bluuebunny/crossref_metadata_2025 huggingface dataset:
Class I HLA antigens in two long‐separated populations: Melanesians and South Amerinds
Authors: Bhatia Kuldeep K. , Black Francis L. , Smith Thomas A. , Prasad Madhuri L. , Koki George N.
Published: February 2006

Class I HLA antigens have been compared in 5,835 Melanesians of Papua New Guinea and 2,028 Amerindians of South America. The sample includes 50 PNGMel ethnolinguistic groups and 22 SAmlnd groups. Both carry 15 serologically defined antigens and an undefined C allele. Except for A2 in Papua New Guinea and Cwl in South America, these antigens are widely distributed in their respective populations. Nine (A2 and A24, B39, B60 and B62, and Cwl, Cw3, Cw4, and Cw7) are common to both. This commonality suggests that these two populations derive from an ancestral population with less polymorphism than modern East Asians. In both populations several theoretically possible haplotypes were absent, and other haplo‐types were in positive disequilibrium in both. The parallels in disequilibria suggest that haplotypes are subject to selective forces acting on the level of allelic interaction. Based on three locus haplotype frequencies, the PNGMel groups form five clusters with internally typical linguistic and geographic characteristics and a miscellaneous category, but Samlnd groups show no cluster. © 1995 Wiley‐Liss, Inc.
Subfossil Indri indri from the Ankarana Massif of northern Madagascar
Authors: Jungers William L. , Godfrey Laurie R. , Simons Elwyn L. , Chatrath Prithijit S.
Published: February 2006

Subfossil specimens of Indri indri have been recovered recently from the Ankarana Massif cave system in the far north of Madagascar. Taken together with material from the central highland site of Ampasamba‐zimba, the range of this species appears to have once included much of the northern half of the island and to have extended north and west beyond the eastern rainforest (not unlike Hapalemur simus). It is probable that forest corridors connected the subfossil localities to the current range at some time in the past. Climatic desiccation (fluctuating or long‐term) and/or human degradation of the environment may have created the disjunct distributions of living and subfossil I. indri. It is also possible that I. indri once included populations or subspecies that were better adapted to dry forest, woodland, or mosaic environments, habitats very different from those occupied by their living conspecifics. Such adaptive diversity would have been similar to that of Propithecus diadema which today has subspecies in the montane forests and one (P.d. perrieri) in the dry forests of the northeast. These discoveries add new information on range extensions to the distributional database for the primates of Madagascar, and illustrate the piecemeal process of their extinctions. © 1995 Wiley‐Liss, Inc.
Status and diet in precontact highland ecuador
Authors: Ubelaker D. H. , Katzenberg M. A. , Doyon L. G.
Published: February 2006

Excavation at the Ecuadorian highland site of La Florida in suburban Quito revealed six deep shaft tombs yielding high‐status individuals (n = 9) as well as apparent sacrifices and other low‐status individuals (n = 23). Determination of sex and age at death of the recovered skeletal remains resulted in a sample of 32 individuals aged from approximately 7 to 50 years of age. The sample of 18 individuals over the age of 18 years included 14 females and 4 males. Temporally, the remains are assigned to the Chaupicruz Phase (circa 100 to 450 AD) of the Regional Developmental Period. In this study, we analyze stable isotopes of carbon and nitrogen from human bone in order to compare the diets of the high‐ and low‐status individuals. Stable carbon isotope analyses were carried out on preserved protein and biological apatite (bioapatite), and stable nitrogen isotope analyses were carried out on preserved protein. There is a statistically significant difference in δ13C between the two groups for both protein and mineral sources of carbon with evidence for the greater consumption of maize in the high‐status group. There is no significant difference in δ15N between the two groups, nor is there a significant difference in the spacing between protein and mineral δ13C values between the two groups. Ethnohistorical evidence for the 16th century AD provides the expectation that the only dietary difference was the higher consumption of animal protein by the elite. There is no evidence for this based on the bone chemistry data from La Florida. Instead, the isotope data, along with the archaeological evidence, indicate that the major dietary difference during the Chaupicruz Phase was the greater intake of maize by the elite, probably in the form of beer (chicha). © 1995 Wiley‐Liss, Inc.
Effects of body size and social context on the arboreal activities of lowland gorillas in the Central African Republic
Authors: Remis Melissa
Published: February 2006

The objectives of this 27 month study were to document the positional behaviors used by lowland gorillas (Gorilla gorilla gorilla) in the Central African Republic and to compare the effects of body size dimorphism on the use of arboreal substrates. During this study, despite their great size, all gorillas used trees regularly. Predictions concerning the relationship of body size to arboreal behavior were generally upheld. Small branch and suspensory activities were rare for silverbacks. Females used smaller and multiple substrates and suspensory postures more frequently than males. Although females foraged in the periphery of trees, males stayed close to the cores and rarely used terminal branches.

