Aircraft soot from conventional fuels and biofuels during ground idle and climb-out conditions: Electron microscopy and X-ray micro-spectroscopy.

Aircraft soot has a significant impact on global and local air pollution and is of particular concern for the population working at airports and living nearby. The morphology and chemistry of soot are related to its reactivity and depend mainly on engine operating conditions and fuel-type. We investigated the morphology (by transmission electron microscopy) and chemistry (by X-ray micro-spectroscopy) of soot from the exhaust of a CFM 56-7B26 turbofan engine, currently the most common engine in aviation fleet, operated in the test cell of SR Technics, Zurich airport. Standard kerosene (Jet A-1) and a biofuel blend (Jet A-1 with 32% HEFA) were used at ground idle and climb-out engine thrust, as these conditions highly influence air quality at airport areas. The results indicate that soot reactivity decreases from ground idle to climb-out conditions for both fuel types. Nearly one third of the primary soot particles generated by the blended fuel at climb-out engine thrust bear an outer amorphous shell implying higher reactivity. This characteristic referring to soot reactivity needs to be taken into account when evaluating the advantage of HEFA blending at high engine thrust. The soot type that is most prone to react with its surrounding is generated by Jet A-1 fuel at ground idle. Biofuel blending slightly lowers soot reactivity at ground idle but does the opposite at climb-out conditions. As far as soot reactivity is concerned, biofuels can prove beneficial for airports where ground idle is a common situation; the benefit of biofuels for climb-out conditions is uncertain.

Integrating Saharan dust forecasts into a regional chemical transport model: a case study over Northern Italy.

The Po Valley in Northern Italy is frequently affected by high PM10 concentrations, where both natural and anthropogenic sources play a significant role. To improve air pollution modeling, 3D dust fields, produced by means of the DREAM dust forecasts, were integrated as boundary conditions into the mesoscale 3D deterministic Transport Chemical Aerosol Model (TCAM). A case study of the TCAM and DREAM integration was implemented over Northern Italy for the period May 15-June 30, 2007. First, the Saharan dust impact on PM10 concentration was analyzed for eleven remote PM10 sites with the lowest level of air pollution. These remote sites are the most sensitive to Saharan dust intrusions into Northern Italy, because of the absence of intensive industrial pollution. At these remote sites, the observed maxima in PM10 concentration during dust events is evidence of dust aerosol near the surface in Northern Italy. Comparisons between modeled PM10 concentrations and measurements at 230 PM10 sites in Northern Italy, showed that the integrated TCAM-DREAM model more accurately reproduced PM10 concentration than the base TCAM model, both in terms of correlation and mean error. Specifically, the correlation median increased from 0.40 to 0.65, while the normalized mean absolute error median dropped from 0.5 to 0.4.

Pharmacy-refill measure of adherence to efavirenz can predict maintenance of HIV viral suppression.

The objective of this study was to determine if a lower rate of adherence (<95%) is sufficient to maintain HIV viral suppression in patients on an efavirenz-based regimen. This study was a retrospective review of pharmacy refill records at an HIV specialty pharmacy at Montefiore Medical Center's outpatient clinic. Data from 151 HIV-positive patients on an efavirenz-based regimen with at least one undetectable viral load (HIV RNA < 400 copies/mL) from December 2003 through March 2005 were reviewed. Adherence was calculated based on the formula: [(pills dispensed/pills prescribed per day/days between refills)x100%]. Calculated adherence for each time-period was correlated to the respective HIV-RNA value for that period. Of 151 patients, viral suppression was maintained in greater than 80% of time periods for adherence rates as low as 85-90%. The periods with 75-80% adherence also had higher than 85% suppression. Rates of suppression began to fall when adherence decreased to < 75%. In conclusion, lower adherence rates (<95%) on an efavirenz-based regimen were more successful in maintaining viral suppression than previously found with unboosted protease inhibitor-based regimens.

A pneumococcal capsular polysaccharide vaccine induces a repertoire shift with increased VH3 expression in peripheral B cells from human immunodeficiency virus (HIV)-uninfected but not HIV-infected persons.

The molecular mechanism of pneumococcal vaccine failure in human immunodeficiency virus (HIV)-infected persons is not fully understood. A polymerase chain reaction ELISA was used to determine the proportion of peripheral IgG, IgA, and IgM CD19-positive B cells expressing 6 immunoglobulin heavy-chain variable region (VH) subgroups before and 7 days after pneumococcal vaccination of 12 HIV-infected and 12 HIV-uninfected subjects. Significant postvaccination increases in the expression of the VH3 subgroup by IgG and IgA and a greater serologic response to vaccination were observed in the HIV-uninfected group. In contrast, the HIV-infected group had reduced prevaccination IgG VH3 and a postvaccination increase in IgG VH5. These results demonstrate that pneumococcal vaccination changes the pattern of B cell VH gene expression and support the concept that aberrant VH3 expression may translate into a poor antipneumococcal response in the setting of HIV infection.

