The photosynthesis and related plant productivity aspects of plants and cyanobacteria depend upon the functioning of photosystem 2 (PS2), associated with D1 and D2 heterodimer reaction centre core proteins. The D1 protein is encoded by psbA gene, genetically localized on the plastid genome (cpDNA), contains functional cofactors of PS2 in association with D2 protein, and also functions for radiant energy transformation through oxidation of water and reduction of plastoquinone. Surprisingly, D1 protein accounts for even less than 1% of the total thylakoid membrane protein content. In spite of that, its rate of turnover is very much comparable to ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPCO) large subunit, most abundantly present in green tissue. The normal functioning of PS2 possesses damage-repair cycles of D1 protein. Generally, rate of photodamage does not exceed the rate of repair under optimal growth conditions, therefore, no adverse effect on photosynthetic efficiency is manifest. However, under strong irradiance coupled with elevated temperature, level of photodamage exceeds the rate of repair, resulting in photoinhibition, photodegradation of D1 protein, and lowering photosynthetic efficiency linked with plant productivity eventually. The features of D1 turnover process are reviewed, particularly with respect to molecular mechanisms.
Fabrication of plasmonic nanoantennas with resonance frequencies in visible range is often challenging due to the necessity of exposure of nonconductive substrates. This work is focused in comparison of conventional fabrication approach using conductive polymer layers and alternative variable pressure electron beam lithography (VP-EBL) method. We have also studied the stability of VP-EBL process for long exposures. and Výroba plazmonických nanoantén s rezonančními frekvencemi ve viditelné oblasti pomocí elektronové litografie mnohdy přináší nutnost expozice nevodivých substrátů. Tato práce je zaměřena na porovnání výsledků dosažitelných konvenčním přístupem za použití vodivých polymerů a alternativního postupu v podobě litografie za variabilního tlaku (VP-EBL). Dále je testována stabilita VP-EBL procesu pro dlouhodobé expozice.
Photometric light curves of TW Cas do not exhibit any apparent complications. Yet, a careful analysis of the light conditions in the system leads to some contradictory results. A nontraditional explanation is suggested.
Mutant Lurcher mice represent an animal model of naturally
occurring cerebellar degeneration. A gene mutation causes the
demise of all Purkinje cells, as along with certain other types, as
well as the functional elimination of the cerebellar cortex.
Involvement in the research using this model of the C3H strain
began at the Department of Physiology, UCL in 1995/96.
It continued in scientific cooperation with other European
laboratories where we obtained Lurcher mice of the B6CBA
strain. The aim of the effort was first to identify the extent to
which the cerebellum is involved in the higher nervous activity,
i.e. cognitive and other functions. In that research, use was
made of an entire array of methodological procedures to examine
learning, memory, motor functions and emotional behavior.
It was completed with an electrophysiological examination of the
brain and special microscopic procedures. The results
demonstrated that the cerebellum (aside from its traditional
tasks) does in fact play a significant role in cognitive function,
emotions, etc. It was further found that the neurodegenerative
processes also affected the immune and endocrine functions,
confirming the concept of the unity of the psychoneuroendocrine-immune system. Surprisingly, despite their
neurological impairment, the affected animals were able to learn
to some extent and, make progress with physical training,
improving not only their motor skills but also learning and
memory, including deferring of signs of aging. These particular
findings may prove useful for human medicine.
The aim of our study was to evaluate the potential differences in blood pressure (BP) profile in subjects with different forms of primary aldosteronism (PA). Simultaneously, we studied the effects of PA treatment on BP curve. We therefore monitored 24-hour ambulatory blood pressure values in 22 subjects with aldosterone-producing adenoma (APA), 22 subjects with idiopathic hyperaldosteronism (IHA) and 33 subjects with essential hypertension (EH) as controls. We found a significantly attenuated nighttime systolic BP decline in the APA group (P=0.02). Patients with IHA had lower nighttime systolic BP values (P=0.01) and also a diastolic BP decline (P=0.02) during the night in comparison with EH. We did not detect any significant differences in BP profile characteristics between APA and IHA. Specific treatment of primary aldosteronism (adrenalectomy, treatment with spironolactone) led to the normalization of the BP curve with a marked BP decline. Our study thus demonstrates a blunted diurnal BP variability in patients with primary aldosteronism the specific treatment of which normalized previously attenuated nocturnal BP fall., T. Zelinka, J. Widimský., and Obsahuje bibliografii