Optimality of the neighbor joining algorithm and faces of the balanced minimum evolution polytope.

Balanced minimum evolution (BME) is a statistically consistent distance-based method to reconstruct a phylogenetic tree from an alignment of molecular data. In 2000, Pauplin showed that the BME method is equivalent to optimizing a linear functional over the BME polytope, the convex hull of the BME vectors obtained from Pauplin's formula applied to all binary trees. The BME method is related to the Neighbor Joining (NJ) Algorithm, now known to be a greedy optimization of the BME principle. Further, the NJ and BME algorithms have been studied previously to understand when the NJ Algorithm returns a BME tree for small numbers of taxa. In this paper we aim to elucidate the structure of the BME polytope and strengthen knowledge of the connection between the BME method and NJ Algorithm. We first prove that any subtree-prune-regraft move from a binary tree to another binary tree corresponds to an edge of the BME polytope. Moreover, we describe an entire family of faces parameterized by disjoint clades. We show that these clade-faces are smaller dimensional BME polytopes themselves. Finally, we show that for any order of joining nodes to form a tree, there exists an associated distance matrix (i.e., dissimilarity map) for which the NJ Algorithm returns the BME tree. More strongly, we show that the BME cone and every NJ cone associated to a tree T have an intersection of positive measure.

Sense of belonging predicts persistence intentions among diverse dental education students: A multi-institutional investigation.

To succeed in dental school, students need both academic and social experiences that are correlated with perceived membership and persistence. In this study, survey data from 247 dental students were analyzed to test for racial differences in dental students' sense of belonging and to measure the extent to which sense of belonging predicted students' intent to persist in dental school, controlling for grade point average (GPA) and sex. Results indicate that sense of belonging varies by race with White dental students feeling stronger connections in school than underrepresented minority (URM) peers. Regression results reveal that sense of belonging is related to dental students' persistence intentions, all other things being equal. In fact, sense of belonging influenced students' intent to persist in dental school 3 times more than GPA alone. Findings have significant implications for future policy, practice, and research, but also raise important questions for dental educators in the U.S.

Exploring the Role of Race in Black Males' Sense of Belonging in Medical School: A Qualitative Pilot Study.

The purpose of this qualitative pilot study was to investigate the role of race (and racism) and sense of belonging for Black men in medical school. A single research question guided this exploratory project: How do Black men in medical school describe their experiences? Analyzing interview data from 8 Black male medical school students revealed frequent encounters with racial discrimination and prejudice. Results show that race adversely affected their academic and social experiences and diminished their sense of belonging in medical school. Consequently, they faced difficulty connecting with White peers and faculty, racist stereotypes, and racial microaggressions that stigmatized them as "out of place," unqualified, or unusual. Implications for policy, practice, and minority medical student success are highlighted.

Designing an Information and Communications Technology Tool With and for Victims of Violence and Their Case Managers in San Francisco: Human-Centered Design Study.

BACKGROUND: Violence is a public health problem. Hospital-based violence intervention programs such as the San Francisco Wraparound Project (WAP) have been shown to reduce future violent injury. The WAP model employs culturally competent case managers who recruit and enroll violently injured patients as clients. Client acceptance of the WAP intervention is variable, and program success depends on streamlined, timely communication and access to resources. High rates of smartphone usage in populations who are at risk for violent reinjury create an opportunity to design a tailored information and communications technology (ICT) tool to support hospital-based violence intervention programs. OBJECTIVE: Current evidence shows that ICT tools developed in the health care space may not be successful in engaging vulnerable populations. The goal of this study was to use human-centered design methodology to identify the unique communication needs of the clients and case managers at WAP to design a mobile ICT. METHODS: We conducted 15 semi-structured interviews with users: clients, their friends and families, case managers, and other stakeholders in violence intervention and prevention. We used a human-centered design and general inductive approach to thematic analysis to identify themes in the qualitative data, which were extrapolated to insight statements and then reframed into design opportunities. Wireframes of potential mobile ICT app screens were developed to depict these opportunities. RESULTS: Thematic analysis revealed four main insights that were characterized by the opposing needs of our users. (1) A successful relationship is both professional and personal. Clients need this around the clock, but case managers can only support this while on the clock. (2) Communications need to feel personal, but they do not always need to be personalized. (3) Healing is a journey of skill development and lifestyle changes that must be acknowledged, monitored, and rewarded. (4) Social networks need to provide peer support for healing rather than peer pressure to propagate violence. These insights resulted in the following associated design opportunities: (1) Maximize personal connection while controlling access, (2) allow case managers to personalize automated client interactions, (3) hold clients accountable to progress and reward achievements, and (4) build a connected, yet confidential community. CONCLUSIONS: Human-centered design enabled us to identify unique insights and design opportunities that may inform the design of a novel and tailored mobile ICT tool for the WAP community.

