Diurnal Activity in the Dusky Cockroach, Ectobius lapponicus L. (Blattodea)

1971 ◽  
Vol 2 (2) ◽  
pp. 132-138 ◽  
Author(s):  
Hans Dreisig
Keyword(s):  
Relative Humidity ◽  
Constant Temperature ◽  
Low Temperatures ◽  
Laboratory Experiments ◽  
Dark Period ◽  
Light Period ◽  
Total Darkness ◽  
Diurnal Activity ◽  
Males And Females ◽  
The Difference

AbstractThe activity of the cockroach Ectobius lapponicus was found to differ in males and females in the field, the males being active during the afternoon, the females after sunset. The difference was thought to be due to an inhibition by low temperatures in the males, displacing the activity towards an earlier period of the day. This is in accordance with a theory concerning sensitization, and different thresholds of release dependent on light and temperature as established for the stridulation in Orthoptera Ensifera and the locomotion in a domestic cockroach. A relationship between the amount of activity and the relative humidity was found in the nymphs. Laboratory experiments showed that the activity at constant temperature was released by a change from light to darkness. If low temperatures were applied during the dark period, the activity was displaced to the latter half of the light period. The influence of illumination on the activity was investigated, a faint illumination being more favourable than total darkness.

DIFFERENTIAL TOLERANCE OF TWO BARLEY CULTIVARS TO METRIBUZIN

1985 ◽  
Vol 65 (2) ◽  
pp. 415-421 ◽  
Author(s):  
C. D. CALDWELL ◽  
P. A. O’SULLIVAN
Keyword(s):  
Hordeum Vulgare ◽  
Relative Humidity ◽  
Opposite Effect ◽  
Dark Period ◽  
Light Period ◽  
Barley Cultivar ◽  
Herbicide Application ◽  
Hordeum Vulgare L ◽  
Barley Cultivars ◽  
Dark Regime

In greenhouse and growth cabinet studies, two cultivars of barley (Hordeum vulgare L. ’Klondike’ and ’Summit’) were found to differ in their tolerance to postemergence applications of metribuzin. Klondike was more susceptible than Summit, although both displayed varying amounts of injury depending on environmental conditions. Klondike was most susceptible following herbicide application at the three-leaf stage; when soil was moist at application; and when application was followed by a period of cold (0 °C). For both cultivars, high relative humidity and increasing duration of a dark period following spraying increased the injury from metribuzin. Increasing the duration of a light period following spraying had the opposite effect. The magnitude of the light/dark regime response was greater for Klondike than for Summit.Key words: Barley cultivar tolerance, metribuzin, environmental factors

Immunocytochemical studies on the behavior of RuBisCO and LHCP II during the cell cycle of synchronized Euglena gracilis

1990 ◽  
Vol 48 (3) ◽  
pp. 662-663
Author(s):  
Tetsuaki Osafune ◽  
Shuji Sumida ◽  
Tomoko Ehara ◽  
Eiji Hase ◽  
Jerome A. Schiff
Keyword(s):  
Cell Cycle ◽  
Immunoelectron Microscopy ◽  
Growth Phase ◽  
Euglena Gracilis ◽  
Dark Period ◽  
Light Period ◽  
Carboxylase Activity ◽  
Immunocytochemical Studies ◽  
Lhcp Ii

Changes in the morphology of pyrenoid and the distribution of RuBisCO in the chloroplast of Euglena gracilis were followed by immunoelectron microscopy during the cell cycle in a light (14 h)- dark (10 h) synchronized culture under photoautotrophic conditions. The imrnunoreactive proteins wereconcentrated in the pyrenoid, and less densely distributed in the stroma during the light period (growth phase, Fig. 1-2), but the pyrenoid disappeared during the dark period (division phase), and RuBisCO was dispersed throughout the stroma. Toward the end of the division phase, the pyrenoid began to form in the center of the stroma, and RuBisCO is again concentrated in that pyrenoid region. From a comparison of photosynthetic CO2-fixation with the total carboxylase activity of RuBisCO extracted from Euglena cells in the growth phase, it is suggested that the carboxylase in the pyrenoid functions in CO2-fixation in photosynthesis.

