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We investigated human understanding of different network visualizations in a large-scale online experiment. Three types of network visualizations were examined: node-link and two different sorting variants of matrix representations on a representative social network of either 20 or 50 nodes. Understanding of the network was quantified using task time and accuracy metrics on questions that were derived from an established task taxonomy. The sample size in our experiment was more than an order of magnitude larger (N = 600) than in previous research, leading to high statistical power and thus more precise estimation of detailed effects. Specifically, high statistical power allowed us to consider modern interaction capabilities as part of the evaluated visualizations, and to evaluate overall learning rates as well as ambient (implicit) learning. Findings indicate that participant understanding was best for the node-link visualization, with higher accuracy and faster task times than the two matrix visualizations. Analysis of participant learning indicated a large initial difference in task time between the node-link and matrix visualizations, with matrix performance steadily approaching that of the node-link visualization over the course of the experiment. This research is reproducible as the web-based module and results have been made available at: https://osf.io/qct84/.
The ~492 Ma Shetland Ophiolite Complex contains an extensive mantle section, within which numerous podiform chromitite bodies formed during melt percolation in a supra-subduction zone setting. One of the Shetland ophiolite chromitite localities has an unusual style of platinum-group element (PGE) mineralization. Specifically, the Cliff chromitite suite has relatively high (>250 ppm) Pt plus Pd, compared to other chromitites in the Shetland Ophiolite Complex. In this study, we apply petrographic observation, mineral chemistry and novel X-ray microtomography data to elucidate the petrogenesis of PGE-bearing phases at Cliff. The combined datasets reveal that the PGE at Cliff have probably been fractionated by an As-rich fluid, concentrating Pt and Ir into visible (0.1–1 µm) platinum-group minerals (PGM) such as sperrylite and irarsite, respectively. The high (>1 ppm) bulk-rock concentrations of the other PGE (e.g. Os) in the Cliff chromitites suggests the presence of abundant fine-grained unidentified PGM in the serpentinized groundmass. The spatial association of arsenide phases and PGM with alteration rims on Cr-spinel grains suggests that the high Pt and Pd abundances at Cliff result from a late-stage low-temperature (e.g. 200–300°C) hydrothermal event. This conclusion highlights the potential effects that secondary alteration processes can have on modifying and upgrading the tenor of PGE deposits.
The History, Electrocardiogram (ECG), Age, Risk Factors, and Troponin (HEART) score is a decision aid designed to risk stratify emergency department (ED) patients with acute chest pain. It has been validated for ED use, but it has yet to be evaluated in a prehospital setting.
A prehospital modified HEART score can predict major adverse cardiac events (MACE) among undifferentiated chest pain patients transported to the ED.
A retrospective cohort study of patients with chest pain transported by two county-based Emergency Medical Service (EMS) agencies to a tertiary care center was conducted. Adults without ST-elevation myocardial infarction (STEMI) were included. Inter-facility transfers and those without a prehospital 12-lead ECG or an ED troponin measurement were excluded. Modified HEART scores were calculated by study investigators using a standardized data collection tool for each patient. All MACE (death, myocardial infarction [MI], or coronary revascularization) were determined by record review at 30 days. The sensitivity and negative predictive values (NPVs) for MACE at 30 days were calculated.
Over the study period, 794 patients met inclusion criteria. A MACE at 30 days was present in 10.7% (85/794) of patients with 12 deaths (1.5%), 66 MIs (8.3%), and 12 coronary revascularizations without MI (1.5%). The modified HEART score identified 33.2% (264/794) of patients as low risk. Among low-risk patients, 1.9% (5/264) had MACE (two MIs and three revascularizations without MI). The sensitivity and NPV for 30-day MACE was 94.1% (95% CI, 86.8-98.1) and 98.1% (95% CI, 95.6-99.4), respectively.
Prehospital modified HEART scores have a high NPV for MACE at 30 days. A study in which prehospital providers prospectively apply this decision aid is warranted.
