Traveling wave solutions for a predator-prey system with Sigmoidal response function

We study the existence of traveling wave solutions for a diffusive predator-prey system. The system considered in this paper is governed by a Sigmoidal response function which is more general than those studied previously. Our method is an improvement to the original method introduced in the work of Dunbar \cite{Dunbar1,Dunbar2}. A bounded Wazewski set is used in this work while unbounded Wazewski sets were used in \cite{Dunbar1,Dunbar2}. The existence of traveling wave solutions connecting two equilibria is established by using the original Wazewski's theorem which is much simpler than the extended version in Dunbar's work

The parent?infant dyad and the construction of the subjective self

Developmental psychology and psychopathology has in the past been more concerned with the quality of self-representation than with the development of the subjective agency which underpins our experience of feeling, thought and action, a key function of mentalisation. This review begins by contrasting a Cartesian view of pre-wired introspective subjectivity with a constructionist model based on the assumption of an innate contingency detector which orients the infant towards aspects of the social world that react congruently and in a specifically cued informative manner that expresses and facilitates the assimilation of cultural knowledge. Research on the neural mechanisms associated with mentalisation and social influences on its development are reviewed. It is suggested that the infant focuses on the attachment figure as a source of reliable information about the world. The construction of the sense of a subjective self is then an aspect of acquiring knowledge about the world through the caregiver's pedagogical communicative displays which in this context focuses on the child's thoughts and feelings. We argue that a number of possible mechanisms, including complementary activation of attachment and mentalisation, the disruptive effect of maltreatment on parent-child communication, the biobehavioural overlap of cues for learning and cues for attachment, may have a role in ensuring that the quality of relationship with the caregiver influences the development of the child's experience of thoughts and feelings

Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Renal biomarkers and outcomes in outpatients with heart failure: The Atlanta cardiomyopathy consortium

Background/objectives Cystatin-C and beta-2-microglobulin may be superior to serum creatinine, blood urea nitrogen (BUN), or estimated glomerular filtration rate (EGFR) in patients hospitalized with heart failure (HF). We compared these renal markers in ambulatory HF patients. Methods We prospectively evaluated the association of baseline renal markers and EGFR (by 4 different formulas) with (1) the composite of death or HF-related hospitalization and (2) rates of hospitalizations and emergency department (ED) visits in 166 outpatients with HF (57.3 ± 11.6 years; 57.2% white, 38.6% black, median left ventricular ejection fraction 27.5% [17.5, 40.0]). Results After a median of 3.9 years, 63 (38.0%) patients met the composite endpoint. There were 458 hospitalizations (177 [38.6%] for HF) and 209 ED visits (51 [24.4%] for HF). Cystatin-based EGFR most consistently predicted (1) the composite endpoint (highest-to-lowest tertile adjusted hazard ratio [HR] 4.92 [95% CI 2.07-11.7; P < 0.001]); and (2) hospitalization rates, including HF hospitalizations (highest-to-lowest tertile, adjusted relative rate 5.24 [95% CI 1.61-17.01; P = 0.006]). Serum creatinine alone was a strong predictor of the composite endpoint (highest-to-lowest tertile, adjusted HR 3.20 [95% CI, 1.51-6.78; P = 0.002]). Only the highest tertile of BUN was associated with rates of ED visits. Conclusions In outpatients with HF, cystatin-based EGFR provides consistent prognostication across outcomes, except ED visits. Serum creatinine is an adequate prognosticator of death or HF hospitalization. © 2016 Elsevier Ireland Ltd. All rights reserved

What Have You Done for Me Lately? Friendship-Selection in the Shadow of the Dark Triad Traits

The current studies examined how the Dark Triad personality traits (i.e., Machiavellianism, narcissism, and psychopathy) facilitate the strategic structuring of an individual's social environment in terms of same- and opposite-sex friends. In one study using normative questions ( N = 267) and another using a budget-allocation task ( N = 114), we found that the Dark Triad traits were associated with choosing friends for strategic purposes and to create a volatile environment. Narcissistic individuals reported relatively more reasons to form friendships, such as shared interests, makes me feel good, and intelligence. Women high in narcissism chose same-sex friends who were attractive and women high on Machiavellianism chose same-sex friends who have social status. Men high on psychopathy devalued traits associated with good social relationships in favor of friends who could facilitate their mating efforts and to offset risks incurred in their life history strategy. Results are discussed using the selection-manipulation-evocation framework for explaining how personality traits interact with social environments and integrated with findings from evolutionary biology

Letters of Recommendation: An Evolutionary Psychological Perspective

This article develops a theoretical framework for understanding the appeal and tone of letters of recommendation using an evolutionary psychological perspective. Several hypotheses derived from this framework are developed and tested. The authors’ theoretical argument makes two major points. First, over the course of human evolution, people developed a preference for narrative information about people, and the format of letters of recommendation is compatible with that preference. Second, because recommenders are acquaintances of applicants, the tone of letters should reflect the degree to which the relationship with the applicant favors the recommender’s interests. We hypothesized that, over and above an applicant’s objective qualifications, letters of recommendation will reflect cooperative, status and mating interests of recommenders. We used 532 letters of recommendation written for 169 applicants for faculty positions to test our hypotheses. The results indicated that the strength of the cooperative relationship between recommenders and applicants influenced the favorability and length of letters. In addition, male recommenders wrote more favorable letters for female than male applicants, suggesting that male mating interests may influence letter favorability. We conclude with implications for practice and future research