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1.
This paper describes the application of a methodology designed to analyse the relationship between climatic conditions and the perception of bioclimatic comfort. The experiment consisted of conducting simultaneous questionnaire surveys and weather measurements during 2 sunny spring days in an open urban area in Lisbon. The results showed that under outdoor conditions, thermal comfort can be maintained with temperatures well above the standard values defined for indoor conditions. There seems to be a spontaneous adaptation in terms of clothing whenever the physiological equivalent temperature threshold of 31°C is surpassed. The perception of air temperature is difficult to separate from the perception of the thermal environment and is modified by other parameters, particularly wind. The perception of solar radiation is related to the intensity of fluxes from various directions (i.e. falling upon both vertical and horizontal surfaces), weighted by the coefficients of incidence upon the human body. Wind was found to be the most intensely perceived variable, usually negatively. Wind perception depends largely on the extreme values of wind speed and wind variability. Women showed a stronger negative reaction to high wind speed than men. The experiment proved that this methodology is well-suited to achieving the proposed objectives and that it may be applied in other areas and in other seasons.  相似文献   

2.
The main objective of the present quasi-experimental study was to examine the influence of culture (Swedish vs Japanese) and environmental attitude (urban vs open-air person) on participants’ thermal, emotional and perceptual assessments of a square, within the PET (physiological equivalent temperature) comfortable interval of 18–23°C. It was predicted that persons living in different cultures with different environmental attitudes would psychologically evaluate a square differently despite similar thermal conditions. Consistent with this prediction, Japanese participants estimated the current weather as warmer than did Swedish participants and, consistent with this, they felt less thermally comfortable on the site, although participants in both countries perceived similar comfortable thermal outdoor conditions according to the PET index. Compared to the Japanese, the Swedes estimated both the current weather and the site as windier and colder, indicating a consistency in weather assessment on calm-windy and warm-cold scales in participants in both cultures. Furthermore, Swedish participants felt more glad and calm on the site and, in line with their character (more glad than gloomy), they estimated the square as more beautiful and pleasant than did Japanese participants. All this indicates that thermal, emotional and perceptual assessments of a physical place may be intertwined with psychological schema-based and socio-cultural processes, rather than fixed by general thermal indices developed in line with physiological heat balance models. In consequence, this implies that thermal comfort indices may not be applicable in different cultural/climate zones without modifications, and that they may not be appropriate if we do not take into account the psychological processes involved in environmental assessment.  相似文献   

3.
We studied proxemic behaviour in an hospital waiting room by recording who chose to stand and who chose to sit and which chair, row and position. We distinguished sex and two categories of age, mature and old. We found that fenales sit together more easily than males and more frequently chose to sit close, especially mature ones. Males tend to keep more distances from neighbours by standing up. In general, proxemic behaviour in a waiting room seems to be an indicator confirming the sexual startegies in partner choice described in the evolutionary psychology paradigm.  相似文献   

4.
Adverse health risks from environmental agents are generally related to average (long-term) exposures. Because a given individual's contact with a pollutant is highly variable and dependent on activity patterns, local sources and exposure pathways, simple ‘snapshot’ measurements of surrounding environmental media may not accurately assign the exposure level. Furthermore, susceptibility to adverse effects from contaminants is considered highly variable in the population so that even similar environmental exposure levels may result in differential health outcomes in different individuals. The use of biomarker measurements coupled to knowledge of rates of uptake, metabolism and elimination has been suggested as a remedy for reducing this type of uncertainty. To demonstrate the utility of such an approach, we invoke results from a series of controlled human exposure tests and classical first-order rate kinetic calculations to estimate how well spot measurements of methyl tertiary butyl ether and the primary metabolite, tertiary butyl alcohol, can be expected to predict different hypothetical scenarios of previous exposures. We found that blood and breath biomarker measurements give similar results and that the biological damping effect of the metabolite production gives more stable estimates of previous exposure. We also explore the value of a potential urinary biomarker, 2-hydroxyisobutyrate suggested in the literature. We find that individual biomarker measurements are a valuable tool in reconstruction of previous exposures and that a simple pharmacokinetic model can identify the time frames over which an exogenous chemical and the related chemical biomarker are useful. These techniques could be applied to broader ranges of environmental contaminants to assess cumulative exposure risks if ADME (Absorption, Distribution, Metabolization and Excretion) is understood and systemic biomarkers can be measured.  相似文献   