Modal decompositions of unperturbed and acoustically driven injector flows from shear coaxial jets are implemented using dynamic-mode decomposition, which is a natural approach in the search for collective oscillatory behaviour in nonlinear systems. Previous studies using proper orthogonal decomposition had revealed the most energetic pairs of coherent structures in injector flows. One of the difficulties in extracting lower-energy coherent structures follows from the need to differentiate robust flow constituents from noise and other irregular facets of a flow. The identification of robust features is critical for applications such as flow control as well, since only they can be used for the tasks. A dynamic-mode decomposition based algorithm for this differentiation is introduced and used to identify different classes of robust dynamic modes. They include (1) background modes located outside the injector flow that decay rapidly, (2) injector modes – including those presented in earlier studies – located in the vicinity of the flow, (3) modes that persist under acoustic driving, (4) modes responding linearly to the driving and, most interestingly, (5) a mode whose density exhibits antiphase oscillatory behaviour in the observation plane and that appears only when
, the outer-to-inner-jet momentum flux ratio, is sufficiently large; we infer that this is a projection of a mode rotating about the symmetry axis and born via a spontaneous symmetry breaking. Each of these classes of modes is analysed as
is increased, and their consequences for the flow patterns are discussed.
The Aravind Eye Care System (Aravind) is a massive network of ophthalmologic hospitals and primary eye care centers in the state of Tamil Nadu in southern India, joined by educational and research institutes, community outreach programs, an eye bank, and a manufacturing arm for lenses. Aravind is famous for its immense contributions to provision of healthcare to the poor. Over the course of its history, Aravind has treated millions of impoverished people in need of eye care. Most remarkably, Aravind has found ways to deliver this care in a financially profitable way.
This history constitutes one of the greatest success stories of providing business solutions to the “bottom of the pyramid,” or BOP (see Chapter 11). The BOP refers to the poorest and largest segment of the population. This is a challenging population segment to serve for several reasons: they have been traditionally underserved, and thus have greater healthcare needs; they have few resources (both capital and human capital); they are a dispersed and heavily rural population; and they enjoy few logistical supports to access care. As a result, the BOP has traditionally not been seen as a favorable customer base. Recently, however, they have begun to attract attention as a viable target for generating revenues and profits. Serving them requires unconventional and innovative strategies.
Aravind's experience in serving this segment has provided both inspiration and valuable lessons for healthcare providers throughout the developing world who wish to reach out to the impoverished masses. This chapter chronicles Aravind's past and present roles in the Indian healthcare space, drawing implications both for Aravind as it looks into the future and for other organizations that wish to provide healthcare to the bottom of the pyramid.
Malignant mesothelioma is a rare, highly aggressive cancer arising from mesothelial cells that line the pleural cavities. Approximately 80% of mesothelioma cases can be directly attributed to asbestos exposure. Additional suspected causes or co-carcinogens include other mineral fibres, simian virus 40 (SV40) and radiation. A mesothelioma epidemic in Turkey has demonstrated a probable genetic predisposition to mineral fibre carcinogenesis and studies of human tissues and animal models of mesothelioma have demonstrated genetic and epigenetic events that contribute to the multistep process of mineral fibre carcinogenesis. Several growth factors and their receptors have a significant role in the oncogenesis, progression and resistance to therapy of mesothelioma. Epidermal growth factor (EGF), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF) and insulin-like growth factor (IGF) have been shown as targets for therapy based on promising preclinical data. However, clinical trials of tyrosine kinase inhibitors in mesothelioma have been disappointing. Bcl-XL is an important antiapoptotic member of the Bcl-2 family and is overexpressed in several solid tumours, including mesothelioma. Reduction of Bcl-XL expression in mesothelioma induces apoptosis and engenders sensitisation to cytotoxic chemotherapeutic agents. Pharmacological inhibitors of antiapoptotic Bcl-2 family members continue to undergo refinement and have shown promise in mesothelioma.
Limb amputations are frequently performed as a result of trauma inflicted during conflict or disasters. As demonstrated during the 2010 earthquake in Haiti, coordinating care of these patients in austere settings is complex. During the 2011 Humanitarian Action Summit, consensus statements were developed for international organizations providing care to limb amputation patients during disasters or humanitarian emergencies. Expanded planning is needed for a multidisciplinary surgical care team, inclusive of surgeons, anesthesiologists, rehabilitation specialists and mental health professionals. Surgical providers should approach amputation using an operative technique that optimizes limb length and prosthetic fitting. Appropriate anesthesia care involves both peri-operative and long-term pain control. Rehabilitation specialists must be involved early in treatment, ideally before amputation, and should educate the surgical team in prosthetic considerations. Mental health specialists must be included to help the patient with community reintegration. A key step in developing local health systemsis the establishment of surgical outcomes monitoring. Such monitoring can optimizepatient follow-up and foster professional accountability for the treatment of amputation patients in disaster settings and humanitarian emergencies.
