Concurrent Sexual Partnerships Among Young Heterosexual Adults at Increased HIV Risk: Types and Characteristics

The impact of concurrency on STI transmission depends upon coital frequency, condom use, duration of relationship overlap, and number of partners. Previous research has identified distinct concurrency types; however, little is known about their risk characteristics

Event-Level Associations of Marijuana and Heavy Alcohol Use With Intercourse and Condom Use

OBJECTIVE: The associations substance use has with sex and condom use among college students appear to be well-documented and of clear public health significance. However, few event-level studies examine marijuana or heavy alcohol use, control for temporal patterns shared among these behaviors, or consider differences by relationship status. METHOD: We recruited 284 18 to 22 year old undergraduate men and women (79%), 61% of whom were in a serious relationship. For 24 consecutive days, participants reported on their prior day marijuana use, heavy alcohol use, vaginal intercourse, and condom use. RESULTS: Most intercourse events (86%) were reported by participants in a serious relationship, and most (62%) were not protected by a condom. Hierarchical generalized linear models indicated participants in a serious relationship were more likely to report intercourse than were others. Adjusting for weekly patterns in intercourse, odds of intercourse were higher on days participants reported marijuana or heavy alcohol use; the latter effect was stronger for single participants. Being drunk during sex, being in a serious relationship, and use of non-condom birth control were associated with less condom use. CONCLUSIONS: Models distinguish among multiple potential influences on undergraduates’ sexual behavior. Findings suggest greater attention to the relationship and other contexts of marijuana and alcohol use may be relevant to understanding young adults’ sexual behavior and preventing health-risking or nonconsensual sex

The ‘mosaic habitat’ concept in human evolution: past and present

The habitats preferred by hominins and other species are an important theme in palaeoanthropology, and the ‘mosaic habitat’ (also referred to as habitat heterogeneity) has been a central concept in this regard for the last four decades. Here we explore the development of this concept – loosely defined as a range of different habitat types, such as woodlands, riverine forest and savannah within a limited spatial area– in studies of human evolution in the last sixty years or so. We outline the key developments that took place before and around the time when the term ‘mosaic’ came to wider palaeoanthropological attention. To achieve this we used an analysis of the published literature, a study of illustrations of hominin evolution from 1925 onwards and an email survey of senior researchers in palaeoanthropology and related fields. We found that the term mosaic starts to be applied in palaeoanthropological thinking during the 1970’s due to the work of a number of researchers, including Karl Butzer and Glynn Isaac , with the earliest usage we have found of ‘mosaic’ in specific reference to hominin habitats being by Adriaan Kortlandt (1972). While we observe a steady increase in the numbers of publications reporting mosaic palaeohabitats, in keeping with the growing interest and specialisation in various methods of palaeoenvironmental reconstruction, we also note that there is a lack of critical studies that define this habitat, or examine the temporal and spatial scales associated with it. The general consensus within the field is that the concept now requires more detailed definition and study to evaluate its role in human evolution

TARP γ-7 selectively enhances synaptic expression of calcium-permeable AMPARs

Regulation of calcium-permeable AMPA receptors (CP-AMPARs) is crucial in normal synaptic function and neurological disease states. Although transmembrane AMPAR regulatory proteins (TARPs) such as stargazin (γ-2) modulate the properties of calcium-impermeable AMPARs (CI-AMPARs) and promote their synaptic targeting, the TARP-specific rules governing CP-AMPAR synaptic trafficking remain unclear. We used RNA interference to manipulate AMPAR-subunit and TARP expression in γ-2–lacking stargazer cerebellar granule cells—the classic model of TARP deficiency. We found that TARP γ-7 selectively enhanced the synaptic expression of CP-AMPARs and suppressed CI-AMPARs, identifying a pivotal role of γ-7 in regulating the prevalence of CP-AMPARs. In the absence of associated TARPs, both CP-AMPARs and CI-AMPARs were able to localize to synapses and mediate transmission, although their properties were altered. Our results also establish that TARPed synaptic receptors in granule cells require both γ-2 and γ-7 and reveal an unexpected basis for the loss of AMPAR-mediated transmission in stargazer mice

