303 research outputs found
Which Is Your Diagnosis? [qual O Seu Diagnóstico?]
[No abstract available]415viiviiiKeogh, C., Torreggiani, W.C., AI-Ismail, K., Musculoskeletal case 21. Insufficiency fracture of the sacrum (2002) Can J Surg, 45 (92), p. 153Grangier, C., Garcia, J., Howarth, N.R., Role of MRI in diagnosis of insufficiency fractures of the sacrum and acetabular roof (1997) Skeletal Radiol, 26, pp. 517-524Peh, W.C., Khong, P.L., Yin, Y., Imaging of pelvic insufficiency fractures (1996) Radiographics, 16, pp. 335-348Mammone, J.F., Schweitzer, M.E., MRI of occult sacral insufficiency fractures following radiotherapy (1995) Skeletal Radiol, 24, pp. 101-104Blake, S.P., Connors, A.M., Sacral insufficiency fracture (2004) Br. J Radiol, 77, pp. 891-896Blomlie, V., Lien, H.H., Iversen, T., Radiationinduced insufficiency fractures of the sacrum: Evaluation with MR imaging (1993) Radiology, 188, pp. 241-24
Collaborative trails in e-learning environments
This deliverable focuses on collaboration within groups of learners, and hence collaborative trails. We begin by reviewing the theoretical background to collaborative learning and looking at the kinds of support that computers can give to groups of learners working collaboratively, and then look more deeply at some of the issues in designing environments to support collaborative learning trails and at tools and techniques, including collaborative filtering, that can be used for analysing collaborative trails. We then review the state-of-the-art in supporting collaborative learning in three different areas – experimental academic systems, systems using mobile technology (which are also generally academic), and commercially available systems. The final part of the deliverable presents three scenarios that show where technology that supports groups working collaboratively and producing collaborative trails may be heading in the near future
The Water Bugs (Heteroptera: Nepomorpha) of the Guyana Region
NEPOMORPHA OF THE GUYANA REGION
The Nepomorpha of the Guyana Region are keyed out and described. In addition distributional, faunistical and comparative notes on the species are given.
New species and subspecies: Ochterus aeneifrons surinamensis, O. tenebrosus; Limnocoris fittkaui surinamensis; Ranatra adelomorpha; Neoplea globoidea; Buenoa amnigenopsis; Tenagobia pseudoromani from Suriname and Ranatra ornitheia from Guyana.
New synonyms (junior ones between parenthesis): Gelaslocorus flavus flavus Guér. (G. nebulosus nebulosus Guér.); Pelocoris impicticollis Stål (P. horváthi Mont.), P. poeyi (Guér.) not identical with P. femoratus (P.-B.) (P. convexus Nieser), P. procurrens White (P. minutus Mont.); Belostoma bicavum Lauck ( B. parvoculum Lauck); Ranatra doesburgi De Carlo (R. usingeri De C.), R. macrophthalma H.-S. (R. surinamensis De C.), R. mediana Mont. (R. williamsi Kuitert), R. obscura Mont. (R. annulipes White 1879 not Stål), R. sarmentoi De C. (R. ameghinoi De C.); Buenoa amnigenopsis n. sp. ( B. amnigenus Nieser 1968, 1970 not White), B. amnigenus (White) (B. amnigenoidea Nieser 1970), B. nitida Truxal (B. doesburgi Nieser); Heterocorixa surinamensis Nieser ( H. boliviensis Nieser 1970 not Hungerford); Tenagobia incerta Lundbl. ( T. signata and T. serrata in part, Nieser 1970 not White and Deay respectively), T. socialis (White) (T. serrata in part, Nieser 1970 not Deay)
A stem cell strategy identifies glycophorin C as a major erythrocyte receptor for the rodent malaria parasite Plasmodium berghei
The clinical complications of malaria are caused by the parasite expansion in the blood. Invasion of erythrocytes is a complex process that depends on multiple receptor-ligand interactions. Identification of host receptors is paramount for fighting the disease as it could reveal new intervention targets, but the enucleated nature of erythrocytes makes genetic approaches impossible and many receptors remain unknown. Host-parasite interactions evolve rapidly and are therefore likely to be species-specific. As a results, understanding of invasion receptors outside the major human pathogen Plasmodium falciparum is very limited. Here we use mouse embryonic stem cells (mESCs) that can be genetically engineered