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1.
Lett Appl Microbiol ; 63(2): 131-8, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27261362

ABSTRACT

UNLABELLED: We isolated, identified and characterized yeast strains from grapes, and their fermented musts, sampled in the small island of Linosa, where there are no wineries and therefore the possibility of territory contamination by industrial strains is minimal. By traditional culture-dependent methods, we isolated 3805 colonies, distinguished by molecular methods in 17 different species. Five hundred and forty-four isolates were analysed for the main oenological characteristics such as fermentative vigour with and without sulphites, sugar consumption and production of alcohol, volatile acidity, hydrogen sulphide, glycerol and ß-glucosidase. This analysis identified Kluyveromyces marxianus (seldomly used in winemaking) as the most interesting candidate yeast for the production of innovative wines. SIGNIFICANCE AND IMPACT OF THE STUDY: In recent years, interest is growing for wine production by non-Saccharomyces yeasts, both in research and in the industry. This study describes the yeast population of the grapes in a small-secluded island in the Mediterranean Sea, useful site for the search of new strains. Evaluation of fundamental oenological characters identifies potential best yeasts to assay in experimental vinifications. We also describe, for the first time, 14 new colony morphologies on WL Nutrient Agar, culture medium used to monitor the yeast population dynamics.


Subject(s)
Vitis/microbiology , Wine/microbiology , Yeasts/classification , Yeasts/isolation & purification , Ethanol/analysis , Ethanol/metabolism , Fermentation/genetics , Glycerol/analysis , Glycerol/metabolism , Mediterranean Islands , Mediterranean Sea , Molecular Typing , Mycological Typing Techniques , Sulfites/analysis , Sulfites/metabolism , Wine/analysis , Yeasts/genetics
2.
Homo ; 61(6): 385-412, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20979998

ABSTRACT

The aim of this work is to explore the pattern of craniofacial morphometric variation and the relationships among five prehistoric Sardinian groups dated from Late Neolithic to the Nuragic Period (Middle and Late Bronze Age), in order to formulate hypotheses on the peopling history of Sardinia. Biological relationships with coeval populations of central peninsular Italy were also analysed to detect influences from and towards extra-Sardinian sources. Furthermore, comparison with samples of contemporary populations from Sardinia and from continental Italy provided an indication of the trend leading to the final part of the peopling history. Finally, Upper Palaeolithic and Mesolithic samples were included in the analyses to compare the prehistoric Sardinians with some of their potential continental ancestors. The analysis is based on multivariate techniques including Mahalanobis D(2) distance, non-parametric multidimensional scaling (MDS) and principal component analysis (PCA). The results showed the tendency to progressive differentiation between Sardinian groups and peninsular Italian groups, with the possible exception of a discontinuity showed by the Bonnànaro (Early Bronze Age) Sardinian sample. Several aspects of the morphological results were found to agree with the current genetic evidence available for the present-day Sardinian population and a Nuragic sample: (1) biological divergence between the Sardinian and peninsular Italian populations; (2) similarity/continuity among Neolithic, Bronze Age and recent Sardinians; (3) biological separation between the Nuragic and Etruscan populations; (4) contribution of a Palaeo-Mesolithic gene pool to the genetic structure of current Sardinians.


Subject(s)
Fossils , Paleontology , Skull/anatomy & histology , Adult , Child , Female , History, Ancient , Humans , Italy , Male
3.
Radiat Prot Dosimetry ; 137(3-4): 197-200, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19880416

ABSTRACT

In this work the compliance of tanning lamps with technical standards EN 60335-2-27 'Household and similar electrical appliances-Safety. Part 2: Particular requirements for appliances for skin exposure to ultraviolet and infrared radiation' was analysed. Results of this analysis showed that none of the examined technical documentation produced by the lamps manufacturers is fully compliant with the standard technique. Furthermore data reported in the same manuals, such as effective radiant exposure or irradiance, would indicate that these sources may be the cause of undue exposure to ultraviolet (UV) radiation. For this reason a measurement campaign on UV lamps used in tanning salons was organised. The first results of these measurements seem to confirm the doubts raised from the analysis of the lamp manuals: the use of a tanning lamp can lead to UV radiation exposure levels higher than reference maximum values recommended by EN 60335-2-27.


