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PubMed2003

Quantum master equation for a system influencing its environment.

A perturbative quantum master equation is derived for a system interacting with its environment, which is more general than the ones derived before. Our master equation takes into account the effect of the energy exchanges between the system and the environment and the conservation of energy in the finite total system. This master equation describes relaxation mechanisms in isolated nanoscopic quantum systems. In its most general form, this equation is non-Markovian and a Markovian version of it rules the long-time relaxation. We show that our equation reduces to the Redfield equation in the limit where the energy of the system does not affect the density of state of its environment. This master equation and the Redfield one are applied to a spin-environment model defined in terms of random matrices and compared with the solutions of the exact von Neumann equation. The comparison proves the necessity to allow energy exchange between the subsystem and the environment in order to correctly describe the relaxation in an isolated nanoscopic total system.

Journal Article↗

PubMed2004

Effects of developmental environment on signal-preference coupling in a Hawaiian cricket.

Previous work has suggested that developmental temperature influences expression of the adult male calling song of the cricket, a sexually selected mate recognition signal. The role of developmental temperature in shaping female preference functions, and thus its influence on signal-preference coupling has not been investigated. In this study, the effects of developmental temperature are examined in both males and females of the Hawaiian cricket, Laupala cerasina, to determine the degree of signal-preference matching between male song and female preference due to developmental environment. We found that rearing females in different temperature environments affected adult female acoustic preference functions in the same direction as male calling song, thereby influencing variation in adult reproductive behavior in such a way that male and female components remain coordinated. However, we further demonstrate that for male song, the effect of the rearing environment is not permanent but appears only to exert influence for a period of days. This mid-term temperature effect is distinct from the effect of short-term ambient temperature, which influences song in a matter of minutes and has been well documented. Signal-preference coordination, and sexual selection pressures due to mismatching within natural populations, likely will be influenced by nymphal developmental environments of males and females, as well as by adult singing and preference environments.

Animal Communication↗

PubMed2006

Transcranial fluorescence imaging of auditory cortical plasticity regulated by acoustic environments in mice.

Functional brain imaging using endogenous fluorescence of mitochondrial flavoprotein is useful for investigating mouse cortical activities via the intact skull, which is thin and sufficiently transparent in mice. We applied this method to investigate auditory cortical plasticity regulated by acoustic environments. Normal mice of the C57BL/6 strain, reared in various acoustic environments for at least 4 weeks after birth, were anaesthetized with urethane (1.7 g/kg, i.p.). Auditory cortical images of endogenous green fluorescence in blue light were recorded by a cooled CCD camera via the intact skull. Cortical responses elicited by tonal stimuli (5, 10 and 20 kHz) exhibited mirror-symmetrical tonotopic maps in the primary auditory cortex (AI) and anterior auditory field (AAF). Depression of auditory cortical responses regarding response duration was observed in sound-deprived mice compared with naïve mice reared in a normal acoustic environment. When mice were exposed to an environmental tonal stimulus at 10 kHz for more than 4 weeks after birth, the cortical responses were potentiated in a frequency-specific manner in respect to peak amplitude of the responses in AI, but not for the size of the responsive areas. Changes in AAF were less clear than those in AI. To determine the modified synapses by acoustic environments, neural responses in cortical slices were investigated with endogenous fluorescence imaging. The vertical thickness of responsive areas after supragranular electrical stimulation was significantly reduced in the slices obtained from sound-deprived mice. These results suggest that acoustic environments regulate the development of vertical intracortical circuits in the mouse auditory cortex.

Acoustic Stimulation↗

PubMed1999

Population health environmental indicators: ecologic monitoring of environment-related health and disease trends.