In addition to body size, this study found that party size, social rank, and tree structure all influence an animal's substrate choice and subsequent positional activities. Lone males typically remained in the cores of trees where substrates are large. Group males may have been forced to use all parts of trees because others were present. Lone males used small crown trees which provided easy access to terminal branch foods. Males and females foraging together used larger trees (containing more feeding sites) than single sex groups. Female positional behavior may have been affected by the presence of males. When apart from males, females used the cores of trees and larger substrates more than when foraging with males. As habitat and social context both influence substrate use, they should be considered essential components of body‐sized based interpretations of the behavior of fossil or extant species. © 1995 Wiley‐Liss, Inc.
Maxillary sinusitis in Medieval Chichester, England
Authors: Boocock P , Roberts C. A. , Manchester K
Published: February 2006

Maxillary sinusitis is a common medical complaint, affecting more than 30 million people per year in the United States alone. Very little palaeopathological work on this disease has been carried out, probably because of the enclosed nature of the sinuses in intact skulls and the lack of a suitable method for examination. This study tested the hypothesis that maxillary sinusitis was more common in people with leprosy than in people without it in Medieval England. The prevalence of maxillary sinusitis by age and sex was recorded in 133 individuals, some diagnosed as being leprous, derived from a later Medieval (12th to 17th centuries AD) urban hospital population at Chichester, Sussex, England using both macroscopic and endoscopic methods of examination. Of the 133 individuals with one or both sinuses available for examination, 54.9% (73) had evidence of bone change within the sinuses. There was no difference in prevalence between those with leprosy and those without, although clinical studies suggest that over 50% of lepromatous leprous individuals may develop sinusitis. Comparison with another study on Medieval British sites with a 3.6% prevalence (3 of 83) indicates that the prevalence at Chichester is much greater. The problems with diagnosing sinusitis are addressed and reasons behind the high frequency in this study are discussed. Aetiological factors predisposing to maxillary sinusitis are considered with reference to possible environmental conditions prevailing in the later Medieval period in Britain. © 1995 Wiley‐Liss, Inc.
Biomechanics of the hip and birth in early Homo
Authors: Ruff Christopher B.
Published: February 2006

A complex of traits in the femur and pelvis of Homo ereclus and early “erectus‐like” specimens has been described, but never satisfactorily explained. Here the functional relationships between pelvic and femoral structure in humans are explored using both theoretical biomechanical models and empirical tests within modern samples of diverse body form (Pecos Amerindians, East Africans). Results indicate that a long femoral neck increases mediolateral bending of the femoral diaphysis and decreases gluteal abductor and hip joint reaction forces. Increasing biacetabular breadth along with femoral neck length further increases M‐L bending of the femoral shaft and maintains abductor and joint reaction forces at near “normal” levels. When compared to modern humans, Homo erectus and early “erectus‐like” specimens are characterized by a long femoral neck and greatly increased M‐L relative to A‐P bending strength of the femoral shaft, coupled with no decrease in hip joint size and a probable increase in abductor force relative to body size. All of this strongly suggests that biacetabular breadth as well as femoral neck length was relatively large in early Homo. Several features preserved in early Homo partial hip bones also indicate that the true (lower) pelvis was very M‐L broad, as well as A‐P narrow. This is similar to the lower pelvic shape of australopithecines and suggests that nonrotational birth, in which the newborn's head is oriented transversely through the pelvic outlet, characterized early Homo as well as Australopithecus. Because M‐L breadth of the pelvis is constrained by other factors, this may have limited increases in cranial capacity within Homo until rotational birth was established during the late Middle Pleistocene. During or after the transition to rotational birth biacetabular breadth decreased, reducing the body weight moment arm about the hip and allowing femoral neck length (abductor moment arm) to also decrease, both of which reduced M‐L bending of the proximal femoral shaft. Variation in femoral structural properties within early Homo and other East African Early Pleistocene specimens has several taxonomic and phylogenetic implications. © 1995 Wiley‐Liss, Inc.
Basicranial flexion, relative brain size, and facial kyphosis in Homo sapiens and some fossil hominids
Authors: Ross Callum , Henneberg Maciej
Published: February 2006

Comparative work among nonhominid primates has demonstrated that the basicranium becomes more flexed with increasing brain size relative to basicranial length and as the ‐upper and lower face become more ventrally deflected (Ross and Ravosa [1993] Am. J. Phys. Anthropol. 91:305–324). In order to determine whether modern humans and fossil hominids follow these trends, the cranial base angle (measure of basicranial flexion), angle of facial kyphosis, and angle of orbital axis orientation were measured from computed tomography (CT) scans of fossil hominids (Sts 5, MLD 37/38, OH9, Kabwe) and lateral radiographs of 99 extant humans. Brain size relative to basicranial length was calculated from measures of neurocranial volume and basicranial length taken from original skulls, radiographs, CT scans, and the literature. Results of bivariate correlation analyses revealed that among modern humans basicranial flexion and brain size/basicranial length are not significantly correlated, nor are the angles of orbital axis orientation and facial kyphosis. However, basicranial flexion and orbit orientation are significantly positively correlated among the humans sampled, as are basicranial flexion and the angle of facial kyphosis. Relative to the comparative sample from Ross and Ravosa (1993), all hominids have more flexed basicrania than other primates: Archaic Homo sapiens, Homo erectus, and Australopithecus africanus do not differ significantly from Modern Homo sapiens in their degree of basicranial flexion, although they differ widely in their relative brain size. Comparison of the hominid values with those predicted by the nonhominid reduced major‐axis equations reveal that, for their brain size/basicranial length, Archaic and Modern Homo sapiens have less flexed basicrania than predicted. H. erectus and A. africanus have the degree of basicranial flexion predicted by the nonhominid reduced major‐axis equation. Modern humans have more ventrally deflected orbits than all other primates and, for their degree of basicranial flexion, have more ventrally deflected orbits than predicted by the regression equations for hominoids. All hominoids have more ventrally deflected orbital axes relative to their palate orientation than other primates. It is argued that hominids do not strictly obey the trend for basicranial flexion to increase with increasing relative brain size because of constraints on the amount of flexion that do not allow it to decrease much below 90°. Therefore, if basicranial flexion is a mechanism for accommodating an expanding brain among non‐hominid primates, other mechanisms must be at work among hominids. © 1995 Wiley‐Liss, Inc.
Linking teratogen information service and birth defects registry databases to improve knowledge of birth defect status
Authors: Archer Natalie P. , Langlois Peter H. , Case Amy P. , Wolfe Lori J.
Published: February 2006

