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PubMed2000

Expression of Fos-related antigens in the nucleus accumbens and associated regions following exposure to a cocaine-paired environment.

This study examined whether conditioned hyperactivity measured in a cocaine-paired environment was associated with increased expression of Fos-related antigens (FRA) within the nucleus accumbens (NAc) and associated forebrain regions of rats. Three groups of rats were given repeated injections of either cocaine in the test environment and saline in the colony room (group Paired), saline in the test environment and cocaine in the colony room (group Unpaired), or saline in both environments (group Control). All rats were subsequently given a drug-free test for conditioned hyperactivity in the test environment, and their brains were removed so that FRA immunohistochemistry could be conducted. Rats in the Paired group showed conditioned hyperactivity during the conditioning test, and this behavioural response was associated with increased FRA expression within the caudal NAc, the medial prefrontal cortex and the lateral septum relative to the Unpaired and Control groups. Paired rats also showed increased FRA expression within the orbital prefrontal cortex, the claustrum, the caudal amygdala (basolateral and central regions), the paraventricular thalamic nucleus, the subiculum of the hippocampus, and the lateral habenula relative to the Control group. However, the FRA levels in these latter sites were not significantly increased relative to those of Unpaired rats, indicating that genomic responses in these regions were not entirely context dependent. The correspondence between conditioned hyperactivity and enhanced FRA expression within the caudal NAc, the medial prefrontal cortex and lateral septum suggests that these regions may participate in the expression of conditioned responses to cocaine-related stimuli.

Amygdala↗

PubMedDate not supplied

Mammalian wound repair environment does not permit skeletal muscle regeneration.

Repair and regeneration are mutually exclusive responses to injury. Previous studies have shown that wound fluids promote proliferation, but not differentiation, of myoblasts in vitro. This study explored the ability of the repair environment within polyvinyl alcohol sponges to support cellular events of skeletal muscle regeneration in vivo. Neonatal rat L8 myoblasts were modified to express beta-galactosidase then inoculated into plain sponges or sponges containing minced muscle. Labeled myoblasts were found in myotubes within minced muscle. In contrast, myoblasts inoculated into sponges lacking muscle remained mononucleate. Occurrence of labeled myoblasts within myotubes, which required fusion, represents differentiation of inoculated myoblasts to participate in regeneration. Failure of myoblasts to form myotubes in sponges lacking muscle suggests that this wound repair environment cannot support morphologic differentiation of myoblasts. Although this repair environment can support the survival of myoblasts, it did not support myogenesis, an event necessary to complete skeletal muscle regeneration. Data from this study reinforce earlier studies in vitro and suggest that the properties attributed to wound fluids are inherent in the wound environment. Whether the inability of this environment to support myogenesis is the consequence of the absence of essential factors or the presence of inhibitors remains to be determined.

Journal Article↗

PubMed2000

Pets and cockroaches: two increasing causes of respiratory allergy in indoor environments. Characteristics of airways sensitization and prevention strategies.

The increasing prevalence of allergic sensitization to indoor allergens such as dust mites, pets and cockroaches is the result of the changes in indoor environments induced by human activities. The Westernized lifestyle and the increasing time spent indoors determine a reduction in natural air ventilation and, consequently, higher levels of allergen concentrations and longer exposure to allergens. The major cat allergen Fel d 1 is carried by small-dimension particles (< 5 microm diameter) that readily become airborne and persist immodified for a long time. Fel d 1 must be considered a ubiquitous allergen because it has been found in indoor environments and even in public places where a cat has never been kept. Recent research has demonstrated that clothing of cat owners may contribute to the dispersal of Fel d 1 in cat-free environments. Therefore, washing Fel d 1-contaminated clothes should be considered a simple and effective method for removing this allergen from clothing and, consequently, reducing the risk of Fel d 1 dispersion. Cockroach allergens constitute another important cause of environment-related respiratory allergy and may trigger asthma exacerbations in sensitized individuals. In the prevention of cockroach allergy, the use of chemical agents associated with an intensive vacuum cleaning of indoor environments is an important tool in removing cockroach material containing allergenic proteins. Early recognition of allergy-predisposed babies, monitoring indoor allergens and adequate strategies of allergen avoidance are likely to be important means for reducing the prevalence of bronchial asthma.

Allergens↗

PubMed1994

State practice environments and the supply of physician assistants, nurse practitioners, and certified nurse-midwives.

