instruction:
In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
question:
Context: In maternal trauma, the Kleihauer-Betke (KB) test has traditionally been used to detect transplacental hemorrhage (TPH), so that Rh-negative women could receive appropriate Rh immune prophylaxis. Reasoning that the magnitude of TPH would reflect uterine injury, we evaluated Kleihauer-Betke testing as an independent predictor of preterm labor (PTL) after maternal trauma.', 'Admissions to the Shock Trauma Center, University of Maryland, from January 1996 to January 2002, were reviewed. Of 30,362 trauma patients admitted, 166 were pregnant, and 93 of these underwent electronic fetal monitoring. Their records were abstracted for demographics, injury type, three separate trauma scores, documented uterine contractions, PTL (contractions with progressive cervical change), and serious perinatal complications. In 71 cases, transplacental hemorrhage was assessed by maternal KB test.', 'TPH, defined as KB-positive for greater than 0.01 mL of fetal blood in the maternal circulation, occurred in 46 women. Forty-four had documented contractions (25 had overt PTL) and 2 had no contractions. In 25 women with a negative KB test, none had uterine contractions. All patients with contractions or PTL had positive KB tests. By logistic regression, KB test result was the single risk factor associated with PTL (p < 0.001; likelihood ratio, 20.8 for positive KB test). Compared with other sites, abdominal trauma was associated more often with uterine contractions (p < 0.001), PTL (p = 0.001), and a positive KB test (p < 0.001, chi). None of the trauma scoring systems predicted PTL.\Question: Is kleihauer-betke testing important in all cases of maternal trauma?
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Kleihauer-Betke testing accurately predicts the risk of preterm labor after maternal trauma. Clinical assessment does not. With a negative KB test, posttrauma electronic fetal monitoring duration may be limited safely. With a positive KB test, the significant risk of PTL mandates detailed monitoring. KB testing has important advantages to all maternal trauma victims, regardless of Rh status.

question:
Context: RNA editing is the process whereby an RNA sequence is modified from the sequence of the corresponding DNA template. In the mitochondria of land plants, some cytidines are converted to uridines before translation. Despite substantial study, the molecular biological mechanism by which C-to-U RNA editing proceeds remains relatively obscure, although several experimental studies have implicated a role for cis-recognition. A highly non-random distribution of nucleotides is observed in the immediate vicinity of edited sites (within 20 nucleotides 5' and 3'), but no precise consensus motif has been identified.", "Data for analysis were derived from the the complete mitochondrial genomes of Arabidopsis thaliana, Brassica napus, and Oryza sativa; additionally, a combined data set of observations across all three genomes was generated. We selected datasets based on the 20 nucleotides 5' and the 20 nucleotides 3' of edited sites and an equivalently sized and appropriately constructed null-set of non-edited sites. We used tree-based statistical methods and random forests to generate models of C-to-U RNA editing based on the nucleotides surrounding the edited/non-edited sites and on the estimated folding energies of those regions. Tree-based statistical methods based on primary sequence data surrounding edited/non-edited sites and estimates of free energy of folding yield models with optimistic re-substitution-based estimates of approximately 0.71 accuracy, approximately 0.64 sensitivity, and approximately 0.88 specificity. Random forest analysis yielded better models and more exact performance estimates with approximately 0.74 accuracy, approximately 0.72 sensitivity, and approximately 0.81 specificity for the combined observations.\Question: Do simple statistical models predict C-to-U edited sites in plant mitochondrial RNA?
answer:
Simple models do moderately well in predicting which cytidines will be edited to uridines, and provide the first quantitative predictive models for RNA edited sites in plant mitochondria. Our analysis shows that the identity of the nucleotide -1 to the edited C and the estimated free energy of folding for a 41 nt region surrounding the edited C are the most important variables that distinguish most edited from non-edited sites. However, the results suggest that primary sequence data and simple free energy of folding calculations alone are insufficient to make highly accurate predictions.

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Context: Mutation of the Chx10 homeobox gene in mice and humans causes congenital blindness and microphthalmia (small eyes). This study used Chx10-/- (ocular retardation) mice to investigate how lack of Chx10 affects progenitor/stem cell behavior in the retina and ciliary epithelium (CE).', 'The distribution of mitotic retinal progenitor cells (RPCs) during embryonic development was analyzed using phosphohistone 3 (H3)-labeling. DNA flow cytometry was used to measure DNA content. The distribution and phenotype of dividing cells in the postnatal retina and CE was analyzed by incorporation of the thymidine analogue BrdU and immunohistochemistry.', 'The Chx10-/- embryonic retina maintained a constantly sized population of mitotic RPCs during development, causing the mitotic index to increase markedly over time compared with the wild type. Also, the proportion of cells in the G1 phase of the cell cycle was increased compared with the wild type. Of interest, division of RPC-like cells with neurogenic properties persisted in the adult Chx10-/- retina. Colabeling for BrdU and the neural progenitor marker nestin or the neuronal markers beta3-tubulin, syntaxin, and VC1.1 showed that new amacrine-like neurons developed in the adult central retina. By contrast, cells with these characteristics were not observed in the mature wild-type retina. In the mature CE, BrdU-positive cells were observed in both wild-type and Chx10-/- mice. However, neurogenesis from this cell population was not evident.\Question: Does absence of chx10 cause neural progenitors to persist in the adult retina?
answer:
Without Chx10, proliferative expansion of the embryonic RPC pool is markedly reduced. In the adult retina, lack of Chx10 results in a population of dividing neural progenitor cells that persist and produce new neurons in the central retina.