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Start Over Rights http://creativecommons.org/licenses/by-nc-sa/4.0/ Date Unknown

2244. Are Acute Changes After Status Epilepticus in Immature Rats Persistent?

Creator:
Suchomelová, L., Hana Kubová, Renata Haugvicová, Rastislav Druga, and Pavel Mareš
Format:
print, bez média, and svazek
Type:
article, studie, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, Status epilepticus, Rat, Development, EEG, Behavior, Histology, Motor performance, 14, and 612
Language:
English
Description:
Early consequences of lithium-pilocarpine convulsive status epilepticus (SE) were studied six days after this status had been induced in rat pups at the age of either 12 or 25 days. Studies of spontaneous EEG activity demonstrated the presence of epileptic phenomena (isolated spikes) in both hippocampus and cortex (cortical spikes were more expressed in the older group). There were no marked behavioral correlates of spikes and transition into the ictal phase was exceptional. The motor performance on a rotorod and a horizontal bar was the same in experimental and control rats of both ages. Behavior in the open field was changed in a reverse manner in the two age groups: the locomotor activity of rats with induced seizures at the age of 12 days was significantly lower than that of their control siblings, whereas animals undergoing status at the age of 25 days were hyperactive. In addition, they also exhibited increased exploratory activity (rearing) and their habituation to the open field was deranged. Nissl-stained brain sections demonstrated extensive brain damage in the older group in contrast to the negative findings in younger animals. EEG, behavioral and morphological changes induced by status epilepticus in developing rats persisted for 6 days after the status. They markedly differed according to the age of animals., L. Suchomelová, H. Kubová, R. Haugvicová, R. Druga, P. Mareš., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2245. Are calcium ions and calcium channels involved in the mechanisms of Cu2+ toxicity in bean plants? The influence of leaf age

Creator:
Maksymiec, W. and Baszyński, T.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence, copper, lanthanum, Phaseolus coccineus, photosystem 2, senescence, toxicity, and verapamil
Language:
Multiple languages
Description:
The influence of calcium channel blockers and ionophore on Cu2+-induced changes of the photosynthetic activity of runner bean plants (Phaseolus coccineus L.) was investigated. Excess Cu2+ was applied to leaves by injection or via the roots to examine a short/local or a long time/systemic effect of this metal, respectively. The changes in fluorescence parameters indicated that the mechanism of toxic action of Cu2+ ions on the photosynthetic apparatus was only partially connected with Ca2+ or Ca2+ channels. In young plants Ca2+ diminished especially photochemical and nonphotochemical dissipative processes induced by short- and long-term influence of excess Cu2+. Blocking of Ca2+ channels did not change direct Cu2+ action on the photosynthetic activity, however, their opening distinctly intensified the inhibitory effect of the metal. After a longer accumulation peri od the effect of Cu2+ ions did not change significantly due to modified Ca2+ penetration through membranes (except that caused by La3+). Copper directly introduced into older leaves diminished only at its highest concentration the activity both of the donor and acceptor sides of photosystem 2 (PS2) connected with Rfd decrease and increase of LNU. A similar effect was observed also after a long-term Cu2+ action, but disturbances on the acceptor side of PS2 were observed only at a higher Ca2+ content in the nutrient solution. Ca2+ ions, particularly after openning of channels, intensified direct inhibitory Cu2+ action on the photosynthetic activity expressed by decreased values of Fv/F0 and Rfd. Lanthanum and verapamil, at a lower Ca2+ content in the medium, decreased the photosynthetic activity of Cu2+-treated plants. This effect was also seen after additional Ca2+ supply to the leaves. and W. Maksymiec, T. Baszyński.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2246. Are diurnal fluctuations in streamflow real?

