295 research outputs found

    What can designing learning-by-concordance clinical reasoning cases teach us about instruction in the health sciences?

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    Introduction: Learning-by-concordance (LbC) is an online learning strategy to practice reasoning skills in clinical situations. Writing LbC clinical cases, comprising an initial hypothesis and supplementary data, differs from typical instructional design. We sought to gain a deeper understanding from experienced LbC designers to better support clinician educators’ broader uptake of LbC. Methods: A dialogic action research approach was selected because it yields triangulated data from a heterogeneous group. We conducted three 90-minute dialogue-group sessions with eight clinical educators. Discussions focused on the challenges and pitfalls of each LbC design stage described in the literature. Recordings were transcribed and analyzed thematically. Results: We identified three themes by thematic analysis about the challenges inherent in designing LbC that are unique for this type of learning strategy: 1) the distinction between pedagogical intent and learning outcome; 2) the contextual cues used to challenge students and advance their learning and 3) the integration of experiential with formalized knowledge for cognitive apprenticeship. Discussion: A clinical situation can be experienced and conceptualized in many ways, and multiple responses are appropriate. LbC designers use contextual cues from their experience and combine them with formalized knowledge and protocols to write effective LbC clinical reasoning cases. LbC focuses learners’ attention on decision-making in grey areas that characterize the nature of professional clinical work. This in-depth study on LbC design, indicating the integration of experiential knowledge, might call for new thinking about instructional design

    Longitudinal changes in HIV-specific IFN-γ secretion in subjects who received Remune™ vaccination prior to treatment interruption

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    BACKGROUND: Despite the benefits of highly active antitretroviral therapy (HAART) for suppressing viral replication in HIV infection, virus persists and rebounds during treatment interruption (TI). This study explored whether HAART intensification with Remune™ vaccination before TI can boost HIV-1-specific immunity, leading to improved control of viremia off HAART. METHODS: Ten chronically HIV-infected adults were enrolled in this proof of concept study. After a 6-month HAART intensification phase with didanosine, hydroxyurea, granulocyte-macrophage colony-stimulating factor, (GM-CSF), and a first dose of Remune™ (HIV-1 Immunogen), HAART was discontinued. Patients continued to receive Remune™ every 3 months until the end of study. HAART was restarted if viral load did not fall below 50,000 copies/ml of plasma within 3 months or if CD4+ counts decreased to <200 cells/mm(3). HIV-specific immunity was monitored with the interferon-γ (IFN-γ) ELISPOT assay. RESULTS: All subjects experienced viral rebound during TIs. Although the magnitude and breadth of HIV-specific responses to HLA-restricted optimal peptide panels and Gag p55 peptide pools increased and viral load decreased by 0.44 log(10 )units from TI#1 to TI#2, no significant correlations between these parameters were observed. The patients spent 50.4% of their 36 months follow up off HAART. CONCLUSION: Stopping HAART in this vaccinated population induced immune responses that persisted after therapy was restarted. Induction of HIV-specific immunity beyond IFN-γ secretion may be contributing to better control of viremia during subsequent TIs allowing for long periods off HAART

    Remote and in situ plume measurements of acid gas release from La Soufrière volcano, Guadeloupe

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    Abstract This paper presents the first remote measurements of La Soufrière gas emissions since the fumarolic and seismic reactivation in 1992. The chemical composition of the plumes has been measured from May 2003 to September 2004 using an Open Path Fourier Transform InfraRed (OP-FTIR) spectrometer, up to 15 m downwind the South Crater. HCl is clearly detected (concentration between 2.4 and 12 ppmv) whereas SO 2 and H 2 S generally remain below the detection limit of the OP-FTIR. Direct measurements of SO 2 and H 2 S near the South Crater with a Lancom III analyzer show a fast decrease of their concentrations with the distance. Calculated Cl / S mass ratios are high: from 9.4 F 1.7 at 15 m from the vent to 2.8 F 0.6 at 140 m. The enrichment in HCl of the gas emitted at La Soufrière, observed since 1998, corresponds to the degassing of a magma enriched in Cl and depleted in S. This result agrees with isotopic measurements which suggest a magmatic origin of the gases. Readjustments inside the volcanic system may have taken place during the seismic activity beginning in 1992 and enhance the transfer of magmatic gases to the summit.

