2,073 research outputs found
The Great Indian Calorie Debate: Explaining Rising Undernourishment during Indiaâs Rapid Economic Growth
The prevalence of undernourishment in India â the percent of people consuming insufficient calories to meet their energy requirements â has been rising steadily since the mid-1980s. Paradoxically, this period has been one of robust poverty reduction and rapid economic growth. The reasons for the apparent reductions in calorie consumption underlying increased undernourishment have been the subject of intense debate both within India and internationally. This paper critically reviews this debate, finding that is has taken place outside of the context of Indiaâs recent nutrition and epidemiological transitions, which appear to have brought with them increased, not decreased, food consumption. The debate has also taken place under the unchallenged assumption that the data on which the conflicting trends are based, collected as part of the countryâs Household Consumption and Expenditure Surveys (HCESs), are reliable. The paper provides supporting literature and empirical evidence that one key factor driving the measured calorie decline is incomplete collection of data on food consumed away from peoplesâ homes, which is widespread and rapidly increasing. The India example shows that complete measurement of this food source in the HCESs of all countries is vital for accurate measurement of undernourishment and, indeed, poverty at national, regional and global levels
Tuning out or Tuned Out? A Critical Discourse Analysis of Youth Political Participation in Britain
Young people do not vote in the same numbers as older generations, which causes considerable concern within British democratic life. They are seen as detached and disengaged, however, the focus on voting and other traditional forms of political participation is arguably a narrow way of assessing this generationâs political engagement. This paper discusses a critical discourse analysis of recent media texts on youth political participation and argues that media coverage of young peopleâs political participation furthers the misconception that the youth of Britain today are not interested in politics and political issues. It is argued that notions of youth political participation must extend beyond traditional political engagement, namely voting
Modelling Social Structures and Hierarchies in Language Evolution
Language evolution might have preferred certain prior social configurations
over others. Experiments conducted with models of different social structures
(varying subgroup interactions and the role of a dominant interlocutor) suggest
that having isolated agent groups rather than an interconnected agent is more
advantageous for the emergence of a social communication system. Distinctive
groups that are closely connected by communication yield systems less like
natural language than fully isolated groups inhabiting the same world.
Furthermore, the addition of a dominant male who is asymmetrically favoured as
a hearer, and equally likely to be a speaker has no positive influence on the
disjoint groups.Comment: 14 pages, 3 figures, 1 table. In proceedings of AI-2010, The
Thirtieth SGAI International Conference on Innovative Techniques and
Applications of Artificial Intelligence, Cambridge, England, UK, 14-16
December 201
What would Jaws do? The tyranny of film and the relationship between gaze and higher-level narrative film comprehension
What is the relationship between film viewersâ eye movements and their film comprehension? Typical Hollywood movies induce strong attentional synchronyâmost viewers look at the same things at the same time. Thus, we asked whether film viewersâ eye movements would differ based on their understandingâthe mental model hypothesisâor whether any such differences would be overwhelmed by viewersâ attentional synchronyâthe tyranny of film hypothesis. To investigate this question, we manipulated the presence/absence of prior film context and measured resulting differences in film comprehension and eye movements. Viewers watched a 12-second James Bond movie clip, ending just as a critical predictive inference should be drawn that Bondâs nemesis, âJaws,â would fall from the sky onto a circus tent. The No-context condition saw only the 12-second clip, but the Context condition also saw the preceding 2.5 minutes of the movie before seeing the critical 12-second portion. Importantly, the Context condition viewers were more likely to draw the critical inference and were more likely to perceive coherence across the entire 6 shot sequence (as shown by event segmentation), indicating greater comprehension. Viewersâ eye movements showed strong attentional synchrony in both conditions as compared to a chance level baseline, but smaller differences between conditions. Specifically, the Context condition viewers showed slightly, but significantly, greater attentional synchrony and lower cognitive load (as shown by fixation probability) during the critical first circus tent shot. Thus, overall, the results were more consistent with the tyranny of film hypothesis than the mental model hypothesis. These results suggest the need for a theory that encompasses processes from the perception to the comprehension of film
