2,298 research outputs found
Authority arguments in academic contexts in social studies and humanities
In academic contexts the appeal to authority is a quite common but seldom tested argument, either because we accept the authority without questioning it, or because we look for alternative experts or reasons to support a different point of view. But, by putting ourselves side by side an already accepted authority, we often rhetorically manoeuvre to displace the burden of the proof to avoid the fear to present our opinions and to allow face saving
Biotreatment of industrial wastewaters under transient-state conditions: process stability with fluctuations of organic load, substrates, toxicants, and environmental parameters
Biotreatment of industrial wastewater is often challenged by operation under transient states with respect to organic loads, pollutants, and physical characteristics. Furthermore, the potential presence of inhibitory compounds requires careful monitoring and adequate process design. This review describes difficulties encountered in biological treatment of wastewater with highly variable influent characteristics. Typical design aspects of biological processes are presented and discussed with respect to their success in treating highly fluctuating wastewaters. In general, biomass retention is a key factor for dealing with highly fluctuating and/or inhibitory wastewater, but the how it operates also affects the stability of performance, as it was shown that dynamic operation instead of operation at a constant flow enhances biodegradation onset and more evenly distributed activity. Although ultimately stable effluent quality must be achieved, the microbial population stability is not necessarily high, as it was shown that microbial diversity and flexibility may play a critical role in functional stability.info:eu-repo/semantics/acceptedVersio
Spectrophotometric Observations of Blue Compact Dwarf Galaxies: Mrk 370
We present results from a detailed spectrophotometric analysis of the blue
compact dwarf galaxy (BCD) Mrk 370, based on deep UBVRI broad-band and Halpha
narrow-band observations, and long-slit and two-dimensional spectroscopy of its
brightest knots. The spectroscopic data are used to derive the internal
extinction, and to compute metallicities, electronic density and temperature in
the knots. By subtracting the contribution of the underlying older stellar
population, modeled by an exponential function, removing the contribution from
emission lines, and correcting for extinction, we can measure the true colors
of the young star-forming knots. We show that the colors obtained this way
differ significantly from those derived without the above corrections, and lead
to different estimates of the ages and star-forming history of the knots. Using
predictions of evolutionary synthesis models, we estimate the ages of both the
starburst regions and the underlying stellar component. We found that we can
reproduce the colors of all the knots with an instantaneous burst of star
formation and the Salpeter initial mass function with an upper mass limit of
100 solar masses. The resulting ages range between 3 and 6 Myrs. The colors of
the low surface brightness component are consistent with ages larger than 5
Gyr. The kinematic results suggest ordered motion around the major axis of the
galaxy.Comment: 26 pages with 14 figures; accepted for publication in Ap
27. New echocardiogram index alternatives to MAPSE and TAPSE z-scores in children
BackgroundMitral annular plane systolic excursion (MAPSE), and tricuspid annular plane systolic excursion (TAPSE) are relatively load independent longitudinal left ventricle (LV) and right ventricle (RV) measurement in both adults and children. Normal paediatric values of MAPSE and TAPSE unlike adults are based on inconvenient z-scores. We hypothesize novel indexes of (LSI) LV longitudinal systolic index and (RSI) RV longitudinal systolic index are BSA, age, gender independent and nullifies the need for MAPSE and TAPSE z-scores.MethodsNormal echocardiograms were retrospectively reviewed from 2009 to 2011. Ejection fraction, LV dimensions, MAPSE, and TAPSE were determined. LSI and RSI were calculated using MAPSE and TAPSE divided by LV length. Echocardiogram indices were correlated. Regression analysis was done for BSA, age, and gender.ResultsTwo hundred and one patients had normal ejection fractions (67.3;±5.1%). Mean MAPSE 10.4;±3.3mm, z-score −0.07;±1.2, and LSI 0.20;±0.03; Mean TAPSE 17.4;±5.4mm, z-score 0.74;±1.7, and RSI 0.34;±0.06. LSI and MAPSE z-scores correlated, r=0.73, p<0.001. Age, gender, and BSA did not correlate with LSI. RSI and TAPSE z-scores correlated with r=0.76, p<0.001. Age influences RSI, R2=0.58, p value <0.001, BSA and gender does not. RSI, with age stratification, is significantly decreased less than 2months.ConclusionLSI obviates need for-MAPSE z scores. RSI offers an additional non TAPSE z-score method to evaluate RV function, but does not nullify age effect. RSI, especially in the first two months is decreased
Kinetics of Plasma- and Erythrocyte-Astaxanthin in Healthy Subjects Following a Single and Maintenance Oral Dose
Aim & background: Astaxanthin is a unique carotenoid of predominantly marine origin providing the pink-red color to certain microalgae and accumulating in various animals higher in the food chain. It is an antioxidant without pro-oxidant properties or known side-effects following oral intake. Methods: We investigated astaxanthin kinetics in plasma and erythrocytes (RBC) of four healthy adults after a single oral 40 mg dose. Plasma- and RBC-astaxanthin were measured during 72h. Subsequently, an 8 mg/day dose was given during 17 days. Plasma- and RBC-astaxanthin were measured each morning. Results: Plasmaastaxanthin reached a peak (from 79 to 315 nmol/L) after 8h and then declined (half-life, 18h). Within 72h, plasma-astaxanthin had returned to baseline. RBC-astaxanthin reached a peak (from 63 to 137 nmol/L packed cells) at 12h and subsequently disappeared (half-life, 28h). During the daily dose, plasmaastaxanthin increased until day 10 (187 nmol/L) and then decreased to a steady concentration similar to that reached after 2 days. RBC-astaxanthin appeared to be highly variable (group median concentration, 86 nmol/L packed cells). Conclusion: We found high intra- and inter-individual variations, especially in RBC, possibly due to non-standardized time difference between astaxanthin intake and sampling, fl uctuating background intake from the diet, variable bioavailability, large distribution volume, degradation or others. Oral astaxanthin is rapidly absorbed and incorporated into RBC. The subsequent rapid decline suggests that, for a higher-than-baseline status, astaxanthin should be taken daily, at least in an early phase when total body equilibrium, if any, has not been reached yet
