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1.
On experimental setup in bioelectromagnetics 总被引:1,自引:1,他引:0
Bioeffects created by electromagnetic field (EMF) are the subject of intensive studies. This paper critically considers estimations
of exposure to EMF in bioelectromagnetic experiments. Results of calculations presented herein show the significant role of
the presence of conducting bodies (the exposure system) near an object under test on EMF energy absorption as well as mutual
interactions between simultaneously exposed objects. Our aims herein are twofold: firstly to find a way to refer measurement
results to free-space conditions in order to enable comparison of results obtained in different laboratories, and secondly
to show that EMF energy absorption in any exposed object is different and that this difference is a function of the size of
the exposure system, the number of exposed objects, and the particular properties (i.e., the electromagnetic structure) of
the objects. In the authors’ opinion the existence of interactions caused by the presence of the exposure system and other
exposed objects is a reason why remarkable differences are observed between experiments performed even under supposedly identical
conditions. The presented considerations and conclusion suggest wider participation of physicists and engineers in bioelectromagnetic
experiments in order to ensure the correctness of metrological aspects of these experiments. 相似文献
2.
环境信息化是环保能力建设的重要组成部分,是涵盖环保各项业务的一项基础性工作。随着环境保护相关应用系统的不断增加,极大增加了系统的运行维护难度,获取准确的系统运行信息、准确定位问题节点已经成为进行应用系统监控管理的重点和难点。针对环境信息化的发展现状和分布式系统的特点,本文将系统监控管理的对象分为应用类对象和系统类对象两类,并给出一种应用系统运行状态监控对象模型,明确的监控对象的确立方式,建立监控对象间的依赖关系,从而建立影响应用系统运行状况的因素拓扑关系。论述了应用类资源和系统类资源监控信息的获取方法,包括操作系统、中间件等系统类资源的监控机制,以及实时拨测、基于性能工具的监控、集成监控机制等应用类资源监控机制。给出了应用系统运行状态监控体系的技术架构,对各组成部分的主要功能进行了描述。在此基础上建立的应用系统运行状态监控系统能对应用系统的运行状态进行全面周期监控,并能准确定位问题发生的关键部位。 相似文献
3.
Alessandro F. Gualtieri Dario Mangano Magdalena Lassinantti Gualtieri Anna Ricchi Elisabetta Foresti Giorgio Lesci Norberto Roveri Mauro Mariotti Giovanni Pecchini 《Journal of environmental management》2009,90(11):3540-3552
This paper presents the results of an intensive monitoring activity of the particulate, fall-out and soil of selected living areas in Italy with the aim to detect the asbestos concentration in air and subsequent risk of exposure for the population in ambient living environments, and to assess the nature of the other mineral phases composing the particulate matrix. Some areas were sorted out because of the presence of asbestos containing materials on site whereas others were used as blank spots in the attempt to detect the background environmental concentration of asbestos in air. Because the concentration of asbestos in ambient environments is presumably very low, and it is well known that conventional low–medium flow sampling systems with filters of small diameter (25 mm) may collect only a very small fraction of particulate over a short period, for the first time here, an intense monitoring activity was conducted with a high flow sampling system. The high flow system requires the use of large cellulose filters with the advantage that, increasing the amount of collected dust, the probability to collect asbestos fibers increases. Both the protocol of monitoring and analysis are novel and prompted by the need to increase the sensitivity towards the small number of expected fibers. With this goal, the collection of fall-out samples (the particulate falling into a collector filled with distilled water during the monitoring shift) and soil samples was also accomplished. The analytical protocol of the matrix particulate included preliminary X-ray powder diffraction (XRPD), optical microscopy and quantitative electron microscopy (SEM and TEM). Correlations with climatic trends and PM10 concentration data were also attempted.The surprising outcome of this work is that, despite the nature of the investigated site, the amount of dispersed asbestos fibers is very low and invariably lower than the theoretical method detection limits of the SEM and TEM techniques for identification and counting of asbestos fibers. The results are compared to the literature data worldwide and an updated model for asbestos fibers dispersion in ambient environments is proposed. 相似文献
4.
