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.

[Q]: Bone and antler collagen δ(13) C and δ(15) N values are often assumed to be equivalent when measured in palaeodietary, palaeoclimate and palaeocological studies. Although compositionally similar, bone grows slowly and is remodelled whereas antler growth is rapid and remodelling does not occur. These different patterns of growth could result in isotopic difference within antler and between the two tissue types. Here we test whether red deer (Cervus elaphus) bone and antler δ(13) C and δ(15) N values are equivalent, and whether intra-antler isotopic values are uniform.', 'Bone and antler were isotopically analysed from six stags that lived in a temperate maritime climate on the Isle of Rum, Scotland. Multiple antlers from different years were sampled per individual, together with a single bone sample per individual. Up to 12 samples were taken along the length of each antler (total of 25 antlers, 259 samples) so that a chronological record of the isotopic composition during antler growth could be obtained. Collagen was extracted and its δ(13) C and δ(15) N values were measured by continuous-flow isotope ratio mass spectrometry.', 'Intra-antler collagen isotope signatures vary, and show that not all antlers from an individual or a growth year are equivalent in carbon and nitrogen isotopic ratios. δ(15) N values typically increase with distance along antler length, but no overall trend is observed in δ(13) C values. An isotopic offset is visible between bone and antler, with bone δ(13) C and δ(15) N values being higher in most cases.
[A]: Are red deer bone and antler collagen isotopically equivalent in carbon and nitrogen?


[Q]: Previous research in fetuses with increased nuchal translucency (NT) showed abnormal lymphatic endothelial differentiation characteristics, including increased vascular endothelial growth factor (VEGF)-A expression, and aberrant smooth muscle cells (SMCs) surrounding enlarged jugular lymphatic sacs (JLS). We hypothesized that abnormal Sonic hedgehog (Shh) expression would result in altered VEGF-A signaling in the lymphatic endothelial cells of the JLS and that aberrant acquisition of SMCs could be caused by downregulation of forkhead transcription factor FOXC2 and upregulation of platelet-derived growth factor (PDGF)-B in the lymphatic endothelial cells of the JLS.', 'Five trisomy 21 fetuses and four controls were investigated using immunohistochemistry for Shh, VEGF-A, FOXC2 and PDGF-B expression in the lymphatic endothelial cells of the JLS.', 'An increased Shh, VEGF-A and PDGF-B expression, and decreased FOXC2 expression were shown in the lymphatic endothelial cells of the JLS of the trisomic fetuses.
[A]: Does abnormal Shh and FOXC2 expression correlate with aberrant lymphatic development in human fetuses with increased nuchal translucency?


[Q]: Cocaine and alcohol are frequently used simultaneously and this combination is associated with enhanced toxicity. We recently showed that active cocaine abusers have a markedly enhanced sensitivity to benzodiazepines. Because both benzodiazepines and alcohol facilitate GABAergic neurotransmission we questioned whether cocaine abusers would also have an enhanced sensitivity to alcohol that could contribute to the toxicity. In this study we compared the effects of alcohol (0.75 g/kg) on regional brain glucose metabolism between cocaine abusers (n = 9) and controls (n = 10) using PET and FDG. Alcohol significantly decreased whole brain metabolism and this effect was greater in controls (26+/-6%) than in abusers (17+/-10%) even though they had equivalent levels of alcohol in plasma. Analysis of the regional measures showed that cocaine abusers had a blunted response to alcohol in limbic regions, cingulate gyrus, medial frontal and orbitofrontal cortices.
[A]:
Do cocaine abusers show a blunted response to alcohol intoxication in limbic brain regions?