502 research outputs found

    The Symmetry of Partner Modelling

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    © 2016, International Society of the Learning Sciences, Inc. Collaborative learning has often been associated with the construction of a shared understanding of the situation at hand. The psycholinguistics mechanisms at work while establishing common grounds are the object of scientific controversy. We postulate that collaborative tasks require some level of mutual modelling, i.e. that each partner needs some model of what the other partners know/want/intend at a given time. We use the term “some model” to stress the fact that this model is not necessarily detailed or complete, but that we acquire some representations of the persons we interact with. The question we address is: Does the quality of the partner model depend upon the modeler’s ability to represent his or her partner? Upon the modelee’s ability to make his state clear to the modeler? Or rather, upon the quality of their interactions? We address this question by comparing the respective accuracies of the models built by different team members. We report on 5 experiments on collaborative problem solving or collaborative learning that vary in terms of tasks (how important it is to build an accurate model) and settings (how difficult it is to build an accurate model). In 4 studies, the accuracy of the model that A built about B was correlated with the accuracy of the model that B built about A, which seems to imply that the quality of interactions matters more than individual abilities when building mutual models. However, these findings do not rule out the fact that individual abilities also contribute to the quality of modelling process

    Phytochemicals as antibiotic alternatives to promote growth and enhance host health

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    There are heightened concerns globally on emerging drug-resistant superbugs and the lack of new antibiotics for treating human and animal diseases. For the agricultural industry, there is an urgent need to develop strategies to replace antibiotics for food-producing animals, especially poultry and livestock. The 2nd International Symposium on Alternatives to Antibiotics was held at the World Organization for Animal Health in Paris, France, December 12-15, 2016 to discuss recent scientific developments on strategic antibiotic-free management plans, to evaluate regional differences in policies regarding the reduction of antibiotics in animal agriculture and to develop antibiotic alternatives to combat the global increase in antibiotic resistance. More than 270 participants from academia, government research institutions, regulatory agencies, and private animal industries from >25 different countries came together to discuss recent research and promising novel technologies that could provide alternatives to antibiotics for use in animal health and production; assess challenges associated with their commercialization; and devise actionable strategies to facilitate the development of alternatives to antibiotic growth promoters (AGPs) without hampering animal production. The 3-day meeting consisted of four scientific sessions including vaccines, microbial products, phytochemicals, immune-related products, and innovative drugs, chemicals and enzymes, followed by the last session on regulation and funding. Each session was followed by an expert panel discussion that included industry representatives and session speakers. The session on phytochemicals included talks describing recent research achievements, with examples of successful agricultural use of various phytochemicals as antibiotic alternatives and their mode of action in major agricultural animals (poultry, swine and ruminants). Scientists from industry and academia and government research institutes shared their experience in developing and applying potential antibiotic-alternative phytochemicals commercially to reduce AGPs and to develop a sustainable animal production system in the absence of antibiotics.Fil: Lillehoj, Hyun. United States Department of Agriculture. Agricultural Research Service; ArgentinaFil: Liu, Yanhong. University of California; Estados UnidosFil: Calsamiglia, Sergio. Universitat AutĂČnoma de Barcelona; EspañaFil: Fernandez Miyakawa, Mariano Enrique. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Instituto Nacional de TecnologĂ­a Agropecuaria. Centro de InvestigaciĂłn en Ciencias Veterinarias y AgronĂłmicas. Instituto de PatobiologĂ­a; ArgentinaFil: Chi, Fang. Amlan International; Estados UnidosFil: Cravens, Ron L.. Amlan International; Estados UnidosFil: Oh, Sungtaek. United States Department of Agriculture. Agricultural Research Service; ArgentinaFil: Gay, Cyril G.. United States Department of Agriculture. Agricultural Research Service; Argentin

    Predicting Housekeeping Genes Based on Fourier Analysis

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    Housekeeping genes (HKGs) generally have fundamental functions in basic biochemical processes in organisms, and usually have relatively steady expression levels across various tissues. They play an important role in the normalization of microarray technology. Using Fourier analysis we transformed gene expression time-series from a Hela cell cycle gene expression dataset into Fourier spectra, and designed an effective computational method for discriminating between HKGs and non-HKGs using the support vector machine (SVM) supervised learning algorithm which can extract significant features of the spectra, providing a basis for identifying specific gene expression patterns. Using our method we identified 510 human HKGs, and then validated them by comparison with two independent sets of tissue expression profiles. Results showed that our predicted HKG set is more reliable than three previously identified sets of HKGs

