Optimal strategies for a game on amenable semigroups

The semigroup game is a two-person zero-sum game defined on a semigroup S as follows: Players 1 and 2 choose elements x and y in S, respectively, and player 1 receives a payoff f(xy) defined by a function f from S to [-1,1]. If the semigroup is amenable in the sense of Day and von Neumann, one can extend the set of classical strategies, namely countably additive probability measures on S, to include some finitely additive measures in a natural way. This extended game has a value and the players have optimal strategies. This theorem extends previous results for the multiplication game on a compact group or on the positive integers with a specific payoff. We also prove that the procedure of extending the set of allowed strategies preserves classical solutions: if a semigroup game has a classical solution, this solution solves also the extended game.Comment: 17 pages. To appear in International Journal of Game Theor

Practicality in POCUS: Benefits of Ultrasound Training in Medical Education

As point-of-care ultrasound (POCUS) becomes an integral component of healthcare, both undergraduate and graduate medical POCUS education is urgently necessary in curricula. Despite the apparent need of POCUS curricula, there remains a lingering question: Are there evidence-based benefits to POCUS training in undergraduate and/or graduate medical education settings? This systematic review utilized PubMed, Google Scholar, and Scopus to identify articles of interest that met the inclusion criteria and relevance to undergraduate and/or graduate medical education. Qualitative evaluation of research was conducted to identify common themes for benefits of POCUS and the requirements or characteristics for effective POCUS educational curricula. Results for undergraduate medical education were separated into pre-clinical and clinical education. In pre-clinical POCUS education, POCUS education improves anatomy education and physical examination skills for sonographic assessment of abdominal, reproductive, cardiovascular, and renal structures. Further enhancement can be achieved via simulation devices that are generalized ultrasound simulation mannequins, one defined body region such as the abdomen, or local regions of interest such as the femoral triangle. In clinical undergraduate POCUS education, benefits involved greater performance on knowledge tests and general ultrasound competency in emergency medicine, surgical, family medicine, and physical medicine and rehabilitation clerkships. These studies also found improved comprehension of specific POCUS examinations such as those for ultrasound-guided injections, FAST, eFAST, and RUSH. Further integration of POCUS education into graduate medical education was found to successfully improve ultrasound knowledge and competency in both academic and military internal medicine residencies. One limitation of this study is that this article is a review resulting in no specific intervention being introduced. The resultant hypothesis of this systematic review cannot be tested; rather evidence-based recommendations are restricted to the currently available literature within the searched databases. From this review, it was found that the inclusion of a properly integrated POCUS curriculum can result in greater confidence in ultrasound use, increased knowledge of anatomy and basic sciences for various organ systems, improved ultrasound knowledge and performance in clinical clerkships, and offers improved confidence and knowledge in ultrasound during residency

Granular Cell Tumor Occurring in the Chest Wall: A Case Report

Granular cell tumors are uncommon soft tissue neoplasm of nerve sheath origin, which are predominately benign. Granular cells can be found at any site in the body including the tongue, skin, subcutaneous tissue, breast, gastrointestinal, and urogenital systems. However, granular cell tumors have only been rarely described in the chest wall. Here we report a case of a granular cell tumor that occurred in the chest wall of a 59-year-old woman, along with a review of the literature

The right brew? An analysis of the tourism experiences in rural Taiwan's coffee estates

The main goal of this research was to analyze the tourism experiences offered by coffee estates in Taiwan. A mixed-methods approach was applied in two main parts. First, the profiles of Taiwan coffee estates were examined in terms of the experiences provided to engage visitors. In-depth interviews with owners indicated they can be categorized into traditional, educational, and comprehensive coffee estates. Second, using the memorable tourism experiences scale (MTES), the resulting visitor survey findings were overwhelmingly positive. However, four specific recommendations were made for the sustainable development of coffee estate tourism in Taiwan: increasing and improving marketing and branding by government-run destination management organizations; developing an integrated tourism supply system and value chain in areas containing coffee estates; creating new coffee tour products with travel agencies and tour operators; and establishing education as the key selling point of coffee estates. These four initiatives will contribute to solving some of the challenges Taiwanese coffee estates are currently facing, while continuously developing the niche market of coffee estate tourism

Formation and Evolution of the Disk System of the Milky Way: [alpha/Fe] Ratios and Kinematics of the SEGUE G-Dwarf Sample

We employ measurements of the [alpha/Fe] ratio derived from low-resolution (R~2000) spectra of 17,277 G-type dwarfs from the SEGUE survey to separate them into likely thin- and thick-disk subsamples. Both subsamples exhibit strong gradients of orbital rotational velocity with metallicity, of opposite signs, -20 to -30 km/s/dex for the thin-disk and +40 to +50 km/s/dex for the thick-disk population. The rotational velocity is uncorrelated with Galactocentric distance for the thin-disk subsample, and exhibits a small trend for the thick-disk subsample. The rotational velocity decreases with distance from the plane for both disk components, with similar slopes (-9.0 {\pm} 1.0 km/s/kpc). Thick-disk stars exhibit a strong trend of orbital eccentricity with metallicity (about -0.2/dex), while the eccentricity does not change with metallicity for the thin-disk subsample. The eccentricity is almost independent of Galactocentric radius for the thin-disk population, while a marginal gradient of the eccentricity with radius exists for the thick-disk population. Both subsamples possess similar positive gradients of eccentricity with distance from the Galactic plane. The shapes of the eccentricity distributions for the thin- and thick-disk populations are independent of distance from the plane, and include no significant numbers of stars with eccentricity above 0.6. Among several contemporary models of disk evolution we consider, radial migration appears to have played an important role in the evolution of the thin-disk population, but possibly less so for the thick disk, relative to the gas-rich merger or disk heating scenarios. We emphasize that more physically realistic models and simulations need to be constructed in order to carry out the detailed quantitative comparisons that our new data enable.Comment: Accepted for publication in ApJ, 18 pages, 12 figures, 2 tables, emulateapj forma

