Carrageenans of gametangial and tetrasporangial stages of Iridaea cordata (Gigartinaceae)

1975 ◽  
Vol 53 (20) ◽  
pp. 2315-2318 ◽  
Author(s):  
E. L. McCandless ◽  
J. S. Craigie ◽  
J. E. Hansen
Keyword(s):  
Infrared Spectra ◽  
Red Alga ◽  
Sulfate Content ◽  
Male And Female ◽  
Iridaea Cordata

Carrageenans from gametangial (male and female) and tetrasporangial plants of the red alga Iridaea cordata were isolated, fractionated, and characterized on the basis of their anhydrogalactose and sulfate content and infrared spectra. As in the case of Chondrus crispas the tetrasporangial plants yielded only λ-carrageenan while the gametangial plants produced carrageenans of the κ-type. The male plants yielded proportionately more KCl-insoluble κ-carrageenan than did the female. The infrared spectra of the various preparations from I. cordata were virtually indistinguishable from those of comparable fractions isolated from C. crispus.

scholarly journals Primary Characterization of a Life-Cycle Mutant akasusabi of the Red Alga Neopyropia yezoensis

Phycology ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 14-26
Author(s):  
Koji Mikami ◽  
Takaharu Matsumura ◽  
Yuji Yamamoto
Keyword(s):  
Life Cycle ◽  
Red Alga ◽  
Spore Production ◽  
Red Seaweed ◽  
Timing Of Reproduction ◽  
Male And Female ◽  
Trade Off ◽  
Highly Sensitive ◽  
Asexual Spore

Gametophyte-to-sporophyte transition in the haploid-diploid life cycle depends on fertilization of male and female gametes. We describe here a mutant of the marine red seaweed Neopyropia yezoensis, designated akasusabi (aks), where the gametophyte-to-sporophyte transition occurs independently of fertilization. Although conchocelis filaments were produced from carpospores, severe defects in the maturation of carposporangia via mitosis to generate conchospores were observed. In the aks mutant, however, somatic cells of gametophytic thalli were able to produce conchocelis filaments without fertilization. Thus, apogamy occurs in aks. In addition, aks was highly sensitive to wounding that promotes both asexual and apogamous reproductive responses by producing spores, which develop either into blades or conchocelis filaments, indicating that aks responds to wounding by enhanced reproduction. These findings indicated that the aks mutation enables the transformation of vegetative cells to carpospores to produce sporophytes by apogamy and wound-inducible life cycle trade-off, stimulating a reset of the timing of reproduction during the life cycle. Therefore, AKS is involved in regulations of the gametophyte-to-sporophyte transition and asexual spore production in N. yezoensis.

Genetics of Gracilaria tikvahiae (Rhodophyceae). VII. Further observations on mitotic recombination and the construction of polyploids

1981 ◽  
Vol 59 (5) ◽  
pp. 787-792 ◽  
Author(s):  
John P. van der Meer
Keyword(s):  
Somatic Cells ◽  
Reproductive Behaviour ◽  
Mitotic Recombination ◽  
Red Alga ◽  
Crossing Experiments ◽  
Free Living ◽  
Male And Female ◽  
Gracilaria Tikvahiae ◽  
Morphological Mutants ◽  
Male Tissue

Tetrasporophytes of the marine red alga Gracilaria tikvahiae produce spermatia as well as tetraspores. It has been demonstrated previously that these spermatia are diploid and are produced as a consequence of mitotic recombination in somatic cells of the fertile thallus. It has now been demonstrated that female tissue is also present, often adjacent to the male tissue as would be expected, but is more difficult to recognize because it rarely becomes fertile. However, it was found that female tissue could be excised from the tetrasporophyte and induced to regenerate into complete fronds. Crossing experiments indicated that this female tissue was functional and diploid like the corresponding male tissue. Diploid male and female fronds have been established in culture as free-living plants. Morphological mutants of Gracilaria were found useful in obtaining stocks of diploid gametophytes. Triploid and tetraploid sporophytes were readily synthesized by using the diploid gametophytes (or spermatia from normal diploid tetrasporophytes) in crosses to each other or to normal haploid gametophytes. In one case an apparent tetraploid was synthesized by crossing a haploid female with a triploid tetrasporophyte. In this work polyploid designations are made on the basis of the method of construction and the reproductive behaviour of the polyploids. Cytological confirmation (made for a triploid previously) is incomplete for tetraploids but supports the designations that have been made.

The Clinical, Roentgenological and Morphological Effects of an Acute Exposure of Phosgene on the Lungs of Dogs

1971 ◽  
Vol 29 ◽  
pp. 236-237
Author(s):  
R. F. Bils ◽  
W. F. Diller ◽  
F. Huth
Keyword(s):  
Latent Period ◽  
Chemical Industry ◽  
Toxic Substance ◽  
Lung Edema ◽  
X Rays ◽  
Beagle Dogs ◽  
Male And Female ◽  
Morphological Alterations ◽  
Before And After ◽  
Electron Microscopes

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.

Ultrastructural investigation of spontaneous pituitary gonadotroph cell adenomas in aging Sprague-Dawley rats

1983 ◽  
Vol 41 ◽  
pp. 702-703
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Electron Microscopy ◽  
Animal Model ◽  
Epoxy Resin ◽  
Immunoelectron Microscopy ◽  
Tumor Type ◽  
Gonadal Function ◽  
Sprague Dawley ◽  
Male And Female ◽  
Reticulin Fibers ◽  
Sprague Dawley Rats

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.

Quantitative ultrastructural reconstruction of small regions within large volumes by correlative light and high voltage electron microscopy of serial 0.25-0.50 μm sections

1987 ◽  
Vol 45 ◽  
pp. 578-581
Author(s):  
Conly L. Rieder ◽  
Frederick J. Miller ◽  
Edwin Davison ◽  
Samuel S. Bowser ◽  
Kirsten Lewis ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Voltage ◽  
Mitotic Spindle ◽  
Meiotic Spindle ◽  
High Voltage Electron Microscopy ◽  
Male And Female ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Differential Stability ◽  
Sperm Aster

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.

A Tape Striation Counting Method for Determining Fundamental Frequency

1979 ◽  
Vol 10 (4) ◽  
pp. 246-248 ◽  
Author(s):  
Peter B. Mueller ◽  
Marla Adams ◽  
Jean Baehr-Rouse ◽  
Debbie Boos
Keyword(s):  
Fundamental Frequency ◽  
Counting Method ◽  
Male And Female ◽  
Fundamental Frequencies ◽  
Counting Procedure ◽  
Female Subjects

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.

Perceptual Evaluation of Speech Naturalness in Speakers of Varying Gender Identities

2020 ◽  
Vol 63 (7) ◽  
pp. 2054-2069
Author(s):  
Brandon Merritt ◽  
Tessa Bent
Keyword(s):  
Spontaneous Speech ◽  
Identification Accuracy ◽  
Rating Task ◽  
Gender Identification ◽  
Identification Task ◽  
Male And Female ◽  
Perceptual Evaluation ◽  
Speech Training ◽  
And Gender ◽  
Speech Naturalness

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

Erratum: Hearing Levels among Elderly Nursing Home Residents

1980 ◽  
Vol 45 (2) ◽  
Author(s):  
Ronald L. Schow ◽  
Michael A. Nerbonne
Keyword(s):  
Nursing Home ◽  
Nursing Home Residents ◽  
Male And Female

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.

Sign in / Sign up

Export Citation Format

Share Document