Cross-strand disulfides in the non-hydrogen bonding site of antiparallel β-sheet (aCSDns): poised for biological switching

Forbidden disulfides are stressed disulfides found in recognisable protein contexts previously defined as structurally forbidden. The torsional strain of forbidden disulfides is typically higher than for structural disulfides, but not so high as to render them immediately susceptible to reduction under physionormal conditions. The meta-stability of forbidden disulfides makes them likely candidates as redox switches. Here we mined the Protein Data Bank for examples of the most common forbidden disulfide, the aCSDn. This is a canonical motif in which disulfide-bonded cysteine residues are positioned directly opposite each other on adjacent anti-parallel β-strands such that the backbone hydrogen bonded moieties are directed away from each other. We grouped these aCSDns into homologous clusters and performed an extensive physicochemical and informatic analysis of the examples found. We estimated their torsional energies using quantum chemical calculations and studied differences between the preferred conformations of the computational model and disulfides found in solved protein structures to understand the interaction between the forces imposed by the disulfide linkage and typical constraints of the surrounding β-sheet. In particular, we assessed the twisting, shearing and buckling of aCSDn-containing β-sheets, as well as the structural and energetic relaxation when hydrogen bonds in the motif are broken. We show the strong preference of aCSDns for the right-handed staple conformation likely arises from its compatibility with the twist, shear and Cα separation of canonical β-sheet. The disulfide can be accommodated with minimal distortion of the sheet, with almost all the strain present as torsional strain within the disulfide itself. For each aCSDn cluster, we summarise the structural and strain data, taxonomic conservation and any evidence of redox activity. aCSDns are known substrates of thioredoxin-like enzymes. This, together with their meta-stability, means they are ideally suited to biological switching roles and are likely to play important roles in the molecular pathways of oxidative stress.

Towards the knittability of graphene oxide fibres

Recent developments in graphene oxide fibre (GO) processing include exciting demonstrations of hand woven textile structures. However, it is uncertain whether the fibres produced can meet the processing requirements of conventional textile manufacturing. This work reports for the first time the production of highly flexible and tough GO fibres that can be knitted using textile machinery. The GO fibres are made by using a dry-jet wet-spinning method, which allows drawing of the spinning solution (the GO dispersion) in several stages of the fibre spinning process. The coagulation composition and spinning conditions are evaluated in detail, which led to the production of densely packed fibres with near-circular cross-sections and highly ordered GO domains. The results are knittable GO fibres with Young's modulus of ~7.9 GPa, tensile strength of ~135.8 MPa, breaking strain of ~5.9%, and toughness of ~5.7 MJ m(-3). The combination of suitable spinning method, coagulation composition, and spinning conditions led to GO fibres with remarkable toughness; the key factor in their successful knitting. This work highlights important progress in realising the full potential of GO fibres as a new class of textile.

Moisture transfer properties of bifacial fabrics

Many biological plants have bifacial leaves with an adaxial surface and an abaxial surface. These two surfaces can often have different morphologies and properties, and they serve different functions in plant growth. This has inspired us to develop novel bifacial fabrics, with a knitted structure on one face and a woven structure on the other. Bifacial fabrics were produced on a purpose-built machine, using wool, acrylic and polyester yarns, with the woven structure being plain weave, and the knitted structure being single jersey. In this study, the moisture properties of these fabrics were compared with conventional woven and knitted fabrics. The water contact angles of the bifacial fabrics were similar to knitted and woven fabrics, but the absorption time on the woven fabric was much higher than the other fabrics. Liquid moisture transfer properties on both faces of the bifacial fabrics were different, with water spreading and absorption on the woven face being quicker than on the knitted face. These unique properties of bifacial fabrics show that these fabrics could be used as moisture management fabrics, without the need for any additional treatments.