Subject(s)
Guideline Adherence , Lighting/instrumentation , Lighting/standards , Radiometry/standards , Suntan , Ultraviolet Therapy/instrumentation , Ultraviolet Therapy/standards , Equipment Design , Equipment Failure Analysis , European Union , Guidelines as Topic , Italy , Ultraviolet Rays
4.
Homo ; 58(1): 13-32, 2007.
Article in English | MEDLINE | ID: mdl-17241630

ABSTRACT

The present study describes human skeletal remains from Riparo della Rossa, a rock shelter in the Marche region (Central Italy). The remains consist of a cranial vault and a few non-articulated postcranial bones, possibly belonging to the same adult individual. As the cranial vault showed some morphological features that are unusual for a modern human (marked prominence of the supraorbital region, very prominent nasal bones and rather high thickness of the vault), an accurate anthropological analysis and quantification of the antiquity of the bones were required. The remains were dated with two different absolute dating methods, AMS (14)C and (235)U-(231)Pa non-destructive gamma-ray spectrometry (NDGRS), which produced discordant results: the uncalibrated (14)C dating produced 5690 +/- 80 BP for the cranial vault and 6110 +/- 80 BP for the clavicle; the NDGRS dating produced 10,000 +/- 3000 BP for the cranial vault. The sex discriminant morphological characters on the skull are not unequivocal, though the masculine ones appear more evident. The aims of the present paper are: to provide a morphological and metric description of the remains; to interpret their unusual morphological features; to attempt to attribute them to male or female sex and to one of the possible prehistoric cultural groups, according to dating results (Upper Palaeolithic, Mesolithic or Neolithic). The attribution was obtained by a Bayesian procedure taking into account the reliability of the combined information of morphological/metric features and absolute dating results. The results suggest that the Riparo della Rossa remains are best attributed to a male individual of the Neolithic age.


Subject(s)
Bone and Bones/anatomy & histology , Fossils , Paleontology/methods , Animals , Bayes Theorem , Carbon Radioisotopes , Hominidae/anatomy & histology , Humans , Italy , Male , Reproducibility of Results , Spectrometry, Gamma/methods
5.
Radiat Prot Dosimetry ; 111(4): 339-42, 2004.
Article in English | MEDLINE | ID: mdl-15550698

ABSTRACT

This paper aims to validate a ray-tracing model for electromagnetic field calculation, which is used in urban environments to predict irradiation from radio base stations for population exposure evaluation. Validation was carried out through a measurement campaign by choosing measurement points in order to test different propagation environments and analysing broadcast control channels through narrow band measurements. Comparison of the calculated and measured fields indicates that the ray-tracing model used calculates electric field with good accuracy, in spite of the fact that the propagation environment is not described in detail, because of difficulties in modelling the geometrical and electrical characteristics of urban areas. Differences between the calculated and measured results remain below 1.5 dB, with a mean value of 1 dB.


Subject(s)
Algorithms , Cities , Electromagnetic Fields , Radiation Monitoring/methods , Radiometry/methods , Risk Assessment/methods , Telecommunications , Italy , Numerical Analysis, Computer-Assisted , Radiation Dosage , Radio Waves , Reproducibility of Results , Risk Factors , Sensitivity and Specificity , Software , Topography, Medical/methods
6.
Radiat Prot Dosimetry ; 111(4): 349-53, 2004.
Article in English | MEDLINE | ID: mdl-15550700

ABSTRACT

In this work, the electromagnetic interference on hearing aids was evaluated. Electromagnetic (EM) immunity tests on different types of hearing aids were carried out, using signals of intensity and modulation comparable to those present in the environment. The purpose of this work is to characterise the interference, establishing the immunity threshold for different frequencies and finding out which types of hearing aids are more susceptible, and in which frequency range. The tests were carried out in a GTEM cell on seven hearing aids, using AM and GSM signals in the radiofrequency (RF) range.


