941 resultados para Active Flow Control


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Temperature, pressure, gas stoichiometry, and residence time were varied to control the yield and product distribution of the palladium-catalyzed aminocarbonylation of aromatic bromides in both a silicon microreactor and a packed-bed tubular reactor. Automation of the system set points and product sampling enabled facile and repeatable reaction analysis with minimal operator supervision. It was observed that the reaction was divided into two temperature regimes. An automated system was used to screen steady-state conditions for offline analysis by gas chromatography to fit a reaction rate model. Additionally, a transient temperature ramp method utilizing online infrared analysis was used, leading to more rapid determination of the reaction activation energy of the lower temperature regimes. The entire reaction spanning both regimes was modeled in good agreement with the experimental data.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

EXECUTIVE SUMMARY Background and context The Grain Legumes CRP was established to bring all research and development work on grain legumes within the CGIAR system under one umbrella. It was set up to provide public goods outcomes to serve the needs of the sustainable production and consumption of grain legumes in the developing world, capitalising upon their properties that enhance the natural resource base upon which production so unequivocally depends. The choice of species and research foci were finalised following extensive consultation with all stakeholders (though perhaps fewer end users), and cover all disciplines that contribute to long-lasting solutions to the issues of developing country production and consumption. ICRISAT leads Grain Legumes and is partnered by the CGIAR centers ICARDA, IITA and CIAT and a number of other important partners, both public and private, and of course farmers in the developed and developing world. Originally in mid-2012 Grain Legumes was structured around eight Product Lines (PL) (i.e. technological innovations) intersecting five Strategic Components (SC) (i.e. arranged as components along the value chain). However, in 2015, it was restructured along a more R4D output model leading to Intermediate Development Outcomes (IDOs). Thus five Flagship Projects (FP) more closely reflecting a systematic pipeline of progression from fundamental science, implementation of interventions and the development of capacity and partnerships to promote and adopt impactful outcomes: FP1) Managing Productivity through crop interactions with biotic and abiotic constraints; FP2) Determination of traits that address production constraints and opportunities; FP3) Trait Deployment of those traits through breeding; FP4) Seed Systems, post-harvest processing and nutrition; FP5) Capacity-Building and Partnerships. Another three cross-cutting FPs analyse the broader environment surrounding the adoption of outputs, the capitalising of investments in genomics research, and a focus on the Management and Governance of Grain Legumes: FP6) Knowledge, impacts, priorities and gender organisation; FP7) Tools and platforms for high throughput genotyping and bioinformatics; and FP8) Management and Governance. Five FPs focus on R4D; FPs 5 and 6 are considered cross-cutting; FP 7 has a technical focus and FP 8 has an overarching objective. Over the three year period since its inception in July 1012, Grain Legumes has had a total budget of $140 million, with $62M originally to come from W1/W2 and the remaining $78M to come from W3/bilateral. In actuality only $45M came from W1/W2 but $106M from W3/bilateral corresponding to 106% of expectation. Purpose, scope and objectives of the external evaluation Principally, the evaluation of Grain Legumes is to ensure that the program is progressing in an effective manner towards addressing the system-level outcomes of the CGIAR as they relate to grain legumes. In essence, the evaluation aims to provide essential evaluative information for decision-making by Program Management and its funders on issues such as extension, expansion and structuring of the program and adjustments in relevant parts of the program. Subsequent to the formal signing of the agreed terms of reference, the evaluation team was also invited to comment upon the mooted options for merging and/or disaggregating of Grain Legumes. The audiences are therefore manifold, from the CGIAR Fund Council and Consortium, the Boards of Trustees of the four component CGIAR centres, the Grain Legumes Steering, Management and Independent Advisory Committees, to the researchers and others involved in the delivery of R4D outcomes and their partner organisations. The evaluation was not only summative in measuring results from Grain Legumes at arm’s length; it was also formative in promoting learning and improvements, and developmental in nurturing adaption to transformational change with time. The evaluation report was written in a manner that allows for engagement of key partners and funders in a dialogue as to how to increase ownership and a common understanding of how the goals are to be achieved. We reviewed research undertaken before the CRPs but leading to impacts during Grain Legumes, and research commenced over the past 2.5 years. For related activities pre- and post-commencement of Grain Legumes, we reviewed the relevance of activities and their relation to CGIAR and the Grain Legumes goals, whether they were likely to lead to the outcomes and impacts as documented in the Grain Legumes proposal, and the quality of the science underpinning the likelihood to deliver outcomes. Throughout, we were cognisant of the extent of the reach of CGIAR centres’ activities, and those of stakeholders upon which the impact of CGIAR R4D depends. Within our remit we evaluated the original and modified management and governance structures, and all the processes/responsibilities managed within those structures. Besides the evaluation of the technical and managerial issues of Grain Legumes, we addressed cross-cutting issues of gender sensitivity, capacity building and the creation and nurturing of partnerships. The evaluation also has the objective to provide information relating to the development of full proposals for the new CRP funding cycle. The evaluation addressed six overarching questions developed from the TOR questions (listed in the Inception Report, 2015 [http://1drv.ms/1POQSZh] and others including cross-cutting issues, phrasing them within the context of traditional evaluation criteria: 1. Relevance: Global development, urbanisation and technological innovation are progressing rapidly, are the aims and focus of Grain Legumes coherent, robust, fit for purpose and relevant to the global community? 2. Efficiency: Is the structure and effectiveness of leadership across Grain Legumes developing efficient partnership management and project management across PLs? 3. Quality of science: Is Grain Legumes utilising a wide range of technologies in a way that will increase our fundamental understanding of the biology that underpins several PLs; and are collected data used in the most effective way? 4. Effectiveness: Are Product Lines strategic contributors to the overarching aims and vision for Grain Legumes? 5. Impact: Are the impact pathways that underlie each PL well defined, measureable and achievable; and are they sufficiently defined in terms of beneficiaries? Does progress towards achieving outputs and outcomes from the major research areas indicate a lasting benefit for CGIAR and the communities it serves? 6. Sustainability: Is Grain Legumes managing the increasing level of restricted funding in terms of program quality and effectiveness, including attracting and retaining quality staff? Questions for the evaluation of governance and management focused on accountability, transparency, the effectiveness and success of program execution, change management processes and communication methods, taking account of the effects of CGIAR reform. The three crosscutting issues were considered as follows: i) gender balance in program delivery, e.g. whether each PL is able to contribute to the increased income, food security, nutrition, environmental and resource conservation for resource-poor women and men existing in rural livelihoods; ii) are internal and external capacity gaps identified/met, is capacity effectively developed within each product line, and are staff at all levels engaged in contributing ideas towards capacity building; and iii) is there effective involvement of partners in research and activity programming, what are the criteria for developing partnerships, how they are formalised and how is communication between partners and within Grain Legumes managed? It was not in remit to search for output, outcomes or impact, however as highlighted later, much of our time was spent on searching for information to support claims of impact, since Grain Legumes had no effective dedicated M&E in place at the time of undertaking the review. Approach and methodology The evaluation was conducted when Grain Legumes had been operational for approximately 3 years. The approach and methodology followed that outlined in the Inception Report [http://1drv.ms/1POQSZh]. The CCEE Team based its findings, conclusions and recommendations on data collection from several sources:  review of program documents, communications with the CO, minutes and presentations from all management and governance committee meetings  review of previous assessments and evaluations  sampling of Grain Legume projects in 7 countries1  more than 66 face to face interviews, a further 133 persons in groups and 4 phone/Skype conversations: ICRISAT, ICARDA, CIAT and IITA staff, partners and stakeholders. Meetings with one Independent Science and Partnership Council (ISPC) member.  