The Eye on Mitochondrial Disorders.

Ophthalmologic manifestations of mitochondrial disorders are frequently neglected or overlooked because they are often not regarded as part of the phenotype. This review aims at summarizing and discussing the etiology, pathogenesis, diagnosis, and treatment of ophthalmologic manifestations of mitochondrial disorders. Review of publications about ophthalmologic involvement in mitochondrial disorders by search of Medline applying appropriate search terms. The eye is frequently affected by syndromic as well as nonsyndromic mitochondrial disorders. Primary and secondary ophthalmologic manifestations can be differentiated. The most frequent ophthalmologic manifestations of mitochondrial disorders include ptosis, progressive external ophthalmoplegia, optic atrophy, retinopathy, and cataract. More rarely occurring are nystagmus and abnormalities of the cornea, ciliary body, intraocular pressure, the choroidea, or the brain secondarily affecting the eyes. It is important to recognize and diagnose ophthalmologic manifestations of mitochondrial disorders as early as possible because most are accessible to symptomatic treatment with partial or complete short-term or long-term beneficial effect. Ophthalmologic manifestations of mitochondrial disorders need to be appropriately diagnosed to initiate the most effective management and guarantee optimal outcome

Analysis of the surface state's influence on the thermohydraulic behavior of an incompressible fluid in convective laminar flow through a microchannel with corrugated surfaces

Le travail entrepris dans cet article présente une étude numérique thermo-énergétique de l'écoulement convectif laminaire dans un microcanal rectangulaire lisse ou la présence de discontinuités sur ses parois. Les ondulations présentent les discontinuités de la surface du mur. La paroi inférieure du microcanal portée à une température constante et uniforme. Le nombre de Reynolds utilisé, Re, a été choisi dans la gamme (50 à 350). La solution du système d'équations régissant le problème a été réalisée par un schéma de volumes finis associé à l'algorithme SIMPLE (Semi Implicit Method for Pressure Linked Equation) pour surmonter le problème de couplage pression-vitesse. L'étude s'est concentrée principalement sur les effets des deux paramètres pertinents : le nombre de Reynolds et la forme géométrique des microcanaux. Les deux champs de vitesse axiale et de température ont été analysés, et le nombre moyen de Nusselt, le coefficient de frottement et la quantité de chaleur évacuée. Les résultats montrent que la structure de l'écoulement est fortement perturbée par la présence de discontinuités sur les parois, et le nombre de Nusselt moyen augmente toujours la fonction du nombre de Reynolds pour les quatre cas étudiés, tandis que l'évolution du coefficient de frottement peut être croissante ou décroissant en fonction du nombre de Reynolds

Three-dimensional analysis of flow characteristics in a heat exchanger equipped with a perforated heat sink

Finning or perforations are frequently used in heat exchange devices to increase the heat exchange between the contact surfaces and the surrounding fluid. Thus, the work undertaken in this paper is in the same context to search for a new design to improve the thermohydrodynamic performance of a heat exchanger.  In this context, the latter considered being equipped with a solid or perforated heat sink to identify the perforations' efficiency in optimizing the heat exchanger's performance. The thermohydrodynamic phenomenon governed by the partial differential equations system derived from the laws of conservation: continuity equation for mass, Navier-Stokes equations for momentum, and the energy equation. For the numerical solution, the finite volume method used, and the problem of pressure-velocity coupling intervening at the level of the Navier-Stokes equations solved using the SIMPLE algorithm. Calculations are made for a perforated deflector with different diameters and an unperforated deflector. For both cases, the inlet velocity was chosen in a range from 0.0018 to 0.009 m/s. The results are presented either as maps for the isothermal fields and velocity contours obtained for the meridian planes shown in the figures or as curves for the axial velocity and heat flow. Finally, a qualitative comparison of the different calculated results made, and it could deduce that a perforated deflector is much more efficient than a solid or solid deflector fixed at the same position. The increase in terms of transfers can go from 1.33% to 12.97%, and an excellent material reduction (from 2.32% to 55.85%) corresponds to a low flow resistance compared to the non-perforated case

Rotating hyperdeformed quasi-molecular states formed in capture of light nuclei and in collision of very heavy ions

International audienceWithin a rotational liquid drop model including the nuclear proximity energy the l-dependent potential barriers governing the capture reactions of light nuclei and of very heavy ions have been determined. Rotating quasi-molecular hyperdeformed states appear at high angular momenta. The energy range of these very deformed high spin states is given for light systems. The same approach explains the observation of ternary cluster decay from56Ni and 60Zn through hyperdeformed shapes at angular momenta around 45 . The apparently observed superheavy nuclear systems in the U+Ni and U+Ge reactions at high excitation energy might correspond to these rotating isomeric states formed at very high angular momenta even though the shell effects vanish

Numerical Evaluation the Impact of the Inserts Shape on Thermo-Flow Behavior in a Heat Exchanger

