Consistent distribution-free KK-sample and independence tests for univariate random variables

A popular approach for testing if two univariate random variables are statistically independent consists of partitioning the sample space into bins, and evaluating a test statistic on the binned data. The partition size matters, and the optimal partition size is data dependent. While for detecting simple relationships coarse partitions may be best, for detecting complex relationships a great gain in power can be achieved by considering finer partitions. We suggest novel consistent distribution-free tests that are based on summation or maximization aggregation of scores over all partitions of a fixed size. We show that our test statistics based on summation can serve as good estimators of the mutual information. Moreover, we suggest regularized tests that aggregate over all partition sizes, and prove those are consistent too. We provide polynomial-time algorithms, which are critical for computing the suggested test statistics efficiently. We show that the power of the regularized tests is excellent compared to existing tests, and almost as powerful as the tests based on the optimal (yet unknown in practice) partition size, in simulations as well as on a real data example.Comment: arXiv admin note: substantial text overlap with arXiv:1308.155

A synthetic biology approach for evaluating the functional contribution of designer cellulosome components to deconstruction of cellulosic substrates

BACKGROUND: Select cellulolytic bacteria produce multi-enzymatic cellulosome complexes that bind to the plant cell wall and catalyze its efficient degradation. The multi-modular interconnecting cellulosomal subunits comprise dockerin-containing enzymes that bind cohesively to cohesin-containing scaffoldins. The organization of the modules into functional polypeptides is achieved by intermodular linkers of different lengths and composition, which provide flexibility to the complex and determine its overall architecture. RESULTS: Using a synthetic biology approach, we systematically investigated the spatial organization of the scaffoldin subunit and its effect on cellulose hydrolysis by designing a combinatorial library of recombinant trivalent designer scaffoldins, which contain a carbohydrate-binding module (CBM) and 3 divergent cohesin modules. The positions of the individual modules were shuffled into 24 different arrangements of chimaeric scaffoldins. This basic set was further extended into three sub-sets for each arrangement with intermodular linkers ranging from zero (no linkers), 5 (short linkers) and native linkers of 27–35 amino acids (long linkers). Of the 72 possible scaffoldins, 56 were successfully cloned and 45 of them expressed, representing 14 full sets of chimaeric scaffoldins. The resultant 42-component scaffoldin library was used to assemble designer cellulosomes, comprising three model C. thermocellum cellulases. Activities were examined using Avicel as a pure microcrystalline cellulose substrate and pretreated cellulose-enriched wheat straw as a model substrate derived from a native source. All scaffoldin combinations yielded active trivalent designer cellulosome assemblies on both substrates that exceeded the levels of the free enzyme systems. A preferred modular arrangement for the trivalent designer scaffoldin was not observed for the three enzymes used in this study, indicating that they could be integrated at any position in the designer cellulosome without significant effect on cellulose-degrading activity. Designer cellulosomes assembled with the long-linker scaffoldins achieved higher levels of activity, compared to those assembled with short-and no-linker scaffoldins. CONCLUSIONS: The results demonstrate the robustness of the cellulosome system. Long intermodular scaffoldin linkers are preferable, thus leading to enhanced degradation of cellulosic substrates, presumably due to the increased flexibility and spatial positioning of the attached enzymes in the complex. These findings provide a general basis for improved designer cellulosome systems as a platform for bioethanol production

Health promotion programs in prison: attendance and role in promoting physical activity and subjective health status

IntroductionMaintaining an inmate’s health can serve as a challenge due to unhealthy background, risky behavior, and long imprisonment. This study aimed to analyze the prevalence of participation in health promotion activities among Israeli inmates and its association with their physical activity levels and subjective health status.MethodsA cross-sectional study was designed to examine 522 inmates (429 males, 93 females). The data were collected by trained face-to-face interviewers and self-report questionnaires.ResultsMost of the participants (82.37%) did not meet the recommended physical activity level. Half of the participants reported that their physical activity levels decreased since they were in prison compared with 29.50% who reported that their physical activity levels increased. Physical activity and subjective health status were significantly higher among younger male inmates. Furthermore, participation in health-promoting activities was associated with higher levels of physical activity and subjective health status.DiscussionHealth promotion activities may play an important role in addressing the challenges of maintaining inmate health. Implications of the findings are further discussed

Self and body esteem perception in multiple sclerosis 1

Self esteem and body esteem were examined in a group of 35 relapsing-remitting multiple sclerosis (MS) patients using the Body Esteem Scale (BES) and the Eysenck Self Esteem Scale (ESES) and compared to age and sex matched normal controls. There were 23 females and 12 males in the MS patient's group; average age 38.9 years (range: 22-52). All participants completed the self-rated BES evaluating the following subscales: females -sexual attractiveness, physical condition and weight concern; males -physical attractiveness, physical condition and upper body strength. In addition all participants were scored, following a semi-structured interview, on the ESES. Psychiatric co-morbidity was excluded using a semi-structured interview by the consulting psychiatrist. All evaluations were carried out during the remitting phase. Statistical analysis, comparing patients to healthy controls, demonstrated lowered self-rating of the physical condition (males < 0.05, females < 0.001). On the other hand, no significant differences were found in the physical (male) or sexual (female)-attractiveness subscales. The mean ESES score in the patients group was 23.2 ± 4.0, slightly above the reported average. The controls mean ESES was 28.4 ± 3.6, (P < 0.05). No correlation was found between self and body esteem amongst M.S. patients. This study emphasizes impaired perception of body esteem in multiple sclerosis patients even in remission. The preservation of physical and sexual attractiveness may be related to the non-disfiguring nature of the disease. Preservation of self-esteem in MS patients suggests that body-esteem should be the focus of supportive treatment