1,258 research outputs found

    Performance of climber common bean (Phaseolus vulgaris L.) lines under Researcher Designed Farmer Managed (RDFM) system in three bean agro-ecological zones of Malawi

    Get PDF
    An on-farm study was carried out in 2003-2004 and 2004-2005 growing seasons under rain-fed condition in five sites namely Thondwe and Matapwata in Zomba and Thyolo districts respectively, Chipuka inNtchisi district, Ntchenachena and Ngong’a in Rumphi district representing three bean agro-ecological zones of Malawi. Seven climber common bean entries; CAB 19, RWV 1046, BCMV B4, AND 659, RWV1042-2-3, 5P/5 and DC 86-244 were evaluated for their performance and stability across sites and two seasons under Researcher Designed Farmer Managed (RDFM) system. Entries DC 86-244, AND 659 andBCMV B4 were early maturing in most sites of the trial. DC 86 244 and AND 659 were also high yielding and had larger seed sizes compared to other entries. RWV 1046 and RVW 1042-2-3 were also highyielding though had smaller seed sizes. Stability analysis identified entries CAB 19 and DC 86 244 as stable entries across sites and seasons. Among environments, Ng’onga, Chipuka and Thondwe werehigh yielding. Ntchenachena was more stable but lower yielding compared to other sites. Matapwata was highly unreliable as heavy rains followed by dry spells characterised the site which resulted in lossof all bean entries in 2004-2005 growing season

    Yield performance of dwarf bean (Phaseolus vulgaris L.) lines under Researcher Designed Farmer Managed (RDFM) system in three bean agro-ecological zones of Malawi

    Get PDF
    An on-farm study was carried out under rain-fed condition in 2003 - 2004 and 2004 - 2005 growing seasons in five sites namely Ntchenachena and Ngong’a in Rumphi district, Chipuka in Ntchisi district, Thondwe and Matapwata in Zomba and Thyolo districts respectively representing three bean agroecological zones of Malawi. Seven dwarf bean entries; DC 96-95, PC 490-D8, BCMV-B2, SDDT-54-C5, APN 130, F6BC (19) and DOR 715 were evaluated for their yield stability across sites and two seasons under Researcher Designed Farmer Managed (RDFM) system. Yield stability of the entries across years varied significantly. Entries SDDT-54-C5, PC490-D8 and DOR 715 were stable across all sites and between the two seasons. DOR 715 was also high yielding entry in Thondwe and Ntchenachena sites followed by BCMV B2 though the latter was unstable. Among sites, Thondwe was the best because yields of most of the bean entries were stable at this site

    Double quick, double click reversible peptide “stapling”

    Get PDF
    The development of constrained peptides for inhibition of protein–protein interactions is an emerging strategy in chemical biology and drug discovery. This manuscript introduces a versatile, rapid and reversible approach to constrain peptides in a bioactive helical conformation using BID and RNase S peptides as models. Dibromomaleimide is used to constrain BID and RNase S peptide sequence variants bearing cysteine (Cys) or homocysteine (hCys) amino acids spaced at i and i + 4 positions by double substitution. The constraint can be readily removed by displacement of the maleimide using excess thiol. This new constraining methodology results in enhanced α-helical conformation (BID and RNase S peptide) as demonstrated by circular dichroism and molecular dynamics simulations, resistance to proteolysis (BID) as demonstrated by trypsin proteolysis experiments and retained or enhanced potency of inhibition for Bcl-2 family protein–protein interactions (BID), or greater capability to restore the hydrolytic activity of the RNAse S protein (RNase S peptide). Finally, use of a dibromomaleimide functionalized with an alkyne permits further divergent functionalization through alkyne–azide cycloaddition chemistry on the constrained peptide with fluorescein, oligoethylene glycol or biotin groups to facilitate biophysical and cellular analyses. Hence this methodology may extend the scope and accessibility of peptide stapling

    A Framework for Formal Modeling and Analysis of Organizations

    Get PDF
    A new, formal, role-based, framework for modeling and analyzing both real world and artificial organizations is introduced. It exploits static and dynamic properties of the organizational model and includes the (frequently ignored) environment. The transition is described from a generic framework of an organization to its deployed model and to the actual agent allocation. For verification and validation of the proposed model, a set of dedicated techniques is introduced. Moreover, where most computational models can handle only two or three layered organizational structures, our framework can handle any arbitrary number of organizational layers. Henceforth, real-world organizations can be modeled and analyzed, as illustrated by a case study, within the DEAL project line. © Springer Science+Business Media, LLC 2007

    Why business angels reject investment opportunities: Is it personal?

