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6242. Diel acid fluctuations in C4 amphibious grasses

Creator:
Keeley, J. E.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
aquatic and terrestrial leaves, 14C labelling, chlorophyll, malic acid, Neostapfia colusana, Orcuttia californica and O. viscida, titratable acidity, and Tuctoria greenie
Language:
Multiple languages
Description:
Orcuttieae is a small tribe of C4 grasses endemic to seasonal pools in the southwestern U.S., comprising the basal genus Neostapfia, Tuctoria, and the most derived group, Orcuttia. Growth is initiated underwater, and when pools dry, species undergo a metamorphosis replacing aquatic foliage with terrestrial foliage. O. californica and O. viscida exhibit CAM-like diel fluctuations in acidity in the aquatic foliage. Pulse-chase studies showed that although CO2 was fixed into malic acid in the dark, an overnight chase in the dark revealed that most label was not retained in organic acids, indicating a role other than CAM. Terrestrial foliage exhibited a very different diel fluctuation; acids accumulated during the day, and diminished overnight. Malic acid predominated and was secreted on the surface of the leaf in a manner similar to another arid land species. This terrestrial daytime acid accumulation may not be related to photosynthetic pathway but may play an anti-herbivore function. No acid fluctuations were observed in either N. colusana or T. greenei.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6244. Dietary flavonoids and risk of coronary heart disease

Creator:
Mojžišová, G. and Kuchta, M.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, flavonoidy, volné radikály, víno, dietní jídla, flavonoids, free radicals, wine, diet, coronary heart diseases, LDL, 14, and 612
Language:
English
Description:
Flavonoids, a group of phenolic compounds found naturally in fruit, vegetables, nuts, flowers, seeds and bark are an integral part of the human diet. They have been reported to exhibit a wide range of biological effects, including anti-ischemic, antiplatelet, antineoplastic, antiinflammatory, antiallergic, antilipoperoxidant or gastroprotective actions. Furthermore, flavonoids are potent antioxidants, free radical scavengers and metal chelators, and inhibit lipid peroxidation. Oxidative modification of low-density lipoproteins (LDLs) is believed to play a crucial role in atherogenesis. Epidemiological studies have shown that the consumption of fruits and vegetables, and regular red wine consumption is related with a reduced risk of cardiovascular diseases., G. Mojžišová, M. Kuchta., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6245. Dieudonné-type theorems for lattice group-valued k-triangular set functions

Creator:
Boccuto , Antonio and Dimitriou, Xenofon
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Dieudonné theorem, limit theorem, lattice group, (D)-convergence, k-triangular set function, (s)-bounded set function, Fremlin lemma, Brooks-Jewett theorem, and Nikodým boundedness theorem
Language:
English
Description:
Some versions of Dieudonné-type convergence and uniform boundedness theorems are proved, for k-triangular and regular lattice group-valued set functions. We use sliding hump techniques and direct methods. We extend earlier results, proved in the real case. Furthermore, we pose some open problems.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

6246. Diferenciace motivů svobodného mateřství: proč neprovdané matky nevstoupily před narozením svého prvního dítěte do manželství?

Creator:
Klímová Chaloupková, Jana
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
svobodné matky, osamělé matky, motivace, názory a postoje, mothers, single mothers, sociological research, svobodné mateřství, neprovdané matky, mimomanželské mateřství, mimomanželská plodnost, 316.356.2-055.52, 316.812.31-055.2, 316.628, 316.64, 316:303, 18, and 316.8
Language:
Czech
Description:
Stať se zaměřuje na zkoumání příčin rostoucí mimomanželské plodnosti. Vychází z dat výzkumného šetření Sociální a ekonomické podmínky mateřství (SEPM) provedeného v roce 2006 v Sociologickém ústavu AV ČR. Tato data umožňují na mikroúrovni poodkrýt důvody, jakými neprovdané matky vysvětlovaly svoji vlastní rodinnou situaci při narození prvního dítěte. Analýza identifikovala tři typy motivací neprovdaných matek: nesouhlas/absence partnera, liberální postoje a pragmatické (ekonomické) důvody. Jednotlivé skupiny neprovdaných matek se lišily nejen postoji k manželství, ale i tím, jak vnímaly budoucnost vztahu s otcem dítěte. Příslušnost k jednotlivým skupinám souvisela s tím, jestli žena v době narození prvního dítěte žila v nesezdaném soužití s jeho otcem, s výší vzdělání a jejím věkem při narození prvního dítěte. Skupiny neprovdaných matek mají navíc rozdílné vyhlídky do dalšího rodinného života. V druhé části se příspěvek zaměřuje na to, jaké partnerské uspořádání považují neprovdané matky za ideální. Data SEPM ukazují, že velká část neprovdaných matek preferuje manželský svazek po předcházejícím nesezdaném soužití., Jana Chaloupková., 1 graf, 4 tabulky, and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

