921 resultados para maturation stage


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In Brazil, although the coffee plantations are predominantly grown under full sunlight, the use of agroforestry systems can lead to socioeconomic advantages, thus providing a favorable environment to the crop by promoting its sustainability as well as environmental preservation. However, there is a lack of information on physiological quality of the coffee seeds produced under different levels of solar radiation. Within this context, the objective of this study was to evaluate the influence of different levels of solar radiation and maturation stages on the physiological quality of coffee (Coffea arabica L.) seeds, cv. Acaiá Cerrado MG-1474. Three levels of solar radiation (plants grown under full sunlight; under plastic screens of 35% shading; and under plastic screens of 50% shading) and three maturation stages (cherry, greenish-yellow and green) were assessed. Physiological quality of seeds was assessed by using germination test, first count of germination, abnormal seedlings, dead seeds, and seedlings with open cotyledonary leaves. Electrophoretic analysis of isoenzymes catalase, esterase, superoxide dismutase and peroxidase was also performed. With the evolution of development the coffee seeds presents increases on physiological quality, and at its beginning the seeds show improvements on quality with the reduction of solar radiation.

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During the expansion of steam in turbine, the steam crosses the saturation line and hence subsequent turbine stages run under wet condition. The stages under wet condition run with low efficiency as compared to stages running with supersaturated steam and the life of the last stage cascade is reduced due to erosion. After the steam crosses the saturation line it does not condense immediately but instead it becomes supersaturated which is a meta-stable state and reversion of equilibrium results in the formation of large number of small droplets in the range of 0.05 - 1 μm. Although these droplets are small enough to follow the stream lines of vapor however some of the fog droplets are deposited on the blade surface. After deposition they coagulate into films and rivulets which are then drawn towards the trailing edge of the blade due to viscous drag of the steam. These large droplets in the range of radius 100 μm are accelerated by steam until they impact on the next blade row causing erosion. The two phenomenon responsible for deposition are inertial impaction and turbulent-diffusion. This work shall discuss the deposition mechanism in steam turbine in detail and numerically model and validate with practical data.

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Attracting outside capital is a common problem for start-up companies. Capital markets define the funding options for companies and firms which suffer the most from these capital market imperfections are small start-up companies. Therefore it is important to study any new funding model which can offer a new solution to this inefficiency of capital markets. This study explains the traditional funding models for start-ups such as founders, friends & family, banks, business angels and venture capitalist. After giving background to traditional start-up funding this study delves into crowfunding (CF) and introduces it as a new funding method. The objective of the thesis is to answer one broad research question: Why and how should start-up companies use CF as an alternative funding method? To properly delve into this, this question has the following sub-questions: What kind of funding alternatives do start-up companies have? What are the pros and cons of CF compared to other funding options? How can start-ups benefit from CF? This study gives background on the rise of CF and the reasons why this new model is needed. Author will explain the different components of CF such as platforms, crowdfunders and projects. Also benefits and challenges of the crowdfunding model are investigated. As a new funding model CF has had to clear out many obstacles from its way. These are, for example, legal and regulatory issues as well education of crowd investors to understand this new investment option. . Start-up entrepreneurs can gain valuable insight from this study. The author has attempted to form best practices and guidelines of how to operate in the CF environment. This study was conducted by performing expert interviews, collecting data from previous studies and performing a content analysis of successful crowdfunding cases. Main findings from the study were that CF has huge potential in funding entrepreneurial projects. It is still a niche way for funding but growing rapidly. CF is earning its place among traditional funding options and has potential to fund projects which otherwise would struggle to find funding. With CF entrepreneur can tap into geographically diverse audience. It is a powerful validation tool for products and ideas and has the power to bring democratic elements to entrepreneurial funding.

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View of the Convocation Stage during the May 26, 1970 ceremonies.

