ABSTRACT
The relationship between acoustic parameters and the microstructure of a Cu30Zn brass plate subjected to plastic deformation was evaluated. The plate, previously annealed at 550 °C for 30 min, was cold rolled to reductions ranging from 10% to 70%. Linear ultrasonic measurements were performed on each of the nine specimens, corresponding to the nine different reductions, using the pulse-echo method to record the times of flight of longitudinal waves along the thickness axis. Subsequently, acoustic measurements were conducted to determine the nonlinear parameter ß through second harmonic generation. Microstructural analysis, carried out by X-ray diffraction, Vickers hardness testing, and optical microscopy, revealed an increase in deformation twins, reaching a maximum at 40% thickness reduction. At higher deformations, the microstructure showed the generation and proliferation of shear bands, coinciding with a decrease in the twinning structure and an increase in dislocation density. The longitudinal wave velocity exhibited a 0.9% decrease at 20% deformation, attributed to dislocations and initial twin formation, followed by a continuous increase up to 2% beyond this point, resulting from the combined effects of twinning and shear banding. The nonlinear parameter ß displayed a notable maximum, approximately one order of magnitude greater than its original value, at 40% deformation. This peak correlates with a roughly tenfold increase in twinning fault probability at the same deformation level.
ABSTRACT
AIM: To develop and validate a self-administered population-specific survey, available in Spanish, Portuguese, and English, which investigates the prevalence of voice symptoms and perceptions of risk factors associated with training among prospective teachers. METHODS: The present study had three stages: the first stage included a literature review and content validation by experts that supported the survey development. From this phase, we defined five aspects of the Prospective Teacher's Voice Questionnaire (PTVQ): (1) target population, (2) research objectives, (3) questions to be included, (4) scales for the answers, and (5) relevance, comprehensiveness, clarityclarity, and understandability of the questions. This process was performed in parallel for the three languages (Spanish, Portuguese, and English). The second stage included pilot testing. This involved administering the first draft of the survey to a group of 120 students to evaluate the feasibility and effectiveness of the survey instrument, identify any potential problems with the survey, and refine the instrument based on feedback from the pilot participants. The third stage includes the restructuring of the questionnaire's voice quality section to eliminate redundant questions. Through Principal Component Analysis, multicollinear variables were condensed, facilitating the removal of redundant items, and ensuring that the final questionnaire comprised only the most relevant and discriminative questions. RESULTS AND DISCUSSION: The final version of the survey, available in Spanish, Portuguese, and English, consists of four sections with a total of 57 questions. The development of the PTVQ represents a significant step toward better understanding and addressing voice disorders among prospective teachers. Future research could further refine the questionnaire and explore its predictive validity in identifying individuals at risk of voice disorders early in their teaching careers. Additionally, interventions based on the findings from the PTVQ could be developed to support the voice health and well-being of prospective teachers, ultimately improving teaching quality and job satisfaction in educational settings.
ABSTRACT
The importance of microbial associations to animals' development, physiology, and fitness is widely recognized. In most animals, these microbial associations must be developed anew with every generation, making microbiome assembly a critical ecological and evolutionary process. To fully understand neonate microbial colonization, we need to study the interacting effects of neonate, parents, nest, and external environment. We propose an integrative approach based on the concept of the 'nidobiome', a new unit of microbiome-host interactions, which brings together these key elements. We discuss the contribution of each element on microbial colonization at different stages of host development, and we provide a framework based on key developmental events to compare microbiome assembly across animal species.
Subject(s)
Microbiota , Animals , Biological Evolution , Humans , Infant, NewbornABSTRACT
Resumen:La granulomatosis con poliangeítis (GPA) es una vasculitis sistémica de pequeño vaso, que afecta más frecuentemente el tracto respiratorio y el riñón. Sus criterios diagnósticos se basan en la clínica, exámenes de laboratorio, imágenes e histología. El 90% son ANCA (anticuerpos anticitoplasma de neutrófilos) positivos. La histología muestra inflamación granulomatosa, necrosis y vasculitis. Los exámenes de imagen son de vital importancia en su estudio inicial y seguimiento, correspondiendo principalmente a técnicas tomográficas. La tomografía Computada (TC) es el método de elección para la evaluación de vía aérea superior y pulmón, con alta sensibilidad en afectación de cavidades nasal/paranasales, árbol bronquial y pulmón. La Resonancia Magnética está indicada en compromiso del sistema nervioso central y corazón. El PET/CT presenta alta sensibilidad en enfermedad tóraco-abdominal, es de utilidad en detectar lesiones no visibles con otras técnicas, y en control de tratamiento. El compromiso renal, de alta ocurrencia en GPA, presenta escasa traducción en las imágenes y es frecuentemente indetectable con imágenes, aunque el PET/CT puede ser positivo en casos de glomerulonefritis acentuada. La radiología simple no debe ser utilizada en el estudio de GPA dado su bajo rendimiento diagnóstico. El tratamiento se basa en terapia corticoidea e inmunosupresora. Las recaídas son frecuentes, por lo que estos pacientes requieren seguimiento a largo plazo.
Abstract:Granulomatosis with polyangiitis (GPA) is a systemic type of vasculitis that affects small vessels, most commonly involving the respiratory tract and kidneys. Diagnosis is based on clinical criteria, laboratory tests, imaging and histology. Ninety percent are ANCA (anti-neutrophilic cytoplasmic antibodies) positive. Histology demonstrates granulomatous inflammation, necrosis and vasculitis. Imaging studies are vital for the initial work-up and follow-up. Computed Tomography (CT) is the method of choice for evaluation of the upper airway and lungs, because of its high sensitivity detecting anomalies of paranasal sinuses, bronchial tree and lungs. Magnetic Resonance is indicated for evaluation of the central nervous system and heart. PET/CT has high sensitivity for thoracic and abdominal disease, is useful at detecting lesions not seen with other imaging techniques, and for follow-up. Renal involvement, very frequent on GPA, is usually undetectable at imaging, but may be seen at PET/CT in cases of marked glomerulonephritis. Plain X-rays should not be used for evaluation of GPA because of their low diagnostic performance. Treatment is based on corticosteroid and immunosuppressive therapy. Relapses are frequent, so these patients require long-term follow-up.