293 research outputs found
First Lattice Study of the Form Factors A_0 and A_3 in the Decay Bbar^0 to rho^+ l^- nubar_l
We report on a lattice calculation of the form factors A_0 and A_3 for the
pseudoscalar to vector meson semileptonic decay Bbar^0 to rho^+ l^- nubar_l. We
find that resonant (or pole-type) contributions alone are unable to describe
these two form factors simultaneously. For the quantity A_0(q^2=0), which is
important phenomenologically for the determination of |Vub|, we extract a range
of values, A_0(q^2=0) = (0.16--0.35) +0.09-0.06, where the range is due to
systematic uncertainty and the quoted error is statistical. We have also
determined A_2(q^2=0) = 0.28 +0.09-0.06 +0.04-0.05.Comment: 14 pages LaTeX209 with 5 figures from 11 encapsulated PostScript
files, using epsf.sty. Also available from
http://wwwhep.phys.soton.ac.uk/hepwww/papers/shep9601
Activity in the brain's valuation and mentalizing networks is associated with propagation of online recommendations
Word of mouth recommendations influence a wide range of choices and behaviors. What takes place in the mind of recommendation receivers that determines whether they will be successfully influenced? Prior work suggests that brain systems implicated in assessing the value of stimuli (i.e., subjective valuation) and understanding others' mental states (i.e., mentalizing) play key roles. The current study used neuroimaging and natural language classifiers to extend these findings in a naturalistic context and tested the extent to which the two systems work together or independently in responding to social influence. First, we show that in response to text-based social media recommendations, activity in both the brain's valuation system and mentalizing system was associated with greater likelihood of opinion change. Second, participants were more likely to update their opinions in response to negative, compared to positive, recommendations, with activity in the mentalizing system scaling with the negativity of the recommendations. Third, decreased functional connectivity between valuation and mentalizing systems was associated with opinion change. Results highlight the role of brain regions involved in mentalizing and positive valuation in recommendation propagation, and further show that mentalizing may be particularly key in processing negative recommendations, whereas the valuation system is relevant in evaluating both positive and negative recommendations
Lattice Study of the Decay B^0-bar -> rho^+ l^- nu_l-bar: Model-Independent Determination of |V_{ub}|
We present results of a lattice computation of the vector and axial-vector
current matrix elements relevant for the semileptonic decay B^0-bar -> rho^+
l^- nu_l-bar. The computations are performed in the quenched approximation of
lattice QCD on a 24^3 x 48 lattice at beta = 6.2, using an O(a) improved
fermionic action. Our principal result is for the differential decay rate,
dGamma/dq^2, for the decay B^0-bar -> rho^+ l^- nu_l-bar in a region beyond the
charm threshold, allowing a model-independent extraction of |V_{ub}| from
experimental measurements. Heavy quark symmetry relations between radiative and
semileptonic decays of B-bar mesons into light vector mesons are also
discussed.Comment: 22 pages LaTeX-209 (dependent on settings in a4.sty), 23 PostScript
figures included with epsf.sty. Complete PostScript file including figures
available at http://wwwhep.phys.soton.ac.uk/hepwww/papers/shep9518
Traditional ecological knowledge in restoration ecology: a call to listen deeply, to engage with, and respect Indigenous voices
The United Nations heralded 2021–2030 as the UN Decade on Ecosystem Restoration. A socioecological approach to restoration has been proposed that honors the diversity in ecological landscapes and their respective cultures and peoples with the goal of repairing degraded ecosystems. Indigenous peoples are intimately interconnected with landscapes, which are under mounting pressure from anthropogenic global environmental change. Article 31 of the UN Declaration on the Rights of Indigenous Peoples states the rights of Indigenous peoples to maintain, protect, and control their culture and traditional ecological knowledge (TEK); however, these rights have not always been acknowledged. We are concerned that large global restoration goals will continue to promote TEK extraction that further perpetuates inequities and discrimination of Indigenous peoples. If the restoration sector wishes to partner with Indigenous communities leading TEK efforts, it needs to understand established international agreements and proactively protect intellectual property and data sovereignty rights. To illustrate a theme of ethical engagement, we present risks to TEK integrity while highlighting engagement that has successfully promoted Indigenous leadership and self‐determination. We propose that a decade of responsible and respectful restoration will be achieved only with shared principles and an ethical code of conduct for TEK partnerships. We argue that deep listening with Indigenous peoples and engagement with humility and respect needs to be the starting point. Finally, we propose an Indigenous‐led workshop to re‐imagine and re‐develop equitable ways forward for TEK partnerships in restoration, with explicit considerations for the rights, livelihoods, and leadership of Indigenous peoples