Fabric and greasy wool handle, their importance to the Australian wool industry: a review

Handle-related properties of woollen fabrics have been demonstrated to be major factors affecting consumer buying attitudes. Handle is the combination of both textural and compressional attributes. Compressional handle has demonstrated processing advantages in woven and knitted fabrics. The handle of processing lots can be manipulated using a variety of technologies but direct manipulation of textural greasy wool handle pre-processing is still crude. On-farm, there is documented evidence that including handle assessment in a selection index provides additional improvements in genetic gain. However, the assessment of greasy wool handle is based on a tactile evaluation of the wool staple by sheep and wool classers, and its application is affected by a lack of framework that instructs assessors on a standard method of assessment. Once a reliable and repeatable protocol is developed, further understanding of the effect greasy wool handle has on final garment quality will be possible.

UV interactions with fibres and fibrous structures

 In this research, the effects of fibre, yarn and fabric parameters on the UV protective properties were studied, and the results were interpreted by various developed models. An optimised knitted fabric for a lightweight spring/summer application with high UV protection and good thermal comfort was proposed from this systematic investigation.

Flax yarn polymer matrix composites: effects of yarn structure and prestressing

 This research focuses on the improvement of mechanical properties of plant fibre based bio-composites using different yarns structures and prestressing technique. Different types of yarns were used to study the effect of structural parameters and prestressing on different properties of the resulting bio-composites.

Assessing the impact of agricultural drought on maize prices in Kenya with the approach of the SPOT-VEGETATION NDVI remote sensing

The high cost of maize in Kenya is basically driven by East African regional commodity demand forces and agricultural drought. The production of maize, which is a common staple food in Kenya, is greatly affected by agricultural drought. However, calculations of drought risk and impact on maize production in Kenya is limited by the scarcity of reliable rainfall data. The objective of this study was to apply a novel hyperspectral remote sensing method to modelling temporal fluctuations of maize production and prices in five markets in Kenya. SPOT-VEGETATION NDVI time series were corrected for seasonal effects by computing the standardized NDVI anomalies. The maize residual price time series was further related to the NDVI seasonal anomalies using a multiple linear regression modelling approach. The result shows a moderately strong positive relationship (0.67) between residual price series and global maize prices. Maize prices were high during drought periods (i.e. negative NDVI anomalies) and low during wet seasons (i.e. positive NDVI anomalies). This study concludes that NDVI is a good index for monitoring the evolution of maize prices and food security emergency planning in Kenya. To obtain a very strong correlation for the relationship between the wholesale maize price and the global maize price, future research could consider adding other price-driving factors into the regression models.

Exportaciones de petróleo de Colombia en relación con cantidades y precios internacionales: 1994-2014

La economía Colombiana, históricamente primarizada, ha dependido fundamentalmente de materias primas provenientes de productos agropecuarios y de la industria extractiva como productos petroleros, oro y carbón. Y siendo el petróleo crudo uno de los productos que junto con su categoría han pasado a representar el 40% del total de las exportaciones totales (DANE, 2016) y el 74% del total de las regalías que recibe el país (DNP, 2016), el desempeño de este producto impacta la economía colombiana de manera colosal. Este estudio brinda un análisis matemático de las variables que afectan la exportación de petróleo crudo en Colombia, seguido de un desafío de los resultados con diferentes postulados teóricos relacionados al crecimiento de economías a través de las exportaciones, así como variables endógenas y exógenas que las impactan. La metodología usada en esta investigación se basó en la recolección de datos en temas de producción, exportación e ingresos nacionales de petróleo crudo, ingresos nacionales por exportaciones totales, y los precios internacionales del petróleo. Al contrastarse entre sí, los resultados demuestran la correlación altamente positiva que la exportación del petróleo crudo tiene con la producción nacional y prueban la marcada concentración e importancia de la exportación de petróleo crudo en las ventas externas colombianas y sus efectos en la economía nacional, según lo acontecido en el periodo de 1994 a 2014.

