On the power of non-local boxes

A non-local box is a virtual device that has the following property: given that Alice inputs a bit at her end of the device and that Bob does likewise, it produces two bits, one at Alice's end and one at Bob's end, such that the XOR of the outputs is equal to the AND of the inputs. This box, inspired from the CHSH inequality, was first proposed by Popescu and Rohrlich to examine the question: given that a maximally entangled pair of qubits is non-local, why is it not maximally non-local? We believe that understanding the power of this box will yield insight into the non-locality of quantum mechanics. It was shown recently by Cerf, Gisin, Massar and Popescu, that this imaginary device is able to simulate correlations from any measurement on a singlet state. Here, we show that the non-local box can in fact do much more: through the simulation of the magic square pseudo-telepathy game and the Mermin-GHZ pseudo-telepathy game, we show that the non-local box can simulate quantum correlations that no entangled pair of qubits can, in a bipartite scenario and even in a multi-party scenario. Finally we show that a single non-local box cannot simulate all quantum correlations and propose a generalization for a multi-party non-local box. In particular, we show quantum correlations whose simulation requires an exponential amount of non-local boxes, in the number of maximally entangled qubit pairs.     

Decision making and set shifting impairments are associated with distinct symptom dimensions in obsessive-compulsive disorder.

Obsessive- compulsive disorder (OCD) is clinically heterogeneous. The authors examined how specific OCD symptom dimensions were related to neuropsychological functions using multiple regression analyses. A total of 39 OCD patients and 40 controls completed the Iowa Gambling Task (IGT; A. Bechara, A. R. Damasio, H. Damasio, & S. W. Anderson, 1994), which is a test of decision making, and the Wisconsin Card Sorting Test (R. K. Heaton, 1981), which is a test of set shifting. OCD patients and controls showed comparable decision making. However, patients with prominent hoarding symptoms showed impaired decision making on the IGT as well as reduced skin conductance responses. OCD patients had poorer set shifting abilities than controls, and symmetry/ordering symptoms were negatively associated with set shifting. These results help explain previous inconsistent findings in neuropsychological research in OCD and support recent neuroimaging data showing dissociable neural mechanisms involved in mediating the different OCD symptom dimensions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality and functional outcome following traumatic brain injury.

Objective: To investigate pre- to postinjury personality change in relation to outcomes following traumatic brain injury (TBI). Design: Prospective analysis of personality ratings, depression, and outcome using multiple regression analyses. Participants: Cohort of 3 clinical trauma groups (mild TBI, moderate-severe TBI, orthopedic injury) and their significant others (SO). Outcome Measures: Independent Living Scale, Vocational Independence Scale, and Mayo-Portland Adaptability Inventory, 1-2 years postinjury. Predictor Variables: Posttraumatic amnesia (PTA); patient and SO NEO Personality Inventory-Revised ratings of preinjury personality taken at 1-2 months postinjury. Results: Personality function was normal for all groups (regardless of rating source) and stable over time. Neuroticism, and specifically depression, accounted for small proportions of variance in functional outcome, beyond PTA. Conclusions: There is little empirical evidence for significant personality disturbance or change up to 2 years post-TBI. Personality and depression contribute modestly to functional outcomes. Results support a distinction between "personality change" and behavior change following TBI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Accuracy assessment of the MODIS 16-day albedo product for snow: comparisons with Greenland in situ measurements

The accuracy of the Moderate Resolution Imaging Spectroradiometer (MODIS) 16-day albedo product (MOD43) is assessed using ground-based albedo observations from automatic weather stations (AWS) over spatially homogeneous snow and semihomogeneous ice-covered surfaces on the Greenland ice sheet. Data from 16 AWS locations, spanning the years 2000-2003, were used for this assessment. In situ reflected shortwave data were corrected for a systematic positive spectral sensitivity bias of between 0.01 and 0.09 on a site-by-site basis using precise optical black radiometer data. Results indicate that the MOD43 albedo product retrieves snow albedo with an average root mean square error (RMSE) of ±0.07 as compared to the station measurements, which have ±0.035 RMSE uncertainty. If we eliminate all satellite retrievals that rely on the backup algorithm and consider only the highest quality results from the primary bidirectional reflectance distribution function (BRDF) algorithm, the MODIS albedo RMSE is ±0.04, slightly larger than the in situ measurement uncertainty. There is general agreement between MODIS and in situ observations for albedo <0.7, while near the upper limit, a −0.05 MODIS albedo bias is evident from the scatter of the 16-site composite.     

