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?


question:
Context: Behavioral studies of spatial navigation in aging indicate that orientation using an allocentric reference frame (object-centered orientation) is impaired, whereas orientation using egocentric processes (self-centered orientation) is not. It has been proposed that navigational deficits may result from more general alterations of perception and attention or executive functions. The purpose of this study is to assess allocentric and egocentric representation in elderly individuals, and to determine if age-related deficits in spatial navigation are related to an attentional decline.', 'We assessed encoding of the position of geometrical shapes, depending specifically on an allocentric or egocentric reference frame, during ERP recording in young and old subjects.', 'Aging was associated with a performance decline in allocentric, but not egocentric, encoding. Both allocentric and egocentric conditions elicited parietal early components P1 and N1, reflecting top-down modulation, and components P2 and N2, reflecting selective attention and stimulus categorization. We observed age-associated effects on N1 and N2 amplitudes and on N2 latency in both spatial conditions. Moreover, impaired allocentric performance in older subjects was associated with a greater P2 amplitude and delayed P2 latency compared with younger subjects.
Answer: These results suggest that elderly individuals present with deficits when spatial orientation relies on allocentric representation, and are associated with age-related deficits in spatial attention.
answer:
Is allocentric but not egocentric orientation impaired during normal aging : an ERP study?


question:
Context: To test the hypothesis that a novel phase-contrast optical coherence tomography (OCT) system can image retinal and choroidal vessels in the living mouse.', 'A high-speed spectral domain optical coherence tomography (SDOCT) system, which measures the reflections for the entire depth of the retina at once with each axial scan (A-scan), was developed for mouse retinal imaging. Acquiring multiple A-scans over a transverse line across the mouse retina offers a two-dimensional cross-sectional image (B-scan); several neighboring B-scans can be assembled into a three-dimensional OCT image. To visualize mobility and transverse flow in retinal vessels, the statistical variance of phase for each location was calculated from multiple B-scans acquired successively for the same retinal cross-section. Such measures of phase variance offer a direct measure of motions over a large dynamic range of flow velocities.', 'Three-dimensional phase-contrast images of the live mouse retina were created using multiple two-dimensional cross-sectional image slices through the retina. For the data presented here, each cross-sectional phase-contrast slice resulted from five images of 100 or 200 transverse pixels, acquired over 25 ms or 50 ms, respectively. The approach offered clear identification of motion regions at different depths, including flow in the retinal microvasculature and in the choroidal vessels.
Answer: Phase-contrast OCT enables three-dimensional visualization of retinal and choroidal vasculature in vivo.
answer:

Does phase-contrast OCT imaging of transverse flow in the mouse retina and choroid?