False Profiles Research Articles

Information exchange and information disclosure in social networking web sites

PurposeThe purpose of this paper is to examine the mediating effect of trust on the relationship between the type of information exchange (IE) and information disclosure (ID) on social networking web sites (SNWs).Design/methodology/approachConstructs were developed for type of IE and trust. To understand the mediating role of trust a mediation analysis was conducted. To test for mediation effects, the four step procedure of partial mediation analysis was used.FindingsThere was found to be a partial mediating effect of trust on the relationship between the type of IE and ID on SNWs.Practical implicationsSince the basis of formation of the communities is similarities, when there is trust amongst the community members they would not post false profiles but real profiles and the extent of ID would be higher.Originality/valueIn most of the studies it is suggested that the type of exchange and trust is dependent upon information disclosure, as against the study in which we found that it is the type of exchange and the trust which lead to increased ID.

A methodology to model flow-thermals inside a domestic gas oven

Abstract In this paper, the authors describe development of a CFD based methodology to evaluate performance of a domestic gas oven. This involves modeling three-dimensional, unsteady, forced convective flow field coupled with radiative participating media. Various strategies for capturing transient heat transfer coupled with mixed convection flow field are evaluated considering the trade-off between computational time and accuracy of predictions. A new technique of modeling gas oven that does not require detailed modeling of flow-thermals through the burner is highlighted. Experiments carried out to support this modeling development shows that heat transfer from burners can be represented as non-dimensional false bottom temperature profiles. Transient validation of this model with experiments show less than 6% discrepancy in thermal field during preheating of bake cycle of gas oven.

Peptizer, a Tool for Assessing False Positive Peptide Identifications and Manually Validating Selected Results

False positive peptide identifications are a major concern in the field of peptidecentric, mass spectrometry-driven gel-free proteomics. They occur in regions where the score distributions of true positives and true negatives overlap. Removal of these false positive identifications necessarily involves a trade-off between sensitivity and specificity. Existing postprocessing tools typically rely on a fixed or semifixed set of assumptions in their attempts to optimize both the sensitivity and the specificity of peptide and protein identification using MS/MS spectra. Because of the expanding diversity in available proteomics technologies, however, these postprocessing tools often struggle to adapt to emerging technology-specific peculiarity. Here we present a novel tool named Peptizer that solves this adaptability issue by making use of pluggable assumptions. This research-oriented postprocessing tool also includes a graphical user interface to perform efficient manual validation of suspect identifications for optimal sensitivity recovery. Peptizer is open source software under the Apache2 license and is written in Java.

Comparative Study of Machine-Learning and Chemometric Tools for Analysis of In-Vivo High-Throughput Screening Data

High-throughput screening (HTS) has become a central tool of many pharmaceutical and crop-protection discovery operations. If HTS screening is carried out at the level of the intact organism, as is commonly done in crop protection, this strategy has the potential of uncovering a completely new mechanism of actions. The challenge in running a cost-effective HTS operation is to identify ways in which to improve the overall success rate in discovering new biologically active compounds. To this end, we describe our efforts directed at making full use of the data stream arising from HTS. This paper describes a comparative study in which several machine learning and chemometric methodologies were used to develop classifiers on the same data sets derived from in vivo HTS campaigns and their predictive performances compared in terms of false negative and false positive error profiles.

An Evaluation of Neighbourhood Formation on the Performance of Collaborative Filtering

Personalisation features are key to the success of many web applications and collaborative recommender systems have been widely implemented. These systems assist users in finding relevant information or products from the vast quantities that are frequently available. In previous work, we have demonstrated that such systems are vulnerable to attack and that recommendations can be manipulated. We introduced the concept of robustness as a performance measure, which is defined as the ability of a system to provide consistent predictions in the presence of noise in the data. In this paper, we expand on our previous work by examining the effects of several neighbourhood formation schemes and similarity measures on system performance. We propose a neighbourhood filtering mechanism for filtering false profiles from the neighbourhood in order to improve the robustness of the system.

Morphometric analysis of horizontal canal nerves of chronically diabetic rats

Horizontal canal nerves of 3-, 6-, 9-, and 12-month-diabetic rats were compared with those of age-matched controls. The myelin sheaths of the horizontal canal nerves in diabetic rats were thinner than those of age-matched controls (mean ± SD 0.63 ± 0.04 μm [n = 16] vs. 0.71 ± 0.05 μm [n = 9]; p < 0.0001, one-tailed t test). Regression analysis revealed that myelin sheath thickness did not correlate with severity of diabetes, but myelin thinning did occur as a function of the duration of diabetes ( p < 0.05, regression ANOVA). The progression of myelin thinning over time is consistent with the possibility of an accelerated decline in vestibular function with age in diabetic patients. That myelin thinning did not correlate with the severity of diabetes suggests that this thinning is not directly related to the aging effects attributed to nonenzymatic glycosylation of myelin proteins. Multivariate analysis revealed a significant difference between diabetic and control groups when fiber diameter and intrasheath diameter were considered together ( p < 0.008, canonical discriminant-function analysis). Diabetic and control groups did not differ significantly in total nerve fiber counts. In the diabetic group, however, nerve fiber counts were higher in animals with higher blood glucose levels ( p < 0.02, linear-regression ANOVA; r 2 = 0.49). The finding of higher nerve fiber counts in more severely diabetic rats is consistent with an earlier transmission electron microscopic finding of false myelinated nerve fiber profiles in micrographs from more severely diabetic rats. These false profiles are believed to represent phagocytosis-like Schwann cell reactions against their own myelin, triggered by excess myelin glycosylation. (Otolaryngol Head Neck Surg 1999;120:174-9.)