6247. Differences between populations of Spinturnix myoti (Acari: Mesostigmata) in breeding and non-breeding colonies of Myotis myotis (Chiroptera) in central Europe: the effect of roost type

Creator:
Postawa, Tomasz, Szubert-Kruszyńska, Agnieszka, and Ferenc, Hanna
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
maternity aggregation, mouse-eared bats, parasite infection, roosting microclimate, and Spinturnicidae
Language:
English
Description:
We studied variations in the abundance of parasitic spinturnicid mites in relation to the gender, age and body condition of bats living in different habitats. Populations of Spinturnix myoti Kolenati, 1856 (Acari: Spinturnicidae), an ectoparasite of the bat Myotis myotis (Borkhausen) (Mammalia: Chiroptera), were investigated in two types of roosts differing in microclimatic conditions: caves (low temperature and high humidity) and attics (high temperature and low humidity). Our data suggest that bats from cave nursery colonies harbour more parasites than those from attic colonies, irrespective of host sex or age. In underground colonies, adult females and their young differ in the mean abundance of parasites, whereas no such differences were found in attic colonies. Non-lactating females from underground roosts and lactating females from attic colonies had similar parasite loads, were lower than those of adult lactating females from caves. A negative correlation between the host body condition index and parasite load was found only in the most infected sex/age group of bats. In spite of significant differences in parasite load, the mean abundance of particular life stages of mites seems to be independent of the type of roost occupied by the host, its sex or age. However, in attic colonies the number of female deutonymphs was twice that of male deutonymphs, whereas in cave colonies the proportions of the sexes were similar. We suggest that the microclimate of the host's roosts may influence ectoparasite abundance through pressure on the sex ratio in the nymphal stages of mites.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6248. Differences in activities of antioxidant superoxide dismutase, glutathione peroxidase and prooxidant xanthine oxidoreductase/xanthine oxidase in the normal corneal epithelium of various mammals

Creator:
Kovačeva, J., Jan Pláteník, Martin Vejražka, Stanislav Štípek, Taras Ardan, Čestmír Čejka, Midelfart, A., and Jitka Čejková
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Biochemie. Molekulární biologie. Biofyzika, biochemie, savci, rohovka, antioxidanty, biochemistry, mammals, cornea, antioxidants, epitel, prooxidanty, epithelium, prooxidants, 2, and 577
Language:
English
Description:
Under normal conditions, antioxidants at the corneal surface are balanced with the production of reactive oxygen species without any toxic effects. Danger from oxidative stress appears when natural antioxidants are overwhelmed leading to antioxidant/prooxidant imbalance. The aim of the present study was to examine the activities of enzymes contributing to the antioxidant/prooxidant balance in normal corneal epithelium of various mammals. The enzyme activities of antioxidant superoxide dismutase and glutathione peroxidase, as well as prooxidant xanthine oxidoreductase/xanthine oxidase were examined using biochemical methods. Results show that superoxide dismutase activity is high in rabbits and guinea pigs, whereas in pigs the activity is low and in cows it is nearly absent. In contrast, glutathione peroxidase activity is high in cows, pigs and rabbits, whereas in guinea pigs the activity is low. As far as prooxidant enzymes are concerned, elevated xanthine oxidoreductase/xanthine oxidase activities were found in rabbits, lower activities in guinea pigs, very low activity in cows and no activity in pigs. In conclusion, the above results demonstrate inter-species variations in activities of enzymes participating in antioxidant/prooxidant balance in the corneal epithelium. It is suggested that the levels of antioxidant and prooxidant enzymes studied in the corneal epithelium might be associated with the diurnal or nocturnal activity of animals. UV rays decompose hydrogen peroxide to damaging hydroxyl radicals and perhaps for this reason large animals with diurnal activity (cow, pig) require more effective peroxide removal (high glutathione peroxidase activity) together with the suppression of peroxide production (low superoxide dismutase activity, low xanthine oxidoreductase activity)., J. Kovačeva, J. Pláteník, M. Vejražka, S. Štípek, T. Ardan, Č. Čejka, A. Midelfart, J. Čejková., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6249. Differences in bisphenol A and estrogen levels in the plasma and seminal plasma of men with different degrees of infertility