meetings with over 100 people in 16 external groups, such as farmers’ groups  online survey completed by 126 (33.4%) scientists who contribute to Grain Legumes and a number of non-CGIAR partners and Management representatives  bibliometric review of 10 publications within each PL to qualitatively assess the design, conduct, analysis and presentation of results  quantitative and qualitative self-assessment of the contributions of each of the PLs to the six criteria and 3 cross-cutting issues of evaluation mentioned above completed by PLCs (see below). We reviewed the Logical Framework that underpins the desired Goals, or Impacts of Grain Legumes, and the links between the outputs and inputs as they related to the organisational units of Grain Legumes. The logical framework approach to planning and management of Grain Legumes activities implies a linear process, leading from activities, outputs, outcomes, to impacts, but within such an approach there may be room for a more systems dynamics approach allowing for feedback at every step and within every step, in order to refine and improve upon the respective activities as new results, ideas, and directions come to light. We then developed a matrix that summarised quantitatively and qualitatively the contributions of each of the PLs to the six criteria and 3 cross-cutting issues of evaluation mentioned above. Main findings and conclusions Grain legume production and consumption remain of great importance to the food security of not inconsiderable populations in the developing world, and merit sustained research investment. We conclude that Grain Legumes continues to contribute significant returns to research investments by the CGIAR, and such investment should continue. The global research community looks to the CGIAR for leadership in Grain legumes, but needs to be assured of value adding when bringing CGIAR centres under the expected umbrella of synergy. However, there is considerable scope for improving the efficiency with which outcomes are achieved. We note that an absence of an effective M&E has hampered the assessment of the effectiveness of proposed impact pathways. Likewise progress has been hampered by the limited numbers of research partnerships with Advanced Institutes and by budgetary constraints (lamented for their stifling effects on continuation of ongoing exciting research). The unworkable management structure constrains the CRP Director’s leadership role; responsibility without authority will never lead to effective outcomes. Good fortune is responsible for many of the successes of Grain Legumes, underpinned by a devoted work force across the participating CGIAR centres and partners. The quality of the science is not uniformly high, and we believe that mentoring of scientists should be given priority where quality is poor. Simplified yet informative reporting is an imperative to this. World class science underpins the identification of, and molecular basis for, traits important for yield improvement and this expertise should be extended to all grain legume species, capitalising upon the germplasm collections. The linking of Grain Legumes with regional research and development consortia has been very successful, with outcomes aligning with those of Grain Legumes. We see that with declining funding consolidation of research effort based on likely successes will be necessary, and welcome the move afoot to incorporate grain legumes into an agri-food system focused on successful value chains that deliver sustainable outcomes. Relevance and Strategy Grain Legumes has geographic and disciplinary relevance, addressing the major supply chain issues of variety development seed system and agronomy, with some attention to quality and postharvest marketing systems. The CRP has provided the opportunity to cut ongoing and to initiate new research. Research funded by the Gates Foundation (Anon, 2014) suggests that the need for improvement is greatest in Africa and advocates reducing the number of crop by country combinations when resources are sparse. The lesser research investment in Latin America, however, is not in line with the regions’ dependency on legumes. In spite of the fact that there is no evidence of strong inter-partner CGIAR centre or internal synergy, the program is still moving ahead on most fronts in line with the overall project logframe. This is in spite of continual pushing and pulling by in particular donors and the CO. However, to quantify real impact, we believe Grain Legumes must have access to reliable baseline data on production and consumption, and this is missing. Similarly, there is little evidence of the proposed ‘Inclusive Market Oriented Development’ (IMOD) framework being used to assist with priority setting. The product lines, eight of which cover most of the historical programmes in place in the partner CGIAR centres at the commencement of the Grain Legumes, do not cover all the constraints for formal constraints analysis was not undertaken at the inception of the Grain Legumes, and some of this additionally identified research is undertaken under the umbrella of the FPs; this needs to be rationalised. We found the PLs to be isolated in activity, even with minimally-integrated activities within each PL, with little evidence of synergy between PLs. Even though the SCs should ensure a systems approach, as with the new FPs, we did not get a feel that this is so. The underplaying of agronomy, and production practices may be one reason for this. We believe that treating legume crops as if they were horticultural crops will increase farmer returns from investment. The choice of Flagship Projects makes sense, with the flow of activity firstly around crop management and agronomy followed by the logical sequence of trait discovery, incorporation into improved varieties, dissemination of those varieties through appropriate seed chains leading to market impacts, and the capacity building required at all steps. One obvious omission, however, is the lack of a central and strategic policy on the role of transgenics in Grain Legumes. We found four notable comparative advantages for Grain Legumes: the access to germplasm of component species, the use of the phenotyping facility at ICRISAT, the approach for village level industry for IPM, and the emphasis on hybrid pigeonpea. Efficiency Each centre has strong control of, and emphasis on, their ‘species’ domains, and ownership of the same detracts from possible synergy. Without synergy or value add, the Grain Legumes brings with it no comparative advantage over each centre continuing their own pre-CRP research agendas. We found little evidence of integration of programmes between centres and almost no cross-centre authorship of publications, such as could have occurred with the integrated cross-centre approaches to stress tolerance including crop modelling: the one publication (Gaur et al., 2015) on heat tolerance by ICRISAT, CIAT and ICARDA does not provide any keys to inter-centre collaboration. The integration of each centre with NARS and university research programmes is good, but the cross-centre links with NARS are poor. A better coordinated integration with Grain Legumes, , rather than through the individual centres, may reduce transactions costs for NARS, Monitoring and evaluation is, as noted throughout our report, one area of Grain Legumes research management that has not been given the attention it should have received. If it had have received proper attention, some of the issues of poor efficiency might have been nipped in the bud. A strong monitoring and evaluation system would have provided the baseline data and set the milestones that would have allowed both efficiency and effectiveness to be better appraised. We found no attempt to define comparative advantages of the CGIAR centres and their R4D activities, although practice showed the better grasp of CIAT in developing innovative seed