Pain perception and migraine

Background: It is well-known that both inter-and intra-individual differences exist in the perception of pain; this is especially true in migraine, an elusive pain disorder of the head. Although electrophysiology and neuroimaging techniques have greatly contributed to a better understanding of the mechanisms involved in migraine during recent decades, the exact characteristics of pain threshold and pain intensity perception remain to be determined, and continue to be a matter of debate.Objective: The aim of this review is to provide a comprehensive overview of clinical, electrophysiological, and functional neuroimaging studies investigating changes during various phases of the so-called "migraine cycle" and in different migraine phenotypes, using pain threshold and pain intensity perception assessments.Methods: A systematic search for qualitative studies was conducted using search terms "migraine," "pain," "headache," "temporal summation," "quantitative sensory testing," and "threshold," alone and in combination (subject headings and keywords). The literature search was updated using the additional keywords "pain intensity," and "neuroimaging"to identify full-text papers written in English and published in peer-reviewed journals, using PubMed and Google Scholar databases. In addition, we manually searched the reference lists of all research articles and review articles.Conclusion: Consistent data indicate that pain threshold is lower during the ictal phase than during the interictal phase of migraine or healthy controls in response to pressure, cold and heat stimuli. There is evidence for preictal sub-allodynia, whereas interictal results are conflicting due to either reduced or no observed difference in pain threshold. On the other hand, despite methodological limitations, converging observations support the concept that migraine attacks may be characterized by an increased pain intensity perception, which normalizes between episodes. Nevertheless, future studies are required to longitudinally evaluate a large group of patients before and after pharmacological and non-pharmacological interventions to investigate phases of the migraine cycle, clinical parameters of disease severity and chronic medication usage

MEASUREMENT OF MACRO-SCALE INDENTATION MODULUS USING THE PRIMARY HARDNESS STANDARD MACHINES AT INRIM

In this paper it is described the experimental procedure and the statistical method for the measurement of indentation modulus by using the primary hardness standard machine at INRIM, in the macro-scale range. Indentation modulus is calculated on the basis of Doerner-Nix linear model and from accurate measurements of indentation load, displacement, contact stiffness and Vickers hardness impression imaging. Load is provided by dead-weight masses and displacement is measured by a laser-interferometric system, perpendicular with respect to the Vickers pyramid vertex. The geometrical dimension of the Diamond Pyramid Hardness (DPH) impression is measured by means of a micro-mechanical system and optical microscopy imaging technique. Applied force and indentation depth are measured simultaneously, 16 Hz of sampling rate, and the resulting indentation curve is obtained. Preliminary tests are performed on metals and alloys samples. Considerations and comments on the accuracy of the proposed method and analysis are discussed

Identification of Novel Wsf1 Mutations in a Sicilian Child with Wolfram Syndrome

Wolfram Syndrome (WS) is a rare hereditary disease with autosomal recessive inheritance with incomplete penetrance. It is characterized by diabetes mellitus associated with progressive optic atrophy. The diagnosis is essentially clinical and mutation analysis is used to confirm the diagnosis. In the present study we describe the clinical and molecular features of a diabetic child carrying two novel WFS1 mutations. The Sicilian proband and his non-affected family were studied. Ophthalmologic examination included: visual acuity determination and funduscopy, optical coherent tomography, retinal fluorangiography, perimetry and electroretinogram. Molecular methods: automatic sequencing of PCR amplified WFS1 gene fragments and qRT-PCR analysis of WFS1 transcripts. 3 WSF1 mutations have been identified in the proband. One allele carries 2 paternally inherited mutations (c.1332 C>G and c.1631C>G) in exon-8, never annotated before, in heterozygosis with one “de novo” classic mutation (c.505 G>A) in exon-5. In addition, we report an unexpected molecular feature: higher WFS1 mRNA levels in the proband compared to the father

The role of temporariness, emptiness and improvisation in uncertain times: evidence from urban responses to COVID-19

