Atrazine and Alachlor Dissipation Rates from Field Experiments

Chemical transport is being monitored in the root zone of three agricultural management systems at the Ohio Management Systems Evaluation Area (OMSEA). Atrazine and alachlor concentration data from soil cores taken to a depth of 0.9 m and partitioned into the increments of 0.0 to 0.15, 0.15 to 0.3, 0.45 to 0.6, and 0.75 to 0.9 m show the herbicides remained in the top 0.15 m of the profile during the 1991 and 1992 growing seasons. The slow movement of herbicides was partly due to below normal rainfall during the period. Since the herbicides have not been transported out of the soil profile, dissipation rates could be determined from the field observations. The data collected follow first-order kinetics in the dissipation of atrazine during the 1991 and 1992 growing season and of alachlor during the 1991 growing season for the two- to three-month period following chemical application. The computed rate constant, k, was 0.02 d–1 and half-life, t1/2, was 35 days for atrazine for both years. A rate constant of 0.04 d–1 and half-life of 17 days were computed for alachlor. The degradation rates became slower with residence time in the soil as a result of decreased availability from sorption/binding in the soil

Manipulation of High Spatial Resolution Aircraft Remote Sensing Data for Use in Site-Specific Farming

Three spatial data sets consisting of high spatial resolution (1 m) remote sensing images acquired in 12 spectral bands, an on-the-go yield map, and a Digital Elevation Model were co-registered and evaluated for spatial variability studies in a Geographic Information Systems environment. Separate on-the-go yield maps were developed for 3, 5, and 12 statistically significant mean yield classes. For each yield class, the corresponding mean spectral and elevation data were extracted. The relationship between mean spectral and yield data was strongly linear (r = 0.99). Also, a strong linear relationship between mean yield and elevation data (r = 0.92) was found. The relationship between the spectral and on-the-go yield data indicated the potential of remote sensing for spatial variability studies

Using Self-Based Methodologies to Unpack Mathematics Teacher Educators\u27 Work

Narrative inquiry, self-study, and autoethnography (i.e., self-based methodologies) are methodologies used by mathematics teacher educators (MTEs). These methodologies have opened up the field by unpacking and unearthing MTEs\u27 work communicating findings from their practices. Building from our previous working groups at PME-NA 2018-2020, we sustain a community where MTEs can feel supported in their study design, implementation, representation of findings, and publication using self-based methodologies. At PME-NA Philadelphia, we will continue our work at PME-NA Mexico on self-based methodologies to develop perspectives on philosophical underpinnings of self-based methodologies and addressing trustworthiness and authenticity in our reports

Mathematics Teacher Educators Using Self-Based Methodologies

Narrative inquiry, self-study, and autoethnography (i.e., self-based methodologies) are becoming a more common choice of mathematics teacher educators (MTEs). This has opened new possibilities and challenges for early career MTEs as they try to disseminate their findings in mathematics education journals. Building from our working group at PME-NA 2018 and 2019, we respond to the need for creating a community where MTEs can feel supported in their study design, implementation, representation of findings, and publication using self-based methodologies. This year, we continue our focus on mentoring and scholarship on self-based methodologies. We invite English- and Spanish-speaking MTEs with research projects in any stage of preparation to join us in discussions meant to promote growth, sustainability, and continued insight into the use of self-based methodologies

Gene expression profiling and expanded immunohistochemistry tests to guide selection of chemotherapy regimens in breast cancer management: a systematic review

OBJECTIVES: The aim of this report was to assess the clinical effectiveness of two Gene expression profiling (GEP) and two expanded immunohistochemistry (IHC) tests compared with current prognostic tools in guiding the use of adjuvant chemotherapy in patients with early breast cancer. METHODS: A systematic review of the evidence on clinical effectiveness of OncotypeDX, IHC4, MammaPrint and Mammostrat, compared with current clinical practice using clinicopathological parameters, in women with early breast cancer was conducted. Ten databases were searched to include citations to May 2016. RESULTS: Searches identified 7064 citations, of which 41 citations satisfied the criteria for the review. A narrative synthesis was performed. Evidence for OncotypeDX demonstrated the impact of the test on decision-making and there was some support for OncotypeDX predicting chemotherapy benefit. There were relatively lower levels of evidence for the other three tests included in the analysis. MammaPrint, Mammostrat and IHC4 tests were limited to a small number of studies. Limitations in relation to study design were identified for all tests. CONCLUSIONS: The evidence base for OncotypeDX is considered to be the most robust. Methodological weaknesses relating to heterogeneity of patient cohorts and issues arising from the retrospective nature of the evidence were identified. Further evidence is required for all of the tests using prospective randomised controlled trial data

