Contextual web searches in Facebook using learning materials and discussion messages

The web is nowadays one of the main information sources, and information search is an important area in which many advances have been registered. One approach to improve web search results is to consider contextual information. Usually, information about context has been provided through user logs on previous searches or the monitoring of clicks on first results, but different approaches can be used in specific environments. In a web based learning environment, existing documents and exchanged messages could provide contextual information. So, the main goal of this work is to provide a contextual web search engine based on shared documents and messages posted in a social network used for collaborative learning. Contextual search is provided through query expansion using learning documents (material provided by the teacher) and discussion messages (posts, links and comments that result from the participants’ interactions). A prototype was implemented and used in a learning scenario to acquire the context in a learning community. The proposed approach makes the context acquisition faster and more dynamic as it considers an automatic approach over text processing of documents and discussions. In addition, the results of the query engine with and without the contextual information were compared and the proposed approach using contextual information showed improvements in the precision of the results.     

Computational system identification for Bayesian NARMAX modelling

In this contribution we derive a computational Bayesian approach to NARMAX model identification. The identification algorithm exploits continuing advances in computational processing power to numerically obtain posterior distributions for both model structure and parameters via sampling methods. The main advantage of this approach over other NARMAX identification algorithms is that for the first time model uncertainty is characterised as a byproduct of the identification procedure. The algorithm is based on the reversible jump Markov chain Monte Carlo (RJMCMC) procedure. Key features of the approach are (i) sampling of unselected model terms for testing for inclusion in the model (the birth move), which encourages global searching of the model term space, (ii) sampling of previously selected model terms for testing for exclusion from the model—a naturally incorporated pruning step (the death move), which leads to model parsimony, and (iii) estimation of model and parameter distributions, which are naturally generated in the Bayesian framework. We present a numerical example to demonstrate the algorithm and a comparison with a forward regression method: the results show that the RJMCMC approach is competitive and gives useful additional information regarding uncertainty in both model parameters and structure.     

The stability of preferences for life-sustaining care among persons with AIDS in the Boston Health Study

In 1982, the World Health Organization (WHO) identified inadequate relief from cancer pain as an international health problem. WHO recommended that governments develop and implement national policies and programs for cancer pain relief. This report evaluates national health policy and the systems of health care delivery in relation to cancer pain management in the new South Africa. This field study included multiple methods of data collection: analysis of documents, field trips with participant observation in sites of care delivery, focused interviews, and in-depth interviews of key informants. The purposive sample of key informants (n = 33) represented multiple stakeholders in a variety of settings. Strengths of the developing health policy include specific recommendations related to palliative care; the shift to universal primary care; policies to support drug availability; the inclusion of morphine and codeine as essential drug at the primary health care level; and the development of a national standard related to cancer pain management. Health services are characterized by two parallel systems of care (private and public) with numerous vestiges of the inequities of apartheid. The management of pain varies by provider and setting; major problems with access exist in the rural areas. Health services in South Africa have been plagued by inequity and inadequate resources. New health policies have set a path to ensure universal access to health care including palliative care for cancer. Their successful implementation is the next necessary step toward improving health services and alleviating the suffering of increasing numbers of individuals with cancer.     

Ultrasonic Attenuation Due to Grain Boundary Scattering in Pure Niobium

Experimental confirmation of various grain scattering theories exist but there are still outstanding questions concerning the characterization of microstructure using ultrasound. In this study, high purity niobium serves as a model material devoid of extrinsic scattering centers (e.g., voids, precipitates, second phase particles etc.) A range of microstructures were obtained by annealing in ultrahigh vacuum at different temperatures (600–800°C) after routine cold-rolling and recrystallization heat treatment. Ultrasonic attenuation is measured as a function of a frequency for each sample. For the samples with an intermediate grain size (typically ∼50 μm), attenuation follows a power law dependence on frequency with an exponent of n∼1.6, which is close to the prediction, n=2, of classical Stochastic scattering theory. However, quantitative comparison shows that the observed attenuation is higher than predicted by the classical theory. The Stanke-Kino unified grain scattering theory may provide an explanation for the lower frequency dependence than traditional theories predict, though it still under predicts the magnitude of the attenuation. In any event, the resulting empirical relations provide a useful approach for practical grain size measurement with an acceptable level of uncertainty. The effect of a layered microstructure typical of some sheets/plates is discussed.     

Chasing the Bad News: An Analysis of 2005 Iraq and Afghanistan War Coverage on NBC and Fox News Channel

This study analyzes all stories aired on NBC Nightly News and Fox News Channel's Special Report With Brit Hume during 2005 about the U.S. wars in Iraq and Afghanistan, and compares that coverage with real‐world indicators to address an important question: Did the news media over‐report bad news from these conflicts, as claimed by the Bush administration and as one might expect given research into the press' negativity bias? This study finds that while both channels focused a fair amount on negative storylines, overall the news actually underplayed bad news from both countries. Fox News was much more sympathetic to the administration than NBC, suggesting that scholars should consider Fox as alternative, rather than mainstream, media.     

