Tunnel shotcrete lining for hydroelectric projects in British Columbia

In British Columbia (BC), Canada, the primary source of power supply is hydroelectricity. The BC government, through its crown corporation, BC Hydro, has been working with private companies to provide sustainable and renewable energy. Private companies are building hydroelectric projects throughout the province of BC. Innergex has been constructing three hydroelectric projects; two are in the Upper Lilllooet area, which is about 250 km north of Vancouver and 80km north of Whistler and the third is in the Big Silver area, which is about 250 km east of Vancouver and 50 km north of Harrison Lake. All of these tunnels are hard rock and have been constructed by the drill and blast method. At the beginning of the projects, dry-mix shotcrete was applied based on the contractor’s previous underground project experience. Wet-mix shotcrete was subsequently introduced as a trial method. The contractor was impressed with its productivity and performance and consequently adopted it as the primary shotcrete placement method. Dry-mix steel fiber reinforced shotcrete continued to be used for special ground conditions. The construction schedule was reduced significantly by using wet-mix shotcrete, with resultant substantial cost savings. The wet-mix shotcrete was initially reinforced with wire mesh and hand-applied. Shortly after, the tunnel lining method was changed to the use of robotic sprayed macrosynthetic fiber reinforced wet-mix shotcrete. A silica fume modified shotcrete mixture was designed and trial shot. Tests results met the project specification requirements for tunnel construction. The wet-mix macrosynthetic fiber reinforced shotcrete was placed, since July 2013, using pre-bagged materials supplied from Vancouver and mixed on site. Later, the contractor set up a dry-batch concrete batch plant on site and started batching shotcrete using local aggregates. The shotcrete mixture was qualified for use on the project by testing for compressive strength, boiled absorption and volume of permeable voids, and flexural toughness based on use of the round determinate panel to ASTM C1550. The effect on shotcrete performance of different addition rates of alkali-free accelerator was tested in trials. An addition rate of 6% alkali-free accelerator by mass of cement was selected and used. Shotcrete nozzlemen were trained with a specially designed shotcrete training program. All shotcrete nozzlemen were qualified to shoot a basic Level I, and a more challenging Level II, for shotcrete with reinforcing steel or lattice girders. The construction quality control tests results for the project from August 2013 to December 2016 demonstrated that the shotcrete quality consistently met the project specification requirements. The projects were completed ahead of schedule because of productivity gains achieved from using wet-mix macrosynthetic fiber reinforced shotcrete. The contractors developed proper skills and techniques for application of wet-mix macrosynthetic fiber reinforced shotcrete applied by robotic sprayers with zero safety incidents or accident

Valutazione ecografica degli indici di resistività (RI) e di pulsatilità (PI) delle arterie oculari e della biometria oculare nei cani affetti da Leishmaniosi

Canine leishmaniosis is a protozoan disease endemic in the Mediterranean area, caused by Leishmania infantum. It is a chronic and severe systemic disease with various manifestation, one of these being ocular lesions. Pulsed Wave Doppler ultrasonography provides indirect information about ocular and orbital vascular flow resistance through the measurements of the Resistive (RI) e and the Pulsatility (PI) indices. The main purposes of the present study were to evaluate the ophthalmic and ciliary artery resistance and to determine the prevalence and type of ocular lesions in a population of dogs naturally infected by Leishmania infantum, before and after medical therapy. 18 dogs naturally infected by Leishmania infantum and 15 healthy dogs as a control group were included in this prospective clinical study. The results showed that ocular flow resistance was significantly higher in the sick dogs compared to the control group and that ocular and periocular tissues were affected in 83% of dogs with systemic Leishmaniasis. The ocular lesions improved or completely resolved and mean PI returned within the reference limits following the therapy, on the contrary, the mean RI remained high in dogs who have undergone therapy. Microcirculatory involvement is well recognised in canine Leishmaniasis, assessment of vascular ocular RI and PI could be a useful tool for assessing disease activity and for monitoring response to treatment

The mechanical behavior of high performance polymer fibers

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1992.Includes bibliographical references (leaves 140-142).by John Edward Moalli.Sc.D

Pathogen Recognition by the Long Pentraxin PTX3

Innate immunity represents the first line of defence against pathogens and plays key roles in activation and orientation of the adaptive immune response. The innate immune system comprises both a cellular and a humoral arm. Components of the humoral arm include soluble pattern recognition molecules (PRMs) that recognise pathogen-associated molecular patterns (PAMPs) and initiate the immune response in coordination with the cellular arm, therefore acting as functional ancestors of antibodies. The long pentraxin PTX3 is a prototypic soluble PRM that is produced at sites of infection and inflammation by both somatic and immune cells. Gene targeting of this evolutionarily conserved protein has revealed a nonredundant role in resistance to selected pathogens. Moreover, PTX3 exerts important functions at the cross-road between innate immunity, inflammation, and female fertility. Here, we review the studies on PTX3, with emphasis on pathogen recognition and cross-talk with other components of the innate immune system

Bone Morphogenetic Protein-Transduced Human Fibroblasts Convert to Osteoblasts and Form Bone in Vivo

