scholarly journals Seasonal variations in the incidence of auroral radio absorption events at very high latitude, and the influence of the magnetotail

2007 ◽  
Vol 25 (3) ◽  
pp. 711-720 ◽  
Author(s):  
J. K. Hargreaves
Keyword(s):  
Statistical Analysis ◽  
Seasonal Variations ◽  
Polar Region ◽  
Winter Season ◽  
Magnetic Activity ◽  
Time Of Day ◽  
Activity Level ◽  
The Sun ◽  
South Pole ◽  
Very High

Abstract. A statistical analysis has been made of the incidence of auroral radio absorption events at South Pole, and of its dependence on basic geophysical parameters such as season, time of day, and magnetic activity level. It is found that at low and moderate levels of activity the incidence of events in the winter season is at least twice that in the summer. However, at high activity no events at all occurred during the local summer night, which appears to be explicable as the effect of the magnetotail and the consequent distortion of the magnetosphere when the southern polar region is tilted strongly towards the Sun. Previous results from even higher latitudes show the effect in an even more exaggerated form, in that both the day and night periods of absorption activity exhibit strong seasonal variations.

scholarly journals Starspot rotation rates versus activity cycle phase: Butterfly diagrams of Kepler stars are unlike that of the Sun

2019 ◽  
Vol 622 ◽  
pp. A85 ◽  
Author(s):  
M. B. Nielsen ◽  
L. Gizon ◽  
R. H. Cameron ◽  
M. Miesch
Keyword(s):  
Effective Temperature ◽  
Rotation Rate ◽  
Activity Cycle ◽  
Magnetic Activity ◽  
Activity Level ◽  
The Sun ◽  
Rotation Rates ◽  
Rotation Periods ◽  
Activity Cycles ◽  
The Mean

Context. During the solar magnetic activity cycle the emergence latitudes of sunspots change, leading to the well-known butterfly diagram. This phenomenon is poorly understood for other stars since starspot latitudes are generally unknown. The related changes in starspot rotation rates caused by latitudinal differential rotation can, however, be measured. Aims. Using the set of 3093 Kepler stars with measured activity cycles, we aim to study the temporal change in starspot rotation rates over magnetic activity cycles, and how this relates to the activity level, the mean rotation rate of the star, and its effective temperature. Methods. We measured the photometric variability as a proxy for the magnetic activity and the spot rotation rate in each quarter over the duration of the Kepler mission. We phase-folded these measurements with the cycle period. To reduce random errors, we performed averages over stars with comparable mean rotation rates and effective temperature at fixed activity-cycle phases. Results. We detect a clear correlation between the variation of activity level and the variation of the starspot rotation rate. The sign and amplitude of this correlation depends on the mean stellar rotation and – to a lesser extent – on the effective temperature. For slowly rotating stars (rotation periods between 15 − 28 days), the starspot rotation rates are clearly anti-correlated with the level of activity during the activity cycles. A transition is observed around rotation periods of 10 − 15 days, where stars with an effective temperature above 4200 K instead show positive correlation. Conclusions. Our measurements can be interpreted in terms of a stellar “butterfly diagram”, but these appear different from that of the Sun since the starspot rotation rates are either in phase or anti-phase with the activity level. Alternatively, the activity cycle periods observed by Kepler are short (around 2.5 years) and may therefore be secondary cycles, perhaps analogous to the solar quasi-biennial oscillations.

التغير المناخي واثره في المقنن المائي لمحصول العنب في محافظة ديالى

2019 ◽  
Vol 1 (34) ◽  
pp. 391-422
Author(s):  
اشواق حسن حميد صالح
Keyword(s):  
Climate Change ◽  
Statistical Analysis ◽  
Wind Speed ◽  
Extreme Temperature ◽  
Solar Brightness ◽  
The Subject ◽  
Climate Station ◽  
The Times ◽  
High Level ◽  
Very High

Climate change and its impact on water resources is the problem of the times. Therefore, this study is concerned with the subject of climate change and its impact on the water ration of the grape harvest in Diyala Governorate. The study was based on the data of the Khanaqin climate station for the period 1973-2017, (1986-2017) due to lack of data at governorate level. The general trend of the elements of the climate and its effect on the water formula was extracted. The equation of change was extracted for the duration of the study. The statistical analysis was also used between the elements of the climate (actual brightness, normal temperature, micro and maximum degrees Celsius, wind speed m / s, relative humidity% The results of the statistical analysis confirm that the water ration for the study area is based mainly on the X7 evaporation / netting variable, which is affected by a set of independent variables X1 Solar Brightness X4 X5 Extreme Temperature Wind Speed ​​3X Minimal Temperature and Very High Level .

scholarly journals Comparative Tissue Responses of Marine Mollusks on Seasonal Changes in the Northern Adriatic Sea