    Influence of pressing temperature on dynamics of strength of adhesive bond

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    Proučevali smo vpliv temperature stiskanja na utrjevanje urea-formaldehidnih (UF) lepil. Uporabili smo dve vrsti UF lepil proizvajalca Basf: Kaurit 345 z nižjo vsebnostjo prostega formaldehida in Kaurit 350 z višjo vsebnostjo. Preizkušanci so bili standardni in sicer iz javorjevega furnirja, debeline 0,6 mm. Preizkušanci so se po razrezu klimatizirali pri sobnih pogojih: 23 °C in 55 % vlažnostjo. Kinetiko utrjevanja UF lepil smo izvedli z ABES (Automated Bonding Evaluation System) instrumentom. Lepilna mešanica je bila skozi vse poizkuse konstantna, sestavljena iz 100 utežnih deležev vodne raztopine lepila in 1,5 % katalizatorja - amonijevega sulfata (glede na suho snov lepila). Testiranje je potekalo pri različnih temperaturah stiskanja: 80, 100, 120, 150, 170 °C. Trajanje stiskanja smo prilagajali glede na razvoj strižne trdnosti. Ko je ABES izmeril strižno trdnost večjo od 0, smo meritev pri enakem času stiskanja ponovili vsaj trikrat. Testirali smo tudi vpliv pH vrednosti različnih furnirjev na utrjevanje UF lepil. Ker katalizator zniža pH vrednost mešanice ter pospeši utrjevanje UF lepil, smo enak princip znižanja pH vrednosti ugotavljali s pomočjo različnih lesnih vrst. Vsaka lesna vrsta ima različno pH vrednost, ki tako dodatno pripomore k spremembi kislosti oz. bazičnosti lepilne mešanice med stiskanjem. Testirali smo preizkušance šestih različnih drevesnih vrst (javor, bukev, hrast, oreh, smreka, brest). S pomočjo termočlena smo raziskali spreminjanje temperature v lepilnem spoju med vročim lepljenjem. Ugotovili smo, da je imela temperatura stiskanja bistveni vpliv na hitrost utrjevanja lepila in da hlajenje preizkušanca po stiskanju ni vplivalo na trdnost spoja. Lepilo z višjim deležem formaldehida je utrjevalo hitreje.We studied the effect of pressing temperature on hardening of urea-formaldehyde (UF) adhesives. We used two types of UF adhesives pre-prepared by manufacturer Basf: Kaurit 345 with a lower content of free formaldehyde and Kaurit 350 with a higher content. For testing of kinetics, we used ABES (Automated Bonding Evaluation System) instrument. To preform standard tests, we used maple veneers, with thickness of 0,6 mm. All veneer was prepared and then left for two day at room conditions of 23 °C and 55 % air humidity, to acclimate. Every test has constant adhesive mixture, consisted of 100 weight units of aqueous adhesive solution and 1,5 % catalyst (ammonium sulphate) (according to dry quantity of glue). Bonding strength was investigated at different pressing temperatures: 80, 100, 120, 150 and 170 °C. Times of gluing were adjusted according to feedback of shear strength. If ABES measured sear strength higher than 0 N/mm2, we carried out at least two more tests of strength. pH value of wood was measured. With usage of different veneers, we tested its influence on bond development. For this test, we used six different species (maple, beech, oak, walnut, spruce, elm). With use of thermocouple we investigated temperature changes in bond during gluing process. We found out that the pressing temperature had a significant influence on hardening time. Cooling specimens after gluing process did not have big effect on joint strength. Adhesive with more formaldehyde was curing faster

    PPARγ Controls Dectin-1 Expression Required for Host Antifungal Defense against Candida albicans

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    We recently showed that IL-13 or peroxisome proliferator activated receptor γ (PPARγ) ligands attenuate Candida albicans colonization of the gastrointestinal tract. Here, using a macrophage-specific Dectin-1 deficient mice model, we demonstrate that Dectin-1 is essential to control fungal gastrointestinal infection by PPARγ ligands. We also show that the phagocytosis of yeast and the release of reactive oxygen intermediates in response to Candida albicans challenge are impaired in macrophages from Dectin-1 deficient mice treated with PPARγ ligands or IL-13. Although the Mannose Receptor is not sufficient to trigger antifungal functions during the alternative activation of macrophages, our data establish the involvement of the Mannose Receptor in the initial recognition of non-opsonized Candida albicans by macrophages. We also demonstrate for the first time that the modulation of Dectin-1 expression by IL-13 involves the PPARγ signaling pathway. These findings are consistent with a crucial role for PPARγ in the alternative activation of macrophages by Th2 cytokines. Altogether these data suggest that PPARγ ligands may be of therapeutic value in esophageal and gastrointestinal candidiasis in patients severely immunocompromised or with metabolic diseases in whom the prevalence of candidiasis is considerable

    BRCA2 polymorphic stop codon K3326X and the risk of breast, prostate, and ovarian cancers

