Lahn and Page previously observed that genes on the human X chromosome were physically arranged along the chromosome in "strata," roughly ordered by degree of divergence from related genes on the Y chromosome. They hypothesized that this ordering results from a historical series of suppressions of recombination along the mammalian Y chromosome, thereby allowing formerly recombining X and Y chro...

This study systematically investigates the overburden movement and strata behavior at a fully-mechanized top coal caving (FMTCC) face in a thick coal seam in a loess-covered gullied region by field measurement and theoretical analysis. A comparative analysis was performed to examine how the attitude of surface gullies and the structure of overburden affect face support resistance. The character...

Post-stratification is used to reduce the variance of estimates of the mean. Because the stratification is not fixed in advance, within-strata sample sizes can be quite small. The survey statistics literature provides some guidance on minimum within-strata sample sizes; however, the recommendations and justifications are inconsistent and apply broadly for many different population structures. T...

The human sex chromosomes have stopped recombining gradually, which has left five evolutionary strata on the X chromosome. Y inversions are thought to have suppressed X-Y recombination but clear evidence is missing. Here, we looked for such evidence by focusing on a region--the X-added region (XAR)--that includes the pseudoautosomal region and the most recent strata 3 to 5. We estimated and ana...

Windmill, machine that converts wind into useful energy. This energy is derived from the force of wind acting on oblique blades or sails that radiate from a shaft. The turning shaft may be connected to machinery used to generate electricity. The present paper makes an attempt to show the effect of wind and earthquake load on tubular type windmill and its foundation considering hard, medium and ...

Breast cancer screening is known to reduce breast cancer mortality. A high breast density may affect this reduction. We assessed the effect of screening on breast cancer mortality in women with dense and fatty breasts separately. Analyses were performed within the Nijmegen (Dutch) screening programme (1975-2008), which invites women (aged 50-74 years) biennially. Performance measures were deter...

the present article has been prepared based on two field research studies undertaken to identify the vulnerable strata in rural areas of iran’s garmsar and dasht-e azadegan regions2. as will be demonstrated below, the findings of the two studies show that the development policies implemented during recent decades--policies emphasizing strategies of structural adjustment, liberalization, and pri...

Longwall mining alters the fluid-flow-related reservoir properties of the rocks overlying and underlying an extracted panel due to fracturing and relaxation of the strata. These mining-related disturbances create new pressure depletion zones and new flow paths for gas migration and may cause unexpected or uncontrolled migration ofgas into the underground workplace. One common technique to contr...

Texts are composed of many different strata on different levels. A method is proposed to find the number of strata at the word-form level in Slovak poetry and to study the relationship between the parameters of the fitting function.

In this paper we construct quantum analogs of strata of coadjoint orbits and describe their representations. This kind objects play an important role in describing quantum groups as repeated extensions of quantum strata.