Clinical and biochemical improvements in a patient with MNGIE following enzyme replacement.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare autosomal recessive metabolic disorder caused by a deficiency of thymidine phosphorylase (TP, EC2.4.2.4) due to mutations in the nuclear gene TYMP. TP deficiency leads to plasma and tissue accumulations of thymidine and deoxyuridine which generate imbalances within the mitochondrial nucleotide pools, ultimately leading to mitochondrial dysfunction.1 MNGIE is characterized clinically by leukoencephalopathy, external ophthalmoplegia, peripheral polyneuropathy, cachexia, and enteric neuromyopathy manifesting as gastrointestinal dysmotility. The condition is relentlessly progressive, with patients usually dying from a combination of nutritional and neuromuscular failure at an average age of 37 years.2 Allogeneic hematopoietic stem cell transplantation (AHSCT) offers a permanent cure. Clinical and biochemical improvements following AHSCT have been reported but it carries a high mortality risk and is limited by matched donor availability.3 A consensus proposal for standardizing AHSCT recommends treatment of patients without irreversible end-stage disease and with an optimally matched donor; a majority of patients are ineligible and thus there is a critical requirement for an alternative treatment

RadioAstron probes the ultra-fine spatial structure in the H2_2O maser emission in the star forming region W49N

H$_2$O maser emission associated with the massive star formation region W49N were observed with the Space-VLBI mission RadioAstron. The procedure for processing of the maser spectral line data obtained in the RadioAstron observations is described. Ultra-fine spatial structures in the maser emission were detected on space-ground baselines of up to 9.6 Earth diameters. The correlated flux densities of these features range from 0.1% to 0.6% of the total flux density. These low values of correlated flux density are probably due to turbulence either in the maser itself or in the interstellar medium.Comment: Accepted for publication in Advances in Space Researc

Improving the reliability of model-based decision-making estimates in the two-stage decision task with reaction-times and drift-diffusion modeling

A well-established notion in cognitive neuroscience proposes that multiple brain systems contribute to choice behaviour. These include: (1) a model-free system that uses values cached from the outcome history of alternative actions, and (2) a model-based system that considers action outcomes and the transition structure of the environment. The widespread use of this distinction, across a range of applications, renders it important to index their distinct influences with high reliability. Here we consider the two-stage task, widely considered as a gold standard measure for the contribution of model-based and model-free systems to human choice. We tested the internal/temporal stability of measures from this task, including those estimated via an established computational model, as well as an extended model using drift-diffusion. Drift-diffusion modeling suggested that both choice in the first stage, and RTs in the second stage, are directly affected by a model-based/free trade-off parameter. Both parameter recovery and the stability of model-based estimates were poor but improved substantially when both choice and RT were used (compared to choice only), and when more trials (than conventionally used in research practice) were included in our analysis. The findings have implications for interpretation of past and future studies based on the use of the two-stage task, as well as for characterising the contribution of model-based processes to choice behaviour

Evolution of the Stellar Mass--Metallicity Relation - I: Galaxies in the z~0.4 Cluster Cl0024

We present the stellar mass-stellar metallicity relationship (MZR) in the Cl0024+1654 galaxy cluster at z~0.4 using full spectrum stellar population synthesis modeling of individual quiescent galaxies. The lower limit of our stellar mass range is $M_*=10^{9.7}M_\odot$, the lowest galaxy mass at which individual stellar metallicity has been measured beyond the local universe. We report a detection of an evolution of the stellar MZR with observed redshift at $0.037\pm0.007$ dex per Gyr, consistent with the predictions from hydrodynamical simulations. Additionally, we find that the evolution of the stellar MZR with observed redshift can be explained by an evolution of the stellar MZR with their formation time, i.e., when the single stellar population (SSP)-equivalent ages of galaxies are taken into account. This behavior is consistent with stars forming out of gas that also has an MZR with a normalization that decreases with redshift. Lastly, we find that over the observed mass range, the MZR can be described by a linear function with a shallow slope, ($[Fe/H] \propto (0.16 \pm 0.03) \log M_*$). The slope suggests that galaxy feedback, in terms of mass-loading factor, might be mass-independent over the observed mass and redshift range.Comment: 22 pages, 10 figures. Accepted for publication in Ap

A method for determining landing runway length for a STOL aircraft

Based on data obtained from flight tests of the augmentor wing jet STOL research aircraft, a method is proposed for determining the length of the landing runway for powered-lift STOL aircraft. The suggested method determines runway landing length by summing three segments: the touchdown-dispersion distance, the transition distance from touchdown to application of brakes, and the stopping distance after brakes are applied. It is shown how the landing field length can be reduced either through improved autoland system design or by providing the pilot with appropriate information to allow him to identify a "low probability" long or short landing and to execute a go-around. The proposed method appears to determine a safe runway landing length for the STOL application and offers the potential for reducing runway length if great emphasis is placed on a short-runway capability. FAR Parts 25 and 121 appear conservative and suitable for the situation where no great emphasis is placed on reducing the runway length requirement

Macular Pigment and Visual Function in Patients With Glaucoma: The San Diego Macular Pigment Study.