Changes of Surface Properties of Yeast Cell Wall Under Exposure of Electromagnetic Field (40.68 MHz) and Action of Nystatin 总被引:1,自引:0,他引:1
S. I. Voychuk E. N. Gromozova P. M. Lytvyn V. S. Podgorsky 《The Environmentalist》2005,25(2-4):139-144
Summary Changes of the surface properties were studied in the cell wall of the yeast Saccharomyces cerevisiae Y-517 under influence of the electromagnetic field (EMF) (40.68 MHz) and lethal doses of the fungicidal antibiotic nystatin
(10 μg/106 cells). Atomic force microscopy was used to study surface topography and visco-elastic properties of the cell walls. Surface
carbohydrates were detected by lectins marked with gold with the help of the scanning electron microscope. Additional polysaccharide
layer appeared over cell surface after EMF exposure. We suggest that electromagnetic fields resulted in the change of the
cell surface, and, accordingly, the sensitivity of organisms to the antifungal antibiotics. 相似文献
5.
A Knowledge-Based Systems Approach to Design of Spatial Decision Support Systems for Environmental Management 总被引:7,自引:0,他引:7
/ This paper describes a framework for designing spatial decision support systems for environmental management using a knowledge-based systems approach. An architecture for knowledge-based spatial decision supportsystems (KBSDSS) is presented that integrates knowledge-based systems with geographical information systems (GIS) and other problem-solving techniques. A method based on spatial influence diagrams is developed for representation of environmental problems. The spatial influence diagram provides an interface through which knowledge-based systems techniques can be applied to build capabilities for problem formulation, automated design, and execution of a solution process. In addition to the flexibility and developmental advantages of knowledge-based systems, the KBSDSS incorporates expert knowledge to provide assistance for structuring spatial influence diagrams and executing a solution process that automatically integrates the GIS, data base, knowledge base, and different types of models. The framework is illustrated with a system, known as the Islay Land Use Decision Support System (ILUDSS), designed to assist planners in strategic planning of land use for the development of the island of Islay, off the west coast of Scotland.KEY WORDS: Geographical information systems; Spatial decision support systems; Knowledge-based systems; Spatial influence diagrams; Environmental management 相似文献
6.
7.
环境社会治理是现代环境治理体系和治理能力中的重要组成部分,但同时也是突出短板。2020年11月13日,环境社会治理专委会2020年年会成功召开,多位专家学者从多种角度围绕“新时代环境社会治理体系的构建和创新”进行了分享与讨论,对推动环境社会治理工作带来启示:一是环境社会治理是调整环境治理主体和客体之间关系的一系列制度手段,需要在新时代背景下完成从“物理”到“人文”的转变,体现平等参与的价值观。二是在转型期社会力量博弈变迁的背景下,环境问题须通过社会力量解决,并配套相应的环境社会治理新策略和手段,提高治理效率、降低治理成本。三是坚持系统性思维,以目的为导向、理清治理主体和客体作用,协调布局环境社会治理的制度安排,以环境社会治理核心要素、重点关注内容为抓手,构建环境社会治理体系。面对当前深刻变化的内外部环境,有必要进一步重点加强环境与社会相互关系与影响研究、环境社会风险防范体系研究、全民行动体系研究、关键理论和技术创新研究等内容。 相似文献
8.