5.
Adverse health risks from environmental agents are generally related to average (long-term) exposures. Because a given individual's contact with a pollutant is highly variable and dependent on activity patterns, local sources and exposure pathways, simple 'snapshot' measurements of surrounding environmental media may not accurately assign the exposure level. Furthermore, susceptibility to adverse effects from contaminants is considered highly variable in the population so that even similar environmental exposure levels may result in differential health outcomes in different individuals. The use of biomarker measurements coupled to knowledge of rates of uptake, metabolism and elimination has been suggested as a remedy for reducing this type of uncertainty. To demonstrate the utility of such an approach, we invoke results from a series of controlled human exposure tests and classical first-order rate kinetic calculations to estimate how well spot measurements of methyl tertiary butyl ether and the primary metabolite, tertiary butyl alcohol, can be expected to predict different hypothetical scenarios of previous exposures. We found that blood and breath biomarker measurements give similar results and that the biological damping effect of the metabolite production gives more stable estimates of previous exposure. We also explore the value of a potential urinary biomarker, 2-hydroxyisobutyrate suggested in the literature. We find that individual biomarker measurements are a valuable tool in reconstruction of previous exposures and that a simple pharmacokinetic model can identify the time frames over which an exogenous chemical and the related chemical biomarker are useful. These techniques could be applied to broader ranges of environmental contaminants to assess cumulative exposure risks if ADME (Absorption, Distribution, Metabolization and Excretion) is understood and systemic biomarkers can be measured.  相似文献   

6.
Current analyses of issues relating to ethnicity and empowerment are silent about the significance of the environment in shaping and being shaped by human relations. For its part, environmental policy research, with few exceptions, has also ignored the dynamics of identity construction and cultural values that inform human relationships with the environment and thus affect environmental sustainability. I address this gap in the scholarship through an analysis of the Sardar Sarovar Project [SSP] in India. I explore the interweaving of the constructions of gender, ethnicity and empowerment and their implications for a new politics of the environment - the politics of environmental justice. I argue that discourses of modernization underpin the arguments of all those who discuss the SSP, whether in favour or against.  相似文献   

7.
Conventional techniques for site characterisation are time consuming, cost intensive, and often do not support decision making with regard to sustainable remediation. Therefore, new techniques for step by step site characterization with smart feed back loops are necessary that are able to support a future “soil framework directive”. Advanced geophysical site characterization techniques combined with new types of vegetation analysis will be developed. Based on these non-invasive surveys, the extension of sources, contamination levels (THP, BTEX, PAH, CHC, explosives, heavy metals and radio nuclides) and soil heterogeneities will be localized first. Hot spots will then be investigated by new direct push probing systems integrated with geophysical and hydrogeological methods and combined with chemical and isotopic contaminant analysis for source localization and identification (environmental forensics). The actually occurring bioprocesses, such as contaminant degradation or sorption and mobilization processes, will be assessed using biosensors, in situ microcosms, and stable isotope and biomarker analysis. These new techniques and tools will be evaluated against best practice of conventional methods. The ModelPROBE project (EU-FP7 collaborative project) gives the opportunity to test, optimize and demonstrate the proposed approach at fully equipped and characterized European brownfield reference sites in Germany, Italy, Norway and the Czech Republic. Integrated statistical analysis and modelling at different stages, the step by step approach will result in an improved view of soil and subsurface contamination and will provide a sound basis for a cost-effective risk assessment and decision in the choice of the most appropriate sustainable remediation strategy.  相似文献   

8.
Males of the aphid hyperparasitoid Dendrocerus carpenteri (Curtis) were attracted by a sex pheromone released by conspecific females. The intensity of this cue, and thus female attractiveness, depended both on the female's mating status and her age. Only virgin females younger than 2 h were consistently recognized as mates by foraging males. Male age did not influence foraging and mating success. Empty mummies, from which females had emerged within the previous 10 min were attractive to males and examined intensively. Rain reduced the searching success of males, although the host plant Vicia faba provided sheltered places. Wind did not reduce mating success but prevented both sexes from leaving the host plant. Since the time of female attractiveness seems to be very limited, wind may have an enormous effect on the mating success of D. carpenteri in the field and thus on the population dynamics of this species. Received: 5 October 1998 / Accepted: 16 December 1998  相似文献   

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Background

Dopamine is a catecholamine that is used as a neurotransmitter both in the periphery and in the central nervous system. Dysfunction in various dopaminergic systems is known to be associated with various disorders, including schizophrenia, Parkinson's disease, and Tourette's syndrome. Furthermore, microdialysis studies have shown that addictive drugs increase extracellular dopamine and brain imaging has shown a correlation between euphoria and psycho-stimulant-induced increases in extracellular dopamine [1]. These consequences of dopamine dysfunction indicate the importance of maintaining dopamine functionality through homeostatic mechanisms that have been attributed to the delicate balance between synthesis, storage, release, metabolism, and reuptake.