Spirituality for nurses and their practice.

This descriptive study compared the inclusion of spirituality in the practice of two groups of nurses: nurses prepared in parish nursing (PN) and nurses not specifically prepared in spiritual care (NonPN). The Spirituality in Nursing Care tool was used to determine sources of spiritual strength and spiritual experiences of the respondents, the application of spirituality in their practice, and the interventions and indicators they used in determining the need for spiritual assistance. Random sampling using U.S. postal codes selected 600 members from a national mailing list of nurses prepared in parish nursing and 600 similarly selected nurses not prepared in parish nursing. A total of 645 questionnaires were returned with complete data. The following question was asked: How do nurses prepared in providing spiritual care (PN) compare to nurses not similarly prepared (NonPN) in terms of: (a) personal sources of spiritual strength, (b) spiritual experiences, (c) application of spirituality in their practice, (d) identification of indicators of spiritual needs in their clients, and (e) interventions used to meet the spiritual needs of their clients? The findings indicate there are differences in how PN and NonPN groups of nurses respond to spirituality of self and their use of spirituality in clinical practice. It is suggested that parish nurses take the lead to further study spirituality and the indicators and appropriate interventions, and identify patient outcomes when spiritual needs are addressed by nurses in providing "holistic nursing practice."

Gender differences in HIV risk behaviors in an adult emergency department in New York City.

BACKGROUND: The human immunodeficiency virus (HIV) epidemic in the US increasingly involves urban heterosexual adults, particularly women, belonging to ethnic minority groups. An understanding of gender-based differences in HIV risk behaviors within these groups would be of value in the ongoing struggle to limit HIV transmission in metropolitan centers. METHODS: This was a prospective study of demographic and historical characteristics and HIV risk behaviors. The study utilized a structured interview format, which was administered to all patients treated by participating emergency department physicians. RESULTS: On univariate analysis of data obtained from 1,460 patients who had neither a known HIV infection nor a chief complaint or final emergency department diagnosis associated with HIV risk behaviors, men were more likely to be older, homeless, to have ever injected drugs, used crack, engaged in same-gender sex, paid for sex, been incarcerated, or had syphilis or gonorrhea. Women were more likely to report prior chlamydia infection or to report that their sole sex partners had other partners within the past year. On multivariate analysis, variables independently associated with male gender included homelessness, injection drug use, crack use, any prior sexually transmitted disease (in subjects 35 years of age or older), and sex with prostitutes. In a separate analysis of patients admitting to drug use, the male predominance of other risk behaviors was not observed; the only significant differences between genders were a higher rate of prostitution among women and a higher rate of sexual contact with a prostitute among men. CONCLUSIONS: In patients visiting an inner-city emergency department in the Bronx, HIV risk behaviors are generally more common in men, but rates of risk behaviors among male and female drug users are comparable.

A prospective study of tuberculosis and HIV disease progression.

OBJECTIVE: To determine whether active tuberculosis alters the rate of progression of HIV infection in dually infected patients. METHODS: HIV-seropositive patients at two Bronx, New York hospitals with tuberculosis confirmed by culture from July 1992 to February 1995, who survived the initial hospitalization for tuberculosis, were matched on gender, age, CD4+ percentage, and calendar time with HIV-seropositive patients without tuberculosis participating in a study of the natural history of HIV infection. Patients received follow-up observation prospectively until May 23, 1995 to determine survival rates and development of AIDS-defining opportunistic infections (OIs). RESULTS: 70 patients had tuberculosis; 120 did not. Mean CD4+ percentages were 12.4% and 12.5%, respectively. At study entry, 27% of those with tuberculosis had prior AIDS-defining OIs other than tuberculosis, compared with 10% of those without tuberculosis (p = .004). In multivariate survival analysis, controlling for CD4+ level, tuberculosis was not an independent predictor of increased other causes of AIDS-related mortality. However, in a logistic regression model, independent predictors of subsequent OIs included tuberculosis (hazard ratio, 4.1; 95% confidence intervals [CI], 1.9, 8.7), CD4+ count <100/mm3 (hazard ratio, 2.4; 95% CI, 1.1, 5.0) and prior OIs (hazard ration, 3.3; 95% CI, 1.3, 8.3). CONCLUSIONS: Tuberculosis was not an independent predictor of increased non-tuberculosis-related mortality in HIV-seropositive patients but was associated with increased risk of development of OIs.

