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An analysis to determine physical and spatial patterns of the surface latent heat flux (LHF) and near surface (5m) salinity (NSS) beneath tropical cyclones (TCs) in the North Atlantic and eastern North Pacific basins during the first 24 hours of rapid intensification (RI) was conducted using empirical orthogonal function (EOF) analysis. To determine if these patterns were unique to RI, TC RI cases were compared to three non-RI intensification thresholds, 10 kt, 15 kt and 20 kt, for both LHF and NSS. Though similarities exist between non-RI and RI cases physical and spatial patterns unique to the RI cases did exist. Sea surface temperatures associated with statistically identified TC groups were assessed for their potential influence on RI. While inconclusive in the eastern North Pacific, NSS in the Atlantic may play a role for RI TCs in areas affected by river discharge from South America.

Herbicides were evaluated for control of non-native and invasive plants namely tropical soda apple (TSA) (Solanum viarum), tropical spiderwort or Benghal dayflower (Commelina benghalensis), and Italian ryegrass (Lolium multiflorum) from 2007 to 2012 in greenhouse at Plant Science Research Center, Mississippi State University, Starkville-Mississippi. In TSA study, aminopyralid at 0.88 or 0.12 kg ae/ha, and triclopyr + picloram + 2,4-D at (0.56 + 0.15 + 0.56) kg ae/ha controlled TSA seedlings emergence ranged from 83 to 96% at premergence (PRE), and 1 month after treatments (MAT). All herbicides failed to provide more than 63% control of TSA at 3 and 6 MAT. In Benghal dayflower study, bentazon, bromoxynil, chlorimuron ethyl plus tribenuron methyl, dimethenamid-P, nicosulfuron plus rimsulfuron, primisulfuron-methyl, S-metolachlor plus glyphosate plus mesotrione, and sulfosulfuron provided less than 50% control of Benghal dayflower during 6 weeks of evaluation whereas other herbicides: aminocyclopyrachlor (34-96%) ametryn (2-55%), atrazine (2-68%), diclosulam (12-67%), flumioxazin (59-83%), saflufenacil (24-78%), and sulfentrazone (67-96%) provided variable control of Benghal dayflower. In Italian ryegrass study, 50 seeds of F1 generation of resistant biotype ’49E’ and susceptible biotypes ‘Gulf’ and ‘Marshall’ of Italian ryegrass which were previously grown in mixture were used. Each biotype’s F1 generation responce to imazapyr at 0, 1, and 2% under PRE, early post emergence (EPOST) and late postemergence (LPOST) was evaluated. At PRE, imazapyr at 1 and 2% reduced ‘49E’ seedlings emerged 3 and 18%, respectively, but both rates failed to have any significant impact on fresh biomass weight compared to untreated. At EPOST, survival of ‘49E’ shoots were reduced 3 to 10% by both rate of imazapyr whereas only imazapyr at 1% caused 0.74 to 3.8 % fresh biomass reduction. At LPOST, ‘49E’ shoot survival was reduced 9 to 12% by both rate of imazapyr whereas both rate of imazapyr reduced ‘49E’ fresh biomass 3 to 31%. In all the PRE, EPOST, and LPOST experiments, ‘Gulf’ and ‘Marshall’ were still susceptible to the imazapyr.

We establish consistent definitions for divisors, principal divisors, and Jacobians of a tropical elliptic curve and show that for a tropical elliptic cubic C , the associated Jacobian (or zero divisor class group) is the group S^1(Q).

<p>Over the last two decades, mycoflorostic studies undertaken in Guyanese forests have uncovered hundreds of new fungal species and genera. One of the recovered fungal families was the Xylariaceae, although most were not identified to species. Members of this family play ecological roles as decomposers, endophytes, and pathogens of vascular plants and grass species. In addition, this group is increasingly recognized as a significant source of novel metabolic products with potential for applications in medicine, agriculture, and industrial biofuel. Given its potential, we took a more targeted approach to the documentation of this group. Our sampling efforts drawing on more than two decades of field collections yielded ca. 90 species in 12 genera, including a putative pathogen, <em>Xylaria karyophthora</em> of the seeds of <em>Chlorocardium</em> spp (Greenheart). Despite the significance of Greenheart to the Guyanese economy, little is known about the biology and ecology of this fungus. Due to the lack of available resources to study this fungus, our objectives were two-fold: first, to sequence and annotate the genome of <em>X. karyophthora</em> to provide a resource for genome-centric explorations, and to use this genome to infer the biology and ecology of this fungus. We focused on identifying and characterizing secretomes, viz. carbohydrate-active enzymes (CAZymes) and secondary metabolites biosynthetic gene clusters (SMBGCs) to infer the nutritional strategy of this fungus. Our results suggest that <em>X. karyophthora</em> has the capacity to act as both an endophyte and a pathogen. To make further inferences about the population, we used SSR markers to elucidate the genetic diversity and population structure of <em>X. karyophthora</em>. <em>X. karyophthora</em> populations have high genetic diversity, potentially exploiting both outcrossing and inbreeding reproductive strategies, and demonstrate a pattern consistent with human-mediated spread. This work will contribute information on new species and records of Xylariaceous fungi and their allies from Guyana with particular emphasis on unraveling the epidemiology, genetic diversity, and population structure of <em>X. karyophthora.</em></p>

