254 lines
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254 lines
10 KiB
Plaintext
Date: Fri, 21 May 93 04:01:00
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From: ISU Space Power Digest <digests@isu.isunet.edu>
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Reply-To: Space-Power-request@isu.isunet.edu
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Subject: Space Power Digest V1 #007
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To: Space.Power.Talkers
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Precedence: bulk
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Space Power Digest Fri, 21 May 93 Volume 1 : Issue 007
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Today's Topics:
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how to evaluate bioeffects of microwaves experiments
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Welcome to the ISU Space Power Digest!! This digest will
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seek to provide a forum for discussion of wireless power
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transmission, solar power systems. It is hosted by alumni
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and faculty of the International Space University, but is
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open to everyone with an interest in this area.
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Send e-mail contributions to: space-power@isu.isunet.edu
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To subscribe or unsubscribe, send your e-mail request to:
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space-power-request@isu.isunet.edu
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If you experience technical problems, send an e-mail message
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detailing the problem to: digests@isu.isunet.edu
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----------------------------------------------------------------------
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Date: Thu, 20 May 1993 17:42 EDT
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From: USRNAME <CANOUGH%BINGVAXA.bitnet@CUNYVM.CUNY.EDU>
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Subject: how to evaluate bioeffects of microwaves experiments
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re: studies of the effects of microwaves on cells, animals
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and humans
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Dr. Martin Meltz at U of Texas, Austin has been doing
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careful studies as to whether microwaves can cause
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mutagenesis in cells. He has obtained only null results so
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far. Reprints of his papers available upon request.
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There are literally thousands of papers on the subject of
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microwave affects, much of them contradictory or confusing.
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Dr. Meltz and David Erwin wrote up a set of criteria for
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evaluating this pile of information. For any experiment
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using microwaves and cells or animals, there are certain
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pieces of information that must be present in order to 1)
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understand the data and 2) compare it to other experiments.
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Without this information, a paper is not very useful, unless
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you can call up the author and obtain the missing
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information. What follows is his "lab notes" on what to look
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for.
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***************************************************
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LAB NOTES
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Essential RFR Study Information
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The authors list "essential items" recommended for inclusion
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in publications describing radio-frequency radiation (RFR)
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bioeffect research. Their list is designed to reduce
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inconsistencies observed in either performing RFR research,
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or in reporting the results. This material was presented in
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part at a workshop on In Vitro Methods at the 1986 annual
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meeting of the Bioelectronics Society. Comments on the
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evaluation criteria listed are encouraged and should be
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addressed to M.L. Meltz.
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INTRODUCTION
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An objective evaluation of the potential health hazards of
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radio-frequency radiation (RFR) is becoming more critical as
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the environmental exposure of the general population and
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occupational subgroups continues to increase.
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When the RFR health effects literature is reviewed, it
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immediately becomes obvious that many articles can be
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criticized for lack of information necessary for the
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evaluation of the research. Some of this information would
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be essential if other investigators are to perform
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confirming experiments. Described herein is a list of
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"essential" items, which we recommend for inclusion in all
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RFR bioeffects reports, and which we expect will reduce
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inconsistencies previously observed in either 1) performing
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the experiments or 2) reporting the results.
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EVALUATION CRITERIA
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In any publication, six major areas of concern are evident
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and represent the "package" in which 15 definable items
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would hopefully be included. Because of the lack of
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robustness in many purported RFR effects (called for by
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Packard 1985-1986), these areas of concern take on even
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greater significance; they include:
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1. Was the experiment adequately described?
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2. Was the numerical data presented?
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3. Was the data accumulated and reported in the manuscript
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sufficient for meaningful statistical analysis?
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4. Was a statistical analysis performed?
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5. Was the experiment independently repeated in the same
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laboratory, and was the data from the minimal second
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experiment also reported and analyzed?
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6. Was the conclusion drawn in the paper adequately
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supported by the data?
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The need for affirmative answer to each of these questions
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would seem to be self-evident. In the existing literature,
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however, this has not always been the case, perhaps due to
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the complex, interdisciplinary nature of the work.
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As just indicated, our objective is to clearly define
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necessary information which should be included in RFR
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bioeffect manuscript. Our suggested list is as follows:
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1. A clear statement of the objective(s).
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2. An adequate description of the biological system:
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a. For in-vitro studies, inclusion of indices of the
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proliferative and/or physiological state of the exposed and
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unexposed cells.
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b. for in-vivo studies, inclusion of indices of the
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physiological state of the exposed and unexposed
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animal/organism. Considerations for in-vivo exposures have
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recently been summarized by Michaelson (1983)
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3. A statement of the relevance of the endpoint chosen for
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measurement.
