218 research outputs found

    Reconciliation in the transformation of conflict: an analysis of the South African experience and implications for its application in international conflict resolution from a peace theoretical perspective

    Full text link
    When violence has ceased it is often assumed that from this very moment peace has been restored. Definitions of peace and war have influenced earlier peace building interventions which in turn constituted the simple act of putting the weapons down as sufficient. Only recently have attempts to incorporate wider angles of facilitating peace and development been utilised. Critical approaches enhancing the perception of peace are put forward by Peace Theory scholars such as Johan Galtung and actual lessons learned serve to counter prevailing criticsm from Realist perspectives on peace. This paper demonstrates a rationale and case for supporting a more promising as well as more realistic view of peace and conflict management offered by peace theoretical considerations and approaches

    Reconciliation in the Transformation of Conflict. An Analysis of the South African Experience and Implications for its Application in International Conflict Resolution from a Peace Theoretical Perspective

    Get PDF
    When violence has ceased it is often assumed that from this very moment peace has been restored. Definitions of peace and war have influenced earlier peace building interventions which in turn constituted the simple act of putting the weapons down as sufficient. Only recently have attempts to incorporate wider angles of facilitating peace and development been utilised. Critical approaches enhancing the perception of peace are put forward by Peace Theory scholars such as Johan Galtung and actual lessons learned serve to counter prevailing criticsm from Realist perspectives on peace. This paper demonstrates a rationale and case for supporting a more promising as well as more realistic view of peace and conflict management offered by peace theoretical considerations and approaches. Transformation of conflicts appears as preliminary requirement for lasting peace in the view of Peace Theory. Upholding this presumption, reconciliation is presented here as an essential process and likewise applicable method for transformation of conflict. The paper examines the advantages of reconciliation against Realist claims about power politics and international relations. After introducing the aim and outline of the paper, a theoretical framework will be established in the second chapter, acknowledging the Christian concept of reconciliation yet evolving towards modern interpretations within socio-political contexts. Scrutinising the applicability of reconciliation for conflict transformation, the third chapter presents reconciliation in practice drawing on the South African expample. Along this case study is highlighted how transitional justice is measured to default standards, what contextual constraints shape structure, mandate and process of applied reconciliation and why success is clearly visible in terms of socio-political reach. The model of the South African Truth and Reconciliation Commission (TRC) also serves to elaborate the feasibility of institutionalising reconciliation in conflict transformation on international level. This paper stresses that conditions and design of the TRC resemble the setting of current international conflict transformation processes. Consequently chapter four discusses the specific impediments for applied peace theory in international context before the last chapter concludes the significance of applied reconciliation and non-retributive justice models for international conflict transformation.

    Learning Arbitrary Statistical Mixtures of Discrete Distributions

    Get PDF
    We study the problem of learning from unlabeled samples very general statistical mixture models on large finite sets. Specifically, the model to be learned, ϑ\vartheta, is a probability distribution over probability distributions pp, where each such pp is a probability distribution over [n]={1,2,,n}[n] = \{1,2,\dots,n\}. When we sample from ϑ\vartheta, we do not observe pp directly, but only indirectly and in very noisy fashion, by sampling from [n][n] repeatedly, independently KK times from the distribution pp. The problem is to infer ϑ\vartheta to high accuracy in transportation (earthmover) distance. We give the first efficient algorithms for learning this mixture model without making any restricting assumptions on the structure of the distribution ϑ\vartheta. We bound the quality of the solution as a function of the size of the samples KK and the number of samples used. Our model and results have applications to a variety of unsupervised learning scenarios, including learning topic models and collaborative filtering.Comment: 23 pages. Preliminary version in the Proceeding of the 47th ACM Symposium on the Theory of Computing (STOC15

    Functional Alterations in Cerebellar Functional Connectivity in Anxiety Disorders

