instruction:
Given a passage with a context and an answer, 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:
Context: The Notch signaling pathway is an evolutionary conserved signal transduction pathway involved in embryonic patterning and regulation of cell fates during development and self-renewal. Recent studies have demonstrated that this pathway is integral to a complex system of interactions, involving as well other signal transduction pathways, and implicated in distinct human diseases. Delta-like 1 (Dll1) is one of the known ligands of the Notch receptors. The role of the Notch ligands is less well understood. Loss-of-function of Dll1 leads to embryonic lethality, but reduction of Delta-like 1 protein levels has not been studied in adult stage.', 'Here we present the haploinsufficient phenotype of Dll1 and a missense mutant Dll1 allele (Dll1(C413Y)). Haploinsufficiency leads to a complex phenotype with several biological processes altered. These alterations reveal the importance of Dll1 mainly in metabolism, energy balance and in immunology. The animals are smaller, lighter, with altered fat to lean ratio and have increased blood pressure and a slight bradycardia. The animals have reduced cholesterol and triglyceride levels in blood. At the immunological level a subtle phenotype is observed due to the effect and fine-tuning of the signaling network at the different levels of differentiation, proliferation and function of lymphocytes. Moreover, the importance of the proteolytic regulation of the Notch signaling network emphasized.
Answer: In conclusion, slight alterations in one player of Notch signaling alter the entire organism, emphasizing the fine-tuning character of this pathway in a high number of processes.
answer:
Does dll1 haploinsufficiency in adult mice lead to a complex phenotype affecting metabolic and immunological processes?

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Context: To evaluate the impact of elevated serum 4A levels on the hormonal and metabolic features of the different phenotypes of PCOS.', '1276 women with PCOS according to the Rotterdam criteria were included, in whom serum hormonal levels were determined.', 'In PCOS women as a whole, as well as in patients presenting clinical and/or biochemical hyperandrogenemia (phenotypes I and II), 4A levels >3.8 ng/ml were positively related to LH, LH/FSH ratio, T, DHEAS, 17 OH progesterone and FAI and negatively related to T/4A ratio. In the milder phenotype III, a positive correlation between 4A levels >3.8 ng/ml and T, DHEAS, 17 OH progesterone and FAI and a negative one between increased 4A and T/4A ratio were reported. In the whole PCOS group with androstenedione >3.8 ng/ml, an increased ovarian volume was observed, while a greater mean follicular number was found only in phenotypes I and II.
Answer: Increased serum 4A levels, which are associated with more severe PCOS phenotypes, possibly contribute to the worsening of PCOS features and therefore could be a valuable marker of biochemical hyperandrogenemia.
answer:
Is elevated serum androstenedione associated with a more severe phenotype in women with polycystic ovary syndrome ( PCOS )?

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Context: Published yields of pH monitoring for suspected laryngopharyngeal reflux (LPR) vary greatly. Hypopharyngeal pH artifacts may be responsible for these inconsistencies.', 'To determine the impact of potential artifacts on pH monitoring of the hypopharynx and esophagus.', 'Patients with suspected LPR were prospectively studied. Single-catheter, triple-sensor pH monitoring was performed off antireflux therapy. Subjects recorded meal times and marked liquid swallows outside of meals on the data recorder. Results were analyzed by excluding six potential pH artifacts individually and all together. Positive pH test was defined as three or more reflux episodes in hypopharynx, total percent of time pH less than 4 was 1.0% or greater in the proximal esophagus, and total percent of time pH less than 4 was 4.2% or greater in the distal esophagus. Wilcoxon rank sum and chi-square tests were used.', 'Thirty-eight subjects (24 females; median age, 47 yr) completed the study. A total of 2,225 hypopharyngeal pH drops less than 4 were identified; 48% were short pH drops at less than 5 seconds, 17% within meal periods, 16% liquid swallows outside of meals, 16% isolated proximal pH drops, 12% pH out of range, and 5% pH drift. Eighty percent of the hypopharyngeal pH drops were at least one of the potential pH artifacts. The yield of the hypopharyngeal sensor was reduced by 45% (from 92% to 47%) after all potential pH artifacts were excluded. Yields of proximal and distal esophageal pH sensors were reduced by 19% and 8%, respectively, significantly less than the hypopharyngeal sensor (P < .01).
Answer: Patients should record all liquid swallows outside of meals. It is essential to exclude all potential artifacts for hypopharyngeal pH monitoring in patients with suspected LPR.
answer:
Is exclusion of pH artifacts essential for hypopharyngeal pH monitoring?