348 research outputs found

    Reconfigurable quasi-optical beamformers for next-generation satellite applications : electromagnetic modeling and design

    Get PDF
    Emerging satellite constellations at low- and medium earth orbits are expected to revolutionize the expansion of broadband connectivity into rural areas. The requirements of wide field of view and the availability of larger bandwidths in the Ka-band have opened new challenges in antenna design. At the same time, highly cost-effective solutions are needed. The main objective of this thesis is to investigate and develop quasi-optical millimeter-wave antennas with enhanced beam scanning and beam reconfiguration capabilities that answer these needs. High-frequency models are developed for the analysis of different parallel-plate beamformers in reception. It is shown that these models can be used efficiently for the design of feed systems with stringent requirements on scanning range. Two novel lens beamformers, operating in the uplink and downlink Ka-band, respectively, are presented. The first is a shaped parallel-plate lens combined with a mechanical scanning feed based on gap waveguide technology. Equivalent circuit models that aid in the design of the feed structure are addressed. The resulting design and experimental results from an all-metal demonstrator are presented. The second corresponds to a lens beamformer implemented in multilayer PCB technology. The developed numerical procedure is applied to the synthesis of overlapping feed clusters. Both designs represent significant advances in terms of scanning performance and low-cost implementation

    Speaking of That: Terms to Avoid or Reconsider in the Eating Disorders Field

    Get PDF
    Inspired by an article on 50 terms that, in the interest of clarity in scientific reasoning and communication in psychology, psychiatry, and allied fields, “should be avoided or at most be used sparingly and only with explicit caveats,”1 we propose a list of terms to avoid or think twice about before using when writing for the International Journal of Eating Disorders (IJED). Drawing upon our experience as reviewers or editors for the IJED, we generated an abridged list of such terms. For each term, we explain why it made our list and what alternatives we recommend. We hope that our list will contribute to improved clarity in scientific thinking about eating disorders, and that it will stimulate discussion of terms that may need to be reconsidered in our field's vocabulary to ensure the use of language that is respectful and sensitive to individuals who experience an eating disorder

    A meta-analysis of the relation between therapeutic alliance and treatment outcome in eating disorders.

    Get PDF
    The therapeutic alliance has demonstrated an association with favorable psychotherapeutic outcomes in the treatment of eating disorders (EDs). However, questions remain about the inter-relationships between early alliance, early symptom improvement, and treatment outcome. We conducted a meta-analysis on the relations among these constructs, and possible moderators of these relations, in psychosocial treatments for EDs. Twenty studies met inclusion criteria and supplied sufficient supplementary data. Results revealed small-to-moderate effect sizes, βs = 0.13 to 0.22 (p < .05), indicating that early symptom improvement was related to subsequent alliance quality and that alliance ratings also were related to subsequent symptom reduction. The relationship between early alliance and treatment outcome was partially accounted for by early symptom improvement. With regard to moderators, early alliance showed weaker associations with outcome in therapies with a strong behavioral component relative to nonbehavioral therapies. However, alliance showed stronger relations to outcome for younger (vs. older) patients, over and above the variance shared with early symptom improvement. In sum, early symptom reduction enhances therapeutic alliance and treatment outcome in EDs, but early alliance may require specific attention for younger patients and for those receiving nonbehaviorally oriented treatments

    Differential effects of α4β7 and GPR15 on homing of effector and regulatory T cells from patients with UC to the inflamed gut in vivo

    Get PDF
    Objective: Gut homing of lymphocytes via adhesion molecules has recently emerged as new target for therapy in inflammatory bowel diseases. We aimed to analyze the in vivo homing of effector (Teff) and regulatory (Treg) T cells to the inflamed gut via α4β7 and GPR15. Design: We assessed the expression of homing receptors on T cells in peripheral blood and inflamed mucosa. We studied the migration pattern and homing of Teff and Treg cells to the inflamed gut using intravital confocal microscopy and FACS in a humanized mouse model in DSS-treated NSG (NOD.Cg-Prkdcscid-Il2rgtm1Wjl/SzJ) mice. Results: Expression of GPR15 and α4β7 was significantly increased on Treg rather than Teff cells in peripheral blood of patients with ulcerative colitis (UC) as compared to Crohn´s disease and controls. In vivo analysis in a humanized mouse model showed augmented gut homing of UC Treg cells as compared to controls. Moreover, suppression of UC (but not control) Teff and Treg cell homing was noted upon treatment with the α4β7 antibody vedolizumab. In contrast, siRNA blockade of GPR15 had only effects on homing of Teff cells but did not affect Treg homing in UC. Clinical vedolizumab treatment was associated with marked expansion of UC Treg cells in peripheral blood. Conclusion: α4β7 rather than GPR15 is crucial for increased colonic homing of UC Treg cells in vivo, while both receptors control UC Teff homing. Vedolizumab treatment impairs homing of UC Treg cells leading to their accumulation in peripheral blood with subsequent suppression of systemic effector T cell expansion

    Examining a staging model for anorexia nervosa: empirical exploration of a four stage model of severity.

    Get PDF
    Background: An illness staging model for anorexia nervosa (AN) has received increasing attention, but assessing the merits of this concept is dependent on empirically examining a model in clinical samples. Building on preliminary findings regarding the reliability and validity of the Clinician Administered Staging Instrument for Anorexia Nervosa (CASIAN), the current study explores operationalising CASIAN severity scores into stages and assesses their relationship with other clinical features. Method: In women with DSM-IV-R AN and sub-threshold AN (all met AN criteria using DSM 5), receiver operating curve (ROC) analysis (n = 67) assessed the relationship between the sensitivity and specificity of each stage of the CASIAN. Thereafter chi-square and post-hoc adjusted residual analysis provided a preliminary assessment of the validity of the stages comparing the relationship between stage and treatment intensity and AN sub-types, and explored movement between stages after six months (Time 3) in a larger cohort (n = 171). Results: The CASIAN significantly distinguished between milder stages of illness (Stage 1 and 2) versus more severe stages of illness (Stages 3 and 4), and approached statistical significance in distinguishing each of the four stages from one other. CASIAN Stages were significantly associated with treatment modality and primary diagnosis, and CASIAN Stage at Time 1 was significantly associated with Stage at 6 month follow-up. Conclusions: Provisional support is provided for a staging model in AN. Larger studies with longer follow-up of cases are now needed to replicate and extend these findings and evaluate the overall utility of staging as well as optimal staging models
    corecore