Machine learning classification of human joint tissue from diffuse reflectance spectroscopy data

Objective: To assess if incorporation of DRS sensing into real-time robotic surgery systems has merit. DRS as a technology is relatively simple, cost-effective and provides a non-contact approach to tissue differentiation. Methods: Supervised machine learning analysis of diffuse reflectance spectra was performed to classify human joint tissue that was collected from surgical procedures. Results: We have used supervised machine learning in the classification of a DRS human joint tissue data set and achieved classification accuracy in excess of 99%. Sensitivity for the various classes were; cartilage 99.7%, subchondral 99.2%, meniscus 100% and cancellous 100%. Full wavelength range is required for maximum classification accuracy. The wavelength resolution must be larger than 8nm. A SNR better than 10:1 was required to achieve a classification accuracy greater than 50%. The 800-900nm wavelength range gave the greatest accuracy amongst those investigated. Conclusion: DRS is a viable method for differentiating human joint tissue and has the potential to be incorporated into robotic orthopaedic surgery

Telemedicine coverage for post-operative ICU patients.

Introduction There is an increased demand for intensive care unit (ICU) beds. We sought to determine if we could create a safe surge capacity model to increase ICU capacity by treating ICU patients in the post-anaesthesia care unit (PACU) utilizing a collaborative model between an ICU service and a telemedicine service during peak ICU bed demand. Methods We evaluated patients managed by the surgical critical care service in the surgical intensive care unit (SICU) compared to patients managed in the virtual intensive care unit (VICU) located within the PACU. A retrospective review of all patients seen by the surgical critical care service from January 1st 2008 to July 31st 2011 was conducted at an urban, academic, tertiary centre and level 1 trauma centre. Results Compared to the SICU group ( n = 6652), patients in the VICU group ( n = 1037) were slightly older (median age 60 (IQR 47-69) versus 58 (IQR 44-70) years, p = 0.002) and had lower acute physiology and chronic health evaluation (APACHE) II scores (median 10 (IQR 7-14) versus 15 (IQR 11-21), p \u3c 0.001). The average amount of time patients spent in the VICU was 13.7 + /-9.6 hours. In the VICU group, 750 (72%) of patients were able to be transferred directly to the floor; 287 (28%) required subsequent admission to the surgical intensive care unit. All patients in the VICU group were alive upon transfer out of the PACU while mortality in the surgical intensive unit cohort was 5.5%. Discussion A collaborative care model between a surgical critical care service and a telemedicine ICU service may safely provide surge capacity during peak periods of ICU bed demand. The specific patient populations for which this approach is most appropriate merits further investigation

Cholecystogastric fistula: a brief report and review of the literature.

Cholecystogastric fistula is a rare, life-threatening complication of cholelithiasis that presents a difficult challenge to the surgeon when it occurs in elderly and co-morbid patients. Following a case of a 68-year-old female who presented with a short history of epigastric pain and vomiting, and in whom a cholecystogastric fistula was identified on abdominal computed tomography and confirmed on upper gastrointestinal endoscopy, we performed a systematic review of the literature on the management of cholecystogastric fistula. Our patient underwent laparotomy without excision of the fistula nor cholecystectomy and had an uncomplicated post-operative course. Surgical management using an open approach remains the mainstay of treatment of cholecystogastric fistula although laparoscopic techniques are used with increasing success. Surgical closure of the fistula is not always necessary. Improved surgical techniques including the use of laparoscopic surgery have led to improved outcomes in the management of cholecystogastric fistula

Edge- and Node-Disjoint Paths in P Systems

In this paper, we continue our development of algorithms used for topological network discovery. We present native P system versions of two fundamental problems in graph theory: finding the maximum number of edge- and node-disjoint paths between a source node and target node. We start from the standard depth-first-search maximum flow algorithms, but our approach is totally distributed, when initially no structural information is available and each P system cell has to even learn its immediate neighbors. For the node-disjoint version, our P system rules are designed to enforce node weight capacities (of one), in addition to edge capacities (of one), which are not readily available in the standard network flow algorithms.Comment: In Proceedings MeCBIC 2010, arXiv:1011.005

