823 research outputs found
MONOPSONY POWER IN MULTIPLE INPUT MARKETS: A Nonparametric Approach
Cigarette manufacturers' monopsony power exertion in procuring domestic and imported tobacco is investigated using nonparametric methods. While it is often assumed that tobacco program rents are captured by growers, results indicate the opposite actually occurs. Cigarette manufacturers appear to exert significant monopsony power in the domestic leaf tobacco market and capture a large portion of program rents. Cigarette manufacturers appear to exert monopsony power of much smaller magnitude in the international leaf tobacco market, but with increasing magnitude in more recent years.market power, tobacco, nonparametric, monopsony, imports., International Relations/Trade, L1,
DISTINGUISHING THE SOURCE OF MARKET POWER: AN APPLICATION TO CIGARETTE MANUFACTURING
We compare nonparametric and nonstructural market power tests using data from the cigarette manufacturing industry. Tests are implemented to examine both monopoly and monopsony power exertion by cigarette manufacturers. Results indicate that market power in the tobacco industry, previously attributed to monopoly power exertion, should at least in part be attributed to monopsony market power in the upstream tobacco market.market power, nonparametric, nonstructural, monopsony, monopoly, cigarette manufacturing, Agribusiness,
Exploring Factors That Influence Computational Thinking Skills in Elementary Students’ Collaborative Robotics
Recently educational robotics has expanded into curriculum beyond traditional STEM fields, and which can also be used to foster computational thinking (CT) skills. Prior research has shown numerous interdisciplinary benefits related to CT, however, these influential factors have often been investigated with relatively few variables. This study investigated factors that may lead to 4th and 5th grade elementary school students’ development of computational thinking skills in collaborative robotics activities by hypothesizing a model which proposed that a problem solving inventory, intrinsic motivation, and enjoyment were the main predictors of computational thinking skills. The model was then tested by surveying students with several psychometric inventories where a revised model was then constructed. The study found significant relationships between perceived competence and enjoyment, and learning motivation, and intrinsic motivation. Another important finding was that problem solving was a significant predictor of computational thinking skills. Results were interpreted with reference to implications for possible means of improving learning outcomes when using collaborative robotics in an educational setting
Roles of binding elements, FOXL2 domains, and interactions with cJUN and SMADs in regulation of FSHβ.
We previously identified FOXL2 as a critical component in FSHβ gene transcription. Here, we show that mice deficient in FOXL2 have lower levels of gonadotropin gene expression and fewer LH- and FSH-containing cells, but the same level of other pituitary hormones compared to wild-type littermates, highlighting a role of FOXL2 in the pituitary gonadotrope. Further, we investigate the function of FOXL2 in the gonadotrope cell and determine which domains of the FOXL2 protein are necessary for induction of FSHβ transcription. There is a stronger induction of FSHβ reporter transcription by truncated FOXL2 proteins, but no induction with the mutant lacking the forkhead domain. Specifically, FOXL2 plays a role in activin induction of FSHβ, functioning in concert with activin-induced SMAD proteins. Activin acts through multiple promoter elements to induce FSHβ expression, some of which bind FOXL2. Each of these FOXL2-binding sites is either juxtaposed or overlapping with a SMAD-binding element. We determined that FOXL2 and SMAD4 proteins form a higher order complex on the most proximal FOXL2 site. Surprisingly, two other sites important for activin induction bind neither SMADs nor FOXL2, suggesting additional factors at work. Furthermore, we show that FOXL2 plays a role in synergistic induction of FSHβ by GnRH and activin through interactions with the cJUN component of the AP1 complex that is necessary for GnRH responsiveness. Collectively, our results demonstrate the necessity of FOXL2 for proper FSH production in mice and implicate FOXL2 in integration of transcription factors at the level of the FSHβ promoter
Parametric frailty models for clustered data with arbitrary censoring: application to effect of male circumcision on HPV clearance
Background
In epidemiological studies, subjects are often followed for a period during which study outcomes are measured at selected time points, such as by diagnostic testing performed on biological samples collected at each visit. Although test results may indicate the presence or absence of a disease or condition, they cannot provide information on when exactly it occurred. Such study designs generate arbitrarily censored time-to-event data, which can include left, interval and right censoring. Adding to this complexity, the data may be clustered such that observations within the same cluster are not independent, such as time to recovery of an infectious disease of family or community members. This data structure is observed when evaluating circumcision\u27s effect on clearance of penile high risk human papillomavirus (HR-HPV) infections using data collected from the male circumcision(MC) trial conducted in Rakai, Uganda, where the multiple infections within individual and HPV testings performed at trial follow-up visits gave rise to the clustered data with arbitrary censoring. Methods
We describe the use of parametric proportional hazards frailty models and accelerated failure time frailty models to examine the relationship between explanatory variables and the survival outcomes that are subject to arbitrary censoring, while accounting for the correlation within clusters. Standard software such as SAS can be used for parameter estimation. Results
