82 research outputs found
Local Extinction and Unintentional Rewilding of Bighorn Sheep (Ovis canadensis) on a Desert Island
Bighorn sheep ( Ovis canadensis) were not known to live on TiburĂłn Island, the largest island in the Gulf of California and Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable island population of âŒ500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet Cave, in the mountains of TiburĂłn Island. To determine the origin of this cave deposit we compared pellet shape to fecal pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA and control regions. The fossil dung was 14C-dated to 1476-1632 calendar years before present and was confirmed as bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep populations in southwest Arizona and southern California and showed subtle differentiation from the extant TiburĂłn population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene, when lower sea levels connected TiburĂłn to the mainland. They were extirpated sometime in the last âŒ1500 years, probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn sheep are not native to TiburĂłn Island, and establishes its recent introduction as an example of unintentional rewilding, defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct
The Statistical Analysis of Roll Call
We develop a Bayesian estimation procedure for spatial models of roll call voting. We show how a Bayesian approach to roll call analysis overcomes shortcomings and idiosyncracies of NOMINATE (some of which are not widely recognized). Our Bayesian approach (a) applies to any legislative setting, irrespective of size, legislative extremism, or the number of roll calls available for analysis; (b) provides a mechanism for directly incorporating auxiliary information as to the dimensionality of the underlying policy space, the identity of extremist legislators, key votes and the evolution of the legislative agenda; (c) lets us integrate measurement of legislative preferences with the analysis of those preferences. Notes to NEMP, May 2002 This paper sets out our ââbasic setupâ â (a Bayesian statistical operationalization of the Euclidean spatial voting model with roll call data), and constrasts it with the NOMINATE algorithms of Poole and Rosenthal. In the talk I will be considering extensions to our model, so as to accommodate and/or test conjectures in the literature on legislative politics (most prominently, the ââparty disciplineâ â hypothesis, and conjectures about legislative responsiveness to constituency interests)
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Automated Additive Construction (AAC) for Earth and Space Using In-situ Resources
Using Automated Additive Construction (AAC), low-fidelity large-scale compressive structures can be produced out of a wide variety of materials found in the environment. Compressionintensive structures need not utilize materials that have tight specifications for internal force management, meaning that the production of the building materials do not require costly methods for their preparation. Where a certain degree of surface roughness can be tolerated, lower-fidelity numerical control of deposited materials can provide a low-cost means for automating building processes, which can be utilized in remote or extreme environments on Earth or in Space. For space missions where every kilogram of mass must be lifted out of Earthâs gravity well, the promise of using in-situ materials for the construction of outposts, facilities, and installations could prove to be enabling if significant reduction of payload mass can be achieved. In a 2015 workshop sponsored by the Keck nstitute for Space Studies, on the topic of Three Dimensional (3D) Additive Construction For Space Using In-situ Resources, was conducted with additive construction experts from around the globe in attendance. The workshop explored disparate efforts, methods, and technologies and established a proposed framework for the field of Additive Construction Using In-situ Resources.
This paper defines the field of Automated Additive Construction Using In-situ Resources, describes the state-of-the-art for various methods, establishes a vision for future efforts, identifies gaps in current technologies, explores investment opportunities, and proposes potential technology demonstration missions for terrestrial, International Space Station (ISS), lunar, deep space zero-gravity, and Mars environments
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Local Extinction and Unintentional Rewilding of Bighorn Sheep (Ovis canadensis) on a Desert Island
Bighorn sheep (Ovis canadensis) were not known to live on TiburĂłn Island, the largest island in the Gulf of California and
Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable
island population of ~500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican
mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet
Cave, in the mountains of TiburĂłn Island. To determine the origin of this cave deposit we compared pellet shape to fecal
pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA
and control regions. The fossil dung was ÂčâŽC-dated to 1476â1632 calendar years before present and was confirmed as
bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known
bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep
populations in southwest Arizona and southern California and showed subtle differentiation from the extant TiburĂłn
population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene,
when lower sea levels connected TiburĂłn to the mainland. They were extirpated sometime in the last ~1500 years,
probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced
population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn
sheep are not native to TiburĂłn Island, and establishes its recent introduction as an example of unintentional rewilding,
defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct
Continuing The Distance Learning Modality of Graduate Studies in Post-Covid Philippines: A Survey
Getting a graduate education is one of the most important parts of a professional in a field. It allows them to climb higher in the professional rankings or even get higher pay for their academic work. All graduate students are adults and self-directed due to their past experiences in work or practice. However, when the pandemic hit the world, these self-directed learners were not spared from shutting of schools. In the Philippines, most graduate schools deliver their lessons through the traditional mode or face-to-face until the pandemic that they shifted in the emerging online learning modality. Using the mixed method of quantitative and qualitative type of study the researchers were able to gather 419 graduate students from various regions of the archipelago to take part in the study. The researchers found out that upon experiencing the benefits of online learning, graduate students want to continue this modality even in the future. More than a third of the respondents also claimed that they want the blended or hybrid type of graduate studies as opposed to going back to the more traditional face-to-face classes. The reasons for these can vary on each learnerâs situation
Crop Updates 2008 - Farming Systems
This session covers thirty nine papers from different authors:
PLENARY
1. Developments in grain end use, Dr John de Majnik, New Grain Products, GRDC, Mr Paul Meibusch, New Farm Products and Services, GRDC, Mr Vince Logan, New Products Executive Manager, GRDC
PRESENTATIONS
2. Global warming potential of wheat production in Western Australia: A life cycle assessment, Louise Barton1, Wahid Biswas2 and Daniel Carter3, 1School of Earth & Geographical Sciences, The University of Western Australia, 2Centre of Excellence in Cleaner Production, Division of Science and Engineering, Curtin University of Technology, 3Department of Agriculture and Food
3. How much fuel does your farm use for different farm operations? Nicolyn Short1, Jodie Bowling1, Glen Riethmuller1, James Fisher2 and Moin
Salam1, 1Department of Agriculture and Food, 2Muresk Institute, Curtin University of Technology
4. Poor soil water storage and soil constraints are common in WA cropping soils, Stephen Davies, Jim Dixon, Dennis Van Gool and Alison Slade, Department of
Agriculture and Food, Bob Gilkes, School of Earth and Geographical Sciences, University of Western Australia
5. Developing potential adaptations to climate change for low rainfall farming system using economic analysis tool. STEP, Megan Abrahams, Caroline Peek, Dennis Van Gool, Daniel Gardiner and Kari-Lee Falconer, Department of Agriculture and Food
6. What soil limitations affect the profitability of claying on non-wetting sandplain soils? David Hall1, Jeremy Lemon1, Harvey Jones1, Yvette Oliver2 and Tania Butler1, 1Department of Agriculture and Food, 2CSIRO Div Sustainable Ecology, Perth
7. Farming systems adapting to a variable climate; Two case studies, Kari-Lee Falconer, Department of Agriculture and Food
8. Importance of accounting for variation in crop yield potential when making fertiliser decisions, Michael Robertson and Yvette Oliver, CSIRO Sustainable Ecosystems, Floreat
9. Soil acidity is a widespread problem across the Avon River Basin, Stephen Carr1, Chris Gazey2, David York1 and Joel Andrew1, 1Precision SoilTech, 2Department of Agriculture and Food
10. The use of soil testing kits and ion-selective electrodes for the analysis of plant available nutrients in Western Australian soils, Michael Simeoni and Bob Gilkes School of Earth and Geographical Sciences, University of Western Australia
11. Redlegged earth mite resistance and integrated strategies for their control in Western Australia, Mangano G. Peter and Micic Svetlana, Department of Agriculture and Food
12. The economics of treating soil pH (liming), Chris Gazey, Steve Davies, Dave Gartner and Adam Clune, Department of Agriculture and Food,
13. Health benefits â A future differentiator for high value grains, Matthew Morell, Theme Leader, CSIRO Food Futures Flagship
14. Carbon in Sustralian cropping soils â We need to be realistic, Alan Umbers (M Rur Sc), GRDC/DAFF Sustainable Industries Initiative Project
15. AGWESTÂź Bartolo bladder clover (Trifolium spumosum) â a low cost annual pasture legume for the wheat/sheep zone, Angelo Loi, Brad Nutt and Clinton Revell, Department of Agriculture and Food
16. Maximising the value of point based soil sampling: Monitering trends in soil pH through time, Joel Andrew1, David York1, Stephen Carr1 and Chris Gazey2, 1Precision SoilTech, 2Department of Agriculture and Food
17. Improved crop root growth and productivity with deep ripping and deep placed lime, Stephen Davies1, Geoff Kew2*, Chris Gazey1, David Gartner1 and Adam Clune1, 1Department of Agriculture and Food, 2School of Earth and Geographical Sciences University of Western Australia, *Presenting author
18. The role of pastures in hosting Root Lesion Nematode (RLN, Pratylenchus neglectus), Vivien Vanstone, Ali Bhatti and Ming Pei You, Department of Agriculture and Food
19. To rip or not to rip. When does it pay? Imma Farre, Bill Bowden and Stephen Davies, Department of Agriculture and Food
20. Can yield be predicted from remotely sensed data, Henry Smolinski, Jane Speijers and John Bruce, Department of Agriculture and Food
21. Rotations for profit, David McCarthy and Gary Lang, Facey Group, Wickepin, WA
22. Rewriting rules for the new cropping economics, David Rees, Consultant, Albany
23. Reducing business risk in Binnu! â A case study, Rob Grima, Department of Agriculture and Food
