The rare semi-leptonic BcB_c decays involving orbitally excited final mesons

The rare processes $B_c\to D_{(s)J} ^{(*)}\mu\bar{\mu}$, where $D_{(s)J}^{(*)}$ stands for the final meson $D_{s0}^*(2317)$, $D_{s1}(2460,2536)$,~$D_{s2}^*(2573)$, $D_0^*(2400)$, $D_{1}(2420,2430)$ or~$D_{2}^*(2460)$, are studied within the Standard Model. The hadronic matrix elements are evaluated in the Bethe-Salpeter approach and furthermore a discussion on the gauge-invariant condition of the annihilation hadronic currents is presented. Considering the penguin, box, annihilation, color-favored cascade and color-suppressed cascade contributions, the observables $\text{d}Br/\text{d}Q^2$, $A_{LPL}$, $A_{FB}$ and $P_L$ are calculated

MATHEMATICAL MODELING REVEALS THAT G2/M CHECKPOINT OVERRIDE

Cell cycle checkpoints determine whether cells meet requirements to progress through the next stage. In response to DNA damage, how cells activate checkpoints have been well studied, but little is known about checkpoint deactivation (recovery), which directly impacts on cell fate. In tumor cells, the signaling network has been rewired due to epigenetic and genetic alterations, which result in resistance to the cell cycle control, and thus resistance to chemotherapy or radiation therapy. Therefore, it is critical to identify molecules required for checkpoint recovery or adaptation after DNA damage. To achieve this goal, we performed a multidisciplinary study combining reverse phase protein array (RPPA) data, molecular biology and mathematical modeling to systematically identify molecules required for DNA damage checkpoint recovery. The mTOR complex 1 (mTORC1) plays an essential role to regulate mitotic entry after irradiation. Inhibition of the mTOR pathway delayed G2/M checkpoint recovery, while TSC2-null cells with hyperactivity of mTORC1 exhibited the opposite results. Furthermore, our mechanistic study revealed that mTOR signaling pathway controls a transcriptional program of mitotic entry through regulating histone lysine demethylase KDM4B, which is required for the epigenetic regulation of key mitosis-related genes including CCNB1 and PLK1. Given accelerated G2/M checkpoint recovery in TSC2-null cells with mTORC1 hyperactivity, we postulated that further abrogation of the G2/M checkpoint may facilitate mitotic catastrophe and selectively kill cells. As we expected, TSC2-null cells were more sensitive to the WEE1 inhibitor, a negative regulator of mitotic entry, compared to wild-type cells. In summary, we reported a novel mechanism of the mTORC1 signaling in regulating a transcriptional program required for G2/M checkpoint recovery after DNA damage. This mechanism provided a therapeutic strategy for TSC patients with mTORC1 hyperactivity using the WEE1 inhibitor, which has a potential to be translated into clinical trials

Socioeconomic geography of organic agriculture in the United States, 2007-2012

Recent trends have shown that organic agriculture in the United States may longer form a homogeneous group. To better understand the spatial pattern of organic farming, the overall research objective is to examine organic agriculture and its ecological, technological, and socioeconomic correlates based on an agroecosystem framework combining Hernandez\u27s model and Flora and Flora\u27s community capitals framework. Using multiple measures of organic agriculture at the meso-scale during the period between 2007 and 2012, results from cluster analysis indicate that the typology of N=3,069 counties includes a majority of Low Intensity places, two groups of Moderate and High Intensity clusters that have seen a relatively large concentrate of organic farms and sales, and a small number of counties in clusters of Growing Farms and Growing Sales are rapidly expanding in place dominated by conventional agriculture. Through multinomial logistic regression, regional differences of organic farming are strongly associated with environmental factors such as climate and topography. Although technology employment has little effects on organic production, organic intensive places tend to have more diverse farm operations by having more women operators and direct sales to people and the community. Results show mixed support to link organic production systems with better socioeconomic settings. Places with moderate organic activity generally are more ethnically diverse and better educated. Nevertheless, they tend to have high dependency ratio. Places with high intensity organic production have higher labor force participation and higher community engagement; they also have higher rates of poverty. Further, organic market expansion is also associated with the services economy, for moderate intensity places tend to have more services occupations and organic service enterprises. To identify significant patterns of organic spatial dependence, a local indicator of spatial association (LISA) using G* statistic is used to examine local pocket of spatial concentration. Results indicate that organic hot spots are primarily located in the New England, along the Pacific Coast, around the Northern Great Lakes, and in the Mountain West. In terms of organic geography, high (low) organic places tend to be located near other high (low) organic places. Despite government support of organic farming has mostly been limited to creating a legislative standard and organic certification, the findings bring awareness that indirect political influences through the markets such as farm-to-school program are more likely to assist with the organic development. While higher intensive of organic production exhibits signs of conventionalization because they tend to be large-scale and capital intensive, the results didn\u27t find that smaller organic growers are been marginalized. By contrast, small- and middle-sized organic production tends to stay true to the traditional and movement-oriented organic. To broadly capture the organic heterogeneity, this study suggests more analytical attention to complex interactions among environmental, socioeconomic, and political drivers, ranging from agricultural nature, such as historical geography, to local socioeconomic contexts and the corresponding community-embedded relations