Creator:
Vítků, J., Sosvorová, L., Chlupacova, T., Richard Hampl, Hill, M., Vladimír Sobotka, Jiří Heráček, Marie Bičíková, and Luboslav Stárka
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, bisfenol A, krevní plazma, neplodnost mužů, bisphenol A, blood plasma, male infertility, estrone, estradiol, estriol, seminal fluid, seminal plasma, LC-MS, 14, and 612
Language:
English
Description:
The general population is potentially exposed to many chemicals that can affect the endocrine system. These substances are called endocrine disruptors (EDs), and among them bisphenol A (BPA) is one of the most widely used and well studied. Nonetheless, there are still no data on simultaneous measurements of various EDs along with steroids directly in the seminal fluid, where deleterious effects of EDs on spermatogenesis and steroidogenesis are assumed. We determined levels of BPA and 3 estrogens using LC-MS/MS in the plasma and seminal plasma of 174 men with different degrees of infertility. These men were divided according their spermiogram values into 4 groups: (1) healthy men, and (2) slightly, (3) moderate, and (4) severely infertile men. Estradiol levels differed across the groups and body fluids. Slightly infertile men have significantly higher BPA plasma and seminal plasma levels in comparison with healthy men (p<0.05 and p<0.01, respectively). Furthermore, seminal BPA, but not plasma BPA, was negatively associated with sperm concentration and total sperm count (-0.27; p<0.001 and -0.24; p<0.01, respectively). These findings point to the importance of seminal plasma in BPA research. Overall, a disruption of estrogen metabolism was observed together with a weak but significant impact of BPA on sperm count and concentration., J. Vitku, L. Sosvorova, T. Chlupacova, R. Hampl, M. Hill, V. Sobotka, J. Heracek, M. Bicikova, L. Starka., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

6250. Differences in cold inactivation of phosphoenolpyruvate carboxylase among C4 species: The effect of pH and of enzyme concentration

Creator:
Zervoudakis, G., Angelopoulos, K., Salahas, G., and Georgiou, C. D.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
Amaranthus sp., Atriplex halimus, Cynodon dactylon, Digitaria sanguinalis, Portulaca oleracea, Saccharum officinarum, Salsola kali, Setaria verticillata, and Zea mays
Language:
Multiple languages
Description:
Among various C4 plants we found a wide range in the level of inactivation of phosphoenolpyruvate carboxylase (PEPC) at low temperature (0 °C). The activity of the 2-fold diluted enzyme in crude leaf extracts after 60 min incubation (compared to zero time incubation) at pH 7.5, remained above 87 % at low temperatures for the species Setaria verticillata, Portulaca oleracea, and Saccharum officinarum, and between 11 and 17 % in the species Cynodon dactylon and Atriplex halimus. The enzyme exhibited intermediate levels of inactivation (42 to 58 %) for the species Amaranthus sp., Zea mays, Salsola kali, and Digitaria sanguinalis. The enzyme activity for S. verticillata was unaffected between pH 5.7 and 8.4 during incubation at room and low temperatures. Under similar conditions, the activity of the enzyme from C. dactylon was stable between pH 5.7 and 7.0 and decreased at pH above 7.0, but for Z. mays it was enhanced between pH 5.7 and 6.8 and decreased at pH above 7.0. and G. Zervoudakis ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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