Availability, outage, and capacity of spatially correlated, Australasian free-space optical networks

Network capacity and reliability for free space optical communication (FSOC) is strongly driven by ground station availability, dominated by local cloud cover causing an outage, and how availability relations between stations produce network diversity. We combine remote sensing data and novel methods to provide a generalised framework for assessing and optimising optical ground station networks. This work is guided by an example network of eight Australian and New Zealand optical communication ground stations which would span approximately $60^\circ$ in longitude and $20^\circ$ in latitude. Utilising time-dependent cloud cover data from five satellites, we present a detailed analysis determining the availability and diversity of the network, finding the Australasian region is well-suited for an optical network with a 69% average site availability and low spatial cloud cover correlations. Employing methods from computational neuroscience, we provide a Monte Carlo method for sampling the joint probability distribution of site availabilities for an arbitrarily sized and point-wise correlated network of ground stations. Furthermore, we develop a general heuristic for site selection under availability and correlation optimisations, and combine this with orbital propagation simulations to compare the data capacity between optimised networks and the example network. We show that the example network may be capable of providing tens of terabits per day to a LEO satellite, and up to 99.97% reliability to GEO satellites. We therefore use the Australasian region to demonstrate novel, generalised tools for assessing and optimising FSOC ground station networks, and additionally, the suitability of the region for hosting such a network.Comment: Accepted in Journal of Optical Communications and Networking. 16 pages, 16 figure

OGA heterozygosity suppresses intestinal tumorigenesis in Apc min/+ mice

Emerging evidence suggests that aberrant O-GlcNAcylation is associated with tumorigenesis. Many oncogenic factors are O-GlcNAcylated, which modulates their functions. However, it remains unclear how O-GlcNAcylation and O-GlcNAc cycling enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), affect the development of cancer in animal models. In this study, we show that reduced level of OGA attenuates colorectal tumorigenesis induced by Adenomatous polyposis coli (Apc) mutation. The levels of O-GlcNAcylation and O-GlcNAc cycling enzymes were simultaneously upregulated in intestinal adenomas from mice, and in human patients. In two independent microarray data sets, the expression of OGA and OGT was significantly associated with poor cancer-specific survival of colorectal cancer (CRC) patients. In addition, OGA heterozygosity, which results in increased levels of O-GlcNAcylation, attenuated intestinal tumor formation in the Apc min/+ background. Apc min/+ OGA +/-mice exhibited a significantly increased survival rate compared with Apc min/+ mice. Consistent with this, Apc min/+ OGA +/-mice expressed lower levels of Wnt target genes than Apc min/+. However, the knockout of OGA did not affect Wnt/??-catenin signaling. Overall, these findings suggest that OGA is crucial for tumor growth in CRC independently of Wnt/??-catenin signaling.open2

INVESTIGATION OF STOCHASTIC PAIRS TRADING STRATEGIES UNDER DIFFERENT VOLATILITY REGIMES

We investigate several market-neutral trading strategies and find empirical evidence that market-neutral equity trading outperforms in 2008, the first full year of the global financial meltdown. In our experiments we use 14 distinct market-neutral trading strategies, using the combination of seven trading methods and two selection methods of pairs trading. Copyright � 2010 The Authors. Journal compilation � 2010 Blackwell Publishing Ltd and The University of Manchester.

COVID-19 Pneumonia and ROX index: Time to set a new threshold for patients admitted outside the ICU

High flow nasal cannula (HFNC) is used to treat acute hypoxemic respiratory failure (AHRF) even outside the ICU and the ROX index (pulse oximetry/fraction of inspired oxygen/respiratory rate) may predict HFNC failure. Objective: The purpose of this investigation was therefore to verify whether the ROX index is an accurate predictor of HFNC failure for COVID-19 patients treated outside the intensive care unit (ICU) and to evaluate the validity of the previously suggested threshold. Design: Multicenter study. Retrospective observational analysis of prospectively collected data. Setting: 3 centres specialized in non-invasive respiratory support (Buenos Aires, Argentina; Bolzano and Treviso, Italy). Patients treated outside the ICU were analysed Measurements: The variables to calculate the ROX index were collected during the first day of therapy at 2, 6, 12 and 24 hours and then recorded every 24 hours. HFNC failure was defined as escalation of respiratory support to invasive mechanical ventilation (IMV) or death. Main results: A total of 35 (29%) patients failed HFNC and required intubation. ROC analysis identified the 12-hour ROX index as the best predictor of intubation with an AUC of 0.7916[CI 95% 0.6905-0.8927] and the best threshold to be 5.99[Specificity 96% Sensitivity 62%]. In the survival analysis, a ROX value <5.99 was associated with an increased risk of failure (p = 0008 log – rank test). The threshold of 4,9 identified by Roca as the best predictor in non-COVID patients, was not able to discriminate between success and failure (p = 0.4 log-rank test) in our patients. Conclusions: ROX index may be useful in guiding the clinicians in their decision to intubate patients, especially in patients with moderate ARF, treated therefore outside the ICU. Indeed, it also demonstrates a different threshold value than reported for non-COVID patients, possibly related to the different mechanisms of hypoxia

Automated meat slicer

Inter-Coastal International Technologies Corporation provides specialized machineries for the industry. ICITC in cooperation with Manufacturing Engineering and Management Department, College of Engineering, De La Salle University Manila, joint their efforts in answering an industry need. The industry uses large automated meat slicers known as herpo motors. The problem about these machines is that it leaves several inches of meat that it can no longer cut. This restriction is caused by the clamping device which defers the machine to cut this small region. When all these uncut meat are summed up, it makes up a significant amount of raw materials. These meats are cut manually. This practice forces laborers to use special techniques in order to come up with uniform cuts. The group automated this process with the use of pneumatic cylinders, stepper motors and a mycom controller. The pneumatic cylinders contribute to the machine\u27s speed while the stepper motors ensure the machines accuracy. These facilitate the slicing process of the group\u27s meat slicer. The group designed a clamping device that will keep the meat in place considering the forces that may act upon it. The group implemented an automated meat slicer that can accommodate the meat that is uncut by industry herpo motors. The group\u27s automated meat slicer compliments the herpo motors of the industry since it cuts at a comparable accuracy. The automated meat slicer also eliminated the special techniques implemented by laborers if they were to cut the meat manually. Lastly, the partnership of these two parties resulted in an automated meat slicer that is acceptable under industry standards in terms of the quality of the cut and safety