Henrietta Nittby Bengt Widegren Morten Krogh Gustav Grafström Henrik Berlin Gustav Rehn Jacob L. Eberhardt Lars Malmgren Bertil R. R. Persson Leif G. Salford 《The Environmentalist》2008,28(4):458-465
We have earlier shown that radio frequency electromagnetic fields can cause significant leakage of albumin through the blood–brain
barrier of exposed rats as compared to non-exposed rats, and also significant neuronal damage in rat brains several weeks
after a 2 h exposure to a mobile phone, at 915 MHz with a global system for mobile communications (GSM) frequency modulation,
at whole-body specific absorption rate values (SAR) of 200, 20, 2, and 0.2 mW/kg. We have now studied whether 6 h of exposure
to the radiation from a GSM mobile test phone at 1,800 MHz (at a whole-body SAR-value of 13 mW/kg, corresponding to a brain
SAR-value of 30 mW/kg) has an effect upon the gene expression pattern in rat brain cortex and hippocampus—areas where we have
observed albumin leakage from capillaries into neurons and neuronal damage. Microarray analysis of 31,099 rat genes, including
splicing variants, was performed in cortex and hippocampus of 8 Fischer 344 rats, 4 animals exposed to global system for mobile
communications electromagnetic fields for 6 h in an anechoic chamber, one rat at a time, and 4 controls kept as long in the
same anechoic chamber without exposure, also in this case one rat at a time. Gene ontology analysis (using the gene ontology
categories biological processes, molecular functions, and cell components) of the differentially expressed genes of the exposed
animals versus the control group revealed the following highly significant altered gene categories in both cortex and hippocampus:
extracellular region, signal transducer activity, intrinsic to membrane, and integral to membrane. The fact that most of these
categories are connected with membrane functions may have a relation to our earlier observation of albumin transport through
brain capillaries. 相似文献
9.
Eleni Nanou Vassilis Tsiafakis E. Kapareliotis Charalabos Papageorgiou Andreas Rabavilas Christos Capsalis 《The Environmentalist》2005,25(2-4):173-179
Summary The effects of electromagnetic fields (EMF) emitted by cellular phones on human electroencephalogram (EEG) were studied during
an auditory memory task. The experimental method and the experimental setup are introduced as a credible measurement method
of EEG. 19 normal subjects (10 women and 9 men) performed the memory task both with and without exposure to a 900 MHz signal,
emitted by a dipole antenna placed near the subjects' head. The energy of the EEG signals was calculated at the time domain.
A Fourier transform of the EEG signals was done and the EEG energy was also calculated at the frequency domain. As the Parseval's
theorem anticipates the energies were identical. The EEG energy was found concentrated at the four basic bands (α (8–13 Hz),
β(14–30 Hz), δ (0–4 Hz) and θ(5–7 Hz)). The primary concern of the present study was the gender related influence of EMF on
the spectral energy of EEG. The results show evidence of a strong gender—radiation interaction effect on the EEG energy and
on the peak amplitudes within each of the four rhythms. Without radiation the spectral power of males is greater than of females,
while under exposure the situation is reversed. Under the influence of EMF the spectral power of the males EEG is decreased
while that of the females is increased. In conclusion both the baseline EEG and the changes effected to the EEG power spectrum
under the influence of EMF seem to be gender dependent. 相似文献
10.
Summary Despite of decades of successful worldwide use of magnetic/electromagnetic field therapy, the answer to the question of possible
mechanisms of action is still lacking. Scientific reports of successful therapeutic use of magnetic/electromagnetic fields
are worldwide; however, our understanding of the underlying mechanism is limited. This paper presents a new hypothesis that
therapeutic benefit of magnetic fields might result from effects that originated on the level of important systems in human
body. It is known now that the life is an electromagnetic event in aqueous medium. Therefore, an appropriate choice of magnetic
and/or electromagnetic field may be expected to initiate systemic changes that result in efficacious effects distant from
the point of application. Observations of this phenomenon have been reported in at least two forms: (1) neutralization of
the pain experience distant to the point of magnetic field exposure; and, (2) various alterations of T-lymphocytes in response
to pain and to magnetic fields. Extrapolating these observations to the level of blood-vessel system, one might hypothesize
that a “healthy” cell does not respond as readily to the applied fields as do abnormal cells (which are in a disease or injury
state). 相似文献
11.
