222 resultados para surrogate end points


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The reliability of micro inverters is an important factor as it would be necessary to reduce cost and maintenance of the small and medium scale distributed PV power conversion systems. Electrolytic capacitors and active power decouple circuits can be avoided in micro inverters with the use of medium voltage DC-link. Such a DC-link based micro inverter is proposed with a front-end dual inductor current-fed push-pull converter. The primary side power switches of the front-end converter have reduced switching losses due to multi-resonant operation. In addition, the voltage and current stresses on the diodes of the secondary diode voltage doubler rectifier are reduced due to the presence of a series resonant circuit in the front-end converter. The operation of the proposed micro inverter is explained using an in-depth analysis of the switching characteristics of the power semiconductor devices. The theoretical analysis of the proposed micro inverter is validated using simulation result.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

It is well known that different arguments appeal to different people. We all process information in ways that are adapted to be consistent with our underlying ideologies. These ideologies can sometimes be framed in terms of particular axes or dimensions, which makes it possible to represent some aspects of an ideology as a region in the kind of vector space that is typical of many generalised quantum models. Such models can then be used to explain and predict, in broad strokes, whether a particular argument or proposal is likely to appeal to an individual with a particular ideology. The choice of suitable arguments to bring about desired actions is traditionally part of the art or science of rhetoric, and today's highly polarised society means that this skill is becoming more important than ever. This paper presents a basic model for understanding how different goals will appeal to people with different ideologies, and thus how different rhetorical positions can be adopted to promote the same desired outcome. As an example, we consider different narratives and hence actions with respect to the environment and climate change, an important but currently highly controversial topic.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: Better understanding of body composition and energy metabolism in pediatric liver disease may provide a scientific basis for improved medical therapy aimed at achieving optimal nutrition, slowing progression to end-stage liver disease (ESLD), and improving the outcome of liver transplantation. Methods: Twenty-one children less than 2 years of age with ESLD awaiting liver transplantation and 15 healthy, aged-matched controls had body compartment analysis using a four compartment model (body cell mass, fat mass, extracellular water, and extracellular solids). Subjects also had measurements of resting energy expenditure (REE) and respiratory quotient (RQ) by indirect calorimetry. Nine patients and 15 control subjects also had measurements of total energy expenditure (TEE) using doubly labelled water. Results: Mean weights and heights were similar in the two groups. Compared with control subjects, children with ESLD had higher relative mean body cell mass (33 ± 2% vs 29 ± 1% of body weight, P < 0.05), but had similar fat mass, extracellular water, and extracellular solid compartments (18% vs 20%, 41% vs 38%, and 7% vs 13% of body weight respectively). Compared with control subjects, children with ESLD had 27% higher mean REE/body weight (0.285 ± 0.013 vs 0.218. ± 0.013 mJ/kg/24h, P < 0.001), 16% higher REE/unit cell mass (P < 0.05); and lower mean RQ (P < 0.05). Mean TEE of patients was 4.70 ± 0.49 mJ/24h vs 3.19 ± 0.76 in controls, (P < 0.01). Conclusions: In children, ESLD is a hypermetabolic state adversely affecting the relationship between metabolic and non-metabolic body compartments. There is increased metabolic activity within the body cell mass with excess lipid oxidation during fasting and at rest. These findings have implications for the design of appropriate nutritional therapy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Malnutrition is a common problem in children with end-stage liver disease (ESLD), and accurate assessment of nutritional status is essential in managing these children. In a retrospective study, we compared nutritional assessment by anthropometry with that by body composition. We analyzed all consecutive measurements of total body potassium (TBK, n = 186) of children less than 3 years old with ESLD awaiting transplantation found in our database. The TBK values obtained by whole body counting of 40K were compared with reference TRK values of healthy children. The prevalence of malnutrition, as assessed by weight (weight Z score < -2) was 28%, which was significantly lower (chi-square test, p < 0.0001) than the prevalence of malnutrition (76%) assessed by TBK (< 90% of expected TRK for age). These results demonstrated that body weight underestimated the nutritional deficit and stressed the importance of measuring body composition as part of assessing nutritional status of children with ESLD.