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At least 1,189 records · Page 66Linked to original sources
PubMed2001

Microbiological profile of a shipboard environment and the flora on contact lenses of seamen.

PURPOSE: The purpose of this study was to culture and identify the spectrum of organisms (and their sensitivities) that contaminate the extended wear contact lenses of seamen in their working environment. A secondary aim was to identify the most appropriate first-line antibiotic regimen to be used on seamen who sustain contact lens-related corneal keratitis on board ship. METHODS: Twenty pairs of contact lenses of 20 seamen in one group and 24 pairs in another group wearing contact lenses were collected at the end of 1 week of extended wear. Groups one and two differed only in the way lenses were stored prior to culturing. All contact lenses were then brought to the microbiological lab within 24 hours for culture and sensitivity testing. RESULTS: The most common contaminants on the contact lenses in this study were Staphylococcus epidermidis and Staphylococcus aureus, organisms resident on the normal eyelids. Enterobacterand Pseudomonas species, present in a shipboard environment, were also identified as contaminants on the contact lenses. The organisms cultured from the contact lenses correlated well with those of normal lid flora as well as from the ship environment and are probably derived from these sources. Storage in saline-containing preservatives yielded significantly less positive bacterial cultures from the contact lenses in our study. All bacterial isolates were sensitive to ciprofloxacin whereas several bacteria resistant to cefazolin and gentamicin were identified. CONCLUSION: The most common contaminants on the contact lenses in this study were Staphylococcus epidermidis and Staphylococcus aureus, organisms resident on the normal eyelids. Enterobacter and Pseudomonas species, which are normally present in a shipboard environment, were also identified as contaminants on the contact lenses. Ciprofloxacin is effective against all organisms identified as contaminants on the contact lenses in this study. Of all the antibiotics tested, it is probably the most suitable agent against contact lensrelated keratitis under such shipboard circumstances and is thus recommended in these situations.

Anti-Infective Agents↗
PubMed2001

A virtual environment for simulated rat dissection.

Animal dissection for the scientific examination of organ subsystems is a delicate procedure. Performing this procedure under the complex environment of microgravity presents additional challenges because of the limited training opportunities available that can recreate the altered gravity environment. Traditional crew training often occurs several months in advance of experimentation, provides limited realism, and involves complicated logistics. We have developed an interactive virtual environment that can simulate several common tasks performed during animal dissection. In this paper, we describe the imaging modality used to reconstruct the rat in virtual space, provide an overview of the simulation environment and briefly discuss some of the techniques used to manipulate the virtual rat.

Animals↗
PubMed1988

Plant productivity in controlled environments.

To assess the cost and area/volume requirements of a farm in a space station or Lunar or Martian base, a few laboratories in the United States, the Soviet Union, France, and Japan are studying optimum controlled environments for the production of selected crops. Temperature, light, photoperiod, CO2, humidity, the root-zone environment, and cultivars are the primary factors being manipulated to increase yields and harvest index. Our best wheat yields on a time basis (24 g m-2 day-1 of edible biomass) are five times good field yields and twice the world record. Similar yields have been obtained in other laboratories with potatoes and lettuce; soybeans are also promising. These figures suggest that approximately 30 m2 under continuous production could support an astronaut with sufficient protein and about 2800 kcal day-1. Scientists under Iosif Gitelzon in Krasnoyarsk, Siberia, have lived in a closed system for up to 5 months, producing 80% of their own food. Thirty square meters for crops were allotted to each of the two men taking part in the experiment. A functional controlled-environment life-support system (CELSS) will require the refined application of several disciplines: controlled-environment agriculture, food preparation, waste disposal, and control-systems technology, to list only the broadest categories. It has seemed intuitively evident that ways could be found to prepare food, regenerate plant nutrients from wastes, and even control and integrate several subsystems of a CELSS. But could sufficient food be produced in the limited areas and with the limited energy that might be available? Clearly, detailed studies of food production were necessary.

Biomass↗
PubMed1988

Minitron II system for precise control of the plant growth environment.