2021 ◽  
Vol 11 (6) ◽  
pp. 2874
Author(s):  
Natalija Topić Popović ◽  
Martina Krbavčić ◽  
Josip Barišić ◽  
Blanka Beer Ljubić ◽  
Ivančica Strunjak-Perović ◽  
...  
Keyword(s):  
Stress Responses ◽  
Seasonal Variations ◽  
Antioxidant Defense ◽  
Winter Season ◽  
Northern Adriatic ◽  
Gonadal Maturation ◽  
Marine Mollusks ◽  
Significant Difference ◽  
Tissue Responses ◽  
Antioxidant Defense Systems

In the shallow Northern Adriatic, marine mollusks are affected by bottom trawling and seafood disturbance. Seasonal oscillations of oceanographic factors additionally influence their physiology, stress responses and survival. Tissue responses to seasonal variations in green ormer (Haliotis tuberculata L.) and Mediterranean scallop (Pecten jacobaeus L.) in the Northern Adriatic have not been reported. Hence, their biochemical and antioxidant defense properties over seasons were studied and the microanatomical structure of their tissue was correlated with function. Histological analysis of gonads revealed two peaks of gonadal maturation and spawning during the spring/summer period and winter season for scallops, and one peak during the fall for ormers. The gonadal maturation of both species was correlated with their seasonal variations of metabolic demands and antioxidant capacity. The lipid vacuoles of tubuloacinar terminations in the digestive gland differed between the two species; in scallop they are several-fold larger in size and number. Low temperatures in winter contributed to a decline in enzymatic antioxidant defense in scallop tissues, having lower superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, and higher concentrations of thiobarbituric acid reactive substances (TBARS) and total antioxidant status (TAS). In ormers, winter induced lower TAS, TBARS, SOD and GPx concentrations. The significant difference of winter TAS and TBARS levels between ormers and scallops was correlated with variations in their reproductive cycles, as well as in antioxidant defense systems. The most important factor for stress-related parameters for both species in this work was found to be the season-induced temperature change.

scholarly journals 82 The impact of feeding treats containing cannabidiol (CBD) on the daily activity level of dogs

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 60-61
Author(s):  
Elizabeth M Morris ◽  
Susanna E Kitts-Morgan ◽  
Dawn M Spangler ◽  
Kyle R McLeod ◽  
David L Harmon
Keyword(s):  
Daily Activity ◽  
Block Design ◽  
Companion Animals ◽  
Total Activity ◽  
Time Of Day ◽  
Activity Level ◽  
Activity Levels ◽  
Quiet Time ◽  
Activity Duration ◽  
The Impact

Abstract Growing public interest in and use of Cannabidiol (CBD) in companion animals has amplified the need to elucidate potential impacts. The purpose of this investigation was to determine the impact of CBD on daily activity of adult dogs. Twenty-four dogs (18.0 ± 3.4 kg) were utilized in a randomized complete block design with treatments consisting of control, 2 mg CBD/kg BW/d, and 4 mg CBD/kg BW/d split between two treats administered after twice-daily exercise (7:00-9:00 and 17:00-19:00). Four hours each day (10:00-12:00, AM and 13:30-15:30, PM), were designated as time when no persons entered the kennels, with 2 h designated as Quiet Time and the other 2 h as Music Time, where calming music played over speakers. Quiet and Music sessions were randomly allotted to daily AM or PM times. Activity monitors were fitted to dogs’ collars for continuous collection of activity parameters. Data were collected over a 2-wk baseline period to block dogs by activity level (high or low) before randomly assigning dogs within each block to treatments. After 1 wk of treatment adaptation, activity parameters were collected for 2 wk. Data were tested for normality using the UNIVARIATE procedure in SAS before examining differences using the MIXED procedure in SAS, including effects of treatment, day, session (Quiet or Music), time of day (AM or PM), and accompanying interactions. CBD did not alter total activity points (P = 0.9971) or activity duration (P = 0.8776). CBD tended (P = 0.0692) to reduce scratching compared to control. Irrespective of treatment, dogs were more active in PM than AM (P < 0.0001). Regardless of session, dogs receiving 4 mg/kg/d tended (P = 0.0914) to be less active in the PM than control. CBD did not affect activity duration during exercise periods (P = 0.1425), but dogs receiving CBD ran more than control (P = 0.0339). These results indicate that when supplemented up to 4 mg/kg/d, CBD does not negatively impact daily activity levels of dogs.

