The effects of severe myopia on the properties of sampling units in peripheral retina

Significance: Poor peripheral visual acuity in myopia may reflect, in part, photoreceptor misalignment with the exit pupil of the eye. We speculate that if such misalignment causes sufficient visual deprivation and/or disrupts retinal feedback processes, it may influence eye growth itself. Purpose: It is known that myopic eyes have a reduced peripheral resolution acuity relative to emmetropic eyes, though it remains unclear how mechanical stretching of the retina in myopia impacts on peripheral visual performance. Our aim was to determine how retinal stretching affects the properties of sampling units in peripheral vision. Methods: Three-dimensional magnetic resonance imaging provided a depiction in vivo of ocular shape, allowing the inter-eye ratio of retinal image surface areas and the relative alignment of surfaces to be determined in our observer, who was unique in having severe myopia in the right eye (~21D) but only modest myopia in the left (~3D). Visual performance was assessed for the detection and direction discrimination of drifting sinusoids positioned 40º in the temporal retina. Applying the sampling theorem to our measures, we estimated the density and cut-off frequency of the underlying sampling units. Results: The retinal image surface area of the right eye was 40% larger than that of the left, and was rotated 8.9º anticlockwise relative to the left eye’s image surface. In agreement with a linear stretch model of myopia, the sampling density of the right eye was reduced by approximately the same ratio as that predicted from the inter-eye MRI data, namely 1.18. However, the cut-off frequency (cycles/mm) of the right eye was approximately half that of the left, a reduction that cannot be explained solely by a linear areal expansion of retinal sampling units. Conclusions: Poor peripheral acuity in severe myopia may be caused, at least in part, by receptoral misalignment with the exit pupil

The impact of modelling and pooled data on the accuracy of genomic prediction in small holder dairy data

The lack of data recording in smallholder dairy cattle system implies that the availability of molecular data could offer some quick wins in terms of using the genomic information in genomic evaluation and therefore genomic selection (GS). Initial studies have reported low to medium accuracy of genomic prediction when the size of data is limited. The African dairy genetic gains (ADGG) project is generating more data across two countries in East Africa and would offer more opportunity to further examine the application of GS. In anticipation of having more data in future, this paper examined the impact of fitting GBLUP models with dominance effects, a multi-trait GBLUP that fits exotic breed and non-exotic breed proportion as different traits and the analysis of pooled data from Kenya and Tanzania on the accuracy of genomic predictions. In addition, it examines if chromosome regions with highest contributions to top GEBV cows with high exotic and high indigenous genes are different. The estimates of dominance variance were essentially zero, possibly due to the limited data set, and therefore the model with dominance effect resulted in no increase of genomic accuracy compared to a model with only additive effects. The fitting of the proportion of exotic and non-exotic genes as different traits resulted in slightly lower accuracies of cows with more than 35% exotic genes but almost doubled the accuracy of those wit

Estimation of variance components for female longevity in Australian Angus cattle using random regression models

Cow longevity is an economically important trait for beef cattle breeding. In this study, random regression models were used to estimate genetic parameters for female longevity in Australian Angus cattle. Longevity was defined using 10 binary records (0 for ‘not in the breeding herd’ and 1 for ‘active in the breeding herd’) between age 2 to 11. A Bayesian random regression model was fitted separately to 5 different groups of disposal reasons supplied by breeders. The heritability estimates were generally low with peaks ranging from 0.03 to 0.12. The highest and lowest heritability estimates were obtained for performance and fertility datasets, respectively. Genetic correlations were high between ages 3 to 5 and age 6 for all groups except for the structural problems group in which age 3 showed a low genetic correlation. This illustrates that selection for longevity could be undertaken early in cow’s life

Genetic structure of the DGEA crossbred dairy cattle population in Kenya. An internal report for ADGG and collaborators

Understanding the genetic structure of crossbred dairy cattle population of East Africa is important because it assists in interpretation of results of analyses using alternative genetic and phenotypic parameters and evaluation models and it allows for simulation of methods of analysis and application of breeding strategies that better reflect the genetic structure of these populations

Effectiveness of Meta-cognitive Therapy on Decreasing of Thought- fusion Beliefs in Patients with Washing Type of Obsessive- compulsive Disorder

Introduction: Obsessive–compulsive disorder (OCD) is a severe disabling psychiatric affliction with a strong impact on life quality. This study was planned to investigate the effectiveness of meta-cognitive therapy on decreasing of thought-fusion beliefs in patients with washing type of obsessive- compulsive disorder. Methods: A single case study with multiple baselines was implemented. The study sample consisted of three subjects who were OCD patients (washers), chosen from private clients of counseling centers of Hamedan city (Iran). They had been registered from Spring of 2013, and were selected via purposeful sampling. In fact, the patients received 10 sessions of meta-cognitive therapy. Thought Fusion Instrument (TFI) was used to determine the baseline in the first step. This questionnaire was also completed in sessions of 2, 4, 6, 8, as well as the end of treatment. Visual analysis and percentage of improvement were used in order to analyze the data via SPSS 18 software. Moreover, descriptive statistics, ANOVA with repeated measure, and paired T- test were used. Results: statistically significant clinical developments were found in improving thought-fusion beliefs after treatment. Moreover, at the 3-month follow-up, the attained improvements during treatment were retained. Conclusion: The study results confirmed the role of meta-cognitive therapy in decreasing thought-fusion beliefs in patients with washing type of obsessive- compulsive disorder