The SEGUE Stellar Parameter Pipeline. IV. Validation with an Extended Sample of Galactic Globular and Open Clusters

Spectroscopic and photometric data for likely member stars of five Galactic globular clusters (M3, M53, M71, M92, and NGC 5053) and three open clusters (M35, NGC 2158, and NGC 6791) are processed by the current version of the SEGUE Stellar Parameter Pipeline (SSPP), in order to determine estimates of metallicities and radial velocities for the clusters. These results are then compared to values from the literature. We find that the mean metallicity () and mean radial velocity () estimates for each cluster are almost all within 2{\sigma} of the adopted literature values; most are within 1{\sigma}. We also demonstrate that the new version of the SSPP achieves small, but noteworthy, improvements in estimates at the extrema of the cluster metallicity range, as compared to a previous version of the pipeline software. These results provide additional confidence in the application of the SSPP for studies of the abundances and kinematics of stellar populations in the Galaxy.Comment: 98 pages, 31 figures; accepted for publication in A

F-theory on Genus-One Fibrations

We argue that M-theory compactified on an arbitrary genus-one fibration, that is, an elliptic fibration which need not have a section, always has an F-theory limit when the area of the genus-one fiber approaches zero. Such genus-one fibrations can be easily constructed as toric hypersurfaces, and various $SU(5)\times U(1)^n$ and $E_6$ models are presented as examples. To each genus-one fibration one can associate a $\tau$-function on the base as well as an $SL(2,\mathbb{Z})$ representation which together define the IIB axio-dilaton and 7-brane content of the theory. The set of genus-one fibrations with the same $\tau$-function and $SL(2,\mathbb{Z})$ representation, known as the Tate-Shafarevich group, supplies an important degree of freedom in the corresponding F-theory model which has not been studied carefully until now. Six-dimensional anomaly cancellation as well as Witten's zero-mode count on wrapped branes both imply corrections to the usual F-theory dictionary for some of these models. In particular, neutral hypermultiplets which are localized at codimension-two fibers can arise. (All previous known examples of localized hypermultiplets were charged under the gauge group of the theory.) Finally, in the absence of a section some novel monodromies of Kodaira fibers are allowed which lead to new breaking patterns of non-Abelian gauge groups.Comment: 53 pages, 9 figures, 6 tables. v2: references adde

Quantitative image analysis of immunohistochemical stains using a CMYK color model

BACKGROUND: Computer image analysis techniques have decreased effects of observer biases, and increased the sensitivity and the throughput of immunohistochemistry (IHC) as a tissue-based procedure for the evaluation of diseases. METHODS: We adapted a Cyan/Magenta/Yellow/Key (CMYK) model for automated computer image analysis to quantify IHC stains in hematoxylin counterstained histological sections. RESULTS: The spectral characteristics of the chromogens AEC, DAB and NovaRed as well as the counterstain hematoxylin were first determined using CMYK, Red/Green/Blue (RGB), normalized RGB and Hue/Saturation/Lightness (HSL) color models. The contrast of chromogen intensities on a 0–255 scale (24-bit image file) as well as compared to the hematoxylin counterstain was greatest using the Yellow channel of a CMYK color model, suggesting an improved sensitivity for IHC evaluation compared to other color models. An increase in activated STAT3 levels due to growth factor stimulation, quantified using the Yellow channel image analysis was associated with an increase detected by Western blotting. Two clinical image data sets were used to compare the Yellow channel automated method with observer-dependent methods. First, a quantification of DAB-labeled carbonic anhydrase IX hypoxia marker in 414 sections obtained from 138 biopsies of cervical carcinoma showed strong association between Yellow channel and positive color selection results. Second, a linear relationship was also demonstrated between Yellow intensity and visual scoring for NovaRed-labeled epidermal growth factor receptor in 256 non-small cell lung cancer biopsies. CONCLUSION: The Yellow channel image analysis method based on a CMYK color model is independent of observer biases for threshold and positive color selection, applicable to different chromogens, tolerant of hematoxylin, sensitive to small changes in IHC intensity and is applicable to simple automation procedures. These characteristics are advantageous for both basic as well as clinical research in an unbiased, reproducible and high throughput evaluation of IHC intensity

Quantifying respirable crystalline silica in the ambient air of the Hunter Valley, NSW - sorting the silica from the silicon

Crystalline forms of silica are known to cause lung damage for which there is no effective treatment. Silicon is abundant in crustal material and silicates are the single largest mineral grouping, with silica (SiO2) being the most abundant crustal compound. Media reports of high levels of silicon in particles in the air in the vicinity of Hunter Valley open-cut coal mines have caused community anxiety and concerns about potential health impacts on local populations. An extensive sampling campaign using continuous air quality monitoring and targeted collection of particles has been carried out in an area close to mining operations. It was determined that silicon as silica was present in the ambient air, although the concentrations of crystalline silica measured suggest that it should not should cause health problems even for sensitive individuals within the general population. The results of the research should inform more rigorous discussions of air quality management plans for fine particles in the Hunter Valley and aid discussions of community concerns over the potential health impacts of coal mining.© 2011-Clean Air Society of Australia & New Zealan