Narrow-linewidth, singlemode erbium-doped fibre laser withintracavity wave mixing in saturable absorber

Narrow-linewidth, single longitudinal mode operation is demonstrated in an erbium-doped fibre laser with an intracavity nonlinear absorptive wave mixing of the counter propagating beams. An unpumped length of erbium-doped fibre serves as the saturable absorber. Linewidths of the order of a few kilohertz are obtained     

Continuous monitoring of EDTA extractable iron from mineral slurries using a microfluidic chip

In mineral processing, iron oxidation species formed on the mineral surface play a dominant role in depressing mineral flotation and must be monitored. Current analytical methods rely on off-line sample preparation followed by conventional analytical techniques, which are labour intensive and time delayed. This paper reports the successful application of an open microfluidic chip for real-time continuous monitoring of ethylenediaminetetraacetic acid (EDTA) extractable iron (derived from iron oxidation species) in mineral slurries. A detailed mineralogical study of the mineral ore before and after leaching by EDTA has been undertaken to understand the leaching behaviour of the EDTA-slurry extraction system, showing good agreement with solution analysis.     

New large-scale production method for C/C-SiC ceramics: Investigating the influence of chopped and nonwoven CF

Carbon fibre reinforced carbon and silicon carbide dual matrix composites are a commercially produced using the liquid silicon infiltration (LSI) process. In comparison to the state of the art LSI process, the first production step—the shaping of the carbon fibre reinforced plastic green body—is realised through thermoset injection moulding. Using this method, the complete process can be automated. Simultaneously, the injection moulding technology allows complex geometries with near net shape in short cycle times of about two to five minutes. Thereby, this large-scale process offers a wide range of shot weights from a few mg up to 100?kg, also in multi-component technology. Also, several manufacturing steps can be omitted. This improves the reproducibility, and working in closed environments improves the employees’ health protection. Further process steps, like pyrolysis and silicon infiltration follow the state of the art. Although, this promising approach significantly shortens the fibres, the defined plastic processing is highly reproducible and generates similar mechanical properties like manual processes, due to the better fibre/matrix interaction in the plastic composite. In addition, continuous fibre preforms can be inserted to fulfil higher requirements.     

Suppression of PGC-1α Drives Metabolic Dysfunction in TGFβ2-Induced EMT of Retinal Pigment Epithelial Cells

PGC-1α, a key orchestrator of mitochondrial metabolism, plays a crucial role in governing the energetically demanding needs of retinal pigment epithelial cells (RPE). We previously showed that silencing PGC-1α induced RPE to undergo an epithelial-mesenchymal-transition (EMT). Here, we show that induction of EMT in RPE using transforming growth factor-beta 2 (TGFβ2) suppressed PGC-1α expression. Correspondingly, TGFβ2 induced defects in mitochondrial network integrity with increased sphericity and fragmentation. TGFβ2 reduced expression of genes regulating mitochondrial dynamics, reduced citrate synthase activity and intracellular ATP content. High-resolution respirometry showed that TGFβ2 reduced mitochondrial OXPHOS levels consistent with reduced expression of NDUFB5. The reduced mitochondrial respiration was associated with a compensatory increase in glycolytic reserve, glucose uptake and gene expression of glycolytic enzymes (PFKFB3, PKM2, LDHA). Treatment with ZLN005, a selective small molecule activator of PGC-1α, blocked TGFβ2-induced upregulation of mesenchymal genes (αSMA, Snai1, CTGF, COL1A1) and TGFβ2-induced migration using the scratch wound assay. Our data show that EMT is accompanied by mitochondrial dysfunction and a metabolic shift towards reduced OXPHOS and increased glycolysis that may be driven by PGC-1α suppression. ZLN005 effectively blocks EMT in RPE and thus serves as a novel therapeutic avenue for treatment of subretinal fibrosis.     

Induced Responses to Herbivory and Jasmonate in Three Milkweed Species

We studied constitutive and induced defensive traits (latex exudation, cardenolides, proteases, and C/N ratio) and resistance to monarch caterpillars (Danaus plexippus) in three closely related milkweed species (Asclepias angustifolia, A. barjoniifolia and A. fascicularis). All traits showed significant induction in at least one of the species. Jasmonate application only partially mimicked the effect of monarch feeding. We found some correspondence between latex and cardenolide content and reduced larval growth. Larvae fed cut leaves of A. angustifolia grew better than larvae fed intact plants. Addition of the cardenolide digitoxin to cut leaves reduced larval growth but ouabain (at the same concentration) had no effect. We, thus, confirm that latex and cardenolides are major defenses in milkweeds, effective against a specialist herbivore. Other traits such as proteases and C/N ratio additionally may be integrated in the defense scheme of those plants. Induction seems to play an important role in plants that have an intermediate level of defense, and we advocate incorporating induction as an additional axis of the plant defense syndrome hypothesis.     