BACKGROUND

Although teratogen information services (TISs) obtain maternal exposure information from their callers, such services often do not know if the pregnancies were affected by a birth defect. This study attempted to improve the completeness of this information for Texas Teratogen Information Service (TTIS) callers by linking their records with the Texas Birth Defects Registry (TBDR) and Texas birth certificates (TBCs).

METHODS

A total of 344 expectant mothers called TTIS with expected dates of delivery between 1 January 2000 and 31 December 2001. These pregnancies were linked with TBDR and TBC data. The percentages of pregnancies with known birth defect information both before and after the linkage were compared.

RESULTS

The TTIS originally collected birth defect status information for 101 of the 344 callers (29.4%) and 0.6% of all 344 callers or 2.0% of callers with birth defect status information had a pregnancy affected by a birth defect. Linking TTIS records with TBDR and TBC data helped to raise the percentage of callers with birth defect status information from 29.4% to 71.5%. Among those callers, the percentage known to have birth defects increased from 2.0% to 4.1%. The sensitivity of TTIS follow‐up calls in identifying birth defects was 50%, and the specificity was 100%.

CONCLUSIONS

Linking TTIS caller records with TBDR and TBC data significantly increased both the percentage of pregnancies with birth defect status information and the percentage of pregnancies identified as affected by birth defects. Such linkage may be a good approach by which TISs can increase the completeness of their birth defect status information. Birth Defects Research (Part A), 2006. © 2006 Wiley‐Liss, Inc.
Teratology public affairs committee position paper: Maternal obesity and pregnancy
Authors: Scialli Anthony R.
Published: February 2006

Compared to normal‐weight women, obese women have an increased risk of infertility and pregnancy complications. The most consistently described pregnancy complications are hypertensive disorders, gestational diabetes mellitus, thromboembolic events, and cesarean section. Fetal and neonatal complications may include congenital malformations, macrosomia, and shoulder dystocia. The literature suggests that women with a body mass index (BMI) ≥30 have approximately double the risk of having a child with a neural tube defect (NTD) compared to normal‐weight women, and the increased risk associated with higher maternal body weight does not appear to be modified by folic acid supplementation. The Public Affairs Committee of the Teratology Society supports the public health initiatives identified by the U.S. Food and Drug Administration in 2004 and the research initiatives identified by the National Institutes of Health in 2004. The Public Affairs Committee recommends that clinicians counsel women about appropriate caloric intake and exercise and that health‐care providers educate parents about appropriate childhood nutrition. Breast‐feeding should be encouraged based on evidence of a protective effect against childhood obesity, as well as other health advantages. Birth Defects Research (Part A), 2006. © 2006 Wiley‐Liss, Inc.
Microwaves modify thermoregulatory behavior in squirrel monkey
Authors: Adair Eleanor R. , Adams Barbara W.
Published: February 2006

Squirrel monkeys (Saimiri sciureus) trained to regulate environmental temperature (Ta) behaviorally were exposed in the far field of a horn antenna to ten‐minute periods of 2,450 MHz CW microwaves. Incident power density ranged from 1 to 22 mW/cm2. The corresponding specific absorption rate (SAR), derived from temperature increments in saline‐filled styrofoam models, ranged from 0.15 to 3.25 W/kg. Controls included exposure to infrared radiation of equivalent incident energy and no radiation exposure. Normal thermoregulatory behavior produces tight control over environmental and body temperatures; most monkeys select a Ta of 34–36°C. Ten‐minute exposures to 2,450 MHz CW microwaves at an incident power density of 6–8 mW/cm2 stimulated all animals to select a lower Ta. This threshold energy represents a whole‐body SAR of 1.1 W/kg, about 20% of the resting metabolic rate of the monkey. Thermoregulatory behavior was highly efficient, and skin and rectal temperatures remained stable, even at 22 mW/cm2 where the preferred Ta was lowered by as much as 4°C. No comparable reduction in selected Ta below control levels occurred during exposure to infrared radiation of equal incident power density.
Induction of calcium‐ion efflux from brain tissue by radiofrequency radiation: Effect of sample number and modulation frequency on the power‐density window
Authors: Blackman C. F. , Benane S. G. , Elder J. A. , House D. E. , Lampe J. A. , Faulk J. M.
Published: February 2006

