7,164 research outputs found
Burned or engaged teachers? The role of mindfulness, self-efficacy, teacher and studentsâ relationships, and the mediating role of intrapersonal and interpersonal mindfulness
This study had the goal to examine factors that are associated with burnout and engagement among teachers from diverse educational stages. Among these factors, we analyzed socio-demographic aspects, such as gender, age and years of experience, and other psychological teacher-related variables like teacherâs self-efficacy and teacher-student relationships. We also considered the potential mediating role of mindfulness in these relationships. The sample was made up by 425 Spanish teachers who answered an online survey. We administered the following measures: Revised version of the Teacherâs Burnout Questionnaire, Utrecht Work Engagement Scale, Mindfulness in Teaching Scale âwhich distinguished between intrapersonal and interpersonal mindfulness-, Teacherâs Sense of Self-efficacy Scale, and some questions related to the relationships between students and teachers in the classroom. We conducted a mediational analysis through structural equation modeling (SEM). Our findings indicated that both intrapersonal and interpersonal mindfulness mediated the relation between self-efficacy, which played a direct and an indirect role, the teacher-student relationship, and burnout and engagement. The socio-demographic variables of gender and years of experience played a significant role in mindfulness. The teachers with more self-efficacy were more likely to pay attention to their daily activity and to show more receptivity with their students, which resulted in lower burnout and more engagement. In addition, better relationships with students led to higher intrapersonal mindfulness levels, which mediated the relation with burnout and engagement. These relations varied depending on specific burnout and engagement dimensions. We discuss the implications of these findings for improving teachersÂŽ implication in the education field. © 2021, The Author(s)
Agreement and clinical comparison between a new swept-source optical coherence tomography-based optical biometer and an optical low-coherence reflectometry biometer
Purpose
To compare measurements taken using a swept-source optical coherence tomography-based optical biometer (IOLmaster 700) and an optical low-coherence reflectometry biometer (Lenstar 900), and to determine the clinical impacts of differences in their measurements on intraocular lens (IOL) power predictions.
Methods
Eighty eyes of 80 patients scheduled to undergo cataract surgery were examined with both biometers. The measurements made using each device were axial length (AL), central corneal thickness (CCT), aqueous depth (AQD), lens thickness (LT), mean keratometry (MK), white-to-white distance (WTW), and pupil diameter (PD). Holladay 2 and SRK/T formulas were used to calculate IOL power. Differences in measurement between the two biometers were determined using the paired t-test. Agreement was assessed through intraclass correlation coefficients (ICC) and BlandâAltman plots.
Results
Mean patient age was 76.3±6.8 years (range 59â89). Using the Lenstar, AL and PD could not be measured in 12.5 and 5.25% of eyes, respectively, while IOLMaster 700 took all measurements in all eyes. The variables CCT, AQD, LT, and MK varied significantly between the two biometers. According to ICCs, correlation between measurements made with both devices was excellent except for WTW and PD. Using the SRK/T formula, IOL power prediction based on the data from the two devices were statistically different, but differences were not clinically significant.
