Fractional Dehn twists in knot theory and contact topology

Fractional Dehn twists give a measure of the difference between the relative isotopy class of a homeomorphism of a bordered surface and the Thurston representative of its free isotopy class. We show how to estimate and compute these invariants. We discuss the the relationship of our work to stabilization problems in classical knot theory, general open book decompositions, and contact topology. We include an elementary characterization of overtwistedness for contact structures described by open book decompositions.Comment: We have removed an incorrect assumption about properties of meridional disks of Heegaard decompositions of S^3 and have added a conjecture about stabilizations of knots in S^

Crystallographic Investigations of Biotin and Carboxybiotin Derivatives a

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73473/1/j.1749-6632.1985.tb18435.x.pd

Cross support overview and operations concept for future space missions

Ground networks must respond to the requirements of future missions, which include smaller sizes, tighter budgets, increased numbers, and shorter development schedules. The Consultative Committee for Space Data Systems (CCSDS) is meeting these challenges by developing a general cross support concept, reference model, and service specifications for Space Link Extension services for space missions involving cross support among Space Agencies. This paper identifies and bounds the problem, describes the need to extend Space Link services, gives an overview of the operations concept, and introduces complimentary CCSDS work on standardizing Space Link Extension services

Code wars: steganography, signals intelligence, and terrorism

This paper describes and discusses the process of secret communication known as steganography. The argument advanced here is that terrorists are unlikely to be employing digital steganography to facilitate secret intra-group communication as has been claimed. This is because terrorist use of digital steganography is both technically and operationally implausible. The position adopted in this paper is that terrorists are likely to employ low-tech steganography such as semagrams and null ciphers instead

Genetic factors are important determinants of impaired growth after infant cardiac surgery

ObjectivesWe sought to estimate the prevalence and identify the predictors of impaired growth after infant cardiac surgery.MethodsWe performed a secondary analysis of a prospective study of the role of apolipoprotein E gene polymorphisms on neurodevelopment in young children after infant cardiac surgery. Prevalence estimates for growth velocity were derived by using anthropometric measures (weight and head circumference) obtained at birth and at 4 years of age. Genetic evaluation was also performed. Growth measure z scores were calculated by using World Health Organization Child Growth Standards. Growth velocity was evaluated by using 2 different techniques: first by clustering the children into one of 3 growth velocity subgroups based on z scores (impaired growth, difference < −0.5 standard deviation; stable growth, difference of −0.5 to 0.5 standard deviation; and improving growth, difference > 0.5 SD) and second by using continuous difference scores. Statistical analyses were conducted with a combination of proportional odds models for the ordered categories and simple linear regression for the continuous outcomes.ResultsThree hundred nineteen full-term subjects had complete anthropometric measures for weight and head circumference at birth and 4 years. The cohort was 56% male. Genetic examinations were available for 97% (309/319) of the cohort (normal, 74%; definite or suspected genetic abnormality, 26%). Frequency counts for weight categories were as follows: impaired growth, 37%; stable growth, 31%; and improving growth, 32%. Frequency counts for head circumference categories were as follows: impaired growth, 39%; stable growth, 28%; and improving growth, 33%. The presence of a definite or suspected genetic syndrome (P = .04) was found to be a predictor of impaired growth for weight but not for head circumference. When growth z scores were used as continuous outcomes, the apolipoprotein E ε2 allele was found to be predictive of lower z scores for both weight (P = .02) and head circumference (P = .03).ConclusionsImpaired growth for both weight and head circumference is common (both >30%) in this cohort of children after infant cardiac surgery. Both the apolipoprotein E ε2 allele and the presence of a definite or suspected genetic syndrome were associated with impaired weight growth velocity. The apolipoprotein E ε2 allele was also associated with impaired growth velocity for head circumference. Persistent poor growth might have long-term implications for the health and development of children with congenital heart defects

Milestones: a Rapid Assessment Method for the Clinical Competency Committee

INTRODUCTION: Educational milestones are now used to assess the developmental progress of all U.S. graduate medical residents during training. Twice annually, each program\u27s Clinical Competency Committee (CCC) makes these determinations and reports its findings to the Accreditation Council for Graduate Medical Education (ACGME). The ideal way to conduct the CCC is not known. After finding that deliberations reliant upon the new milestones were time intensive, our internal medicine residency program tested an approach designed to produce rapid but accurate assessments. MATERIAL AND METHODS: For this study, we modified our usual CCC process to include pre-meeting faculty ratings of resident milestones progress with in-meeting reconciliation of their ratings. Data were considered largely via standard report and presented in a pre-arranged pattern. Participants were surveyed regarding their perceptions of data management strategies and use of milestones. Reliability of competence assessments was estimated by comparing pre-/post-intervention class rank lists produced by individual committee members with a master class rank list produced by the collective CCC after full deliberation. RESULTS: Use of the study CCC approach reduced committee deliberation time from 25 min to 9 min per resident (p \u3c 0.001). Committee members believed milestones improved their ability to identify and assess expected elements of competency development (p = 0.026). Individual committee member assessments of trainee progress agreed well with collective CCC assessments. CONCLUSIONS: Modification of the clinical competency process to include pre-meeting competence ratings with in-meeting reconciliation of these ratings led to shorter deliberation times, improved evaluator satisfaction and resulted in reliable milestone assessments

An Economic Framework for Evaluating Personalized Medicine

Individual variation accounts for a wide range of medical and economic consequences, from inefficiencies in drug discovery and development to ineffectiveness of drug treatment to drug-induced morbidity and mortality. Addressing these consequences could benefit patients, health care providers and payers, and the pharmaceutical industry. When appropriate markers are known, diagnostic tests allow precise diagnosis and dosing, prediction of disease progression, prediction of treatment response and prediction of adverse drug reactions for individual patients. There may also be substantial savings realized by eliminating costs associated with failed treatment. We developed an analytical framework for analyzing the potential value of using a diagnostic test in clinical practice. Our framework determines the economic consequences of implementing pharmacogenomics in the clinic using a diagnostic test to predict drug response. We offer an empirical test of these ideas: we calculated the cost offset realized by predicting the likelihood of response to an alternative existing treatment using a hypothetical pharmacogenomic test in an asthma population. Because the diagnostic test is hypothetical, our framework is general and could be applied to other indications where diagnostic tests have not been developed. Our results could potentially guide future economic evaluation of new diagnostic tests. Importantly, they may also influence biomarker discovery strategies to ensure consistency between market priorities and the future stream of product introductions

Crystal and molecular structure of analgesics. II. Dezocine hydrobromide

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44834/1/10870_2005_Article_BF01200881.pd