364 research outputs found
Wind turbine wakes for wind energy
During recent years, wind energy has moved from an emerging technology to a nearly competitive technology. This fact, coupled with an increasing global focus on environmental concern and a political desire of a certain level of diversification in the energy supply, ensures wind energy an important role in the future electricity market. For this challenge to be met in a cost-efficient way, a substantial part of new wind turbine installations is foreseen to be erected in big onshore or offshore wind farms. This fact makes the production, loading and reliability of turbines operating under such conditions of particular interest
What Are Preschool Teachersâ Perceptions about Professional Development in Science Content and Pedagogy When Using a Novel Approach?
Background: Many variables determine student success in preschool, as it relates to STEM knowledge and engagement in later school and career development. Students need a well-rounded, engaging, and rigorous curriculum (Anderson, 2006). Second, teachers must be properly trained in STEM pedagogy and content (Marcum-Dietrich, 2011). Purpose: The study investigated how ongoing professional development affects teacher knowledge, confidence, and skillset (Piasta, 2012) while using a new classroom approach. The initial STEMscopes Early Explorer was designed to provide science education to low socioeconomic students. STEMscopes is an international Pre-K -12th-grade digital science curriculum. The curriculum offers foundational science content, hands-on learning, and integration of technology, engineering, literacy, math, and arts. STEMscopes Pre-K curriculum allows teachers access to substantive STEM content to help engage and deepen their studentsâ understanding of science. Methods: A qualitative research study using a case study approach addressed the research question, What are preschool teachersâ perceptions about professional development in science content and pedagogy when using a novel approach? A case study method allows for the discovery and development of theory, based on the experiences and perceptions of study participants (Creswell, 1982). The study examined archival teacher interviews and questionnaire data regarding teacher perceptions of ongoing professional development as new and experienced pre-K teachers begin to implement a science-based program--STEMscopes Early Explorer. The original data was collected through interviews, observations, lesson logs, surveys, and professional development session. All pre-K teachers in a central school district in Texas participated in the study. All 51 participants were primary level teachers, with a wide range of experience. The district required all of their pre-k teachers to participate in the study. Of the 51 teachers, 3 were selected for this archival study. These 3 teachers offer a range of teaching experience, age, gender, and ethnicity. The data sources consisted of two rounds of individual teacher interviews and a Preschool Teacher Attitudes and Beliefs towards Science Questionnaire (PTABS) (Bell, 2014). Coding software was used to identify themes and their implications related to the research question. The teacher interviews were transcribed into a word document. After multiple reads through the interviews, particular themes and then nodes were developed. The nodes provided themes and emerging patterns for the fall and spring data Identifying the nodes and themes for the questionnaire was also a similar process. The questionnaire data highlighted more comparison in perceptions between the three teachers. Two of the three teachers believed there is enough time in the day to teach science. Results: Findings revealed 1) teachers value professional development that is created with teacher input, as it allows them to feel heard; 2) an improvement needed in current professional development is to provide teachers with more collaborative time with peers, and 3) teachers desire more hands-on modeling and content training. After two professional development sessions, teachers were able to provide feedback in needing more collaboration and modeling. As a result, STEMscopes made adjustments to the last two sessions in order to meet the needs of the teachers. Through teacherâs usage of STEMscopes and undergoing 30 hours of professional development, they provided feedback to enhance the product and professional development. Pre-K teacherâs desire to teach science when professional development is tailored to their needs, allows them support, and time to practice new strategies. The findings are significant as they illustrate the importance of a highly effective curriculum, but they also highlight the importance of ongoing professional development that is customizable and flexible to meet teachersâ needs. Conclusion: The findings of this study will help to extend current research pertaining to ongoing professional development. Teachersâ perceptions of professional development in science and pedagogy are centered around teacher-led professional development. Teachers should have an ample amount of time to implement what has been learned. As teachers are utilizing new material, they should be observed and provided feedback in order to create a cycle of learning, practicing, and improving.Curriculum and Instruction, Department o
Modeling Atmospheric Turbulence via Rapid Distortion Theory: Spectral Tensor of Velocity and Buoyancy
Abstract
A spectral tensor model is presented for turbulent fluctuations of wind velocity components and temperature, assuming uniform vertical gradients in mean temperature and mean wind speed. The model is built upon rapid distortion theory (RDT) following studies by Mann and by Hanazaki and Hunt, using the eddy lifetime parameterization of Mann to make the model stationary. The buoyant spectral tensor model is driven via five parameters: the viscous dissipation rate Δ, length scale of energy-containing eddies L, a turbulence anisotropy parameter , gradient Richardson number (Ri) representing the local atmospheric stability, and the rate of destruction of temperature variance . Model output includes velocity and temperature spectra and associated cospectra, including those of longitudinal and vertical temperature fluxes. The model also produces two-point statistics, such as coherences and phases of velocity components and temperature. The statistics of uniformly sheared and stratified turbulence from the model are compared with atmospheric observations taken from the Horizontal Array Turbulence Study (HATS) field program, and model results fit observed one-dimensional spectra quite well. For highly unstable stratification, however, the model has deficiencies at low wavenumbers that limit its prediction of longitudinal velocity component spectra at scales on the order of 0.6 km. The model predicts coherences well for horizontal separations but overestimates vertical coherence with increasing separation. Finally, it is shown that the RDT output can deviate from MoninâObukhov similarity theory.</jats:p