PurposeAlthough recent studies have shown that macular pigment (MP) is significantly lower in glaucoma patients, this relationship merits further investigation.MethodsThis cross-sectional study included 85 glaucoma patients and 22 controls. All subjects had standard automated perimetry (SAP) and retinal nerve fiber layer (RNFL) thickness measurements. Intake of lutein (L) and zeaxanthin (Z) was estimated using a novel dietary screener. The Heidelberg Spectralis dual-wavelength autofluorescence (AF) technology was employed to study the relationship between MP and glaucoma. The association between MP volume and glaucoma was investigated using linear regression models accounting for potential confounding factors.ResultsGlaucoma patients had significantly worse SAP mean deviation (MD) and lower RNFL thickness in the study eye compared to control subjects (P < 0.001 for both). MP (volume) was comparable between groups (P = 0.436). In the univariable model, diagnosis of glaucoma was not associated with MP volume (R2 = 1.22%; P = 0.257). Dietary intake of L and Z was positively and significantly related to MP in the univariable (P = 0.022) and multivariable (P = 0.020) models.ConclusionsThese results challenge previous studies that reported that glaucoma is associated with low MP. Dietary habits were found to be the main predictor of MP in this sample. Further research is merited to better understand the relationship between glaucoma, MP, and visual performance in these patients

Effet inhibiteur à la longues chaînes et de dérivés thiazolés sur la corrosion du laiton Amirauté.optimale des petites stations d'épuration à boues activées

Dans cette étude, des mesures électrochimiques ont été réalisées pour caractériser le comportement du laiton Amirauté dans une solution de chlorure de sodium 0,5 M en l'absence d'inhibiteur et en présence d'un mélange d'amines à longue chaîne et de dérivés thiazolés. Cette formulation est utilisée pour le traitement des eaux des circuits de refroidissement. Les courbes courant-tension stationnaires et les diagrammes d'impédance électrochimique ont été obtenus avec une electrode tournante.La première partie de cette étude présente les résultats obtenus pour deux concentrations du mélange et deux temps d'immersion préalable au potentiel de corrosion. Les essais électrochimiques montrent que l'effet inhibiteur est d'autant plus marqué que la concentration augmente. Une légère diminution de la protection de la surface du laiton Amirauté est observée avec l'augmentation du temps de maintien au potentiel de corrosion.La deuxième partie de l'étude compare les effets inhibiteurs de chacun des constituants du mélange, d'une part, pour les valeurs de concentration utilisées lors du traitement des eaux des circuits de refroidissement (0,1 mg/l de solution contenant les dérivés thiazolés et 1 mg/l de solution contenant les alkylamines) et, d'autre part, pour des valeurs de concentration comparables (5 mg/l).Pour la concentration de 0,1 mg/l l'action inhibitrice des dérivés thiazolés n'a pas été clairement mise en évidence. Ainsi, la protection contre la corrosion des circuits de refroidissement en laiton Amirauté avec le mélange est apportée principalement par les alkylamines. Celles-ci forment un film compact très protecteur à la surface de l'électrode.Pour des valeurs de concentration plus importantes, l'addition de 0,5 mg/l de dérivés thiazolés à 5 mg/l d'alkylamines améliore la protection du matériau.In this study, electrochemical measurements were carriet out to characterize the behaviour of Admiralty Brass in a 0.5 M sodium chloride solution in the absence of inhibitors and in the presence of a mixture of alkylamines and thiazol-derived products. This formulation is employed for water treatment in cooling circuits.The steady-state current voltage curves and the impedance diagrams were obtained with a rotating disc electrode in order to control the hydrodynamic conditions.The first part of this study deals with the results obtained for two concentrations of the mixture and for two immersion times at the corrosion potential. It has been shown that the inhibitive effect is more marked when the concentration increases from 10 to 50 mg/l. A slight decrease of the protection of the brass surface is observed when the immersion time increasesThe second part of this study is a comparison of the inhibitive effects of each compound of the mixture, on one hand, for concentration values used in the water treatment (0.1 mg/l of tbe solution containing the thiazol-derived products and 1 mg/l of the solution containing the alkylamines) and on the other hand, for identical concentration values (5 mg/l ). For 0.1 mg/l, no inhibitive action of thiazol-derived products could be detected. Thus, the corrosion protection of cooling circuits in Admiralty brass is attributed essentially to the alkylamines. They form a thick, protective film at the electrode surface. For higher concentration values, the addition of 0.5 mg/l of thiazol-derived products to 5 mg/l of alkylamines improves the corrosion resistance of brass

Inhibition de la corrosion d'un acier au carbone par des produits dérivés de phosphonates en association avec des sels de zinc