BACKGROUND: Current State of the Environment (SoE) reporting focuses primarily on indicators directly related to the physical environment such as climate, and air, water and soil quality. As the environment has both direct and indirect effects on human health, an opportunity exists to include environment-related human disease indicators as an SoE indicator theme. OBJECTIVE: To develop a set of population health environmental indicators (PHEIs, phi s) that can illustrate environment-related disease (ERD) trends at the population level. METHODS: A literature review was conducted on environmental health monitoring and the current knowledge of environmental effects on human health. Key PHEIs were identified and routine health data collections accessed and analysed to illustrate temporal and geographic trends. RESULTS: Diseases with an environmental aetiology are tabulated and examples are given of the type and range of PHEIs that can be developed for an Australian geographic area. CONCLUSIONS: Illustrating environmental degradation in terms of resultant human diseases is a potent tool for promoting environmental protection measures. This paper examines a range of PHEIs that may be used as indicators of both environmental disease and environmental quality. IMPLICATIONS: PHEIs could be developed as a useful SoE indicator theme, and as a tool to help foster the convergence which is occurring between environmental health and public health fields.

Australia↗

PubMed2001

[Detection of gram-negative bacteria in patients and hospital environment at a room in geriatric wards under the infection control against MRSA].

We prospectively surveyed gram-negative bacteria in patients and hospital environment in a room in the geriatric ward which was specifically under the infection control against MRSA once every two weeks between September and December 1996. We investigated the inpatients in an 8-bed room in the geriatric wards (190 beds) of AINO Memorial Hospital, affiliated with Nagasaki University. During the study period, we performed a total of 431 cultures. The number of specimens cultured was 116 from airways (nose, 42; pharynx, 42; sputum, 32), 24 from decubitus ulcer, 40 from urine, 42 from feces, a total of 125 from skin (head, 42; forearm, 42; inguinal region, 41), and 84 from the hospital environment (floor swab, 42; settled agar plate, 42), respectively. A total of 15 species were isolated from the hospital environment. Some species were the same as those which were recovered from the hospital environment were those observed on each body site. In the hospital environment, the isolation rates of Acinetobacter baumanii and Klebsiella pneumoniae were significantly high in the settled agar plate (A. baumanii, p < 0.01; K. pneumoniae, p < 0.05, respectively). Isolation rates of Pseudomonas aeruginosa, Citrobacter spp., and Enterobacter sakazakii were also high in the settled agar plate (p = 0.078, 0.078, 0.078, respectively). In conclusion, gram-negative bacteria in patients may be associated with the environmental bacteria in the room in the geriatric wards.

Aged↗

PubMed2006

Survival and transmission of Salmonella enterica serovar typhimurium in an outdoor organic pig farming environment.

It was investigated how organic rearing conditions influence the Salmonella enterica infection dynamics in pigs and whether Salmonella persists in the paddock environment. Pigs inoculated with S. enterica serovar Typhimurium were grouped with Salmonella-negative tracer pigs. Bacteriological and serological testing indicated that organic pigs were susceptible to Salmonella infections, as 26 of 46 (56%) tracer pigs turned culture positive. An intermittent and mainly low-level excretion of Salmonella (<100 cells g-1) partly explains why the bacteriological prevalence appeared lower than the seroprevalence. Salmonella persisted in the paddock environment, as Salmonella was isolated from 46% of soil and water samples (n=294). After removal of pigs, Salmonella was found in soil samples for up to 5 weeks and in shelter huts during the entire test period (7 weeks). Subsequent introduction of Salmonella-negative pigs into four naturally Salmonella-contaminated paddocks caused Salmonella infections of pigs in two paddocks. In one of these paddocks, all tracer pigs (n=10) became infected, coinciding with a previous high Salmonella infection rate and high Salmonella excretion level. Our results showed that pigs reared under organic conditions were susceptible to Salmonella infections (just like conventional pigs) and that Salmonella persisting in the paddock environment could pose an infection risk. A driving force for these infections seemed to be pigs with a high Salmonella excretion level, which caused substantial contamination of the environment. This suggests that isolation of animals as soon as a Salmonella infection is indicated by clinical symptoms of diarrhea could be a means of reducing and controlling the spread and persistence of Salmonella in outdoor organic pig production environments.

Animal Husbandry↗

PubMed1988

Temporal relationship of Vibrio parahaemolyticus in patients and the environment.

