Coding repeat instability in the FLO11 gene of Saccharomyces yeasts

In Saccharomyces yeasts, the FLO11 gene encodes an adhesin involved in filamentation, invasive growth, flocculation and adherence to solid surfaces. In wild Saccharomyces flor yeasts, a particularly expanded FLO11 allele also confers to these yeasts the ability to float under stressing liquid environments. We report here that, under optimal laboratory conditions, the repeats domain of the FLO11 gene in these wild yeasts is extremely unstable. Changes in length in the FLO11 coding repeats domain affected Flo11p‐associated functions but, interestingly, some of these functions were affected more than others. Therefore, length variations in this single gene provide a combinatorial diversity, which may contribute to a very rapid adaptation to fluctuating environments. Functional analysis of contracted alleles indicated that buoyancy was not associated to FLO11 length. In contrast, this property depended on the different types of repetitive units found in this gene. Thus, not only variations in the number of intragenic repeats but also the abundance and/or distribution of the different repetitive units may have phenotypic and evolutionary implications. Copyright © 2009 John Wiley & Sons, Ltd.     

Apportionment of primary and secondary organic aerosols in southern California during the 2005 study of organic aerosols in riverside (SOAR-1)

Ambient sampling was conducted in Riverside, California during the 2005 Study of Organic Aerosols in Riverside to characterize the composition and sources of organic aerosol using a variety of state-of-the-art instrumentation and source apportionmenttechniques. The secondary organic aerosol (SOA) mass is estimated by elemental carbon and carbon monoxide tracer methods, water soluble organic carbon content, chemical mass balance of organic molecular markers, and positive matrix factorization of high-resolution aerosol mass spectrometer data. Estimates obtained from each ofthese methods indicate that the organic fraction in ambient aerosol is overwhelmingly secondary in nature during a period of several weeks with moderate ozone concentrations and that SOA is the single largest component of PM1 aerosol in Riverside. Average SOA/OA contributions of 70-90% were observed during midday periods, whereas minimum SOA contributions of approximately 45% were observed during peak morning traffic periods. These results are contraryto previous estimates of SOAthroughout the Los Angeles Basin which reported that, other than during severe photochemical smog episodes, SOA was lower than primary OA. Possible reasons for these differences are discussed.     

Sustainable sludge management in developing countries.

Worldwide, unsanitary conditions are responsible for more than three million deaths annually. One of the reasons is the low level of sanitation in developing countries. Particularly, sludge from these regions has a high parasite concentration and low heavy metal content even though the available information is limited. Different issues needed to achieve a sustainable sludge management in developing nations are analysed. Based on this analysis some conclusions arise: sludge management plays an important role in sanitation programs by helping reduce health problems and associated risks; investments in sanitation should consider sludge management within the overall projects; the main restriction for reusing sludge is the high microbial concentration, which requires a science-based decision on the treatment process, while heavy metals are generally low; adequate sludge management needs the commitment of those sectors involved in the development and enforcement of the regulations as well as those that are directly related to its generation, treatment, reuse or disposal; current regulations have followed different approaches, based mainly on local conditions, but they favour sludge reuse to fight problems like soil degradation, reduced crop production, and the increased use of inorganic fertilizers. This paper summarises an overview of these issues.     

Photovoltaic textile structure using polyaniline/carbon nanotube composite materials

In this paper, an investigation of flexible electrodes for photovoltaic textile structures utilizing polymer‐based organic materials is presented. The composite structure consisting of a blend of water dispersible carbon nanotube:polyaniline (CNT:PANI) components with poly(3,4 ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was applied to be used as the hole collecting electrode in photovoltaic textile applications. Both photovoltaic textiles and conventional solar cells were fabricated by using a blend of poly(3‐hexylthiophene‐2,5‐diyl) (P3HT):(6,6)‐phenyl C61‐butyric acid methyl ester (PCBM). All devices were characterized by measuring current versus voltage characteristics under AM 1.5 conditions. The nanoscale morphology of the photovoltaic structures was investigated using scanning electron microscopy and atomic force microscopy.     

