B meson decays to baryons in the diquark model

We study B meson decays to two charmless baryons in the diquark model, including strong and electroweak penguins as well as the tree operators. It is shown that penguin operators can enhance \bar{B} \to \Bb_s \bar{\Bb} considerably, but affect \bar{B} \to \Bb_1 \bar{\Bb}_2 only slightly, where \Bb_{(1,2)} and \Bb_s are non-strange and strange baryons, respectively. The $\gamma$ dependence of the decay rates due to tree-penguin interference is illustrated. In principle, some of the \Bb_s \bar{\Bb} modes could dominate over \Bb_1 \bar{\Bb}_2 for $\gamma > 90^\circ$, but in general the effect is milder than their mesonic counterparts. This is because the $O_6$ operator can only produce vector but not scalar diquarks, while the opposite is true for $O_1$ and $O_4$. Predictions from diquark model are compared to those from the sum rule calculation. The decays \bar{B} \to \Bb_s \bar{\Bb}_s and inclusive baryonic decays are also discussed.Comment: 9 pages, 6 figures, Revte

A Study on the Social and the Environmental Impacts of Bottled Water & A Design Solution to Improve the User Experience of Reusable Water Bottles

The consumption of bottled water is likely to emerge as a global trend in the coming decades. The expansion of the bottled water industry and rapid growth of bottled water sales has caused serious concerns regarding the possible contamination of bottled water, the impact of its refuse on the environment, and the management of water resources. Some factors accelerating the sales and use of bottled water are complex and multifaceted and involve pollution, values, politics, water shortages, commercial behaviors, consumption behaviors, a widening disparity between the rich and poor within society, and the unfair distribution of resources. Any single solution is unlikely to alter the overall circumstances. However, some relevant issues may be altered or alleviated through individual effort, such as the habit of drinking bottled water. Based on the data collected through surveys and interviews, if the user experience of a reusable water bottle can be improved by increasing its portability, the consumers’ intention to use reusable water bottles will increase, resulting in encouragement of the habit of drinking tap water and a decrease in the reliance on bottled water. The more that people drink tap water, then the less that bottled water consumption will negatively affect the environment, society, and the public health

Coordinated Multicasting with Opportunistic User Selection in Multicell Wireless Systems

Physical layer multicasting with opportunistic user selection (OUS) is examined for multicell multi-antenna wireless systems. By adopting a two-layer encoding scheme, a rate-adaptive channel code is applied in each fading block to enable successful decoding by a chosen subset of users (which varies over different blocks) and an application layer erasure code is employed across multiple blocks to ensure that every user is able to recover the message after decoding successfully in a sufficient number of blocks. The transmit signal and code-rate in each block determine opportunistically the subset of users that are able to successfully decode and can be chosen to maximize the long-term multicast efficiency. The employment of OUS not only helps avoid rate-limitations caused by the user with the worst channel, but also helps coordinate interference among different cells and multicast groups. In this work, efficient algorithms are proposed for the design of the transmit covariance matrices, the physical layer code-rates, and the target user subsets in each block. In the single group scenario, the system parameters are determined by maximizing the group-rate, defined as the physical layer code-rate times the fraction of users that can successfully decode in each block. In the multi-group scenario, the system parameters are determined by considering a group-rate balancing optimization problem, which is solved by a successive convex approximation (SCA) approach. To further reduce the feedback overhead, we also consider the case where only part of the users feed back their channel vectors in each block and propose a design based on the balancing of the expected group-rates. In addition to SCA, a sample average approximation technique is also introduced to handle the probabilistic terms arising in this problem. The effectiveness of the proposed schemes is demonstrated by computer simulations.Comment: Accepted by IEEE Transactions on Signal Processin

Relationship between GDP growth and deforestation in the Central American and Caribbean countries with further analysis on the major GDP earning industries among these countries and their contribution to deforestation

Thesis(Master) --KDI School:Master of Public Policy,2017Latin America and the Caribbean experiences most serious deforestation trend in the world. There is a total decrease of 970,000 square kilometers of forest area between 1990 and 2015 in the region, which translates to 10% loss in the original forest coverage. Conventionally, economists had based their study on the entire Latin America. However, this research paper will focus only on Central America and the Caribbean for that they demonstrate distinctive features that are different form the South American countries. The research attempts to identify how economic development can affect the forest coverage in Central American and Caribbean countries. It further argues that economic development will cause higher burden on the supply of natural resources and results in the decline of forest coverage. The econometrics model evaluates the contribution to deforestation from the major GDP earner industries, such as tourism and agriculture. It also considers other development factors like forest burned, population growth and urbanization into the model. Finally, this paper provides results that can lead to feasible policy recommendations that can assist the region in conserving its natural resources for future growth and developments.I. Introduction II. Literature Review III. Empirical Strategy and Data IV. Main result V. ConclusionmasterpublishedChia-Wei CHANG