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reports, the players did not show an anticipatory rise in either Cortisol or testosterone prior to competition. In addition to the effects of status outcome on hormonal levels, it was also found that these hormonal responses were specific to competition. The athletes in the current study did not demonstrate any hormonal responses to the practice sessions. Last, there were significant differences in pre-game testosterone as well as in selfconfidence, cognitive, and somatic anxiety levels depending on the location at which the status contest took place. Pre-game testosterone and self-confidence levels were significantly higher prior to games played in the home venue. In contrast, pre-game somatic and cognitive anxiety levels were significantly higher prior to games played in the away venue. The current findings add to the developing literature on the relationship between hormones and competition. This was the first study to detect a moderating effect of status outcome on testosterone responses in a team sport. Furthermore, this was also the first study in humans to demonstrate that post-contest Cortisol levels were significantly higher after a loss of status. Last, the current study also adds to the sport psychology literature by demonstrating that pre-game psychological variables differ depending on where the status contest is being held: higher self-confidence at home and higher somatic and cognitive anxiety away. Taken together, the results from the current thesis may have important practical relevance to coaches, trainers and sport psychologists who are always trying to find ways to maximize performance. the cycle. The sex-specific age differences in locomotor responses to amphetamine are not due to gonadal immaturity, as females are cycling at this stage of adolescence. However, age differences may reflect the ongoing maturation of the neural substrates that that are involved in locomotor sensitizing, but not rewarding effects of amphetamine.

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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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The objective of this study was to examine the association between body composition and arterial stiffuess in peri-pubescent boys and girls. Differences in arterial distensibility were measured in 68 children (45 normal weight, 12 overweight, and 11 obese) between the ages of9 to 12 years. Weight classification was based on age and gender-specific body mass index cut-offs, while pubertal maturation was self-reported using Tanner staging. Distensibility was determined using two-dimensional, B-Mode echo Doppler ultrasound to measure changes at the right common carotid artery (CCA) diameter changes, while carotid pulse pressure (cPP) was measured at the left CCA by applanation tonometry. One-way ANOV A analysis revealed significant differences (p<0.001) in all anthropometric measures between the normal weight and overweight children, as well as the normal weight and obese children. Body stature was only higher in obese children compared to normal weight children (p<0.01). No significant differences were found between groups regarding age or Tanner stage. Common carotid artery distensibility showed a significant difference (p<0.01) between normal weight children (0.008 ± 0.002 mmHg-1 ) compared to obese children (0.005 ± 0.002 mmHg-1 ), with a borderline significant difference between the normal and overweight subjects (p=0.06). There was no significant effect for gender between males and females across all independent variables. The strongest determinants of distensibility in children were cPP (r= -0.52, p

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The relationship between the child's cogni tive development and neurological maturation has been of theoretical interest for many year s. Due to diff iculties such as the lack of sophisticated techniques for measur ing neurolog ical changes and a paucity of normative data, few studies exist that have attempted to correlate the two factors. Recent theory on intellectual development has proposed that neurological maturation may be a factor in the increase of short-term memory storage space. Improved technology has allowed reliable recordings of neurolog ical maturation.. In an attempt to correlate cogni tive development and neurological maturation, this study tested 3-and II-year old children. Fine motor and gross motor short-term memory tests were used to index cogni tive development. Somatosensory evoked potentials elici ted by median nerve stimulation were used to measure the time required for the sensation to pass along the nerve to specific points on the somatosensory pathway. Times were recorded for N14, N20, and P22 interpeak latencies. Maturation of the central nervous system (brain and spinal cord) and the peripheral nervous system (outside the brain and spinal cord) was indi~ated by the recorded times. Signif icant developmental di fferences occurred between 3-and ll-year-olds in memory levels, per ipheral conduction velocity and central conduction times. Linear regression analyses showed that as age increased, memory levels increased and central conduction times decreased. Between the ll-year-old groups, there were no significant differences in central or peripheral nervous system maturation between subjects who achieved a 12 plus score on the digit span test of the WISC-R and those who scored 7 or lower on the same test. Levels achieved on the experimental gross and fine motor short-term memory tests differed significantly within the ll-year-old group.

