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Classifcation of Conics in the Tropical Projective PlaneEllis, Amanda 18 November 2005 (has links)
This paper defines tropical projective space, TP^n, and the tropical general linear group TPGL(n). After discussing some simple examples of tropical polynomials and their hypersurfaces, a strategy is given for finding all conics in the tropical projective plane. The classification of conics and an analysis of the coefficient space corresponding to such conics is given.
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Monarchs of the Gulf Coast: Effects of novel environmental conditions on wing morphology of the Eastern migratory monarch butterfly (Danaus plexippus)January 2020 (has links)
archives@tulane.edu / The Eastern migratory monarch butterfly undertakes one of the longest annual migrations known among animal taxa, journeying from as far north as Canada down to central Mexico. A small subpopulation of monarchs has been found dropping out of migration in favor of breeding year-round along the U.S. Gulf Coast. The majority of these dropouts, known as winter-breeders, are feeding and breeding on a non-native milkweed species called tropical milkweed (Asclepias curassavica) that has greater concentrations of toxic cardenolides. The effects of tropical milkweed on monarchs are not yet fully understood, but it is correlated to breakage of reproductive diapause and migratory drop-out. The drop-out phenomenon is concerning due to the increased prevalence of infection by the monarch’s specialized protozoan parasite, Ophryocystis elektroscirrha (OE). OE is often physically damaging and can be lethal to monarchs. Here, we investigate the effects of a colder climate that winter-breeders experience on the Gulf Coast in the winter, exposure to OE, and a diet of exclusively tropical milkweed on larval development and adult wing morphology and pigmentation. Morphology and pigmentation are often functional traits that enhance fitness; thus, we use these measures as proxies for fitness components such as flight performance and immune function. In the first chapter, we found that monarchs reared on tropical milkweed developed faster and had larger wings and higher aspect ratios than monarchs reared on a low-cardenolide native milkweed species, swamp milkweed (Asclepias incarnata). In the second chapter, we found that monarchs reared in a suboptimal temperature developed slower and emerged with smaller, darker (redder and more melanized) wings than monarchs reared in a warmer or ‘normal’ temperature. Additionally, exposure to OE affected wing shape such that exposed monarchs had rounder wings with a slightly lower aspect ratio than unexposed monarchs. Lower temperature did not significantly affect melanism in monarch wings, but monarchs exposed to OE had less melanin deposited onto their wings than unexposed monarchs. Together, the findings from both chapters suggest that the conditions experienced by winter-breeders on the Gulf Coast are detrimental to monarch morphology. Smaller, rounder wings with lower aspect ratios are not conducive to migratory success, and paler color or less melanin are potential negative responses to exposure or infection by OE. While monarchs reared on tropical milkweed were larger and slightly redder which is a seemingly positive result, it may be limited to nonmigratory monarchs or winter breeders who may be adapted to tropical milkweed. Thus, it remains unclear how tropical milkweed is affecting the biology of migratory monarchs versus winter-breeders, but we suggest that the colder winter and increased risk of OE infection are negatively affecting winter-breeding populations and possibly migratory behavior. Migratory monarchs are already of conservation concern, and further monitoring and studying of the winter-breeding population and migrant populations are necessary to ensure the stability of monarch populations if and when they encounter tropical milkweed and whether the milkweed is driving population-level shifts in migratory behavior. / 1 / Caitlin Ducat
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ZOO BRNO – TROPICKÝ PAVILON / ZOO BRNO – TROPICAL PAVILONMalík, Lukáš January 2018 (has links)
The assignment was to create a design of a tropical pavilion at the Brno Zoo. The most important aspect influencing the overall solution is the unique location of the existing pavilion, located at the top of the hill. In the wider area there is a forested landscape. There is an opportunity to build new exhibition spaces with regard to the future development of the zoo. So how to proceed with such assignment? The exhibition of the pavilion focuses on fauna and flora of the rainforest: Central America and the Amazon. The proposal envisages the demolition of the existing pavilion, which is currently unsuitable and obsolete. Part of the new pavilion is also the design of outdoor exposure areas. The main inspiration for the new pavilion was the Mayan Pyramid in the jungle. The outdoor expositions are inspired by the relief of the Amazonian landscape.
