THE DEPENDENCE OF GERMINATION ON PHOTOPERIOD, LIGHT QUALITY, AND TEMPERATURE, IN CHENOPODIUM SPP.

1963 ◽  
Vol 41 (8) ◽  
pp. 1211-1233 ◽  
Author(s):  
Bruce G. Cumming
Keyword(s):  
Indirect Evidence ◽  
Spectral Energy ◽  
Floral Initiation ◽  
Optimum Conditions ◽  
Adaptive Value ◽  
Light Requirements ◽  
Dark Reversion ◽  
Green Vegetation ◽  
Energy Ratios ◽  
Optimum Response

In Chenopodium botrys, darkness was suboptimal for germination at all temperatures. At low to intermediate temperatures (10 to 20 °C) short photoperiods were optimal while longer ones were supraoptimal. At high temperatures (25° to 35 °C) extremely long photoperiods were optimal and all shorter ones were suboptimal. There was less germination in light of low than high red to far-red (R/FR) spectral energy ratios, particularly in long photoperiods. Decreasing the R/FR ratio for the terminal 30 minutes of daily photoperiods restricted germination considerably in short but not in extreme long photoperiods (18 and 20 hours). It is postulated that sub- and supra-optimal amounts of phytochrome-Pfr were produced, respectively, in the sub- and supra-optimal photoperiods, which resulted in less germination; further, that the temperature-induced responses may be due to a lower optimum requirement for Pfr at low than at higher temperatures and, or, a faster rate of dark reversion of Pfr to Pr may occur with increase in temperature. This provides a correlative scheme similar to that postulated for floral initiation of C. rubrum, whether optimum response is in short or long photoperiods.Ambiphotoperiodism, resembling the response previously shown in C. rubrum floral initiation, occurred in C. botrys germination. This may be indicative of endogenously controlled rhythms interacting with the phytochrome system.Several Chenopodium spp. germinated more in darkness than in long photoperiods of low R/FR ratio. Indirect evidence suggests that there may be formation of phytochrome-Pfr in darkness, sufficient to promote germination.On the basis of laboratory tests with Chenopodium spp. two ecologically significant phenomena are postulated. Firstly, there may be restriction of germination in areas shaded by green plants. There was more germination in light with R/FR ratios similar to that of sunlight (1.3) than sunlight transmitted through green vegetation (0.70 to 0.12). Secondly, stages of incomplete germination of seeds, in which there is rupture of the testa and loss of previous light requirements, may be of adaptive value, particularly under arid conditions. Seeds with incomplete germination remained viable for prolonged periods, whether kept moist or dried, but germinated very rapidly when transferred to optimum conditions.

scholarly journals VI. Radiative equilibrium: the relation between the spectral energy curve of a star and the law of darkening of the disc towards the limb, special reference to the effects of scattering and the solar spectrum

1923 ◽  
Vol 223 (605-615) ◽  
pp. 201-255 ◽  
Keyword(s):  
Binary Stars ◽  
Solar Spectrum ◽  
Indirect Evidence ◽  
Light Curves ◽  
Spectral Energy ◽  
Energy Curve ◽  
Converse Problem ◽  
Different Temperatures ◽  
The Law ◽  
Angular Diameters

An examination from a theoretical standpoint of the form of the law of darkening of a stellar disc towards the limb needs no apology at the present time. A knowledge of this law is required in two astronomical studies of the first importance: one is the deduction of the orbits and densities of eclipsing binary stars from observations of the light curves, the other is the deduction of the angular diameters of stars from interferometer measurements. In both cases some assumption has to be made as to the distribution of intensity over the disc before the solution becomes precise. Now the sun is the only star for which the intensity-distribution is at present known in any detail; the observations of Abbot, Fowle and Aldrich, as well as those of earlier investigators, have determined the law of darkening both for the integrated radiation and for the separate wave-lengths. As regards other stars, indirect evidence is indeed provided as to the existence of darkening at the limb by the results for eclipsing variables, since in most cases the darkened solution gives a better agreement between the observed and computed light-curves, but as yet numerical precision as to the amount of darkening is hardly to be expected. The interferometer method of measuring angular diameters is theoretically capable of determining the light distribution also from the position of the second minimum of visibility of the fringes; but here again the realisation of this possibility is a matter for the future. In the absence, therefore, of direct observations, it would seem worth while to investigate the types of darkening predicted by theory, for stars of different temperatures and of different atmospheric constitutions, on suitable assumptions; and to examine also the converse problem, namely, that of the deductions it is possible to make as to the state of the star if its law of darkening is given. It seems the more desirable to elucidate the principles underlying the existence of darkening, since certain misconceptions appear to exist on the subject.

Some laboratory germination responses of the seeds of river red gum, Eucalyptus camaldulensis Dehn. Syn. Eucalyptus rostrata Schlecht

1958 ◽  
Vol 6 (2) ◽  
pp. 129 ◽  
Author(s):  
RJ Grose ◽  
WJ Zimmer
Keyword(s):  
Constant Temperature ◽  
Environmental Conditions ◽  
Eucalyptus Camaldulensis ◽  
Special Technique ◽  
Optimum Conditions ◽  
Light Requirements ◽  
Petri Dishes ◽  
River Red Gum

A method for sampling from bulked eucalypt seed for germination tests, and a special technique for testing germination of these seeds in Petri dishes are described. The seeds of Eucalyptus camaldulensis Dehn. will germinate both at constant and at alternating temperatures. They germinate best at a constant temperature of about 95°F. The seeds require light for satisfactory germination. The light requirements of all seed-lots tested were satisfied by 8 hours of light daily at a constant temperature of 95°F. Light requirements are least at temperatures close to 95°F. There is an interaction between light and temperature and the requirement for light is reduced as the temperature is increased. Stratification also reduces the requirement for light in germination. Thirty-one different lots of seeds have been studied. It has been shown that no relationship exists between environmental conditions of the locality of collection and optimum conditions for germination.

