6 research outputs found
Plant vibration of american pepper cultivars for fruit production in protected environment with and without closed sides
The aim of this research was to evaluate plant vibration for fruit and seed production of american pepper in greenhouse with open and closed sides. The experiment was carried out at Fazenda Experimental da Unesp/FCA located in the municipality of São Manuel-SP. Six treatments were carried out, in a split plot design, two plots with plant vibration or without plant vibration and three subplots with cultivars ('Dirce', 'Dínamo' and 'Doce Comprida'). Plants were vibrated by shaking the wire where the stake was fixed, manually, for about 5 seconds, twice a day. Randomized block design with three replications were used. The same experiment was performed in two environments: with and without closed sides with screen. The traits evaluated were: mass of fruit and total and marketable number of fruits (no visible defects) per plant; percentage of marketable fruit; mass, diameter and length of the fruit; mass and number of seeds per fruit; and plant height. The fruit production was higher in the environment with sides closed, with 24 marketable fruits per plant whereas in the open environment, 7 marketable fruits. American pepper plant vibration did not affect production, length, diameter and average mass of the fruits. Exceptionally for the cultivar 'Doce Comprida', a higher seed production per fruit was obtained in open environment in the absence of plant vibration, in comparison to close environment, with average of 259 and 126 seeds per fruit, respectively. American pepper plant vibration did not affect production, length, diameter and average mass of marketable fruit
Insights into the physiological function of cellular prion protein
Prions have been extensively studied since they represent a new class of infectious agents in which a protein, PrPsc (prion scrapie), appears to be the sole component of the infectious particle. They are responsible for transmissible spongiform encephalopathies, which affect both humans and animals. The mechanism of disease propagation is well understood and involves the interaction of PrPsc with its cellular isoform (PrPc) and subsequently abnormal structural conversion of the latter. PrPc is a glycoprotein anchored on the cell surface by a glycosylphosphatidylinositol moiety and expressed in most cell types but mainly in neurons. Prion diseases have been associated with the accumulation of the abnormally folded protein and its neurotoxic effects; however, it is not known if PrPc loss of function is an important component. New efforts are addressing this question and trying to characterize the physiological function of PrPc. At least four different mouse strains in which the PrP gene was ablated were generated and the results regarding their phenotype are controversial. Localization of PrPc on the cell membrane makes it a potential candidate for a ligand uptake, cell adhesion and recognition molecule or a membrane signaling molecule. Recent data have shown a potential role for PrPc in the metabolism of copper and moreover that this metal stimulates PrPc endocytosis. Our group has recently demonstrated that PrPc is a high affinity laminin ligand and that this interaction mediates neuronal cell adhesion and neurite extension and maintenance. Moreover, PrPc-caveolin-1 dependent coupling seems to trigger the tyrosine kinase Fyn activation. These data provide the first evidence for PrPc involvement in signal transduction
Insights into the physiological function of cellular prion protein
Prions have been extensively studied since they represent a new class of infectious agents in which a protein, PrPsc (prion scrapie), appears to be the sole component of the infectious particle. They are responsible for transmissible spongiform encephalopathies, which affect both humans and animals. The mechanism of disease propagation is well understood and involves the interaction of PrPsc with its cellular isoform (PrPc) and subsequently abnormal structural conversion of the latter. PrPc is a glycoprotein anchored on the cell surface by a glycosylphosphatidylinositol moiety and expressed in most cell types but mainly in neurons. Prion diseases have been associated with the accumulation of the abnormally folded protein and its neurotoxic effects; however, it is not known if PrPc loss of function is an important component. New efforts are addressing this question and trying to characterize the physiological function of PrPc. At least four different mouse strains in which the PrP gene was ablated were generated and the results regarding their phenotype are controversial. Localization of PrPc on the cell membrane makes it a potential candidate for a ligand uptake, cell adhesion and recognition molecule or a membrane signaling molecule. Recent data have shown a potential role for PrPc in the metabolism of copper and moreover that this metal stimulates PrPc endocytosis. Our group has recently demonstrated that PrPc is a high affinity laminin ligand and that this interaction mediates neuronal cell adhesion and neurite extension and maintenance. Moreover, PrPc-caveolin-1 dependent coupling seems to trigger the tyrosine kinase Fyn activation. These data provide the first evidence for PrPc involvement in signal transduction
