394 research outputs found
Impact!: Improving Student Learning through an Inquiry Crater Investigation
The fight against student compartmentalization of science concepts is an ongoing battle for all science educators. When an inquiry-based investigation of natural phenomena, like that presented here, is integrated into curricula new links between science concepts are created. These new connections promote a deep and robust understanding of science content. This cratering activity has students applying prior knowledge of gravitational forces, momentum, conservation of energy, and density while exploring the intricate relationships between these fundamental concepts. This activity also provides abundant opportunities for explicit connections to the nature of science. Impact cratering is a phenomena which can be easily modeled within a classroom, and deeply understanding it requires application of several fundamental science concepts. This article addresses National Science Education Standards A, B, D, and G and Iowa Teaching Standards 1, 2, 3, 4, and 5
Endothelial progenitor cells and burn injury - exploring the relationship.
Burn wounds result in varying degrees of soft tissue damage that are typically graded clinically. Recently a key participant in neovascularization, the endothelial progenitor cell, has been the subject of intense cardiovascular research to explore whether it can serve as a biomarker for vascular injury. In this review, we examine the identity of the endothelial progenitor cell as well as the evidence that support its role as a key responder after burn insult. While there is conflicting evidence with regards to the delta of endothelial progenitor cell mobilization and burn severity, it is clear that they play an important role in wound healing. Systematic and controlled studies are needed to clarify this relationship, and whether this population can serve as a biomarker for burn severity
COVID-19: Examining the Impact of the Global Pandemic on Violent Crime Rates in the Central Valley of California
This study focuses on how a global pandemic like COVID-19 affects violent crimes in the city of Stockton, California. The violent crimes that we will be examining are homicide, robbery, rape, simple assault, and aggravated assault. We obtained crime data from the LexisNexis Community Crime Map and obtained COVID-19 data from the San Joaquin County Health Department regarding the city of Stockton. We developed the results of this research by using time-series plots and interrupted time-series analysis. Our results demonstrate that COVID-19 caused a statistically significant change in the slope for rape, robbery, and simple assault violent crimes. Finally, we discuss in our policy implications section that the Stockton Police Department should establish more community outreach programs that could help prevent these types of violent crimes
Dysbindin-1 in dorsolateral prefrontal cortex of schizophrenia cases is reduced in an isoform-specific manner unrelated to altered dysbindin-1 gene expression
DTNBP1 (dystrobrevin binding protein 1) remains one of the top candidate genes in schizophrenia. Reduced expression of this gene and the protein it encodes, dysbindin-1, has been reported in the dorsolateral prefrontal cortex (DLPFC) of schizophrenia cases. It has not been established, however, if all dysbindin-1 isoforms are reduced in the DLPFC or if the reduction is associated with reduced DTNBP1 gene expression. Using Western blotting of whole-tissue lysates of the DLPFC with antibodies differentially sensitive to the three major isoforms of this protein (dysbindin-1A, -1B, and -1C), we found no significant differences between our schizophrenia cases and matched controls in dysbindin-1A or -1B, but did find a mean 46% reduction in dysbindin-1C in 71% of 28 case-control pairs (p = 0.022). This occurred in the absence of the one DTNBP1 risk haplotype for schizophrenia reported in the US and without alteration in levels of dysbindin-1C transcripts. Conversely, the absence of changes in the dysbindin-1A and -1B isoforms was accompanied by increased levels of their transcripts. We thus found no correspondence between alterations in dysbindin-1 gene and protein expression, the latter of which might be due to posttranslational modifications such as ubiquitination. Reduced DLPFC dysbindin-1C in schizophrenia probably occurs in PSDs, where we find dysbindin-1C to be heavily concentrated in the human brain. Given known postsynaptic effects of dysbindin-1 reductions in the rodent homolog of the prefrontal cortex, these findings suggest that reduced dysbindin-1C in the DLPFC may contribute to cognitive deficits of schizophrenia by promoting NMDA receptor hypofunction
Modeling Human Driving Behavior through Generative Adversarial Imitation Learning
Imitation learning is an approach for generating intelligent behavior when
the cost function is unknown or difficult to specify. Building upon work in
inverse reinforcement learning (IRL), Generative Adversarial Imitation Learning
(GAIL) aims to provide effective imitation even for problems with large or
continuous state and action spaces. Driver modeling is one example of a problem
