Ultrastructural study of the intercellular bridges between female germinal cells in "Chirocephalus diaphanus" Prevost (Crustaceas: Branchiopoda)

S'ha efectuat un estudi en detall de la morfologia dels ponts intercel•lulars trobats entre les cèl•lules germinals femenines de Chirocephalus diaphanus. Sembla que provenen de citodièresis incompletes durant el procés de multiplicació de les oogònies. En l'interior dels ponts es pot observar una gran varietat d'orgànuls citoplasmàtics: mitocondris, reticle endoplasmàtic rugós, ribosomes lliures i vesícules que molt possiblement deriven dels dictiosomes, situats al voltant dels ponts. Cal destacar que en els ponts intercel•lulars que relacionen oòcits en estat de paquitè a la profase meiòtica, el nombre de vesícules és més abundant. En les zones properes als ponts intercel•lulars, l'espai intercel•lular presenta una dilatació en forma de canalicles, i es poden comptar un gran nombre d'unions cel•lulars del tipus macula adherens. Pel que fa al paper dels ponts intercel•lulars, sembla que concorren a la creació d'un tipus de sincronisme de la diferenciació cel•lular en el decurs de la gametogènesi

RBF neural net based classifier for the AIRIX accelerator fault diagnosis

The AIRIX facility is a high current linear accelerator (2-3.5kA) used for flash-radiography at the CEA of Moronvilliers France. The general background of this study is the diagnosis and the predictive maintenance of AIRIX. We will present a tool for fault diagnosis and monitoring based on pattern recognition using artificial neural network. Parameters extracted from the signals recorded on each shot are used to define a vector to be classified. The principal component analysis permits us to select the most pertinent information and reduce the redundancy. A three layer Radial Basis Function (RBF) neural network is used to classify the states of the accelerator. We initialize the network by applying an unsupervised fuzzy technique to the training base. This allows us to determine the number of clusters and real classes, which define the number of cells on the hidden and output layers of the network. The weights between the hidden and the output layers, realising the non-convex union of the clusters, are determined by a least square method. Membership and ambiguity rejection enable the network to learn unknown failures, and to monitor accelerator operations to predict future failures. We will present the first results obtained on the injector.Comment: 3 pages, 4 figures, LINAC'2000 conferenc

The Dynamic Formation of Prominence Condensations

We present simulations of a model for the formation of a prominence condensation in a coronal loop. The key idea behind the model is that the spatial localization of loop heating near the chromosphere leads to a catastrophic cooling in the corona (Antiochos & Klimchuk 1991). Using a new adaptive grid code, we simulate the complete growth of a condensation, and find that after approx. 5,000 s it reaches a quasi-steady state. We show that the size and the growth time of the condensation are in good agreement with data, and discuss the implications of the model for coronal heating and SOHO/TRACE observations.Comment: Astrophysical Journal latex file, 20 pages, 7 b-w figures (gif files

The solar differential rotation in the 18th century

The sunspot drawings of Johann Staudacher of 1749--1799 were used to determine the solar differential rotation in that period. These drawings of the full disk lack any indication of their orientation. We used a Bayesian estimator to obtain the position angles of the drawings, the corresponding heliographic spot positions, a time offset between the drawings and the differential rotation parameter \delta\Omega, assuming the equatorial rotation period is the same as today. The drawings are grouped in pairs, and the resulting marginal distributions for \delta\Omega were multiplied. We obtain \delta\Omega=-0.048 \pm 0.025 d^-1 (-2.75^o/d) for the entire period. There is no significant difference to the value of the present Sun. We find an (insignificant) indication for a change of \delta\Omega throughout the observing period from strong differential rotation, \delta\Omega\approx -0.07 d^-1, to weaker differential rotation, \delta\Omega\approx-0.04 d^-1.Comment: 6 pages, 6 figures, accepted for Astronomy and Astrophysic

Thermo-oxidative characterisation of the residues from persimmon harvest for its use in energy recovery processes

[EN] The residues from the harvest of persimmon fruit will be thermally valorised by means of high temperature reactions within a spouted bed reactor. With the aim to obtain valuable information for the design of the device, the thermo-chemical processes were simulated by multi-rate linear non-isothermal Thermogravimetric Analysis (TGA) using O-2 as carrier gas. In addition, a set of analyses were carried out using Ar as carrier gas in order to evaluate the influence of the atmosphere (oxidative or inert conditions) on the decomposition of the samples evaluating the reactions of pyrolysis. The release of gases was monitored by Evolved Gas Analysis (EGA) with in-line Fourier Transformed Infrared (FT-IR) analysis. The thermochemical reaction was mathematically described through the definition of the main kinetic parameters: activation energy (Ea), pre-exponential factor (In A) and model and order of reaction (n). The so-called kinetic triplet was calculated through the application of a methodology based on complementary isoconversional methods. These results will be the initial parameters that will help design the Spouted Bed Reactor and it is envisaged that they will be used in computer simulation software to achieve a better understanding of the process to obtain the optimum operational parameters. (C) 2016 Published by Elsevier B.V.Moliner, C.; Aguilar, A.; Bosio, B.; Arato, E.; Ribes-Greus, A. (2016). Thermo-oxidative characterisation of the residues from persimmon harvest for its use in energy recovery processes. Fuel Processing Technology. 152:421-429. https://doi.org/10.1016/j.fuproc.2016.07.008S42142915

