6,840 research outputs found
Las TIC y el aprendizaje en estudiantes de secundaria técnica Maynas, 2021
Este trabajo de investigación se realizó en La Institución Educativa Pública”
Maynas” de la Ciudad de Iquitos. Teniendo como objetivo el estudio fue diagnosticar
la relación que existe entre las TIC y el aprendizaje en estudiantes de secundaria
técnica, Maynas, 2021.
El proyecto metodológico concierne al estudio elemental de alcance descriptivo
correlacional, diseño de corte transversal, trabajando con una muestra de 109
estudiantes del 4° grado de secundaria del turno mañana. La recolección de datos
de la primera variable las TIC empleó la técnica de la encuesta que hizo uso de un
cuestionario de escala tipo Likert asimismo para la segunda variable el aprendizaje
se usó un cuestionario de escala tipo Likert.
Los resultados revelaron que existe relación entre las TIC y el aprendizaje en
estudiantes de secundaria técnica Maynas,2021. Según el coeficiente de
correlación de Pearson 0,669 lo que indica que existe una correlación alta inversa
con un nivel de significancia de 0.000 < 0,005
Serotypes, virulence genes profiles and antimicrobial resistance patterns of Escherichia coli recovered from feces of healthy lambs in Mexico
Articulo que habla de la resistencia a los antibióticos en corderosHealthy lambs are one of the major reservoirs of Shiga toxin-producing Escherichia coli (STEC) and it is known as
the cause of foodborne diseases (FBD). The work objective is to characterize (STEC) isolates obtained from rectal
swabs of healthy lambs herds, a total of 183 samples were obtained from sheep production units of the State of
Mexico. E. coli isolates were confirmed through the amplification of the uid A gene. antimicrobial sensitivity
pattern was determined through Kirby-Bauer (CLSI, 2012) test and the presence stx1, stx2 and eae genes from
isolates by multiplex PCR. Serotyping was performed using specific anti-O and anti-H sera (SERUNAM, Mexico)
for 185 Somatic and 56 flagellar antigens. 126 isolates biochemically and molecularly identified as E. coli were
obtained, of which 80 did not express any virulence factor and 46 expressed at least some (STEC) virulence
factor. The highest percentage of E. coli resistance was for tetracycline 48.7% (39/80), followed by nalidixic acid
13.7% (11/80), gentamicin 6.2% (5/80) and Ciprofloxacin 3.7% (3/80). Resistance to amikacin, cefotaxime and
ceftazidime were not detected. A frequency of 46 STEC isolates (36.2%) were obtained, of which 28/46 (22.0%)
expressed stx1, stx2 3/46 (6.5%), stx1, stx2 13/46 (10.2%) and eae 2/46 (1.6%). Thirty different serotypes were
obtained. The three serotypes with the highest number of isolates (four each) were: O76:H19, O118:H27 and
O146:H21 which have been identified as a cause of diarrhea in human population. An isolate of serogroup O104
was obtained, with a significant importance for European public health. In virtue of the discovered serotypes and
the virulence factors distribution, we can affirm that the obtained isolates from lambs in the State of Mexico are
classifiable as atypical STEC of low virulence
Finalizing the CCSDS Space-Data Link Layer Security Protocol: Setup and Execution of the Interoperability Testing
The protection of data transmitted over the space-link is an issue of growing importance also for civilian space missions. Through the Consultative Committee for Space Data Systems (CCSDS), space agencies have reacted to this need by specifying the Space Data-Link Layer Security (SDLS) protocol which provides confidentiality and integrity services for the CCSDS Telemetry (TM), Telecommand (TC) and Advanced Orbiting Services (AOS) space data-link protocols. This paper describes the approach of the CCSDS SDLS working group to specify and execute the necessary interoperability tests. It first details the individual SDLS implementations that have been produced by ESA, NASA, and CNES and then the overall architecture that allows the interoperability tests between them. The paper reports on the results of the interoperability tests and identifies relevant aspects for the evolution of the test environment
In vitro characterization of a nanostructured fibrin agarose bio-artificial nerve substitute
"This is the peer reviewed version of the following article: Carriel, V., Scionti, G., Campos, F., Roda, O., Castro, B., Cornelissen, M., Garzón, I., and Alaminos, M. (2017) In vitro characterization of a nanostructured fibrin agarose bio-artificial nerve substitute. J Tissue Eng Regen Med, 11: 1412–1426., which has been published in final form at [10.1002/term.2039. . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."Neural tissue engineering is focused on the design of novel biocompatible substitutes to repair peripheral nerve injuries. In this paper we describe a nanostructured fibrin–agarose bioartificial nerve substitute (NFABNS), based on nanostructured fibrin–agarose hydrogels (FAHs) with human adipose-derived mesenchymal stem cells (HADMSCs). These NFABNSs were mechanically characterized and HADMSCs behaviour was evaluated using histological and ultrastructural techniques. Mechanical characterization showed that the NFABNSs were resistant, flexible and elastic, with a high deformation capability. Histological analyses carried out in vitro during 16 days revealed that the number of HADMSCs decreased over time, with a significant increase after 16 days. HADMSCs formed cell clusters and degraded the surrounding scaffold during this time; additionally, HADMSCs showed active cell proliferation and cytoskeletal remodelling, with a progressive synthesis of extracellular matrix molecules. Finally, this study demonstrated that it is possible to generate biologically active and mechanically stable tissue-like substitutes with specific dimensions, based on the use of HADMSCs, FAHs and a nanostructure technique. However, in vivo analyses are needed to demonstrate their potential usefulness in peripheral nerve repairPeer ReviewedPostprint (author's final draft
