919 resultados para nitrification breakdown
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The effects of sucrose and water contents on cassava flour processed by extrusion at varied concentrations of sucrose (0-20% w/w) and water (28-42% w/w) were studied by applying response surface methodology. The extrusion of the mixtures was performed in a twin screw extruder fitted to a torque rheometer. The specific mechanical energy (SME) dissipated inside a conical twin-screw extruder was measured. Water absorption index (WAI), water solubility index (WSI) and paste viscosity readings (cold viscosity (CV), peak viscosity (PV), breakdown (BD) and set back (SB)) during a gelatinization-retrogradation cycle measured in a Rapid Visco Analyzer were determined on non-directly extruded products. The results indicated that SME and WSI decreased as a function of water and sucrose contents. WAI and pasting properties were influenced by water content. A non antiplasticizing effect of the sucrose content was observed on pasting properties, suggesting that sucrose did not reduce the availability of water available for gelatinizing cassava flour during the extrusion process. The nature of the optimum point was characterized as a saddle point for WAI, WSI, PV and BD, whereas SME showed a maximum and CV and SB a minimum. The results indicated to be valuable for the production of non-expanded cassava flour extrudates with desirable functional properties for specific end users.
Resumo:
Existing data about the aroma of fresh-cut watermelon and the metabolic changes that occur with minimal processing are scarce. Given the close relationship that exists between aroma, texture, and quality characteristics, it is necessary to investigate the changes in the volatile profile and texture of watermelon, a fruit extensively sold in supermarket chains throughout Brazil. The objective of this work was to analyze the volatile profile using solid phase microextraction (SPME) as well as texture changes in fresh-cut watermelon stored at 5 °C for ten days. Chromatography associated with sensory analysis (sniffing) led us to conclude that 9-carbon (C9) alcohols and aldehydes are the major responsible for the flavor and aroma of minimally processed watermelon stored at 5 ± 1 °C/90 ± 5% RH for ten days, and also that the aroma diminishes in intensity with storage, but it does not affect the final quality of the product. It was noted that the amount of drained liquid, soluble pectin, and weight loss increased during storage concurrently with a reduction in firmness and a structural breakdown of the cells. Pectin methyl esterase activity remained constant and polygalacturonase activity was not detected.
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This thesis explores how the project charter development, project scope management, and project time management are executed in a Finnish movie production. The deviations and analogies between a case movie production and best practices suggested in PMBOK are presented. Empirical material from the case is gathered with two semi-structured interviews with a producer and a line producer. The interview data is categorized according to PMBOK knowledge areas. The analysis is complemented with movie industry specific norms found in popular movie production guides. The described and observed methods are linked together and the relationship between them is discussed. The project charter development, which is referred as a green light process in the movie industry, is mostly analogous between all areas. The deviations are in the level of formality. The green lighting in the case movie was accomplished without bureaucratic reports described in movie production guides. The empirical material shows that project management conventions and movie industry employ similar methods especially in scope management. Project management practices introduce a work breakdown structure (WBS) method, and movie production accomplishes the same task by developing a shooting script. Time management of the case movie deviates on most parts from the methods suggested in PMBOK. The major deviation is resource management. PMBOK suggests creating a resource breakdown structure. The case movie production accomplished this through budgeting process. Furthermore the popular movie production guides also disregard resource management as sovereign process. However the activity listing is quite analogous between the case movie and PMBOK. The final key observation is that although there is a broad set of effective and detailed movie industry specific methods, a comprehensive methodology that would cover the whole production process, such as Prince2 or Scrum, seems to be missing from the movie industry.
Characterization and nutritional value of precooked products of kiwicha grains (Amaranthus caudatus)
Resumo:
AbstractKiwicha has significant nutritional characteristics. It is commonly used as a puffed product, but there is little research on the lamination process. In this paper, the physical, functional properties, chemical composition and acceptability of the precooked kiwicha grains were studied. Puffed (PK) and laminated kiwicha (LK) were made. Puffed amaranth (CPA) was used as a commercial reference standard. The raw grain (RG) showed a higher bulk density (0.85 g/ml) than in PK (0.18 g/ml) and LK (0.38 g/ml). Both products had a good expansion. The yellow index decreased in PK (50.92) and LK (45.87) respect to RG (65.64). The largest was CPA (58.54). In all the products, the precooking increased the index of absorption, solubility and swelling power. Also, they showed major pasting temperature, low peak viscosity and breakdown viscosity. In both formulated products, the content of total, soluble and insoluble dietary fibre decreased during the precooking process. The content of protein was optimal (between 14.57-14.59 g/100g). PK had high acceptability (5.84), preference (84.48%), purchase (38.79%) and consumption (43.96%) intention. The lowest was CPA. This work demonstrates that it’s feasible to make precooked products with good quality characteristics, chemical composition and acceptability for the development of new products.
