57,048 research outputs found
Crystal vs glass formation in lattice models with many coexisting ordered phases
We present here new evidence that after a quench the planar Potts model on
the square lattice relaxes towards a glassy state if the number of states q is
larger than four. By extrapolating the finite size data we compute the average
energy of these states for the infinite system with periodic boundary
conditions, and find that it is comparable with that previously found using
fixed boundary conditions. We also report preliminary results on the behaviour
of these states in the presence of thermal fluctuationsComment: 7 pages with 5 figure
Lactobacillus crispatus as the etiological agent in cytolytic vaginosis
Introduction: Lactobacillus spp. dominate the vaginal niche but can also be involved in other vaginal dysbiosis, such as cytolytic vaginosis (CV), which remains poorly studied. It is characterized by a cryptic symptomatology, that often confounds the clinic.
Goals: The aim of this work was to search for the etiological agent of CV, by studying the vaginal microbiome and metabolomics of women afflicted with this disease and compare it with women with other clinical diagnostic.
Methods: Twenty-one vaginal washes have been collected from women attending a gynaecology consultation of a private clinic. The samples were categorized according with clinical diagnosis at the time of sampling (CV, 11; vulvovaginal candidosis, 8; Healthy, 2). The distribution of bacterial species, and their prevalence was assessed by next-generation sequencing of the 16S V4 region. In addition, total lactate D-lactic acid and L-lactic acid was quantified in all washes by a commercial kit, as well as lactate dehydrogenase (LDH) activity.
Results: L. crispatus was dominant (>70%) in all CV samples. Lactate was increased in CV in comparison with other cases. The presence of D-lactic acid isomer was associated with presence of L. crispatus. LDH activity was increased in vaginal washes that tested positive for the presence of L. crispatus, however no direct association was found with CV cases.
Discussion/Conclusions: The microbiome of women afflicted with CV was dominated in all cases by L. crispatus, contrarily with the results obtained for women diagnosed with other clinical symptomatology. In addition, the finding that an increase in D-lactic acid is associated with CV patients can be related to the role of L. crispatus in CV. The determination of LDH activity did not correlate exclusively with CV cases. On the other hand, D-lactic acid and total lactate quantification could be used as a valuable biomarker to diagnose this cryptic vaginal infection.info:eu-repo/semantics/publishedVersio
The role of four-hour blocks in promoting active learning strategies: the impressions of students and teachers
The technological degrees offered at the Polytechnic School of Ăgueda â University of Aveiro have been organized, since 2001, around a project-based learning environment [1]. One of the features of the curriculum implementation is that coursesâ contact hours are not divided in several types of classes, as in traditional learning environments. Following an idea adapted from the Aalborg model [2], all courses are taught in four-hour blocks that can be organized differently according to the course, or the learning needs at any stage of the process, thus enhancing flexibility and allowing for reorganization of the provision for teaching according to studentsâ needs. This format was also meant to encourage the adoption of active learning strategies within the classroom, since traditional lectures in such a format would be little less than excruciating.
This article describes an investigation into the âon the fieldâ experience of both students and teachers with these four-hour blocks. The research questions were: How are four-hour classes being implemented âon the fieldâ? What are the advantages and disadvantages of this format? Does the format actually foster the implementation of active learning strategies? Discussion sessions were organized for three groups of students, one for each of the academic years of the Electrical Engineering program, with the goal of identifying the various categories of four-hour classes to which they have been exposed so far. Each group of students elected a âsecretaryâ and were left alone to discuss for about twenty minutes, after which the Author re-entered the room and discussed with the students any issues in need of clarification. Afterwards, each of the participating students was asked to list, in writing, the three most positive and the three least positive aspects of each of the blocksâ categories identified earlier [3]. All teachers involved in the program were also asked to list, in writing, the three most positive and the three least positive aspects of teaching in four-hour blocks. The results of the discussion sessions and the lists, from both students and teachers, were qualitatively analysed to answer the research questions.
The results of the investigation show that students identify four categories of classes, ranging from more traditional approaches, to very engaging active-learning organized sessions, namely: âFull lectureâ, âTraditional layoutâ, âTutorial-like organisationâ and âActive learning sessionsâ.
