The Development of an Interactive Videodisc System

The thesis traces the development of interactive videodisc from origins based on early automatic machines through large-scale computer assisted learning (CAL) to microcomputer-based multi-media CAL. A comprehensive discussion of the interactive videodisc medium is provided, in terms of its features, advantages, problems, authoring and production processes, and educational applications. The requirements for interactive systems, and essential elements of video and videodisc technology are described. A relatively low-cost demonstration interactive videodisc system is developed in three phases, based on a BBC 'B' microcomputer and a Pioneer LD1100 videodisc player. In the first phase, software interfacing routines are developed in assembly language to control the player from the versatile interface adaptor (VIA) of the BBC micro. The signal control codes are based on a pulse code modulated format with uni-directional synchronous transmission. The interfacing routines are linked to, and driven by, a Basic program which provides full manual control of all player functions using the microcomputer keyboard. In the second phase, the interfacing routines are further extended to provide control linkage for interactive video application programs. Using a pilot videodisc, these Basic programs demonstrate interactive video techniques, including still frame access and the presentation of video sequences and sub-sequences. In the third phase, the application programs are converted to the authoring language, Microtext. The assembly language interfacing routines are developed into a corresponding Microtext extension command module. A mixer/genlock unit is used to provide graphics overlay of video still frames. An evaluation of the demonstration system is provided, in terms of developmental difficulties, its hardware and software features and capabilities, and its potential as a base for further suggested research work

CNC Application and Design

Machining is an important manufacturing process that is used in wide range of applications. We acquired primary machine shop skills that provide us an opportunity to mill and drill a class of components to specified dimensions and tolerances. For each component, we created a detailed engineering working drawing that helps to shape and construct all the operations and procedures that must be undertaken, and controlled, to attain component machining without any breakdown or failure. Through hands-on machining, we discovered many different factors involved in milling, drilling, and the effects they exhibit on the tolerance and surface finish of a part

Towards an Environment Supporting Resilience, High-Availability, Reproducibility and Reliability for Clud Applications

Cloud Challenge at Utility and Cloud Computing 2015 (UCC 2015), Proceedings of the UCC 2015, Limassol, Cyprus

Novel Glycomimetics Protect Against Glycated Low-Density Lipoprotein-Induced Vascular Calcification In Vitro by Attenuation of the RAGE/ERK/CREB Pathway

Heparan sulphate (HS) can act as a co-receptor on the cell surface and alterations in this process underpin many pathological conditions. We have previously described the usefulness of mimics of HS (glycomimetics) in protection against β-glycerophosphate-induced vascular calcification and in the restoration of the functional capacity of diabetic endothelial colony-forming cells in vitro. This study aims to investigate whether our novel glycomimetic compounds can attenuate glycated low-density lipoprotein (g-LDL)-induced calcification by inhibiting RAGE signalling within the context of critical limb ischemia (CLI). We used an established osteogenic in vitro vascular smooth muscle cell (VSMC) model. Osteoprotegerin (OPG), sclerostin and glycation levels were all significantly increased in CLI serum compared to healthy controls, while the vascular calcification marker osteocalcin (OCN) was down-regulated in CLI patients vs. controls. Incubation with both CLI serum and g-LDL (10 µg/mL) significantly increased VSMC calcification vs. controls after 21 days, with CLI serum-induced calcification apparent after only 10 days. Glycomimetics (C2 and C3) significantly inhibited g-LDL and CLI serum-induced mineralisation, as shown by a reduction in alizarin red (AR) staining and alkaline phosphatase (ALP) activity. Furthermore, secretion of the osteogenic marker OCN was significantly reduced in VSMCs incubated with CLI serum in the presence of glycomimetics. Phosphorylation of cyclic AMP response element-binding protein (CREB) was significantly increased in g-LDL-treated cells vs. untreated controls, which was attenuated with glycomimetics. Blocking CREB activation with a pharmacological inhibitor 666-15 replicated the protective effects of glycomimetics, evidenced by elevated AR staining. In silico molecular docking simulations revealed the binding affinity of the glycomimetics C2 and C3 with the V domain of RAGE. In conclusion, these findings demonstrate that novel glycomimetics, C2 and C3 have potent anti-calcification properties in vitro, inhibiting both g-LDL and CLI serum-induced VSMC mineralisation via the inhibition of LDLR, RAGE, CREB and subsequent expression of the downstream osteogenic markers, ALP and OCN

Ringed, Bearded, and Ribbon Seal Vocalizations North of Barrow, Alaska: Seasonal Presence and Relationship with Sea Ice