Observation and Experimentation

2018 ◽  
Author(s):  
Massimiliano Di Ventra
Keyword(s):  
Laboratory Experiments ◽  
The Difference

This chapter expands on the previous one on the role of experiments in Science. It explains the difference between observations of phenomena and controlled laboratory experiments.

scholarly journals Development and reproduction of Podisus distinctus (Heteroptera: Pentatomidae) fed on larva of Bombyx mori (Lepidoptera: Bombycidae)

2004 ◽  
Vol 64 (2) ◽  
pp. 237-242 ◽  
Author(s):  
M. C. Lacerda ◽  
A. M. R. M. Ferreira ◽  
T. V. Zanuncio ◽  
J. C. Zanuncio ◽  
A. S. Bernardino ◽  
...  
Keyword(s):  
Biological Control ◽  
Life Cycle ◽  
Relative Humidity ◽  
Bombyx Mori ◽  
Insect Pests ◽  
Males And Females ◽  
Heteroptera Pentatomidae ◽  
Bombyx Mori L ◽  
Chemical Products ◽  
Coleoptera Tenebrionidae

Biological control has been reducing the use of chemical products against insect pests, specially predatory Pentatomidae. Species of this group can present high variations in their life cycle as a result of their diet. Thus, the objective of this research was to study nymph development and reproduction of Podisus distinctus (Stäl, 1860) (Heteroptera: Pentatomidae) fed on Bombyx mori L., 1758 (Lepidoptera: Bombycidae) larvae (T1), compared to those fed on Tenebrio molitor L., 1758 (Coleoptera: Tenebrionidae) (T2) and Musca domestica L., 1758 (Diptera: Muscidae) larvae (T3) at a temperature of 25 ± 0.5ºC, relative humidity of 70 ± 2%, and photophase of 12 h. Predators fed on B. mori showed duration of the nymph phase (18.68 ± 1.02) similar to those fed on T. molitor (18.32 ± 1.49). Pre-oviposition and oviposition periods and number of egg masses, besides eggs and nymphs per female, were higher with B. mori (5.83 ± 2.02; 15.00 ± 7.40; 8.42 ± 1.84; 296.69 ± 154.75; and 228.55 ± 141.04, respectively) while longevity of males and females of P. distinctus was 25.76 ± 16.15 and 35.00 ± 16.15 days with T. molitor, and 20.57 ± 13.60 and 23.46 ± 12.35 days with B. mori, respectively.

scholarly journals Does Consumption of Nitrate Containing Beetroot Juice Affect Indoor Rowing Performance in Males and Females?

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1754-1754
Author(s):  
Giselle Greisman ◽  
June Kloubec ◽  
Alexandra Kazaks ◽  
Kelly Morrow ◽  
Cristen Harris
Keyword(s):  
P Value ◽  
Beetroot Juice ◽  
Double Blind ◽  
Male Athletes ◽  
Funding Sources ◽  
Beverage Type ◽  
Rowing Performance ◽  
Males And Females ◽  
The Difference ◽  
Research Grant

Abstract Objectives The nitrates found in beetroot juice (BR) are known to be a precursor of nitric oxide (NO). NO is a known vasodilator which allows more oxygen to travel in the blood and may improve muscle efficiency. This study aims to measure the effect of BR supplementation on performance on 500-meter row time for trained CrossFit athletes. Many past studies have analyzed the effect of BR on male athletes, this study aimed to include both males and females. Methods This study used a randomized, cross-over, double-blind, placebo-controlled design to measure 500-meter row time. Thirty athletes age 18–60 consumed either a 2.7 oz shot of BR (6.5 mmol nitrate) or a placebo nitrate-free beetroot juice (PL). Two hours later, they rowed 500 meters. After at least a seven-day washout period, athletes repeated the 500-meter row with either BR or PL for comparison. This study was performed from July 2019 – January 2020 and was conducted in Mercer Island, Washington. Results Ten males age 18.0 to 60.3 (median 47.7) and twenty females age 26.7 to 58.3 (median 43.8), participated in this study. Row times for the 500-meter row ranged from 88.2 seconds to 150.7 seconds. Data indicate that although 60% of all participants rowed faster with BR (mean 112.83 seconds), compared to PL (mean 113.40 seconds), the difference in the means of row times (−0.563) was not significant overall (P = 0.29). However, for the 10 males, row times were significantly faster (1.02 second difference, P = 0.04) on average with BR compared to PL. For the 20 females, the difference in mean row time (−0.335 seconds) was not significant (P = 0.66). Competitive rowers were defined as those who rowed under 110 seconds (N = 15). For competitive rowers (10 males, 5 females), row times were significantly faster with BR compared to PL (difference in means −0.94, P = 0.009). However, for those rowers, the P-value of drink * group was 0.015. Conclusions Dietary nitrate improved indoor rowing performance in males but not in females. In addition, competitive rowers were also significantly faster with BR, however, there may be an order bias, since there was significant interaction between beverage type and testing order. Food based nitrate supplements may increase rowing performance with male rowers. Funding Sources Supported by Bastyr Faculty Student Research Grant.