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Growth ring formation of selected tropical rainforest trees in Peninsular Malaysia / 半島マレーシアの熱帯林樹種における成長輪形成Amir Affan Abdul Azim 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18338号 / 農博第2063号 / 新制||農||1023(附属図書館) / 学位論文||H26||N4845(農学部図書室) / 31196 / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 大澤 晃, 教授 髙部 圭司, 教授 北山 兼弘 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
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Colonizing abilities of six alien weeds in the coastal farmlands of Guyana, S.A.Thompson, Sheila R. January 1984 (has links)
No description available.
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The Evolution and Distribution of Precipitation during Tropical Cyclone Landfalls using the GPM IMERG ProductSauda, Samrin Sumaiya 07 June 2023 (has links)
Landfalling tropical cyclone (TC) induced precipitation poses a great risk to the rising coastal population globally. However, the impacts of tropical cyclone precipitation (TCP) are still difficult to predict due to rapid structural changes during landfall. This study applies a shape metric methodology to quantify the spatiotemporal evolution of TCP in the North Indian (NI), Western Pacific (WP), and North Atlantic (NA) basins. The International Best Track Archive for Climate Stewardship (IBTrACS) data and the Global Precipitation Mission (GPM)'s advanced Integrated Multisatellite Retrievals for GPM (IMERG) dataset is employed to study the 2014-2020 landfalling TCP at three analysis times: pre-landfall, landfall, and post-landfall. We examine three thresholds (2, 5, and 10 mm hr-1) and use six spatial metrics (area, closure, solidity, fragmentation, dispersion, and elongation) to quantify the shape of the precipitation pattern. To identify precipitation changes among the three analysis times and three basins, the Kruskal-Wallis test is applied. The three basins show important differences in size evolution. The greatest structural changes occur during post-landfall when the rainfall extent shrinks. The WP has the largest area of TCP and generates the highest maximum TCP of all basins. NA is the only basin where the precipitation area expands after landfall. NA also has the lowest closure for the three precipitation thresholds. NI precipitation has the lowest dispersion and maximum closure. Shape metrics such as closure and dispersion show a consistent inverse correlation. The maximum precipitation direction within the TCs is also examined in each basin. These results can inform guidelines that contribute to improved TCP forecasting and disaster mitigation strategies for vulnerable coastal populations globally. Future studies can apply shape metrics to the sub-basins in NI and WP to examine regional variability as there has been no such study in these basins. Future work can also investigate if the location of heavy rainfall within the TC structure affects flooding or other water hazards. / Master of Science / Landfalling tropical cyclones (TC) pose a significant threat to coastal populations worldwide, primarily due to the heavy rainfall. Predicting the rainfall during landfall is challenging as they undergo rapid changes. This study uses shape metrics to measure how this rainfall changes over time and space in three ocean basins: North Indian (NI), Western Pacific (WP), and North Atlantic (NA). The study uses a comprehensive collection of global TC best-track data i.e., International Best Track Archive for Climate Stewardship (IBTrACS). The rainfall measurement is derived from the satellite data i.e., the Global Precipitation Mission (GPM)'s advanced Integrated Multisatellite Retrievals for GPM (IMERG) to study landfalling rainfall between 2014 to 2020. Six spatial metrics (area, closure, solidity, fragmentation, dispersion, and elongation) were applied to quantify the shape and size of the precipitation pattern at three landfall times: pre-landfall, landfall, and post-landfall. The values of the shape metrics are compared between the ocean basins and landfall times using a statistical test. The results show that the most significant changes occur after landfall when the rainfall area decreases. WP has the largest area of rainfall and generates the highest maximum rainfall of all basins. NA is the only basin where the rainfall area expands after landfall. Shape metrics such as closure and dispersion share a consistent negative relationship. The maximum precipitation direction within the TCs is also examined in each basin. These results can contribute to improved tropical cyclone rainfall forecasting and disaster mitigation strategies for vulnerable coastal populations globally. Future studies can apply shape metrics to the sub-basins in NI and WP to examine regional variability as there has been no such study in these basins.
