Search results for "Diurnal temperature variation"
showing 10 items of 21 documents
Diel vertical movements of zooplankton in lake La Cruz (Cuenca, Spain)
2000
The study of diel vertical movements of zooplankton in a small meromictic karstic lake (lake La Cruz), presenting highly stratified waters, was performed using two different methodologies: (i) samples were taken along the vertical profile and were compared at different hours in a diel cycle; (ii) some plankton traps were located at different depths, covering different periods of time, to catch organisms going upwards and downwards. The main subject of this study has been the vertical movements affecting rotifers since they were dominant in the zooplankton of this lake, but we have also included the results obtained for other zooplankton groups. The results indicate an almost general movemen…
Diurnal variation of tree pollen in the air in finland
1984
Abstract The pollen was collected with Burkard spore traps in Turku and Jyvaskyla, in southern and central Finland. Selected days of high concentration were analysed for hour to hour concentrations. The diurnal variation of pollen concentration was variable in Alnus, Betula, Juniperus and Pinus, while Picea, Populus, Quercus, Salix and Ulmus had regular daytime maxima och nightly minima. The pollen concentrations were closely correlated with increasing temperatures and decreasing relative humidities. A significant relationship with wind speed was also found, except in Alnuts and Betula. The most significant relationships with wind speed were found in Salix and Quercus, the pollen of which t…
Neural network prediction of the AE index from the PC index
1999
Abstract It is shown that although the power spectra of the AE and PC data are quite similar they show differencies in structure function analysis. While the AE time series has a clear drop in the slope of the structure function (SF) after the first 2 hours, the slope of the SF of the PC data decreases gradually and at a little longer time scale. It is also shown by using 15-min averaged data, that both SFs are periodic with a clear diurnal variation. The PC time series seems to have a more pronounced periodicity, probably because it is measured at a single station at Thule. The AE index has been derived from the PC index for 7.5 minutes ahead by different methods. All these predictions gav…
Investigations on the content indole-3-acetic spruce needles of healthy and damaged trees of various sites
1993
Summary Surveys were made on the concentration of indole-3-acetic acid (IAA) in spruce trees of various sites. The concentrations of the hormone were specified with a radioimmunoassay after the needle extract had been purified in several steps. The content of IAA in needles of damaged trees was distinctly lower than the content in needles of healthy trees. Another feature was the annual rythm of the IAA content with the maximum of concentration in June. A distinct diurnal course with highest level of concentration during the early afternoon hours was also observed. The diurnal rhythm of the damaged trees was clearly lower. The supposition is that the lower IAA content is responsible for a p…
Large diurnal variation of intraocular pressure in open angle glaucoma in subjects with type A behaviour pattern
2014
Aim : To evaluate the possible causes of the greater perimetric damage found in OAG subjects with type A behaviour and the possible role of psycho-physiological stress. Materials and methods : 80 patients with OAG, 44 women and 36 men, 40 with type A behaviour and 40 with type B studied with the Type A/B Personality Questionnaire (A modified version of the Jenkins Activity Survey), underwent a complete ophthalmologic examination consisting of bio-microscopy, tonometry and daily tonometric curve, examination of the visual field by means of Octopus 1-2-3 computerised perimeter and its assessment with the Glaucoma Staging System 2 (GSS2), morphological monitoring of the Retinal Nerve Fibre Lay…
Diurnal blood pressure curve in children and adolescents
1996
Objective To investigate the diurnal blood pressure curve in healthy normotensive children. Thirty-one children were re-examined after a median interval of 123 days in order to study the reproducibility of the diurnal profile. Subjects Twenty-four-hour ambulatory blood pressure monitoring and conventional blood pressure readings were obtained in 228 normotensive children, whose ages ranged from 6 to 16 years and of whom 116 were boys and 112 girls. Results The conventional blood pressure averaged 99+/-11/57+/-9 mmHg in boys and 98+/-12/56+/-9 mmHg in girls (means+/-SD); the corresponding 24 h pressures were 111+/-7/66+/-5 mmHg and 109+/-7/65+/-5 mmHg, respectively. Of the children, 83% had …
Effect of time-of-day-specific strength training on serum hormone concentrations and isometric strength in men.
2007
A time-of-day influence on the neuromuscular response to strength training has been previously reported. However, no scientific study has examined the influence of the time of day when strength training is performed on hormonal adaptations. Therefore, the primary purpose of this study was to examine the effects of time-of-day-specific strength training on resting serum concentrations and diurnal patterns of testosterone (T) and cortisol (CORT) as well as maximum isometric strength of knee extensors. Thirty eight diurnally active healthy, previously untrained men (age 20-45 yrs) underwent a ten-week preparatory strength training period when sessions were conducted between 17:00-19:00 h. Ther…
Effects of reduced irradiance on hydraulic architecture and water relations of two olive clones with different growth potentials
2009
Abstract The hydraulic architecture and water relations of two olive genotypes, ‘Leccino Dwarf’ (LD) and ‘Leccino Minerva’ (LM) growing at two irradiance levels i.e. full sunlight irradiance (HI) and 50% sunlight irradiance (LI) were studied. The two clones showed similar plant hydraulic conductances (Kplant) and similar conductance of roots and leaves (Kroot and Kleaf) when growing at equal irradiance levels. However, both Kplant and Kroot were significantly lower in LI plants than in HI ones. On the contrary, Kleaf was unaffected by the light regime. One-year-old twigs of LI plants produced longer xylem conduits but lower average diameter of conduits and less conduits per unit xylem cross…
An evaluation of the microscopical counting methods of the tape in hirst-burkard pollen and spore trap
1981
Abstract Three different sampling units in current use and different sampling strategies were tested. Randomly placed microscope fields are good in estimating the daily mean concentration, but very big sample size is needed. Traverses across the slide in systematic order are best to estimate the shortterm concentrations and diurnal variation. A formula for the estimation of the error in one transverse traverse is given. Twelve transverse traverses in systematic order is also enough to estimate the daily mean concentration. One or two traverses along the length of the slide give often unreliable estimates because of the irregularities in the transverse variation of the particle concentration…
The effect of climate on Burgundy vintage quality rankings.
2019
Aim: Based on consensus rankings from prominent rating authorities, we examined the importance of a suite of climatic variables, organized by winegrape phenological stage, in distinguishing between high- and low-ranked vintages in Burgundy.Methods and Results: Vintage ratings of Burgundy wines acquired from 12 sources were evaluated to develop consensus rankings for red and white wines from 1961–2015. Climate variables (air temperature, precipitation, degree-day accumulations, etc.) were organized by mean phenological stage and compared between good and poor vintages using Mann-Whitney U tests and multivariate stepwise discriminant function analysis. High temperatures, particularly during t…