Changes have been found in calcium‐ion binding to brain tissue exposed in vitro to a specific power density (0.83 mW/cm2) of 147‐MHz radiation, amplitude modulated by a 16‐Hz sine wave. This report replicates and extends this previous work. To define more precisely the range of effective power densities, two different numbers of samples were treated in a Crawford cell. In one series, four brain tissues were exposed at a time; in the other series, four brain tissues plus six dummy loads were exposed together. While the four‐sample configuration produced a narrow power‐density window, the ten pseudosample configuration resulted in a broader power‐density window. The reason for the sample‐number dependence is unresolved, but may be due to interactions between samples and field distortions caused by the close spacing. The ten pseudosample configuration was used to test for the presence and range of a power‐density window at a sinusoidal modulation frequency of 9 Hz. The response curve at 9 Hz was essentially identical to the results for 16‐Hz sinewave modulation.
Microwave‐induced pressure waves in a model of muscle tissue
Authors: Olsen Richard G. , Hammer Wayne C.
Published: February 2006

Microwave‐induced mechanical stress waves were studied in simulated muscle tissue. Pulsed microwave energy at 5.655 GHz induced pressure waves that were recorded with a hydrophone transducer. Each pulse produced a peak power density greater than 1.5 kW/cm2. Microwave absorption measurements within the model showed energy deposition to be mostly confined to a region within 2 cm of the irradiated surface. The average specific absorption rate (SAR) at the surface of the sample was about 100 W/kg. The microwave‐induced stress wave propagated at a velocity of 1,600 m/sec with peak pressures of approximately 300 pascals and was detectable after having traveled a total distance of 0.61 m on a path that included two reflections at model‐container interfaces.
Immunologic and hematopoietic alterations by 2,450‐MHz electromagnetic radiation
Authors: Huang Andrew Ta‐Fu , Mold Nelda G.
Published: February 2006

A biphasic modulation of responsiveness of spleen lymphocytes to mitogens was observed in mice exposed to 2,450‐MHz radiation at power densities of 5–15 mW/cm2 over various periods ranging between one and 17 days. This modulated phenomenon may be explained on the basis of 1) suppression of lymphocyte response by microwave‐activated macrophages which persists throughout the entire course of radiation, and 2) concurrent progressive direct stimulation of lymphocytes which culminates around day 9 of exposure. Tumor cytotoxicity of killer lymphocytes from mice exposed to five or nine days of radiation did not appear different from sham controls. The highly proliferative hematopoietic marrow cells were sensitive to microwave radiation. Nine days of exposure to radiation (15 mW/cm2) reduced the colonyforming units of myeloid and erythroid series by 50%. This observation may offer a new and more sensitive assay for studying biological effects of electromagnetic radiation.
Failure of rats to escape from a potentially lethal microwave field
Authors: Carroll Donna R. , Levinson Daniel M. , Justesen Don R. , Clarke Rex L.
Published: February 2006

Ocularly pigmented rats, all mature females of the Long‐Evans strain, were repeatedly presented an opportunity to escape from an intense 918‐MHz field (whole‐body dose rate = 60 mW/g) to a field of lower intensity (40, 30, 20, or 2 mW/g) by performing a simple locomotor response. Other rats could escape 800‐μA faradic shock to the feet and tail by performing the same response in the same milieu, a multimode cavity. None of 20 irradiated rats learned to associate entry into a visually well‐demarcated area of the cavity with immediate reduction of dose rate, in spite of field‐induced elevations of body temperature to levels that exceeded 41°C and would have been lethal but for a limit on durations of irradiation. In contrast, all of ten rats motivated by faradic shock rapidly learned to escape. The failure of escape learning by irradiated animals probably arose from deficiencies of motivation and, especially, sensory feedback. Whole‐body hyperthermia induced by a multipath field may lack the painful or directional sensory properties that optimally promote the motive to escape. Moreover, a decline of body temperature after an escape‐response‐contingent reduction of field strength will be relatively slow because of the large thermal time constants of mammalian tissues. Without timely sensory feedback, which is an essential element of negative reinforcement, stimulus‐response associability would be imparied, which could retard or preclude learning of an escape response.
Chronic exposure to a 60‐Hz electric field: Effects on synaptic transmission and peripheral nerve function in the rat
Authors: Jaffe R. A. , Laszewski B. L. , Carr D. B. , Phillips R. D.
Published: February 2006