Mobilizing Greater Crop and Land Potentials Sustainably

The supply side of the food security engine is the way we farm. The current engine of conventional tillage farming is faltering and needs to be replaced. This presentation will address supply side issues of agriculture to meet future agricultural demands for food and industry using the alternate no-till Conservation Agriculture (CA) paradigm (involving no-till farming with mulch soil cover and diversified cropping) that is able to raise productivity sustainably and efficiently, reduce inputs, regenerate degraded land, minimise soil erosion, and harness the flow of ecosystem services. CA is an ecosystems approach to farming capable of enhancing not only the economic and environmental performance of crop production and land management, but also promotes a mindset change for producing ‘more from less’, the key attitude towards sustainable production intensification. CA is now spreading globally in all continents at an annual rate of 10 Mha and covers some 157 Mha of cropland. Today global agriculture produces enough food to feed three times the current population of 7.21 billion. In 1976, when the world population was 4.15 billion, world food production far exceeded the amount necessary to feed that population. However, our urban and industrialised lifestyle leads to wastage of food of some 30%-40%, as well as waste of enormous amount of energy and protein while transforming crop-based food into animal-derived food; we have a higher proportion of people than ever before who are obese; we continue to degrade our ecosystems including much of our agricultural land of which some 400 Mha is reported to be abandoned due to severe soil and land degradation; and yields of staple cereals appear to have stagnated. These are signs of unsustainability at the structural level in the society, and it is at the structural level, for both supply side and demand side, that we need transformed mind sets about production, consumption and distribution. CA not only provides the possibility of increased crop yields for the low input smallholder farmer, it also provides a pro-poor rural and agricultural development model to support agricultural intensification in an affordable manner. For the high output farmer, it offers greater efficiency (productivity) and profit, resilience and stewardship. For farming anywhere, it addresses the root causes of agricultural land degradation, sub-optimal ecological crop and land potentials or yield ceilings, and poor crop phenotypic expressions or yield gaps. As national economies expand and diversify, more people become integrated into the economy and are able to access food. However, for those whose livelihoods continue to depend on agriculture to feed themselves and the rest of the world population, the challenge is for agriculture to produce the needed food and raw material for industry with minimum harm to the environment and the society, and to produce it with maximum efficiency and resilience against abiotic and biotic stresses, including those arising from climate change. There is growing empirical and scientific evidence worldwide that the future global supplies of food and agricultural raw materials can be assured sustainably at much lower environmental and economic cost by shifting away from conventional tillage-based food and agriculture systems to no-till CA-based food and agriculture systems. To achieve this goal will require effective national and global policy and institutional support (including research and education).

Creative Practices Around the Production of Cork

Cork, as a natural product provided by the bark of the cork oak tree, is an important staple of the Portuguese economy and important to Portuguese culture. It is a sustainable product with a positive ecological footprint, from harvesting to industrial production, with the advantage of creating a local economic model through regional labour activity and distribution. Within the balance between nature-human-economy to create a sustainable system, cork production in Portugal represents a human and social dimension. By focusing on that dimension and by creating an awareness of the cultural and social impact of the activity and by re-appraising the meaning of the material within the culture, the study reframes a consideration of the actual place of labour and production. The human, geophysical, historical, social, economic, ecological and cultural aspects of the place are observed as regards their relation to work or labour in that physical space. A pilot study is being developed in the village of Azaruja in the district of Évora, Portugal. In this small locality, cork is very important in terms of the relationships between the physical subsistence of their residents and the local natural resources, because it structures the place in its cultural, social and economical dimensions. This paper outlines the theoretical foundations, the process and the outcomes of the participatory ecodesign project titled Creative Practices Around the Production of Cork which was initiated by a Portuguese artist/design researcher and developed further through the collaboration with the other two authors, one a Portuguese visual artist/researcher and the other a Turkish fashion designer/theorist. The investigation focuses on questions that expand the notion of place for artists and designers, filtered through the lenses of manual labourers in order to understand their physical, social, cultural and economic relationship with the environment. To create the process of interaction with the place and the people, a creative collaborative dynamic is developed between the authors with their range of artistic sensibilities and the local population. To adopt a holistic notion of sustainability and cultural identity a process of investigation is designated to: (1) analyse, test and interpret - through the dissemination of life stories, visual representation of the place and the creation of cork objects - the importance of culture related to the labour activity of a local natural resource that determines and structures the region; (2) to give public recognition to those involved, taking into account their sense of belonging to the place and in order to show the value of their sustainable labour activities related to local natural resources; (3) to contribute to the knowledge of the place and to its dynamism through an aesthetic approach to labour activities. With reference to fields of knowledge such as anthropology, the social arts and sustainable design, a practice-based research is conducted with collaborative and participatory design methods to create an open model of interaction which involves local people in the realization of the project. Outcomes of this research will be presented in the paper as a survey analysis with theoretical conclusions.

