Special Supplement: Ethical and Policy Issues in Rehabilitation Medicine

The field of medical rehabilitation is relatively new, a product in great part of the rapid developments in medical science during and after the Second World War. Until recently, the ethical problems of this new field were neglected. There seemed to be more pressing concerns as rehabilitation medicine struggled to establish itself, somtimes in the face of considerable skepticism or hostility. There also seemed no pressing moral questions of the kind and intensity to be encountered, say, in high technology acute care medicine or genetic engineering. With eyes focused on the dramatic and wrenching problems, those in biomedical ethics could and did easily overlook the quiet, less obtrusive, issues of rehabilitation

The Bioethics of Chronic Illness

There is a specter haunting the American health care system. It is the prospect of widespread chronic illness and disability in an aging society. With it comes a daunting challenge to our health care delivery system, social welfare services, families, and communities. And it presents an equally difficult challenge to millions of us as individuals. For prolonged, slowly debilitating chronic illnesses will most likely be our companions in the twilight of our lives. At present, it is unclear whether the American health care and social service systems are prepared to cope with the challenges, both financial and ethical, that chronic illness poses to our society. Innovative policy ideas are needed, as are continuing research, extended and better coordinated social senvice programs, and educational programs that will equip health care providers to meet the special needs of persons with chronic illnesses

Reducing Disparities by way of a Cancer Disparities Research Training Program

Background: For minority populations, there is a continuing disparity in the burden of death and illness from cancer. Research to address this disparity should be conducted by investigators who can best understand and address the needs of culturally diverse communities. However, minorities are under-represented in health-related research. The goal of this project was to develop and evaluate an approach to motivating and preparing master’s degree students for careers dedicated to cancer disparities research. Method: A Cancer Disparities Research Training Program (CDRTP) was initiated in 2010. The program consists of coursework, practicum experiences, and research opportunities. Assessment of the curriculum is based on monitoring achievement of evaluation indicators and includes a quantitative assessment and qualitative approach. Results: In its first three years, the program graduated 20 trainees, all of whom were minorities (18 African Americans and two Asians). When asked about career goals, two-thirds of the trainees indicated interest in pursuing careers in research on cancer prevention and control. The trainees expressed high satisfaction with the courses, instructor, materials, and curriculum. Although trainees had suggestions about course details, evaluations overall were positive. Across focus groups, three recurrent themes emerged regarding activities to enhance the student experience: having a wider variety of topics, more guest speakers, and field trips. Conclusion: The CDRTP was intended to recruit students – primarily African Americans – into research on prevention and control of cancer disparities. Although final evaluation of the program’s overall outcome will not be available for several years, a preliminary evaluation indicates the program is being successful

Current Concepts of Cerebrovascular Disease - Stroke: Stroke and Drug Abuse

This Review Summarizes Available Information Concerning Cerebral Vascular Complications of the Most Commonly Abused Substances and Discusses Possible Mechanisms of Vascular Injury and Cerebral Damage. Although Alcohol is Frequently Abused and May Have Important Cerebrovascular Effects, its Consideration is Beyond the Scope of This Review

Persistent delirium in older hospital patients: an updated systematic review and meta-analysis

Introduction: Delirium is associated with future dementia progression. Yet whether this occurs subclinically over months and years, or persistent delirium merges into worsened dementia is not understood. Our objective was to estimate the prevalence of persistent delirium and understand variation in its duration. Methods: We adopted an identical search strategy to a previous systematic review, only including studies using a recognised diagnostic framework for ascertaining delirium at follow-up (persistent delirium). Studies included hospitalised older patients outside critical and palliative care settings. We searched MEDLINE, EMBASE, PsycINFO and the Cochrane Database of Systematic Reviews on 11th January 2022. We applied risk of bias assessments based on Standards of Reporting of Neurological Disorders criteria and assessed strength of recommendations using the grading of recommendation, assessment, development and evaluation (GRADE) approach. Estimates were pooled across studies using random-effects meta-analysis, and we estimated associations with follow-up duration using robust error meta-regression. Results: We identified 13 new cohorts, which we added to 10 from the previous systematic review (23 relevant studies, with 39 reports of persistent delirium at 7 time-points in 3186 individuals admitted to hospital care (mean age 82 years and 41% dementia prevalence). Studies were mainly at moderate risk of bias. Pooled delirium prevalence estimates at discharge were 36% (95% CI 22% to 51%, 13 studies). Robust error meta-regression did not show variation in prevalence of persistent delirium over time (-1.6% per month, 95% CI -4.8 to 1.6, p=0.08). Margins estimates for this model indicate a prevalence of persistent delirium of 16% (95% CI 6% to 25%) at 12 months. Conclusions: This systematic review emphasises the importance of delirium as a persistent and extensive problem (GRADE certainty = moderate), raising questions on chronic delirium as a clinical entity and how it might evolve into dementia. Addressing persistent delirium will require a whole-system, integrated approach to detect, follow-up and implement opportunities for recovery across all healthcare settings