A transparent, cylindrical chamber system was developed to allow measurement of gas-exchange by small crop canopies in the undisturbed plant growth environment. The system is an elaboration of the Minitron system developed previously to compare growth of small plants in different environments within the same general growth area. The Minitron II system described herein accommodates hydroponic culture and separate control of atmospheric composition in individual chambers. Root and shoot environments are compartmented separately to accommodate atmospheres of different flow rate and/or gaseous composition. A series of 0-rings and tension-adjustable springs allow carbon dioxide in the flowing atmosphere to be analyzed without cross-contamination between chamber compartments or from external gas sources. Carbon dioxide has been maintained at set point +/- 9 g m-3 over a range of CO2 concentrations from 382 to 2725 g m-3 and with an atmosphere turnover rate of 136.7 cm3 s-1 by computer-assisted mass flow controllers. Each chamber has dimensions large enough (61 cm internal diameter, 0.151 m3 internal volume) to allow adequate replication of individual plants for statistical purposes (e.g., up to 36 equally-spaced plant holders). No significant variation in growth or photosynthetic rate of leaf lettuce occurred between chambers for a given set of environmental conditions. Gas-exchange rates in different chambers changed to a similar extent as CO2 concentration in the flowing atmosphere or chamber temperature were varied by the same amount. When coupled with appropriate control systems, Minitron II chambers can provide separate controlled environments for multiple small plants with adequate precision and at relatively low cost.

Atmosphere↗
PubMed2000

[Detection of microbes adherent to particles in a closed environment].

OBJECTIVE: In order to provide reference for controlling and monitoring the environmental contamination in the spacecraft, the species and amount of microbes, which adhere to the suspended particles with different size in a closed environment were detected. METHOD: According to USA EPA IP-10, particles were continuously sampled by an impactor in a closed environment. The particles were divided into three grades by their aerodynamic diameters (AD): 100 micrometers > or = AD > 10 micrometers, 10 micrometers > or = AD>2 micrometers and AD < or = 2 micrometers. Clean outdoor air was collected as control by the same way. The collected particles were precisely weighed. The microbes that adhere to the particles were cultivated, counted and identified. RESULT: By calculating total suspended particles (TSP) and inhalant particles (IP) of the closed environment, counting, clarifying and identifying the microbes, 6 kinds of bacteria, 2 genus of actinomyces and 6 kinds of fungi that adhere to the particles were detected. CONCLUSION: The particles in a closed environment may have some effect on human health and instruments.

Actinomyces↗
PubMed1975

Infants' home environments: a comparison of high-risk families and families from the general population.

Home environments of 30 infants at high-risk for developmental retardation were compared with those of 30 infants from the general population (matched for age, sex, and parity) by means of the Home Observation Measurement of the Environment. Fifteen high-risk infants attended a day-care intervention program; 15 did not. The Home Observation for Measurement of the Environment showed significant differences (ps less than .001) between the high-risk groups and the general population, favoring the general population, on all factors (maternal-warmth, absence of restriction and punishment, organization of the environment, appropriate toys, maternal involvement, and opportunities for variety) but none between the two high-risk groups.

Child Day Care Centers↗
PubMed2001

Interaction with the environment: anthropological cybernetic model.

Cybernetics is primarily concerned with the transfer of information through, and (re)actions of systems. The research aim was to investigate models of interaction dynamics between an anthropological system and its environment. Equifinality dynamic model defined by three compartments and propensity for establishment of a steady state regardless of the initial conditions was applied. The intention was to apply this concept in anthropological research using the OPSIM procedure. DYNOPS model defined by four age-group compartments and the environment was also used. The model was applied on the census of the Bogomolje village on the island of Hvar (R. Croatia). Through numerous simulations, it was found that the influence of the environment increases with the decrease of time spent in the young age compartment. A drawback of DYNOPS model is that it places the environment in an unchangeable category, while in reality it necessarily changes through numerous interactions with various agents. Finally, cybernetics should not only be used to explicate, but also predict and correct undesired communal developments.

Adolescent↗
PubMed2001

[Some issues on assessing natural capital of environment and ecosystems].

