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.

Q: Context: We quantitatively evaluated the collagen-to-smooth muscle tissue matrix ratio in ureteropelvic junction obstruction, and compared the ratio with the degree of obstruction, patient age and postoperative renal recovery.', "We analyzed histological sections from 65 patients with ureteropelvic junction obstruction and 6 normal controls. Morphological and functional grading systems were adapted to determine the degree of renal obstruction. To examine smooth muscle and collagen tissue, sections were stained using Masson's trichrome. Two distinct populations of collagen versus smooth muscle were identified and the tissue matrix ratio was calculated by color image analysis.", 'The mean tissue matrix ratio plus or minus standard deviation was 1.32+/-0.79 in all patients with ureteropelvic junction obstruction but only 0.30+/-0.10 in normal controls (p <0.0001). It appeared that the lower the tissue matrix ratio, the better the improvement in postoperative hydronephrosis (r = -0.50, p = 0.0001). Better recovery of renal function after pyeloplasty was observed with a decrease in the tissue matrix ratio (r = -0.43, p = 0.0004). We divided patients according to the tissue matrix ratio into groups 1--ratio 1 or less, 2--greater than 1 to 1.5 and 3--greater than 1.5 to determine a more detailed and clinically applicable correlation of tissue matrix ratio with postoperative renal functional changes. Better improvement in postoperative renal function was observed in group 1 than in group 3 (p = 0.002). Also, the tissue matrix ratio increased with patient age (r = 0.33, p = 0.007).
Answer: Since our data represent an objective and quantitative parameter associated with ureteropelvic junction obstruction, we believe that our findings may help to predict the prognosis after pyeloplasty.

A: Does collagen-to-smooth muscle ratio help prediction of prognosis after pyeloplasty?
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Q: Context: Biotechnological screening processes are performed since more than 8 decades in small scale shaken bioreactors like shake flasks or microtiter plates. One of the major issues of such reactors is the sufficient oxygen supply of suspended microorganisms. Oxygen transfer into the bulk liquid can in general be increased by introducing suitable baffles at the reactor wall. However, a comprehensive and systematic characterization of baffled shaken bioreactors has never been carried out so far. Baffles often differ in number, size and shape. The exact geometry of baffles in glass lab ware like shake flasks is very difficult to reproduce from piece to piece due to the hard to control flow behavior of molten glass during manufacturing. Thus, reproducibility of the maximum oxygen transfer capacity in such baffled shake flasks is hardly given.', 'As a first step to systematically elucidate the general effect of different baffle geometries on shaken bioreactor performance, the maximum oxygen transfer capacity (OTRmax) in baffled 48-well microtiter plates as shaken model reactor was characterized. This type of bioreactor made of plastic material was chosen, as the exact geometry of the baffles can be fabricated by highly reproducible laser cutting. As a result, thirty different geometries were investigated regarding their maximum oxygen transfer capacity (OTRmax) and liquid distribution during shaking. The relative perimeter of the cross-section area as new fundamental geometric key parameter is introduced. An empirical correlation for the OTRmax as function of the relative perimeter, shaking frequency and filling volume is derived. For the first time, this correlation allows a systematic description of the maximum oxygen transfer capacity in baffled microtiter plates.
Answer: Calculated and experimentally determined OTRmax values agree within ± 30% accuracy. Furthermore, undesired out-of-phase operating conditions can be identified by using the relative perimeter as key parameter. Finally, an optimum well geometry characterized by an increased perimeter of 10% compared to the unbaffled round geometry is identified. This study may also assist to comprehensively describe and optimize the baffles of shake flasks in future.

A: Is cross-section perimeter a suitable parameter to describe the effects of different baffle geometries in shaken microtiter plates?
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Q: Context: Chlorophyll b is a major photosynthetic pigment in green plants that is synthesized by chlorophyllide a oxygenase (CAO). The regulation of chlorophyll b biosynthesis is an important determinant for the antenna size of photosystems. Chlorophyll b synthesis is partly regulated on a transcriptional level by the expression of the CAO gene. In addition, the synthesis of chlorophyll b is strictly regulated on a protein level by the stability of the CAO enzyme. CAO consists of three domains, which are sequentially named from the N terminus as the A, B and C domains. The A domain of CAO participates in the regulation of the CAO protein stability.', 'In order to clarify the physiological function of the A domain, we constructed transgenic Arabidopsis (Arabidopsis thaliana) plants which either overexpressed the complete CAO or a truncated version of CAO lacking the A domain. The transgenic plants overexpressing the A-domain-deleted CAO accumulated an excess amount of chlorophyll b during greening. The transgenic plants which lacked the A domain either died or were obviously retarded when they were exposed to continuous light immediately after etiolation. In addition, the loss of the A domain in CAO impaired another step of chlorophyll biosynthesis, namely the conversion of divinyl-protochlorophyllide a to monovinyl protochlorophyllide a under dark conditions.
Answer: The A domain of CAO regulates the level of CAO, and thus prevents the excess accumulation of chlorophyll b. This function of the A domain is especially important during the greening stage of etiolated seedlings. At this stage, the plants are vulnerable to photodamages which could be caused by excessive chlorophyll b accumulation. In addition, de-regulation of the CAO level affects monovinyl-protochlorophyllide biosynthesis in darkness by unknown mechanisms. In conclusion, the A domain of CAO is essential in the control of chlorophyll biosynthesis and in the survival of seedlings during de-etiolation especially under strong illumination.

A:
Does loss of the N-terminal domain of chlorophyllide a oxygenase induce photodamage during greening of Arabidopsis seedlings?
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