18 research outputs found

    Antecedents of Teachers' Emotions in the Classroom: An Intraindividual Approach

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    Using a preexisting, but as yet empirically untested theoretical model, the present study investigated antecedents of teachers' emotions in the classroom. More specifically, the relationships between students' motivation and discipline and teachers' enjoyment and anger were explored, as well as if these relationships are mediated by teachers' subjective appraisals (goal conduciveness and coping potential). The study employed an intraindividual approach by collecting data through a diary. The sample consisted of 39 teachers who each participated with one of their 9th or 10th grade mathematics classes (N = 758 students). Both teachers and students filled out diaries for 2-3 weeks pertaining to 8.10 lessons on average (N = 316 lessons). Multilevel structural equation modeling revealed that students' motivation and discipline explained 24% of variance in teachers' enjoyment and 26% of variance in teachers' anger. In line with theoretical assumptions, after introducing teachers' subjective appraisals as a mediating mechanism into the model, the explained variance systematically increased to 65 and 61%,for teachers' enjoyment and anger respectively. The effects of students' motivation and discipline level on teachers' emotions were partially mediated by teachers' appraisals of goal conduciveness and coping potential. The findings imply that since teachers' emotions depend to a large extent on subjective evaluations of a situation, teachers should be able to directly modify their emotional experiences during a lesson through cognitive reappraisals

    Neutralization of SARS-CoV-2 by highly potent, hyperthermostable, and mutation-tolerant nanobodies

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    Monoclonal anti-SARS-CoV-2 immunoglobulins represent a treatment option for COVID-19. However, their production in mammalian cells is not scalable to meet the global demand. Single-domain (VHH) antibodies (also called nanobodies) provide an alternative suitable for microbial production. Using alpaca immune libraries against the receptor-binding domain (RBD) of the SARS-CoV-2 Spike protein, we isolated 45 infection-blocking VHH antibodies. These include nanobodies that can withstand 95°C. The most effective VHH antibody neutralizes SARS-CoV-2 at 17–50 pM concentration (0.2–0.7 µg per liter), binds the open and closed states of the Spike, and shows a tight RBD interaction in the X-ray and cryo-EM structures. The best VHH trimers neutralize even at 40 ng per liter. We constructed nanobody tandems and identified nanobody monomers that tolerate the K417N/T, E484K, N501Y, and L452R immune-escape mutations found in the Alpha, Beta, Gamma, Epsilon, Iota, and Delta/Kappa lineages. We also demonstrate neutralization of the Beta strain at low-picomolar VHH concentrations. We further discovered VHH antibodies that enforce native folding of the RBD in the E. coli cytosol, where its folding normally fails. Such “fold-promoting” nanobodies may allow for simplified production of vaccines and their adaptation to viral escape-mutations

    Crystal structures of FNIP/FGxxFN motif-containing leucine-rich repeat proteins

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    The Cafeteria roenbergensis virus (Crov), Dictyostelium, and other species encode a large family of leucine-rich repeat (LRR) proteins with FGxxFN motifs. We determined the structures of two of them and observed several unique structural features that set them aside from previously characterized LRR family members. Crov588 comprises 25 regular repeats with a LxxLxFGxxFNQxIxENVLPxx consensus, forming a unique closed circular repeat structure. Novel features include a repositioning of a conserved asparagine at the middle of the repeat, a double phenylalanine spine that generates an alternate core packing arrangement, and a histidine/tyrosine ladder on the concave surface. Crov539 is smaller, comprising 12 repeats of a similar LxxLxFGxxFNQPIExVxW/LPxx consensus and forming an unusual cap-swapped dimer structure. The phenylalanine spine of Crov539 is supplemented with a tryptophan spine, while a hydrophobic isoleucine-rich patch is found on the central concave surface. We present a detailed analysis of the structures of Crov588 and Crov539 and compare them to related repeat proteins and other LRR classes

    Electronic spectroscopy and nanocalorimetry of hydrated magnesium ions [Mg(H2O)n]+, n = 20-70: spontaneous formation of a hydrated electron?

