Risk and Growth: Theoretical Relationships and Preliminary Estimates for South Africa

In the recent literature on economic growth there is disagreement over the relationship between growth and volatility and their relative benefits and costs in welfare terms. An analytical resolution of this issue, which has serious implications for domestic and international development policies, has been seen to be contingent upon how relative risk aversion and intertemporal substitutability are related in frameworks characterizing utility maximization of representative agents. It is commonly assumed that these aspects of preferences are rigidly linked, casting doubt on the expected utility maximizing paradigm as an appropriate modeling methodology for analyzing this important issue. In this paper it is first shown that these concerns are only relevant for special functional forms that enforce a unitary consumption elasticity of wealth. Next, a theoretical approach is employed to specify a more general relationship between risk aversion and intertemporal substitutability. The theoretical model is developed in the context of a two country representative agent model where risk affects domestic and direct foreign investment in both countries. The two country orientation is also capable of interpretation of the relationship between one country and the rest of the world. In a preliminary empirical application of the methodology to South African data, we attempt estimation of the parameters of generalized functions for preferences and technology which are capable of distinguishing between risk aversion and intertemporal substitutability.

Improved grazing management practices in the catchments of the Great Barrier Reef, Australia: Does climate variability influence their adoption by landholders?

The declining health of the Great Barrier Reef from diffuse source pollutants has resulted in substantial policy attention on increasing the adoption of improved management practices by agricultural producers. Although economic modelling indicates that many improved management practices are financially rewarding, landholders with dated management practices remain hesitant to change. This research involved bio-economic modelling to understand the variance in private returns for grazing enterprises across a climate cycle. Results show that financial returns to landholders can vary substantially across different 20-year periods of a climate cycle, demonstrating that the variability in expected returns may be an important reason why landholders are cautious about changing their management practices. Although previous research has separately identified financial returns and attitudes to risk and uncertainty of landholders as key influences on decisions concerning adoption of improved management practices, this research demonstrates that it is the interaction between these factors that is important to understand when designing policy settings. © Australian Rangeland Society

Cobimetinib and trametinib inhibit platelet MEK but do not cause platelet dysfunction

The MEK inhibitors cobimetinib and trametinib are used in combination with BRAF inhibitors to treat metastatic melanoma but increase rates of hemorrhage relative to BRAF inhibitors alone. Platelets express several members of the MAPK signalling cascade including MEK1 and MEK2 and ERK1 and ERK2 but their role in platelet function and haemostasis is ambiguous as previous reports have been contradictory. It is therefore unclear if MEK inhibitors might be causing platelet dysfunction and contributing to increased hemorrhage. In the present study we performed pharmacological characterisation of cobimetinib and trametinib in vitro to investigate potential for MEK inhibitors to cause platelet dysfunction. We report that whilst both cobimetinib and trametinib are potent inhibitors of platelet MEK activity, treatment with trametinib did not alter platelet function. Treatment with cobimetinib results in inhibition of platelet aggregation, integrin activation, alpha-granule secretion and adhesion but only at suprapharmacological concentrations. We identified that the inhibitory effects of high concentrations of cobimetinib are associated with off-target inhibition on Akt and PKC. Neither inhibitor caused any alteration in thrombus formation on collagen under flow conditions in vitro. Our findings demonstrate that platelets are able to function normally when MEK activity is fully inhibited, indicating MEK activity is dispensable for normal platelet function. We conclude that the MEK inhibitors cobimetinib and trametinib do not induce platelet dysfunction and are therefore unlikely to contribute to increased incidence of bleeding reported during MEK inhibitor therapy

Effect of Defoliation Interval on Regrowth of Leaves and Roots, and Tiller Number of Cocksfoot Plants

The key to defoliation management for optimal production and persistence of pasture lies in the use of a physiological basis for defoliation interval (specific to plant type), as opposed to a regime based on time or the height of herbage. The full expansion of a particular number of leaves/tiller is a useful plant-related indicator of optimal defoliation timing. Leaf regrowth stage (\u27leaf stage\u27) reflects the stage of plant recovery from defoliation as regards plant energy levels (Fulkerson & Donaghy, 2001). The level of water-soluble carbohydrate (WSC) reserves in grass tiller bases influences the rate of regrowth after defoliation, affecting the rate of shoot growth, root growth and tillering. This study was aimed to determine the influence of leaf stage based defoliation interval on regrowth of leaves and root, and on tiller number of \u27Kara\u27 cocksfoot plants up to 24 days after defoliation

The Nutritional Value of Cocksfoot (\u3ci\u3eDactylis glomerata L.) and Perennial Ryegrass (\u3ci\u3eLolium perenne L.\u3c/i\u3e) Under Leaf-Stage Based Defoliation Management

The perception that cocksfoot is of lower nutritional value and less productive than perennial ryegrass is largely the result of studies in which management was based on perennial ryegrass (to the detriment of cocksfoot) or involved defoliation of both species at the same time (Greenhalgh & Reid, 1969; Johnson & Thomson, 1996). Maintaining plants in a vegetative state through species-specific management is essential to retain the high quality and productivity of cocksfoot. Defoliation at or before 4-5 fully expanded live leaves per tiller is recommended as the ideal physiological regrowth stage for defoliation of cocksfoot, resulting in metabolisable energy (ME) levels in excess of 11MJ/kg dry matter (DM) (Rawnsley et al., 2002). The aim of the current study was to provide an objective comparison of the nutritional value of cocksfoot and perennial ryegrass grown in dryland conditions under a management regime based on the physiological status of each grass species