Many researchers recently have paid attentions to analyzing ecosystem services and assessing natural capital stocks of environment and ecosystems. However, some works failed to make a distinction among the concepts, to evaluate the value and merit of ecosystems, and to integrate assessment approaches. This paper attempts to calibrate those deviations and to present new paradigm for monetary evaluation of ecosystem services and its capital stocks. Firstly, capital value of environment and ecosystems as well as species' value should be evaluated. Secondly, new comprehensive paradigm should be employed to assess the service value of environment and ecosystems, which integrates type and regional models. Thirdly, special attentions should be paid to patterns of natural capital of environment and ecosystems due to their spatial and temporal accumulations and flows. Finally, some suggestions are proposed for assessing natural capital.

Conservation of Natural Resources↗
PubMed2003

The effects of confinement environment on reproductive efficiency in the baboon.

Historically, to supply animals for medical research, both captive-bred baboons and imported wild-caught animals have been available. Now that imported animals are difficult to obtain, it is important to maximize domestic production. To this end, it is necessary to determine the optimum housing conditions (i.e., environmentally dependent factors) under which baboons have the greatest reproductive efficiency. At our institution, the Oklahoma University Health Sciences Center Primate Facility, we recently moved the majority of our baboon breeding colony into a large indoor-outdoor facility (El Reno) from a small, indoor facility (Annex). Fortuitously, this move allowed a direct comparison of baboon reproductive efficiency between the two radically different environments. The environment at the Annex is exclusively indoor and possesses limited but adequate living space (per Guide for the Care and Use of Laboratory Animals recommendations), whereas the El Reno environment is indoor-outdoor and naturalistic with living space exceeding Guide recommendations. Although we expected animals at the El Reno facility to exhibit somewhat increased reproductive efficiency, the magnitude of the increase was surprising: the mean number of days post-partum to first estrus was 165 for animals housed in the Annex, but 69 for those at the El Reno facility. In addition, the mean number of days from first estrus to conception was 61 for baboons in the Annex compared with 47 for those at El Reno, and the mean number of days from conception to next conception was 403 for animals in the Annex but 296 for those at El Reno. These results demonstrate that a change in housing environment can dramatically increase baboon breeding efficiency.

Animals↗
PubMed2003

Rethinking twins and environments: possible social sources for assumed genetic influences in twin research.

A central sociological problem is the extent to which genetics and the environment influence human behavior. Studies of twins are a core method in attempts to disentangle and to determine the comparative strength of genetic and environmental influences on psychosocial outcomes. A critical assumption of twin studies is that both monozygotic "identical" twins and dizygotic "fraternal" twins share common social environments. Therefore, any greater similarity of monozygotic than dizygotic twins is attributed to genetic influences. This paper tests the equal environment assumption by examining the extent to which greater concordance of adolescent monozygotic compared to dizygotic twins results from social, as well as genetic, influences. Bivariate comparisons indicate that monozygotic twins show greater similarity than dizygotic twins in socially-based characteristics including physical attractiveness, time spent in each other's company, the overlap in friendship networks, and friends' use of alcohol. Multivariate analyses indicate that measures of the social environment sometimes reduce or eliminate apparent genetic effects. In comparison with genetic indicators, social variables are usually stronger predictors of depression and alcohol use and abuse. These findings suggest that past twin studies could overstate the strength of genetic influences because some similarities in behavior among monozygotic compared to dizygotic twins stem from social influences.

Adolescent↗
PubMed2003

Plant-centered biosystems in space environments: technological concepts for developing a plant genetic assessment and control system.

Plants will play an essential role in providing life support for any long-term space exploration or habitation. We are evaluating the feasibility of an adaptable system for measuring the response of plants to any unique space condition and optimizing plant performance under those conditions. The proposed system is based on a unique combination of systems including the rapid advances in the field of plant genomics, microarray technology for measuring gene expression, bioinformatics, gene pathways and networks, physiological measurements in controlled environments, and advances in automation and robotics. The resulting flexible module for monitoring and optimizing plant responses will be able to be inserted as a cassette into a variety of platforms and missions for either experimental or life support purposes. The results from future plant functional genomics projects have great potential to be applied to those plant species most likely to be used in space environments. Eventually, it will be possible to use the plant genetic assessment and control system to optimize the performance of any plant in any space environment. In addition to allowing the effective control of environmental parameters for enhanced plant productivity and other life support functions, the proposed module will also allow the selection or engineering of plants to thrive in specific space environments. The proposed project will advance human exploration of space in the near- and mid-term future on the International Space Station and free-flying satellites and in the far-term for longer duration missions and eventual space habitation.

