A fabric denuder for sampling semi-volatile species.

A new style of diffusion denuder has been evaluated specifically for sampling HNO3. A coated fabric is used as the denuder substrate, which can be loaded directly into a standard filter holder. This approach allows direct denuder sampling with no additional capital costs over filter sampling and simplifies the coating and extraction process. Potential denuder materials and coatings were evaluated in the laboratory to test the removal efficiency. NaCl coatings were used to assess more than 20 materials for HNO3 collection efficiency. Particle retention, which would cause a denuder to have a positive bias for gas concentration measurements, was evaluated by ambient air sampling using particulate sulfate as the reference aerosol. Particle retention varied from 0 to 15%, depending on the denuder material tested. The best performing material showed an average particle retention of less than 3%. Denuder efficiency of four fabric materials was tested under ambient conditions to determine removal efficiency. The fabric denuder method was compared with a long path-length Fourier transform infrared (FTIR) spectrometer, a tunable diode laser absorption spectrometer (TDLAS), and a denuder difference sampler to independently measure HNO3. HNO3 collection efficiency was typically 90% for the denuders, whether coated with NaCl or not. For 10-L/min sampling rates with the fabric denuder, the square of the correlation coefficient with the FTIR spectrometer was 0.73, compared to 0.24 with the TDLAS.

Evaluation of watering to control dust in high winds.

A field study was conducted to determine the effectiveness of watering in controlling PM10 emissions under high wind conditions. The focus of the study was the pickup of soil by a belly scraper at a landfill. Four low-volume PM10 samplers were positioned downwind of the storage pile (at two distances, 80 and 110 m, and two elevations, 1 and 3 m) and one was located upwind at 3 m elevation. Integrating nephelometers, which measure the particulate light scattering coefficient, bsp, were also set up at locations 80 and 110 m downwind of the storage pile. Wind speed and direction were measured on-site. Samples were collected for two periods, one with and one without water being applied. Watering was effective at reducing PM10 emissions at wind speeds up to the maximum 18 m sec-1 observed at the landfill soil pickup operation. Measurement of bsp provided an indication of PM10 concentrations with better time resolution than samplers, but not with sufficient resolution, under the instrumental conditions used, to correlate with wind gusts.

Determination of PM10 emission rates from street sweepers.

The use of street sweepers to clean paved roads, particularly after high-wind events, has been proposed as a PM10 control method. Using an artificial tunnel, the emission rates for several street sweepers were quantified under actual operating conditions. The tunnel was a tent enclosure, 6.1 x 4.3 x 73 m, open on both ends. PM10 concentrations were measured at the inlet and outlet while a sweeper removed sand deposited along the length. Measurements were made using a specialized low-volume filter sampler and an integrating nephelometer. The volume of air passing through the tunnel was measured by releasing an inert tracer, sulfur hexafluoride, at the inlet and measuring its concentration at the outlet. A large difference in emission rates between vacuum-type sweepers was observed, with rates varying from 5 to 100 mg m-1 swept. For the cleanest sweepers, the background rates (collected by sweeping clean pavement) were about half of the total PM10 emission rate. These background emission rates likely were from diesel exhaust; background rates for the single gasoline-powered sweeper were below detection. Particle light scattering data confirmed the filter collection results. The artificial tunnel approach would be useful in measuring total emissions from other mobile and stationary sources.

A validity study of the St. Louis Inventory of Community Living Skills.

Clinicians who work with the long term mentally ill often need an instrument which measures the level of community living skills. Independent raters scored 60 clients of the St. Louis Community Placement Program on the St. Louis Inventory of Community Living Skills (SLICLS), a 15-item instrument that requires little training and only a few minutes to complete. There was good inter-rater reliability and internal consistency. Construct validity was demonstrated for clients in three types of residences. Concurrent validity was demonstrated in relation to the longer Missouri Level of Care Instrument.

Discontinuation of a psychogeriatric program for nursing home residents: psychotropic medication changes and behavioral reactions.

Changes in medications and behavior were recorded for residents of three nursing homes where a psychogeriatric rehabilitative program was either absent, maintained, or discontinued. Residents without the program received the greatest number of psychotropics. Discontinuation of the program was associated with two problems: (a) fewer reductions in medications and (b) more behavioral difficulties among clients with medication increases. The nursing home with continuous services was the only one where all types of medication changes were followed by an overall decrease in behavior problems or no problems at all.

