86 research outputs found

    Mining eighteenth century ontologies: Machine learning and knowledge classification in the encyclopédie

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    The Encyclopédie of Denis Diderot and Jean le Rond d'Alembert was one of the most important and revolutionary intellectual products of the French Enlightenment. Mobilizing many of the great – and the notsogreat – philosophes of the 18th century, the Encyclopédie was a massive reference work for the arts and sciences, which sought to organize and transmit the totality of human knowledge while at the same time serving as a vehicle for critical thinking. In its digital form, it is a highly structured corpus; some 55,000 of its 77,000 articles were labeled with classes of knowledge by the editors making it a perfect sandbox for experiments with supervised learning algorithms. In this study, we train a Naive Bayesian classifier on the labeled articles and use this model to determine class membership for the remaining articles. This model is then used to make binary comparisons between labeled texts from different classes in an effort to extract the most important features in terms of class distinction. Reapplying the model onto the original classified articles leads us to question our previous assumptions about the consistency and coherency of the ontology developed by the Encyclopedists. Finally, by applying this model to another corpus from 18th century France, the Journal de Trévoux, or Mémoires pour l'Histoire des Sciences & des BeauxArts, new light is shed on the domain of Literature as it was understood and defined by 18th century writers

    Association entre les affections buccodentaires et le cancer colorectal : une revue et synthèse de la littérature

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    Position du problème: La parodontite chronique et l’édentement sont des affections buccodentaires chroniques qui, depuis quelques décennies, sont incriminées dans la survenue de différents types de cancers. Cette revue de littérature avait pour but d’examiner l’association entre le cancer colorectal et ces affections buccodentaires. Résultats: Les études épidémiologiques évaluant une association potentielle entre la parodontite, l’édentement et le cancer colorectal sont peu nombreuses. Cependant, plusieurs mécanismes plaident en faveur de cette association, notamment l’inflammation, la nutrition et possiblement l’infection par certains pathogènes, comme le suggère cette revue de la littérature.Background: Chronic periodontitis and tooth loss are chronic oral conditions that, in recent decades, have been implicated in the occurence of certain types of cancer. In this review, we address the question of whether colorectal cancer is associated with these oral conditions. Results: Epidemiological studies evaluating a potential association between periodontitis, tooth loss and colorectal cancer are scarce. However, several mechanisms argue in favor of this association, notably inflammation, nutrition and possibly infection by specific bacteria, as suggested by this literature review

    Rapid Identification of Synthetic Cannabinoids in Herbal Incenses with DART-MS and NMR

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    The usage of herbal incenses containing synthetic cannabinoids has caused an increase in medical incidents and triggered legislations to ban these products throughout the world. Law enforcement agencies are experiencing sample backlogs due to the variety of the products and the addition of new and still-legal compounds. In our study, proton nuclear magnetic resonance (NMR) spectroscopy was employed to promptly screen the synthetic cannabinoids after their rapid, direct detection on the herbs and in the powders by direct analysis in real time mass spectrometry (DART-MS). A simple sample preparation protocol was employed on 50 mg of herbal sample matrices for quick NMR detection. Ten synthetic cannabinoids were discovered in fifteen herbal incenses. The combined DART-MS and NMR methods can be used to quickly screen synthetic cannabinoids in powder and herbal samples, serving as a complementary approach to conventional GC-MS or LC-MS methods

    Gender Differences in Visuospatial Abilities and Complex Mathematical Problem Solving

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    Mathematical problem-solving and spatial visualization are areas in which performance has been shown to vary with sex. This article describes the impact of gender on spatial relations measured in 331 secondary school students (202 males, 129 females), 145 (105 males, 40 females) of whom had been selected to participate in a mathematical talent stimulation project after passing a complex problem-solving test. In the two tests administered, the Differential Aptitude Tests-Space Relations (DAT-SR) and the Primary Mental Abilities-Space Relations (PMA-SR), performance was assessed on the grounds of both absolute scores and the ratio to the number of items answered. The students participating in the talent program earned higher scores on both tests, although no interaction was identified between mathematical abilities and gender in connection with the differences in spatial habilities observed. In PMA-SR, boys answered more items and scored higher, whereas in DAT-SR girls tended to omit more items. None of the indicators studied exhibited differences between the sexes in both tests and in some cases the differences in the absolute values of the indicators were absent when expressed as ratios

    Wide-Field Infrared Survey Telescope (WFIRST) - Optical Telescope Assembly (OTA) Status

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    The WFIRST Mission is the next large astrophysical observatory for NASA after the James Webb Space Telescope and is the top priority mission from the 2010 National Academy of Sciences' decadal survey. The WFIRST OTA includes the inherited primary and secondary mirrors with precision metering structures that are to be integrated to new mirror assemblies to provide optical feeds to the two WFIRST science instruments. We present here: (1) the results for the review of the inherited hardware for WFIRST through a thorough technical pedigree process, (2) the status of the effort to establish the capability of the telescope to perform at a cooler operational temperature of 265K, and (3) the status of the work in requirement development for OTA to incorporate the inherited hardware, and (4) the path forward

    Men and Women Exhibit a Differential Bias for Processing Movement versus Objects

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    Sex differences in many spatial and verbal tasks appear to reflect an inherent low-level processing bias for movement in males and objects in females. We explored this potential movement/object bias in men and women using a computer task that measured targeting performance and/or color recognition. The targeting task showed a ball moving vertically towards a horizontal line. Before reaching the line, the ball disappeared behind a masking screen, requiring the participant to imagine the movement vector and identify the intersection point. For the color recognition task, the ball briefly changed color before disappearing beneath the mask and participants were required only to identify the color shade. Results showed that targeting accuracy for slow and fast moving balls was significantly better in males compared to females. No sex difference was observed for color shade recognition. We also studied a third, dual attention task comprised of the first two, where the moving ball briefly changed color randomly just before passing beneath the masking screen. When the ball changed color, participants were required only to identify the color shade. If the ball didn't change color, participants estimated the intersection point. Participants in this dual attention condition were first tested with the targeting and color tasks alone and showed results that were similar to the previous groups tested on a single task. However, under the dual attention condition, male accuracy in targeting, as well as color shade recognition, declined significantly compared to their performance when the tasks were tested alone. No significant changes were found in female performance. Finally, reaction times for targeting and color choices in both sexes correlated highly with ball speed, but not accuracy. Overall, these results provide evidence of a sex-related bias in processing objects versus movement, which may reflect sex differences in bottom up versus top-down analytical strategies

    Effects of FVB/NJ and C57Bl/6J strain backgrounds on mammary tumor phenotype in inducible nitric oxide synthase deficient mice

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    The ability to genetically manipulate mice has led to rapid progress in our understanding of the roles of different gene products in human disease. Transgenic mice have often been created in the FVB/NJ (FVB) strain due to its high fecundity, while gene-targeted mice have been developed in the 129/SvJ-C57Bl/6J strains due to the capacity of 129/SvJ embryonic stem cells to facilitate germline transmission. Gene-targeted mice are commonly backcrossed into the C57Bl/6J (B6) background for comparison with existing data. Genetic modifiers have been shown to modulate mammary tumor latency in mouse models of breast cancer and it is commonly known that the FVB strain is susceptible to mammary tumors while the B6 strain is more resistant. Since gene-targeted mice in the B6 background are frequently bred into the polyomavirus middle T (PyMT) mouse model of breast cancer in the FVB strain, we have sought to understand the impact of the different genetic backgrounds on the resulting phenotype. We bred mice deficient in the inducible nitric oxide synthase (iNOS) until they were congenic in the PyMT model in the FVB and B6 strains. Our results reveal that the large difference in mean tumor latencies in the two backgrounds of 53 and 92 days respectively affect the ability to discern smaller differences in latency due to the Nos2 genetic mutation. Furthermore, the longer latency in the B6 strain enables a more detailed analysis of tumor formation indicating that individual tumor development is not stoichastic, but is initiated in the #1 glands and proceeds in early and late phases. NO production affects tumors that develop early suggesting an association of iNOS-induced NO with a more aggressive tumor phenotype, consistent with human clinical data positively correlating iNOS expression with breast cancer progression. An examination of lung metastases, which are significantly reduced in PyMT/iNOS(−/−) mice compared with PyMT/iNOS(+/+) mice only in the B6 background, is concordant with these findings. Our data suggest that PyMT in the B6 background provides a useful model for the study of inflammation-induced breast cancer

    Evaluation of lymph node numbers for adequate staging of Stage II and III colon cancer

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    <p>Abstract</p> <p>Background</p> <p>Although evaluation of at least 12 lymph nodes (LNs) is recommended as the minimum number of nodes required for accurate staging of colon cancer patients, there is disagreement on what constitutes an adequate identification of such LNs.</p> <p>Methods</p> <p>To evaluate the minimum number of LNs for adequate staging of Stage II and III colon cancer, 490 patients were categorized into groups based on 1-6, 7-11, 12-19, and ≥ 20 LNs collected.</p> <p>Results</p> <p>For patients with Stage II or III disease, examination of 12 LNs was not significantly associated with recurrence or mortality. For Stage II (HR = 0.33; 95% CI, 0.12-0.91), but not for Stage III patients (HR = 1.59; 95% CI, 0.54-4.64), examination of ≥20 LNs was associated with a reduced risk of recurrence within 2 years. However, examination of ≥20 LNs had a 55% (Stage II, HR = 0.45; 95% CI, 0.23-0.87) and a 31% (Stage III, HR = 0.69; 95% CI, 0.38-1.26) decreased risk of mortality, respectively. For each six additional LNs examined from Stage III patients, there was a 19% increased probability of finding a positive LN (parameter estimate = 0.18510, p < 0.0001). For Stage II and III colon cancers, there was improved survival and a decreased risk of recurrence with an increased number of LNs examined, regardless of the cutoff-points. Examination of ≥7 or ≥12 LNs had similar outcomes, but there were significant outcome benefits at the ≥20 cutoff-point only for Stage II patients. For Stage III patients, examination of 6 additional LNs detected one additional positive LN.</p> <p>Conclusions</p> <p>Thus, the 12 LN cut-off point cannot be supported as requisite in determining adequate staging of colon cancer based on current data. However, a minimum of 6 LNs should be examined for adequate staging of Stage II and III colon cancer patients.</p
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