SS-IDS: Statistical Signature based IDS

Security of web servers has become a sensitive subject today. Prediction of normal and abnormal request is problematic due to large number of false alarms in many anomaly based Intrusion Detection Systems(IDS). SS-IDS derives automatically the parameter profiles from the analyzed data thereby generating the Statistical Signatures. Statistical Signatures are based on modeling of normal requests and their distribution value without explicit intervention. Several attributes are used to calculate the behavior of the legitimate request on the web server. SS-IDS is best suited for the newly installed web servers which doesn’t have large number of requests in the data set to train the IDS and can be used on top of currently used signature based IDS like SNORT. Experiments conducted on real data sets have shown high accuracy up to 99.98 % for predicting valid request as valid and false positive rate ranges from 3.82-7.84%. 1

Semantic Knowledge Influences Prewired Hedonic Responses to Odors

Background Odor hedonic perception relies on decoding the physicochemical properties of odorant molecules and can be influenced in humans by semantic knowledge. The effect of semantic knowledge on such prewired hedonic processing over the life span has remained unclear. Methodology/Principal Findings The present study measured hedonic response to odors in different age groups (children, teenagers, young adults, and seniors) and found that children and seniors, two age groups characterized by either low level of (children) or weak access to (seniors) odor semantic knowledge, processed odor hedonics more on the basis of their physicochemical properties. In contrast, in teenagers and young adults, who show better levels of semantic odor representation, the role of physicochemical properties was less marked. Conclusions/Significance These findings demonstrate for the first time that the biological determinants that make an odor pleasant or unpleasant are more powerful at either end of the life span

Dissociated Representations of Pleasant and Unpleasant Olfacto-Trigeminal Mixtures: An fMRI Study

How the pleasantness of chemosensory stimuli such as odorants or intranasal trigeminal compounds is processed in the human brain has been the focus of considerable recent interest. Yet, so far, only the unimodal form of this hedonic processing has been explored, and not its bimodal form during crossmodal integration of olfactory and trigeminal stimuli. The main purpose of the present study was to investigate this question. To this end, functional magnetic resonance imaging (fMRI) was used in an experiment comparing brain activation related to a pleasant and a relatively unpleasant olfacto-trigeminal mixture, and to their individual components (CO2 alone, Orange alone, Rose alone). Results revealed first common neural activity patterns in response to both mixtures in a number of regions: notably the superior temporal gyrus and the caudate nucleus. Common activations were also observed in the insula, although the pleasant mixture activated the right insula whereas the unpleasant mixture activated the left insula. However, specific activations were observed in anterior cingulate gyrus and the ventral tegmental area only during the perception of the pleasant mixture. These findings emphasized for the firs time the involvement of the latter structures in processing of pleasantness during crossmodal integration of chemosensory stimuli

Trust in the Transplant Team Associated With the Level of Chronic Illness Management—A Secondary Data Analysis of the International BRIGHT Study

A trustful relationship between transplant patients and their transplant team (interpersonal trust) is essential in order to achieve positive health outcomes and behaviors. We aimed to 1) explore variability of trust in transplant teams; 2) explore the association between the level of chronic illness management and trust; 3) investigate the relationship of trust on behavioral outcomes. A secondary data analysis of the BRIGHT study (ID: NCT01608477; https://clinicaltrials.gov/ct2/show/NCT01608477?id=NCT01608477&rank=1) was conducted, including multicenter data from 36 heart transplant centers from 11 countries across four different continents. A total of 1,397 heart transplant recipients and 100 clinicians were enrolled. Trust significantly varied among the transplant centers. Higher levels of chronic illness management were significantly associated with greater trust in the transplant team (patients: AOR= 1.85, 95% CI = 1.47–2.33, p < 0.001; clinicians: AOR = 1.35, 95% CI = 1.07–1.71, p = 0.012). Consultation time significantly moderated the relationship between chronic illness management levels and trust only when clinicians spent ≥30 min with patients. Trust was significantly associated with better diet adherence (OR = 1.34, 95%CI = 1.01–1.77, p = 0.040). Findings indicate the relevance of trust and chronic illness management in the transplant ecosystem to achieve improved transplant outcomes. Thus, further investment in re-engineering of transplant follow-up toward chronic illness management, and sufficient time for consultations is required

Influence of early exposure and of acquired semantic knowledge on hedonic responses to odor : psychophysics and neurophysiological studies

Pour une grande majorité d’espèces, l’olfaction contribue à la survie, et pour d’autres elle suscite en plus des réponses hédoniques qui guident les comportements, qu’ils soient appétitifs ou aversifs. C’est le cas notamment de l’espèce humaine chez qui les réponses hédoniques aux odeurs contribuent de façon importante à la régulation de certains de nos comportements (plaisir alimentaire, plaisir d’humer, reproductif peut être). Bien que cette valeur émotive que l’on confère à l’odorat soit incontestée, son déterminisme reste encore flou et finalement peu étudié. Un grand nombre de données de la littérature mettent l’accent sur le rôle de l’expérience et de l’apprentissage sur la mise en place des réponses hédoniques chez l’Homme. Cependant, même si ces données nous éclairent sur les déterminants de la perception émotionnelle des odeurs à l’âge adulte, elles ne précisent pas leur évolution temporelle : quel rôle jouent le développement humain, les connaissances acquises durant les apprentissages, qu’ils soient implicites ou explicites ? La présente thèse a tenté d’apporter des éléments de réponse à ces deux questions à travers deux études. Pris dans leur ensemble, les résultats de ce travail de thèse suggèrent ainsi que les réponses hédoniques aux odeurs seraient la résultante d’un équilibre entre des facteurs externes, tels que les caractéristiques physicochimiques des odorants, et des facteurs internes plus cognitifs, tels que les connaissances sémantiques acquises à travers l’expérience et plus particulièrement l’exposition précoceFor a large majority of species, olfaction contributes to survival, and for others it induces hedonic responses that guide behavior, whether appetitive or aversive. This is particularly true for the human species in which the hedonic responses to odors contribute significantly to the regulation of some behaviors (food pleasure, the pleasure of smelling flowers, reproduction may be). While the emotional value of smells is undisputed, its determinism is still unclear, and little studied. A large number of scientific data emphasize the role of experience and learning on the development of hedonic responses in humans. However, although these data highlight the determinants of emotional perception of odors in adulthood, they do not specify their temporal evolution: what is the role of human development and of knowledge acquired during learning? This thesis has attempted to provide answers to these questions through two studies. Taken together, the results of this work suggest that hedonic responses to odors are the result of a balance between external factors such as physicochemical properties of odorants, and internal and more cognitive factors, such as semantic knowledge acquired through experience and especially early exposur

Repeated exposure to odors induces affective habituation of perception and sniffing

International audienceOlfactory perception, and especially hedonic evaluation of odors, is highly flexible, but some mechanisms involved in this flexibility remain to be elucidated. In the present study we aimed at better understanding how repeated exposure to odors can affect their pleasantness. We tested the hypothesis of an affective habituation to the stimuli, namely a decrease of emotional intensity over repetitions. More specifically, we tested whether this effect is subject to inter-individual variability and whether it can also be observed at the olfactomotor level. Twenty-six participants took part in the experiment during which they had to smell two odorants, anise and chocolate, presented 20 times each. On each trial, sniff duration and volume were recorded and paired with ratings of odor pleasantness and intensity. For each smell, we distinguished between “likers” and “dislikers,” namely individuals giving positive and negative initial hedonic evaluations. Results showed a significant decrease in pleasantness with time when the odor was initially pleasant (“likers”), while unpleasantness remained stable or slightly decreased when the odor was initially unpleasant (“dislikers”). This deviation toward neutrality was interpreted as affective habituation. This effect was all the more robust as it was observed for both odors and corroborated by sniffing, an objective measurement of odor pleasantness. Affective habituation to odors can be interpreted as an adaptive response to stimuli that prove over time to be devoid of positive or negative outcome on the organism. This study contributes to a better understanding of how olfactory preferences are shaped through exposure, depending on the individual's own initial perception of the odor

'I don't want to know about it !' Unpleasantness prevents odor identification

Affective evaluation is one of the critical early stages in the cognitive processing of olfactory information and may involve different mechanisms for unpleasant and pleasant odorants. One hypothesis for such dissociation is that as opposed to pleasant odors, unpleasant smells would entail a "quick and dirty" pathway that may have weak links with the high-level cognitive function of language. In the present study we tested this hypothesis. Forty participants (age 19-25 years) were exposed to 9 odorants known to cover a wide range of hedonic responses (pleasant, neutral, unpleasant). The experiment consisted in 3 sessions: 1) in a 1-second sniff, we analyzed facial mimics and spontaneous verbal responses; 2) in a 2nd task subjects were to rank odorants from the most pleasant to the most unpleasant; 3) in a 3rd delayed task, participants smelled again the odorants, and described their impressions as precisely as possible. Statistical analyses included a variable named "identification rate" that was based on providing a label, no matter correct or not. "Identification rate" was entered into an ANOVA with duration of exposure (first task / third task) and odor valence (unpleasant, neutral vs. pleasant) as within-subject variables. Results showed effects of odor valence during both the first spontaneous task (p<.0008) and the third delayed task (p<.0001): in line with our hypothesis, odor "identification rate" was enhanced with pleasant odors and reduced with unpleasant odors (compared to neutral odors). Taken together, these results showed that attempting to identify a smell is a spontaneous mechanism dedicated to pleasant odorants and at a very less degree to bad smells

Perceptual and Sensorimotor Differences between “Good” and “Poor” Olfactory Mental Imagers

International audienc

Web Analyzing Traffic Challenge: Description and Results

International audienceThis paper describes the Web Analyzing Traffic Challenge (Discovery Challenge of ECML/PKDD'07) and the results. Using the data from query logs it is possible to recognize an attack and define its class. Then the aim of this challenge is the filtering of attacks in Web traffic