925 resultados para aggregate volatility


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Slumping of hardsetting seedbeds upon wetting has not been extensively studied despite the likelihood that it determines the physical properties after drying. Slumping results from processes similar to those involved in crusting except that overburden pressure can dominate rather than rainfall kinetic energy. Only a few studies have dealt with the morphological description of slumping. To simulate different climatic and management conditions, repacked seedbeds of a hardsetting sandy-loam soil were subjected to a range of wetting conditions, e.g. capillary rise, immersion, and rainfall simulation. Slumping processes were characterized using qualitative and quantitative micromorphological observations of polished blocks and thin sections from resin-impregnated samples. A morphogenetical framework was proposed to help description of the complex associations of processes which can lead to structural collapse (crusting and slumping) on wetting. Three main stages were considered, i.e. aggregate disruption or abrasion, relocation of the released material, and compaction. In the hardsetting material studied here, structural collapse under slow wetting occurred at the bottom of cores due to aggregate coalescence under overburden pressure. Coalescence required aggregate cohesion being reduced by microcracking; therefore, it differed from the coalescence previously described in unstable silty loam soils where microcracking was not necessary for aggregates to coalesce. Macroporosity decreased most strongly under fast wetting due to physical dispersion and aggregate breakdown. Under simulated rainfall, compaction by raindrops could not be distinguish from aggregate breakdown. The role of overburden pressure and of rainfall kinetic energy remains to be stated; new data are required including measurement of total porosity in the initial, wet, and dry states. (C) 2003 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Overcommitment of development capacity or development resource deficiencies are important problems in new product development (NPD). Existing approaches to development resource planning have largely neglected the issue of resource magnitude required for NPD. This research aims to fill the void by developing a simple higher-level aggregate model based on an intuitive idea: The number of new product families that a firm can effectively undertake is bound by the complexity of its products or systems and the total amount of resources allocated to NPD. This study examines three manufacturing companies to verify the proposed model. The empirical results confirm the study`s initial hypothesis: The more complex the product family, the smaller the number of product families that are launched per unit of revenue. Several suggestions and implications for managing NPD resources are discussed, such as how this study`s model can establish an upper limit for the capacity to develop and launch new product families.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The traditional theory of price index numbers is based on the law of one price. But in the real world, we frequently observe the existence of an equilibrium price dispersion instead of one price of equilibrium. This article discusses the effects of price dispersion on two price indexes: the cost of living index and the consumer price index. With price dispersion and consumer searching for the lowest price, these indexes cannot be interpreted as deterministic indicators, but as stochastic indicators, and they can be biased if price dispersion is not taken into account. A measure for the bias of the consumer price index is proposed and the article ends with an estimation of the bias based on data obtained from the consumer price index calculated for the city of Sao Paulo, Brazil, from January 1988 through December 2004. The period analysed is very interesting, because it exhibits different inflationary environments: high levels and high volatility of the rates of inflation with great price dispersion until July 1994 and low and relatively stable rates of inflation with prices less dispersed after August 1994.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In a recent thought-provoking paper, Ball and Sheridan [Ball, L., Sheridan, N., 2005. Does inflation targeting matter? In: Bernanke, B.S., Woodford, M. (Eds.), The Inflation-Targeting Debate, University of Chicago Press] show that the available evidence for a group of developed economies does not lend credence to the belief that adopting an inflation targeting regime (IT) was instrumental in bringing inflation and inflation volatility down. Here, we extend Ball and Sheridan`s analysis for a subset of 36 emerging market economies and find that, for them, the story is quite different. Compared to non-targeters, developing countries adopting the IT regime not only experienced greater drops in inflation, but also in growth volatility, thus corroborating the view that the regime`s ""constrained flexibility"" to deal with adverse shocks delivered concrete welfare gains. (c) 2006 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The research analyzed critical aspects of the knowledge management process based on the analyses of knowledge, abilities and attitudes required to individual knowledge workers and to organizations responsible for the management process. In the present work a characterization of the knowledge management process was developed and information and knowledge wokers defined. Competence concept was discussed and specialists gave opinions about critical competences to knowledge management process. The opinions were organized and analyzed by the Delphi method. The results aggregate to the management context by discussing an extremely important resource to organizations - knowledge - and because they support its management process. The research identified wide critical aspects that are compatible with current organizational challenges, directing the process management to important themes as: the worker able to create, the organization able to convert individual knowledge into organizational knowledge, knowledge sharing while still tacit, the maximization organizational knowledge use, information and knowledge generation and preservation, among others important topics to be observed by knowledge workers and by administrators responsible for the knowledge management process.