145 research outputs found
Multiple Inflation, Cosmic String Networks and the String Landscape
Motivated by the string landscape we examine scenarios for which inflation is
a two-step process, with a comparatively short inflationary epoch near the
string scale and a longer period at a much lower energy (like the TeV scale).
We quantify the number of -foldings of inflation which are required to yield
successful inflation within this picture. The constraints are very sensitive to
the equation of state during the epoch between the two inflationary periods, as
the extra-horizon modes can come back inside the horizon and become
reprocessed. We find that the number of -foldings during the first
inflationary epoch can be as small as 12, but only if the inter-inflationary
period is dominated by a network of cosmic strings (such as might be produced
if the initial inflationary period is due to the brane-antibrane mechanism). In
this case a further 20 -foldings of inflation would be required at lower
energies to solve the late universe's flatness and horizon problems.Comment: 27 pages, 6 figures; v2: refences adde
SUSY Breaking and Moduli Stabilization from Fluxes in Gauged 6D Supergravity
We construct the 4D N=1 supergravity which describes the low-energy limit of
6D supergravity compactified on a sphere with a monopole background a la Salam
and Sezgin. This provides a simple setting sharing the main properties of
realistic string compactifications such as flat 4D spacetime, chiral fermions
and N=1 supersymmetry as well as Fayet-Iliopoulos terms induced by the
Green-Schwarz mechanism. The matter content of the resulting theory is a
supersymmetric SO(3)xU(1) gauge model with two chiral multiplets, S and T. The
expectation value of T is fixed by the classical potential, and S describes a
flat direction to all orders in perturbation theory. We consider possible
perturbative corrections to the Kahler potential in inverse powers of
and , and find that under certain circumstances, and when taken together
with low-energy gaugino condensation, these can lift the degeneracy of the flat
direction for . The resulting vacuum breaks supersymmetry at moderately
low energies in comparison with the compactification scale, with positive
cosmological constant. It is argued that the 6D model might itself be obtained
from string compactifications, giving rise to realistic string
compactifications on non Ricci flat manifolds. Possible phenomenological and
cosmological applications are briefly discussed.Comment: 32 pages, 2 figures. Uses JHEP3.cls. References fixed and updated,
some minor typos fixed. Corrected minor error concerning Kaluza-Klein scales.
Results remain unchange
Implications of ACC/AHA Versus ESC/EAS LDL-C recommendations for residual risk reduction in ASCVD: a simulation study from DA VINCI
Purpose Low-density lipoprotein cholesterol (LDL-C) recommendations differ between the 2018 American College of Cardiology/American Heart Association (ACC/AHA) and 2019 European Society of Cardiology/European Atherosclerosis Society (ESC/EAS) guidelines for patients with atherosclerotic cardiovascular disease (ASCVD) (< 70 vs. < 55 mg/dl, respectively). In the DA VINCI study, residual cardiovascular risk was predicted in ASCVD patients. The extent to which relative and absolute risk might be lowered by achieving ACC/AHA versus ESC/EAS LDL-C recommended approaches was simulated. Methods DA VINCI was a cross-sectional observational study of patients prescribed lipid-lowering therapy (LLT) across 18 European countries. Ten-year cardiovascular risk (CVR) was predicted among ASCVD patients receiving stabilized LLT. For patients with LDL-C ≥ 70 mg/dl, the absolute LDL-C reduction required to achieve an LDL-C of < 70 or < 55 mg/dl (LDL-C of 69 or 54 mg/dl, respectively) was calculated. Relative and absolute risk reductions (RRRs and ARRs) were simulated. Results Of the 2039 patients, 61% did not achieve LDL-C < 70 mg/dl. For patients with LDL-C ≥ 70 mg/dl, median (interquartile range) baseline LDL-C and 10-year CVR were 93 (81–115) mg/dl and 32% (25–43%), respectively. Median LDL-C reductions of 24 (12–46) and 39 (27–91) mg/dl were needed to achieve an LDL-C of 69 and 54 mg/dl, respectively. Attaining ACC/AHA or ESC/EAS goals resulted in simulated RRRs of 14% (7–25%) and 22% (15–32%), respectively, and ARRs of 4% (2–7%) and 6% (4–9%), respectively. Conclusion In ASCVD patients, achieving ESC/EAS LDL-C goals could result in a 2% additional ARR over 10 years versus the ACC/AHA approach
EU-wide cross-sectional observational study of lipid-modifying therapy use in secondary and primary care: the DA VINCI study