distribution systems. During field visits and interviews, the CCEE Team observed shortcomings in the communication processes within Grain Legumes and with the broader scientific community and the public. For example, the public face of the program on the internet is out of date. Survey findings, however, suggest that information is shared freely and routinely within the PL within which scientists work. Some external issues, such as those with funding, low W1/W2 and poor sustainability of funding (especially if funding is top heavy with a few agencies), undermine research investment and confidence of partners in the system (e.g. as voiced by researchers working on crops and countries not included in TL III and the cessation of ongoing competitively-funded projects especially in India), but other issues attributable to the governance and management of the Grain Legumes, such as opaque integration of W3/bilaterals with W1/W2 funding require attention. Offsetting this, the existence of the Grain Legumes did mobilise additional funding [that it would not have if Grain Legumes did not exist]. We were concerned that Grain Legumes is simply not recognised outside of the CRP, with a limited www presence and centres promote themselves, rather than Grain Legumes (with exception in IITA). This is not a good move if one wishes to increase investment in the Grain Legumes. Although funding agencies require cost:benefit ratios, for example for each PL we faced difficulty in determining comparative value for money between investment in different types of research, and in being able to clearly attribute research and development outcomes to financial investment. There was also a time CCEE frame issue too. There is poor interaction with the private sector, notably in areas where they have a comparative financial advantage. We questioned in particular the apparent lack of interaction with the major agro-chemical companies, with respect to the development of herbicide tolerant (HT) grain legumes and the lack of evidence that the regulatory and trade aspects related to herbicide tolerant crops had been considered. Quality of science The quality of the science is highly variable across Grain Legumes, with pockets of real excellence that are linked to good levels of productivity, whereas other PLs are struggling to deliver quality publications, and outputs and outcomes that are based on these. There is much evidence of gradualism in terms of research output and outcomes, i.e. essentially the same activities that were ongoing at the time of the launch of Grain Legumes are still in place. However, there are examples of game changers including those from valuable investments in genomics, phenotyping, and bio-control. We were pleased to see large proportions of collaboration on publications with non-CGIAR centres, reflecting cooperation with partners in developed and developing countries. The value of collaboration when ensuring quality of science cannot be stressed highly enough both within the CRP, and with other global and national partners. PLs should be given incentives to collaborate with other CRPs and external institutions. There is little cohesion between PLs and with other CRPs as evidenced by publications, although there are some exceptions. We suspect the reasons for this are driven by funding. Productivity from the different PLs is also highly variable and it is not clear what other activities staff are engaged in since, in some PLs, they do not appear to lead to quality publications. Effectiveness Grain Legumes has been very effective in addressing component issues of research, but not the continuum from variety development to legumes on someone’s dinner plate. Our overall assessment of the effectiveness of Grain Legumes in stimulating synergy, innovation and impact indicate that gradualism is more prevalent than innovation. It also shows, as do publications, that there is little integration of disciplines or a focus on ‘systems’. The absence of socio-economists from research teams is evident in the general lack of an end user focus. However, research on genomics, plant breeding and seed systems have made great strides forward, on the brink of delivering impact. Agronomy has been a poor sister, but some of the competitive grants within Grain Legumes have unearthed some potential game changers, such as objective use of transplanting as an agronomic practice. As mentioned earlier, the lack of effective M&E (however, this was part of some major projects such as TL II/TL III), and therefore the ability to monitor impact pathways and achievement of impact, implies no systematic management of data. This creates difficulty when attempting to evaluate the achievement of the Grain Legumes objectives. One might have expected at least one attempt to try to develop publications between centres arguing for similar biologies/research approaches, bringing species together under one umbrella, but we did not find any evidence for this. It is most unfortunate that, due to budgetary cuts, the new ‘schemes’, e.g. competitive grants and scholarships, were cut off before gaining a foothold. With 8 species addressed by Grain Legumes, it is not unexpected that there will be little evidence of shared protocols across centres/species. One rare example was that hosted by the United States Department of Agriculture (USDA) on shared methods for phenotyping of legume germplasm. Researchers from CIAT, IITA, ICRISAT and three USDA stations attended, focusing in simple canopy temperature and root morphology measurements. It is our belief that as a set of research centres, the CGIAR centres should be focusing on the research for which they have a comparative advantage. While imposing the restructure to FPs, which is fine for development objectives and outcomes (funded through W3/bilateral), it is less so for a research institute, and the structure should not detract from the more basic work expected of an international CGIAR centre (or set of centres as in a CRP). Impact It is well known that research does not always lead to scientific breakthroughs. Also, activities such as plant breeding are long term; making impacts difficult to assess. We believe that sufficient progress with genomics and associated research has been made to warrant impact, but we are unable to quantify the levels of impact, or the timeframe for the same. Work in Grain Legumes has enormous potential for real impact in scientific research, commercial, farming, smallholder and household communities, much of which is being realised. However, the PLs need to become more adept at providing convincing cases that are strongly evidenced for these impacts, as this is likely to be a key factor in leveraging future funding. Claimed gains must be referenced against baseline data, and these are not always readily available. The CCEE Team realises that such impact evaluation represents a significant drain on resources, and Grain Legumes should determine whether the balance of costs to benefits favours such investment. Interviews conducted by the CCEE during site visits showed that PLs are quantifying the area of adoption of varieties, but in most cases they are not measuring the impact on environment, health/nutrition. Since the health and nutritional benefits and the environmental gains from growing legumes are major arguments for supporting grain legume research, the community is currently missing substantial opportunities to strengthen its own case for continued support. Whilst there are some impressive examples of considering the whole value chain, e.g. white beans from production through to export; in the main, the pipeline to end user is somewhat piece-meal, with no clear definition of the end user nor differential responsibility of Grain Legumes and of partners. The lack of robust time-defined impact pathways is highlighted in Section 7.4, and even though developed for PL5, timeframes are essential for measuring progress against prediction. Sustainability In summary, there is general acknowledgement that future funding is likely to become more limited, specifically in W1&2 and there is understandable concern over the support for the staff and basic infrastructure that underpin the Grain Legumes programme. For example, it is reported that staffing in parts of CIAT has been dependent on W1&2 and that this is too unstable to re-establish a critical mass. The present system whereby W3 and bilateral projects do not pay a realistic level of overheads means that such projects are being effectively subsidised by W1&2. This position is not sustainable in the long term as there will be a progressive but definite loss of basic skills and resources in the core centres. The only obvious options to prevent this outcome include a severe reduction in the fixed costs of the centres and/or a refusal to accept W3 and bilateral funding with an inadequate overhead component. In the latter