Physiological lentiviral vectors for the generation of improved CAR-T cells
Anti-CD19 chimeric antigen receptor (CAR)-T cells have achieved impressive outcomes for the treatment of relapsed and refractory B-lineage neoplasms. However, important limitations still remain due to severe adverse events (i.e., cytokine release syndrome and neuroinflammation) and relapse of 40%-50% of the treated patients. Most CAR-T cells are generated using retroviral vectors with strong promoters that lead to high CAR expression levels, tonic signaling, premature exhaustion, and overstimulation, reducing efficacy and increasing side effects. Here, we show that lentiviral vectors (LVs) expressing the transgene through a WAS gene promoter (AW-LVs) closely mimic the T cell receptor (TCR)/CD3 expression kinetic upon stimulation. These AW-LVs can generate improved CAR-T cells as a consequence of their moderate and TCR-like expression profile. Compared with CAR-T cells generated with human elongation factor alpha (EF1 alpha)-driven-LVs, AW-CAR-T cells exhibited lower tonic signaling, higher proportion of naive and stem cell memory T cells, less exhausted phenotype, and milder secretion of tumor necrosis factor alpha (TNF-alpha) and interferon (IFN)-gamma after efficient destruction of CD19(+) lymphoma cells, both in vitro and in vivo. Moreover, we also showed their improved efficiency using an in vitro CD19(+) pancreatic tumor model. We finally demonstrated the feasibility of large-scale manufacturing of AW-CAR-T cells in guanosine monophosphate (GMP)-like conditions. Based on these data, we propose the use of AWLVs for the generation of improved CAR-T products
Mitigating the noise of DESI mocks using analytic control variates
In order to address fundamental questions related to the expansion history of
the Universe and its primordial nature with the next generation of galaxy
experiments, we need to model reliably large-scale structure observables such
as the correlation function and the power spectrum. Cosmological -body
simulations provide a reference through which we can test our models, but their
output suffers from sample variance on large scales. Fortunately, this is the
regime where accurate analytic approximations exist. To reduce the variance,
which is key to making optimal use of these simulations, we can leverage the
accuracy and precision of such analytic descriptions using Control Variates
(CV). We apply two control variate formulations to mock catalogs generated in
anticipation of upcoming data from the Dark Energy Spectroscopic Instrument
(DESI) to test the robustness of its analysis pipeline. Our CV-reduced
measurements, of the power spectrum and correlation function, both pre- and
post-reconstruction, offer a factor of 5-10 improvement in the measurement
error compared with the raw measurements from the DESI mock catalogs. We
explore the relevant properties of the galaxy samples that dictate this
reduction and comment on the improvements we find on some of the derived
quantities relevant to Baryon Acoustic Oscillation (BAO) analysis. We also
provide an optimized package for computing the power spectra and other
two-point statistics of an arbitrary galaxy catalog as well as a pipeline for
obtaining CV-reduced measurements on any of the AbacusSummit cubic box outputs.
We make our scripts, notebooks, and benchmark tests against existing software
publicly available and report a speed improvement of a factor of 10 for a
grid size of compared with .Comment: 15 pages, 9 figures, public package (for power spectrum and control
variates estimation
The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project
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Mature iPSC-derived astrocytes of an ALS/FTD patient carrying the TDP43A90V mutation display a mild reactive state and release polyP toxic to motoneurons
Astrocytes play a critical role in the maintenance of a healthy central nervous system and astrocyte dysfunction has been implicated in various neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). There is compelling evidence that mouse and human ALS and ALS/FTD astrocytes can reduce the number of healthy wild-type motoneurons (MNs) in co-cultures or after treatment with astrocyte conditioned media (ACM), independently of their genotype. A growing number of studies have shown that soluble toxic factor(s) in the ACM cause non-cell autonomous MN death, including our recent identification of inorganic polyphosphate (polyP) that is excessively released from mouse primary astrocytes (SOD1, TARDBP, and C9ORF72) and human induced pluripotent stem cells (iPSC)-derived astrocytes (TARDBP) to kill MNs. However, others have reported that astrocytes carrying mutant TDP43 do not produce detectable MN toxicity. This controversy is likely to arise from the findings that human iPSC-derived astrocytes exhibit a rather immature and/or reactive phenotype in a number of studies. Here, we have succeeded in generating a highly homogenous population of functional quiescent mature astrocytes from control subject iPSCs. Using identical conditions, we also generated mature astrocytes from an ALS/FTD patient carrying the TDP43A90V mutation. These mutant TDP43 patient-derived astrocytes exhibit key pathological hallmarks, including enhanced cytoplasmic TDP-43 and polyP levels. Additionally, mutant TDP43 astrocytes displayed a mild reactive signature and an aberrant function as they were unable to promote synaptogenesis of hippocampal neurons. The polyP-dependent neurotoxic nature of the TDP43A90V mutation was further confirmed as neutralization of polyP in ACM derived from mutant TDP43 astrocytes prevented MN death. Our results establish that human astrocytes carrying the TDP43A90V mutation exhibit a cell-autonomous pathological signature, hence providing an experimental model to decipher the molecular mechanisms underlying the generation of the neurotoxic phenotype
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