Stereoscopic Photography of Shear Flow Turbulence

The last several years have seen numerous advances in the understanding of the coherent motions that exist in turbulent shear flows. These studies have provided the underlying basis of most of the experimental investigations of coherent motions using conditional sampling, quadrant splitting, pattern recognition, etc. Lacking, however, in the visual work is a true three- dimensional view of the processes, which are known to be three-dimensional in nature. Possible means of providing information about the third dimension are reviewed. Details of an evaluation of a stereoscopic-photographic, high-speed motion picture system are given. The system utilizes the boundary layer flow channel previously developed in our work by Nychas, Hershey and Brodkey (J. Fluid Mech. (1973) 6l, 513)

An Experimental Facility for the Visual Study of Turbulent Flows

An experimental technique which allows visual observations of the wall area in turbulent pipe flow is described in detail. It requires neither the introduction of any injection or measuring device into the flow nor the presence of a two-phase flow or of a non-Newtonian fluid. The technique involves suspending solid MgO particles of colloidal size in trichloroethylene and photographing their motions near the wall with a high speed movie camera moving with the flow. Trichloroethylene was chosen in order to eliminate the index of refraction problem in a curved wall. Evaluation of the technique including a discussion of limitations is included. Also the technique is compared with previous methods of visual observations of turbulent flow

Defining and measuring gender: A social determinant of health whose time has come

This paper contributes to a nascent scholarly discussion of sex and gender as determinants of health. Health is a composite of biological makeup and socioeconomic circumstances. Differences in health and illness patterns of men and women are attributable both to sex, or biology, and to gender, that is, social factors such as powerlessness, access to resources, and constrained roles. Using examples such as the greater life expectancy of women in most of the world, despite their relative social disadvantage, and the disproportionate risk of myocardial infarction amongst men, but death from MI amongst women, the independent and combined associations of sex and gender on health are explored. A model for incorporating gender into epidemiologic analyses is proposed

Educating Health Professionals about Drug and Device Promotion: Advocates' Recommendations

Mansfield and colleagues outline the recommendations from four advocacy groups for improving the education of health professionals on promotion of drugs and devices

Early versus Delayed Decompression for Traumatic Cervical Spinal Cord Injury: Results of the Surgical Timing in Acute Spinal Cord Injury Study (STASCIS)

BACKGROUND:There is convincing preclinical evidence that early decompression in the setting of spinal cord injury (SCI) improves neurologic outcomes. However, the effect of early surgical decompression in patients with acute SCI remains uncertain. Our objective was to evaluate the relative effectiveness of early (<24 hours after injury) versus late (≥ 24 hours after injury) decompressive surgery after traumatic cervical SCI. METHODS:We performed a multicenter, international, prospective cohort study (Surgical Timing In Acute Spinal Cord Injury Study: STASCIS) in adults aged 16-80 with cervical SCI. Enrolment occurred between 2002 and 2009 at 6 North American centers. The primary outcome was ordinal change in ASIA Impairment Scale (AIS) grade at 6 months follow-up. Secondary outcomes included assessments of complications rates and mortality. FINDINGS:A total of 313 patients with acute cervical SCI were enrolled. Of these, 182 underwent early surgery, at a mean of 14.2(± 5.4) hours, with the remaining 131 having late surgery, at a mean of 48.3(± 29.3) hours. Of the 222 patients with follow-up available at 6 months post injury, 19.8% of patients undergoing early surgery showed a ≥ 2 grade improvement in AIS compared to 8.8% in the late decompression group (OR = 2.57, 95% CI:1.11,5.97). In the multivariate analysis, adjusted for preoperative neurological status and steroid administration, the odds of at least a 2 grade AIS improvement were 2.8 times higher amongst those who underwent early surgery as compared to those who underwent late surgery (OR = 2.83, 95% CI:1.10,7.28). During the 30 day post injury period, there was 1 mortality in both of the surgical groups. Complications occurred in 24.2% of early surgery patients and 30.5% of late surgery patients (p = 0.21). CONCLUSION:Decompression prior to 24 hours after SCI can be performed safely and is associated with improved neurologic outcome, defined as at least a 2 grade AIS improvement at 6 months follow-up

Christopher Hitchens' Public dying: Toward a Secular-Humanist Ars Moriendi?

This article explores the public dying of journalist, writer, provocateur, public intellectual, and renowned atheist, Christopher Hitchens. It does so primarily through an analysis of television interviews given by Hitchens following his diagnosis with esophageal cancer in June 2010. Four key themes are identified as emerging from analysis of the interviews: (a) Hitchens’ explicit sense of mission in challenging myths and superstitions surrounding cancer, dying, and death; (b) the personal experience of terminal illness and dying and the particular way (or style of dying) by which it is approached; (c) issues of regret and a life well lived; and (d) questions surrounding religion, the afterlife, and possibility of deathbed conversion. In light of the claim that ours is a culture in search of an ars moriendi, the article examines what we can learn from Hitchens’ auto/pathographic interviews (and writings) and the extent to which this rational-humanist, atheistic, and stoical style of dying provides a useable “template” for others nearing the end of life