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    Hydrated singly charged magnesium ions [Mg(H2O)n]+ are thought to consist of an Mg2+ ion and a hydrated electron for n > 15. This idea is based on mass spectra, which exhibit a transition from [MgOH(H2O)n-1]+ to [Mg(H2O)n]+ around n = 15-22, black-body infrared radiative dissociation, and quantum chemical calculations. Here, we present photodissociation spectra of size-selected [Mg(H2O)n]+ in the range of n = 20-70 measured for photon energies of 1.0-5.0 eV. The spectra exhibit a broad absorption from 1.4 to 3.2 eV, with two local maxima around 1.7-1.8 eV and 2.1-2.5 eV, depending on cluster size. The spectra shift slowly from n = 20 to n = 50, but no significant change is observed for n = 50-70. Quantum chemical modeling of the spectra yields several candidates for the observed absorptions, including five- and six-fold coordinated Mg2+ with a hydrated electron in its immediate vicinity, as well as a solvent-separated Mg2+/e- pair. The photochemical behavior resembles that of the hydrated electron, with barrierless interconversion into the ground state following the excitation.(VLID)4795200Version of recor

    Photochemistry and spectroscopy of small hydrated magnesium clusters Mg+(H2O)n, n = 1-5

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    Hydrated singly charged magnesium ions Mg+(H2O)n, n 5, in the gas phase are ideal model systems to study photochemical hydrogen evolution since atomic hydrogen is formed over a wide range of wavelengths, with a strong cluster size dependence. Mass selected clusters are stored in the cell of an Fourier transform ion cyclotron resonance mass spectrometer at a temperature of 130 K for several seconds, which allows thermal equilibration via blackbody radiation. Tunable laser light is used for photodissociation. Strong transitions to D1-3 states (correlating with the 3s-3px,y,z transitions of Mg+) are observed for all cluster sizes, as well as a second absorption band at 4-5 eV for n = 3-5. Due to the lifted degeneracy of the 3px,y,z energy levels of Mg+, the absorptions are broad and red shifted with increasing coordination number of the Mg+ center, from 4.5 eV for n = 1 to 1.8 eV for n = 5. In all cases, H atom formation is the dominant photochemical reaction channel. Quantum chemical calculations using the full range of methods for excited state calculations reproduce the experimental spectra and explain all observed features. In particular, they show that H atom formation occurs in excited states, where the potential energy surface becomes repulsive along the OH coordinate at relatively small distances. The loss of H2O, although thermochemically favorable, is a minor channel because, at least for the clusters n = 1-3, the conical intersection through which the system could relax to the electronic ground state is too high in energy. In some absorption bands, sequential absorption of multiple photons is required for photodissociation. For n = 1, these multiphoton spectra can be modeled on the basis of quantum chemical calculations.(VLID)4795218Version of recor

    Calcificação nos núcleos da base na tomografia computadorizada: correlação clínica em 25 pacientes consecutivos Basal ganglia calcification on computed tomography: clinical characteristics in 25 patients

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    Analisamos os aspectos clínicos de 25 pacientes consecutivos que apresentaram calcificação nos núcleos da base na tomografia computadorizada (TC) de crânio. Esta ocorreu em 0,68% de todos os exames realizados no período. Vinte e três pacientes apresentavam condições clínicas diversas, a saber: cefaléia em 7 casos, acidente vascular cerebral em 5, síndrome extrapiramidal em 2, processo expansivo cerebral em 2, epilepsia, retardo do desenvolvimento neuropsicomotor, demência e trauma de crânio em um caso cada ou outras condições neurológicas em 3. Não havia sintomas neurológicos em 2 casos. Em 15 pacientes (60,0%) havia, além da calcificação dos núcleos da base, outras alterações na TC. Correlação clínica foi observada apenas com as outras alterações da TC e não com a calcificação dos núcleos da base, corroborando a hipótese de que esta possa ser um achado incidental.<br>Twenty-five patients presenting basal ganglia calcification were assessed. This finding comprised 0.68% of all skull CT scan carried out during the period. Two patients were neurologically asymptomatic and 23 presented a variety neurological disorders - headache (7 patients), stroke (5 patients), extrapyramidal syndromes (2 patients), tumor (2 patients), epilepsy (1 patient), mental retardation (1 patient), dementia (1 patient), cranial trauma (1 patient), other neurological conditions (3 patients) - or were asymptomatic from the neurological point of view (2 patients). Findings in the CT scan other than the basal ganglia calcification were observed in 15 (60%) patients. There was a clinical-CT scan correlation in these cases but not in those in which the basal ganglia calcification was an isolated finding. This study highlights the fact that basal ganglia calcification is often a nonspecific finding on CT scan and that it may not be possible to establish a clinical-pathological correlation between them
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