Several reports have suggested that the nervous system can be affected by exposure to electric fields and that these effects may have detrimental health consequences for the exposed organism. The purpose of this study was to investigate the effects of chronic (30‐day) exposure of rats to a 60‐Hz, 100‐kV/m electric field on synaptic transmission and peripheral‐nerve function. One hundred forty‐four rats, housed in individual polycarbonate cages were exposed to uniform, vertical, 60‐Hz electric fields in a system free of corona discharge and ozone formation and in which the animals did not receive spark discharges or other shocks during exposure. Following 30 days of exposure to the electric field, superior cervical sympathetic ganglia, vagus and sciatic nerves were removed from rats anesthetized with urethan, placed in a temperature‐controlled chamber, and superfused with a modified mammalian Ringer's solution equilibrated with 95% O2 and 5% CO2. Several measures and tests were used to characterize synaptic transmission and peripheral‐nerve function. These included amplitude, area, and configuration of the postsynaptic or whole‐nerve compound‐action potential; conduction velocity; accommodation; refractory period; strength‐duration curves; conditioning‐test (C‐T) response, frequency response; post‐tetanic response; and high‐frequency‐induced fatigue. The results of a series of neurophysiologic tests and measurements indicate that only synaptic transmission is significantly and consistently affected by chronic (30‐day) exposure to a 60‐Hz, 100‐kV/m electric field. Specifically, an increase in synaptic excitability was detected in replicated measurements of the C‐T response ratio. In addition, there are trends in other data that can be interpreted to suggest a generalized increase in neuronal excitability in exposed animals.
Far‐field microwave dosimetry in a rhesus monkey model
Authors: Olsen Richard G. , Griner Toby A. , Prettyman George D.
Published: February 2006

Dosimetric measurements were made in a muscle‐equivalent model of an adult rhesus monkey subjected to far‐field irradiation at 1.29 GHz. Profiles of microwave‐induced heating in the model were obtained at eight locations, and a gradient‐layer whole‐body calorimeter was used to measure total absorbed energy. Average specific absorption rate (SAR) was calculated both from the calorimeter experiments and from the local temperature measurements. Thermographic imaging techniques were used to qualitatively show the microwave‐induced surface heating patterns. For this model the calculated average SAR was 0.155 (W/kg)/(mW/cm2) which, at 1.29 GHs, makes the absorption cross section 84% of the geometric shadow cross section. The SAR is about three times that predicted for a prolate spheroidal model of similar mass. A disproportionally high absorption occured in the legs of the model positioned parallel to the E‐polarization because of what is believed to be partial‐body resonance.
A thermal model of the human body exposed to an electromagnetic field
Authors: Spiegel R. J. , Deffenbaugh D. M. , Mann J. E.
Published: February 2006

The human body was modeled by numerical procedures to determine the thermal response under varied electromagnetic (EM) exposures. The basic approach taken was to modify the heat transfer equations for man in air to account for thermal loading due to the energy absorbed from the EM field. The human body was represented in an EM model by a large number of small cubical cells of tissue, and the energy density was determined for each cell. This information was then analyzed by a thermal response model consisting of a series of two‐dimensional transient conduction equations with internal heat generation due to metabolism, internal convective heat transfer due to blood flow, external interaction by convection and radiation, and cooling of the skin by sweating and evaporation. This model simulated the human body by a series of cylindrical segments. The local temperature at 61 discrete locations as well as the thermoregulatory responses of vasodilatation and sweating were computed for a number of EM field intensities and two frequencies, one near whole‐body resonance.
Power density, field intensity, and carrier frequency determinants of RF‐energy‐lnduced calcium‐ion efflux from brain tissue
Authors: Joines William T. , Blackman Carl F.
Published: February 2006

To explain a carrier frequency dependence reported for radiofrequency (RF)‐induced calcium‐ion efflux from brain tissue, a chick‐brain hemisphere bathed in buffer solution is modeled as a sphere within the uniform field of the incident electromagnetic wave. Calculations on a spherical model show that the average electric‐field intensity within the sample remains the same at different carrier frequencies if the incident power density (Pi) is adjusted by an amount that compensates for the change in complex permittivity (ϵ) and the change of wavelength, as a function of carrier frequency. The resulting formula for transforming Pi is seen to follow the pattern of both positive and negative demonstrations of calcium‐ion efflux that have been observed at carrier frequencies of 50, 147, and 450 MHz. Indeed, all results obtained at these three frequencies, when related by Pi's that produce the same average electric‐field intensity within the sample, are seen to be in agreement; no prediction is contradicted by an experiment.
Calcium‐ion efflux from brain tissue: Power‐density versus internal field‐intensity dependencies at 50‐MHz RF radiation
Authors: Blackman C. F. , Benane S. G. , Joines W. T. , Hollis M. A. , House D. E.
Published: February 2006

In previous experiments changes were found in calcium‐ion efflux from chickbrain tissue that had been exposed in vitro to 147‐MHz radiation across a specific range of power densities when the field was amplitude modulated at 16 Hz. In the present study, 50‐MHz radiation, similarly modulated as a sinusoid, was found to produce changes in calcium‐ion efflux from chick brains exposed in vitro in a Crawford cell. Exposure conditions were optimized to broaden any power‐density window and to enhance the opportunity to detect changes in the calcium‐ion efflux. The results of a power‐density series demonstrated two effective ranges: One spanning a range from 1.44 to 1.67 mW/cm2, and the other including 3.64 mW/cm2, which were bracketed by no‐effect results at 0.72, 2.17, and 4.32 mW/cm2. Peaks of positive findings are associated with near‐identical rates of energy absorption: 1.4 μW/g at 147 MHz, and 1.3 μW/g at 50 MHz, which indicates that the enhanced‐efflux phenomenon is more dependent on the intensity of fields in the brain than on the power density of incident radiation. In addition, the phenomenon appears to occur at multiples of some, as yet unknown, rate of radiofrequency (RF) energy absorption. Because of the extremely small increments of temperature associated with positive findings (< 4 × 10−4°C), and the existence of more than one productive absorption rate, a solely thermal explanation appears extremely unlikely.
Millimeter wave absorption spectra of biological samples
Authors: Gandhi O. P. , Hagmann M. J. , Hill D. W. , Partlow L. M. , Bush L.
Published: February 2006

