acase@tulane.edu

Myanmar remained largely closed to the world through political instability for several years, when it continued to suffer terribly at the hands of nature that remained largely unknown. Of note is the period between 2008 and 2013, during which the country suffered at least eight major natural calamities that killed more than 141,000 people and affected 3.2 million. The worst of these was Cyclone Nargis in May 2008 that killed more than 130,000. With an estimated $4 billion in damages, Nargis remains the deadliest and most destructive named cyclone ever to have occurred in the North Indian Ocean. Recent studies have shown that, due to increased greenhouse gases and aerosol loading in the atmosphere, more and stronger tropical cyclones (TCs) in the last three decades are tracking eastwards toward the Indochina peninsula. Unfortunately, the Burmese lack the capacity to deal with the impacts of such storms. Myanmar was left behind as the world made significant technological and industrial advancement; but agriculture, which employs at least 65% of the active labor force, has remained the backbone of the Myanmar economy – an industry that is heavily reliant on monsoon rainfall. The pre-monsoon TC season in the Bay of Bengal (BoB) precedes the onset of the Myanmar monsoon but sometimes the two (i.e.TC formation and the monsoon onset) occur in unison. This work studied the mechanism by which the Madden Julian Oscillation (MJO) modulates the Myanmar monsoon onset and TC activity collectively (i.e. ISO-Onset-TC connection). Avoiding TC destruction at the beginning of the planting season is crucial, so is the monsoon onset date critical for planning. Additional understanding of the aforementioned ISO-Onset-TC connection could provide further insight into predicting the Myanmar monsoon onset and aid in disaster planning for TC impact. This research is part of a two-year NASA funded project to study extreme climate and weather events.

In the Zapotitan Valley near San Andres, El Salvador, Central America, an experiment was conducted to determine the availability of residual soil N to corn grown during the rainy season. This was an extension of an experiment conducted during the preceding dry season. The variables of the dry season experiment were irrigation method, crop, and rate of fertilizer N application. Soil N03-N and NH4-N were determined by soil sample analysis to a soil depth of 120 em by 30 em depth increments. The samples were taken at the end of the dry season experiment and again at harvest time of the wet season experiment. Yield of corn grown during the rainy season was measured. The results indicate the following: (1) soil N03-N alone was an efficient indicator of residual soil N; (2) there was a linear increase of soil N03-N with N applied four months previously at the beginning of the dry season crops; (3) soil sampled to the 30 cm depth was sufficient to estimate availability of the residual N; (4) corn yields increased linearly with the increase of soil N03-N; (5) the measurement of residual soil N03-N can be used as a soil text index in connection with N prediction equations for estimating fertilizer N requirements. The measurements of soil N03-N can, therefore, increase the efficiency of fertilizer use in a wet-dry tropical climate.

Wood for firewood, fence posts and construction material and forage for domestic livestock are key resources in the caatinga vegetation zone of northeastern Brazil. This experiment was designed as a preliminary assessment of thinned caatinga as the basis of a production system which optimizes forage and wood production. Two levels of thinning (25% and 55% tree canopy cover) were compared to cleared (0% tree canopy cover) and undisturbed (95% tree canopy cover) caatinga in terms of forage and wood production and goat nutrition. Clearing and thinning of caatinga vegetation resulted in higher amounts of available forage through the wet ·season and up to the time of leaf fall. After leaf fall, total available forage was similar for all four treatments. Dietary selection differed among the treatments only in February and May, when goats on treated pastures selected higher amounts of herbaceous vegetation than those on control pastures. Herbaceous vegetation was the primary dietary constituent on treated pastures throughout the wet season. During mid to late dry season, when herbaceous vegetation was dead and leaf:stem ratios were low, browse was consistently selected at high levels. Nutrient content of diets were not different among treatments, but forage and digestible energy intakes were higher (P<.OS) on treated pastures than on control. Due to lack of wood production on cleared plots from an intact tree component, total aboveground biomass production for the cleared treatment was 30% less than that for the control and about 25% less than that for the two thinned treatments. Overall, cleared and thinned treatments had similar positive forage and animal responses but thinned treatments had the added benefit of an intact tree canopy producing valuable wood. The dry season has been identified as the most critical time of the year for livestock due to low forage availability and quality resulting in weight losses and mortality. Results of this study indicated that either supplementation or increased availability of nutritious forage would be necessary for goats to continue to grow beyond the first half of the dry season. Thinning may be a means of increasing the availability of nutritious forage.

Brugia malayi is a filarial nematode causing lymphatic filariasis in humans characterized by swelling of the lower extremities. The aim of this study was to conduct a real time PCR (qRT-PCR) to verify gene expression levels of Brugia malayi nematodes treated with 20 hydroxyecdysone. Transcriptome analysis was previously performed resulting in the identification of 44 genes that were upregulated by exposure to 20-hydroxyecdysone. Based on transcriptome results, known GO Terms and functions, four genes and one endogenous housekeeping gene were chosen for validation by RT-PCR. Induced samples showed a mean increase of microfilarie by 2.2 fold. Induced wells exhibited a 2.8 fold increase of pre- microfilarie production. On day two adult females treated with 20-HE displayed 3.8-fold increase of microfilaria production as compared to uninduced controls. Overall, all four genes showed upregulation with treatment of 20-hydroxyecdysone at levels that corresponded to the results obtained from the transcriptome analysis. Findings in this experiment expand on the understanding of the ecdysone response system in Brugia malayi, which could serve as a potential drug target against filarial disease.

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

acase@tulane.edu