Induction of Differentiated Activity of the Genes by Cytoplasmic and Chromosomal Factors and Its Role in the General Organization of Morphogenesis

1970 ◽  
pp. 295-341
Author(s):  
Zhores A. Medvedev
Keyword(s):  
General Organization

scholarly journals II.—Description of a Fossil Shark (Ctenacanthus costellatus) from the Lower Carboniferous Rocks of Eskdale, Dumfriesshire

1884 ◽  
Vol 1 (1) ◽  
pp. 3-8 ◽  
Author(s):  
R. H. Traquair
Keyword(s):  
Lower Carboniferous ◽  
General Organization

The deficiency of our knowledge of the organization and configuration of the Palaeozoic Selachii is an unfortunate fact too well known to biologists to render it necessary for me to dilate upon here. Immense numbers of genera and species have been founded upon detached teeth and spines; but as yet very few specimens have occurred, which threw any light upon the general organization and configuration of the ancient possessors of these now scattered relics.

The fine structure of the alimentary tract of third-stage larvae of Haemonchus placei and Trichostrongylus colubriformis

Parasitology ◽  
1971 ◽  
Vol 62 (3) ◽  
pp. 355-360 ◽  
Author(s):  
Kenneth Smith ◽  
Eric Harness
Keyword(s):  
Alimentary Tract ◽  
Buccal Cavity ◽  
Secretory Granules ◽  
Intestinal Cells ◽  
Similar Morphology ◽  
Gland Cells ◽  
Dense Bodies ◽  
Third Stage ◽  
General Organization ◽  
Haemonchus Placei

A comparative study was made of defined regions of the alimentary tract of third-stage larvae of T. colubriformis and H. placei. The general organization of the tract was similar in both nematodes. The mouth, buccal cavity and oesophagus were lined with cuticle. Muscle cells, apical cells and gland cells were present in the oesophagus. In both species the gland cells contained secretory granules of similar morphology. The lumen of the intestine was ill-defined and apparently nonfunctional. Dense bodies observed in the intestinal cells differed in the two species.We are grateful to Dr D. W. Brocklesby for his help and advice. We would also like to thank Dr D. L. Lee and Dr W. G. MacMillan for helpful discussions.

scholarly journals Academic autopsies in Brazil - a national survey

2014 ◽  
Vol 60 (2) ◽  
pp. 145-150 ◽  
Author(s):  
Aloísio Felipe-Silva ◽  
Márcia Ishigai ◽  
Thaís Mauad
Keyword(s):  
Medical Education ◽  
Undergraduate Education ◽  
Limiting Factor ◽  
Autopsy Rate ◽  
Residency Programs ◽  
Steady Decrease ◽  
Healthcare Practice ◽  
Minimum Number ◽  
Academic Services ◽  
General Organization

Objective: To investigate the number and rate of academic autopsies, general organization, educational and research in Brazilian academic services. Methods: Standardized questionnaires were sent to Brazilian medical schools (n=177) and active pathology residency programs (n=53) from March to June 2009. Data were collected for years 2003 to 2008. Results: Thirty-two academic services in 11 Brazilian states answered the survey. Twenty-one (65.6%) perform less than a hundred autopsies for natural causes and less than fifty pediatric or fetal autopsies/year. Twenty-four (75%) perform less than a hundred adult autopsies/year. Many institutions (46.9%) reported a drop in the number of autopsies in a six-year period. The total autopsy count and autopsy rate in 2008 ranged 1-632 (median = 80), and 0-66% (mean = 10.6%), respectively. A steady decrease in the total count of autopsies in a pool of 19 institutions was observed (p<0.01). Median autopsy rates have fallen from 19.3%, in 2003, to 10.6%, in 2008 (p=0.07). Significant discrepancies at autopsies led to changes in institutional healthcare practice in 37.5% of the services. The low number of autopsies was a limiting factor in undergraduate education for 25% of respondents. A minimum number of autopsies is required to complete the pathology residency program in 34.6% of the services. Conclusion: The total number and the rate of academic autopsies have decreased in Brazil between 2003 and 2008. The number of autopsies and the general organization of academic services must be enhanced to improve medical education, research, and the quality control of patient care.

scholarly journals Structure and expression of the RH locus in the Rh-deficiency syndrome

Blood ◽  
1993 ◽  
Vol 82 (2) ◽  
pp. 656-662 ◽  
Author(s):  
B Cherif-Zahar ◽  
V Raynal ◽  
C Le Van Kim ◽  
AM D'Ambrosio ◽  
P Bailly ◽  
...  
Keyword(s):  
Transcriptional Activity ◽  
Deficiency Syndrome ◽  
Autosomal Locus ◽  
Chain Reaction ◽  
Rh Proteins ◽  
Polymerase Chain ◽  
Silent Allele ◽  
General Organization ◽  
Chronic Hemolytic Anemia ◽  
Inhibitor Gene

