101 research outputs found
Multi-omic signatures of atherogenic dyslipidaemia : pre-clinical target identification and validation in humans
Dyslipidaemia is a major risk factor for atherosclerosis and cardiovascular diseases. The molecular mechanisms that translate dyslipidaemia into atherogenesis and reliable markers of its progression are yet to be fully elucidated. To address this issue, we conducted a comprehensive metabolomic and proteomic analysis in an experimental model of dyslipidaemia and in patients with familial hypercholesterolemia (FH)
Complexity Bounds for Ordinal-Based Termination
`What more than its truth do we know if we have a proof of a theorem in a
given formal system?' We examine Kreisel's question in the particular context
of program termination proofs, with an eye to deriving complexity bounds on
program running times.
Our main tool for this are length function theorems, which provide complexity
bounds on the use of well quasi orders. We illustrate how to prove such
theorems in the simple yet until now untreated case of ordinals. We show how to
apply this new theorem to derive complexity bounds on programs when they are
proven to terminate thanks to a ranking function into some ordinal.Comment: Invited talk at the 8th International Workshop on Reachability
Problems (RP 2014, 22-24 September 2014, Oxford
A Girsanov Result through Birkhoff Integral
A vector-valued version of the Girsanov theorem is presented, for a scalar
process with respect to a Banach-valued measure. Previously, a short discussion
about the Birkhoff-type integration is outlined, as for example integration by
substitution, in order to fix the measure-theoretic tools needed for the main
result, Theorem 6, where a martingale equivalent to the underlying vector
probability has been obtained in order to represent the modified process as a
martingale with the same marginals as the original one
Interspecific transfer of parasites following a range-shift in Ficedula flycatchers
Human‐induced climate change is expected to cause major biotic changes in species distributions and thereby including escalation of novel host‐parasite associations. Closely related host species that come into secondary contact are especially likely to exchange parasites and pathogens. Both the Enemy Release Hypothesis (where invading hosts escape their original parasites) and the Novel Weapon Hypothesis (where invading hosts bring new parasites that have detrimental effects on native hosts) predict that the local host will be most likely to experience a disadvantage. However, few studies evaluate the occurrence of interspecific parasite transfer by performing wide‐scale geographic sampling of pathogen lineages, both within and far from host contact zones. In this study, we investigate how haemosporidian (avian malaria) prevalence and lineage diversity vary in two, closely related species of passerine birds; the pied flycatcher Ficedula hypoleuca and the collared flycatcher F. albicollis in both allopatry and sympatry. We find that host species is generally a better predictor of parasite diversity than location, but both prevalence and diversity of parasites vary widely among populations of the same bird species. We also find a limited and unidirectional transfer of parasites from pied flycatchers to collared flycatchers in a recent contact zone. This study therefore rejects both the Enemy Release Hypothesis and the Novel Weapon Hypothesis and highlights the complexity and importance of studying host‐parasite relationships in an era of global climate change and species range shifts.</p
Renalase is associated with adverse left atrial remodelling and disease burden in patients with atrial fibrillation undergoing pulmonary vein isolation
Background: Renalase is a catecholamine-metabolising enzyme, but its possible association with atrial fibrillation (AF) remains unknown.
Aim: We sought to evaluate plasma renalase concentration in patients with AF undergoing pulmonary vein isolation (PVI) with respect to AF clinical characteristics, left atrial (LA) remodelling, and PVI efficacy.
Methods: This case-control study included 69 patients (median age 58 years) with either paroxysmal (89%) or persistent (11%) AF, referred for PVI, and a control group consisting of 15 patients without AF, matched for age, sex, and comorbidities. An evaluation of transthoracic echocardiography with LA speckle tracking and plasma renalase concentration using an enzyme-linked immunosorbent assay was performed. AF recurrence was defined as any AF episode on seven-day electrocardiographic monitoring at six-month follow-up.
Results: Renalase level was higher in the study group than in the control group (mean 27.99 vs. 21.48 μg/mL, p = 0.004), but it was lower in patients with persistent AF (19.05 vs. 28.77 μg/mL; p = 0.023) and among patients with AF episodes directly preceding PVI (24.50 vs. 29.66 μg/mL; p = 0.04). Renalase concentration within the first quartile was associated with higher mean heart rate (70 vs. 61 bpm, p = 0.029), greater AF burden (36.9% vs. 9.3%, p = 0.027), greater LA diameter (41.1 vs. 37.9 mm, p = 0.011), and a trend towards less negative global LA strain (–9.4 vs. –13.5, p = 0.082). Logistic regression revealed that global four-chamber LA strain was the only independent predictor of renalase variability (p = 0.0045). Renalase concentration did not predict AF recurrence at six-month follow-up (area under curve [AUC] = 0.614, p = 0.216).
