366 research outputs found
Making Bank irrigation investments more sustainable
This paper is about sustainability of irrigation investments in both the financial and physical senses. Finance provides the claim on resources necessary to accomplish physical operations in an economic system, while physical operations provide a flow of services for which beneficiaries are willing to pay in terms of claims on resources. This paper discusses two polar models of irrigation finance, followed by a discussion of quality control in irrigation and reviews of World Bank irrigation pricing policy, irrigation cost recovery and operations and maintenance funding conditionality experience. It includes a discussion of reasons for noncompliance with Bank irrigation lending conditionality. A framework for the design of sustainable irrigation investments is presented and a summary of results and recommendations is given.Environmental Economics&Policies,Agricultural Research,Drylands&Desertification,Agricultural Irrigation and Drainage,Banks&Banking Reform
Analyzing the effects of U.S. agricultural policy on Mexican agricultural markets using the MEXAGMKTS model
This paper uses results from simulations of the FAIRMODEL, USAGMKTS, and MEXAGMKTS models to analyze the effects of changes in U.S. agricultural policy on Mexican agricultural markets. The author concludes that under a scenario of trade liberalization for Mexico, Mexican agricultural production, prices, and trade are quite sensitive to agricultural policy changes in the U.S. The genesis of the research project was the perception that agricultural policies in Mexico (and many other countries) are often second best responses to the negative side effects of broad economic policies aimed primarily at macroeconomic and international trade objectives. The paper also discusses the role of agriculture in Mexican economic policy, and MEXAGMKTS, FAIR and USAGMKTS models. The paper includes an analysis of the sensitivity of Mexican agricultural markets to U.S. agricultural policy and a brief summary of the implications of the results.Environmental Economics&Policies,Economic Theory&Research,Agricultural Research,Access to Markets,Markets and Market Access
MEXAGMKTS : a model of crop and livestock markets in Mexico
The genesis of the model MEXAGMKTS was the perception that agricultural policies in Mexico (and many other countries) are often second-best responses to the negative side effects of broad macroeconomic and international trade policies. MEXAGMKTS was designed to allow analysis of the relationship between such agricultural policies and different macroeconomic and international trade regimes. MEXAGMKTS is part of a set of interlinked macroeconomic and sectoral models of Mexico and the United States (with enough specifications for the rest of the world to close the system). The authors discuss the historical context in which MEXAGMKTS was developed as well as its economic structure, estimates, and validation. They present a stand-alone, counterfactural application of a trade liberalization scenario for Mexico.Economic Theory&Research,Environmental Economics&Policies,Agricultural Research,Access to Markets,Markets and Market Access
Comments on alternative calculations of the broadening of spectral lines of neutral sodium by H-atom collisions
With the exception of the sodium D-lines recent calculations of line
broadening cross-sections for several multiplets of sodium by Leininger et al
(2000) are in substantial disagreement with cross-sections interpolated from
the tables of Anstee and O'Mara (1995) and Barklem and O'Mara (1997). The
discrepancy is as large as a factor of three for the 3p-4d multiplet. The two
theories are tested by using the results of each to synthesize lines in the
solar spectrum. It is found that generally the data from the theory of Anstee,
Barklem and O'Mara produce the best match to the observed solar spectrum. It is
found, using a simple model for reflection of the optical electron by the
potential barrier between the two atoms, that the reflection coefficient is too
large for avoided crossings with the upper states of subordinate lines to
contribute to line broadening, supporting the neglect of avoided ionic
crossings by Anstee, Barklem and O'Mara for these lines. The large
discrepancies between the two sets of calculations is a result of an
approximate treatment of avoided ionic crossings for these lines by Leininger
et al (2000).Comment: 18 pages, 5 ps figures included, to appear in J Phys B: At. Mol. Opt.
Phy
The allosteric inhibition of glycine transporter 2 by bioactive lipid analgesics is controlled by penetration into a deep lipid cavity.
