Polymeric Branched Flocculant Effect on the Flocculation Process of Pulp Suspensions in the Papermaking Industry

This paper presents the effect of the structure of cationic polyacrylamides (CPAMs) on flocculation of pulp suspensions and floc properties. A focused beam reflectance measurement (FBRM) probe was used to monitor flocculation, deflocculation, and reflocculation processes in real time. To carry out the study, 1% elemental chlorine free (ECF) eucalyptus kraft pulp containing 20% ground calcium carbonate (GCC) was used. Results show that the effect of the CPAM structure depends on charge density and polymer dose. Floc size does not always decrease with branching degree, whereas floc stability and reflocculation ability increased when highly charged and branched CPAM was used. These findings indicate that the use of highly branched CPAMs with very high molecular weight is very promising as a retention aid method to improve the papermaking process

Symptomatic and Subclinical Infection with Rotavirus P[8]G9, Rural Ecuador

Prevalence of this genotype is increasing

Origin of Class 1 and 2 Integrons and Gene Cassettes in a Population-Based Sample of Uropathogenic Escherichia coli

The prevalence of urinary tract infections (UTI) caused by trimethoprim-sulfamethoxazole (TMP-SMX)-resistant Escherichia coli is increasing and varies geographically in the United States. Recent community-based UTI studies have demonstrated geographic clustering of an Escherichia coli clonal group, suggesting occurrence of a community outbreak of UTI. A large proportion of this clonal group (designated CgA) isolated from women in a California college community was found to be resistant to TMP-SMX. We wished to determine if the acquisition of TMP-SMX resistance by CgA occurred before or after the CgA strains were introduced into this community. Between October 1999 and January 2000 and between October 2000 and January 2001, 482 E. coli isolates were consecutively collected from the urine samples of women with UTI at a student health clinic and analyzed for determinants of TMP-SMX resistance. In particular, the distribution of integrons harboring resistance cassettes for TMP-SMX (dfr) was examined. Among 95 TMP-SMX-resistant isolates, 68 and 27 isolates carried class 1 and class 2 integrons, respectively. A class 1 integron was found in 25 (93%) of 27 TMP-SMX-resistant CgA isolates but in only 43 (63%) of 68 TMP-SMX-resistant non-CgA isolates (P < 0.001) and in none of 44 TMP-SMX-susceptible E. coli isolates (P < 0.0001). CgA strains carried only a single arrangement of class 1 gene cassettes (dfrA17-aadA5), while the non-clonal group strains carried nine different cassette arrangements. These results support the idea that CgA strains acquired their resistance at a common site prior to their spread to the college community

Lightning talk: PyPop - a software pipeline for large-scale multilocus population genomics

PyPop (Python for Population Genomics) is an open-source framework for performing large-scale population genetic analyses on multilocus genotype and allele frequency data. It computes tests and measures of Hardy-Weinberg equilibrium (locus-level and individual genotype-level), linkage disequilibrum, and selection, and estimates multi-locus haplotypes. PyPop supplements and extends existing population genetic software incorporating them as modules, modified to accommodate highly polymorphic data, rather than reimplementing them from scratch. It facilitates evolutionary analyses by integrating population genetic statistics within and across populations.&#xd;&#xa;&#xd;&#xa;Originally developed to analyze the highly polymorphic genetic data of the human leukocyte antigen region of the human genome, PyPop has applicability to any kind of multilocus genetic data. It was the primary platform for evolutionary analysis of data collected for a major NIH-funded collaborative grant that included over 30 laboratories and 200 populations (Lancaster et al., 2007a,b). PyPop has also been successfully used in studies by our group, with collaborators, and in publications by many independent research teams in over 70 peer reviewed papers.&#xd;&#xa;&#xd;&#xa;PyPop deploys a standard Extensible Markup Language (XML) output format and integrates the results of multiple analyses on various populations that were performed at different times into a common output format that can be read into a spreadsheet. The XML output format allows PyPop to be embedded as part of larger analysis pipelines. It also features an Application Programming Interface (API) allowing functionality to be incorporated into other programs. This lightning talk will focus on recent features of PyPop which include the prefiltering of the input genotype data and the ability to translate arbitrary allele names into full amino acid or nucleotide sequences.&#xd;&#xa;&#xd;&#xa;All code is made available under the terms of the GNU General Public License (GNU GPL):&#xd;&#xa;&#xd;&#xa;Homepage: http://www.pypop.org/&#xd;&#xa;&#xd;&#xa;References:&#xd;&#xa;&#xd;&#xa;Lancaster, A. K., M. P. Nelson, R. M. Single, D. Meyer, and G. Thomson, 2007a Software framework for the Biostatistics Core of the International Histocompatibility Working Group. In J. A. Hansen, editor, Immunobiology of the Human MHC: Proceedings of the 13th International Histocompatibility Workshop and Conference, volume I. Seattle, WA: IHWG Press, 510-517.&#xd;&#xa;&#xd;&#xa;Lancaster, A. K., R. M. Single, O. D. Solberg, M. P. Nelson, and G. Thomson, 2007b PyPop update&#x2013;a software pipeline for large-scale multilocus population genomics. Tissue Antigens 69 Suppl 1:192-7

A qPCR-based metric of Th2 airway inflammation in asthma

Abstract Background Using microarray profiling of airway epithelial cells, we previously identified a Th2-high molecular phenotype of asthma based on expression of periostin, CLCA1 and serpinB2 and characterized by specific inflammatory, remodeling, and treatment response features. The goal of the current study was to develop a qPCR-based assay of Th2 inflammation to overcome the limitations of microarray-based methods. Methods Airway epithelial brushings were obtained by bronchoscopy from two clinical studies comprising 44 healthy controls and 62 subjects with asthma, 39 of whom were studied before and after a standardized 8 week course of inhaled corticosteroids (ICS). The qPCR-based expression of periostin, CLCA1 and serpinB2 were combined into a single metric. Results In asthma, the three-gene-mean of periostin, CLCA1 and serpinB2 correlated with FeNO (r = 0.75, p = 0.0002), blood eosinophils (r = 0.58, p = 0.003) and PC20 methacholine (r = -0.65, p = 0.0006), but not total serum IgE (r = 0.33, p = 0.1). Higher baseline three-gene-mean correlated with greater improvement in FEV1 with ICS at 2, 4 and 8 weeks (all p &lt; 0.05). By ROC analysis, the area under the curve (AUC) of the three-gene-mean for FEV1 improvement with ICS at 4 and 8 weeks was 0.94 and 0.87, respectively, which are higher than the AUCs of FeNO, blood eosinophils, IgE or PC20. Th2 airway inflammation as measured by this three-gene-mean also had predictive capacity for an improvement in symptoms. Conclusions The three-gene-mean of periostin, CLCA1 and serpinB2 in airway epithelial brushings identifies Th2-high and low populations, is correlated with other Th2 biomarkers, and performs well for prediction of FEV1 improvement with ICS. The three-gene-mean provides a measurement of Th2 airway inflammation that is clinically relevant and that can serve as a valuable tool to evaluate non-invasive biomarkers to predict treatment responses to existing and emerging asthma therapies