Biomass burning (BB) largely modifies the chemical composition of atmospheric aerosols on the globe. We collected aerosol samples (TSP) at Cape Hedo, on subtropical Okinawa Island, from October 2009 ...to February 2012 to study anhydrosugars as BB tracers. Levoglucosan was detected as the dominant anhydrosugar followed by its isomers, mannosan and galactosan. We found a clear seasonal trend of levoglucosan and mannosan with winter maxima and summer minima. Positive correlation was found between levoglucosan and nss-K+ (r = 0.38, p < 0.001); the latter is another BB tracer. The analyses of air mass trajectories and fire spots demonstrated that the seasonal variations of anhydrosugars are caused by long-range transport of BB emissions from the Asian continent. We found winter maxima of anhydrosugars, which may be associated with open burning and domestic heating and cooking in northern and northeastern China, Mongolia and Russia and with the enhanced westerly winds. The monthly averaged levoglucosan / mannosan ratios were lower (2.1–4.8) in May–June and higher (13.3–13.9) in November–December. The lower values may be associated with softwood burning in northern China, Korea and southwestern Japan whereas the higher values are probably caused by agricultural waste burning of maize straw in the North China Plain. Anhydrosugars comprised 0.22% of water-soluble organic carbon (WSOC) and 0.13% of organic carbon (OC). The highest values to WSOC (0.37%) and OC (0.25%) were found in winter, again indicating an important BB contribution to Okinawa aerosols in winter. This study provides useful information to better understand the effect of East Asian biomass burning on the air quality in the western North Pacific Rim.
Reliable assignment of an unknown query sequence to its correct species remains a methodological problem for the growing field of DNA barcoding. While great advances have been achieved recently, ...species identification from barcodes can still be unreliable if the relevant biodiversity has been insufficiently sampled. We here propose a new notion of species membership for DNA barcoding—fuzzy membership, based on fuzzy set theory—and illustrate its successful application to four real data sets (bats, fishes, butterflies and flies) with more than 5000 random simulations. Two of the data sets comprise especially dense species/population‐level samples. In comparison with current DNA barcoding methods, the newly proposed minimum distance (MD) plus fuzzy set approach, and another computationally simple method, ‘best close match’, outperform two computationally sophisticated Bayesian and BootstrapNJ methods. The new method proposed here has great power in reducing false‐positive species identification compared with other methods when conspecifics of the query are absent from the reference database.
The relation between inflammation and brain MRI findings in the elderly remains poorly known. We investigated the association of circulating interleukin-6 (IL-6) and C-reactive protein (CRP) levels ...with baseline and longitudinal white matter hyperintensities (WMH), silent brain infarction, and brain volumes in community-dwelling elderly free of dementia.
We included 1,841 participants aged 65 to 80 years from the Three City-Dijon cohort. Participants followed an MRI examination at baseline and after a 4-year follow-up (n = 1,316). IL-6 and CRP concentrations were measured at baseline from fasting blood samples. WMH were detected with an automatic imaging processing method and gray matter, hippocampal, white matter, and CSF volumes were estimated with voxel-based morphometry. Silent brain infarctions were assessed visually and defined as focal lesions of ≥3 mm in the absence of stroke. We used analysis of covariance and logistic regression to model the associations between inflammatory biomarkers and brain MRI findings adjusting for potential confounders.
In cross-sectional analyses, higher IL-6 levels were associated with higher WMH volumes (p < 0.01), lower gray matter (p = 0.001) and hippocampal (p = 0.01) volumes, and increasing CSF volumes (p = 0.002) in a dose-relationship pattern. Similar but weaker relations were observed for CRP. We observed no associations between baseline inflammatory biomarker levels and the evolution of MRI findings over 4 years.
IL-6, and, to a lesser degree, CRP levels were associated with WMH severity as well as global markers of brain atrophy. These results suggest that an inflammatory process may be involved in both age-associated brain alterations.
Steady state flow behavior of the FeCoNiCrMn high-entropy alloy at temperatures ranging from 1023 to 1123 K was systematically characterized. It was found that the stress exponent (i.e., the ...reciprocal of strain-rate sensitivity) was dependent on the applied strain rate, and specifically the stress exponent is high (∼5) in the high strain rate regime, but decreases with decreasing strain rate. Microstructural examinations of the samples before and after deformation were performed to understand the interplay of the microstructures with the corresponding properties. Based on the observations, it was proposed that, at high strain rates, the deformation of the current high-entropy alloy was controlled by dislocation climb and the rate limiting process was the diffusion of Ni. At low strain rates, however, the deformation appeared to be controlled by the viscous glide of dislocations. Moreover, at the slowest strain rate (i.e., the longest thermal exposure time), new phases evolved, which caused elemental redistribution and weakening of the material.
•The high-temperature deformation mechanism of the FeCoNiCrMn HEA is characterized.•Two stages of stress exponent (n) depending on the strain rates are obtained.•Activation volume was calculated and verified through stress relaxation tests.•Dislocation climb mechanism controls the high strain rate region.•Viscous glide of dislocations mechanism controls the low strain rate region.
Focusing on competitive Lotka–Volterra model in random environments, this paper uses regime-switching diffusions to model the dynamics of the population sizes of
n different species in an ecosystem ...subject to the random changes of the external environment. It is demonstrated that the growth rates of the population sizes of the species are bounded above. Moreover, certain long-run-average limits of the solution are examined from several angles. A partial stochastic principle of competitive exclusion is also derived. Finally, simple examples are used to demonstrate our findings.
