Positivity of the English language

Over the last million years, human language has emerged and evolved as a fundamental instrument of social communication and semiotic representation. People use language in part to convey emotional information, leading to the central and contingent questions: (1) What is the emotional spectrum of natural language? and (2) Are natural languages neutrally, positively, or negatively biased? Here, we report that the human-perceived positivity of over 10,000 of the most frequently used English words exhibits a clear positive bias. More deeply, we characterize and quantify distributions of word positivity for four large and distinct corpora, demonstrating that their form is broadly invariant with respect to frequency of word use.Comment: Manuscript: 9 pages, 3 tables, 5 figures; Supplementary Information: 12 pages, 3 tables, 8 figure

Ultrastructure of the Intramandibular Gland of Workers and Queens of the Stingless Bee, Melipona quadrifasciata

The intramandibular glands of workers and queens of Melipona quadrifasciata Lepeletier (Hymenoptera: Apidae), at different ages and from different functional groups, were studied using light and transmission electron microscopy. The results demonstrated that these glands are composed of two types of secretory structures: 1.A hypertrophied epidermis on the dorsal side of the mandible that is an epithelial gland. 2. Free secretory cells filling the inner spaces of the appendices that constitute a unicellular gland. The epithelial gland is larger in the young (1-2-day-old workers), and the gland becomes involuted during the nurse worker stage. The unicellular glands of the workers posses some secretion during all of the studied phases, but secretory activity is more intensive in the foraging workers. Vesicles of secretion are absent in the unicellular glands of queens. These results demonstrate that these glands show functional adaptations in different castes corresponding to the functions of each caste

A new approach to bad news effects on volatilit y: the multiple-sign-volume sensitive regime EGARCH model (MSV-EGARCH)

In this paper, using daily data for six major international stock market indexes and a modified EGARCH specification, the links between stock market returns, volatility and trading volume are investigated in a new nonlinear conditional variance framework with multiple regimes and volume eff ects. Volatility forecast comparisons, using the Harvey-Newbold test for multiple forecasts encompassing, seem to demonstrate that the MSV- EGARCH complex threshold structure is able to correctly fit GARCH- type dynamics of the series under study and dominates competing standard asymmetric models in several of the considered stock indexes.info:eu-repo/semantics/publishedVersio

Network 'small-world-ness': a quantitative method for determining canonical network equivalence

Background: Many technological, biological, social, and information networks fall into the broad class of 'small-world' networks: they have tightly interconnected clusters of nodes, and a shortest mean path length that is similar to a matched random graph (same number of nodes and edges). This semi-quantitative definition leads to a categorical distinction ('small/not-small') rather than a quantitative, continuous grading of networks, and can lead to uncertainty about a network's small-world status. Moreover, systems described by small-world networks are often studied using an equivalent canonical network model-the Watts-Strogatz (WS) model. However, the process of establishing an equivalent WS model is imprecise and there is a pressing need to discover ways in which this equivalence may be quantified. Methodology/Principal Findings: We defined a precise measure of 'small-world-ness' S based on the trade off between high local clustering and short path length. A network is now deemed a 'small-world' if S. 1-an assertion which may be tested statistically. We then examined the behavior of S on a large data-set of real-world systems. We found that all these systems were linked by a linear relationship between their S values and the network size n. Moreover, we show a method for assigning a unique Watts-Strogatz (WS) model to any real-world network, and show analytically that the WS models associated with our sample of networks also show linearity between S and n. Linearity between S and n is not, however, inevitable, and neither is S maximal for an arbitrary network of given size. Linearity may, however, be explained by a common limiting growth process. Conclusions/Significance: We have shown how the notion of a small-world network may be quantified. Several key properties of the metric are described and the use of WS canonical models is placed on a more secure footing

New insights into the classification and nomenclature of cortical GABAergic interneurons.

A systematic classification and accepted nomenclature of neuron types is much needed but is currently lacking. This article describes a possible taxonomical solution for classifying GABAergic interneurons of the cerebral cortex based on a novel, web-based interactive system that allows experts to classify neurons with pre-determined criteria. Using Bayesian analysis and clustering algorithms on the resulting data, we investigated the suitability of several anatomical terms and neuron names for cortical GABAergic interneurons. Moreover, we show that supervised classification models could automatically categorize interneurons in agreement with experts' assignments. These results demonstrate a practical and objective approach to the naming, characterization and classification of neurons based on community consensus

Reactive Oxygen Species Production and Mitochondrial Dysfunction Contribute to Quercetin Induced Death in Leishmania amazonensis

BACKGROUND: Leishmaniasis, a parasitic disease caused by protozoa of the genus Leishmania, affects more than 12 million people worldwide. Quercetin has generated considerable interest as a pharmaceutical compound with a wide range of therapeutic activities. One such activity is exhibited against the bloodstream parasite Trypanosoma brucei and amastigotes of Leishmania donovani. However, the mechanism of protozoan action of quercetin has not been studied. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, we report here the mechanism for the antileishmanial activity of quercetin against Leishmania amazonensis promastigotes. Quercetin inhibited L. amazonensis promastigote growth in a dose- and time- dependent manner beginning at 48 hours of treatment and with maximum growth inhibition observed at 96 hours. The IC(50) for quercetin at 48 hours was 31.4 µM. Quercetin increased ROS generation in a dose-dependent manner after 48 hours of treatment. The antioxidant GSH and NAC each significantly reduced quercetin-induced cell death. In addition, quercetin caused mitochondrial dysfunction due to collapse of mitochondrial membrane potential. CONCLUSIONS/SIGNIFICANCE: The effects of several drugs that interfere directly with mitochondrial physiology in parasites such as Leishmania have been described. The unique mitochondrial features of Leishmania make this organelle an ideal drug target while minimizing toxicity. Quercetin has been described as a pro-oxidant, generating ROS which are responsible for cell death in some cancer cells. Mitochondrial membrane potential loss can be brought about by ROS added directly in vitro or induced by chemical agents. Taken together, our results demonstrate that quercetin eventually exerts its antileishmanial effect on L. amazonensis promastigotes due to the generation of ROS and disrupted parasite mitochondrial function

Syzygium jambolanum treatment improves survival in lethal sepsis induced in mice

<p>Abstract</p> <p>Background</p> <p>The leaves and the fruits from <it>Syzygium jambolanum </it>DC.(Myrtaceae), a plant known in Brazil as sweet olive or 'jambolão', have been used by native people to treat infectious diseases, diabetes, and stomachache. Since the bactericidal activity of <it>S. jambolanum </it>has been confirmed <it>in vitro</it>, the aim of this work was to evaluate the effect of the prophylactic treatment with <it>S. jambolanum </it>on the <it>in vivo </it>polymicrobial infection induced by cecal ligation and puncture (CLP) in mice.</p> <p>Methods</p> <p>C57Bl/6 mice were treated by the subcutaneous route with a hydroalcoholic extract from fresh leaves of <it>S. jambolanum </it>(HCE). After 6 h, a bacterial infection was induced in the peritoneum using the lethal CLP model. The mice were killed 12 h after the CLP induction to evaluate the cellular influx and local and systemic inflammatory mediators' production. Some animals were maintained alive to evaluate the survival rate.</p> <p>Results</p> <p>The prophylactic HCE treatment increased the mice survival, the neutrophil migration to infectious site, the spreading ability and the hydrogen peroxide release, but decreased the serum TNF and nitrite. Despite the increased migration and activation of peritoneal cells the HCE treatment did not decrease the number of CFU. The HCE treatment induced a significant decrease on the bone marrow cells number but did not alter the cell number of the spleen and lymph node.</p> <p>Conclusion</p> <p>We conclude that the treatment with <it>S. jambolanum </it>has a potent prophylactic anti-septic effect that is not associated to a direct microbicidal effect but it is associated to a recruitment of activated neutrophils to the infectious site and to a diminished systemic inflammatory response.</p