971 resultados para Conceptual design
Resumo:
In epidemiologic studies, measurement error in dietary variables often attenuates association between dietary intake and disease occurrence. To adjust for the attenuation caused by error in dietary intake, regression calibration is commonly used. To apply regression calibration, unbiased reference measurements are required. Short-term reference measurements for foods that are not consumed daily contain excess zeroes that pose challenges in the calibration model. We adapted two-part regression calibration model, initially developed for multiple replicates of reference measurements per individual to a single-replicate setting. We showed how to handle excess zero reference measurements by two-step modeling approach, how to explore heteroscedasticity in the consumed amount with variance-mean graph, how to explore nonlinearity with the generalized additive modeling (GAM) and the empirical logit approaches, and how to select covariates in the calibration model. The performance of two-part calibration model was compared with the one-part counterpart. We used vegetable intake and mortality data from European Prospective Investigation on Cancer and Nutrition (EPIC) study. In the EPIC, reference measurements were taken with 24-hour recalls. For each of the three vegetable subgroups assessed separately, correcting for error with an appropriately specified two-part calibration model resulted in about three fold increase in the strength of association with all-cause mortality, as measured by the log hazard ratio. Further found is that the standard way of including covariates in the calibration model can lead to over fitting the two-part calibration model. Moreover, the extent of adjusting for error is influenced by the number and forms of covariates in the calibration model. For episodically consumed foods, we advise researchers to pay special attention to response distribution, nonlinearity, and covariate inclusion in specifying the calibration model.
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Objective: To identify the underlying interests of the Living Will Declaration (LWD) process and to determine the consensus, using a questionnaire, of the knowledge and attitudes of health professionals. Design: A study was performed in two phases using a Delphi technique with a Rand method. 1. Dimensions proposed: generation of ideas and their subsequent prioritizing; 2. Proposal andprioritizing of items grouped into blocks of Knowledge and Attitudes, developed between August 2012 and January 2013.Setting: The work was carried out by initial telephone contact with panellists, and then later by the panellists belonged to the Andalusia Public Health System.Participants: The criteria for selecting the eight components of the panel were knowledge andexperience in the field of the freedom of the patient in Andalusia. Results: The Knowledge identified included: 1 A) Legal and general aspects; 2 A) A conceptual definition; 3 A) Standardised LWD documents: 4 A) Practical experience; 5 A) Procedure and registering of the LWDs. The second block included Attitudes: 1 B) Attitudes of the professional in the application of LWDs in clinical practice, and 2 B) Attitudes of the professional in «complex» ethical scenarios The 7 panellists who finally took part proposed 165 items. After applying the prioritizing criteria, scores, and scenario selection, 58 (35.2%) items were identified as suitable scenarios. Conclusions: The proposed questionnaire included wide parcels of concepts and contents that, once validated, will help to measure the training interventions carried out on health professionals in order to improve knowledge and attitudes on the subject of LWDs.
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Reverse transcriptase (RT) is a multifunctional enzyme in the human immunodeficiency virus (HIV)-1 life cycle and represents a primary target for drug discovery efforts against HIV-1 infection. Two classes of RT inhibitors, the nucleoside RT inhibitors (NRTIs) and the nonnucleoside transcriptase inhibitors are prominently used in the highly active antiretroviral therapy in combination with other anti-HIV drugs. However, the rapid emergence of drug-resistant viral strains has limited the successful rate of the anti-HIV agents. Computational methods are a significant part of the drug design process and indispensable to study drug resistance. In this review, recent advances in computer-aided drug design for the rational design of new compounds against HIV-1 RT using methods such as molecular docking, molecular dynamics, free energy calculations, quantitative structure-activity relationships, pharmacophore modelling and absorption, distribution, metabolism, excretion and toxicity prediction are discussed. Successful applications of these methodologies are also highlighted.
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We study experimentally how the ability to communicate affects the frequency and effectiveness of flexible and inflexible contracts in a bilateral trade context where sellers can adjust trade quality after observing a post-contractual cost shock and a discretionary buyer transfer. In the absence of communication, we find that rigid contracts are more frequent and lead to higher earnings for both buyer and seller. By contrast, in the presence of communication, flexible contracts are much more frequent and considerably more productive, both for buyers and sellers. Also, both buyer and seller earn considerably more from flexible with communication than rigid without communication. Our results show quite strongly that communication, a normal feature in contracting, can remove the potential cost of flexibility (disagreements caused by conflicting perceptions). We offer an explanation based on social norms.
