Root growth and crop yield of two varieties of wheat grown under differing irrigation regimes : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Plant Science at Massey University

Root growth and crop yield of Gamenya, a standard height variety, and Karamu, a semi-dwarf, spring wheat were compared under 3 irrigation regimes: daily watering; infrequent (fortnightly) watering; and sub-irrigation, where water was introduced into the soil profile at 40cm, the plots being protected from rainfall. Root growth and development were similar between varieties apart from an indication that the Karamu root system was more extensive at depth. The three irrigation treatments grew distinctly different root systems which was probably due partly to soil compaction differences between the treatments rather than the spatial distribution of the soil water supply. Karamu outyielded Gamenya because of a higher grain weight per ear due to higher floret viability and greater grain weight. Yield differences between irrigation treatments, where the infrequently irrigated treatment was superior, was due to ear population differences related to the differing root systems. With daily irrigation Gamenya used more water, due possibly to the lower leaf water potentials developed in the crop. An inverted water potential difference between the ear and the flag leaf was observed during the middle of the day

Epigenetic Switching: Bacteria Hedge Bets about Staying or Moving

SummaryGrowing populations of Bacillus subtilis exhibit bistability: motile cells co-exist with long chains of sessile cells. An epigenetic switch has been characterized that controls the transition between the two cell types

Incentive Effects of Retirement Income Transfers

The paper explores the incentive effects of retirement income transfers – essentially, non-contributory cash transfers aimed at reducing poverty among the elderly. A literature review reveals how little academic analysis of the impact of these transfers has been completed. We begin with a taxonomy of retirement income transfers, differentiating between ex-ante and ex-post interventions and universal and targeted arrangements. This distinction allows important differences across designs to be highlighted. We then provide a simple framework for thinking about what the incentive impacts of the transfers might be, distinguishing between effects related to the transfer itself and those related to the financing mechanism. Thus, from theory and available empirical evidence we derive a few policy relevant findings. First, incentive effects will depend on the level of the transfer relative to average earnings and the degree of integration between the formal and informal sectors in the economy. In general, for modest transfers, negative impacts on savings and labor supply would be contained. Second, we highlight the tradeoff between maintaining low effective marginal tax rates (EMTRs) to reduce distortions and keeping the program costs at affordable levels. This tradeoff suggests that universal programs are suboptimal. Third, in terms of design features, we emphasize the importance of implementing a gradual withdrawal of the benefit to avoid crowding-out contributory pensions among low income individuals and of indexing the eligibility age with life expectancy to contain costs. Finally we find that matching contributions can be a promising instrument to promote savings among individuals with limited savings capacity.Social pensions, Pension coverage, Retirement Insurance, matching contributions

Shifting ground: agricultural R&D worldwide

This brief summarizes the book, Agricultural R&D in the Developing World: Too Little, Too Late?, edited by Philip G. Pardey, Julian M. Alston, and Roley R. Piggott. The authors of the brief look at topics such as: International spillovers of public agricultural R&D; patterns of worldwide public investments in agricultural research; pervasive underfunding of agricultural research; divergent research agendas. The brief examines policy implications and concludes that "The issues are large scale and long term and demand serious attention, including further, more specific analysis. The national governments of developing countries can take some initiative, as indicated by the analysis of case studies in the book, in areas of national agricultural research policy such as: (1) enhancing IPR and tailoring the institutional and policy details of intellectual property to best fit local circumstances, (2) increasing the total amount of government funding for their national agricultural research systems, (3) introducing institutional arrangements and incentives for private and joint public–private funding, such as matching grants and check-off funds, and (4) improving the processes by which agricultural research resources are administered and allocated." From textAgricultural R&D, Public investments, Agricultural economics and policies, Agricultural innovations, Agricultural policy, Government spending policy, intellectual property,

Effectiveness of dermoscopy in skin cancer diagnosis

Clinical Inquiries question: Does dermoscopy improve the effectiveness of skin cancer diagnosis when used for skin cancer screening? Evidence-based answer: Dermoscopy added to visual inspection is more accurate than visual inspection alone in the diagnosis of melanoma and basal cell carcinoma (BCC). However, there is insufficient evidence to draw conclusions on the effectiveness of dermoscopy in the diagnosis of squamous cell carcinoma (SCC; strength of recommendation B: based on systematic reviews of randomized controlled trials [RCTs], and prospective and retrospective observational studies).Sydney Davis, MD; Cleveland Piggott, MD, MPH; Corey Lyon, DO; Kristen DeSanto, MSLS, MS, RD, AHIPDr Davis is a resident family physician, Dr Piggott is Assistant Professor and Director of Diversity & Health Equity for Family Medicine, Dr Lyon is Associate Professor in the Department of Family Medicine, and Ms DeSanto is Clinical Librarian in the Strauss Health Sciences Library, all at the University of Colorado in Denver.Includes bibliographical reference

Mobility of the SecA 2-helix-finger is not essential for polypeptide translocation via the SecYEG complex

The bacterial ATPase SecA and protein channel complex SecYEG form the core of an essential protein translocation machinery. The nature of the conformational changes induced by each stage of the hydrolytic cycle of ATP and how they are coupled to protein translocation are not well understood. The structure of the SecA–SecYEG complex revealed a 2-helix-finger (2HF) of SecA in an ideal position to contact the substrate protein and push it through the membrane. Surprisingly, immobilization of this finger at the edge of the protein channel had no effect on translocation, whereas its imposition inside the channel blocked transport. This analysis resolves the stoichiometry of the active complex, demonstrating that after the initiation process translocation requires only one copy each of SecA and SecYEG. The results also have important implications on the mechanism of energy transduction and the power stroke driving transport. Evidently, the 2HF is not a highly mobile transducing element of polypeptide translocation