924 research outputs found
Structural characterization of Si(m)Ge(n) strained layer superlattices
SimGen strained layer superlattice (SLS) structures were grown by molecular beam epitaxy on GexSi1-x buffer layers on Si substrates to determine the effects of buffer layer composition, SLS thickness ratio, and superlattice periodicity, on the overall quality of these structures. X-ray diffraction methods were used to determine how closely actual periodicities and compositions met targeted values, and to evaluate the quality of these samples. In most instances the as-grown structures matched the targeted values to within 10%, though in some instances deviations of 20-25% in either the period or composition were observed. The quality of the SLS structures was greatly dependent on the composition of the buffer layer on which it was grown. SimGen SLS structures grown on Si- and Ge-rich buffer layers were of much higher quality than SimGem SLSs grown on Ge0.50Si0.50 layers, but the x-ray rocking curves of the SimGen samples indicated that they were far from perfect and contained moderate levels of defects. These results were confirmed by cross sectional transmission electron microscopy, which showed that the SimGem structures contained significant numbers of dislocations and that the layers were nonuniform in thickness and wavy in appearance. SimGen structures, however, displayed fewer defects but some dislocations and nonparallelism of layers were still observed
Riemann Surfaces of genus g with an automorphism of order p prime and p>g
The present work completes the classification of the compact Riemann surfaces
of genus g with an analytic automorphism of order p (prime number) and p > g.
More precisely, we construct a parameteriza- tion space for them, we compute
their groups of uniformization and we compute their full automorphism groups.
Also, we give affine equations for special cases and some implications on the
components of the singular locus of the moduli space of smooth curves of genus
g.Comment: 28 pages, 5 figure
Action des Nématodes Entomopathogènes du genre Heterorhabditis sur les oeufs de criquet, Locusta migratoria (L.) (Orthoptera : acrididae)
Les nématodes entomopathogènes (EPN) ont été décelés pour la première fois sur les oeufs de criquets. Quelques populations d’Heterorhabditis isolées sur les oeufs de Schistocera gregaria Forsskål, de Locusta migratoria L. (Orthoptera : Acrididae) et sur les chenilles de Galleria mellonella L. (Lepidoptera : Pyralidae) ont été isolées. La pathogénie des populations du nématode isolées sur les oeufs est plus importante que celle sur les chenilles. A l’inverse la pathogénie des EPN isolée sur les chenilles est plus importante sur les chenilles de l’insecte modèle. Les potentialités biochimiques des nématodes entomopathogènes et de leurs bactéries symbiontes en rapport avec l’activité protéolytique et chitinase ont été étudiées. Les bactéries mutualistes des nématodes isolées sur les oeufs de criquet montrent une importante activité protéolytique.Mots Clés: Heterorhabditis, nématode entomopathogène, oeuf, criquet, Locusta migratoriaEnglish Title: Effect of entomopathogenic nematode, heterorhabditis on eggs, Locusta migratoria (L.)English AbstractEffect of entomopathogenic nematode, Heterorhabditis on eggs locust, Locusta migratoria (L.) First report of entomopathogenic nematodes have been detected in locusts eggs. Some Heterorhabditis populations isolated on eggs of Schistocera gregaria Forsskål, of Locusta migratoria L. (Orthoptera : Acrididae) and caterpillars of Galleria mellonella L. (Lepidoptera : Pyralidae) were isolated. Nematode populations isolated from insect eggs aremore aggressive on locust eggs than those obtained by greater wax moth traps. Pathogenesis on nematodes isolated on carterpillar larvae bait, is greater on Galleria mellonella, insect model of EPN, than those bait by locust eggs. Biochemical potential of EPN and their symbiotic bacteria is related on proteolytic and kinetics activity. Mutualistic bacteria of nematode isolated on locust eggs show a significant proteolytic activity.Keywords: Heterorhabditis, entomopathogenetic nematode, Egg, locust, Locusta migratori
An improved geometric inequality via vanishing moments, with applications to singular Liouville equations
We consider a class of singular Liouville equations on compact surfaces
motivated by the study of Electroweak and Self-Dual Chern-Simons theories, the
Gaussian curvature prescription with conical singularities and Onsager's
description of turbulence. We analyse the problem of existence variationally,
and show how the angular distribution of the conformal volume near the
singularities may lead to improvements in the Moser-Trudinger inequality, and
in turn to lower bounds on the Euler-Lagrange functional. We then discuss
existence and non-existence results.Comment: some references adde
Synovialosarcome cervical: a propos d’un cas
Introduction : Le synovialosarcome est une tumeur maligne agressive. Les localisations cervico-faciales sont très rares. Nous rapportons un nouveau cas de synovialosarcome dans la région antéro-latérale du cou.Observation : Il s’agit d’un patient âgé de 37 ans, qui a consulté pour une volumineuse tuméfaction latéro-cervicale évoluant depuis 8 mois. La TDM a montré une masse tissulaire bien limitée de la région antérolatérale gauche du cou qui se rehausse faiblement après injection de produit de contraste. Le patient a eu une exérèse tumorale complète. L’examen anatomopathologique a conclu à un synovialosarcome. L’évolution était marquée par la récidive locale rapide, après 15 jours, pour laquelle il a été réopéré avec une radio-chimiothérapie post opératoire. Cependant le patient a présenté une métastase pulmonaire avec une poursuite évolutive.Conclusion : Le synovialosarcome cervical ne présente pas de spécificité clinique et radiologique. Le traitement de choix est la chirurgie.La valeur du traitement adjuvant n’est pas encore bien définie. Le pronostic est mauvais.Mots clés : synovialosarcome, région cervicale, chirurgie, radiothérapie, récidiveIntroduction : The synovial sarcoma is a malignant and aggressive tumor. The cervicofacial locations are rares. We report a new case of synovial sarcoma in the anterolateral region of the neck.Observation : He is a 37 years old patient, with a large latero-cervical tumefaction evolving for 8 months. CT showed well circumscribed tissue mass of the left anterolateral area neck which enhances low after contrast injection. The patient had a complete tumor resection. Histological examination concluded a synovial sarcoma. The evolution was marked by rapid local recurrence, after 15 days, for which he was reoperated with postoperative chemoradiotherapy. However, the patient had a pulmonary metastasis with continued progression.Conclusion : The cervical synovial sarcoma has no specific clinical and radiological character. The treatment of choice is surgery. The value of adjuvant therapy is not well defined. The prognosis is poor.Keywords : synovial sarcoma, neck, surgery, radiotherapy, recurrenc
Efecto de la germinación sobre la composición química y la actividad antioxidante de aceites de linaza (Linum usitatissimum L).