where the state and action spaces are continuous. Human driving behavior is
characterized by non-linearity and stochasticity, and the underlying cost
function is unknown. As a result, learning from human driving demonstrations is
a promising approach for generating human-like driving behavior. This article
describes the use of GAIL for learning-based driver modeling. Because driver
modeling is inherently a multi-agent problem, where the interaction between
agents needs to be modeled, this paper describes a parameter-sharing extension
of GAIL called PS-GAIL to tackle multi-agent driver modeling. In addition, GAIL
is domain agnostic, making it difficult to encode specific knowledge relevant
to driving in the learning process. This paper describes Reward Augmented
Imitation Learning (RAIL), which modifies the reward signal to provide
domain-specific knowledge to the agent. Finally, human demonstrations are
dependent upon latent factors that may not be captured by GAIL. This paper
describes Burn-InfoGAIL, which allows for disentanglement of latent variability
in demonstrations. Imitation learning experiments are performed using NGSIM, a
real-world highway driving dataset. Experiments show that these modifications
to GAIL can successfully model highway driving behavior, accurately replicating
human demonstrations and generating realistic, emergent behavior in the traffic
flow arising from the interaction between driving agents.Comment: 28 pages, 8 figures. arXiv admin note: text overlap with
arXiv:1803.0104
Source gases: Concentrations, emissions, and trends
Source gases are defined as those gases that influence levels of stratospheric ozone (O3) by transporting species containing halogen, hydrogen, and nitrogen to the stratosphere. Examples are the CFC's, methane (CH4), and nitrous oxide (N2O). Other source gases that also come under consideration in an atmospheric O3 context are those that are involved in the O3 or hydroxyl (OH) radical chemistry of the troposphere. Examples are CH4, carbon monoxide (CO), and nonmethane hydrocarbons (NMHC's). Most of the source gases, along with carbon dioxide (CO2) and water vapor (H2O), are climatically significant and thus affect stratospheric O3 levels by their influence on stratospheric temperatures. Carbonyl sulphide (COS) could affect stratospheric O3 through maintenance of the stratospheric sulphate aerosol layer, which may be involved in heterogeneous chlorine-catalyzed O3 destruction. The previous reviews of trends and emissions of source gases, either from the context of their influence on atmospheric O3 or global climate change, are updated. The current global abundances and concentration trends of the trace gases are given in tabular format
Communicating and Co-Producing Information with Stakeholders: Examples of Participatory Mapping Approaches Related to Sea Level Rise Risks and Impacts
This chapter discusses practical approaches for using participatory mapping as a tool to visualize and communicate sea level rise (SLR) and climate change risks, to share information about the vulnerability to, and threats of, climate change, and to co-produce knowledge with stakeholders. The examples presented in this chapter are from demonstrated applications in communities in Virginia (USA) that involve participatory mapping and that utilize a web-Geographic Information System (GIS). The web-GIS is innovatively combined with other technologies and participatory processes to create low-cost high-tech approaches so that even people with little to no knowledge of GIS can interact with maps and can contribute to knowledge creation in the complex issues of SLR and climate change
Unprecedented early-summer heat stress and forecast of coral bleaching on the Great Barrier Reef, 2021-2022
The Great Barrier Reef (GBR) is predicted to undergo its sixth mass coral bleaching event during the Southern Hemisphere summer of 2021-2022. Coral bleaching-level heat stress over the GBR is forecast to start earlier than any previous year in the satellite record (1985-present). The National Oceanic and Atmospheric Administration (NOAA) Coral Reef Watch (CRW) near real-time satellite-based heat stress products were used to investigate early-summer sea surface temperature (SST) and heat stress conditions on the GBR during late 2021. As of 14 December 2021, values of instantaneous heat stress (Coral Bleaching HotSpots) and accumulated heat stress over a 12-week running window (Degree Heating Weeks) on the GBR were unprecedented in the satellite record. Further, 89% of GBR satellite reef pixels for this date in 2021 had a positive seven-day SST trend of greater than 0.2 degrees Celsius/week. Background temperatures (the minimum temperature over the previous 29 days) were alarmingly high, with 87% of GBR reef pixels on 14 December 2021 being greater than the maximum SST over that same 29-day period for any year from 1985-2020. The GBR is starting the 2021-2022 summer season with more accumulated heat than ever before, which could have disastrous consequences for the health, recovery, and future of this critical reef system
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