Computational methods for higher real K-theory with applications to tmf

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2006.Includes bibliographical references (p. 67-69).We begin by present a new Hopf algebra which can be used to compute the tmf homology of a space or spectrum at the prime 3. Generalizing work of Mahowald and Davis, we use this Hopf algebra to compute the tmf homology of the classifying space of the symmetric group on three elements. We also discuss the E3 Tate spectrum of tmf at the prime 3. We then build on work of Hopkins and his collaborators, first computing the Adams-Novikov zero line of the homotopy of the spectrum eo4 at 5 and then generalizing the Hopf algebra for tmf to a family of Hopf algebras, one for each spectrum eop_l at p. Using these, and using a K(p - 1)-local version, we further generalize the Davis-Mahowald result, computing the eop_1 homology of the cofiber of the transfer map [...]. We conclude by computing the initial computations needed to understand the homotopy groups of the Hopkins-Miller real K-theory spectra for heights large than p- 1 at p. The basic computations are supplemented with conjectures as to the collapse of the spectral sequences used herein to compute the homotopy.by Michael Anthony Hill.Ph.D

Evidence of widespread selection on standing variation in Europe at height-associated SNPs.

Strong signatures of positive selection at newly arising genetic variants are well documented in humans(1-8), but this form of selection may not be widespread in recent human evolution(9). Because many human traits are highly polygenic and partly determined by common, ancient genetic variation, an alternative model for rapid genetic adaptation has been proposed: weak selection acting on many pre-existing (standing) genetic variants, or polygenic adaptation(10-12). By studying height, a classic polygenic trait, we demonstrate the first human signature of widespread selection on standing variation. We show that frequencies of alleles associated with increased height, both at known loci and genome wide, are systematically elevated in Northern Europeans compared with Southern Europeans (P < 4.3 × 10(-4)). This pattern mirrors intra-European height differences and is not confounded by ancestry or other ascertainment biases. The systematic frequency differences are consistent with the presence of widespread weak selection (selection coefficients ∼10(-3)-10(-5) per allele) rather than genetic drift alone (P < 10(-15))

Managing for change: October 11, 1989

Bi-weekly newsletter of University Hospital's Change Project, provided to managers at the hospital

Run, Jump, Throw and Catch: How proficient are children attending English schools at the Fundamental Motor Skills identified as key within the school curriculum?

This study examined proficiency levels in fundamental motor skills (FMS) in children within Key Stage 1 and 2 of the English school system. Four hundred and ninety-two children aged 6–9 Years old (245 boys, 247 girls) from school Years Two (n = 130), Three (n = 154) and Four (n = 208) participated in this study. FMS for the run, jump, throw and catch were assessed using the Test of Gross Motor Development – 2. The proportion of children who achieved mastery or near mastery of the skills was determined. For the whole sample, 18.5% (n = 91) did not achieve mastery in any of the four skills. A similar proportion (18.7%, n = 92) achieved mastery in all four of the FMS examined in this study. The proportion of children achieving mastery of all four skills was lower for Year Two children (0%) compared to children in years Three (24%) and Four (25%). More boys (25.7%) achieved mastery in all four of the FMS compared to girls (11.7%). Individual behavioural components in skill performance were also examined. The results of the present study highlight that less than one-fifth of children aged 6–9 years old have mastered the four key FMS identified by the physical education (PE) curriculum despite having the developmental potential to become fundamentally competent by six years of age. Fostering positive trajectories of FMS development presents a challenge for PE specialists given the association between FMS mastery in childhood and physical activity, weight status and health.N/

Changes in undergraduate student alcohol consumption as they progress through university

BACKGROUND: Unhealthy alcohol use amongst university students is a major public health concern. Although previous studies suggest a raised level of consumption amongst the UK student population there is little consistent information available about the pattern of alcohol consumption as they progress through university. The aim of the current research was to describe drinking patterns of UK full-time undergraduate students as they progress through their degree course. METHOD: Data were collected over three years from 5895 undergraduate students who began their studies in either 2000 or 2001. Longitudinal data (i.e. Years 1–3) were available from 225 students. The remaining 5670 students all responded to at least one of the three surveys (Year 1 n = 2843; Year 2 n = 2219; Year 3 n = 1805). Results: Students reported consuming significantly more units of alcohol per week at Year 1 than at Years 2 or 3 of their degree. Male students reported a higher consumption of units of alcohol than their female peers. When alcohol intake was classified using the Royal College of Physicians guidelines [1] there was no difference between male and females students in terms of the percentage exceeding recommended limits. Compared to those who were low level consumers students who reported drinking above low levels at Year 1 had at least 10 times the odds of continuing to consume above low levels at year 3. Students who reported higher levels of drinking were more likely to report that alcohol had a negative impact on their studies, finances and physical health. Consistent with the reduction in units over time students reported lower levels of negative impact during Year 3 when compared to Year 1. CONCLUSION: The current findings suggest that student alcohol consumption declines over their undergraduate studies; however weekly levels of consumption at Year 3 remain high for a substantial number of students. The persistence of high levels of consumption in a large population of students suggests the need for effective preventative and treatment interventions for all year groups

