The social context of school playground games: Sex and ethnic differences, and changes over time after entry to junior school

This short term longitudinal study examined activities at recess and peer relations. Interest was in changes over the school year, and the sex and ethnic mix of groups. Data came from systematic observations of 129 pupils (61 boys and 68 girls) aged 7-8 years. Results showed that peer interaction dominated recess. Ball games increased over the year, and chasing games decreased. Aggression was most common during vigorous play and conversation, but not ball games. Cleavage in boys' and girls' play and activity was common but not inevitable. Mixed sex play was not supported by particular game types. Boys’ game networks were larger than those of girls but there were no sex differences in active networks. There was little ethnic group segregation on playgrounds, and games became more integrated with time. Results indicate that playground activities can have a positive role in social relations between different ethnic groups

The retention power of pre- and post-matriculated first semester student perspectives

This research analyzed the first semester perspectives of university freshmen at the University of Nevada, Las Vegas during the Fall semester of 1991. This study employed the use of inferential and descriptive statistics on pre- and post-matriculated attitudes and perspectives of a power analyzed, randomly selected sample of freshmen students; Summary of data and conclusions. (1) Some respondents were pleased with their visits to the university while they were still in high school. They perceived that the community was behind the university and that there were strong ties between the two entities. Comments regarding the positive appearance of the University and its energetic qualities were noted. (2) Other students felt that there should be greater emphasis and advertisement of tutoring services for students who were representing the university in some official capacity. (3) A few students expressed anger and frustration that they didn\u27t receive the necessary information to be admitted and registered on time. This necessitated waiting for a period of at least four months on the part of the students in their progress towards their academic goals. (4) Some students responded by suggesting that the process of admission, registration, and receipt of financial aid was extremely complex and chose to attend other institutions where institutional hyperrationalization and bureaucracy was less oppressive and confusing. (5) Respondents noted that when they approached Student Services representatives it seemed as if no one was really listening. Sentiments expressed by the students contained apprehension and frustration. Respondents noted that when approaching the Minority Affairs Office it seemed as if no one was really listening to them. The staff appeared helpful and facilitative, but didn\u27t answer specific questions or concerns. (6) Student expectations of success and involvement were found to be strong before arrival on campus. Although common experiences such as admission, registration, and the obtaining of financial aid disillusioned some. (Abstract shortened by UMI.)

Poly Canyon Observation Deck

This senior project paper will delve into the background, setbacks and triumphs that where undergone during the course of this project based senior project- The first permanent structure in Poly Canyon in 15 years. Built in true “Learn By Doing Fashion” in the experimental, hands-on lab that some may better know as “Architecture Graveyard.” The project was one of extreme adversity, from fundraising difficulties and a condensed schedule, to unique site conditions and lack of manpower. The students involved in this project showed a strong sense of purpose and determination to see this structure through to completion

Phenotypic and functional characterization of corneal endothelial cells during in vitro expansion.

The advent of cell culture-based methods for the establishment and expansion of human corneal endothelial cells (CEnC) has provided a source of transplantable corneal endothelium, with a significant potential to challenge the one donor-one recipient paradigm. However, concerns over cell identity remain, and a comprehensive characterization of the cultured CEnC across serial passages has not been performed. To this end, we compared two established CEnC culture methods by assessing the transcriptomic changes that occur during in vitro expansion. In confluent monolayers, low mitogenic culture conditions preserved corneal endothelial cell state identity better than culture in high mitogenic conditions. Expansion by continuous passaging induced replicative cell senescence. Transcriptomic analysis of the senescent phenotype identified a cell senescence signature distinct for CEnC. We identified activation of both classic and new cell signaling pathways that may be targeted to prevent senescence, a significant barrier to realizing the potential clinical utility of in vitro expansion

Public communication by research institutes compared across countries and sciences: building capacity for engagement or competing for visibility?

Leading academic institutions, governments, and funders of research across the world have spent the last few decades fretting publicly about the need for scientists and research organisations to engage more widely with the public and be open about their research. While a global literature asserts that public communication has changed from a virtue to a duty for scientists in many countries and disciplines, our knowledge about what research institutions are doing and what factors drive their 'going public' is very limited. Here we present the first cross-national study of N = 2,030 research institutes within universities and large scientific organisations in Brazil, Germany, Italy, Japan, the Netherlands, Portugal, the United Kingdom, and the United States of America. We find that institutes embrace communication with non-peers and do so through a variety of public events and traditional news media-less so through new media channels-and we find variation across countries and sciences, yet these are less evident than we expected. Country and disciplinary cultures contribute to the level of this communication, as do the resources that institutes make available for the effort; institutes with professionalised staff show higher activity online. Future research should examine whether a real change in the organisational culture is happening or whether this activity and resource allocation is merely a means to increase institutional visibility

Low-intensity frequent fires in coniferous forests transform soil organic matter in ways that may offset ecosystem carbon losses.