A solid‐state computer‐controlled system has been used to make swept‐frequency measurements of absorption of biological specimens from 26.5 to 90.0 GHz. A wide range of samples was used, including solutions of DNA and RNA, and suspensions of BHK‐21/C13 cells, Candida albicans, C krusei, and Escherichia coli. Sharp spectra reported by other workers were not observed. The strong absorbance of water (10–30 dB/mm) caused the absorbance of all aqueous preparations that we examined to have a water‐like dependence on frequency. Reduction of incident power (to below 1.0 μW), elimination of modulation, and control of temperature to assure cell viability were not found to significantly alter the water‐dominated absorbance. Frozen samples of BHK‐21/C13 cells tested at dry ice and liquid nitrogen temperatures were found to have average insertion loss reduced to 0.2 dB/cm but still showed no reproducible peaks that could be attributed to absorption spectra. It is concluded that the spectral resonances reported by others are likely to be in error.
Studies of exposure of rabbits to electromagnetic pulsed fields
Authors: Cleary S. F. , Nickless F. , Liu L. M. , Hoffman R.
Published: February 2006

Dutch rabbits were acutely exposed to electromagnetic pulsed (EMP) fields (pulse duration 0.4μs, field strengths of 1–2 kV/cm and pulse repetition rates in the range of 10 to 38 Hz) for periods of up to two hours. The dependent variables investigated were pentobarbital‐induced sleeping time and serum chemistry (including serum triglycerides, creatine phosphokinase (CPK) isoenzymes, and sodium and potassium). Core temperature measured immediately pre‐exposure and postexposure revealed no exposure‐related alterations. Over the range of field strengths and pulse durations investigated no consistent, statistically significant alterations were found in the end‐points investigated.
Effects of 2.45‐GHz microwave radiation on embryonic quail hearts
Authors: Galvin M. J. , McRee D. I. , Lieberman M.
Published: February 2006

Although exposure to nonionizing electromagnetic radiation has been reported to cause a variety of systemic alterations during embryonic development, there are few reports of the induction of specific physiologic or morphologic changes in the myocardium. This study was designed to examine the effects of microwave radiation on cardiogenesis in Japanese quail embryos exposed during the first eight days of development to 2.45‐GHz continuous‐wave microwaves at power densities of 5 or 20 mW/cm2. The specific absorption rates were 4.0 and 16.2 mW/g, respectively. The ambient temperature for each exposure was set to maintain the embryonated eggs at 37.5 °C. This did not preclude thermal gradients in the irradiated embryos since microwaves may not be uniformly absorbed. The test exposure levels did not induce changes in either the morphology of the embryonic heart or the ultrastructure of the myocardial cells. Analysis of the enzymatic activities of lactate dehydrogenase, glutamic oxaloacetic transaminase, and creatine phosphokinase failed to reveal any statistically significant differences between the nonexposed controls and those groups exposed to either 5 or 20 mW/cm2. The data indicate that 2.45‐GHz microwave radiation at 5 or 20 mW/cm2 has no effect on the measured variables of the Japanese quail myocardium exposed during the first eight days of development.
Flight, orientation, and homing abilities of honeybees following exposure to 2.45‐GHz CW microwaves
Authors: Gary Norman E. , Westerdahl Becky Brown
Published: February 2006

Foraging‐experienced honeybees retained normal flight, orientation, and memory functions after 30 minutes' exposure to 2.45‐GHz CW microwaves at power densities from 3 to 50 mW/cm2. These experiments were conducted at power densities approximating and exceeding those that would be present above receiving antennas of the proposed solar power satellite (SPS) energy transmission system and for a duration exceeding that which honeybees living outside a rectenna might be expected to spend within the rectenna on individual foraging trips. There was no evidence that airborne invertebrates would be significantly affected during transient passage through microwaves associated with SPS ground‐based microwave receiving stations.
Experimental results contradicting claimed 1009‐MHz influence on erythrocyte mobility
Authors: Bamberger S. , Storch F. , Roth G. , Ruhenstroth‐Bauer G. , Keilmann F.
Published: February 2006

An attempt was made to detect the influence of ultrahigh frequency radiation (1009 MHz) on the electrophoretic mobility of human erythrocytes. Ines. In contradiction to an earlier report by Ismailov no effect was observed.
Effects of millimeter‐wave radiation on monolayer cell cultures. II. Scanning and transmission electron microscopy
Authors: Stensaas L. J. , Partlow L. M. , Bush L. G. , Iversen P. L. , Hill D. W. , Hagmann M. J. , Gandhi O. P.
Published: February 2006

Both thermal and athermal effects of millimeter‐wave radiation on BHK‐21/C13 cells were sought using scanning and transmission electron microscopy in conjunction with an in vitro technique that allows direct exposure of monolayer cultures to high average power densities. Culture dishes were irradiated by placing them on the open end of an E‐ or U‐band wave guide. This technique exposes different regions of the cell monolayer lying along the longer axis of the wave guide aperture to varying power densities ranging from zero at each edge to twice the average power density at the center.

