Scalar leptoquarks and the rare B meson decays

We study some rare decays of $B$ meson involving the quark level transition $b \to q l^+l^- (q=d,s)$ in the scalar leptoquark model. We constrain the leptoquark parameter space using the recently measured branching ratios of $B_{s,d} \to \mu^+ \mu^-$ processes. Using such parameters, we obtain the branching ratios, direct CP violation parameters and isospin asymmetries in $B \to K \mu^+ \mu^-$ and $B \to \pi \mu^+ \mu^-$ processes. We also obtain the branching ratios for some lepton flavour violating decays $B \to l_i^+ l_j^-$. We find that the various anomalies associated with the isospin asymmetries of $B \to K \mu^+ \mu^-$ process can be explained in the scalar leptoquark model.Comment: 28 pages, 7 figures. typos corrected, to appear in Phys. Rev.

Propulsive and logistical feasibility of alternative future human-robotic Mars exploration architectures

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 75-77).This thesis extends the work on a shared human and robotic mission to the Martian system presented at the Revolutionary Aerospace Systems Concepts Academic Linkage (RASC-AL) 2010 competition by a team of MIT graduate students. Particular attention is paid to the transportation infrastructure and its ability to support the human and robotic mission from a logistics and supply chain standpoint. The original human and robotic mission was analyzed along with several variants including the use of Advanced Chemical Propulsion instead of Nuclear Thermal Rockets and the decomposition of the original mission into several that could, in the spirit of the Flexible Path, form the final steps on the way to a human landing on Mars. Comparison of selected figures of merit, such as the mass required in Low- Earth Orbit, number of sites explored, and crew-exploration days, gives mission designers a means to begin down-selecting mission concepts at this early phase and focus analysis efforts on the most promising concepts. In general, compared to NASA's Human Exploration of Mars Design Reference Architecture 5.0, the human and robotic mission concept requires 16% less mass in Low-Earth Orbit, is less complex, and explores six areas as opposed to a single locale. Further, mission variants, including one that hypothesizes a progression of Mars missions on the Flexible Path, are feasible and offer a flexible and modular way of progressively exploring the Martian system with the ultimate goal of landing humans on the surface of Mars.by Howard K. Yue.S.M

Mitochondrial ROS production correlates with, but does not directly regulate lifespan in drosophila

The Mitochondrial Free Radical Theory of Aging (MFRTA) is currently one of the most widely accepted theories used to explain aging. From MFRTA three basic predictions can be made: long-lived individuals or species should produce fewer mitochondrial Reactive Oxygen Species (mtROS) than short-lived individuals or species; a decrease in mtROS production will increase lifespan; and an increase in mtROS production will decrease lifespan. It is possible to add a further fourth prediction: if ROS is controlling longevity separating these parameters through selection would be impossible. These predictions have been tested in Drosophila melanogaster. Firstly, we studied levels of mtROS production and lifespan of three wild-type strains of Drosophila, Oregon R, Canton S and Dahomey. Oregon R flies live the longest and produce significantly fewer mtROS than both Canton S and Dahomey. These results are therefore in accordance with the first prediction. A new transgenic Drosophila model expressing the Ciona intestinalis Alternative Oxidase (AOX) was used to test the second prediction. In fungi and plants, AOX expression regulates both free radical production and lifespan. In Drosophila, AOX expression decreases mtROS production, but does not increase lifespan. This result contradicts the second prediction of MFRTA. The third prediction was tested in flies mutant for the gene dj-1β. These flies are characterized by an age-associated decline in locomotor function and increased levels of mtROS production. Nevertheless, dj-1β mutant flies do not display decreased lifespan, which again is in contradiction with MFRTA. In our final experiment we utilized flies with DAH mitochondrial DNA in an OR nuclear background, and OR mitochondrial DNA in DAH nuclear background. From this, Mitochondrial DNA does not control free radical production, but it does determine longevity of females independently of mtROS production. In summary, these results do not systematically support the predictions of the MFRTA. Accordingly, MFRTA should be revised to accommodate these findings

What factors determine the choice of public engagement undertaken by health technology assessment decision-making organizations?