    Cardiac Procedures among American Indians and Alaska Natives compared to Non-Hispanic Whites Hospitalized with Ischemic Heart Disease in California

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    BackgroundAmerican Indians/Alaska Natives (AIAN) experience a high burden of cardiovascular disease with rates for fatal and nonfatal heart disease approximately twofold higher than the U.S. population.ObjectiveTo determine if disparities exist in cardiac procedure rates among AIAN compared to non-Hispanic whites hospitalized in California for ischemic heart disease defined as acute myocardial infarction or unstable angina.DesignCross-sectional study. EVENTS: A total of 796 ischemic heart disease hospitalizations among AIAN and 90971 among non-Hispanic whites in 37 of 58 counties in California from 1998-2002.MeasurementsCardiac catheterization, percutaneous cardiac intervention, and coronary artery bypass graft surgery procedure rates from hospitalization administrative data.Main resultsAIAN did not have lower cardiac procedure rates for cardiac catheterization and percutaneous cardiac intervention compared to non-Hispanic whites (unadjusted OR 1.00, 95% CI 0.87-1.16 and OR 1.04, 95% CI 0.90-1.20, respectively). Adjustment for age, sex, comorbidities, and payer source did not alter the results (adjusted OR 0.95, 95% CI 0.82-1.10 and OR 0.98, 95% CI 0.85-1.14, respectively). We found higher odds (unadjusted OR 1.36, 95% CI 1.09-1.70) for receipt of coronary artery bypass graft surgery among AIAN hospitalized for ischemic heart disease compared to non-Hispanic whites which after adjustment attenuated some and was no longer statistically significant (adjusted OR 1.26, 95% CI 1.00-1.58).ConclusionAIAN were not less likely to receive cardiac procedures as non-Hispanic whites during hospitalizations for ischemic heart disease. Additional research is needed to determine whether differences in specialty referral patterns, patients' treatment preferences, or outpatient management may explain some of the health disparities due to cardiovascular disease that is found among AIAN

    Expression Profiling of CYP1B1 in Oral Squamous Cell Carcinoma: Counterintuitive Downregulation in Tumors

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    Oral Squamous Cell Carcinoma (OSCC) has a very flagitious treatment regime. A prodrug approach is thought to aid in targeting chemotherapy. CYP1B1, a member of cytochrome P450 family, has been implicated in chemical carcinogenesis. There exists a general accordance that this protein is overexpressed in a variety of cancers, making it an ideal candidate for a prodrug therapy. The activation of the prodrug facilitated by CYP1B1 would enable the targeting of chemotherapy to tumor tissues in which CYP1B1 is specifically overexpressed as a result reducing the non-specific side effects that the current chemotherapy elicits. This study was aimed at validating the use of CYP1B1 as a target for the prodrug therapy in OSCC. The expression profile of CYP1B1 was analysed in a panel of 51 OSCC tumors, their corresponding normal tissues, an epithelial dysplasia lesion and its matched normal tissue by qRT-PCR, Western blotting and Immunohistochemistry. CYP1B1 was found to be downregulated in 77.78% (28/36) tumor tissues in comparison to their corresponding normal tissues as well as in the epithelial dysplasia lesion compared to its matched normal tissue at the transcriptional level, and in 92.86% (26/28) of tumor tissues at the protein level. This report therefore clearly demonstrates the downregulation of CYP1B1 at the transcriptional and translational levels in tumor tissues in comparison to their corresponding normal tissues. These observations indicate that caution should be observed as this therapy may not be applicable universally to all cancers and also suggest the possibility of a prophylactic therapy for oral cancer

    Impact of the ABCDE triage in primary care emergency department on the number of patient visits to different parts of the health care system in Espoo City

