276 research outputs found
Effectiveness of Career and Technology Student Organizations (CTSOs) in Texas
The purpose of this study was to determine the extent to which public school administrators believe that Career and Technology Student Organizations (CTSOs) are providing students the necessary skills for employability and academic success. Objectives focused on whether CTSOs are effective in developing students’ leadership skills, keeping them engaged in school, developing technical skills, and improving academic achievement. School administrators were surveyed via the internet. A 28% response rate was achieved.
Ninety-two percent of respondents indicated that their school offered students the opportunity to participate in CTSO activities. Administrators indicated that the FFA was the CTSO that was either most effective or second most effective in teaching leadership skills, keeping students engaged in school, improving technical skills, and improving academic achievement. HOSA and Skills USA also were consistent in being among the top three CTSOs that were effective in providing one of the four characteristics. Considering 80 percent as a benchmark, administrators perceived CTSOs very favorably as being either mostly effective or very effective in meeting students’ needs
Strong-field physics with mid-IR fields
Strong-field physics is currently experiencing a shift towards the use of
mid-IR driving wavelengths. This is because they permit conducting experiments
unambiguously in the quasi-static regime and enable exploiting the effects
related to ponderomotive scaling of electron recollisions. Initial measurements
taken in the mid-IR immediately led to a deeper understanding of
photo-ionization and allowed a discrimination amongst different theoretical
models. Ponderomotive scaling of rescattering has enabled new avenues towards
time resolved probing of molecular structure. Essential for this paradigm shift
was the convergence of two experimental tools: 1) intense mid-IR sources that
can create high energy photons and electrons while operating within the
quasi-static regime, and 2) detection systems that can detect the generated
high energy particles and image the entire momentum space of the interaction in
full coincidence. Here we present a unique combination of these two essential
ingredients, namely a 160\~kHz mid-IR source and a reaction microscope
detection system, to present an experimental methodology that provides an
unprecedented three-dimensional view of strong-field interactions. The system
is capable of generating and detecting electron energies that span a six order
of magnitude dynamic range. We demonstrate the versatility of the system by
investigating electron recollisions, the core process that drives strong-field
phenomena, at both low (meV) and high (hundreds of eV) energies. The low energy
region is used to investigate recently discovered low-energy structures, while
the high energy electrons are used to probe atomic structure via laser-induced
electron diffraction. Moreover we present, for the first time, the correlated
momentum distribution of electrons from non-sequential double-ionization driven
by mid-IR pulses.Comment: 17 pages, 11 figure
Cyclic Deformation Induced Residual Stress Evolution and 3D Short Fatigue Crack Growth Investigated by Advanced Synchrotron Tomography Techniques
Butterfly gyroid nanostructures as a time-frozen glimpse of intracellular membrane development
The formation of the biophotonic gyroid material in butterflywing scales is an exceptional feat of evolutionary engineering of functional nanostructures. It is hypothesized that this nanostructure forms by chitin polymerization inside a convolutedmembrane of corresponding shape in the endoplasmic reticulum. However, this dynamic formation process, including whether membrane folding and chitin expression are simultaneous or sequential processes, cannot yet be elucidated by in vivo imaging. We report an unusual hierarchical ultrastructure in the butterfly Thecla opisena that, as a solid material, allows high-resolution three-dimensional microscopy. Rather than the conventional polycrystalline spacefilling arrangement, a gyroid occurs in isolated facetted crystallites with a pronounced size gradient.When interpreted as a sequence of time-frozen snapshots of the morphogenesis, this arrangement provides insight into the formation mechanisms of the nanoporous gyroid material as well as of the intracellular organelle membrane that acts as the template
LapSeg3D: Weakly Supervised Semantic Segmentation of Point Clouds Representing Laparoscopic Scenes
The semantic segmentation of surgical scenes is a prerequisite for task automation in robot assisted interventions. We propose LapSeg3D, a novel DNN-based approach for the voxel-wise annotation of point clouds representing surgical scenes. As the manual annotation of training data is highly time consuming, we introduce a semi-autonomous clustering-based pipeline for the annotation of the gallbladder, which is used to generate segmented labels for the DNN. When evaluated against manually annotated data, LapSeg3D achieves an F1 score of 0.94 for gallbladder segmentation on various datasets of ex-vivo porcine livers. We show LapSeg3D to generalize accurately across different gallbladders and datasets recorded with different RGB-D camera systems