Cyber-Systemic Themes in MFT Literature
Abstract: In the fifteen years since the explosion of the Internet, using cyber technology for work & social functions has exponentially increased. Yet the questions around how to manage such changes remain elusive in family therapy literature. In this investigation, we conducted a content analysis to determine to what extent marriage & family therapy (MFT) journals have responded to the integration of the Internet in couple & family life. We found 79 of 13,274 articles across seventeen journals focused on the Internet in some capacity supporting the contention that cyber issues are largely ignored within the MFT field
Estimation of river discharge, propagation speed, and hydraulic geometry from space: Lena River, Siberia
Moderate Resolution Imaging Spectroradiometer (MODIS)-derived measurements of Lena River effective width (We) display a high predictive capacity (r2 = 0.81, mean absolute error < 25%) to forecast downstream discharge conditions at Kusur station, some 8 d and âŒ700 km later. Satellite-derived mean flow propagation speed (88 km d-1 or 1.01 m s-1) compares well with that estimated from ground data (84 km d -1 or 0.97 m s-1). Scaling analysis of a âŒ300 km heavily braided study reach suggests that at length scales > 60-90 km (âŒ2-3 time valley width), satellite-derived We - Q rating curves and hydraulic geometry (b exponents) converge upon stable values (b = 0.48), indicating transferability of the discharge retrieval method between different locations. Put another way, at length scales exceeding âŒ60-90 km all subreaches display similar behavior everywhere. At finer reach length scales (e.g., 0.25-1 km), longitudinal extraction of b exponents represents the first continuous mapping of a classical hydraulic geometry parameter from space. While at least one gauging station is required for calibration, results suggest that multitemporal satellite data can powerfully enhance our understanding of water discharge and flow conveyance in remote river systems
Remote sensing of suspended sediment concentration, flow velocity, and lake recharge in the Peace-Athabasca Delta, Canada
The transport of fine sediment, carried in suspension by water, is central to the hydrology, geomorphology, and ecological functioning of river floodplains and deltas. An extensive new field data set for the Peace-Athabasca Delta (PAD), Canada quantifies robust positive relationships between in situ suspended sediment concentration (SSC) and remotely sensed visible/near-infrared reflectance. These relationships are exploited using SPOT and ASTER satellite images to map suspended sediment concentrations across the PAD for four days in 2006 and 2007, revealing strong variations in water sources and flow patterns, including flow reversals in major distributaries. Near-daily monitoring with 276 MODIS satellite images tracks hydrologic recharge of floodplain lakes, as revealed by episodic infusions of sediment-rich water from the Athabasca River. The timing and magnitude of lake recharge are linked to springtime water level on the Athabasca River, suggesting a system sensitive to changes in river flow regime. Moreover, recharge timing differentiates lakes that are frequently and extensively recharged from those recharged more rarely. Finally, we present a first estimation of river flow velocity based on remotely sensed SSC, though saturation may occur at velocities >0.6 m/s. Viewed collectively, the different remote sensing methodologies presented here suggest strong value for visible/near-infrared remote sensing of suspended sediment to assess hydrologic and sediment transport processes in complex flow environments. Field observations including nephelometric turbidity, specific conductivity, water temperature, Secchi disk depth, suspended sediment concentration, and water level are archived at the Oak Ridge National Laboratory Distributed Active Archive Center for Biogeochemical Dynamics (available at http://daac.ornl.gov// HYDROCLIMATOLOGY/guides/PAD.html)
Remote sensing of hydrologic recharge in the Peace-Athabasca Delta, Canada
