Previous systematic reviews that examined whether atrial fibrillation (AF) is associated with dementia have relied on different study designs (including retrospective ones) and did not evaluate risk ...using meta-analysis.
We searched Medline, Embase, and PsychINFO in September 2010 for published prospective studies reporting on the association between baseline AF and incident dementia. Pooled odds ratios for AF and dementia were calculated using the random effects model, with heterogeneity assessed using I(2).
We identified 15 relevant studies covering 46,637 participants, mean age 71.7 years. One study that reported no significant difference in Mini-Mental State Examination scores between patients with or without AF could not be pooled. Meta-analysis of the remaining 14 studies showed that AF was associated with a significant increase in dementia overall (odds ratio OR 2.0, 95% confidence interval CI 1.4 to 2.7, p < 0.0001), with substantial heterogeneity (I(2) = 75%). When stratified by participants, the association was significant (with little heterogeneity) in studies focusing solely on patients with stroke (7 studies, OR 2.4, 95% CI 1.7 to 3.5, p < 0.001, I(2) = 10%), and of borderline significance (with substantial heterogeneity) for studies in broader populations (7 studies, OR 1.6, 95% CI 1.0 to 2.7, p = 0.05, I(2) = 87%). For conversion of mild cognitive impairment to dementia, one study showed a significant association with AF (OR 4.6, 95% CI 1.7 to 12.5).
There is consistent evidence supporting an association between AF and increased incidence of dementia in patients with stroke whereas there remains considerable uncertainty about any link in the broader population. The potential association between AF and incident dementia in mild cognitive impairment merits further investigation.
Solving the structure of macromolecular complexes using transmission electron microscopy can be an arduous task. Many of the steps in this process rely strongly on the aid of pre-existing structural ...knowledge, and are greatly complicated when this information is unavailable. Here, we present two software tools meant to facilitate particle picking, an early stage in the single-particle processing of unknown macromolecules. The first tool, DoG Picker, is an efficient and reasonably general, particle picker based on the Difference of Gaussians (DoG) image transform. It can function alone, as a reference-free particle picker with the unique ability to sort particles based on size, or it can also be used as a way to bootstrap the creation of templates or training datasets for other particle pickers. The second tool is TiltPicker, an interactive graphical interface application designed to streamline the selection of particle pairs from tilted-pair datasets. In many respects, TiltPicker is a re-implementation of the SPIDER WEB tilted-particle picker, but built on modern computer frameworks making it easier to deploy and maintain. The TiltPicker program also includes several useful new features beyond those of its predecessor.
The availability of large data sets with stellar distance and polarization information will enable a tomographic reconstruction of the (plane-of-the-sky-projected) interstellar magnetic field in the ...near future. We demonstrate the feasibility of such a decomposition within a small region of the diffuse interstellar medium (ISM). We combine measurements of starlight (R-band) linear polarization obtained using the RoboPol polarimeter with stellar distances from the second Gaia data release. The stellar sample is brighter than 17 mag in the R-band and reaches out to several kiloparsecs from the Sun. H i emission spectra reveal the existence of two distinct clouds along the line of sight. We decompose the line-of-sight-integrated stellar polarizations to obtain the mean polarization properties of the two clouds. The two clouds exhibit significant differences in terms of column density and polarization properties. Their mean plane-of-the-sky magnetic field orientation differs by 60°. We show how our tomographic decomposition can be used to constrain our estimates of the polarizing efficiency of the clouds as well as the frequency dependence of the polarization angle of polarized dust emission. We also demonstrate a new method to constrain cloud distances based on this decomposition. Our results represent a preview of the wealth of information that can be obtained from a tomographic map of the ISM magnetic field.
We report on spectroscopic observations covering most of the 475 BL Lacs in the second Fermi Large Area Telescope (LAT) catalog of active galactic nuclei (AGNs). Including archival measurements ...(correcting several erroneous literature values) we now have spectroscopic redshifts for 44% of the BL Lacs. We establish firm lower redshift limits via intervening absorption systems and statistical lower limits via searches for host galaxies for an additional 51% of the sample leaving only 5% of the BL Lacs unconstrained. The new redshifts raise the median spectroscopic z from 0.23 to 0.33 and include redshifts as large as z = 2.471. Spectroscopic redshift minima from intervening absorbers have z = 0.70, showing a substantial fraction at large z and arguing against strong negative evolution. We find that detected BL Lac hosts are bright ellipticals with black hole masses M sub( times ) ~ 10 super(8.5)-10 super(9), substantially larger than the mean of optical AGNs and LAT Flat Spectrum Radio Quasar samples. A slow increase in M sub( times ) with z may be due to selection bias. We find that the power-law dominance of the optical spectrum extends to extreme values, but this does not strongly correlate with the gamma -ray properties, suggesting that strong beaming is the primary cause of the range in continuum dominance.