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Counting Plane Tropical Curves via Lattice Paths in PolygonsZhang, Yingyu 12 1900 (has links)
A projective plane tropical curve is a proper immersion of a graph into the real Cartesian plane subject to some conditions such as that the images of all the edges must be lines with rational slopes. Two important combinatorial invariants of a projective plane tropical curve are its degree, d, and genus g. First, we explore Gathmann and Markwig's approach to the study of the moduli spaces of such curves and explain their proof that the number of projective plane tropical curves, counting multiplicity, passing through n = 3d + g -1 points does not depend on the choice of points, provided they are in tropical general position. This number of curves is called a Gromov-Written invariant. Second, we discuss the proof of a theorem of Mikhalkin that allows one to compute the Gromov-Written invariant by a purely combinatorial process of counting certain lattice paths.
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Onchocerciasis, lymphatic filariasis, soil transmitted helminthiasis, and schistosomiasis: integration and economic evaluation of mass drug administration using ivermectin, albendazole, and praziquantelEvans, Darin S. January 2013 (has links)
Thesis (Dr.P.H.)--Boston University / The recently classified neglected tropical diseases (NTD), -- onchocerciasis, lymphatic filariasis, schistosomiasis, and soil-transmitted helminthiasis -- are all coendemic in Nigeria. The World Health Organization recommended strategy for addressing these diseases is preventive chemotherapy through annual mass drug administration (MDA) with ivermectin, albendazole, and praziquantel. Integrated delivery of these medicines has become the de facto strategy advocated for in the literature as a means of reducing costs through shared resources. Little empirical evidence, however, exists to support this. This paper explores these diseases and the concept of integration in the context of the global strategies for their control.
A literature review was conducted using PubMed to identify articles published containing any of the disease names and costs. Of the 2,028 articles returned, only 14 published between 1998 and 2011 met the criteria for review. All costs were adjusted for inflation. Overall, the mean cost of MDA by any means was 0.83 cents. No data comparing separate MDA to integrated MDA were found. To examine this, a model was created comparing MDA programs with similar distribution strategies and targeting similar diseases. Data from separate articles presenting stand alone MDA were combined to give a mean cost of 0.42 cents to deliver two medicines in two rounds. This was compared with articles showing integrated MDA, which gave a mean cost of 0.25 cents to deliver two medicines in a single round. This suggests a cost savings of 40 percent.
To verify this, data from a NTD program in Nigeria that transitioned to integrated MDA was examined in detail. In 2008, eight districts received a single round of ivermectin with albendazole followed at least 1 week later by a single round of praziquantel to school-aged children. The following year, a single round of all three drugs was co-administered. The number of treated individuals was essentially unchanged during both years (1,301,864 in 2008 and 1,297,509 in 2009). The total programmatic costs for the MDA, not including drug and overhead costs, reduced by 41% from $123,624 to $72,870, similar to savings seen in the literature review. Cost savings were attributed largely to transportation and personnel costs.
Integrated delivery of medicines is recommended for mature programs targeting these diseases.
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The Impact of Ivermectin Treatment in Cattle on Dung Degradation and Fauna Abundance and Diversity in TanzaniaRuhinda, Miriam Shani 08 June 2023 (has links)
Ivermectin also called the wonder drug has been used over the years to control internal and external parasites in livestock. In humans it has been used for the control of several neglected tropical diseases. With regards to efforts to control malaria, mass drug administration (MDA) of ivermectin in humans and livestock has been considered as a potential tool. This is due to challenges in malaria preventive strategies such as insecticide resistance in mosquitoes, shift in their behaviors and residual transmission. Ivermectin reduces malaria transmission by targeting the mosquito nervous system resulting in their death. Ivermectin and its metabolites could have great impacts on the environment as well as human and health. In temperate settings, impacts of ivermectin in the environment were studied due to intense use of the drug in livestock. There is also a necessity to study effects of ivermectin in the tropics before MDA for malaria vector control. Despite its great potential, previous studies done recorded toxicity and sensitivity of the drug to most arthropods mainly dung organisms because ivermectin is released in dung at high concentrations for the case of livestock. With dung organism activity being affected the dung decomposition process is disrupted, cattle avoid these grazing areas leading to financial losses. In the tropics where