scholarly journals Differential survival of male and female dove embryos in increased and decreased pressures of oxygen: A test of the metabolic theory of sex

1920 ◽  
Vol 18 (3) ◽  
pp. 88-91 ◽  
Author(s):  
O. Riddle
1979 ◽  
Vol 111 (1) ◽  
pp. 105-109 ◽  
Author(s):  
H. G. Wylie

AbstractFemales of Muscidifurax zaraptor K. & L. produce a smaller percentage of female progeny as the ratio of ovipositing females to hosts (house fly pupae) increases. Delays in oviposition are apparently responsible for the sex ratio change, because they reduce the percentage of fertilized eggs, i.e. female eggs, that the parasites lay. Delays increase in frequency as the parasite:host ratio increases, and result mostly from interference among the ovipositing females; the interference is mostly or entirely physical. Solitary females of M. zaraptor produce slightly fewer though not significantly fewer female progeny when low host densities delay oviposition; more tests would be required to confirm this effect. There is no evidence for differential survival of the male and female parasite larvae on superparasitized hosts.


2020 ◽  
Vol 656 ◽  
pp. 239-251 ◽  
Author(s):  
JJ Minuti ◽  
BD Russell

Future ocean CO2 and temperatures are predicted to increase primary productivity across tropical marine habitats, potentially driving a shift towards algal-dominated systems. However, increased consumption of algae by benthic grazers could potentially counter this shift. Yet, the response of different grazer species to future conditions will be moderated by their physiologies, meaning that they may not be functional equivalents. Here, we experimentally assessed the physiological response of key grazers—the sea urchin Heliocidaris crassispina and 2 gastropod species, Astralium haematragum and Trochus maculatus—to predicted CO2 concentrations (400, 700 and 1000 ppm) and temperature conditions (ambient, +3 and +5°C). In line with metabolic theory, we found that urchin metabolic rate increased at future temperatures regardless of CO2 conditions, with evidence of metabolic acclimation to higher temperatures. The metabolic rate of A. haematragum was depressed only by CO2, whereas T. maculatus initially had elevated metabolic rates at moderate CO2, which were depressed by the combination of the highest CO2 concentration and temperatures. Taxa showed differential survival, with no urchin mortality under any future conditions but substantial mortality of both gastropods under elevated temperatures regardless of CO2 concentration. Importantly, all species had substantially reduced algal consumption in response to elevated CO2, though the urchins only demonstrated an energetic mismatch under combined future CO2 and temperature. Therefore, despite sharing an ecological niche, these key grazers are likely to be differentially affected by future environmental conditions, potentially reducing the strength of ecological compensatory responses depending on the functional redundancy in this grazing community.


Plant Gene ◽  
2018 ◽  
Vol 15 ◽  
pp. 37-43 ◽  
Author(s):  
Anthony S. Valente ◽  
Michaela Tutone ◽  
Emily Brodie ◽  
Haley Peper ◽  
Lynn J. Pillitteri

Author(s):  
R. F. Bils ◽  
W. F. Diller ◽  
F. Huth

Phosgene still plays an important role as a toxic substance in the chemical industry. Thiess (1968) recently reported observations on numerous cases of phosgene poisoning. A serious difficulty in the clinical handling of phosgene poisoning cases is a relatively long latent period, up to 12 hours, with no obvious signs of severity. At about 12 hours heavy lung edema appears suddenly, however changes can be seen in routine X-rays taken after only a few hours' exposure (Diller et al., 1969). This study was undertaken to correlate these early changes seen by the roengenologist with morphological alterations in the lungs seen in the'light and electron microscopes.Forty-two adult male and female Beagle dogs were selected for these exposure experiments. Treated animals were exposed to 94.5-107-5 ppm phosgene for 10 min. in a 15 m3 chamber. Roentgenograms were made of the thorax of each animal before and after exposure, up to 24 hrs.


Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs

Gonadotroph cell adenomas of the pituitary are infrequent in human patients and are not invariably associated with altered gonadal function. To date, no animal model of this tumor type exists. Herein, we describe spontaneous gonadotroph cell adenomas in old male and female Sprague-Dawley rats by histology, immunocytology and electron microscopy.The material consisted of the pituitaries of 27 male and 38 female Sprague Dawley rats, all 26 months of age or older, removed at routine autopsy. Sections of formal in-fixed, paraffin-embedded tissue were stained with hematoxylin-phloxine-saffron (HPS), the PAS method and the Gordon-Sweet technique for the demonstration of reticulin fibers. For immunostaining, sections were exposed to anti-rat β-LH, anti-ratβ-TSH, anti-rat PRL, anti-rat GH and anti-rat ACTH 1-39. For electron microscopy, tissue was fixed in 2.5% glutaraldehyde, postfixed in 1% OsO4 and embedded in epoxy-resin. Tissue fixed in 10% formalin, embedded in epoxy resin without osmification, was used for immunoelectron microscopy.


Author(s):  
Conly L. Rieder ◽  
Frederick J. Miller ◽  
Edwin Davison ◽  
Samuel S. Bowser ◽  
Kirsten Lewis ◽  
...  

In this abstract we Illustrate how same-section correlative light and high voltage electron microscopy (HVEM) of serial 0.25-0.50-μm sections can answer questions which are difficult to approach by EM of 60-100 nm sections.Starfish (Pisaster and Asterlas) eggs are fertilized at meiosis I when the oocyte contains two maternal centrosomes (e.g., asters) which form the poles of the first meiotic spindle. Immediately after fertilization a sperm aster is assembled in the vicinity of the male pronucleus and persists throughout meiosis. At syngamy the sperm aster splits to form the poles of the first mitotic spindle. During this time the functional and replicative properties of the maternal centrosome, inherited from the last meiotic division, are lost. The basis for this differential stability, of male and female centrosomes in the same cytoplasm, is a mystery.


1979 ◽  
Vol 10 (4) ◽  
pp. 246-248 ◽  
Author(s):  
Peter B. Mueller ◽  
Marla Adams ◽  
Jean Baehr-Rouse ◽  
Debbie Boos

Mean fundamental frequencies of male and female subjects obtained with FLORIDA I and a tape striation counting procedure were compared. The fundamental frequencies obtained with these two methods were similar and it appears that the tape striation counting procedure is a viable, simple, and inexpensive alternative to more costly and complicated procedures and instrumentation.


2020 ◽  
Vol 63 (7) ◽  
pp. 2054-2069
Author(s):  
Brandon Merritt ◽  
Tessa Bent

Purpose The purpose of this study was to investigate how speech naturalness relates to masculinity–femininity and gender identification (accuracy and reaction time) for cisgender male and female speakers as well as transmasculine and transfeminine speakers. Method Stimuli included spontaneous speech samples from 20 speakers who are transgender (10 transmasculine and 10 transfeminine) and 20 speakers who are cisgender (10 male and 10 female). Fifty-two listeners completed three tasks: a two-alternative forced-choice gender identification task, a speech naturalness rating task, and a masculinity/femininity rating task. Results Transfeminine and transmasculine speakers were rated as significantly less natural sounding than cisgender speakers. Speakers rated as less natural took longer to identify and were identified less accurately in the gender identification task; furthermore, they were rated as less prototypically masculine/feminine. Conclusions Perceptual speech naturalness for both transfeminine and transmasculine speakers is strongly associated with gender cues in spontaneous speech. Training to align a speaker's voice with their gender identity may concurrently improve perceptual speech naturalness. Supplemental Material https://doi.org/10.23641/asha.12543158


1980 ◽  
Vol 45 (2) ◽  
Author(s):  
Ronald L. Schow ◽  
Michael A. Nerbonne

In the February 1980 issue of this journal, the report by Ronald L. Schow and Michael A. Nerbonne ("Hearing Levels Among Elderly Nursing Home Residents") contains an error. On page 128, the labels "Male" and "Female" in Table 2 should be reversed.


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