From the analysis of the results presented in the article, it is possible to hint that the four-hour format pressures teachers to engage in less traditionally organized classes. Students also value more engaging learning environments, which are fostered by this format of classes. This trend becomes more apparent for students in more advanced stages of the programme, which may reflect their greater exposure to the PBL environment and also their increased maturity. However, students also value the formal structure provided by more traditional environments, possibly a consequence of their previous learning experiences and study habits.
Naturally, further research into these findings is needed in order to get a better grasp of the dynamics of four-hour blocks and their role in ESTGAâs PBL environment. The results of this study will guide that research, establishing the general lines on which to pursue further enquiries.
REFERENCES
[1] Oliveira, J.M, Estima de Oliveira, J.P. (2009), Project-Based Learning in Engineering: an Actual Case, Proc. of the 37th SEFI Annual Conference (CD, ISBN: 978-2-87352-001-4), Rotterdam, The Netherlands.
[2] Kjersdam, F, Enemark, S. (1994), The Aalborg Experiment, project innovation in university education, The University of Aalborg Press, Aalborg.
[3] Savin-Baden, M. (2000), Problem-Based Learning in Higher Education: Untold Stories, SRHE & Open University Press, Buckingham
Assessment of Lactobacillus crispatusÂŽ role in vaginal infections: friend or foe?
Lactobacillus spp. are the most prevalent microorganisms in the vaginal milleu. Several probiotic mechanisms have been associated with Lactobacillus, but the most relevant one is lactate production â resulting in a low pH value, typical of the healthy vagina. However, its pathogenic state is still unknown. We aim to elucidate the role of a commensal vaginal microorganism, Lactobacillus crispatus, in vaginal infections. Twenty-four vaginal washes have been collected from women attending a gynaecology consultation of a private clinic. The samples were categorized according with clinical diagnosis at the time of sampling. The distribution of bacterial species, and their prevalence was assessed by Next-Generation Sequencing of the 16S rRNA V4 region. In addition, L- and D-lactate concentration, and LDH enzymatic activity was quantified in all washes by a commercial kit. Detection of Candida spp. was performed by PCR. L. crispatus was dominant (>70%) in 11 out of 24 samples â diagnosed for vaginal atrophy (VA, 3), cytolytic vaginosis (CV, 2) and lactobacillosis (LB, 2). Lactate was increased in CV, LB and VA cases only. The remaining samples, diagnosed for vulvovaginal candidosis in its majority, had lower prevalence of L. crispatus; and lower to moderate lactate metabolite. There was not a direct relationship between LDH enzymatic activity and clinical diagnosis. L. crispatus dominance, associated with increased lactate production, was observed in CV, LB and VA cases. These results indicate that this microorganism might have a role in dysbiosis of the vagina associated with these specific pathologies.info:eu-repo/semantics/publishedVersio
Role of Lactobacillus crispatus in vaginal infections: insights from metagenomics and metabolomics studies
Objective: Lactobacillus spp. constitute the most prevalent bacterial microorganism in the vaginal milleu. Several probiotic mechanisms have been associated with Lactobacillus, but the most relevant one is lactate production â resulting in a low pH value, typical of the healthy vagina. We aim to elucidate the role of a native vaginal microorganism, Lactobacillus crispatus, in vaginal infections.
Methods: Twenty-four vaginal washes have been collected from women (mean 38±14 years of age) attending a gynecology consultation of a private clinic. The samples were categorized according with clinical diagnosis at the time of sampling. The distribution of bacterial species, and their prevalence was assessed by next-generation sequencing of the 16S V4 region. In addition, lactate was quantified in all washes by a commercial kit.
Results: L. crispatus was dominant (>70%) in 11 out of 24 samples â diagnosed for vaginal atrophy (VA, 3), cytolytic vaginosis (CV, 2), lactobacillosis (LB, 2) and vulvovaginal candidosis (VVC, 1). For three samples, diagnostic was inconclusive. Lactate was increased in CV, LB and VA cases only. One sample, diagnosed with VVC had 23% dominance of L. crispatus; and lower lactate metabolite. L. crispatus was not detected in the remaining 12 cases (6 VVC, 4 VA, 1 healthy and 1 inconclusive). Of these, only 5 samples had moderate lactate metabolite.
Conclusions: L. crispatus dominance, associated with increased lactate production, was observed in CV, LB and VA cases. These results indicate that this microorganism might have a role in dysbiosis of the vagina associated with these specific pathologies.info:eu-repo/semantics/publishedVersio
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