Pancreatic nitric oxide and oxygen free radicals in the early stages of streptozotocin-induced diabetes mellitus in the rat

The objective of the present study was to explore the regulatory mechanisms of free radicals during streptozotocin (STZ)-induced pancreatic damage, which may involve nitric oxide (NO) production as a modulator of cellular oxidative stress. Removal of oxygen species by incubating pancreatic tissues in the presence of polyethylene glycol-conjugated superoxide dismutase (PEG-SOD) (1 U/ml) produced a decrease in nitrite levels (42%) and NO synthase (NOS) activity (50%) in diabetic but not in control samples. When NO production was blocked by N G-monomethyl-L-arginine (L-NMMA) (600 µM), SOD activity increased (15.21 ± 1.23 vs 24.40 ± 2.01 U/mg dry weight). The increase was abolished when the NO donor, spermine nonoate, was added to the incubating medium (13.2 ± 1.32). Lipid peroxidation was lower in diabetic tissues when PEG-SOD was added (0.40 ± 0.02 vs 0.20 ± 0.03 nmol/mg protein), and when L-NMMA blocked NOS activity in the incubating medium (0.28 ± 0.05); spermine nonoate (100 µM) abolished the decrease in lipoperoxide level (0.70 ± 0.02). We conclude that removal of oxygen species produces a decrease in pancreatic NO and NOS levels in STZ-treated rats. Moreover, inhibition of NOS activity produces an increase in SOD activity and a decrease in lipoperoxidation in diabetic pancreatic tissues. Oxidative stress and NO pathway are related and seem to modulate each other in acute STZ-induced diabetic pancreas in the rat.

Sm14 gene expression in different stages of the Schistosoma mansoni life cycle and immunolocalization of the Sm14 protein within the adult worm

Sm14 is a 14-kDa vaccine candidate antigen from Schistosoma mansoni that seems to be involved in cytoplasmic trafficking of fatty acids. Although schistosomes have a high requirement for lipids, they are not able to synthesize fatty acids and sterols de novo. Thus, they must acquire host lipids. In order to determine whether Sm14 is present in different stages of the life cycle of the parasite, we performed RT-PCR. Sm14 mRNA was identified in all stages of the life cycle studied, mainly schistosomulum, adult worm and egg. Additionally, we used a rabbit anti-Sm14 polyclonal antibody in an indirect immunofluorescence assay to localize Sm14 in adult worm sections. The basal lamella of the tegument and the gut epithelium were strongly labeled. These tissues have a high flow of and demand for lipids, a finding that supports the putative role of Sm14 as an intracellular transporter of fatty acids from host cells.

Challenges of user-driven innovations on late stages of innovation process: evidence from ICT companies

The goal of this thesis is to study user-driven innovations and user involvement throughout the innovation process in context of B2B companies. Significant emphasis in the analysis put onto the late stages of innovation process and commercialization of innovations. Thesis includes detailed review of theoretical concepts and underlying frameworks of innovation process, lead users and user-driven innovations. The empirical part of the thesis consist of interviews of the four companies from ICT industry, followed by the comprehensive analysis and comparison of the results. The presented findings indicate common challenges, which ICT companies face, when shifting towards innovation by users paradigm. Linkages and connections among current situation and theoretical frameworks presented in the discussion part of the thesis allow to draw practical managerial implications. The results of the research emphasize valuable insights and challenges of user interactions within innovation process as well as output and participation related benefits for the companies and users. The research points out current state of the user involvement techniques and tools used for user interactions as well as suggests the possibilities for improvement in the future.

Chemical characterization of leaves of organically grown carrot Dacus carota L.) in various stages of development for use as food

In Brazil, street markets and vegetable distributors discard vegetable leaves and stems, including those of carrot (Dacus carota L.). Seeking to reduce the waste of vegetable parts, this study characterized chemically the leaves of organically grown carrot in three stages of development to determine the best time for their removal and consumption as food. The leaves were dehydrated in an oven at 70 °C for 43 hours and analyzed for chemical composition, antioxidant activity, chlorophyll content, fatty acid composition, and also calcium (Ca), sodium (Na), potassium (K), magnesium (Mg), manganese (Mn), iron (Fe), zinc (Zn), and copper (Cu) contents. The analyses indicated 100 days of development as the ideal stage for the removal and consumption of carrot leaves with good antioxidant activity requiring only 63.78 ± 0.5 mg.L-1 methanol leaf extract to inhibit 50% of the concentration of the free radical DPPH (2,2-diphenyl-1picrilidrazil), and total protein and alpha-linolenic acid (18:3 n-3/LNA) contents of 18.23% ± 2.8 and 876.55 ± 20.62 mg.100 g-1 of dry matter, respectively.