Subject(s)
Cell Phone , Electromagnetic Fields , Environmental Pollution/analysis , Equipment Failure Analysis/methods , Equipment Failure , Hearing Aids , Radio Waves , Equipment Failure Analysis/instrumentation , Radiation Monitoring , Radiation Protection/instrumentation , Radiation Protection/methods
7.
Radiat Prot Dosimetry ; 111(4): 429-33, 2004.
Article in English | MEDLINE | ID: mdl-15550716

ABSTRACT

The paper illustrates the limits and performances of different experimental monitoring techniques, which are applied to digitally modulated radiofrequency electromagnetic fields used for mobile telecommunications. Different experimental set-ups have been developed, verified and applied for the analysis and characterisation of wide band probes and narrow band measuring procedures.


Subject(s)
Cell Phone , Electromagnetic Fields , Environmental Exposure/analysis , Radio Waves , Radiometry/methods , Software , Algorithms , Equipment Failure Analysis , Italy , Models, Statistical , Radiation Monitoring/instrumentation , Radiation Monitoring/methods , Radiometry/instrumentation , Reproducibility of Results , Risk Assessment/methods , Risk Factors , Sensitivity and Specificity , Systems Integration , User-Computer Interface
8.
J Clin Endocrinol Metab ; 86(10): 4674-8, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11600524

ABSTRACT

A cross-sectional study on young dancers and exdancers was performed to evaluate the effects of intense weight-bearing exercise and dietary restriction, started during puberty, on bone mineral density (BMD), menarche age, menstrual function, and gonadotropin structure. Twenty current dancers (group 1) and 9 exdancers (group 2) were compared with a control group of 30 age-matched, regularly cycling women. Body weight, body mass index, total daily caloric intake, and nutritional markers were significantly lower (P < 0.05) in groups 1 and 2 than in controls. Using Quantitative Computed Tomography for the BMD evaluation, 12 dancers and 5 exdancers had Z-scores less than 2.5 SD below the mean of the controls; whereas, in 6 dancers and in 2 exdancers, BMD was between 1 and 2.5 SD. Groups 1 and 2 had a delay of menarche, which correlated positively with years of dance before menarche (r = 0.8; P < 0.001). Dancers had low levels and altered structure of circulating gonadotropins, which improved after GnRH stimulation. In conclusion, ballet training performed by dancers during puberty, dietary restriction, and low body mass index can all be associated with reduction in BMD and altered gonadotropin isoforms, with subsequent delay of menarche, menstrual dysfunctions, and insufficient peak bone mass. A longitudinal study must be conducted to confirm the persistence of low lumbar spine bone density in adult age.


Subject(s)
Bone Density , Exercise , Adult , Cross-Sectional Studies , Energy Intake , Female , Follicle Stimulating Hormone/blood , Gonadotropin-Releasing Hormone/pharmacology , Humans , Luteinizing Hormone/blood
9.
Radiat Prot Dosimetry ; 94(4): 375-80, 2001.
Article in English | MEDLINE | ID: mdl-11499442

ABSTRACT

Classification of 'exposed/non-exposed' subjects in epidemiological studies concerning the possible cancer risk associated with ELF magnetic field exposure is based on the a priori assumption of magnetic field value cut-off points that, often, are defined equal to minimum exposure levels typical of a population residing near high voltage facilities (0.1-4.2 microT), but in some cases an environmental magnetic field level not associated with transmission lines can exist. The results of an ELF magnetic field survey in an Italian urban area (about 1 million inhabitants) are presented: average field levels are correlated with population density of different districts. Exposure indexes are obtained, which are compared with those evaluated in studies regarding domestic exposure: background average levels result in comparable to cut-off points in epidemiological studies, but in some districts with high population density, they are much higher. This shows that knowledge of background magnetic field level in urban areas can assume a significant role in exposure assessment.