Resumo:
This thesis explores how the project charter development, project scope management, and project time management are executed in a Finnish movie production. The deviations and analogies between a case movie production and best practices suggested in PMBOK are presented. Empirical material from the case is gathered with two semi-structured interviews with a producer and a line producer. The interview data is categorized according to PMBOK knowledge areas. The analysis is complemented with movie industry specific norms found in popular movie production guides. The described and observed methods are linked together and the relationship between them is discussed. The project charter development, which is referred as a green light process in the movie industry, is mostly analogous between all areas. The deviations are in the level of formality. The green lighting in the case movie was accomplished without bureaucratic reports described in movie production guides. The empirical material shows that project management conventions and movie industry employ similar methods especially in scope management. Project management practices introduce a work breakdown structure (WBS) method, and movie production accomplishes the same task by developing a shooting script. Time management of the case movie deviates on most parts from the methods suggested in PMBOK. The major deviation is resource management. PMBOK suggests creating a resource breakdown structure. The case movie production accomplished this through budgeting process. Furthermore the popular movie production guides also disregard resource management as sovereign process. However the activity listing is quite analogous between the case movie and PMBOK. The final key observation is that although there is a broad set of effective and detailed movie industry specific methods, a comprehensive methodology that would cover the whole production process, such as Prince2 or Scrum, seems to be missing from the movie industry.
Resumo:
Tämän työn tavoitteena on vastata hypoteesiin jonka mukaan kosteus aiheuttaisi IGBT:n estojännitteen aleneman ja siitä seuraavan taajuusmuuttajan vikaantumisen. Työssä tarkastellaan erään ABB Drivesin käyttämän IGBT-moduulin estojännitteen käyttäytymistä kosteudelle altistamisen jälkeen. Työn teoriaosuudessa kerrotaan taajuusmuuttajasta sekä IGBT:n rakenteesta ja käyttäytymisestä erilaisissa tilanteissa. Estojännitettä tutkitaan käyräseuraajan avulla, kun IGBT on altistettu kosteudelle. Tutkimuksessa toteutettiin yhteensä kolme erilaista olosuhdesimulaatiota. Tutkittavissa IGBT-moduuleissa havaittiin vähäistä estojännitteen alenemaa sekä vuotovirran kasvua. Estojännitteen aleneman todetti-in olevan riittämätön vikaannuttaakseen taajuusmuuttajan. Estojännite säilyi korkeampana kuin valmistajan datalehdessä ilmoittama maksimiarvo. Tutkimuksen johtopäätöksenä on ettei kosteus ole aiheuttanut taajuusmuuttajan vikaantumista. Työn lopussa esitellään tapoja joilla taajuusmuuttajan kokemia olosuhteita voitaisiin seurata jatkossa tarkemmin.
Resumo:
Työn päätavoite on selvittää kohdeyrityksen projektien tehtävien jakoon ja työn jäsentämiseen käytettävän työn osituksen rakenteen ongelmat projektikustannusten kirjaamisessa. Tämän lisäksi tavoitellaan kustannusläpi-näkyvyyden kasvua, mittaamisen helpottumista ja kustannusarvioinnin tarkentumista antamalla kehitys-ehdotuksia rakenteen tarkentamiseksi ja yksinkertaistamiseksi. Työ on laadullista ja toiminnallista tapaus-tutkimusta. Teoriaosuuden aineistona on tieteellisiä artikkeleita, kirjoja, lehtiä ja muita aiheeseen liittyviä julkaisuja. Empiirinen osa koostuu yrityksen sisäisistä haastatteluista sekä esikuva-analyysihaastatteluista. Kehitysehdotusten analysointiin ja valintaan käytetään GAP–analyysiä ja toteutettavuustarkastelua. Työn keskeisimpänä tuloksena on neljä kehitysehdotusta, jotka pohjautuvat teorioiden suosituksiin työn osituksen rakenteen sisällöstä. Tällä työllä pyritään myös tuomaan esille kehitystarvetta yrityksessä ja antamaan suunta sekä alkusysäys kehitysprosessille kohti toimivampaa projektien kustannusseurantaa.