BACKGROUND: Most proposals to increase access to primary care in the United States emphasize increasing the proportion of generalist physicians. Another approach is to increase the number of physician assistants, nurse practitioners, and certified nurse-midwives. METHODS: We analyzed variations in the regulation of nurse practitioners, physician assistants, and certified nurse-midwives in all 50 states and the District of Columbia. Using a 100-point scoring system, we assigned numerical values to specific characteristics of the practice environment in each state for each group of practitioners, awarding a maximum of 20 points for legal status, 40 points for reimbursement for services, and 40 points for the authority to write prescriptions. We calculated coefficients for the correlation of summary measures of these values within states with estimates of the supply of practitioners per 100,000 population. RESULTS: There was wide variation among states in both practice-environment scores and practitioner-to-population ratios for all three groups of practitioners. We found positive correlations within states between the supply of physician assistants, nurse practitioners, and certified nurse-midwives and the practice-environment score for the state (Spearman rank-correlation coefficients, 0.63 [P < 0.001], 0.41 [P = 0.003], and 0.51 [P < 0.001], respectively). Positive associations were also found in the states between the supply of generalist physicians and the supply of physician assistants (r = 0.54, P < 0.001) and nurse practitioners (r = 0.35, P = 0.014). Nevertheless, in the 17 states with the greatest shortages of primary care physicians, favorable practice-environment scores were still associated with higher practitioner-to-population ratios for physician assistants (r = 0.68, P = 0.003), nurse practitioners (r = 0.54, P = 0.026), and certified nurse-midwives (r = 0.42, P = 0.09). CONCLUSIONS: State regulation of physician assistants, nurse practitioners, and certified nurse-midwives varies widely. Favorable practice environments are strongly associated with a larger supply of these practitioners.

Health Services Accessibility↗

PubMed2005

Utilising the synergy between plants and rhizosphere microorganisms to enhance breakdown of organic pollutants in the environment.

BACKGROUND: Phytoremediation is a promising technology for the cleanup of polluted environments. The technology has so far been used mainly to remove toxic heavy metals from contaminated soil, but there is a growing interest in broadening its applications to remove/degrade organic pollutants in the environment. Both plants and soil microorganisms have certain limitations with respect to their individual abilities to remove/breakdown organic compounds. A synergistic action by both rhizosphere microorganisms that leads to increased availability of hydrophobic compounds, and plants that leads to their removal and/or degradation, may overcome many of the limitations, and thus provide a useful basis for enhancing remediation of contaminated environments. MAIN FEATURES: The review of literature presented in this article provides an insight to the nature of plant-microbial interactions in the rhizosphere, with a focus on those processes that are relevant to the breakdown and/or removal of organic pollutants. Due consideration has been given to identify opportunities for utilising the plant-microbial synergy in the rhizosphere to enhance remediation of contaminated environments, RESULTS AND DISCUSSION: The literature review has highlighted the existence of a synergistic interaction between plants and microbial communities in the rhizosphere. This interaction benefits both microorganisms through provision of nutrients by root exudates, and plants through enhanced nutrient uptake and reduced toxicity of soil contaminants. The ability of the plant-microbial interaction to tackle some of the most recalcitrant organic chemicals is of particular interest with regard to enhancing and extending the scope of remediation technologies. CONCLUSIONS: Plant-microbial interactions in the rhizosphere offer very useful means for remediating environments contaminated with recalcitrant organic compounds. OUTLOOK: A better knowledge of plant-microbial interactions will provide a basis for improving the efficacy of biological remediations. Further research is, however, needed to investigate different feedback mechanisms that select and regulate microbial activity in the rhizosphere.

Biodegradation, Environmental↗

PubMed1994

Formation of receptive fields in realistic visual environments according to the Bienenstock, Cooper, and Munro (BCM) theory.

The Bienenstock, Cooper, and Munro (BCM) theory of synaptic plasticity has successfully reproduced the development of orientation selectivity and ocular dominance in kitten visual cortex in normal, as well as deprived, visual environments. To better compare the consequences of this theory with experiment, previous abstractions of the visual environment are replaced in this work by real visual images with retinal processing. The visual environment is represented by 24 gray-scale natural images that are shifted across retinal fields. In this environment, the BCM neuron develops receptive fields similar to the fields of simple cells found in kitten striate cortex. These fields display adjacent excitatory and inhibitory bands when tested with spot stimuli, orientation selectivity when tested with bar stimuli, and spatial-frequency selectivity when tested with sinusoidal gratings. In addition, their development in various deprived visual environments agrees with experimental results.

Animals↗

PubMed2005

Development of an instrument to measure the Practice Vocational Training Environment in Ireland.