The absence of African-American men in higher education and veterinary medicine.

Many studies have consistently indicated that the educational outcomes of Black men and boys are not on par with those of their White and female counterparts. Recent data suggest the same holds true for Black men in veterinary medicine. Drawing on national statistics and findings from an analysis of National Educational Longitudinal Study data, I present several recommendations for future policy and practice that can help combat the absence of Black men in the profession.

Gender differences in presentation, management, and cardiac event-free survival in patients with syncope.

In a MEDLINE search of published English studies (1966 to 1996), no prior study was identified that examined gender-based differences in the management and prognosis of patients admitted with syncope. We studied 109 consecutive patients (48 women) admitted with syncope at the Massachusetts General Hospital (1989 to 1990). All patients underwent Holter monitoring, signal-averaged electrocardiography, and echocardiography according to study protocol. Follow-up was 100% complete (10 +/- 4 months). Women were older (74 +/- 2 vs 66 +/- 2 years, p <0.01) and less likely to have premonitory symptoms when compared with men (46% vs 66%, p <0.05). A greater proportion of men had left ventricular ejection fractions of <0.40 (18% vs 0%, p <0.01), abnormal signal-averaged electrocardiograms (28% vs 8%, p <0.01), and a cardiac cause for syncope (49% vs 25%, p <0.01). Although referral for diagnostic electrophysiologic testing was >3 times as frequent for men compared with women (20% of men vs 6% of women, p <0.05), this difference was not significant after adjustment for age, ventricular arrhythmia, and referral for coronary angiography. During follow-up, 21% of men versus 6% of women (p <0.05) had cardiac events (recurrent syncope, myocardial infarction, or sudden death). Cardiac event-free survival rates were worse for men (p = 0.045). Thus, we have identified gender-based differences in the clinical presentation of syncope for hospital admission. Left ventricular dysfunction and an abnormal signal-averaged electrocardiogram occur more frequently in men. Men are more likely to have cardiac syncope and worse cardiac event-free survival when compared with women.

Glyoxalase I typing and phosphoglucomutase-1 subtyping of a single hair.

A technique is described for the typing of glyoxalase I (GLO I) and the subtyping of phosphoglucomutase-1 (PGM-1) from the root sheath cells of a single forcibly removed hair. This procedure does not require sample preparation and does not alter the morphological characteristics of the hair. The combined discrimination probability (DP) of the two markers taken together is 0.90 for whites and 0.89 for blacks. GLO I can be typed after four weeks, and PGM-1 can be typed after eight to fifteen weeks in hairs maintained at room temperature. Hairs mounted with Permount showed loss of enzyme activity and loss of band sharpness.

Presumptive screening of suspected semen stain in situ using cotton swabs and bromochloroindolyl phosphate to detect prostatic acid phosphatase activity.

A novel approach to the presumptive screening of questioned semen stains has been developed which enables the rapid identification of stains which are devoid of semen. Questioned semen stains can be swabbed with a moist cotton swab, and the prostatic acid phosphatase (SAP) activity transferred to the swab identified through assay with 5-bromo-4-chloro-3-indolyl phosphate (BCIP). Controlled laboratory studies revealed that the BCIP swab procedure was as sensitive as the semiquantitative SAP test currently employed in the FBI Laboratory for the presumptive screening of semen stains. A validation study of the BCIP swab procedure in parallel with the current procedure using 4305 case evidence stains indicated that the BCIP swab procedure was as effective as the current procedure in identifying those questioned stains which lack semen. The advantage of the BCIP swab procedure is that it can be performed on questioned stains in situ and thereby avoids the requirement of removing and extracting the stain before assay of SAP activity.

Sexual health issues in inflammatory bowel disease.

Alterations in sexual health caused by inflammatory bowel disease (IBD) may affect quality of life and disease status. IBD usually strikes adolescents or young adults, who are also facing developmental milestones important to sexual health. Issues include growth and development, body image, intimacy and sexual functioning, fertility, and pregnancy. A review of published research regarding these issues, in addition to suggestions for nursing assessment and interventions, is included in this article. Nurses must offer sensitive support and suggestions for coping. Nurses must be aware of the issues influencing sexual health when providing total care to clients with IBD.

In vitro activity of carbenicillin against gram-negative bacilli.

The activity of a new semisynthetic penicillin, carbenicillin, was determined against 241 strains of gram-negative bacilli with the tube-dilution technique. Of 143 strains of Pseudomonas sp., 99 had a minimal inhibitory concentration of 200 to 300 mug/ml. The majority of strains of Escherichia coli and Proteus spp. were sensitive to this antibiotic, with minimal inhibitory concentrations of 25 mug/ml or less. Strains of Klebsiella sp. were quite resistant to carbenicillin. The size of inoculum had no significant effect on the minimal inhibitory concentration for Pseudomonas sp.