Institutional finance for agricultural development

The authors review the literature to see at how rural financial institutions (RFIs) are organized, how they can improve their financial viability, and how real interest rates affect the demand for rural loans, the supply of rural deposits, and rural savings. Their purpose is to make the findings of the extensive literature on agricultural credit policy accessible to developing-country policymakers. The review addresses six major questions: Why promote formal RFIs? How should RFIs be organized? What are the transaction costs of RFIs and how should they be measured? What effects do real interest rates and other factors have on rural loans, deposits, and savings? What determines whether an RFI system is a net contributor to or a drain on public resources? And, what policy conclusions can be drawn from this analysis? To answer these questions, Desai and Mellor look at the literature on RFIs in high-, middle-, and low-income countries, both developed and developing. They include countries in four developing regions Sub-Saharan Africa, Asia, the Near East and Mediterranean Basin, and Latin America and the Caribbean as well as Western Europe and North America.Rural credit Developing countries. ,Financial institutions. ,

Pressure Dependence of Fragile-to-Strong Transition and a Possible Second Critical Point in Supercooled Confined Water

By confining water in nano-pores of silica glass, we can bypass the crystallization and study the pressure effect on the dynamical behavior in deeply supercooled state using neutron scattering. We observe a clear evidence of a cusp-like fragile-to-strong (F-S) dynamic transition. Here we show that the transition temperature decreases steadily with an increasing pressure, until it intersects the homogenous nucleation temperature line of bulk water at a pressure of 1600 bar. Above this pressure, it is no longer possible to discern the characteristic feature of the F-S transition. Identification of this end point with the possible second critical point is discussed.Comment: 4 pages, 3 figure

Reductive Cleavage of the Nitrogen-Nitrogen Bond in Hydrazine Derivatives

The reductions of the 1,2-disubstituted hydrazines (4)-(7) having the activating groups toluene-psulphonyl, acetyl, ethoxycarbonyl, and trifluoroacetyl respectively have been studied with zinc in acetic acid, aluminium amalgam, sodium in liquid ammonia, sodium in ethanol, and Raney nickel. Satisfactory conditions have been defined for the reductive cleavage of each of these substituted hydrazines (4)-(7). The Diels-Alder adduct (1 2) of cyclopentadiene and diethyl azodicarboxylate has been oxidised, by m-chloroperoxybenzoic acid to give the epoxide (ZO), by osmium tetraoxide to give the diol (21), and via hydroboration to give the alcohol (22). Using sodium in liquid ammonia these hydrazine derivatives (20)-(22) and others have been reduced by cleavage of the nitrogen-nitrogen bond to give derivatives of oxygenated cyclic diamines. Although the reaction of the esters of azodicarboxylic acid with many different dienes to give Diels-Alder adducts is well established,' with the exception of a single recent example these adducts have not been used in the synthesis of diamine derivatives via a reductive cleavage of the nitrogen-nitrogen bond. Recently Forrest and Schmidt reported the transformation of the Diels-Alder adduct (1) via several steps to the amide (2). A key step was the reductive cleavage of the hydrazine derivative (3) carried out in unstated yield by sodium in liquid ammonia. In this paper we report our studies of the reductive cleavage of hydrazine derivatives. Following preliminary studies which establish the optimum conditions for cleavage of different hydrazine derivatives, we show that products readily obtained from Diels-Alder adducts of cyclic dienes are efficiently reduced to give derivatives of cyclic diamines. Such diamines are the present focus of much synthetic i n t e r e~t .~'~ This route based on elaboration of Diels-Alder adducts of cyclic dienes with azo-dienophiles complements similar routes which stereospecifically afford sugar derivatives by the elaboration of Diels-Alder adducts of furans or cyclic dienes with substituted ethylenes. Previous studies of the reductive cleavage of the nitrogen--nitrogen bond in hydrazine derivatives have established that cleavage to give amine derivatives may be achieved by hydrogenation,6 by reduction with aluminium ' or boron hydrides,* or by successive single electron and proton transfer^.^ In general, non-aromatic hydrazines are much more difficult to reduce than aromatic hydrazines, and partially substituted hydrazines are more resistent to reduction than fully substituted hydrazines. Simple alkylhydrazines are readily cleaved to give amines by hydrogenation under acidic conditions. However their amide derivatives are resistant to hydrogenolytic cleavage. Thus reductive cleavage of some cyclic hydrazines in the synthesis of amino sugars l o can require hydrogenation under elevated pressure conditions. Reductive cleavage of the nitrogen-nitrogen bond in aliphatic hydrazines '1' by aluminium hydride or boron hydride is very sluggish. These reagents can be efficiently used to reduce the carbonyl functionality in hydrazide derivatives, but forcing conditions are required to give amine products. Our attention focussed on the methods of possible nitrogen-nitrogen cleavage by successive electron and proton transfers. The constraints imposed by the choice of a good dienophile for the Diels-Alder reaction establish that the most efficient route involving a reductive cleavage would be by cleavage of a diacyl hydrazide or related compound. Variation of the acyl moiety controls the relative electron affinity of the hydrazine derivative to be cleaved. Hence the choice of acyl moiety could dictate the appropriate dissolving metal conditions necessary to effect cleavage of the nitrogen-nitrogen bond. The control by acyl substitution of the ease of reduction of hydrazine derivatives has been demonstrated in an electrochemical study l 1 by Horner and Jordan. The importance of adequate activation of the hydrazine derivative is shown by the successful reduction using sodium in liquid ammonia of the diacylhydrazine derivative (3) which contrast with the failure to reduce the nitrogen-nitrogen bond in an unactivated hydrazine l 2 using sodium in liquid ammonia. Zinc has been used as an alternative reducing agent,I3 but examples indicate the resistance to cleavage of the nitrogen-nitrogen bond with this metal as an electron source. The lack of comparative data relating the degree of activation of hydrazine derivatives with the possible metal reducing agents prompted us to examine briefly the behaviour of some metals with some simple hydrazine derivatives. The hydrazine derivatives (4j-47) were chosen to illustrate different degrees of activation with respect to dissolving metal reductants. In the Table the results of the attempted reduction of the hydrazine derivatives (4)-47) are described. The ditosylhydrazine (4) can be reductively cleaved to give the toluenep-sulphonyl derivative (9) of methylamine by zinc in acetic acid or by aluminium amalgam. Under similar conditions the les