A prospective study of tuberculosis and human immunodeficiency virus infection: clinical manifestations and factors associated with survival.

We prospectively studied the effect of human immunodeficiency virus (HIV) infection on the presentation and outcome of tuberculosis. A total of 216 patients with tuberculosis were identified; 162 (75%) of these patients were tested for antibodies to HIV; 92 (57%) were seropositive. The patients who were seropositive for HIV were more likely to be male and Hispanic and to have been homeless or incarcerated. Eighty-one percent of these patients had CD4 lymphocyte counts of < or =200/mm3. The seropositive patients had extrapulmonary tuberculosis more often than did the seronegative patients (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.2-4.8). Smears for acid-fast bacilli were positive more often for non-HIV-infected patients with pulmonary tuberculosis (74.5%) than for HIV-infected patients (54.3%) [OR, 2.46; 95% CI, 1.01-6.02]-even those with focal or cavitary disease. A delay in initiating therapy was associated with in-hospital mortality: the median time from admission to the start of treatment was 4 days for patients who survived and 15 days for those who died (P = .02). The median survival was 22.7 months for HIV-infected patients who did not die during the initial hospitalization. Factors independently associated with reduced rates of survival included the severity of immunodeficiency, nonuse of directly observed therapy, infection due to drug-resistant Mycobacterium tuberculosis, and a history of injection drug use.

Rates of and factors associated with self-reported prior HIV testing among adult medical patients in an inner city emergency department in the Bronx, New York City.

We studied the rates of and factors associated with self-reported prior human immunodeficiency virus (HIV) testing in adult patients visiting an emergency department (ED) in the Bronx, New York City. A total of 1,744 consecutive noncritical adult medical emergency patients responded to a standardized interview administered by ED physicians. The interview included questions pertaining to demographic characteristics, prior HIV testing, and HIV risk behaviors. On multivariate analysis, female gender, younger age, history of weight loss, injecting drug use (IDU), syphilis, and genital herpes were all associated with increased reported prior testing rates. Race (i.e., black race) was an independent predictor of increased rates among male subjects; comparatively low rates were reported by patients with a first language other than English, patients lacking medical insurance, and highly sexually active, nonblack men. Increased HIV testing rates were reported by subjects with recognized HIV risk behaviors in a New York City ED population; however, substantial proportions of subjects at risk had not been tested. Programs of HIV testing and counseling need to include older, uninsured, and non-English-speaking segments of the population who engage in high-risk behaviors.

Factors associated with unrecognized HIV-1 infection in an inner-city emergency department.

STUDY OBJECTIVE: To determine the prevalence of and risk factors associated with unrecognized HIV-1 infection among medical patients presenting to an inner-city emergency department. METHODS: We conducted anonymous HIV-1 testing in subjects interviewed for risk behaviors and knowledge of HIV status at an inner-city ED in the Bronx, New York. Our subjects were consecutive adult medical patients in noncritical condition (N = 1,744) who were evaluated by three physicians providing primary emergency care. Each patient was given a structured interview for demographic characteristics, risk behaviors, and knowledge of HIV status. Excess serum, drawn for clinical purposes, was linked without identifiers to responses and tested for antibodies to HIV-1. In subjects who denied HIV infection, we tested associations with seropositivity using univariate analyses and logistic-regression techniques (multivariate). RESULTS: Of the 1,744 patients interviewed, 656 (37.6%) reported HIV risk behaviors. Of 970 tested for HIV-1 antibodies, 125 (12.9%) were seropositive. The prevalence of HIV-1 infection among those who denied known infection was 4.0% (35 of 875). In the multivariate model, independent predictors of unrecognized HIV-1 infection were age 35 to 44 years, crack cocaine use, history of syphilis, and ED diagnosis of an infection not necessarily related to HIV infection. Unrecognized HIV-1 infection was more likely among patients admitted to the hospital, but 21 of the 35 with unrecognized infection (60%) were not admitted and in 9(25.7%) no risk factors were identified. CONCLUSION: More than one third of patients who visited one inner-city ED acknowledged HIV risk behaviors. One quarter of patients with unrecognized HIV-1 infection reported no identifiable risk factors. Easily accessible HIV counseling and testing should be considered in EDs in areas serving persons at risk for HIV infection.

Multidrug-resistant tuberculosis in patients without HIV infection.

