Re: Finescale Modeler 25 Year Collec
Genciana Haggins
This e-book is the product of a second workshop that was funded and promoted by the United States Geological Survey to enhance cooperation between states for the management of chronic wasting disease (CWD). The first workshop addressed issues surrounding the statistical design and collection of surveillance data for CWD. The second workshop, from which this document arose, followed logically from the first workshop and focused on appropriate methods for analysis, interpretation, and use of CWD surveillance and related epidemiology data. Consequently, the emphasis of this e-book is on modeling approaches to describe and gain insight of the spatial epidemiology of CWD. We designed this e-book for wildlife managers and biologists who are responsible for the surveillance of CWD in their state or agency. We chose spatial methods that are popular or common in the spatial epidemiology literature and evaluated them for their relevance to modeling CWD. Our opinion of the usefulness and relevance of each method was based on the type of field data commonly collected as part of CWD surveillance programs and what we know about CWD biology, ecology, and epidemiology. Specifically, we expected the field data to consist primarily of the infection status of a harvested or culled sample along with its date of collection (not date of infection), location, and demographic status. We evaluated methods in light of the fact that CWD does not appear to spread rapidly through wild populations, relative to more highly contagious viruses, and can be spread directly from animal to animal or indirectly through environmental contamination.
We discovered that many of the wellpublished methods were developed for fast-spreading human diseases, such as influenza and measles. While these methods are applicable to fast spreading wildlife diseases, such as foot-and-mouth disease or West Nile virus, many are not likely to work well for CWD. Only limited data exist to evaluate geographic and spatial spread because many locations where we find CWD tend to be locations where samples have just been taken or sample sizes have just become large enough to have a high probability of detecting a low prevalence. Consequently, methods that work well to describe or predict the spread of foot-and-mouth disease throughout England, which occurred within a year, do not work well for describing or predicting CWD spread. We did not exclude methods that we regarded as inappropriate; rather, we included methods that are commonly used for disease epidemiology and then discussed their applicability for modeling the spatial epidemiology of CWD. We hope including inappropriate methods with an explanation of why they are ill-suited for CWD will make it easier to drop them from consideration and explain to others why they were not recommended for spatial modeling of CWD.
There is also a question of resolution as well as scale and extent for each method. CWD surveillance data have been collected over large areas, such as a wildlife management unit or state, but the resolution of the data may be fine scale with GPS locations for many samples. For each method, we described the required resolution of the data and describe the type of data required, as well as what questions the method could answer and how useful the method is, given typical CWD data.
Mountain pine beetles are significant forest disturbance agents, capable of inducing widespread mortality in coniferous forests in western North America. Various remote sensing approaches have assessed the impacts of beetle outbreaks over the last two decades. However, few studies have addressed the impacts of historical mountain pine beetle outbreaks, including the 1970s event that impacted Glacier National Park. The lack of spatially explicit data on this disturbance represents both a major data gap and a critical research challenge in that wildfire has removed some of the evidence from the landscape. We utilized multiple lines of evidence to model forest canopy mortality as a proxy for outbreak severity. We incorporate historical aerial and landscape photos, aerial detection survey data, a nine-year collection of satellite imagery and abiotic data. This study presents a remote sensing based framework to (1) relate measurements of canopy mortality from fine-scale aerial photography to coarse-scale multispectral imagery and (2) classify the severity of mountain pine beetle affected areas using a temporal sequence of Landsat data and other landscape variables. We sampled canopy mortality in 261 plots from aerial photos and found that insect effects on mortality were evident in changes to the Normalized Difference Vegetation Index (NDVI) over time. We tested multiple spectral indices and found that a combination of NDVI and the green band resulted in the strongest model. We report a two-step process where we utilize a generalized least squares model to account for the large-scale variability in the data and a binary regression tree to describe the small-scale variability. The final model had a root mean square error estimate of 9.8% canopy mortality, a mean absolute error of 7.6% and an R2 of 0.82. The results demonstrate that a model of percent canopy mortality as a continuous variable can be developed to identify a gradient of mountain pine beetle severity on the landscape.
