Microbial isolation and characterization from two flex lines from the urine processor assembly onboard the international space station

Urine, humidity condensate, and other sources of non-potable water are processed onboard the International Space Station (ISS) by the Water Recovery System (WRS) yielding potable water. While some means of microbial control are in place, including a phosphoric acid/hexavalent chromium urine pretreatment solution, many areas within the WRS are not available for routine microbial monitoring. Due to refurbishment needs, two flex lines from the Urine Processor Assembly (UPA) within the WRS were removed and returned to Earth. The water from within these lines, as well as flush water, was microbially evaluated. Culture and culture-independent analysis revealed the presence of Burkholderia, Paraburkholderia, and Leifsonia. Fungal culture also identified Fusarium and Lecythophora. Hybrid de novo genome analysis of the five distinct Burkholderia isolates identified them as B. contaminans, while the two Paraburkholderia isolates were identified as P. fungorum. Chromate-resistance gene clusters were identified through pangenomic analysis that differentiated these genomes from previously studied isolates recovered from the point-of-use potable water dispenser and/or current NCBI references, indicating that unique populations exist within distinct niches in the WRS. Beyond genomic analysis, fixed samples directly from the lines were imaged by environmental scanning electron microscopy, which detailed networks of fungal-bacterial biofilms. This is the first evidence of biofilm formation within flex lines from the UPA onboard the ISS. For all bacteria isolated, biofilm potential was further characterized, with the B. contaminans isolates demonstrating the most considerable biofilm formation. Moreover, the genomes of the B. contaminans revealed secondary metabolite gene clusters associated with quorum sensing, biofilm formation, antifungal compounds, and hemolysins. The potential production of these gene cluster metabolites was phenotypically evaluated through biofilm, bacterial-fungal interaction, and hemolytic assays. Collectively, these data identify the UPA flex lines as a unique ecological niche and novel area of biofilm growth within the WRS. Further investigation of these organisms and their resistance profiles will enable engineering controls directed toward biofilm prevention in future space station water systems.

Repeated exposure of rats to JP-4 vapor induces changes in neurobehavioral capacity and 5-HT/5-HIAA levels

Thirty-two Sprague-Dawley rats were exposed for 6 h/d for 14 consecutive days to JP-4 jet fuel vapor (2 mg/L) or room air control conditions. Following a 14- or 60-d recovery period, rats completed a battery of 8 tests selected from the Navy Neurobehavioral Toxicity Assessment Battery (NTAB) to evaluate changes in performance capacity. Exposure to JP-4 vapor resulted in significant changes in neurobehavioral capacity on several tests that varied as a function of the duration of the recovery period. Rats were evaluated for major neurotransmitter and metabolite levels in five brain regions and in the blood serum. Levels of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were shown to be significantly elevated in several brain regions as well as in the blood serum in the vapor-exposed groups. Results of the rat study are compared to previously reported neurobehavioral evaluations of European manufacturing personnel exposed chronically to jet fuel vapor.

Caloric and nitrogen balances as predictors of nutritional outcome in patients with burns

Measurement of energy expenditure with indirect calorimetry allows determination of caloric balance. The present study was done to determine the predictive value of caloric and nitrogen balances for nutritional outcome. Energy expenditure was obtained weekly and interpolated between measurements for daily caloric balance. Nitrogen balance was obtained weekly. Because nitrogen output fluctuated, interpolation of daily values was not possible. Nutritional outcome was defined by whether body weight was lost or maintained and by levels of visceral proteins (albumin, prealbumin, and transferrin). The study group included 12 patients with 7% to 82.5% total body surface area burns. Eleven patients survived their burn injuries, and one died of congestive heart failure at 38 days, after her burn wounds had healed. Nine patients had good nutritional outcomes (group 1) and three had poor nutritional outcomes (group 2) (including the one who died). Nitrogen balance was 1.3 +/- 1.0 gm/day in group 1 and 4.5 +/- 1.7 gm/day in group 2 (mean +/- SEM; p > 0.10). Caloric balance was 515 +/- 130 kcal/day in group 1 and -667 +/- 140 in group 2 (p < 0.001). Caloric balance was significantly different between the two groups, whereas nitrogen balance was not. Caloric intake correlated positively with nitrogen intake (r = 0.92). Nitrogen intake was 16% of total caloric intake. Nitrogen intake from blood products was appreciable and averaged 15% of total nitrogen intake (range, 0% to 47%); 11.3 +/- 1.6 gm/day in group 1 and 14.8 +/- 3 gm/day in group 2 (p > 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)

Buffalo and Bali cattle--exploiting their reproductive behaviour and physiology

Water buffalo (Bubalus bubalis) and Bali cattle (Bos sondaicus) occupy production niches in much of the developing world's agricultural systems which in the developed world are occupied by Bos indicus and Bos taurus. Both the former species are better-adapted to these environments and systems. Both depend on population survival strategies different from each other's and from those of B. indicus and B. taurus. Water buffalo rely on longevity and late sexual maturity, while Bali cattle rely on high conception rates and sacrifice of juveniles when the population is under stress. Knowledge of these different strategies will help in formulation of management strategies for maximising nett reproductive rates. This paper briefly describes each species, reviews its survival strategies and summarises the available data on the reproductive characteristics of each.

