Admixture and Genetic Diversity Distribution Patterns of Non-Recombining Lineages of Native American Ancestry in Colombian Populations

Genetic diversity of present American populations results from very complex demographic events involving different types and degrees of admixture. Through the analysis of lineage markers such as mtDNA and Y chromosome it is possible to recover the original Native American haplotypes, which remained identical since the admixture events due to the absence of recombination. However, the decrease in the effective population sizes and the consequent genetic drift effects suffered by these populations during the European colonization resulted in the loss or under-representation of a substantial fraction of the Native American lineages. In this study, we aim to clarify how the diversity and distribution of uniparental lineages vary with the different demographic characteristics (size, degree of isolation) and the different levels of admixture of extant Native groups in Colombia. We present new data resulting from the analyses of mtDNA whole control region, Y chromosome SNP haplogroups and STR haplotypes, and autosomal ancestry informative insertion-deletion polymorphisms in Colombian individuals from different ethnic and linguistic groups. The results demonstrate that populations presenting a high proportion of non-Native American ancestry have preserved nevertheless a substantial diversity of Native American lineages, for both mtDNA and Y chromosome. We suggest that, by maintaining the effective population sizes high, admixture allowed for a decrease in the effects of genetic drift due to Native population size reduction and thus resulting in an effective preservation of the Native American non-recombining lineages.     

Growth and laccase production kinetics of <Emphasis Type="Italic">Trametes versicolor</Emphasis> in a stirred tank reactor

White rot fungi are a promising option to treat recalcitrant organic molecules, such as lignin, polycyclic aromatic hydrocarbons, and textile dyes, because of the lignin-modifying enzymes (LMEs) they secrete. Because knowledge of the kinetic parameters is important to better design and operate bioreactors to cultivate these fungi for degradation and/or to produce LME(s), these parameters were determined using Trametes versicolor ATCC 20869 (ATCC, American Type Culture Collection) in a magnetic stir bar reactor. A complete set of kinetic data has not been previously published for this culture. Higher than previously reported growth rates with high laccase production of up to 1,385 U l⁻¹ occurred during growth without or glucose limitation. The maximum specific growth rate averaged 0.94 ± 0.23 day⁻¹, whereas the maximum specific substrate consumption rates for glucose and ammonium were 3.37 ± 1.16 and 0.15 ± 0.04 day⁻¹, respectively. The maximum specific oxygen consumption rate was 1.63 ± 0.36 day⁻¹.     

Immunohistopathological studies of blastomycosis: the use of labeled specific antigens in a hamster model of disease

We applied a modified immunofluorescence and immunoperoxidase method, utilizing labeled Blastomyces dermatitidis antigens, to look for specific antibody-bearing B/ plasma cells in the tissue infiltrates of blastomycosis lesions induced in hamsters. No specific anti-blastomyces antibodies were detectable by this method, although such antibodies were present in blood samples as demonstrated by routine immunodiffusion techniques. These studies suggest that humoral immune reactions do not play a major role in the pathogenesis of lesions of blastomycosis in hamsters.     

Additional observations on the gross morphology and microstructure of Baccaconularia Hughes, Gunderson et Weedon, 2000, a Cambrian (Furongian) conulariid from the north-central USA