case, there is an obvious danger that funders will move their resources away from the CGIAR system towards other, perhaps less expensive, suppliers of research, and possibly more relevant development expertise. This issue must be addressed. As the Grain Legumes moves into the future, and if sustainable funding cannot be assured, decisions must be made concerning a reduction in activities, keeping some caretaker breeding maintenance, and focus (as has TL III) on fewer species and a reduced geographic focus. Cross cutting issues: Gender, capacity building and partnerships Gender is not mainstreamed, but there is some evidence that this is improving, especially with dedicated gender specialists and the slow integration of gender across CRPs. There is a need to approach gender through the vision of agriculture as a social practice, with recognition of what changes will be acceptable culturally and what not, and capitalising upon the perceived and actual features of production and processing that grain legumes are primarily women-based crops. Gender awareness may be high among Scientists, but it appears to be a predominantly passive attribute with few proactively seeking opportunities for gender equity. It is, however, a sound sensitivity base on which to build. Nevertheless, examples of notable gender initiatives were identified during field visits. For example, in Benin, the development of biocontrol technologies has enthusiastically integrated diversity, engaging with women farmers’ and youths while maintaining cultural norms. Women are gathering and processing, youths are taking the product to market. The implication is that several groups benefit, rather than domination by the majority group. In Malawi, innovative approaches have been developed to improving nutrition for children, such as incorporating nutrient enriched bean flour products into snacks. In India, scientists collaborating with gender scientists and socio-economists are identifying the impact of mechanical harvesting on agricultural labour and the potential displacement of female labourers. In Kenya, a novel initiative is improving the accessibility of certified seed for new varieties. Seed suppliers have introduced small packs of grain legume seed at low unit cost, which are being purchased by young people and women. Capacity building efforts for external partners are not clearly aligned with the research mandate and delivery of Grain Legumes. However, there are a number of training activities that are being undertaken by Grain Legumes, largely through the W3/bilateral project. Gender balance never reaches parity, but it appears that efforts are made to include female participants. Within the evaluation timeframe it was not possible to conduct external surveys to further validate or review external capacity building efforts in Grain Legumes. Training of scientists is significant, with >40 benefiting. Postgraduate training is varied across PLs, and there is some opportunity to increase the numbers being supervised. We consider that support for postgraduates at ICRISAT could be better coordinated, satisfying more of the students’ needs. It is important, however, to follow up investments in capacity building by monitoring effectiveness, career progressions and so on. Training activities appear to be rather centre-specific, not following a coordinated programme managed by, nor at the level of, the Grain Legumes. Numbers of persons trained and their gender are important, but a measure of the effectiveness of the training is more important. Although optimism is expressed by the great majority of Research Managers that partnerships were working well to leverage knowledge and research capacities, scientists have a less favourable view, particularly in terms of their incentives to participate. It seems likely that the activities taking place within Grain Legumes were, in the most part, continuations of previous collaborations. This is not surprising in light of the reduction in the emphasis on partnerships as Grain Legumes evolved to a funded project, and the consequent lack of opportunity and ambition for establishing novel partnerships. Where they exist, partnerships are good on the whole, especially with US. They could be expanded where comparative advantages exist (for example with Canada and Australia for machine harvestable legumes), but some earlier identified partnerships, e.g. with Turkey, have not been capitalised upon. Others experience problems of variety access (the embargo on exports of some sources of materials from India), yet others do have relevance e.g. imported Brazilian varieties in pre-release in Ethiopia (even though two of the three are from CIAT materials). Governance and Management The standard format of committee structure and responsibilities is common to other CRPs, as are the attendant problems. One of the major problems is that the Grain Legumes Director has responsibility but no authority; hence, even with the support of the RMC, the Director is unable to ‘direct’ in the literal sense of the work the activities of Grain Legumes. We also see the same sense of helplessness with the role of the PLCs. They have responsibility but no authority in managing the affairs of their PL, and they have no access to funds with which to promote intellectual collaboration and cooperation. Minutes from governance and management meetings do not reflect the compromised weak position of the Director and the associated difficulties in the management of Grain Legumes. Nor do the minutes reflect concerns about the amount of time spent by scientists in meetings for planning, integration, evaluation and reporting. Many scientists reported significant opportunity costs in participating in the ongoing imposed [by the CO] evolution of Grain Legumes and CRPs in general. The changes brought in by the CO have not helped promote any greater authority and capacity of the Grain Legumes Director to direct. Likewise, they do not address any of the issues with the conflict of interest in having the Lead Centre chair the Steering Committee. Indeed, we believe that the combining of the Steering Committee with the Independent Advisory Committee, besides becoming unwieldy in number, annuls any sense of independence in advice offered to the Grain Legumes management. We have concerns with the declining proportion of W1/W2 funds (as expressed in the section on Sustainability), and believe that when basic financial planning takes place, integration of W1/W2 and W3/bilateral sources must occur, and be linked to anticipated outcomes and impacts. This will ensure a close alignment of collaborators’ and partners’ objectives and contributions to that of the Grain Legumes. We also queried the process for, and the formality, or lack of, surrounding, the approval of annual budgets, and the level of priority setting when budgets are cut. Recommendations for Grain Legumes The CCEE Team makes the following recommendations, critical issues are highlighted in bold, and those that require action by an entity other than the Grain Legumes Research Management Committee or Project Management united are identified in a footnote. Relevance and Strategy Recommendation 1: A period of consistency is necessary to raise confidence, morale and trust across scientists, managers and partners to foster the assembly of enduring Grain Legumes outcomes2.  There needs to be a concerted effort to undertake baseline studies and to implement a robust M&E activity during this period. Without these data the foundation for integrated research in grain legumes is jeopardised.  There is a strong need to link more closely with the private sector, especially where there are financial and other comparative advantages to do so. Recommendation 2: The agronomic and physiological trait targets of Grain Legumes (tolerance to changing climate patterns, to the pests and diseases of today and of the future, incorporation of quality traits and adaptations to intensive production systems [machine-harvestability and herbicide tolerance], and short season high yielding characters) are all worthy of continued investment when selecting for improved varieties.  There needs to be a common strategy, implemented across centres and species, as to how to address these trait targets through conventional and modern breeding approaches, but only if adequate funding is assured and secured and if a consistency and unity of purpose can be achieved across a large-scale. This should take the form of cross-species coordinated research programmes to address these breeding targets that cooperate across centres and make efficient use of facilities and other resources.  The CRP should undertake a detailed strategic review of the role of transgenics across the range of targets in the mandate crops. Efficiency Recommendation 3: The lack of an effective M&E process is a significant omission, not least in terms of more efficient use of resources and the lack of baseline data with which to measure impact, and must be rectified.  