Funder: Sequoia Parks ConservancyFunder: Gordon and Betty Moore Foundation; Id: http://dx.doi.org/10.13039/100000936The impact of shifting disturbance regimes on soil carbon (C) storage is a key uncertainty in global change research. Wildfires in coniferous forests are becoming more frequent in many regions, potentially causing large C emissions. Repeated low-intensity prescribed fires can mitigate wildfire severity, but repeated combustion may decrease soil C unless compensatory responses stabilize soil organic matter. Here, we tested how 30 years of decadal prescribed burning affected C and nitrogen (N) in plants, detritus, and soils in coniferous forests in the Sierra Nevada mountains, USA. Tree basal area and litter stocks were resilient to fire, but fire reduced forest floor C by 77% (-36.4 Mg C/ha). In mineral soils, fire reduced C that was free from minerals by 41% (-4.4 Mg C/ha) but not C associated with minerals, and only in depths ≤ 5 cm. Fire also transformed the properties of remaining mineral soil organic matter by increasing the proportion of C in a pyrogenic form (from 3.2% to 7.5%) and associated with minerals (from 46% to 58%), suggesting the remaining soil C is more resistant to decomposition. Laboratory assays illustrated that fire reduced microbial CO2 respiration rates by 55% and the activity of eight extracellular enzymes that degrade cellulosic and aromatic compounds by 40-66%. Lower decomposition was correlated with lower inorganic N (-49%), especially ammonium, suggesting N availability is coupled with decomposition. The relative increase in forms of soil organic matter that are resistant to decay or stabilized onto mineral surfaces, and the associated decline in decomposition suggest that low-intensity fires may promote mineral soil C storage in pools with long mean residence times in coniferous forests

Dynamic Mechanical Interactions Between Neighboring Airspaces Determine Cyclic Opening and Closure in Injured Lung

OBJECTIVES:: Positive pressure ventilation exposes the lung to mechanical stresses that can exacerbate injury. The exact mechanism of this pathologic process remains elusive. The goal of this study was to describe recruitment/derecruitment at acinar length scales over short-time frames and test the hypothesis that mechanical interdependence between neighboring lung units determines the spatial and temporal distributions of recruitment/derecruitment, using a computational model. DESIGN:: Experimental animal study. SETTING:: International synchrotron radiation laboratory. SUBJECTS:: Four anesthetized rabbits, ventilated in pressure controlled mode. INTERVENTIONS:: The lung was consecutively imaged at ~ 1.5-minute intervals using phase-contrast synchrotron imaging, at positive end-expiratory pressures of 12, 9, 6, 3, and 0 cm H2O before and after lavage and mechanical ventilation induced injury. The extent and spatial distribution of recruitment/derecruitment was analyzed by subtracting subsequent images. In a realistic lung structure, we implemented a mechanistic model in which each unit has individual pressures and speeds of opening and closing. Derecruited and recruited lung fractions (Fderecruited, Frecruited) were computed based on the comparison of the aerated volumes at successive time points. MEASUREMENTS AND MAIN RESULTS:: Alternative recruitment/derecruitment occurred in neighboring alveoli over short-time scales in all tested positive end-expiratory pressure levels and despite stable pressure controlled mode. The computational model reproduced this behavior only when parenchymal interdependence between neighboring acini was accounted for. Simulations closely mimicked the experimental magnitude of Fderecruited and Frecruited when mechanical interdependence was included, while its exclusion gave Frecruited values of zero at positive end-expiratory pressure greater than or equal to 3 cm H2O. CONCLUSIONS:: These findings give further insight into the microscopic behavior of the injured lung and provide a means of testing protective-ventilation strategies to prevent recruitment/derecruitment and subsequent lung damage

Autophosphorylation at serine 1981 stabilizes ATM at DNA damage sites

Initial localization of ATM to double-strand breaks requires the MRE11–RAD50–NBS1 complex, but prolonged association requires ATM autophosphorylation

Decadal changes in fire frequencies shift tree communities and functional traits

Global change has resulted in chronic shifts in fire regimes. Variability in the sensitivity of tree communities to multi-decadal changes in fire regimes is critical to anticipating shifts in ecosystem structure and function, yet remains poorly understood. Here, we address the overall effects of fire on tree communities and the factors controlling their sensitivity in 29 sites that experienced multi-decadal alterations in fire frequencies in savanna and forest ecosystems across tropical and temperate regions. Fire had a strong overall effect on tree communities, with an average fire frequency (one fire every three years) reducing stem density by 48% and basal area by 53% after 50 years, relative to unburned plots. The largest changes occurred in savanna ecosystems and in sites with strong wet seasons or strong dry seasons, pointing to fire characteristics and species composition as important. Analyses of functional traits highlighted the impact of fire-driven changes in soil nutrients because frequent burning favoured trees with low biomass nitrogen and phosphorus content, and with more efficient nitrogen acquisition through ectomycorrhizal symbioses. Taken together, the response of trees to altered fire frequencies depends both on climatic and vegetation determinants of fire behaviour and tree growth, and the coupling between fire-driven nutrient losses and plant traits