From Gondwanaland, with love : the tale of how Boston got its rocks

Thesis (S.M. in Science Writing)--Massachusetts Institute of Technology, Dept. of Humanities, Graduate Program in Science Writing, 2006.Includes bibliographical references (leaves 26-27).The rocks on which the city of Boston was built did not form as part of North America. They formed about 600 million years ago, at the South Pole, as the northern coast of a supercontinent called Gondwanaland. Boston's journey from the South Pole to its current location traces the world's geologic history over that period of time, including the emergence of animal life as we know it, the formation and destruction of Pangaea, and the rise and fall of the dinosaurs. More than that, though: the history of our understanding of Boston's journey illustrates how geologists think about their world, and how their ideas have changed over the last 150 years in one of science's great revolutions.by Selby Cull.S.M.in Science Writin

Role of chloride in hot salt stress-corrosion cracking of titanium-aluminum alloys

Role of chloride in hot salt stress corrosion cracking of titanium-aluminum alloy

Stress corrosion cracking of titanium alloys progress report, apr. 1 - jun. 30, 1964

Hot salt stress corrosion cracking in titanium alloys - chloride corrosion role determination using chlorine isotopes and relation between crack morphology and alloy structur

The Effect of Cigarette Smoking on Diabetic Peripheral Neuropathy: A Systematic Review and Meta-Analysis.

OBJECTIVE: Studies suggest that smoking may be a risk factor for the development of microvascular complications such as diabetic peripheral neuropathy (DPN). The objective of this study was to assess the relationship between smoking and DPN in persons with type 1 or type 2 diabetes. RESEARCH DESIGN AND METHODS: A systematic review of the PubMed, Embase, and Cochrane clinical trials databases was conducted for the period from January 1966 to November 2014 for cohort, cross-sectional and case-control studies that assessed the relationship between smoking and DPN. Separate meta-analyses for prospective cohort studies and case-control or cross-sectional studies were performed using random effects models. RESULTS: Thirty-eight studies (10 prospective cohort and 28 cross-sectional) were included. The prospective cohort studies included 5558 participants without DPN at baseline. During follow-up ranging from 2 to 10 years, 1550 cases of DPN occurred. The pooled unadjusted odds ratio (OR) of developing DPN associated with smoking was 1.26 (95% CI 0.86-1.85; I(2) = 74%; evidence grade: low strength). Stratified analyses of the prospective studies revealed that studies of higher quality and with better levels of adjustment and longer follow-up showed a significant positive association between smoking and DPN, with less heterogeneity. The cross-sectional studies included 27,594 participants. The pooled OR of DPN associated with smoking was 1.42 (95% CI 1.21-1.65; I(2) = 65%; evidence grade: low strength). There was no evidence of publication bias. CONCLUSIONS: Smoking may be associated with an increased risk of DPN in persons with diabetes. Further studies are needed to test whether this association is causal and whether smoking cessation reduces the risk of DPN in adults with diabetes

Next generation software environments : principles, problems, and research directions

The past decade has seen a burgeoning of research and development in software environments. Conferences have been devoted to the topic of practical environments, journal papers produced, and commercial systems sold. Given all the activity, one might expect a great deal of consensus on issues, approaches, and techniques. This is not the case, however. Indeed, the term "environment" is still used in a variety of conflicting ways. Nevertheless substantial progress has been made and we are at least nearing consensus on many critical issues.The purpose of this paper is to characterize environments, describe several important principles that have emerged in the last decade or so, note current open problems, and describe some approaches to these problems, with particular emphasis on the activities of one large-scale research program, the Arcadia project. Consideration is also given to two related topics: empirical evaluation and technology transition. That is, how can environments and their constituents be evaluated, and how can new developments be moved effectively into the production sector

Simple and objective prediction of survival in patients with lung cancer: staging the host systemic inflammatory response

Background. Prediction of survival in patients diagnosed with lung cancer remains problematical. The aim of the present study was to examine the clinical utility of an established objective marker of the systemic inflammatory response, the Glasgow Prognostic Score, as the basis of risk stratification in patients with lung cancer. Methods. Between 2005 and 2008 all newly diagnosed lung cancer patients coming through the multidisciplinary meetings (MDTs) of four Scottish centres were included in the study. The details of 882 patients with a confirmed new diagnosis of any subtype or stage of lung cancer were collected prospectively. Results. The median survival was 5.6 months (IQR 4.8–6.5). Survival analysis was undertaken in three separate groups based on mGPS score. In the mGPS 0 group the most highly predictive factors were performance status, weight loss, stage of NSCLC, and palliative treatment offered. In the mGPS 1 group performance status, stage of NSCLC, and radical treatment offered were significant. In the mGPS 2 group only performance status and weight loss were statistically significant. Discussion. This present study confirms previous work supporting the use of mGPS in predicting cancer survival; however, it goes further by showing how it might be used to provide more objective risk stratification in patients diagnosed with lung cancer

Training primary care physicians to offer their patients faecal occult blood testing and colonoscopy for colorectal cancer screening on an equal basis: a pilot intervention with before-after and parallel group surveys.

