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111.
 The cytoplasmic male-sterile (CMS) carrot (Daucus carota ssp. sativus) with the petaloid phenotype was asymmetrically fused with eight different fertile cytoplasms to convert the CMS to a fertile state. Restoration to the fertile phenotype was successful with an over 20% efficiency. Cybrids with brown anther sterile, incomplete petaloid sterile, or "combined flower" fused on the same axis were also observed. Restricted DNA fragment patterns revealed that the mitochondrial genome organizations of the cybrids were not identical to those of their parents but were of an intermediate type. Repeated cell fusion to introduce two different foreign cytoplasms into the CMS cytoplasm was effective for obtaining fertile plants. The role of mitochondrial factors which regulate flower organ morphogenesis was demonstrated. Received: 14 December 1998 / Revision received: 7 March 1999 · Accepted: 3 June 1999  相似文献   
112.
To analyze responses of solid tumors to treatment with antitumor therapy, we applied nonparametric mixed-effects models to investigate tumor volumes measured over a fixed. The population and individual response functions were approximated by penalized splines. Linear mixed-effects modeling was applied in the implementation of the estimation. We applied the approach to an analysis of a real xenograft study of a new antitumor agent, temozolomide, combined with irinotecan. The model fitted the data very well. We conducted a sensitivity analysis to determine the effect of informative dropout. We also propose an intuitive approach to a comparison of the antitumor effects of two different treatments. Biological interpretations and clinical implications are discussed.  相似文献   
113.
A repeated batch process was performed to culture Bifidobacterium longum CCRC 14634. An on-line device, oxidation-reduction potential (ORP), was used to monitor cell growth and uptake of nutrients in the culture. The ORP of the culture medium decreased substantially during fermentation until nutrients were depleted. Six cycles of batch fermentation using ORP as a control parameter were successfully carried out. As soon as ORP remained constant or increased, three-quarters of the broth was removed, and the same volume of fresh medium was fed to the fermenter for a new cycle of cultivation. Average cell concentrations of 1.9×109 and 3.4×109 cfu ml–1 for repeated batch fermentation in MRS (Lactobacilli MRS broth) and WY (containing whey hydrolyzates, yeast extract, l-cysteine) medium, respectively, were achieved. Cell mass productivities for batch, fed-batch and repeated batch fermentation using MRS medium were 0.51, 0.41, and 0.64 g l–1 h–1, respectively, and those for batch and repeated batch using WY medium were 0.76, 0.99 g l–1 h–1, respectively. The results indicate a possible industrial process to culture Bifidobacteria sp.  相似文献   
114.
Identifying changepoints is an important problem in molecular genetics. Our motivating example is from cancer genetics where interest focuses on identifying areas of a chromosome with an increased likelihood of a tumor suppressor gene. Loss of heterozygosity (LOH) is a binary measure of allelic loss in which abrupt changes in LOH frequency along the chromosome may identify boundaries indicative of a region containing a tumor suppressor gene. Our interest was on testing for the presence of multiple changepoints in order to identify regions of increased LOH frequency. A complicating factor is the substantial heterogeneity in LOH frequency across patients, where some patients have a very high LOH frequency while others have a low frequency. We develop a procedure for identifying multiple changepoints in heterogeneous binary data. We propose both approximate and full maximum-likelihood approaches and compare these two approaches with a naive approach in which we ignore the heterogeneity in the binary data. The methodology is used to estimate the pattern in LOH frequency on chromosome 13 in esophageal cancer patients and to isolate an area of inflated LOH frequency on chromosome 13 which may contain a tumor suppressor gene. Using simulations, we show that our approach works well and that it is robust to departures from some key modeling assumptions.  相似文献   
115.
The motivation for the methodological development is a double-blind clinical trial designed to estimate the effect of regular injection of growth hormone, with the purpose of identifying growth hormone abusers in sport. The data formed part of a multicentre investigation jointly sponsored by the European Union and the International Olympic Committee. The data are such that for each individual there is a matrix of marker variables by time point (nominally 8 markers at each of 7 time points). Data arise out of a double-blind trial in which individuals are given growth hormone at one of two dose levels or placebo daily for 28 days. Monitoring by means of blood samples is at 0, 21, 28, 30, 33, 42 and 84 days. We give a new method of Bayesian discrimination for multivariate longitudinal data. This involves a Kronecker product covariance structure for the time by measurements (markers) data on each individual. This structure is estimated by an empirical Bayes approach, using an ECM algorithm, within a Bayesian Gaussian discrimination model. In future one may have markers for an individual at one or more time points. The method gives probabilities that an individual is on placebo or on one of the two dose regimes.  相似文献   
116.
The aim of this study was to compare the capability of a cluster-based exposure variation (C-EVA) with a conventional exposure variation analysis (EVA) to detect muscular adaptation in the shoulder joint to subsequent sessions of eccentric exercise (ECC). Eleven healthy subjects performed work with a computer mouse for 10 min at three instants, i.e., before, immediately after, and 24 h after ECC. The subjects repeated an identical procedure one week after the first session. Surface electromyography was recorded from descending and ascending part of the trapezius, deltoid anterior, and serratus anterior muscles. EVA and C-EVA were performed and their marginal distributions were extracted. A principal component analysis was applied to the marginal distributions of both EVA and C-EVA. Principal component difference was computed by subtraction of the corresponding principal components before the ECC from immediately after and 24 h after the ECC. The first component extracted from C-EVA revealed an interactive effect between the sessions of ECC and instants whereas this effect was absent using the conventional EVA. The current study highlights the importance of a multivariate approach to analyze the potentially important changes in muscular activity in response to the repeated bout effect.  相似文献   
117.