Yury Grigoriev 《The Environmentalist》2012,32(2):193-200
Today world population lives in a new electromagnetic environment, characterized with (i) around the clock enforcement of
chronic exposure of all age and gender groups to a wide range of modulated electromagnetic fields (EMF) from base stations;
(ii) daily, repeated from early childhood throughout entire life exposure to EMF RF mobile phone the brain and vestibular
receptor apparatus and auditory analyzers, located directly “under the EMF beam” in the inner ear. On the other hand, the
world science and epidemiology is missing well-planned and executed research results of prolonged exposure of EMF RF on the
brain. International recommendations and domestic guidelines do not include changing conditions of RF EMF on the population:
the brain has become a critical organ, and the children entered the risk group. The population continues to actively use the
mobile phone. In this situation the problem of assessing the risk of mobile communications has become a social and ethical. 相似文献
12.
Sessile benthic organisms are universally accepted as bio-indicators of environmental pollution and lysosomal membrane is
often the target of injury by xenobiotics resulting in destabilization. Effect of mercury on the activity pattern of the marker
enzyme, Acid Phosphatase in the gill and hepatopancreas of the freshwater mussel, Lamellidens corrianus (Lea) at 24, 72, and 168 h, post-exposure discussed. ACP activity was determined as given in Sigma Technical Bulletin (No.
104) and μmol of p-nitrophenol liberated/mg protein/h calculated. The work aimed to study the duration of exposure and concentration of the
metal influence, the direction of the response of the enzyme in the two tissues studied and results show that the concentration
of the metal as well as the period of exposure do influence the enzyme activity and may have predictive value as a biomarker
of impending population changes. Higher concentration of the metal is assumed to have induced stress proteins like metallothioneins. 相似文献
13.
D. T. O'Laoghaire 《Journal of the American Water Resources Association》1978,14(4):809-826
ABSTRACT: This paper describes a mathematical model, an algorithm and a computer program that were specially developed to study the problem of a water quality management system undergoing a rapidly increasing environmental stress. The model output will determine the locations, sizes and the timing of construction of new treatment plants plus an overall treatment plant operating policy so that environmental standards are maintained at a minimum cost. The model, as formulated, is a 0-1 mixed integer programming problem which is solved by decomposing it into a capital budgeting problem (solved by Little's branch and bound algorithm) and an operational policy problem (solved by linear programming). The coded algorithm (in FORTRAN 10) has been tested with a semi-realistic example. 相似文献
14.
Occupational exposure to radiofrequency (RF) and static magnetic fields at magnetic resonance imaging (MRI) suites is of continuing
concern to personnel who routinely work in this environment. Questions regarding the levels of occupational RF and static
field exposure have increased with the increasing demand for anesthetics to be administered in this environment. The present
study was thus designed towards addressing the above-mentioned problem by gaining information regarding exposure levels of
clinical personnel at MRI units in South Africa. Three 1.5 MRI units in Bloemfontein, South Africa were utilized to evaluate
the exposure of clinical personnel to the electromagnetic fields present in the MRI environment over a period of time and
during different clinical MRI procedures. Three rounds of measurements of RF fields in the MRI environment were done. All
the three measurement rounds were focused on the low frequencies, 5 Hz–32 kHz, as well as on the high frequencies, 300 kHz–40 GHz.
First round measurements were done to establish the background of the RF fields in and around the magnet room during an MRI
examination. Second round RF field measurements were done at a specific location, 1 m away from the bore on the right-hand
side of the bed, in the MRI room. The third round measurements were of the same format as the second round, but the specific
location was against the magnet bore. Two pieces of Narda Safety Test Solution instruments, the EFA-300 and EMR-300, were
used to measure the electromagnetic and magnetic exposure fields generated from the MRI scanners. Results of the measurements
indicate that the electromagnetic fields measured during different clinical procedures do not exceed the International Commission
on Non-Ionizing Radiation Protection (2000) guidelines in these units. Results from round two and three showed that the RF
and gradient exposure 1 m and up against the bore entrance does not exceed these guidelines (rms average over 6 min). Ongoing
new developments in MRI scanning create the need for continuously monitoring exposure of patients and workers to the EMF fields
in the MRI environment. 相似文献
15.
