1,903 research outputs found
Breaking the habit: measuring and predicting departures from routine in individual human mobility
Researchers studying daily life mobility patterns have recently shown that humans are typically highly predictable in their movements. However, no existing work has examined the boundaries of this predictability, where human behaviour transitions temporarily from routine patterns to highly unpredictable states. To address this shortcoming, we tackle two interrelated challenges. First, we develop a novel information-theoretic metric, called instantaneous entropy, to analyse an individual’s mobility patterns and identify temporary departures from routine. Second, to predict such departures in the future, we propose the first Bayesian framework that explicitly models breaks from routine, showing that it outperforms current state-of-the-art predictor
Effects of common pharmacologic agents on reproductive outcomes among male and female pregnancy planners
Infertility and spontaneous abortion (SAB) affect up to one-third of couples planning a family.1–3 While common, there are few known risk factors. Medication use may play a role but the extent is unknown because, for most agents, use during reproduction has been understudied. The objective of this dissertation was to examine the associations between use of common pharmacologic agents and reproductive outcomes in three interrelated prospective cohort studies of pregnancy planners in Denmark, the United States, and Canada.
In study 1, we examined fecundability, the average per-cycle probability of conception and a measure of time-to-pregnancy (TTP), in relation to past contraceptive use. Exposures of interest included oral contraceptives, IUDs (hormonal, copper), rings, implants, patches, injectables, natural methods, and barrier methods. Among 9,350 female pregnancy planners, we first examined TTP by the last method of contraception used before pregnancy attempt. We then examined the association between total lifetime duration of use of hormonal contraceptive methods and TTP. On average, injectable users had the longest delay in the return of fertility (8 cycles), followed by OC, ring, implant and patch (3 cycles), hormonal IUD (2 cycles), and copper IUD users (1 cycle). We did not find any evidence that long-term use of these methods was detrimental to fecundability.
Study 2 examined the association between male use of pain medications and fecundability among 1,065 couples planning pregnancy in North America. Medications examined include ibuprofen, acetaminophen, naproxen, and aspirin. We examined fecundability in relation to any use and cumulative monthly dose of each of these medications. Our study showed little evidence of a deleterious effect of male preconception use of common pain medications on fecundability.
In study 3, we examined use of pain medications between pregnancy conception and 12 gestational weeks and risk of SAB. Medications examined include ibuprofen, acetaminophen, naproxen, aspirin, and opioids. In the three cohorts of women recruited before conception, we observed 9,196 pregnancies and 1,597 SABs (17.4%). We found that low-dose use of ibuprofen, naproxen, or opioids before 12 weeks of gestation was associated with slightly increased risk of SAB. Overall, low-dose use of acetaminophen or aspirin did not appreciably increase risk of SAB
The tree of genomes: An empirical comparison of genome-phylogeny reconstruction methods
<p>Abstract</p> <p>Background</p> <p>In the past decade or more, the emphasis for reconstructing species phylogenies has moved from the analysis of a single gene to the analysis of multiple genes and even completed genomes. The simplest method of scaling up is to use familiar analysis methods on a larger scale and this is the most popular approach. However, duplications and losses of genes along with horizontal gene transfer (HGT) can lead to a situation where there is only an indirect relationship between gene and genome phylogenies. In this study we examine five widely-used approaches and their variants to see if indeed they are more-or-less saying the same thing. In particular, we focus on Conditioned Reconstruction as it is a method that is designed to work well even if HGT is present.</p> <p>Results</p> <p>We confirm a previous suggestion that this method has a systematic bias. We show that no two methods produce the same results and most current methods of inferring genome phylogenies produce results that are significantly different to other methods.</p> <p>Conclusion</p> <p>We conclude that genome phylogenies need to be interpreted differently, depending on the method used to construct them.</p
A Study of Curriculum Customization in the Era of Standardization of Education
The turn of the 19th Century in the United States was a period of immense economic, social and political growth. The Progressive Era was born out of this rapid change and led to a shift in educational theory creating a debate over curriculum. Curriculum has been a fervent point of discussion among educational theorists and practitioners with politicians and businessmen having all had something to add to the fray. The current movement in curriculum content has been at the forefront since 2010 where education has been besieged by a strong impetus toward standardization. This has taken the form of the Common Core State Standards (Common Core or CCSS). Until the advent of the Common Core the individual States in the United States each had their own curriculum standards that were meant to be guidelines for local curriculum writers. John Dewey, the philosopher and educational theorist wrote that curriculum should be local. In the United States, the movement toward a national curriculum and with this movement is the need for an assessment test(s). A scripted curriculum, however, does not lead to conceptual change nor does it foster intellectual curiosity. This study focused on whether or not teachers rigidly follow the adopted curriculum and if the teacher’s had the power to customize that curriculum in their daily classroom practice. Finally, if the teachers engaged in active curriculum making, what if any, were the measurable or perceived effects in terms of teacher efficacy and in terms empowerment
A Study of Curriculum Customization in the Era of Standardization of Education
The turn of the 19th Century in the United States was a period of immense economic, social and political growth. The Progressive Era was born out of this rapid change and led to a shift in educational theory creating a debate over curriculum. Curriculum has been a fervent point of discussion among educational theorists and practitioners with politicians and businessmen having all had something to add to the fray. The current movement in curriculum content has been at the forefront since 2010 where education has been besieged by a strong impetus toward standardization. This has taken the form of the Common Core State Standards (Common Core or CCSS). Until the advent of the Common Core the individual States in the United States each had their own curriculum standards that were meant to be guidelines for local curriculum writers. John Dewey, the philosopher and educational theorist wrote that curriculum should be local. In the United States, the movement toward a national curriculum and with this movement is the need for an assessment test(s). A scripted curriculum, however, does not lead to conceptual change nor does it foster intellectual curiosity. This study focused on whether or not teachers rigidly follow the adopted curriculum and if the teacher’s had the power to customize that curriculum in their daily classroom practice. Finally, if the teachers engaged in active curriculum making, what if any, were the measurable or perceived effects in terms of teacher efficacy and in terms empowerment
Microbiology: Mind the gaps in cellular evolution
Eukaryotic cells, with complex features such as membrane-bound nuclei, evolved from prokaryotic cells that lack these components. A newly identified prokaryotic group reveals intermediate steps in eukaryotic-cell evolution
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