1,579 research outputs found

    Freshwater fishes of Shipstern Nature Reserve

    Get PDF
    A survey of fishes in and around Shipstern Nature Reserve in Northern Belize, Central America, was carried out over a period of eight months, from February to September 1990. Its purpose was to establish a preliminary list of the fishes of Shipstern Nature Reserve, including descriptions, distribution and collecting data and additionally to describe some of the habitats in which the fishes were found. This study focuses on fishes considered to be freshwater species. These occurred for the greater part in brackish habitats. Nevertheless, a few fish considered as marine species were caught in the waters of the reserve and these equally received attention. Findings include 15 species of fresh or brackish water and 3 marine species. Two species are of particular interest: Cyprinodon variegatus (Cyprinodontidae) is a new species for the Belizean fauna, while Rivulus ocellatus (Rivulidae), which was recorded from Twin Cays on the barrier reef (Davis et al., 1990), is now also confirmed for a mainland coastal habitats

    Imaging the Visual Pathway in Neuromyelitis Optica

    Get PDF
    The focus of this paper is to summarize the current knowledge on visual pathway damage in neuromyelitis optica (NMO) assessed by magnetic resonance imaging (MRI) and optical coherence tomography (OCT)

    Using case formulation for prediction of the therapeutic alliance in treatment for borderline personality disorder.

    Get PDF
    Case formulation is a central tool for psychotherapists, which helps them tailor psychotherapy to the individual patient, particularly for treatments for complex and multilayered clinical problems, such as personality disorders (Kramer, 2019). Case formulation methodologies are still underutilized in psychotherapy research in the prediction of therapy processes. The present study included N = 60 patients with borderline personality disorder undergoing a brief treatment using an individualized treatment component (n = 31), as compared with a standard brief treatment (n = 29; Kramer et al., 2014). For each patient (in both groups as post hoc analysis based on videos), we performed a Plan analysis case formulation (Caspar, 2019): the idiographic information from the formulation was translated into quantitative scores (on a Likert-type scale) assessing patient's interactional agreeableness (vs. antagonism; Zufferey et al., 2019). We modeled the session-by-session predictions of the progression of the therapeutic alliance-rated by the patient and the therapist-over the course of treatment, as a function of interactional agreeableness, the individualization of treatment, as well as their interaction with the session number. Patients with high levels of agreeableness have a significant increase in their alliance assessment over time. Treatment based on the case formulation predicted session-by-session increase of the therapeutic alliance as rated by the therapists. This study was the first to explore intra- and interindividual dynamics of the therapeutic alliance in relationship with idiographic information extracted from case formulations. The results may help understand relationship struggles at the beginning of therapy for complex clinical problems, such as borderline personality disorder. (PsycInfo Database Record (c) 2022 APA, all rights reserved)

    The Role of Interactional Agreeableness in Responsive Treatments for Patients With Borderline Personality Disorder.

    Get PDF
    It has been shown that agreeableness of patients with borderline personality disorder (BPD) had an impact on therapy process and outcome (Hirsh, Quilty, Bagby, & McMain, 2012). The goal of our study was to test whether agreeableness affects the therapeutic alliance and outcome assessed after brief treatment for BPD, and whether this link is moderated by therapist responsiveness. We compared two types of interventions (N = 60) in 10-session treatments (Kramer et al., 2014): a general psychiatric management (GPM)-based treatment and the same treatment supplemented with motive-oriented therapeutic relationship (MOTR), based on plan analysis case conceptualizations (PA; Caspar, 1995), as operationalization of therapist responsiveness. The results showed that there was a significant link between agreeableness and outcome for the GPM, but not for the MOTR. No links between agreeableness and the therapeutic alliance were found in both conditions. MOTR enables suppression of the influences of the patient's initial characteristics on the therapeutic results

    Soft modes near the buckling transition of icosahedral shells

    Full text link
    Icosahedral shells undergo a buckling transition as the ratio of Young's modulus to bending stiffness increases. Strong bending stiffness favors smooth, nearly spherical shapes, while weak bending stiffness leads to a sharply faceted icosahedral shape. Based on the phonon spectrum of a simplified mass-and-spring model of the shell, we interpret the transition from smooth to faceted as a soft-mode transition. In contrast to the case of a disclinated planar network where the transition is sharply defined, the mean curvature of the sphere smooths the transitition. We define elastic susceptibilities as the response to forces applied at vertices, edges and faces of an icosahedron. At the soft-mode transition the vertex susceptibility is the largest, but as the shell becomes more faceted the edge and face susceptibilities greatly exceed the vertex susceptibility. Limiting behaviors of the susceptibilities are analyzed and related to the ridge-scaling behavior of elastic sheets. Our results apply to virus capsids, liposomes with crystalline order and other shell-like structures with icosahedral symmetry.Comment: 28 pages, 6 figure