Natural variation in expression of genes associated with carotenoid biosynthesis and accumulation in cassava (Manihot esculenta Crantz) storage root.

ABSTRACT: BACKGROUND: Cassava (Manihot esculenta Crantz) storage root provides a staple food source for millions of people worldwide. Increasing the carotenoid content in storage root of cassava could provide improved nutritional and health benefits. Because carotenoid accumulation has been associated with storage root color, this study characterized carotenoid profiles, and abundance of key transcripts associated with carotenoid biosynthesis, from 23 landraces of cassava storage root ranging in color from white-to-yellow-to-pink. This study provides important information to plant breeding programs aimed at improving cassava storage root nutritional quality. RESULTS: Among the 23 landraces, five carotenoid types were detected in storage root with white color, while carotenoid types ranged from 1 to 21 in storage root with pink and yellow color. The majority of storage root in these landraces ranged in color from pale-to-intense yellow. In this color group, total ß-carotene, containing all-E-, 9-Z-, and 13-Z-ß-carotene isomers, was the major carotenoid type detected, varying from 26.13 to 76.72 %. Although no ?-carotene was observed, variable amounts of a ?-ring derived xanthophyll, lutein, was detected; with greater accumulation of ?-ring xanthophylls than of ß-ring xanthophyll. Lycopene was detected in a landrace (Cas51) with pink color storage root, but it was not detected in storage root with yellow color. Based on microarray and qRT-PCR analyses, abundance of transcripts coding for enzymes involved in carotenoid biosynthesis were consistent with carotenoid composition determined by contrasting HPLC-Diode Array profiles from storage root of landraces IAC12, Cas64, and Cas51. Abundance of transcripts encoding for proteins regulating plastid division were also consistent with the observed differences in total ß-carotene accumulation. CONCLUSIONS: Among the 23 cassava landraces with varying storage root color and diverse carotenoid types and profiles, landrace Cas51 (pink color storage root) had low LYCb transcript abundance, whereas landrace Cas64 (intense yellow storage root) had decreased HYb transcript abundance. These results may explain the increased amounts of lycopene and total ß-carotene observed in landraces Cas51 and Cas64, respectively. Overall, total carotenoid content in cassava storage root of color class representatives were associated with spatial patterns of secondary growth, color, and abundance of transcripts linked to plastid division. Finally, a partial carotenoid biosynthesis pathway is proposed.

Migraciones e inserción ocupacional de los cafetaleros en Honduras

ResumenEn este trabajo los autores explicitan en primer lugar la relación histórica entre expansión ganadera. Migración campesina y desarrollo cafetalero en el interior de Honduras, para luego proponer una caracterización de las inserciones ocupacionales de los caficultores. Exploran especialmente sus distintas participaciones en la producción de granos básicos, las combinaciones de actividades principales y secundarias así como sus variaciones durante el año y las categorías ocupacionales o relaciones de trabajo en la caficultura.AbstractThe authors first explain the historical connections among expansion of livestock raising, peasant migrations and development of coffee production in Honduras. Subsequently, they suggest characteristics of the occupational status of coffee farmers. They also explore the participation in the production of staple grain, their combination of activities during the years, as well as occupational categories or labor relations in coffee production.