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4. An adequate description of the technique used (with
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specifics of size and shape of containers, the composition
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of liquids used, volumes, etc.)
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5. A description of the physical exposure system, including:
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a. Specifics of the equipment used to generate the
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radiation
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b. A description of the antenna, horn, or waveguide,
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etc.
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c. The forward and net forward power; and an indication
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of how measured.
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d. The frequency and whether the radiation is AM or FM;
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if modulated, the percent modulation used and its frequency.
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A description of how any modulation was achieved.
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e. For pulse-wave (PW) radiation, specification of
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1. the pulse repetition rate
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2. the pulse width
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3. the duty factor
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4. the pulse shape
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6. If applicable, the antenna/horn to sample distance.
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Indication should be given as to whether the sample is in
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the near or far field.
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7. The power density in air at the sample position. An
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indication whether this value is at the center of the field
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or averaged over the field.
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8. For low frequencies, a description of both the electric
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and magnetic field components and how they are determined.
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(In some cases, it is more appropriate to describe the
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applied voltage and currents or current densities, such as
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for electrodes immersed in preparation.)
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9. A description of the instrumentation used for measuring
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the power density or the electric and magnetic field
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components.
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10. A description of the sample environment.
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a. for in-vitro studies, a description of the immediate
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environment of the sample and/or its container (e.g.
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waterbath, support, etc.). Is there enough information to
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reproduce the exposure in another laboratory?
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b. For in-vivo studies, a description of the animal
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holder/container and its positioning in the RFR field,
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especially with regard to orientation,
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11. Specification of the specific absorption rate (SAR) for
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each experimental protocol. A report of not only the
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average, but also the distribution in the sample (as
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applicable).
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12. A description of the technique and instrumentation used
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for SAR measurement or calculation.
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13. A description of how the temperature is monitored; this
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should include:
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a. A statement as to whether the measurement is made
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before, during, after or continuously during the exposure
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b. The temperature distribution in the sample
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c. the sample temperature before the exposure begins
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d. the pattern (rate) of temperature increases
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e. the technique used to reach the final temperature
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(medium exchange, immersion in a hot waterbath, etc.)
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f. how temperature controls compare to the above radio-
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frequency exposed samples.
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14. A description of the ambient temperature and humidity
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conditions; this is essential for in-vivo investigations and
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can be important for in-vitro studies also.
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15. Data analysis
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a. Provision for quantifiable data from a minimum of 2
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independent experiments performed using equivalent
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conditions, with replicate independent samples in each
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experiment.
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b. A statistical analysis of the data, with
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specification of statistical method used
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c. A clear statement as to whether or not the data is
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statistically significant.
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d. A statement of whether or not double-blind scoring
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was employed; this is most desirable, and for some
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experimental end points, a requirement.
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CONCLUSION
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We have found in drafting manuscripts summarizing our own
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experiments, that it is very easy to leave out portions of
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the essential information just described. We would suggest a
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checklist approach, i.e., after the manuscript is drafted,
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check its contents against the previously listed essential
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items. Obviously, awareness of the need for this essential
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information can also be of assistance in experimental
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design. While inclusion of all the recommended information
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might not be possible in every case, this list is proposed
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as and ideal to which we can all aspire.
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Finally, while we have made an attempt to be inclusive, we
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do not expect that this first listing will be complete. We
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solicit comments and recommendations from other involved
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scientists.
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Martin L. Meltz
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The U of Texas Health Science Center
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7703 Floyd Curl Dr.
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San Antonio, TX 78284
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David N. Erwin
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USAF School of Aerospace Medicine
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Human Systems Division (AFSC)
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Brooks AFB, San Antonio, TX 78235-5301
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References:
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Pickard WF (1985-1986): Bioelectromagnetics Society
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Newsletter, Nos 64-66
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Michaelson SM (1983): Criteria for electric, magnetic or
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electromagnetic field bioeffects investigations. In:
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Biological Effects and Dosimetry of Static and ELF
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Electromagnetic Fields, ed. Michaelson and Rindi, New York
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Plenum Press p 15-29
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**************************************************
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e-mail(Internet): CANOUGH@BINGVAXA.CC.BINGHAMTON.EDU
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(GEnie) : G.CANOUGH
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phone/fax= 607 785 6499 voice mail = 800 673 8265
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radio call sign: KB2OXA
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'Snail Mail:
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ETM, Inc.
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PO Box 67
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Endicott, NY 13761
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------------------------------
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End of Space Power Digest Volume 1 : Issue 007
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------------------------------
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