Comparing Predictive Accuracy

Using research designs patterned after randomized experiments, many recent economic studies examine outcome measures for treatment groups and comparison groups that are not randomly assigned. By using variation in explanatory variables generated by changes in state laws, government draft mechanisms, or other means, these studies obtain variation that is readily examined and is plausibly exogenous. This paper describes the advantages of these studies and suggests how they can be improved. It also provides aids in judging the validity of inferences they draw. Design complications such as multiple treatment and comparison groups and multiple pre- or post-intervention observations are advocated.

Identification of the design variables of e-learning tools using concept mapping techniques

Thanks to the use of stadisthic techniques is posible to stablish an technological acceptation model of e- Learning tools. This article describes the application of concept mapping techniques to identify the most relevant extern variables on the design process of an e-learning tool and a reliability analisys of the concept map obtained as result of the experimen

Identification of Designing Variable of an Elearning Tool

En este artículo se muestran, a través de mapas bidimensionales, los resultados procedentes de un proyecto de investigación mediante el cual se han identificado las variables externas a tener en cuenta en el diseño de una herramienta de eLearning para conseguir evaluar, posteriormente, su uso real. La técnica empleada para ello es la "Elaboración de mapas conceptuales". Asimismo, se observa la necesidad de tener en cuenta cómo llevar a cabo la gestión de la herramienta por parte del usuario. Finalmente, se ha analizado la fiabilidad de nuestros mapasIn this paper the results from a research project1 are shown. A scientific technique called "Concept Mapping Process" has been used to identify the external variables to be kept in mind in the design of an eLearning tool, in order to evaluate its true usage later. Results are shown through two-dimensional maps. Another important result is the necessity of designing tools to carry out the management of the tool on the part of the user. Finally, there has been analysed the reliability of our mapsMinisterio de Educación y Ciencia EA2005-017

Multiferroicity in an organic charge-transfer salt: Electric-dipole-driven magnetism

Multiferroics, showing simultaneous ordering of electrical and magnetic degrees of freedom, are remarkable materials as seen from both the academic and technological points of view. A prominent mechanism of multiferroicity is the spin-driven ferroelectricity, often found in frustrated antiferromagnets with helical spin order. There, similar to conventional ferroelectrics, the electrical dipoles arise from an off-centre displacement of ions. However, recently a different mechanism, namely purely electronic ferroelectricity, where charge order breaks inversion symmetry, has attracted considerable interest. Here we provide evidence for this exotic type of ferroelectricity, accompanied by antiferromagnetic spin order, in a two-dimensional organic charge-transfer salt, thus representing a new class of multiferroics. Quite unexpectedly for electronic ferroelectrics, dipolar and spin order arise nearly simultaneously. This can be ascribed to the loss of spin frustration induced by the ferroelectric ordering. Hence, here the spin order is driven by the ferroelectricity, in marked contrast to the spin-driven ferroelectricity in helical magnets.Comment: 8 pages, 9 figures (including 4 pages and 6 figures in supplementary information). Version 2 with minor errors corrected (legend of Fig. 3c and definition of vectors e and Q

Border Integrations: The Fusion of Political Ecology and Land Change Science to Inform and Contest Transboundary Integration in Amazonia

In the southwestern Amazon lies the Sierra del Divisor, an isolated cluster of mist-covered peaks and ridges rising out of the steamy lowland rainforest. The forests of these fiercely dissected crests and valleys still ring with the low grunt of jaguar and the thunderous clacks of hundreds-strong herds of whitelipped peccaries, while the canopy sways with troops of the rare red Uakari monkey. This biodiversity inspired the Serra do Divisor National Park, and its transboundary sister reserve, but these forests are also home to humans: the descendants of Asheninka warriors and rubber tappers, a re-emergent Nawa people, I and most elusive, the uncontacted lsconahua. These homelands and ecosystems are crisscrossed with the ephemeral scars made by more recent arrivals: loggers, miners, and drug traffickers. However, the most important line in the Sierra del Divisor is the border itself, the international boundary that follows the Sierra\u27s ridge dividing Peru\u27s Ucayali river basin from Brazil\u27s Jurua basin in the state of Acre. Relatively equidistant from the boundary ridgeline lie rwo cities, Ucayali\u27s capital of Pucallpa, and Western Acre\u27s commercial center, Cruzeiro do Sul. Both cities are the end of the road for their country\u27s nerwork of thoroughfares. For now. Planners and government officials increasingly view the 160 kilometers of forest separating the rwo cities as a temporary obstruction to continental integration. A road connecting the rwo cities would bisect the border and have an impact on flora, fauna, and people. This chapter documents the struggle against this road, a struggle to defend local livelihoods, flora, and fauna from a development initiative pushed at continental, national, and regional scales. In particular, we analyze the synergy of two divergent analytical approaches, land change science (LCS) and political ecology (PE), to gain the best understanding of the impacts of a transboundary road bridging the Brazilian and Peruvian Amazon between the cities of Cruzeiro do Sui and Pucallpa

