Length Sensing and Control in the Virgo Gravitational Wave Interferometer

The gravitational wave detector Virgo is presently being commissioned. A significant part of last year was spent in setting up the cavity length control system. This work was carried out with steps of increasing complexity: locking a simple Fabry-Perot cavity, then a Michelson interferometer with Fabry-Perot cavities in both arms, and finally recycling the light beam into the interferometer. The applied strategy and the main results obtained are describe

Editing the genome of chicken primordial germ cells to introduce alleles and study gene function

With continuing advances in genome sequencing technology, the chicken genome assembly is now better annotated with improved accuracy to the level of single nucleotide polymorphisms. Additionally, the genomes of other birds such as the duck, turkey and zebra finch have now been sequenced. A great opportunity exists in avian biology to use genome editing technology to introduce small and defined sequence changes to create specific haplotypes in chicken to investigate gene regulatory function, and also perform rapid and seamless transfer of specific alleles between chicken breeds. The methods for performing such precise genome editing are well established for mammalian species but are not readily applicable in birds due to evolutionary differences in reproductive biology. A significant leap forward to address this challenge in avian biology was the development of long-term culture methods for chicken primordial germ cells (PGCs). PGCs present a cell line in which to perform targeted genetic manipulations that will be heritable. Chicken PGCs have been successfully targeted to generate genetically modified chickens. However, genome editing to introduce small and defined sequence changes has not been demonstrated in any avian species. To address this deficit, the application of CRISPR/Cas9 and short oligonucleotide donors in chicken PGCs for performing small and defined sequence changes was investigated in this thesis. Specifically, homology-directed DNA repair (HDR) using oligonucleotide donors along with wild-type CRISPR/Cas9 (SpCas9-WT) or high fidelity CRISPR/Cas9 (SpCas9-HF1) was investigated in cultured chicken PGCs. The results obtained showed that small sequences changes ranging from a single to a few nucleotides could be precisely edited in many loci in chicken PGCs. In comparison to SpCas9-WT, SpCas9-HF1 increased the frequency of biallelic and single allele editing to generate specific homozygous and heterozygous genotypes. This finding demonstrates the utility of high fidelity CRISPR/Cas9 variants for performing sequence editing with high efficiency in PGCs. Since PGCs can be converted into pluripotent stem cells that can potentially differentiate into many cell types from the three germ layers, genome editing of PGCs can, therefore, be used to generate PGC-derived avian cell types with defined genetic alterations to investigate the host-pathogen interactions of infectious avian diseases. To investigate this possibility, the chicken ANP32A gene was investigated as a target for genetic resistance to avian influenza virus in PGC-derived chicken cell lines. Targeted modification of ANP32A was performed to generate clonal lines of genome-edited PGCs. Avian influenza minigenome replication assays were subsequently performed in the ANP32A-mutant PGC-derived cell lines. The results verified that ANP32A function is crucial for the function of both avian virus polymerase and human-adapted virus polymerase in chicken cells. Importantly, an asparagine to isoleucine mutation at position 129 (N129I) in chicken ANP32A failed to support avian influenza polymerase function. This genetic change can be introduced into chickens and validated in virological studies. Importantly, the results of my investigation demonstrate the potential to use genome editing of PGCs as an approach to generate many types of unique cell models for the study of avian biology. Genome editing of PGCs may also be applied to unravel the genes that control the development of the avian germ cell lineage. In the mouse, gene targeting has been extensively applied to generate loss-of-function mouse models to use the reverse genetics approach to identify key genes that regulate the migration of specified PGCs to the genital ridges. Avian PGCs express similar cytokine receptors as their mammalian counterparts. However, the factors guiding the migration of avian PGCs are largely unknown. To address this, CRISPR/Cas9 was used in this thesis to generate clonal lines of chicken PGCs with loss-of-function deletions in the CXCR4 and c-Kit genes which have been implicated in controlling mouse PGC migration. The results showed that CXCR4-deficient PGCs are absent from the gonads whereas c-Kit-deficient PGCs colonise the developing gonads in reduced numbers and are significantly reduced or absent from older stages. This finding shows a conserved role for CXCR4 and c-Kit signalling in chicken PGC development. Importantly, other genes suspected to be involved in controlling the development of avian germ cells can be investigated using this approach to increase our understanding of avian reproductive biology. Finally, the methods developed in this thesis for editing of the chicken genome may be applied in other avian species once culture methods for the PGCs from these species are develope

Propositions du groupe d Initiative de la Société Civile pour la Paix face à l évolution politique du pays

Document collected by the University of Texas Libraries from the web-site of the Reseau Documentaire International Sur La Region Des Grands Lacs Africains (International Documentation Network on the Great African Lakes Region). The Reseau distributes "gray literature", non-published or limited distribution government or NGO documents regarding the Great Lakes area of central Africa including Rwanda, Burundi, and the Democratic Republic of Congo.UT Librarie

Repair of distal biceps tendon rupture: A new technique using the Endobutton

Previously published: 10.1016/S1058-2746(00)90040-5The authors describe a technique with a single anterior incision and fixation with an internal button, the Endobutton. The procedure is performed through a 5-cm transverse skin incision, and the tendon is sutured to the Endobutton with 2 number 5 Ethibond sutures. Surgical repair in the depths of the muscular forearm is not required, because the tendon is simply sutured external to the wound. The Endobutton delivers and locks the tendon into a hole in the radial tuberosity. The Endobutton technique was used in 12 patients who were allowed early active mobilization. All were satisfied, returned to activities, and regained grade 5 strength. Average flexion was from 5 degrees to 146 degrees with 81 degrees supination and 80 degrees pronation. No neurovascular complications or synostosis occurred. In cadaveric studies the average distance from the biceps tendon were ulnar artery 6 mm, median nerve 12 mm, and posterior interosseous nerve 18 mm. The average distance from the posterior interosseous nerve to a Steinman pin advanced through the proximal radius was 14 mm. This technique is a safe and effective method of repair of distal biceps tendon avulsion that allows active mobilization with minimal risk of complication.Bain, Gregory I. ; Prem, Hari ; Heptinstall, Ronald J. ; Verhellen, Rik ; Poix, Debora

Actinomycotic granuloma masquerading as an infraorbital nerve neoplasm.

Actinomycotic infections of the head and neck region are rare and frequently present a confusing clinical picture. We document a case of actinomycosis that simulated a neoplasm of the infraorbital nerve, both clinically and surgically. To the best of our knowledge, this is the first report of actinomycosis involving this nerve. Correct diagnosis of actinomycotic infection in the head and neck relies most heavily on clinical suspicion. It is, therefore, imperative for the head and neck surgeon to be familiar with the etiology of this infection and its various modes of presentation as well as its appropriate management