and differentiated into erythrocytes to identify receptors for the rodent malaria parasite Plasmodium berghei. Two proteins previously implicated in human malaria infection: glycophorin C (GYPC) and Band-3 (Slc4a1) were deleted in mESCs to generate stable cell lines, which were differentiated towards erythropoiesis. In vitro infection assays revealed that while deletion of Band-3 has no effect, absence of GYPC results in a dramatic decrease in invasion, demonstrating the crucial role of this protein for P. berghei infection. This stem cell approach offers the possibility of targeting genes that may be essential and therefore difficult to disrupt in whole organisms and has the potential to be applied to a variety of parasites in diverse host cell types
Accessible lifelong learning at higher education:outcomes and lessons Learned at two different PilotSites in the EU4ALL Project
[EN] The EU4ALL project (IST-FP6-034778) has developed a general framework to
address the needs of accessible lifelong learning at Higher Education level consisting of several
standards-based interoperable components integrated into an open web service architecture
aimed at supporting adapted interaction to guarantee students' accessibility needs. Its flexibility
has supported the project implementation at several sites with different settings and various
learning management systems. Large-scale evaluations involving hundreds of users,
considering diverse disability types, and key staff roles have allowed obtaining valuable lessons
with respect to "how to adopt or enhance eLearning accessibility" at university. The project was
evaluated at four higher education institutions, two of the largest in Europe and two mediumsized.
In this paper, we focus on describing the implementation and main conclusions at the
largest project evaluation site (UNED), which was involved in the project from the beginning,
and thus, in the design process, and a medium-sized university that adopted the EU4ALL
approach (UPV). This implies dealing with two well-known open source learning environments
(i.e. dotLRN and Sakai), and considering a wide variety of stakeholders and requirements. Thus
the results of this evaluation serve to illustrate the coverage of both the approach and
developments.The authors would like to thank the European Commission for the financial support of the EU4ALL project (IST-2006-034478). The work at aDeNu is also supported by the Spanish Ministry of Science and Innovation (TIN2008-06862-C04-01/TSI “A2UN@”). Authors would also like to thank all the EU4ALL partners for their
collaboration.Boticario, JG.; Rodriguez-Ascaso, A.; Santos, OC.; Raffenne, E.; Montandon, L.; Roldán Martínez, D.; Buendía García, F. (2012). Accessible lifelong learning at higher education:outcomes and lessons Learned at two different PilotSites in the EU4ALL Project. Journal of Universal Computer Science. 18(1):62-85. http://hdl.handle.net/10251/37117628518
Treatment of ongoing autoimmune encephalomyelitis with activated B-cell progenitors maturing into regulatory B cells.
The influence of signals perceived by immature B cells during their development in bone marrow on their subsequent functions as mature cells are poorly defined. Here, we show that bone marrow cells transiently stimulated in vivo or in vitro through the Toll-like receptor 9 generate proB cells (CpG-proBs) that interrupt experimental autoimmune encephalomyelitis (EAE) when transferred at the onset of clinical symptoms. Protection requires differentiation of CpG-proBs into mature B cells that home to reactive lymph nodes, where they trap T cells by releasing the CCR7 ligand, CCL19, and to inflamed central nervous system, where they locally limit immunopathogenesis through interleukin-10 production, thereby cooperatively inhibiting ongoing EAE. These data demonstrate that a transient inflammation at the environment, where proB cells develop, is sufficient to confer regulatory functions onto their mature B-cell progeny. In addition, these properties of CpG-proBs open interesting perspectives for cell therapy of autoimmune diseases
Long-lasting stem cell-like memory CD8+ T cells with a naïve-like profile upon yellow fever vaccination.
