985 research outputs found
Three-Body approach to the K^- d Scattering Length in Particle Basis
We report on the first calculation of the scattering length A_{K^-d} based on
a relativistic three-body approach where the two-body input amplitudes coupled
to the Kbar N channels have been obtained with the chiral SU(3) constraint, but
with isospin symmetry breaking effects taken into account. Results are compared
with a recent calculation applying a similar set of two-body amplitudes,based
on the fixed center approximation, considered as a good approximation for a
loosely bound target, and for which we find significant deviations from the
exact three-body results. Effects of the hyperon-nucleon interaction, and
deuteron -wave component are also evaluated.Comment: 5 pages, Submitted to Phys. Rev.
Ancient DNA SNP-panel data suggests stability in bluefin tuna genetic diversity despite centuries of fluctuating catches in the eastern Atlantic and Mediterranean
Atlantic bluefin tuna (Thunnus thynnus; BFT) abundance was depleted in the late 20th and early 21st century due to overfishing. Historical catch records further indicate that the abundance of BFT in the Mediterranean has been fluctuating since at least the 16th century. Here we build upon previous work on ancient DNA of BFT in the Mediterranean by comparing contemporary (2009–2012) specimens with archival (1911–1926) and archaeological (2nd century BCE–15th century CE) specimens that represent population states prior to these two major periods of exploitation, respectively. We successfully genotyped and analysed 259 contemporary and 123 historical (91 archival and 32 archaeological) specimens at 92 SNP loci that were selected for their ability to differentiate contemporary populations or their association with core biological functions. We found no evidence of genetic bottlenecks, inbreeding or population restructuring between temporal sample groups that might explain what has driven catch fluctuations since the 16th century. We also detected a putative adaptive response, involving the cytoskeletal protein synemin which may be related to muscle stress. However, these results require further investigation with more extensive genome-wide data to rule out demographic changes due to overfishing, and other natural and anthropogenic factors, in addition to elucidating the adaptive drivers related to these
Mechanisms underlying disorders of consciousness: Bridging gaps to move toward an integrated translational science
AIM: In order to successfully detect, classify, prognosticate, and develop targeted therapies for patients with disorders of consciousness (DOC), it is crucial to improve our mechanistic understanding of how severe brain injuries result in these disorders.
METHODS: To address this need, the Curing Coma Campaign convened a Mechanisms Sub-Group of the Coma Science Work Group (CSWG), aiming to identify the most pressing knowledge gaps and the most promising approaches to bridge them.
RESULTS: We identified a key conceptual gap in the need to differentiate the neural mechanisms of consciousness per se, from those underpinning connectedness to the environment and behavioral responsiveness. Further, we characterised three fundamental gaps in DOC research: (1) a lack of mechanistic integration between structural brain damage and abnormal brain function in DOC; (2) a lack of translational bridges between micro- and macro-scale neural phenomena; and (3) an incomplete exploration of possible synergies between data-driven and theory-driven approaches.
CONCLUSION: In this white paper, we discuss research priorities that would enable us to begin to close these knowledge gaps. We propose that a fundamental step towards this goal will be to combine translational, multi-scale, and multimodal data, with new biomarkers, theory-driven approaches, and computational models, to produce an integrated account of neural mechanisms in DOC. Importantly, we envision that reciprocal interaction between domains will establish a virtuous cycle, leading towards a critical vantage point of integrated knowledge that will enable the advancement of the scientific understanding of DOC and consequently, an improvement of clinical practice
Chiral unitary theory: application to nuclear problems
In this talk we briefly describe some basic elements of chiral perturbation
theory, , and how the implementation of unitarity and other novel
elements lead to a better expansion of the matrix for meson meson and meson
baryon interactions. Applications are then done to the interaction
in nuclear matter in the scalar and vector channels, antikaons in nuclei and
atoms, and how the meson properties are changed in a nuclear
medium.Comment: 15 pages, 9 figures, Invited talk in the International Symposium on
Nuclear Physics, Bombay, december 200
The Electrical-Thermal Switching in Carbon Black-Polymer Composites as a Local Effect
Following the lack of microscopic information about the intriguing well-known
electrical-thermal switching mechanism in Carbon Black-Polymer composites, we
applied atomic force microscopy in order to reveal the local nature of the
process and correlated it with the characteristics of the widely used
commercial switches. We conclude that the switching events take place in
critical interparticle tunneling junctions that carry most of the current. The
macroscopic switched state is then a result of a dynamic-stationary state of
fast switching and slow reconnection of the corresponding junctions.Comment: 14 pages, 5 figures,Typographic correctio
Chiral dynamics in systems with strangeness
In this talk a brief review of several problems involving systems with strangeness is made. In the first place one shows how the Λ(1405), Λ(1670) and Σ(1620) states, for S=−1, and the Ξ(1620) for S=−2 are generated dynamically in the context of unitarized chiral perturbation theory. The results for the K¯N interaction are then used to evaluate the K−d scattering length. Results obtained for the kaon selfenergy in a nuclear medium within this approach, with application to K− atoms, are also mentioned. Finally a few words are said about recent developments in the weak decay of Λ hypernuclei and the puzzle of the Γn/Γp ratio
Estimating the impact of achieving Turkey's non-communicable disease policy targets: A macro-simulation modelling study.
BACKGROUND: The Burden of non-communicable disease (NCDs) has continued to rise globally, particularly in low- and middle-income countries. In Turkey, NCDs account for 89% of all deaths, with nearly one in five deaths occurring before age 70. This study investigates the number of NCD deaths that could be prevented if Turkey met national and international targets for major modifiable NCD risk factors. METHODS: Preventable deaths were estimated using the World Health Organization (WHO) 'Preventable Risk Integrated ModEl' (PRIME), by combining: 1) Baseline exposure data for risk factors, referenced from national surveillance and cohort studies; 2) Aetiological associations from published meta-analyses; and 3) Demographic and mortality statistics obtained from the Turkish Statistical Institute (TurkStat). Confidence intervals were estimated using Monte Carlo simulations. FINDINGS: If Turkey met its NCD risk factor targets for reducing tobacco and salt consumption by 30%, and physical inactivity by 10% in 2017, an estimated 19,859 deaths (95%CI: 12,802 to 26,609) could have been prevented. Approximately two thirds of these preventable deaths were in men, and one in three were in adults below 75 years. A 30% relative reduction in the consumption of alcohol, tobacco, and salt, as well as physical inactivity, would prevent 180 (107 to 259); 4,786 (3,679 to 5,836); 13,112 (5,819 to 19,952); and 7,124 (5,053 to 9,212) deaths, respectively. INTERPRETATION: Among major modifiable NCD risk factors, population-level reductions in salt intake and physical inactivity present the greatest opportunity for reducing NCD mortality in Turkey. These findings can help Turkey prioritise interventions to meet the Sustainable Development Goal target of reducing NCD mortality by one third, by 2030
Gothic visions of classical architecture in Hablot Knight Browne’s “dark” illustrations for the novels of Charles Dickens
In the early gothic literature of the eighteenth century danger lurked in the darkness beneath the pointed arches of gothic buildings. During the nineteenth century there was a progressive, although never complete, dislocation of gothic literary readings from gothic architecture. This article explores a phase in that development through discussion of a series of ‘dark’ illustrations produced by Hablot Knight Browne to illustrate novels by Charles Dickens. These show the way in which the rounded arches of neo-classical architecture were depicted in the mid-nineteenth century as locales of oppression and obscurity. Such depictions acted, in an age of political and moral reform, to critique the values of the system of power and authority that such architecture represented
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