Effect of Farm-Level Constraints, Existing and Prospective Policies on Expansion of Coconut-Based Intercropping in Sri Lanka

Coconut-based intercropping (CBI) in Sri Lanka was introduced some 20 years ago to overcome the two main limitations of traditional coconut monocropping, inefficient land use and low incomes to farmers, but it has not been widely adopted. This study analyses the effect of farm-level resource constraints, and government policies on the intensity of adoption of CBI. A multiperiod linear programming (MLP) model was applied for three farmer groups - resource poor, medium endowed, well endowed - categorised using cluster analysis. Data was collected from a survey of randomly selected 113 intercroppers. Empirical results reveal that expansion of CBI is mainly constrained by seasonal labour shortages for all farmer groups, particularly the well endowed, and by the scarcity of cash in the case of resource-poor farmers. CBI policies aimed at subsidising inputs or intercrop prices are not likely to be efficient in raising adoption, but alternative policies aimed at alleviating resource constraints would be more effective. The study concluded that the low adoption of CBI is mainly attributable to the scarcity of different farm-level resources (other than land), at varying degrees among different farmer groups. Hence a targeted approach to alleviate them is suggested.Crop Production/Industries,

Labour Management for Profit and Welfare in Extensive Sheep Farming

Sheep welfare is an emerging topic in research and food marketing, and recent studies suggest that farm labour is a key factor for both animal welfare and productivity in extensive sheep farming systems, although little research has been done into labour utilisation in these systems. This paper reports field data collection on two commercial farms and the use of a linear programming (LP) model to link labour economics and animal welfare analysis. The model maximises the number of ewes to clooked after over the lambing period, when constrained by labour availability for various key tasks and by a pre-determined level of sheep welfare. The results show a trade-off between welfare level and labour input per sheep. Dropping tasks with less significant welfare and productivity consequences is an effective way of increasing carrying capacity (from 977 ewes/shepherd to 1428), as is working longer hours (1174 ewes/shepherd) or only doing the legal minimum of welfare checking (labour reduced from 0.68 min/ewe to 0.44 min/ewe) . The field data suggest that farmers currently provide high welfare, and that, despite much time spent away from the flock (e.g. driving), they spend a large amount of time (39% of total) with their sheep.Labour, Sheep, Linear Programming, Animal Welfare, Livestock Production/Industries, Q10, Q19, Y1,

Ultra wideband: applications, technology and future perspectives

Ultra Wide Band (UWB) wireless communications offers a radically different approach to wireless communication compared to conventional narrow band systems. Global interest in the technology is huge. This paper reports on the state of the art of UWB wireless technology and highlights key application areas, technological challenges, higher layer protocol issues, spectrum operating zones and future drivers. The majority of the discussion focuses on the state of the art of UWB technology as it is today and in the near future

Amyloid peptide mixtures: self-assembly, hydrogelation, nematic ordering and catalysts in aldol reactions

Morphological, spectroscopic and scattering studies of the self-assembly and aggregation process of mixtures of [RF]4 and P[RF]4 peptides (where: R = arginine; F = phenylalanine; P = proline), in solution and as hydrogels, were performed to obtain information about polymorphism. CD data confirmed a β-sheet secondary structure conformation for the solutions and TEM images revealed nanofibers with diameters of ~ 10 nm and micrometer lengths. SAXS curves were fitted using a mass fractal-component and a long cylinder shell form factor for the liquid samples, and only a long cylinder shell form factor for the gels. Increasing the P[RF]4 content in the systems leads to a reduction in cylinder radius and core density scattering, suggesting an increase in packing of the peptide molecules; however, the opposite effect was observed for the gels. Remarkably, the gels are birefringent, indicating nematic ordering of the gel fibrils. These compounds show potential as catalysts in the asymmetric aldol reactions, with cyclohexanone and p-nitrobenzaldehyde in aqueous media. A moderate conversion (36.9 %) and a good stereoselectivity (69:31) were observed for the system containing only [RF]4, and with the increase of the P[RF]4, a considerable decrease of the conversion was observed, suggesting differences in the self-assembly and packing factor. Rheological measurements were performed to determine the shear moduli for the soft gels. These model amyloid peptides demonstrate a range of tunable self-assembly behaviors and additionally have potential as biocatalysts

First evidence of cryptotephra in palaeoenvironmental records associated with Norse occupation sites in Greenland

