Characterisation of Xenopus Origin Recognition Complex

The Origin Recognition Complex (ORC) of S. cerevisiae plays a crucial role in recognition of origins of DNA replication within the yeast genome. In Xenopus egg extracts DNA replication initiates from random DNA sequences suggesting that origins of DNA replication are not required. Despite this apparent lack of requirement for DNA sequences serving as origins of DNA replication, a protein homologous to the Ore Ip subunit of yeast ORC has been identified in Xenopus. This discovery has indicated that the mechanism which recognises replication origins in higher eukaryotes could be similar to that in yeast. Work described in this thesis started at the time when Xenopus Ore Ip was identified. In the quest to understand Xenopus ORC and it's function in origin recognition I set out to purify this protein complex. I produced monoclonal antibodies which recognised Xenopus Ore Ip subunit of ORC with high affinity and specificity. Using these antibodies, I purified a protein complex which contained Xenopus Ore Ip in association with at least four other polypeptides. I showed that one of these polypeptides was Xenopus Orc2p which was meanwhile identified by an independent research. Microsequencing of another Ore Ip associated protein led to identification of mouse Orc4 gene from the EST database. I used the identified mouse Orc4 sequence to screen Xenopus cDNA library and I cloned Xenopus Orc4 gene. Microsequencing of another two proteins co-purified with Ore Ip confirmed that they were Xenopus Orc3p and Orc5p and helped identification of their corresponding genes from frogs and humans. I described a mobility shift of Xenopus Ore Ip occurring upon the exit from mitosis and showed that it correlated with dephosphorylation of the protein. I determined that the amount of ORC present in a single frog egg is 100 000 fold higher than in a single somatic cell. Finally, I showed that ORC purified from Xenopus egg extract binds to S. cerevisiae ARSl sequence, as well as to DNA sequences derived from a bacterial plasmid. I observed that this ORC-DNA interaction was dependent on ATP. However, the way by which ORC determines the sites of initiation of DNA replication in higher eukaryotes remains unknown

Ajuden les tasques de Teoria de la ment i Pragmàtica en la diferenciació de xiquets amb trastorn pragmàtic del llenguatge i síndrome d’Asperger?

XVIII Jornades de Foment de la Investigació de la Facultat de Ciències Humanes i Socials (Any 2013)A partir del debat existent sobre la confusió entre els trastorns que presenten dèficits comunicatius, com són aquells del continu del Trastorn de l’Espectre Autista (TEA) i Trastorn Específic del Llenguatge (TEL), les investigacions més actuals es basen en les tasques de teoria de la ment i pragmàtica per intentar explorar la comprensió dels estats mentals per part d’aquests xiquets i xiquetes i, així, poder discriminar el TEA de la resta de trastorns. Amb aquest treball es pretén comprovar si les tasques de teoria de la ment i pragmàtica ajuden a diferenciar els diagnòstics de Trastorn Pragmàtic del Llenguatge (TPL) i Síndrome d’Asperger (SA), ja que són propers en el continu esmentat pel que fa a la simptomatologia que manifesten en edat infantil. Es presenta un estudi sobre dos casos, una xiqueta de 7 anys amb possible TPL (cas A) i un xiquet de 8 anys amb possible SA (cas B), als quals se’ls administren diferents tasques de teoria de la ment i pragmàtica i es revisen els seus informes anteriors. Els resultats demostren un perfil més agreujat de B en les tasques de Teoria de la Ment (ToM). En la línia d’estudis anteriors, es conclou que les tasques d’avaluació de ToM i pragmàtica sí que contribueixen a millorar el diagnòstic dels dos casos

The pyretic sulphide deposits of the lahanos mine area, eastern black sea region, Turkey

The Lahanos pyritic sulphide deposit is one of the important copper deposits occurring within the submarine volcanic environment of the Eastern Pontus Ore province. It is situated 10 miles to the south of Espiye, Giresun Vilayeti. Petrographic study of the Lahanos rocks, despite their heavy alteration, shows that they belong mainly to the calc alkaline and tholeiitic basalt suites, and in addition, there are some high-alumina basalts. The intense igneous activity took place during the Mesozoic and the early and middle Tertiary periods. This phase of igneous activity culminated in the intrusion of syntectonic granites, tonolites and adamellites, and was followed by aplitic and hydrothermal phases, in the Pontid Geosyncline. The ore mineralisation, associated with dacites, is characterised by large quantities of pyrite associated with other base metal sulphides such as chalcopyrite, sphalerite, galena and other sulphides and sulphosalts. Field, underground and borehole evidence shows that the Lahanos ore body displays a zonal arrangement, which is similar to the well documented "Kuroko" type ore deposits in Japan. The results of detailed chemical and mineralogical study of the ore and country rock are given and the temperature of formation is estimated. Comparative details are given for the Murgul and Karadere deposits. The evidence supports an epigenetic hydrothermal origin for this "strata bound" deposit, but the volcanicity alone is inadequate to explain the source of the base metals, which are probably derived from the granites. The role of pyroclastic horizons of restricted permeability as a control of precipitation is discussed

Pediatric Uveitis

Uveitis is less common in children than in adults, and its diagnosis and management can be particularly challenging. Young children are often asymptomatic either because of inability to express complaints or because of the truly asymptomatic nature of their disease. Even in advanced cases, parents may not be aware of severe visual impairment until the development of externally visible changes such as band keratopathy, strabismus, or leukocoria. Therefore, the diagnosis is often delayed and severe complications may be seen at the time of initial visit. Young children may not be cooperative for a complete ocular examination and subtle findings of intraocular inflammation such as trace cells may be easily missed in the early stages of the disease. Children, in general, tend to have more severe and chronic intraocular inflammation that frequently results in ocular complications and visual loss. In children who present with amblyopia or strabismus, a careful examination is required to rule out uveitis as an underlying cause. Delayed and variable presentations cause a distinct challenge in the diagnosis of uveitis in children, furthermore differential diagnosis also requires awareness of etiologies which are different from adults. There are unique forms of uveitis and masquerade syndromes in this age group, while some entities commonly encountered in adults are rare in children

On the Influence of Grouping Practices on Classroom Teaching

The article starts with a historical overview, discusses the arguments for and against ability grouping. It surveys the literature on different practices of grouping that exist in the American and British literature. The study mainly focuses on instructional grouping practices based on ability and on cooperation. It discusses arguments for and against ability grouping. The study also presents information about the use of mastery learning with cooperative strategies