The Role of Dwarf Galaxies in Building Large Stellar Halos

The hierarchical theory of galaxy formation rests on the idea that smaller galactic structures merge to form the galaxies that we see today. The past decade has provided remarkable observational support for this scenario, driven in part by advances in spectroscopic instrumentation. Multi-object spectroscopy enabled the discovery of kinematically cold substructures around the Milky Way and M31 that are likely the debris of disrupting satellites. Improvements in high-resolution spectroscopy have produced key evidence that the abundance patterns of the Milky Way halo and its dwarf satellites can be explained by Galactic chemical evolution models based on hierarchical assembly. These breakthroughs have depended almost entirely on observations of nearby stars in the Milky Way and luminous red giant stars in M31 and Local Group dwarf satellites. In the next decade, extremely large telescopes will allow observations far down the luminosity function in the known dwarf galaxies, and they will enable observations of individual stars far out in the Galactic halo. The chemical abundance census now available for the Milky Way will become possible for our nearest neighbor, M31. Velocity dispersion measurements now available in M31 will become possible for systems beyond the Local Group such as Sculptor and M81 Group galaxies. Detailed studies of a greater number of individual stars in a greater number of spiral galaxies and their satellites will test hierarchical assembly in new ways because dynamical and chemical evolution models predict different outcomes for halos of different masses in different environments.Comment: Astro2010 Decadal Survey White Paper, 8 page

Detection of a Hot Gaseous Halo Around the Giant Spiral Galaxy NGC 1961

Hot gaseous halos are predicted around all large galaxies and are critically important for our understanding of galaxy formation, but they have never been detected at distances beyond a few kpc around a spiral galaxy. We used the Chandra ACIS-I instrument to search for diffuse X-ray emission around an ideal candidate galaxy: the isolated giant spiral NGC 1961. We observed four quadrants around the galaxy for 30 ks each, carefully subtracting background and point source emission, and found diffuse emission that appears to extend to 40-50 kpc. We fit $\beta$-models to the emission, and estimate a hot halo mass within 50 kpc of $5\times10^9 M_{\odot}$. When this profile is extrapolated to 500 kpc (the approximate virial radius), the implied hot halo mass is $1-3\times10^{11} M_{\odot}$. These mass estimates assume a gas metallicity of $Z = 0.5 Z_{\odot}$. This galaxy's hot halo is a large reservoir of gas, but falls significantly below observational upper limits set by pervious searches, and suggests that NGC 1961 is missing 75% of its baryons relative to the cosmic mean, which would tentatively place it below an extrapolation of the baryon Tully-Fisher relationship of less massive galaxies. The cooling rate of the gas is no more than 0.4 $M_{\odot}$/year, more than an order of magnitude below the gas consumption rate through star formation. We discuss the implications of this halo for galaxy formation models.Comment: 26 pages, 5 figures, accepted to ApJ. Updated to include journal ref and small changes added in proof

Early warning and response to fires in Kalimantan, Indonesia

Scientists at the International Research Institute for Climate and Society (IRI) collaborated with Bogor Agriculture University Indonesia to investigate links between climate anomalies and fire hotspots in Kalimantan, Indonesia. During their investigation, a close relationship between satellite rainfall data and fire hotspot activity was found. Rainfall anomalies during the dry season from June-October were particularly critical in determining fire activity. Vegetation greenness and moisture indices derived from MODIS images, however, did not appear to demonstrate a relationship. These findings were used to develop a prototype online tool that enables stakeholders to view satellite rainfall anomalies and forecast fire activity in Kalimantan. Potential fire activity can be inferred from these data and steps can be taken early on to prevent or minimize the effects of regional fire occurrences

Open source drug discovery - A limited tutorial

Open science is a new concept for the practice of experimental laboratory-based research, such as drug discovery. The authors have recently gained experience in how to run such projects and here describe some straightforward steps others may wish to take towards more openness in their own research programmes. Existing and inexpensive online tools can solve many challenges, while some psychological barriers to the free sharing of all data and ideas are more substantia

An evaluation of the stimulants and impediments to innovation within PFI/PPP projects

This paper identifies the theoretical stimulants and impediments associated with the implementation of PFI/PPP (Private Finance Initiative/Public Private Partnership) projects. A current defect of this procurement approach is the unintentional constraint upon the innovations incorporated into the development of PFI projects. A critical evaluation of the published literature has been utilized to synthesize a theoretical model. The paper proposes a theoretical model for the identification of potential innovation stimulants and impediments within this type of procurement. This theoretical model is then utilised to evaluate four previously completed PFI projects. These project case-studies have been examined in detail. The evaluation demonstrates how ineffective current procedures are. The application of this model before project letting could eliminate unintentional constraints and stimulate improved innovation within the process. The implementation of the model could improve the successful delivery of innovation within the entire PFI/PPP procurement process