The Norse/Viking occupation of Greenland is part of a dispersal of communities across the North Atlantic coincident with the supposed Medieval Warm Period of the late 1st millennium AD. The abandonment of the Greenland settlements has been linked to climatic deterioration in the Little Ice Age as well as other possible explanations. There are significant dating uncertainties over the time of European abandonment of Greenland and the potential influence of climatic deterioration. Dating issues largely revolve around radiocarbon chronologies for Norse settlements and associated mire sequences close to settlement sites. Here we show the potential for moving this situation forward by a combination of palynological, radiocarbon and cryptotephra analyses of environmental records close to three ‘iconic’ Norse sites in the former Eastern Settlement of Greenland – Herjolfsnes, Hvalsey and Garðar (the modern Igaliku). While much work remains to be undertaken, our results show that palynological evidence can provide a useful marker for both the onset and end of Norse occupation in the region, while the radiocarbon chronologies for these sequences remain difficult. Significantly, we here demonstrate the potential for cryptotephra to become a useful tool in resolving the chronology of Norse occupation, when coupled with palynology. For the first time, we show that cryptotephra are present within palaeoenvironmental sequences located within or close to Norse settlement ruin-groups, with tephra horizons detected at all three sites. While shard concentrations were small at Herjolfsnes, concentrations sufficient for geochemical analyses were detected at Igaliku and Hvalsey. WDS-EPMA analyses of these tephra indicate that, unlike the predominantly Icelandic tephra sources reported in the Greenland ice core records, the tephra associated with the Norse sites correlate more closely with volcanic centres in the Aleutians and Cascades. Recent investigations of cryptotephra dispersal from North American centres, along with our new findings, point to the potential for cryptotephra to facilitate hypothesis testing, providing a key chronological tool for refining the timing of Norse activities in Greenland (e.g. abandonment) and of environmental contexts and drivers (e.g. climate forcing)

Self-assembly, nematic phase formation and organocatalytic behaviour of a proline-functionalized lipopeptide

The self-assembly of the amphiphilic lipopeptide PAEPKI-C16 (P = proline, A = alanine, E = glutamic acid, K = lysine, I = isoleucine, C16 = hexadecyl) was investigated using a combination of spectroscopic, microscopic and scattering methods and compared to C16-IKPEAP with the same (reversed) peptide sequence and the alkyl chain positioned N-terminally and which lacks a free N-terminal proline residue. The catalytic activity of these peptides were then compared using a model aldol reaction system. For PAEPKI-C16, Cryo-TEM images showed the formation of micrometer length fibers, which by Small-angle X-ray scattering (SAXS) were found to have a radius of 2.5 - 2.6 nm. Spectroscopic analysis shows these fibers are built from -sheets. This behaviour is in complete contrast to that of C16-IKPEAP which forms spherical micelles with peptides in a disordered conformation [Hutchinson, J. A. et al. J. Phys. Chem. B 2019, 123, 613]. For PAEPKI-C16, the spontaneous alignment of fibers was observed upon increasing pH, which was accompanied by observed birefringence and anisotropy of SAXS patterns. This shows the formation of a nematic liquids and unprecedented nematic hydrogel formation was also observed these lipopeptides at sufficiently high concentrations. SAXS shows retention of an ultrafine (1.7 nm core radius) fibrillar network within the hydrogel. PAEPKI-C16 with free N-terminal proline shows enhanced anti:syn diastereoselectivity and better conversion compared to C16-IKPEAP. The cytotoxicity of PAEPKI-C16 was also lower than C16-IKPEAP for both fibroblast and cancer cell lines. These results highlight the sensitivity of lipopeptide properties to the presence of a free proline residue. The spontaneous nematic phase formation by PAEPKI-C16 points to the highly anisotropy of its ultrafine fibrillar structure and the formation of such a phase at low concentration in aqueous solution may be valuable for future applications

Next-generation sequencing of advanced prostate cancer treated with androgen-deprivation therapy

