Measurement of Muscular Activity Associated With Peristalsis in the Human Gut Using Fiber Bragg Grating Arrays

Author version made available under Publisher copyright policy.Diagnostic catheters based on fibre Bragg gratings (FBG’s) are proving to be highly effective for measurement of the muscular activity associated with peristalsis in the human gut. The primary muscular contractions that generate peristalsis are circumferential in nature; however, it has long been known that there is also a component of longitudinal contractility present, acting in harmony with the circumferential component to improve the overall efficiency of material movement. We report on the development of, and latest results from, catheter based sensors capable of detecting both forms of muscular activity. While detection of the circumferential contractions has been possible using solid state, hydraulic, and pneumatic sensor arrays in the oesophagus and anorectum, FBG based devices allow access into the complex and convoluted regions of the gut below the stomach. We report early results from FBG catheters used during trials of novel therapies in patients with both slow transit constipation and faecal incontinence. In addition, there have been relatively few reports on the measurement or inference of longitudinal contractions in humans. This is due to the lack of a viable recording technique suitable for real-time in-vivo measurement of this type of activity over extended lengths of the gut. We report preliminary data on the detection of longitudinal motion in lengths of excised mammalian colon using an FBG technique that should be viable for similar detection in humans. The longitudinal sensors have been combined with pressure sensing elements to form a composite catheter that allows the relative phase between the two components to be detected. The output of both types of catheter has been validated using digital video mapping in an ex-vivo animal preparation using lengths of rabbit ileum

Towards an understanding of the Of?p star HD 191612: optical spectroscopy

We present extensive optical spectroscopy of the early-type magnetic star HD 191612 (O6.5f?pe-O8fp). The Balmer and HeI lines show strongly variable emission which is highly reproducible on a well-determined 538-d period. Metal lines and HeII absorptions (including many selective emission lines but excluding He II 4686A emission) are essentially constant in line strength, but are variable in velocity, establishing a double-lined binary orbit with P(orb) = 1542d, e=0.45. We conduct a model-atmosphere analysis of the primary, and find that the system is consistent with a O8: giant with a B1: main-sequence secondary. Since the periodic 538-d changes are unrelated to orbital motion, rotational modulation of a magnetically constrained plasma is strongly favoured as the most likely underlying `clock'. An upper limit on the equatorial rotation is consistent with this hypothesis, but is too weak to provide a strong constraint.Comment: Accepted for MNRA

Instrumental performance and results from testing of the BLAST-TNG receiver, submillimeter optics, and MKID arrays

Polarized thermal emission from interstellar dust grains can be used to map magnetic fields in star forming molecular clouds and the diffuse interstellar medium (ISM). The Balloon-borne Large Aperture Submillimeter Telescope for Polarimetry (BLASTPol) flew from Antarctica in 2010 and 2012 and produced degree-scale polarization maps of several nearby molecular clouds with arcminute resolution. The success of BLASTPol has motivated a next-generation instrument, BLAST-TNG, which will use more than 3000 linear polarization sensitive microwave kinetic inductance detectors (MKIDs) combined with a 2.5m diameter carbon fiber primary mirror to make diffraction-limited observations at 250, 350, and 500 $\mu$m. With 16 times the mapping speed of BLASTPol, sub-arcminute resolution, and a longer flight time, BLAST-TNG will be able to examine nearby molecular clouds and the diffuse galactic dust polarization spectrum in unprecedented detail. The 250 $\mu$m detector array has been integrated into the new cryogenic receiver, and is undergoing testing to establish the optical and polarization characteristics of the instrument. BLAST-TNG will demonstrate the effectiveness of kilo-pixel MKID arrays for applications in submillimeter astronomy. BLAST-TNG is scheduled to fly from Antarctica in December 2017 for 28 days and will be the first balloon-borne telescope to offer a quarter of the flight for "shared risk" observing by the community.Comment: Presented at SPIE Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VIII, June 29th, 201

Interaction of Pattern Recognition Receptors with Mycobacterium Tuberculosis.

Tuberculosis (TB) is considered a major worldwide health problem with 10 million new cases diagnosed each year. Our understanding of TB immunology has become greater and more refined since the identification of Mycobacterium tuberculosis (MTB) as an etiologic agent and the recognition of new signaling pathways modulating infection. Understanding the mechanisms through which the cells of the immune system recognize MTB can be an important step in designing novel therapeutic approaches, as well as improving the limited success of current vaccination strategies. A great challenge in chronic disease is to understand the complexities, mechanisms, and consequences of host interactions with pathogens. Innate immune responses along with the involvement of distinct inflammatory mediators and cells play an important role in the host defense against the MTB. Several classes of pattern recognition receptors (PRRs) are involved in the recognition of MTB including Toll-Like Receptors (TLRs), C-type lectin receptors (CLRs) and Nod-like receptors (NLRs) linked to inflammasome activation. Among the TLR family, TLR1, TLR2, TLR4, and TLR9 and their down-stream signaling proteins play critical roles in the initiation of the immune response in the pathogenesis of TB. The inflammasome pathway is associated with the coordinated release of cytokines such as IL-1β and IL-18 which also play a role in the pathogenesis of TB. Understanding the cross-talk between these signaling pathways will impact on the design of novel therapeutic strategies and in the development of vaccines and immunotherapy regimes. Abnormalities in PRR signaling pathways regulated by TB will affect disease pathogenesis and need to be elucidated. In this review we provide an update on PRR signaling during M. tuberculosis infection and indicate how greater knowledge of these pathways may lead to new therapeutic opportunities

Structural solutions to produce long timber Veneer Based Composite hollow sections

