Information choice in a social learning experiment

We document heterogeneity of rationality and bias in information acquisition in a social learning experiment, where subjects, prior to guessing an unknown binary state of the world, must choose between receiving a private signal or seeing social information containing the guesses made by previous subjects in the sequence - rather than observing both pieces of information as in the classic design of Anderson and Holt (1997). By requiring subjects to make this information choice at different points in the sequence, our within-subject design allows us to separate biased from optimal information choices. Overall, the majority of subjects exhibit a suboptimal bias in favor of choosing social rather than private information, consistent with underestimating both mistakes made by other subjects and the frequency of uninformative social information. Furthermore, a substantial minority behave according to a refined equilibrium prediction, while some subjects consistently choose social information and others consistently choose private information

Clinical evaluation of the IONA test: a non-invasive prenatal screening test for trisomies 21, 18 and 13.

OBJECTIVE: To evaluate the clinical accuracy of the IONA® test for aneuploidy screening. METHODS: This was a multicenter blinded study in which plasma samples from pregnant women at increased risk of trisomy 21 underwent cell-free DNA analysis utilizing the IONA test. For each sample, the IONA software generated a likelihood ratio and a maternal age-adjusted probability risk score for trisomies 21, 18 and 13. All results from the IONA test were compared against accepted diagnostic karyotyping. RESULTS: A total of 442 maternal samples were obtained, of which 437 had test results available for analysis and assessment of clinical accuracy. The IONA test had a detection rate of 100% for trisomies 21 (n = 43; 95% CI, 87.98-100%), 18 (n = 10; 95% CI, 58.72-100%) and 13 (n = 5; 95% CI, 35.88-100%) with cut-offs applied to likelihood ratio (cut-off > 1 considered high risk for trisomy) and probability risk score incorporating adjustment for maternal age (cut-off ≥ 1/150 considered high risk for trisomy). The false-positive rate (FPR) was 0% for trisomies 18 and 13 with both analysis outputs. For trisomy 21, a FPR of 0.3% was observed for the likelihood ratio, but became 0% with adjustment for maternal age. CONCLUSION: This study indicates that the IONA test is suitable for trisomy screening in a high-risk screening population. The result-interpretation feature of the IONA software should facilitate wider implementation, particularly in local laboratories, and should be a useful addition to the current screening methods for trisomies 21, 18 and 13. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd

Simplification and Shift in Cognition of Political Difference: Applying the Geometric Modeling to the Analysis of Semantic Similarity Judgment

Perceiving differences by means of spatial analogies is intrinsic to human cognition. Multi-dimensional scaling (MDS) analysis based on Minkowski geometry has been used primarily on data on sensory similarity judgments, leaving judgments on abstractive differences unanalyzed. Indeed, analysts have failed to find appropriate experimental or real-life data in this regard. Our MDS analysis used survey data on political scientists' judgments of the similarities and differences between political positions expressed in terms of distance. Both distance smoothing and majorization techniques were applied to a three-way dataset of similarity judgments provided by at least seven experts on at least five parties' positions on at least seven policies (i.e., originally yielding 245 dimensions) to substantially reduce the risk of local minima. The analysis found two dimensions, which were sufficient for mapping differences, and fit the city-block dimensions better than the Euclidean metric in all datasets obtained from 13 countries. Most city-block dimensions were highly correlated with the simplified criterion (i.e., the left–right ideology) for differences that are actually used in real politics. The isometry of the city-block and dominance metrics in two-dimensional space carries further implications. More specifically, individuals may pay attention to two dimensions (if represented in the city-block metric) or focus on a single dimension (if represented in the dominance metric) when judging differences between the same objects. Switching between metrics may be expected to occur during cognitive processing as frequently as the apparent discontinuities and shifts in human attention that may underlie changing judgments in real situations occur. Consequently, the result has extended strong support for the validity of the geometric models to represent an important social cognition, i.e., the one of political differences, which is deeply rooted in human nature

PCB-containing wood floor finish is a likely source of elevated PCBs in residents' blood, household air and dust: a case study of exposure

© 2008 Rudel et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Spatial analysis of lung, colorectal, and breast cancer on Cape Cod: An application of generalized additive models to case-control data