The acoustic repertoires of ringed, bearded, and ribbon seals are described, along with their seasonal occurrence and relationship to sea ice concentration. Acoustic recordings were made between September and June over three years (2006 – 09) along the continental slope break in the Chukchi Sea, 120 km north-northwest of Barrow, Alaska. Vocalizations of ringed and bearded seals occurred in winter and during periods of 80% – 100% ice cover but were mostly absent during open water periods. The presence of ringed and bearded seal calls throughout winter and spring suggests that some portion of their population is overwintering. Analysis of the repertoire of ringed and bearded seal calls shows seasonal variation. Ringed seal calls are primarily barks in winter and yelps in spring, while bearded seal moans increase during spring. Ribbon seal calls were detected only in the fall of 2008 during the open water period. The repertoire of known ribbon seal vocalizations was expanded to include three additional calls, and two stereotyped call sequences were common. Retrospective analyses of ringed seal recordings from 1982 and ribbon seal recordings from 1967 showed a high degree of stability in call repertoire across large spatial and temporal scales.Le répertoire acoustique des phoques annelés, des phoques barbus et des phoques à bandes sont décrits, de même que leur présence saisonnière et leur rapport avec la concentration de glace de mer. Des enregistrements acoustiques ont été effectués entre septembre et juin sur une période de trois ans (2006 – 2009), le long de la rupture de la pente continentale, dans la mer des Tchouktches, à 120 km au nord-nord-ouest de Barrow, en Alaska. Les vocalisations de phoques annelés et de phoques barbus étaient présentes pendant l’hiver et pendant les périodes où la concentration de glace était de 80 % à 100 %, mais elles se faisaient rares pendant les périodes d’eau libre. La présence des cris de phoques annelés et de phoques barbus tout au long de l’hiver et du printemps suggère qu’une partie de leur population hiverne. L’analyse du répertoire de cris de phoques annelés et de phoques barbus indique une variation saisonnière. L’hiver, le cri du phoque annelé prend principalement la forme d’aboiements, tandis que le printemps, il prend la forme de glapissements. Les gémissements du phoque barbu s’intensifient au printemps. Le cri des phoques à bandes n’a été capté qu’à l’automne 2008, pendant la période des eaux libres. Le répertoire des vocalisations connues du phoque à bandes a été élargi pour inclure trois autres cris, bien que deux séquences de cris stéréotypées étaient courantes. L’analyse rétrospective des enregistrements de cris de phoques annelés de 1982 et de phoques à bandes de 1967 a laissé entrevoir une grande stabilité du point de vue du répertoire des cris, et ce, sur de vastes échelles spatiales et temporelles

Near-infrared (NIR) perfusion angiography in minimally invasive colorectal surgery

Background: Anastomotic leakage is a devastating complication of colorectal surgery. However, there is no technology indicative of in situ perfusion of a laparoscopic colorectal anastomosis. Methods: We detail the use of near-infrared (NIR) laparoscopy (PinPoint System, NOVADAQ, Canada) in association with fluorophore [indocyanine green (ICG), 2.5mg/ml] injection in 30 consecutive patients who underwent elective minimally invasive colorectal resection using the simultaneous appearance of the cecum or distal ileum as positive control. Results: The median (range) age of the patients was 64 (40-81) years with a median (range) BMI of 26.7 (20-35.5)kg/m2. Twenty-four patients had left-sided resections (including six low anterior resections) and six had right-sided resections. Of the total, 25 operations were cancer resections and five were for benign disease [either diverticular strictures (n=3) or Crohn's disease (n=2)]. A high-quality intraoperative ICG angiogram was achieved in 29/30 patients. After ICG injection, median (range) time to perfusion fluorescence was 35 (15-45)s. Median (range) added time for the technique was 5 (3-9)min. Anastomotic perfusion was documented as satisfactory in every successful case and encouraged avoidance of defunctioning stomas in three patients with low anastomoses. There were no postoperative anastomotic leaks. Conclusion: Perfusion angiography of colorectal anastomosis at the time of their laparoscopic construction is feasible and readily achievable with minimal added intraoperative time. Further work is required to determine optimum sensitivity and threshold levels for assessment of perfusion sufficiency, in particular with regard to anastomotic viability

The 2dF galaxy redshift survey: clustering properties of radio galaxies

The clustering properties of local, S1.4 GHz≥ 1 mJy, radio sources are investigated for a sample of 820 objects drawn from the joint use of the Faint Images of the Radio Sky at 20 cm (FIRST) and 2dF Galaxy Redshift surveys. To this aim, we present 271 new bJ≤ 19.45 spectroscopic counterparts of FIRST radio sources to be added to those already introduced in our previous paper. The two-point correlation function for the local radio population is found to be entirely consistent with estimates obtained for the whole sample of 2dFGRS galaxies. From measurements of the redshift-space correlation function ξ(s) we derive a redshift-space clustering length s0 = 10.7+0.8 −0.7 Mpc, while from the projected correlation function Ξ(rT) we estimate the parameters of the real-space correlation function ξ(r) = (r/r0) −γ, r0 = 6.7+0.9 −1.1 Mpc and γ= 1.6 ± 0.1, where h = 0.7 is assumed. Different results are instead obtained if we only consider sources that present signatures of active galactic nucleus (AGN) activity in their spectra. These objects are shown to be very strongly correlated, with r0 = 10.9+1.0 −1.2 Mpc and γ= 2 ± 0.1, a steeper slope than has been claimed in other recent works. No difference is found in the clustering properties of radio-AGNs of different radio luminosity. Comparisons with models for ξ(r) show that AGN-fuelled sources reside in dark matter haloes more massive than ∼1013.4 M⊙, higher than the corresponding figure for radio-quiet quasi-stellar objects. This value can be converted into a minimum black hole mass associated with radio-loud, AGN-fuelled objects of MminBH∼ 109 M⊙. The above results then suggest - at least for relatively faint radio objects - the existence of a threshold black hole mass associated with the onset of significant radio activity such as that of radio-loud AGNs; however, once the activity is triggered, there appears to be no evidence for a connection between black hole mass and level of radio outpu