340 research outputs found
Preciseness is a virtue: What are critical questions?
The paper compares the uses of âcritical questionâ in recent publications on the topic, contrasting explicit definitions where they exist and reconstructing implicit definitions where possible, and suggests a taxonomy of different âcritical questionsâ as they are used in argumentative evaluation and criticism. In distinguishing different meanings of âcritical questionâ horizontally between authors and vertically within the analysis, it strives to make a contribution to the ongoing work on the systematization of argumentative criticism
Commentary on: Paul van den Hoven\u27s Mimetics in judicial argumentation: A theoretical exploration
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Altruism and Prosocial Behavior
This is the author accepted manuscript. The final version is available from Springer via the DOI in this recor
Platelet ice, the Southern Oceanâs hidden ice: a review
Basal melt of ice shelves is not only an important part of Antarcticaâs ice-sheet mass budget, but it is
also the origin of one of the most peculiar types of sea ice found in the polar oceans: platelet ice. In
many regions around coastal Antarctica, tiny ice crystals form and grow in supercooled plumes of
Ice Shelf Water, releasing heat into the surrounding ocean. They usually rise towards the surface,
eventually becoming trapped under an ice shelf as marine ice. Frequently, masses of those crystals
are advected out of the ice-shelf cavity, and accumulate below a solid sea-ice cover to form a semiconsolidated
layer. When the overlying sea ice grows into this so-called sub-ice platelet layer, the
loose crystals are consolidated, adding additional thickness to the sea ice. These phenomena are
generally referred to as platelet ice, although confusion about the terminology is widespread in
the literature. The presence of platelet ice has a profound impact on sea-ice properties and processes
in several regions of Antarctica, with numerous implications for the local polar marine biosphere.
Most notably, sub-ice platelet layers provide a stable, sheltered, nutrient- and food-rich habitat
which usually results in a highly productive and uniquely adapted ecosystem. It has also been
hypothesised that platelet ice may be an indicator of the state of an ice shelf, although comprehensive
time series are limited to the Ross Sea. This paper clears up the terminology by providing exact
definitions of the relevant terms.We review platelet-ice formation, observational methods as well as
geographical and seasonal occurrence. The physical properties and ecological implications are
merged in a way understandable for physicists and biologists alike, to lay the foundation for the
interdisciplinary research that is necessary to tackle the current knowledge gaps
Site-specific incorporation of phosphotyrosine using an expanded genetic code.
Access to phosphoproteins with stoichiometric and site-specific phosphorylation status is key to understanding the role of protein phosphorylation. Here we report an efficient method to generate pure, active phosphotyrosine-containing proteins by genetically encoding a stable phosphotyrosine analog that is convertible to native phosphotyrosine. We demonstrate its general compatibility with proteins of various sizes, phosphotyrosine sites and functions, and reveal a possible role of tyrosine phosphorylation in negative regulation of ubiquitination
Photoswitchable peptide-based âon-offâ biosensor for electrochemical detection and control of protein-protein interactions
Neuronal nitric oxide synthase (nNOS) is an enzyme responsible for catalyzing the production of the crucial cellular signalling molecule, nitric oxide (NO), through its interaction with the PDZ domain of α-syntrophin protein. In this study, a novel light-driven photoswitchable peptide-based biosensor, modelled on the nNOS ÎČ-finger, is used to detect and control its interaction with α-syntrophin. An azobenzene photoswitch incorporated into the peptide backbone allows reversible switching between a trans photostationary state devoid of secondary structure, and a cis photostationary state possessing a well-defined antiparallel ÎČ-strand geometry, as revealed by molecular modelling. Electrochemical impedance spectroscopy (EIS) is used to successfully detect the interaction between the gold electrode bound peptide in its cis photostationary state and a wide range of concentrations of α-syntrophin protein, highlighting both the qualitative and quantitative properties of the sensor. Furthermore, EIS demonstrates that the probe in its random trans photostationary state does not bind to the target protein. The effectiveness of the biosensor is further endorsed by the high thermal stability of the photostationary state of the cis-isomer, and the ability to actively control biomolecular interactions using light. This approach allows detection and control of binding to yield a regenerable on-off biosensor.John R.Horsley, Jingxian Yu, Kate L.Wegener, Christian Hoppmann, Karola RĂŒck-Braun, Andrew D.Abel
Differential and shared genetic effects on kidney function between diabetic and non-diabetic individuals
Reduced glomerular filtration rate (GFR) can progress to kidney failure. Risk factors include genetics and diabetes mellitus (DM), but little is known about their interaction. We conducted genome-wide association meta-analyses for estimated GFR based on serum creatinine (eGFR), separately for individuals with or without DM (nDMâ=â178,691, nnoDMâ=â1,296,113). Our genome-wide searches identified (i) seven eGFR loci with significant DM/noDM-difference, (ii) four additional novel loci with suggestive difference and (iii) 28 further novel loci (including CUBN) by allowing for potential difference. GWAS on eGFR among DM individuals identified 2 known and 27 potentially responsible loci for diabetic kidney disease. Gene prioritization highlighted 18 genes that may inform reno-protective drug development. We highlight the existence of DM-only and noDM-only effects, which can inform about the target group, if respective genes are advanced as drug targets. Largely shared effects suggest that most drug interventions to alter eGFR should be effective in DM and noDM
Positive and negative affect are associated with salivary cortisol in the everyday life of older adults: A quantitative synthesis of four aging studies
Research on time-fluctuating links between positive affect and cortisol is inconsistent and mostly based on young to middle-aged samples. The current project investigated how moment-to-moment changes in positive and negative affect are associated with moment-to-moment changes in cortisol levels in older adultsâ daily lives and whether those associations are moderated by differences in health status (as indicated by the number of comorbidities). Affect and cortisol data collected in four separately conducted momentary assessment studies with parallel protocols were pooled to obtain a sample of N=476 individuals aged 56â88 years (Mage=71.9, SD=6.6; 52% female). Participants provided affect reports and collected salivary cortisol 5â7 times a day for a 7-day period and reported the presence of 13 different health conditions. Data were analyzed using multilevel models, with time since waking, daily behaviors associated with cortisol secretion, age, and sex controlled. Feeling more positive affect than usual was associated with lower momentary cortisol. In contrast, feeling more negative affect than usual was associated with higher momentary cortisol. Associations of momentary positive and negative affect with cortisol were weaker among participants in worse as compared to those in better health. Trait positive affectivity was associated with more curvature of waking cortisol profiles and trait negative affectivity was associated with smaller cortisol awakening responses. Findings suggest that HPA axis responses fluctuate with everyday changes in positive and negative affect in older adults, and that higher HPA reactivity may indicate preserved health in this age group
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