In many ant species, queen size is dimorphic, with small microgynes and large macrogynes, which differ, for example, in size, insemination rate, ovary development, and dispersal tactics. These ...polymorphic queens often correspond with alternative reproductive strategies. The Palearctic ant, Manica rubida (Latreille) (Hymenoptera: Formicidae), lives mostly in mountainous regions in either monogynous colonies, containing one macrogynous queen or polygynous colonies, containing a few large macrogynous queens. In 1998, a colony of M. rubida was discovered containing macrogynes and many small alate microgynes that did not engage in a nuptial flight but, instead, stayed in the home nest the following winter. These microgynes were studied more closely by investigating their size, behavior, and spermatheca in relation to M. rubida macrogynes and workers. Mitochondrial DNA of macrogynes, microgynes and workers from four nests was sequenced to detect possible genetic differences between them. The microgynes were significantly smaller than the macrogynes, and the head width of the gynes was completely bimodal. The microgynes behaved like workers of the macrogynes in every experiment tested. Furthermore, the microgynes had a normal spermatheca and could be fecundated, but rarely (only one in several years). Finally, all the individuals were genetically identical, except three workers that differed by only one codon position. Because these microgynes have features of both queens and workers, their functional significance in the colony is not yet clear.
Post-transplant lymphoproliferative disorder (PTLD) is a recognized severe complication arising in allograft recipients treated with immunosuppressive drugs. Although not common, PTLD is one of the ...most frequent tumours among graft recipients, comprising 15-25% of neoplasms, compared with 5% in the general population. The introduction of cyclosporin A (CyA) in the early 1980's and the very potent new immunosuppressants such as anti-CD3 monoclonal OKT3 and FK506 have been associated with a significant rise in the incidence of PTLD and with their earlier presentation. The incidence of this malignancy varies with the organ transplanted (1-2% of renal transplant recipients) and with the nature and severity of the accompanying immunosuppressive regimen. While the precise etiology of PTLD is still unclear, significant advances have been made recently in the understanding of its pathogenesis. Most PTLD tumour cells present an activated B-cell phenotype and an unrestricted pattern of latent EBV gene products. It is generally accepted that Epstein-Barr virus (EBV) infection or reactivation and intensive anti-T lymphocyte regimens play a major role in the genesis of PTLD. They include a spectrum of EBV-related disorders ranging from lymphoid hyperplasia to frank malignant non-Hodgkin's lymphoma. Although different therapeutic attempts have been proposed, optimal treatment remains elusive. The mortality rate for monoclonal lymphomas was reported to be as high as 80%. Infusion of anti-B monoclonal antibodies seems to be a promising modality. Different preventive approaches have been proposed, including EBV sero-negative donor/recipient matching and careful monitoring of EBV infection. Cautious use of anti-rejection treatment in combination with prophylactic antiviral therapy is recommended.
Several approaches have been investigated to prepare fluorite-type compositions within the (1-x) CeO{sub 2}-xYO{sub 1.5} system. The optical properties of the resulting modified-ceria materials have ...been characterized in order to evaluate their potential abilities as inorganic UV absorbers. Diffuse reflectance analyses reveal a strong optical absorption between 390 and 400 nm for all substituted compositions and the spectral selectivities are estimated suitable for the targeted application. Additionally, time resolved microwave conductivity (TRMC) and phenol photodegradation analyses do not indicate any photocalatytic activity for these compositions. Aqueous colloidal suspensions of the Ce{sub 0.7}Y{sub 0.3}O{sub 1.85} UV absorber have been carried out. - Graphical abstract: Comparison between diffuse reflectance spectra of ceria (x=0) and yttrium modified ceria (x=0.3)
Comment penser l'économie autrement ? Depuis trente ans, des chercheurs de différentes disciplines participent au développement d’une économie des conventions qui construit une nouvelle ...représentation de l’économie. Les 75 auteurs réunis dans cet ouvrage fournissent un éclairage exceptionnel sur cette approche à partir des travaux de l’un de ses principaux artisans, Olivier Favereau. Plus que tout autre économiste, il a œuvré tout au long de sa carrière aux échanges interdisciplinaires pour renouveler notre compréhension des phénomènes économiques. Les différentes entrées de ce dictionnaire non standard discutent, utilisent ou prolongent ces travaux. Le lecteur dispose ainsi d’une introduction sans équivalent aux débats contemporains sur l’évolution des savoirs économiques : les nouvelles représentations de l’entreprise, du travail, de la finance et plus généralement des comportements économiques et de leur dimension politique.
Several approaches have been investigated to prepare fluorite-type compositions within the (1−
x) CeO
2–
xYO
1.5 system. The optical properties of the resulting modified-ceria materials have been ...characterized in order to evaluate their potential abilities as inorganic UV absorbers. Diffuse reflectance analyses reveal a strong optical absorption between 390 and 400
nm for all substituted compositions and the spectral selectivities are estimated suitable for the targeted application. Additionally, time resolved microwave conductivity (TRMC) and phenol photodegradation analyses do not indicate any photocalatytic activity for these compositions. Aqueous colloidal suspensions of the Ce
0.7Y
0.3O
1.85 UV absorber have been carried out.
Comparison between diffuse reflectance spectra of ceria (
x=0) and yttrium modified ceria (
x=0.3).
Le lecteur est invité à une balade patrimoniale à la découverte d'ouvrages anciens et précieux couvrant les domaines de la médecine, de la pharmacie et des sciences biomédicales. Parmi ces trésors, ...on peut pointer une édition grecque de 1538 d'Hippocrate, un ouvrage d’exception en couleurs de 1549 de Dioscoride, deux atlas d’anatomie à feuillets mobiles, de très beaux ouvrages de botanique médicale, etc. Grâce à une iconographie variée et grâce aux commentaires rédigés pour la plupart par des membres de la Faculté de Médecine, le lecteur pourra notamment se rendre compte des progrès considérables qui ont été réalisés dans divers secteurs de la santé. Un beau livre richement illustré, pour toute personne désireuse de s’informer sur la médecine d’autrefois. Ce catalogue, complément à l’exposition Quand la médecine rencontre son patrimoine (18 novembre 2017 - 31 janvier 2018) est le fruit d’une collaboration entre la Bibliothèque Universitaire Moretus Plantin (BUMP) et la Faculté de Médecine de l’Université de Namur.
This work concerns the design and safety analysis of gas cooled reactors. The CATHARE code is used to test the design and safety of two different concepts, a High Temperature Gas Reactor concept ...(HTGR) and a Gas Fast Reactor concept (GFR). Relative to the HTGR concept, three transient simulations are performed and described in this paper: loss of electrical load without turbo-machine trip, 10
in. cold duct break, 10
in. break in cold duct combined with a tube rupture of a cooling exchanger. A second step consists in modelling a GFR concept. A nominal steady state situation at a power of 600
MW is obtained and first transient simulations are carried out to study decay heat removal situations after primary loop depressurisation. The turbo-machine contribution is discussed and can offer a help or an alternative to “active” heat extraction systems.
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