We prospectively compared the occurrence of Vibrio parahaemolyticus in patients and the environment in the Pacific Northwest. Inpatient and outpatient stool and wound specimens and water samples from 10 estuarine sites were cultured for V. parahaemolyticus over a period of 3 years. V. parahaemolyticus infections were detected in 13 patients (8 with gastroenteritis; 5 with wound infections), and all of the infections were found in outpatients in physicians' offices. Ten of the infections were locally acquired, and three occurred in patients returning from tropical travel. V. parahaemolyticus was isolated from 11 to 33% of the environmental samples, and each sampling site yielded the organism at some time during the study. V. parahaemolyticus was found in the environment only during the summer months, when water temperatures were greater than or equal to 17 degrees C and salinities were less than or equal to 13% (parts per thousand), and locally acquired infections were detected only when the organism was present in large numbers in the environment. We conclude that V. parahaemolyticus causes locally acquired gastroenteritis and wound infections, as well as traveler's diarrhea, in the Pacific Northwest, that patients with V. parahaemolyticus infections are likely to be seen in physicians' offices rather than hospitals, that locally acquired V. parahaemolyticus infections occur only when the organism is present in the environment, and that the organism is likely to be present during the summer months, when warm, low-salinity water conditions prevail in the coastal marine environment.

Gastroenteritis↗

PubMed2005

Isolation and molecular characterization of Staphylococcus sciuri in the hospital environment.

Staphylococcus sciuri is a principally animal-associated bacterial species, but its clinical relevance for humans is increasing. Our study aimed to provide the first insight into the prevalence of this bacterium in a hospital environment. A 3-month surveillance was conducted in a hospital located in Belgrade, Serbia, and 1,028 samples taken from hands of medical personnel, medical devices, and various hospital surfaces were screened for S. sciuri presence. In total, 108 isolates were obtained, which resulted in a relatively high rate of colonization (10.5%). These isolates, along with 7 S. sciuri strains previously isolated in the same hospital (n = 115), were phenotypically and genotypically characterized. Antimicrobial susceptibility testing revealed that 73% of the strains were resistant to one or more antibiotics, with 4.3% strains displaying multiresistance. Examination of 16S-23S ribosomal DNA intergenic spacer length polymorphism identified the strains at the subspecies level, and 74 (64.3%) strains of S. sciuri subsp. sciuri, 37 (32.2%) strains of S. sciuri subsp. rodentium, and 4 (3.5%) strains of S. sciuri subsp. carnaticus were established. Pulsed-field gel electrophoresis (PFGE) analysis showed 21 distinct pulsotypes, including 17 main types and 4 subtypes. One dominant cluster with 62 strains was found, while 19 (90.5%) of the PFGE types and subtypes identified had 5 or fewer strains. The predominance of small PFGE clusters suggests that the ubiquitous presence of S. sciuri in the outside environment presents the continuous source for colonization of the hospital environment. The presence of one dominant PFGE cluster of strains indicates that some S. sciuri strains may be capable for adaptation to hospital environment conditions and continuous existence in this environment.

Anti-Bacterial Agents↗

PubMed2003

Examination of EmrE conformational differences in various membrane mimetic environments.

Ethidium multidrug resistance protein (EmrE) is a member of the small multidrug resistance family of proteins and is responsible for resistance in Escherichia coli to a diverse group of lipophilic cations. Research is beginning to elucidate structural information as well as substrate binding and extrusion mechanisms for this protein. However, the choice of membrane mimetic environment to perform structural studies needs to be made. In this study EmrE was solubilized in different membrane mimetic environments to investigate the influence of environment on the structure and dynamics of the protein by comparing the fluorescence properties of emission maxima, peak shifts, relative intensities, acrylamide quenching constants, and polarization. Taken together, the different fluorescence observations on EmrE in the various membrane mimetic systems tested suggest that the tryptophan residues in EmrE are present in the most flexible and exposed state when solubilized in methanol, followed by sodium dodecyl sulfate and urea. The two detergents N-dodecyl-beta-D-maltoside (DM) and polyoxyethylene(8)dodecyl ether, for the most part, only display subtle differences between the spectral properties with DM best representing the lipid environment. The conformation of EmrE is clearly more open and dynamic in detergent relative to being reconstituted in small unilamellar vesicles. The fluorescence observations of EmrE solubilized in trifluoroethanol shows an environment that is similar to that of EmrE solubilized in detergents. Additionally, secondary structure was monitored by circular dichroism (CD). The CD spectra were similar among the different solubilizing conditions, suggesting little difference in alpha-helical content. This work establishes groundwork for the choice of solubilizing conditions for future structural, folding, and ligand binding studies.

