| 1. |
- Estabrooks, Carole A, et al.
(författare)
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Towards better measures of research utilization : a collaborative study in Canada and Sweden
- 2011
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Ingår i: Journal of Advanced Nursing. - : Wiley-Blackwell. - 0309-2402 .- 1365-2648. ; 67:8, s. 1705-18
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: This paper is a report of a study examining research utilization in nursing. The specific aims were to (1) clarify the construct of research utilization, and (2) identify observable indicators of research utilization.BACKGROUND: Robust measures of research utilization do not exist despite steadily increasing numbers of studies in the field. One reason for this is theoretical confusion surrounding the central concepts in the field.METHOD: A qualitative (focus group) design was used to explore the construct of research utilization in two countries: Canada and Sweden. A systematic and sequential (three phases) approach to expert sampling framed the study. Phase 1 consisted of initial construct clarification by the research team (2005). In Phase 2, a face-to-face meeting with a panel of international research utilization nursing experts was held (2005). Phase 3 consisted of a series of focus groups with nursing care (direct and non-direct) providers (2005-2007). Data were analysed using content analysis.FINDINGS: The nursing care providers did not commonly use the term 'research utilization'. Several examples of research utilization were provided; a majority of these examples related to instrumental research utilization and became increasingly concrete as one moved from non-direct to direct care participants. Participants identified several indicators of research utilization (instrumental and conceptual). From these indicators, a measurement schematic was derived.CONCLUSIONS: The construct of research utilization is multi-faceted. Several indicators of research utilization were identified, which can be used to augment existing or develop a new and improved measure that taps both instrumental and conceptual use.
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| 2. |
- Mulder, Han A., et al.
(författare)
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Estimation of genetic variance for macro- and micro-environmental sensitivity using double hierarchical generalized linear models
- 2013
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Ingår i: Genetics Selection Evolution. - : BioMed Central. - 0999-193X .- 1297-9686. ; 45
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Tidskriftsartikel (refereegranskat)abstract
- Background: Genetic variation for environmental sensitivity indicates that animals are genetically different in their response to environmental factors. Environmental factors are either identifiable (e.g. temperature) and called macro-environmental or unknown and called micro-environmental. The objectives of this study were to develop a statistical method to estimate genetic parameters for macro- and micro-environmental sensitivities simultaneously, to investigate bias and precision of resulting estimates of genetic parameters and to develop and evaluate use of Akaike’s information criterion using h-likelihood to select the best fitting model.Methods: We assumed that genetic variation in macro- and micro-environmental sensitivities is expressed as genetic variance in the slope of a linear reaction norm and environmental variance, respectively. A reaction norm model to estimate genetic variance for macro-environmental sensitivity was combined with a structural model for residual variance to estimate genetic variance for micro-environmental sensitivity using a double hierarchical generalized linear model in ASReml. Akaike’s information criterion was constructed as model selection criterion using approximated h-likelihood. Populations of sires with large half-sib offspring groups were simulated to investigate bias and precision of estimated genetic parameters.Results: Designs with 100 sires, each with at least 100 offspring, are required to have standard deviations of estimated variances lower than 50% of the true value. When the number of offspring increased, standard deviations of estimates across replicates decreased substantially, especially for genetic variances of macro- and micro-environmental sensitivities. Standard deviations of estimated genetic correlations across replicates were quite large (between 0.1 and 0.4), especially when sires had few offspring. Practically, no bias was observed for estimates of any of the parameters. Using Akaike’s information criterion the true genetic model was selected as the best statistical model in at least 90% of 100 replicates when the number of offspring per sire was 100. Application of the model to lactation milk yield in dairy cattle showed that genetic variance for micro- and macro-environmental sensitivities existed.Conclusion: The algorithm and model selection criterion presented here can contribute to better understand genetic control of macro- and micro-environmental sensitivities. Designs or datasets should have at least 100 sires each with 100 offspring.
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| 3. |
- Rönnegård, Lars, et al.
(författare)
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Genetic heterogeneity of residual variance - estimation of variance components using double hierarchical generalized linear models
- 2010
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Ingår i: Genetics Selection Evolution. - : Springer Science and Business Media LLC. - 0999-193X .- 1297-9686. ; 42
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Tidskriftsartikel (refereegranskat)abstract
- Background: The sensitivity to microenvironmental changes varies among animals and may be under genetic control. It is essential to take this element into account when aiming at breeding robust farm animals. Here, linear mixed models with genetic effects in the residual variance part of the model can be used. Such models have previously been fitted using EM and MCMC algorithms.Results: We propose the use of double hierarchical generalized linear models (DHGLM), where the squared residuals are assumed to be gamma distributed and the residual variance is fitted using a generalized linear model. The algorithm iterates between two sets of mixed model equations, one on the level of observations and one on the level of variances. The method was validated using simulations and also by re-analyzing a data set on pig litter size that was previously analyzed using a Bayesian approach. The pig litter size data contained 10,060 records from 4,149 sows. The DHGLM was implemented using the ASReml software and the algorithm converged within three minutes on a Linux server. The estimates were similar to those previously obtained using Bayesian methodology, especially the variance components in the residual variance part of the model.Conclusions: We have shown that variance components in the residual variance part of a linear mixed model can be estimated using a DHGLM approach. The method enables analyses of animal models with large numbers of observations. An important future development of the DHGLM methodology is to include the genetic correlation between the random effects in the mean and residual variance parts of the model as a parameter of the DHGLM.