Constant Temperature Dewar for NMR Spectra at Low Temperatures

1966 ◽  
Vol 37 (2) ◽  
pp. 238-239 ◽  
Author(s):  
W. B. Rose ◽  
J. W. Nebgen ◽  
F. I. Metz
Keyword(s):  
Constant Temperature ◽  
Low Temperatures ◽  
Nmr Spectra

Male-biased sex ratio in Argulus canadensis Wilson, 1916 (Crustacea: Branchiura) ectoparasitic on sticklebacks

1989 ◽  
Vol 67 (8) ◽  
pp. 2078-2080 ◽  
Author(s):  
Robert Poulin ◽  
Gerard J. FitzGerald
Keyword(s):  
Salt Marsh ◽  
Sex Ratio ◽  
Laboratory Experiments ◽  
Fish Predation ◽  
Reproductive Behaviour ◽  
Egg Deposition ◽  
Alternative Hypotheses ◽  
Biased Sex Ratio ◽  
The Difference ◽  
Fish Hosts

Females of the ectoparasitic crustacean Argulus canadensis must leave their fish hosts at least temporarily to deposit their eggs on the substrate. To test the hypothesis that this difference in reproductive behaviour between the two sexes could result in male-biased sex ratios on their stickleback hosts, we sampled sticklebacks in tide pools of a Quebec salt marsh from early July to early September 1986. During this period, fish harboured significantly more male than female A. canadensis. Laboratory experiments were done to test two alternative hypotheses offered to explain this biased sex ratio. The first hypothesis was that male A. canadensis were more successful than females in attacking their stickleback hosts; however, we found no differences in attack success on their hosts between the two parasite sexes. The second hypothesis was that sticklebacks ate more female than male A. canadensis. Although males were less vulnerable to fish predation than females, the difference was not significant. We conclude that sexual differences in reproductive behaviour, i.e., egg deposition behaviour of females, can account for the male-biased sex ratio of A. canadensis on sticklebacks.

scholarly journals Chromosomal anomalies that cause male sterility in the mouse also reduce ovary size

1984 ◽  
Vol 44 (2) ◽  
pp. 219-224 ◽  
Author(s):  
Ursula Mittwoch ◽  
Shantha Mahadevaiah ◽  
Leslie A. Setterfield
Keyword(s):  
Male Sterility ◽  
Germ Cells ◽  
Reciprocal Translocation ◽  
Chromosomal Anomalies ◽  
Male Sterile ◽  
Chromosome Anomalies ◽  
Ovarian Size ◽  
Males And Females ◽  
The Difference ◽  
Ovarian Involvement

SUMMARYTwo male-sterile chromosome anomalies, the insertion Is(7; 1)40H and the tertiary trisomy, Ts(512)31H, were found to be associated with reduced ovarian volumes in immature females. Together with the reciprocal translocation, T(11; 19)42H, in which this effect was described previously, reduced ovaries have been found in all three male-sterile chromosome anomalies investigated so far, suggesting that ovarian involvement is likely to be common in these conditions. Assuming that the smaller ovarian size reflects a reduction in the number of oocytes, it is suggested that male-sterile chromosome anomalies may exert basically similar deleterious effects on meiotic germ cells in males and females, the difference in outcome being due to cell-physiological differences between spermatocytes and oocytes and to the small number of surviving oocytes required for fertility in females.

scholarly journals Enhancer of rudimentaryp1, e(r)p1, a highly conserved enhancer of the rudimentary gene.

Genetics ◽  
1994 ◽  
Vol 138 (4) ◽  
pp. 1163-1170 ◽  
Author(s):  
E Wojcik ◽  
A M Murphy ◽  
H Fares ◽  
K Dang-Vu ◽  
S I Tsubota
Keyword(s):  
Amino Acid Sequences ◽  
Drosophila Virilis ◽  
P Element ◽  
R Gene ◽  
Adult Males ◽  
Males And Females ◽  
Polyadenylation Sites ◽  
The Difference ◽  
Polyadenylation Signals ◽  
Untranslated Leader Region

Abstract A hybrid dysgenesis-induced mutation, enhancer of rudimentaryp1 (e(r)p1), is a recessive enhancer of a weak rudimentary mutant phenotype in Drosophila melanogaster. The e(r) gene was cloned using P element tagging and localized to region 8B on the X chromosome. It encodes a 1.0-kb and a 1.2-kb transcript. The 1.0-kb transcript is present in both adult males and females, while the 1.2-kb transcript is predominantly found in females. The difference in the lengths of the two e(r) transcripts is caused by two different polyadenylation sites spaced 228 bp apart. The amounts of both of these transcripts are drastically reduced in the e(r)p1 mutant. The P element in e(r)p1 is inserted in the 5'-untranslated leader region near the start of transcription. It may be producing its effect by suppressing transcription and/or by providing transcription termination and polyadenylation signals. The putative e(r) protein is 104 amino acids in length and bears no striking resemblance to protein sequences in GenBank or PIR. While its biochemical function is unknown at this time, sequence analysis indicates that the e(r) protein is highly conserved and, presumably, functionally very important. The amino acid sequences of the D. melanogaster and the Drosophila virilis proteins are 95% identical.

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