214 research outputs found
Some notes on Ricardo's analysis of the convergence process of the market rate of interest to the natural rate
This paper aims to be a preliminary critical discussion about one of the main accepted results of Ricardo’s theory of money and interest, i.e., that the ‘natural’ rate of interest is determined by the profit rate.
It will be argued that some logical inconsistencies seem to affect Ricardo’s representation of the tendency of the market rate of interest to the natural rate, with the latter ultimately determined by the rate of profits.
According to Ricardo, exogenous changes in the supply of, or demand for money generate short-run changes of the money-prices ratio and the market interest rate, and permanent changes in the price level play the role of bringing them back to their natural values (the natural rate of interest being taken as a fraction of the natural profit rate).
We will try to show that the convergence process envisaged by Ricardo seems to be not free from some critical considerations about its internal coherence if one takes into due account what he conceives to be the specific inducement for the public to borrow a larger quantity of money at a lower interest rate—namely, an above normal difference between profit rate and interest rate, together with the behavior of the banking system and with the main institutional features of a monetary system
Regularized transport between singular covariance matrices
We consider the problem of steering a linear stochastic system between two
end-point degenerate Gaussian distributions in finite time. This accounts for
those situations in which some but not all of the state entries are uncertain
at the initial, t = 0, and final time, t = T . This problem entails non-trivial
technical challenges as the singularity of terminal state-covariance causes the
control to grow unbounded at the final time T. Consequently, the entropic
interpolation (Schroedinger Bridge) is provided by a diffusion process which is
not finite-energy, thereby placing this case outside of most of the current
theory. In this paper, we show that a feasible interpolation can be derived as
a limiting case of earlier results for non-degenerate cases, and that it can be
expressed in closed form. Moreover, we show that such interpolation belongs to
the same reciprocal class of the uncontrolled evolution. By doing so we also
highlight a time-symmetry of the problem, contrasting dual formulations in the
forward and reverse time-directions, where in each the control grows unbounded
as time approaches the end-point (in the forward and reverse time-direction,
respectively).Comment: 8 page
Coronary tortuosity: normal variant or pathological condition?
HighlightsCoronary tortuosity is a common coronary angiography finding. The aetiology and the clinical significant are not well defined, generally considered a normal variant. We showed a case of marked tortuosity of all coronary arteries associated with myocardial ischemia. </p
Early and Late Infections in Newborns: Where Do We Stand? A Review
Neonatal sepsis still represents an important cause of mortality and morbidity among infants. According to the onset, we can distinguish "early onset sepsis" when microbiological cultures positive for external pathogens come from newborns during the first 7 days of life (maternal intrapartum transmission); "late onset sepsis" when microbiological cultures positive for external pathogens come from newborns after the first 7 days from delivery (postnatal acquisition). In this review we synthesize the incidence, risk factors, clinical manifestations, and methods of diagnosis and treatment of each type of neonatal infection, in order to better define such a pathological condition which is of great importance in common clinical practice
Tetrameric Transthyretin as a Protective Factor Against Alzheimer’s Disease
: Transthyretin (TTR) is a tetrameric protein traditionally recognized for its role in transporting thyroxine and retinol. Recent research has highlighted the potential neuroprotective functions of TTR in the setting of Alzheimer's disease (AD), which is the most common form of dementia and is caused by the deposition of amyloid beta (Aβ) and the resulting cytotoxic effects. This paper explores the mechanisms of TTR protective action, including its interaction with Aβ to prevent fibril formation and promote Aβ clearance from the brain. It also synthesizes experimental evidence suggesting that enhanced TTR stability may mitigate neurodegeneration and cognitive decline in AD. Potential therapeutic strategies such as small molecule stabilizers of TTR are discussed, highlighting their role in enhancing TTR binding to Aβ and facilitating its clearance. By consolidating current knowledge and proposing directions for future research, this review aims to underscore the significance of TTR as a neuroprotective factor in AD and the potential implications for future research
Cardiovascular dysfunction and vitamin D status in childhood acute lymphoblastic leukemia survivors
Vitamin D (25-OHD) has a role in bone health after treatment for cancer. 25-OHD deficiency has been associated with risk factors for cardiovascular disease, but no data focusing on this topic in childhood cancer survivors have been published. We investigated the 25-OHD status in children treated for acute lymphoblastic leukemia (ALL), and evaluated its influence on vascular function
Neutrophil-dependent pentraxin-3 and reactive oxygen species production modulate endothelial dysfunction in haemodialysis patients.
