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PubMedDate not supplied

[Changes in fluorescence spectral characteristics of blood nuclear cells by the action of physical factors associated with 11- and 22-year cyclic variations in solar activity].

A correlation between the functional (synthetic) activity of animal blood lymphocytes and the intensity of radiation of the Sun at a frequency of 2800 MHz in 2000 and 2002 was studied. The results were compared with the data obtained in 1993 and 1994. These data suggest that there are seasonal regularities in the interrelationship of the processes studied. A change in the sign of the correlation coefficients at the maximum of the 23rd solar cycle was shown. Possible mechanisms of the phenomena are discussed.

Animals↗
PubMed2004

Concentration measurements of 7Be at ground level air at Palermo, Italy-comparison with solar activity over a period of 21 years.

Air activity concentrations of (7)Be in Palermo determined for the period January 1995-December 2002 by gamma-ray spectrometric analysis of particulate samples collected on paper filter by a high-volume sampler (approximately 900 m(3) h(-1)) are reported. The temporal behaviour of (7)Be concentration presents the same characteristics already observed in the measurements carried out over the previous 13-year (1982-1994) investigated period. The mean value of 5.06 mBq m(-3) obtained from the analysis of the 4636 particulate samples collected from 1982 to 2002 can be considered a representative value of (7)Be air concentration at ground level in our geographical zone. The comparison of long-term variation in the (7)Be concentrations with the cyclic solar activity-extended to the whole period of 21 years-confirms the inverse correlation between the two quantities.

Beryllium↗
PubMed1994

Radiation risk of the crew members of the expeditions on the "MIR" station during the 22nd solar activity cycle.

The radiation risk at the end of the flight was calculated for the members of the main expeditions on the "Mir" station. It was based on the absorbed dose dynamics data measured by the board dosimeter. The radiation damage models created for standards of the radiation safety of the space flights were used in the calculations. The analysis of the obtained values of the risk and its dynamics for some cosmonauts are presented in the topic. The risk values delta P are close to the limited levels given by equation of delta P = 0.6 x 10 x T(-4), [this equation appears also as delta RHrad = 0.6 x 10(-4) x T later in the text] where T--is flight duration in months.

Adult↗
PubMed1992

Geophysical variables and behavior: LXIX. Solar activity and admission of psychiatric patients.

Numbers of first admissions per month for a single psychiatric unit, from 1977 to 1987, were examined for 1829 psychiatric inpatients to assess whether this measure was correlated with 10 parameters of geophysical activity. Four statistically significant values were 0.197 with level of solar radioflux at 2800 MHZ in the corresponding month, -0.274 with sudden magnetic disturbances of the ionosphere, -0.216 with the index of geomagnetic activity, and -0.262 with the number of hours of positive ionization of the ionosphere in the corresponding month. Percentages of variance accounted for were very small.

Adolescent↗
PubMed1992

Solar proton events at the growth phase of the 22nd solar activity cycle.

Meteor satellite observations in March, August, September and October 1989 recorded intensive solar proton events which caused a disturbed radiation situation in the near-Earth space. The paper presents the results of analyzing flux and spectral characteristics of the events and their relation to heliogeophysical situation.

Earth, Planet↗
PubMed1991

Solar activity and admissions of psychiatric inpatients, relations and possible implications on seasonality.

Admission data for a month, from a single psychiatric unit, were examined for over 1800 psychiatric inpatients during the period of 1977 to 1987, to assess their correlation with 10 parameters of geophysical activity. This pilot study indicates two statistically significant correlations between the numbers of first psychiatric admissions per month and the level of solar radioflux in the corresponding month (p less than 0.05) and sudden magnetic disturbances of the ionosphere (p less than 0.01). There is a statistically significant inverse correlation between the number of first psychiatric admissions per month, with the index of geomagnetic activity (GMA) (p less than 0.05) and with the number of hours of positive ionization of the ionosphere in the corresponding month (p less than 0.01).

Adolescent↗
PubMed2003

A "space experiment" examining the response of a geosynchronous quartz crystal oscillator to various levels of solar activity.

Viewing the frequency history of the high-quality quartz crystal oscillator onboard Milstar FLT-1 as a "space experiment," we have examined the response of the crystal to various solar flares that have occurred over the past 4 years. Our results show that, even for the largest solar flares that can be expected, timekeeping onboard a geosynchronous communications satellite need not be unduly perturbed by the enhanced space-radiation environment of a solar flare, so long as the ground station can take mitigating action within a few hours of the flare's onset.

Journal Article↗
PubMedDate not supplied

[Effect of solar activity on the physiological rhythms of biological systems].

The infradian components, including those with a period of about 3.5, 7, 30 days, are ubiquitously found in biology, from unicells to complex biological organisms. It can be hypothesized that heliogeophysical factors other than the solar visible light, likely at the origin of the circadian system (with a period of about 24 hours), may be responsible for the infradian biosystems.

Animals↗
PubMed1991

The spectral distribution of biologically active solar radiation at Miami, Florida, USA.

The spectral distribution of solar radiation was studied under different sky conditions during a 15-month period in Miami, Florida (USA), and over a latitudinal gradient at solar maximum. Spectroradiometric scans were characterized for total irradiance (300-3000 nm) and the relative energetic and photon contributions of the following wavelength regions: UV-B (300-320 nm); UV-A (320-400 nm); B (400-500 nm); PAR (400-700 nm); R (600-700 nm); and FR (728-732 nm). Notable results include: (i) significantly higher UV-A energy fluxes than currently in use for laboratory experiments involving the biological effects of this bandwidth (values ranged from 33.6 to 55.4 W/m2 in Miami over the year); (ii) marked diurnal shifts in B:R and R:FR, with elevated R:FR values in early morning: (iii) a strong correlation between R:FR and atmospheric water content; and (iv) unusually high PAR values under direct sunlight with cloudy skies (2484 mumol/2 per s).

Cosmic Radiation↗
PubMed2003

Solar activated ozonation of phenol and malic acid.

The effect that sunlight has on the degradation rate of two model organic compounds, phenol and malic acid, by ozone is studied. The effect seems to be due to both direct light absorption (300-320 nm photons) by ozone, which produces the pollutant degradation, and light absorption by reaction intermediates. The presence of such a light notably improves the reactivity of ozone toward the organic species, leading to a faster and complete mineralization even at large initial total organic carbon values. The use of artificial sunlight (Xe lamp) is also explored. Finally, the simultaneous presence of sunlight and other ozone degradation catalyst like transition metal ions is studied, showing the beneficial effect of such a combination.

Absorption↗