144 research outputs found
Foliar Expression of Candidate Genes Involved in Condensed Tannin Biosynthesis in White Clover (\u3cem\u3eTrifolium Repens\u3c/em\u3e)
Bloat disease in cattle and sheep is caused by the rapid microbial degradation of protein-rich fodder in the rumen. This leads to the production of protein foams that trap gases, causing bloat, a condition that is often fatal to livestock and costly to farmers. Condensed tannins (CTs) are phenolic polymers produced by the phenylpropanoid pathway of plants (Figure 1). CTs bind to proteins under acidic to neutral conditions, such as those present in the rumen, slowing their breakdown. A diet with a CT content of between 2% and 4% by dry weight, which is provided by some pasture legumes (e.g. Lotus corniculatus), protects livestock against bloat and improves the absorption of amino acids from the diet. White clover (Trifolium repens L.), a protein rich legume widely used in temperate regions, has virtually no CTs in leaves, although they are present in flowers
Production and Analysis of Transgenic White Clover (\u3cem\u3eTrifolium Repens\u3c/em\u3e) Plants Over-Expressing Organic Acid Biosynthetic Genes
Aluminium (Al) toxicity is a major environmental limitation for plant production in acid soils, which represent more than one third of the world’s agricultural land. Al-induced secretion in roots of organic acids (OA), such as malate and citrate, chelates the toxic Al cation excluding it from the root. This mechanism of Al-tolerance appears also to be associated with enhanced P-use efficiency. The development of transgenic plants for enhanced synthesis and secretion of OA from roots is a promising approach to confer Al-tolerance and enhanced P-acquisition efficiency. In order to understand the association between OA biosynthesis and secretion from roots in white clover (Trifolium repens L.), the physiological consequences of over-expressing 3 key white clover OA biosynthetic genes, individually and in combination, were assessed in transgenic plants
Geometry-material coordination for passive adaptive solar morphing envelopes
The cost-intensive and mechanical complexity natures of the adaptive facades of the past decades drifted designers and researchers’ interest towards passive material-based actuation systems. Architectural applications using the latter showed, however, a few limitations restricting the output possibility space to options that rely entirely on one material’s phase characteristic. This study aims to investigate the potential of expanding a shape memory alloy-actuated facade’s output from one that is limited and hardly controllable in the case of entirely passive actuation to one that can produce a specific desired performative target. This is explored through coordinating between geometry movement connections of an adaptive component of four integrated shape memory alloys, which work on tailoring the geometry-material-climate relations of the responsive system. The research findings suggest that the integration of geometry, material, and their connections in the design of a SMA solar morphing envelope lead to the development of a wider range of behavioural system outputs. The variety instilled through these added dimensions promoted diversity and adaptability of output for a flexible range of responses and higher performative gains
Recommended from our members
Understanding the influence of processing conditions on the extraction of rhamnogalacturonan-I “hairy” pectin from sugar beet pulp
Sugar beet pectin is rich in rhamnogalacturonan-I (RG-I) region, which is a potential source of prebiotics. RG-I
pectin cannot be extracted the same way as commercial homogalacturan-rich pectin using hot acid. Therefore,
this study has explored several alternative methods, including microwave-assisted extraction (MAE) and conventional-
solvent extraction (CSE) at atmospheric pressure using different solvents, and microwave-assisted
hydrothermal extraction (MAHE) under pressure using water. No conclusive differences in microwave and
conventional heating were found with heating rate controlled. The optimum treatment times of both MAE and
CSE at 90 °C atmospheric pressure and regardless of the solvents used were 120 min; however, MAHE at 130 °C
under pressure can dramatically reduce the time to 10 min. Alcohol-insoluble solids (AIS) extracted using pH13
solvent by MAE had both the highest RG-I yield at 25.3% and purity at 260.2 mg/g AIS, followed by AIS extracts
using water by MAHE with 7.5% and 166.7 mg/g AIS respectively
Placing the Fijian Honeyeaters within the meliphagid radiation: implications for origins and conservation
Understanding the evolutionary relationships of threatened species provides an important framework for
making decisions about their conservation. However, unrecognised problems with the underlying phylogenetic analyses
may bias the decision-making process. Recent phylogenetic studies have improved our understanding of Meliphagidae,
but also indicate discordance between molecular datasets. Here, we examine the causes of this discordance using
maximum likelihood tree-building and network analyses of identically sampled datasets for four genetic loci. Our results
suggest that while we can be reasonably confident of relationships within species groups, discordance within and between
molecular datasets tends to obscure relationships towards the base of the meliphagid tree. This ongoing uncertainty likely
reflects differences in the sampling of markers and taxa between previously published analyses. To avoid the problems of
conflicting data we used divergence time analyses of only the most densely sampled marker, NADH-ubiquinone
oxidoreductase chain 2, to investigate the age and origins of the Fijian Meliphagidae. Our analyses suggest two temporally
distinct colonisations of the Fijian archipelago. The large-bodied honeyeaters arrived ,15.6 million years ago,
subsequently diversifying and spreading to Tonga and Samoa. In contrast, Myzomela appears to have arrived within