Purpose: Public engagement in health technology assessment (HTA) is increasingly considered crucial for good decision-making. Determining the “right” type of engagement activity is key in achieving the appropriate consideration of public values. Little is known about the factors that determine how HTA organizations decide on their method of public engagement, and there are a number of possible factors that might shape these decisions. This paper seeks to understand the potential drivers of public engagement choice from an organizational perspective. Design/Methodology/: The published HTA literature is reviewed alongside existing frameworks of public engagement in order to elucidate key factors influencing the choice of public engagement process undertaken by HTA organizations. A conceptual framework is then developed to illustrate the factors identified from the literature that appear to influence public engagement choice. Findings: Determining the type of public engagement to be undertaken in HTA is based on multiple factors, some of which are not always explicitly acknowledged. These factors include: perceived complexity of the policymaking issue, perceived impact of the decision, transparency and opportunities for public involvement in governance, as well as time and resource constraints. The influence of these factors varies depending on the context, indicating that a one size fits all approach to public engagement may not be effective. Originality/value: Awareness of the various factors that might influence the type of public engagement undertaken would enable decision-makers to reflect on their choices and be more accountable and transparent about their choice of engagement process in eliciting public values and preferences in a HTA organization.SW was in receipt of an Australian Postgraduate Awar

Mitochondrial ROS production correlates with, but does not directly regulate lifespan in drosophila

This is an open-access article distributed under the terms of the Creative Commons Attribution License.The Mitochondrial Free Radical Theory of Aging (MFRTA) is currently one of the most widely accepted theories used to explain aging. From MFRTA three basic predictions can be made: long-lived individuals or species should produce fewer mitochondrial Reactive Oxygen Species (mtROS) than short-lived individuals or species; a decrease in mtROS production will increase lifespan; and an increase in mtROS production will decrease lifespan. It is possible to add a further fourth prediction: if ROS is controlling longevity separating these parameters through selection would be impossible. These predictions have been tested in Drosophila melanogaster. Firstly, we studied levels of mtROS production and lifespan of three wild-type strains of Drosophila, Oregon R, Canton S and Dahomey. Oregon R flies live the longest and produce significantly fewer mtROS than both Canton S and Dahomey. These results are therefore in accordance with the first prediction. A new transgenic Drosophila model expressing the Ciona intestinalis Alternative Oxidase (AOX) was used to test the second prediction. In fungi and plants, AOX expression regulates both free radical production and lifespan. In Drosophila, AOX expression decreases mtROS production, but does not increase lifespan. This result contradicts the second prediction of MFRTA. The third prediction was tested in flies mutant for the gene dj-1β. These flies are characterized by an age-associated decline in locomotor function and increased levels of mtROS production. Nevertheless, dj-1β mutant flies do not display decreased lifespan, which again is in contradiction with MFRTA. In our final experiment we utilized flies with DAH mitochondrial DNA in an OR nuclear background, and OR mitochondrial DNA in DAH nuclear background. From this, Mitochondrial DNA does not control free radical production, but it does determine longevity of females independently of mtROS production. In summary, these results do not systematically support the predictions of the MFRTA. Accordingly, MFRTA should be revised to accommodate these findings.Our work is supported by funding from the Academy of Finland, Tampere Hospital Medical Research Fund, Juselius Foundation, the European Union and EMBO (long-term fellowship to AS).Peer Reviewe

Reinstated episodic context guides sampling-based decisions for reward.

How does experience inform decisions? In episodic sampling, decisions are guided by a few episodic memories of past choices. This process can yield choice patterns similar to model-free reinforcement learning; however, samples can vary from trial to trial, causing decisions to vary. Here we show that context retrieved during episodic sampling can cause choice behavior to deviate sharply from the predictions of reinforcement learning. Specifically, we show that, when a given memory is sampled, choices (in the present) are influenced by the properties of other decisions made in the same context as the sampled event. This effect is mediated by fMRI measures of context retrieval on each trial, suggesting a mechanism whereby cues trigger retrieval of context, which then triggers retrieval of other decisions from that context. This result establishes a new avenue by which experience can guide choice and, as such, has broad implications for the study of decisions

Regulation of Gdf5 expression in joint remodelling, repair and osteoarthritis

Funding: Arthritis Research UK (grants no. 20775, 19667, 20865, 21156); European Union’s Horizon 2020 research and innovation programme under Marie Sklodowska Curie grant agreement no. 642414; Medical Research Council (grant MR/L022893/1); A.H.K.R. was supported by the Wellcome Trust through the Scottish Translational Medicine and Therapeutics Initiative (grant no. WT 085664). The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.Peer reviewedPublisher PD

Inhalant use, inhalant-use disorders, and antisocial behavior: findings from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC).

