2,242 research outputs found
Fill predilecte: Samuel Huntington defensa la pĂ tria
A ÂżQui som?, el seu Ășltim llibre (2004), Samuel Huntington aborda els mĂșltiples reptes que actualment tĂ© plantejats la identitat nacional nord-americana, especialment a causa de la singularitat de la immigraciĂł mexicana. Lâautor dâaquest article considera que, malauradament, Huntington ha abandonat el realisme clarivident de les seves obres anteriors en favor dâun moralisme desdenyĂłs, que atia la histĂšria dels nadius en comptes dâoferir solucions reals
Exposure to Glycolytic Carbon Sources Reveals a Novel Layer of Regulation for the MalT Regulon
Bacteria adapt to changing environments by means of tightly coordinated regulatory circuits. The use of synthetic lethality, a genetic phenomenon in which the combination of two nonlethal mutations causes cell death, facilitates identification and study of such circuitry. In this study, we show that the E. coli ompR malTcon double mutant exhibits a synthetic lethal phenotype that is environmentally conditional. MalTcon, the constitutively active form of the maltose system regulator MalT, causes elevated expression of the outer membrane porin LamB, which leads to death in the absence of the osmoregulator OmpR. However, the presence and metabolism of glycolytic carbon sources, such as sorbitol, promotes viability and unveils a novel layer of regulation within the complex circuitry that controls maltose transport and metabolism
Microarray Analysis of PBMC after Plasmodium falciparum Infection: Molecular Insights into Disease Pathogenesis
Our laboratory’s previous microarray analysis of subjects with Plasmodium falciparum revealed up-regulation of Toll-like receptor, NF-kB, TNF-α, IFN-γ, IL-1β, p38 MAPK, and MHC molecules. We performed further time-course microarray analysis focusing on malaria pathogenesis by using peripheral leukocytes as a cellular model. We found up-regulation of coagulation-related genes (SERPINB2, thrombomodulin, thrombospondin), heat shock proteins, glycolytic enzymes, glucose transporters, and vacuolar H+-ATPases in acute febrile malaria. In early malaria, prior to detectable parasitemia, CD36 and ICAM1 were up-regulated. During acute malaria, a correlation was observed between IL-1ß and heat shock proteins, suggesting heat shock protein response may be in the febrile response induced by IL-1ß. CD163, a hemoglobin scavenger receptor, was up-regulated in acute malaria to potentially facilitate free hemoglobin up-take by peripheral leukocytes. In acute malaria, high MafB gene expression was negatively correlated with down-regulation of hemoglobin and platelet counts. Consistent with a down-regulation of hemoglobin expression, peripheral RBC counts tended to increase during the acute malaria. In our model, up-regulations of RBC and/or leucocyte binding mediators like CD36, ICAM1, thrombospondin, and thrombomodulin may contribute to the pathogenesis of cerebral malaria. Similarly, up-regulation of genes coding for glycolytic enzymes, glucose transporter and H+-ATPases may contribute to the hypoglycemia and metabolic acidosis frequently observed in seriously ill malaria patients. Overall gender effects on gene expression profiles between male and female subjects were not apparent, except that some hemoglobins were significantly down-regulated in male versus female; suggesting males may be more prone to the development of malaria associate anemia
Characterization of the ÏCTX-like Pseudomonas aeruginosa phage Dobby Isolated from the Kidney Stone Microbiota
Bacteriophages (phages) are vital members of the human microbiota. They are abundant even within low biomass niches of the human body, including the lower urinary tract. While several prior studies have cultured bacteria from kidney stones, this is the first study to explore phages within the kidney stone microbiota. Here we report Dobby, a temperate phage isolated from a strain of Pseudomonas aeruginosa cultured from a kidney stone. Dobby is capable of lysing clinical P. aeruginosa strains within our collection from the urinary tract. Sequencing was performed producing a 37â152âbp genome that closely resembles the temperate P. aeruginosa phage ÏCTX, a member of the P2 phage group. Dobby does not, however, encode for the cytotoxin CTX. Dobbyâs genome was queried against publicly available bacterial sequences identifying 44 other ÏCTX-like prophages. These prophages are integrated within the genomes of P. aeruginosa strains from a variety of environments, including strains isolated from urine samples and other niches of the human body. Phylogenetic analysis suggests that the temperate ÏCTX phage species is widespread. With the isolation of Dobby, we now have evidence that phages are members of the kidney stone microbiota. Further investigation, however, is needed to determine their abundance and diversity within these communities