Methods

We construct a mathematical model of dopamine synthesis, release, and reuptake and use it to study homeostasis in single dopaminergic neuron terminals. We investigate the substrate inhibition of tyrosine hydroxylase by tyrosine, the consequences of the rapid uptake of extracellular dopamine by the dopamine transporters, and the effects of the autoreceoptors on dopaminergic function. The main focus is to understand the regulation and control of synthesis and release and to explicate and interpret experimental findings.

Results

We show that the substrate inhibition of tyrosine hydroxylase by tyrosine stabilizes cytosolic and vesicular dopamine against changes in tyrosine availability due to meals. We find that the autoreceptors dampen the fluctuations in extracellular dopamine caused by changes in tyrosine hydroxylase expression and changes in the rate of firing. We show that short bursts of action potentials create significant dopamine signals against the background of tonic firing. We explain the observed time courses of extracellular dopamine responses to stimulation in wild type mice and mice that have genetically altered dopamine transporter densities and the observed half-lives of extracellular dopamine under various treatment protocols.

Conclusion

Dopaminergic systems must respond robustly to important biological signals such as bursts, while at the same time maintaining homeostasis in the face of normal biological fluctuations in inputs, expression levels, and firing rates. This is accomplished through the cooperative effect of many different homeostatic mechanisms including special properties of tyrosine hydroxylase, the dopamine transporters, and the dopamine autoreceptors.  相似文献   

13.
To understand the mercury (Hg) pollution characteristics and health risks in indoor and outdoor dust of Huainan residential areas, 122 dust samples were collected indoors and outdoors. Average Hg contents in indoor and outdoor dusts of Huainan city were 0.321 ± 0.724 (n = 61) and 0.072 ± 0.163 (n = 61) mg/kg respectively. The average Hg content in indoor dust was characterized by PJ (Panji district) > XJJ (Xiejiaji district) > DT (Datong district) > TJA (Tianjiaan district), and in the order of PJ > DT > XJJ >TJA in outdoor dust. According to enrichment factor and geo-accumulation index, the enrichment degree and pollution intensity for Hg are ranked as “very high enrichment” and “heavily polluted” in indoor dust, and “significant enrichment” and “moderately polluted” in outdoor dust Hg concentrations in indoor dust were highly significantly associated with the coal combustion and frequency of open windows, and Hg concentrations in outdoor dust were significantly associated with the coal combustion and traffic density. The inhalation of Hg vapor is the main route of Hg exposure to adult and children. The hazard risks of Hg for different exposure ways in indoor and outdoor dust were more risk for children than for adults, but have no obvious health risk for them.  相似文献   

14.
Invasion biology suffers from a lack of the ability to predict the outcome of particular invasions because of reliance on verbal models and lack of rigorous experimental data at the appropriate scale. More progress is likely to be made by considering invasions as population-level phenomena and initially focusing on specific taxa or particular categories of invasions. To this end, we propose a simple conceptual framework to motivate studies of invasion by salmonids (salmon, trout, grayling, and whitefish) in streams that emphasizes population-level mechanisms affecting native species and promoting spread by the invader. Specifically, the only direct mechanisms by which the abundance of the native species can decline are through biotic interactions which cause decreased reproductive rates or survival at specific life stages, net emigration, debilitating or fatal diseases introduced by the invader, or a combination of these factors. Conversely, abundance of the invader must increase by local reproduction, high survival, net immigration, or a combination of these factors. Review of existing salmonid invasion literature suggests that future studies could be improved by using manipulative field experiments at a spatial and temporal scale appropriate to address population-level processes, characterizing how movement affects the establishment and spread of an invader, and including abiotic context in experimental designs. Using the example of brook trout (Salvelinus fontinalis) invasion into streams containing native Colorado River cutthroat trout (Oncorhynchus clarki pleuriticus) in the central Rocky Mountains (USA), we demonstrate how the framework can be used to design a manipulative field experiment to test for population-level mechanisms causing ecological effects and promoting invasion success. Experiments of this type will give invasion ecologists a useful example of how a taxon-specific invasion framework can improve the ability to predict ecological effects, and provide fishery biologists with the quantitative foundation necessary to better manage stream salmonid invasions.  相似文献   