The nuclear factor-kappa B RelA transcription factor is constitutively activated in human pancreatic adenocarcinoma cells

To assess the efficiency of nasally administered cartilage-specific collagens as vaccination against development of arthritis and to ameliorate already established chronic arthritis, experimental models which develop chronic arthritis, pristane-induced arthritis (PIA), and homologous collagen-induced arthritis (CIA) in the rat were selected. Cartilage-specific collagens type IX (CIX) and type II (CII) were used for vaccination intranasally. A single dose of 250 microg CII instilled intranasally in rats with established PIA ameliorated the disease. For the prevention of disease, the same dose given before immunization was found to be most effective. Most importantly, the disease was more severe if this dose was given three times. For treatment of PIA, CIX was found to be more effective than CII, whereas for treatment of CIA only CII was effective. The amelioration of CIA was associated with a marked suppression of delayed type hypersensitivity and the flare reaction to CII and lower levels of IgG2b anti-CII antibodies in serum, i.e., with suppression of the TH1 rather than the TH2 response to CII. These findings, that cartilage proteins, if given intranasally, can both prevent and ameliorate established chronic arthritis in rats, are of significant importance for possible use in rheumatoid arthritis. The identification of two different cartilage-specific proteins (CII and CIX) effective against a disease induced with a well-defined nonimmunogenic adjuvant such as pristane will be of value for enhancing the effectiveness of the treatment.     

Mechanisms of molecular interactions in polybase–polyacid complex formed by copolymers of N,N‐dimethylaminoethylmethacrylate with alkylmethacrylates and methacrylic acid with ethylacrylate

Mechanisms of molecular interaction in the blends of a polybase, a copolymer of N,N‐dimethylaminoethylmethacrylate with methylmethacrylate and butylmethacrylate (PDMAEMA–MMA/BMA), with a polyacid, a copolymer of methacrylic acid with ethylacrylate (PMAA‐co‐EA), and plasticizer, triethylcitrate (TEC), have been investigated with FTIR Spectroscopy and potentiometry. To evaluate the strengths of hydrogen and ionic bonds in the polyelectrolyte complexes, quantum‐chemical calculations were performed. According to this analysis, the energy of ionic and hydrogen bonding diminishes in the order: multi‐component complexes involving protonated aminogroup of DMAEMA (ammonium cation) in the presence of chlorine counterion with ionized or unchanged carboxyl groups and water molecules (690–520 kJ/mol) > ternary H‐bonded acid‐base complexes associated with molecule of water (520–420 kJ/mol) > binary ionic complex of carboxylate anion and ammonium cation (404 kJ/mol) > H‐bonded complex of carboxylate and ammonium ions (257 kJ/mol) > binary H‐bonded complex of uncharged carboxyl group with ammonium cation (114 kJ/mol) > ternary H‐bonded complex of uncharged carboxyl group, aminogroup and water molecule (43 kJ/mol) > binary H‐bonded complex between nonionized carboxyl and amino groups (26 kJ/mol). Proton‐donating capability of functional groups in the studied polyelectrolyte blends diminishes in the order: HN⁺(CH₃)₂ ? > HOOC? > HO? . The proton‐donating capacity can be significantly improved in the presence of Cl^? ions, the effect of which may be appreciably inhibited if Na⁺ cations are available in the blend or solution. Proton‐accepting capability weakens in the order: uncharged aminogroup > carboxylate anion > uncharged carboxyl group > hydroxyl group. The results of quantum chemical calculations facilitate interpretation of FTIR spectra. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Semantic cuing and the scale insensitivity of recency and contiguity.

In recalling a set of previously experienced events, people exhibit striking effects of recency, contiguity, and similarity: Recent items tend to be recalled best and first, and items that were studied in neighboring positions or that are similar to one another in some other way tend to evoke one another during recall. Effects of recency and contiguity have most often been investigated in tasks that require people to recall random word lists. Similarity effects have most often been studied in tasks that require people to recall categorized word lists. Here we examine recency and contiguity effects in lists composed of items drawn from 3 distinct taxonomic categories and in which items from a given category are temporally separated from one another by items from other categories, all of which are tested for recall. We find evidence for long-term recency and for long-range contiguity, bolstering support for temporally sensitive models of memory and highlighting the importance of understanding the interaction between temporal and semantic information during memory search. (PsycINFO Database Record (c) 2011 APA, all rights reserved)