《Mammalian Biology》2014,79(4):254-258
Low density occurrence of large carnivore species and direct hunting of predators and prey make carnivore conservation complex. Vital baseline information on population status of large carnivores is still deficient in most forests of eastern Himalaya, which are known to be the biodiversity hotspots. To fill this information gap, we estimated the large carnivore population status and abundance in an intricate eastern Himalayan lowland tropical forest in Pakke Tiger Reserve, Arunachal Pradesh. Population status and abundance estimates of tigers and leopards were made through individual identification using closed capture-recapture sampling. To estimate the dhole abundance photographic encounter rate was used. For individually non-identifiable species photographic rate seemed to correlate well with animal abundance. The estimated tiger and leopard density through 1/2 MMDM was 2.14 ± 0.04/100 km2 and 2.99 ± 1.13/100 km2 respectively. Maximum likelihood estimates shows density of tiger 1.86 ± 0.7 and for leopard 2.82 ± 1.2.The estimated dhole abundance was (N) 10.6 ± 0.94, and density 6.62 ± 0.58 individuals in 100 km2. Further, occupancy estimation of large carnivores may be tried along with assessing the comparative efficacy of other population estimation methods to establish better monitoring methods for this region.  相似文献   
118.
摘要 目的:研究重复经颅磁刺激以及阿普唑仑联用治疗失眠症伴焦虑患者的效果。方法:选择2015年1月~2019年12月我院神经内科收治的81例失眠症伴焦虑患者,将其随机分为两组。对照组每晚在睡前30 min服用阿普唑仑0.8 mg,观察组联用重复经颅磁刺激。比较两组的临床疗效,治疗前后焦虑评分、生活质量和睡眠质量评分的变化。结果:治疗后,观察组的有效率为95.00 %,明显高于对照组(73.17 %,P<0.05);两组焦虑评分均较治疗前明显降低(P<0.05),心理领域、社会领域、环境领域和生理领域评分均较治疗前明显升高(P<0.05),且观察组的焦虑评分和心理领域、社会领域、环境领域、生理领域评分明显优于对照组(P<0.05);两组的睡眠持续性、主观睡眠质量、睡眠障碍、日间功能、睡眠潜伏期、安眠药物和入睡时间评分均较治疗前明显升高(P<0.05),且观察组以上指标均明显高于对照组(P<0.05)。结论:重复经颅磁刺激以及阿普唑仑联用治疗失眠症伴焦虑患者的效果明显优于单用阿普唑仑治疗,其能有效减轻其焦虑程度,提高患者生活质量及睡眠质量。  相似文献   
119.
The aim of this study was (i) to evaluate whether homocysteine (Hcy), total antioxidant status (TAS), and biological markers of muscle injury would be affected by time of day (TOD) in football players and (ii) to establish a relationship between diurnal variation of these biomarkers and the daytime rhythm of power and muscle fatigue during repeated sprint ability (RSA) exercise. In counterbalanced order, 12 football (soccer) players performed an RSA test (5?×?[6 s of maximal cycling sprint?+?24 s of rest]) on two different occasions: 07:00–08:30?h and 17:00–18:30?h. Fasting blood samples were collected from a forearm vein before and 3–5?min after each RSA test. Core temperature, rating of perceived exertion, and performances (i.e., Sprint 1, Sprint 2, and power decrease) during the RSA test were significantly higher at 17:00 than 07:00?h (p?<?.001, p?<?.05, and p?<?.05, respectively). The results also showed significant diurnal variation of resting Hcy levels and all biological markers of muscle injury with acrophases (peak times) observed at 17:00?h. These fluctuations persisted after the RSA test. However, biomarkers of antioxidant status' resting levels (i.e., total antioxidant status, uric acid, and total bilirubin) were higher in the morning. This TOD effect was suppressed after exercise for TAS and uric acid. In conclusion, the present study confirms diurnal variation of Hcy, selected biological markers of cellular damage, and antioxidant status in young football players. Also, the higher performances and muscle fatigue showed in the evening during RSA exercise might be due to higher levels of biological markers of muscle injury and lower antioxidant status at this TOD. (Author correspondence: )  相似文献   
120.
ObjectivesTo present a new predictive model for repeated prostate biopsy outcomes. Several practical problems are described that arise when searching for a proper model among those that already exist. A new model is developed with only two explanatory variables and a simple graphical output.MethodsThis is a retrospective cohort study based on data collected from December 2006 to June 2011 at the Clinic of Urology of the University Hospital in Olomouc, Czech Republic. The cohort consists of 221 patients who underwent the first repeated biopsy after an initial biopsy with a negative outcome. All patients had prostate-specific antigen (PSA) levels between 1.5 and 16.5 ng/mL and a prostate volume not greater than 100 mL. A logistic regression model was fitted.ResultsOf the 221 patients, 29 (13%) were diagnosed with prostate cancer on the repeated biopsy. The final model includes the PSA level and the transitory zone volume as predictors. Its accuracy is 76.4%. The cut-off point of 0.0687 in the predicted positive repeated biopsy outcome assures 95% sensitivity and prevents 42% of unnecessary biopsies.ConclusionsThe accuracy of the model is comparable to that of more complex models (with more than two predictors) published in the literature. The model includes only two routinely measured variables, and hence it is accessible for a wide range of practitioners. The simple graphical outcome makes the model even more attractive.  相似文献   
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