An A4 flavor model for quarks and leptons in warped geometry

We propose a spontaneous A4 flavor symmetry breaking scheme implemented in a warped extra dimensional setup to explain the observed pattern of quark and lepton masses and mixings. The main advantages of this choice are the explanation of fermion mass hierarchies by wave function overlaps, the emergence of tribimaximal neutrino mixing and zero quark mixing at the leading order and the absence of tree-level gauge mediated flavor violations. Quark mixing is induced by the presence of bulk flavons, which allow for cross-brane interactions and a cross-talk between the quark and neutrino sectors, realizing the spontaneous symmetry breaking pattern A4 --> nothing first proposed in [X.G.\,He, Y.Y.\,Keum, R.R.\,Volkas, JHEP{0604}, 039 (2006)]. We show that the observed quark mixing pattern can be explained in a rather economical way, including the CP violating phase, with leading order cross-interactions, while the observed difference between the smallest CKM entries V_{ub} and V_{td} must arise from higher order corrections. We briefly discuss bounds on the Kaluza-Klein scale implied by flavor changing neutral current processes in our model and show that the residual little CP problem is milder than in flavor anarchic models.Comment: 34 pages, 2 figures; version published in JHE

Witness artistic rendition and its impacts on visual memory for forensic facial composite creation

In the absence of photographic or other identifying evidence, composites provide crucial intelligence in police investigations, though their accuracy depends on a witness’s facial memory and recall. The purpose of this study is to investigate a novel technique aimed at increasing face recall and composite effectiveness. In this study, participants viewed a facial photograph, recalled the face using a cognitive interview and created a composite with a forensic artist. One group of participants (control) who worked with an artist, the usual procedure, were compared with another group (experimental) who sketched the face themselves prior to the cognitive interview. Witness memory was then measured by assessing the number of “units of information” produced during free recall of the face, as well as the identifiability of the composites, evaluated by an additional group of participants who attempted to name the sketched composites. Results showed, relative to the control group, that the experimental witness group provided more detailed descriptions of the face and that this improvement to memory led to the creation of more identifiable composites. Therefore, the findings suggest that this artistic rendition technique enhances both the cognitive interview and the accuracy of forensic facial composites. It was also found that participants’ self-rated measures of drawing and observant behaviour were positively related to the accuracy of the participants’ composites. This simple technique could be implemented by police forces with minimal effort and impact on budget. It presents a straightforward and cost-efficient way to increase the identifiability of composite images without the need for additional lengthy training for forensic practitioners. Results suggest that the witness artistic rendition technique represents a novel, low-cost and simple method that could be used to increase composite accuracy

Dispelling urban myths about default uncertainty factors in chemical risk assessment - Sufficient protection against mixture effects?

© 2013 Martin et al.; licensee BioMed Central LtdThis article has been made available through the Brunel Open Access Publishing Fund.Assessing the detrimental health effects of chemicals requires the extrapolation of experimental data in animals to human populations. This is achieved by applying a default uncertainty factor of 100 to doses not found to be associated with observable effects in laboratory animals. It is commonly assumed that the toxicokinetic and toxicodynamic sub-components of this default uncertainty factor represent worst-case scenarios and that the multiplication of those components yields conservative estimates of safe levels for humans. It is sometimes claimed that this conservatism also offers adequate protection from mixture effects. By analysing the evolution of uncertainty factors from a historical perspective, we expose that the default factor and its sub-components are intended to represent adequate rather than worst-case scenarios. The intention of using assessment factors for mixture effects was abandoned thirty years ago. It is also often ignored that the conservatism (or otherwise) of uncertainty factors can only be considered in relation to a defined level of protection. A protection equivalent to an effect magnitude of 0.001-0.0001% over background incidence is generally considered acceptable. However, it is impossible to say whether this level of protection is in fact realised with the tolerable doses that are derived by employing uncertainty factors. Accordingly, it is difficult to assess whether uncertainty factors overestimate or underestimate the sensitivity differences in human populations. It is also often not appreciated that the outcome of probabilistic approaches to the multiplication of sub-factors is dependent on the choice of probability distributions. Therefore, the idea that default uncertainty factors are overly conservative worst-case scenarios which can account both for the lack of statistical power in animal experiments and protect against potential mixture effects is ill-founded. We contend that precautionary regulation should provide an incentive to generate better data and recommend adopting a pragmatic, but scientifically better founded approach to mixture risk assessment. © 2013 Martin et al.; licensee BioMed Central Ltd.Oak Foundatio

