Evaluation of pectin-reinforced supported liquid membranes containing carbonic anhydrase: The role of ionic liquid on enzyme stability and CO2 separation performance

In this paper, pectin-reinforced, supported liquid membranes (SLMs) prepared with carbonic anhydrase (CA) were investigated for CO2/N2 separation. In the first part of the study, the effect of [Bmim][NTf2] ionic liquid (IL) – as possible solvent to fill the pores of cellulose acetate support during SLM fabrication – on enzyme activity was tested. It turned out that this particular IL caused rapid and severe loss of initial biocatalyst activity, which fact can be seen as a threat in the membrane process design. Afterwards, the stability of pectin-containing SLMs (containing CA but lacking the IL having adverse impact) was addressed and their improved resistance against higher transmembrane pressures (up to 7.2 bar) was found, representing an approx. 3-fold enhancement compared to their control. Thereafter, the performance of the membranes was tested under single and mixed gas conditions with carbon dioxide and nitrogen. Employing single gases, it was demonstrated that CA enzyme could notably increase CO2 permeability (from 55 to 93 Barrer), while that of N2 remained unchanged (1.6-1.7 Barrer). Thus, the highest CO2/N2 theoretical selectivity was attained as 54 using the pectin-reinforced SLMs enriched with CA biocatalyst. For comparison, the outcomes were plotted on the Robeson upper-bound

Evidence of Simultaneous Circulation of West Nile and Usutu Viruses in Mosquitoes Sampled in Emilia-Romagna Region (Italy) in 2009

BACKGROUND: In recent years human diseases due to mosquito-borne viruses were increasingly reported in Emilia-Romagna region (Italy), from the chikungunya virus in 2007 to the West Nile virus (WNV) in 2008. An extensive entomological survey was performed in 2009 to establish the presence and distribution of mosquito arboviruses in this region, with particular reference to flaviviruses. METHODOLOGY/PRINCIPAL FINDINGS: From May 6 to October 31, a total of 190,516 mosquitoes were sampled in georeferenced stations, grouped in 1,789 pools according date of collection, location, and species, and analyzed by reverse transcription polymerase chain reaction (RT-PCR) to detect the presence of RNA belong to Flavivirus genus. WNV was detected in 27 mosquito pools, producing sequences similar to those of birds and human strains obtained in 2008 outbreak, pointed out the probable virus overwintering. Isolation of WNV was achieved from one of these pools. Moreover 56 pools of mosquitoes tested positive for Usutu virus (USUV). Most PCR positive pools consisted of Culex pipiens, which also was the most analyzed mosquito species (81.4% of specimens); interestingly, USUV RNA was also found in two Aedes albopictus mosquito pools. Simultaneous circulation of WNV and USUV in the survey area was highlighted by occurrence of 8 mosquito WNV- and USUV-positive pools and by the overlaying of the viruses "hot spots", obtained by kernel density estimation (KDE) analysis. Land use of sampled stations pointed out a higher proportion of WNV-positive Cx. pipiens pool in rural environments respect the provenience of total sampled pool, while the USUV-positive pools were uniformly captured in the different environments. CONCLUSIONS/SIGNIFICANCE: Obtained data highlighting the possible role of Cx. pipiens mosquito as the main vector for WNV and USUV in Northern Italy, and the possible involvement of Ae. albopictus mosquito in USUV cycle. The described mosquito-based surveillance could constitute the foundation for a public health alert system targeting mosquito borne arboviruses

Recombination in West Nile Virus: minimal contribution to genomic diversity

Recombination is known to play a role in the ability of various viruses to acquire sequence diversity. We consequently examined all available West Nile virus (WNV) whole genome sequences both phylogenetically and with a variety of computational recombination detection algorithms. We found that the number of distinct lineages present on a phylogenetic tree reconstruction to be identical to the 6 previously reported. Statistically-significant evidence for recombination was only observed in one whole genome sequence. This recombination event was within the NS5 polymerase coding region. All three viruses contributing to the recombination event were originally isolated in Africa at various times, with the major parent (SPU116_89_B), minor parent (KN3829), and recombinant sequence (AnMg798) belonging to WNV taxonomic lineages 2, 1a, and 2 respectively. This one isolated recombinant genome was out of a total of 154 sequences analyzed. It therefore does not seem likely that recombination contributes in any significant manner to the overall sequence variation within the WNV genome

Adaptation and Mal-Adaptation to Ambient Hypoxia; Andean, Ethiopian and Himalayan Patterns

The study of the biology of evolution has been confined to laboratories and model organisms. However, controlled laboratory conditions are unlikely to model variations in environments that influence selection in wild populations. Thus, the study of “fitness” for survival and the genetics that influence this are best carried out in the field and in matching environments