Reinforcing Recommendation 1, an effective M&E system initially directed towards baseline studies must be implemented.  Transaction costs may be reduced through bilateral projects, which are seen as more cost effective than W1/W2 where transaction costs are disproportionately higher. Recommendation 4: To improve communication and coordination within the CRP, and with a broader audience:  There is a priority need for a central database containing, names of staff associated with Grain Legumes and their time commitments, their responsibilities, and involvement in CRP activities, their progress and achievements, their publications, plans of training, travel, and other opportunities for interaction.  Regular global meetings of staff involved in managing PLs, the entire CRP management staff and the IAC are essential for effective coordination of all activity within Grain Legumes.  The website must be given a complete overhaul and improvement and then regular maintenance must be provided to keep it current. Quality of Science Recommendation 5: It is essential to continue investment in good science and to institute a change from gradualism in research output and outcomes to an expectation of innovative and concrete achievements that can be attributed clearly to people, centres and core facilities.  A cost:benefit analysis and subsequent strategic planning must be undertaken to justify further investment in the genomics and phenotyping facilities at ICRISAT especially as such technologies advance rapidly. Strategic planning and coordination must also be implemented for capitalising on the investment in crop simulation modelling. (The phenotyping facility of ICRISAT needs to focus on delivering some outcomes, not only outputs.)  PLs should be given incentives to collaborate with other CRPs and external institutions. The CCEE recommends special recognition of high quality collaborative papers, thereby encouraging increased quality of the research programmes and widening the penetration of research impacts.  More importance should be placed on the quality of publication, rather than quantity of outputs and there should be recognition of other types of outputs from Grain Legumes. The CRP Director must be party to this.  If staff are engaged in activities that relate more to impact than publication then this needs to be monitored and recorded and a clearer understanding developed of what constitutes a pathway to impact and how success of such activities can be evaluated. A system must be devised and incorporated into the M&E to enable recognition of other types of outputs (non- publication based) from Grain Legumes, e.g. varieties for breeders. Effectiveness Recommendation 6: To develop greater synergy, Grain Legumes should review management processes and the direction of research activities. In particular, far more extensive integration of research and knowledge exchange should take place across both African and Asian continents so that the best aspects of both can be shared. A multidisciplinary approach is recommended that considers processing solutions, as well as breeding solutions, to capitalise upon the nutritional benefits of the grain legume crops. We recommend:  A better collaboration with social scientists at the design stage of experiments in order to improve the utility of the work carried out and to understand its reach.  Supporting3 the adoption of best practice electronic data collection, central storage and open access, particularly of genomic data, for public use.  Given the focus on the link between phenotyping and genotyping, we note that there is a lack of congruence between the populations that are being phenotyped and those being genotyped, and therefore these could be better aligned within each species.  Concentrating investment external to Grain Legumes on scaling up production of varieties with the most promising trait profiles to meet the basic seed requirement.  Developing a more holistic approach that coordinates an understanding of the disease pathology and epidemiology, and of new chemicals before they become commercially available, together with agronomic practice such that recommendations can be made for growers. Continuing work to establish whether agronomic factors hold true in different environments and to assess GxE effects within breeding programmes. Such rigorous trial practices should be used to inform the evaluation of breeding lines and to provide phenotype data to associate with markers for traits such as heat, drought and herbicide tolerance.  Considering grain legumes as if they were vegetable crops in terms of the strategy for intensification of production, both from the management perspective and for seed systems, will be a useful development objective into the future. This will bring about more rapid intensification and is likely to increase farmer returns from investment. Recommendation 7: The CGIAR centres should focus in on the research for which they have a comparative advantage. While imposing the restructure to FPs, which is fine for development objectives and outcomes (funded through W3/bilateral) it is less so for a research institute, and should not detract from the more basic work expected of an international CGIAR centre (or set of centres in a CRP).  Collaborative approaches should be explored within Grain Legumes, e.g. similar biologies/research approaches, bringing species together under one umbrella. Similarly better alignment is needed to address the lack of congruence between the populations that are being phenotyped and those being genotyped.  Despite positive impacts from research in genomics, plant breeding and seed systems, the lack of an effective M&E, already mentioned elsewhere, has reduced the ability to monitor impact pathways. This must be addressed.  The absence of socio-economists from research teams is evident in the general lack of an end user focus. Responsibilities of the different actors in the whole value chain must be considered and identified when developing impact targets, and the pathway leading to them, for individual projects. People with socio-economist skills must be part of the team from project inception so that appropriate frameworks are incorporated for measuring and influencing sociological and economic changes brought about by Grain Legumes research. Impact Recommendation 8: PLs need to become more adept at providing convincing cases in which impact is strongly evidenced, as this is likely to be a key factor in leveraging future funding.  Claimed gains must be referenced against baseline data, and these are not always readily available. The CCEE Team realises that such impact evaluation represents a significant drain on resources, and Grain Legumes should determine whether the balance of costs to benefits favours such investment.  It is essential that Grain Legumes provides training to staff on what constitutes impact and how it can be recorded.  Specific, rather than generalised, potential impacts arising from activity within Grain Legumes should be defined at the time of justifying the programme of work and a pathway to impact should form part of the documentation prepared ahead of a piece of research commencing. . In other words, centres should submit work plans to Grain Legumes before they are undertaken using W1/W2 funds Recommendation 9: The reporting activity must be streamlined to a single (brief) format that can be used to report to Grain Legumes, Centres and to donors for special project activities4. Sustainability Recommendation 10: As Grain Legumes moves into the future, and if sustainable funding cannot be assured, decisions must be made concerning a reduction in activities, keeping some caretaker breeding maintenance, and focus (as has TL III) on fewer species and a reduced geographic focus. Zeigler (Director General of IRRI) states “…time and effort would be better spent … making tough decisions about which programs deserve the precious support.”  The present system whereby W3 and bilateral projects do not pay a realistic level of overheads means that such projects are being effectively subsidised by W1&2 and there will be a progressive but definite loss of basic skills and resources in the core centres. To prevent this outcome it is necessary to significantly reduce the fixed costs of the centres and/or refuse to accept W3 and bilateral funding without an adequate overhead component.  In the absence of long term certainty, the scale of the budget allocated to each of the new CRPs should be very conservative, a feature that can only be achieved by restricting/reducing the scope, probably quite significantly. Cross cutting issues: Gender, capacity building and partnerships Recommendation 11: The challenge for Grain Legumes is to achieve pro-active gender mainstreaming, which facilitates opportunities for gender diversity within all activities, from employment processes through research to end users.  