The Tiger Foundation: A Profile in Engaged Philanthropy
Tiger Management was one of the most successful hedge funds of the 1990s. But founder Julian Robertson also wanted to foster a lifelong commitment to giving back among his staff. So in 1990, he created Tiger Foundation with a unique dual mission: To provide financial support to the top nonprofit organizations serving New York City's neediest families;To encourage active, informed philanthropy among the staff at the firm The Foundation marries the rigor and analytics of the investment process to grantor/grantee relationships. Individual trustees not only pore over analytics compiled by Foundation staff, but also meet their grantees face to face and champion them at trustee meetings.The result is nothing short of transformative -- for the organizations Tiger funds and for the decision makers
Discriminating between jcpyv and bkpyv in urinary virome data sets
Polyomaviruses are abundant in the human body. The polyomaviruses JC virus (JCPyV) and BK virus (BKPyV) are common viruses in the human urinary tract. Prior studies have estimated that JCPyV infects between 20 and 80% of adults and that BKPyV infects between 65 and 90% of individuals by age 10. However, these two viruses encode for the same six genes and share 75% nucleotide sequence identity across their genomes. While prior urinary virome studies have repeatedly reported the presence of JCPyV, we were interested in seeing how JCPyV prevalence compares to BKPyV. We retrieved all publicly available shotgun metagenomic sequencing reads from urinary microbiome and virome studies (n = 165). While one third of the data sets produced hits to JCPyV, upon further investigation were we able to determine that the majority of these were in fact BKPyV. This distinction was made by specifically mining for JCPyV and BKPyV and considering uniform coverage across the genome. This approach provides confidence in taxon calls, even between closely related viruses with significant sequence similarity
Draft Genome Sequence of Staphylococcus epidermidis UMB7543, Isolated from a Female Patient with Recurrent Urinary Tract Infections
Staphylococcus epidermidis is a Gram-positive bacterium that is part of the normal human flora, found in multiple anatomical sites. Here, we present the 2.6-Mbp draft genome sequence of S. epidermidis UMB7543, isolated from a catheterized urine sample from a female patient with a documented diagnosis of recurrent urinary tract infection
Genomic insights into Lactobacillus gasseri and Lactobacillus paragasseri
Background. Antimicrobial and antifungal species are essential members of the healthy human microbiota. Several different species of lactobacilli that naturally inhabit the human body have been explored for their probiotic capabilities including strains of the species Lactobacillus gasseri. However, L. gasseri (identified by 16S rRNA gene sequencing) has been associated with urogenital symptoms. Recently a new sister taxon of L. gasseri was described: L. paragasseri. L. paragasseri is also posited to have probiotic qualities. Methods. Here, we present a genomic investigation of all (nD79) publicly available genome assemblies for both species. These strains include isolates from the vaginal tract, gastrointestinal tract, urinary tract, oral cavity, wounds, and lungs. Results. The two species cannot be distinguished from short-read sequencing of the 16S rRNA as the full-length gene sequences differ only by two nucleotides. Based upon average nucleotide identity (ANI), we identified 20 strains deposited as L. gasseri that are in fact representatives of L. paragasseri. Investigation of the genic content of the strains of these two species suggests recent divergence and/or frequent gene exchange between the two species. The genomes frequently harbored intact prophage sequences, including prophages identified in strains of both species. To further explore the antimicrobial potential associated with both species, genome assemblies were examined for biosynthetic gene clusters. Gassericin T and S were identified in 46 of the genome assemblies, with all L. paragasseri strains including one or both bacteriocins. This suggests that the properties once ascribed to L. gasseri may better represent the L. paragasseri species
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