Aims To provide contemporary data on the implementation of European guideline recommendations for lipid-lowering therapies (LLTs) across different settings and populations and how this impacts low-density lipoprotein cholesterol (LDL-C) goal achievement.Methods and results An 18 country, cross-sectional, observational study of patients prescribed LLT for primary or secondary prevention in primary or secondary care across Europe. Between June 2017 and November 2018, data were collected at a single visit, including LLT in the preceding 12 months and most recent LDL-C. Primary outcome was the achievement of risk-based 2016 European Society of Cardiology (ESC)/European Atherosclerosis Society (EAS) LDL-C goal while receiving stabilized LLT; 2019 goal achievement was also assessed. Overall, 5888 patients (3000 primary and 2888 secondary prevention patients) were enrolled; 54% [95% confidence interval (CI) 52-56] achieved their risk-based 2016 goal and 33% (95% CI 32-35) achieved their risk-based 2019 goal. High-intensity statin monotherapy was used in 20% and 38% of very high-risk primary and secondary prevention patients, respectively. Corresponding 2016 goal attainment was 22% and 45% (17% and 22% for 2019 goals) for very high-risk primary and secondary prevention patients, respectively. Use of moderate-high-intensity statins in combination with ezetimibe (9%), or any LLT with PCSK9 inhibitors (1%), was low; corresponding 2016 and 2019 goal attainment was 53% and 20% (ezetimibe combination), and 67% and 58% (PCSK9i combination).Conclusion Gaps between clinical guidelines and clinical practice for lipid management across Europe persist, which will be exacerbated by the 2019 guidelines. Even with optimized statins, greater utilization of non-statin LLT is likely needed to reduce these gaps for patients at highest risk.Cardiolog
The Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory is a second generation water Cherenkov
detector designed to determine whether the currently observed solar neutrino
deficit is a result of neutrino oscillations. The detector is unique in its use
of D2O as a detection medium, permitting it to make a solar model-independent
test of the neutrino oscillation hypothesis by comparison of the charged- and
neutral-current interaction rates. In this paper the physical properties,
construction, and preliminary operation of the Sudbury Neutrino Observatory are
described. Data and predicted operating parameters are provided whenever
possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and
epsf style files. For additional information about SNO see
http://www.sno.phy.queensu.ca . This version has some new reference
Novel genetic loci associated with hippocampal volume
The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness
O Memorial de Imigração Polonesa em Curitiba: dinâmicas culturais e interesses políticos no âmbito memoralista
Neste artigo, analisa-se o conceito de memorial, considerando as atuais definições de Museu propostas pelo Conselho Internacional de Museus e pelo Instituto Brasileiro de Museus, tendo como objeto de investigação o Memorial de Imigração Polonesa de Curitiba. Evidenciam-se a importância e a complexidade no trato com o patrimônio e as dificuldades de pensá-lo a partir dos sujeitos e das referências culturais de determinado grupo em contraponto aos interesses políticos e econômicos; no caso em questão, voltadas às necessidades da política de city marketing como estratégia de construção da imagem da cidade. Para tanto, foram considerados os perfis de atuação dos memoriais em diferentes partes do mundo, na tentativa de delimitação conceitual, exemplificando-se a pluralidade de temas e formatos dessas instituições no âmbito nacional e global. As discussões levantadas permitem pensar que os Museus Memoriais desempenham as atividades de um memorial no âmbito museológico, confirmando a ambivalência dessas duas instituições e sua interface privilegiada com o poder político.This article analyzes the memorial concept, considering the Museum definition presented by the International Council of Museums and the Brazilian Institute of Museums. The aim of this study was the Curitiba Polish Immigration Memorial. It highlights the importance and complexity in dealing with the heritage and the difficulties of thinking it from the individuals and the cultural references of certain groups as opposed to political and economic interests; in this case the needs of the city marketing policy as city image building strategy. Therefore, the memorials performance profiles in different parts of the world in an attempt to conceptual definition, exemplifying the diversity of themes and formats of these institutions at the national and global levels. The discussions show that it is possible to consider that the Memorials Museums perform the same activities of a memorial within the museological context, confirming the ambivalence of these two institutions and prime interface with political power
Association of common genetic variants with brain microbleeds
OBJECTIVE: To identify common genetic variants associated with the presence of brain microbleeds (BMBs). METHODS: We performed geno
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