    Get PDF
    Adolescents with anxiety disorders exhibit excessive emotional and somatic arousal. Neuroimaging studies have shown abnormal cerebral cortical activation and connectivity in this patient population. The specific role of cerebellar output circuitry, specifically the dentate nuclei (DN), in adolescent anxiety disorders remains largely unexplored. Resting-state functional connectivity analyses have parcellated the DN, the major output nuclei of the cerebellum, into three functional territories (FTs) that include default-mode, salience-motor, and visual networks. The objective of this study was to understand whether FTs of the DN are implicated in adolescent anxiety disorders. Forty-one adolescents (mean age 15.19 ± 0.82, 26 females) with one or more anxiety disorders and 55 age- and gender-matched healthy controls completed resting-state fMRI scans and a self-report survey on anxiety symptoms. Seed-to-voxel functional connectivity analyses were performed using the FTs from DN parcellation. Brain connectivity metrics were then correlated with State-Trait Anxiety Inventory (STAI) measures within each group. Adolescents with an anxiety disorder showed significant hyperconnectivity between salience-motor DN FT and cerebral cortical salience-motor regions compared to controls. Salience-motor FT connectivity with cerebral cortical sensorimotor regions was significantly correlated with STAI-trait scores in HC (R2 = 0.41). Here, we report DN functional connectivity differences in adolescents diagnosed with anxiety, as well as in HC with variable degrees of anxiety traits. These observations highlight the relevance of DN as a potential clinical and sub-clinical marker of anxiety

    Functional polymorphisms in the promoter regions of MMP2 and MMP3 are not associated with melanoma progression

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The matrix metalloproteinases (MMPs) are enzymes that cleave various components of the extracellular matrix (ECM) and basement membranes. MMPs are expressed in melanocytes and their overexpression has been linked to tumor development, progression and metastasis. At the genetic level, the following functional promoter polymorphisms are known to modify the gene transcription: -1306 C/T and -735 C/T in the MMP2 gene, and -1171 5A/6A in the MMP3 gene. Functional polymorphisms in MMP genes' promoter regions may modulate the risk for melanoma progression.</p> <p>Methods</p> <p>We evaluated MMP2 and MMP3 germline polymorphisms in a group of 1002 melanoma patients using PCR-based methods, including fragment size analysis and melting temperature profiles. Two-sided Chi-Square, Cochran-Armitage tests for trend, Fisher's exact tests, and Kendall's Tau tests were performed to evaluate the associations between genotype and various clinical and epidemiologic factors. Multivariate analyses were conducted using logistic regression, adjusting for known melanoma confounders such as age, sex, phenotypic index, moles, freckles, and race. Survival estimates were computed using the Kaplan-Meier method and differences in survival were assessed using the log rank test.</p> <p>Results</p> <p>All genotypes were in Hardy-Weinberg equilibrium. After adjustment for age, sex and phenotypic characteristics of melanoma risk, no significant associations were identified with the clinical, pathological, and epidemiological variables studied. The melting profile for MMP2 -735 C/T identified a new change in one sample. A new PCR-amplification followed by direct sequencing confirmed a heterozygote G to A substitution at position -729.</p> <p>Conclusion</p> <p>This study does not provide strong evidence for further investigation into the role of the MMP2 and MMP3 variants in melanoma progression.</p

    Hypoxia increases membrane metallo-endopeptidase expression in a novel lung cancer ex vivo model - role of tumor stroma cells