Conclusions
No clinically relevant differences were detected between the biometers in terms of their measurements and IOL power predictions. Using the IOLMaster 700, it was easier to obtain biometric measurements in eyes with less transparent ocular media or longer AL
Effect of butanol and salt concentration on solid-state nanopores resistance
The objective of this study was to demonstrate the possibility of using 1-butanol to detect in a reliable way the open pore current of pyramidal solid-state nanopores produced in silicon wafers. The nanopores were produced through controlled pore formation by neutralizing an etchant (KOH) with a strong acid (HCl). Since nanopores produced by this method have a larger depth than those made in nanometer thick membranes, they behave as nanochannels. As a consequence, the open pore current detection is more challenging. Thus, we report that low amounts of butanol considerably aid in the detection of the open pore current of nanopores.Fil: Vega, M.. Universidad TecnolĂłgica Nacional. Facultad Regional Haedo; ArgentinaFil: Perez, Maximiliano Sebastian. Universidad TecnolĂłgica Nacional. Facultad Regional Haedo; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Granell, Pablo NicolĂĄs. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Golmar, Federico. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Wloka, C.. University of Groningen; PaĂses BajosFil: Maglia, G.. University of Groningen; PaĂses BajosFil: Dieguez, M.J.. Instituto Nacional de TecnologĂa Agropecuaria; ArgentinaFil: Del Valle, E.M.. Universidad de Salamanca; EspañaFil: Lasorsa, Carlos Alberto. Universidad TecnolĂłgica Nacional. Facultad Regional Haedo; ArgentinaFil: Lerner, Betiana. Universidad TecnolĂłgica Nacional. Facultad Regional Haedo; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentin
The CT20 peptide causes detachment and death of metastatic breast cancer cells by promoting mitochondrial aggregation and cytoskeletal disruption
Metastasis accounts for most deaths from breast cancer, driving the need for new therapeutics that can impede disease progression. Rationally designed peptides that take advantage of cancer-specific differences in cellular physiology are an emerging technology that offer promise as a treatment for metastatic breast cancer. We developed CT20p, a hydrophobic peptide based on the C terminus of Bax that exhibits similarities with antimicrobial peptides, and previously reported that CT20p has unique cytotoxic actions independent of full-length Bax. In this study, we identified the intracellular actions of CT20p which precede cancer cell-specific detachment and death. Previously, we found that CT20p migrated in the heavy membrane fractions of cancer cell lysates. Here, using MDA-MB-231 breast cancer cells, we demonstrated that CT20p localizes to the mitochondria, leading to fusion-like aggregation and mitochondrial membrane hyperpolarization. As a result, the distribution and movement of mitochondria in CT20p-treated MDA-MB-231 cells was markedly impaired, particularly in cell protrusions. In contrast, CT20p did not associate with the mitochondria of normal breast epithelial MCF-10A cells, causing little change in the mitochondrial membrane potential, morphology or localization. In MDA-MB-231 cells, CT20p triggered cell detachment that was preceded by decreased levels of alpha 5 beta 1 integrins and reduced F-actin polymerization. Using folate-targeted nanoparticles to encapsulate and deliver CT20p to murine tumors, we achieved significant tumor regression within days of peptide treatment. These results suggest that CT20p has application in the treatment of metastatic disease as a cancer-specific therapeutic peptide that perturbs mitochondrial morphology and movement ultimately culminating in disruption of the actin cytoskeleton, cell detachment, and loss of cell viability
Vaginal neutrophil infiltration is contingent on ovarian cycle phase and independent of pathogen infection
The mucosa of the female reproductive tract must reconcile the presence of commensal microbiota and the transit of exogenous spermatozoa with the elimination of sexually transmitted pathogens. In the vagina, neutrophils are the principal cellular arm of innate immunity and constitute the first line of protection in response to infections or injury. Neutrophils are absent from the vaginal lumen during the ovulatory phase, probably to allow sperm to fertilize; however, the mechanisms that regulate neutrophil influx to the vagina in response to aggressions remain controversial. We have used mouse inseminations and infections of Neisseria gonorrhoeae, Candida albicans, Trichomonas vaginalis, and HSV-2 models. We demonstrate that neutrophil infiltration of the vaginal mucosa is distinctively contingent on the ovarian cycle phase and independent of the sperm and pathogen challenge, probably to prevent sperm from being attacked by neutrophils. Neutrophils extravasation is a multi-step cascade of events, which includes their adhesion through selectins (E, P and L) and integrins of the endothelial cells. We have discovered that cervical endothelial cells expressed selectin-E (SELE, CD62E) to favor neutrophils recruitment and estradiol down-regulated SELE expression during ovulation, which impaired neutrophil transendothelial migration and orchestrated sperm tolerance. Progesterone up-regulated SELE to restore surveillance after ovulation
Core-collapse and Type Ia supernovae with the SKA
Core-collapse SNe (CCSNe): Systematic searches of radio emission from CCSNe
are still lacking, and only targeted searches of radio emission from just some
of the optically discovered CCSNe in the local universe have been carried out.