This paper focusses on the complex relationship between vacancy, temporary responses and uncertainty during turbulent times by analysing how a selection of cities—New York City, São Paulo, Milan, Moscow, Abu Dhabi, Esfahan, Karachi, Mumbai and Jakarta—addressed testing, treating, isolating and vaccinating the public in response to the coronavirus (COVID-19) pandemic. These highly visible spatial responses offer immediate, pragmatic answers to unexpected conditions and, we argue, allow a more nuanced understanding of how planning might leverage flexibility and adaptability in a (post-)pandemic world

Inclusion of Horizontal Branch stars in the derivation of star formation histories of dwarf galaxies: the Carina dSph

We present a detailed analysis of the Horizontal Branch of the Carina Dwarf Spheroidal Galaxy by means of synthetic modelling techniques, taking consistently into account the star formation history and metallicity evolution as determined from main sequence and red giant branch spectroscopic observations. We found that a range of integrated red giant branch mass loss values of 0.1-0.14 M, increasing with metallicity, is able to reproduce the colour extension of the old Horizontal Branch. However, leaving the mass loss as the only free parameter is not enough to match the detailed morphology of Carina Horizontal Branch. We explored the role played by the star formation history on the discrepancies between synthetic and observed Horizontal Branches. We derived a toy bursty star formation history that reproduces the horizontal branch star counts, and also matches qualitatively the red giant and the turn off regions. This star formation history is made of a subset of age and [M/H] components of the star formation history based on turn off and red giants only, and entails four separate bursts of star formation of different strenghts, centred at 2, 5, 8.6 and 11.5 Gyr, with mean [M/H] decreasing from \sim -1.7 to \sim -2.2 for increasing ages, and a Gaussian spread of 0.1 dex. The comparison between the metallicity distribution function of our star formation history and the one measured from the infrared CaT feature using a CaT-[Fe/H] calibration shows a qualitative agreement, once taken into account the range of [Ca/Fe] abundances measured in a sample of Carina stars, that biases the derived [Fe/H] distribution toward too low values. In conclusion, we have shown how the information contained within the horizontal branch of Carina (and dwarf galaxies in general) can be extracted and interpreted to refine the star formation history derived from red giants and turn off stars only. Abridge

Entropy conservative discretization of compressible Euler equations with an arbitrary equation of state

This study proposes a novel spatial discretization procedure for the compressible Euler equations which guarantees entropy conservation at a discrete level when an arbitrary equation of state is assumed. The proposed method, based on a locally-conservative discretization, guarantees also the spatial conservation of mass, momentum, and total energy and is kinetic-energy-preserving. In order to achieve the entropy-conservation property for an arbitrary non-ideal gas, a general strategy is adopted based on the manipulation of discrete balance equations through the imposition of global entropy conservation and the use of a summation-by-parts rule. The procedure, which is extended to an arbitrary order of accuracy, conducts to a general form of the internal-energy numerical flux which results in a nonlinear function of thermodynamic and dynamic variables and still admits the mass flux as a residual degree of freedom. The effectiveness of the novel entropy-conservative formulation is demonstrated through numerical tests making use of some of the most popular cubic equations of state

Unsteady heat transfer analysis of an impinging jet with high-order spectral element methods

Numerical simulations are a powerful tool to understand the kinematic and thermodynamic behaviour of impinging jet, which is of great interest in many industrial application. However, in addition to the usual difficulties of computer simulation of incompressible fluid motion and heat exchange, this flow also presents the added issue of involving severely truncated open boundaries. The most commonly used boundary conditions either cause numerical instabilities or have an exceedingly high computational cost. A two-dimensional simulation of the confined impinging jet at Re = 2500 with a non-dimensional nozzle-to-plate distance H/D = 2 has been used to test the effectiveness of alternative boundary conditions designed to correctly reproduce the physics of the phenomenon. A large eddy simulation of the three-dimensional case with the same parameters has been performed as well. In both cases, the boundary conditions prevented the divergence of the simulation and the production of non-physical reflections