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Conservation tillage offers economic and soil quality benefits, yet conventional tillage remains the prevailing system in some regions. The purpose of this study is to identify the effect of profitability factors, risk attitudes, crop rotations, and other farmer and farm characteristics on farmers’ choices to use no-till (NT), strip-till (ST) and reduced/conventional tillage (RCT) in producing dryland corn, wheat, and soybean in Kansas. The results show that factors such as crop yields, risk aversion, crop insurance, baling and grazing of crop residue, crop acreage, and farmers’ approach to adopting new technologies are significant factors in farmers’ choice of tillage practice.
Over the past few decades, farmers have increasingly integrated cover crops into their cropping systems. Cover-crop benefits can help a farmer to achieve sustainability or reduce negative environmental externalities, such as soil erosion or chemical runoff. However, the impact on farm economics will likely be the strongest incentive to adopt cover crops. These impacts can include farm profits, cash crop yields or both. This paper provides a review of cover-crop adoption, production, risk and policy considerations from an economic perspective. These dimensions are examined through a review of cover-crop literature. This review was written to provide an overview of cover crops and their impacts on the farm business and the environment, especially with regard to economic considerations. Through increasing knowledge about cover crops, the intent here is to inform producers contemplating adoption and policy makers seeking to encourage adoption.
The current study examines the impact of a nutrition rating system on consumers’ food purchases in supermarkets.
Aggregate sales data for 102 categories of food (over 60 000 brands) on a weekly basis for 2005–2007 from a supermarket chain of over 150 stores are analysed. Change in weekly sales of nutritious and less nutritious foods, after the introduction of a nutrition rating system on store shelves, is calculated, controlling for seasonality and time trends in sales.
One hundred and sixty-eight supermarket stores in the north-east USA, from January 2005 to December 2007.
Consumers purchasing goods at the supermarket chain during the study period.
After the introduction of the nutrition ratings, overall weekly food sales declined by an average of 3637 units per category (95 % CI –5961, –1313; P<0·01). Sales of less nutritious foods fell by 8·31 % (95 % CI –13·50, –2·80 %; P=0·004), while sales of nutritious foods did not change significantly (P=0·21); as a result, the percentage of food purchases rated as nutritious rose by 1·39 % (95 % CI 0·58, 2·20 %; P<0·01). The decrease in sales of less nutritious foods was greatest in the categories of canned meat and fish, soda pop, bakery and canned vegetables.
The introduction of the nutrition ratings led shoppers to buy a more nutritious mix of products. Interestingly, it did so by reducing purchases of less nutritious foods rather than by increasing purchases of nutritious foods. In evaluating nutrition information systems, researchers should focus on the entire market basket, not just sales of nutritious foods.
This study evaluates the Adjusted Gross Revenue-Lite (AGR-Lite) whole-farm adjusted gross revenue insurance program on net farm income risk using panel data from 49 southeast Kansas beef farms. On average for the group, but not each individual farm, AGR-Lite reduces the mean and standard deviation of net farm income, raises the average minimum, and lowers the average maximum observations of the net income distribution. Thirty-four farms (69%) received at least one indemnity payment. Stochastic efficiency with respect to a function reveals that AGR-Lite is preferred by 18 of the farm managers (37%) when an upper bound on the risk-aversion coefficient is used.
The economic feasibility of soybeans, grain sorghum, and corn in annual rotation with winter wheat using reduced tillage and no-tillage systems in the Central Great Plains was evaluated, with continuous wheat and grain sorghum also analyzed. Net returns were calculated using simulated yield and price distributions based on historical yields, two historical annual price series, and 2011 costs. Stochastic Efficiency with Respect to a Function was used to determine the preferred strategies under various risk preferences. The no-till wheat-soybean and reduced-till wheat-soybean systems are the first and second most preferred, regardless of the level of risk aversion.
We have demonstrated conformal deposition of amorphous GeSbTe films in high aspect ratio structures by MOCVD. SEM analysis showed the as-deposited GeSbTe films had smooth morphologies and were well controlled for void free amorphous conformal deposition. GeSbTe films adhere well to SiO2, TiN, and TiAlN. The morphology and adhesion are stable in 420°C post process. By annealing at 365°C, amorphous GeSbTe films converted into crystalline GeSbTe with polycrystalline grain sizes of 5nm. Film resistivity in the crystalline phase ranged from 0.001 to 0.1 Ω-cm, suitable for device applications. Phase change devices fabricated with confined via structures filled with MOCVD GeSbTe showed cycle endurances up to 1×1010 with a dynamic set/rest resistance of two orders of magnitude.
It is known that levels of brain natriuretic peptide predict outcomes of treatment for adults with decompensated heart failure. We hypothesized that it could predict outcomes in children with this condition.
We divided retrospectively 82 patients with serial measurements of brain natriuretic peptide into 3 groups: those who survived and did not need readmission within less than 60 days; those who survived but needed readmission within less than 60 days; and those who died in hospital or within less than 60 days. Initial and final levels of the peptide correlated with adverse outcomes.