TruncTrimmer: A First Step Towards Automating Standard Bioinformatic Analysis
Bioinformatic analysis is a time-consuming process for labs performing research on various microbiomes. Researchers use tools like Qiime2 to help standardize the bioinformatic analysis methods, but even large, extensible platforms like Qiime2 have drawbacks due to the attention required by researchers. In this project, we propose to automate additional standard lab bioinformatic procedures by eliminating the existing manual process of determining the trim and truncate locations for paired end 2 sequences. We introduce a new Qiime2 plugin called TruncTrimmer to automate the process that usually requires the researcher to make a decision on where to trim and truncate manually after importing and demultiplexing sequences in the Qiime2 pipeline. By automating this process and removing the need for manual interaction by the researcher, this plugin provides another opportunity to automate another standard bioinformatic analysis procedure
Simplification and Validation of a Spectral-Tensor Model for Turbulence Including Atmospheric Stability
Renal colic and childbirth pain: female experience versus male perception
Renal colic is often described by patients as the worst pain ever experienced.1
Pain
during childbirth is also similarly described.2
To date, no study has comparatively
evaluated the pain of renal colic to that of childbirth in female patients who have
experienced both. Furthermore, no such study has evaluated the perception that men
with renal colic have with respect to the pain experienced during childbirth. Here we
present our cross-sectional observational study to address these questions. The primary
objectives of our study were to answer these questions and highlight the severity of
renal colic which is not always faced and treated aggressively
Characterization of NGFFYamide Signaling in Starfish Reveals Roles in Regulation of Feeding Behavior and Locomotory Systems
Neuropeptides in deuterostomian invertebrates that have an Asn-Gly motif (NG peptides) have been identified as orthologs of vertebrate neuropeptide-S (NPS)-type peptides and protostomian crustacean cardioactive peptide (CCAP)-type neuropeptides. To obtain new insights into the physiological roles of NG peptides in deuterostomian invertebrates, here we have characterized the NG peptide signaling system in an echinodermâthe starfish Asterias rubens. The neuropeptide NGFFYamide was identified as the ligand for an A. rubens NPS/CCAP-type receptor, providing further confirmation that NG peptides are orthologs of NPS/CCAP-type neuropeptides. Using mRNA in situ hybridization, cells expressing the NGFFYamide precursor transcript were revealed in the radial nerve cords, circumoral nerve ring, coelomic epithelium, apical muscle, body wall, stomach, and tube feet of A. rubens, indicating that NGFFYamide may have a variety of physiological roles in starfish. One of the most remarkable aspects of starfish biology is their feeding behavior, where the stomach is everted out of the mouth over the soft tissue of prey. Previously, we reported that NGFFYamide triggers retraction of the everted stomach in A. rubens and here we show that in vivo injection of NGFFYamide causes a significant delay in the onset of feeding on prey. To investigate roles in regulating other aspects of starfish physiology, we examined the in vitro effects of NGFFYamide and found that it causes relaxation of acetylcholine-contracted apical muscle preparations and induction of tonic and phasic contraction of tube feet. Furthermore, analysis of the effects of in vivo injection of NGFFYamide on starfish locomotor activity revealed that it causes a significant reduction in mean velocity and distance traveled. Interestingly, experimental studies on mammals have revealed that NPS is an anxiolytic that suppresses appetite and induces hyperactivity in mammals. Our characterization of the actions of NGFFYamide in starfish indicates that NPS/NG peptide/CCAP-type signaling is an evolutionarily ancient regulator of feeding and locomotion
An âorientation sphereâ visualization for examining animal head movements
Animal behavior is elicited, in part, in response to external conditions, but understanding how animals perceive the environment and make the decisions that bring about these behavioral responses is challenging.Animal heads often move during specific behaviors and, additionally, typically have sensory systems (notably vision, smell, and hearing) sampling in defined arcs (normally to the front of their heads). As such, headâmounted electronic sensors consisting of accelerometers and magnetometers, which can be used to determine the movement and directionality of animal heads (where head âmovementâ is defined here as changes in heading [azimuth] and/or pitch [elevation angle]), can potentially provide information both on behaviors in general and also clarify which parts of the environment the animals might be prioritizing (âenvironmental framingâ).We propose a new approach to visualize the data of such headâmounted tags that combines the instantaneous outputs of head heading and pitch in a single intuitive spherical plot. This sphere has magnetic heading denoted by âlongitudeâ position and head pitch by âlatitudeâ on this âorientation sphereâ (Oâsphere).We construct the Oâsphere for the head rotations of a number of vertebrates with contrasting body shape and ecology (oryx, sheep, tortoises, and turtles), illustrating various behaviors, including foraging, walking, and environmental scanning. We also propose correcting head orientations for body orientations to highlight specific headingâindependent head rotation, and propose the derivation of Oâsphereâmetrics, such as angular speed across the sphere. This should help identify the functions of various head behaviors.Visualizations of the Oâsphere provide an intuitive representation of animal behavior manifest via head orientation and rotation. This has ramifications for quantifying and understanding behaviors ranging from navigation through vigilance to feeding and, when used in tandem with body movement, should provide an important link between perception of the environment and response to it in freeâranging animals
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