Search

Start Over Type article

25212. Sperm viability in the male accessory testes and female spermathecae of the bumblebee Bombus terrestris (Hymenoptera: Apidae)

Creator:
Freeff, Michael and Schmid-Hempel, Paul
Type:
article, model:article, and TEXT
Subject:
Apidae, sperm storage, sperm viability, sperm competition, accessory testes, spermatheca, Bombus terrestris, bumblebees, and colony cycle end
Language:
English
Description:
In many species sperm competition selects for large ejaculates while females eliminate or disable a high percentage of the spermatozoa in their storage organs in order to control paternity. Therefore, sperm viability is an excellent measure of the reproductive success of both males and females. Here we assess the viability of spermatozoa in males, freshly mated queens and old queens at the end of a colony cycle of the monandrous bumblebee Bombus terrestris. We found that the accessory testes of males contained a significantly lower percentage of dead sperm (i.e. higher average viability) than the spermathecae of both freshly mated and old queens. In each case, however, the percentage of dead spermatozoa was very small. No differences could be detected between sperm viability in freshly mated and old queens. To test for the possible incompatibility of the sperm and the environment provided by female spermathecae males and females either from different geographic regions (north and south of the Alps) or the same region were mated. We did not find any differences between matings of individuals from within or between regions. The mechanism that causes the lower sperm viability in females remains unknown.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

25213. Spermathecal morphology and sperm dynamics in the female Schizocosa malitiosa (Araneae: Lycosidae)

Creator:
Useta, Gonzalo, Huber, Bernhard A., and Costa, Fernando G.
Type:
article, model:article, and TEXT
Subject:
Genital morphology, spermathecae design, sperm dynamics, reproductive strategies, and wolf spiders
Language:
English
Description:
The linkage between spermathecal morphology and sperm dynamics was experimentally analysed in Schizocosa malitiosa (Tullgren, 1905) using histological serial sections and SEM. We recognised three connected sections for each spermatheca: basal atrium, stalk and head. The head ends blindly, is sclerotized, provided with few large pores, and surrounded by thick, presumably glandular epithelium. The atrium is also sclerotized, and connects with both copulatory and fertilization ducts, lying close to each other. A porous plate is located in the stalk-atrium connection. Nine adult females were fixed in eight reproductive conditions for reconstructing sperm dynamics: virgin, immediately after mating, one day after mating, three days after mating, one day after remating without oviposition (first male with a single useful palp, second male normal), immediately before oviposition, three days after oviposition, and one day after remating with oviposition (female had eaten first egg-sac and had remated). Our results suggest female control of sperm transport because the penetration of encapsulated sperm into the spermathecal head continues after mating. Stored sperm is maintained in an encapsulated condition until oviposition, when sperm is totally activated. Sperm cells may remain viable for a long time in the decapsulated state. There was evidence for sperm mixing in the female that remated after oviposition.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

25214. Sphincterpreserving operations in lower ampullar cancer of the rectum

Creator:
Hakimov, A. M. and Bobokulov, H. B.
Format:
braille, electronic resource, remote, and elektronický zdroj
Type:
model:article, article, Text, statistics, and TEXT
Subject:
nádory rekta--chirurgie, anální kanál--chirurgie, chirurgie trávicího traktu--metody, statistika jako téma, výsledek terapie, staří, lidé, mužské pohlaví, and lidé středního věku
Language:
English
Description:
The Purpose of the study: define the indications and contraindications to sphincterpreserving operation in lowerampullar cancer of rectum. The Materials and methods: In coloproctological branch of National Oncological Scientific centre (NOSC) in 20052009 years 142 patients were performed radical operations, 64 (45,1%) patients were performed sphincterpreserving operations – abdominoanal resection of rectum (AARR), medium age of patients 59,8 years, beside 78 (54,9%) patients were performed abdomeno perineal extirpation of rectum (APER), medium age 54,2 years. The Results: Studied results of the morphological research of removed preparation by histological structure of tumors and by form of the growing, depending on locations of the tumors on toothed line. The remote postoperative results studied beside 51 (79,7%) patient with AARR and beside 63 (80,1%) patients with APER. The Findings: sphincterpreserving operations (SPO) of the rectum can be the operation of the choice in treatment of high differentiated adenocarcinoma (HDA) and medium differentiated adenocarcinoma (MDA) in stages T23 in localization of the lower pole of tumors, not below 1 centimeter of toothed line (TL) and carries combined character, in location of the lower edge of tumors on toothed line in patients with HDA MDA in 4% and 2,2% cases are shown that completing intrasphincternal resections of rectum, in connection with particular aggressiveness LDA question about choice of the method of the treatment under their localizations directly on TL must be solved in favour of complete APER, in exophytic tumor located onto and above TL is indication for sphincterpreserving operation in type of AARR, indices recurrencefree and not metastatic period, oneyear deathrate, threeyear survivability after SPO at inferior ampular cancer of rectum has not an essential distinction from results after APER., A. M. Hakimov, H. B. Bobokulov, and Literatura
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