Learner Autonomy: The Role of Motivation in Foreign Language Learning

Among the many learner variables that may influence language learning, autonomy is a very unique one because it involves learners being responsible for their own learning. In the current study, autonomy is operationally defined as a construct comprising three components: sense of responsibility, engagement in learning activities, and perceived ability. This study aimed to provide insights into the construct and gain a further understanding of its relationship with motivation among students learning English as a foreign language. The sample included university freshmen who were non-English majors and were taking required English classes at the time of the study. The results suggested that participants possessed a satisfactory level of autonomy when asked about their perceptions of responsibility, whereas they tended to possess an unsatisfactory level of autonomy regarding engagement in learning activities inside or outside the classroom. In addition, the results indicated that students of all three proficiency levels tended to perceive their ability as being mediocre. Significant differences in all three aspects of learner autonomy were observed for participants with different motivation levels. Furthermore, the findings establish that motivation and autonomy had a high level of positive correlation. Engagement frequency of learning activities had the strongest association with motivation, followed by perceived ability and responsibility. Finally, the results revealed that motivation effectively contributed to predicting autonomy, accounting for a relatively high amount (50%) of variance in the dependent variable

Reinsurance: Bad Faith Considerations and Insolvency Dilemma

Reinsurance is insurance that an insurance company purchases from another insurance company. The original insurance company is called the reinsured, and the insurance company that is contracted is called the reinsurer. The main purpose of reinsurance is to disperse or spread the risk of loss. The reinsurance relationship is frequently characterized as an exercise of fiduciary responsibility based upon an undertaking of utmost good faith between contracting parties. However, disputes arise; most litigation involving reinsurance has been between reinsurers and persons not party to the reinsurance agreement. This paper’s first major area of discussion is the relationship between the reinsurer and the reinsured. In particular this paper will focus on whether the duty of disclosure in the reinsurance context rises to a fiduciary duty, issues concerning reinsurers’ involvement in the defense of claims, and the liability of the reinsurer to reimburse ceding companies for losses resulting from the ceding company’s failure to perform contractual obligations. This paper’s second major area of analysis concerns reinsurance-related issues stemming from the insolvency of insurers. Finally, this paper discusses the insolvency dilemma that the insurance industry has recently encountered and examines possible options available to reinsurers and the reinsured in their efforts to stabilize practices in the reinsurance business

Exploring college students’ motivational beliefs in ability-grouped English classes in Taiwan

According to research on social-cognitive theory, motivation can be defined as a way of belief in one’s own competence, to value the task and further to achieve the set goals. Researchers have suggested a direct link between motivation beliefs and student achievement. In order to understand whether the motivation beliefs of students would be different in an EFL ability grouping context, this study examined an integrated motivation model including instrumentality, achievement goal, self-efficacy, expectancy-value, attribution, and self-regulation amongst three different ability groups at one university in Taiwan. Participants were grouped in three different level based on their pre-test scores: advanced level group, higher-intermediate level group and intermediate level group. Their academic achievements were demonstrated comparing their attitude towards ability grouping with their perception of the motivation variables. The purpose of this research is to discover whether ability grouping setting is beneficial for both student motivation and performance in EFL classes. In a survey study, 681 college students in a first-year undergraduate English course completed a motivation questionnaire. The results of this study revealed that student instrumentality, achievement goal, expectancy-value, self-efficacy and self-regulation are significantly positively correlated with their attitudes in an ability grouping context. Linear regression analyses demonstrate that expectancy-value was the strongest predictor of students’ post-test scores, and there are other predictors such as student level and their perception of attributions. However, self-efficacy, performance goals, and self-regulation were not significant predictors to student academic performance in the integrated model. In addition, the study revealed a preference of mastery goals for students in higher ability groups and a preference of attributions for lower-achieving group. However, there were no differences in instrumentality, performance goals, and self-regulation amongst the three ability groups, suggesting that students at ability grouping classes are no difference in the motivational belief of instrumental goal, performance goals and self-regulation. By contrast, there were differences in student motivation in attitudes, instrumentality, expectancy-value, mastery goal, self-efficacy and mastery goals in an ability grouping class. Consequently, the findings suggest teachers should be encouraged to create an environment where developing student motivation is encouraged in order to develop further the achievement rate within the confines of an EFL ability grouping class

COMPARISON OF METHODS INCORPORATING COVARIATES INTO AFFECTED SIB PAIR LINKAGE ANALYSIS

Complex diseases such as type 2 diabetes, hypertension and psychiatric disorders have been major public health problems in US. In order to increase the power in the linkage analysis of complex traits, genetic heterogeneity has to be taken into account. During the past few years, several methods have been proposed for dealing with this issue by incorporating covariate information into the affected sib pair (ASP) analysis. However, it is still not clear how these approaches perform under different gene-environment (G x E) interactions. The covariate statistics evaluated in this study are: (1) mixture model; (2) general conditional-logistic model (LODPAL); (3) multinomial logistic regression models (MLRM under no dominance, no additive and min-max restriction); (4) extension of the maximum-likelihood-binomial approach (MLB); (5) ordered-subset analysis (OSA with three different rank orders: high-to-low, low-to-high and optimal-slice); (6) logistic regression modeling (COVLINK). Based on the chromosome-based approach, we have written simulation programs to generate data under various G x E models and disease models. We first define the empirical statistical significance thresholds using C2, the environmental risk factor, under the null hypothesis. We then evaluate the power of the covariate statistics when different covariates are used. We also compare the performance of the covariate statistics with the model-free methods (Sall and Spair). In all three G x E interaction models, most covariate methods perform better when using C1, the covariate with G x E interaction effect, than when using C2 or the random noise covariate C3, except for MLB and the low-to-high OSA method. Comparing with the model-free methods (using Sall as the baseline), mixture model and the high-to-low OSA method perform the best of the covariate statistics when using C1. However, when using C2 or C3, most covariate statistics provide less power than Sall. Only MLB has comparable power to Sall across all genetic models. According to our results, in different G x E interactions, one should apply the appropriate covariate statistic and include the suitable type of covariates carefully