2,454 research outputs found

    Testing the Paleolithic-human-warfare hypothesis of blood-injectiion phobia in the Balitmore ECA Follow-up Study-Towards a more etiologically-based conceptualization for DSM-V

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    Objective: The research agenda for the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) has emphasized the need for a more etiologically-based classification system, especially for stress-induced and fear-circuitry disorders. Testable hypotheses based on threats to survival during particular segments of the human era of evolutionary adaptedness (EEA) may be useful in developing a brain-evolution-based classification for the wide spectrum of disorders ranging from disorders which are mostly overconsolidationally such as PTSD, to fear-circuitry disorders which are mostly innate such as specific phobias. The recently presented Paleolithic-human-warfare hypothesis posits that blood–injection phobia can be traced to a “survival (fitness) enhancing” trait, which evolved in some females of reproductive-age during the millennia of intergroup warfare in the Paleolithic EEA. The study presented here tests the key a priori prediction of this hypothesis—that current blood–injection phobia will have higher prevalence in reproductive-age women than in post-menopausal women. Method: The Diagnostic Interview Schedule (version III-R) , which included a section on blood and injection phobia, was administered to 1920 subjects in the Baltimore ECA Follow-up Study. Results: Data on BII phobia was available on 1724 subjects (1078 women and 646 males) . The prevalence of current blood– injection phobia was 3.3% in women aged 27–49 and 1.1% in women over age 50 (OR 3.05, 95% CI 1.20–7.73) . [The corresponding figures for males were 0.8% and 0.7% (OR 1.19, 95% CI 0.20–7.14)] . Conclusions: This epidemiological study provides one source of support for the Paleolithic-human-warfare (Paleolithic-threat) hypothesis regarding the evolutionary (distal) etiology of bloodletting-related phobia, and may contribute to a more brain- evolution-based re-conceptualization and classification of this fear circuitry-related trait for the DSM-V. In addition, the finding reported here may also stimulate new research directions on more proximal mechanisms which can lead to the development of evidence-based psychopharmacological preventive interventions for this common and sometimes disabling fear-circuitry disorder

    Maximizing nearest neighbour entanglement in finitely correlated qubit--chains

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    We consider translationally invariant states of an infinite one dimensional chain of qubits or spin-1/2 particles. We maximize the entanglement shared by nearest neighbours via a variational approach based on finitely correlated states. We find an upper bound of nearest neighbour concurrence equal to C=0.434095 which is 0.09% away from the bound C_W=0.434467 obtained by a completely different procedure. The obtained state maximizing nearest neighbour entanglement seems to approximate the maximally entangled mixed states (MEMS). Further we investigate in detail several other properties of the so obtained optimal state.Comment: 12 pages, 4 figures, 2nd version minor change

    Prevalence and Comorbidity of Alcohol Dependence, Depression, and Anxiety Disorders in their Association with the Serotonin Transporter Gene

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    Introduction: Depression and anxiety disorders have been found to be highly comorbid in epidemiologic studies. Furthermore, the presence of the short allele of the serotonin transporter gene (5HTT) has been found to be associated with an increased prevalence of major depressive disorder (MDD), bipolar disorder, anxiety disorders, as well as personality disorders. Aims: To examine the association of the 5HTT and the risk of prevalence and comorbidity for, Major Depressive Disorder, Bipolar Disorder, as well as several anxiety disorders in a sample of the Baltimore Epidemiologic Catchment Area Survey Follow-up Study. Methods: We estimated lifetime prevalence and the risk of comorbidity for Major Depressive Disorder, Bipolar Disorder, Panic Disorder, Agoraphobia, Social Phobia, Obsessive Compulsive Disorder, Generalized Anxiety Disorder, Simple Phobia, Dysthymic Disorder. All subjects were evaluated by a psychiatrist using the Schedules for Clinical Assessment in Neuropsychiatry. In addition, we assessed the impact of the carrier status into the prevalence and comorbidity estimates of the aforementioned disorders. Results: A significant association was found between an increased risk for the lifetime prevalence of Panic Disorder and the 5-HTT “s” polymorphism (OR (95% CI): 3.10 (1.33; 7.27). A higher risk for lifetime prevalence of Panic Disorder and the 5-HTT “s” polymorphism was found in women carriers as compared to men(OR (95% CI): 3.54 (1.41; 8.91)). Panic Disorder had significant comorbidities with Alcohol Dependence, Alcohol Abuse, MDD, Bipolar Disorder, Agoraphobia, Social Phobia, OCD, Simple Phobia and Adjustment Disorder. These associations were higher in women as compared to men carriers. Comorbidities for Simple Phobia were highly significant in males for most anxiety disorders and MDD. Conclusions: There was a high prevalence of comorbidity amongst most of the anxiety disorders in this population. The effect of the 5HTT carrier status was only associated with an increment in the risk of having a Panic Disorder

    Prismane C_8: A New Form of Carbon?