    Fluctuation-dissipation ratios in the dynamics of self-assembly

    Full text link
    We consider two seemingly very different self-assembly processes: formation of viral capsids, and crystallization of sticky discs. At low temperatures, assembly is ineffective, since there are many metastable disordered states, which are a source of kinetic frustration. We use fluctuation-dissipation ratios to extract information about the degree of this frustration. We show that our analysis is a useful indicator of the long term fate of the system, based on the early stages of assembly.Comment: 8 pages, 6 figure

    Anomalous coupling between topological defects and curvature

    Full text link
    We investigate a counterintuitive geometric interaction between defects and curvature in thin layers of superfluids, superconductors and liquid crystals deposited on curved surfaces. Each defect feels a geometric potential whose functional form is determined only by the shape of the surface, but whose sign and strength depend on the transformation properties of the order parameter. For superfluids and superconductors, the strength of this interaction is proportional to the square of the charge and causes all defects to be repelled (attracted) by regions of positive (negative) Gaussian curvature. For liquid crystals in the one elastic constant approximation, charges between 0 and 4π4\pi are attracted by regions of positive curvature while all other charges are repelled.Comment: 5 pages, 4 figures, minor changes, accepted for publication in Phys. Rev. Let

    Exercise in multiple sclerosis -- an integral component of disease management

    Get PDF
    Multiple sclerosis (MS) is the most common chronic inflammatory disorder of the central nervous system (CNS) in young adults. The disease causes a wide range of symptoms depending on the localization and characteristics of the CNS pathology. In addition to drug-based immunomodulatory treatment, both drug-based and non-drug approaches are established as complementary strategies to alleviate existing symptoms and to prevent secondary diseases. In particular, physical therapy like exercise and physiotherapy can be customized to the individual patient's needs and has the potential to improve the individual outcome. However, high quality systematic data on physical therapy in MS are rare. This article summarizes the current knowledge on the influence of physical activity and exercise on disease-related symptoms and physical restrictions in MS patients. Other treatment strategies such as drug treatments or cognitive training were deliberately excluded for the purposes of this article

    Elasticity Theory and Shape Transitions of Viral Shells

    Full text link
    Recently, continuum elasticity theory has been applied to explain the shape transition of icosahedral viral capsids - single-protein-thick crystalline shells - from spherical to buckled/faceted as their radius increases through a critical value determined by the competition between stretching and bending energies of a closed 2D elastic network. In the present work we generalize this approach to capsids with non-icosahedral symmetries, e.g., spherocylindrical and conical shells. One key new physical ingredient is the role played by nonzero spontaneous curvature. Another is associated with the special way in which the energy of the twelve topologically-required five-fold sites depends on the background local curvature of the shell in which they are embedded. Systematic evaluation of these contributions leads to a shape phase diagram in which transitions are observed from icosahedral to spherocylindrical capsids as a function of the ratio of stretching to bending energies and of the spontaneous curvature of the 2D protein network. We find that the transition from icosahedral to spherocylindrical symmetry is continuous or weakly first-order near the onset of buckling, leading to extensive shape degeneracy. These results are discussed in the context of experimentally observed variations in the shapes of a variety of viral capsids.Comment: 53 pages, 17 figure

    Simulation studies of a phenomenological model for elongated virus capsid formation

    Full text link
    We study a phenomenological model in which the simulated packing of hard, attractive spheres on a prolate spheroid surface with convexity constraints produces structures identical to those of prolate virus capsid structures. Our simulation approach combines the traditional Monte Carlo method with a modified method of random sampling on an ellipsoidal surface and a convex hull searching algorithm. Using this approach we identify the minimum physical requirements for non-icosahedral, elongated virus capsids, such as two aberrant flock house virus (FHV) particles and the prolate prohead of bacteriophage ϕ29\phi_{29}, and discuss the implication of our simulation results in the context of recent experimental findings. Our predicted structures may also be experimentally realized by evaporation-driven assembly of colloidal spheres
    corecore