instruction:
Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
question:
Are low vitamin D levels linked with semen quality and sex steroids in infertile men?
answer:
Are vitamin D deficiency and low ionized calcium linked with semen quality and sex steroid levels in infertile men?

question:
Brain-derived neurotrophic factor (BDNF) acts rapidly to modulate synaptic neurotransmission in the brain. Although present in neurons, glial cells, and mucosal cells of the colon, and in higher concentrations than in brain, the action of BDNF in gut have not been characterized. The aim of this study was to identify the role of BDNF in mediating the peristaltic reflex.', 'BDNF and a specific antiserum were examined for their effects on the peristaltic reflex and release of the sensory mediators serotonin and calcitonin gene-related peptide in rat colon. The peristaltic reflex and release of serotonin and calcitonin gene-related peptide were also examined in genetically modified mice (BDNF(+/-)) with reduced levels of BDNF.', 'Endogenous brain-derived neurotrophic factor was released into the sensory compartment in a stimulus-dependent manner during the peristaltic reflex induced by mucosal stimulation but not muscle stretch. BDNF stimulated and immunoneutralization of endogenous BDNF reduced ascending contraction and descending relaxation of circular muscle and release of serotonin and calcitonin gene-related peptide during the peristaltic reflex induced by mucosal stimulation but not muscle stretch. The peristaltic reflex and release of serotonin and calcitonin gene-related peptide during the peristaltic reflex induced by mucosal stimulation but not muscle stretch were significantly reduced in BDNF(+/-) mice.
answer:
Does brain-derived neurotrophic factor augment peristalsis by augmenting 5-HT and calcitonin gene-related peptide release?

question:
To assessdoctor's knowledge on the relevance of the problem of sleep disorders, methods of their diagnosis and treatment.", 'The survey was conducted among90physicians of different the rapeuticspecialties of Kazan medical institutions.', 'The doctors believe that main causes of sleep disorders are stressors (20%), depression (13%), neurosis (13%), chronic diseases (13%), asthenia (10%), pain (10%). An analysis of treatment prescribed to patients with sleep disorders revealed large differences.
answer:
Do [ What do the doctors of different specialties know about sleep disorders and their treatment ]?