Changes in serum lactate to aerobic exercise among amateur athletes and non-athletes

Lactate is an end product of glucose metabolism that is usually produced in a larger quantity during exercise. This increase in production during exercise has been understood to be the reason for fatigue. The aim of this study is to determine the responses of serum lactate to aerobic exercise among amateur athletes and non-athletes. 48 consenting males (24 amateur athletes and 24 non-athletes) participated in this comparative quasi-experimental design. Subjects cycled on a bicycle ergometer to attain moderate intensity exercise target heart rate (MIETHR) and maintained the MIETHR till exhaustion (15 on Borgs scale or volitional exertion) while the serum lactate was measured at intervals. Data were analyzed with descriptive statistics and inferential statistics of Analysis of variance (ANOVA). Alpha level was set at p < 0.05. The mean age of the participants was 26.08±2.28 and 28.13±1.51 for the athletes and non-athletes respectively. There was a significant difference p=0.001 Training induced adaptations include a lower serum lactate level, a point that should be noted in studying of metabolic adaptations.Keywords: Lactate, Athletes, Exercise, Response, Fitnes

Millennial changes in North American wildfire and soil activity over the last glacial cycle

Climate changes in the North Atlantic region during the last glacial cycle were dominated by the slow waxing and waning of the North American ice sheet as well as by intermittent Dansgaard-­‐Oeschger (DO) events. However prior to the last deglaciation, little is known about the response of North American vegetation to such rapid climate changes and especially about the response of biomass burning, an important factor for regional changes in radiative forcing. Here we use continuous, high-­‐resolution ammonium (NH4+) records derived from the NGRIP and GRIP ice cores to document both North American NH4+ background emissions from soils and wildfire frequency over the last 110,000 yr. Soil emissions increased on orbital timescales with warmer climate, related to the northward expansion of vegetation due to reduced ice-­‐covered areas. During Marine Isotope Stage (MIS) 3 DO warm events, a higher fire recurrence rate is recorded, while NH4+ soil emissions rose only slowly during longer interstadial warm periods, in line with slow ice sheet shrinkage and delayed ecosystem changes. Our results indicate that sudden warming events had little impact on NH4+ soil emissions and NH4+ aerosol transport to Greenland during the glacial but triggered a significant increase in the frequency of fire occurrence.This paper has greatly benefitted from the Sir Nicholas Shackleton fellowship, Clare Hall, University of Cambridge, U.K., awarded to HF in 2014. The Division for Climate and Environmental Physics, Physics Institute, University of Bern acknowledges the long-­‐term financial support of ice core research by the Swiss National Science Foundation (SNSF) and the Oeschger Centre for Climate Change Research. EW is supported by a Royal Society professorship. NGRIP is directed and organized by the Department of Geophysics at the Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen. It is supported by funding agencies in Denmark (SNF), Belgium (FNRS-­‐CFB), France (IPEV and INSU/CNRS), Germany (AWI), Iceland (RannIs), Japan (MEXT), Sweden (SPRS), Switzerland (SNSF) and the USA (NSF, Office of Polar Programs).This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/ngeo249

Money, Social Relationships and the Sense of Self: The Consequences of an Improved Financial Situation for Persons Suffering from Serious Mental Illness

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Urban Airborne Lead: X-Ray Absorption Spectroscopy Establishes Soil as Dominant Source

