183 research outputs found
El caso IRICE: un espacio socio-técnico para investigación y diseminación de conocimiento
Esta comunicación presenta aspectos significativos del diseño y desarrollo de un espacio institucional virtual multiplataforma de una unidad ejecutora de investigación en el campo de las Ciencias de la Educación. La arquitectura propuesta tiene por objetivo tanto la conformación y promoción de redes socio-técnicas en contextos investigativos, como la promoción de estrategias que transformen paulatinamente las prácticas participativas de la comunidad académica, consolidando el vínculo con la ciudadanía en su conjunto.
El marco teórico-metodológico se fundamentó en la perspectiva de los Dispositivos Hipermediales Dinámicos, atendiendo a condiciones de inclusión social y a la implementación de tecnologías de código abierto considerando los marcos jurídicos del estado argentino.Sociedad Argentina de Informática e Investigación Operativa (SADIO
El caso IRICE: un espacio socio-técnico para investigación y diseminación de conocimiento
Esta comunicación presenta aspectos significativos del diseño y desarrollo de un espacio institucional virtual multiplataforma de una unidad ejecutora de investigación en el campo de las Ciencias de la Educación. La arquitectura propuesta tiene por objetivo tanto la conformación y promoción de redes socio-técnicas en contextos investigativos, como la promoción de estrategias que transformen paulatinamente las prácticas participativas de la comunidad académica, consolidando el vínculo con la ciudadanía en su conjunto.
El marco teórico-metodológico se fundamentó en la perspectiva de los Dispositivos Hipermediales Dinámicos, atendiendo a condiciones de inclusión social y a la implementación de tecnologías de código abierto considerando los marcos jurídicos del estado argentino.Sociedad Argentina de Informática e Investigación Operativa (SADIO
Full-Stokes polarimetry with circularly polarized feeds - Sources with stable linear and circular polarization in the GHz regime
We present a pipeline that allows recovering reliable information for all
four Stokes parameters with high accuracy. Its novelty relies on the treatment
of the instrumental effects already prior to the computation of the Stokes
parameters contrary to conventional methods, such as the M\"uller matrix one.
The instrumental linear polarization is corrected across the whole telescope
beam and significant Stokes and can be recovered even when the recorded
signals are severely corrupted. The accuracy we reach in terms of polarization
degree is of the order of 0.1-0.2 %. The polarization angles are determined
with an accuracy of almost 1. The presented methodology was applied
to recover the linear and circular polarization of around 150 Active Galactic
Nuclei. The sources were monitored from July 2010 to April 2016 with the
Effelsberg 100-m telescope at 4.85 GHz and 8.35 GHz with a cadence of around
1.2 months. The polarized emission of the Moon was used to calibrate the
polarization angle. Our analysis showed a small system-induced rotation of
about 1 at both observing frequencies. Finally, we identify five
sources with significant and stable linear polarization; three sources remain
constantly linearly unpolarized over the period we examined; a total of 11
sources have stable circular polarization degree and four of
them with non-zero . We also identify eight sources that maintain
a stable polarization angle over the examined period. All this is provided to
the community for polarization observations reference. We finally show that our
analysis method is conceptually different from the traditionally used ones and
performs better than the M\"uller matrix method. Although it was developed for
a system equipped with circularly polarized feeds it can easily be modified for
systems with linearly polarized feeds as well.Comment: 19 pages, 17 figures, accepted for publication in Astronomy &
Astrophysics on May 30, 201
ITA-MNGIE: an Italian regional and national survey for mitochondrial neuro-gastro-intestinal encephalomyopathy
Mitochondrial neuro-gastro-intestinal encephalomyopathy (MNGIE) is a rare and unavoidably fatal disease due to mutations in thymidine phosphorylase (TP). Clinically it is characterized by gastrointestinal dysfunction, malnutrition/cachexia and neurological manifestations. MNGIE diagnosis remains a challenge mainly because of the complexity and rarity of the disease. Thus, our purposes were to promote a better knowledge of the disease in Emilia-Romagna region (ERR) by creating an accurate and dedicated network; to establish the minimal prevalence of MNGIE in Italy starting from ERR. Blood TP activity level was used as screening test to direct candidates to complete diagnostic work-up. During the study period of 1 year, only 10/71 units of ERR recruited 14 candidates. Their screening did not show TP activity changes. An Italian patient not resident in ERR was actually proved to have MNGIE. At the end of study in Italy there were nine cases of MNGIE; thus, the Italian prevalence of the disease is ~0.15/1,000,000 as a gross estimation. Our study confirms that MNGIE diagnosis is a difficult process which reflects the rarity of the disease and, as a result, a low level of awareness among specialists and physicians. Having available novel therapeutic options (e.g., allogenic hematopoietic stem cell transplantation and, more recently, liver transplantation) and an easy screening test, an early diagnosis should be sought before tissue damage occurs irreversibly
Mesenchymal stem cells in renal function recovery after acute kidney injury. Use of a differentiating agent in a rat model.