BACKGROUND: The availability of geographic information from cancer and birth defect registries has increased public demands for investigation of perceived disease clusters. Many neighborhood-level cluster investigations are methodologically problematic, while maps made from registry data often ignore latency and many known risk factors. Population-based case-control and cohort studies provide a stronger foundation for spatial epidemiology because potential confounders and disease latency can be addressed. METHODS: We investigated the association between residence and colorectal, lung, and breast cancer on upper Cape Cod, Massachusetts (USA) using extensive data on covariates and residential history from two case-control studies for 1983–1993. We generated maps using generalized additive models, smoothing on longitude and latitude while adjusting for covariates. The resulting continuous surface estimates disease rates relative to the whole study area. We used permutation tests to examine the overall importance of location in the model and identify areas of increased and decreased risk. RESULTS: Maps of colorectal cancer were relatively flat. Assuming 15 years of latency, lung cancer was significantly elevated just northeast of the Massachusetts Military Reservation, although the result did not hold when we restricted to residences of longest duration. Earlier non-spatial epidemiology had found a weak association between lung cancer and proximity to gun and mortar positions on the reservation. Breast cancer hot spots tended to increase in magnitude as we increased latency and adjusted for covariates, indicating that confounders were partly hiding these areas. Significant breast cancer hot spots were located near known groundwater plumes and the Massachusetts Military Reservation. DISCUSSION: Spatial epidemiology of population-based case-control studies addresses many methodological criticisms of cluster studies and generates new exposure hypotheses. Our results provide evidence for spatial clustering of breast cancer on upper Cape Cod. The analysis suggests further investigation of the potential association between breast cancer and pollution plumes based on detailed exposure modeling

Learning in Games with Unstable Equilibria

We propose a new concept for the analysis of games, the TASP, which gives a precise prediction about non-equilibrium play in games whose Nash equilibria are mixed and are unstable under fictitious play-like learning. We show that, when players learn using weighted stochastic fictitious play and so place greater weight on recent experience, the time average of play often converges in these “unstable ” games, even while mixed strategies and beliefs continue to cycle. This time average, the TASP, is related to the cycle identified by Shapley [L.S. Shapley, Some topics in two person games, in: M. Dresher, et al. (Eds.), Advances in Gam

Single-cell analysis tools for drug discovery and development

The genetic, functional or compositional heterogeneity of healthy and diseased tissues presents major challenges in drug discovery and development. Such heterogeneity hinders the design of accurate disease models and can confound the interpretation of biomarker levels and of patient responses to specific therapies. The complex nature of virtually all tissues has motivated the development of tools for single-cell genomic, transcriptomic and multiplex proteomic analyses. Here, we review these tools and assess their advantages and limitations. Emerging applications of single cell analysis tools in drug discovery and development, particularly in the field of oncology, are discussed

Estrategia de competencias gerenciales y comunicación organizacional interna en el sector hotelero de 3 y 4 estrellas de Cajamarca

TesisLa investigación tiene como objetivo determinar la relación que existe entre la estrategia de competencias gerenciales con la comunicación organizacional interna del sector hotelero de 3 y 4 estrellas de la ciudad de Cajamarca, conociendo la problemática por la que esta atraviesa puesto que no existen antecedentes de estudios de este tipo en dichas organizaciones; se formuló como hipótesis que “Existe influencia directa de la estrategia de competencias gerenciales en la comunicación organizacional interna en el Sector Hotelero de 3 y 4 estrellas de Cajamarca”. Las estrategias competitivas gerenciales se dividieron en tres áreas de análisis aspecto personal, aspecto social y aspecto laboral. Para medir las competencias gerenciales, se recogió información de 25 gerentes del sector hotelero. Luego del diagnóstico de las competencias gerenciales, se concluye que los gerentes tienen una tendencia valores medios bajos a nivel de la variable y por ende a nivel de las dimensiones. La dimensión aspecto social, el porcentaje más alto es el de 43.6%. La dimensión aspecto social, también se ubica dentro de los valores medios, el valor más elevado es de 42.4%, que se encuentra ubicada en la escala de valor medio bajo. La dimensión aspecto laboral, también se ubica dentro de los valores medios, el porcentaje más alto de esta dimensión es el de 43.2% que se ubica en la escala de valor medio bajo. La dimensión objetivos que persigue, el porcentaje más alto el de 40.3% que se sitúa en la escala de valor medio bajo; la dimensión flujos de comunicación, sus porcentajes también tienen valores medios el porcentaje más alto alcanzado es el 37.3%, en relación a la dimensión funciones de la comunicación, esta también a ha alcanzado valores medios. La correlación existente entre el competencias gerenciales y comunicación organizacional se encontró que para un nivel de confianza de 0.05 y con 100 grados de libertad, el coeficiente de correlación es de r = 0.715 y es mayor al valor del error del stándar multiplicado por la tabla t de Student siendo el valor de 0.111, resultando nuestro valor mayor que el esperado por lo tanto se rechaza la hipótesis nula y se acepta la hipótesis de investigación concluyendo que sí existe relació