Efficient and persisting immune memory is essential for long-term protection from infectious and malignant diseases. The yellow fever (YF) vaccine is a live attenuated virus that mediates lifelong protection, with recent studies showing that the CD8(+) T cell response is particularly robust. Yet, limited data exist regarding the long-term CD8(+) T cell response, with no studies beyond 5 years after vaccination. We investigated 41 vaccinees, spanning 0.27 to 35 years after vaccination. YF-specific CD8(+) T cells were readily detected in almost all donors (38 of 41), with frequencies decreasing with time. As previously described, effector cells dominated the response early after vaccination. We detected a population of naïve-like YF-specific CD8(+) T cells that was stably maintained for more than 25 years and was capable of self-renewal ex vivo. In-depth analyses of markers and genome-wide mRNA profiling showed that naïve-like YF-specific CD8(+) T cells in vaccinees (i) were distinct from genuine naïve cells in unvaccinated donors, (ii) resembled the recently described stem cell-like memory subset (Tscm), and (iii) among all differentiated subsets, had profiles closest to naïve cells. Our findings reveal that CD8(+) Tscm are efficiently induced by a vaccine in humans, persist for decades, and preserve a naïveness-like profile. These data support YF vaccination as an optimal mechanistic model for the study of long-lasting memory CD8(+) T cells in humans
Novel stem cell technologies are powerful tools to understand the impact of human factors on Plasmodium falciparum malaria
© 2023 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/Plasmodium falciparum parasites have a complex life cycle, but the most clinically relevant stage of the disease is the invasion of erythrocytes and the proliferation of the parasite in the blood. The influence of human genetic traits on malaria has been known for a long time, however understanding the role of the proteins involved is hampered by the a nuclear nature of erythrocytes that makes them inaccessible to genetic tools. Here we overcome this limitation using stem cells to generate erythroid cells with an in-vitro differentiation protocol and assess parasite invasion with an adaptation of flow cytometry to detect parasite hemozoin. We combine this strategy with reprogramming of patient cells to Induced Pluripotent Stem Cells and genome editing to understand the role of key genes and human traits in malaria infection. We show that deletion of basigin ablates invasion while deletion of ATP2B4 has a minor effect and that erythroid cells from reprogrammed patient-derived HbBart α-thalassemia samples poorly support infection. The possibility to obtain patient-secific and genetically modifed erythoid cells offers an unparalleled opportunity to study the role of human genes and polymorphisms in malaria allowing preservation of the genomic background to demonstrate their function and understand their mechanisms.Peer reviewe
Defining multiplicity of vector uptake in transfected Plasmodium parasites
Abstract: The recurrent emergence of drug resistance in Plasmodium falciparum increases the urgency to genetically validate drug resistance mechanisms and identify new targets. Reverse genetics have facilitated genome-scale knockout screens in Plasmodium berghei and Toxoplasma gondii, in which pooled transfections of multiple vectors were critical to increasing scale and throughput. These approaches have not yet been implemented in human malaria species such as P. falciparum and P. knowlesi, in part because the extent to which pooled transfections can be performed in these species remains to be evaluated. Here we use next-generation sequencing to quantitate uptake of a pool of 94 barcoded vectors. The distribution of vector acquisition allowed us to estimate the number of barcodes and DNA molecules taken up by the parasite population. Dilution cloning of P. falciparum transfectants showed that individual clones possess as many as seven episomal barcodes, revealing that an intake of multiple vectors is a frequent event despite the inefficient transfection efficiency. Transfection of three spectrally-distinct fluorescent reporters allowed us to evaluate different transfection methods and revealed that schizont-stage transfection limited the tendency for parasites to take up multiple vectors. In contrast to P. falciparum, we observed that the higher transfection efficiency of P. knowlesi resulted in near complete representation of the library. These findings have important implications for how reverse genetics can be scaled in culturable Plasmodium species
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