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In the current work, we studied the effect of the nonionic detergent dodecyloctaethyleneglycol, C(12)E(8), on the structure and oligomeric form of the Na,K-ATPase membrane enzyme (sodium-potassium pump) in aqueous suspension, by means of small-angle X-ray scattering (SAXS). Samples composed of 2 mg/mL of Na,K-ATPase, extracted from rabbit kidney medulla, in the presence of a small amount of C(12)E(8) (0.005 mg/mL) and in larger concentrations ranging from 2.7 to 27 mg/mL did not present catalytic activity. Under this condition, an oligomerization of the alpha subunits is expected. SAXS data were analyzed by means of a global fitting procedure supposing that the scattering is due to two independent contributions: one coming from the enzyme and the other one from C(12)E(8) micelles. In the small detergent content (0.005 mg/mL), the SAXS results evidenced that Na,K-ATPase is associated into aggregates larger than (alpha beta)(2) form. When 2.7 mg/mL of C(12)E(8) is added, the data analysis revealed the presence of alpha(4) aggregates in the solution and some free micelles. Increasing the detergent amount up to 27 mg/mL does not disturb the alpha(4) aggregate: just more micelles of the same size and shape are proportionally formed in solution. We believe that our results shed light on a better understanding of how nonionic detergents induce subunit dissociation and reassembling to minimize the exposure of hydrophobic residues to the aqueous solvent.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objectives: To evaluate the effect of a radio and newspaper campaign encouraging Italian-speaking women aged 50-69 years to attend a population-based mammography screening program. Methods: A series of radio scripts and newspaper advertisements ran weekly in the Italian-language media over two, four-week periods. Monthly mammography screens were analysed to determine if numbers of Italian-speaking women in the program increased during the two campaign periods, using interrupted time series regression analysis. A survey of Italian-speaking women attending BreastScreen NSW during the campaign period (n=240) investigated whether individuals had heard or seen the advertisements. Results: There was no statistically significant difference in the number of initial or subsequent mammograms in Italian-speaking women between the campaign periods and the period prior to (or after) the campaign. Twenty per cent of respondents cited the Italian media campaign as a prompt to attend. Fifty per cent had heard the radio ad and 30% had seen the newspaper ad encouraging Italian-speaking women to attend BSNSW. The most common prompt to attend was the BSNSW invitation letter, followed by information or recommendation from a GP. Conclusion: Radio and newspaper advertisements developed for the Italian community did not significantly increase attendance to BSNSW. Implications: Measures of program effectiveness based on self-report may not correspond to aggregate screening behaviour. The development of the media campaign in conjunction with the Italian community, and the provision of appropriate levels of resourcing, did not ensure the media campaign's success.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper describes the ways in which older people contribute to their communities and families as informal volunteers. It challenges current ways of thinking that assign an economic value to the productive activities undertaken by older people. Using qualitative data from a study of older people resident in Queensland, Australia, the paper explores the ways that older people contribute to their families and to the community and the outcomes associated with these activities. Two specific themes emerged from the data: first, the ways' in which older people contribute to strong inter-generational relations, and second, how they provide essential mutual support that permits many older people to remain living in the community. These contributions, while often small in themselves, are in aggregate critical both to family functioning and to the maintenance of sustainable and healthy communities. Many are reciprocal interactions that add value to the lives of individuals and offer positive social roles in later life, and they may be particularly important for those from minority cultural backgrounds or at risk of social isolation. The findings suggest that older people are integral to community and civil society and, therefore, that social policy should respond to the ageing of Australia's population and recognise the positive contributions of older people, rather than emphasising the costs of demographic change.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

China's state sector reform process is examined through the key sector of agriculture. A preview of aggregate statistics and broader reform measures indicate the declining role of the state. However, a systematic analysis of administrative, service and enterprise structures reveal the nuances of how the state has retained strong capacity to guide development of the agricultural sector. State and Party policy makers aim not only to support the livelihoods of hundreds of millions of farmers, but also to pursue agricultural modernization in the context of rapid industrialization. These goals are unlikely to be achieved through a wholesale transfer of functions to the private sector, so the state has maintained or developed new mechanisms of influence, particularly in the areas of service provision and enterprise development.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