Lipid profile in Venezuelan preschoolers by socioeconomic status

Epidemiological studies have shown that unfavorable serum lipids levels in childhood are predictors of development of atherosclerosis lesions in adulthood. We assessed the lipid profile of 297 Venezuelan preschool children (4-7 years old) from two socioeconomic levels in order to compare them by this characteristic. Their social level was determined according to modified Graffar method, and two groups were obtained: high socioeconomic status (HSES, n=103) and low socioeconomic status (LSES, n=194). Nutritional anthropometric evaluation was performed by weight to height, and NCHS/OMS cut-off point was used. Lipid profile was determined by colorimetric biochemical methods and atherogenic risks factors were calculated. Underweight for HSES was 5.8% and for LSES: 14.9%, while normal status was 78.6% and 70.1%, and overweight was 15.5% and 14.9%, respectively. Mean values for triglycerides were 0.66 +/- 0.27and 0.76 +/- 0.31 mmol/L, total cholesterol (TC): 3.61 +/- 0.65 and 2.98 +/- 0.71 mmol/L, HDL-C: 1.04 +/- 0.18 and 0.62 +/- 0.16 mmol/L, LDL-C: 2.27 +/- 0.61 and 2.01 +/- 0.71 mmol/L, TC/HDL-C: 3.5 +/- 0.78 and 5.0 +/- 1.5; LDL-C/HDL-C: 2.0 +/- 0.71 and 3.4 +/- 1.4 with significant differences between HSES and LSES as shown respectively. A significant association was found (p < 0.01) between lipid values and socioeconomic status, being the LSES preschoolers those with the higher atherogenic risk. Its pattern was of lower HDL-C levels, and higher TC/HDL-C and LDL-C/HDL-C ratio. Comparisons of lipid profile by nutritional status or gender did not show significant differences. Findings indicate that children from low socioeconomic status are at a higher risk for cardiovascular disease and atherosclerosis than children from high socioeconomic status.     

Exposure of infants to fumonisins in maize-based complementary foods in rural Tanzania

Feeding children with maize may expose them to fumonisins (FBs). This study assessed FB exposure for infants consuming maize in Tanzania by modeling maize consumption data (kg/kg body weight (bw)/day) with previously collected total FB contamination (microg/kg) patterns for sorted and unsorted maize harvested in 2005 and 2006. Consumption was estimated by twice conducting a 24 h dietary recall for 254 infants. The exposure assessment was performed with the @RISK analysis software. Of the infants, 89% consumed maize from 2.37 to 158 g/person/day (mean; 43 g/person/day +/- 28). Based on the contamination for sorted maize; in 2005, the percentage of infants with FB exposures above the provisional maximum tolerable daily intake (PMTDI) of 2 microg/kg (bw) (26% (95% confidence interval (CI); 23-30)) was significantly higher than the level of 3% (90% CI; 2-12) in 2006. Pooling the datasets for sorted maize from the two seasons resulted in a seemingly more representative risk (10% (95% CI; 6-17)) of exceeding the PMTDI. However, infants who might have consumed unsorted maize would still be at a significantly higher risk (24% (95% CI; 15-34)) of exceeding the PMTDI. Sorting and other good maize management practices should be advocated to farmers in order to minimize FB exposure in rural areas.     

Applying a Genetic Algorithm-Based Multiobjective Approach for Time-Cost Optimization

Reducing both project cost and time (duration) is critical in a competitive environment. However, a trade-off between project time and cost is required. This in turn requires contracting organizations to carefully evaluate various approaches to attaining an optimal time-cost equilibrium. Although several analytical models have been developed for time-cost optimization (TCO), they mainly focus on projects where the contract duration is fixed. The optimization objective in those cases is therefore restricted to identifying the minimum total cost only. With the increasing popularity of alternative project delivery systems, clients and contractors are targeting the increased benefits and opportunities of seeking an earlier project completion. The multiobjective model for TCO proposed in this paper is powered by techniques using genetic algorithms (GAs). The proposed model integrates the adaptive weights derived from previous generations, and induces a search pressure toward an ideal point. The concept of the GA-based multiobjective TCO model is illustrated through a simple manual simulation, and the results indicate that the model could assist decision-makers in concurrently arriving at an optimal project duration and total cost.     

Lymphocyte subpopulations in preschool Venezuelan children of high socioeconomic status

Nutrition is a critical determinant of immune response being the most common cause of immunodeficiency in the world. 104 preschool children, apparently healthy, from a private school were chosen to determine lymphocyte subpopulations and to evaluate its relationship to the anthropometric nutritional status and serum zinc. Nutritional status was measured by the indicator weight for height, lymphocyte subpopulations by flow cytometry and serum zinc by atomic absorption spectrophotometry A high percentage of the population (87.5%) belonged to socioeconomic level II (Graffar). Nutritional deficit was present in 9.5 percent of the studied children, while 16.2% were overweight. Values for lymphocytes subpopulations and serum zinc were within reference ranges, similar to other reports and there were no significant differences by sex, age or nutritional status. Low concentrations of serum zinc were present in 6.7% of children. There was a tendency to lower values of the T lymphocyte populations in hypozincemic children but it did not reach statistical significance. As there are not reference values for lymphocyte subpopulation in Venezuelan children, these results could be used as reference for future investigations. Continuity of research is needed to understand relationship of micronutrients levels and immune response.