24. Does improved ewe management offer grain farmers much extra profit? John Young, Farming Systems Analysis Service, Ross Kingwell, Department of Agriculture and Food, and UWA, Chris Oldham, Department of Agriculture and Food
RESEARCH HIGHLIGHTS
25. Crop establishment and productivity with improved root zone drainage, Dr Derk Bakker, Research Officer, Department of Agriculture and Food
26. Will wheat production in Western Australia be more risky in the future? Imma Farre and Ian Foster, Department of Agriculture and Food
PAPERS
27. Building farmersâ adaptive capacity to manage seasonal variability and climate change, David Beard, Department of Agriculture and Food
28. Precision placement increases crop phosphorus uptake under variable rainfall: Simulation studies, Wen Chen1 2, Richard Bell1, Bill Bowden2, Ross Brennan2, Art Diggle2 and Reg Lunt2, 1School of Environmental Science, Murdoch University, 2Department of Agriculture and Food
29. What is the role of grain legumes on red soil farms? Rob Grima, Department of Agriculture and Food
30. Fertiliser placement influences plant growth and seed yield of grain crops at different locations of WA, Qifu Ma1, Zed Rengel1, Bill Bowden2, Ross Brennan2, Reg Lunt2 and Tim Hilder2, 1Soil Science & Plant Nutrition, University of Western Australia, 2Department of Agriculture and Food
31. A review of pest and disease occurrences for 2007, Peter Mangano and Dusty Severtson, Department of Agriculture and Food
32. Effect of stocking rates on grain yield and quality of wheat in Western Australia in 2007, Shahajahan Miyan, Sam Clune, Barb Sage and Tenielle Martin, Department of Agriculture and Food
33. Storing grain is not âset and forgetâ management, Chris Newman, Department of Agriculture and Food
34. Improving understanding of soil plant available water capacity (PAWC): The WA soil water database (APSoil), Yvette Oliver, Neal Dalgliesh and Michael Robertson, CSIRO Sustainable Ecosystems
35. The impact of management decisions in drought on a low rainfall northern wheatbelt farm, Caroline Peek and Andrew Blake, Department of Agriculture and Food
37. Cullen â A native pasture legume shows promise for the low-medium rainfall cropping zone, Megan Ryan, Richard Bennett, Tim Colmer, Daniel Real, Jiayin Pang, Lori Kroiss, Dion Nicol and Tammy Edmonds-Tibbett, School of Plant Biology, The University of Western Australia and Future Farm Industries CRC
38. Climate risk management tools â useful, or just another gadget? Lisa Sherriff, Kari-Lee Falconer, Daniel Gardiner and Ron McTaggart Department of Agriculture and Food
39. Benefits of crop rotation for management of Root Lesion Nematode (RLN, Pratylenchus neglectus), Vivien Vanstone, Sean Kelly and Helen Hunter, Department of Agriculture and Foo
Diving into the vertical dimension of elasmobranch movement ecology
Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements
Diving into the vertical dimension of elasmobranch movement ecology
Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements
Diving into the vertical dimension of elasmobranch movement ecology
Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first global synthesis of vertical habitat use by elasmobranchs from data obtained by deployment of 989 biotelemetry tags on 38 elasmobranch species. Elasmobranchs displayed high intra- and interspecific variability in vertical movement patterns. Substantial vertical overlap was observed for many epipelagic elasmobranchs, indicating an increased likelihood to display spatial overlap, biologically interact, and share similar risk to anthropogenic threats that vary on a vertical gradient. We highlight the critical next steps toward incorporating vertical movement into global management and monitoring strategies for elasmobranchs, emphasizing the need to address geographic and taxonomic biases in deployments and to concurrently consider both horizontal and vertical movements
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Initial results from the InSight mission on Mars
NASAâs InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) mission landed in Elysium Planitia on Mars on 26 November 2018. It aims to determine the interior structure, composition and thermal state of Mars, as well as constrain present-day seismicity and impact cratering rates. Such information is key to understanding the differentiation and subsequent thermal evolution of Mars, and thus the forces that shape the planetâs surface geology and volatile
processes. Here we report an overview of the first ten months of geophysical observations by InSight. As of 30 September
2019, 174 seismic events have been recorded by the landerâs seismometer, including over 20 events of moment magnitude Mw
= 3â4. The detections thus far are consistent with tectonic origins, with no impact-induced seismicity yet observed, and indi-
cate a seismically active planet. An assessment of these detections suggests that the frequency of global seismic events below
approximately Mw = 3 is similar to that of terrestrial intraplate seismic activity, but there are fewer larger quakes; no quakes
exceeding Mw = 4 have been observed. The landerâs other instrumentsâtwo cameras, atmospheric pressure, temperature and
wind sensors, a magnetometer and a radiometerâhave yielded much more than the intended supporting data for seismometer
noise characterization: magnetic field measurements indicate a local magnetic field that is ten-times stronger than orbital
estimates and meteorological measurements reveal a more dynamic atmosphere than expected, hosting baroclinic and gravity
waves and convective vortices. With the mission due to last for an entire Martian year or longer, these results will be built on by
further measurements by the InSight lander
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