We used a climate‐driven regression model to develop spatially resolved estimates of soil‐CO2 emissions from the terrestrial land surface for each month from January 1980 to December 1994, to ...evaluate the effects of interannual variations in climate on global soil‐to‐atmosphere CO2 fluxes. The mean annual global soil‐CO2 flux over this 15‐y period was estimated to be 80.4 (range 79.3–81.8) Pg C. Monthly variations in global soil‐CO2 emissions followed closely the mean temperature cycle of the Northern Hemisphere. Globally, soil‐CO2 emissions reached their minima in February and peaked in July and August. Tropical and subtropical evergreen broad‐leaved forests contributed more soil‐derived CO2 to the atmosphere than did any other vegetation type (∼30% of the total) and exhibited a biannual cycle in their emissions. Soil‐CO2 emissions in other biomes exhibited a single annual cycle that paralleled the seasonal temperature cycle. Interannual variability in estimated global soil‐CO2 production is substantially less than is variability in net carbon uptake by plants (i.e., net primary productivity). Thus, soils appear to buffer atmospheric CO2 concentrations against far more dramatic seasonal and interannual differences in plant growth. Within seasonally dry biomes (savannas, bushlands and deserts), interannual variability in soil‐CO2 emissions correlated significantly with interannual differences in precipitation. At the global scale, however, annual soil‐CO2 fluxes correlated with mean annual temperature, with a slope of 3.3 Pg C y−1 per °C. Although the distribution of precipitation influences seasonal and spatial patterns of soil‐CO2 emissions, global warming is likely to stimulate CO2 emissions from soils.
We report on optical spectroscopy of 165 flat spectrum radio quasars (FSRQs) in the Fermi 1LAC sample, which have helped allow a nearly complete study of this population. Fermi FSRQs show significant ...evidence for non-thermal emission even in the optical; the degree depends on the gamma -ray hardness. They also have smaller virial estimates of hole mass than the optical quasar sample. This appears to be largely due to a preferred (axial) view of the gamma -ray FSRQ and non-isotropic (H/R ~ 0.4) distribution of broad-line velocities. Even after correction for this bias, the Fermi FSRQs show higher mean Eddington ratios than the optical population. A comparison of optical spectral properties with Owens Valley Radio Observatory radio flare activity shows no strong correlation.
Phylogeny and classification of Rosaceae Potter, D; Eriksson, T; Evans, R. C ...
Plant systematics and evolution,
07/2007, Letnik:
266, Številka:
1-2
Journal Article
Recenzirano
Phylogenetic relationships among 88 genera of Rosaceae were investigated using nucleotide sequence data from six nuclear (18S, gbssi1, gbssi2, ITS, pgip, and ppo) and four chloroplast (matK, ndhF, ...rbcL, and trnL-trnF) regions, separately and in various combinations, with parsimony and likelihood-based Bayesian approaches. The results were used to examine evolution of non-molecular characters and to develop a new phylogenetically based infrafamilial classification. As in previous molecular phylogenetic analyses of the family, we found strong support for monophyly of groups corresponding closely to many previously recognized tribes and subfamilies, but no previous classification was entirely supported, and relationships among the strongly supported clades were weakly resolved and/or conflicted between some data sets. We recognize three subfamilies in Rosaceae: Rosoideae, including Filipendula, Rubus, Rosa, and three tribes; Dryadoideae, comprising the four actinorhizal genera; and Spiraeoideae, comprising Lyonothamnus and seven tribes. All genera previously assigned to Amygdaloideae and Maloideae are included in Spiraeoideae. Three supertribes, one in Rosoideae and two in Spiraeoideae, are recognized.
The carbonic anhydrases (CAs) comprise a family of evolutionarily ancient enzymes found ubiquitously in nature. They have important roles in facilitating transport of carbon dioxide and protons in ...the intracellular space, across biological membranes and in the unstirred layers of the extracellular space. The tumour-associated isoenzymes, CAIX and CAXII, are expressed in a wide variety of malignancies and appear to be tightly regulated by microenvironmental hypoxia. CAIX expression is linked to poor prognosis in a number of human tumours, and may be a marker of aggressive malignant phenotype and a mechanism of progression. Inhibitors of CA may inhibit tumour growth and invasion, with consequent therapeutic potential.
The Gravity Recovery and Climate Experiment space gravity mission provides one of the principal means of estimating present‐day mass loss occurring in polar regions. Extraction of the mass loss ...signal from the observed gravity changes is complicated by the need to first remove the signal of ongoing glacial isostatic adjustment (GIA) since the Last Glacial Maximum. This can be problematic in regions such as Antarctica where the GIA models are poorly constrained by observation and their accuracy is not well known. We present a new methodology that permits the GIA component to be represented mathematically by a simple, linear expression of the ratio of viscoelastic Love numbers that is valid for a broad range of Earth and ice‐load models. The expression is shown to reproduce rigorous computations of surface uplift rates to within 0.3 mm/yr, thus providing a means of inverting simultaneously for present‐day mass loss and ongoing GIA with all the accuracy of a fully detailed forward model.
Key Points
Ratio of deformational & gravitational Love numbers is independent of ice model
Ratio of deformational & gravitational Love numbers is independent of rheology
Numerically‐derived ratio values offer greater accuracy than earlier theory
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