Changes in enzymes, phenolic compounds, tannins, and vitamin C in various stages of jambolan (Syzygium cumini Lamark) development

The physiological state of a fruit is closely related to ripening and climatic conditions during the growing period when the fruit undergo changes in color, texture, and flavor. The ripening of the fruit can involve a complex series of biochemical reactions with alteration in enzymes activities, phenols, tannins, and ascorbic acid. The activity of enzymes (carboximethylcellulase, polygalacturonase, and pectinlyase), the total concentration of phenolic compounds, condensed tannins, and vitamin C in five stages of maturation were studied. Significant changes were observed between the maturity stages. The phenolic compounds were higher at green stage (705.01 ± 7.41); tannins were higher at green/purple stage (699.45 ± 0.22). The results showed that the ascorbic acid levels of the pulp varied significantly from 50.81 ± 1.43 to 6.61 ± 1.04 mg.100 g-1 during maturation. The specific activity of pectin lyase was higher at green stage (1531.90 ± 5.83). The specific activity of polygalacturonase was higher at mature stage (1.83 ± 0.0018). The specific activity of carboximetilcelulose was higher at ripe mature stage (4.61 ± 0.0024). The low ascorbic acid content found in jambolan fruit indicates that this fruit is not a rich source of this nutrient; however, other characteristics can make jambolan products fit for human consumption.

Prevalent fatty acids in cashew nuts obtained from conventional and organic cultivation in different stages of processing

Brazil is one of the three largest producers of fruits in the world, and among those fruit trees, the cashew tree stands out due to the high nutritional and commercial value of its products. During its fruit processing, there are losses in some compounds and few studies address this issue. Over the last decade the conventional system of food production has been substituted for the organic cultivation system, which is a promising alternative source of income given the global demand for healthy food. Therefore, this research aimed to characterize and quantify the prevalent fatty acids found in cashew nuts obtained from conventional and organic cultivation during various stages of processing. The prevalent fatty acids found were palmitic, linoleic, oleic, and stearic acid. The average of these fatty acids were 6.93 ± 0.55; 16.99 ± 0.61; 67.62 ± 1.00 and 8.42 ± 0.55 g/100 g, respectively. There was no reduction in the palmitic, oleic and stearic fatty acid contents during processing. Very little difference was observed between the nuts obtained from conventional and organic cultivation, indicating that the method of cultivation used has little or no influence on the content of cashew nut fatty acids.

RR soybean seed quality after application of glyphosate in different stages of crop development

In consequence of several studies and speculations concerning the issue of RR transgenic soybean after the application of glyphosate, additional scientific investigations became necessary to clarify the actual viability of the product use when applied in different developmental stages of the soybean crop. Therefore, this study was aimed to evaluate the physiological quality as well as seed health quality of RR soybean subjected to application of the herbicide glyphosate in different phonological stages of the transgenic soybean, cultivar CD 219RR. For this, an experiment with a complete block experimental design with treatments randomly distributed within the block, with four replications, was carried out. The assessed treatments were foliar sprayings of glyphosate in three increasing dosages [0 (control); 1,440 g ha-1; and 2,880 g ha-1] of acid equivalent, applied in two crop developmental stages: vegetative (V6) and reproductive (R2). The variables assessed were: germination; first count of germination; fresh and dry mass of seedlings, lengths of seedling and root; vigor and viability by the tetrazolium test; and seed health quality. Glyphosate application may adversely affect physiological quality of RR soybean seeds, when applied in dosages varying from 1,440 to 2,880 g acid equivalent per hectare at the stages V6 and R2.

Gendered inequality in academia : exploring women's experiences during the pre-tenure stages of their academic career

This research uses the work of Pierre Bourdieu as a starting point for an examination of women's experiences during the pre-tenure stages of their academic career. This thesis is based on six semi-structured interviews with six tenured academic women in the Faculty of Social Sciences at a medium sized Ontario University. I explore the ranges of experiences that the women report encountering during their pre-tenure years, as well as demonstrate how these experiences are gendered. Through my analysis, I find that women's experiences in academia are shaped by a culture that legitimates their existence in the academic field insofar as they embody the dispositions that reinforce the gendered structure of the academic institution. I argue that being measured according to a prototypical male standard creates difficulties for academic women during their pre-tenure years.