Acute kidney injury (AKI) is a major health care condition with limited current treatment options. Within this context, stem cells may provide a clinical approach for AKI. Moreover, a synthetic compound previously developed, hyaluronan monoesters with butyric acid (HB), able to induce metanephric differentiation, formation of capillary-like structures, and secretion of angiogenic cytokines, was tested in vitro. Thereafter, we investigated the effects of human mesenchymal stem cells from fetal membranes (FMhMSCs), both treated and untreated with HB, after induction of ischemic AKI in a rat model. At reperfusion following 45-min clamping of renal pedicles, each rat was randomly assigned to one of four groups: CTR, PBS, MSC, and MSC-HB. Renal function at 1, 3, 5, and 7 days was assessed. Histological samples were analyzed by light and electron microscopy and renal injury was graded. Cytokine analysis on serum samples was performed. FMhMSCs induced an accelerated renal functional recovery, demonstrated by biochemical parameters and confirmed by histology showing that histopathological alterations associated with ischemic injury were less severe in cell-treated kidneys. HB-treated rats showed a minor degree of inflammation, both at cytokine and TEM analyses. Better functional and morphological recovery were not associated to stem cells' regenerative processes, but possibly suggest paracrine effects on microenvironment that induce retrieval of renal damaged tissues. These results suggest that FMhMSCs could be useful in the treatment of AKI and the utilization of synthetic compounds could enhance the recovery induction ability of cells
cDNA array-CGH profiling identifies genomic alterations specific to stage and MYCN-amplification in neuroblastoma
BACKGROUND: Recurrent non-random genomic alterations are the hallmarks of cancer and the characterization of these imbalances is critical to our understanding of tumorigenesis and cancer progression. RESULTS: We performed array-comparative genomic hybridization (A-CGH) on cDNA microarrays containing 42,000 elements in neuroblastoma (NB). We found that only two chromosomes (2p and 12q) had gene amplifications and all were in the MYCN amplified samples. There were 6 independent non-contiguous amplicons (10.4–69.4 Mb) on chromosome 2, and the largest contiguous region was 1.7 Mb bounded by NAG and an EST (clone: 757451); the smallest region was 27 Kb including an EST (clone: 241343), NCYM, and MYCN. Using a probabilistic approach to identify single copy number changes, we systemically investigated the genomic alterations occurring in Stage 1 and Stage 4 NBs with and without MYCN amplification (stage 1-, 4-, and 4+). We have not found genomic alterations universally present in all (100%) three subgroups of NBs. However we identified both common and unique patterns of genomic imbalance in NB including gain of 7q32, 17q21, 17q23-24 and loss of 3p21 were common to all three categories. Finally we confirm that the most frequent specific changes in Stage 4+ tumors were the loss of 1p36 with gain of 2p24-25 and they had fewer genomic alterations compared to either stage 1 or 4-, indicating that for this subgroup of poor risk NB requires a smaller number of genomic changes are required to develop the malignant phenotype. CONCLUSIONS: cDNA A-CGH analysis is an efficient method for the detection and characterization of amplicons. Furthermore we were able to detect single copy number changes using our probabilistic approach and identified genomic alterations specific to stage and MYCN amplification
Infections caused by filamentous fungi in patients with hematologic malignancies. A report of 391 cases by GIMEMA Infection Program.
BACKGROUND AND OBJECTIVES: To evaluate the clinical characteristics of patients with hematologic malignancies developing a filamentous fungi infection (FFI) and to define the prognostic factors for their outcome.
DESIGN AND METHODS: A retrospective study, conducted on patients admitted to 14 Hematology divisions of tertiary care or university hospitals, participating in the GIMEMA Infection Program, over a ten-year period (1988-1997). The study included patients with hematological malignancies and a histologically and/or microbiologically proven or probable FFI.
RESULTS: We included 391 patients (male/female: 262/129, median age 49 years) with hematologic malignancies (225 acute myeloid leukemia, 67 acute lymphocytic leukemia, 30 chronic myeloid leukemia, 22 non-Hodgkin's lymphoma, 12 myelodysplastic syndrome, 10 aplastic anemia, 7 Hodgkin's disease, 8 chronic lymphocytic leukemia, 5 multiple myeloma, and 5 hairy cell leukemia) who developed a proven FFI. Eighty percent of the patients had been neutropenic for an average of 14 days before the infection, and 71% had an absolute neutrophil count lower than 0.5 x 10(9)/L at the time of FFI diagnosis. The primary sites of infection were: lungs (85%), nose and paranasal sinus (10%), and other sites (5%). The diagnosis was made while still alive in 310 patients (79%), and at autopsy in the remaining 81 patients (21%). Chest X-ray was diagnostic in 77% of patients with pulmonary FFI, while computed tomography (CT) scan of the thorax was positive in 95% of cases. A significant diagnostic advantage for CT scan was observed in 145 patients who had both a chest X-ray and CT scan. Aspergillus was identified as the cause of FFI in 296 patients, Mucorales in 45 patients, Fusarium in 6 patients and other filamentous fungi species in 4 patients, while in a further 40 patients no agent was identifiable. The overall mortality rate three months after the diagnosis of FFI was 74%, and fungal infection had been the cause of death in 51% of patients.
INTERPRETATION AND CONCLUSIONS: Our retrospective study shows that FFI still remains a life-threatening complication in neutropenic patients. Despite appropriate treatment, half of the patients die due to this complication. The use of glucocorticoids and recovery from neutropenia are the most important prognostic factors. Mucorales infections are associated with a significantly poorer prognosis than those due to Aspergillus spp
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