Acrylamide↗

PubMed1995

Cellulose degradation in anaerobic environments.

In anaerobic environments rich in decaying plant material, the decomposition of cellulose is brought about by complex communities of interacting microorganisms. Because the substrate, cellulose, is insoluble, bacterial and fungal degradation occurs exocellularly, either in association with the outer cell envelope layer or extracellularly. Products of cellulose hydrolysis are available as carbon and energy sources for other microbes that inhabit environments in which cellulose is biodegraded, and this availability forms the basis of many microbial interactions that occur in these environments. This review discusses interactions among members of cellulose-decomposing microbial communities in various environments. It considers cellulose decomposing communities in soils, sediments, and aquatic environments, as well as those that degrade cellulose in association with animals. These microbial communities contribute significantly to the cycling of carbon on a global scale.

Anaerobiosis↗

PubMed1991

Ultrastructural studies on the effects of hypergravity environment on the parathyroid glands in golden hamsters of different ages.

The ultrastructure of the parathyroid glands of infantile, young, adult and senile golden hamsters subjected to a hypergravity environment was studied. In the parathyroid glands of 5-, 10- and 20-day-old, and 1- and 3-month-old golden hamsters exposed to a hypergravity environment, the Golgi complexes were significantly increased, and in 5-, 10- and 20-day-old, and 1- and 8-month-old animals exposed to a hypergravity environment, the cisternae of the granular endoplasmic reticulum appeared to be increased as compared to those of each control group. In addition, in centrifuged animals numerous prosecretory granules were observed in the Golgi areas, and many secretory granules were located in the peripheral cytoplasm. The ultrastructure of the parathyroid glands of 14-month-old centrifuged animals resembled that of 14-month-old control animals. These results suggest that the secretory activity of the parathyroid gland may be stimulated in infantile, young and adult golden hamsters subjected to a hypergravity environment and may not be stimulated in senile animals subjected to a hypergravity environment.

Aging↗

PubMed1993

Quaternary environments and the evolution of primates in East Asia, with notes on two new specimens of fossil Cercopithecidae from China.

Primate faunas in East Asia since the mid-Tertiary have undergone a series of major changes in response to a complex sequence of environmental changes. As a consequence of the Himalayan orogeny and the rapid, episodic uplift of the Tibetan plateau, the climate of East Asia during the late Tertiary became monsoonal and thus more strongly seasonal. This led to the expansion of seasonal tropical forests and, in some areas, grasslands. During the Pleistocene, the climatic consequences of continued rapid uplift of the Tibetan plateau and other land masses (e.g. the Qinling mountains) were combined with those of glaciations, resulting in dramatic climatic oscillations between warm-humid and cold-dry phases. The contraction of tropical environments that began in the late Tertiary reached its peak at the last glacial maximum (LGM) and was responsible for the decline in the distribution and diversity of hominoids in East Asia. Cercopithecids, which were only minor elements of the late Tertiary primate faunas, colonized tropical, subtropical and temperate environments in the Pleistocene and were able to reradiate into those environments after the LGM. The abilities of monkeys to populate a wide range of terrestrial environments (eurytopy) contrast with those of apes, which are restricted to tropical forest environments (stenotopy).

Animals↗

PubMedDate not supplied

The effects of exercise in forest and urban environments on sympathetic nervous activity of normal young adults.