Subject(s)
Electromagnetic Fields , Radiation Monitoring/methods , Background Radiation , Humans , Italy , Maps as Topic , Radiation Dosage , Statistics as Topic , Urban Health
10.
Radiat Prot Dosimetry ; 97(4): 355-8, 2001.
Article in English | MEDLINE | ID: mdl-11878419

ABSTRACT

Electromagnetic radiation, which is used by broadcasting and mobile telephone systems to transmit information, permeates the city environment. In order to properly evaluate population exposure to electromagnetic fields, knowledge of their intensity and spectral components is necessary. In this study the results of radiofrequency field monitoring carried out in Torino, a large town located in the north-west of Italy are shown: the variation of the electromagnetic field strength is evaluated as a function of the height from the ground, the location in the urban area and the frequency. separating the contributions of the different sources (broadcasting antennas and radio base stations for mobile phones). Furthermore, the contribution of the radio base stations is theoretically evaluated, adding the emissions off all installations situated in Torino and examining the field strength maps calculated, considering the orography, for different heights. The theoretical values are also compared with those measured in the frequency range of mobile telephony emissions.


Subject(s)
Electromagnetic Fields/adverse effects , Environmental Exposure/analysis , Radiation Monitoring/methods , Radio Waves/adverse effects , Background Radiation , Humans , Italy , Models, Theoretical , Population Surveillance , Public Health , Telephone , Urban Population
11.
Radiat Prot Dosimetry ; 97(4): 363-8, 2001.
Article in English | MEDLINE | ID: mdl-11878421

ABSTRACT

After a brief description of the reference systems for the calibration of the electromagnetic field meters set up at IEN and the Ivrea Department of ARPA, the procedures for the evaluation of the measurement uncertainty are discussed, with reference to the problem of identifying and quantifying the different uncertainty components. which are due both to the field meter characteristics and to the measurement procedure and conditions. The problem of how to compare a measurement result, which consists of the measurement value and its associated uncertainty, with a limit fixed by the standards is also faced.


Subject(s)
Calibration , Electromagnetic Fields , Environmental Exposure/analysis , Radiation Monitoring/standards , Environmental Pollution , Humans
12.
Radiat Prot Dosimetry ; 97(4): 405-8, 2001.
Article in English | MEDLINE | ID: mdl-11878429

ABSTRACT

Based on the numerical determination of the complete irradiation volume of a commercial RBS antenna--performed using the FDTD method and the Kirchhoff integral formula for near to far field transformation--open site estimations of the electric field are made and compared with experimentally measured values. To describe the actual behaviour of the radiation field, the inherently complex phasic nature of plane waves is taken into account, together with their two independent states of polarisation. This information is contained in the radiation pattern previously deduced. Moreover, a reflected contribution from flat ground is introduced, along with the line-of-sight ray. Amplitude and phase of the reflected wave are calculated using Fresnel formulae for stratified ground and two polarisation states, i.e. normal and parallel to the plane of incidence. Good agreement with measured values is achieved only by using such assumptions.