A qualitative study of primary care professionals’ views of case finding for depression in patients with diabetes or coronary heart disease in the UK

<p>Background Routinely conducting case finding (also commonly referred to as screening) in patients with chronic illness for depression in primary care appears to have little impact. We explored the views and experiences of primary care nurses, doctors and managers to understand how the implementation of case finding/screening might impact on its effectiveness.</p> <p>Methods Two complementary qualitative focus group studies of primary care professionals including nurses, doctors and managers, in five primary care practices and five Community Health Partnerships, were conducted in Scotland.</p> <p>Results We identified several features of the way case finding/screening was implemented that may lead to systematic under-detection of depression. These included obstacles to incorporating case finding/screening into a clinical review consultation; a perception of replacing individualised care with mechanistic assessment, and a disconnection for nurses between management of physical and mental health. Far from being a standardised process that encouraged detection of depression, participants described case finding/screening as being conducted in a way which biased it towards negative responses, and for nurses, it was an uncomfortable task for which they lacked the necessary skills to provide immediate support to patients at the time of diagnosis.</p> <p>Conclusion The introduction of case finding/screening for depression into routine chronic illness management is not straightforward. Routinized case finding/screening for depression can be implemented in ways that may be counterproductive to engagement (particularly by nurses), with the mental health needs of patients living with long term conditions. If case finding/screening or engagement with mental health problems is to be promoted, primary care nurses require more training to increase their confidence in raising and dealing with mental health issues and GPs and nurses need to work collectively to develop the relational work required to promote cognitive participation in case finding/screening.</p&gt

Implications of using an extended lactation to change from a spring-calving to an autumn-calving farm system in South Taranaki

Recent changes to pasture-supply curves in South Taranaki, and the availability of winter milk premiums have increased farmer interest in changing from a spring-calving to an autumn-calving farm system. One approach to changing the season of calving from spring to autumn is to extend the calving interval (CI) by delaying the mating period by ~8 months, so that they next calve in autumn and undertake an extended lactation [>305 days in milk (DIM)]. A large-scale farmlet experiment was established in South Taranaki to investigate the production and reproduction responses of cows using this approach. In June 2017, 602 springcalving cows were allocated to two farmlets. In one farmlet (SPR) 301 cows were mated in October to maintain a 12-month CI spring-calving pattern. In the other farmlet (AUT, n=301 cows), mating was delayed for eight months, and cows underwent an extended lactation (mean DIM, 488; max DIM, 577) to calve next in autumn 2019. The experiment analysed two lactations for the AUT farmlet and two and a half lactations for the SPR farmlet. Across the total experimental period, milksolids (MS) production was similar between farmlets (1,194 vs. 1,174 kg MS/cow), however, cows in the AUT farmlet were fed more supplementary feed [2,371 vs. 1,951 kg dry matter (DM)/cow]. The extended lactation changed the relationship between feed supply and herd demand, which led to excessive BCS gain and ryegrass staggers for AUT farmlet cows. Further research is required to examine grazing management during extended lactations and to assess the economic implications of this approach.fals

Genetic and phenotypic factors inuencing milk, protein and fat yields of dairy cows in Tasmania, Australia

The Australian State of Tasmania enjoys a cool, temperate climate that remains the backbone of its pasture-based dairy production system. In this study, 330,366 lactation records from 428 Tasmanian dairy herds collected between 2000 and 2005 were analysed. The objective was to determine the inuence of genetic and non-genetic factors on milk, protein and fat yields of pasture-based dairy cows. The data were statistically subjected to analyses of variance using general linear mixed model procedures with repeated measures. State-wide average milk yield per lactation over a standard 305-day lactation length was 5200.7 ± 1239.7 litres (ranging from 1107 to 13256 litres), while fat and protein yields averaged 205.5 ± 47.0 kg (ranging from 53 to 385 kg) and 166.2 ± 41.5 kg (ranging from 47 to 297 kg), respectively. Highly signicant (P<0.001) effects on milk, protein and fat yields attributable to variation in herd size, cow’s parity, breed, season and year of calving were detected. Milk yield increased linearly with increase in parity (means of 3482.4, 4019.5, 4615.4, 4826.1 and 5018.8 litres per lactation for parities 1, 2, 3, 4 and >4, respectively). Milk, fat and protein yields were highest in cows calving during the spring season (4769.8 litres, 215.2kg and 168 kg respectively), Holstein-Friesian genotypes produced the most milk (5211 litres), protein (171 kg) and fat (210kg) yields per lactation. Herd sizes of more than 1110 cows produced the most milk, fat and protein. Productivity per cow increased with calving year except in 2003 when total milk yield was lower than in 2002. We conclude that herd size, breed, parity, season and year of calving were among the main factors driving production of dairy cows in Tasmania and adjustments for these factors would be mandatory for any unbiased comparison of lactation performance within and between pasture-based dairy production systems