823 research outputs found

    Nuclear Weapons Free Zones: Time for a Fresh Look

    Get PDF

    Energy Independence and Climate Change: The Economic and National Security Consequences of Failing to Act

    Get PDF
    This article draws heavily from the works of the CNA MAB, namely the twin and interrelated challenges arising from imprudent reliance on fossil fuels by developed and developing countries, as well as the serious environmental and national security externalities that directly result from current consumptive trends

    An EUV Study of the Intermediate Polar EX Hydrae

    Full text link
    On 2000 May 5, we began a large multi-wavelength campaign to study the intermediate polar, EX Hydrae. The simultaneous observations from six satellites and four telescopes were centered around a one million second observation with EUVE. Although EX Hydrae has been studied previously with EUVE, our higher signal-to-noise observations present new results and challenge the current IP models. Previously unseen dips in the light curve are reminiscent of the stream dips seen in polar light curves. Also of interest is the temporal extent of the bulge dip; approximately 0.5 in phase, implying that the bulge extends over half of the accretion disk. We propose that the magnetic field in EX Hydrae is strong enough (a few MG) to begin pulling material directly from the outer edge of the disk, thereby forming a large accretion curtain which would produce a very broad bulge dip. This would also result in magnetically controlled accretion streams originating from the outer edge of the disk. We also present a period analysis of the photometric data which shows numerous beat frequencies with strong power and also intermittent and wandering frequencies, an indication that physical conditions within EX Hya changed over the course of the observation. Iron spectral line ratios give a temperature of log T=6.5-6.9 K for all spin phases and a poorly constrained density of n_e=10^10-10^11 cm^-3 for the emitting plasma. This paper is the first in a series detailing our results from this multi-wavelength observational campaign.Comment: 27 pages, 7 figures, accepted for publication in Ap

    Transient advanced mental impairment: An underappreciated morbidity after aortic surgery

    Get PDF
    AbstractObjectives: To determine the incidence, risk factors, and associated morbidity of transient advanced mental impairment (TAMI) after aortic surgery. Methods: We retrospectively studied the charts of 188 consecutive patients undergoing elective aortic reconstruction during a recent 6-year period at a university hospital. All patients were lucid on admission and nonintubated at the time of evaluation at least 2 days after operation. TAMI was defined as disorientation or confusion on 2 or more postoperative days. Preoperative, intraoperative, and postoperative clinical variables were examined statistically for associations with TAMI. Results: Fifty-three patients (28%) had development of TAMI 3.9 ± 2.8 days after operation. Stepwise logistic regression analysis selected the following independent predictors for TAMI: age >65 years (odds ratio [OR], 7.9; 95% confidence interval [CI], 2.7 to 23.7), American Society of Anesthesiology physical status classification >3 (OR, 2.8; 95% CI, 1.3 to 5.9), diabetes mellitus (OR, 3.4; 95% CI, 1.2 to 9.8), old myocardial infarction (OR, 2.4; 95% CI, 1.1 to 5.3), and hypertension (OR, 2.3; 95% CI, 1.0 to 5.3). Alcohol consumption was not significantly associated with TAMI. In the postoperative period, patients with TAMI were more likely to have hypoxia (P <.001), a need for reintubation (P <.001), pneumonia (P <.001), congestive heart failure (P =.003), and kidney failure (P =.05). In addition, patients with TAMI had a longer duration of endotracheal intubation (3.7 ± 7.8 vs 0.6 ± 1.2 days, P <.001), stay in the intensive care unit (8.9 ± 9 vs 3.9 ± 2 days, P <.001), and postoperative hospital stay (14.8 ± 11 vs 9.2 ± 5 days, P <.001) than patients without TAMI. Twenty (38%) patients with TAMI were discharged to intermediate-care facilities, compared with 11 (8%) patients without TAMI (P <.001). Postoperative variables conferring the largest relative risks for development of TAMI included oxygen saturation less than 92% (5.4), the need for reintubation (3.3), congestive heart failure (3.3), and pneumonia (3.2). TAMI, conversely, conferred the largest relative risks for development of postoperative congestive heart failure (15.3), the need for reintubation (9.3), pneumonia (7.1), and the need for ICU readmission (3.8). Conclusions: These data show that TAMI is prevalent among patients undergoing aortic reconstruction and is associated with dramatically increased morbidity and postoperative hospitalization rates. (J Vasc Surg 2002;35:376-81.