Comparative evaluation of the use of artificial neural networks for modelling the epidemiology of schistosomiasis mansoni

There has been a marked increase in the application of approaches based on artificial intelligence (AI) in the field of computer science and medical diagnosis, but AI is still relatively unused in epidemiological settings. In this study we report results of the application of neural networks (NN; a special category of AI) to schistosomiasis. It was possible to design an NN structure which can process and fit epidemiological data collected from 251 schoolchildren in Egypt using the first year's data to predict second and third years' infection rates. Data collected over 3 years included age, gender, exposure to canal water and agricultural activities, medical history and examination, and stool and urine parasitology. Schistosoma mansoni infection rates were 50%, 78% and 66% at the baseline and the 2 follow-up periods, respectively. NN modelling was based on the standard back-propagation algorithm, in which we built a suitable configuration of the network, using the first year's data, that optimized performance. It was implemented on an IBM compatible computer using commercially available software. The performance of the NN model in the first year compared favourably with logistic regression (NN sensitivity = 83% (95% confidence interval [CI] 78–88%) and positive predictive value (PPV) = 63% (95% CI 57–69%); logistic regression sensitivity = 66% (95% CI 60%–72%) and PPV = 59% (95% CI 53%–65%). The NN model generalized the criteria for predicting infection over time better than logistic regression and showed more stability over time, as it retained its sensitivity and specificity and had better false positive and negative profiles than logistic regression. The potential of NN-based models to analyse and predict wide-scale control programme data, which are inevitably based on unstable egg excretion rates and insensitive laboratory techniques, is promising but still untapped.

Probing the cognitive representation of musical time: Structural constraints on the perception of timing perturbations

To determine whether structural factors interact with the perception of musical time, musically literate listeners were presented repeatedly with eight-bar musical excerpts, realized with physically regular timing on an electronic piano. On each trial, one or two randomly chosen time intervals were lengthened by a small amount, and the listeners had to detect these “hesitations” and mark their positions in the score. The resulting detection accuracy profile across all positions in each musical excerpt showed pronounced dips in places where lenghtening would typically occur in an expressive (temporally modulated) performance. False alarm percentages indicated that certain tones seemed longer a priori, and these were among the ones whose actual lenghtening was easiest to detect. The detection accuracy and false alarm profiles were significantly correlated with each other and with the temporal microstructure of expert performances, as measured from sound recordings by famous artists. Thus the detection task apparently tapped into listeners' musical thought and revealed their expectations about the temporal microstructure of music performance. These expectations, like the timing patterns of actual performances, derive from the cognitive representation of musical structure, as cued by a variety of systemic factors (grouping, meter, harmonic progression) and their acoustic correlates. No simple psycho-acoustic explanation of the detection accuracy profiles was evident. The results suggest that the perception of musical time is not veridical but “warped” by the structural representation. This warping may provide a natural basis for performance evaluation: expected timing patterns sound more or less regular, unexpected ones irregular. Parallels to language performance and perception are noted.

Traditional construction in the architecture of Gaudi

In order to create the original and beautiful architectural forms which made Gaudi famous, the architect solely employed traditional materials (brick, stone, glazed ceramic lime and quick-drying cement for mortar, plaster, etc.) and techniques, or their derivations. The author reviews these Gaudinian construction techniques, from the simple column to hyperbolic paraboloids, the square column, the false arch, festoon arches or catenary profiles, spiral arches. Catalan vaults (brick vault of one, two or more ceilings of brick laid flat), ribbed vaulting, cupolas, penditives, partition arches, etc.

Visualization of non-synaptic release sites in the myenteric plexus of the snail Helix pomatia

Following conventional glutaraldehyde osmium tetroxidc fixation, a rich mycnteric plexus was detected in the gastrointestinal tract of the snail Helix pomatia. Although hundreds of nerve processes were observed in the extensive myoneural neuropil, true synaptic specializations were not recognized in them. In the absence of synaptic specializations, tannic acid Ringer incubation was applied to visualize the non-synaptic release sites in the enteric nerve plexus. After incubation for I h. a great number of exocytosis profiles were recorded at nerve muscle contacts, at axoglial connections and in the myoneural neuropil.The frequency of occurrence of exocytosis profiles was the same for adrenergic and peptidergic libres. In some gut wall areas, a dense staining of both basal lamina and collagen Ohres was observed. Invagination of dense basal lamina into the omega-shaped profiles of the axolemma led to ȁfalse exocytosisȁ profiles. A detailed morphological analysis is needed to distinguish false exocytosis profiles from the true transmitter-releasing loci.