the last 5.0 million years. The phylogenetic results therefore imply that conserving the evolutionary diversity of
Meliphagidae in Polynesia requires that effort be spread across both the currently recognised taxa and geographical range
Barriers and facilitators to implementing community outreach work, and inter-professional collaboration with regional partners
Abstract : Objective. Community outreach workers support individuals in accessing the health and community services they require through various forms of proximity approaches. Even though community outreach has been available in the province of Quebec (Canada) for the past 40 years, it is still difficult to implement and sustain, especially with families of young children. The aim of this study was to document barriers and facilitators to implementing community outreach practices, and to describe how such workers collaborate with sectoral (e.g. health care) and inter-sectoral (e.g. municipalities, community organizations, schools) partners. Methodology. We performed a content analysis on 55 scientific and grey literature documents, and transcriptions of 24 individual interviews and 3 focus groups with stakeholders including parents, community outreach workers, health care employees, and inter-sectoral partners. Results. This study reveals four categories of barriers and facilitators to the implementation of community outreach work (i.e. organizational factors, nature of the work and worker-related factors, family-related factors, external factors). With regards to collaboration, community outreach workers deal with various partners. Good inter-professional collaboration is achieved through positive interactions and communication, shared or co-developed activities for the families, co-intervention with families, and strategies to enhance role awareness and inter-sectoral meetings. Conclusion. Results highlighted that many factors interact and can either influence, positively or negatively, the opportunity to implement community outreach work. The collaborative practices identified may help to maximize facilitators and overcome barriers. Advocacy and a better understanding of how to integrate community outreach work within health services while maintaining the workers’ flexibility are needed to sustain this practice
The existence and break-up of the Antarctic land bridge as indicated by both amphi-Pacific distributions and tectonics
Amphi-Pacific disjunct distributions between South America and Australasia are correlated with the breakup and changing palaeo-climate of Gondwana. For a long period, with a temperate climate, Antarctica formed a land bridge between Australia and South America, allowing species to disperse/vicariate between both continents. Dated phylogenies in the literature, showing sister-clades with a distribution disjunction between South America and Australia, were used for the correlation. The initiation of the Antarctic Circumpolar Current, and a change to a colder Antarctic climate is associated with the opening of the Drake Passage between South America and Antarctica at c. 30 Ma, and the final separation of Australia and Antarctica along the South Tasman Rise at c. 45 Ma. The distribution data highlighted the existence of a southern disjunct distribution pattern, which may be the result of continental vicariance/dispersal. This is strongly indicative of a connection between Antarctica, South America and Australia; which later provided a dispersal pathway and facilitated vicariance after break up. The taxa that likely dispersed/vicariated via Antarctica included all species with a more (sub)tropical climate preference. Twelve distributions, younger than 30 Ma, are interpreted as the result of long distance dispersal between South America and Australia; these taxa are suited to a temperate climate. The climatic signal shown by all taxa is possibly a consequence of the Australian plate\u27s asynchronous rifting over tens of millions of years in combination with climate changes. These events may have provided opportunities for tropical and sub-tropical species to disperse and speciate earlier than what we observe for the more temperate taxa
Molecular identification of zoonotic and livestock-specific Giardia-species in faecal samples of calves in Southern Germany
Impact of wildfire on interdune ecology and sediments: An example from the Simpson Desert, Australia
The stability of many sand dunes and their interdunes is dependent on vegetation and surface crust cover. When this cover is removed, the sand can be activated and fine sediments deflated making the dunefields into sources of dust. This paper reports the impact of devegetation by wildfire on an interdune in the Simpson Desert, Australia. The fire occurred in 2001 and six years after the event pronounced differences between a pair of burnt and unburnt sites was clearly discernible. The variables examined included vegetation assemblage, cyanobacteria abundance and sediment aggregation, particle-size distribution and colour; but whether they apply to all such situations is uncertain. Rate of recovery has been slow and the differences are likely to have been sustained by a combination of negative feedback processes and climate
Multilocus Genotyping of Human Giardia Isolates Suggests Limited Zoonotic Transmission and Association between Assemblage B and Flatulence in Children
Giardia intestinalis is a protozoan parasite found world-wide and it is a major cause of diarrhea in humans and other mammals. The genetic variability within G. intestinalis is high with eight distinct genotypes or assemblages (A-H). Here we performed sequence-based multilocus genotyping of around 200 human Giardia isolates. We found evidence of limited zoonotic transmission of certain A subtypes and an association between flatulence and assemblage B infection in children. This shows that it is important to investigate different assemblages and sub-assemblages of G. intestinalis in human infections in order to understand the clinical significance, zoonotic potential, sequence divergence, and transmission pathways of this parasite
- …