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Background: The success of orthotopic liver transplantation as treatment for end-stage liver disease has prompted investigation of strategies to maintain or improve nutrition and growth in children awaiting transplantation, because malnutrition is an adverse prognostic factor. The purpose of this study was to evaluate the effect of recombinant human growth hormone therapy on body composition and indices of liver function in patients awaiting transplant. Methods: The study was designed as a placebo- controlled, double-blind, crossover trial. Patients received 0.2 U/kg growth hormone, subcutaneously, or placebo daily for 28 days during two treatment periods, separated by a 2-week washout period. Ten patients (mean age, 3.06 ± 1.15 years; range, 0.51-11.65 years, five men), with extrahepatic biliary atresia (n = 8) or two with Alagille's syndrome (n = 2), with end-stage liver disease, completed the trial while awaiting orthotopic liver transplantation. Height, weight, total body potassium, total body fat, resting energy expenditure, respiratory quotient, hematologic and multiple biochemical profile, number of albumin infusions, insulin-like growth factor-1 and 1, growth hormone binding protein (GHBP), and insulin-like growth factor binding protein-1 (IGFBP-1) and insulin-like growth factor binding protein (IGFBP-3) were measured at the beginning and end of each treatment period. Results: Growth hormone treatment was associated with a significant decline in serum bilirubin (-34.6 ± 16.5 μmol/l vs. 18.2 ± 11.59 μmol/l; p < 0.02) but there was no significant effect on any anthropometric or body composition measurements, or on any biochemical or hematologic parameters. Conclusions: These children with end-stage liver disease displayed growth hormone resistance, particularly in relation to the somatomedin axis. Exogenous growth hormone administration may be of limited value in these patients

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Japan is in the midst of massive law reform. Mired in ongoing recession since the early 1990s, Japan has been implementing a new regulatory blueprint to kickstart a sluggish economy through structural change. A key element to this reform process is a rethink of corporate governance and its stakeholder relations. With a patchwork of legislative initiatives in areas as diverse as corporate law, finance, labour relations, consumer protection, public administration and civil justice, this new model is beginning to take shape. But to what extent does this model represent a break from the past? Some commentators are breathlessly predicting the "Americanisation" of Japanese law. They see the triumph of Western-style capitalism - the "End of History", to borrow the words of Francis Fukuyama - with its emphasis on market-based, arms-length transactions. Others are more cautious, advancing the view that there new reforms are merely "creative twists" on what is a uniquely (although slowly evolving) strand of Japanese capitalism. This paper takes issue with both interpretations. It argues that the new reforms merely follow Japan's long tradition of 'adopting and adapting' foreign models to suit domestic purposes. They are neither the wholesale importation of "Anglo-Saxon" regulatory principles nor a thin veneer over a 'uniquely unique' form of Confucian cultural capitalism. Rather, they represent a specific and largely political solution (conservative reformism) to a current economic problem (recession). The larger themes of this paper are 'change' and 'continuity'. 'Change' suggests evolution to something identifiable; 'continuity' suggests adhering to an existing state of affairs. Although notionally opposites, 'change' and 'continuity' have something in common - they both suggest some form of predictability and coherence in regulatory reform. Our paper, by contrast, submits that Japanese corporate governance reform or, indeed, law reform more generally in Japan, is context-specific, multi-layered (with different dimensions not necessarily pulling all in the same direction for example, in relations with key outside suppliers), and therefore more random or 'chaotic'.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Malnutrition is common in children with end-stage liver disease (ESLD) awaiting orthotopic liver transplantation (OLT), and nutritional support is assuming an important role in preoperative management. To evaluate preoperative nutritional therapy, 19 children (median age 1.25 y) with ESLD awaiting OLT were prospectively studied. Two high-energy, isoenergetic and isonitrogenous nutritional formulations delivered nasogastrically were compared: a branched-chain amino acid (BCAA)-enriched semielemental formulation and a matched standard semielemental formulation. Twelve of 19 patients completed a randomized controlled study before OLT and 10 of 19 completed a full crossover study. Improvements in weight and height occurred during the BCAA supplements, with no statistical change on the standard formulation. Significant increases in total body potassium, midupper arm circumference, and subscapular skinfold thickness occurred during the BCAA supplements, whereas no significant changes occurred during the standard formulation period. Significantly fewer albumin infusions were required during the BCAA supplement. These findings suggest that BCAA-enriched formulas have advantages over standard semielemental formulas in improving nutritional status in children with ESLD. and are deserving of wider application and study.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

To evaluate malnutrition in chronic liver disease, and its relationship to nutrient deficiencies and hepatic dysfunction. 27 children with end-stage liver disease were studied. Mean protein-energy intakes were 70% of recommended daily intakes. The patients were underweight and stunted with reduced mean triceps and subscapular skinfold thicknesses and midupper arm circumference. Mean total body potassium was only 63 ± 18% of that expected for age and sex. Deficiency of essential fatty acids (32%), and low concentrations of fat-soluble vitamins (A, 92%; E, 32%), iron (32%), zinc (42%), and selenium (13%) were common. Serum ammonia concentrations were raised in all patients, and increased methionine, tyrosine, and glutamic acid, and reduced glutamine concentrations were noted. There was no correlation between the degree of malnutrition and the degree of liver synthetic function, the degree of cholestasis, or the degree of liver injury. We suggest that potentially correctable factors in addition to liver failure (eg, inadequate absorbed intake) were important determinants of malnutrition in these patients.