Creator:
Cuevas, Jaime G., Calvo, Matías, Little, Christian, Pino, Mario, and Dassori, Paul
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
iInstrumental analysis, methodological artifacts, southern rainforests, stream and air temperatures, inštrumentálna analýza, metodologické artefakty, južné dažďové pralesy, and teploty vzduchu a vody
Language:
Slovak
Description:
Diurnal variations in streamflow (DVS) have been studied in detail by underwater pressure loggers. Some of this equipment requires barometric compensation with a logger or sensor located outside the water. Studies related to this topic have not offered a critical report of the validity of patterns inferred with these instruments. While studying a forested watershed in Southern Chile (40° S), we detected a DVS when the external logger was placed 1.5 m above ground, under a marked diurnal fluctuation in air temperature (amplitude 12.4 °C) and a dampened fluctuation in stream temperature (amplitude 1.4 °C). Synchronization was apparent between air and stream temperature in a direct relationship, but the synchronization between air/stream temperature and streamflow was negative, with some hours of lag time. In laboratory experiments, when the external logger is considerably warmer than the water-level logger, depth measurements can be underestimated by up to 1.5 cm. When the opposite occurs, water depths can be overestimated by up to 0.9 cm and are large instrumental/methodological artifacts compared to the field water diurnal variation of 1.3 cm. Finally, we relocated the external logger in front of the water-level logger and inside a weir, but exposed to the air. Results confirmed the pattern previously detected in the field, but streamflow fluctuations were 19% less accentuated. We conclude that the incorrect placement of the external logger, along with an instrumental artifact, can intensify a DVS pattern. and Počas dňa sme podrobne sledovali zmeny prietokov v tokoch tlakovými snímačmi, umiestnenými pod vodou. Niektoré z týchto zariadení vyžadujú barometrickú kompenzáciu snímačov, ktoré nie sú umiestnené vo vode. Štúdie z tejto oblasti obyčajne nehodnotia kriticky správnosť výsledkov meraní týmito zariadeniami. Počas meraní v zalesnenom povodí na juhu Chile (40° S), sme zistili zmeny prietokov v tokoch počas dňa, ak bol externý tlakový snímač (logger) uložený 1,5 m nad zemou, počas výrazných denných zmien teploty vzduchu (amplitúda 12.4 °C) a stlmené fluktuácie teploty vody v toku (amplitúda 1.4 °C). Synchronizácia medzi teplotami vody a vzduchu bola zrejmá, ale synchronizácia medzi teplotami vody v toku a prietokmi bola negatívna, s hodinovými posunmi voči sebe. V experimentoch v laboratóriu, keď bol externý snímač podstatne teplejší ako snímač vo vode, meranie hĺbok bolo podhodnotené až o 1,5 cm. V opačnom prípade, hĺbka hladiny vody bola nadhodnotená až o 0,9 cm a boli zistené významné inštrumentálne/metodologické artefakty v porovnaní s poľnými meraniami až o 1,3 cm. Nakoniec, externý snímač bol umiestnený pred snímač s údajmi o vodnej hladine a dovnútra prepadu, ale bol vo vzduchu. Výsledky meraní potvrdili chody prietokov namerané v teréne, ale fluktuácie prietokov boli nižšie o 19 %. Z toho vyplýva, že nesprávne umiestnenie externého snímača, spolu s prístrojovými artefaktmi, môžu intenzifikovať zmeny prietokov v tokoch počas dňa.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2247. Are embryonal neurones used for transplantation "sufficiently immature"?

Creator:
Pokorný, J., Langmeier, M., and Trojan, S.
Type:
article, model:article, and TEXT
Subject:
hippocampus, embryonal neurones, neuronal suspension, and dendritic development
Language:
English
Description:
Live neuronal suspensions, prepared from the hippocampal region of donors aged 20 embryonal days, were observed in the Nomarski Differential Interference Contrast. Many neurones displayed profiles, resembling dendrites or axons and both principal hippocampal neurones (pyramidal and granular cells) were identified. For transplantation studies, donors of a younger embryonal age are thus recommended.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2248. Are mammal communities occurring at a regional scale reliably represented in “hub” bushmeat markets? A case study with Bayelsa State (Niger Delta, Nigeria)

Creator:
Akani, Godfrey C., Amadi, Nioking, Eniang, Edem A., Luiselli, Luca, and Petrozzi, Fabio
Type:
article, model:article, and TEXT
Subject:
mammalia, hunting, marketing of wildlife, and West Africa
Language:
English
Description:
Monitoring of bushmeat markets has traditionally been seen as a source of faunistic and ecological data on mammal communities in West Africa. Nonetheless, it is largely unexplored whether datasets coming from monitoring of large “hub” markets in towns can reliably picture the mammal faunas and community compositions at the local level. Here, Swali market in Bayelsa State, Nigeria, that is one of the largest bushmeat markets in the Niger Delta, was monitored for six months in 2013-2014. Data from Swali market were compared with those collected during regular field surveys at five protected forests situated within 15 km radius from the market. A total of 21 mammal species was recorded at Swali versus 29 in the five protected forests. The trade was more intense by wet season. There was a statistically significant linear relationship between mean weight of the sold mammal and its price. A considerable portion of species that occur at the protected forests did not occur in the market samples, including the very rare species and the small-sized species. However, the abundance in the market of the common species was positively related to their apparent field abundance in the forest reserves. Therefore, it is concluded that large-sized bushmeat markets did not depict reliably the whole faunal composition and the community structure of mammals in West Africa, although these types of surveys are sufficient to characterize the abundance distribution of the common species at the regional scale.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2249. Are the effects of salinity on growth and leaf gas exchange related?