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Lipid movement in cells occurs by a variety of methods. Lipids diffuse freely along the lateral plane of a membrane and can translocate between the lipid leaflets, either spontaneously or with the help of enzymes. Lipid translocation between the different cellular compartments predominantly takes place through vesicular transport. Specialized lipid transport proteins (LTPs) have also emerged as important players in lipid movement, as well as other cellular processes. In this thesis we have studied the glycolipid transport protein (GLTP), a protein that transports glycosphingolipids (GSLs). While the in vitro properties of GLTP have been well characterized, its cell biological role remains elusive. By altering GSL and GLTP levels in cells, we have extracted clues towards the protein's function. Based on the results presented in this thesis and in previous works, we hypothesize that GLTP is involved in the GSL homeostasis in cells. GLTP most likely functions as a transporter or sensor of newly synthesized glucosylceramide (GlcCer), at or near the site of GlcCer synthesis. GLTP also seems to be involved in the synthesis of globotriacylceramide, perhaps in a manner that is similar to that of the fourphosphate adaptor protein 2, another GlcCer-transporting LTP. Additionally, we have developed and studied a novel method of introducing ceramides to cells, using a solvent-free approach. Ceramides are important lipids that are implicated in several cellular functions. Their role as proapoptotic molecules is particularly evident. Ceramides form stable bilayer structures when complexed with cholesterol phosphocholine (CholPC), a large-headgroup sterol. By adding ceramide/CholPC complexes to the growth medium, various chain length ceramides were successfully delivered to cells in culture. The uptake rate was dependent on the chain length of the ceramide, where shorter lipids were internalized more quickly. The rate of uptake also determined how the cells metabolised the ceramides. Faster uptake favored conversion of ceramide to GlcCer, whereas slower delivery resulted mainly in breakdown of the lipid.
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This study explores the tension that has emerged around the rise of home schooling in a faith-community strongly committed to establishing and maintaining day schools in the tradition of John Calvin. It aims to identify and understand factors that contributed to this tension and to find ways to bridge, diffuse, reduce, or eliminate it. In line with Calvin, personal convictions, and the nature of the community, the study takes a Christian epistemological and axiological stance. Its premise is that the integrity of the commvmity is more important than the manner in which its children are taught. The study reviews relevant literature and several interviews. It considers both secular and Christian literature to understand communities, community breakdown, and community restoration. It also examines literature about the significance of home, school, and community relationships; the attraction of Reformed day schools; and the appeal of home schooling. Interviews were conducted with 4 home schooling couples and 2 focus groups. One focus group included local school representatives, and the other home schoolers and school representatives from an area with reputedly less tension on the issue. Interviews were designed for participants to give their perspectives on reasons for home schooling, the existing tension, and ways to resolve the issues. The study identifies the rise of home schooling in this particular context as the initial issue and the community's deficiency to properly deal with it as the chief cause for the rising tensions. However, I argue that, within the norms the community firmly believes in, home schooling need not jeopardize its integrity. I call for personal, social, and spiritual renewal to restore the covenant community in gratitude to God.
