The excretion of urea by the larvae ofSpodoptera mauritia boisd. (Noctuidae: Lepidoptera) during development

Summary The concentration of urea in the excreta of the 6th instar larvae ofSpodoptera mauritiavaries from 4.017±0.541 to 31.052±1.193 moles/g dry excreta (mean±SE). The observation confirms that urea excreted is of metabolic origin.     

Identification of cells initiating human melanomas

Tumour-initiating cells capable of self-renewal and differentiation, which are responsible for tumour growth, have been identified in human haematological malignancies and solid cancers. If such minority populations are associated with tumour progression in human patients, specific targeting of tumour-initiating cells could be a strategy to eradicate cancers currently resistant to systemic therapy. Here we identify a subpopulation enriched for human malignant-melanoma-initiating cells (MMIC) defined by expression of the chemoresistance mediator ABCB5 (refs 7, 8) and show that specific targeting of this tumorigenic minority population inhibits tumour growth. ABCB5+ tumour cells detected in human melanoma patients show a primitive molecular phenotype and correlate with clinical melanoma progression. In serial human-to-mouse xenotransplantation experiments, ABCB5+ melanoma cells possess greater tumorigenic capacity than ABCB5- bulk populations and re-establish clinical tumour heterogeneity. In vivo genetic lineage tracking demonstrates a specific capacity of ABCB5+ subpopulations for self-renewal and differentiation, because ABCB5+ cancer cells generate both ABCB5+ and ABCB5- progeny, whereas ABCB5- tumour populations give rise, at lower rates, exclusively to ABCB5- cells. In an initial proof-of-principle analysis, designed to test the hypothesis that MMIC are also required for growth of established tumours, systemic administration of a monoclonal antibody directed at ABCB5, shown to be capable of inducing antibody-dependent cell-mediated cytotoxicity in ABCB5+ MMIC, exerted tumour-inhibitory effects. Identification of tumour-initiating cells with enhanced abundance in more advanced disease but susceptibility to specific targeting through a defining chemoresistance determinant has important implications for cancer therapy.     

Mutations in sodium-borate cotransporter SLC4A11 cause recessive congenital hereditary endothelial dystrophy (CHED2)

Congenital hereditary endothelial dystrophy (CHED) is a heritable, bilateral corneal dystrophy characterized by corneal opacification and nystagmus. We describe seven different mutations in the SLC4A11 gene in ten families with autosomal recessive CHED. Mutations in SLC4A11, which encodes a membrane-bound sodium-borate cotransporter, cause loss of function of the protein either by blocking its membrane targeting or nonsense-mediated decay.     

Electroless copper-phosphorus coatings with the addition of silicon carbide (SiC) particles

Cu-P-silicon carbide (SiC) composite coatings were deposited by means of electroless plating. The effects of pH values, temperature, and different concentrations of sodium hypophosphite (NaH₂PO₂·H₂O), nickel sulfate (NiSO₄·6H₂O), sodium citrate (C₆H₅Na₃O₇·2H₂O) and SiC on the deposition rate and coating compositions were evaluated, and the bath formulation for Cu-P-SiC composite coatings was optimised. The coating compositions were determined using energy-dispersive X-ray analysis (EDX). The corresponding optimal operating parameters for depositing Cu-P-SiC are as follows: pH 9; temperature, 90℃; NaH₂PO₂·H₂O concentration, 125 g/L; NiSO₄·6H₂O concentration, 3.125 g/L; SiC concentration, 5 g/L; and C₆H₅Na₃O₇·2H₂O concentration, 50 g/L. The surface morphology of the coatings analysed by scanning electron microscopy (SEM) shows that Cu particles are uniformly distributed. The hardness and wear resistance of Cu-P composite coatings are improved with the addition of SiC particles and increase with the increase of SiC content.     

Martensitic transformation and magnetic properties of aged Ni-Fe-Ga-Ti shape memory alloy

This article reports the effect of ageing on the microstructure, martensitic transformation, magnetic properties, and mechanical properties of Ni₅₁Fe₁₈Ga₂₇Ti₄ shape memory alloy. There are five specimens of this alloy aged at 573 up to 973 K for 3 h per each. This range of ageing temperature greatly affects the microstructure of the alloy. As the ageing temperature increased from 573 up to 973 K, the microstructure of Ni₅₁Fe₁₈Ga₂₇Ti₄ alloy gradually changed from the entirely martensitic matrix at 573 K to the fully austenitic microstructure at 973 K. The volume fraction of precipitated Ni₃Ti particles increased with the ageing temperature increasing from 573 to 773 K. Further increasing the ageing temperature to 973 K decreased the content of Ni₃Ti in the microstructure. The martensitic transformation temperature was decreased steadily by increasing the ageing temperature. The magnetization saturation, remnant magnetization, and coercivity increased with the ageing temperature increasing up to 773 K. A further increase in ageing temperature decreased these magnetic properties. Moreover, the hardness values were gradually increased at first by increasing the ageing temperature to 773 K, and then dramatically decreased to the lowest value at 973 K.     