Strategic measurable gender indicators need to be embedded in research design, for instance, through specific IDOs for each of the flagships projects. Accurate baseline data are also required to facilitate M&E reviews of progress.  Implementation of the Gender Strategy is the responsibility of everyone, not solely the Gender Team. Thus, ownership could be encouraged by setting personal development for key personnel objectives with specific outcomes, e.g. employment practices or research outcomes.  Recognising the positive gender initiatives in progress or planned, feedback must be communicated and integrated into broader research planning to share opportunities, methods and outcomes.  In addition to promoting gender equity in research, Grain Legumes also needs to ensure that working environments are gender sensitive and that recruitment processes, including promotion opportunities are equitable. Gender imbalance in management should be actively examined to identify further opportunities for developing female leadership. Recommendation 12: It is recommended that a training plan be devised to ensure that capacity building efforts are more clearly aligned with the research mandate, delivery and timeframe of Grain Legumes. Moreover, we recommend that ICRISAT develop a strategy to treat their new cohort of researchers more equitably in the future. Recommendation 13: To develop a more coherent strategic programme designed to eliminate overlap and promote synergy between programmes with common aims, Grain Legumes should hold a meeting with a range of partners. Governance Recommendation 14: Governance processes should be re-assessed and the structure altered to ensure that the Grain Legumes Director has the authority and budget control to drive the execution of strategy.  The ISC should be truly independent and given the power to influence strategic decisions before they become final. We also recommend that PLCs are provided with the authority to manage the direction and finances of their PL; and that ring-fenced funds are provided for the promotion of collaboration, coordination and staff training5. The way ahead In our view, having seen the ineffectiveness of much of the attempts [or lack of attempts] to harness synergies between multiple centres, and of the strength in few or sole centre partnerships, we believe that there is little to justify a full retention of the 8 legume species and 4 CGIAR centres in a CRP. TL I and II and PABRA have shown to be reasonably good cross-centre and single centre integrated programmes, but even they suffer from incomplete value chain approaches to increasing rural incomes while increasing food and nutritional security; they both need multi-faceted solutions which are not immediately forthcoming from Grain Legumes. It is important to embed Grain Legumes research within the agri-food systems these crops serve. Figure ES1 broadly shows the perceived current and potential degrees of synergy between centres, PLs and species, and is discussed more in the text. It is clear that the value chains for individual species from trait determination to nutritional impact have more cohesion than do the individual activities (e.g. trait deployment) across species. For this reason we believe that the future for research in Grain Legumes is best addressed by focusing on each of the species separately, and within an ecosystem framework; any synergy for research across species can be effected through communication and not necessarily through obligatory cooperative research. The ecosystem framework will allow for strengthening of agronomy type systems research, the arguments for benefits of inclusion of grain legumes in cropping systems, which is notable by its absence in much of what Grain Legumes currently undertakes. Figure ES1. Current and potential degrees of synergy between centres, PLs and crop species We therefore agree with the innovation in agri-food systems approach of the CG, and believe that Grain Legumes rightly belongs in the Dryland Cereals and Legumes Agri-food Systems. We believe that the option of combining the crops of dryland cereals and legumes in the cereal-legume-livestock systems of subsistence farming communities for whole-farm productivity is closest to the best way forward. Indeed the inclusion of grain legumes may not warrant even a CRP alone, rather the legume components should fit in with the major crops that determine the production systems. Legumes will always be subservient to the major cereals, as necessary adjuncts to the whole production system, providing both nutritional diversity and environmental services, neither achievable from cereals alone. Figure ES2. Most suitable option for integration of Grain Legumes and Dryland Cereals into an Agri-Food Systems CRP Most suitable option for integration of Grain Legumes and Dryland Cereals into an Agri-Food Systems CRP, which  Incorporates ex-Dryland Systems, Dryland Cereals, Grain Legumes, some HumidTropics, some ex-Livestock &Fisheries into a new CRP  Will cover full agri-food system VC for all 8 legumes in all ecologies, but must interact (dock) with the relevant AFS-CRPs for the dominant cereal in the relevant ecology  Hence, will need to negotiate with other Agrifood Systems-CRPs on who does what for legumes  In addition, responsible for sorghum and millet in the mixed dryland crop-livestock agro-ecologies For major game changers to be effected, we believe that the game has to change, and there is little evidence of this. The direction of CRPs is the correct route, but the journey has not yet come to its destination. A major change of game [such as the adoption of a Flagship Project approach as exemplified by the Australian CSIRO – where flagships contract services from centres of research excellence] would be painful to implant. The CGIAR system is going down the right pathway but it has not gone far enough.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Purpose: To evaluate in vitro the influence of water flow rate on shear bond strength of a resin composite to enamel and dentin after Er:YAG cavity preparation. Methods: Ten bovine incisors were selected and roots removed. Crowns were sectioned in four pieces, resulting in 40 samples that were individually embedded in polyester resin (n=10), and ground to plane the enamel and expose the dentin. The bonding site was delimited and samples were randomly assigned according to cavity preparation: (1) Er:YAG/1.0 mL/minute; (2) Er:YAG/1.5 mL/minute; (3) Er:YAG/2.0 mL/minute and (4) High speed handpiece/bur (control group). Samples were fixed to a metallic device, where composite resin cylinders were prepared. Subsequently, they were stored for 24 hours and subjected to a shear bond strength test (500N at 0.5 mm/minute). Results: Means (MPa) were: enamel: 1: 12.8; 2: 16.8; 3: 17.5; 4: 36.0 and Dentin: 1: 13.6; 2: 18.7; 3: 12.1; 4: 21.3. Data were submitted to ANOVA and Tukey`s test. Adhesion to enamel was more efficient than for dentin. The cavities prepared with conventional bur (control) presented higher statistically significant bond strength values (P<0.05) than for Er:YAG laser for both enamel and dentin. No significant differences were observed between water flow rates employed during enamel ablation. For dentin, the shear bond strength of 2.0 mL/minute water flow rate was lower than for 1.5 mL/minute and 1.0 mL/minute rates. The Er:YAG laser adversely affected shear bond strength of resin composite to both enamel and dentin, regardless of the water flow rate used.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Ogihara CA, Schoorlemmer GHM, Levada AC, Pithon-Curi TC, Curi R, Lopes OU, Colombari E, Sato MA. Exercise changes regional vascular control by commissural NTS in spontaneously hypertensive rats. Am J Physiol Regul Integr Comp Physiol 299: R291-R297, 2010. First published April 21, 2010; doi: 10.1152/ajpregu.00055.2009.-Inhibition of the commissural nucleus of the solitary tract (commNTS) induces a fall in sympathetic nerve activity and blood pressure in spontaneously hypertensive rats (SHR), which suggests that this subnucleus of the NTS is a source of sympathoexcitation. Exercise training reduces sympathetic activity and arterial pressure. The purpose of the present study was to investigate whether the swimming exercise can modify the regional vascular responses evoked by inhibition of the commNTS neurons in SHR and normotensive Wistar-Kyoto (WKY) rats. Exercise consisted of swimming, 1 h/day, 5 days/wk for 6 wks, with a load of 2% of the body weight. The day after the last exercise session, the rats were anesthetized with intravenous alpha-chloralose, tracheostomized, and artificially ventilated. The femoral artery was cannulated for mean arterial pressure (MAP) and heart rate recordings, and Doppler flow probes were placed around the lower abdominal aorta and superior mesenteric artery. Microinjection of 50 mM GABA into the commNTS caused similar reductions in MAP in swimming and sedentary SHR (-25 +/- 6 and -30 +/- 5 mmHg, respectively), but hindlimb vascular conductance increased twofold in exercised vs. sedentary SHR (54 +/- 8 vs. 24 +/- 5%). GABA into the commNTS caused smaller reductions in MAP in swimming and sedentary WKY rats (-20 +/- 4 and -16 +/- 2 mmHg). Hindlimb conductance increased fourfold in exercised vs. sedentary WKY rats (75 +/- 2% vs. 19 +/- 3%). Therefore, our data suggest that the swimming exercise induced changes in commNTS neurons, as shown by a greater enhancement of hindlimb vasodilatation in WKY vs. SHR rats in response to GABAergic inhibition of these neurons.