Cerebral Embolism in the Michael Reese Stroke Registry

Infarction Secondary to Cerebral Embolism Was Diagnosed in 127 (23.5%) of 540 Patients in the Michael Reese Stroke Registry. Coronary Artery Disease, Atrial Fibrillation, Valvular Heart Disease, Mitral Annulus Calcification, and Cardiomyopathy Were the Commonest Etiologies. Echocardiography Documented a Potential Embolic Source in 7 Patients Without Previously Known Heart Disease and Clarified the Cardiac Pathology in Many of the Patients with Known Heart Disease. the Left Anterior Circulation Was Affected in 48%, Right Anterior in 37%, and Posterior Circulation in 15% of patients. CT Was Abnormal in 71% of the Patients and Was Approximately Equally Helpful in All Locations. Nineteen Percent of Emboli Presented with a Deficit that Was Other Than Maximal at Onset. Concurrent Systemic Embolism Was Unusual (2.3%). Prognosis Was Somewhat Worse Than in Thrombotic Stroke. Grouping of Patients According to Embolic Source (Intra-Arterial, Cardiac, and Uncertain Source) Showed No Differences in Activity at Onset, Early Course, or in Subsequent Course of the Illness

Temperature Evolution of Nonreacting Spark Kernels at Sub-Atmospheric Pressures

In the event of a mid-flight flameout of a gas turbine engine, reignition is paramount to occupant safety. Ignition at high altitude can be challenging, due in part to the potentially lower ambient pressures. An understanding of the effects of sub-atmospheric pressures on the temperature evolution of spark kernels is needed to better understand the ignition process at high altitudes. Ultimately such information can be used to maximize ignition probability at high altitudes. The objective of this work was to determine the effects of decreasing pressure on the spatial and temperature evolution of spark kernels. Spark kernels were produced inside a vacuum chamber using a sunken fire igniter. An infrared camera was used to collect radiation intensity measurements from the spark kernels. An inverse deconvolution technique was employed to determine path-averaged temperatures from the radiation measurements. The technique determined temperatures using a narrow-band radiation emissions model (RADCAL). Temperatures determined using the technique agreed within 3% to temperature measurements using a thermocouple over a flat flame calibration burner. Spark kernel temperatures were determined in quiescent air at absolute pressures from 300 to 1000 mbar. Kernel temperatures were measured from 0.67 to 4 ms after plasma was detected. Decreasing the ambient pressure caused an increase in average kernel temperature, and conversely a decrease in peak temperatures. For example, average kernel temperatures after 0.67 ms were 1270 K at 300 mbar, and 1125 K at 1000 mbar. Peak temperatures (i.e. the 90th percentile temperatures) were 2070 and 2360 K at 380 and 1000 mbar, respectively. Peak temperatures were hottest in a small region 0.6 igniter diameters from the igniter tip. Kernel temperatures decreased until the kernels became undetectable after 4 ms. Electrical energy deposition and conversion efficiency to sensible energy decreased with decreasing pressure. For example, energy deposition decreased from 1.02 J at 1000 mbar to 0.85 J at 300 mbar, while conversion efficiency decreased from 80% to 30% at the same pressures. This pressure dependence of energy deposition and conversion efficiency is attributed to increased heat loss to the electrodes at decreased pressures due to lower breakdown voltage of air causing higher electrical current through the electrodes. The decrease in energy deposition and efficiency at lower pressure helps explain part of the challenge with achieving ignition at high altitude. Kernel volume was independent of pressure. Kernels formed into a toroidal shape with an apparent volume of approximately 2.1 cubic igniter diameters (i.e., 3.7 cm3) after 0.67 ms. The apparent kernel volume decreased approximately linearly over the kernels’ lifetimes. Kernels penetrated faster and further from the igniter at lower pressures. For example, radiation from kernels at 1000 mbar was detected as far as 3 igniter diameters from the igniter tip, while at 300 mbar kernels were detected at least 3.4 diameters from the igniter tip. This observation is significant because the fuel-air mixture within combustors is not homogenous, hence the placement of the spark kernel within the flow is an important design consideration. The increased speed and penetration depth at lower pressure is attributed to an increased ratio of energy deposition to kernel mass due to the decreased gas density at lower pressure. The energy to mass ratio also explains the relationship between pressure and average kernel temperature

