RESUMO
BACKGROUND: Currently, much is unknown about the taxonomic diversity and the mechanisms of methane metabolism in the Florida Everglades ecosystem. The Loxahatchee National Wildlife Refuge is a section of the Florida Everglades that is almost entirely unstudied in regard to taxonomic profiling. This short report analyzes the metagenome of soil samples from this Refuge to investigate the predominant taxa, as well as the abundance of genes involved in environmentally significant metabolic pathways related to methane production (nitrogen fixation and dissimilatory sulfite reduction). METHODS: Shotgun metagenomic sequencing using the Illumina platform was performed on 17 soil samples from four different sites within the Loxahatchee National Wildlife Refuge, and underwent quality control, assembly, and annotation. The soil from each sample was tested for water content and concentrations of organic carbon and nitrogen. RESULTS: The three most common phyla of bacteria for every site were Actinobacteria, Acidobacteria, and Proteobacteria; however, there was variation in relative phylum composition. The most common phylum of Archaea was Euryarchaeota for all sites. Alpha and beta diversity analyses indicated significant congruity in taxonomic diversity in most samples from Sites 1, 3, and 4 and negligible congruity between Site 2 and the other sites. Shotgun metagenomic sequencing revealed the presence of biogeochemical biomarkers of particular interest (e.g., mrcA, nifH, and dsrB) within the samples. The normalized abundances of mcrA, nifH, and dsrB exhibited a positive correlation with nitrogen concentration and water content, and a negative correlation with organic carbon concentration. CONCLUSION: This Everglades soil metagenomic study allowed examination of wetlands biological processes and showed expected correlations between measured organic constituents and prokaryotic gene frequency. Additionally, the taxonomic profile generated gives a basis for the diversity of prokaryotic microbial life throughout the Everglades.
RESUMO
BACKGROUND: For more than a decade, a large proportion of research on caffeine use in college students has focused on energy drinks (ED), demonstrating an association between ED consumption and heavy/problem alcohol use. The present study examined the relationship between daily coffee consumption and varied measures of alcohol use and problems in a sample of college women. METHODS: Participants were undergraduate females (N=360) attending an urban university in 2001-02 and prior to the rise in ED popularity on college campuses. Analyses compared women who reported drinking coffee daily (DC; 16.9%), to women who did not (NDC; 83.1%) on standardized measures of alcohol use and problems. RESULTS: For both past month and year of drinking, DC women generally reported consuming more alcohol and were 2.1-2.6 times more likely to screen at risk for alcohol problems than their NDC counterparts. DC women were also more likely than NDC women to report problems related to drinking (e.g., experiencing blackouts, inability to stop drinking after they had started). CONCLUSIONS: Findings support potential benefits of health education and screening that goes beyond EDs, focusing on varied forms of caffeine consumption.