    Evaluation of complication rates after coronary artery bypass surgery using administrative data

    Get PDF
    Our objectives were (1) to determine if studying hospital complication rates after coronary artery bypass graft (CABG) surgery provides information not available when only mortality is studied, and (2) to reexplore the utility of ICD-9-CM administrative data for CABG outcomes assessment. Using data from Massachusetts, we identified CABG cohorts from 1990 and 1992 to respectively develop and validate multivariate risk adjustment models predicting in-hospital mortality and complications. The resulting models had good discrimination and calibration. In 1992, adjusted hospital complication rates ranged widely from 13.0% to 57.6%, while mortality rates ranged from 1.4% to 6.1%. Hospitals with high complication rates tended to have high mortality (r = 0.74, p = 0.006), but 2 of the 12 hospitals studied ranked quite differently when judged by complications rather than mortality. We conclude that (1) complications after CABG occur frequently and may provide information about hospital quality beyond that obtained from hospital mortality rates, and that (2) administrative data continue to be a promising resource for outcomes research

    Comprehensive Management of the Paranasal Sinuses in Patients Undergoing Endoscopic Endonasal Skull Base Surgery.

    Get PDF
    OBJECTIVE: The endonasal route often provides the most direct and safe approach to skull base pathology. In this article we review the literature with regard to management of the paranasal sinuses in the setting of skull base surgery. METHODS: We describe our institutional experience and review the literature of concurrent management of the sinusitis in patients undergoing endoscopic skull base surgery. RESULTS: Patients should be optimized preoperatively to ensure the endonasal route is a safe corridor to enter the intracranial cavity. Often the paranasal sinuses can be surgically addressed at the same time as endoscopic skull base surgery. We describe the technical details of management of the paranasal sinuses when addressing skull base pathology. CONCLUSIONS: Careful management of the paranasal sinuses throughout the peri-operative course is paramount to optimizing sinonasal function and safety

    Malaria chemoprophylaxis and the serologic response to measles and diphtheria-tetanus-whole-cell pertussis vaccines

    Get PDF
    BACKGROUND: Acute malaria has been associated with a decreased antibody response to tetanus and diphtheria toxoids, meningococcal, salmonella, and Hib vaccines. Interest in giving malaria drug therapy and prevention at the time of childhood immunizations has increased greatly following recent trials of intermittent preventive therapy during infancy (IPTi), stimulating this re-analysis of unpublished data. The effect of malaria chemoprophylaxis on vaccine response was studied following administration of measles vaccines and diphtheria-tetanus-whole cell pertussis (DTP) vaccines. METHODS: In 1975, six villages divided into two groups of children ≤74 months of age from Burkina Faso, were assigned to receive amodiaquine hydrochloride chemoprophylaxis (CH+) every two weeks for seven months or no chemoprophylaxis (CH-). After five months, children in each group received either one dose of measles or two doses of DTP vaccines. RESULTS: For recipients of the measles vaccine, the seroconversion rates in CH+ and CH- children, respectively, were 93% and 96% (P > 0.05). The seroresponse rates in CH+ and CH- children respectively, were 73% and 86% for diphtheria (P > 0.05) and 77% and 91% for tetanus toxoid (P > 0.05). In a subset analysis, in which only children who strictly adhered to chemoprophylaxis criteria were included, there were, likewise, no significant differences in seroconversion or seroresponse for measles, diphtheria, or tetanus vaccines (P > 0.05). While analysis for pertussis showed a 43% (CH+) and 67% (CH-) response (P < 0.05), analyses using logistic regression to control for sex, age, chemoprophylaxis, weight-for-height Z-score, and pre-vaccination geometric mean titer (GMT), demonstrated that chemoprophylaxis was not associated with a significantly different conversion rate following DTP and measles vaccines. Seven months of chemoprophylaxis decreased significantly the malaria IFA and ELISA GMTs in the CH+ group. CONCLUSION: Malaria chemoprophylaxis prior to vaccination in malaria endemic settings did not improve or impair immunogenicity of DTP and measles vaccines. This is the first human study to look at the association between malaria chemoprophylaxis and the serologic response to whole-cell pertussis vaccine

    Creation of fundamental particles in Wesson's IMT

    Full text link
    Fundamental particles, regarded as the constituents of quarks and leptons, are described classicaly in the framework of the Weyl-Dirac version of Wesson's Induced Matter Theory. There are neutral particles and particles having charge Q=+/-(1/3e). The particles appear on the 4D brane, our universe, and are filled with a substance induced by the 5D bulk. This substace is taken to have mass density, charge density, pressure and is characterized by the prematter eq. of state P+\rho=0. The interior is separated from the surrounding vacuum by a boundary surface where the 4D metric tensor satisfies an a'la Schwarzschild condition. Outside of the boundary holds the Schwarzschild, or the Reissner-Nordstroem Metric, while the particles are characterized by mass, radius, charge.Comment: 29 pages. Submitted for publication in the Gen. Rel. and Grav. Journa
    • …
    corecore