Rietveld quantitative amorphous content analysis

2001 ◽  
Vol 34 (2) ◽  
pp. 196-202 ◽  
Author(s):  
A. G. De La Torre ◽  
S. Bruque ◽  
M. A. G. Aranda
Keyword(s):  
Content Analysis ◽  
Statistical Analysis ◽  
Systematic Errors ◽  
Rietveld Analysis ◽  
Tricalcium Silicate ◽  
Absorption Coefficients ◽  
Amorphous Content ◽  
Orientation Effects ◽  
Main Component ◽  
Very High

A procedure for Rietveld quantitative amorphous content analysis (RQACA) is outlined, in which the effects of systematic errors in the powder patterns are studied. The method derives the amorphous content from the small overestimation of an internal crystalline standard in a Rietveld refinement of an appropriate mixture. Of several standards studied, Al2O3gave the best results. The statistical analysis of standard mixtures with a known amount of amorphous content indicated that this is a precise and accurate tool. It enables the measurement of the amorphous content with an accuracy close to 1%. Sample preparation and Rietveld analysis need to be optimized in order to minimize the systematic errors. The analysis of samples with phases displaying strong preferred orientation effects gives very high errors in the amorphous content. Samples with different absorption coefficients have also been studied in order to evaluate the importance of microabsorption. This plays an important role but it can be adequately corrected if the absorption coefficients of the standard and the sample are not very different. RQACA has been applied to tricalcium silicate, C3S, which is the main component of Portland cement. The average amorphous content of C3S, after microabsorption correction using two standards of higher and lower absorption coefficients, was found to be 19%.

FUNGI IN AIR MASSES OVER MONTREAL DURING 1950 AND 1951

1956 ◽  
Vol 34 (1) ◽  
pp. 1-15 ◽  
Author(s):  
S. M. Pady ◽  
L. Kapica
Keyword(s):  
Seasonal Variation ◽  
Pollen Grains ◽  
Average Concentration ◽  
Yeast Cells ◽  
The Sun ◽  
Air Masses ◽  
Air Sampler ◽  
Agricultural Areas ◽  
Very High ◽  
Made In

Numbers and kinds of fungi were determined from nutrient plate and silicone slide studies from the roof of the Sun Life Building, Montreal, between September 1950 and December 1951. Exposures of plates were made in the General Electric Bacterial Air Sampler, and plates and silicone slides in the Bourdillon Slit Sampler. A total of 978 exposures was made on 113 sampling days during 16 months; 507 plates in the G. E. Sampler, 344 plates and 127 slides in the Slit Sampler. Of 40,359 colonies examined, Cladosporium, Penicillium, yeasts, Aspergillus, Alternaria, and Actinomycetes were commonest, constituting 47.7, 15.8, 10.4, 4.6, 4.2, and 2.2% of the total. The next commonest fungi were Pullularia, Oöspora, Fusarium, Stemphylium, Verticillium, Rhizopus, Spicaria, Scopulariopsis, Phoma, Mucor, Botrytis, Cephalosporium, Trichoderma, Helmin-thosporium, Neurospora, Papularia, Cephalothecium, Pyrenochaeta, Zythia, and Nigrospora. In addition 12 genera were infrequently found. Unidentified colonies numbered 174 and nonsporulating 3371 (8.3%). On a cubic foot basis numbers in the plates varied from 17.7 per cu. ft. in August to 0.4 per cu. ft in February.Fungus spores showed a seasonal variation with summer highs averaging 244 per cu. ft. in July to a low of 0.8 per cu. ft. in December. The most abundant spores were Cladosporium, yeasts, smuts, Fusarium, Alternaria, Venturia-like, Stemphylium, rusts, Septoria, and Helminthosporium. Hyphal fragments and pollen grains were present also. On eight occasions during the summer, readings of over 200 spores per cu. ft. were recorded, the maximum being 445 per cu. ft. on September 6, 1951. Cladosporium in August reached a peak of 74.1 per cu. ft. and yeast cells in July had an average concentration of 100 per cu. ft.An analysis of the air masses indicated that pure polar air carried low numbers of fungi, whereas tropical air had very high numbers. Most of the air masses were modified polar air and their fungus content varied considerably. The fungi in the air over Montreal are believed to have had their origin in agricultural areas.

scholarly journals Photometric magnetic-activity metrics tested with the Sun: application toKeplerM dwarfs

2014 ◽  
Vol 4 ◽  
pp. A15 ◽  
Author(s):  
Savita Mathur ◽  
David Salabert ◽  
Rafael A. García ◽  
Tugdual Ceillier
Keyword(s):  
Magnetic Activity ◽  
The Sun

scholarly journals Seasonal variations and north–south asymmetries in polar wind outflow due to solar illumination

2016 ◽  
Vol 34 (11) ◽  
pp. 961-974 ◽  
Author(s):  
Lukas Maes ◽  
Romain Maggiolo ◽  
Johan De Keyser
Keyword(s):  
Seasonal Variations ◽  
Solar Zenith Angle ◽  
The Sun ◽  
Polar Ionosphere ◽  
Polar Cap ◽  
Polar Wind ◽  
Simple Set ◽  
The Earth ◽  
Rotation Of The Earth ◽  
Set Up