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Objectives: The aim of this study was to evaluate the effects of low-dose (10 mg) and high-dose (80 mg) atorvastatin on carotid plaque inflammation as determined by ultrasmall superparamagnetic iron oxide (USPIO)-enhanced carotid magnetic resonance imaging (MRI). The hypothesis was that treatment with 80 mg atorvastatin would demonstrate quantifiable changes in USPIO-enhanced MRI-defined inflammation within the first 3 months of therapy. Background: Preliminary studies indicate that USPIO-enhanced MRI can identify macrophage infiltration in human carotid atheroma in vivo and hence may be a surrogate marker of plaque inflammation. Methods: Forty-seven patients with carotid stenosis >40% on duplex ultrasonography and who demonstrated intraplaque accumulation of USPIO on MRI at baseline were randomly assigned in a balanced, double-blind manner to either 10 or 80 mg atorvastatin daily for 12 weeks. Baseline statin therapy was equivalent to 10 mg of atorvastatin or less. The primary end point was change from baseline in signal intensity (ΔSI) on USPIO-enhanced MRI in carotid plaque at 6 and 12 weeks. Results: Twenty patients completed 12 weeks of treatment in each group. A significant reduction from baseline in USPIO-defined inflammation was observed in the 80-mg group at both 6 weeks (ΔSI 0.13; p = 0.0003) and at 12 weeks (ΔSI 0.20; p < 0.0001). No difference was observed with the low-dose regimen. The 80-mg atorvastatin dose significantly reduced total cholesterol by 15% (p = 0.0003) and low-density lipoprotein cholesterol by 29% (p = 0.0001) at 12 weeks. Conclusions: Aggressive lipid-lowering therapy over a 3-month period is associated with significant reduction in USPIO-defined inflammation. USPIO-enhanced MRI methodology may be a useful imaging biomarker for the screening and assessment of therapeutic response to "anti-inflammatory" interventions in patients with atherosclerotic lesions. (Effects of Atorvastatin on Macrophage Activity and Plaque Inflammation Using Magnetic Resonance Imaging [ATHEROMA]; NCT00368589).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Pre-operative nutritional support was studied in 28 children with end-stage liver disease awaiting orthotopic liver transplantation. Nasogastric supplemental administration of a standard semi-elemental enteral nutritional formula was compared with a similar formula enriched with branched chain amino acids, and with a group receiving oral nutrition only. The duration of treatment in all groups was similar (mean 90 days). Energy intakes in the supplemented groups were 120-150% of recommended daily intakes (RDI), whereas ad libitum intakes in the oral group ranged 58-100% RDI. A significant improvement in mean Z-score for body weight (denoting catch-up) was noted only in those children who received nasogastric supplements enriched with branched-chain amino acids. The standard enterally-fed group maintained their body weight and Z-scores did not change significantly. In contrast, body weight Z-scores in those fed orally declined significantly. Nutritional supportive therapy of malnourished children with end-stage liver disease can minimize or improve nutritional status in children awaiting liver transplantation. The use of nutritional formulae rich in branche-chain amino acids may have nutritional advantages in children with chronic liver disease which require further study and evaluation.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The current study explored the reasons that primary school teachers reported were tipping points for them in deciding whether or not and when to refer a child to the school student support team for excessive anxiety. Twenty teachers in two Queensland primary schools were interviewed. Content analysis of interview transcripts revealed six themes reflecting teachers' perceived reasons for deciding to refer anxious children: 1)impact on learning; 2)atypical child behavior; 3)repeated difficulties that do not improve over time; 4)poor response to strategies; 5)teachers' need for support; and 6)information from parents/carers. Teachers considered different combinations of reasons, and had many different tipping points for making a referral. Both teacher-and system-level influences impacted referral decisions. Implications and future research are discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Three major changes in drink driving enforcement have occurred in South Australia since 1981. The effect of these changes on a number of surrogate measures of alcohol involvement in accidents were investigated. The surrogates included alcohol involvement of driver fatalities, and combinations of casualty, serious casualty, single vehicle and nighttime accidents. Data from previous studies were also cited. It was found that relationships between surrogate measures were inconsistent, and incompatible with assumptions about drink driving levels and related accidents. It was concluded that until these effects are understood the use of surrogate measures should be treated with caution.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An important decision brand managers have to make when positioning their products in a retail setting is to whether price new line extensions at parity or let products vary in the price/quality spectrum. Despite the growing interest in vertical line extension issues, there has been little research investigating how product-line length affects extension favorability. Therefore, this paper investigates the framing effect that a product line price structure has on consumer judgments of vertical extensions and, in particular, of upscale extensions. A basic proposition of this research is that the parent brand price range affects the perceived or psychological distance between extension and parent brand, influencing extension favorability ratings. In two experiments, it is shown that positioning an upscale extension in the context of a wide product-line will lead to higher consistency perceptions between the parent brand and a new upscale extension than an equivalent upscale extension positioned in the context of a narrow parent brand product-line.