Effect of natural extracts on the formation of acrylamide in fried potatoes

The objective of the present work was to evaluate the effect of natural extracts on the formation of acrylamide in fried potatoes. The aqueous extracts used were obtained from wild oregano (Origanum vulgare), thyme (Thymus vulgaris), cinnamon (Cinnamomum verum), bougainvillea (Bougainvillea spp) and green tea (Camellia sinensis), which presented a high percentage of free radical inhibition (DPPH) (48–99%) and content of total phenolic compounds (205–547 μg EAG/μg of d.w.). Potatoes were submerged in the antioxidant extracts at a concentration of 1 g/L for 1 min, before being fried and their acrylamide concentration quantified by GC–MS. The extracts from green tea, cinnamon and oregano reduced the acrylamide level by 62%, 39% and 17%, respectively. The potatoes submerged in cinnamon and bougainvillea extracts showed differences in the color parameters compared to the control potatoes (P < 0.05); however, no significant differences (P > 0.05) were found in the texture and the peroxide values. The sensorial evaluation showed that the acceptance of the potatoes was not affected by the treatment applied. Thus, we can conclude that pre-treating potatoes with antioxidants before frying produces beneficial effects such as a reduction in acrylamide content, without any significant changes in their physicochemical, sensorial and textural properties.     

Complementing retrofit with engagement: exploring energy consumption with social housing tenants

Councils and social housing organisations are looking to retrofit as a way to make their housing more energy efficient. Previous studies on energy use in social housing have generally focussed on the technological aspects (such as the potential savings possible by retrofitting this class of housing across the UK) or have involved one‐off interventions or measures. During a 2‐year period, we worked with previously homeless people to reduce their energy consumption. The 32 participants lived in small blocks of flats (owned by a social housing organisation) that underwent retrofitting with air source heat pumps. We ran a three‐phase tenant engagement programme to compare a range of approaches aimed at energy reduction. It was found that education, social norms and self‐awareness are all key components when it comes to initiating environmentally responsible behaviours. The three approaches complemented each other, and these ought to be considered alongside technology provision if the aim is to reduce energy consumption. A number of reflections on the implementation of medium‐term tenant engagement programmes are also presented. Copyright © 2016 John Wiley & Sons, Ltd.     

Sensitive detection of sulfhydryl groups in surface-confined metallothioneins and related species via ferrocene-capped gold nanoparticle/streptavidin conjugates

Metallothionein (MT), a cysteine-rich metalloprotein that is purported to play an important role in heavy metal accumulation and detoxification, and its related peptidic species were attached onto dithiobissuccinimidyl propionate self-assembled monolayers. The spatially accessible sulfhydryl groups present in these immobilized biomolecules, tagged with N-biotinoyl-N'-[6-maleimidohexanoyl]hydrazide, were detected voltammetrically at a sensitive level via the use of ferrocene (Fc)-capped gold nanoparticle/streptavidin conjugates. The method was established first by examining relatively simple peptides (e.g., glutathione). For the hexapeptidic species that resembles the N-terminus of MT with a sequence of Lys-Cys-Thr-Cys-Cys-Ala, concentration levels as low as 0.050 nM can be determined. Such a remarkable sensitivity is attributed to the presence of a large number of Fc caps present at each gold nanoparticle, which enhances the detection of a small number of surface-bound sulfhydryl groups. Microgravimetric measurements, performed with a quartz crystal microbalance, were used in tandem with voltammetry to quantify the number of tagged sulfhydryl groups. Through extraction of the metals present in MT adsorbate, it is demonstrated that this amplified voltammetric detection is also suitable for the investigation of the variation of the number of sulfhydryl groups present at an electrode and sensitive to the change of surface structure of an immobilized biomolecule. This work represents a new method for the determination of sulfhydryl groups inherent in surface-bound proteins or peptides and can facilitate the study on the environmental issues related to MTs.