Abstract. The cold ions (energy less than several tens of electronvolts) flowing out from the polar ionosphere, called the polar wind, are an important source of plasma for the magnetosphere. The main source of energy driving the polar wind is solar illumination, which therefore has a large influence on the outflow. Observations have shown that solar illumination creates roughly two distinct regimes where the outflow from a sunlit ionosphere is higher than that from a dark one. The transition between both regimes is at a solar zenith angle larger than 90°. The rotation of the Earth and its orbit around the Sun causes the magnetic polar cap to move into and out of the sunlight. In this paper we use a simple set-up to study qualitatively the effects of these variations in solar illumination of the polar cap on the ion flux from the whole polar cap. We find that this flux exhibits diurnal and seasonal variations even when combining the flux from both hemispheres. In addition there are asymmetries between the outflows from the Northern Hemisphere and the Southern Hemisphere.

scholarly journals Seasonal Variation in Essential Oils Composition and the Biological and Pharmaceutical Protective Effects of Mentha longifolia Leaves Grown in Tunisia

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Karama Zouari-Bouassida ◽  
Mohamed Trigui ◽  
Samar Makni ◽  
Lobna Jlaiel ◽  
Slim Tounsi
Keyword(s):  
Seasonal Variation ◽  
Essential Oils ◽  
Biological Activities ◽  
Winter Season ◽  
Inflammatory Cells ◽  
Ethyl Acetate Fraction ◽  
Activity Level ◽  
Potential Candidate ◽  
Protective Effects ◽  
Bacterial Strains

This research assessed the seasonal variation of the chemical composition and antibacterial and anticholinesterase activities of essential oils extracted from M. longifolia leaves. The leaves organic fractions were also investigated for their biological activities and pharmacological functions. The essential oil highest yield was recorded in the spring season. Pulegone (26.92%), 1.8 cineole (21.3 %), and L-menthone (10.66 %) were determined as its major compounds in the winter season. In the spring oil, the main components were pulegone (38.2 %) and oleic and palmitic acids (23.79 % and 15. 26 %, respectively). Oxygenated monoterpenes were predominant in the two analyzed samples. The tested oils and organic extracts exhibited promising antibacterial effects against all of the tested bacterial strains. Thanks to its richness in phenolic and flavonoid compounds, the ethyl acetate fraction (Ml EtOAcF) displayed the most active DPPH scavenging ability (IC50 =12.64 μg/ml) and an interesting β-carotene bleaching inhibition (IC50 =34.75 μg/ml) making it a potential candidate for anti-inflammatory evaluation on rats. This evaluation evidenced that M. longifolia pretreated rats showed a marked decrease in paw oedema and inflammatory cells. Additionally, a remarkable acetylcholinesterase inhibitory activity of the Ml EtOAcF (IC50 = 12.3μg/ml) and essential oils were also observed suggesting their neuroprotective property against Alzheimer’s disease. Moreover, it was found that its activity level was season dependent. Our investigation, therefore, clearly revealed the medicinal characteristics of M. longifolia leave indicating their potential uses for natural remedies.

scholarly journals ‘Sumer’ – Solar Ultraviolet Measurements of Emitted Radiation

1994 ◽  
Vol 144 ◽  
pp. 619-624 ◽  
Author(s):  
K. Wilhelm ◽  
W. Curdt ◽  
A. H. Gabriel ◽  
M. Grewing ◽  
M. C. E. Huber ◽  
...  
Keyword(s):  
Spectral Resolution ◽  
Extreme Ultraviolet ◽  
Flow Characteristics ◽  
Magnetic Activity ◽  
High Accuracy ◽  
The Sun ◽  
Lower Corona ◽  
Doppler Shifts ◽  
Solar Magnetic Activity ◽  
Solar Ultraviolet

AbstractThe experiment Solar Ultraviolet Measurements of Emitted Radiation (SUMER) is designed for the investigations of plasma flow characteristics, turbulence and wave motions, plasma densities and temperatures, structures and events associated with solar magnetic activity in the chromosphere, the transition zone and the corona. Specifically, SUMER will measure profiles and intensities of extreme ultraviolet (EUV) lines emitted in the solar atmosphere ranging from the upper chromosphere to the lower corona; determine line broadenings, spectral positions and Doppler shifts with high accuracy; provide stigmatic images of selected areas of the Sun in the EUV with high spatial, temporal and spectral resolution and obtain full images of the Sun and the inner corona in selectable EUV lines, corresponding to a temperature range from 104to more than 1.8 x 106K. The spatial and spectral resolution capabilities of the instrument will be considered in this contribution in some detail, and a new detector concept will be introduced.

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