In Japan, forest-air bathing and walking (shinrin-yoku) has been proposed as a health-facilitating activity in which people spend a short period of time in a forest environment. Initially, we examined the usefulness of salivary amylase activity as an indicator of an individual's stress levels in a forest environment. The circadian rhythm of salivary amylase activity was measured in healthy young male subjects under stress-free conditions. The salivary amylase activity remained relatively constant throughout the day. Salivary amylase activity was then measured before and after walking in both urban and forest environments using a hand-held monitor. Our results indicated that (i) the circadian rhythm fluctuations in salivary amylase activity were much smaller than the stressor-induced variations; (ii) salivary amylase activity was an excellent indicator of the changes in sympathetic nervous activity; and (iii) the forest was a good environment in which people could experience much less environment-derived stress.

Adult↗

PubMed2006

High fidelity medical simulation in the difficult environment of a helicopter: feasibility, self-efficacy and cost.

BACKGROUND: This study assessed the feasibility, self-efficacy and cost of providing a high fidelity medical simulation experience in the difficult environment of an air ambulance helicopter. METHODS: Seven of 12 EM residents in their first postgraduate year participated in an EMS flight simulation as the flight physician. The simulation used the Laerdal SimMantrade mark to present a cardiac and a trauma case in an EMS helicopter while running at flight idle. Before and after the simulation, subjects completed visual analog scales and a semi-structured interview to measure their self-efficacy, i.e. comfort with their ability to treat patients in the helicopter, and recognition of obstacles to care in the helicopter environment. After all 12 residents had completed their first non-simulated flight as the flight physician; they were surveyed about self-assessed comfort and perceived value of the simulation. Continuous data were compared between pre- and post-simulation using a paired samples t-test, and between residents participating in the simulation and those who did not using an independent samples t-test. Categorical data were compared using Fisher's exact test. Cost data for the simulation experience were estimated by the investigators. RESULTS: The simulations functioned correctly 5 out of 7 times; suggesting some refinement is necessary. Cost data indicated a monetary cost of 440 dollars and a time cost of 22 hours of skilled instructor time. The simulation and non-simulation groups were similar in their demographics and pre-hospital experiences. The simulation did not improve residents' self-assessed comfort prior to their first flight (p > 0.234), but did improve understanding of the obstacles to patient care in the helicopter (p = 0.029). Every resident undertaking the simulation agreed it was educational and it should be included in their training. Qualitative data suggested residents would benefit from high fidelity simulation in other environments, including ground transport and for running codes in hospital. CONCLUSION: It is feasible to provide a high fidelity medical simulation experience in the difficult environment of the air ambulance helicopter, although further experience is necessary to eliminate practical problems. Simulation improves recognition of the challenges present and provides an important opportunity for training in challenging environments. However, use of simulation technology is expensive both in terms of monetary outlay and of personnel involvement. The benefits of this technology must be weighed against the cost for each institution.

Adult↗

PubMed2006

Do attributes in the physical environment influence children's physical activity? A review of the literature.

BACKGROUND: Many youth today are physically inactive. Recent attention linking the physical or built environment to physical activity in adults suggests an investigation into the relationship between the built environment and physical activity in children could guide appropriate intervention strategies. METHOD: Thirty three quantitative studies that assessed associations between the physical environment (perceived or objectively measured) and physical activity among children (ages 3 to 18-years) and fulfilled selection criteria were reviewed. Findings were categorized and discussed according to three dimensions of the physical environment including recreational infrastructure, transport infrastructure, and local conditions. RESULTS: Results across the various studies showed that children's participation in physical activity is positively associated with publicly provided recreational infrastructure (access to recreational facilities and schools) and transport infrastructure (presence of sidewalks and controlled intersections, access to destinations and public transportation). At the same time, transport infrastructure (number of roads to cross and traffic density/speed) and local conditions (crime, area deprivation) are negatively associated with children's participation in physical activity. CONCLUSION: Results highlight links between the physical environment and children's physical activity. Additional research using a transdisciplinary approach and assessing moderating and mediating variables is necessary to appropriately inform policy efforts.

