The Power of the Pill for the Next Generation

In this paper we ask how the diffusion of oral contraception to young unmarried women affected the number and maternal characteristics of children born to these women. Using census data, we find that early pill access led to an increase in the share of children whose mothers were married, college-educated, and had professional occupations. The pill's effects on the average mother are different from the pill's effects on the average woman, and the effects of the pill on maternal characteristics are in some instances different from the effects of abortion. We investigate the mechanisms by which the pill led to these differential effects and find that access to the pill led to falls in short-term fertility rates for young women and led to decreases in lifetime fertility at the intensive and extensive margins. The impacts of the pill on household characteristics are thus associated with retiming of births, changes in the characteristics of potential mothers, changes in which women become mothers, and by reductions in completed family size. Finally, while the pill affected maternal characteristics differently than abortion, we find suggestive results that availability of the pill lowered abortions among young women.

Quantifying the Effect of Matrix Structure on Multithreaded Performance of the SpMV Kernel

Sparse matrix-vector multiplication (SpMV) is the core operation in many common network and graph analytics, but poor performance of the SpMV kernel handicaps these applications. This work quantifies the effect of matrix structure on SpMV performance, using Intel's VTune tool for the Sandy Bridge architecture. Two types of sparse matrices are considered: finite difference (FD) matrices, which are structured, and R-MAT matrices, which are unstructured. Analysis of cache behavior and prefetcher activity reveals that the SpMV kernel performs far worse with R-MAT matrices than with FD matrices, due to the difference in matrix structure. To address the problems caused by unstructured matrices, novel architecture improvements are proposed.Comment: 6 pages, 7 figures. IEEE HPEC 201

Checkerboard Julia Sets for Rational Maps

In this paper, we consider the family of rational maps \F(z) = z^n + \frac{\la}{z^d}, where $n \geq 2$, $d\geq 1$, and\la \in \bbC. We consider the case where \la lies in the main cardioid of one of the $n-1$ principal Mandelbrot sets in these families. We show that the Julia sets of these maps are always homeomorphic. However, two such maps \F and $F_\mu$ are conjugate on these Julia sets only if the parameters at the centers of the given cardioids satisfy \mu = \nu^{j(d+1)}\la or \mu = \nu^{j(d+1)}\bar{\la} where j \in \bbZ and $\nu$ is an $n-1^{\rm st}$ root of unity. We define a dynamical invariant, which we call the minimal rotation number. It determines which of these maps are are conjugate on their Julia sets, and we obtain an exact count of the number of distinct conjugacy classes of maps drawn from these main cardioids.Comment: 25 pages, 14 figures; Changes since March 19 version: added nine figures, fixed one proof, added a section on a group actio

Modification and Assessment of the Bedside Pediatric Early Warning Score in the Pediatric Allogeneic Hematopoietic Cell Transplant Population

OBJECTIVES: To determine the validity of the Bedside Pediatric Early Warning Score system in the hematopoietic cell transplant population, and to determine if the addition of weight gain further strengthens the association with need for PICU admission. DESIGN: Retrospective cohort study of pediatric allogeneic hematopoietic cell transplant patients from 2009 to 2016. Daily Pediatric Early Warning Score and weights were collected during hospitalization. Logistic regression was used to identify associations between maximum Pediatric Early Warning Score or Pediatric Early Warning Score plus weight gain and the need for PICU intervention. The primary outcome was need for PICU intervention; secondary outcomes included mortality and intubation. SETTING: A large quaternary free-standing children's hospital. PATIENTS: One-hundred two pediatric allogeneic hematopoietic cell transplant recipients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 102 hematopoietic cell transplant patients included in the study, 29 were admitted to the PICU. The median peak Pediatric Early Warning Score was 11 (interquartile range, 8-13) in the PICU admission cohort, compared with 4 (interquartile range, 3-5) in the cohort without a PICU admission (p < 0.0001). Pediatric Early Warning Score greater than or equal to 8 had a sensitivity of 76% and a specificity of 90%. The area under the receiver operating characteristics curve was 0.83. There was a high negative predictive value at this Pediatric Early Warning Score of 90%. When Pediatric Early Warning Score greater than or equal to 8 and weight gain greater than or equal to 7% were compared together, the area under the receiver operating characteristic curve increased to 0.88. CONCLUSIONS: In this study, a Pediatric Early Warning Score greater than or equal to 8 was associated with PICU admission, having a moderately high sensitivity and high specificity. This study adds to literature supporting Pediatric Early Warning Score monitoring for hematopoietic cell transplant patients. Combining weight gain with Pediatric Early Warning Score improved the discriminative ability of the model to predict the need for critical care, suggesting that incorporation of weight gain into Pediatric Early Warning Score may be beneficial for monitoring of hematopoietic cell transplant patients

The Health-Related Uses and Gratifications of YouTube: Motive, Cognitive Involvement, Online Activity, and Sense of Empowerment