Ships "were among the most technologically complex mechanisms of the ancient world."[2] Ships made far-flung travel and trade more comfortable and economical, and they added a whole new facet to warfare. Thus, ships carried a great deal of significance to the people of the ancient world, and this is expressed partly through the creation of boat and ship models. Ancient boat and ship models are made of a variety of materials and are intended for different purposes. The most common purposes for boat and ship models include burial votives, house hold articles, art, and toys. While archaeologists have found ship and boat models from societies all around the Mediterranean, the three of the most prolific ship model building cultures were the Greeks, Phoenicians, and Egyptians.
Archaeologists have determined that Ancient Greek ship models were used as burial or votive offerings and as household articles such as lamps or drinking vessels.[3] The kinds of ships depicted in Ancient Greek models can be classified broadly as small craft, merchant vessels, and warships.[4] Models were cast in different materials, including wood, bronze, lead, and clay.
Greek warships were popular subjects to be made in miniature. One particular model, acquired by the Staatliches Museum (engl.: Land museum) in Kassel, Germany, proves to be helpful to archaeologists and historians in understanding what a hemiolia warship was like. Archaeologists have tentatively dated the Kassel model to be from the 6th or 5th centuries BC through iconographic and literary sources.[5] This ship model is made of clay and features a distinctive prow shaped like a boar's head that is described by Herodotus in The History, and depicted on pottery, coins seals and drinking cups.[6] The model is a miniature of a vessel that would have been too small to be a typical warship. The presence of holes bored into 8 thwarts in the ship suggests that the thwarts may have been seats for a pegged-in dummy crew.[7] If the holes bored into the thwarts are indeed meant to accommodate a dummy crew, the crew seating would have been arranged with two men per bench amidships, and one man per bench fore and aft where the ship narrows so that there is only room for one man.[7] Alec Tilley (former Royal Navy and Navy of Oman officer)[8] suggests that a small ship with this type of seating arrangement would have been called a hemiolia, or a one-and-a-halfer. The name indicates that two oarsmen would have been seated on half of the benches and one on the others.[7] Until this ship model was discovered, archaeologists, classicists, and historians had only been able to hypothesize on what the seating arrangement might have been like on a hemiolia based on its name.
Ship models are helpful to archaeologists in that they allow archaeologists to make estimates regarding the size the vessel would be in real life. While this technique makes the assumption that artists scaled the models appropriately, it is useful to get some sense of how large these ships and boats may have been in real life. Archaeologists estimate the Phoenician vessel above (H-3134) to be about 6 meters long and the beam about 2 meters.[12] Archaeologists are able to calculate these estimates of size by employing a series of assumptions about the distance between benches, the lateral distance between rowers, and a maximum draft of the vessel.[12]
Egyptian ship and boat models are perhaps some of the most well-preserved types of ship models available to archaeologists. Ancient Egyptian ship and boat models were most frequently placed in tombs of prominent people as "magical substitutes for the actual objects which the deceased has used in life and which he expected to use again in the next world."[13] These boats have been categorised into two types: boat models that represent actual vessels used on the Nile, and boat models that represent boats that are considered necessary for religious purposes. The second type of model may or may not have been used in real life, but were purely magical boats.[14] The majority of boats found in tombs are carved from wood.[14]
The boat models discovered at Meketre's tomb feature several different kinds of boats, including traveling boats, sporting boats, and several papyriform crafts.[16] Two of the papyriform skiffs have a trawling net slung between them.[17] It is uncertain whether or not the net is meant to be depicted as being under the water or being pulled out of the water by the fishermen. In the event that the artist meant for the net to be in the water, it is upside down. Needless to say, the upside down net would not work for catching fish.[18] This ambiguity points up the question of artistic veracity of the craftsmen who make ship models. As is attested by the ambiguity of the holes in the sides of the Phoenician model, and the skiff from Meketre, archaeologists need to be aware of the possibility of artistic error while interpreting ancient ship models. While a mistake involving an inverted trawling net may seem trivial, the lesson is important. It is important for archaeologists to be aware of the possibility that ancient artists may not have been familiar with the finer details of ships and boats.
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