    Get PDF
    A major focus of research on business angels has examined their decision-making processes and investment criteria. As business angels reject most of the opportunities that they receive, this article explores the reasons informing such decisions. In view of angel heterogeneity, investment opportunities might be expected to be rejected for differing reasons. Two sources of data are used to examine this issue. Face-to-face interviews with 30 business angels in Scotland and Northern Ireland provided information on typical ‘deal killers’. This was complemented by an Internet survey of United Kingdom that attracted responses from 238 UK business angels. The findings confirm that the main reason for rejection relates to the entrepreneur/management team. However, angel characteristics do not explain the number of reasons given for opportunity rejection nor do they predict the reasons for rejecting investment opportunities. This could be related to the increasing trend for business angels to join organised groups which, in turn, leads to the development of a shared repertoire of investment approaches. We suggest the concept of ‘communities-of-practice’ as an explanation for this finding

    30 days wild: development and evaluation of a large-scale nature engagement campaign to improve well-being

    Get PDF
    There is a need to increase people’s engagement with and connection to nature, both for human well-being and the conservation of nature itself. In order to suggest ways for people to engage with nature and create a wider social context to normalise nature engagement, The Wildlife Trusts developed a mass engagement campaign, 30 Days Wild. The campaign asked people to engage with nature every day for a month. 12,400 people signed up for 30 Days Wild via an online sign-up with an estimated 18,500 taking part overall, resulting in an estimated 300,000 engagements with nature by participants. Samples of those taking part were found to have sustained increases in happiness, health, connection to nature and pro-nature behaviours. With the improvement in health being predicted by the improvement in happiness, this relationship was mediated by the change in connection to nature

    Making mathematics and science integration happen: key aspects of practice

    Get PDF
    The integration of mathematics and science teaching and learning facilitates student learning, engagement, motivation, problem-solving, criticality and real-life application. However, the actual implementation of an integrative approach to the teaching and learning of both subjects at classroom level, with in-service teachers working collaboratively, at second-level education, is under-researched due to the complexities of school-based research. This study reports on a year-long case study on the implementation of an integrated unit of learning on distance, speed and time, within three second-level schools in Ireland. This study employed a qualitative approach and examined the key aspects of practice that impact on the integration of mathematics and science teaching and learning. We argue that teacher perspective, teacher knowledge of the ‘other subject’ and of technological pedagogical content knowledge (TPACK), and teacher collaboration and support all impact on the implementation of an integrative approach to mathematics and science education

    Optically trapped bacteria pairs reveal discrete motile response to control aggregation upon cell–cell approach

    Get PDF
    Aggregation of bacteria plays a key role in the formation of many biofilms. The critical first step is cell–cell approach, and yet the ability of bacteria to control the likelihood of aggregation during this primary phase is unknown. Here, we use optical tweezers to measure the force between isolated Bacillus subtilis cells during approach. As we move the bacteria towards each other, cell motility (bacterial swimming) initiates the generation of repulsive forces at bacterial separations of ~3 μm. Moreover, the motile response displays spatial sensitivity with greater cell–cell repulsion evident as inter-bacterial distances decrease. To examine the environmental influence on the inter-bacterial forces, we perform the experiment with bacteria suspended in Tryptic Soy Broth, NaCl solution and deionised water. Our experiments demonstrate that repulsive forces are strongest in systems that inhibit biofilm formation (Tryptic Soy Broth), while attractive forces are weak and rare, even in systems where biofilms develop (NaCl solution). These results reveal that bacteria are able to control the likelihood of aggregation during the approach phase through a discretely modulated motile response. Clearly, the force-generating motility we observe during approach promotes biofilm prevention, rather than biofilm formation

    A QM/MM approach for the study of monolayer-protected gold clusters

    Full text link
    We report the development and implementation of hybrid methods that combine quantum mechanics (QM) with molecular mechanics (MM) to theoretically characterize thiolated gold clusters. We use, as training systems, structures such as Au25(SCH2-R)18 and Au38(SCH2-R)24, which can be readily compared with recent crystallographic data. We envision that such an approach will lead to an accurate description of key structural and electronic signatures at a fraction of the cost of a full quantum chemical treatment. As an example, we demonstrate that calculations of the 1H and 13C NMR shielding constants with our proposed QM/MM model maintain the qualitative features of a full DFT calculation, with an order-of-magnitude increase in computational efficiency.Comment: Journal of Materials Science, 201
    corecore