39 research outputs found
Genetic and population studies of quantitative levels of adenosine triphosphate in human erythrocytes
The mean content of ATP in red cells of American Negroes is significantly less than the mean level in American Caucasians. This is compatible with the hypothesis that the quantitative level of ATP in red cells may be involved in selective processes related to falciparum malaria. There is no evidence of a sex effect on levels of ATP in either population. Family studies conducted in both populations indicate that the quantitative level of red cell ATP is at least partially inherited. Studies of a number of biochemical characteristics of red cells have been conducted in an effort to elucidate the mechanism of genetic and biochemical control of quantitative levels of erythrocytic ATP. These studies have been negative. Although other studies have demonstrated that thalassemia trait influences the level of red cell ATP, the presence of sickle cell trait or G-6-PD deficiency, the other two systems postulated to be involved in malaria protection, did not result in significant differences in mean red cell ATP content.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44114/1/10528_2004_Article_BF00487733.pd
The Trichoptera barcode initiative: a strategy for generating a species-level Tree of Life
DNA barcoding was intended as a means to provide species-level identifications through associating DNA sequences from unknown specimens to those from curated reference specimens. Although barcodes were not designed for phylogenetics, they can be beneficial to the completion of the Tree of Life. The barcode database for Trichoptera is relatively comprehensive, with data from every family, approximately two-thirds of the genera, and one-third of the described species. Most Trichoptera, as with most of life’s species, have never been subjected to any formal phylogenetic analysis. Here, we present a phylogeny with over 16 000 unique haplotypes as a working hypothesis that can be updated as our estimates improve. We suggest a strategy of implementing constrained tree searches, which allow larger datasets to
dictate the backbone phylogeny, while the barcode data fill out the tips of the tree. We also discuss how this phylogeny could be used to focus taxonomic attention on ambiguous species boundaries and hidden biodiversity. We suggest that systematists continue to differentiate
between ‘Barcode Index Numbers’ (BINs) and ‘species’ that have been formally described. Each has utility, but they are not synonyms. We highlight examples of integrative taxonomy, using both barcodes and morphology for species description. This article is part of the themed issue ‘From DNA barcodes to biomes’
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Neurological illnesses associated with Florida red tide (Karenia brevis) blooms
•Brevetoxins are produced by the marine harmful alga, Karenia brevis (K. brevis); and humans can be exposed to these toxins through a variety of pathways, including inhalation of aerosols and consumption of toxin-contaminated seafood;•Neurological illnesses may also be associated with human exposures to brevetoxins, but to date there has been little research on this specific effect;•During K. brevis blooms in nearby coastal waters, significant increases in visits to emergency departments by older coastal residents (≥55 years) were found specifically for the primary diagnosis of headache (ICD-9 784.0);•In previous studies, older coastal residents were also at increased risk for respiratory illnesses associated with K. brevis blooms;•Preventive measures designed to reduce and limit human exposures to brevetoxins are recommended; and healthcare providers should be instructed to consider brevetoxin exposures and resultant neurological illness as possible diagnoses.
Human respiratory and gastrointestinal illnesses can result from exposures to brevetoxins originating from coastal Florida red tide blooms, comprising the marine alga Karenia brevis (K. brevis). Only limited research on the extent of human health risks and illness costs due to K. brevis blooms has been undertaken to date. Because brevetoxins are known neurotoxins that are able to cross the blood-brain barrier, it is possible that exposure to brevetoxins may be associated with neurological illnesses. This study explored whether K. brevis blooms may be associated with increases in the numbers of emergency department visits for neurological illness. An exposure-response framework was applied to test the effects of K. brevis blooms on human health, using secondary data from diverse sources. After controlling for resident population, seasonal and annual effects, significant increases in emergency department visits were found specifically for headache (ICD-9 784.0) as a primary diagnosis during proximate coastal K. brevis blooms. In particular, an increased risk for older residents (≥55 years) was identified in the coastal communities of six southwest Florida counties during K. brevis bloom events. The incidence of headache associated with K. brevis blooms showed a small but increasing association with K. brevis cell densities. Rough estimates of the costs of this illness were developed for hypothetical bloom occurrences