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The purpose of this cross-sectional exploratory study was to examine the relationships among self-efficacy, stage of change, and exercise behaviour in a sample of younger (Grade 9) and older (Grade 12) adolescents. A secondary objective of this study was to apply the transtheoretical model of Stage of Change, as a measure of intention to change, in order to discover the applicability of the model to an adolescent cohort in relation to exercise behaviour. This five-stage model is a self-report measure of an individual's readiness to adopt a new behaviour (e.g., regular exercise). The transtheoretical model incorporates Bandura's self-efficacy factor, which is purported to be a predictive measure of exercise behaviour and a covariant of stage. Exercise behaviour was measured with the Physical Activity Scale, and the University of Rhode Island Change Assessment Scale (URleA) was used to measure the stage of change and self-efficacy variables. The results of this study indicated significant differences between younger and older adolescents, and between males and females in their exercise behaviour. No significant differences were found for grade and gender on stage of change as measured by either a single-item question or a continuous measure of stage. Although grade and gender subgroups were not significantly different in their self-efficacy, significant interaction was found in the grade*gender variable.

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Fourteen nursing s tudents enrolled in a community coll ege were chosen by purposeful se lection to be i nterviewed in a qualitative survey. A proposed mode l of Learner Motivation Development was examined . The mode l describes four stages of motivati on development progression across the lifespan: I Survival (infancy to childhood), I I Expl oration (childhood to adolescence), III Identification (pre- adulthood), and IV Reflection ( adulthood ). This r esearch examined the last two stages. The criteria used to categorize the students within the fr amework were bas ed on human development theories as described by Maslow (1954) and Erikson (1950). The concept of critica l thinking proposed by Brookfield (1987) and the ideas of transformative learning expressed by Mezirow (1991) were also incorporated. The researcher' s criteria , antici pated behaviours and characteri stics, were used to ana lyze the students' responses to open-ended questions. The central theme of the research was based on the assumption that motivation to learn is intrinsic and inherent in pre-adult and adult learners. Six pre-adults and two adults met the descriptors set for stage III Identification. Five adults and one pre-adult met the criteria for stage IV Reflection. The impact of life e xperiences and maturation were clearly demonstrated.

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In 2003, prostate cancer (PCa) is estimated to be the most commonly diagnosed cancer and third leading cause of cancer death in Canada. During PCa population screening, approximately 25% of patients with a normal digital rectal examination (DRE) and intermediate serum prostate specific antigen (PSA) level have PCa. Since all patients typically undergo biopsy, it is expected that approximately 75% of these procedures are unnecessary. The purpose of this study was to compare the degree of efficacy of clinical tests and algorithms in stage II screening for PCa while preventing unnecessary biopsies from occurring. The sample consisted of 201 consecutive men who were suspected of PCa based on the results of a DRE and serum PSA. These men were referred for venipuncture and transrectal ultrasound (TRUS). Clinical tests included TRUS, agespecific reference range PSA (Age-PSA), prostate specific antigen density (PSAD), and free-to-total prostate specific antigen ratio (%fPSA). Clinical results were evaluated individually and within algorithms. Cutoffs of 0.12 and 0.15 ng/ml/cc were employed for PSAD. Cutoffs that would provide a minimum sensitivity of 0.90 and 0.95, respectively were utilized for %fPSA. Statistical analysis included ROC curve analysis, calculated sensitivity (Sens), specificity (Spec), and positive likelihood ratio (LR), with corresponding confidence intervals (Cl). The %fPSA, at a 23% cutoff ({ Sens=0.92; CI, 0.06}, {Spec=0.4l; CI, 0.09}, {LR=1.56; CI, O.ll}), proved to be the most efficacious independent clinical test. The combination of PSAD (cutoff 0.15 ng/ml/cc) and %fPSA (cutoff 23%) ({Sens=0.93; CI, 0.06}, {Spec=0.38; CI, 0.08}, {LR=1.50; CI, 0.10}) was the most efficacious clinical algorithm. This study advocates the use of %fPSA at a cutoff of 23% when screening patients with an intermediate serum PSA and benign DRE.