Structural And Surface Morphological Investigation Of Formation Stages Of Highly (002) Oriented Zno Films On Glass Substrates By Spray Pyrolysis Method

ZnO thin films were coated on amorphous glass substrate at various temperatures in the range 160-500 0C by spray pyrolysis method. The as deposited films were characterised by using XRD and SEM. Wurtzite phase of ZnO was formed at a substrate temperature of 400 0C, highly oriented (002) phase was developed with respect to increase of substrate temperature from 450 to 500 0C. Morphological and growth mode of these films were analyzed with respect to structural orientation of films from wurtzite to highly (002) oriented phase. Present study reveals that substrate temperature was one of the important parameters which determine the crystalline quality, population of defects, grain size, orientation and morphology of the films

Experimentation and Stages of Acquisition for Tobacco Consumption in Spanish Adolescents

One area which has been largely neglected when studying the acquisition of addiction to smoking with the transtheoretical model is whether the individual had previously experimented with smoking. The importance of including the experimentation variable was supported by this research

Stages of organizational transformation in transition economies: A dynamic capabilities approach

How do organizations previously dominated by the state develop dynamic capabilities that would support their growth in a competitive market economy? We develop a theoretical framework of organizational transformation that explains the processes by which organizations learn and develop dynamic capabilities in transition economies. Specifically, the framework theorizes about the importance of, and inter-relationships between, leadership, organizational learning, dynamic capabilities, and performance over three stages of transformation. Propositions derived from this framework explain the pre-conditions enabling organizational learning, the linkages between types of learning and functions of dynamic capabilities, and the feedback from dynamic capabilities to organizational learning that allows firms in transition economies to regain their footing and build long-term competitive advantage. We focus on transition contexts, where these processes have been magnified and thus offer new insights into strategizing in radically altered environments.

Glucosinolate-accumulating S-cells in Arabidopsis leaves and flower stalks undergo programmed cell death at early stages of differentiation

Plant secondary metabolites glucosinolates (GSL) have important functions in plant resistance to herbivores and pathogens. We identified all major GSL that are accumulated in S-cells in Arabidopsis by MALDI-TOF MS, and estimated by LC-MS that the total GSL concentration in these cells is above 130 mM. The precise locations of the S-cells outside phloem bundles in rosette and cauline leaves and in flower stalks were visualised using sulphur mapping by cryo-SEM/EDX. S-cells contain up to 40% of total sulphur in flower stalk tissues. S-cells in emerging flower stalks and developing leaf tissues show typical signs of Programmed Cell Death (PCD) or apoptosis, such as chromatin condensation in the nucleus and blebbing of the membranes. TUNEL staining for DNA double strand breaks confirmed PCD in S-cells in postmeristematic tissues in the flower stalk as well as in the leaf. Our results show that S-cells in postmeristematic tissues proceed to an extreme degree of metabolic specialisation besides PCD. Accumulation and maintenance of a high concentration of GSL in these cells are accompanied by degradation of a number of cell organelles. The substantial changes in the cell composition during S-cell differentiation indicate the importance of this particular GSL-based phloem defence system. The specific anatomy of the S-cells and ability to accumulate specialised secondary metabolites is similar to that of the non-articulated laticifer cells in latex plants and thus indicates a common evolutionary origin.

Apparent digestibility and nitrogen utilization of diets based on maize silage harvested at three stages of maturity and fed to steers

Advancing maize crop maturity is associated with changes in ear-to-stover ratio which may have consequences for the digestibility of the ensiled crop. The apparent digestibility and nitrogen retention of three diets (Early, Mid and Late) containing maize silages made from maize of advancing harvest date [dry matter (DM) contents of the maize silages were 273, 314 and 367 g kg(-1) for the silages in the Early, Mid and Late diets respectively], together with a protein supplement offered in sufficient quantities to make the diets isonitrogenous, were measured in six Holstein-Friesian steers in an incomplete Latin square design with four periods. Dry-matter intake of maize silage tended to be least for the Early diet and greatest for the Medium diet (P=0(.)182). Apparent digestibility of DM and organic matter did not differ between diets. Apparent digestibility of energy was lowest in the Late diet (P = 0(.)057) and the metabolizable energy concentrations of the three silages were calculated as 11(.)0, 11(.)1 and 10(.)6 MJ kg(-1) DM for the Early, Medium and Late diets respectively (P = 0(.)068). No differences were detected between diets in starch digestibility but the number of undamaged grains present in the faeces of animals fed the Late diet was significantly higher than with the Early and Mid diets (P = 0(.)006). The apparent digestibility of neutral-detergent fibre of the diets reduced significantly as silage DM content increased (P = 0(.)012) with a similar trend for the apparent digestibility of acid-detergent fibre (P = 0(.)078). Apparent digestibility of nitrogen (N) was similar for the Early and Mid diets, both being greater than the Late diet (P = 0(.)035). Nitrogen retention did not differ between diets. It was concluded that delaying harvest until the DM content is above 300 g kg(-1) can negatively affect the nutritive value of maize silage in the UK.