Deep Near Infrared Mapping of Young and Old Stars in Blue Compact Dwarf Galaxies
We analyze J, H and Ks near-infrared data for 9 Blue Compact Dwarf (BCD)
galaxies, selected from a larger sample that we have already studied in the
optical. We present contour maps, surface brightness and color profiles, as
well as color maps of the sample galaxies. The morphology of the BCDs in the
NIR has been found to be basically the same as in the optical. The inner
regions of these systems are dominated by the starburst component. At low
surface brightness levels the emission is due to the underlying host galaxy;
the latter is characterized by red, radially constant colors and isophotes well
fit by ellipses. We derive accurate optical near--infrared host galaxy colors
for eight of the sample galaxies; these colors are typical of an evolved
stellar population. Interestingly, optical near--infrared color maps reveal the
presence of a complex, large-scale absorption pattern in three of the sample
galaxies. We study the applicability of the Sersic law to describe the surface
brightness profiles of the underlying host galaxy, and find that, because of
the limited surface brightness interval over which the fit can be made, the
derived Sersic parameters are very sensitive to the selected radial interval
and to errors in the sky subtraction. Fitting an exponential model gives
generally more stable results, and can provide a useful tool to quantify the
structural properties of the host galaxy and compare them with those of other
dwarf classes as well as with those of star-forming dwarfs at higher redshifts.Comment: 49 pages, 9 figures, 10 tables, accepted for publication in the
Astrophysical Journa
Analytical techniques for multiplex analysis of protein biomarkers
Introduction: The importance of biomarkers for pharmaceutical drug development and clinical diagnostics is more significant than ever in the current shift toward personalized medicine. Biomarkers have taken a central position either as companion markers to support drug development and patient selection, or as indicators aiming to detect the earliest perturbations indicative of disease, minimizing therapeutic intervention or even enabling disease reversal. Protein biomarkers are of particular interest given their central role in biochemical pathways. Hence, capabilities to analyze multiple protein biomarkers in one assay are highly interesting for biomedical research. Areas covered: We here review multiple methods that are suitable for robust, high throughput, standardized, and affordable analysis of protein biomarkers in a multiplex format. We describe innovative developments in immunoassays, the vanguard of methods in clinical laboratories, and mass spectrometry, increasingly implemented for protein biomarker analysis. Moreover, emerging techniques are discussed with potentially improved protein capture, separation, and detection that will further boost multiplex analyses. Expert commentary: The development of clinically applied multiplex protein biomarker assays is essential as multi-protein signatures provide more comprehensive information about biological systems than single biomarkers, leading to improved insights in mechanisms of disease, diagnostics, and the effect of personalized medicine
Characterization of regulatory T cells in urban newborns
© 2009 Ly et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Large-Scale Meta-GWAS Reveals Common Genetic Factors Linked to Radiation-Induced Acute Toxicities across Cancers
BACKGROUND: This study was designed to identify common genetic susceptibility and shared genetic variants associated with acute radiation-induced toxicity (RIT) across four cancer types (prostate, head and neck, breast, and lung).METHODS: A GWAS meta-analysis was performed using 19 cohorts including 12,042 patients. Acute standardized total average toxicity (rSTATacute) was modelled using a generalized linear regression model for additive effect of genetic variants adjusted for demographic and clinical covariates. LD score regression estimated shared SNP-based heritability of rSTATacute in all patients and for each cancer type.RESULTS: Shared SNP-based heritability of STATacute among all cancer types was estimated at 10% (se = 0.02), and was higher for prostate (17%, se = 0.07), head and neck (27%, se = 0.09), and breast (16%, se = 0.09) cancers. We identified 130 suggestive associated SNPs with rSTATacute (5.0x10-8<P-value<1.0x10-5) across 25 genomic regions. rs142667902 showed the strongest association (effect allele A; effect size -0.17; P-value=1.7x10-7), which is located near DPPA4, encoding a protein involved in pluripotency in stem cells, which are essential for repair of radiation-induced tissue injury. Gene-set enrichment analysis identified 'RNA splicing via endonucleolytic cleavage and ligation' (P = 5.1 x10-6, Pcorrected =0.079) as the top gene set associated with rSTATacute among all patients. In-silico gene expression analysis showed the genes associated with rSTATacute were statistically significantly up-regulated in skin (not sun exposed Pcorrected=0.004; sun exposed Pcorrected=0.026).CONCLUSIONS: There is shared SNP-based heritability for acute RIT across and within individual cancer sites. Future meta-GWAS among large radiotherapy patient cohorts are worthwhile to identify the common causal variants for acute radiotoxicity across cancer types.</p
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