15.
The purpose of this study was to determine if associated characteristics of muscle dysmorphia (MD) were different between elite-level competitive bodybuilders and power lifters. Elite-level competitive bodybuilders (n = 100) and power lifters (n = 68) completed the muscle dysmorphia inventory (MDI) at the time of or immediately before competition. A 2 x 6 (group x MDI subscales) multivariate analysis of variance indicated that bodybuilders were significantly more likely to report body size-symmetry concerns (F(1, 167) = 10.31, p < 0.001), physique protection (F(1, 167) = 10.27, p < 0.001), dietary behavior (F(1, 167) = 28.38, p < 0.001), and pharmacological use (F(1, 167) = 19.64, p < 0.001) than were power lifters. These results suggest that elite-level bodybuilders are significantly more likely to engage in characteristics associated with MD than are elite-level power lifters.  相似文献   

16.
Human beings are thought to be unique amongst the primates in their capacity to produce rapid changes in the shape of their vocal tracts during speech production. Acoustically, vocal tracts act as resonance chambers, whose geometry determines the position and bandwidth of the formants. Formants provide the acoustic basis for vowels, which enable speakers to refer to external events and to produce other kinds of meaningful communication. Formant-based referential communication is also present in non-human primates, most prominently in Diana monkey alarm calls. Previous work has suggested that the acoustic structure of these calls is the product of a non-uniform vocal tract capable of some degree of articulation. In this study we test this hypothesis by providing morphological measurements of the vocal tract of three adult Diana monkeys, using both radiography and dissection. We use these data to generate a vocal tract computational model capable of simulating the formant structures produced by wild individuals. The model performed best when it combined a non-uniform vocal tract consisting of three different tubes with a number of articulatory manoeuvres. We discuss the implications of these findings for evolutionary theories of human and non-human vocal production.  相似文献   

17.
The quantitative relationship between chemoreceptor activity during food intake and total amount of food ingested per unit of time has been studied in last instar larvae of Pieris brassicae. Data on sensory responses and feeding intensity, derived from a study by Blom (1978), show a strong correlation between receptor activity during 1 sec periods of stimulation and food intake during 24 h. It is concluded that nerve impulses from chemoreceptors, which signal the presence of different phagostimulants, are summated algebraically in the central nervous system. Impulses from feeding deterrent receptors counteract the effects of phagostimulants. One impulse from a deterrent receptor neutralizes 2.5 impulses from phagostimulant receptors. Based on the relationships observed a simple model of a feeding centre in the central nervous system has been constructed (Fig. 8).  相似文献   

18.
Substantial progress in understanding thermal transduction in peripheral sensory nerve endings was achieved with the recent cloning of six thermally gated ion channels from the TRP (transient receptor potential) super-family. Two of these channels, TRP melastatin 8 (TRPM8) and TRP ankyrin 1 (TRPA1), are expressed in dorsal root ganglion (DRG) and trigeminal ganglion (TG) neurons, are activated by various degrees of cooling, and are candidates for mediating gentle cooling and noxious cold, respectively. However, accumulating evidence suggests that more than just these two channels are involved in cold sensing in mammals. A recent report described a critical role of the voltage-gated tetrodotoxin-resistant sodium channel Nav1.8 in perceiving intense cold and noxious stimuli at cold temperatures. Other ion channels, such as two-pore domain background potassium channels (K2P), are known to be expressed in peripheral nerves, have pronounced temperature dependence, and may contribute to cold sensing and/or cold hypersensitivity in pain states. This article reviews the evidence supporting a role for each of these channels in cold transduction, focusing on their biophysical properties, expression pattern, and modulation by pro-inflammatory mediators.  相似文献   

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Food waste (FW) management is a global conundrum because of the rapid population growth and growing economic activity. Currently, incineration and landfill are still the main means for FW management, while their environmental sustainability and economic viability have been in question. Recently, the biological processes including anaerobic digestion, aerobic composting, bioethanol fermentation, feed fermentation etc. have attracted increasing interest with the aims for energy and resource recovery from FW. However, these biological approaches have inherent drawbacks, and cannot provide a comprehensive solution for future FW management. Therefore, this review attempts to offer a critical and holistic analysis of current biotechnologies for FW management with the focus on the challenges and solutions forward. The biological approaches towards future FW management should be able to achieve both environmental sustainability and economic viability. In this instance, the concept of zero solid discharge-driven resource recovery has thus been put forward. According to which, several innovative biological processes for FW management are further elucidated with critical analysis on their engineering feasibility and environmental sustainability. It turns out that is an urgent need for turning current single task-orientated bioprocess to an integrated biological process with multiple tasks of concurrent recovery of water, resource and energy together with zero-solid discharge.  相似文献   

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