Expanding the horizons in treatment of severe peripheral vascular disease using microsurgical techniques.

The use of microvascular tissue transfer as an adjunct to arterial reconstruction has begun to have a positive impact on limb salvage in patients with advanced arteriosclerosis and nonhealing ischemic wounds. However, many patients with severe peripheral vascular insufficiency not amenable to conventional arterial reconstructive procedures eventually require limb amputation. We have treated 12 patients with advanced peripheral vascular disease and nonhealing ischemic wounds by three different methods. These included distal bypass alone, distal bypass done in conjunction with free-tissue transfer, and free-tissue transfer alone. All bypass grafts were done to vessels at or below the ankle using a reversed saphenous vein. In each case, the distal anastomosis was performed, using the operating microscope and standard microvascular technique. Mean follow-up for these patients is 18 months. Distal bypass alone resulted in limb salvage in three of five patients. In the combined bypass and free-flap group, three of five patients had salvage of their threatened extremity at a 1-year follow-up. Two patients with ischemic ulcers, rest pain, and unsuitable distal vessels for bypass were treated with free-tissue transfer alone. This resulted in healed wounds, limb salvage, and complete resolution of the rest pain symptoms in both patients. When advanced ischemia is complicated by large areas of tissue loss, combined bypass and microvascular free-issue transfer, performed in stages or simultaneously, is safe and can often result in limb salvage. In the rare instance of a completely obliterated distal runoff bed, free-tissue transfer alone may provide not only a healed wound, but also a means of "indirect" revascularization of the extremity and limb salvage.

Gangrenous cellulitis associated with gram-negative bacilli in pancytopenic patients: dilemma with respect to effective therapy.

INTRODUCTION: Gangrenous (necrotizing) cellulitis is a progressive bacterial infection of skin and soft tissue; the infection can spread into subcutaneous tissue with involvement of superficial and deep fascia (necrotizing fasciitis). We describe two pancytopenic patients with polymicrobial gram-negative bacteremia and fulminating gangrenous cellulitis. CASE REPORTS: Pseudomonas aeruginosa was isolated from a localized hemorrhagic area of the face in one patient. The chronology of infection in these two patients is documented in a series of dramatic color photographs. Despite appropriate antibiotic therapy, the infections progressed relentlessly and both patients died. COMMENTS: We discuss the dilemma of establishing the correct diagnosis prior to the appearance of the characteristic cutaneous manifestations of hemorrhagic necrosis and gangrene. Once the diagnosis is established, surgical excision is universally recommended. Unfortunately, bleeding diatheses in pancytopenic patients with co-existing coagulation deficiencies pose logistic obstacles in urgent, real-life situations. The timing and conditions for surgery need to be elucidated in these patients. An approach to this infection is proposed. The utility of frozen-section biopsy of the involved tissue and computed tomographic scans of the involved area remains to be evaluated.

Hostility reduction in married and unacquainted couples.

Fifty-two persons (26 married couples) competed in a complex reaction time task and set durations of 100 db noise for either their respective spouses or an opposite sex stranger. Each S's punitive settings were countered by four presequenced counteraggression strategies. Wives were responsive to a broader range of aggression reduction strategies than were husbands. Results suggest that minimum retaliation is most consistently effective across sex and may be a behavior skill necessary to avoid escalation of aggression and to keep communication channels open.

Delivery of the topical antimicrobial agents silver sulfadiazine, gentamicin and nystatin to infected burn wounds in rats from preloaded synthetic dressings.

1. A synthetic burn dressing made from polyethylene glycol - 400 (PEG) and poly-2-hydroxyethyl methacrylate (PHEMA) can be prepared to contain topical antimicrobial agents. 2. Sheets of these antimicrobial loaded dressings may be applied to the wounds or alternatively, the synthetic dressing incorporating the active drugs may be formed directly on the burn wound from the PEG-PHEMA drug mixture. 3. The antimicrobials (silver sulfadiazine, gentamicin and nystatin) are continuously and effectively released from the solid dressing over 2-11 days.

Effects of external incentive and aggressive predisposition on aggression reduction.