Creator:
Dunn, G. M. and Neales, T. F.
Format:
print
Type:
model:internalpart and TEXT
Language:
Multiple languages
Description:
The responses of growth and leaf gas exchange to increasing salinity were measured in two halophytes [Atriplex nummularia (C4), Atriplex hastata (C3)] and one glycophyte [Hordeum vulgare (C3)]. The growth (dry mass) of both the halophytes was significantly increased, by 54 and 17 %, respectively, as salinity was increased in the range 0-200 mol m-^ NaCl. However, net CO2 assimilation rate (Pn)- the intercellular CO2 concentration (Cj) and leaf conductance (^1) were unaffected. At higher levels of salinity (in the range 400 - 600 mol m"^ NaCl) the growth of the two halophytes was severely reduced (by 44 and 51 %, respectively). At these levels of salinity q were significantly depressed. 25 mol m*^ NaCl significantly reduced the growth of H. vulgare by 44 %, but had no effect on Py^, g| and Cj. However, at 100 mol m'^ NaCl, where growth was decreased by 62 %, and g| were significantly reduced while q was unaltered. There was thus, no association between the effects of salinity on growth and leaf gas exchange at low salinities (25- 200 mol m'3 NaCl). At higher salinities, leaf gas exchange and growth were both severely inhibited but it is unlikely that a direct causal relationship existed. At these salinities sodium concentration in the leaves (tissue water basis) was above 400 mol m'3 in the halophytes and above 100 mol m'^ in H. vulgare which possibly affected both growth and leaf gas exchange independently. Also, the effects of salinity on total leaf chlorophyll concentration and net CO2 assimilation rate expressed on a chlorophyll (chl) basis (Pchi) were no better related to growth than was Pn
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

2250. Are the fluorescence parameters of German chamomile leaves the first indicators of the anthodia yield in drought conditions?

Creator:
Bączek-Kwinta, R., Kozieł, A., and Seidler-Lożykowska, K.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, carotenoids, chlorophyll, ploidy, and wild type
Language:
Multiple languages
Description:
7-day soil drought followed by 7-day rehydration was applied to potted German chamomile (Chamomilla recutita) plants at the beginning of their generative stage. Plants of a wild type (WT), plus two diploid (2n) and two tetraploid (4n) genotypes were studied, in order to examine the alterations in chlorophyll (Chl) and carotenoids (Car) contents, and chlorophyll fluorescence (CF) parameters during water shortage and rehydration. The fresh mass of the anthodia after the recovery was also studied. WT plants adjust better to water stress than modern breeding genotypes, because drought resulted in the low fall in leaf water content of WT, the lowest decrease in the fresh mass of its anthodia (a 41% decrease from the control), and the most elastic response of the photosynthetic apparatus. 4n C11/2 strain plants suffered from the highest reduction in anthodia yield (87%), and had the lowest constitutive pigment contents. It was also the only genotype which revealed nontypical alterations in various CF parameters obtained on a dark- and light-adapted leaf. During drought, a big increase was noticed in minimal, maximal, and variable fluorescence of PSII reaction centres in the dark- adapted (F0, Fm and Fv, respectively), and in the light-adapted state (F0', Fm' and Fv')., It was accompanied by the biggest decline in linear electron transport rate (ETR), quantum efficiency of PSII electron transport (ΦPSII) and photochemical quenching coefficient (qP). These alterations were prolonged to the stage when the normal leaf water content was retained. On the contrary, C6/2 strain plants had the highest constitutive Chl and Car contents, which additionally increased after rehydration, similarly to the values of F0, Fm and Fv, which reflects the high photosynthetic potential of this genotype. It was accompanied by the relatively high yield of its anthodia after drought. Considering the drop in the yield triggered by drought, it seems to be the only parameter which may be linked with the ploidy level. Although the yield formation of chamomile strains cannot simply be estimated by CF assay, this technique may serve as an additional tool in the selection of plants to drought. The following circumstances should be submitted; namely: measurement at the proper developmental stage of plants, in different water regimes, and an analysis of various CF parameters. The increase in F0 and F0', and the reduction in ETR, Fv'/Fm', ΦPSII and qP values in response to water deficit should be an indicator of the impairment of the photosynthetic apparatus through drought., and R. Bączek-Kwinta ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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