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    Background: The K3326X variant in BRCA2 (BRCA2*c.9976A&gt;T; p.Lys3326*; rs11571833) has been found to be associated with small increased risks of breast cancer. However, it is not clear to what extent linkage disequilibrium with fully pathogenic mutations might account for this association. There is scant information about the effect of K3326X in other hormone-related cancers. Methods: Using weighted logistic regression, we analyzed data from the large iCOGS study including 76 637 cancer case patients and 83 796 control patients to estimate odds ratios (ORw) and 95% confidence intervals (CIs) for K3326X variant carriers in relation to breast, ovarian, and prostate cancer risks, with weights defined as probability of not having a pathogenic BRCA2 variant. Using Cox proportional hazards modeling, we also examined the associations of K3326X with breast and ovarian cancer risks among 7183 BRCA1 variant carriers. All statistical tests were two-sided. Results: The K3326X variant was associated with breast (ORw = 1.28, 95% CI = 1.17 to 1.40, P = 5.9x10- 6) and invasive ovarian cancer (ORw = 1.26, 95% CI = 1.10 to 1.43, P = 3.8x10-3). These associations were stronger for serous ovarian cancer and for estrogen receptor–negative breast cancer (ORw = 1.46, 95% CI = 1.2 to 1.70, P = 3.4x10-5 and ORw = 1.50, 95% CI = 1.28 to 1.76, P = 4.1x10-5, respectively). For BRCA1 mutation carriers, there was a statistically significant inverse association of the K3326X variant with risk of ovarian cancer (HR = 0.43, 95% CI = 0.22 to 0.84, P = .013) but no association with breast cancer. No association with prostate cancer was observed. Conclusions: Our study provides evidence that the K3326X variant is associated with risk of developing breast and ovarian cancers independent of other pathogenic variants in BRCA2. Further studies are needed to determine the biological mechanism of action responsible for these associations

    Le musée, un lieu éducatif

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    This anthology contains essays on various aspects of museum education, by 35 members of the Special Interest Group on Education and Museums (SIGEM). Originally presented at a conference held in Montreal in 1995, the essays in this book address a wide range of issues related to the educational function of museums. Topics discussed include: educational, scientific and museological research; the value of guided tours and visual arts workshops; the question of evaluation; and relationships between museums and schools. 21 diagrams and 19 charts. 4 texts in English 31 texts in French. Circa 480 bibl. ref

    Factors associated with breastfeeding initiation:A comparison between France and French-speaking Canada

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    Background: Breastfeeding is associated with multiple domains of health for both mothers and children. Nevertheless, breastfeeding initiation is low within certain developed countries. Furthermore, comparative studies of initiation rates using harmonised data across multiple regions is scarce. Objective: The aim of the present study was to investigate and compare individual-level determinants of breastfeeding initiation using two French-speaking cohorts. Methods: Participants included ~ 3,900 mothers enrolled in two cohort studies in Canada and France. Interviews, questionnaires, and medical records were utilised to collect information on maternal, family, and medical factors associated with breastfeeding initiation. Results: Rates of breastfeeding initiation were similar across cohorts, slightly above 70%. Women in both Canada and France who had higher levels of maternal education, were born outside of their respective countries and who did not smoke during pregnancy were more likely to initiate breastfeeding with the cohort infant. Notably, cohort effects of maternal education at the university level were found, whereby having 'some university' was not statistically significant for mothers in France. Further, younger mothers in Canada, who delivered by caesarean section and who had previous children had reduced odds of breastfeeding initiation. These results were not found for mothers in France. Conclusions and Implications for Practice: While some similar determinants were observed, programming efforts to increase breastfeeding initiation should be tailored to the characteristics of specific geographical regions which may be heavily impacted by the social, cultural and political climate of the region, in addition to individual and family level factors.European Commission - Seventh Framework Programme (FP7

    Polygenic risk scores and breast and epithelial ovarian cancer risks for carriers of BRCA1 and BRCA2 pathogenic variants

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    Purpose We assessed the associations between population-based polygenic risk scores (PRS) for breast (BC) or epithelial ovarian cancer (EOC) with cancer risks forBRCA1andBRCA2pathogenic variant carriers. Methods Retrospective cohort data on 18,935BRCA1and 12,339BRCA2female pathogenic variant carriers of European ancestry were available. Three versions of a 313 single-nucleotide polymorphism (SNP) BC PRS were evaluated based on whether they predict overall, estrogen receptor (ER)-negative, or ER-positive BC, and two PRS for overall or high-grade serous EOC. Associations were validated in a prospective cohort. Results The ER-negative PRS showed the strongest association with BC risk forBRCA1carriers (hazard ratio [HR] per standard deviation = 1.29 [95% CI 1.25-1.33],P = 3x10(-72)). ForBRCA2, the strongest association was with overall BC PRS (HR = 1.31 [95% CI 1.27-1.36],P = 7x10(-50)). HR estimates decreased significantly with age and there was evidence for differences in associations by predicted variant effects on protein expression. The HR estimates were smaller than general population estimates. The high-grade serous PRS yielded the strongest associations with EOC risk forBRCA1(HR = 1.32 [95% CI 1.25-1.40],P = 3x10(-22)) andBRCA2(HR = 1.44 [95% CI 1.30-1.60],P = 4x10(-12)) carriers. The associations in the prospective cohort were similar. Conclusion Population-based PRS are strongly associated with BC and EOC risks forBRCA1/2carriers and predict substantial absolute risk differences for women at PRS distribution extremes.Peer reviewe
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