Optical searches miss a significant fraction of CCSNe due to dust obscuration;
CCSN radio searches are thus more promising for yielding the complete,
unobscured star-formation rates in the local universe. The SKA yields the
possibility to piggyback for free in this area of research by carrying out
commensal, wide-field, blind transient survey observations. SKA1-SUR should be
able to discover several hundreds of CCSNe in just one year, compared to about
a dozen CCSNe that the VLASS would be able to detect in one year, at most. SKA,
with an expected sensitivity ten times that of SKA1, is expected to detect
CCSNe in the local Universe by the thousands. Therefore, commensal SKA
observations could easily result in an essentially complete census of all CCSNe
in the local universe, thus yielding an accurate determination of the
volumetric CCSN rate. Type Ia SNe: We advocate for the use of the SKA to search
for the putative prompt (~first few days after the explosion) radio emission of
any nearby type Ia SN, via target-of-opportunity observations. The huge
improvement in sensitivity of the SKA with respect to its predecessors will
allow to unambiguously discern which progenitor scenario (single-degenerate vs.
double-degenerate) applies to them.Comment: Proceedings of Science: Advancing Astrophysics with the Square
Kilometre Array. Accepted version, including comments by the refere
Influenza virus infections in infants aged less than two years old
[ES] IntroducciĂłn: Las infecciones por virus influenza son una importante causa de morbilidad en lactantes. El cuadro clĂnico es inespecĂfico y a menudo se infraestima la importancia de lagripe en los menores de 2 años. El objetivo del estudio fue describir las infecciones con firmadas por virus influenza en niños menores de 2 años atendidos en un hospital de segundo nivel. Como objetivo secundario, se pretende comparar las infecciones por gripe en lactantes hospitalizados con las infecciones por virus respiratorio sincitial (VRS) en la misma poblaciĂłn. Pacientes y mĂ©todos: Estudio descriptivo prospectivo de las infecciones con firmadas por virus influenza en los niños menores de
2 años hospitalizados por fiebre o infecciĂłn respiratoria entre 1991 y 2003. Para el diagnĂłstico virolĂłgico se realizĂł inmunofluorescencia y reacciĂłn en cadena de la poli merasa en el aspirado nasofarĂngeo. Se describen las caracterĂsticas clĂnicas de los pacientes. Se realiza una comparaciĂłn con un grupo de lactantes de similares caracterĂsticas ingresados por infecciĂłn por VRS. Resultados: Se describen 100 lactantes hospitalizados con infecciĂłn
por virus influenza. Las infecciones gripales supusieron el 4,1 % de los pacientes hospitalizados por procesos respiratorios o fiebre. Se aislĂł virus influenza tipo A en el 83 % de los casos, tipo B en el 12 % y tipo C en el 5 %. La
edad media fue 8,3 +/- 5,9 meses, y los diagnĂłsticos mĂĄs fre cuentes fueron bronquiolitis en el 38 %, sibilancias recurrentes en el 25%, infecciĂłn respiratoria de vĂas altas en el 19% y neumonĂa en el 9%. Presentaron fiebre superior
a 38 °C el 83% de los niños e infiltrado radiolĂłgico el 65%. Presentaron hipoxia el 44 % de los niños. En los niños menores de 6 meses la fiebre fue menos frecuente (p = 0,049), y en los diagnĂłsticos predominaron las infecciones respiratorias de vĂas altas (p = 0,01). Los niños afectados de infecciĂłn por virus influenza tu vieron mayor edad (p = 0,002), presentaron con mayor frecuencia fiebre (p 38 degrees C was present in 83% of the patients. Radiologic infiltrate was found in 65% of the children. Oxygen saturation less then 95% was present in 44%. In children under 6 months of age fever was less frequent (p = 0.049) and upper respiratory tract infection was more frequent (p = 0.01). Patients with influenza virus infection were older (p = 0.002), more frequently presented fever (p < 0.0001) and radiologic infiltrate (p < 0.001) than infants with RSV infection. Bronchiolitis was more frequent in the RSV group (p = 0.006). Conclusions: Influenza infection is a major cause of respiratory tract disease in hospitalized infants. It is an etiologic cause of bronchiolitis, recurrent wheezing, and fever and radiologic consolidations are frequent. Clinical presentation is milder in children under 6 month of age. The characteristics of influenza infection differ substantially from those of RSV infection.S
