| 1. |
- Carlén, Emma, et al.
(författare)
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Random regression models for genetic evaluation of clinical mastitis in dairy cattle
- 2009
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Ingår i: Animal. - 1751-7311 .- 1751-732X. ; 3, s. 1100-1108
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Tidskriftsartikel (refereegranskat)abstract
- A genetic analysis of longitudinal binary clinical mastitis (CM) data recorded on about 90000 first-lactation Swedish Holstein cows was carried out using linear random regression models (RRM). This method for genetic evaluation of CM has theoretical advantages compared to the method of linear cross-sectional models (CSM), which is currently being used The aim of this study was to investigate the feasibility and suitability of estimating genetic parameters and predicting breeding values for CM with a linear sire RRM. For validation purposes, the estimates and predictions from the RRM were compared to those from linear sire longitudinal multivariate models (LMVM) and CSM. For each cow, the period from 10 days before to 241 days after calving was divided into four 1-week intervals followed by eight 4-week intervals. Within each interval, presence or absence of CM was scored as '1' or '0' The linear RRM used to explain the trajectory of CM over time included a set of explanatory variables plus a third-order Legendre polynomial function of time for the sire effect The time-dependent heritabilities and genetic correlations from the chosen RRM corresponded fairly well with estimates obtained from the linear LMVM for the separate intervals. Some discrepancy between the two methods was observed, with the more unstable results being obtained from the linear LMVM. Both methods indicated clearly that CM was not genetically the same trait throughout lactation. The correlations between predicted sire breeding values from the RRM, summarized over different time periods, and from linear CSM were rather high. They were, however, less than unity (0.74 to 0.96), which indicated some re-ranking of sires. Sire curves based on the time-specific breeding values from the RRM illustrated differences in intercept and slope among the best and the worst sires. To conclude, a linear sire RRM seemed to work well for genetic evaluation purposes, but was sensitive for estimation of genetic parameters.
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| 2. |
- Carlen, Marie, et al.
(författare)
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Forebrain ependymal cells are Notch-dependent and generate neuroblasts and astrocytes after stroke
- 2009
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Ingår i: Nature Neuroscience. - : Springer Science and Business Media LLC. - 1546-1726 .- 1097-6256. ; 12:3, s. 259-267
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Tidskriftsartikel (refereegranskat)abstract
- Neurons are continuously generated from stem cells in discrete regions in the adult mammalian brain. We found that ependymal cells lining the lateral ventricles were quiescent and did not contribute to adult neurogenesis under normal conditions in mice but instead gave rise to neuroblasts and astrocytes in response to stroke. Ependymal cell quiescence was actively maintained by canonical Notch signaling. Inhibition of this pathway in uninjured animals allowed ependymal cells to enter the cell cycle and produce olfactory bulb neurons, whereas forced Notch signaling was sufficient to block the ependymal cell response to stroke. Ependymal cells were depleted by stroke and failed to self-renew sufficiently to maintain their own population. Thus, although ependymal cells act as primary cells in the neural lineage to produce neurons and glial cells after stroke, they do not fulfill defining criteria for stem cells under these conditions and instead serve as a reservoir that is recruited by injury.
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| 3. |
- Fikse, Freddy, et al.
(författare)
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Genetic evaluation of claw health traits accounting for potential preselection of cows to be trimmed
- 2017
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 0022-0302 .- 1525-3198. ; 100, s. 8197-8204
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Tidskriftsartikel (refereegranskat)abstract
- Claw lesions are one of the most important health issues in dairy cattle. Although the frequency of claw lesions depends greatly on herd management, the frequency can be lowered through genetic selection. A genetic evaluation could be developed based on trimming records collected by claw trimmers; however, not all cows present in a herd are usually selected by the breeder to be trimmed. The objectives of this study were to investigate the importance of the preselection of cows for trimming, to account for this preselection, and to estimate genetic parameters of claw health traits. The final data set contained 25,511 trimming records of French Holstein cows. Analyzed claw lesion traits were digital dermatitis, heel horn erosion, inter digital hyperplasia, sole hemorrhage circumscribed, sole hemorrhage diffused, sole ulcer, and white line fissure. All traits were analyzed as binary traits in a multitrait linear animal model. Three scenarios were considered: including only trimmed cows in a 7-trait model (scenario 1); or trimmed cows and contemporary cows not trimmed but present at the time of a visit (considering that nontrimmed cows were healthy) in a 7-trait model (scenario 2); or trimmed cows and contemporary cows not trimmed but present at the time of a visit (considering lesion records for trimmed cows only), in an 8-trait model, including a 0/1 trimming status trait (scenario 3). For scenario 3, heritability estimates ranged from 0.02 to 0.09 on the observed scale. Genetic correlations clearly revealed 2 groups of traits (digital dermatitis, heel horn erosion, and interdigital hyperplasia on the one hand, and sole hemorrhage circumscribed, sole hemorrhage diffused, sole ulcer, and white line fissure on the other hand). Heritabilities on the underlying scale did not vary much depending on the scenario: the effect of the preselection of cows for trimming on the estimation of heritabilities appeared to be negligible. However, including untrimmed cows as healthy caused bias in the estimation of genetic correlations. The use of a trimming status trait to account for preselection appears promising, as it allows consideration of the exhaustive population of cows present at the time a trimmer visited a farm without causing bias in genetic parameters.