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    Our numerical calculations on small carbon clusters point to the existence of a metastable three-dimensional eight-atom cluster C8_8 which has a shape of a six-atom triangular prism with two excess atoms above and below its bases. We gave this cluster the name "prismane". The binding energy of the prismane equals to 5.1 eV/atom, i.e., is 0.45 eV/atom lower than the binding energy of the stable one-dimensional eight-atom cluster and 2.3 eV/atom lower than the binding energy of the bulk graphite or diamond. Molecular dynamics simulations give evidence for a rather high stability of the prismane, the activation energy for a prismane decay being about 0.8 eV. The prismane lifetime increases rapidly as the temperature decreases indicating a possibility of experimental observation of this cluster.Comment: 5 pages (revtex), 3 figures (eps

    Tunable Raman photons in singly charged p

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    Absolute instruments and perfect imaging in geometrical optics

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    We investigate imaging by spherically symmetric absolute instruments that provide perfect imaging in the sense of geometrical optics. We derive a number of properties of such devices, present a general method for designing them and use this method to propose several new absolute instruments, in particular a lens providing a stigmatic image of an optically homogeneous region and having a moderate refractive index range.Comment: 20 pages, 9 image

    Influence of the Soret effect on convection of binary fluids

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    Convection in horizontal layers of binary fluids heated from below and in particular the influence of the Soret effect on the bifurcation properties of extended stationary and traveling patterns that occur for negative Soret coupling is investigated theoretically. The fixed points corresponding to these two convection structures are determined for realistic boundary conditions with a many mode Galerkin scheme for temperature and concentration and an accurate one mode truncation of the velocity field. This solution procedure yields the stable and unstable solutions for all stationary and traveling patterns so that complete phase diagrams for the different convection types in typical binary liquid mixtures can easily be computed. Also the transition from weakly to strongly nonlinear states can be analyzed in detail. An investigation of the concentration current and of the relevance of its constituents shows the way for a simplification of the mode representation of temperature and concentration field as well as for an analytically manageable few mode description.Comment: 30 pages, 12 figure

    On two problems in graph Ramsey theory

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    We study two classical problems in graph Ramsey theory, that of determining the Ramsey number of bounded-degree graphs and that of estimating the induced Ramsey number for a graph with a given number of vertices. The Ramsey number r(H) of a graph H is the least positive integer N such that every two-coloring of the edges of the complete graph KNK_N contains a monochromatic copy of H. A famous result of Chv\'atal, R\"{o}dl, Szemer\'edi and Trotter states that there exists a constant c(\Delta) such that r(H) \leq c(\Delta) n for every graph H with n vertices and maximum degree \Delta. The important open question is to determine the constant c(\Delta). The best results, both due to Graham, R\"{o}dl and Ruci\'nski, state that there are constants c and c' such that 2^{c' \Delta} \leq c(\Delta) \leq 2^{c \Delta \log^2 \Delta}. We improve this upper bound, showing that there is a constant c for which c(\Delta) \leq 2^{c \Delta \log \Delta}. The induced Ramsey number r_{ind}(H) of a graph H is the least positive integer N for which there exists a graph G on N vertices such that every two-coloring of the edges of G contains an induced monochromatic copy of H. Erd\H{o}s conjectured the existence of a constant c such that, for any graph H on n vertices, r_{ind}(H) \leq 2^{c n}. We move a step closer to proving this conjecture, showing that r_{ind} (H) \leq 2^{c n \log n}. This improves upon an earlier result of Kohayakawa, Pr\"{o}mel and R\"{o}dl by a factor of \log n in the exponent.Comment: 18 page

    Bounds for graph regularity and removal lemmas

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    We show, for any positive integer k, that there exists a graph in which any equitable partition of its vertices into k parts has at least ck^2/\log^* k pairs of parts which are not \epsilon-regular, where c,\epsilon>0 are absolute constants. This bound is tight up to the constant c and addresses a question of Gowers on the number of irregular pairs in Szemer\'edi's regularity lemma. In order to gain some control over irregular pairs, another regularity lemma, known as the strong regularity lemma, was developed by Alon, Fischer, Krivelevich, and Szegedy. For this lemma, we prove a lower bound of wowzer-type, which is one level higher in the Ackermann hierarchy than the tower function, on the number of parts in the strong regularity lemma, essentially matching the upper bound. On the other hand, for the induced graph removal lemma, the standard application of the strong regularity lemma, we find a different proof which yields a tower-type bound. We also discuss bounds on several related regularity lemmas, including the weak regularity lemma of Frieze and Kannan and the recently established regular approximation theorem. In particular, we show that a weak partition with approximation parameter \epsilon may require as many as 2^{\Omega(\epsilon^{-2})} parts. This is tight up to the implied constant and solves a problem studied by Lov\'asz and Szegedy.Comment: 62 page

    Region of Excessive Flux of PeV Cosmic Rays in the Direction Toward Pulsars PSR J1840+5640 and LAT PSR J1836+5925

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    An analysis of arrival directions of extensive air showers (EAS) registered with the EAS MSU and EAS-1000 prototype arrays has revealed a region of excessive flux of PeV cosmic rays in the direction toward pulsars PSR J1840+5640 and LAT PSR J1836+5925 at significance level up to 4.5sigma. The first of the pulsars was discovered almost 30 years ago and is a well-studied old radio pulsar located at the distance of 1.7pc from the Solar system. The second pulsar belongs to a new type of pulsars, discovered by the space gamma-ray observatory Fermi, pulsations of which are not observed in optical and radio wavelengths but only in the gamma-ray range of energies (gamma-ray-only pulsars). In our opinion, the existence of the region of excessive flux of cosmic rays registered with two different arrays provides a strong evidence that isolated pulsars can give a noticeable contribution to the flux of Galactic cosmic rays in the PeV energy range.Comment: 14 pages; v.2: a few remarks to match a version accepted for Astronomy Letters added. They can be found by redefining the \NEW command in the preamble of the LaTeX fil
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