Topological representations of matroid maps

The Topological Representation Theorem for (oriented) matroids states that every (oriented) matroid can be realized as the intersection lattice of an arrangement of codimension one homotopy spheres on a homotopy sphere. In this paper, we use a construction of Engstr\"om to show that structure-preserving maps between matroids induce topological mappings between their representations; a result previously known only in the oriented case. Specifically, we show that weak maps induce continuous maps and that the process is a functor from the category of matroids with weak maps to the homotopy category of topological spaces. We also give a new and conceptual proof of a result regarding the Whitney numbers of the first kind of a matroid.Comment: Final version, 21 pages, 8 figures; Journal of Algebraic Combinatorics, 201

Automatic wheeze detection based on auditory modelling

Automatic wheeze detection has several potential benefits compared with reliance on human auscultation: it is experience independent, an automated historical record can easily be kept, and it allows quantification of wheeze severity. Previous attempts to detect wheezes automatically have had partial success but have not been reliable enough to become widely accepted as a useful tool. In this paper an improved algorithm for automatic wheeze detection based on auditory modelling is developed, called the frequency- and duration-dependent threshold algorithm. The mean frequency and duration of each wheeze component are obtained automatically. The detected wheezes are marked on a spectrogram. In the new algorithm, the concept of a frequency- and duration-dependent threshold for wheeze detection is introduced. Another departure from previous work is that the threshold is based not on global power but on power corresponding to a particular frequency range. The algorithm has been tested on 36 subjects, 11 of whom exhibited characteristics of wheeze. The results show a marked improvement in the accuracy of wheeze detection when compared with previous algorithms

Active Thermal Architecture: Design and Status

This paper presents a design update for the Active Thermal Architecture (ATA) project. ATA is a joint effort between Utah State University and the Jet Propulsion Laboratory, funded by the NASA Small Spacecraft Technology Program (SSTP). The objective of the ATA is to develop advanced active thermal control technologies for Small Satellites in support of cryogenic electro-optical instrumentation. Specifically, the development of a 1U ground-based prototype of a single-phase, two-stage mechanically pumped fluid loop based active thermal control subsystem targeted at 6U CubeSat platforms and above. The first stage utilizes a micro-pump to circulate working fluid between an integrated heat exchanger and a deployed tracking radiator. This heat exchange provides general thermal management to the ATA system and CubeSat. The second stage consists of a miniature cryocooler, which directly provides cryogenic cooling to payload instrumentation. Ultrasonic Additive Manufacturing techniques simplify and miniaturize the ATA system by embedding the flow channels directly into the heat exchanger and the external radiator. The ATA system features dual rotary union fluid joints that, along with a micro-motor, allow for a two-axis deployment of the radiator and solar tracking. The ATA also includes a passive vibration control system which, isolates the optical payload from the jitter induced by the active systems. ATA has been fully prototyped and tested for radiator deployment and tracking. ATA is a second phase effort with the integrated pumped fluid loop and radiator previously demonstrated by the Active CryoCubeSat SSTP. This technology is suited for the thermal control of any high-powered spacecraft subsystem or the general thermal maintenance of a CubeSat’s environment. This project hopes to maturate all relevant technologies to a TRL of 5 or

Land Cover Data for the Mississippi-Alabama Barrier Islands, 2010-2011

Land cover on the Mississippi–Alabama barrier islands was surveyed in 2010–2011 as part of continuing research on island geomorphic and vegetation dynamics following the 2005 impact of Hurricane Katrina. Results of the survey include sub-meter GPS location, a listing of dominant vegetation species and field photographs recorded at 375 sampling locations distributed among Cat, West Ship, East Ship, Horn, Sand, Petit Bois and Dauphin Islands. The survey was conducted in a period of intensive remote sensing data acquisition over the northern Gulf of Mexico by federal, state and commercial organizations in response to the 2010 Macondo Well (Deepwater Horizon) oil spill. The data are useful in providing ground reference information for thematic classification of remotely-sensed imagery, and a record of land cover which may be used in future research

High Failure Rates of Concomitant Periprosthetic Joint Infection and Extensor Mechanism Disruption