Cell ultrastructure was unaffected by microwave radiation for 1 hour (41.8 or 74.0 GHz, average power densitites = 320 or 450 mW/cm2, respectively) with or without cooling by rapid recirculation of the culture medium. Temperature in recirculated cultures was held at 37.2 °C, and that in noncooled cultures never exceeded 42 °C during irradiation at either power density. In contrast, cell morphology was affected by microwave exposure whenever irradiation conditions were altered so that the temperature of the monolayer reached or exceeded 44.5 °C. Ultrastructural alterations included breakage of cell processes, progressive detachment of cells from the substrate, increased clumping of heterochromatin in the nuclei, and the appearance of large empty vesicles in the cytoplasm. Such morphological changes resulted from either application of higher average power densities or irradiation at the power densities described above at a higher ambient temperature (>38.5°C).
In vitro microwave effects on human neutrophil precursor cells (CFU‐C)
Authors: Ottenbreit Mark J. , Inoue Susumu , Peterson Ward D. , Lin James C.
Published: February 2006

Human marrow cells were irradiated with 2450‐MHz CW microwaves in a fluid‐filled waveguide irradiation system. Cell exposure was conducted by placing a marrow cell suspension in 20‐μl glass microcapillary tubes that were positioned in the exposure chamber, and irradiated at power densities from 31 to 1,000 mW/cm2 (with corresponding specific absorption rates of 62 to 2,000 mW/g) for 15 minutes. The temperature of the sample was maintained at a fixed point. Sham‐irradiated (SI) and microwave‐irradiated (MWI) cells were cultured in a methylcellulose culture system for neutrophil colony proliferation. There was no reduction in neutrophil colony number on days 6–7 or 12–14 in cells exposed at 31 or 62 mW/cm2, but as the power density was increased to 1,000 mW/cm2, there was a reduction in colony number of MWI cells compared with SI cells. The microwave interaction with the human neutrophil colony‐forming cells was apparently not related to temperature rise, or to the state of cell cycle, and was irreversible.
Transbilayer movement of 24Na in sonicated phosphatidylcholine vesicles exposed to frequency‐modulated microwave radiation
Authors: Fisher Paul D. , Voss W. A. G. , Poznansky Mark J.
Published: February 2006

Sonicated egg phosphatidylcholine vesicles loaded with 24Na+ were exposed at 20mW to a frequency‐modulated (3 Hz) microwave field in the range of 2350 to 2550 MHz, or at 80 mW to a 2450‐MHz CW (continuous wave) field, in a waveguide. The vesicle suspension absorbed microwaves at about 1 mW/ml and 25 mW/ml (CW experiment). The average temperature change of the irradiated suspension was < 0.1 °C from ambient. Leakage of 24Na+ from the vesicles for up to 19 hours was measured. No difference was noted in the movement of 24Na+ from the vesicles in the irradiated and control dispersions.
Humoral and cell‐mediated immune function in adult japanese quail following exposure to 2.45‐GHz microwave radiation during embryogeny
Authors: Galvin Michael J. , McRee Donald I. , Hall Cynthia A. , Thaxton J. Paul , Parkhurst Carmen R.
Published: February 2006

Japanese quail, Coturnix coturnix japonica, eggs were subjected to 2.45‐GHz CW microwave radiation at 5 mW/cm2 (SAR = 4.03 mW/g) during the first 12 days of embryogeny. Following hatching the exposed embryos, as well as nonexposed controls, were reared to 22 weeks of age. Humoral immune potential, as indicated by comparable anti‐CRBC antibody, IgM and IgG, levels at 0, 4, and 7 days postimmunization in both exposed and control quail was not affected significantly. However, cell‐mediated immune potential, measured by the reaction to intradermal injection of phytohemagglutinin‐P in the wing web, was reduced in the exposed females, but not in the exposed males. Additionally, total leukocyte numbers and absolute circulating numbers of lymphocytes, monocytes, and heterophils were increased significantly only in the exposed females. These data show that exposure of Japanese quail during embryogenesis reduced cell‐mediated immune potential and induced a general leukocytosis in females.
Alterations in the rat electrocardiogram induced by stationary magnetic fields
Authors: Gaffey C. T. , Tenforde T. S.
Published: February 2006

A field strength dependent increase in the amplitude of the T‐wave signal in the rat electrocardiogram (ECG) was observed during exposure to homogeneous, stationary magnetic fields. For 24 adult Sprague‐Dawley and Buffalo rats of both sexes, the T‐wave amplitude was found to increase by an average of 408% in a 2.0 Tesla (1 Tesla = 104 Gauss) field. No significant magnetically induced changes were observed in other components of the ECG record, including the P wave and the QRS complex. The minimum field level at which augmentation of the T wave could be detected was 0.3 Tesla. The magnetically induced increase in T‐wave amplitude occurred instantaneously, and was immediately reversible after exposure to fields as high as 2.0 Tesla. No abnormalities in any component of the ECG record, including the T wave, were noted during a period of 3 weeks following cessation of a continuous 5‐h exposure of rats to a 1.5‐Tesla field. The heart rate and breathing rate of adult rats were not altered during, or subsequent to, application of fields up to 2.0 Tesla. The effect of animal orientation within the field was tested using juvenile rats 3–14 days old. The maximum increase in T‐wave amplitude was observed when subjects were placed with the long axis of the body perpendicular to the lines of magnetic induction. These experimental observations, as well as theoretical considerations, suggest that augmentation of the signal amplitude in the T‐wave segment of the ECG may result from a superimposed electrical potential generated by aortic blood flow in the presence of a stationary magnetic field.
Comparison of RF‐induced calcium efflux from chick brain tissue at different frequencies: Do the scaled power density windows align?
Authors: Athey T. Whit
Published: February 2006