The role of cyclic nucleotides in modulation of crayfish neuromuscular junctions by a neuropeptide /
Resumo:
DF2, a heptapeptide, is a member of the family of FMRFamide-like peptides and has been shown to increase the amount of transmitter released at neuromuscular junctions of the crayfish, Procambarus clarkit Recent evidence has shown that protein kinase C (PKC), calcium/calmodulin-dependent protein kinase II (CaMKII) and the cAMPdependent protein kinase (PKA) play a role in the neuromodulatory pathway of DF2. The involvement of these kinases led to the prediction that a G-protein-coupled receptor (GPCR) is activated by DF2 due to the role that each kinase plays in traditional GPCR pathways seen in other organisms and in other cells. G-proteins can also act on an enzyme that generates cyclic guanosine monophosphate (cGMP) which mediates its effects through a cGMP-dependent protein kinase (PKG). This thesis addresses the question of whether or not DF2's effects on synaptic transmission in crayfish are mediated by the cyclic nucleotides cAMP and cGMP. The effects of DF2 on synaptic transmission were examined using deep abdominal extensor muscles of the crayfish Procambarus clarkii. An identified motor neuron was stimulated, and excitatory post-synaptic potentials (EPSPs) were recorded in abdominal extensor muscle LI . A number of activators and inhibitors were used to determine whether or not cAMP, PKA, cGMP and PKG mediate the effect of this peptide. Chemicals that are known to activate PKA (Sp-cAMPS) and/or PKG (8-pCPTcGMP) mimic and potentiate DF2's effect by increasing EPSP amplitude. Inhibitors of either PKA (Rp-cAMPS) or PKG (Rp-8-pCPT-cGMPS) block a portion of the increase in EPSP amplitude induced by the peptide. When both kinase inhibitors are applied simultaneously, the entire effect of DF2 on EPSPs is blocked. The PKG inhibitor blocks the effects of a PKG activator but does not alter the effect of a PKA activator on EPSP amplitude. Thus, the PKG inhibitor appears to be relatively specific for PKG. A trend in the data suggests that the PKA inhibitor blocks a portion of the response elicited by the PKG activator. Thus, the PKA inhibitor may be less specific for PKA. Phosphodiesterase inhibitors, which are known to inhibit the breakdown of cAMP (IBMX) and/or cGMP (mdBAMQ), potentiate the effect of the peptide. These results support the hypothesis that cAMP and cGMP, acting through their respective protein kinase enzymes, mediate the ability of DFi to increase transmitter output.
Resumo:
Presently non-commercial occurrences of Mississippi Valley-type ore assemblages in the Middle Silurian strata of the Niagara Peninsula have been studied. Based on this detailed study, a new poly-stage genetic model is proposed which relates ore mineralization in carbonate environments to the evolution of the sedimentary basin. Sulphide ore mineralization occurred during two episodes: 1. During the late diagenesis stage, which is characterized by compaction-maturation of the sediments, the initial mineralization took place by upward and outward movement of connate waters. Metals were probably supplied from all the sediments regardless of their specific lithologies. However, clay minerals were possibly the main contributors. The possible source of sulphur was from petroleum-type hydrocarbons presently mixed with the sediments at the site of ore deposition. Evidence for this is the fact that the greatest abundance of ore minerals is in petroliferous carbonates. The hydrocarbons probably represent liquids remaining after upward migration to the overlying Guelph-Salina reservoirs. The majority of sphalerite and galena formed during this period, as well as accessory pyrite, marcasite, chalcopyrite, chalcocite, arsenopyrite, and pyrrhotite; and secondary dolomite, calcite, celestite, and gypsum. 2. During the presently ongoing surface erosion and weathering phase, which is marked by the downward movement of groundwater, preexisting sulphides were probably remobilized, and trace amounts of lead and zinc were leached from the host material, by groundwaters. Metal sulphides precipitated at, or below, the water table, or where atmospheric oxygen could raise the Eh of groundwaters to the point where soluble metal complexes are unstable and native sulphur co-precipitates with sphalerite and galena. This process, which can be observed today, also results in the transport and deposition of the host rock material. Breakdown of pre-existing sulphide and sulphate, as well as hydrocarbon present in the host rock, provided sulphur necessary for sulphide precipitation. The galena and sphalerite are accompanied by dolomite, calcite, gypsum, anglesite, native sulphur and possibly zincite.
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This study evaluated a preschool parent enrichment programme to assess if child and parent involvement in the programme facilitated the children's subsequent school adjustment. Also examined were the programme's effects on parent-child relationships. Participants were 56 Junior-Senior Kindergarten and Grade One students from one elementary school. Parent participants were 12 parents from the preschool parent enrichment programme, 6 parents whose children had attended other preschool programmes, and 6 parents whose children had remained at home prior to school. Five elementary teachers and both nursery school teachers from the parent enrichment programme also participated. Measures used included the Florida Key to assess children's inferred self-concept as learner and four subscales (relating, asserting, coping and investing), and interviews to assess parent and teacher perceptions. Findings indicated that there was little difference between parent and teacher perceptions about children who had attended a preschool programme. Both groups showed improved social, emotional, and behavioural skill development, together with increased self-esteem, and the ability to cope with separation from their parents. This enabled children to make the transition from preschool to primary school more successful. Children from the parent enrichment programme were not readily identifiable in terms of the profile promulgated for disadvantaged children. The Florida Key showed a main effect for the coping subscale, indicating that children from the parent enrichment programme may show more confidence in their abilities, and seek assistance from teachers than children who had no preschool experience. The parent enrichment programme appeared to have the biggest impact on the parents. Parents reported improved relationships with their children, increased confidence and self-esteem, as well as improved parenting and general life skills. The implications for short-term gains for children from this type of programme are better readiness for school, more positive self-esteem, improved social behaviour, and a higher achievement motivation. The long-term gains for children are predicted to be fewer special education placements, less grade retention, and a lower dropout rate from school. The short-term gains for parents are better social support networks," greater self-confidence, better interactions with children, and improved parenting skills. The long-term benefits may be an increased motivation to continue education, gain employment, and less family breakdown and abuse.