Agriculture↗
PubMed2003

Role of probiotics on the environment of shrimp pond.

Recent disease outbreak in shrimp farming caused mainly by bacteria, virus, fungi or a combination of these etiologic agents is attributed to disturbance in the environment of pond. To combat this, different antibiotics and chemicals are being used which are reported to be not environment friendly. Of late, a new and unique biotechnological product called "Probiotics " is being used widely by all the shrimp farmers worldwide, which is found to be more effective and environmentally safe also. In the present study 2 probiotics were used in a small 0.7 ha shrimp farm near Pattukottai in Tamil Nadu State for one culture period for the management of pond environment and also the gut ecology of Penaeus monodon. The environmental parameters analysed were within the acceptable limits. It was evident from the results that the production was better in the experimental pond where the probiotics were used. The biological parameters such as the average body weight, FCR and total harvest achieved were better in the experimental pond than the control pond, all due to congenial environment, which obtained in the former mainly due to the use of probiotics.

Animals↗
PubMed1992

Repressive adaptation and family environment.

The hypothesized connection between adaptive style, specifically repressive adaptation, and the family environments of adolescent clinical samples was investigated. Adolescent patients (n = 221) were studied, who were then divided into four groups matched for sex, age, and socioeconomic status (mean age = 15.7 years, SD 2; sex = 14% boys, 86% girls; SES = 2.4). Grouping was based on the Marlowe Crowne Social Desirability Scale and Spielberger's Trait Anxiety Inventory Scores [repressors (n = 43), impression managers (n = 54), high anxious (n = 55) and low anxious (n = 69)]. Results by MANOVA, Scheffe and discriminate function analysis confirmed our hypothesis. Repressors had distinct family environments as measured by the Family Environment Scale (p = 0.0001). Families were characterized by high levels of cohesion, expressiveness, independence, and organization, displaying correspondingly low levels of achievement orientation, conflict, control and incongruence. Repression may be an effort to adapt to an idealized family environment.

Adaptation, Psychological↗
PubMed2003

Enriched environment confers resistance to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and cocaine: involvement of dopamine transporter and trophic factors.

We investigated, in mice, the influence of life experience on the vulnerability to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a major neurotoxin that induces a Parkinson's disease-like syndrome in humans, and to cocaine, a potent psychostimulant that promotes drug addiction. Our findings show that adult C57BL/6 mice raised in an enriched environment (EE) for only 2 months are significantly more resistant to both drugs compared with mice raised in a standard environment (SE). Indeed, EE mice showed decreased locomotor activity in response to cocaine (10 and 20 mg/kg) as well as a different pattern of c-fos expression in the striatum compared with SE mice. After MPTP treatment, SE mice showed a 75% loss of dopamine neurons, whereas EE mice showed only a 40% loss. The dopamine transporter plays a key role in mediating the effects of both drugs. We thus investigated the regulation of its expression. EE mice showed less dopamine transporter binding in the striatum and less dopamine transporter mRNA per dopamine neuron at the cellular level as demonstrated by in situ hybridization. In addition, enriched environment promoted an increase in the expression of brain-derived neurotrophic factor in the striatum. These data provide a direct demonstration of the beneficial consequences that a positive environment has in preventing neurodegeneration and in decreasing responsiveness to cocaine. Furthermore, they suggest that the probability of developing neurological disorders such as Parkinson's disease or vulnerability to psychostimulants may be related to life experience.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed2003

Staff nurses' perceptions of the work environment in freestanding hemodialysis facilities.

While one suggested cause of the current nursing shortage is nurses' negative perceptions of the work environment, little is known of nephrology nurses' perceptions of the dialysis work environment. The purpose of this study was to assess the extent to which staff nurses who work in freestanding hemodialysis facilities rate the presence of organizational characteristics common to magnet hospitals in their current job. Study findings indicate that staff nurses in hemodialysis units identify several notable features of magnet hospitals in their work settings. However, a majority of nurses disagreed that many attributes of magnet hospitals are present in hemodialysis work environments. This study provides a preliminary description of some of the factors that affect nurses' perceptions of the work environment in freestanding dialysis facilities. Further work is needed in this area.

