202 research outputs found
Reply to discussion on 'A high-precision U-Pb age constraint on the Rhynie Chert Konservat-Lagerstatte: time scale and other implications': Journal, 168, 863-872
We welcome the opportunity to address the points raised by Mark et al. in their discussion of the chemical abrasion isotope dilution thermal ionization mass spectrometry (CA–ID–TIMS) U–Pb age constraint on the Rhynie Chert Konservat-Lagerstätte presented by Parry et al. (2011) and also to make some further observations of our own. We begin by briefly providing some context for the benefit of the wider readership. Two radio-isotopic age constraints on the Rhynie Chert Konservat-Lagerstätte and, by corollary, its parental hydrothermal (hot-spring) system have recently been published. The first of these is a weighted mean 40Ar/39Ar plateau age of 403.9 ± 2.1 Ma (2σ) derived from the analysis of two samples of vein-hosted hydrothermal K-feldspar and a single sample of hydrothermally altered andesite (Mark et al. 2011). In order to account for systematic uncertainties associated with the 40Ar/39Ar geochronometer, Mark et al. (2011) recalculated their individual sample ages with reference to the Fish Canyon Tuff sanidine (FCs) age of 28.201 Ma (Kuiper et al. 2008), thereby producing a ‘U–Pb comparable’ mean age of 407.1 ± 2.2 Ma (2σ). An alternative ‘preferred age’ for the Rhynie hot-spring activity (407.6 ± 2.2 Ma (2σ)) has now been produced from the ‘raw’ data using the optimization model of Renne et al. (2010, 2011) (this discussion). The 40Ar/39Ar system calibrations on which these various ages are based are summarized in Table 1. The second radio-isotopic age constraint in question is a weighted mean 206Pb/238U zircon age of 411.5 ± 1.3 Ma (2σ, including decay constant- and tracer calibration-related uncertainties; MSWD = 0.12, n = 4) yielded by the Milton of Noth Andesite, a moderately altered basaltic andesite lava flow (cum near-surface sill?) that lies along the northwestern margin of the Rhynie Outlier (Parry et al. 2011). U–Pb titanite data corroborate the zircon data, and c. 411.5 Ma is interpreted as the crystallization-eruption age of the Milton of Noth Andesite. Lavas and tuffs of andesitic composition occur elsewhere within the northern half of the Rhynie Outlier (Rice & Ashcroft 2004) and a holistic view of the available evidence would suggest that these volcanic rocks represent the surficial expression of the thermal drive for the Rhynie hot-spring system. Parry et al. (2011) therefore concluded that that the U–Pb zircon age yielded by the Milton of Noth Andesite dates the Rhynie hydrothermal activity within error [our italics]
On the Fluctuation Relation for Nose-Hoover Boundary Thermostated Systems
We discuss the transient and steady state fluctuation relation for a
mechanical system in contact with two deterministic thermostats at different
temperatures. The system is a modified Lorentz gas in which the fixed
scatterers exchange energy with the gas of particles, and the thermostats are
modelled by two Nos\'e-Hoover thermostats applied at the boundaries of the
system. The transient fluctuation relation, which holds only for a precise
choice of the initial ensemble, is verified at all times, as expected. Times
longer than the mesoscopic scale, needed for local equilibrium to be settled,
are required if a different initial ensemble is considered. This shows how the
transient fluctuation relation asymptotically leads to the steady state
relation when, as explicitly checked in our systems, the condition found in
[D.J. Searles, {\em et al.}, J. Stat. Phys. 128, 1337 (2007)], for the validity
of the steady state fluctuation relation, is verified. For the steady state
fluctuations of the phase space contraction rate \zL and of the dissipation
function \zW, a similar relaxation regime at shorter averaging times is
found. The quantity \zW satisfies with good accuracy the fluctuation relation
for times larger than the mesoscopic time scale; the quantity \zL appears to
begin a monotonic convergence after such times. This is consistent with the
fact that \zW and \zL differ by a total time derivative, and that the tails
of the probability distribution function of \zL are Gaussian.Comment: Major revision. Fig.10 was added. Version to appear in Journal of
Statistical Physic
The Steady State Fluctuation Relation for the Dissipation Function
We give a proof of transient fluctuation relations for the entropy production
(dissipation function) in nonequilibrium systems, which is valid for most time
reversible dynamics. We then consider the conditions under which a transient
fluctuation relation yields a steady state fluctuation relation for driven
nonequilibrium systems whose transients relax, producing a unique
nonequilibrium steady state. Although the necessary and sufficient conditions
for the production of a unique nonequilibrium steady state are unknown, if such
a steady state exists, the generation of the steady state fluctuation relation
from the transient relation is shown to be very general. It is essentially a
consequence of time reversibility and of a form of decay of correlations in the
dissipation, which is needed also for, e.g., the existence of transport
coefficients. Because of this generality the resulting steady state fluctuation