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A. strain of Drosophila melanog-aster deficient in null amylase activity (Amylase ) was isolated from a wild null population of flies. The survivorship of Amylase homozygous flies is very low when the principal dietary carbohydrate source is starch. However, the survivorship of the null Amylase genotype is comparable to the wild type when the dietary starch is replaced by glucose. In addition, the null viability of the amylase-producing and Amylase strains is comparable v and very lm<] f on a medium with no carbohydrates . Furthermore, amylase-producing genotypes were shovm to excrete enzymatically active amylase protein into the food medium. The excreted amylase causes the external breakdown of dietary starch to sugar. These results led to the following null prediction: the viability of the A.mvlase genotype (fed on a starch rich diet) might increase in the presence of individuals which were amylase-producing. It was shown experimentally that such an increase in viability did in fact occur and that this increase v\Tas proportional to the number of mnylase..::producing fli.es present. These results provide a unique example of a non-"competi ti ve inter-genotype interaction, and one where the underlying physio~ logical and biochemical mechanism has been fully understood.
Resumo:
Individuals who have sustained a traumatic brain injury (TBI) often complain of t roubl e sleeping and daytime fatigue but little is known about the neurophysiological underpinnings of the s e sleep difficulties. The fragile sleep of thos e with a TBI was predicted to be characterized by impairments in gating, hyperarousal and a breakdown in sleep homeostatic mechanisms. To test these hypotheses, 20 individuals with a TBI (18- 64 years old, 10 men) and 20 age-matched controls (18-61 years old, 9 men) took part in a comprehensive investigation of their sleep. While TBI participants were not recruited based on sleep complaint, the fmal sample was comprised of individuals with a variety of sleep complaints, across a range of injury severities. Rigorous screening procedures were used to reduce potential confounds (e.g., medication). Sleep and waking data were recorded with a 20-channel montage on three consecutive nights. Results showed dysregulation in sleep/wake mechanisms. The sleep of individuals with a TBI was less efficient than that of controls, as measured by sleep architecture variables. There was a clear breakdown in both spontaneous and evoked K-complexes in those with a TBI. Greater injury severities were associated with reductions in spindle density, though sleep spindles in slow wave sleep were longer for individuals with TBI than controls. Quantitative EEG revealed an impairment in sleep homeostatic mechanisms during sleep in the TBI group. As well, results showed the presence of hyper arousal based on quantitative EEG during sleep. In wakefulness, quantitative EEG showed a clear dissociation in arousal level between TBls with complaints of insomnia and TBls with daytime fatigue. In addition, ERPs indicated that the experience of hyper arousal in persons with a TBI was supported by neural evidence, particularly in wakefulness and Stage 2 sleep, and especially for those with insomnia symptoms. ERPs during sleep suggested that individuals with a TBI experienced impairments in information processing and sensory gating. Whereas neuropsychological testing and subjective data confirmed predicted deficits in the waking function of those with a TBI, particularly for those with more severe injuries, there were few group differences on laboratory computer-based tasks. Finally, the use of correlation analyses confirmed distinct sleep-wake relationships for each group. In sum, the mechanisms contributing to sleep disruption in TBI are particular to this condition, and unique neurobiological mechanisms predict the experience of insomnia versus daytime fatigue following a TBI. An understanding of how sleep becomes disrupted after a TBI is important to directing future research and neurorehabilitation.
Resumo:
Affiliation: Département de Médecine, Faculté de médecine, Université de Montréal & Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CHUM), Hôpital Notre-Dame du CHUM