Veneer Based Composite (VBC) hollow sections are currently being developed in Australia as alternative products to sawn timber. However, due to the limited log length that peeling lathes can accommodate, solutions to manufacture long sections need to be investigated to create useable beams and columns. This paper experimentally assesses the bending capacity of three different concepts. Two concepts consist of manufacturing short sub-sections and connecting them together with (i) a sleeve inserted into the hollow-form and (ii) wrapping Fibre Reinforced Polymer (FRP) around the sub-sections at the connection. The third concept consists of manufacturing the sections in a continuous process, similar to LVL products. Three sets of four nominally identical circular hollow sections (1.2 m long, nominal 76.1 mm internal diameter and 15 mm wall thickness) were manufactured from Hoop pine (Araucaria cunninghamii) veneers. In each set, one section was used as the reference capacity, two sections were cut in half with the two halves being connected back together with either an aluminium sleeve or Glass Fibre Reinforced Polymer (GFRP). The last section had the veneers staggered and end joined, to mimic a continuous manufacturing process. Once cured the sections were then tested in four points bending. The sleeved sections were found to have the lowest bending capacity, while the GFRP and continuous sections reached more than 80% of the capacity of the reference sections. The latter two designs, therefore offer a potential solution for creating useable lengths of VBC hollow sections. Further research is required to refine and validate the design

The retinoic acid binding protein CRABP2 is increased in murine models of degenerative joint disease

Introduction: Osteoarthritis (OA) is a debilitating disease with poorly defined aetiology. Multiple signals are involved in directing the formation of cartilage during development and the vitamin A derivatives, the retinoids, figure prominently in embryonic cartilage formation. In the present study, we examined the expression of a retinoid-regulated gene in murine models of OA. Methods: Mild and moderate forms of an OA-like degenerative disease were created in the mouse stifle joint by meniscotibial transection (MTX) and partial meniscectomy (PMX), respectively. Joint histopathology was scored using an Osteoarthritis Research Society International (OARSI) system and gene expression (Col1a1, Col10a1, Sox9 and Crabp2) in individual joints was determined using TaqMan quantitative PCR on RNA from microdissected articular knee cartilage. Results: For MTX, there was a significant increase in the joint score at 10 weeks (n = 4, p < 0.001) in comparison to sham surgeries. PMX surgery was slightly more severe and produced significant changes in joint score at six (n = 4, p < 0.01), eight (n = 4, p < 0.001) and 10 (n = 4, p < 0.001) weeks. The expression of Col1a1 was increased in both surgical models at two, four and six weeks post-surgery. In contrast, Col10a1 and Sox9 for the most part showed no significant difference in expression from two to six weeks post-surgery. Crabp2 expression is induced upon activation of the retinoid signalling pathway. At two weeks after surgery in the MTX and PMX animals, Crabp2 expression was increased about 18-fold and about 10-fold over the sham control, respectively. By 10 weeks, Crabp2 expression was increased about three-fold (n = 7, not significant) in the MTX animals and about five-fold (n = 7, p < 0.05) in the PMX animals in comparison to the contralateral control joint. Conclusions: Together, these findings suggest that the retinoid signalling pathway is activated early in the osteoarthritic process and is sustained during the course of the disease.Cellular and Physiological Sciences, Department ofMedicine, Faculty ofNon UBCReviewedFacult

Structural behaviour of hardwood veneer-based circular hollow sections of different compactness

This paper presents the capacity and structural behaviour of hardwood veneer-based circular hollow sections (CHS) tested in bending, shear and compression. The sections were manufactured from early to mid-rotation (juvenile) Gympie messmate (Eucalyptus cloeziana) plantation thinned logs. In total twenty-one 167 mm Outside Diameter (OD) × 1.2 m long CHS were manufactured in seven sets of three nominally identical sections. Two different wall thicknesses were investigated to produce nine compact and twelve more slender cross-sections. The sections were also manufactured in three different structural grades. A sudden failure mode was observed in the compression zone of the slender sections tested in bending. In compression, the compact sections showed a ductile behaviour, while the slender sections showed a more brittle behaviour, with the sections bursting into longitudinal strips. While a relationship was observed between the bending and compressive capacities, and the structural grade, no such relationship was noticed for the shear capacity. Comparison to steel and concrete sections of similar outside diameter proved that the timber sections are the most efficient in terms of bending and compressive capacity to linear weight ratio. The timber sections fall behind their steel and concrete counterparts in terms of shear efficiency, however they still have enough shear capacity for representative structural applications

Veneer based composite hollow utility poles manufactured from hardwood plantation thinned trees

Australia’s utility pole network is aging and approaching its end of life. It is estimated that 70% of the 5 million poles currently in-service nationally were installed within the 20 years following the end of World War II and require replacement or remedial maintenance. Additionally, an estimated 21,700 high-durability new poles are required each year to support the expansion of the energy network. Utility poles were traditionally cut from native forest hardwood species. However, due to agreements which progressively phase out logging of native forests around Australia, finding new sources for utility poles presents a challenge. This paper presents the development of veneer based composite hardwood hollow utility poles manufactured from mid-rotation Gympie messmate (Eucalyptus cloeziana) plantation thinned trees (also referred to as “thinning”), as an alternative to solid hardwood poles. The incentives behind the project and benefits of the proposed products are introduced in the paper. Small diameter poles, of nominal 115 mm internal diameter and 15 mm wall-thickness, were manufactured in two half-poles butt jointed together, using 9 hardwood veneers per half-pole. The poles were tested in bending and shear, and experimental test results are presented. The mechanical performance of the hollow poles is discussed and compared to hardwood poles sourced from mature trees and of similar size. Additionally, the required dimensions of the proposed hollow pole to replace actual solid poles are estimated. Results show that the proposed product represents a viable technical solution to the current shortage of utility poles. Future research and different options for improving the current concept are proposed in order to provide a more reliable and cost effective product for structural and architectural applications in general