    Get PDF
    Background: Hypoxia-induced genes are potential targets in cancer therapy. Responses to hypoxia have been extensively studied in vitro, however, they may differ in vivo due to the specific tumor microenvironment. In this study gene expression profiles were obtained from fresh human lung cancer tissue fragments cultured ex vivo under different oxygen concentrations in order to study responses to hypoxia in a model that mimics human lung cancer in vivo.Methods: Non-small cell lung cancer (NSCLC) fragments from altogether 70 patients were maintained ex vivo in normoxia or hypoxia in short-term culture. Viability, apoptosis rates and tissue hypoxia were assessed. Gene expression profiles were studied using Affymetrix GeneChip 1.0 ST microarrays.Results: Apoptosis rates were comparable in normoxia and hypoxia despite different oxygenation levels, suggesting adaptation of tumor cells to hypoxia. Gene expression profiles in hypoxic compared to normoxic fragments largely overlapped with published hypoxia-signatures. While most of these genes were up-regulated by hypoxia also in NSCLC cell lines, membrane metallo-endopeptidase (MME, neprilysin, CD10) expression was not increased in hypoxia in NSCLC cell lines, but in carcinoma-associated fibroblasts isolated from non-small cell lung cancers. High MME expression was significantly associated with poor overall survival in 342 NSCLC patients in a meta-analysis of published microarray datasets.Conclusions: The novel ex vivo model allowed for the first time to analyze hypoxia-regulated gene expression in preserved human lung cancer tissue. Gene expression profiles in human hypoxic lung cancer tissue overlapped with hypoxia-signatures from cancer cell lines, however, the elastase MME was identified as a novel hypoxia-induced gene in lung cancer. Due to the lack of hypoxia effects on MME expression in NSCLC cell lines in contrast to carcinoma-associated fibroblasts, a direct up-regulation of stroma fibroblast MME expression under hypoxia might contribute to enhanced aggressiveness of hypoxic cancers

    Image acquisition and quality assurance in the Boston Adolescent Neuroimaging of Depression and Anxiety study

    Get PDF
    The Connectomes Related to Human Diseases (CRHD) initiative was developed with the Human Connectome Project (HCP) to provide high-resolution, open-access, multi-modal MRI data to better understand the neural correlates of human disease. Here, we present an introduction to a CRHD project, the Boston Adolescent Neuroimaging of Depression and Anxiety (BANDA) study, which is collecting multimodal neuroimaging, clinical, and neuropsychological data from 225 adolescents (ages 14–17), 150 of whom are expected to have a diagnosis of depression and/or anxiety. Our transdiagnostic recruitment approach samples the full spectrum of depressed/anxious symptoms and their comorbidity, consistent with NIMH Research Domain Criteria (RDoC). We focused on an age range that is critical for brain development and for the onset of mental illness. This project sought to harmonize imaging sequences, hardware, and functional tasks with other HCP studies, although some changes were made to canonical HCP methods to accommodate our study population and questions. We present a thorough overview of our imaging sequences, hardware, and scanning protocol. We detail similarities and dif-ferences between this study and other HCP studies. We evaluate structural-, diffusion-, and functional-image-quality measures that may be influenced by clinical factors (e.g., disorder, symptomatology). Signal-to-noise and motion estimates from the first 140 adolescents suggest minimal influence of clinical factors on image quality. We anticipate enrollment of an additional 85 participants, most of whom are expected to have a diagnosis of anxiety and/or depression. Clinical and neuropsychological data from the first 140 participants are currently freely available through the National Institute of Mental Health Data Archive (NDA)

    The Fermi energy as common parameter to describe charge compensation mechanisms: A path to Fermi level engineering of oxide electroceramics

    Get PDF
    Chemical substitution, which can be iso- or heterovalent, is the primary strategy to tailor material properties. There are various ways how a material can react to substitution. Isovalent substitution changes the density of states while heterovalent substitution, i.e. doping, can induce electronic compensation, ionic compensation, valence changes of cations or anions, or result in the segregation or neutralization of the dopant. While all these can, in principle, occur simultaneously, it is often desirable to select a certain mechanism in order to determine material properties. Being able to predict and control the individual compensation mechanism should therefore be a key target of materials science. This contribution outlines the perspective that this could be achieved by taking the Fermi energy as a common descriptor for the different compensation mechanisms. This generalization becomes possible since the formation enthalpies of the defects involved in the various compensation mechanisms do all depend on the Fermi energy. In order to control material properties, it is then necessary to adjust the formation enthalpies and charge transition levels of the involved defects. Understanding how these depend on material composition will open up a new path for the design of materials by Fermi level engineering
    corecore