An aggregate-forming coccus, isolated twice as the predominant microorganism in sputa from a cystic fibrosis patient on consecutive days, was shown to belong to the species Lautropia mirabilis on the bases of similarities of 16S rRNA gene sequences and phenotype. These isolates of L. mirabilis appear to be the first reported from a patient with cystic fibrosis and outside of Denmark.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Context: There is limited information on the prevalence and correlates of bipolar spectrum disorder in international population-based studies using common methods. Objectives: To describe the prevalence, impact, patterns of comorbidity, and patterns of service utilization for bipolar spectrum disorder (BPS) in the World Health Organization World Mental Health Survey Initiative. Design, Setting, and Participants: Crosssectional, face-to-face, household surveys of 61 392 community adults in 11 countries in the Americas, Europe, and Asia assessed with the World Mental Health version of the World Health Organization Composite International Diagnostic Interview, version 3.0, a fully structured, lay-administered psychiatric diagnostic interview. Main Outcome Measures: Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) disorders, severity, and treatment. Results: The aggregate lifetime prevalences were 0.6% for bipolar type I disorder (BP-I), 0.4% for BP-II, 1.4% for subthreshold BP, and 2.4% for BPS. Twelve-month prevalences were 0.4% for BP-I, 0.3% for BP-II, 0.8% for subthreshold BP, and 1.5% for BPS. Severity of both manic and depressive symptoms as well as suicidal behavior increased monotonically from subthreshold BP to BP-I. By contrast, role impairment was similar across BP subtypes. Symptom severity was greater for depressive episodes than manic episodes, with approximately 74.0% of respondents with depression and 50.9% of respondents with mania reporting severe role impairment. Three-quarters of those with BPS met criteria for at least 1 other disorder, with anxiety disorders (particularly panic attacks) being the most common comorbid condition. Less than half of those with lifetime BPS received mental health treatment, particularly in low-income countries, where only 25.2% reported contact with the mental health system. Conclusions: Despite cross-site variation in the prevalence rates of BPS, the severity, impact, and patterns of comorbidity were remarkably similar internationally. The uniform increases in clinical correlates, suicidal behavior, and comorbidity across each diagnostic category provide evidence for the validity of the concept of BPS. Treatment needs for BPS are often unmet, particularly in low-income countries.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this paper we study the possible microscopic origin of heavy-tailed probability density distributions for the price variation of financial instruments. We extend the standard log-normal process to include another random component in the so-called stochastic volatility models. We study these models under an assumption, akin to the Born-Oppenheimer approximation, in which the volatility has already relaxed to its equilibrium distribution and acts as a background to the evolution of the price process. In this approximation, we show that all models of stochastic volatility should exhibit a scaling relation in the time lag of zero-drift modified log-returns. We verify that the Dow-Jones Industrial Average index indeed follows this scaling. We then focus on two popular stochastic volatility models, the Heston and Hull-White models. In particular, we show that in the Hull-White model the resulting probability distribution of log-returns in this approximation corresponds to the Tsallis (t-Student) distribution. The Tsallis parameters are given in terms of the microscopic stochastic volatility model. Finally, we show that the log-returns for 30 years Dow Jones index data is well fitted by a Tsallis distribution, obtaining the relevant parameters. (c) 2007 Elsevier B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The NO donor trans-[Ru(NO)(NH(3))(4)(py)](BF(4))(3).H(2)O (py = pyridine) was loaded into poly-lactic-co-glycolic acid (PLGA) microparticles using the double emulsification technique. Scanning electron microscopy (SEM) and dynamic light scattering revealed that the particles are spherical in shape, have a diameter of 1600 nm, and have low tendency to aggregate. The entrapment efficiency was 25%. SEM analysis of the melanoma cell B16-F10 in the presence of the microparticles containing the complex trans-[Ru(NO)(NH(3))(4)(py)](BF(4))(3).H(2)O (pyMP) showed that the microparticles were adhered to the cell surface after 2 h of incubation. The complex with concentrations lower than 1 x 10(-4) M did not show toxicity in B16-F 10 murine cells. The complex in solution is toxic at higher concentrations (> 1 x 10(-3) M), with cell death attributed to NO release following the reduction of the complex. pyMP is not cytotoxic due to the lower bioavailability and availability of the entrapped complex to the medium and its reducing agents. However, pyMP is phototoxic upon light irradiation. The phototoxicity strongly suggests that cell death is due to NO release from trans-[Ru(NO)(NH(3))(4)(py)](3+). This work shows that pyMP can serve as a model for a drug delivery system carrying the NO donor trans-[Ru(NO)(NH(3))(4)(py)](BF(4))(3).H(2)O, which can release NO locally at the tumor cell by radiation with light only. (c) 2007 Elsevier Inc. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This chapter is a detailed analysis of the most recent state election and places it in the context of the preceding (2001) election. The state is divided into regions for analytic reasons with each being dissected to demonstrate that, in a decentralised state such as Queensland, the aggregate result conceals certain key variations as among the state's identifiable regional components.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective. The objective of this study was to investigate the mediators and the resident peritoneal cells involved in the neutrophil migration (NM) induced by mineral trioxide aggregate (MTA) in mice. Study design. MTA (25 mg/cavity) was injected into normal and pretreated peritoneal cavities (PC) with indomethacin (IND), dexamethasone (DEX), BWA4C, U75302, antimacrophage inflammatory protein-2 (MIP-2), and anti-interleukin-1 beta (IL-1 beta) antibodies and the NM was determined. The role of macrophage (MO) and mast cells (MAST) was determined by administration of thioglycollate 3% or 48/80 compound, respectively. The concentration of IL-1 beta and MIP-2 exudates was measured by ELISA. Results. MTA induced dose-and time-dependent NM into mice PC, with the participation of MO and MAST. NM was inhibited by DEX, BWA4C, and U75302, as well as anti-MIP-2 and anti-IL-1 beta antibodies. In the exudates, IL-1 beta and MIP-2 were detected. Conclusions. This study suggests that MTA induces NM via a mechanism dependent on MAST and MO mediated by IL-1 beta, MIP-2, and LTB(4).