Animals use neutral lipids, particularly triacylglycerols (TAGs), to store energy. TAGs are universally organized into dynamic cytoplasmic structures called lipid droplets (LDs). In mammals TAG breakdown is catalysed by lipases, such as hormonesensitive lipase (HSL). LD membrane-resident proteins called perilipins (PLINs) regulate some of these lipases. The model organism Caenorhabditis elegans has a single known PLIN homologue and orthologues of most lipases including HSL. HOSL-1 (the HSL orthologue in C. elegans) is responsible for production of cryoprotective glycerol in cold conditions, in addition to its role in fasting-induced lipolysis. We employed this model of cold exposure to study the role of PLIN-1 in the regulation of HOSL-1. Our results suggest that both HOSL-1 and PLIN-1 are required for cold tolerance and for lipid breakdown in cold. However, the loss of PLIN-1 partially rescued the phenotype of hosl-1 null mutants exposed to cold, suggesting the presence of an alternative pathway generating glycerol via lipolysis. In early embryos, PLIN-1 knock-out results in accumulation of lipids and formation of cytoplasmic clusters of autophagic marker LGG-1, supporting the role of autophagy as an alternative lipolytic pathway in C. elegans, as is the case in mammals.
Tomato (Lycopersicon esculentum Mill. cv. Pearson) plants were grown in growth chambers for 25 days with cadmium (Cd) and then exposed briefly to ozone (O3). Gas exchange, chlorophyll a fluorescence, and pigment composition were analysed in leaves at the end of the treatment to assess the effects of a single pollutant and their combination on photosynthesis. The CO2 assimilation rate was dramatically reduced in plants subjected to the combined treatment, while the single effect of Cd appeared less severe than that of O3. The decline of CO2 photoassimilation found in all
O3-exposed plants was attributed to both stomatal and nonstomatal limitations. Tomato plants seemed to detoxify Cd to a great extent, but this resulted in growth suppression. In response to O3 exposure, the plants protected their photosystems by heat dissipation of excess energy via the xanthophyll cycle. Cd combined with O3 affected adversely this cycle resulting in an increase in photosynthetic performance under the same experimental light conditions., E. Degl’Innocenti, A. Castagna, A. Ranieri, L. Guidi., and Obsahuje bibliografii
The study considers the pertinence of Searle’s speech act theory to literary studies, more specifically to the definition of fictional and factual autobiography. Searle’s conception of fictional discourse as a pretended assertion influenced Gérard Genette in his definition of the necessary condition of factual autobiography, which he sees in the identity of the author with the narrator, meaning that in autobiography, the author bears full responsibility for what he or she asserts. According to Genette, if the narrator and the author are not identical, the autobiography is fictional. These theoretical arguments are then applied to the interpretation of Bohumil Hrabal’s trilogy In-House Weddings, Vita Nuova and Gaps and the fictional autobiography Boyhood, Youth and Summertime by John Maxwell Coetzee., Studie zvažuje vhodnost Searleovy teorie řeči k literárním studiím, více specificky k definici smyšlené a faktické autobiografie. Searleovo pojetí fiktivního diskurzu jako předstíraného tvrzení ovlivnilo Gérard Genette v jeho definici nezbytné podmínky faktické autobiografie, kterou vidí v identitě autora s vypravěčem, což znamená, že v autobiografii nese plnou odpovědnost za to, co on nebo on tvrdí. Podle Genette, jestliže vypravěč a autor nejsou identičtí, autobiografie je smyšlená. Tyto teoretické argumenty jsou pak aplikovány na výklad trilogie Bohumila Hrabala In-House Weddings , Vita Nuova a Gaps a fiktivní autobiografieBoyhood, mládí a léto John Maxwell Coetzee., and Jan Tlustý
Tobacco (Nicotiana tabacum L.) has been transformed to accumulate different compatible solutes (proline, fructans, or glycine betaine) in order to improve its tolerance to abiotic stress. Photosynthetic activity of wild Type (wt) and transformed tobacco plants before and after freezing stress was studied by measuring chlorophyll (Chl) fluorescence. The JIP test of Chl fluorescence induction was used to analyze in details the functional activity of photosystem 2. No significant differences were found among wild Type and transgenic plants after 12 h of freezing. Both plant Types maintained the same values of the measured parameters [FV/FM, PI(CSM), ABS/RC, TR0/RC, ET/RC] after recovery of stress. The studied Chl fluorescence parameters decreased only for the wild Type plants, stressed for 24 h at -2 °C. The strong inhibition of photosynthetic reactions in the wt plant after 24 h of freezing could not be restored. The evaluated parameters of transgenic plants did not change significantly after 24 h at -2 °C and successfully survived freezing stress. and D. Parvanova ... [et al.].
In this paper the concept of a fuzzy contraction∗ mapping on a fuzzy metric space is introduced and it is proved that every fuzzy contraction∗ mapping on a complete fuzzy metric space has a unique fixed point.