Adult↗
PubMed2005

Modeling human behaviors and reactions under dangerous environment.

This paper describes the framework of a real-time simulation system to model human behavior and reactions in dangerous environments. The system utilizes the latest 3D computer animation techniques, combined with artificial intelligence, robotics and psychology, to model human behavior, reactions and decision making under expected/unexpected dangers in real-time in virtual environments. The development of the system includes: classification on the conscious/subconscious behaviors and reactions of different people; capturing different motion postures by the Eagle Digital System; establishing 3D character animation models; establishing 3D models for the scene; planning the scenario and the contents; and programming within Virtools Dev. Programming within Virtools Dev is subdivided into modeling dangerous events, modeling character's perceptions, modeling character's decision making, modeling character's movements, modeling character's interaction with environment and setting up the virtual cameras. The real-time simulation of human reactions in hazardous environments is invaluable in military defense, fire escape, rescue operation planning, traffic safety studies, and safety planning in chemical factories, the design of buildings, airplanes, ships and trains. Currently, human motion modeling can be realized through established technology, whereas to integrate perception and intelligence into virtual human's motion is still a huge undertaking. The challenges here are the synchronization of motion and intelligence, the accurate modeling of human's vision, smell, touch and hearing, the diversity and effects of emotion and personality in decision making. There are three types of software platforms which could be employed to realize the motion and intelligence within one system, and their advantages and disadvantages are discussed.

Artificial Intelligence↗
PubMed2005

[Perception of their social environment and their future in institutionalized school-age children].

Family home and institutions for children without parental care represent the rearing-environments where, from the early years, whole human development goes on. It's known today that despite the recognized importance of inborn traits, the influence of child-rearing environments dominates current models of development. The aim of the study was to investigate the satisfaction with the rearing-environment of school-aged institutionalized children, their dominating feeling and if institutionalization affects life optimism for now and for the future. The study was conducted in two institutions in Bosnia and Herzegovina who share the same care model imitating the traditional Bosnian families where the older children care for the younger siblings. We took as a sample 30 institutionalized children aged 8-12, and for the control group 60 children matched by age and sex. Parents, children and teachers who gave their informed consent answered the questionnaires. It was confirmed that children without parental care are vulnerable group and in a great risk who need urgent help of professional multidisciplinary team of their close and broad environment. Lack of social support cause the withdrawing and suffering and can lead soon or later to problematic behaviour.

Bosnia and Herzegovina↗
PubMed2005

Appraisal of the dental school learning environment: the students' view.

The majority of studies examining dental school curriculum have addressed organization, structure, and content issues from the perspectives of administrators, faculty, practitioners/alumni, and professional organizations. However, few studies have focused on students' opinions of dental school. The purpose of this study was to determine students' perceptions of the learning environment, intellectual climate, and teacher-student relationships in dental school. This report describes how the "dental version" of the Medical Student Learning Environment Survey (MSLES) was used to identify students' perceptions of their dental education. Freshman and junior dental students' perceptions were measured with the Dental Student Learning Environment Survey (DSLES), which evaluates learning environment, intellectual climate, and relationships among students and teachers in seven areas: flexibility, student-to-student interaction, emotional climate, supportiveness, meaningful experience, organization, and breadth of interest. The DSLES was mailed to twenty-three dental schools in North America with eighteen of the schools distributing the inventory. A total of 619 dental students responded. Results were differentiated between freshman and junior dental students. Both freshman and junior students provided the highest (most positive) ratings for the DSLES subscales of "breadth of interest" (interest in dentistry and outside interests are encouraged) and "meaningful learning experience" (significance of courses to dentistry). Freshman students provided the lowest (least positive) ratings for "emotional climate" (students' responses to the way their courses were conducted and stress levels), and junior students provided the least positive ratings for "faculty supportiveness" (extent of faculty support and encouragement provided to students). The DSLES identified students' perceptions of their educational experience and localized areas for improvement. By addressing these areas of concern, faculty can increase student satisfaction with their dental education.

Curriculum↗