A high-risk study of bipolar disorder. Childhood clinical phenotypes as precursors of major mood disorders

CONTEXT: The childhood precursors of adult bipolar disorder (BP) are still a matter of controversy. OBJECTIVE: To report the lifetime prevalence and early clinical predictors of psychiatric disorders in offspring from families of probands with DSM-IV BP compared with offspring of control subjects. DESIGN: A longitudinal, prospective study of individuals at risk for BP and related disorders. We report initial (cross-sectional and retrospective) diagnostic and clinical characteristics following best-estimate procedures. SETTING: Assessment was performed at 4 university medical centers in the United States between June 1, 2006, and September 30, 2009. PARTICIPANTS: Offspring aged 12 to 21 years in families with a proband with BP (n = 141, designated as cases) and similarly aged offspring of control parents (n = 91). MAIN OUTCOME MEASURE: Lifetime DSM-IV diagnosis of a major affective disorder (BP type I; schizoaffective disorder, bipolar type; BP type II; or major depression). RESULTS: At a mean age of 17 years, cases showed a 23.4% lifetime prevalence of major affective disorders compared with 4.4% in controls (P = .002, adjusting for age, sex, ethnicity, and correlation between siblings). The prevalence of BP in cases was 8.5% vs 0% in controls (adjusted P = .007). No significant difference was seen in the prevalence of other affective, anxiety, disruptive behavior, or substance use disorders. Among case subjects manifesting major affective disorders (n = 33), there was an increased risk of anxiety and externalizing disorders compared with cases without mood disorder. In cases but not controls, a childhood diagnosis of an anxiety disorder (relative risk = 2.6; 95% CI, 1.1-6.3; P = .04) or an externalizing disorder (3.6; 1.4-9.0; P = .007) was predictive of later onset of major affective disorders. CONCLUSIONS: Childhood anxiety and externalizing diagnoses predict major affective illness in adolescent offspring in families with probands with BP

Ultrafast measurements of mode-specific deformation potentials of Bi2_2Te3_3 and Bi2_2Se3_3

Quantifying electron-phonon interactions for the surface states of topological materials can provide key insights into surface-state transport, topological superconductivity, and potentially how to manipulate the surface state using a structural degree of freedom. We perform time-resolved x-ray diffraction (XRD) and angle-resolved photoemission (ARPES) measurements on Bi$_2$Te$_3$ and Bi$_2$Se$_3$, following the excitation of coherent A$_{1g}$ optical phonons. We extract and compare the deformation potentials coupling the surface electronic states to local A$_{1g}$-like displacements in these two materials using the experimentally determined atomic displacements from XRD and electron band shifts from ARPES.We find the coupling in Bi$_2$Te$_3$ and Bi$_2$Se$_3$ to be similar and in general in agreement with expectations from density functional theory. We establish a methodology that quantifies the mode-specific electron-phonon coupling experimentally, allowing detailed comparison to theory. Our results shed light on fundamental processes in topological insulators involving electron-phonon coupling

Multinational evidence-based recommendations for the diagnosis and management of gout: integrating systematic literature review and expert opinion of a broad panel of rheumatologists in the 3e initiative