Circumcision\u27s effect on HPV infection was a secondary end point in the Rakai MC trial, and HPV genotyping was conducted for penile samples of a subset of trial participants collected at enrollment, 6, 12 and 24-month follow up visits. At enrollment, 36.7% intervention arm men (immediate circumcision) and 36.6% control arm men (delayed circumcision at 2 years) were infected with HR-HPV, with the number of infections per man being 1-5. The proposed models were used to examine whether MC facilitated clearance of the prevalent infections. Results show that clearance of multiple infections within each man is highly correlated, and clearance was 60% faster if a man was circumcised. Conclusions
Parametric frailty models provide viable ways to study the relationship between exposure variables and clustered survival outcome that is subject to arbitrary censoring, as is often observed in HPV epidemiology studies
A Tri-state Investigation of Firearms Confiscation on Three Regional University Campuses
While the use of firearms is pronounced throughout the US, there are few studies that address the availability of firearms on university campuses in states that are adjacent to each other. This study uses a five-year longitudinal design to investigate three universities that were randomly selected in the neighboring states of North Carolina, Virginia, and South Carolina to examine the extent of firearm confiscation by public safety officers. In the final analysis, we conclude that unless viable strategies that target preventing firearms used in domestic violence, alleviating access to guns, and addressing mental health illnesses among college students are created to effectively confiscate firearms on university campuses, deadly violence could become an inevitable occurrence
HIV Mother-to-Child Transmission, Mode of Delivery, and Duration of Rupture of Membranes: Experience in the Current Era
Objective. To evaluate whether the length of time of rupture of membranes (ROM) in optimally managed HIV-positive women on highly active antiretroviral therapy (HAART) with low viral loads (VL) is predictive of the risk of mother to child transmission (MTCT) of the human immunodeficiency virus (HIV). Study Methods. A retrospective case series of all HIV-positive women who delivered at two academic tertiary centers in Toronto, Canada from January 2000 to November 2010 was completed. Results. Two hundred and ten HIV-positive women with viral loads <1,000 copies/ml delivered during the study period. VL was undetectable (<50 copies/mL) for the majority of the women (167, 80%), and <1,000 copies/mL for all women. Mode of delivery was vaginal in 107 (51%) and cesarean in 103 (49%). The median length of time of ROM was 0.63 hours (range 0 to 77.87 hours) for the entire group and 2.56 hours (range 0 to 53.90 hours) for those who had a vaginal birth. Among women with undetectable VL, 90 (54%) had a vaginal birth and 77 (46%) had a cesarean birth. Among the women in this cohort there were no cases of MTCT of HIV. Conclusions. There was no association between duration of ROM or mode of delivery and MTCT in this cohort of 210 virally suppressed HIV-positive pregnant women
Working with Students, Learning from Students through a Special Programme in Science at National University of Singapore
What is the evidence that can inform the implementation of a preceptorship scheme for general practice nurses, and what is the evidence for the benefits of such a scheme?: A literature review and synthesis
Objectives:
This is a literature review of the published evidence of the benefits and suggested structure of preceptorship programmes for General Practice Nursing, with the aim of informing General Practices and networks who are instituting preceptorship programmes.
Design & data sources:
A literature search was carried out in the CINAHL Plus database of English language papers from the year 2000–2019 using the search terms; (Precept* or mentor*) AND (“community practice” OR “primary care” or “general practice” or “new GPN” or “new general practice nurse” or “nurse new to general practice” or “induction GPN” or “GPN”).
Review method:
A literature review and narrative synthesis of the evidence.
Results:
Our searches produced twelve papers. Seven papers reported on single preceptorship programmes in General Practice or primary care, with qualitative or quantitative evaluation of their effects. Three qualitative papers reported participant experience of preceptorship, or discussed the learning needs that preceptorship must address. Two literature reviews reported the evidence for preceptorship in General Practice or nurse practitioner programmes.
Conclusion:
The quality of the evidence on General Practice Nurse preceptorship is low. There is a lack of robust evidence on the effects, and the benefits. These should be evaluated as preceptorship programmes are implemented.
The limited available evidence suggests that a structured preceptorship programme, of more than 4 months duration, which allows the development of peer-to-peer support, is a good model for General Practice Nurse preceptorship. The involvement of doctors and the wider practice team is essential for the success of such a programme. Preceptors require training and support in the role. General Practice Nurse preceptorship should support the development of existing professional competencies, including the ability to make real-time autonomous clinical decisions. The financial costs, and cost of time away from clinical care, should be ameliorated as far as possible, when instituting a national General Practice Nurse preceptorship programme
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