Biochemical and physiological studies of certain ticks (Ixodoidea): Isolation and partial identification of a new fatty acid in eggs ofDermacentor andersoni Stiles (Ixodidae)

Gas liquid chromatographic analysis of the fatty acid methyl esters from eggs ofDermacentor andersoni Stiles (Ixodidae) revealed the presence of significant quantities (15% total fatty acids) of an unidentified component with a retention time between C_18∶3−C_22∶0 fatty acids. Smaller amounts of the unidentified component (ca. 5% total fatty acid) also were detected in host rabbit serum. Purified, the unidentified component's methyl ester collected from the tick eggs by preparative gas liquid chromatography was partially identified and characterized by chemical and spectroscopic analyses. The evidence suggests that the unidentified component is a methyl branched C₁₅ tricarboxylic acid containing two vicinal carboxylic acid groups. Biosynthesis of the unidentified component by the tick is under investigation.     

Increased messenger RNA from protein synthesis inhibited human fibroblasts

Numerous reports have demonstrated that specific protein synthesis in response to specific inducers is markedly stimulated by a simultaneous brief exposure to protein synthesis inhibitors such as cycloheximide. This phenomenon is known as "superinduction" and is most often attributed to the accumulation of cytoplasmic messenger RNA during the inhibition period. Messenger RNA, as defined by rapid labeling, oligo (dt)-cellulose binding, and cell free protein synthesis stimulation was measured in cycloheximide treated human fibroblasts. In spite of a consistent 40% decrease in total polysomal 3H-uridine labeled RNA, a 1.5- to 2-fold increase in extractable mRNA was observed. These data provide direct evidence that protein synthesis inhibition stimulates the appearance of cytoplasmic mRNA and/or completely blocks its degradation and, are consistent with the hypothesis that mRNA accumulation partly underlies the superinduction phenomena.     

Signal evaluation of a novel dual-energy multimedia imaging sensor

In this study, experimental results on the signal quality of a multimedia imaging detector, operating on gaseous solid state ionization principles, with specific emphasis on single X-ray exposure dual-energy radiography, are presented. The results of this study indicate that the multimedia detector technology exhibits excellent signal characteristics suitable for a large number of imaging applications.     

World trade agreements and nursing

There are plenty of challenges ahead as countries move to make freer and fairer trade agreements which cover services, such as nursing, as well as goods. But the work to get agreements right will bring its own reward.     

MicroRNA Profiling of B Cell Subsets from Systemic Lupus Erythematosus Patients Reveals Promising Novel Biomarkers

MicroRNAs control the differentiation and function of B cells, which are considered key elements in the pathogenesis of systemic lupus erythematosus (SLE). However, a common micro(mi)RNA signature has not emerged since published data includes patients of variable ethnic background, type of disease, and organ involvement, as well as heterogeneous cell populations. Here, we aimed at identifying a miRNA signature of purified B cells from renal and non-renal severe SLE patients of Latin American background, a population known to express severe disease. Genome-wide miRNA expression analyses were performed on naive and memory B cells and revealed two categories of miRNA signatures. The first signature represents B cell subset-specific miRNAs deregulated in SLE: 11 and six miRNAs discriminating naive and memory B cells of SLE patients from healthy controls (HC), respectively. Whether the miRNA was up or down-regulated in memory B cells as compared with naive B cells in HC, this difference was abolished in SLE patients, and vice versa. The second signature identifies six miRNAs associated with specific pathologic features affecting renal outcome, providing a further understanding for SLE pathogenesis. Overall, the present work provided promising biomarkers in molecular diagnostics for disease severity as well as potential new targets for therapeutic intervention in SLE.     

Wired mobile phones: the case of community technology centers in favelas of Brazil*

ABSTRACT

The growing spread of mobile phones and internet has some practitioners and scholars arguing about the possible irrelevance of community technology centers (CTCs) serving low-income communities. However, although mobile internet is making great strides, it does not yet substitute for public access; in actuality, mobile phones and computers at CTCs complement each other in providing those who face digital inequalities with a broader sociotechnical experience. In order to explore this problem, this paper explores this experience by investigating how favela residents appropriate mobile phones, posing the question, “how do marginalized populations perceive CTCs in the mobile internet era?” To address this question, I draw on a 10-month ethnography in the favelas of Vitória, Brazil which examines slum residents’ uses of information and communication technologies (ICTs) such as computers and smartphones. Through this research, I demonstrate how marginalized people take advantage of smartphones and computers in a complementary way, using these ICTs to best meet their needs as they experience daily life in a relatively severe environment.     

Start-up of anaerobic digestion of source-sorted organic municipal solid waste in the absence of classical inocula

This study investigates the start-up and operation of bench-scale anaerobic digesters treating the source-sorted organic fraction of municipal solid waste in the absence of mesophilic inocula. The experimental program consisted of starting up a digester with two consecutive interventions implemented to approach steady state. While start-up was relatively slow, re-inoculation with cattle manure together with effluent dilution reduced the acclimation period and achieved better stability and effectiveness, accommodating a feeding rate at an OLR = 2.03 kg total volatile solids (TVS) m(-3) day(-1) and an equivalent hydraulic retention time (HRT)=148 days. The latter highlights the long duration that should be taken into consideration in the design and start-up of anaerobic digestion systems for municipal solid waste, in countries where this system is not established, before reaching optimal steady-state conditions.     

Topology optimization of heat and mass transfer problems in two fluids—one solid domains

Abstract

Among various topology optimization methods used in fluid flow problems, density approach has gained more interest compared to other techniques as level set approach, topological derivative technique, and phase field method. The key part of density approach is the penalized interpolation function, which forces progressively porous cells made of fluid and solid simultaneously to belong discretely to fluid or solid sub-domains. However this type of problem was only solved in mono-fluid domains, in which the method accounts for the distribution of a single fluid and a single solid. The actual work aims to extend topology optimization in fluid flow problems to bi-fluid domain. A new interpolation function was developed for this purpose. Furthermore a penalization function was integrated in the multiobjective function, which ensure that each fluid takes its own path in the device, while maintaining a minimal required solid thickness between the channels of different fluids. The results showed the capacity of the proposed method to deal with multiple fluid phases in minimizing the pressure drop while maximizing heat exchange between different flows. The main conclusion is the potential of density approach to be applied on optimization of heat exchangers.