Efficacy of Crisis Intervention

Crisis ◽  
1999 ◽  
Vol 20 (2) ◽  
pp. 78-85 ◽  
Author(s):  
Thomas Reisch ◽  
Petra Schlatter ◽  
Wolfgang Tschacher
Keyword(s):  
Crisis Intervention ◽  
Intervention Program ◽  
Suicide Ideation ◽  
Indirect Evidence ◽  
Well Being ◽  
Term Therapy ◽  
Contributing Factors ◽  
Step Therapy ◽  
Long Term Therapy ◽  
The Impact

This study assesses the efficacy of the treatment approach implemented in the Bern Crisis Intervention Program, where particular emphasis is placed on the remediation of suicide ideation and suicidal behavior, and depression, fear, and phobia are generally considered to be contributing factors. Four questionnaires addressing psychopathology, emotional well-being, social anxiety, and personality were administered prior to and after the treatment of 51 patients over a period of 2 to 3 weeks. The reduction of symptoms contributing to suicidal ideation and behavior was interpreted as indirect evidence of an antisuicidal effect of the program. Significant improvements were found in the psychopathology ratings, with depression and anxiety showing the largest reductions. The impact on personality and social phobia, however, was only moderate, and on average patients still exhibited symptoms after attending the program. This residual symptomatology points to the necessity of introducing a two-step therapy approach of intensive intervention targeted at the precipitating causes of the crisis, augmented by long-term therapy to treat underlying problems.

Trait self-enhancement: Moderators of the adaptive value

2007 ◽  
Author(s):  
Delroy L. Paulhus ◽  
Aliye Kurt ◽  
Jennifer D. Campbell
Keyword(s):  
Adaptive Value

Prevalence of Factor V Leiden Mutation in Non-European Populations

1997 ◽  
Vol 77 (02) ◽  
pp. 329-331 ◽  
Author(s):  
Guglielmina Pepe ◽  
Olga Rickards ◽  
Olga Camacho Vanegas ◽  
Tamara Brunelli ◽  
Anna Maria Gori ◽  
...  
Keyword(s):  
Factor V Leiden ◽  
Indirect Evidence ◽  
Factor V ◽  
Factor V Leiden Mutation ◽  
The World ◽  
Fv Leiden ◽  
Sub Saharan ◽  
Low Prevalence ◽  
European Populations ◽  
Apparently Healthy

SummaryA difference in the prevalence of venous thromboembolism (TE) in major human groups has been described and an uneven distribution of FV Leiden mutation over the world has recently been reported.We investigated FV Leiden mutation in 584 apparently healthy sub#jects mostly from populations different from those previously investi#gated: 170 Europeans (Spanish, Italians), 101 sub-saharan Africans (Fon, Bariba, Berba, Dendi), 115 Asians (Indonesians, Chinese, Tharus), 57 Amerindians (Cayapa), 84 Afroamericans (Rio Cayapa, Viche), and 57 Ethiopians (Amhara, Oromo).The mutation was detected in only 1/115 Asian (Tharu) and in 5/170 Europeans (4 Italians, 1 Spanish).These data confirm that in non-Europeans the prevalence of FV mutation is at least 7 times lower than in Europeans and provide indirect evidence of a low prevalence not only of the FV Leiden gene but also of other genes leading to more severe thrombophilia. Finally, findings from the literature together with those pertaining to this study clearly show a marked heterogeneity among Europeans.

Blood Viscosity and Platelet Aggregation in Male and Female Patients with Transient Ischaemic Attacks (TIA)

1979 ◽  
Author(s):  
G. Palareti ◽  
M. Poggi ◽  
G. Fortunato ◽  
S. Coccheri
Keyword(s):  
Platelet Aggregation ◽  
Blood Viscosity ◽  
Indirect Evidence ◽  
Vascular Lesions ◽  
Transient Ischaemic Attacks ◽  
Group A ◽  
Circulating Platelet Aggregates ◽  
Male Patients ◽  
Group B ◽  
Almost All

A series of 40 patients with TIA (25 males and 15 females) was thoroughly investigated by means of angiography and computerized tomography, and divided into a group (A) of 15 “sine materia”, and a group (B) of 25 with direct or indirect evidence of vascular occlusive or stenotic changes. Blood viscosity at 230 sec-1 37° was cp 4.2 ± 0.3 in the controls, cp 4.7 ± 0.7 in all patients (p < 0.05) cp 4.98 ± 0.7 in all male patients (p < 0.01 versus male controls), and cp 4.75 ± 0.8 in group B (p < 0.02). Haematocrit and Fibrinogen were also significantly increased in all male patients and in group B. Circulating platelet aggregates (CPA) were increased in 40% of the patients. Almost all patients with elevated CPA were males, with a slight prevalence in group B. Changes in blood viscosity parameters and in platelet aggregation in TIA patients were therefore related both to evidence of vascular lesions, and to sex, since they were found to prevail in male patients of both groups.

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