relation has the same degree of robustness as do equilibrium thermodynamic
equalities. The steady state fluctuation relation for the dissipation stands in
contrast with the one for the phase space compression factor, whose convergence
is problematic, for systems close to equilibrium. We examine some model
dynamics that have been considered previously, and show how they are described
in the context of this work.Comment: 30 pages, 1 figur
Extended free-form deformation : a sculpturing tool for 3D geometric modeling
Projet SYNTIMCurrent research efforts focus on providing more efficient and effective design methods for 3D modeling systems. In this paper a new deformation technique is presented. Among other things, arbitrarily shaped bump can be designed and surfaces can be bent along arbitrarily shaped curves. The purpose of this research is to define a highly interactive and intuitive modeling technique for designers and stylists. A natural way of thinking is to mimic traditional trades, such as sculpturing and moulding. Furthermore, with this deformation technique, the modeling tool paradigm is introduced. The object is deformed with a user-defined deformation tool. This method is an extension of the Free-Form Deformation (FFD) technique proposed by Sederberg and Parry
Supersymmetry beyond minimal flavour violation
We review the sources and phenomenology of non-minimal flavour violation in
the MSSM. We discuss in some detail the most important theoretical and
experimental constraints, as well as promising observables to look for
supersymmetric effects at the LHC and in the future. We emphasize the
sensitivity of flavour physics to the mechanism of supersymmetry breaking and
to new degrees of freedom present at fundamental scales, such as the grand
unification scale. We include a discussion of present data that may hint at
departures from the Standard Model.Comment: 23pp. Version to appear in the EPJC special volume "Supersymmetry on
the Eve of the LHC", dedicated to the memory of Julius Wess. References and
brief discussion on collider signatures adde
Prevalência e perfil de resistência a antimicrobianos de sorovares de Salmonella isolados de lingüiças suínas tipo frescal em Lages, SC
Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980–2015: a systematic analysis for the Global Burden of Disease Study 2015
Background Improving survival and extending the longevity of life for all populations requires timely, robust evidence on local mortality levels and trends. The Global Burden of Disease 2015 Study (GBD 2015) provides a comprehensive assessment of all-cause and cause-specific mortality for 249 causes in 195 countries and territories from 1980 to 2015. These results informed an in-depth investigation of observed and expected mortality patterns based on sociodemographic measures. Methods We estimated all-cause mortality by age, sex, geography, and year using an improved analytical approach originally developed for GBD 2013 and GBD 2010. Improvements included refinements to the estimation of child and adult mortality and corresponding uncertainty, parameter selection for under-5 mortality synthesis by spatiotemporal Gaussian process regression, and sibling history data processing. We also expanded the database of vital registration, survey, and census data to 14 294 geography–year datapoints. For GBD 2015, eight causes, including Ebola virus disease, were added to the previous GBD cause list for mortality. We used six modelling approaches to assess cause-specific mortality, with the Cause of Death Ensemble Model (CODEm) generating estimates for most causes. We used a series of novel analyses to systematically quantify the drivers of trends in mortality across geographies. First, we assessed observed and expected levels and trends of cause-specific mortality as they relate to the Socio-demographic Index (SDI), a summary indicator derived from measures of income per capita, educational attainment, and fertility. Second, we examined factors affecting total mortality patterns through a series of counterfactual scenarios, testing the magnitude by which population growth, population age structures, and epidemiological changes contributed to shifts in mortality. Finally, we attributed changes in life expectancy to changes in cause of death. We documented each step of the GBD 2015 estimation processes, as well as data sources, in accordance with Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). Findings Globally, life expectancy from birth increased from 61·7 years (95% uncertainty interval 61·4–61·9) in 1980 to 71·8 years (71·5–72·2) in 2015. Several countries in sub-Saharan Africa had very large gains in life expectancy from 2005 to 2015, rebounding from an era of exceedingly high loss of life due to HIV/AIDS. At the same time, many geographies saw life expectancy stagnate or decline, particularly for men and in countries with rising mortality from war or interpersonal violence. From 2005 to 2015, male life expectancy in Syria dropped by 11·3 years (3·7–17·4), to 62·6 years (56·5–70·2). Total deaths increased by 4·1% (2·6–5·6) from 2005 to 2015, rising to 55·8 million (54·9 million to 56·6 million) in 2015, but age-standardised death rates fell by 17·0% (15·8–18·1) during this time, underscoring changes in population growth and shifts in global age