Historically, economic development has been strongly correlated with increasing energy use and growth of greenhouse gas (GHG) emissions. Renewable energy (RE) can help decouple that correlation, contributing to sustainable development (SD). In addition, RE offers the opportunity to improve access to modern energy services for the poorest members of society, which is crucial for the achievement of any single of the eight Millennium Development Goals.
Theoretical concepts of SD can provide useful frameworks to assess the interactions between SD and RE. SD addresses concerns about relationships between human society and nature. Traditionally, SD has been framed in the three-pillar model—Economy, Ecology, and Society—allowing a schematic categorization of development goals, with the three pillars being interdependent and mutually reinforcing. Within another conceptual framework, SD can be oriented along a continuum between the two paradigms of weak sustainability and strong sustainability. The two paradigms differ in assumptions about the substitutability of natural and human-made capital. RE can contribute to the development goals of the three-pillar model and can be assessed in terms of both weak and strong SD, since RE utilization is defined as sustaining natural capital as long as its resource use does not reduce the potential for future harvest.
Metal-catalyzed graphitization from vapor phase sources of carbon is now an established technique for producing few-layer graphene, a candidate material of interest for post-silicon electronics. Here we describe two alternative metal-catalyzed graphene formation processes utilizing solid phase sources of carbon. In the first, carbon is introduced as part of a cosputtered Ni-C alloy; in the second, carbon is introduced as one of the layers in an amorphous carbon (a-C)/Ni bilayer stack. We examine the quality and characteristics of the resulting graphene as a function of starting film thicknesses, Ni-C alloy composition or a-C deposition method (physical or chemical vapor deposition), and annealing conditions. We then discuss some of the competing processes playing a role in graphitic carbon formation and review recent evidence showing that the graphitic carbon in the a-C/Ni system initially forms by a metal-induced crystallization mechanism (analogous to what is seen with Al-induced crystallization of amorphous Si) rather than by the dissolution-upon-heating/precipitation-upon-cooling mechanism seen when graphene is grown by metal-catalyzed chemical vapor deposition methods.
In this present work we report the growth of Cd0.9Zn0.1Te doped with In by a modified THM technique. It has been demonstrated that by controlling the microscopically flat growth interface, the size distribution and concentration of Te inclusions can be drastically reduced in the as-grown ingots. This results in as-grown detector-grade CZT by the THM technique. The three-dimensional size distribution and concentrations of Te inclusions/precipitations were studied. The size distributions of the Te precipitations/inclusions were observed to be below the 10-μm range with the total concentration less than 105 cm-3. The relatively low value of Te inclusions/precipitations results in excellent charge transport properties of our as-grown samples. The (μτ)e values for different as-grown samples varied between 6-20 x10-3 cm2/V. The as-grown samples also showed fairly good detector response with resolution of ∼1.5%, 2.7% and about 3.8% at 662 keV for quasi-hemispherical geometry for detector volumes of 0.18 cm3, 1 cm3 and 4.2 cm3, respectively.
The science of extra-solar planets is one of the most rapidly changing areas of astrophysics and since 1995 the number of planets known has increased by almost two orders of magnitude. A combination of ground-based surveys and dedicated space missions has resulted in 560-plus planets being detected, and over 1200 that await confirmation. NASA's Kepler mission has opened up the possibility of discovering Earth-like planets in the habitable zone around some of the 100,000 stars it is surveying during its 3 to 4-year lifetime. The new ESA's Gaia mission is expected to discover thousands of new planets around stars within 200 parsecs of the Sun. The key challenge now is moving on from discovery, important though that remains, to characterisation: what are these planets actually like, and why are they as they are?
In the past ten years, we have learned how to obtain the first spectra of exoplanets using transit transmission and emission spectroscopy. With the high stability of Spitzer, Hubble, and large ground-based telescopes the spectra of bright close-in massive planets can be obtained and species like water vapour, methane, carbon monoxide and dioxide have been detected. With transit science came the first tangible remote sensing of these planetary bodies and so one can start to extrapolate from what has been learnt from Solar System probes to what one might plan to learn about their faraway siblings. As we learn more about the atmospheres, surfaces and near-surfaces of these remote bodies, we will begin to build up a clearer picture of their construction, history and suitability for life.
The Exoplanet Characterisation Observatory, EChO, will be the first dedicated mission to investigate the physics and chemistry of Exoplanetary Atmospheres. By characterising spectroscopically more bodies in different environments we will take detailed planetology out of the Solar System and into the Galaxy as a whole.
EChO has now been selected by the European Space Agency to be assessed as one of four M3 mission candidates.