The role of lipids in modulating membrane protein function is an emerging and rapidly growing area of research. The rational design of lipids that target membrane proteins for the treatment of pathological conditions is a novel extension in this field and provides a step forward in our understanding of membrane transporters. Bioactive lipids show considerable promise as analgesics for the treatment of chronic pain and bind to a high-affinity allosteric binding site on the human glycine transporter 2 (GlyT2 or SLC6A5). Here we use a combination of medicinal chemistry, electrophysiology, and computational modelling to develop a rational structure activity relationship for lipid inhibitors and demonstrate the key role of the lipid tail interactions for GlyT2 inhibition. Specifically, we examine how lipid inhibitor head group stereochemistry, tail length and double bond position promote enhanced inhibition. Overall, the L-stereoisomer is generally a better inhibitor than the D-stereoisomer, longer tail length correlates with greater potency, and the position of the double bond influences the activity of the inhibitor. We propose that the binding of the lipid inhibitor deep into the allosteric binding pocket is critical for inhibition. Furthermore, this provides insight into the mechanism of inhibition of GlyT2 and highlights how lipids can modulate the activity of membrane proteins by binding to cavities between helices. The principles identified in this work have broader implications for the development of a larger class of compounds that could target SLC6 transporters for disease treatment
Precision public health – A critical review of the opportunities and obstacles
The term ‘precision public health’ (PPH) refers to a new approach in public health which involves the use of novel data sources and/or computer science-driven methods of data analysis to predict risk or outcomes, in order to improve how interventions are targeted or tailored, with the aim of making them more individualised and therefore more effective and cost-effective than methods currently in use. These data may include, for example, information from social media or devices, genomic or clinical data, and information from healthcare services. In this critical review, which was conducted between March and October 2019, we outline key assumptions underpinning the PPH approach and identify potential challenges in its application. We adopted a pragmatic, non-systematic review methodology to examine: (i) the general principles underlying PPH; (ii) the validity of claims made about PPH in empirical studies and commentaries; and (iii) the potential opportunities and challenges of adopting a PPH approach through examining two case studies: health checks and community-based interventions. Non-empirical studies (commentaries and think-pieces) were included in this review because PPH represents an emerging approach and many of the ideas around the potential of PPH are only described in such studies Commentary studies emphasise that precision can be achieved in targeting interventions towards narrow social profiles of people through the incorporation of data reflecting micro-level day-to-day insights into the lives of individuals. Structured analysis of commentary studies shows that (i) the PPH field may be highly influenced by commentary and non-systematic review pieces that lack transparent methods but make claims about the potential of PPH; (ii) commentators on PPH often attempt to provide evidence for claims but the link between the evidence and the claim is often unsubstantiated when critically examined; and (iii) many of the assumptions underlying PPH are not supported by empirical evidence suggesting that there needs to be a measured approach to adopting PPH approaches. Claims around the effectiveness of PPH and around PPH being an advance on current public health approaches tended not to be supported by empirical evidence. As a relatively new concept therefore, there is limited direct empirical evidence showing PPH to be effective, and the theoretical arguments in its favour are often not well supported by evidence. The more ambitious claims made for PPH in the literature often rest on questionable readings of the evidence – for example, citing the possibility of identifying subgroups of the population through better targeting as though this automatically promises greater effectiveness among interventions targeting those subgroups. In practice, it seems that PPH is less a radically new paradigm and more a range of incremental improvements to public health interventions. Hypothetical case studies outlining the potential of a PPH approach applied to health checks and community-based interventions indicate several ways in which new data or tools could be productively used to inform the design and implementation of public health interventions. Current evidence suggests the impact of these is likely to be fairly modest, although further focused research (e.g. exploring the utility of strategies for targeting or involving communities using PPH) may merit further exploration and evaluation. Defining PPH is contentious and our findings reflect the difficulty in assessing and operationalising the broad ambition of using emerging data and technologies to better understand profiles, predict risk and outcomes, and act upon this evidence. Future work in this area should seek to introduce more focus around the concept of PPH, including being clearer about the goals and breaking down the concept into a series of components that can each be evaluated. The bulk of the work presented here took place between March and October 2019. There is scope for further analysis to understand the potential of PPH in the future, as the number of studies adopting a PPH approach grows. This larger pool of studies may also lend itself to more systematic approaches to reviewing the evidence, particularly if there is an interest in evaluating a particular component or principle of PPH. In addition, the evidence examined in this report predates the COVID-19 global pandemic, and many of the measures taken to mitigate the spread of the pandemic may provide a further source of evidence and data to understand the potential role of PPH in public health decision-making
Is Cu instability during the CO<inf>2</inf>reduction reaction governed by the applied potential or the local CO concentration?