A core mechanism for specifying root vascular patterning can replicate the anatomical variation seen in diverse plant species

Pattern formation is typically controlled through the interaction between molecular signals within a given tissue. During early embryonic development, roots of the model plant Arabidopsis thatiana have a radially symmetric pattern, but a heterogeneous input of the hormone auxin from the two cotyledons forces the vascular cylinder to develop a diarch pattern with two xylem poles. Molecular analyses and mathematical approaches have uncovered the regulatory circuit that propagates this initial auxin signal into a stable cellular pattern. The diarch pattern seen in Arabidopsis is relatively uncommon among flowering plants, with most species having between three and eight xylem poles. Here, we have used multiscale mathematical modelling to demonstrate that this regulatory module does not require a heterogeneous auxin input to specify the vascular pattern. Instead, the pattern can emerge dynamically, with its final form dependent upon spatial constraints and growth. The predictions of our simulations compare to experimental observations of xylem pole number across a range of species, as well as in transgenic systems in Arabidopsis in which we manipulate the size of the vascular cylinder. By considering the spatial constraints, our model is able to explain much of the diversity seen in different flowering plant species.Peer reviewe

Activation of Muscarinic M1 Acetylcholine Receptors Induces Long-Term Potentiation in the Hippocampus

Muscarinic M1 acetylcholine receptors (M1Rs) are highly expressed in the hippocampus, and their inhibition or ablation disrupts the encoding of spatial memory. It has been hypothesized that the principal mechanism by which M1Rs influence spatial memory is by the regulation of hippocampal synaptic plasticity. Here, we use a combination of recently developed, well characterized, selective M1R agonists and M1R knock-out mice to define the roles of M1Rs in the regulation of hippocampal neuronal and synaptic function. We confirm that M1R activation increases input resistance and depolarizes hippocampal CA1 pyramidal neurons and show that this profoundly increases excitatory postsynaptic potential-spike coupling. Consistent with a critical role for M1Rs in synaptic plasticity, we now show that M1R activation produces a robust potentiation of glutamatergic synaptic transmission onto CA1 pyramidal neurons that has all the hallmarks of long-term potentiation (LTP): The potentiation requires NMDA receptor activity and bi-directionally occludes with synaptically induced LTP. Thus, we describe synergistic mechanisms by which acetylcholine acting through M1Rs excites CA1 pyramidal neurons and induces LTP, to profoundly increase activation of CA1 pyramidal neurons. These features are predicted to make a major contribution to the pro-cognitive effects of cholinergic transmission in rodents and humans