Ward Identities, B-> \rho Form Factors and |V_ub|
The exclusive FCNC beauty semileptonic decay B-> \rho is studied using Ward
identities in a general vector meson dominance framework, predicting vector
meson couplings involved. The long distance contributions are discussed which
results to obtain form factors and |V_ub|. A detailed comparison is given with
other approaches.Comment: 30 pages+four postscript figures, an Appendix adde
Fathers, physical child abuse, and neglect: Advancing the knowledge base
Fathers are overrepresented as perpetrators of physical child maltreatment, particularly in its most severe forms. Despite this, the research literature continues to lack specificity regarding the role fathers play in risk for physical child abuse or neglect (PCAN). Furthermore, although fathers have received more attention with respect to child sexual abuse and its treatment, their influence has been largely disregarded in many intervention efforts to reduce PCAN. Inadequate attention to the role of fathers, both in research and practice, has numerous problematic implications for the prevention of child maltreatment. The goal of this special issue is to disseminate new research that examines fathers’ roles by focusing on multiple fathering factors that may directly and indirectly shape both maternal and paternal risk of engaging in PCAN. In the introduction to the special issue, we highlight key questions in the research literature and present our perspective on how the articles included in this special issue address some of these gaps.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106173/1/2009-Lee-Bellamy-Guterman-CM-Intro.pd
Low and decreasing vaccine effectiveness against influenza A(H3) in 2011/12 among vaccination target groups in Europe: results from the I-MOVE multicentre case-control study
Within the Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE) project we conducted a multicentre case–control study in eight European Union (EU) Member States to estimate the 2011/12 influenza vaccine effectiveness against medically attended influenza-like illness (ILI) laboratory-confirmed as influenza A(H3) among the vaccination target groups. Practitioners systematically selected ILI / acute respiratory infection patients to swab within seven days of symptom onset. We restricted the study population to those meeting the EU ILI case definition and compared influenza A(H3) positive to influenza laboratory-negative patients. We used logistic regression with study site as fixed effect and calculated adjusted influenza vaccine effectiveness (IVE), controlling for potential confounders (age group, sex, month of symptom onset, chronic diseases and related hospitalisations, number of practitioner visits in the previous year). Adjusted IVE was 25% (95% confidence intervals (CI): -6 to 47) among all ages (n=1,014), 63% (95% CI: 26 to 82) in adults aged between 15 and 59 years and 15% (95% CI: -33 to 46) among those aged 60 years and above. Adjusted IVE was 38% (95%CI: -8 to 65) in the early influenza season (up to week 6 of 2012) and -1% (95% CI: -60 to 37) in the late phase. The results suggested a low adjusted IVE in 2011/12. The lower IVE in the late season could be due to virus changes through the season or waning immunity. Virological surveillance should be enhanced to quantify change over time and understand its relation with duration of immunological protection. Seasonal influenza vaccines should be improved to achieve acceptable levels of protection.ECD
Partial γ-ray production cross sections for (n,xnγ) reactions in natural argon at 1-30 MeV
Background: Neutron-induced backgrounds are a significant concern for experiments that require extremely low levels of radioactive backgrounds such as direct dark matter searches and neutrinoless double-β decay experiments. Unmeasured neutron scattering cross sections are often accounted for incorrectly in Monte Carlo simulations.Purpose: The purpose of this article is to determine partial γ-ray production cross sections for (n,xnγ) reactions in natural argon for incident neutron energies between 1 and 30 MeV.Methods: The broad-spectrum neutron beam at the Los Alamos Neutron Science Center (LANSCE) was used used for the measurement. Neutron energies were determined using time of flight, and resulting γ rays from neutron-induced reactions were detected using the GErmanium Array for Neutron Induced Excitations (GEANIE).Results: Partial γ-ray cross sections were measured for six excited states in 40Ar and two excited states in 39Ar. Measured (n,xnγ) cross sections were compared to the talys and CoH3 nuclear reaction codes.Conclusions: These new measurements will help to identify potential backgrounds in neutrinoless double-β decay and dark matter experiments that use argon as a detection medium or shielding. The measurements will also aid in the identification of neutron interactions in these experiments through the detection of γ rays produced by (n,xnγ) reactions
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