<p> The radiation balance at a ship station in the eastern tropical Atlantic Ocean is calculated using a term-by-term approach. Irradiances are calculated using upper air data from four daily radiosonde ascents and hourly surface weather observations made at the Canadian vessel 'Quadra' during GATE Phase 1 (June- July, 1974).</p> <p> Global irradiance is calculated by a cloud layer model similar to that used by Davies et al in Southern Ontario, Canada. The model considers first, cloudless sky attenuation of solar irradiance by water vapour, ozone and Rayleigh scattering. Second, cloud effects are added by considering contributions from three cloud layers - high, middle and low and secondary radiation from cloud base of reflected surface radiation. Reflected solar irradiance is calculated using a mean sea-surface albedo of 6% suggested by Payne for that part of the Atlantic Ocean.</p> <p> Estimates of incoming longwave irradiance are made first, from a numerical flux emissivity model which uses radiosonde ascent data and cloud amount at three heights and second, from a simple model which uses surface temperature and total cloud amount.</p> <p> Outgoing longwave emittance is evaluated using surface temperature and an emissivity of 0.98. The radiation balance is then obtained as the algebraic sum of the four components.</p> <p> The estimated values are compared with values measured at 'Quadra'. In 70% of the cases, calculated and measured solar irradiance agree to within 20%. Model performance for cloud amount > 5/10 is least satisfactory.</p> <p> In all cases, model and measured values of daily incoming longwave irradiance agree to within 5%. In 60% of the cases, measured and calculated radiation balance agree to within 20%.</p> / Thesis / Master of Science (MSc)

Forensic anthropology, forensic taphonomy and forensic entomology are specialties that greatly contribute to judicial investigations and the identification of a decomposing corpse. This research examines the effect of calcium oxide (CaO), known as “quicklime”, on the decomposition process of human remains in a tropical climate. Quicklime has been used since the Early Iron Age, in wars, mass graves and today by criminals, as there is a belief or social myth that it can speed up the process of decomposition of bodies. However, there are no studies on the effect of this chemical on decomposing bodies in a tropical climate. Puerto Rico, in addition to having this climate, has a high crime rate related to drug trafficking. This study uses a series (n=10) of pig (Sus scrofa) burials as a model for human corpses, which were documented through photographs and state of decomposition, as well as climatic conditions, soil pH, odor of decomposition, and the lost mass. The author hypothesizes that the tropical climate contributes to the rapid decomposition of bodies by altering their appearance and morphology; since it is warmer, bacteria multiply more quickly and the entomofauna is more active, in comparison with studies already carried out in temperate climates. In addition, quicklime helps soft tissue decomposition proceed faster and reduces decomposition odor. Among the results, it was observed that there was no acceleration in the decomposition process due to the application of calcium oxide, and this chemical does not have the qualities attributed to it by social myths regarding the complete destruction of human remains, which could be considered an advantage for investigators in cases where there is a buried corpse covered in quicklime. However, it was possible to show that among other effects of quicklime, it subjectively reduces the odor of decomposition, inhibits and/or reduces the activity of the entomofauna, maintains a soil with an alkaline pH and therefore caused the mummification of the body. It can be suggested that the tropical climate helps in an effective decomposition due to the high temperatures, the humidity, and the activity of the entomofauna. Therefore, in both temperate and tropical climates, quicklime does not accelerate the decomposition process, but in a tropical climate it can inhibit the activity of entomofauna and the odor of decomposition. Statistically, results show that the Total Body Score (TBS) did not vary significantly, but the percentage of Mass Loss (ML) had a statistical difference due to the adhesion of the compacted quicklime to the experimental carcasses which increased the overall mass and not because a difference in the actual tissue loss was measured. This is since the decay process almost stopped after 77 days of burial and the mass loss nearly ceased, because with more days of rain and humidity, the more chemical reaction quicklime does (turning it into hydrated lime), causing solidification and mummification in the experimental pig carcasses. The quicklime also maintained an alkaline pH in the pig carcasses compared to the acidic pH of the controls after the decomposition. Therefore, quicklime causes a very sudden dehydration, and, in this sense, it prevents the proliferation of bacteria and, therefore, putrefaction, causing a mummification process. In addition, with the results obtained in this investigation and in other future ones, it will be possible to add scientific, anthropological, and forensic data on the analysis of the effects of quicklime in the stages of decomposition of human remain and in different deposition environments, to establish the time elapsed between death and the moment in which the body has been buried (exposed or not to quicklime) and contribute to criminal cases.

Forecasting rapid intensification (RI) of tropical cyclones (TCs) is considered one of the most challenging problems for the TC operational and research communities and remains a top priority for the National Hurricane Center. Upon landfall, these systems can have detrimental impacts to life and property. To support continued improvement of TC RI forecasts, this study investigated large-scale TC environments undergoing RI in the North Atlantic basin, specifically identifying important diagnostic variables in three-dimensional space. These results were subsequently used in the development of prognostic machine learning algorithms designed to predict RI 24 hours prior to occurrence. Using three RI definitions, this study evaluated base-state and derived meteorological parameters through S-mode and T-mode rotated principal component analysis, hierarchical compositing analysis, and hypothesis testing. Additionally, nine blended intelligence ensembles were developed using three RI definitions trained on data from the Statistical Hurricane Intensity Prediction Scheme- Rapid Intensification Index, Global Ensemble Forecast System Reforecast, and Final Operational Global Analysis. Performance metrics for the intelligence ensembles were compared against traditional linear methods. Additionally, a tenth ensemble was created using forecast data generated from Weather Research and Forecasting model simulations of TC RI events in the open North Atlantic and compared against linear methods. Results revealed modest classification ability of machine learning algorithms in predicting the onset of RI 24 hours in advance by including TC environmental spatial information of temperature and moisture variables, as well as variables indicative of ambient environmental interactions.

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No description available.