25215. Sphingosine-1-phosphate is a possible fibrogenic factor in gluteal muscle fibrosis

Creator:
Zhao, C. G., Qin, J., He, X. J., Guan, Y. C., Jia, Y., and Lei, W.
Format:
print
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, svaly, muscles, sphingosine-1-phosphate, S1P, gluteal muscle contraction, GMC, fibrosis, TGF-β, PAI-1, 14, and 612
Language:
English
Description:
Gluteal muscle contracture (GMC) is a chronic fibrotic disease of gluteal muscles due to multiple etiologies. The main pathologic process is characterized by proliferation of fibroblasts and excessive accumulation of collagen in the extracellular matrix of the muscle. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid and has been reported to be associated with various fibrotic diseases. However, the role of S1P in GMC remains unknown. Here in this articl e, High-perform ance liquid chromatography and immunohistochemistry were applied to evaluate S1P localization and expression in clinical samples from patients with GMC, Quantitative real time PCR, Western blot, and enzyme-linked immunosorbent assa y were used to explore the link between transforming growth factor-β 1 (TGF- β 1), plasminogen activator inhibitor-1 (PAI-1) and S1P. The results showed that S1P was enhanced in contraction band (CB) tissues. Studies using the cell proliferation and transformation assay indicated that exogenous S1P stimulated CB fibroblast proliferation in a time-depen dent manner and in higher concentration also in a dose-dependent manner. Furthermore, we demonstrated that S1P not only promoted collagen type I production, but also up-regulated mRNA and protein expression of transforming growth factor-β 1 and plasminogen activator inhibitor-1. These findings suggest that S1P may regulate increased synthesis of collagen and other fibrogenic factors, and significantly contributes to the process of gluteal muscle scarring in patients with GMC., C. G. Zhao ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

25217. Špičkový výzkum je pro nás prioritou: projev předsedy akademie věd ČR Jiřího Drahoše

Creator:
Jiří Drahoš
Type:
article, projevy, model:article, and TEXT
Subject:
Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce, akademie věd, academies of science, 12, and 00
Language:
Czech
Description:
The Academy Assembly, the Academy of Science´s highest body responsible for the highest priority decisions related to the ASCR, held its XXXIX meeting on December 16, 2011. Among invited guests were Petr Fiala, the Prime Minister´s Chief Science Advisor; Karel Pospíšil, Head of Board of Public Applied Research Institutions; Václav Pačes, President of the Learned Society of the Czech Republic; Rudolf Zahradník, Honorary President of the ASCR; Helena Illnerová, former President of the ASCR; Václav Hampl, Rector of Charles University of Prague; Přemysl Sobotka, First Vice-President of the Senate of the Parliament of the Czech Republic, and Vladimír Haasz, Vice-Chairperson of the R&D Council of the Czech Republic, and others. The main agenda item of this meeting was discussion the results of the Evaluation of Academy Instituties. and Jiří Drahoš.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

25218. Špičkový výzkum ve veřejném zájmu

Creator:
Marina Hužvárová
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce, Drahoš, Jiří, 1949-, Akademie věd České republiky, věda a společnost, strategický management, rozhovor, science and society, strategic planning, interview, strategie rozvoje, 12, and 00
Language:
Czech
Description:
Akademie věd ČR představila na prosincovém Akademickém sněmu novou strategii, která se připravovala dlouhou dobu kromě jiného v diskusi s řediteli pracovišť. Každá změna samozřejmě vyvolává ohlasy v celé šíři škály - od záporných reakcí až po ty kladné. Strategii AV21 představujeme čtenářům na následujících stránkách současně s informacemi ze sněmovního zasedání, ale přesto jsem požádala předsedu AV ČR prof. Jiřího Drahoše o zodpovězení několika otázek. and Marina Hužvárová.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

25219. Špičkový výzkum ve veřejném zájmu - rozhovor s Jiřím Drahošem

Creator:
Marina Hužvárová
Format:
bez média and svazek
Type:
article, text, články, journal articles, model:article, and TEXT
Subject:
Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce, Drahoš, Jiří, 1949-, Akademie věd České republiky, věda a společnost, výzkum a vývoj, rozhovor, interview, science and society, research and development, 12, and 00
Language:
Czech
Description:
Marina Hužvárová. and Rozhovor vyšel v Akademickém bulletinu č. 1 (2015)
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

Limit your search

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

Show values starting with
more »

View distribution

Current results range from 1997 to 2016

View larger »