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A synthetic version of the metal-regulated gene A (mrgA) promoter from Bacillus subtilis, which in this Gram-positive bacterium is negatively regulated by manganese, iron, cobalt, or copper turned out to promote high level of basal gene expression that is further enhanced by Co(II), Cd(II), Mn(II), Zn(II), Cu(II), or Ni(II), when cloned in the Gram-negative bacterium Cupriavidus metallidurans. Promoter activity was monitored by expression of the reporter gene coding for the enhanced green fluorescent protein (EGFP), and cellular intensity fluorescence was quantified by flow cytometry. Expression levels in C. metallidurans driven by the heterologous promoter, here called pan, ranged from 20- to 53-fold the expression level driven by the Escherichia coli lac promoter (which is constitutively expressed in C. metallidurans), whether in the absence or presence of metal ions, respectively. The pan promoter did also function in E. coli in a constitutive pattern, regardless of the presence of Mn(II) or Fe(II). In conclusion, the pan promoter proved to be a powerful tool to express heterologous proteins in Gram-negative bacteria, especially in C. metallidurans grown upon high levels of toxic metals, with potential applications in bioremediation. Biotechnol. Bioeng. 2010; 107: 469-477. (C) 2010 Wiley Periodicals, Inc.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Leptin is involved in the control of energy storage by the body. Low serum leptin levels, as seen in starvation, are associated with impaired inflammatory T cell responses that can be reversed by exogenous leptin. Common variable immunodeficiency (CVID) is characterized by hypogammaglobulinemia and recurrent infections. Several defects in T cell function have also been described, and allergy, autoimmune disease, and lymphomas or other malignancies can be present. Previous studies in Brazilian CVID patients have shown that, in contrast with mononuclear cells from healthy controls, CVID cells cultured with phytohemagglutinin and added leptin increased the proliferative response and decreased activation-induced apoptosis. Interleukin (IL)-2 and especially IL-4 production also increased significantly, although the effects of exposure to leptin were not observed uniformly in CVID patients. The majority, however, responded in some degree, and some exhibited completely restored values of the four parameters. These remarkable results indicate leptin could be used to improve immune function in these patients. On the other hand, we found no specific correlation between serum leptin levels and the number of infectious events over a 24-month period, presence of autoimmunity, allergies, or cancer in these patients. The results suggest that the absolute value of serum leptin does not determine the clinical behavior of patients or responses to leptin in vitro. Of note is the divergence between serum leptin, response to leptin in vitro, and the presence of autoimmunity, indicating the need to identify the cellular and molecular players involved in the regulation of the immune response by leptin in CVID.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Purpose - The purpose of this paper is to develop a novel unstructured simulation approach for injection molding processes described by the Hele-Shaw model. Design/methodology/approach - The scheme involves dual dynamic meshes with active and inactive cells determined from an initial background pointset. The quasi-static pressure solution in each timestep for this evolving unstructured mesh system is approximated using a control volume finite element method formulation coupled to a corresponding modified volume of fluid method. The flow is considered to be isothermal and non-Newtonian. Findings - Supporting numerical tests and performance studies for polystyrene described by Carreau, Cross, Ellis and Power-law fluid models are conducted. Results for the present method are shown to be comparable to those from other methods for both Newtonian fluid and polystyrene fluid injected in different mold geometries. Research limitations/implications - With respect to the methodology, the background pointset infers a mesh that is dynamically reconstructed here, and there are a number of efficiency issues and improvements that would be relevant to industrial applications. For instance, one can use the pointset to construct special bases and invoke a so-called ""meshless"" scheme using the basis. This would require some interesting strategies to deal with the dynamic point enrichment of the moving front that could benefit from the present front treatment strategy. There are also issues related to mass conservation and fill-time errors that might be addressed by introducing suitable projections. The general question of ""rate of convergence"" of these schemes requires analysis. Numerical results here suggest first-order accuracy and are consistent with the approximations made, but theoretical results are not available yet for these methods. Originality/value - This novel unstructured simulation approach involves dual meshes with active and inactive cells determined from an initial background pointset: local active dual patches are constructed ""on-the-fly"" for each ""active point"" to form a dynamic virtual mesh of active elements that evolves with the moving interface.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND Oxidized lipoproteins and antioxidized low-density lipoprotein (anti-oxLDL) antibodies (Abs) have been detected in plasma in response to blood pressure (BP) elevation, suggesting the participation of the adaptive immune system. Therefore, treatment of hypertension may act on the immune response by decreasing oxidation stimuli. However, this issue has not been addressed. Thus, we have here analyzed anti-oxLDL Abs in untreated (naive) hypertensive patients shortly after initiation of anti hypertensive therapeutic regimens. METHODS Titers of anti-oxLDL Abs were measured in subjects with recently diagnosed hypertension on stage 1 (n = 94), in primary prevention of coronary disease, with no other risk factors, and naive of anti hypertensive medication at entry. Subjects were randomly assigned to receive perindopril, hydrochlorothiazide (HCTZ), or indapamide (INDA) for 12 weeks, with additional perindopril if necessary to achieve BP control. Abs against copper-oxidized LDL were measured by enzyme-linked immunosorbent assay. RESULTS Twelve-week antihypertensive treatment reduced both office-based and 24-h ambulatory BP measurements (P < 0.0005). The decrease in BP was accompanied by reduction in thiobarbituric acid-reactive substances (TBARS) (P < 0.05), increase in anti-oxLDL Ab titers (P < 0.005), and improvement in flow-mediated dilation (FMD) (P < 0.0005), independently of treatment. Although BP was reduced, we observed favorable changes in anti-oxLDL titers and FMD. CONCLUSIONS We observed that anti-oxLDL Ab titers increase after antihypertensive therapy in primary prevention when achieving BP targets. Our results are in agreement with the concept that propensity to oxidation is increased by essential hypertension and anti-oxLDL Abs may be protective and potential biomarkers for the follow-up of hypertension treatment.