Subject(s)
Electromagnetic Fields , Environmental Exposure/analysis , Models, Theoretical , Radio Waves , Scattering, Radiation , Humans , Numerical Analysis, Computer-Assisted , Radiation Dosage , Radiometry/methods
13.
Dev Biol ; 228(2): 270-86, 2000 Dec 15.
Article in English | MEDLINE | ID: mdl-11112329

ABSTRACT

New technologies for isolating differentially expressed genes from large arrayed cDNA libraries are reported. These methods can be used to identify genes that lie downstream of developmentally important transcription factors and genes that are expressed in specific tissues, processes, or stages of embryonic development. Though developed for the study of gene expression during the early embryogenesis of the sea urchin Strongylocentrotus purpuratus, these technologies can be applied generally. Hybridization parameters were determined for the reaction of complex cDNA probes to cDNA libraries carried on six nylon filters, each containing duplicate spots from 18,432 bacterial clones (macroarrays). These libraries are of sufficient size to include nearly all genes expressed in the embryo. The screening strategy we have devised is designed to overcome inherent sensitivity limitations of macroarray hybridization and thus to isolate differentially expressed genes that are represented only by low-prevalence mRNAs. To this end, we have developed improved methods for the amplification of cDNA from small amounts of tissue (as little as approximately 300 sea urchin embryos, or 2 x 10(5) cells, or about 10 ng of mRNA) and for the differential enhancement of probe sequence concentration by subtractive hybridization. Quantitative analysis of macroarray hybridization shows that these probes now suffice for detection of differentially expressed mRNAs down to a level below five molecules per average embryo cell.


Subject(s)
Embryo, Nonmammalian/physiology , Gene Expression Regulation, Developmental , Gene Library , Oligonucleotide Array Sequence Analysis , Sea Urchins/embryology , Sea Urchins/genetics , Animals , Animals, Genetically Modified , DNA Probes , DNA, Complementary , Genes, Reporter , Green Fluorescent Proteins , Luminescent Proteins/analysis , Luminescent Proteins/genetics , RNA, Messenger/genetics , Transcription Factors/metabolism
14.
J Clin Microbiol ; 37(7): 2230-5, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10364590

ABSTRACT

Although vaginitis caused by Saccharomyces cerevisiae is extremely rare, in recent years we have experienced an increasing frequency of S. cerevisiae isolation from the vaginas of fertile-age women. In order to investigate the epidemiology of these vaginal infections, a total of 40 isolates of S. cerevisiae derived from symptomatic and asymptomatic women were characterized by two DNA typing approaches, named ribosomal DNA (rDNA) hybridization and Ty917 hybridization, based on the Southern blotting technique. After transfer, the polymorphic DNA restriction fragments were hybridized with the entire repeat of S. cerevisiae rDNA for one method and with the entire sequence of the Ty917 retrotransposon for the other. After elaboration with computer-assisted analysis, the results of each method showed that Ty917 hybridization is endowed with a discriminatory power higher than that of rDNA hybridization. With the Ty917 hybridization method, all of the S. cerevisiae isolates tested appeared very heterogeneous, with the exception of those collected from individual patients with recurrent vaginitis. This allowed us to exclude a possible common source of infection while the high relatedness among S. cerevisiae sequential isolates from recurrent-vaginitis patients could suggest a pattern of relapse rather than frequent reinfection.


Subject(s)
Mycoses/diagnosis , Mycoses/epidemiology , Pregnancy Complications, Infectious/epidemiology , Retroelements , Saccharomyces cerevisiae/isolation & purification , Vagina/microbiology , Vaginitis/epidemiology , Adult , Bacterial Typing Techniques , Computing Methodologies , DNA Fingerprinting , DNA Probes , DNA, Ribosomal/genetics , Female , Humans , Phylogeny , Pregnancy , Saccharomyces cerevisiae/classification , Saccharomyces cerevisiae/genetics , Vaginitis/microbiology
15.
J Clin Microbiol ; 37(6): 1871-5, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10325339

ABSTRACT

Blood samples were drawn daily from 72 patients who had hematological malignancies, neutropenia, and fever and who had failed to respond to broad-spectrum antibiotics. Each sample was used for conventional fungal blood cultures and for detection and identification of Candida DNA by a PCR method with subsequent restriction enzyme analysis (REA) recently developed in our laboratory. The PCR method was able to detect five CFU of Candida spp. per ml of blood, and subsequent REA of the amplicons allowed the identification of the Candida species most commonly implicated in cases of candidiasis. Thirty-one patients were PCR-REA positive, and four of these patients were also culture positive. The ultimate diagnosis for 13 of these patients and 1 patient who was PCR-REA negative was disseminated candidiasis (confirmed by clinical data, multiple cultures, histology, autopsy, and/or ultrasonographic evidence of hepatosplenic candidiasis). The molecular method is significantly more sensitive than conventional fungal blood cultures and has a high negative predictive value (97.5%) for the development of disseminated candidiasis in neutropenic patients.