Summary
Background
There have been inconsistent results reported for leptin levels in patients with psoriasis.
Aim
To evaluate leptin levels in patients with psoriasis using a meta‐analysis of ...studies comparing leptin levels in controls and in patients with psoriasis.
Methods
PubMed (MEDLINE), EMBASE and the Cochrane Library were searched for relevant papers published in English. Pooled weighted mean differences (WMDs) and 95% CIs were calculated using random‐effects and fixed‐effects models. Heterogeneity between studies was assessed using the Cochran Q and I2 statistics.
Results
In total, 11 studies, comprising 773 patients with psoriasis and 570 healthy controls, were identified. Leptin levels were significantly higher in patients with psoriasis compared with controls (WMD = 7.24, 95% CI 4.55–9.93; P < 0.001). On stratified analysis, significant differences in leptin levels between patients with psoriasis and controls were reported only in serum samples (P < 0.001), and not in plasma samples (P = 0.025). Sensitivity analysis showed that there were no changes in the direction of effect when any one study was excluded. No publication bias was detected.
Conclusions
Leptin levels are higher in patients with psoriasis compared with those in controls. Future studies are warranted to clarify the association between leptin levels and the pathomechanism of psoriasis.
The ability to express thoughts through fluent speech production is a most human faculty, one that is often taken for granted. Stuttering, which disrupts the smooth flow of speech, affects 5% of ...preschool-age children and 1% of the general population, and can lead to significant communication difficulties and negative psychosocial consequences throughout one's lifetime. Despite the fact that symptom onset typically occurs during early childhood, few studies have yet examined the possible neural bases of developmental stuttering during childhood. Here we present a diffusion tensor imaging study that examined white matter measures reflecting neuroanatomical connectivity (fractional anisotropy) in 77 children 40 controls (20 females), 37 who stutter (16 females) between 3 and 10 years of age. We asked whether previously reported anomalous white matter measures in adults and older children who stutter that were found primarily in major left hemisphere tracts (e.g. superior longitudinal fasciculus) are also present in younger children who stutter. All children exhibited normal speech, language, and cognitive development as assessed through a battery of assessments. The two groups were matched in chronological age and socioeconomic status. Voxel-wise whole brain comparisons using tract-based spatial statistics and region of interest analyses of fractional anisotropy were conducted to examine white matter changes associated with stuttering status, age, sex, and stuttering severity. Children who stutter exhibited significantly reduced fractional anisotropy relative to controls in white matter tracts that interconnect auditory and motor structures, corpus callosum, and in tracts interconnecting cortical and subcortical areas. In contrast to control subjects, fractional anisotropy changes with age were either stagnant or showed dissociated development among major perisylvian brain areas in children who stutter. These results provide first glimpses into the neuroanatomical bases of early childhood stuttering, and possible white matter developmental changes that may lead to recovery versus persistent stuttering. The white matter changes point to possible structural connectivity deficits in children who stutter, in interrelated neural circuits that enable skilled movement control through efficient sensorimotor integration and timing of movements.
Abstract Background The purpose of this study was to compare patient outcomes between immediate breast reconstruction (IBR) after mastectomy and mastectomy alone. Methods We conducted a comprehensive ...literature search of PUBMED, EMBASE, Web of Science, and Cochrane Library. The primary outcomes evaluated in this review were overall survival, disease-free survival and local recurrence. Secondary outcome was the incidence of surgical site infection. All data were analyzed using Review Manager 5.3. Results Thirty-one studies, involving of 139,894 participants were included in this paper. Pooled data demonstrated that women who had IBR after mastectomy were more likely to experience surgical site infection than those treated with mastectomy alone (risk ratios 1.51, 95% CI: 1.22–1.87; p = 0.0001). There were no significant differences in overall survival (hazard ratios 0.92, 95% CI: 0.80–1.06; p = 0.25) and disease-free survival (hazard ratios 0.96, 95% CI: 0.84–1.10; p = 0.54) between IBR after mastectomy and mastectomy alone. No significant difference was found in local recurrence between two groups (risk ratios 0.92, 95% CI: 0.75–1.13; p = 0.41). Conclusions Our study demonstrates that IBR after mastectomy does not affect the overall survival and disease-free survival of breast cancer. Besides, no evidence shows that IBR after mastectomy increases the frequency of local recurrence.
Vertical chutes and pipes are a common component of many industrial apparatus used in the transport and processing of powders and grains. Here, a typical arrangement is considered first in which a ...hopper at the top feeds the chute and a converging outlet at the bottom controls the mass flux. Discrete element method (DEM) simulations reveal that steady uniform flow is only observed for intermediate flow rates, with jamming and unsteady waves dominating slow flows and non-uniform wall detachment in fast flow. Focusing on the steady uniform regimes, a progressive idealisation is carried out by matching with equivalent DEM simulations in periodic cells. These investigations justify a one-dimensional continuum modelling of the problem and provide key test data. Novel exact solutions are derived here for vertical flow using a linear version of the ‘$\mu(I),\varPhi(I)$-rheology’, for which the bulk friction $\mu$ and steady solid volume fraction $\varPhi$ depend on the inertial number I. Despite not capturing the full nonlinear complexities, the solutions match important aspects of the DEM flow fields and reveal simple scaling laws linking many quantities of interest. In particular, this study clearly demonstrates a linear relation between the chute width and the size of the shear zones at the walls. This finding contrasts with previous works on purely quasi-static flow, which instead predict a roughly constant shear zone width, a difference which implies that finite-size effects are minimal for the inertial flows studied here.
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