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Factors determining the diurnal dynamics of blooming of chosen plant species

100%
Denisow B.
Acta Agrobotanica
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2009
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tom 62
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nr 1
The paper attempts to synthesize the determinants which may influence the diurnal rhythm of blooming. Additionally, I tried to explore and bring together topics that concern blooming and have always been considered separately because of their origin in different disciplines. The following species were included: Hydrangea arborescens L subsp. discolor (Raf.), H. paniculata Sieb., Viburnum opulus L, Chaenomeles japonica Lindl., Knautia arvensis L., Adonis vernalis L., Aster saggitifolius Willd., Taraxacum officinale L. Chelidonium majus L. The taxons were observed in Lublin (51 08’ – 51 18’ N and 21 27’ – 21 41’ E) in the years 2001-2007. The blooming of species was determined at least for two vegetation seasons. During observations all flowers developed in one-hour intervals were counted. The diurnal dynamics of blooming differs among species and is modified by different endogenous and exogenous factors. The endogenous determinants of diurnal dynamics of blooming are morphological diversity of flowers (fertility or sterility) within species or heterostyly. The different pattern of blooming succour different mechanisms which prevent self-pollination (Chaenomeles japonica Lindl., Knautia arvensis L.). The abiotic factors, such as day length and temperature during the vegetation season, influence the change in the process of diurnal dynamics of blooming (e. g. Taraxacum officinale, Chelidonium majus)
2

Intracerebral transplantation of human umbilical cord blood-derived neural stem cells (HUCB-NSC) in rats after focal brain ischemia ameliorates tissue expression of endogenous and exogenous neurotrophic factors

67%
Jablonska A., Drela K., Wojcik-Stanaszek L., Wanacka E., Zalewska T., Lukomska B.
Acta Neurobiologiae Experimentalis
|
2013
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tom 73
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nr 1
There is a great interest in the possibility of repairing the nervous system by transplantation new cells that can replace those lost through damage in neurological disorders. Key functions such as the replacement of neural cells have been recently challenged by intrinsic bystander capacities of undifferentiated donor cells to restore these cells. A comprehensive knowledge how transplanted stem cells exert their therapeutic achievements is still lacking. Here we investigated the effects of HUCB-NSC infused into the damaged rat brain at 72 h post ischemia on endogenous neurogenesis. The goal of our studies was to examine the proliferation and migration of host progenitor cells, analyze the substantial matrix remodeling of tissue and the presence of neurotrophic factors in rat brain after focal ischemia followed by HUCB-NSC transplantation. Methods: 2×104 HUCB-NSC were transplanted into corpus callosum of naive or focally injured rat brain 3 days after ischemic insult. At 1, 3, 7 and 14 days rat brains were removed. Endogenous cell proliferation was determined by BrdU incorporation. Then immunocytochemical analysis of doublecortin (DCX) and PSA-NCAM (markers expressed by immature migratory neuroblasts), and in situ zymography of MMPs activity was performed. Additionally, total RNA was isolated from rat brain tissue and RTPCR was performed using sets of primers of each of human and rat neurotrophic factor genes. Results: OUA-induced brain lesion resulted in increase of proliferating (BrdU+) and migrating (DCX+ and PSA-NCAM+) cells in subventricular zone (SVZ) and subgranular zone (SGZ) regions in comparison to intact rats. This response has been potentiated by HUCB-NSC transplantation. At 7th day after HUCB-NSC infusion the intense migration of DCX+cells from SVZ towards ischemic boundary regions of the striatum was observed. Moreover, the activation of MMPs in cells was visible in SVZ. Double-labeling showed co-localization of DCX marker with MMPs activity. The presence of MMPs appeared to be associated with cell nuclei and cytoplasm but interestingly it was also seen outside the cell bodies and in the neuronal protrusions. In OUAinduced lesion rat brain tissue, the expression pattern of rat-origin neurotrophic factors mRNA was higher than in intact rats. HUCBNSC transplantation into focal brain ischemic tissue significantly increased mRNA expression of several rat-origin growth factors, such as GDNF, CNTF responsible for regulation of proliferation and maturation of stem cells as well as IGF-1, HGF and presaposin functioning as anti-apoptotic mediators. The significant increment was observed 7 days after HUCB-NSC infusion. Using Real Time PCR method we were able to detect the presence of mRNA of BDNF, GDNF, NT3, IGF-1, HGF, semaphorin and presaposin of human-origin factors in the rat brain recipients of HUCB-NSC grafts. Conclusions: Transplantation of HUCB-NSC triggers early expansion of endogenous progenitor pool increasing fraction of proliferating cells in SVZ and SGZ of brain ischemic rats. Proteolytic activity of MMPs in extracellular compartment suggests its ability to remodel extracellular matrix and facilitate migration of neuroblasts to the damaged brain areas. The mechanism promoting recovery from ischemic injury remains to be clarified, although it is likely that it might be due to HUCB-NSC graft-induced release of neurotrophic factors by the host cells as well as the presence of human neural stem cells derived factors. Supported by MMRC statutory fund.
3

Population dynamics of the bank vole in the Eastern part of its distribution range

67%
Ivanter E. V., Osipova O. V.
Polish Journal of Ecology
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2000
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tom 48
|
nr Suppl.
4

The effect of some exogenous factors on the formation of intranuclear membranaceus inclusions in the nerve cells

67%
Dambska M., Maslinska D., Pluta R.
Acta Neurobiologiae Experimentalis
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1992
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tom 52
|
nr 1
5

Analysis of aquaporin gene expression in Pharbitis nil during the photoperiodic flower induction

67%
Glowacka K., Dabrowska G., Ligman S. B., Gorecki R. J., Tretyn A.
Biological Letters
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2005
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tom 42
|
nr 2 Spec.Vol.
6

Stezenie aldehydu dimalonowego [MDA] w surowicy krwi pracownikow wytwarzajacych stopy zelazomanganu

59%
Misiewicz A., Radwan K., Dziewit T., Sierantowicz-Zdaniewicz U.
Bromatologia i Chemia Toksykologiczna
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1998
|
tom 31
|
nr 1
9-12
W surowicy krwi osób wytwarzających stopy żelazomanganu stwierdzono znamienny wzrost stężenia aldehydu w porównaniu z grupą kontrolną.
7

Effects of light and temperature on the emergence of Haplorchis pumilio cercariae from the snail host, Thiara tuberculata

59%
Umadevi K., Madhavi R.
Acta Parasitologica
|
1997
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tom 42
|
nr 1
The cercaria of Haplorchis pumilio exhibited diurnal pattern in the emergence from the snail host, with peak between 10 am and 12 noon and limited emergence during night. Continuous light permitted emergence to continue rhythmically while continuous dark has suppressed the emergence. Inversion of photoperiod has resulted in immediate reversal of the emergence pattern. Variation is found in the numbers of cercariae released by different individuals of snails and by the single snail on different days, but consistency is maintained in the emergence pattern. Temperature of 30-35°C is found to be favourable for the cercarial emergence. The results of the study demonstrate that emergence pattern is influenced by both exogenous and endogenous factors.
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