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The objective of the study was to evaluate saliva flow rate, buffer capacity, pH levels, and dental caries experience (DCE) in autistic individuals, comparing the results with a control group (CG). The study was performed on 25 noninstitutionalized autistic boys, divided in two groups. G1 composed of ten children, ages 3-8. G2 composed of 15 adolescents ages 9-13. The CG was composed of 25 healthy boys, randomly selected and also divided in two groups: CG3 composed of 14 children ages 4-8, and CG4 composed of 11 adolescents ages 9-14. Whole saliva was collected under slight suction, and pH and buffer capacity were determined using a digital pHmeter. Buffer capacity was measured by titration using 0.01 N HCl, and the flow rate expressed in ml/min, and the DCE was expressed by decayed, missing, and filled teeth (permanent dentition [DMFT] and primary dentition [dmft]). Data were plotted and submitted to nonparametric (Kruskal-Wallis) and parametric (Student`s t test) statistical tests with a significance level less than 0.05. When comparing G1 and CG3, groups did not differ in flow rate, pH levels, buffer capacity, or DMFT. Groups G2 and CG4 differ significantly in pH (p = 0.007) and pHi = 7.0 (p = 0.001), with lower scores for G2. In autistic individuals aged 3-8 and 9-13, medicated or not, there was no significant statistical difference in flow rate, pH, and buffer capacity. The comparison of DCE among autistic children and CG children with deciduous (dmft) and mixed/permanent decayed, missing, and filled teeth (DMFT) did not show statistical difference (p = 0.743). Data suggest that autistic individuals have neither a higher flow rate nor a better buffer capacity. Similar DCE was observed in both groups studied.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The necessity to adapt sensors based on electrochemical techniques for high throughput analysis control increases the interest to develop new analytical systems able to perform measurements under buffer now. In this report we explored the possibility of employing a new system to make impedimetric measurements to detect the interaction between proteins and small molecules. The well-known biotin-streptavidin interaction was adopted to evaluate the proposed assembly. This system allows us to perform experiments under flow. Magnetic beads functionalized with streptavidin were used and first characterized using AFM and FTIR. Non-faradic impedance spectroscopy allowed the detection of the biotin-streptavidin interaction. Using our new system and under a flow of PBS buffer, 5 10-5 M of biotin was detected with a stable signal. (c) 2007 Elsevier B.V. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The ethanol extract from Xyris pteygoblephara aerial parts was evaluated against five microorganism strains, by the microdilution and agar diffusion methods. Extract fractionation led to the isolation of three compounds, whose structures were assigned by spectrometric data (113 and 2D NMR, IR, MS and UV) as (3R,4R)-(-)-6-methoxy-3,4-dihydro-3-n-pentil-4-acethoxy-1H-2-benzopyran-1-one (1), moronic acid and quercetin. The absolute configuration of I was defined by circular dichroism spectroscopy and comparison with data reported for other dihydroisocoumarins. Assay of 1 (100 mu g/disc) by the agar diffusion method against clinical isolates of the dermatophytes Epidermophyton floccosum (inhibition zone, mm +/- s.d.: 4.5 +/- 0.8), Trichophyton mentagrophytes (4.8 +/- 0.4) and Trichophyton rubrum (10.2 +/- 0.8) revealed similar inhibition zones to the positive control amphotericin B (32 mu g/disc; 5.0 +/- 0.2; 5.0 +/- 0.6 and 8.8 +/- 1.2, respectively). The result corroborates the ethnomedical use of Xyris species to treat dermatitis. (C) 2007 Elsevier Ltd. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Time-dependent fluctuations in surface-enhanced Raman scattering (SERS) intensities were recorded from a roughened silver electrode immersed in diluted solutions of rhodamine 6G (R6G) and congo red (CR). These fluctuations were attributed to a small number of SERS-active molecules probing regions of extremely high electromagnetic field (hot spots) at the nanostructured surface. The time-dependent distribution of SERS intensities followed a tailed statistics at certain applied potentials, which has been linked to single-molecule dynamics. The shape of the distribution was reversibly tuned by the applied voltage. Mixtures of both dyes, R6G and CR, at low concentrations were also investigated. Since R6G is a cationic dye and CR is an anionic dye, the statistics of the SERS intensity distribution of either dye in a mixture were independently controlled by adjusting the applied potential. The potential-controlled distribution of SERS intensities was interpreted by considering the modulation of the surface coverage of the adsorbed dye by the interfacial electric field. This interpretation was supported by a two-dimensional Monte Carlo simulation that took into account the time evolution of the surface configuration of the adsorbed species and their probability to populate a hypothetical hot spot. The potential-controlled SERS dynamics reported here is a first step toward the spectroelectrochemical investigation of redox processes at the single-molecule level by SERS.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A biomimetic sensor is proposed as a promising new analytical method for determination of captopril in different classes of samples. The sensor was prepared by modifying a carbon paste electrode with iron (II) phthalocyanine bis(pyridine) [FePe(dipy)] complex. Amperometric measurements in a batch analytical mode were first carried out in order to optimize the sensor response. An applied potential lower than 0.2 V vs Ag vertical bar AgCl in 0.1 mol L(-1) of TRIS buffer at pH 8.0 provided the best response, with a linear range of 2.5 x 10(-5) to 1.7 x 10(-4) mol L(-1). A detailed investigation of the selectivity of the sensor, employing seventeen other drugs, was also performed. Recovery studies were carried out using biological and environment samples in order to evaluate the sensor`s potential for use with these sample classes. Finally, the performance of the biomimetic sensor was optimized in a flow injection (FIA) system using a wall jet electrochemical cell. Under optimized flow conditions, a broad linear response range, from 5.0 x 10(-4) to 2.5 x 10(-2) mol L(-1), was obtained for captopril, with a sensitivity of 210 +/- 1 mu A L mol(-1).

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background Overcrowding in emergency departments is a worldwide problem. A systematic literature review was undertaken to scientifically explore which interventions improve patient flow in emergency departments. Methods A systematic literature search for flow processes in emergency departments was followed by assessment of relevance and methodological quality of each individual study fulfilling the inclusion criteria. Studies were excluded if they did not present data on waiting time, length of stay, patients leaving the emergency department without being seen or other flow parameters based on a nonselected material of patients. Only studies with a control group, either in a randomized controlled trial or in an observational study with historical controls, were included. For each intervention, the level of scientific evidence was rated according to the GRADE system, launched by a WHO-supported working group. Results The interventions were grouped into streaming, fast track, team triage, point-of-care testing (performing laboratory analysis in the emergency department), and nurse-requested x-ray. Thirty-three studies, including over 800,000 patients in total, were included. Scientific evidence on the effect of fast track on waiting time, length of stay, and left without being seen was moderately strong. The effect of team triage on left without being seen was relatively strong, but the evidence for all other interventions was limited or insufficient. Conclusions Introducing fast track for patients with less severe symptoms results in shorter waiting time, shorter length of stay, and fewer patients leaving without being seen. Team triage, with a physician in the team, will probably result in shorter waiting time and shorter length of stay and most likely in fewer patients leaving without being seen. There is only limited scientific evidence that streaming of patients into different tracks, performing laboratory analysis in the emergency department or having nurses to request certain x-rays results in shorter waiting time and length of stay.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This article discusses teachers’ attitudes towards immigrant students in poor settings and the effect these attitudes have on organization of education on classroom level. It draws on results from two ethnographic studies where some primary school classes in Sweden were followed with participant observation and interviews as main research methods. The article focuses on classroom activities and teachers’ attitudes towards immigrant students and students with low socio-economic status. In the article is argued for the importance of presenting students in poor settings with demanding tasks and challenging education. In these cases, intellectually undemanding tasks in combination with little room for students’ own initiatives resulted in low enthusiasm among students regarding schoolwork and accordingly low learning, while classroom work that demanded active involvement by students in combination with high level of students’ influence on what took place in classrooms resulted in high level of students’ engagement and high outcome.