Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

[EX Q]: The calcium-sensing receptor (CaSR) is a G-protein-coupled receptor that plays an essential role in maintaining calcium homeostasis. In the present study, we analyzed the CaSR gene in a Korean family with familial hypocalciuric hypercalcemia (FHH). Genetic studies were performed by direct sequence analysis of the CaSR gene in genomic DNA obtained from peripheral leukocytes. A novel heterozygous G to T substitution at nucleotide position 1711 in exon 6, resulting in the G571W mutation, was identified in the CaSR gene in a 26-year-old female with asymptomatic hypercalcemia, a low calcium/creatinine clearance ratio, and normal intact parathyroid hormone. To study CaSR expression, the mutation was introduced by site-directed mutagenesis into a wild-type (WT) CaSR-expressing pCR3.1 vector, and COS-7 cells were transfected with either the WT or mutant CaSR-containing vector. Transfected cells loaded with Fura-2/AM, a fluorescent indicator of Ca
[EX A]: What is the function of calcium-sensing receptor (CaSR)?

[EX Q]: Ring finger protein 5 pseudogene 1, also known as RNF5P1, is a human gene.
[EX A]: In what living being can RNF5P1 be found?

[EX Q]: Can storms in Africa cause asthma in the Caribbean ? Islanders point to the desert insects that land on beaches after a 5,000-kilometer flight across the Atlantic. If they can use winds to get from one continent to another, so can clouds of dust that carry disease. Scientists think that as Africa becomes drier, dust from expanding deserts is being blown away into Caribbean islands. A study in Barbados shows that asthma has increased 17 times since Africa's drought began in 1973. Other forms of life are suffering, too. Among them are the Caribbean's famous coral reefs( ), which began dying in large numbers in the 1900s. Eugene Shinn of the U.S. Geiological Sudrvey(USGS) in Florida went to the virgin Islands to study the reefs. The tests he and his colleagues carried out showed that the coral was dying of disease caused by Africa microbes from across the ocean. William Sprigg of the University of Arizona is studying the problem as part of a major UN project. He says that dust is causing problems in the U.S., too. "We are just beginning to collect the evidence of airborne dust influences on human health," he toldThe Washington Post.
[EX A]:
Where does the dust talked about in this passage come from?