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| 4. |
- Shebehe, Jacques, 1983-, et al.
(författare)
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Knowledge about infections is associated with antibiotic use : cross-sectional evidence from the health survey Northern Ireland
- 2021
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Ingår i: BMC Public Health. - : Springer Nature. - 1471-2458. ; 21:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Antibiotic overuse is the main modifiable driver of antibiotic resistance. Factors associated with overuse have been inconsistently reported and vary across populations. Given the burgeoning occurrence of infectious diseases around the world, there remains a great need to identify barriers and solutions to the control of infections. We examined whether knowledge about infections and antibiotic resistance is associated with antibiotic use in a northern European population sample. Methods: The Health Survey Northern Ireland 2014/15 was completed by a cross-sectional sample of 4135 participants aged > 16 years. Participants were asked whether they had taken an antibiotic in the past 12 months; and six questions were asked concerning knowledge about infections and antibiotic resistance. Correct answers to the six knowledge questions defined a knowledge score (score range 0–6 correct answers). We used multivariable logistic regression to estimate odds of self-reported antibiotic use during the last 12 months in association with knowledge score (lowest score, 0/6, as referent), and response to each knowledge question. Covariates included sex, age group, smoking, alcohol drinking, deprivation index, self-rated health, and satisfaction with life. Results were outputted as Odds Ratios (OR) and 95% Confidence Intervals (CI). Results: Antibiotic use in the past 12 months was reported by 39.0% (1614/4135); and 84.2% (3482/4135) scored < 6/6 correct on knowledge statements. Compared to the lowest knowledge score (0/6 correct), the highest knowledge score (6/6 correct) was associated with higher odds of antibiotic use (adjusted OR 2.03, 95% CI [1.46, 2.81], p < 0.001), with a P-value < 0.001 for trend with increasing knowledge score. Female sex, age, high deprivation, and poor general health, were independently associated with higher odds of antibiotic use. Stratified analyses showed sex and age group differences. Conclusion: Knowledge, and other modifiable and non-modifiable risk factors, were positively associated with antibiotic use in the past 12 months. While the causal direction of these associations could not be determined, given the high prevalence of lesser knowledge, as well as independent contributions of other factors including socioeconomic characteristics, health literacy campaigns to raise awareness of antibiotic resistance should take a multi-pronged approach. © 2021, The Author(s).
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| 5. |
- Strömberg Celind, Frida, 1980, et al.
(författare)
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Infants were introduced to complementary feeding earlier in 2018 compared with 2003
- 2023
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Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 112:7, s. 1485-1492
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Tidskriftsartikel (refereegranskat)abstract
- Until 2001, the Swedish advice was to postpone the introduction of eggs, fish and peanuts until the age of one year. One reason was to reduce the risk of food allergy. The earlier introduction of complementary feeding is now advised. Our aim was to study adherence to current recommendations and whether the time of introduction changed between 2003 and 2018.Data were obtained from two prospective, longitudinal, population-based cohort studies of children born in 2003 (n=4,987) and in 2018 (n=3,936). Parents answered comparable questionnaires when the children were six and twelve months old.At six months, in the 2018 cohort, eggs were introduced to 67.2% of the infants, fish to 78.9%, gluten to 89.1%, cow's milk to 76.6% and peanuts to 46.2%. In adjusted Cox regression analyses, introduction of complementary feeding with gluten, fish and eggs was made significantly earlier in the 2018 cohort compared with the 2003 cohort, adjusted for heredity, own allergic disease and parental educational level (p <0.01).Complementary feeding with eggs, fish and gluten was introduced earlier in infants born in 2018 compared with 2003, possibly reducing the risk of developing allergic disease. Current recommendations from child welfare centres are being followed.
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