Elaboration of AlSi10Mg casting alloys using directional solidification processing

The effects of pulling velocity on the solidification behavior and microstructural parameters of AlSi10Mg alloys prepared in a Bridgman-type directional solidification furnace were investigated. The microstructure, particularly the secondary dendritic arm spacing (SDAS), and the Brinell hardness (BH) of the solidified AlSi10Mg alloys were characterized for samples with cylindrical shapes and different conicities (θ=0°, 5°, and 10°). Microstructural studies revealed an increased density of α-Al phase dendrites and a decreased interdendritic distance with increasing pulling velocity. The dendrites were found to be preferentially oriented along the pulling direction for low pulling velocities. For larger pulling velocities, the dendrites grew first in the cooling direction but then broke as others nucleated and coarsened. The HB values of the solidified samples increased as the pulling velocity increased. In regard to sample conicity, smaller dendrites were observed for an apex angle of θ=5°, resulting in the largest HB value. This result was interpreted in terms of the favorable orientation of the dendrite along the pulling direction.     

Relating abundance of purpleback flying squid Sthenoteuthis oualaniensis (Cephalopoda: Ommastrephidae) to environmental parameters using GIS and GAM in south-eastern Arabian Sea

The distribution pattern of purpleback flying squid and the relationship between its abundance and environmental variables in the south-eastern Arabian Sea were analysed using a geographical information system (GIS) and a generalised additive model (GAM). Highest abundances were observed during December and January within 10 and 13°N and 71 and 72°E around the Lakshadweep Islands. The mean abundance in the area was 4.21 tonnes/km² and the maximum sustainable yield (MSY) was estimated as 0.63 million tonnes. GAM indicated that very high squid abundance was associated with low values of dissolved oxygen (6.01–6.27 mg/L), sea surface temperature (28.03–28.62°C), pH (7.75–8.56), salinity (30.42–34.48 psu), chlorophyll-a (0.4–0.6 mg/m³), zooplankton biomass (0.23–0.64 mL/m³), and shallow 20°C isotherm (101.2–134.7 m) and mixed layer depth (17.8–29.8 m). As a carnivore from paralarval stages, S. oualaniensis depends on secondary and tertiary production to sustain its population for which primary production is used up. In the tropical Arabian Sea where temperature differences are not so pronounced, S. oualaniensis distribution was found to be related to a low but very narrow sea surface temperature (SST) band. There is sufficient fishable biomass in the area to possibly launch a new targeted oceanic squid fishery from the western seaboard of India.     

Effect of tropical monsoon on fishery abundance of Indian squid (Uroteuthis (Photololigo) duvaucelii)

Indian squid, Uroteuthis (Photololigo) duvaucelii (Loliginidae) constitute an important component of the inshore cephalopod fisheries along the eastern Arabian Sea. Local environmental variation plays an important role in species–environment interactions in neritic squids, which inhabit nearshore/coastal waters. Such ‘active’ and ‘passive’ responses of squids to environmental changes is crucial in understanding their relationships and influence on the biological processes, distribution and abundance of the fast-growing short-lived coastal loliginids. The empirical relationship between squid abundance and the variability in rainfall and sea surface temperature (SST) were explored in a tropical monsoon fishery. Monthly catch rates (catch per fishing hour) of squids in commercial trawl during 1987–2009 were used as the abundance index. Linear regression models with ARIMA errors were fitted with catch per unit hour time series as dependent variable and rainfall and SST as exogenous variables. While rainfall was observed to have a negative effect on squid abundance, the SST recorded a positive impact. ARIMA models provided satisfactory fit to observed data and forecast of 22 months. Given that the squid life-cycle is a function of their environment, this result is relevant in forecasting squid biomass for the management of tropical monsoon fisheries.     

On the design of a neuro-fuzzy controller — application to the control of a bioreactor

This paper presents a new methodological approach for the synthesis of a neuro-fuzzy controller, using an on-line learning procedure. A simple algebraic formulation of a Sugeno fuzzy inference system that ensures a coherent universe of discourse, making easy its interpretation by a human being, is proposed and implemented in the case of the control of a bioreactor, which is considered as a complex non linear process.