Cu-based catalysts have shown structural instability during the electrochemical CO2reduction reaction (CO2RR). However, studies on monometallic Cu catalysts do not allow a nuanced differentiation between the contribution of the applied potential and the local concentration of CO as the reaction intermediate since both are inevitably linked. We first use bimetallic Ag-core/porous Cu-shell nanoparticles, which utilise nanoconfinement to generate high local CO concentrations at the Ag core at potentials at which the Cu shell is still inactive for the CO2RR. Usingoperandoliquid cell TEM in combination withex situTEM, we can unequivocally confirm that the local CO concentration is the main source for the Cu instability. The local CO concentration is then modulated by replacing the Ag-core with a Pd-core which further confirms the role of high local CO concentrations. Product quantification during CO2RR reveals an inherent trade-off between stability, selectivity and activity in both systems
Beef production from feedstuffs conserved using new technologies to reduce negative environmental impacts
End of project reportMost (ca. 86%) Irish farms make some silage. Besides directly providing feed for livestock, the provision of grass silage within integrated grassland systems makes an important positive contribution to effective grazing management and improved forage utilisation by grazing animals, and to effective feed budgeting by farmers. It can also contribute to maintaining the content of desirable species in pastures, and to livestock not succumbing to parasites at sensitive times of the year. Furthermore, the optimal recycling of nutrients collected from housed livestock can often be best achieved by spreading the manures on the land used for producing the conserved feed. On most Irish farms, grass silage will remain the main conserved forage for feeding to livestock during winter for the foreseeable future. However, on some farms high yields of whole-crop (i.e. grain + straw) cereals such as wheat, barley and triticale, and of forage maize, will be an alternative option provided that losses during harvesting, storage and feedout are minimised and that input costs are restrained. These alternative forages have the potential to reliably support high levels of animal performance while avoiding the production of effluent. Their production and use however will need to advantageously integrate into ruminant production systems. A range of technologies can be employed for crop production and conservation, and for beef production, and the optimal options need to be identified. Beef cattle being finished indoors are offered concentrate feedstuffs at rates that range from modest inputs through to ad libitum access. Such concentrates frequently contain high levels of cereals such as barley or wheat. These cereals are generally between 14% to 18% moisture content and tend to be rolled shortly before being included in coarse rations or are more finely processed prior to pelleting. Farmers thinking of using ‘high-moisture grain’ techniques for preserving and processing cereal grains destined for feeding to beef cattle need to know how the yield, conservation efficiency and feeding value of such grains compares with grains conserved using more conventional techniques. European Union policy strongly encourages a sustainable and multifunctional agriculture. Therefore, in addition to providing European consumers with quality food produced within approved systems, agriculture must also contribute positively to the conservation of natural resources and the upkeep of the rural landscape. Plastics are widely used in agriculture and their post-use fate on farms must not harm the environment - they must be managed to support the enduring sustainability of farming systems. There is an absence of information on the efficacy of some new options for covering and sealing silage with plastic sheeting and tyres, and an absence of an inventory of the use, re-use and post-use fate of plastic film on farms. Irish cattle farmers operate a large number of beef production systems, half of which use dairy bred calves. In the current, continuously changing production and market conditions, new beef systems must be considered. A computer package is required that will allow the rapid, repeatable simulation and assessment of alternate beef production systems using appropriate, standardised procedures. There is thus a need to construct, evaluate and utilise computer models of components of beef production systems and to develop mathematical relationships to link system components into a network that would support their integration into an optimal system model. This will provide a framework to integrate physical and financial on-farm conditions with models for estimating feed supply and animal growth patterns. Cash flow and profit/loss results will be developed. This will help identify optimal systems, indicate the cause of failure of imperfect systems and identify areas where applied research data are currently lacking, or more basic research is required
Fornical and non-fornical projections from the rat hippocampal formation to the anterior thalamic nuclei
The hippocampal formation and anterior thalamic nuclei form part of an interconnected network thought to support memory. A central pathway in this mnemonic network comprises the direct projections from the hippocampal formation to the anterior thalamic nuclei, projections that, in the primate brain, originate in the subicular cortices to reach the anterior thalamic nuclei by way of the fornix. In the rat brain, additional pathways involving the internal capsule have been described, linking the dorsal subiculum to the anteromedial thalamic nucleus, as well as the postsubiculum to the anterodorsal thalamic nucleus. Confirming such pathways is essential in order to appreciate how information is transferred from the hippocampal formation to the anterior thalamus and how it may be disrupted by fornix pathology. Accordingly, in the present study, pathway tracers were injected into the anterior thalamic nuclei and the dorsal subiculum of rats with fornix lesions. Contrary to previous descriptions, projections from the subiculum to the anteromedial thalamic nucleus overwhelmingly relied on the fornix. Dorsal subiculum projections to the majority of the anteroventral nucleus also predominantly relied on the fornix, although postsubicular inputs to the lateral dorsal part of the anteroventral nucleus, as well as to the anterodorsal and laterodorsal thalamic nuclei, largely involved a non-fornical pathway, via the internal capsule
A double shunt technique for the prevention of ischaemia of a congenital, solitary, pelvic kidney during abdominal aortic aneurysm repair: a case report
<p>Abstract</p> <p>Introduction</p> <p>Congenital solitary pelvic kidney is a rare condition, and its association with an abdominal aortic aneurysm is even more unusual. To the best of our knowledge, only two such cases have been reported in the literature to date.</p> <p>Case presentation</p> <p>We report the case of a 59-year-old Caucasian man with a congenital solitary pelvic kidney, who was found to have an abdominal aortic aneurysm 83 mm in diameter. Abdominal computed tomography angiography clearly identified two renal arteries, one originating from the aortic bifurcation. and the other from the proximal portion of the right common iliac artery. At surgery, renal ischaemia was prevented by introduction of an axillofemoral shunt (consisting of two femoral cannulas and a vent tube of extracorporeal circulation) from the right axillary to the right femoral artery, and a second Argyle shunt from the right common iliac artery to the origin of the left renal artery. A 20 mm Dacron tube graft was then implanted. Our patient's postoperative renal function was normal.</p> <p>Conclusion</p> <p>The renal preservation double shunt technique used in this case seems to be effective during abdominal aortic aneurysm repair.</p
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