Similarity between therapists' and clients' locus of control: Implications for therapeutic expectations and outcome.

Investigated the possible influence of locus of control (LOC) similarity between clients and therapists on therapeutic process and outcome with 21 practicing therapists (mean age 42 yrs) and 78 of their current clients (mean age 35 yrs). LOC was measured for both therapists and clients using Rotter's Internal–External Locus of Control Scale. Therapists self-administered questionnaires on their clinical expectations and therapy evaluations at the beginning and end of therapy, respectively. Questionnaires about the clients' characteristics and clinical expectations were administered at the initial stages of therapy, and questionnaires about the client's LOC and therapy evaluations were administered at the end of therapy. Results indicate that initial similarity in LOC between client and therapist significantly influenced clinical expectations, while the posttest similarity between client's and therapist's LOC significantly influenced evaluations of therapy outcome. Pretherapy matches on the LOC variable were insufficient to predict outcome; however, contemporaneous LOC scores appeared to have utility for client's and therapist's expectations and evaluations. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

3D Visualization for 2D GIS: an Analysis of the Users' Needs and a Review of Techniques*

Most of the existing geographical information systems (GIS) make limited use of algorithms for advanced computer graphics and visualization. One explanation is that few attempts are made to identify the visualization needs for different uses of GIS, and to couple such needs to the available algorithms. Another explanation is that most GIS are designed to handle two-dimensional (20) data with few obvious relationships to three-dimensional (30) visualization. In an attempt to provide a better understanding of the application of visualization in GIS, we propose a conceptual framework linking several aspects of the two fields. At the user-level, we link different uses of GIS to different categories of audience and presentation styles. At the level of implementation, we first propose different ways to create 3D data for visualization from 2D GIS data, and then we review algorithms and techniques for 3D visualization with respect to support of different presentation styles.     

Synthesis and radical polymerization of p-(2,3-dicyano-2,3-dicarbomethoxycyclopropyl)phenyl acrylate and methacrylate

Summary p-(2,3-Dicyano-2,3-dicarbomethoxycyclopropyl)phenyl acrylate 3a and methacrylate 3b were prepared by the reactions of methyl bromocyanoacetate with methyl acryloyloxybenzylidenecyanoacetate 2a or methyl p-methacryloyloxybenzylidenecyanoacetate 2b, respectively. Monomers 3a and 3b were polymerized with free-radical initiators to obtain polymers with multicyanocyclopropane functionalities in the pendant group. The resulting polymers 4a-b were soluble in acetone and the inherent viscosities were in the range of 0.15–0.25 dL/g. Solution-cast films were brittle, showing T_g values in the range of 120–150°C.     

Relationship between social and personal identities: Segregation or integration.

Recognition that self-representation includes both social and personal identities raises questions about the cognitive organization of these elements. Two models of identity structure are compared: (a) a segregation model (D. Trafimow, H. C. Triandis, & S. G. Goto; see record 1991-24271-001), which assumes that (social) identities and (personal) attributes are two distinct categories, and (b) an integration model (K. Deaux, 1992), which proposes that identities and attributes often coexist in a limited set of cognitive structures. Clustering of self-relevant information in free recall was used to assess cognitive organization in a sample of 57 students. Identities and attributes clustered separately at greater-than-chance rates, consistent with the segregation model. More detailed analysis of recall data, in which individual patterns of association between identities and attributes were considered, provides stronger support for an integration model of self-representation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)