Cohort profile : the Scottish Diabetes Research Network national diabetes cohort - a population-based cohort of people with diabetes in Scotland

© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.Peer reviewedPublisher PD

Rising Rates And Widening Socio-economic Disparities In Diabetic Ketoacidosis In Type 1 Diabetes In Scotland:A Nationwide Retrospective Cohort Observational Study

OBJECTIVE: Whether advances in the management of type 1 diabetes are reducing rates of diabetic ketoacidosis (DKA) is unclear. We investigated time trends in DKA rates in a national cohort of individuals with type 1 diabetes monitored for 14 years, overall and by socioeconomic characteristics. RESEARCH DESIGN AND METHODS: All individuals in Scotland with type 1 diabetes who were alive and at least 1 year old between 1 January 2004 and 31 December 2018 were identified using the national register (N 5 37,939). DKA deaths and hospital admissions were obtained through linkage to Scottish national death and morbidity records. Bayesian regression was used to test for DKA time trends and association with risk markers, including socioeconomic deprivation. RESULTS: There were 30,427 DKA admissions and 472 DKA deaths observed over 393,223 person-years at risk. DKA event rates increased over the study period (incidence rate ratio [IRR] per year 1.058 [95% credibility interval 1.054–1.061]). Males had lower rates than females (IRR male-to-female 0.814 [0.776–0.855]). DKA incidence rose in all age-groups other than 10- to 19-year-olds, in whom rates were the highest, but fell over the study. There was a large socioeconomic differential (IRR least-to-most deprived quintile 0.446 [0.406–0.490]), which increased during follow-up. Insulin pump use or completion of structured education were associated with lower DKA rates, and antidepressant and methadone prescription were associated with higher DKA rates. CONCLUSIONS: DKA incidence has risen since 2004, except in 10- to 19-year-olds. Of particular concern are the strong and widening socioeconomic disparities in DKA outcomes. Efforts to prevent DKA, especially in vulnerable groups, require strengthening

Receptionist rECognition and rEferral of PaTients with Stroke (RECEPTS) study - protocol of a mixed methods study

BACKGROUND: As the first point of contact for patients and witnesses of stroke, General Practice receptionists can be instrumental in deciding the urgency of clinical contact. Despite the considerable complexity of this task, reception staff are not clinically trained. Minimising the time taken to access thrombolysis is crucial in acute stroke as treatment must be initiated within 4.5 hours of the onset, and the earlier the better, to achieve the best outcomes. Research suggests that patients who first contact their General Practice following the onset of stroke symptoms are less likely to receive thrombolysis, in part due to significant delays within Primary Care.This study therefore aims to understand the role of General Practice receptionists, with particular interest in receptionist's ability to recognise people who may be suffering from a stroke and to handle such patients as a medical emergency. METHODS: The Receptionist rECognition and rEferral of PaTients with Stroke (RECEPTS) study will be a Primary Care based mixed methods study. 60 General Practices in the West Midlands will be recruited. Each practice will receive 10 unannounced simulated patient telephone calls, after the 10 calls questionnaires will be administered to each receptionist. These will examine the behaviour of receptionists towards patients presenting in Primary Care with stroke symptoms, and their knowledge of stroke symptoms. An embedded qualitative study will use interviews and focus groups to investigate the views of General Practice staff on the receptionists' role in patient referral and whether training in this area would be helpful. DISCUSSION: The results of the RECEPTS study will have important implications for providers of Primary Care. The study will establish current practice in UK primary care in terms of General Practice receptionists' knowledge of the presentation and appropriate referral of those who may be suffering a stroke. It will highlight training needs and how such training might be best delivered