Field evidence for the upwind velocity shift at the crest of low dunes

Wind topographically forced by hills and sand dunes accelerates on the upwind (stoss) slopes and reduces on the downwind (lee) slopes. This secondary wind regime, however, possesses a subtle effect, reported here for the first time from field measurements of near-surface wind velocity over a low dune: the wind velocity close to the surface reaches its maximum upwind of the crest. Our field-measured data show that this upwind phase shift of velocity with respect to topography is found to be in quantitative agreement with the prediction of hydrodynamical linear analysis for turbulent flows with first order closures. This effect, together with sand transport spatial relaxation, is at the origin of the mechanisms of dune initiation, instability and growth.Comment: 13 pages, 6 figures. Version accepted for publication in Boundary-Layer Meteorolog

Niche as a determinant of word fate in online groups

Patterns of word use both reflect and influence a myriad of human activities and interactions. Like other entities that are reproduced and evolve, words rise or decline depending upon a complex interplay between {their intrinsic properties and the environments in which they function}. Using Internet discussion communities as model systems, we define the concept of a word niche as the relationship between the word and the characteristic features of the environments in which it is used. We develop a method to quantify two important aspects of the size of the word niche: the range of individuals using the word and the range of topics it is used to discuss. Controlling for word frequency, we show that these aspects of the word niche are strong determinants of changes in word frequency. Previous studies have already indicated that word frequency itself is a correlate of word success at historical time scales. Our analysis of changes in word frequencies over time reveals that the relative sizes of word niches are far more important than word frequencies in the dynamics of the entire vocabulary at shorter time scales, as the language adapts to new concepts and social groupings. We also distinguish endogenous versus exogenous factors as additional contributors to the fates of words, and demonstrate the force of this distinction in the rise of novel words. Our results indicate that short-term nonstationarity in word statistics is strongly driven by individual proclivities, including inclinations to provide novel information and to project a distinctive social identity.Comment: Supporting Information is available here: http://www.plosone.org/article/fetchSingleRepresentation.action?uri=info:doi/10.1371/journal.pone.0019009.s00

The influence of personality and ability on undergraduate teamwork and team performance

The ability to work effectively on a team is highly valued by employers, and collaboration among students can lead to intrinsic motivation, increased persistence, and greater transferability of skills. Moreover, innovation often arises from multidisciplinary teamwork. The influence of personality and ability on undergraduate teamwork and performance is not comprehensively understood. An investigation was undertaken to explore correlations between team outcomes, personality measures and ability in an undergraduate population. Team outcomes included various self-, peer- and instructor ratings of skills, performance, and experience. Personality measures and ability involved the Five-Factor Model personality traits and GPA. Personality, GPA, and teamwork survey data, as well as instructor evaluations were collected from upper division team project courses in engineering, business, political science, and industrial design at a large public university. Characteristics of a multidisciplinary student team project were briefly examined. Personality, in terms of extraversion scores, was positively correlated with instructors’ assessment of team performance in terms of oral and written presentation scores, which is consistent with prior research. Other correlations to instructor-, students’ self- and peer-ratings were revealed and merit further study. The findings in this study can be used to understand important influences on successful teamwork, teamwork instruction and intervention and to understand the design of effective curricula in this area moving forward

Force spectroscopy in studying infection

Biophysical force spectroscopy tools - for example optical tweezers, magnetic tweezers, atomic force microscopy, - have been used to study elastic, mechanical, conformational and dynamic properties of single biological specimens from single proteins to whole cells to reveal information not accessible by ensemble average methods such as X-ray crystallography, mass spectroscopy, gel electrophoresis and so on. Here we review the application of these tools on a range of infection-related questions from antibody-inhibited protein processivity to virus-cell adhesion. In each case we focus on how the instrumental design tailored to the biological system in question translates into the functionality suitable for that particular study. The unique insights that force spectroscopy has gained to complement knowledge learned through population averaging techniques in interrogating biomolecular details prove to be instrumental in therapeutic innovations such as those in structure-based drug design

Extensive coronavirus-induced membrane rearrangements are not a determinant of pathogenicity

Positive-strand RNA (+RNA) viruses rearrange cellular membranes during replication, possibly in order to concentrate and arrange viral replication machinery for efficient viral RNA synthesis. Our previous work showed that in addition to the conserved coronavirus double membrane vesicles (DMVs), Beau-R, an apathogenic strain of avian Gammacoronavirus infectious bronchitis virus (IBV), induces regions of ER that are zippered together and tethered open-necked double membrane spherules that resemble replication organelles induced by other +RNA viruses. Here we compared structures induced by Beau-R with the pathogenic lab strain M41 to determine whether membrane rearrangements are strain dependent. Interestingly, M41 was found to have a low spherule phenotype. We then compared a panel of pathogenic, mild and attenuated IBV strains in ex vivo tracheal organ culture (TOC). Although the low spherule phenotype of M41 was conserved in TOCs, each of the other tested IBV strains produced DMVs, zippered ER and spherules. Furthermore, there was a significant correlation for the presence of DMVs with spherules, suggesting that these structures are spatially and temporally linked. Our data indicate that virus induced membrane rearrangements are fundamentally linked to the viral replicative machinery. However, coronavirus replicative apparatus clearly has the plasticity to function in different structural contexts