BACKGROUND: Investigations of outbreaks of multidrug-resistant tuberculosis have found low rates of treatment response and very high mortality, and they have mainly involved patients with advanced human immunodeficiency virus (HIV) infection. For patients without HIV infection, one study reported an overall rate of response to treatment of 56 percent, and the mortality from tuberculosis was 22 percent. We investigated treatment response and mortality rates in 26 HIV-negative patients in New York with multidrug-resistant tuberculosis. METHODS: We obtained detailed data from seven teaching hospitals in New York City on patients with multidrug-resistant tuberculosis--defined as tuberculosis resistant at least to isoniazid and rifampin--who were HIV-negative on serologic testing. Lengths of times from diagnosis to the initiation of appropriate therapy and from the initiation of appropriate therapy to conversion to negative cultures were assessed. Therapeutic responses were evaluated by both microbiologic and clinical criteria. RESULTS: Between March 1991 and September 1994, 26 HIV-negative patients were identified and treated. Of the 25 patients for whom adequate data were available for analysis, 24 (96 percent) had clinical responses; all 17 patients for whom data on microbiologic response were available had such a response. The median times from diagnosis to the initiation of appropriate therapy and from the initiation of therapy to culture conversion were 44 days (range, 0 to 181) and 69 days (range, 2 to 705), respectively. Side effects requiring the discontinuation of medication occurred in 4 of 23 patients (17 percent) who were treated with second-line antituberculosis medications. The median follow-up for the 23 patients who responded and who received appropriate therapy was 91 weeks (range, 41 to 225). CONCLUSIONS: In this report from New York City, HIV-negative patients with multidrug-resistant tuberculosis, contrary to previous reports, responded well to appropriate chemotherapy, both clinically and microbiologically.

Effects of light quality and quantity on growth of the clonal plant Eichhornia crassipes.

Plant canopy shade reduces photosynthetic photon flux density (PPFD) and ratio of red to far-red light (z). Both effects can cause plants to increase potential for light acquisition through vertical growth and leaf area expansion. Clonal plants such as Eichhornia crassipes might alternatively increase light interception via horizontal growth of stolons or rhizomes and placement of new ramets in less shaded microsites. Effect of simulated canopy shade and component effects of PPFD and z were tested by filtering or adding light uniformly, to a whole group of connected ramets, or locally, to individual ramets within a group. In uniform treatments, low PPFD reduced total growth but low z did not. Low PPFD and low z independently reduced stolon and ramet production and caused etiolation of petioles; effect of low PPFD plus low z on ramet production was greater than that of either factor alone. Lateral clonal growth thus did not seem to be a response to uniform shading; instead, uniformly low PPFD or low z increased partitioning to established ramets. Low z changed partitioning without changing total growth. In local treatments, reduction of growth of individual ramets due to low PPFD and inhibition of new ramet production attributable to spectral composition of light were mitigated when connected ramets were unshaded; plants may respond differently to patchy than to uniform shade.

Resource sharing among ramets in the clonal herb, Fragaria chiloensis.

The herbaceous perennial, Fragaria chiloensis, reproduces vegetatively on coastal sand dunes in California by growth of stolons that bear rosettes. Movement of water and photosynthates through stolons integrates water and carbon metabolism of rosettes both before and after they root. New, unrooted rosettes import sufficient water and nitrogen to maintain levels near those of established rosettes; yet support of an unrooted rosette did not decrease growth of a connected, rooted sibling given abundant light, water, and soil nutrients. Under such conditions strings of unrooted rosettes with the associated stolon appeared self-sufficient for carbon; shade and drought induced import of photosynthates. New rosettes produced and maintained a limited root mass upon contact with dry sand, which could increase probability of establishment. Rooting did not induce senescence of stolons. Connection between two established rosettes prevented death by drought and shade, even when neither rosette could have survived singly. Results suggest that physiological integration of connected rosettes may increase total growth of clones of F. chiloensis through sharing of resources among ramets, especially when resource availability is changeable or patchy.

Spermatogenesis in the unilateral cryptorchid testis after orchiopexy.

We herein examine the role of orchiopexy in the child with unilateral cryptorchidism and specifically discuss whether this operation produces a testis capable of good sperm production. Contralateral vasectomy was performed in subjects who previously had undergone unilateral orchiopexy. Semen analysis from the previously operated testes showed marked diminution in spermatogenesis.

Radiation pressure on randomly oriented infinite cylinders.

Expressions are developed for the radiation pressure on infinite dielectric cylinders caused by an oblique incidence as a function of the size parameter alpha = 2pialpha/lambda. It is shown that for nonabsorbing cylinders the radiation pressure is always perpendicular to the axis of the cylinder and thus not along the direction of the incident radiation except for the case of normal incidence. This result applies also for other small nonspherical particles. Consequently, the radiation pressure on a randomly oriented nonspinning group of small nonspherical particles causes the particles to spread away from the direction of propagation of the incident radiation. It is suggested that this conclusion should be taken into account when discussing the effect of the radiation pressure on small particles in space, as compared with other forces such as the dynamic pressure on the solar wind.