<b>Background:</b> Androgen-deprivation therapy (ADT) is standard treatment for locally advanced or metastatic prostate cancer (PCa). Many patients develop castration resistance (castration-resistant PCa [CRPC]) after approximately 2–3 yr, with a poor prognosis. The molecular mechanisms underlying CRPC progression are unclear.<p></p> <b>Objective:</b> To undertake quantitative tumour transcriptome profiling prior to and following ADT to identify functionally important androgen-regulated pathways or genes that may be reactivated in CRPC.<p></p> <b>Design, setting, and participants:</b> RNA sequencing (RNA-seq) was performed on tumour-rich, targeted prostatic biopsies from seven patients with locally advanced or metastatic PCa before and approximately 22 wk after ADT initiation. Differentially regulated genes were identified in treatment pairs and further investigated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) on cell lines and immunohistochemistry on a separate CRPC patient cohort. Functional assays were used to determine the effect of pathway modulation on cell phenotypes.<p></p> <b>Outcome measurements and statistical analysis:</b> We searched for gene expression changes affecting key cell signalling pathways that may be targeted as proof of principle in a CRPC in vitro cell line model.<p></p> <b>Results and limitations:</b> We identified ADT-regulated signalling pathways, including the Wnt/β-catenin signalling pathway, and observed overexpression of β-catenin in a subset of CRPC by immunohistochemistry. We validated 6 of 12 (50%) pathway members by qRT-PCR on LNCaP/LNCaP-AI cell RNAs, of which 4 (67%) demonstrated expression changes consistent with RNA-seq data. We show that the tankyrase inhibitor XAV939 (which promotes β-catenin degradation) reduced androgen-independent LNCaP-AI cell line growth compared with androgen-responsive LNCaP cells via an accumulation of cell proportions in the G0/G1 phase and reduction in the S and G2/M phases. Our biopsy protocol did not account for tumour heterogeneity, and pathway inhibition was limited to pharmacologic approaches.<p></p> <b>Conclusions:</b> RNA-seq of paired PCa samples revealed ADT-regulated signalling pathways. Proof-of-principle inhibition of the Wnt/β-catenin signalling pathway specifically delays androgen-independent PCa cell cycle progression and proliferation and warrants further investigation as a potential target for therapy for CRPC.<p></p&gt

Cold- and light-induced changes in the transcriptome of wheat leading to phase transition from vegetative to reproductive growth

<p>Abstract</p> <p>Background</p> <p>For plants to flower at the appropriate time, they must be able to perceive and respond to various internal and external cues. Wheat is generally a long-day plant that will go through phase transition from vegetative to floral growth as days are lengthening in spring and early summer. In addition to this response to day-length, wheat cultivars may be classified as either winter or spring varieties depending on whether they require to be exposed to an extended period of cold in order to become competent to flower. Using a growth regime to mimic the conditions that occur during a typical winter in Britain, and a microarray approach to determine changes in gene expression over time, we have surveyed the genes of the major pathways involved in floral transition. We have paid particular attention to wheat orthologues and functional equivalents of genes involved in the phase transition in <it>Arabidopsis</it>. We also surveyed all the MADS-box genes that could be identified as such on the Affymetrix genechip wheat genome array.</p> <p>Results</p> <p>We observed novel responses of several genes thought to be of major importance in vernalisation-induced phase transition, and identified several MADS-box genes that might play an important role in the onset of flowering. In addition, we saw responses in genes of the Gibberellin pathway that would indicate that this pathway also has some role to play in phase transition.</p> <p>Conclusion</p> <p>Phase transition in wheat is more complex than previously reported, and there is evidence that day-length has an influence on genes that were once thought to respond exclusively to an extended period of cold.</p

Europeanization of sub-arctic environments : perspectives from Norse Greenland's outer fjords

Acknowledgements The authors gratefully acknowledge the financial support of the Leverhulme Trust Footprints on the Edge of Thule Programme Award. ECL acknowledges the support of the Weissman International Internship Program, the Department of Earth and Planetary Sciences and the Department of Anthropology at Harvard. We would also like to thank George McLeod (University of Stirling) for manufacturing soil thin sections.Peer reviewedPostprin

Isolation of polymorphic microsatellites in the stemless thistle (Cirsium acaule) and their utility in other Cirsium species

The genus Cirsium includes species with both widespread and restricted geographical distributions, several of which are serious weeds. Nine polymorphic microsatellite loci were isolated from the stemless thistle Cirsium acaule. Eight were polymorphic in C. acaule, six in C. arvense and seven in C. heterophyllum. One locus monomorphic in C. acaule showed polymorphism in C. heterophyllum. The mean number of alleles per locus was 4.1 in C. acaule, 6.2 in C. arvense and 2.9 in C. heterophyllum. These nine loci were also amplified in C. eriophorum and C. vulgare, suggesting that these markers may be of use throughout the genus