590 research outputs found
Sedimentological and Geochemical Analysis of Deep-Water Deposits in the Mojón De Hierro Formation at Arroyo Garrido, Tepuel-Genoa Basin, Patagonia, Argentina
The Earth has had multiple Phanerozoic glacial intervals but the Late Paleozoic Ice Age (LPIA) was its longest and most extensive, lasting from the Late Devonian (~372 Ma) until the Late Permian (~254 Ma). The LPIA is the last complete climate shift from a greenhouse to icehouse and back to a greenhouse state and the only one to occur on a biologically complex Earth. Therefore, it provides perspectives on deep-time climatic transitions, the parameters controlling them, and the Earth’s physical, chemical and biological responses to such climate changes. Research on mid to high-latitude deposits in Gondwana provides evidence that the LPIA had a highly dynamic climate, with multiple ice sheets and ice caps, that fluctuated asynchronously and diachronously across the supercontinent as it drifted across the paleo South Pole. Numerous questions remain on the spatial and temporal extent of the ice centers, the timing of expansion and contraction of the ice sheets and the distribution of ice across Gondwana through time. The Tepuel-Genoa Basin, in Patagonia, Argentina, was situated within the paleo South Polar Circle as part of Gondwana and contains a nearly continuous sedimentary succession of Carboniferous to Lower Permian strata. The Mojón de Hierro Formation has been described as both non-glacial and glacial in origin. This study investigates a unit within the Mojón de Hierro Formation which was used in a detrital zircon analysis which implies a large ice sheet covered the basin at the time of deposition, which extended from an ice center in the Ellsworth Mountains all the way to the Panthalassan Margin in west-central Gondwana. These strata contain mudrocks, some with outsized clasts, diamictites and sandstones. Five stratigraphic sections were measured at Arroyo Garrido and the strata were categorized into five lithofacies associations; 1) laminated mudrock, 2) laminated mudrock with dispersed clasts, 3) graded rhythmites, 4) laminated and bedded diamictites, and 5) deformed bedded sandstones. The strata were deposited in a basinal slope environment from suspension settling, ice rafted debris, sediment gravity flows and mass transport complexes. The mass transport complexes were deposited on a lower slope and formed deep-water topography that resulted in a ponded mini basin behind the sand blocks. Paleo-flow is indicated as flowing to the northwest. The Chemical Index of Alteration (CIA) indicates average marine shale values and that muds are of temperate terrestrial sediment sources. A glacial source could not be substantiated using CIA values. Vanadium/chromium ratios indicate dysoxic values in samples between the mass transport sand blocks and oxic values in samples above the filled ponded mini basin. The detailed facies analysis and geochemistry data do not indicate the Arroyo Garrido strata to be of glacial origin. However, facies analysis data suggest that icebergs from a distant source transited the basin during emplacement of the mass transport and sediment gravity flow deposits
Living with HIV after Release from Prison: An Evaluation of the Long-term Health of Formerly Incarcerated Individuals who used Michigan’s Community Reentry Service
In 2003, Michigan implemented a reentry service to assist HIV-infected people incarcerated in state prisons in linking to HIV medical care immediately upon their release. We examined whether formerly incarcerated people were linked to care successfully, remained in care, and were in good health 3 years after their date of release. In all, 190 people used the service over the 5 years following its inception. Only a minority of those who were alive and not reincarcerated at the time of the evaluation engaged consistently with medical care. Unsurprisingly given low rates of engagement in care, 3 years after their release only 27% had achieved viral suppression. Concerted efforts to support formerly incarcerated HIV-infected individuals’ engagement in care over the long term are urgently needed
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South Western Agriculture Teachers' Mathematical Content Knowledge
The purpose of this study was to determine South Western agriculture teacher’s mathematical content knowledge. Mathematics and science are both essential to the field of agriculture; however, while science curriculum is currently integrated in many high school agricultural education classrooms, mathematics coverage is limited (Stubbs & Myers, 2015). The opportunity for students to engage in real world applications of mathematical content through school-based agricultural education programs exists, but if teachers do not possess the content knowledge necessary to teach mathematics, students are then left at a disadvantage. Therefore, the objectives of this study were to describe agriculture teachers perceived mathematical content knowledge, actual mathematical content knowledge, and the relationship between perceived and actual mathematical content knowledge for South Western agriculture teachers. The Content Knowledge Framework was utilized in determining agriculture teacher’s content knowledge for the subject area of mathematics (Even, 1990). A quantitative analysis revealed South Western agriculture teachers perceived their average mathematical ability as being at a moderate level, while their average actual mathematical ability was 44%. The analysis also revealed a negative correlation to teachers’ perceived ability and years spent teaching and a positive correlation between teachers’ actual ability and years teaching. It is recommended that mathematics requirements at the agricultural teacher preparation level be reexamined. Additionally, professional development for South Western agriculture teachers in various mathematics content is encouraged
Utilizing UAS to Support Sustainability and Wildlife Hazard Management
Wildlife strikes to aviation are a serious economic and safety concern. The Federal Aviation Administration requires Part 139 airport operators to conduct a wildlife hazard assessment (WHA) when certain wildlife strike events occur at or around the airport. Furthermore, the implementation of a systematic, proactive, and well-defined scientific approach to mitigate wildlife hazards to aviation while ensuring sustainability may allow airport operators to spawn a realistic and efficient balance between safety and sustainable development. Utilizing wildlife behavior and location data collected by UAS, airport officials can efficiently identify harmless sustainability methods that can be incorporated to mitigate wildlife hazards. Data have been collected using a DJI Matrice 210 drone with a Zenmuse X5S camera and with a DJI Mavic 2 Enterprise Dual drone at Coe Field (8FA4), a privately used, general aviation airport located in Class G airspace. Different strategies to mitigate risks associated with manned air traffic and remote-controlled aircraft were implemented in our study, such as incorporating an automatic detection surveillance-broadcast flight box and Foreflight technologies as well as numerous visual observers during data collection
Roundtable Discussion – The Great War and Education
The panelists will discus their experiences in teaching the First World War to students at the secondary and post-sencondary level
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