Background Patients presenting with both chronic periprosthetic joint infection (PJI) and extensor mechanism disruption (EMD) pose a significant challenge. As there is little in the literature regarding outcomes of patients with concomitant PJI and EMD, we performed a multicenter study to evaluate the outcomes. Methods Sixty patients with concomitant diagnoses of PJI and EMD were evaluated from 5 institutions. Patient demographics, presentation type, surgical management, and outcomes including recurrent infections, final surgery, and ambulatory status were documented. Results Fifty-three of 60 patients had an attempted extensor mechanism reconstruction/repair (EMR) of which 12 (23%) were successful, averaging 3.5 (range, 2-7) intervening surgeries. Forty-one patients (77%) were considered failures with recurrence of infection as most common failure (80%); 26 ended in fusion, 10 in above knee amputation, 3 with chronic resection arthroplasty, and 2 with chronic spacers/EMD. Seven patients had no attempt at EMR but proceeded directly to fusion (n = 6) or amputation (n = 1). There was no statistical difference between groups that had success or failure of EMR in age, American Society of Anesthesiologists Physical Status Classification System, or body mass index. Conclusion Our study demonstrates that concomitant EMD and PJI is a dreaded combination with poor outcomes regardless of treatment. Eradication of infection and reconstruction of the extensor mechanism often require numerous surgeries and despite great effort often end in failure. Consideration of early fusion or amputation may be preferable in some patients to avoid the morbidity and mortality of repeated surgeries

Epistemic Beliefs: Relationship to Future Expectancies and Quality of Life in Cancer Patients.

CONTEXT: Expectations about the future (future expectancies) are important determinants of psychological well-being among cancer patients, but the strategies patients use to maintain positive and cope with negative expectancies are incompletely understood. OBJECTIVES: To obtain preliminary evidence on the potential role of one strategy for managing future expectancies: the adoption of epistemic beliefs in fundamental limits to medical knowledge. METHODS: A sample of 1307 primarily advanced-stage cancer patients participating in a genomic tumor testing study in community oncology practices completed measures of epistemic beliefs, positive future expectancies, and mental and physical health-related quality of life (HRQOL). Descriptive and linear regression analyses were conducted to assess the relationships between these factors and test two hypotheses: 1) epistemic beliefs affirming fundamental limits to medical knowledge ( fallibilistic epistemic beliefs ) are associated with positive future expectancies and mental HRQOL, and 2) positive future expectancies mediate this association. RESULTS: Participants reported relatively high beliefs in limits to medical knowledge (M = 2.94, s.d.=.67) and positive future expectancies (M = 3.01, s.d.=.62) (range 0-4), and relatively low mental and physical HRQOL. Consistent with hypotheses, fallibilistic epistemic beliefs were associated with positive future expectancies (b = 0.11, SE=.03, P\u3c 0.001) and greater mental HRQOL (b = 0.99, SE=.34, P = 0.004); positive expectancies also mediated the association between epistemic beliefs and mental HRQOL (Sobel Z=4.27, P\u3c0.001). CONCLUSIONS: Epistemic beliefs in limits to medical knowledge are associated with positive future expectancies and greater mental HRQOL; positive expectancies mediate the association between epistemic beliefs and HRQOL. More research is needed to confirm these relationships and elucidate their causal mechanisms

Influence of anthropogenic factors on the geographical distribution of triatomine vectors of Chagas Disease / Influência de fatores antropogênicos na distribuição geográfica de triatomíneos vetores da Doença de Chagas

Estudos anteriores sobre a doença de Chagas em grandes escalas espaciais não exploraram como a interação com humanos pode afetar as projeções para a distribuição geográfica da aptidão ambiental das espécies de vetores. Aqui, comparamos modelos de distribuição de espécies usando apenas variáveis climáticas como preditores (SDMClim) com modelos que incluem variáveis climáticas + densidade populacional humana (SDMHuman). Nossos resultados mostram que considerar a densidade da população humana ajuda a refinar os modelos para escalas geográficas mais finas. Além disso, diferentes padrões espaciais de adequabilidade ambiental acumulada foram obtidos por SDMClim e SDMHuman. Ainda, as projeções foram mais precisas para SDMHuman do que para SDMClim. Nossos resultados mostram que considerar fatores antropogênicos em SDMs para espécies de triatomianos epidemiologicamente relevantes pode melhorar nossa compreensão da macroecologia e biogeografia para vetores da doença de Chagas.