“Same But Different”: The Role and Perceptions of the Simulation Clinical Educator

Simulated learning programs are an important component of allied health education. Although the role of simulation clinical educators has been highlighted as critical for student learning within simulation, their perceptions of their role have not yet been investigated. This study aimed to explore the experiences of simulation clinical educators. Participants were ten simulation clinical educators who had supported speech-language pathology students’ learning during a 5-day simulation program focussed on speech-language pathology practice with adult clients in acute hospital and rehabilitation settings. Educators participated in individual semi-structured interviews exploring their role and their perceptions of the simulation-based learning program. Data were analysed using inductive thematic analysis. Three inter-related themes emerged from participants’ views. The major theme of Unique teaching and learning environment incorporated five subthemes: focus on teaching; safe learning environment; authenticity and engagement; structure and intensity of learning, and; feedback opportunities. Two additional themes were identified: Clinical educator role same but different, and Simulation bridges the gap between theory and practice. This study offers new insights into simulation clinical educators’ perceptions of their role when supporting students within simulation and highlight the importance of harnessing the unique benefits of simulation as a teaching pedagogy to maximize its impacts on student learning and justify its costs

Clades of huge phages from across Earth's ecosystems.

Bacteriophages typically have small genomes1 and depend on their bacterial hosts for replication2. Here we sequenced DNA from diverse ecosystems and found hundreds of phage genomes with lengths of more than 200 kilobases (kb), including a genome of 735 kb, which is-to our knowledge-the largest phage genome to be described to date. Thirty-five genomes were manually curated to completion (circular and no gaps). Expanded genetic repertoires include diverse and previously undescribed CRISPR-Cas systems, transfer RNAs (tRNAs), tRNA synthetases, tRNA-modification enzymes, translation-initiation and elongation factors, and ribosomal proteins. The CRISPR-Cas systems of phages have the capacity to silence host transcription factors and translational genes, potentially as part of a larger interaction network that intercepts translation to redirect biosynthesis to phage-encoded functions. In addition, some phages may repurpose bacterial CRISPR-Cas systems to eliminate competing phages. We phylogenetically define the major clades of huge phages from human and other animal microbiomes, as well as from oceans, lakes, sediments, soils and the built environment. We conclude that the large gene inventories of huge phages reflect a conserved biological strategy, and that the phages are distributed across a broad bacterial host range and across Earth's ecosystems

Urban Multi-scale Environmental Predictor - an extensive tool for climate services in urban areas

The city based climate service tool UMEP (Urban Multi-scale Environmental Predictor) is a coupled modelling system that combines models essential for urban climate processes and is developed as an extensive QGIS plugin. An application is presented to illustrate its potential, specifically of the identification of heat waves and cold waves in cities. The tool has broad utility for applications related to outdoor thermal comfort, urban energy consumption, climate change mitigation etc. It includes tools to: enable users to input atmospheric and surface data from multiple sources, prepare meteorological data for use in urban areas, undertake simulations and consider scenarios, and compare and visualize different combinations of climate indicators

Failure mechanisms in alloy of polyamide 6,6/polyphenylene oxide under severe conditions

Toughening mechanisms of a polyamide 6,6/polyphenylene oxide alloy containing an elastomer tested under a slow rate, an impact rate, and a low temperature have been investigated using various microscopy techniques. It is found that the toughening mechanisms of the alloy may change from crazing/shear yielding, to crack bridging/crazing, and to transparticle failure, depending on the testing conditions. Except for the low temperature high strain rate testing condition and in the plane stress region of the crack, the crazing mechanism has been observed in all the conditions we studied. When the testing rate is high, the shear yielding mechanism is suppressed; multiple crazing and particle bridging mechanisms appear to dominate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44700/1/10853_2004_Article_BF00557130.pd