LapSeg3D: Weakly Supervised Semantic Segmentation of Point Clouds Representing Laparoscopic Scenes
The semantic segmentation of surgical scenes is a prerequisite for task
automation in robot assisted interventions. We propose LapSeg3D, a novel
DNN-based approach for the voxel-wise annotation of point clouds representing
surgical scenes. As the manual annotation of training data is highly time
consuming, we introduce a semi-autonomous clustering-based pipeline for the
annotation of the gallbladder, which is used to generate segmented labels for
the DNN. When evaluated against manually annotated data, LapSeg3D achieves an
F1 score of 0.94 for gallbladder segmentation on various datasets of ex-vivo
porcine livers. We show LapSeg3D to generalize accurately across different
gallbladders and datasets recorded with different RGB-D camera systems.Comment: 6 pages, 5 figures, accepted at the 2022 IEEE/RSJ International
Conference on Intelligent Robots and Systems (IROS 2022), Kyoto, Japa
Extension of corporate services brands: the effect of perceived similarity extension and perceived quality brand
O principal objetivo deste estudo é avaliar o efeito da qualidade percebida da marca-mãe e da similaridade percebida sobre as avaliações de extensões de marcas corporativas de serviços. Adicionalmente, também se deseja verificar se a elaboração das caracterÃsticas da extensão contribuem para a sua avaliação. As hipóteses foram testadas por meio de três experimentos que envolveram no total 1.131 respondentes. No Estudo 1 foram utilizadas marcas fictÃcias como estÃmulo e verificou-se que a qualidade da marca-mãe teve efeito mais importante que a similaridade percebida sobre as avaliações de uma extensão de marca de serviços. No Estudo 2, utilizando como estÃmulos marcas reais, os mesmos resultados do Estudo 1 foram obtidos. No Estudo 3 verificou-se que a elaboração das caracterÃsticas da extensão contribuiu positivamente apenas para uma das extensões propostas para a marca-mãe de alta qualidade, mas não teve nenhum efeito para as extensões propostas para a marca-mãe de baixa qualidade. Tomados em conjunto, os resultados sugerem que a qualidade percebida da marca-mãe tem papel fundamental na avaliação de extensões de marcas corporativas de serviços. O estudo contribui ainda com diversas hipóteses para estudos futuros e implicações gerenciais para gerentes de marcas corporativas de serviços.The main objective of this study is to assess the effect of parent brand perceived quality and perceived similarity on the evaluation of corporate service brand extensions. It is also the intention of this study to verify whether providing information cues about the characteristics of the extension contributes to the brand extension evaluation. The hypotheses were tested by means of three experiments involving 1,131 subjects. The results of Study 1, conducted with fictitious brands as stimuli, demonstrated that the perceived quality of the parent brand played a more significant role than perceived similarity on the evaluations of brand extensions. In Study 2, where real brands were used as stimuli, the results were the same as in Study 1. Study 3 found that providing information cues about the characteristics of the extensions had a positive effect for one of the extensions of the high quality parent brand but not for the two proposed extensions of the low quality parent brand. Taken as a whole, the results suggest that the perceived quality of the parent-brand plays a fundamental role in the evaluation of corporate service brand extensions. The study also contributes several hypotheses for future studies and managerial implications for managers of corporate service brands
Imaging the Renner-Teller effect using laser-induced electron diffraction
Structural information on electronically excited neutral molecules can be
indirectly retrieved, largely through pump-probe and rotational spectroscopy
measurements with the aid of calculations. Here, we demonstrate the direct
structural retrieval of neutral carbonyl disulfide (CS) in the BB
excited electronic state using laser-induced electron diffraction (LIED). We
unambiguously identify the ultrafast symmetric stretching and bending of the
field-dressed neutral CS molecule with combined picometer and attosecond
resolution using intrapulse pump-probe excitation and measurement. We invoke
the Renner-Teller effect to populate the BB excited state in neutral
CS, leading to bending and stretching of the molecule. Our results
demonstrate the sensitivity of LIED in retrieving the geometric structure of
CS, which is known to appear as a two-center scatterer
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