OBJECTIVE: Few studies have explored the topography of antisocial behavior in a nationally representative sample of inhalant users. We examined (a) the lifetime prevalence of 20 childhood and adult antisocial behaviors in inhalant users with inhalant-use disorders (IUD+) and without IUDs (IUD-); (b) the nature and strength of associations between inhalant use, IUDs, and specific antisocial behaviors in multivariate analyses; and (c) the relationships between inhalant use, IUDs, and antisocial behaviors in a national sample of adults with antisocial personality disorder. METHOD: The National Epidemiologic Survey on Alcohol and Related Conditions was a multistage national survey of 43,093 U.S. residents. Respondents completed a structured psychiatric interview. RESULTS: IUD+ and IUD- respondents were significantly younger and more likely to be unemployed, to be male, to have never married, and to report family and personal histories of alcohol and drug problems than inhalant nonusers. Family histories of alcohol problems and personal histories of drug problems were significantly more prevalent among IUD+ respondents, compared with IUD- respondents. In bivariate analyses, IUD+ and IUD- respondents evidenced significantly higher lifetime levels of all childhood and adult antisocial behaviors than inhalant nonusers. IUD+ respondents were significantly more likely than their IUD- counterparts to report bullying behavior, starting physical fights, using dangerous weapons, physical cruelty to people, staying out all night without permission, running away, and frequent truancy in childhood, as well as greater deceitfulness, impulsivity, irritability/aggressiveness, recklessness, and irresponsibility in adulthood. Multivariate analyses indicated that IUD+ respondents had a significantly elevated risk for childhood and adult antisocial behaviors, compared with inhalant nonusers, with the strongest effects for using dangerous weapons, physical cruelty to animals, and physical cruelty to people. Similarly, IUD+ respondents differed significantly from their IUD- counterparts primarily across measures of interpersonal violence. Among persons with antisocial personality disorder, inhalant use and IUDs were associated with greater antisocial behavior, albeit with fewer and weaker effects. CONCLUSIONS: Respondents with IUDs had pervasively elevated levels of antisocial conduct, including diverse forms of early-onset and interpersonally violent behavior.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78177/1/4743.pd

Promoting Quality Use of Medicines in South-East Asia: Reports from Country Situational Analyses

Irrational use of medicines is widespread in the South-East Asia Region (SEAR), where policy implementation to encourage quality use of medicines (QUM) is often low. The aim was to determine whether public-sector QUM is better in SEAR countries implementing essential medicines (EM) policies than in those not implementing them

Chess databases as a research vehicle in psychology : modeling large data

The game of chess has often been used for psychological investigations, particularly in cognitive science. The clear-cut rules and well-defined environment of chess provide a model for investigations of basic cognitive processes, such as perception, memory, and problem solving, while the precise rating system for the measurement of skill has enabled investigations of individual differences and expertise-related effects. In the present study, we focus on another appealing feature of chess—namely, the large archive databases associated with the game. The German national chess database presented in this study represents a fruitful ground for the investigation of multiple longitudinal research questions, since it collects the data of over 130,000 players and spans over 25 years. The German chess database collects the data of all players, including hobby players, and all tournaments played. This results in a rich and complete collection of the skill, age, and activity of the whole population of chess players in Germany. The database therefore complements the commonly used expertise approach in cognitive science by opening up new possibilities for the investigation of multiple factors that underlie expertise and skill acquisition. Since large datasets are not common in psychology, their introduction also raises the question of optimal and efficient statistical analysis. We offer the database for download and illustrate how it can be used by providing concrete examples and a step-by-step tutorial using different statistical analyses on a range of topics, including skill development over the lifetime, birth cohort effects, effects of activity and inactivity on skill, and gender differences