We aimed to develop evidence-based multinational recommendations for the diagnosis and management of gout. Using a formal voting process, a panel of 78 international rheumatologists developed 10 key clinical questions pertinent to the diagnosis and management of gout. Each question was investigated with a systematic literature review. Medline, Embase, Cochrane CENTRAL and abstracts from 2010-2011 European League Against Rheumatism and American College of Rheumatology meetings were searched in each review. Relevant studies were independently reviewed by two individuals for data extraction and synthesis and risk of bias assessment. Using this evidence, rheumatologists from 14 countries (Europe, South America and Australasia) developed national recommendations. After rounds of discussion and voting, multinational recommendations were formulated. Each recommendation was graded according to the level of evidence. Agreement and potential impact on clinical practice were assessed. Combining evidence and clinical expertise, 10 recommendations were produced. One recommendation referred to the diagnosis of gout, two referred to cardiovascular and renal comorbidities, six focused on different aspects of the management of gout (including drug treatment and monitoring), and the last recommendation referred to the management of asymptomatic hyperuricaemia. the level of agreement with the recommendations ranged from 8.1 to 9.2 (mean 8.7) on a 1-10 scale, with 10 representing full agreement. Ten recommendations on the diagnosis and management of gout were established. They are evidence-based and supported by a large panel of rheumatologists from 14 countries, enhancing their utility in clinical practice.AbbVieAustralian National Health and Medical Research Council (NHMRC)Hosp Gen Univ Elda, Dept Reumatol, Elda 03600, SpainHosp Gen Univ Alicante, Dept Reumatol, Alicante, SpainUniv Camilo Jose Cela, Fac Ciencias Salud, Madrid, SpainUniv British Columbia, Div Rheumatol, Vancouver, BC V5Z 1M9, CanadaRoyal Melbourne Hosp, Parkville, Vic 3050, AustraliaUniv Hosp Southampton NHS Fdn Trust, Southampton, Hants, EnglandNIHR Wellcome Trust Clin Res Facil, Southampton, Hants, EnglandCtr Hosp Univ Liege, Liege, BelgiumMaastricht Univ, Med Ctr, Dept Internal Med Rheumatol, Maastricht, NetherlandsAtrium Med Ctr, Heerlen, NetherlandsUniv Toronto, Div Rheumatol, Toronto, ON, CanadaRepatriat Gen Hosp, Rheumatol Res Unit, Adelaide, SA, AustraliaFlinders Univ S Australia, Adelaide, SA 5001, AustraliaMed Univ Vienna, Dept Internal Med 3, Div Rheumatol, Vienna, AustriaUniv Toronto, Dept Hlth Policy Management & Evaluat, Toronto, ON, CanadaMt Sinai Hosp, Univ Hlth Network, Toronto Gen Res Inst, Div Clin Decis Making & Hlth Care, Toronto, ON M5G 1X5, CanadaCabrini Hosp, Monash Dept Clin Epidemiol, Malvern, Vic, AustraliaMonash Univ, Dept Epidemiol & Prevent Med, Malvern, Vic, AustraliaUniv Amsterdam, Acad Med Ctr, Dept Clin Immunol & Rheumatol, NL-1105 AZ Amsterdam, NetherlandsUniv Med Ctr Utrecht, Dept Rheumatol & Clin Immunol, Utrecht, NetherlandsUniv Nova Lisboa, Fac Ciencias Med, CEDOC, P-1200 Lisbon, PortugalEPE Hosp Egas Moniz, CHLO, Dept Rheumatol, Lisbon, PortugalHosp Gen Mexico City, Rheumatol Unit, Mexico City, DF, MexicoKarolinska Univ Hosp, Dept Rheumatol, Stockholm, SwedenKarolinska Inst, Stockholm, SwedenGhent Univ Hosp, Dept Rheumatol, Ghent, BelgiumUniversidade Federal de São Paulo, Div Rheumatol, São Paulo, BrazilSt Georges Healthcare NHS Trust, Dept Rheumatol, London, EnglandState Hosp Stockerau, Ctr Rheumatol, Lower Austria, Stockerau, AustriaUniv Pavia, IRCCS Policlin S Matteo, Cattedra Reumatol, I-27100 Pavia, ItalyUniv Giessen, Kerckhoff Klin, Dept Rheumatol & Clin Immunol, Bad Nauheim, GermanyCopenhagen Univ Hosp, Ctr Rheumatol & Spine Dis, Copenhagen Ctr Arthrit Res, Glostrup, DenmarkMenzies Res Inst Tasmania, Hobart, Tas, AustraliaColumbia Univ, Med Ctr, New York, NY USALeiden Univ, Med Ctr, Leiden, NetherlandsUniversidade Federal de São Paulo, Div Rheumatol, São Paulo, BrazilWeb of Scienc