structures. The result was similar for non-communicable diseases (NCDs), with total deaths from these causes increasing by 14·1% (12·6–16·0) to 39·8 million (39·2 million to 40·5 million) in 2015, whereas age-standardised rates decreased by 13·1% (11·9–14·3). Globally, this mortality pattern emerged for several NCDs, including several types of cancer, ischaemic heart disease, cirrhosis, and Alzheimer's disease and other dementias. By contrast, both total deaths and age-standardised death rates due to communicable, maternal, neonatal, and nutritional conditions significantly declined from 2005 to 2015, gains largely attributable to decreases in mortality rates due to HIV/AIDS (42·1%, 39·1–44·6), malaria (43·1%, 34·7–51·8), neonatal preterm birth complications (29·8%, 24·8–34·9), and maternal disorders (29·1%, 19·3–37·1). Progress was slower for several causes, such as lower respiratory infections and nutritional deficiencies, whereas deaths increased for others, including dengue and drug use disorders. Age-standardised death rates due to injuries significantly declined from 2005 to 2015, yet interpersonal violence and war claimed increasingly more lives in some regions, particularly in the Middle East. In 2015, rotaviral enteritis (rotavirus) was the leading cause of under-5 deaths due to diarrhoea (146 000 deaths, 118 000–183 000) and pneumococcal pneumonia was the leading cause of under-5 deaths due to lower respiratory infections (393 000 deaths, 228 000–532 000), although pathogen-specific mortality varied by region. Globally, the effects of population growth, ageing, and changes in age-standardised death rates substantially differed by cause. Our analyses on the expected associations between cause-specific mortality and SDI show the regular shifts in cause of death composition and population age structure with rising SDI. Country patterns of premature mortality (measured as years of life lost [YLLs]) and how they differ from the level expected on the basis of SDI alone revealed distinct but highly heterogeneous patterns by region and country or territory. Ischaemic heart disease, stroke, and diabetes were among the leading causes of YLLs in most regions, but in many cases, intraregional results sharply diverged for ratios of observed and expected YLLs based on SDI. Communicable, maternal, neonatal, and nutritional diseases caused the most YLLs throughout sub-Saharan Africa, with observed YLLs far exceeding expected YLLs for countries in which malaria or HIV/AIDS remained the leading causes of early death. Interpretation At the global scale, age-specific mortality has steadily improved over the past 35 years; this pattern of general progress continued in the past decade. Progress has been faster in most countries than expected on the basis of development measured by the SDI. Against this background of progress, some countries have seen falls in life expectancy, and age-standardised death rates for some causes are increasing. Despite progress in reducing age-standardised death rates, population growth and ageing mean that the number of deaths from most non-communicable causes are increasing in most countries, putting increased demands on health systems. Funding Bill & Melinda Gates Foundation
EuFeAs under high pressure: an antiferromagnetic bulk superconductor
We report the ac magnetic susceptibility and resistivity
measurements of EuFeAs under high pressure . By observing nearly
100% superconducting shielding and zero resistivity at = 28 kbar, we
establish that -induced superconductivity occurs at ~30 K in
EuFeAs. shows an anomalous nearly linear temperature dependence
from room temperature down to at the same . indicates that
an antiferromagnetic order of Eu moments with ~20 K persists
in the superconducting phase. The temperature dependence of the upper critical
field is also determined.Comment: To appear in J. Phys. Soc. Jpn., Vol. 78 No.
Os principais desafios da gestão de competências humanas em um instituto público de pesquisa
WHO global research priorities for antimicrobial resistance in human health
The WHO research agenda for antimicrobial resistance (AMR) in human health has identified 40 research priorities to be addressed by the year 2030. These priorities focus on bacterial and fungal pathogens of crucial importance in addressing AMR, including drug-resistant pathogens causing tuberculosis. These research priorities encompass the entire people-centred journey, covering prevention, diagnosis, and treatment of antimicrobial-resistant infections, in addition to addressing the overarching knowledge gaps in AMR epidemiology, burden and drivers, policies and regulations, and awareness and education. The research priorities were identified through a multistage process, starting with a comprehensive scoping review of knowledge gaps, with expert inputs gathered through a survey and open call. The priority setting involved a rigorous modified Child Health and Nutrition Research Initiative approach, ensuring global representation and applicability of the findings. The ultimate goal of this research agenda is to encourage research and investment in the generation of evidence to better understand AMR dynamics and facilitate policy translation for reducing the burden and consequences of AMR
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