The separation of organic coatings from fibrous substrates is a key problem in recycling processes. This problem applies to carpets, technical textiles and automotive interior components. This paper reports about results of laboratory studies involving the application of high-speed liquid jets to solve this problem. Results from high-speed video images are used to qualify the principal erosion process. It is shown that the coating material is first ground by the jet; the generated erosion debris is then pushed through the permeable fibrous fabric of the substrate. It is also found that threshold conditions exist for the coating grinding process and for the debris transportation. These threshold conditions depend on target composition and process parameters. A phenomenological separation model is introduced. The influence of key process parameters, namely jet velocity, exposure time, stand-off distance and impact angle, is also investigated. It is found that high-speed liquid jets are suitable tools for separating organic coatings completely and selectively from fibrous substrates. Recommendations on how to optimise the erosion process are derived from the results. 相似文献
16.
Summary In an effort to explain the benefit of therapeutic use of electromagnetic fields (EMF) a systemic effect has been proposed
by us. To assess the efficacy of this approach, an objective biochemical approach was developed. Ten patients with Reflex
Sympathetic Dystrophy (RSD) were clinically evaluated, and lymphocytes were isolated from their blood samples obtained before
and after exposure of the uninvolved limb to an EMF. Utilizing a SpectraCell method that includes radio labeled molecules
and protein-free media for culturing the lymphocytes, an elevation of the content of fructose, serine, glycine, and calcium
cellular metabolic uptake were found following in the culture to EMF in comparison with non-exposed lymphocytes (p < 0.01). In addition, the pain level was determined by a conventional visual analogue scale (VAS) before and after EMF exposure,
evidencing a significant pain relief. Specifically, after exposure to 120 pps semi sinewave, 1500Gauss EMF, generated by a
THERAMAG∘ledR device, an improvement in the flexibility of the limb and a reduction in swelling of the affected extremity were detected
clinically. These findings are in concert with the new hypothesis that, with relief of pain, lymphocytes are predominately
altered in their cell cycle from M phase to S phases associated with increased structuring of intracellular water. A consideration
of the basic understanding of the role lymphocytes may be inferred from this preliminary study. An extensive review of the
literature on the basic science and therapeutic use of magnetic fields in humans is provided in an attempt to understand the
relevance of magnetic therapy of specific pain syndromes. 相似文献
17.
Alan R. Collins Scott Steinback 《Journal of the American Water Resources Association》1993,29(2):199-209
ABSTRACT: About one-third of all West Virginians obtain domestic water from private water wells. In this research, mail and telephone surveys were used to investigate household responses to bacteria, mineral, and organic chemical contamination of domestic water supplies. Of households who were informed of contamination and acknowledged the problem, over 85 percent took action to avoid exposure to water contamination problems. The most common action was to clean and/or repair the water system (55.9 percent of valid surveys). Approximately 45 percent of households made investments of either a water treatment system, a new water source, or correction of contamination source. The average, annual economic cost of rural household actions was $320 for bacteria, $357 for minerals, and $1,090 for organic contamination. These economic costs represent a lower bound estimate for rural household willingness-to-pay (WTP) for a reduction in domestic water contamination from government action. On average, investment actions had lower annual economic costs than noninvestment actions of boiling and hauling water so that households who undertook investment actions in response to water contamination would have a lower WTP for government action to reduce water contamination. When effectiveness of water treatment systems was evaluated, treatment systems which require minimal household maintenance were found to reduce exposure to water contamination to safe levels as households intended when they installed the system. Treatment systems which were commonly ineffective included those which required continual maintenance (e.g., chiorinators) or were not designed to solve the contaminant problem for which they were purchased (e.g., filter systems for bacteria). 相似文献
18.