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    <p>Abstract</p> <p>Background</p> <p>Many Finnish emergency departments (ED) serve both primary and secondary health care patients and are therefore referred to as combined emergency departments. Primary care doctors are responsible for the initial assessment and treatment. They, thereby, also regulate referral and access to secondary care. Primary health care EDs are easy for the public to access, leading to non-acute patient visits to the emergency department. This has caused increased queues and unnecessary difficulties in providing immediate treatment for urgent patients. The primary aim of this study was to assess whether the flow of patients was changed by implementing the ABCDE-triage system in the EDs of Espoo City, Finland.</p> <p>Methods</p> <p>The numbers of monthly visits to doctors were recorded before and after intervention in Espoo primary care EDs. To study if the implementation of the triage system redirects patients to other health services, the numbers of monthly visits to doctors were also scored in the private health care, the public sector health services of Espoo primary care during office hours and local secondary health care ED (Jorvi hospital). A face-to-face triage system was applied in the primary care EDs as an attempt to provide immediate treatment for the most acute patients. It is based on the letters A (patient sent directly to secondary care), B (to be examined within 10 min), C (to be examined within 1 h), D (to be examined within 2 h) and E (no need for immediate treatment) for assessing the urgency of patients' treatment needs. The first step was an initial patient assessment by a health care professional (triage nurse). The introduction of this triage system was combined with information to the public on the "correct" use of emergency services.</p> <p>Results</p> <p>After implementation of the ABCDE-triage system the number of patient visits to a primary care doctor decreased by up to 24% (962 visits/month) as compared to the three previous years in the EDs. The Number of visits to public sector GPs during office hours did not alter. Implementation of ABCDE-triage combined with public guidance was associated with decreased total number of doctor visits in public health care. During same period, the number of patient visits in the private health care increased. Simultaneously, the number of doctor visits in secondary health care ED did not alter.</p> <p>Conclusions</p> <p>The present ABCDE-triage system combined with public guidance may reduce patient visits to primary health care EDs but not to the secondary health care EDs. Limiting the access of less urgent patients to ED may redirect the demands of patients to private sector rather than office hours GP services.</p

    MicroRNA let-7 suppresses nasopharyngeal carcinoma cells proliferation through downregulating c-Myc expression

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    Aims: This study aimed at evaluating the potential anti-proliferative effects of the microRNA let-7 family in nasopharyngeal carcinoma (NPC) cells. In addition, the association between let-7 suppression and DNA hypermethylation is examined. Materials and methods: Levels of mature let-7 family members (-a,-b,-d,-e,-g, and-i) in normal nasopharyngeal cells (NP69 and NP460) and nasopharyngeal carcinoma cells (HK1 and HONE1) were measured by real-time quantitative PCR. Cell-proliferation assay and c-Myc immunohistochemical staining were performed on NPC cells transfected with let-7 precursor molecules. In addition, expression changes in let-7 family members in response to demethylating agents (5-azacytidine and zebularine) were also examined. Results: In comparison with the normal nasopharyngeal cells, let-7 (-a,-b,-d,-e,-g, and-i) levels were reduced in nasopharyngeal carcinoma cells. Ectopic expression of the let-7 family in nasopharyngeal carcinoma cells resulted in inhibition of cell proliferation through downregulation of c-Myc expression. Demethylation treatment of nasopharyngeal carcinoma cells caused activation of let-7 expression in poorly differentiated nasopharyngeal carcinoma cells only. Conclusion: Our results suggested that miRNA let-7 might play a role in the proliferation of NPC. DNA methylation is a potential regulatory pathway, which is affected when let-7 is suppressed in NPC cells. However, the extent of DNA hypermethylation/hypomethylation in regulating let-7 expression requires further elucidation. © The Author(s) 2010. This article is published with open access at Springerlink.com.published_or_final_versionSpringer Open Choice, 21 Feb 201

    Conscious thought beats deliberation without attention in diagnostic decision-making: at least when you are an expert

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    Contrary to what common sense makes us believe, deliberation without attention has recently been suggested to produce better decisions in complex situations than deliberation with attention. Based on differences between cognitive processes of experts and novices, we hypothesized that experts make in fact better decisions after consciously thinking about complex problems whereas novices may benefit from deliberation-without-attention. These hypotheses were confirmed in a study among doctors and medical students. They diagnosed complex and routine problems under three conditions, an immediate-decision condition and two delayed conditions: conscious thought and deliberation-without-attention. Doctors did better with conscious deliberation when problems were complex, whereas reasoning mode did not matter in simple problems. In contrast, deliberation-without-attention improved novices’ decisions, but only in simple problems. Experts benefit from consciously thinking about complex problems; for novices thinking does not help in those cases

    Phenotypic Signatures Arising from Unbalanced Bacterial Growth

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    Fluctuations in the growth rate of a bacterial culture during unbalanced growth are generally considered undesirable in quantitative studies of bacterial physiology. Under well-controlled experimental conditions, however, these fluctuations are not random but instead reflect the interplay between intra-cellular networks underlying bacterial growth and the growth environment. Therefore, these fluctuations could be considered quantitative phenotypes of the bacteria under a specific growth condition. Here, we present a method to identify “phenotypic signatures” by time-frequency analysis of unbalanced growth curves measured with high temporal resolution. The signatures are then applied to differentiate amongst different bacterial strains or the same strain under different growth conditions, and to identify the essential architecture of the gene network underlying the observed growth dynamics. Our method has implications for both basic understanding of bacterial physiology and for the classification of bacterial strains
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