Experimental cell or ex vivo gene therapy for localized bone formation typically uses osteoprogenitor cells propagated from periosteum or bone marrow. Both require bone or marrow biopsies to obtain cells. We have demonstrated that implantation of gingival or dermal fibroblasts transduced with BMP ex vivo, using a recombinant adenovirus (AdCMVBMP) attached to porous biodegradable scaffolds, form bone in vivo. Here we show that BMP-7-transduced fibroblasts suspended in injectable thermoset hydrogels form complete ossicles on subcutaneous injection and repair segmental defects in rat femurs. Bone formation was preceded by an intermediate cartilage stage. To determine the fate of the implanted transduced cells, thermoset hydrogel suspensions of ex vivo BMP-7-transduced or nontransduced fibroblasts were placed in diffusion chambers and implanted to allow development in vivo without direct contact with host cells. Only the BMP-transduced fibroblasts formed bone within the diffusion chambers in vivo, revealing that BMP transduction induces osteoblastic conversion of these cells.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63216/1/107632702760184709.pd

pMHC affinity controls duration of CD8+ T cell-DC interactions and imprints timing of effector differentiation versus expansion.

During adaptive immune responses, CD8(+) T cells with low TCR affinities are released early into the circulation before high-affinity clones become dominant at later time points. How functional avidity maturation is orchestrated in lymphoid tissue and how low-affinity cells contribute to host protection remains unclear. In this study, we used intravital imaging of reactive lymph nodes (LNs) to show that T cells rapidly attached to dendritic cells irrespective of TCR affinity, whereas one day later, the duration of these stable interactions ceased progressively with lowering peptide major histocompatibility complex (pMHC) affinity. This correlated inversely BATF (basic leucine zipper transcription factor, ATF-like) and IRF4 (interferon-regulated factor 4) induction and timing of effector differentiation, as low affinity-primed T cells acquired cytotoxic activity earlier than high affinity-primed ones. After activation, low-affinity effector CD8(+) T cells accumulated at efferent lymphatic vessels for egress, whereas high affinity-stimulated CD8(+) T cells moved to interfollicular regions in a CXCR3-dependent manner for sustained pMHC stimulation and prolonged expansion. The early release of low-affinity effector T cells led to rapid target cell elimination outside reactive LNs. Our data provide a model for affinity-dependent spatiotemporal orchestration of CD8(+) T cell activation inside LNs leading to functional avidity maturation and uncover a role for low-affinity effector T cells during early microbial containment

PTX3 Polymorphisms Influence Cytomegalovirus Reactivation After Stem-Cell Transplantation

Background: Reactivation of latent human cytomegalovirus (CMV) in patients undergoing allogeneic stem-cell transplantation (HSCT) predisposes to several clinical complications and is therefore a major cause of morbidity and mortality. Although pentraxin-3 (PTX3) has been previously described to bind both human and murine CMV and mediate several host antiviral mechanisms, whether genetic variation in the PTX3 locus influences the risk of CMV infection is currently unknown. Methods: To dissect the contribution of genetic variation within PTX3 to the development of CMV infection, we analyzed described loss-of-function variants at the PTX3 locus in 394 recipients of HSCT and their corresponding donors and assessed the associated risk of CMV reactivation. Results: We report that the donor, but not recipient, h2/h2 haplotype in PTX3 increased the risk of CMV reactivation after 24 months following transplantation, with a significant effect on survival. Among recipients with h2/h2 donors, CMV seropositive patients as well as those receiving grafts from unrelated donors, regardless of the CMV serostatus, were more prone to develop viral reactivation after transplantation. Most importantly, the h2/h2 haplotype was demonstrated to display an influence toward risk of CMV reactivation comparable to that conferred by the unrelated status of the donor alone. Conclusions: Our findings demonstrate the important contribution of genetic variation in donor PTX3 to the risk of CMV reactivation in patients undergoing HSCT, highlighting a promising prognostic value of donor PTX3 to predict risk of CMV reactivation in this clinical setting.Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) (NORTE-01-0145-FEDER-000013), and the Fundação para a Ciência e Tecnologia (FCT) (SFRH/BPD/96176/2013 to CC, IF/01390/2014 to ET, IF/00021/2014 to RS, and IF/00735/2014 to AgC

XRCC1 Deficiency Sensitizes Human Lung Epithelial Cells to Genotoxicity by Crocidolite Asbestos and Libby Amphibole

Background: Asbestos induces DNA and chromosomal damage, but the DNA repair pathways protecting human cells against its genotoxicity are largely unknown. Polymorphisms in XRCC1 have been associated with altered susceptibility to asbestos-related diseases. However, it is unclear whether oxidative DNA damage repaired by XRCC1 contributes to asbestos-induced chromosomal damage

The humoral pattern recognition receptor PTX3 is stored in neutrophil granules and localizes in extracellular traps

The long pentraxin (PTX) 3 is produced by macrophages and myeloid dendritic cells in response to Toll-like receptor agonists and represents a nonredundant component of humoral innate immunity against selected pathogens. We report that, unexpectedly, PTX3 is stored in specific granules and undergoes release in response to microbial recognition and inflammatory signals. Released PTX3 can partially localize in neutrophil extracellular traps formed by extruded DNA. Eosinophils and basophils do not contain preformed PTX3. PTX3-deficient neutrophils have defective microbial recognition and phagocytosis, and PTX3 is nonredundant for neutrophil-mediated resistance against Aspergillus fumigatus. Thus, neutrophils serve as a reservoir, ready for rapid release, of the long PTX3, a key component of humoral innate immunity with opsonic activity