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Multipliers are routinely used for impact evaluation of private projects and public policies at the national and subnational levels. Oosterhaven and Stelder (2002) correctly pointed out the misuse of standard 'gross' multipliers and proposed the concept of 'net' multiplier as a solution to this bad practice. We prove their proposal is not well founded. We do so by showing that supporting theorems are faulty in enunciation and demonstration. The proofs are flawed due to an analytical error but the theorems themselves cannot be salvaged as generic, non-curiosum counterexamples demonstrate. We also provide a general analytical framework for multipliers and, using it, we show that standard 'gross' multipliers are all that is needed within the interindustry model since they follow the causal logic of the economic model, are well defined and independent of exogenous shocks, and are interpretable as predictors for change.
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Despite the increasing popularity of enterprise architecture management (EAM) in practice, many EAM initiatives either do not fully meet the expected targets or fail. Several frameworks have been suggested as guidelines to EA implementation, but companies seldom follow prescriptive frameworks. Instead, they follow very diverse implementation approaches that depend on their organizational contingencies and the way of adopting and evolving EAM over time. This research strives for a broader understanding of EAM by exploring context-dependent EAM adoption approaches as well as identifying the main EA principles that affect EA effectiveness. Based on two studies, this dissertation aims to address two main questions: (1) EAM design: Which approaches do companies follow when adopting EAM? (2) EA principles and their impact: What impact does EA principles have on EA effectiveness/quality? By utilizing both qualitative and quantitative research methods, this research contributes to exploring different EAM designs in different organizational contingencies as well as using EA principles as an effective means to achieve principle-based EAM design. My research can help companies identify a suitable EAM design that fits their organizational settings and shape their EA through a set of principles.
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AIMS: To review the concept of binge drinking as a measure of risky single occasion drinking (RSOD), to illustrate its differential impact on selected health outcomes and to identify research gaps. METHODS: Narrative literature review with focus on conceptual and methodological differences, trajectories of RSOD and effects of RSOD on fetal outcomes, coronary heart disease (CHD) and injuries. RESULTS: Effects ascribed commonly to RSOD may often be the effects of an undifferentiated mixture of risky single occasions and regular heavy volume drinking, constituted by frequent, successive RSOD. This leads to the problem that additional risks due to RSOD are mis-specified and remain unidentified or underestimated in some cases, such as for injuries or CHD, but are probably overstated for some chronic consequences or for effects of maternal drinking on newborns. CONCLUSION: A stronger focus should be placed upon methods that can differentiate the effects of RSOD from those due to frequent occasions of heavy drinking that result in heavy volume drinking.
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L’objectiu principal és presentar un nou prototipus d’eina per al disseny de les plantes de tractament d’aigües residuals utilitzant models mecànics dinàmics quantificant la incertesa
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The objective of this project consists of designing and constructing a RTM mould for a loose flange of glass fibre reinforced plastic (GRP). The design phase has the mission to realise a quality and simple design of the RTM mould, with the objective to obtain an easy and economic phase of construction and the more possible great characteristics of the loose flange. In fact this RTM mould will be a mould prototype, which will be developed in the future to obtain an RTM mould able to support a loose flange production. Therefore when more steps are developed in this project, then the future objective will be near
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The SwissBioisostere database (http://www.swissbioisostere.ch) contains information on molecular replacements and their performance in biochemical assays. It is meant to provide researchers in drug discovery projects with ideas for bioisosteric modifications of their current lead molecule, as well as to give interested scientists access to the details on particular molecular replacements. As of August 2012, the database contains 21 293 355 datapoints corresponding to 5 586 462 unique replacements that have been measured in 35 039 assays against 1948 molecular targets representing 30 target classes. The accessible data were created through detection of matched molecular pairs and mining bioactivity data in the ChEMBL database. The SwissBioisostere database is hosted by the Swiss Institute of Bioinformatics and available via a web-based interface.
