147 research outputs found
Quantifying relationships between rock hardness, shore platform topography, and intertidal biota: Oregon Coast
To test the link between rock hardness and meter-scale shore platform morphology and the link between rock hardness and biodiversity, we examined six locations on the Oregon Coast, USA with varying rock types. At each site, we collected rock hardness data along a transect using a Schmidt hammer. To quantify topography, we processed hand-held photographs of each site using structure-from-motion photogrammetry in Agisoft PhotoScan, calculating surface roughness and related statistics in CloudCompare. Our preliminary results confirm that sites with softer rocks tend to have smoother shore platforms and higher levels of biodiversity
Female sterilization in the life course: Understanding trends and differentials in early sterilization
Background: Socioeconomically disadvantaged women and women of color are more likely than other women both to undergo contraceptive sterilization and to desire sterilization reversal. Although younger age at sterilization is associated with greater likelihood of regret, we know little about socioeconomic and racial/ethnic differences in sterilization timing within the life course. Objective: We examine racial, ethnic, and educational differences in the prevalence of sterilization and its timing in the life course. Methods: Using data from the 1995, 2002, 2006-2010, 2011-2013, 2013-2015, 2015-2017, and 2017-2019 National Survey of Family Growth, we estimate the prevalence and life timing of sterilization by subgroup and investigate associations with women's demographic and reproductive characteristics. Results: We find differing patterns of sterilization timing across racial, ethnic, and educational groups. Among sterilized women, Black women are more likely than White women to have undergone their procedures by age 30, but these differences in sterilization timing are attributable to reproductive background characteristics. On the other hand, Hispanic women are more likely than White women to become sterilized, but our findings suggest they are less likely to undergo the procedure by age 30, conditional on becoming sterilized. Women without a college degree are both considerably more likely than college-educated women to become sterilized and, conditional on becoming sterilized, to do so by age 30. Contribution: Our study sheds new light on racial, ethnic, and educational differences in the life timing of female sterilization over the past quarter century
Beyond Educational Videogames to Educational Systems-That-Incorporate Videogames: A Case Study of a System for Learning about Energy
A common goal for designers of educational videogames is to make learning fun. Unfortunately, the result is often a game that tries to combine the fun aspects of videogames with learning elements, but that is neither fun nor effective for learning. In this paper we present our discovery of an alternative approach—a system that combines both education and entertainment, but that separates them into different modules that are loosely-coupled. Entertainment motivates education through a reward mechanism, where performance in the education module yields tokens that can be redeemed for in-game assets in the entertainment module. We present a case study of our specific implementation of this system, and we discuss how it can be generalized to motivate the learning of any topic where performance can be measured. This research contributes to our understanding of designing cognitive artifacts, and to our understanding of designing educational systems as distributed services
Reconsidering (in)equality in the use of IUDs in the United States: A closer look across the reproductive life course
Background: Long-acting reversible contraceptives (LARCs), such as the intrauterine device (IUD), have received increased attention for their contraceptive effectiveness and reversibility. Although demographers have long acknowledged the importance of parity and childbearing intentions for contraceptive choice, we know little about how contraceptive use varies across the reproductive life course. Objective: Guided by the expectation that contraceptive method characteristics (e.g., reversibility, effectiveness) contribute to method choice ‒ and that the salience of method characteristics vary by reproductive life stage and education ‒ we investigate variability in IUD use patterns. Methods: We use 2008-2010 and 2011-2013 National Survey of Family Growth data to compare women's IUD-use patterns across educational groups and at three reproductive life stages: before a first birth occurs ("starters"), between births ("spacers"), and after planned childbearing ends altogether ("limiters"). Results: IUD use is more common among spacers than among starters or limiters. Moreover, IUD use is associated with educational advantage among starters and limiters, but not among spacers. Educational differences in IUD use among starters and limiters persist when demographic background characteristics are controlled. Conclusions: Our understanding of variability in IUD use changes considerably when viewing educational gradients through the lens of the reproductive life course. Contribution: We shed new light on variability in IUD use across the reproductive life course. To best support women's contraceptive preferences, it is important to consider the ways in which structural determinants (e.g., education, reproductive health policies and programs) shape women's contraceptive choices at various stages of the reproductive life course
Development and evaluation of a high-throughput, low-cost genotyping platform based on oligonucleotide microarrays in rice
<p>Abstract</p> <p>Background</p> <p>We report the development of a microarray platform for rapid and cost-effective genetic mapping, and its evaluation using rice as a model. In contrast to methods employing whole-genome tiling microarrays for genotyping, our method is based on low-cost spotted microarray production, focusing only on known polymorphic features.</p> <p>Results</p> <p>We have produced a genotyping microarray for rice, comprising 880 single feature polymorphism (SFP) elements derived from insertions/deletions identified by aligning genomic sequences of the <it>japonica </it>cultivar Nipponbare and the <it>indica </it>cultivar 93-11. The SFPs were experimentally verified by hybridization with labeled genomic DNA prepared from the two cultivars. Using the genotyping microarrays, we found high levels of polymorphism across diverse rice accessions, and were able to classify all five subpopulations of rice with high bootstrap support. The microarrays were used for mapping of a gene conferring resistance to <it>Magnaporthe grisea</it>, the causative organism of rice blast disease, by quantitative genotyping of samples from a recombinant inbred line population pooled by phenotype.</p> <p>Conclusion</p> <p>We anticipate this microarray-based genotyping platform, based on its low cost-per-sample, to be particularly useful in applications requiring whole-genome molecular marker coverage across large numbers of individuals.</p
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