Socioeconomic Factors Affecting Farmers’ Perceptions of Land Degradation and Stonewall Terraces in Central Palestine 总被引:1,自引:0,他引:1
Land degradation by soil erosion is a socioeconomic and environmental problem facing many developing countries. Application
of stonewall terraces for soil moisture conservation is vital to reducing the environmental impacts of this phenomenon. To
this end, a field plot experiment was conducted in the study area along with the use of a closed-ended questionnaire. The
object of the experiment was to study the socioeconomic impacts of soil erosion on local farmers and their adoption of the
stonewall terrace technique. The study showed a higher net profit in areas that had implemented terrace conservation practices
than in areas that had not (i.e., 3.5 to 6 times higher net profit). Correlation analysis indicated that the farmers’ perceptions,
land ownership, and geomorphology were significantly related to the farmers’ incentives and willingness to adopt terraces
as soil conservation measures (P < 0.05), although the correlations were negative. Smallholder farmers (52% of the interviewed farmers) were involved in the
sale of the agricultural land for urban uses, largely because of the high price and immediate returns offered. However, the
associated land use changes warrant greater involvement of both the private and public sectors. This cooperation may be accomplished
through the introduction of a long-term agricultural loan system and the development of proper legislation accompanied by
a comprehensive and durable infrastructure and service system with the goal of reducing the negative impact of land use changes
and encouraging sustainable use of resources. 相似文献
19.
生态保护与建设是我国生态文明建设的重要任务,生态保护与建设支出账户核算是环境经济核算的重要内容,但我国目前尚未开展系统的生态保护与建设支出核算。本文首先梳理了生态保护与建设支出核算的国际经验,指出我国生态保护与建设支出账户核算面临统计口径不完善、统计体系尚未建立、统计主体和对象仍不完整、统计数据呈部门化和分散化等问题。在此基础上,本文从生态保护与建设支出主体、支出分类、支出资金来源等方面初步构建了支出账户核算体系,并以2013年为例进行了初步估算。结果表明,我国财政资金用于生态保护与建设的支出总量不足,仅占当年GDP的0.25%。为推动生态保护与建设支出账户核算工作,建议应从预算科目、统计口径、统计主体、统计对象等方面不断完善生态保护与建设统计体系,加快推进生态保护与建设支出账户的构建与核算,并争取尽快纳入国民经济核算体系,以推进生态文明体制改革与制度建设的进程,促进我国生态保护与经济社会的协调发展。 相似文献
20.
G. Duranti A. Rossi N. Rosato G. Fazio G. Sacerdoti P. Rossi R. Falsaperla V. Cannelli R. Supino 《The Environmentalist》2005,25(2-4):113-119
Summary The biological effects of electromagnetic radiation at ultra high frequency on human keratinocytes were investigated. HaCaT
cell system, a spontaneously immortalized human keratinocytes cell line, was chosen as model since skin is usually exposed
to electromagnetic radiation at considered frequency more than inner tissues. HaCaT cells were exposed to a pure sinusoidal
field at a frequency of 900 MHz (average SAR levels ranging from 0.04 to 0.08 W/kg) in plane wave condition inside a GTEM
chamber for time intervals of 18 hours at a controlled temperature of 37∘C. Growth curves were obtained for exposed and control cells, and a reduction in the number of exposed cells in comparison
to unexposed ones was found; however the number of dead cells was not significantly different in exposed and unexposed samples.
In order to investigate whether the reduction in cell proliferation of exposed cells was due to the activation of a differentiative
process, the expression of two hallmarks of differentiation was examined. Both keratin 1 and involucrin expression was increased
in exposed in comparison to unexposed cells. These results suggest that this protocol of exposure to 900 MHz electromagnetic
field can trigger a differentiation program in HaCaT cells. 相似文献