The concept of the learning environment is increasingly recognized as an important feature within educational settings. Research on health-related educational environments has clearly demonstrated their impact on important outcomes such as student satisfaction and achievement, stress levels and ultimately on patient care. To date limited research has been carried out on the practice-based component of general practice training. This study was devised to measure the practice based training environment as experienced by GPs in training. A questionnaire was devised using a triangulated methodology and was administered to all practice-based general practice trainees in the Republic of Ireland. The results confirmed a high level of satisfaction with the educational environment in practice but several deficiencies were identified. These included the lack of availability of a stress support system, a lack of good clinical supervision at all times and a lack of understanding among practice staff regarding the role of the trainee in the practice. Having identified the deficiencies, the challenge to educators is to improve the educational environment for the benefit of the GPs in training and ultimately the communities they serve.

Ireland↗

PubMed1998

Molecular dynamic simulations of environment and sequence dependent DNA conformations: the development of the BMS nucleic acid force field and comparison with experimental results.

Molecular dynamic (MD) simulations using the BMS nucleic acid force field produce environment and sequence dependent DNA conformations that closely mimic experimentally derived structures. The parameters were initially developed to reproduce the potential energy surface, as defined by quantum mechanics, for a set of small molecules that can be used as the building blocks for nucleic acid macromolecules (dimethyl phosphate, cyclopentane, tetrahydrofuran, etc.). Then the dihedral parameters were fine tuned using a series of condensed phase MD simulations of DNA and RNA (in zero added salt, 4M NaCl, and 75% ethanol solutions). In the tuning process the free energy surface for each dihedral was derived from the MD ensemble and fitted to the conformational distributions and populations observed in 87 A- and B-DNA x-ray and 17 B-DNA NMR structures. Over 41 nanoseconds of MD simulations are presented which demonstrate that the force field is capable of producing stable trajectories, in the correct environments, of A-DNA, double stranded A-form RNA, B-DNA, Z-DNA, and a netropsin-DNA complex that closely reproduce the experimentally determined and/or canonical DNA conformations. Frequently the MD averaged structure is closer to the experimentally determined structure than to the canonical DNA conformation. MD simulations of A- to B- and B- to A-DNA transitions are also shown. A-DNA simulations in a low salt environment cleanly convert into the B-DNA conformation and converge into the RMS space sampled by a low salt simulation of the same sequence starting from B-DNA. In MD simulations using the BMS force field the B-form of d(GGGCCC)2 in a 75% ethanol solution converts into the A-form. Using the same methodology, parameters, and conditions the A-form of d(AAATTT)2 correctly converts into the B-DNA conformation. These studies demonstrate that the force field is capable of reproducing both environment and sequence dependent DNA structures. The 41 nanoseconds (nsec) of MD simulations presented in this paper paint a global picture which suggests that the DNA structures observed in low salt solutions are largely due to the favorable internal energy brought about by the nearly uniform screening of the DNA electrostatics. While the conformations sampled in high salt or mixed solvent environments occur from selective and asymmetric screening of the phosphate groups and DNA grooves, respectively, brought about by sequence induced ion and solvent packing.

Adenine↗

PubMedDate not supplied

An exploratory investigation into the usability and usefulness of training people with learning disabilities in a virtual environment.

PURPOSE: Two studies sought to answer the following questions. Are people with learning disabilities capable of using a virtual environment? Are they motivated to learn using this training method? Do they show any benefit from using a virtual environment? Does any benefit transfer to improved real world performance? METHOD: In the first study, 30 students with learning disabilities were sequentially allocated to an active or a passive experimental group. Active participants explored a virtual bungalow searching for a toy car. Passive participants watched the exploration undertaken by the preceding active participant and searched for the toy car. All participants then performed spatial and object recognition tests of their knowledge of the virtual environment. In the second study, the errors of 45 participants on a real steadiness tester task were noted before they were randomly allocated to three groups-a real training group, a virtual training group and a no training group. After training, the participants performed a second test trial on the real steadiness tester. RESULTS: The students were capable of using a virtual environment and were motivated to use this training method. Active exploration of a virtual environment was found to enhance their memory of the spatial layout of the bungalow but not their memory of the virtual objects. In the second study, virtual training was found to transfer to real task performance. CONCLUSIONS: These two laboratory-based studies provide answers to four important questions concerning virtual training of people with learning disabilities. Hopefully, the findings will encourage this training aid to be used more widely.

Achievement↗

PubMed2004

Evaluating rural nursing home environments: dementia special care units versus integrated facilities.