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| 4. |
- Rönnegård, Lars, et al.
(författare)
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Variance component and breeding value estimation for genetic heterogeneity of residual variance in Swedish Holstein dairy cattle
- 2013
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Ingår i: Journal of Dairy Science. - : Elsevier. - 0022-0302 .- 1525-3198. ; 96:4, s. 2627-2636
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Tidskriftsartikel (refereegranskat)abstract
- Trait uniformity, or micro-environmental sensitivity, may be studied through individual differences in residual variance. These differences appear to be heritable, and the need exists, therefore, to fit models to predict breeding values explaining differences in residual variance. The aim of this paper is to estimate breeding values for micro-environmental sensitivity (vEBV) in milk yield and somatic cell score, and their associated variance components, on a large dairy cattle data set having more than 1.6 million records. Estimation of variance components, ordinary breeding values, and vEBV was performed using standard variance component estimation software (ASReml), applying the methodology for double hierarchical generalized linear models. Estimation using ASReml took less than 7 d on a Linux server. The genetic standard deviations for residual variance were 0.21 and 0.22 for somatic cell score and milk yield, respectively, which indicate moderate genetic variance for residual variance and imply that a standard deviation change in vEBV for one of these traits would alter the residual variance by 20%. This study shows that estimation of variance components, estimated breeding values and vEBV, is feasible for large dairy cattle data sets using standard variance component estimation software. The possibility to select for uniformity in Holstein dairy cattle based on these estimates is discussed.
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| 5. |
- Strandberg, Erling, et al.
(författare)
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Statistical tools to select for robustness and milk quality
- 2013
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Ingår i: Advances in Animal Biosciences. - : Cambridge University Press. - 2040-4700 .- 2040-4719. ; 4:3, s. 606-611
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Tidskriftsartikel (refereegranskat)abstract
- This work was part of the EU RobustMilk project. In this work package, we have focused on two aspects of robustness, micro- and macro-environmental sensitivity and applied these to somatic cell count (SCC), one aspect of milk quality. We showed that it is possible to combine both categorical and continuous descriptions of the environment in one analysis of genotype by environment interaction. We also developed a method to estimate genetic variation in residual variance and applied it to both simulated and a large field data set of dairy cattle. We showed that it is possible to estimate genetic variation in both micro- and macro-environmental sensitivity in the same data, but that there is a need for good data structure. In a dairy cattle example, this would mean at least 100 bulls with at least 100 daughters each. We also developed methods for improved genetic evaluation of SCC. We estimated genetic variance for some alternative SCC traits, both in an experimental herd data and in field data. Most of them were highly correlated with subclinical mastitis (>0.9) and clinical mastitis (0.7 to 0.8), and were also highly correlated with each other. We studied whether the fact that animals in different herds are differentially exposed to mastitis pathogens could be a reason for the low heritabilities for mastitis, but did not find strong evidence for that. We also created a new model to estimate breeding values not only for the probability of getting mastitis but also for recovering from it. In a progeny-testing situation, this approach resulted in accuracies of 0.75 and 0.4 for these two traits, respectively, which means that it is possible to also select for cows that recover more quickly if they get mastitis.
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| 6. |
- Strandberg, Karin, et al.
(författare)
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Fyra nya instrument för analys av blodgaser testade: Behändiga kassetter skall ge bättre användarvänlighet
- 2000
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Ingår i: Läkartidningen. - : Swedish Medical Association. - 0023-7205 .- 1652-7518. ; 97:7, s. 698-701
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Tidskriftsartikel (refereegranskat)abstract
- An entirely new type of blood gas analyser has made its way into the marketplace, to be used, for example, in emergency rooms, intensive care units, ambulances, and bedside with quarantined patients in infectious diseases units. The instruments reviewed here employ new miniaturised analysis circuitry, integrated into the cassette on which the blood sample is applied. These instruments are designed for use by care-givers without specific laboratory training. Four point-of-care blood gas analysers are tested: OPTI 1 (AVL), I-STAT (HP), IRMA (Infiniti) och ABL 70 (Radiometer).
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| 7. |
- Wahlberg, Olof, et al.
(författare)
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How a Medium Sized Enterprise Applies the CRM Approach in its Marketing
- 2009
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Ingår i: Proceedings of the 3rd European Conference on Information Management and Evaluation. - : Academic Conferences Limited. - 9781906638443 - 9781906638436 ; , s. 448-459
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Konferensbidrag (refereegranskat)abstract
- The purpose is to describe how a medium sized enterprise with an international scope, positive economic development, and relatively high ICT maturity applies the CRM approach in its marketing. Medium sized enterprises with these features are assumed to be role models for smaller enterprises, and in particular for smaller enterprises with growth ambitions. This case study is based on structured interviews conducted with the CEO and the manager responsible for IT and IS development in the enterprise. The findings show that the enterprise endorses a customer-oriented business strategy, supported by fairly simple information gathering and analysing methods; that the dependency on agents and dealers is a problem in an CRM perspective; and that the development of the Web offers new possibilities for CRM practices and policies.
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