Female undergraduates (N = 40) received four counteraggression strategies (0%, 10%, 50%, and 150% retaliation) in response to their aggression in a complex reaction time task. They either were or were not offered a monetary incentive to beat their opponent and were divided into those low and high in their initial predisposition to aggression. Four major findings resulted: 1) escalation of aggression to 150% retaliation supported reciprocity over contingent punishment theory. 2) Ss low in aggression were unaffected by strategies, rather than being most responsive to pacifism, as predicted. 3) Ss high in aggression reduced their aggression most to the intermediate 10% and 50% retaliation strategies. 4) An external (monetary) incentive for beating the opponent did not parallel the aggressiveness personality factor as expected. The external incentive reduced the difference between low and high aggression participants and resulted in a linear relationship between retaliation strategy and aggression reduction. This is the first study showing minimum (10%) retaliation to be more effective than pacifism (0% retaliation), but the effect occurred only among the 25% most aggressive Ss when there was no monetary incentive.

Atmospheric reactions of polycyclic aromatic hydrocarbons: facile formation of mutagenic nitro derivatives.

Directly active mutagens are formed on exposure of the promutagen benzo[a]pyrene to gaseous pollutants in smog. In simulated atmospheres containing 1 part per million nitrogen dioxide and traces of nitric acid, directly mutagenic nitro derivatives are readily formed from both benzo[a]pyrene and perylene, a non-mutagen in the Ames reversion assay. Possible formation of direct mutagens by such reactions on sample collection filters, in exhaust effluents, and in the atmosphere should be recognized.

Perception of a non-ill participant in a mental health discussion.

Describing a mental patient's claim to sanity as symptomatic may increase the probability that others will assimilate non-ill behavior into a pathological framework. In two experiments subjects saw a simulated session of group therapy on videotape. Each videotape contained a therapist, four persons role-playing specific disorders, and one person acting normally. After receiving different instructions, all subjects were asked to categorize the five patients. In Exp. 1 no consistent conclusions were possible because only 2 of 59 subjects said the normal person was not ill. Exp. 2 avoided this "floor effect" by the videotape therapist's agreeing with the normal person's claim of not being ill. The subjects precautioned against believing claims of sanity were most likely to categorize the person exhibiting non-ill behavior. A second group of subjects were not precautioned against believing sanity claims. A third group of subjects, informed of one patient's non-illness, were most likely to differentiate the normal person from those portraying pathological behavior.

Enhancement of photochemical smog by n,n'-diethylhydroxylamine in polluted ambient air.

A recent proposal for controlling photochemical smog by the addition to ambient air of 0.03 to 0.05 part per million of diethylhydroxylamine (DEHA) is shown to be invalid. The addition of DEHA in the range of 0.05 to 0.5 part per million to ambient air irradiated with sunlight in a dual outdoor environmental chamber caused marked increases in the rates of formation and concentrations of ozone, peroxyacetyl nitrate, and light-scattering particles.

Effectiveness of counteraggression strategies in reducing interactive aggression by males.

Studies on techniques of reducing aggression have typically examined passive, matching, and punitive strategies of counteraggression and have been remarkably inconsistent in their findings. This research was designed to resolve the contradictory results by reconceptuallzing the strategies in terms of counteraggression/aggression (cA/A) ratios. We predicted that the norm of reciprocity and the tendency to exploit weakness would make a cA/A ratio of less than but close to 1.0 (matching) most effective in reducing aggression. Ten cA/A ratios were used. One hundred male subjects set punishment level set by their opponent (a confederate) on 25 trials, and, on 13 losing trials, received punishment. The most effective cA/A ratios for reducing aggression were the lowest ones. Lower cA/A ratios reduced aggression and ratios greater than 1.0 increased aggresion. Contrary to the results of previous studies, the matching strategy was ineffective in reducing aggresion.

A renewed look at Miller's conflict theory of aggression displacement.

The present study is the first to examine Miller's theoretical assumptions of displaced aggression using human subjects. Subjects in the present study either served as nonangered controls, were angered by the experimenter's confederate, or were both angered by and led to fear the confederate. All subjects were then able to three targets: the confederate, a person described as a friend of the confederate, and a person having no association with the confederate. Targets received the most intense aggression from angered subjects. The difference between the aggression gradients for high-anger-low-fear and control subject. Frightened subjects gave their most intense aggression to the displaced targets. Results also support the suggestion that direct aggression is most likely if the aggressor can first extinguish some of his fear by attacking more indirect targets.