Northern wetlands like Canada's Peace-Athabasca Delta (PAD) have global environmental significance, yet fundamental processes of hydrologic recharge critical to their functionality remain poorly understood. We use in situ water level and MODIS satellite data to examine how mainstem river level fluctuations drive inundation across the delta. Temporal covariance between the two datasets allows inference of hydrologic connectivity processes, not just inundation extent. A strong contrast is found between hydrologic connectivity properties in a high-water (2007) vs. low-water year (2006). Results suggest that existing theoretical models of floodplain recharge fail to capture observed patterns of inundation in the PAD. Instead, we find a dichotomy between the distributary channel network, which responds to summer high-water events, and floodplain lakes and wetlands, which do not. The latter occurs even where hydrologic connections do exist between the two. Results have strong management implications for the impact of proposed up-river water diversion on PAD hydrology
Intercomparison of four global precipitation data sets and their correlation with increased Eurasian river discharge to the Arctic Ocean
Recent increases in Eurasian river discharge to the Arctic Ocean have attracted considerable scientific attention but remain poorly understood. Previous studies have examined fire frequency, permafrost thaw, and dam construction as potential mechanisms. Here we focus on precipitation as a driver, using 198 dam-free Eurasian river basins ranging from 151 to 897,000 km2. Using R-ArcticNet monthly discharge data and four observational and reanalysis precipitation products from the University of Delaware (UDel), University of Washington (UW), NCEP/NCAR (NCEP), and ECMWF (ERA-40), we (1) assess which precipitation data sets best capture spatially realistic patterns as inferred from agreement with river discharge (198 basins; 1958-1989); and (2) determine to what extent observed discharge trends follow Udel precipitation changes (66 basins; 1936-1999). Results from the precipitation intercomparison show for the 74 (of 198) basins displaying statistically significant discharge trends (24 positive, 50 negative; -74% to +89%, mean = -1%), interpolated precipitation products significantly outperform reanalysis data sets, perhaps owing to the fine-scale resolutions examined here. Agreement between discharge and precipitation is 42-86% and 42-97% for UDel and UW, respectively, but approaches zero for NCEP and ERA-40. Comparison of precipitation and discharge trends suggests that precipitation increases play a significant role in observed long-term discharge increases. For the 40 (of 66) basins displaying statistically significant trends in discharge (32 positive, 8 negative; -23% to +50%, mean = +11%), 29 display corresponding trends in precipitation with 35-62% agreement between discharge and precipitation trend. Comparison of discharge trends with basin permafrost properties indicates a possible, but not strong role for permafrost thaw in the observed increases
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PETSc 2.0 Users Manual: Revision 2.0.16
This manual describes the use of PETSc 2.0 for the numerical solution of partial differential equations and related problems on high-performance computers. The Portable, Extensible Toolkit for Scientific Computation (PETSc) is a suite of data structures and routines that provide the building blocks for the implementation of large-scale application codes on parallel (and serial) computers. PETSc 2.0 uses the MPI standard for all message-passing communication. PETSc includes an expanding suite of parallel linear and nonlinear equation solvers that may be used in application codes written in Fortran, C, and C++. PETSc provides many of the mechanisms needed thin parallel application codes, such as simple parallel matrix and vector assembly routines that allow the overlap of communication and computation. In addition, PETSc includes growing support for distributed arrays. The library is organized hierarchically, enabling users to employ the level of abstraction that is most appropriate for a particular problem. By using techniques of object-oriented programming, PETSc provides enormous flexibility for users. PETSc is a sophisticated set of software tools; as such, for some users it initially has a much steeper learning curve than a simple subroutine library. In particular, for individuals without some computer science background or experience programming in C, Pascal, or C++, it may require a large amount of time to take full advantage of the features that enable efficient software use. However, the power of the PETSc design and the algorithms it incorporates make the efficient implementation of many application codes much simpler than rolling them yourself. For many simple tasks a package such as Matlab is often the best tool; PETSc is not intended for the classes of problems for which effective Matlab code can be written. Since PETSc is still under development, small changes in usage and calling sequences of PETSc routines will continue to occur
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