Genome-wide Analyses Identify KIF5A as a Novel ALS Gene

To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.Peer reviewe

Predictors of High-Risk Sexual Behavior among Gay Men and Men Who Have Sex with Men

This study of 576 gay men and men who have sex with men examined the predictive value of peer norms, self-efficacy, stigma, social support, age, and recreational drug use on high-risk sexual behavior that enables human immunodeficiency virus transmission. A bivariate analysis found each of these factors significant. A discriminant function analysis revealed that significant predictors of high-risk sexual behavior included low self-efficacy and low outcome expectancy with regard to successfully using a condom, disclosing infection status, and negotiating safer sex and low peer norms for safer sex. Counseling implications for this population are discussed

Infusing Multicultural and Social Justice Competencies within Counseling Practice: A Guide for Trainers

In light of rapidly changing demographics within the United States, counselors are challenged to provide culturally responsive services to facilitate optimal client functioning. This article highlights recommended training strategies within a developmental framework to promote multicultural and social justice competencies for trainers of mental health professionals

Hooking Up and Identity Development of Female College Students

Hooking up generally involves casual sex with noncommittal partners. Hooking up is prevalent on college campuses today andean negatively affect the identity development of female students. The authors examined this phenomenon with a feminist developmental perspective, evaluating hooking up in the context of sexual risk taking with physical and psychosocial consequences

Speciation chronology of rockhopper penguins inferred from molecular, geological and palaeoceanographic data

The Southern Ocean is split into several biogeographical provinces between convergence zones that separate watermasses of different temperatures. Recent molecular phylogenies have uncovered a strong phylogeographic structure among rockhopper penguin populations, Eudyptes chrysocome sensu lato, from different biogeographical provinces. These studies suggested a reclassification as three species in two major clades, corresponding, respectively, to warm, subtropical and cold sub-Antarctic watermasses rather than to geographic proximity. Such a phylogeographic pattern, also observed in plants, invertebrates and fishes of the Southern Ocean, suggests that past changes in the positions of watermasses may have affected the evolutionary history of penguins. We calculated divergence times among various rockhopper penguin clades and calibrated these data with palaeomagmatic and palaeoceanographic events to generate a speciation chronology in rockhopper penguins. Southern Ocean. Divergence times between populations were calculated using five distinct mitochondrial DNA loci, and assuming a molecular clock model as implemented in mdiv. The molecular evolution rate of rockhopper penguins was calibrated using the radiochronological age of St Paul Island and Amsterdam Island in the southern Indian Ocean. Separations within other clades were correlated with palaeoceanographic data using this calibrated rate. The split between the Atlantic and Indian populations of rockhopper penguins was dated as 0.25 Ma, using the date of emergence of St Paul and Amsterdam islands, and the divergence between sub-Antarctic and subtropical rockhopper penguins was dated as c. 0.9 Ma (i.e. during the mid-Pleistocene transition, a major change in the Earth's climate cycles). The mid-Pleistocene transition is known to have caused a major southward shift in watermasses in the Southern Ocean, thus changing the environment around the northernmost rockhopper penguin breeding sites. This ecological isolation of northernmost populations may have caused vicariant speciation, splitting the species into two major clades. After the emergence of St Paul and Amsterdam islands in the subtropical Indian Ocean 0.25 Ma, these islands were colonized by penguins from the subtropical Atlantic, 6000 km away, rather than by penguins from the sub-Antarctic Indian Ocean, 5000 km closer

Postglacial viability and colonization in North America’s ice-free corridor

During the Last Glacial Maximum, continental ice sheets isolated Beringia (northeast Siberia and northwest North America) from unglaciated North America. By around 15 to 14 thousand calibrated radiocarbon years before present (cal. kyr bp), glacial retreat opened an approximately 1,500-km-long corridor between the ice sheets. It remains unclear when plants and animals colonized this corridor and it became biologically viable for human migration. We obtained radiocarbon dates, pollen, macrofossils and metagenomic DNA from lake sediment cores in a bottleneck portion of the corridor. We find evidence of steppe vegetation, bison and mammoth by approximately 12.6 cal. kyr bp, followed by open forest, with evidence of moose and elk at about 11.5 cal. kyr bp, and boreal forest approximately 10 cal. kyr bp. Our findings reveal that the first Americans, whether Clovis or earlier groups in unglaciated North America before 12.6 cal. kyr bp, are unlikely to have travelled by this route into the Americas. However, later groups may have used this north–south passageway