BACKGROUND:
The aim of this study was to investigate neutrophil activation and its role in long pentraxin-3 (PTX3) release and oxidative stress generation during haemodialysis (HD) and to correlate neutrophil PTX3 and oxidant expression with endothelial dysfunction.
METHODS:
Forty-seven uraemic patients on stable HD, 12 healthy subjects and 15 patients with congestive heart failure (New York Heart Association classes III and IV) were enrolled. Neutrophil PTX3 protein expression was evaluated by confocal microscopy. l-selectin expression, intracellular PTX3 localization and reactive oxygen species (ROS) generation in human neutrophils were measured by flow cytometry. NADPH-dependent superoxide generation was investigated by chemiluminescence. PTX3 plasma concentrations were measured by ELISA. Endothelial dysfunction was studied by flow-mediated dilation (FMD).
RESULTS:
The low baseline levels of FMD significantly improved after HD, but worsened by 24 h. A significant up-regulation of PTX3 protein expression, localized within secondary granules, was detected in neutrophils isolated at 30 and 240 min of HD, along with an increase in l-selectin expression. The up-regulation in intracellular PTX3 in neutrophils was associated with a significant increase in PTX3 plasma concentrations at 240 min. HD increased ROS production and NADPH oxidase activity in neutrophils. In a univariate analysis, pre-treatment with FMD was inversely correlated with PTX3 expression and ROS generation in neutrophils. In a multivariate analysis, both circulating pre-HD PTX3 and intracellular ROS generation by neutrophils were independent predictors of abnormal FMD.
CONCLUSIONS:
Neutrophil overexpression of PTX3 is associated with ROS overproduction and endothelial dysfunction and may represent an emerging marker of vascular damage progression in HD patients.
© The Author 2016. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved
Doppler ultrasound venous mapping of the lower limbs
Aldo Innocente Galeandro1, Giovanni Quistelli2, Pietro Scicchitano2, Michele Gesualdo2, Annapaola Zito2, Paola Caputo2, Rosa Carbonara2, Giuseppe Galgano3, Francesco Ciciarello4, Sandro Mandolesi4, Claude Franceschi5, Marco Matteo Ciccone21Centro Diagnostica Globale and ASL-TA, Taranto, Italy; 2Cardiovascular Diseases Section, Department of Emergency and Organ Transplantation (DETO), University of Bari, Bari, Italy; 3Cardiovascular Diseases Section, Ente Ecclesiastico Ospedale Generale Regionale F Miulli, Acquaviva delle Fonti, Bari, Italy; 4Cardiology Department, Policlinico Umberto I, Sapienza University of Rome, Italy; 5Vascular Laboratories of Hospitals Saint Joseph and Piti&eacute;-Salp&eacute;tri&egrave;re, Paris, FranceBackground: The study aim was to test the accuracy (intra and interobserver variability), sensitivity, and specificity of a simplified noninvasive ultrasound methodology for mapping superficial and deep veins of the lower limbs.Methods: 62 consecutive patients, aged 62 &plusmn; 11 years, were enrolled. All underwent US-examinations, performed by two different investigators, of both legs, four anatomical parts, and 17 veins, to assess the interobserver variability of evaluation of superficial and deep veins of the lower limbs.Results: Overall the agreement between the second versus the first operator was very high in detecting reflux (sensitivity 97.9, specificity 99.7, accuracy 99.5; P = 0.80 at McNemar test). The higher CEAP classification stages were significantly associated with reflux (odds ratio: 1.778, 95% confidence interval: 1.552&ndash;2.038; P &lt; 0.001) as well as with thrombosis (odds ratio: 2.765, 95% confidence interval: 1.741&ndash;4.389; P &lt; 0.001). Thus, our findings show a strict association between the symptoms of venous disorders and ultrasound evaluation results for thrombosis or reflux.Conclusion: This study demonstrated that our venous mapping protocol is a reliable method showing a very low interobserver variability, which makes it accurate and reproducible for the assessment of the morphofunctional status of the lower limb veins.Keywords: venous mapping, new methodology, sensitivity, specificity, accurac
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