Characteristics and Barriers Impacting the Diffusion of Facebook among Smallholder Farmers in Central Taiwan

Social media helps farmers located in geographically isolated rural areas stay connected to the world. Social media is an effective tool used in extension services and mass/distance education. Facebook is a successful social network site for information gathering and sharing. In Taiwan, Facebook's penetration rate is higher than in any other Asian country. The purpose of this study was to determine the influences of selected factors on the adoption of Facebook by Taiwanese smallholder farmers. The study examined the relationships between characteristics of smallholder farmers, innovation characteristics, stage in the innovation-decision process, and potential barriers to the adoption of Facebook. A descriptive and correlational research design was used for this study. Three hundred and fifty one smallholder farmers participated in the survey. Nearly half of the responding farmers were at the stage of “implementation.” Sixteen respondents were at stage of “confirmation.” Ninety-seven respondents were at the stage of “knowledge.” Thirty respondents were at the stage of “no knowledge.” Most respondents had Facebook accounts. The most common usages of Facebook were to connect with friends, receive agricultural information, read daily news and information, share daily life stories with others, and share professional knowledge with others. Nearly half of respondents with Facebook accounts used Facebook for farm marketing purposes. Respondents held positive perceptions of relative advantage, compatibility, trialability, observability and low complexity as characteristics of Facebook. Respondents held neutral perceptions regarding technology concerns, financial concerns, concerns about time, planning issues, and concern about incentives for the adoption of Facebook. The respondents were significantly different in perception of Facebook based on years of farming experience, gender, age, education, and income. Responding farmers also expressed significant differences between their perceptions of potential barriers by years of farming experience, farm size, gender, age, education level, and income status. Significant negative relationships existed between smallholder farmers’ perceptions of Facebook and potential barriers to Facebook. Trialability, planning issues, relative advantage, compatibility, observability, education, complexity, technology concerns, and age served as powerful predictors of respondents’ stages in the innovation-decision process

Selected Agriculture Students' Perceptions of International Educational Experience

This study examined College of Agriculture students' perceptions and concerns about international educational experiences. The purpose of this study was to determine students' perceptions about international educational experiences, students' interests in gaining international educational experiences, students' ratings of selected factors that may prompt them to acquire these experiences, or barriers that prohibit them from gaining international educational experiences. A stratified random sample of students (N = 153) was asked to complete an online questionnaire. The response rate was 67 percent. Participants (n = 98) included 27 from Tarleton State University and 71 from Texas A & M University. The instrument included items to measure students' interests and preferences for international educational experiences, factors that influenced (motivated or prohibited) students' desires to gain international educational experiences, and perceptions of international educational experiences. Descriptive statistics (mean, standard deviation) and correlations were used to analyze the data. The results showed that only 4 percent of the respondents had participated in study abroad programs. About 77 percent of the respondents were interested in gaining international educational experiences. Students believed that gaining international educational experiences helped them enrich their overall life experience, seek opportunities to live in another country or culture, and helped their resume. Respondents were willing to join the study abroad program held by their universities. They preferred to register for a university faculty-led study abroad, spending one to ten weeks abroad, university study abroad course as an internship, directed study, research project, or similar international experience, and register for university courses at a university study center. The barriers students faced were financial constraints -- paying for the program or funding personal living expenses and studies during the study abroad, finding affordable and adequate housing -- and language barriers. Students who believed that joining in study abroad programs would improve their competitiveness in the global marketplace were more willing to gain international educational experiences than students who didn't think that joining in study abroad programs would improve their competitiveness in the global marketplace

Receptor-Mediated Hypertrophic Signaling Via Protein Kinase D and Histone Deacetylase 5 in Adult Myocytes

Hemodynamic stress and neurohumoral signaling are common causes of cardiac hypertrophy. These extrinsic stress stimuli typically act on GPCR and induce a cascade of signal transduction to re-program terminally differentiated myocytes to grow in length or width. The compensatory hypertrophic response can enhance cardiac output briefly due to increased work load. However, prolonged stress results in maladaptive changes in the heart and gradually deteriorates ventricular function to supply blood throughout the body. Sustained hypertrophic signaling can also progress toward heart failure. My dissertation research focuses on the hypertrophic signaling in adult cardiac myocytes in response to neurohumoral stimuli, ET-1 and PE. In particular, I am interested in the spatiotemporal activation of PKD and its functional role in regulation of HDAC5 translocation. HDAC5 is a transcriptional repressor whose dynamic shuttling between the nucleus and the cytosol determines the outcome of transcriptional control for MEF2-dependent genes. I use a combination of biochemical approach with fluorescence imaging techniques to study the regulation of epigenetic re-programming mediated by PKD and HDAC5 in adult cardiac myocytes during hypertrophy and heart failure