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Cobre Las Cruces is a renowned copper mining company located in Sevilla, with unexpected problems in wireless communications that have a direct affectation in production. Therefore, the main goals are to improve the WiFi infrastructure, to secure it and to detect and prevent from attacks and from the installation of rogue (and non-authorized) APs. All of that integrated with the current ICT infrastructure.This project has been divided into four phases, although only two of them have been included into the TFC; they are the analysis of the current situation and the design of a WLAN solution.Once the analysis part was finished, some weaknesses were detected. Subjects such as lack of connectivity and control, ignorance about installed WiFi devices and their localization and state and, by and large, the use of weak security mechanisms were some of the problems found. Additionally, due to the fact that the working area became larger and new WiFi infrastructures were added, the first phase took more time than expected.As a result of the detailed analysis, some goals were defined to solve and it was designed a centralized approach able to cope with them. A solution based on 802.11i and 802.1x protocols, digital certificates, a probe system running as IDS/IPS and ligthweight APs in conjunction with a Wireless LAN Controller are the main features.
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We have previously shown that a 28-amino acid peptide derived from the BRC4 motif of BRCA2 tumor suppressor inhibits selectively human RAD51 recombinase (HsRad51). With the aim of designing better inhibitors for cancer treatment, we combined an in silico docking approach with in vitro biochemical testing to construct a highly efficient chimera peptide from eight existing human BRC motifs. We built a molecular model of all BRC motifs complexed with HsRad51 based on the crystal structure of the BRC4 motif-HsRad51 complex, computed the interaction energy of each residue in each BRC motif, and selected the best amino acid residue at each binding position. This analysis enabled us to propose four amino acid substitutions in the BRC4 motif. Three of these increased the inhibitory effect in vitro, and this effect was found to be additive. We thus obtained a peptide that is about 10 times more efficient in inhibiting HsRad51-ssDNA complex formation than the original peptide.
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Chemosensory receptors convert an enormous diversity of chemical signals from the external world into a common language of electrical activity in the brain. Mammals and insects use several families of transmembrane receptor proteins to recognize distinct classes of volatile and non-volatile chemicals that are produced by conspecifics or other environmental sources. A comparison of the signalling mechanisms of mammalian and insect receptors has revealed an unexpected functional distinction: mammals rely almost exclusively on metabotropic ligand-binding receptors, which use second messenger signalling cascades to indirectly activate ion channels, whereas insects use ionotropic receptors, which are gated directly by chemical stimuli, thereby leading to neuronal depolarization. In this review, we consider possible reasons for this dichotomy, taking into account biophysical, cell biological, ecological and evolutionary influences on how information is extracted from chemosensory cues by these animal classes.
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BACKGROUND: This integrative review of the literature describes the evolution in knowledge and the paradigm shift that is necessary to switch from advance directives to advance care planning. AIMS AND OBJECTIVES: It presents an analysis of concepts, trends, models and experiments that enables identification of the best treatment strategies, particularly for older people living in nursing homes. DESIGN: Based on 23 articles published between 1999 and 2012, this review distinguishes theoretical from empirical research and presents a classification of studies based on their methodological robustness (descriptive, qualitative, associative or experimental). RESULTS: It thus provides nursing professionals with evidence-based information in the form of a synthetic vision and conceptual framework to support the development of innovative care practices in the end-of-life context. While theoretical work places particular emphasis on the impact of changes in practice on the quality of care received by residents, empirical research highlights the importance of communication between the different persons involved about care preferences at the end of life and the need for agreement between them. CONCLUSIONS: The concept of quality of life and the dimensions and factors that compose it form the basis of Advance care planning (ACP) and enable the identification of the similarities and differences between various actors. They inform professionals of the need to ease off the biomedical approach to consider the attributes prioritised by those concerned, whether patients or families, so as to improve the quality of care at the end of life. IMPLICATIONS FOR PRACTICE: It is particularly recommended that all professionals involved take into account key stakeholders' expectations concerning what is essential at the end of life, to enable enhanced communication and decision-making when faced with this difficult subject.
Resumo:
Review of the book: The Tinkerer's Accomplice: How Design Emerges From Life Itself by J. Scott TurnerHarvard University Press: 2007. 304 pp.