Conclusions: Low renalase level may be associated with impaired rate control, higher AF burden, and advanced LA remodelling in AF patients undergoing PVI, but it does not predict sinus rhythm maintenance
Mutation Accumulation May Be a Minor Force in Shaping Life History Traits
Is senescence the adaptive result of tradeoffs between younger and older ages or the nonadaptive burden of deleterious mutations that act at older ages? To shed new light on this unresolved question we combine adaptive and nonadaptive processes in a single model. Our model uses Penna's bit-strings to capture different age-specific mutational patterns. Each pattern represents a genotype and for each genotype we find the life history strategy that maximizes fitness. Genotypes compete with each other and are subject to selection and to new mutations over generations until equilibrium in gene-frequencies is reached. The mutation-selection equilibrium provides information about mutational load and the differential effects of mutations on a life history trait - the optimal age at maturity. We find that mutations accumulate only at ages with negligible impact on fitness and that mutation accumulation has very little effect on the optimal age at maturity. These results suggest that life histories are largely determined by adaptive processes. The non-adaptive process of mutation accumulation seems to be unimportant at evolutionarily relevant ages
Physicochemical and biological characterisation of diclofenac oligomeric poly(3-hydroxyoctanoate) hybrids as β-TCP ceramics modifiers for bone tissue regeneration
Nowadays, regenerative medicine faces a major challenge in providing new, functional materials that will meet the characteristics desired to replenish and grow new tissue. Therefore, this study presents new ceramic-polymer composites in which the matrix consists of tricalcium phosphates covered with blends containing a chemically bounded diclofenac with the biocompatible polymer—poly(3-hydroxyoctanoate), P(3HO). Modification of P(3HO) oligomers was confirmed by NMR, IR and XPS. Moreover, obtained oligomers and their blends were subjected to an in-depth characterisation using GPC, TGA, DSC and AFM. Furthermore, we demonstrate that the hydrophobicity and surface free energy values of blends decreased with the amount of diclofenac modified oligomers. Subsequently, the designed composites were used as a substrate for growth of the pre-osteoblast cell line (MC3T3-E1). An in vitro biocompatibility study showed that the composite with the lowest concentration of the proposed drug is within the range assumed to be non-toxic (viability above 70%). Cell proliferation was visualised using the SEM method, whereas the observation of cell penetration into the scaffold was carried out by confocal microscopy. Thus, it can be an ideal new functional bone tissue substitute, allowing not only the regeneration and restoration of the defect but also inhibiting the development of chronic inflammation
Origami voting: a non-cryptographic approach to transparent ballot verification
International audienceOver the past four decades, fear of election manipulation and hacking has spurred the security technology community to propose a variety of voting systems to implement verifiable voting. Most of these rely on hard to understand cryptographic protocols, which can affect whether users actually verify their selections. Three-Ballot and Vote/Anti-Vote/Vote, two related systems among the few non-cryptographic end-to-end verifiable voting systems, made improvements in security while eliminating complex protocols. They unfortunately suffered from usability issues, and although they did not require cryptographic primitives, they still relied on electronic devices. To address this, we introduce three folded-paper based systems that allow verifiable voting and resist common attacks despite not relying on any cryptography or electronic devices. The proposals are based on 1) semi-translucent ballots, 2) masking tape, or 3) folding and punching. These Origami voting methods help users understand the underlying mechanisms and give them a direct geometric approach to verification
Differential Effects of Early- and Late-Life Access to Carotenoids on Adult Immune Function and Ornamentation in Mallard Ducks (Anas platyrhynchos)
Environmental conditions early in life can affect an organism’s phenotype at adulthood, which may be tuned to perform optimally in conditions that mimic those experienced during development (Environmental Matching hypothesis), or may be generally superior when conditions during development were of higher quality (Silver Spoon hypothesis). Here, we tested these hypotheses by examining how diet during development interacted with diet during adulthood to affect adult sexually selected ornamentation and immune function in male mallard ducks (Anas platyrhynchos). Mallards have yellow, carotenoid-pigmented beaks that are used in mate choice, and the degree of beak coloration has been linked to adult immune function. Using a 2×2 factorial experimental design, we reared mallards on diets containing either low or high levels of carotenoids (nutrients that cannot be synthesized de novo) throughout the period of growth, and then provided adults with one of these two diets while simultaneously quantifying beak coloration and response to a variety of immune challenges. We found that both developmental and adult carotenoid supplementation increased circulating carotenoid levels during dietary treatment, but that birds that received low-carotenoid diets during development maintained relatively higher circulating carotenoid levels during an adult immune challenge. Individuals that received low levels of carotenoids during development had larger phytohemagglutinin (PHA)-induced cutaneous immune responses at adulthood; however, dietary treatment during development and adulthood did not affect antibody response to a novel antigen, nitric oxide production, natural antibody levels, hemolytic capacity of the plasma, or beak coloration. However, beak coloration prior to immune challenges positively predicted PHA response, and strong PHA responses were correlated with losses in carotenoid-pigmented coloration. In sum, we did not find consistent support for either the Environmental Matching or Silver Spoon hypotheses. We then describe a new hypothesis that should be tested in future studies examining developmental plasticity
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