To better understand the utility of YouTube as a health communication medium, this study utilizes Uses and Gratifications Theory to examine a relationship among motives for health-related YouTube use, cognitive involvement with health information on YouTube, post-exposure online activity, and health-related sense of empowerment. Surveys were analyzed from 263 participants who reported using YouTube for health-related reasons. Results revealed specific motives for health-related YouTube use and a significant relationship among the variables. Implications for how health care professionals could use YouTube for communicating with users about health-related topics and empowering them in health care are discussed

Marketing in Online Businesses: The Case of Migrant Entrepreneurial Businesses in the UK

The study presents an empirical investigation of the marketing activities undertaken by online businesses owned by migrant entrepreneurs and is framed by the theoretical lens of entrepreneurial marketing. Key informant interviews are undertaken with 22 entrepreneurs operating online businesses in the UK and augmented by other sources of data. The study finds that the resources available to the entrepreneurs are shaped by their migrant heritage and that they draw on these resources to market their online businesses. The study also finds that, consistent with notions from entrepreneurial marketing, the online nature of their businesses allow the entrepreneurs to meet their own needs and preferences, which are also shaped by their migrant heritage. The study is important since it provides empirical evidence and a theoretically grounded understanding of how online businesses offer migrant entrepreneurs the opportunity to break out of the low growth, low margin, vacancy chain openings and enter high growth, high margin, post-industrial sectors

Incident Ischemic Heart Disease After Long-Term Occupational Exposure to Fine Particulate Matter: Accounting for 2 Forms of Survivor Bias.

Little is known about the heart disease risks associated with occupational, rather than traffic-related, exposure to particulate matter with aerodynamic diameter of 2.5 µm or less (PM2.5). We examined long-term exposure to PM2.5 in cohorts of aluminum smelters and fabrication workers in the United States who were followed for incident ischemic heart disease from 1998 to 2012, and we addressed 2 forms of survivor bias. Left truncation bias was addressed by restricting analyses to the subcohort hired after the start of follow up. Healthy worker survivor bias, which is characterized by time-varying confounding that is affected by prior exposure, was documented only in the smelters and required the use of marginal structural Cox models. When comparing always-exposed participants above the 10th percentile of annual exposure with those below, the hazard ratios were 1.67 (95% confidence interval (CI): 1.11, 2.52) and 3.95 (95% CI: 0.87, 18.00) in the full and restricted subcohorts of smelter workers, respectively. In the fabrication stratum, hazard ratios based on conditional Cox models were 0.98 (95% CI: 0.94, 1.02) and 1.17 (95% CI: 1.00, 1.37) per 1 mg/m(3)-year in the full and restricted subcohorts, respectively. Long-term exposure to occupational PM2.5 was associated with a higher risk of ischemic heart disease among aluminum manufacturing workers, particularly in smelters, after adjustment for survivor bias

Yeast-based High-throughput Screens To Identify Novel Compounds Active Against Brugia Malayi

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Lymphatic filariasis is caused by the parasitic worms Wuchereria bancrofti, Brugia malayi or B. timori, which are transmitted via the bites from infected mosquitoes. Once in the human body, the parasites develop into adult worms in the lymphatic vessels, causing severe damage and swelling of the affected tissues. According to the World Health Organization, over 1.2 billion people in 58 countries are at risk of contracting lymphatic filariasis. Very few drugs are available to treat patients infected with these parasites, and these have low efficacy against the adult stages of the worms, which can live for 7-15 years in the human body. The requirement for annual treatment increases the risk of drug-resistant worms emerging, making it imperative to develop new drugs against these devastating diseases. Methodology/Principal Findings We have developed a yeast-based, high-throughput screening system whereby essential yeast genes are replaced with their filarial or human counterparts. These strains are labeled with different fluorescent proteins to allow the simultaneous monitoring of strains with parasite or human genes in competition, and hence the identification of compounds that inhibit the parasite target without affecting its human ortholog. We constructed yeast strains expressing eight different Brugia malayi drug targets (as well as seven of their human counterparts), and performed medium-throughput drug screens for compounds that specifically inhibit the parasite enzymes. Using the Malaria Box collection (400 compounds), we identified nine filarial specific inhibitors and confirmed the antifilarial activity of five of these using in vitro assays against Brugia pahangi. Conclusions/Significance We were able to functionally complement yeast deletions with eight different Brugia malayi enzymes that represent potential drug targets. We demonstrated that our yeast-basedscreening platform is efficient in identifying compounds that can discriminate between human and filarial enzymes. Hence, we are confident that we can extend our efforts to the construction of strains with further filarial targets (in particular for those species that cannot be cultivated in the laboratory), and perform high-throughput drug screens to identify specific inhibitors of the parasite enzymes. By establishing synergistic collaborations with researchers working directly on different parasitic worms, we aim to aid antihelmintic drug development for both human and veterinary infections.101Bill and Melinda Gates FoundationGrand Challenges Explorations [OP1087646, OPP1098441]Sao Paulo Research Foundation [2015/19103-0]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP