1,721,056 research outputs found
Speeding up Vision Transformers Through Reinforcement Learning
No full textIn recent years, Transformers have led a revolution in Natural Language Processing, and Vision Transformers (ViTs) promise to do the same in Computer Vision. The main obstacle to the widespread use of ViTs is their computational cost. Indeed, given an image divided into a list of patches, ViTs compute, for each layer, the attention of each patch with respect to all others. In the literature, many solutions try to reduce the computational cost of attention layers using quantization, knowledge distillation, and input perturbation. In this paper, we aim to make a contribution in this setting. In particular, we propose AgentViT, a framework that uses Reinforcement Learning to train an agent whose task is to identify the least important patches during the training of a ViT. Once such patches are identified, AgentViT removes them, thus reducing the number of patches processed by the ViT. Our goal is to reduce the training time of the ViT while maintaining competitive performance
Chronic obstructive pulmonary disease: patho-physiology, current methods of treatment and the potential for simvastatin in disease management
No full textBackground. Chronic obstructive pulmonary disease (COPD) is a debilitating disease, causing severe and irreversible respiratory problems, affecting millions of people worldwide. Consequently, in recent years, research has focused on investigating new therapeutic approaches for the treatment of this pathology. Some drug classes, such as ACE inhibitors, PDE4 inhibitors and statins have demonstrated to have anti-inflammatory properties and an effect in improving COPD. Specifically, simvastatin (SV) has shown to be effective in reducing COPD morbidity and mortality.
Methods. For the SV transport study, Calu-3 cell monolayers were grown on a liquid covered culture method using 0.33 cm2 Transwell supports (0.4 μm pore size). 100μM SV solution was placed alternatively in the apical or in the basolateral chamber, and samples were collected in the other compartment every hour for 4 hours. For the effect of SV on mucus inhibition study, Calu-3 cell monolayers were grown using an air interface culture model [3]. Samples for microscope analysis were collected at day 2, 7, 11 and 14, respectively. Each sample was fixed with paraformaldheyde (4%), stained with alcian blue and placed onto a glass slide; photos of the stained cell surface were taken and mucus layer quantified as RGBB ratio.
Results: Simvastatin was transported in both the apical to basal (1.78% ± 0.09%) and basal to apical directions (1.00% ± 0.22%) suggesting a rational for delivery to the lung. Analysis of the microscopy images showed that chronic administration of simvastatin for 14 days caused a significant inhibition in mucus production.
Conclusion: Simvastatin can penetrate by passive diffusion into Calu-3 monolayer. Also, the administration of simvastatin at chronic doses inhibits mucus production. These preliminary findings suggest that local delivery to simvastatin directly to the lung may have a therapeutic effect on mucus reduction and consequently be used for COPD treatmen
Preparation and in vitro evaluation of salbutamol-loaded lipid microparticles for sustained release pulmonary therapy
No full textThe aim of this study was to prepare lipid microparticles (LMs) loaded with the polar bronchodilator agent salbutamol, and designed for sustained release pulmonary delivery. The microparticles were produced by melt emulsification followed by a sonication step, using different biocompatible lipid carriers (tristearin, stearic acid and glyceryl behenate) and phosphatidylcholine as the surfactant. The use of salbutamol free base, rather than salbutamol sulphate, was necessary to obtain the incorporation of the drug in the lipid particle matrix. The prolonged release of salbutamol base was achieved only by the glyceryl behenate microparticles (40.9% of encapsulated drug being released after 8h). The salbutamol loading was 4.2%±0.1 and the mass median diameter, determined by laser diffraction, ranged from 4.8 to 5.4m. The sustained release of LMs were formulated as a carrier-free dry powder for inhalation and exhibited a fine particle fraction of 17.3%±2.2, as measured by multi-stage liquid impinger. © 2012 Informa UK Ltd. All rights reserved
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Comparison of spray congealing and melt emulsification methods for the incorporation of the water-soluble salbutamol sulphate in lipid microparticles
No full textCONTEXT:
Salbutamol sulphate is widely used as bronchodilator for the treatment of asthma. Its use is limited by the relatively short duration of action and hence sustained delivery of salbutamol sulphate offers potential benefits to patients.
OBJECTIVE:
This study explores the preparation of lipid microparticles (LMs) as biocompatible carrier for the prolonged release of salbutamol sulphate.
MATERIALS AND METHODS:
The LMs were produced using different lipidic materials and surfactants, by classical melt emulsification-based methods (oil-in-water and water-in-oil-in-water emulsions) and the spray congealing technique.
RESULTS:
For the LMs obtained by melt emulsification a lack of release modulation was observed. On the other hand, the sustained release of salbutamol sulphate was achieved with glyceryl behenate microparticles prepared by spray congealing. These LMs were characterized by scanning electron microscopy, X-ray diffractometry and differential scanning calorimetry. The drug loading was 4.72% (w/w). The particle size distribution measured by laser diffraction and electrical zone sensing was represented by a volume median diameter (Dv(50)) of 51.7-71.4 μm. Increasing the atomization air pressure from 4 to 8 bar produced a decrease of the Dv(50) to 12.7-17.5 μm.
CONCLUSIONS:
Incorporation of the hydrophilic salbutamol sulphate into LMs with sustained release characteristics was achieved by spray congealing
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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