there is a high number of malaria cases, there is no information on the impacts of the drug in the environment. We placed standardized dung pats from ivermectin-treated and control cattle to determine the effect of ivermectin on dung degradation and dung fauna in Tanzania. For the dung degradation study, at 15, 30 and 45 days post placement, we observed a total of 220 dung pats in the field. We measured termite colonization; wet weight of the entire pat; water content; dry weight of the 10 g subsamples and organic matter from subsamples and the whole pat. For the dung fauna study, we collected fresh dung 3, 10 and 29 days post treatment and put the pats out in the field to be colonized by insects before being transferred to emergence traps. We also did a semi field study where we collected dung pats 1,2,3 and 5 days post treatment to obtain larvae counts. We qualitatively assessed insect larvae activity in the field experiment and observed and counted larvae in the semi field study. We found that termites colonized pats from cattle treated with ivermectin more readily compared to controls (p < 0.001). Compared to control pats, the treated pats' wet weight decreased more slowly on day 15 (p < 0.001), day 30 (p < 0.001), and on day 45 (p = 0.037). Percent dry weight increased over time and similarly between the treatments as water content decreased. Organic matter of the 10g sub samples was similar between the treatments. Total organic matter in the whole pats showed significant differences on day 15 (p < 0.001), and day 30 (p = 0.003), but not on day 45 (p = 0.291). Qualitatively, we observed that pats from treated cattle had less insect larvae activity as compared to controls in the field study. In the semi field study, we counted less larvae in the pats from ivermectin-treated cattle than in the control pats (p < 0.001). Our results indicate that ivermectin and its residues affect dung degradation and dung fauna in tropical savanna settings, and the environmental safety may be at risk upon mass drug administration in livestock. / Master of Science in Life Sciences / Ivermectin is a drug commonly used in livestock and humans to control most parasitic infections. Malaria is a disease transmitted by female Anopheles mosquitoes and prevalent in tropical regions mostly the sub-Saharan Africa. There are efforts worldwide to reduce transmission of malaria such as the used of insecticide treated bed nets as well as use of repellents and spraying insecticides indoors. These efforts are challenged by insecticide resistance in mosquitoes, change in mosquito behavior as well as remaining malaria cases after such interventions are applied. With such challenges comes a need to use ivermectin which has the ability to kill mosquitoes. Despite its great potential, evidence from temperate regions record that ivermectin affects the environment by decreasing dung insect activity, affecting the developmental process and causing a delay in dung decomposition. These effects cause cattle to avoid such pasture areas, resulting in an increase in pest pressure and affecting the economy in general. In the tropics where malaria is prevalent and plans are in place to use ivermectin in mass drug administration for mosquito control, there is a need to look at the environmental impact of the drug. We placed 1 kg dung pats from ivermectin-treated and control cattle to determine the effect of ivermectin on dung degradation and dung fauna in Tanzania. For the dung degradation study; at 15, 30 and 45 days after pats were placed in the field, we observed a total of 220 dung pats. We measured termite colonization; wet weight of the entire pat; water content; dry weight of the 10 g subsamples and organic matter from subsamples and the whole pat. For the dung fauna study, we collected fresh dung 3,10 and 29 days post treatment and put the pats out in the field to be colonized by insects before being transferred to emergence traps. We also did a semi field study where pats were collected 1,2,3 and 5 days post treatment to obtain larvae counts. We qualitatively assessed insect larvae activity in the field experiment and observed and counted larvae in the semi field study. We found that termites colonized pats from cattle treated with ivermectin more readily compared to controls, and treated pats' wet weight decreased more slowly. Dry weight of dung increased as water content decreased with no differences between the treatments. Organic matter of the subsamples did not differ in the treatments but the average mass of organic matter of the individual dung pats decreased slower in ivermectin-treated pats. Qualitatively, we observed that pats from treated cattle had less insect larvae activity as compared to controls in the field study. In the semi field study, we counted more larvae in control pats than the ivermectin pats. Our results indicate that ivermectin and its residues affect dung degradation and dung fauna in tropical savanna settings, and the environmental safety may be at risk upon mass drug administration setting.
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On ENSO-Modified Hurricane Formation in the North AtlanticWelty, Joshua Stephen 22 May 2015 (has links)
No description available.
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