Decadal-scale shifts in soil hydraulic properties as induced by altered precipitation

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.Soil hydraulic properties influence the partitioning of rainfall into infiltration versus runoff, determine plant-available water, and constrain evapotranspiration. Although rapid changes in soil hydraulic properties from direct human disturbance are well documented, climate change may also induce such shifts on decadal time scales. Using soils from a 25-year precipitation manipulation experiment, we found that a 35% increase in water inputs substantially reduced infiltration rates and modestly increased water retention. We posit that these shifts were catalyzed by greater pore blockage by plant roots and reduced shrink-swell cycles. Given that precipitation regimes are expected to change at accelerating rates globally, shifts in soil structure could occur over broad regions more rapidly than expected and thus alter water storage and movement in numerous terrestrial ecosystems

ROSAT and ASCA observations of the Crab-Like Supernova Remnant N157B in the Large Magellanic Cloud

We report the results of ROSAT and ASCA X-ray observations of the supernova remnant N157B (or 30 Dor B, SNR 0539-69.1) in the Large Magellanic Cloud. For comparison, we also briefly describe the results on SNR 0540-69.3, the only confirmed Crab-like remnant in the Cloud. The X-ray emission from N157B can be decomposed into a bright comet-shaped feature, superimposed on a diffuse emission region of a dimension $\sim 20$ pc. The flat and nearly featureless spectrum of the remnant is distinctly different from those of young shell-like remnants, suggesting a predominantly Crab-like nature of N157B. Characterized by a power law with an energy slope $\sim 1.5$, the spectrum of N157B above $\sim 2$ keV is, however, considerably steeper than that of SNR 0540-69.3, which has a slope of $\sim 1.0$. At lower energies, the spectrum of N157B presents marginal evidence for emission lines, which if real most likely arise in hot gas of the diffuse emission region. The hot gas has a characteristic thermal temperature of 0.4-0.7 keV. No significant periodic signal is detected from N157B in the period range of $3 \times 10^{-3}-2000$ s. The pulsed fraction is $\lesssim 9$ (99% confidence) in the $2-7$ keV range. We discuss the nature of the individual X-ray components. In particular, we suggest that the synchrotron radiation of relativistic particles from a fast-moving ($\sim 10^3 km s^{-1}$) pulsar explains the size, morphology, spectrum, and energetics of the comet-shaped X-ray feature. We infer the age of the remnant as $\sim 5 \times 10^3$ yrs. The lack of radio polarization of the remnant may be due to Faraday dispersion by foreground \ion{H}{2} gas.Comment: To be published in The Astrophysical Journal, 21 pages, plus 11 images in the PS, GIF, or jpeg format. Postscript files of images are available at http://www.astro.nwu.edu/astro/wqd/paper/n157b

Chloride channels regulate differentiation and barrier functions of the mammalian airway.

The conducting airway forms a protective mucosal barrier and is the primary target of airway disorders. The molecular events required for the formation and function of the airway mucosal barrier, as well as the mechanisms by which barrier dysfunction leads to early onset airway diseases, remain unclear. In this study, we systematically characterized the developmental landscape of the mouse airway using single-cell RNA sequencing and identified remarkably conserved cellular programs operating during human fetal development. We demonstrated that in mouse, genetic inactivation of chloride channel Ano1/Tmem16a compromises airway barrier function, results in early signs of inflammation, and alters the airway cellular landscape by depleting epithelial progenitors. Mouse Ano1-/-mutants exhibited mucus obstruction and abnormal mucociliary clearance that resemble the airway defects associated with cystic fibrosis. The data reveal critical and non-redundant roles for Ano1 in organogenesis, and show that chloride channels are essential for mammalian airway formation and function