The improvement of transfers in a heat exchanger can be achieved either by increasing its coolant thermal conductivity or by modifying its geometrical configuration. In this paper, we will be interested in the latter technique by choosing a three-dimensional configuration represented by a channel of rectangular section, on which solid fins of square, circular, or diamond section (vortex generator) have been transversally mounted, which are moreover adiabatic and non-rotating. A convective and forced airflow traverses the channel, and the study focused in principle on the effects of the shape of the fins on the structure of the flow and the rate of heat transfer. The problem is governed by the Navier-Stokes system, coupled with the energy equation de-scribing the thermal process. The resolution of the equation system governing the hydrodynamic phenomenon is performed numerically in three dimensions. To do this, the governing equations of the thermo-hydrodynamic phenomenon are discretized by a finite volume scheme. As for turbulence, it is modeled using the standard model k-ɛ, and the problem of pressure-velocity coupling is solved by the SIMPLE algorithm (Semi Implicit Method for Pressure Linked Equation). The computed results are presented as curves for the Nusselt number, friction factor, thermal enhancement factor, or amount of heat dissipated, and as a map for the contour of the axial velocity norm and the temperature field distribution

Transient pressure analysis of geothermal wells fractured during well testing

Fracturing during injectivity testing can take place in geothermal wells when the reservoir has low permeability or when the well has significant skin damage. The transient behavior (pressure falloff) of these wells cannot be matched using existing well test analysis methods. At the same time, modelling fracturing in geothermal re-servoirs using rock mechanics and commercial finite element software is complicated due to several field un-certainties (e.g. formation height, reservoir permeability and porosity). In addition, rock mechanics data (rock stress, strain and Young’s modulus) are normally unknown in geothermal fields. This makes it difficult to develop an appropriate fracture model that matches the field test data. This study attempts to develop a fracture model without integrating rock mechanics. The model is setup with a simple grid using the TOUGH2 geothermal reservoir simulator and validated using the advanced pressure derivative transient analysis. Multiple subsets of fracture geometries were developed to represent the different stages of fracture closure during pressure falloff. The PyTOUGH code was used to simplify the running of the different fracture stages. The results are very promising and provide a clear justification and explanation for the commonly en-countered fractured well behavior. This model should be of use in matching data from geothermal wells with similar pressure response

Quality study of wastewater treated by waste Water Treatment plant (WWTP) in the city of Sana'a (Yemen) used for agriculture.

The wastewater treated by the PWTS Sanaa (Yemen), are discharged into Wadi Bani Houat to be used for irrigation of agricultural fields (cereals and "qat"). The quality of water discharged by the station is affected by neo-contamination part of untreated water diverted through bypass and also untreated effluent intake of a river that flows into the canal about 15 Km from the station. The various measurements show that the levels of contaminants studied, decrease at the exit of the station but undergo severe degradation after canal-branch river. Similarly, we noted illegal contributions at this place made of waste thrown into the canal by the surrounding population. The salinity is classified C4S2, C3S3, C4S3 and C4S4 in RICHARDS diagram, leading to poor quality water for irrigation. The ratio COD / BOD5 reaching a value of 2 after treatment and self purification of water, up to a value of 4, at a distance of 12 km along the canal before dropping to a value below 2 at the areas of retention dams located north of the study area, showing a self-purification capacity. NO2- (nitrite ions) appear downstream canal in the dams, highlighting the impact of agricultural activity on water quality. Minors cations and traces show different concentrations varying spatially and temporally along the canal during the dry and wet seasons. Overruns by FAO and Yemen standards were observed for some components such as phenol, organic micropolluant showing levels higher than standard along the canal in all seasons. The principal component analysis showed the correlation between the measured quantities and the vulnerability of sampling sites to different pollutants.  

Constraining νΛ\nu \LambdaCDM with density-split clustering

The dependence of galaxy clustering on local density provides an effective method for extracting non-Gaussian information from galaxy surveys. The two-point correlation function (2PCF) provides a complete statistical description of a Gaussian density field. However, the late-time density field becomes non-Gaussian due to non-linear gravitational evolution and higher-order summary statistics are required to capture all of its cosmological information. Using a Fisher formalism based on halo catalogues from the Quijote simulations, we explore the possibility of retrieving this information using the density-split clustering (DS) method, which combines clustering statistics from regions of different environmental density. We show that DS provides more precise constraints on the parameters of the $\nu \Lambda$CDM model compared to the 2PCF, and we provide suggestions for where the extra information may come from. DS improves the constraints on the sum of neutrino masses by a factor of $8$ and by factors of 5, 3, 4, 6, and 6 for $\Omega_m$, $\Omega_b$, $h$, $n_s$, and $\sigma_8$, respectively. We compare DS statistics when the local density environment is estimated from the real or redshift-space positions of haloes. The inclusion of DS autocorrelation functions, in addition to the cross-correlation functions between DS environments and haloes, recovers most of the information that is lost when using the redshift-space halo positions to estimate the environment. We discuss the possibility of constructing simulation-based methods to model DS clustering statistics in different scenarios.Comment: Submitted to MNRAS. Source code for all figures in the paper is provided in the caption