Effects of twinning on lactation and days open in Holsteins were studied from calving records compiled by member surveys of Eastern Artificial Insemination Cooperative. Records of cows with 305-day mature-equivalent records from the Northeast Dairy Records Processing Laboratory were grouped according to whether the twin calving was associated with dystocia. Records of each cow that had a twin c...

BACKGROUND This study attempts to identify risk factors for monozygotic (MZ) twinning following assisted conception. METHODS Eighty-one MZ twinning pregnancies that occurred over a 7-year period in our IVF/embryo transfer programme were evaluated. These were compared with 4224 non-MZ pregnancies from the same period. RESULTS The overall incidence of MZ twinning was 1.88% (81/4305) of all cl...

A theoretical model for the plastic deformation of calcite, based on symmetry arguments and dislocation theory, is presented. Flow mechanisms suggested by the model conflict with those previously determined by Turner. Predictions from the model include translation gliding on e., ri, f and mI parallel to <110 ( i = 1,2,3; j = 1,2,3,4 ), and twin gliding on r (+) and (-) senses; s = 2.065, 0.630 ...

Twinning rates have changed substantially over time for reasons that are only partly known. In this study we studied smoking, coffee and alcohol intake, and their possible interaction with obesity as potential determinants of twinning rates using data from the Danish National Birth Cohort between 1996 and 2002. We identified 82,985 pregnancies: 81,954 singleton and 1031 twins. For the twins we ...

The high hardness or yield strength of an alloy is known to benefit from the presence of small-scale precipitation, whose hardening effect is extensively applied in various engineering materials. Stability of the precipitates is of critical importance in maintaining the high performance of a material under mechanical loading. The long period stacking ordered (LPSO) structures play an important ...

Advanced high strength steels (AHSS) have recently attracted great attention because of their superior mechanical properties. A modern group of these steels, known as twinning induced plasticity (TWIP) steels, shows a unique combination of strength and ductility even at high rates of strain. In order to examine the functionality of such steels in dynamic loading conditions, their mechanical beh...

three hundred twin births from a hospital in tehran, iran have been analyzed for seasonal variation at birth and physical measurements. the results show that the highest twinning rates for mm (5.61), ff (7.73) and mf (5.36) were seen in april, january and september, respectively. the four physical measurements at birth showed non-significant differences among the male and female twins, but mm a...

Twinning is a critical deformation mode in Mg alloys. Understanding twinning (DT) essential to improving mechanical properties of To address the experimentally observed conspicuous hardening effects Mg-1.8Zn-0.2Ca alloys, interactions between {10–12} twin boundaries (TBs) and solute clusters Mg-Zn-Ca alloys were examined via molecular dynamics (MD) simulations. We find that Zn/Ca-containing sho...

The {101} transformation twinning bands in Mn–Cu alloys are considered to be the dominant microstructural feature contributing to the high damping capacity of the alloys. Because the face-centered-tetragonal (fct) phase of Mn–Cu alloys has an axis ratio ðc=aÞ of nearly 1, an angular resolution for Kikuchi diffraction bands of better than 0.5 is necessary to identify the twin boundaries by the e...