Subject(s)
Candida/isolation & purification , Candidiasis/diagnosis , DNA, Fungal/blood , Fever , Hematologic Neoplasms/complications , Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Candida/classification , Candidiasis/blood , Candidiasis/prevention & control , Female , Hematologic Neoplasms/microbiology , Humans , Male , Mycology/methods , Mycoses/prevention & control , Neutropenia , Polymerase Chain Reaction/methods , Prohibitins , Reproducibility of Results , Restriction Mapping/methods , Sensitivity and Specificity
16.
J Endocrinol Invest ; 21(3): 142-7, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9591208

ABSTRACT

Aim of this study was to plot height, weight and height velocity values of primary school civic population of Portici and Ercolano, Campania towns, on Tanner's charts in order to verify the overlapping of percentile distribution. On May 1994 height and weight were measured in 3504 children (1735 boys and 1769 girls, aged 5.4-16.1 years, mean age = 8.6 years) from the 1st, 2nd and 5th year of primary schools in Portici and Ercolano. One year later, on May 1995, we remeasured and reweighed 1583 (781 boys and 802 girls, aged 6.4-14.2 years, mean age = 9.6 years) out of total children and we calculated height velocity (HV). The height and weight profiles of our population sample show that children in Portici and Ercolano are taller and fatter than those measured by Tanner and Whitehouse 25-30 years ago. The calculation of body mass index (BMI) confirmed that 30% of total children were obese. Furthermore, the evaluation of one-year HV revealed a clear improvement of linear growth. Our data suggest that Tanner and Whitehouse charts should be updated, and it should be useful to elaborate also height, weight and HV standards derived from present-day population.


Subject(s)
Body Height , Body Weight , Growth/physiology , Adolescent , Child , Child, Preschool , Female , Humans , Italy , Male , Population , Reference Values , Regression Analysis
17.
Cell Biol Int ; 22(2): 91-4, 1998.
Article in English | MEDLINE | ID: mdl-9878095

ABSTRACT

A variety of concentrations of the IMPase inhibitor L690,330 were added to sea urchin embryos. Immediate arrest of development was obtained for concentrations from 7.5 mm on. Concentrations lower than 3.5 mm permitted gastrulation but inhibited skeletogenesis and disturbed elongation along the animal-vegetal axis. The latter results are similar to those obtained by counteracting lithium effect with myoinositol, which are suggested to be due to partial relief of IMPase inhibition.


Subject(s)
5'-Nucleotidase/antagonists & inhibitors , Abnormalities, Drug-Induced/etiology , Diphosphonates/toxicity , Enzyme Inhibitors/toxicity , Sea Urchins/drug effects , 5'-Nucleotidase/physiology , Abnormalities, Drug-Induced/embryology , Abnormalities, Drug-Induced/enzymology , Animals , Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors , Calcium-Calmodulin-Dependent Protein Kinases/physiology , Diphosphonates/pharmacology , Embryo, Nonmammalian/abnormalities , Embryo, Nonmammalian/drug effects , Embryo, Nonmammalian/ultrastructure , Enzyme Inhibitors/pharmacology , Glycogen Synthase Kinase 3 , Inositol/pharmacology , Lithium Chloride/pharmacology , Lithium Chloride/toxicity , Morphogenesis/drug effects , Morula/drug effects , Morula/ultrastructure , Sea Urchins/embryology
18.
Biochem Biophys Res Commun ; 234(1): 24-9, 1997 May 08.
Article in English | MEDLINE | ID: mdl-9168953

ABSTRACT

An antiserum against a hsp of the 70-kDa family was prepared, by means of a fusion protein, which was able to detect a constitutive 75-kDa hsc in the sea urchin P. lividus. This hsc was present both during oogenesis and at all developmental stages. A two-dimensional electrophoresis has revealed four isolectric forms of this 75-kDa hsc. The amino acid sequence of the fragment used to prepare the anti-hsp70 antibodies revealed a 43% identity with the corresponding part of sea urchin sperm receptor, and in mature eggs a brighter immunofluorescence was seen all around the cell cortex where the receptor for sea urchin sperm is localized. In oocytes the hsp75 was localized in the cytoplasms but not in the nuclei. In the embryos a higher hsp75 concentration was found in the portion facing the lumen of the cells which invaginate at gastrulation.


Subject(s)
Embryo, Nonmammalian/chemistry , HSP70 Heat-Shock Proteins/analysis , Amino Acid Sequence , Animals , Blotting, Western , Cytoplasm/chemistry , Electrophoresis, Polyacrylamide Gel , Embryonic Development , Female , HSP70 Heat-Shock Proteins/chemistry , Immunohistochemistry , Isoelectric Point , Male , Molecular Sequence Data , Molecular Weight , Oocytes/chemistry , Oogenesis , Ovary/cytology , Plasmids/genetics , Receptors, Cell Surface/chemistry , Receptors, Cell Surface/metabolism , Recombinant Fusion Proteins , Sea Urchins , Sequence Homology, Amino Acid , Spermatozoa/chemistry
19.
Biochem Biophys Res Commun ; 217(3): 1032-8, 1995 Dec 26.
Article in English | MEDLINE | ID: mdl-8554554

ABSTRACT

We had previously shown that P. lividus embryos subjected to heat shock are unable to synthesize proteins of the hsp70 family at a detectable level before the hatching blastula stage. We show here that this is not due to the inability to synthesize the hsp70 mRNAs, which are detectable following heat shock also in early stages, although in much lower amounts per embryo than in later stages. These mRNAs are also translated, as judged by the facts that they are present in the polysomal pellet, and that they are translatable in a cell free system. As to the question of the amount of hsp70 RNAs per nucleus, we conclude that this is also higher in later than in earlier stages. The presence of hsp70 mRNAs is already detectable after heating at 4 centigrades above 20 and their amount increases with the increase of temperature in the range between 24 degrees C and 28 degrees C.


Subject(s)
HSP70 Heat-Shock Proteins/genetics , Sea Urchins/embryology , Animals , Gene Expression Regulation, Developmental , Polyribosomes/metabolism , Protein Biosynthesis , RNA, Messenger/genetics , Transcription, Genetic
20.
Health Phys ; 68(1): 71-9, 1995 Jan.
Article in English | MEDLINE | ID: mdl-7989198

ABSTRACT

We have used the impedance method to calculate the induced electric (E) fields and current densities (J) for the spatially varying vector magnetic fields due to a hair dryer. In this method, applicable for low-frequency exposures where the quasi-static approximation may be made, the biological body or the exposed parts thereof are represented by a three-dimensional (3-D) network of impedances whose individual values are obtained from the electrical properties sigma, epsilon r for the various tissues. We have measured the 3-D variations of the 50-Hz magnetic fields from a typical hair dryer and found that the various components correlate well with those for a helical coil. The non-uniform magnetic fields thus obtained are used to calculate the induced E and J with a resolution of 1.31 cm for the model of the head and neck. The induced E values are compared with the fields endogenous to the body and the minimum detectable E-field limits based on the cellular thermal noise model proposed by Weaver and Astumian (1990, 1992).


Subject(s)
Electromagnetic Fields , Head , Humans , Models, Structural
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