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One of the fundamental problems with image processing of petrographic thin sections is that the appearance (colour I intensity) of a mineral grain will vary with the orientation of the crystal lattice to the preferred direction of the polarizing filters on a petrographic microscope. This makes it very difficult to determine grain boundaries, grain orientation and mineral species from a single captured image. To overcome this problem, the Rotating Polarizer Stage was used to replace the fixed polarizer and analyzer on a standard petrographic microscope. The Rotating Polarizer Stage rotates the polarizers while the thin section remains stationary, allowing for better data gathering possibilities. Instead of capturing a single image of a thin section, six composite data sets are created by rotating the polarizers through 900 (or 1800 if quartz c-axes measurements need to be taken) in both plane and cross polarized light. The composite data sets can be viewed as separate images and consist of the average intensity image, the maximum intensity image, the minimum intensity image, the maximum position image, the minimum position image and the gradient image. The overall strategy used by the image processing system is to gather the composite data sets, determine the grain boundaries using the gradient image, classify the different mineral species present using the minimum and maximum intensity images and then perform measurements of grain shape and, where possible, partial crystallographic orientation using the maximum intensity and maximum position images.

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Geochemical examination of the rock matrix and cements from core material extracted from four oil wells within southwestern Ontario suggest various stages of diagenetic alteration and preservation of the Trenton Group carbonates. The geochemical compositions of Middle Ordovician (LMC) brachiopods reflect the physicochemical water conditions of the ambient depositional environment. The sediments appear to have been altered in the presence of mixed waters during burial in a relatively open diagenetic microenvironment. Conodont CAl determination suggests that the maturation levels of the Trenton Group carbonates are low and proceeded at temperatures of about 30 - 50°C within the shallow burial environment. The Trenton Group carbonates are characterized by two distinct stages of dolomitization which proceeded at elevated temperatures. Preexisting fracture patterns, and block faulting controlled the initial dolomitization of the precursor carbonate matrix. Dolomitization progressed In the presence of warm fluids (60 75°C) with physicochemical conditions characteristic of a progressively depleted basinal water. The matrix is mostly Idiotopic-S and Idiotopic-E dolomite, with Xenotopic-A dolomite dominating the matrix where fractures occur. The second stage of dolomitization involved hydrothermal basinal fluid(s) with temperatures of about 60 - 70°C. These are the postulated source for the saddle dolomite and blocky calcite cements occurring in pore space and fractures. Rock porosity was partly occluded by Idiotopic-E type dolomite. Late stage saddle dolomite, calcite, anhydrite, pyrite, marcasite and minor sphalerite and celestite cements effectively fill any remaining porosity within specific horizons. Based on cathode luminescence, precipitation of the different diagenetic phases probably proceeded in open diagenetic systems from chemically homogeneous fluids. Ultraviolet fluorescence of 11 the matrix and cements demonstrated that hydrocarbons were present during the earliest formation of saddle dolomite. Oxygen isotope values of -7.6 to -8.5 %0 (PDB), and carbon isotope values of - 0.5 and -3.0 %0 (PDB) from the latest stage dog-tooth calcite cement suggest that meteoric water was introduced into the system during their formation. This is estimated to have occurred at temperatures of about 25 - 40°C. Specific facies associations within the Trenton Group carbonates exhibit good hydrocarbon generating potential based on organic carbon preservation (1-3.5%). Thermal maturation and Lopatin burial-history evaluations suggest that hydrocarbons were generated within the Trenton Group carbonates some time after 300 Ma . Progressively depleted vanadium trends measured from hydrocarbon samples within southwestern Ontario suggests its potential use as a hydrocarbon migration indicator on local (within an oilfield) and on regional scales.