Material valorisation of amorphous polylactide. Influence of thermo-mechanical degradation on the morphology, segmental dynamics, thermal and mechanical performance

This paper reports the effects of multiple mechanical recycling on the structure and properties of amorphous polylactide (PLA). The influence of the thermo-mechanical degradation induced by means of five successive injection cycles was initially addressed in terms of macroscopic mechanical properties and surface modification. A deeper inspection on the structure and morphology of PLA was associated to the thermal properties and viscoelastic behaviour. Although FT-IR analysis did not show significant changes in functional groups, a remarkable reduction in molar mass was found by viscometry. PLA remained amorphous throughout the reprocessing cycles, but the occurrence of a cold-crystallization during DSC and DMTA measurements, which enthalpy increased with each reprocessing step, suggested chain scission due to thermo-mechanical degradation. The effect of chain shortening on the glass-rubber relaxation studied by DMTA showed an increase in free volume affecting the segmental dynamics of PLA, particularly after the application of the second reprocessing step, in connection to the overall loss of performance showed by the remaining properties

\u3cem\u3eMycobacterium marinum\u3c/em\u3e Infection After Exposure to Coal Mine Water

Mycobacterium marinum infection has been historically associated with exposure to aquariums, swimming pools, fish, or other marine fauna. We present a case of M marinum left wrist tenosynovitis and elbow bursitis associated with a puncture injury and exposure to coal mine water in Illinois

Effect of the dissolution time into an acid hydrolytic solvent to taylor electrospun nanofibrous polycaprolactone scaffolds

The hydrolysis of the polycaprolactone (PCL) as a function of the dissolution time in a formic/ acetic acid mixture was considered as a method for tailoring the morphology of nanofibrous PCL scaffolds. Hence, the aim of this research was to establish a correlation between the dissolution time of the polymer in the acid solvent with the physicochemical properties of the electrospun nanofibrous scaffolds and their further service life behaviour. The physico-chemical properties of the scaffolds were assessed in terms of fibre morphology, molar mass and thermal behaviour. A reduction of the molar mass and the lamellar thickness as well as an increase of the crystallinity degree were observed as a function of dissolution time. Bead-free fibres were found after 24 and 48 h of dissolution time, with similar diameter distributions. The decrease of the fibre diameter distributions along with the apparition of beads was especially significant for scaffolds prepared after 72 h and 120 h of dissolution time in the acid mixture. The service life of the obtained devices was evaluated by means of in vitro validation under abiotic physiological conditions. All the scaffolds maintained the nanofibrous structure after 100 days of immersion in water and PBS. The molar mass was barely affected and the crystallinity degree and the lamellar thickness increased along immersion, preventing scaffolds from degradation. Scaffolds prepared after 24 h and 48 h kept their fibre diameters, whereas those prepared after 72 h and 120 h showed a significant reduction. This PCL tailoring procedure to obtain scaffolds that maintain the nanoscaled structure after such long in vitro evaluation will bring new opportunities in the design of longterm biomedical patches

Impaired hepatic drug and steroid metabolism in congenital adrenal hyperplasia due to P450 oxidoreductase deficiency

Objective: Patients with congenital adrenal hyperplasia due to P450 oxidoreductase (POR) deficiency(ORD) present with disordered sex development and glucocorticoid deficiency. This is due to disruption of electron transfer from mutant POR to microsomal cytochrome P450 (CYP) enzymes that play a key role in glucocorticoid and sex steroid synthesis. POR also transfers electrons to all major drugmetabolizing CYP enzymes, including CYP3A4 that inactivates glucocorticoid and oestrogens. However, whether ORD results in impairment of in vivo drug metabolism has never been studied. Design:We studied an adult patient with ORD due to homozygous POR A287P, the most frequent POR mutation in Caucasians, and her clinically unaffected, heterozygous mother. The patient had received standard dose oestrogen replacement from 17 until 37 years of age when it was stopped after she developed breast cancer. Methods: Both subjects underwent in vivo cocktail phenotyping comprising the oral administration of caffeine, tolbutamide, omeprazole, dextromethorphan hydrobromide and midazolam to assess the five major drug-metabolizing CYP enzymes. We also performed genotyping for variant CYP alleles known to affect drug metabolism. Results: Though CYP enzyme genotyping predicted normal or high enzymatic activities in both subjects, in vivo assessment showed subnormal activities of CYP1A2, CYP2C9, CYP2D6 and CYP3A4 in the patient and of CYP1A2 and CYP2C9 in her mother. Conclusions: Our results provide in vivo evidence for an important role of POR in regulating drug metabolism and detoxification. In patients with ORD, in vivo assessment of drug-metabolizing activities with subsequent tailoring of drug therapy and steroid replacement should be considered