Primary care physicians (PCPs) should prescribe faecal immunochemical testing (FIT) or colonoscopy for colorectal cancer screening based on their patient's values and preferences. However, there are wide variations between PCPs in the screening method prescribed. The objective was to assess the impact of an educational intervention on PCPs' intent to offer FIT or colonoscopy on an equal basis. Survey before and after training seminars, with a parallel comparison through a mailed survey to PCPs not attending the training seminars. All PCPs in the canton of Vaud, Switzerland. Of 592 eligible PCPs, 133 (22%) attended a seminar and 106 (80%) filled both surveys. 109 (24%) PCPs who did not attend the seminars returned the mailed survey. A 2 h-long interactive seminar targeting PCP knowledge, skills and attitudes regarding offering a choice of colorectal cancer (CRC) screening options. The primary outcome was PCP intention of having their patients screened with FIT and colonoscopy in equal proportions (between 40% and 60% each). Secondary outcomes were the perceived role of PCPs in screening decisions (from paternalistic to informed decision-making) and correct answer to a clinical vignette. Before the seminars, 8% of PCPs reported that they had equal proportions of their patients screened for CRC by FIT and colonoscopy; after the seminar, 33% foresaw having their patients screened in equal proportions (p<0.001). Among those not attending, there was no change (13% vs 14%, p=0.8). Of those attending, there was no change in their perceived role in screening decisions, while the proportion responding correctly to a clinical vignette increased (88-99%, p<0.001). An interactive training seminar increased the proportion of physicians with the intention to prescribe FIT and colonoscopy in equal proportions

How do Swiss general practitioners agree with and report adhering to a top-five list of unnecessary tests and treatments? Results of a cross-sectional survey.

In 2014, the 'Smarter Medicine' campaign released a top five list of unnecessary tests and treatments in Swiss primary care, such as imaging for acute low-back pain and long-term prescribing of proton pump inhibitors. Measure general practitioners' (GPs) agreement with the recommendations and self-reported adherence. Cross-sectional, online survey of GPs in the 'Swiss primary care active monitoring' (SPAM) network, which assessed awareness of 'Smarter Medicine' and views on each recommendation. Questions included whether the clinical situation is common, whether the recommendation is followed, whether GPs agree with the recommendation and reasons why the recommendation would not be followed. One-hundred-and-sixty-seven of 277 GPs from the SPAM network participated (60%), of which 104 (62%) knew of 'Smarter Medicine', including 79% in German areas, 49% in French areas and 38% in Italian areas (P < 0.001). Agreement with the five recommendations was high, with scores around nine out of 10. The proportion saying they typically follow each recommendation was 68 to 74%, except not continuing long-term PPI prescriptions without attempting dose reduction, with only 34%. Common reasons for not following the recommendations were patient or other provider requests and situations that might suggest the need for more aggressive care. Two years after the launch of the campaign, awareness and acceptance of 'Smarter Medicine' appear to be high among Swiss GPs. By self-report, the recommendations are adhered to by most of the respondents but there may be room for improvement, especially for long-term PPI prescriptions

Friction of the surface plasmon by high-energy particle-hole pairs: Are memory effects important?

We show that the dynamics of the surface plasmon in metallic nanoparticles damped by its interaction with particle-hole excitations can be modelled by a single degree of freedom coupled to an environment. In this approach, the fast decrease of the dipole matrix elements that couple the plasmon to particle-hole pairs with the energy of the excitation allows a separation of the Hilbert space into low- and high-energy subspaces at a characteristic energy that we estimate. A picture of the spectrum consisting of a collective excitation built from low-energy excitations which interacts with high-energy particle-hole states can be formalised. The high-energy excitations yield an approximate description of a dissipative environment (or "bath") within a finite confined system. Estimates for the relevant timescales establish the Markovian character of the bath dynamics with respect to the surface plasmon evolution for nanoparticles with a radius larger than about 1 nm.Comment: 8 pages, 1 figure; see also cond-mat/070372