Baccaconularia Hughes, Gunderson et Weedon, 2000, from the Furongian Series (Cambrian System) of the north-central USA, has been interpreted as a conulariid cnidarian, based on a suite of gross morphological similarities shared only with other post-Cambrian genera currently assigned to this group. Closely spaced, squarish to subrectangular facial nodes of Baccaconularia are aligned in distinct longitudinal files. Nodes also display a subtler, more or less rectilinear transverse alignment, though this pattern commonly is disrupted by offset parallel to the longitudinal files. In their shape and pattern of arrangement, the nodes of Baccaconularia are most similar to the squarish to elongate nodes of Pseudoconularia Bouček, 1939. Longitudinal node files of Baccaconularia may also be compared with the longitudinal facial ridges of Conularia cambria Walcott, 1890 from the Furongian of Wisconsin. Apical angles of Baccaconularia range from approximately 13° to 14.5°. Scanning electron imaging of B. cf. robinsoni shows that its thin, phosphatic skeleton is finely lamellar, with the thickness of individual lamellae measuring approximately 1 μm. The skeleton also exhibits microscopic circular pores and crater-like pits that range from approximately 5 to 10 μm in diameter. These pores and pits are similar in size, geometry, areal density and pattern of arrangement to those of many post-Cambrian conulariids. Microscopic circular pores are documented here for the first time in the genus Archaeoconularia Bouček, 1939 from the Upper Ordovician of the Czech Republic. Although the origin of the pores and pits is open to alternative interpretations, the discovery of these features and fine lamination in Baccaconularia strengthens the argument that this genus is a Cambrian conulariid.     

Movement patterns and space use of the first giant anteater (Myrmecophaga tridactyla) monitored in São Paulo State,Brazil

This study analyzes a giant anteater’s (Myrmecophaga tridactyla) movement patterns and space use in São Paulo, Brazil. It is the first study to track a giant anteater with Iridium-GPS. The anteater traveled an average distance of 1326 m day^–1 with an average speed of 1.04 m min^–1. Home range by Kernel was 2.46 km² while the core area was 0.75 km², and estimates by Brownian bridge and minimum convex polygon were also provided. The anteater used shrub savanna, open savanna, and water habitats more than expected. Monitoring ended just after 10 days when the female giant anteater’s GPS was found on an illegal trail.     

Exogenous heat shock protein-70 inhibits cigarette smoke-induced intimal thickening

Cigarette smoke is associated with increased carotid intimal thickening or stroke. Preliminary work showed that exposure to smoke resulted in a 4.5-fold reduction of heat shock protein-70 (HSP70) expression in spleens of mice using gene microarray analysis. In the current study, we investigated the role of extracellular HSP70 in carotid intimal thickening of mice exposed to cigarette smoke. Intimal thickening was induced by placement of a cuff around the right carotid artery of mice. Cuff injury resulted in increased HSP70 mRNA expression in carotid arteries that persisted for 21 days. Cigarette smoke exposure decreased arterial HSP70 expression and significantly increased intimal thickening compared with mice exposed to air. Treatment of mice exposed to cigarette smoke with intravenous recombinant HSP70 attenuated intimal thickening through reduced phosphorylated extracellular signal-regulated kinase (pERK) expression in the arterial wall. In vitro experiments with rat aortic smooth muscle cells confirmed that recombinant HSP70 decreases pERK and proliferating cell nuclear antigen (PCNA) expression in cells exposed to cigarette smoke extract and H(2)O(2). Our study suggests that decreased expression of arterial HSP70 is an important mechanism by which exposure to cigarette smoke augments intimal thickening. The effects of recombinant HSP70 suggest a role for extracellular HSP70.     

Crystallization and preliminary X-ray diffraction analysis of an acidic phospholipase A(2) complexed with p-bromophenacyl bromide and alpha-tocopherol inhibitors at 1.9- and 1.45-A resolution

An acidic phospholipase A(2) (PLA(2)) isolated from Bothrops jararacussu snake venom was crystallized with two inhibitors: alpha-tocopherol (vitamin E) and p-bromophenacyl bromide (BPB). The crystals diffracted at 1.45- and 1.85-A resolution, respectively, for the complexes with alpha-tocopherol and p-bromophenacyl bromide. The crystals are not isomorphous with those of the native protein, suggesting the inhibitors binding was successful and changes in the quaternary structure may have occurred.     

Characterization,Toxicity, and Optimization for the Growth and Production of Bacteriocin-like Substances by Lactobacillus curvatus

Probiotics and Antimicrobial Proteins - This study aimed to characterize, evaluate toxicity and optimize the conditions for the growth and production of bacteriocin-like substances by Lactobacillus...