Hollow glass microspheres (HGMS) have been widely used in the hydrocarbon industry for cementing wells with low-density slurries. These consist of amorphous siliceous hollow spheres filled gas, providing a material high compressive strength. The present study aims to characterize interaction between HGMS and cement paste, focusing mainly on development pozzolanic activity, given nature silica. ...

Hybridization between native and non-native species has serious biological consequences, but our understanding of how dispersal and selection interact to influence invasive hybridization is limited. Here, we document the spread of genetic introgression between a native (Oncorhynchus clarkii) and invasive (Oncorhynchus mykiss) trout, and identify the mechanisms influencing genetic admixture. In ...

Recent genomic studies have highlighted the important role of admixture in shaping genome-wide patterns of diversity. Past admixture leaves a population genomic signature of linkage disequilibrium (LD), reflecting the mixing of parental chromosomes by segregation and recombination. These patterns of LD can be used to infer the timing of admixture, but the results of inference can depend strongl...

In many temperate regions, ice ages promoted range contractions into refugia resulting in divergence (and potentially speciation), while warmer periods led to range expansions and hybridization. However, the impact these climatic oscillations had in many parts of the tropics remains elusive. Here, we investigate this issue using genome sequences of three pig (Sus) species, two of which are foun...

Uganda has a large population of goats, predominantly from indigenous breeds reared in diverse production systems, whose existence is threatened by crossbreeding with exotic Boer goats. Knowledge about the genetic characteristics and relationships among these Ugandan goat breeds and the potential admixture with Boer goats is still limited. Using a medium-density single nucleotide polymorphism (...

T he efficacy of various types of pulmonary therapy is often questioned. This may stem from investigative methods. Evaluation of pulmonary gas exchange usually involves the determination of arterial oxygen tension (Pa02) and the calculation of the alveolar-to-arterial oxygen tension difference (P[Aa]O2), or pulmonary venous admixture, while pure oxygen is administered. Evaluation performed with...

Admixed populations are formed by the merging of two or more ancestral populations, and the ancestry of each locus in an admixed genome derives from either source. Consider a simple “pulse” admixture model, where populations A and B merged t generations ago without subsequent gene flow. We derive the distribution of the proportion of an admixed chromosome that has A (or B) ancestry, as a functi...

The Ashkenazi Jewish (AJ) population has long been viewed as a genetic isolate, yet it is still unclear how population bottlenecks, admixture, or positive selection contribute to its genetic structure. Here we analyzed a large AJ cohort and found higher linkage disequilibrium (LD) and identity-by-descent relative to Europeans, as expected for an isolate. However, paradoxically we also found hig...