Standards Competition In The Presence Of Digital Conversion Technology:An Empirical Analysis Of The Flash Memory Card Market

Both theoretical and empirical evidence suggest that in markets with standards competition, strong network effects can make the strong grow stronger and, in some circumstances, even 'tip' the market towards a single, winner-take-all standard. We theorize that in the presence of low cost conversion technologies and digital content, the tendency towards market dominance can be lessened to the point where multiple incompatible standards are viable. Our hypotheses are empirically examined in the context of the flash memory card market where both network effects and high quality conversion are present. The results show that the availability of digital converters reduces the price premium of the leading flash card formats more than of the minority formats. Therefore, producers of the non-dominant standards can be better off with the provision of conversion technology as this technology neutralizes the impact of network effects that would have otherwise been more potent. We discuss both the social and private implications of our findings

Life-Expectancy Disparities Among Adults With HIV in the United States and Canada: The Impact of a Reduction in Drug- and Alcohol-Related Deaths Using the Lives Saved Simulation Model.

Improvements in life expectancy among people living with human immunodeficiency virus (PLWH) receiving antiretroviral treatment in the United States and Canada might differ among key populations. Given the difference in substance use among key populations and the current opioid epidemic, drug- and alcohol-related deaths might be contributing to the disparities in life expectancy. We sought to estimate life expectancy at age 20 years in key populations (and their comparison groups) in 3 time periods (2004-2007, 2008-2011, and 2012-2015) and the potential increase in expected life expectancy with a simulated 20% reduction in drug- and alcohol-related deaths using the novel Lives Saved Simulation model. Among 92,289 PLWH, life expectancy increased in all key populations and comparison groups from 2004-2007 to 2012-2015. Disparities in survival of approximately a decade persisted among black versus white men who have sex with men and people with (vs. without) a history of injection drug use. A 20% reduction in drug- and alcohol-related mortality would have the greatest life-expectancy benefit for black men who have sex with men, white women, and people with a history of injection drug use. Our findings suggest that preventing drug- and alcohol-related deaths among PLWH could narrow disparities in life expectancy among some key populations, but other causes of death must be addressed to further narrow the disparities

Inhaled PGE1 in neonates with hypoxemic respiratory failure: two pilot feasibility randomized clinical trials.

BackgroundInhaled nitric oxide (INO), a selective pulmonary vasodilator, has revolutionized the treatment of neonatal hypoxemic respiratory failure (NHRF). However, there is lack of sustained improvement in 30 to 46% of infants. Aerosolized prostaglandins I2 (PGI2) and E1 (PGE1) have been reported to be effective selective pulmonary vasodilators. The objective of this study was to evaluate the feasibility of a randomized controlled trial (RCT) of inhaled PGE1 (IPGE1) in NHRF.MethodsTwo pilot multicenter phase II RCTs are included in this report. In the first pilot, late preterm and term neonates with NHRF, who had an oxygenation index (OI) of ≥15 and <25 on two arterial blood gases and had not previously received INO, were randomly assigned to receive two doses of IPGE1 (300 and 150 ng/kg/min) or placebo. The primary outcome was the enrollment of 50 infants in six to nine months at 10 sites. The first pilot was halted after four months for failure to enroll a single infant. The most common cause for non-enrollment was prior initiation of INO. In a re-designed second pilot, co-administration of IPGE1 and INO was permitted. Infants with suboptimal response to INO received either aerosolized saline or IPGE1 at a low (150 ng/kg/min) or high dose (300 ng/kg/min) for a maximum duration of 72 hours. The primary outcome was the recruitment of an adequate number of patients (n = 50) in a nine-month-period, with fewer than 20% protocol violations.ResultsNo infants were enrolled in the first pilot. Seven patients were enrolled in the second pilot; three in the control, two in the low-dose IPGE1, and two in the high-dose IPGE1 groups. The study was halted for recruitment futility after approximately six months as enrollment targets were not met. No serious adverse events, one minor protocol deviation and one pharmacy protocol violation were reported.ConclusionsThese two pilot RCTs failed to recruit adequate eligible newborns with NHRF. Complex management RCTs of novel therapies for persistent pulmonary hypertension of the newborn (PPHN) may require novel study designs and a longer period of time from study approval to commencement of enrollment.Trial registrationCLINICALTRIALS.GOV: Pilot one: NCT number: 00598429 registered on 10 January 2008. Last updated: 3 February 2011. Pilot two: NCT number: 01467076 17 October 2011. Last updated: 13 February 2013