Modeling the Past: The Paleoethnological Evidence

This chapter considers the earliest Paleolithic, Oldowan (Mode 1), and Acheulean (Mode 2) cultures of the Old Continent and the traces left by the earliest hominids since their departure from Africa. According to the most recent archaeological data, they seem to have followed two main dispersal routes across the Arabian Peninsula toward the Levant, to the north, and the Indian subcontinent, to the east. According to recent discoveries at Dmanisi in the Caucasus, the first Paleolithic settlement of Europe is dated to some 1.75 Myr ago, which indicates that the first “out of Africa” took place at least slightly before this date. The data available for Western Europe show that the first Paleolithic sites can be attributed to the period slightly before 1.0 Myr ago. The first well-defined “structural remains” so far discovered in Europe are those of Isernia La Pineta in Southern Italy, where a semicircular artificial platform made of stone boulders and animal bones has been excavated. The first hand-thrown hunting weapons come from the site of Scho¨ningen in north Germany, where the first occurrence of wooden spears, more than 2 m long, has been recorded from a site attributed to some 0.37 Myr ago. Slightly later began the regular control of fire. Although most of the archaeological finds of these ages consist of chipped stone artifacts, indications of art seem to be already present in the Acheulean of Africa and the Indian subcontinent

Evaluation of a social-emotional and character development program

The effects of a school-based social-emotional and character development program, Positive Action, on the developmental trajectory of character development was evaluated using data from three randomized trials. Results come from 1) 4-years of data from elementary children in 20 Hawai`i schools, 2) 3-years of data from elementary children in 14 schools in Chicago, and 3) 3-years of data from elementary children in 8 schools in a southeastern state. Random intercept, multilevel, growth curve analyses supported recent research on the trajectory of character development, in that students in both control and Positive Action schools reported a general decline in the number of behaviors associated with character they endorsed in all three trials. However, the Positive Action intervention significantly reduced the declines in all three trials. Taken together, the three analyses give insight into the normative trajectory of behaviors associated with character and evidence for the effectiveness of Positive Action in helping children maintain a relatively beneficial, though declining, developmental trajectory. A further more in-depth analysis was run in Chicago, looking for multiple trajectories of character development and links to a distal outcome, as well as, the evaluation of Positive Action. The same scale of positive behaviors associated with character was used in connection to delinquent behavior to determine multiple trajectories of character development. These trajectories were also connected to delinquent behavior recorded at the end of the study. Results suggested that two distinct groups existed in the Chicago data, identified both by their intercept and slope on positive behavior, and also by their level of delinquent behavior at the end of the study. The effect of Positive Action was similar on both of these groups

Modelling Opportunity: An Examination of Quadratic Effects of Adolescent Venezuelan Substance Use

Introduction and Aims Numerous studies have found a linear relationship between an exposure opportunity and age of first drug use. This study further tests this relationship by exploring whether a quadratic exposure opportunity best fits the data on age of first use and whether gender moderates this relationship. That is, is there a peak age in which the transition to use occurs for male compared to female adolescents? Design and Methods A sample of 1716 adolescents from 14 public and private schools, representative of two school districts in Caracas, Venezuela, was examined using a zero‐inflated Poisson modelling approach to test for quadratic effects. A series of models were tested for each set of substances (alcohol, tobacco and other drugs) to assess whether a quadratic model has better predictive ability than linear models and to test whether gender moderates the quadratic relationship. Results After controlling for common covariates, the quadratic models for alcohol indicated the peak age of transition from an exposure opportunity to use was 10‐years of age in this Venezuelan sample. Gender did not moderate these models suggesting an important move toward gender equality in substance use. Discussion and Conclusions Focused efforts on preventing exposure to alcohol use during these windows of rapid transition is likely to have the greatest impact on delaying age of onset, which will reduce the overall prevalence of alcohol related problems among adolescents