The effects of acute sleep deprivation during residency training

Verbal and symbol concentration, learning, problem solving, clear thinking, manual skills, and memory were tested in 42 surgical residents to assess the effects of acute sleep deprivation on specific neuropsychological parameters. A series of eight neuropsychological tests--digit symbols, digit vigilance, story memory, trail making, PASAT, Raven matrices, delayed story, and pegboard--and a questionnaire on mood states were completed by the residents both when fatigued (less than 4 hours of sleep: mean, 2.0 +/- 1.5 hours) and when rested (more than 4 hours of sleep: mean, 6.5 +/- 1.0 hours), with at least 7 days between tests. In order to eliminate the effects of learning from the first test series, randomization of residents was performed so that one half were first evaluated when rested and one half when fatigued. ANOVA, multiple regression analysis, and the Student t test were used to assess differences. In the acute sleep-deprived state, residents were less vigorous and more fatigued, depressed, tense, confused, and angry (p less than 0.05) than they were in rested state. Despite these changes in mood, however, the responses on all of the functional tests were no different statistically in those who were rested and those who were fatigued (even in those with less than 2 hours' sleep). We conclude that acute sleep deprivation of less than 4 hours alters mood state but does not change performance in test situations in which concentration, clear thinking, and problem solving are important.

Unresponsiveness to exogenous TSH in obesity

(1). Assessment of thyroidal and other indices in 275 instances of obesity with body weight excesses up to 200 percent or more of the ideal revealed absent thyroidal I131 uptake responses to TSH in about one out of five patients. Moreover, basal thyroidal I131 uptake of 10 percent or less, prolongation of ankle reflex time, or high levels of serum cholesterol were present in a minority. Also, occasional instances of unduly elevated serum TSH titers were found. Some of the indices deviated from normal more often with the greater excesses of body weight or with increased age. (2). These findings are consonant with a hypothesis that routine thyroidal or related indices are sporadically abnormal in massive obesity almost always without overt hypothyroidism or myxedema, that total unresponsiveness to exogenous TSH is surprisingly frequent, and that such unresponsiveness represents an unexplained endocrine anomaly in association with gross overweight. (3). Our data suggest that some obese persons are not able to respond to exogenous TSH, nor, presumably, to increases of endogenous TSH. This could result in an economy of caloric expenditure and play a contributory role in the genesis or the perpetuation of the obesity.

Transient insulin increase in reactive hypoglycemia in obese and non-obese subjects

(1). Insulin levels at the moment of glucose-induced reactive hypoglycemia have been compared with zero-hour insulin levels in 108 subjects in whom the blood glucose had decreased to 50 mg percent or less (50 to 31 mg) at the third, fourth, or fifth hour in the course of an oral glucose tolerance test (1.75 g/kg of body weight). (2). Of the 47 obese subjects, insulin levels at the time of the reactive hypoglycemia were inappropriately high, ie exceeded the fasting insulin level by 20 uU/ml or more in 38 percent and by 40 microunits/ml or higher in 26 percent of the tests. (3). In 61 non-obese subjects, employing the same criteria, inappropriately high insulinemia at the time of reactive hypoglycemia was recorded with about the same frequency. (4). In each instance of reactive hypoglycemia of 50 mg percent or less with concomitant insulin levels above the starting value to the degree stipulated, the so-termed inappropriate hyperinsulinemia was transient. In other words, judging by levels preceding and/or following the reactive hypoglycemia, insulin titers were decreasing and hence, the inappropriately high insulin level at the moment of hypoglycemia represented a lag phenomenon. (5). The above data suggest that insulin levels elevated above the starting value may play a role in reactive hypoglycemia. In subjects with insulin levels at the time of reactive hypoglycemia equal to or below the starting value, the low blood glucose level cannot be attributed to insulin. In such instances, delay or lag in hepatic glucose output and/or counter-regulatory responses probably play the dominant or sole role in the reactive hypoglycemia.

FURTHER STUDY OF NITINOL WIRE AS CONTRACTILE ARTIFICIAL MUSCLE FOR AN ARTIFICIAL HEART

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