Although one in four seniors currently lives in a rural area, little is known about the capacity of rural nursing homes to provide specialized dementia services. The physical and social environments are increasingly recognized as important factors in the quality of life and functional ability of persons with dementia. This study compared eight rural nursing homes (those located in centres with populations < or =15,000) that had created dementia Special Care Units (SCUs) to eight same-sized rural nursing homes that did not have SCUs. Outcomes were assessed in relation to residents, staff, family members, and the environment. In this paper we describe the overall study design and findings from the environmental assessment. Analysis of variance (ANOVA) was used to compare the SCU versus non-SCU environments on the nine dimensions of the Physical Environmental Assessment Protocol (PEAP), which was used to assess the physical environment. The SCUs were more supportive on six dimensions: maximizing awareness and orientation, maximizing safety and security, regulation of stimulation, quality of stimulation, opportunities for personal control, and continuity of the self. Analysis of variance was also used to compare the groups on the six subscales of the Nursing Unit Rating Scale (NURS), which assesses the social environment of dementia care settings. The SCUs were more supportive on the Separation and Stimulation subscales, indicating that SCUs had greater separation of residents with dementia from other residents for activities of daily living and programming, and better control of non-meaningful stimulation.

Aged↗

PubMed2005

Occupation, work environment, and disability pension: a prospective study of construction workers.

AIMS: This study investigated the importance of occupation and work environment for the risk of disability pension among construction workers in Sweden. METHODS: The data include around 389,000 construction workers who participated in health examinations from 1971 to 1992. During that period 68,000 participants received disability pension in some form. Between 1985 and 1992 questionnaires were used to collect data regarding hazards in the work environment. Some 87,000 participants answered that questionnaire, and almost 6,000 of these were in receipt of a disability pension. To analyse the risk of disability pension in different occupations, incidence rates (SIR) were calculated according to the person-year method. Logistic regression was used to calculate age-controlled odds ratios according to physical and psychosocial work environment factors. RESULTS: The results show considerable variation in risk for disability pension between different occupations within the construction industry. Furthermore, analysis of work environment factors indicated associations with physical, ergonomic, and psychosocial work environment factors. DISCUSSION: A considerable variation between occupations indicates that characteristics in the work situation are important when explaining the risk of disability pension. The results from this study indicate that improvements in working conditions are an important area of intervention in order to facilitate and prolong labour market participation among elderly people.

Adult↗

PubMed1993

Effects of exposure to a to-be-shocked environment upon the rat's freezing response: evidence for facilitation, latent inhibition, and perceptual learning.

Three experiments used the freezing response of rats to examine the effects of pre-exposure to an environment upon (1) its associability with shock and (2) its discriminability from a second environment. Experiments 1 and 2 demonstrated that freezing was proportional to the interval between exposure to the environment at time T1 and the occurrence of shock at T2. This function was shifted by pre-exposure to the to-be-shocked environment, with brief pre-exposures increasing (facilitation) and extended pre-exposures decreasing (latent inhibition) the impact of a given T1-T2 interval on freezing. Experiment 3 provided evidence that the facilitatory and latent inhibitory effects resulting from brief and extended exposures to the to-be-shocked environment were accompanied by an increase in discriminability. The results were taken to have supported the claim that pre-exposure changes associability as well as discriminability (Hall & Honey, 1989) and were discussed in terms of the model for perceptual learning proposed by McLaren, Kaye, and Mackintosh (1990).

Animals↗

PubMed1999

The specificity of memory enhancement during interaction with a virtual environment.

Two experiments investigated differences between active and passive participation in a computer-generated virtual environment in terms of spatial memory, object memory, and object location memory. It was found that active participants, who controlled their movements in the virtual environment using a joystick, recalled the spatial layout of the virtual environment better than passive participants, who merely watched the active participants' progress. Conversely, there were no significant differences between the active and passive participants' recall or recognition of the virtual objects, nor in their recall of the correct locations of objects in the virtual environment. These findings are discussed in terms of subject-performed task research and the specificity of memory enhancement in virtual environments.

Humans↗

PubMed2003

Arsenic in Australian environment: an overview.

The most common source of elevated As concentrations in the Australian environment are attributable to anthropogenic activities. Mining activities have contributed to the contamination of soil and water primarily in Western Australia and Victoria. However, other anthropogenic activities such as agriculture, forestry and industry have also contaminated soil and water at a localized scale. Currently there are over 1000 As contaminated sites previously used as cattle dips for eradicating cattle ticks. Although As contamination of the environment may be severe enough to limit plant growth there appears to be few other reports identifying the impacts of the contaminants on other organisms, such as fish, mammals and humans. In Australia the impacts of metal/metalloid contamination of the environment are often unnoticed or ignored. However, the impacts of elements such as As may pass unnoticed by the public or regulators due to the perception of the minimal impact a contaminant has on the environment. This paper presents an overview of As in the Australian environment including the sources of As contamination, soil, water and plant As content, and the pathways of exposure.