The present study was carried out to determine the changes in proximate composition and physicochemical characteristics of flaxseed during germination. Flaxseed was germinated for 4 days and observations were taken every day throughout the study. Changes in the seed reserve and antioxidant activity were determined during germination. The oil content of the cultivar decreased from 35.10 to 27.22%. During the germination period, the total protein content increased to 23.84%. Germinated flaxseed showed significantly higher unsaturated as compared to saturated fatty acid ratios and higher calculated oxidizability (Cox) values. The Saponification value ranged from 182 to 192 mg KOH·g–1 oil during germination. The highest peroxide value (2.4 mequiv O2·kg−1 oil) was observed at the end of germination. The unsaponifiable contents ranged from 1.62 to 1.18%. The oxidation value of the oil samples were statistically in the same range (4.1–6.4%). After 4 days of germination, oil stability was reduced to 1.0 h. The increase in ascorbic acid content was steady. Total phenolic acid contents differed significantly. The greatest concentration was detected in non germinated flaxseed oil. Germinated Flaxssed oil showed an important free radical scavenging activity towards 1-1-diphenyl-2-picrylhydrazyl (DPPH) free radicals.El presente estudio se llevó a cabo para determinar los cambios en la composición y características físico-químicas de aceites de linaza durante la germinación. La linaza se germinó durante 4 días y el estudio se realizó todos los días durante este proceso. Se determinaron los cambios en la reserva de las semilla y la actividad antioxidante. El contenido de aceite de los cultivos disminuyó de 35,10 a 27,22%. Durante este periodo, el contenido de proteína total aumentó a 23,84%. La linaza germinada mostró valores significativamente más altos de la relación de ácidos grasos insaturados frente a saturados y mayor facilidad de oxidación (Cox). El índice de saponificación varió desde 182 hasta 192 mg KOH·g−1 de aceite durante la germinación. El índice de peróxido más alto (2,4 mequiv O2·kg−1 de aceite) se observó al final de la germinación. El contenido de materia insaponificable varió desde 1,62 hasta 1,18%. La oxidación de las muestras de aceite fueron estadísticamente del mismo rango (4.1 a 6.4%). Después de 4 días de germinación, la estabilidad del aceite se redujo a 1,0 h. El aumento en contenido de ácido ascórbico fue estable. Los contenidos totales de ácidos fenólicos diferían significativamente. La mayor concentración se detectó en el aceite de linaza no germinado. El aceite de linaza germinado mostró una importante actividad de eliminación de radicales libres hacia 1-1-difenil-2-picrilhidrazil (DPPH)
Constitutively elevated levels of SOCS1 suppress innate responses in DF-1 immortalised chicken fibroblast cells.
The spontaneously immortalised DF-1 cell line is rapidly replacing its progenitor primary chicken embryo fibroblasts (CEFs) for studies on avian viruses such as avian influenza but no comprehensive study has as yet been reported comparing their innate immunity phenotypes. We conducted microarray analyses of DF-1 and CEFs, under both normal and stimulated conditions using chicken interferon-α (chIFN-α) and the attenuated infectious bursal disease virus vaccine strain PBG98. We found that DF-1 have an attenuated innate response compared to CEFs. Basal expression levels of Suppressor of Cytokine Signalling 1 (chSOCS1), a negative regulator of cytokine signalling in mammals, are 16-fold higher in DF-1 than in CEFs. The chSOCS1 “SOCS box” domain (which in mammals, interacts with an E3 ubiquitin ligase complex) is not essential for the inhibition of cytokine-induced JAK/STAT signalling activation in DF-1. Overexpression of SOCS1 in chIFN-α-stimulated DF-1 led to a relative decrease in expression of interferon-stimulated genes (ISGs; MX1 and IFIT5) and increased viral yield in response to PBG98 infection. Conversely, knockdown of SOCS1 enhanced induction of ISGs and reduced viral yield in chIFN-α-stimulated DF-1. Consequently, SOCS1 reduces induction of the IFN signalling pathway in chicken cells and can potentiate virus replication
Metastase de la voûte crânienne Revelant un carcinome differencie De la thyroïde
Les métastases des carcinomes thyroïdiens au niveau de la voûte crânienne sont extrêmement rares. Bien que ces métastases soient de mauvais pronostic, la détection précoce et l’administration d’un traitement approprié peuvent améliorer la survie et la qualité de vie. Nous rapportons deux cas de carcinomes différenciés thyroïdiens révélés par une métastase de la voûte crânienne.Mots clés: métastase, voûte crânienne, cancer de la thyroïdeThyroid carcinoma with metastasis to the cranial vault is extremely rare. Although these metastasis had poor prognosis, early detection and administration of appropriate therapy using radioactive iodine seems likely to improve the survival rate and quality of life. We report two cases of differentiated thyroid carcinoma revealed by vault metastasis.Keywords: metastasis, cranial vault, thyroid carcinom
- …