Red blood cell deficiency of Rh proteins is associated with morphologic and functional abnormalities of erythrocytes and with a chronic hemolytic anemia of varying severity. Rh-deficiency may be the result of homozygosity either for a silent allele at the RH locus (Rhnull amorph type) or for a recessive inhibitor gene(s) at an autosomal locus unlinked to RH locus (Rhnull regulator and Rhmod). In this report, we investigated the RH locus structure of Rh-deficient individuals by Southern analysis using cDNA and exon-specific probes deduced from the recent cloning of Rh genes (CcEe and D). As expected from family studies indicating that Rhmod and Rhnull regulator individuals are unable to express Rh antigens but are able to convey functional Rh genes from one generation to another, no alteration of the Rh genes was detected in these variants. Although Rhnull of the amorph type arose by inheritance of a pair of silent alleles at the RH locus, the general organization of the unique CcEe gene in the genome of the particular individual under examination was apparently normal and indistinguishable from a Rh-negative chromosome. More surprisingly, no mutation could be detected by sequencing the polymerase chain reaction (PCR)-amplified reticulocyte mRNAs, suggesting that the RH locus of this patient might be altered in its transcriptional activity. Through hybridization with exon-specific probes, we were also able to determine the zygosity for the D gene in DNA samples from individuals of known genotypes; using this approach, we found that Rhnull regulator variants could be either of the DD, Dd, or dd genotypes. These findings suggest that the postulated inhibitor gene(s) can negatively suppress the RH locus expression from chromosomes carrying either one or two of the Rh genes.

scholarly journals The Competence of Professors of Physical and Sports Education in the Use of Modern Teaching Strategies for Middle School Under the Second Generation Curriculum

2021 ◽  
Vol 61 (1) ◽  
pp. 52-61
Author(s):  
Bengueneb Abdarahmane ◽  
Atallah Ahmed ◽  
Djourdem Bendehiba
Keyword(s):  
Middle School ◽  
Standard Deviation ◽  
Physical Education ◽  
Teaching Strategies ◽  
Research Team ◽  
Second Generation ◽  
Arithmetic Means ◽  
General Organization

Summary The study aims at identifying the degree of competency of the teacher of physical education and sports in using modern teaching strategies in light of what was stipulated by the second generation. The Study sample consists of 60 intermediate education teachers, and relies on a list prepared by the research team consisting of two axises, each axis containing 16 items that include familiarity with and employing modern strategies in the study of physical education and sports, as well as the general organization of the lesson the data are processed statistically using the arithmetic means standard deviation, and the results showed that the teachers of Physical education and sports in middle school do not use modern teaching strategies. This is due to their lack of competence.

Mutations affecting neurogenesis and brain morphology in the zebrafish, Danio rerio

Development ◽  
1996 ◽  
Vol 123 (1) ◽  
pp. 205-216 ◽  
Author(s):  
Y.J. Jiang ◽  
M. Brand ◽  
C.P. Heisenberg ◽  
D. Beuchle ◽  
M. Furutani-Seiki ◽  
...  
Keyword(s):  
Cell Types ◽  
Brain Morphology ◽  
Abnormal Development ◽  
Radial Glial Cells ◽  
Complementation Groups ◽  
Early Neurogenesis ◽  
Radial Glial ◽  
General Organization ◽  
Neurogenic Mutants ◽  
The Brain

In a screen for embryonic mutants in the zebrafish a large number of mutants were isolated with abnormal brain morphology. We describe here 26 mutants in 13 complementation groups that show abnormal development of large regions of the brain. Early neurogenesis is affected in white tail (wit). During segmentation stages, homozygous wit embryos display an irregularly formed neural keel, particularly in the hindbrain. Using a variety of molecular markers, a severe increase in the number of various early differentiating neurons can be demonstrated. In contrast, late differentiating neurons, radial glial cells and some nonneural cell types, such as the neural crest-derived melanoblasts, are much reduced. Somitogenesis appears delayed. In addition, very reduced numbers of melanophores are present posterior to the mid-trunk. The wit phenotype is reminiscent of neurogenic mutants in Drosophila, such as Notch or Delta. In mutant parachute (pac) embryos the general organization of the hindbrain is disturbed and many rounded cells accumulate loosely in the hindbrain and midbrain ventricles. Mutants in a group of 6 genes, snakehead(snk), natter (nat), otter (ott), fullbrain (ful), viper (vip) and white snake (wis) develop collapsed brain ventricles, before showing signs of general degeneration. atlantis (atl), big head (bid), wicked brain (win), scabland (sbd) and eisspalte (ele) mutants have different malformation of the brain folds. Some of them have transient phenotypes, and mutant individuals may grow up to adults.

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