Agriculture↗

PubMed2002

Radiological protection of the environment from the Swedish point of view.

The current system of radiological protection is aimed at protecting human health, and largely neglects both the effects of radiation on the environment and the managerial aspects of environmental protection. The Swedish Radiation Protection Act was revised in 1988 and includes environmental protection as one of its aims. In practice, little guidance had been given in the regulations based on the Act until 1998, when the Swedish Radiation Protection Authority (SSI) formulated environmental aims in its regulations concerning protection of human health and the environment in connection to the final management of spent nuclear fuel and waste. These regulations focus on protection of biodiversity and biological resources, based on ecosystem characterisation. In a broader perspective, the Swedish Parliament established 15 national environmental quality objectives in 1999, covering all aspects of protecting the environment, including the effects of radiation. This paper reviews the background for radiological protection of the environment from both an international and a Swedish perspective, describing the aims and current activities in establishing a system for assessing environmental effects and their consequences that can be used in decision-making. Such activities are largely a result of the European Union research project FASSET (Framework for Assessment of Environmental Impact), carried out under the 5th Framework Programme of the Union. This work is complemented at the Swedish national level by government support to initiate a national environmental monitoring and assessment programme for characterising the radiation environment, which will provide the foundation for decision-making.

Environmental Exposure↗

PubMed2000

Women's health and the environment: innovations in science and policy.

Current scientific findings indicate that environmental factors affect women's health. Specifically, evidence has accumulated on the effects of the environment on reproductive health, cancer, injury, respiratory problems, autoimmune diseases, and other health problems. To review the current state of the science and policies related to women's health and the environment, the Federal Interagency Working Group on Women's Health and the Environment of the Department of Health and Human Services and the Society for Women's Health Research jointly sponsored a conference in 1998 entitled Women's Health and the Environment: Innovations in Science and Policy. The aim of the conference was to provide a forum for scientists to share recent findings, promising avenues of research, methodological barriers, and data gaps about women's susceptibility to environmental agents. The conference generated 22 recommendations for policy, 17 recommendations for communication and training, and 48 recommendations for research to be considered by the federal government. The purpose of this review is to bring to the attention of the scientific community and policymakers the breadth of the women's health implications associated with environmental factors by highlighting key research findings presented at the conference. This review summarizes the current status of science in women's health, it describes relevant activities by the federal government, and it suggests recommendations for future research and policy initiatives in the context of women's health and the environment.

Environmental Exposure↗

PubMed2005

Scene perception, gaze behavior, and perceptual learning in virtual environments.

More and more immersive environments are developed to provide support for learning or training purposes. Ecological validity of such environments is usually based on learning performance comparisons between virtual environments and their genuine counterparts. Little is known about learning processes occurring in immersive environments. A new technique is proposed for testing perceptual learning during virtual immersion. This methodology relies upon eye-tracking technologies to analyze gaze behavior recorded in relation to virtual objects' features and tasks' requirements. It is proposed that perceptual learning mechanisms engaged could be detected through eye movements. In this study, nine subjects performed perceptual learning tasks in virtual immersion. Results obtained indicated that perceptual learning influences gaze behavior dynamics. More precisely, analysis revealed that fixation number and variability in fixation duration varied with perceptual learning level. Such findings could contribute in shedding light on learning mechanisms as well as providing additional support for validating virtual learning environments.

Adult↗

PubMed2006

Three-dimensional virtual environments for blind children.

Information technologies are increasingly helping to integrate and socially include people with visual disabilities. Computing technologies have contributed grandly to attain this goal through innovative techniques and applications. Virtual environments, I/O interfaces, and sound based applications altogether with usability and cognitive impact studies are some of the most used research designs for children with visual disabilities. This study presents the design and usability evaluation of three-dimensional (3D) interactive environments for children with visual disabilities. We introduce AudioChile and AudioVida, interactive virtual environments that can be navigated through 3D sound to enhance spatiality and immersion throughout the environments 3D sound is used to orientate, to avoid obstacles, and to identify the position of diverse personages and objects within the environment. Usability evaluation results indicated that sound can be fundamental for attention and motivation purposes during interaction.

Acoustic Stimulation↗