Protection from Staphylococcus aureus mastitis associated with poly-N-acetyl beta-1,6 glucosamine specific antibody production using biofilm-embedded bacteria
Staphylococcus aureus vaccines based on bacterins surrounded by slime, surface polysaccharides
coupled to protein carriers and polysaccharides embedded in liposomes administered together with
non-biofilm bacterins confer protection against mastitis. However, it remains unknown whether
protective antibodies are directed to slime-associated known exopolysaccharides and could be
produced in the absence of bacterin immunizations. Here, a sheep mastitis vaccination study was
carried out using bacterins, crude bacterial extracts or a purified exopolysaccharide from biofil
Evaluation of different bowel preparations for small bowel capsule endoscopy: a prospective, randomized, controlled study
To obtain an adequate view of the whole small
intestine during capsule endoscopy (CE) a clear liquid diet and overnight fasting
is recommended. However, intestinal content can hamper vision in spite of these
measures. Our aim was to evaluate tolerance and degree of intestinal cleanliness
during CE following three types of bowel preparation. PATIENTS AND METHODS: This
was a prospective, multicenter, randomized, controlled study. Two-hundred
ninety-one patients underwent one of the following preparations: 4 L of clear
liquids (CL) (group A; 92 patients); 90 mL of aqueous sodium phosphate (group B;
89 patients); or 4 L of a polyethylene glycol electrolyte solution (group C; 92
patients). The degree of cleanliness of the small bowel was classified by blinded
examiners according to four categories (excellent, good, fair or poor). The
degree of patient satisfaction, gastric and small bowel transit times, and
diagnostic yield were measured. RESULTS: The degree of cleanliness did not differ
significantly between the groups (P = 0.496). Interobserver concordance was fair
(k = 0.38). No significant differences were detected between the diagnostic
yields of the CE (P = 0.601). Gastric transit time was 35.7 +/- 3.7 min (group
A), 46.1 +/- 8.6 min (group B) and 34.6 +/- 5.0 min (group C) (P = 0.417).
Small-intestinal transit time was 276.9 +/- 10.7 min (group A), 249.7 +/- 13.1
min (group B) and 245.6 +/- 11.6 min (group C) (P = 0.120). CL was the best
tolerated preparation. Compliance with the bowel preparation regimen was lowest
in group C (P = 0.008). CONCLUSIONS: A clear liquid diet and overnight fasting is
sufficient to achieve an adequate level of cleanliness and is better tolerated by
patients than other forms of preparation
On supersymmetric quantum mechanics
This paper constitutes a review on N=2 fractional supersymmetric Quantum
Mechanics of order k. The presentation is based on the introduction of a
generalized Weyl-Heisenberg algebra W_k. It is shown how a general Hamiltonian
can be associated with the algebra W_k. This general Hamiltonian covers various
supersymmetrical versions of dynamical systems (Morse system, Poschl-Teller
system, fractional supersymmetric oscillator of order k, etc.). The case of
ordinary supersymmetric Quantum Mechanics corresponds to k=2. A connection
between fractional supersymmetric Quantum Mechanics and ordinary supersymmetric
Quantum Mechanics is briefly described. A realization of the algebra W_k, of
the N=2 supercharges and of the corresponding Hamiltonian is given in terms of
deformed-bosons and k-fermions as well as in terms of differential operators.Comment: Review paper (31 pages) to be published in: Fundamental World of
Quantum Chemistry, A Tribute to the Memory of Per-Olov Lowdin, Volume 3, E.
Brandas and E.S. Kryachko (Eds.), Springer-Verlag, Berlin, 200
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