Dans cette étude, des mesures électrochimiques ont été utilisées pour caractériser l'efficacité inhibitrice de produits dérivés de phosphonates associés à des sels de zinc, employés pour le traitement des eaux des circuits de refroidissement. L'influence de la concentration de cette formulation ainsi que l'effet du pH du milieu ont été étudiés.Les courbes courant-tension stationnaires et les diagrammes d'impédance électrochimique ont été obtenus avec des électrodes tournantes en acier au carbone dans une solution de chlorure de sodium à 200 mg l-1. Ce milieu a été choisi car sa faible conductivité électrique est proche de celle rencontrée dans les eaux naturelles.La méthode stationnaire (relevé des courbes courant-tension) a permis de déterminer la vitesse de corrosion en l'absence et en présence de l'inhibiteur et par conséquent, le taux de protection. Ainsi, le composé présente une très bonne efficacité dès les faibles concentrations (50 mg · l-1). Entre 50 et 200 mg · l-1, l'efficacité inhibitrice augmente de 95 à 98 %. Pour la concentration de 100 mg · l-1 il est efficace dans un large domaine de pH (de 5,5 à 9). Cette efficacité apparaît légèrement supérieure à pH = 7 et à pH = 8.Les valeurs des résistances de polarisation mesurées à partir des diagrammes d'impédance confirment les résultats obtenus à partir des courbes stationnaires.En outre, l'efficacité inhibitrice du composé a été comparée à celle de produits déjà testés au Laboratoire pour des utilisations identiques. Le chlorure de zinc, le monofluorophosphate de zinc et l'association d'une amine grasse et d'acide phosphonique présentent des efficacités moindres que le mélange testé ici à base de produits dérivés de phosphonates associés aux sels de zinc.In this study, electrochemical measurements were carried out to characterize the inhibitive efficiency of the association of phosphonate-derived products with zinc salts, employed for water treatment in cooling circuits.The influence of parameters such as the concentration of the formulation and the effect of the solutions pH on the protection of the metal were studied.Steady-state current-voltage curves and electrochemical impedance diagrams have been obtained for a carbon steel rotating disc in a 200 mg · l-1 NaCl solution. The choice of this medium is based upon the following criteria :(i) its low electrical conductivity is close to that encountered in natural saline waters ;(ii) its corrosivity is fairly high ;(iii) it Is formed by an easily reproducible baseline solution.The inhibitive efficiency has been determined tram the plotting of the cathodic potentiostatic curves. It is important to note that in low conductivity media, the current-voltage curves are distorted by a non-negligible uncompensated ohmic drop (I.Re), Re being the electrolyte resistance between the working and the reference electrodes. The interpretation of these curves (i.e. corrosion rate evaluation, Tafel slopes determination) is only possible if they have been corrected according to the following relationship. Eapparent = Etrue + ReIIn this study, the electrolytic resistance value has been determined from electrochemical Impedance measurements : the high frequency limit of the impedance gives Re.The ohmic drop is then automatically compensated by the potentiostat to obtain the corrected steady-state curve.The inhibitive efficiency is evaluated by the relationship :Ei = (icorr0-icorr / icorr0) x 100in which iocorr and icorr represent the current densities without and with inhibitor, respectively.In addition to the determination of the current densities obtained from the steady-state current-voltage curves, the polarization resistance, Rp, has been measured from the impedance diagram : the low frequency limit of the impedance gives the sum Re + Rp ; Rp is equal to the slope of the steady-state current voltage curve.In this study, only the evolution of this value as a function of concentration has been examined.It has been shown from the steady-state technique that the compound presents a very good efficiency for low concentrations (50 mg · l-1). Between 50 and 200 mg · l-1, the inhibitive efficiency increases from 95 to 98 %. For 100 mg · l-1 it is effective over a wide pH range (5.5 to 9) with a better protection for pH = 7 and pH = 8.The measurements of the polarization resistance corroborate these results.In a second part, the inhibitive efficiency of the compound has been compared to different inhibitors used for similar uses and tested in the laboratory. Thus, zinc chloride, zinc fluorophosphate and the association of fatty amine and phosphonic acid present a lower efficiency than the product tested here

The Distribution of H2O Maser Emission in the Nucleus of NGC 4945

We present the first interferometer map of the water maser emission in the active nucleus of NGC 4945. Although the declination of the galaxy is about -49 degrees, we were able to make the observations with the southernmost antennas of the Very Long Baseline Array. Strong maser emission is present in three velocity ranges, one near the systemic velocity and two shifted roughly symmetrically by +/-(100-150) km/s. This is the first detection of highly blue-shifted water emission in NGC 4945. We determined the position of the maser to be RA(B1950)= 13 02 32.28 +/- 0.02 ; Dec(B1950)= -49 12 01.9 +/- 0.1. The uncertainties in earlier estimates are at least several arcseconds. The maser lies within 2'' (36 pc at a distance of 3.7 Mpc) of the peaks in 1.4 GHz continuum and 1.6 micron emission from the nucleus. The mappable maser emission is distributed roughly linearly over about 40 milliarcseconds (0.7 pc) at a position angle of about 45 degrees, which is close to the 43 +/- 2 degree position angle of the galactic disk. The red and blue-shifted emission symmetrically stradle the systemic emission on the sky, which suggests material in edge-on circular motion around a central object. The position-velocity structure indicates a binding mass of about one million Suns, within a volume of radius about 0.3 pc. This implies that the central engine radiates on the order of 10% of its Eddington luminosity.Comment: 18 pages, including 5 Postscript figures. Accepted for publication in ApJ Letter