Journal Article↗

PubMed2005

Effect of the hospital nursing environment on patient mortality: a systematic review.

OBJECTIVE: Research has examined the effect of the structure of health systems on health outcomes, but not how outcomes are affected by the nursing environments in hospitals. Our objective was to gather, critically appraise and synthesize all relevant primary research on the effect of the nursing environment on patient mortality. METHODS: Five electronic bibliographic databases were searched from their beginning through to May/June 2001, and Medline and CINAHL were updated to March 2004, using pre-determined search strategies and inclusion criteria. Studies were included if they met pre-determined criteria, reporting primary data both on a hospital environment and patient mortality. Methodological rigour was appraised using accepted criteria for the evaluation of research protocols, including case-mix adjustment. RESULTS: This paper focuses on 27 identified studies that investigated the impact of one or more attributes of the nursing environment on patient mortality. Nineteen studies found an association between one or more unfavourable attributes and higher mortality. There was considerable variability in attribute and outcome measures, settings and research quality across studies. This precluded statistical pooling of results. CONCLUSIONS: On balance, current evidence indicates that social and environmental attributes of hospital nursing practice have an effect on the outcomes of care. Before optimal practice settings can be designed, further research of greater rigour is needed to provide a better understanding of the mechanisms that link the nursing environment to patient outcomes.

Health Services Research↗

PubMed2002

Impact of current good manufacturing practices and emission regulations and guidances on the discharge of pharmaceutical chemicals into the environment from manufacturing, use, and disposal.

The current Good Manufacturing Practice (cGMP) and effluent emission (use and disposal) regulations of the U.S. Food and Drug Administration (FDA) and manufacturing effluent discharge and emission regulations of the U.S. Environmental Protection Agency (U.S. EPA) require contained manufacture, use, and disposal of pharmaceuticals with the goal of minimizing the release of pharmaceutical chemicals into the environment. However, debate has recently arisen in several scientific forums over whether these regulations adequately protect human and environmental health from the new pharmaceutical drugs introduced each year into the marketplace and the multitude of existing products, each with many distinct biochemical modes of actions. To address this issue, it is important to understand the relevance of current cGMP regulations and emission regulations that have a direct bearing on the releases of pharmaceutical chemicals into the environment during the manufacture, use, and disposal of active pharmaceutical ingredients (drug substances) and drug products. This knowledge may help us assess the quantity of residues that may be released into the environment. Additionally, the information on physical, chemical, and degradation and sorption properties of the pharmaceutical chemicals may help determine the net residue levels that could persist in the environment to evaluate if such residues have any bearing on human and environmental health. The scientific and regulatory aspects of issues related to the manufacture, use, and disposal of pharmaceutical chemicals are discussed in this article, with special emphasis on potential environmental exposure pathways during the life cycle of an active pharmaceutical ingredient or drug product. The mechanisms of degradation (transformation or depletion) and dilution of pharmaceutical residues that may be released into aquatic or terrestrial environmental compartments are described. Such degradation and dilution of pharmaceutical chemicals in the environment may significantly reduce the residues. It is important to evaluate whether such residue levels have any measurable impact on human and/or environmental health.

Drug Industry↗

PubMed2002

Environmental justice: building a unified vision of health and the environment.

The assorted and multidimensional concerns that give rise to the issue of environmental justice have proved to be intellectually daunting and highly resistant to positive change. Low-income, people of color, and tribal communities confronting environmental stressors are beset by stressors in both the physical and social environments. For this reason, while the bifurcation of the public health and environmental fields taking place over the past several decades has yielded generally negative impacts in areas of public health, environment, and planning, the consequences for low-income and disadvantaged communities have been especially grievous. This commentary builds on the recent Institute of Medicine workshop titled "Rebuilding the Unity of Health and the Environment: A New Vision of Environmental Health for the 21st Century." The workshop organizers posited that only by thinking about environmental health on multiple levels will it be possible to merge various strategies to protect both the environment and health. In this commentary we examine how such a new vision of uniting public health and the environment can contribute to attaining environmental justice for all populations.

Environmental Health↗