Time-resolved transillumination of turbid media

The suitability and limits of time-resolved transillumination to determine inner details of biological tissues are investigated by phantom experiments. The achievable improvement is demonstrated by using different phantoms (absorbing objects embedded in a turbid medium). By means of line-scans across a sharp edge the spatial resolution and its dependence on temporal resolution can be determined. To demonstrate the physical resolution according to the Rayleigh-criterion, measurements were performed on blackened bead pairs. Investigations with partially transparent beads demonstrate the high sensitivity of time-resolving techniques with respect to variations in scattering or absorption coefficients

Genetic association between somatic cell score and milk lactose in early- to mid-lactation of first calving Fleckvieh cows

The present study aimed to assess genetic correlations of milk lactose (percentage and yield), lactose to fat ratio and lactose to protein ratio with somatic cell score (SCS) in the first half of lactation, the period with the highest risk of mastitis in cows. More than 35,000 first lactation records from Austrian Fleckvieh breed were available for this purpose. A linear animal model was adopted for the genetic analysis, with inclusion of age at calving and year-month of calving as fixed effects, and additive genetic animal, herd-year of calving and residual as random effects. The average SCS in the first 150 days in milk was low (1.53 \ub11.29) compared with values reported in literature for other breeds in first lactation. Heritabilities of lactose percentage, lactose to fat ratio and lactose to protein ratio were high, ranging between 0.65 and 0.71. According to lactose yield and SCS, their heritabilities were equal to 0.3 and 0.2, respectively. Since the focus was on the first lactation, where the heritability of lactose is reported to be the highest, these results agreed with expectations. The strongest genetic correlation was found between SCS and lactose percentage, and the weakest between SCS and lactose yield, suggesting that lactose percentage and yield have different variability at animal level and different potential roles at genetic level. Both lactose to fat ratio and lactose to protein ratio showed weak and negative genetic correlation with SCS. Further research is required to assess relations between lactose and recorded mastitis data, with the final goal of validating lactose level as udder inflammation indicator and explore its potential role in breeding programs to reduce cow\u2019s susceptibility to mastitis

Pulsed-laser Doppler flowmetry provides basis for deep perfusion probing

A setup for pulsed-laser Doppler flowmetry ~LDF! measurements has been built and tested. Measurements were carried out comparing continuous-wave and pulsed LDF. With pulsed LDF a higher peak power can be injected into the tissue without exceeding the safety limits. This enables a much larger spacing between the locations of illumination and detection. Thus, the penetration depth, and thus the measurement volume, can be enlarged using the pulsed-LDF method. This method will allow, e.g., monitoring of the cerebral perfusion

Imputation of non-genotyped individuals using genotyped progeny in Nellore, a Bos indicus cattle breed

This study aimed at imputing non(un)-genotyped sires using a stepwise imputation approach that combines identity by descent (IBD) detection methods with other imputation algorithms. We also studied the effect of using actual or imputed genotypes of non-genotyped sires in estimating genomic relationships.Simulations and real data were used for the analysis. Fifty sire families were simulated and 23 sire families were derived from 995 Brazilian Nellore cattle genotyped with Illumina (R) Bovine HD (777,962 SNPs) SNP Chip. Un-genotyped sires were imputed using genotype information from progeny (5 or 10); progeny and grand offspring; a combination of progeny, mates of genotyped progeny and grand offspring; and the entire genotyped population. Stepwise imputation was done with an IBD detection method that uses simple inheritance rules (MERLIN) as a First step and subsequently with FImpute, MaCH or BEAGLE as the second step to infer genotypes that were not imputed unambiguously by MERLIN. The stepwise imputation procedure was compared to an approach that ignores the first step (MERLIN) but uses only prior pedigree information to impute non-genotyped animals. Imputation accuracy was assessed as percent of correctly called genotypes and the correlation between imputed and actual genotypes (in brackets).With real data, imputation accuracy ranged from 81.6% (0.856) to 97.4% (0.981) depending on the amount of genotyped information considered for the first step (MERLIN) and imputation algorithms used for the second step. Greater accuracies of imputing non-genotyped sires were obtained when the stepwise imputation approach was used with 10 genotyped offspring as the first step. The stepwise approach resulted in an increase of 1.2% (5 offsprings) and 4.7% (10 offsprings) in imputation accuracy. MaCH was more accurate in the second step, followed by FImpute then BEAGLE. Similar trends in imputation accuracy were observed for the simulated population. Generally, imputed genotypes were successfully used to estimate genomic relationships among close relatives but considerable bias was observed for true pairwise relationships of zero.In conclusion, high imputation accuracies can be achieved for non-genotyped animals when genotype information of 5 or 10 direct progeny is available for imputation. Performing preliminary IBD analysis and using non-ambiguous genotypes from that analysis in conventional imputation increased the imputation accuracy considerably. (C) 2014 Elsevier B.V. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP