335 research outputs found
Extraction of User Navigation Pattern Based on Particle Swarm Optimization
With current projections regarding the growth of Internet sales, online retailing raises many questions about how to market on the Net. A Recommender System (RS) is a composition of software tools that provides valuable piece of advice for items or services chosen by a user. Recommender systems are currently useful in both the research and in the commercial areas. Recommender systems are a means of personalizing a site and a solution to the customer?s information overload problem. Recommender Systems (RS) are software tools and techniques providing suggestions for items and/or services to be of use to a user. These systems are achieving widespread success in e-commerce applications nowadays, with the advent of internet. This paper presents a categorical review of the field of recommender systems and describes the state-of-the-art of the recommendation methods that are usually classified into four categories: Content based Collaborative, Demographic and Hybrid systems. To build our recommender system we will use fuzzy logic and Markov chain algorithm
Инфекционная составляющая и иммунопатология при хронических воспалительных заболеваниях слизистой оболочки гастродуоденальной области
Выявлено коинфицирование слизистой оболочки желудочно−кишечного тракта Helicobacter pylori и вирусами группы герпеса у больных хроническим гастритом, язвенной болезнью желудка и двенадцатиперстной кишки. Проведена оценка общих и специфических иммунных реакций организма на указанные инфекционные агенты. Обнаруженные изменения в клеточном и гуморальном звене иммунитета могут свидетельствовать об обусловленном ими системном иммунопатологическом процессе.Co−infection of the gastrointestinal mucosa with Helicobacter pylori and herpes viruses in patients with chronic gastritis, gastric and duodenal ulcer was revealed. General and specific immune reactions of the organism to the above agents were evaluated. The revealed changes in the cellular and humoral immunity can suggest systemic immunopathological process
New technologies for examining neuronal ensembles in drug addiction and fear
Correlational data suggest that learned associations are encoded within neuronal ensembles. However, it has been difficult to prove that neuronal ensembles mediate learned behaviours because traditional pharmacological and lesion methods, and even newer cell type-specific methods, affect both activated and non-activated neurons. Additionally, previous studies on synaptic and molecular alterations induced by learning did not distinguish between behaviourally activated and non-activated neurons. Here, we describe three new approaches—Daun02 inactivation, FACS sorting of activated neurons and c-fos-GFP transgenic rats — that have been used to selectively target and study activated neuronal ensembles in models of conditioned drug effects and relapse. We also describe two new tools — c-fos-tTA mice and inactivation of CREB-overexpressing neurons — that have been used to study the role of neuronal ensembles in conditioned fear
Surgical resection of a giant peripheral ossifying fibroma in mouth floor managed with fiberscopic intubation
Tracheal intubation for general anesthesia can sometimes be difficult in patients with a large mass in the mouth floor. Preoperative evaluation of the patient's airway is most important when treating large oral disease
sOilFauna: a global synthesis effort on the drivers of soil macrofauna communities and functionning. 00499
Understanding global biodiversity change, its drivers, and its consequences on ecosystems requires to include soil macrofauna, a highly diverse group involved in numerous ecosystem processes. So far, our knowledge of both the factors that shape soil macrofauna communities and the ecosystem effects of these organisms is limited at the global scale, while numerous local studies exist. The project “sOilFauna” fosters the gathering of literature data on macrofauna communities and produced the most comprehensive soil macrofauna database - the MACROFAUNA database - which collates abundance and biomass data of 17 soil invertebrate groups assessed with a standardized method at ~8700 sites around the world. This dataset will allow testing many important theories in macroecology such as latitudinal gradients and productivity/perturbation-diversity relationships), as well as quantifying the responses of functional and trophic groups of soil macrofauna to different climatic, edaphic, and human-induced drivers (e.g. land use type and change). We will display preliminary results on macrofauna abundance, diversity, and biomass, with the identification of their main drivers at a global scale. The sOilFauna project and consortium also aim at encouraging the global community of soil ecologists to use and share standardized data for future research that will allow even further increase of our knowledge on this understudied group
Ability of Group IVB metallocene polyethers containing dienestrol to arrest the growth of selected cancer cell lines
<p>Abstract</p> <p>Background</p> <p>Monomeric Group IVB (Ti, Zr and Hf) metallocenes represent a new class of antitumor compounds. There is literature on the general biological activities of some organotin compounds. Unfortunately, there is little information with respect to the molecular level activity of these organotin compounds. We recently started focusing on the anti-cancer activity of organotin polymers that we had made for other purposes and as part of our platinum anti-cancer effort.</p> <p>Methods</p> <p>For this study, we synthesized a new series of metallocene-containing compounds coupling the metallocene unit with dienestrol, a synthetic, nonsteroidal estrogen. This is part of our effort to couple known moieties that offer antitumor activity with biologically active units hoping to increase the biological activity of the combination. The materials were confirmed to be polymeric using light scattering photometry and the structural repeat unit was verified employing matrix assisted laser desorption ionization mass spectrometry and infrared spectroscopy results.</p> <p>Results</p> <p>The polymers demonstrated the ability to suppress the growth of a series of tumor cell lines originating from breast, colon, prostrate, and lung cancers at concentrations generally lower than those required for inhibition of cell growth by the commonly used antitumor drug cisplatin.</p> <p>Conclusion</p> <p>These drugs show great promise in vitro against a number of cancer cell lines and due to their polymeric nature will most likely be less toxic than currently used metal-containing drugs such as cisplatin. These drugs also offer several addition positive aspects. First, the reactants are commercially available so that additional synthetic steps are not needed. Second, synthesis of the polymer is rapid, occurring within about 15 seconds. Third, the interfacial synthetic system is already industrially employed in the synthesis of aromatic nylons and polycarbonates. Thus, the ability to synthesize large amounts of the drugs is straight forward.</p
Large body size constrains dispersal assembly of communities even across short distances
International audienc
Desert Farming Benefits from Microbial Potential in Arid Soils and Promotes Diversity and Plant Health
BACKGROUND: To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known. METHODOLOGY/PRINCIPAL FINDINGS: We studied the impact of long-term agriculture on desert soil in one of the most prominent examples for organic desert farming in Sekem (Egypt). Using a polyphasic methodological approach to analyse microbial communities in soil as well as associated with cultivated plants, drastic effects caused by 30 years of agriculture were detected. Analysing bacterial fingerprints, we found statistically significant differences between agricultural and native desert soil of about 60%. A pyrosequencing-based analysis of the 16S rRNA gene regions showed higher diversity in agricultural than in desert soil (Shannon diversity indices: 11.21/7.90), and displayed structural differences. The proportion of Firmicutes in field soil was significantly higher (37%) than in the desert (11%). Bacillus and Paenibacillus play the key role: they represented 96% of the antagonists towards phytopathogens, and identical 16S rRNA sequences in the amplicon library and for isolates were detected. The proportion of antagonistic strains was doubled in field in comparison to desert soil (21.6%/12.4%); disease-suppressive bacteria were especially enriched in plant roots. On the opposite, several extremophilic bacterial groups, e.g., Acidimicrobium, Rubellimicrobium and Deinococcus-Thermus, disappeared from soil after agricultural use. The N-fixing Herbaspirillum group only occurred in desert soil. Soil bacterial communities were strongly driven by the a-biotic factors water supply and pH. CONCLUSIONS/SIGNIFICANCE: After long-term farming, a drastic shift in the bacterial communities in desert soil was observed. Bacterial communities in agricultural soil showed a higher diversity and a better ecosystem function for plant health but a loss of extremophilic bacteria. Interestingly, we detected that indigenous desert microorganisms promoted plant health in desert agro-ecosystems
General anaesthetic and airway management practice for obstetric surgery in England: a prospective, multicentre observational study
There are no current descriptions of general anaesthesia characteristics for obstetric surgery, despite recent changes to patient baseline characteristics and airway management guidelines. This analysis of data from the direct reporting of awareness in maternity patients’ (DREAMY) study of accidental awareness during obstetric anaesthesia aimed to describe practice for obstetric general anaesthesia in England and compare with earlier surveys and best-practice recommendations. Consenting patients who received general anaesthesia for obstetric surgery in 72 hospitals from May 2017 to August 2018 were included. Baseline characteristics, airway management, anaesthetic techniques and major complications were collected. Descriptive analysis, binary logistic regression modelling and comparisons with earlier data were conducted. Data were collected from 3117 procedures, including 2554 (81.9%) caesarean deliveries. Thiopental was the induction drug in 1649 (52.9%) patients, compared with propofol in 1419 (45.5%). Suxamethonium was the neuromuscular blocking drug for tracheal intubation in 2631 (86.1%), compared with rocuronium in 367 (11.8%). Difficult tracheal intubation was reported in 1 in 19 (95%CI 1 in 16–22) and failed intubation in 1 in 312 (95%CI 1 in 169–667). Obese patients were over-represented compared with national baselines and associated with difficult, but not failed intubation. There was more evidence of change in practice for induction drugs (increased use of propofol) than neuromuscular blocking drugs (suxamethonium remains the most popular). There was evidence of improvement in practice, with increased monitoring and reversal of neuromuscular blockade (although this remains suboptimal). Despite a high risk of difficult intubation in this population, videolaryngoscopy was rarely used (1.9%)
- …