The feasibility of introducing rapid diagnostic tests for malaria in drug shops in Uganda

BACKGROUND: National malaria control programmes and international agencies are keen to scale-up the use of effective rapid diagnostic tests (RDTs) for malaria. The high proportion of the Ugandan population seeking care at drug shops makes these outlets attractive as providers of malaria RDTs. However, there is no precedent for blood testing at drug shops and little is known about how such tests might be perceived and used. Understanding use of drug shops by communities in Uganda is essential to inform the design of interventions to introduce RDTs. METHODS: We conducted a qualitative study, with 10 community focus group discussions, and 18 in-depth interviews with drug shop attendants, health workers and district health officials. The formative study was carried out in Mukono district, central Uganda an area of high malaria endemicity from May-July 2009. RESULTS: Drug shops were perceived by the community as important in treating malaria and there was awareness among most drug sellers and the community that not all febrile illnesses were malaria. The idea of introducing RDTs for malaria diagnosis in drug shops was attractive to most respondents. It was anticipated that RDTs would improve access to effective treatment of malaria, offset high costs associated with poor treatment, and avoid irrational drug use. However, communities did express fear that drug shops would overprice RDTs, raising the overall treatment cost for malaria. Other fears included poor adherence to the RDT result, reuse of RDTs leading to infections and fear that RDTs would be used to test for human immune deficiency virus (HIV). All drug shops visited had no record on patient data and referral of cases to health units was noted to be poor. CONCLUSION: These results not only provide useful lessons for implementing the intervention study but have wide implications for scaling up malaria treatment in drug shops

How does Brazil measure up? Comparing rankings through the lenses of nation brand indexes

A considerable amount of literature has been published on nation brand and yet not much regarding measurement. The purpose of this paper is to examine nation brand indexes and explore the unbalanced outcomes of a country’s position in these recognized instruments. Although research has been carried out on nation brand, no single study exists comparing a country in four diverse nation brand indexes, which are the reputable ones by Anholt (2007), Fetscherin (2010), Fombrun (2014) and Anholt and Govers (2014). This paper also reflects on the critical studies perspective of the place branding research domain, discussed by Lucarelli and Berg (2011). After a qualitative approach applied to Brazil, it is believed that these indexes mutually support and complement each other - even though they use different approaches, methodologies, samples, and data. Moreover, each of them has their own strengths and weaknesses in terms of accuracy and rationality. Findings from this paper’s evaluation may guide nation brand managers, governments, and researchers to recognize that indexes should be taken into account when analysing a nation brand and its complex image. Therefore, this paper contributes to existing knowledge on the critical studies perspective of the contemporary theoretical structure of the place branding research domain by providing a comparative study based on real data-based rankings of nation brand indexes

Correlates of loneliness among university students

Background The purpose of this study was to investigate level of loneliness, essential needs during university education, and relationships between loneliness, essential needs, and characteristics of university students. A sample comprising 721 students participated in the study. The mean age was 21.58 (SD = 1.73) with a range from 18 to 25. The majority of the students were female (70.6%) and were living in students' dormitory (67.5%) with low (87.8%) income, away from their parents. Methods The UCLA-R loneliness scale and sociodemographic questionnaire which includes an open-ended question on essential needs during university education were administered. Pearson-Product-Moment correlations were used to explore the relationships between participants' loneliness, needs, and characteristics. Results It was found that 60.2% of the participants experienced loneliness. Economical support (81.6%), social interaction (46.9%) and psychosocial support (35%) were the essential needs during university education reported by the participants. The study findings indicate that there were significant relationships between the needs of economical support, social interaction, and loneliness level of university students. Results also show that there were significant relationships among romantic relationship, parents' status and loneliness. Participants' loneliness levels were relatively higher who had not any romantic relationship and were not from married families. Conclusion The findings of this study provided essential information, about Turkish university students, concerning: level of loneliness and relationships that exist among loneliness, needs and sociodemographic characteristics. The findings also suggest implications for psychosocial practice. Because of the mean of loneliness were found to be high (45.49 ± 10.07), for this study, professionals need to pay attention to Turkish university students' psychosocial state, and need to empower them in establishing social relations

The pathology of familial breast cancer: Immunohistochemistry and molecular analysis

Extensive studies of BRCA1- and BRCA2-associated breast tumours have been carried out in the few years since the identification of these familial breast cancer predisposing genes. The morphological studies suggest that BRCA1 tumours differ from BRCA2 tumours and from sporadic breast cancers. Recent progress in immunohistochemistry and molecular biology techniques has enabled in-depth investigation of molecular pathology of these tumours. Studies to date have investigated issues such as steroid hormone receptor expression, mutation status of tumour suppressor genes TP53 and c-erbB2, and expression profiles of cell cycle proteins p21, p27 and cyclin D(1). Despite relative paucity of data, strong evidence of unique biological characteristics of BRCA1-associated breast cancer is accumulating. BRCA1-associated tumours appear to show an increased frequency of TP53 mutations, frequent p53 protein stabilization and absence of imunoreactivity for steroid hormone receptors. Further studies of larger number of samples of both BRCA1- and BRCA2-associated tumours are necessary to clarify and confirm these observations