The recent suggestion that the pattern of positive and negative results of RF‐induced calcium efflux from chick brain tissue, when appropriately scaled, matches at three frequencies is examined. Close scrutiny of this recently reported analysis by Joines and Blackman suggests that the uncertainties in the calculated scaling quantities are too large to permit meaningful conclusions.
Microwave dielectric studies on proteins, tissues, and heterogeneous suspensions
Authors: Foster Kenneth R. , Schepps Jonathan L. , Epstein Benjamin R.
Published: February 2006

We summarize the results of several of our recent studies on the dielectric properties of protein solutions, tissues, and nonionic microemulsions at microwave frequencies extending to 18 GHz. The data in all cases are analyzed using the Maxwell mixture theory to determine the dielectric properties of the suspending water and the amount and dielectric properties of the water of hydration associated with the suspended phase. The dielectric data from the protein solutions and tissues are broadly consistent with the results of previous studies at UHF frequencies; they indicate hydration values in the range of 0.4–0.6 g water/g protein. There is evidence of a dielectric relaxation process occurring at low‐GHz frequencies that can be attributed in part to dielectric relaxation of the “bound” water in the system. The remaining solvent water appears to have dielectric properties close to, if not precisely the same as, those of pure water. The average relaxation frequency of the suspending water in the microemulsions is reduced from that of pure water, evidently reflecting an average of that of the water of hydration (∼5–6 GHz) and that of pure water. This reduced average relaxation frequency implies an increased average viscosity of the water and (by Walden's rule) accounts for the unexpectedly low ionic conductivity of the preparations.
An approach to inverse scattering problems
Authors: Saito Masao , Hayashi Takehisa
Published: February 2006

There are several reasons for investigating the inverse scattering problem in medical image processing. A typical case, that of ultrasonic fields, is considered. Assuming that a plane wave illuminates a weakly inhomogeneous two‐dimensional object, the fundamental equation is derived for the scattered waves in integral as well as in differential forms. It is shown that the scattered waves observed on a circle surrounding the object is sufficient to specify the structure of the object. This information is summarized in a single term, which is a function of the wavenumber as well as the angles of incidence and observation. A successive approximation is applied to reconstruct the image of the object from this function. Since no analytic solution is available, several methods of approximations are proposed, and examples of computations are shown for the case of a cylindrical object.
Physiologic regulation in electromagnetic fields
Authors: Michaelson Sol M.
Published: February 2006

Electromagnetic fields have been demonstrated to elicit thermoregulatory responses, neuroen‐docrine, neurochemical modulations, and behavioral reactions. These physiologic regulatory processes are exquisitely tuned, interrelated functions that constitute sensitive indicators of organismic responses to radiofrequency energy absorption (the radio frequency portion of the electromagnetic spectrum includes as one part microwaves). Assessment of the integration and correlation of these functions relative to the thermal inputs and homeokinetic reactions of the individual subjected to radiofrequency energy should permit differentiation between potential hazards that might compromise the individual's ability to maintain normal physiologic function and effects that are compensated by physiologic redundancy.
A comparative study of human sensory thresholds: 2450‐MHz Microwaves vs far‐infrared radiation
Authors: Justesen Don R. , Adair Eleanor R. , Stevens Joseph C. , Brucewolfe Virginia
Published: February 2006

Three male and three female adults individually placed the ventral surface of the right and upright forearm against a 15‐cm‐diameter aperture in a wall of microwave‐absorbent material. Tensecond exposures occurred to E‐vector‐vertically polarized, 2450‐MHz‐CW microwave (MW) fields. Comparable exposure to infrared (IR) waves was repeated with four of the six observers. Thresholds of detection of just‐noticeable warming by MW and IR radiation were determined by the double‐staircase psychophysical method. Although the exposed surface areas of male observers' arm were larger than those of female observers, thresholds of warming by either source of energy overlapped; the pooled means of irradiance at threshold are 26.7 mW/cm2 (MW) and 1.7 mW/cm2 (IR). Dosimetric measures on saline models indicated virtually perfect absorption of the incident IR, but nearly two‐thirds of the MW energy was scattered. Accordingly, the 15‐fold difference in means of MW and IR thresholds resolves to a 5‐fold difference in threshold quantities of absorbed energy. In the light of the high correlation between thresholds of IR and MW irradiation (r = .97), it is concluded that the same set of superficial thermoreceptors was being stimulated, only less efficiently so, by the more deeply penetrating, more diffusely absorbed MW energy.