BACKGROUND: Despite the dramatic decrease in airborne lead over the past three decades, there are calls for regulatory limits on this potent pediatric neurotoxin lower even than the new (2008) US Environmental Protection Agency standard. To achieve further decreases in airborne lead, what sources would need to be decreased and what costs would ensue? Our aim was to identify and, if possible, quantify the major species (compounds) of lead in recent ambient airborne particulate matter collected in El Paso, TX, USA. METHODOLOGY/PRINCIPAL FINDINGS: We used synchrotron-based XAFS (x-ray absorption fine structure) to identify and quantify the major Pb species. XAFS provides molecular-level structural information about a specific element in a bulk sample. Pb-humate is the dominant form of lead in contemporary El Paso air. Pb-humate is a stable, sorbed complex produced exclusively in the humus fraction of Pb-contaminated soils; it also is the major lead species in El Paso soils. Thus such soil must be the dominant source, and its resuspension into the air, the transfer process, providing lead particles to the local air. CONCLUSIONS/SIGNIFICANCE: Current industrial and commercial activity apparently is not a major source of airborne lead in El Paso, and presumably other locales that have eliminated such traditional sources as leaded gasoline. Instead, local contaminated soil, legacy of earlier anthropogenic Pb releases, serves as a long-term reservoir that gradually leaks particulate lead to the atmosphere. Given the difficulty and expense of large-scale soil remediation or removal, fugitive soil likely constrains a lower limit for airborne lead levels in many urban settings

cGMP-Phosphodiesterase Inhibition Enhances Photic Responses and Synchronization of the Biological Circadian Clock in Rodents

The master circadian clock in mammals is located in the hypothalamic suprachiasmatic nuclei (SCN) and is synchronized by several environmental stimuli, mainly the light-dark (LD) cycle. Light pulses in the late subjective night induce phase advances in locomotor circadian rhythms and the expression of clock genes (such as Per1-2). The mechanism responsible for light-induced phase advances involves the activation of guanylyl cyclase (GC), cGMP and its related protein kinase (PKG). Pharmacological manipulation of cGMP by phosphodiesterase (PDE) inhibition (e.g., sildenafil) increases low-intensity light-induced circadian responses, which could reflect the ability of the cGMP-dependent pathway to directly affect the photic sensitivity of the master circadian clock within the SCN. Indeed, sildenafil is also able to increase the phase-shifting effect of saturating (1200 lux) light pulses leading to phase advances of about 9 hours, as well as in C57 a mouse strain that shows reduced phase advances. In addition, sildenafil was effective in both male and female hamsters, as well as after oral administration. Other PDE inhibitors (such as vardenafil and tadalafil) also increased light-induced phase advances of locomotor activity rhythms and accelerated reentrainment after a phase advance in the LD cycle. Pharmacological inhibition of the main downstream target of cGMP, PKG, blocked light-induced expression of Per1. Our results indicate that the cGMP-dependent pathway can directly modulate the light-induced expression of clock-genes within the SCN and the magnitude of light-induced phase advances of overt rhythms, and provide promising tools to design treatments for human circadian disruptions

The Temporal Dynamics of Voluntary Emotion Regulation

Background: Neuroimaging has demonstrated that voluntary emotion regulation is effective in reducing amygdala activation to aversive stimuli during regulation. However, to date little is known about the sustainability of these neural effects once active emotion regulation has been terminated. Methodology/Principal Findings: We addressed this issue by means of functional magnetic resonance imaging (fMRI) in healthy female subjects. We performed an active emotion regulation task using aversive visual scenes (task 1) and a subsequent passive viewing task using the same stimuli (task 2). Here we demonstrate not only a significantly reduced amygdala activation during active regulation but also a sustained regulation effect on the amygdala in the subsequent passive viewing task. This effect was related to an immediate increase of amygdala signal in task 1 once active emotion regulation has been terminated: The larger this peak postregulation signal in the amygdala in task 1, the smaller the sustained regulation effect in task 2. Conclusions/Significance: In summary, we found clear evidence that effects of voluntary emotion regulation extend beyond the period of active regulation. These findings are of importance for the understanding of emotion regulation i