transition. Our approach consists of the two parts. First, we construct an effective lattice fermion model for the manganese 3d-bands and derive parameters of this model from the first-principles electronic structure calculations. Then, we solve this model in the Hartree-Fock approximation (HFA) and analyze the behavior of interatomic magnetic interactions. We argue that the nearest-neighbor interactions decrease with the distortion and at certain stage start to compete with the longer range (particularly, second- and third-neighbor) AFM interactions in the orthorhombic ab-plane, which lead to the formation of the E-phase. The origin of these interactions is closely related to the orbital ordering, which takes place in the distorted orthorhombic structure. The model is able to capture the experimental trend and explain why LaMnO3_3 develops the A-type AFM order and why it tends to transform to the E-type AFM order in the more distorted compounds. Nevertheless, the quantitative agreement with the experimental data crucially depends on other factors, such as the magnetic polarization of the oxygen sites and the correlation interactions beyond HFA.Comment: 26 pages, 15 figure

    Toll-like receptors in cellular subsets of human tonsil T cells: altered expression during recurrent tonsillitis

    Get PDF
    BACKGROUND: The palatine tonsils have a pivotal role in immunological detection of airborne and ingested antigens like bacteria and viruses. They have recently been demonstrated to express Toll-like receptors (TLRs), known to recognize molecular structures on such microbes and activate innate immune responses. Their activation might also provide a link between innate and adaptive immunity. In the present study, the expression profile of TLR1-TLR10 was characterized in human tonsil T cells, focusing on differences between subsets of CD4(+ )T helper (Th) cells and CD8(+ )cytotoxic T lymphocytes (CTL). The study was also designed to compare the TLR expression in T cells from patients with recurrent tonsillitis and tonsillar hyperplasia. METHODS: Tonsils were obtained from children undergoing tonsillectomy, and classified according to the clinical diagnoses and the outcome of tonsillar core culture tests. Two groups were defined; recurrently infected tonsils and hyperplastic tonsils that served as controls. Subsets of T cells were isolated using magnetic beads. The expression of TLR transcripts in purified cells was assessed using quantitative real-time RT-PCR. The corresponding protein expression was investigated using flow cytometry and immunohistochemistry. RESULTS: T cells expressed a broad repertoire of TLRs, in which TLR1, TLR2, TLR5, TLR9 and TLR10 predominated. Also, a differential expression of TLRs in CD4(+ )and CD8(+ )T cells was obtained. TLR1 and TLR9 mRNA was expressed to a greater extent in CD4(+ )cells, whereas expression of TLR3 mRNA and protein and TLR4 protein was higher in CD8(+ )cells. CD8(+ )cells from infected tonsils expressed higher levels of TLR2, TLR3 and TLR5 compared to control. In contrast, CD4(+ )cells exhibited a down-regulated TLR9 as a consequence of infection. CONCLUSION: The present study demonstrates the presence of a broad repertoire of TLRs in T cells, a differential expression in CD4(+ )and CD8(+ )cells, along with infection-dependent alterations in TLR expression. Collectively, these results support the idea that TLRs are of importance to adaptive immune cells. It might be that TLRs have a direct role in adaptive immune reactions against infections. Thus, further functional studies of the relevance of TLR stimulation on T cells will be of importance

    Fashioning Entitlements: A Comparative Law and Economic Analysis of the Judicial Role in Environmental Centralization in the U.S. and Europe

    Get PDF
    This paper identifies and evaluates, from an economic point of view, the role of the judiciary the steady shift of environmental regulatory authority to higher, more centralized levels of government in both the U.S. and Europe. We supply both a positive analysis of how the decisions made by judges have affected the incentives of both private and public actors to pollute the natural environment, and normative answers to the question of whether judges have acted so as to create incentives that move levels of pollution in an efficient direction, toward their optimal, cost-minimizing (or net-benefit-maximizing) levels. Highlights of the analysis include the following points: 1) Industrial-era local (state or national) legislation awarding entitlements to pollute was almost certainly inefficient due to a fundamental economic obstacle faced by those who suffer harm from the over-pollution of publicly owned natural resources: the inability to monetize and credibly commit to repay the future economic value of reducing pollution. 2) When industrial era pollution spilled across state lines in the US, the federal courts, in particular the Supreme Court, fashioned a federal common law of interstate nuisance that set up essentially the same sort of blurry, uncertain entitlements to pollute or be free of pollution that had been created by the state courts in resolving local pollution disputes. We argue that for the typical pollution problem, a legal regime of blurry interstate entitlements - with neither jurisdiction having a clear right either to pollute or be free of pollution from the other - is likely to generate efficient incentives for interjursidictional bargaining, even despite the public choice problems besetting majority-rule government. Interestingly, a very similar system of de facto entitlements arose and often stimulated interjursidictional bargaining in Europe as well as in the U.S. 3) The US federal courts have generally interpreted the federal environmental statutes in ways that give clear primacy to federal regulators. Through such judicial interpretation, state and local regulators face a continuing risk of having their decisions overridden by federal regulators. This reduces the incentives for regulatory innovation at the state and local level. Judicial authorization of federal overrides has thus weakened the economic rationale for cooperative federalism suggested by economic models of principal-agent relationships. As a result of the principle of attribution, there is less risk in Europe that (like in the US) courts would enlarge the federal purview and thereby limit the powers of the Member States. Despite this principle, the power of the European bureaucracy (that is, the European Commission) has steadily increased and led to a steady shift of environmental regulatory competencies to the European level. This shift is only sometimes normatively desirable, and yet there is little that the ECJ can or will do to slow it

    Spatial Language Processing in the Blind: Evidence for a Supramodal Representation and Cortical Reorganization

    Get PDF
    Neuropsychological and imaging studies have shown that the left supramarginal gyrus (SMG) is specifically involved in processing spatial terms (e.g. above, left of), which locate places and objects in the world. The current fMRI study focused on the nature and specificity of representing spatial language in the left SMG by combining behavioral and neuronal activation data in blind and sighted individuals. Data from the blind provide an elegant way to test the supramodal representation hypothesis, i.e. abstract codes representing spatial relations yielding no activation differences between blind and sighted. Indeed, the left SMG was activated during spatial language processing in both blind and sighted individuals implying a supramodal representation of spatial and other dimensional relations which does not require visual experience to develop. However, in the absence of vision functional reorganization of the visual cortex is known to take place. An important consideration with respect to our finding is the amount of functional reorganization during language processing in our blind participants. Therefore, the participants also performed a verb generation task. We observed that only in the blind occipital areas were activated during covert language generation. Additionally, in the first task there was functional reorganization observed for processing language with a high linguistic load. As the visual cortex was not specifically active for spatial contents in the first task, and no reorganization was observed in the SMG, the latter finding further supports the notion that the left SMG is the main node for a supramodal representation of verbal spatial relations
    • …
    corecore