The percent change in level of the peptide was minus 78 percent, minus 38 percent, and 138 percent in the readmission-free group, the readmitted, and nonsurviving groups, respectively. Final levels were significantly lower in the readmission-free group than in the readmitted and nonsurviving groups (p equals 0.013 and p is less than 0.00001, respectively) and in the readmitted group than in the nonsurvivors (p equals 0.013). On univariate analysis, the final level, the change in level, and the percentage change in level significantly predicted outcomes (p equals 0.0002, 0.0072 and 0.0005, respectively). On multivariate analysis, only the final level of the peptide significantly predicted outcomes (p equals 0.01).
A final level of brain natriuretic peptide of greater than or equal to 760 picograms per millilitre strongly predicted an adverse outcome. Patients with higher final levels may be at higher risk of death and readmission, suggesting that this variable effectively predicts the response to treatment and prognosis in children with heart failure.
With increasingly thin margins and new technologies, it is important that farm managers know their cost of field operations on a per unit basis (e.g., acre, ton, bale). Accurate per unit costs give confidence when constructing enterprise budgets and evaluating new technologies, such as no-till. Custom rates are often used as a proxy for per unit costs; however, this research, using entropy and jackknife estimation procedures, found that custom rates understate total ownership and operating costs by approximately 25% for an average Kansas farm. Estimates from these models are then used to benchmark actual costs against expected cost.
The effects of dietary saturated fatty acids and polyunsaturated fatty acids (PUFA) of the n-3 and n-6 series on weight gain, body composition and substrate oxidation were investigated in broiler chickens. At 3 weeks of age three groups of chickens (n 30; ten birds per group) were fed the fat-enriched experimental diets for 5 weeks. These diets were isonitrogenous, isoenergetic and contained 208 g protein/kg and 80 g edible tallow, fish oil or sunflower oil/kg; the dietary fatty acid profiles were thus dominated by saturated fatty acids, n-3 PUFA or n-6 PUFA respectively. Resting RQ was measured in five birds from each treatment group during weeks 4 and 5 of the experiment. There were no significant differences between treatments in total feed intake or final body mass. Birds fed the PUFA diets had lower RQ and significantly reduced abdominal fat pad weights (P<0·01) compared with those fed tallow. The dietary lipid profile changes resulted in significantly greater partitioning of energy into lean tissue than into fat tissue (calculated as breast lean tissue weight:abdominal fat mass) in the PUFA groups compared with the saturated fat group (P<0·01; with no difference between the n-3 and n-6 PUFA groups). In addition, the PUFA-rich diets lowered plasma concentrations of serum triacylglycerols and cholesterol. The findings indicate that dietary fatty acid profile influences nutrient partitioning in broiler chickens.
Ascidian development is reviewed and a model is presented for specification of the larval body plan and cell fate during embryogenesis. The model involves the combined activity of determinants inherited from the egg and inductive cell interactions in the embryo. It is suggested that there are four determinant systems in the egg which are segregated to different blastomeres during cleavage. The ectodermal, endodermal, and muscle determinants specify cell fate autonomously, while the axial determinants initiate cell-shape changes at gastrulation and generate a cascade of inductive activities establishing the larval body plan. In the proposed signalling cascade, the endoderm induces notochord by generating a planar inductive signal late during the cleavage phase, and the notochord cells in turn induce the nervous system by generating a vertical inductive signal in the overlying ectoderm during gastrulation. Ultraviolet (UV) irradiation experiments are described which suggest that axial and muscle determinants exhibit UV-sensitive components resembling nucleic acids and proteins, respectively. The model is evaluated in terms of developmental changes during the evolutionary transition from indirect to direct development. This transition can be explained according to the model by loss or inactivation of the muscle determinants and modification of the inductive activities generated by the axial determinants. These changes are supported by recent studies of embryogenesis in direct-developing ascidians.
An erythrochyte anti-ankryin antibody was used to investigate the presence and distribution of ankryin in eggs and embryos of ascidian species with different modes of development. In eggs of the indirect developer Ascidia ceratodes anti-ankryin reacted with a 210 kDa polypeptide which has an electrophoretic mobility similar to the vertebrate ankryins. Immunofluorescence microscopy showed that the ankryin-like protein is co-distributed with the myoplasm throughout development. It is restricted to a thin layer under the plasma membrane in unfertilised eggs, undergoes ooplasmic segregation to the posterior pole of the zygote after fertilisation, and is distributed to the tail muscle cells during cleavage and embryogenesis. After gastrulation and neurulation, lower levels of the ankryin-like protein, presumably of zygotic origin, were observed in brain cells and in the apical margin of epidermal cells. The ankryin-like protein was also localised in the myoplasm in eggs and embryos of another indirect developing species, Halocynthia roretzi. The ankryin-like protein may link the cytoskeleton with the plasma membrane in ascidian eggs, as it does in vertebrate erythrocytes. In contrast to A. ceratodes and H. rorefzi, which are members of the families Ascidiidae and Pyuridae respectively, the pattern of ankryin-like protein expression was changed in five species in the family Molgulidae. These molgulid ascidians exhibit either indirect or direct development, and eggs of the direct developing species have lost or modified the myoplasm. The ankryir like protein was present in young oocytes but failed to persist during oogenesis and disappeared in mature eggs and embryos of these molgulid species. The change in ankryin-like protein expression may be a preadaptation for loss of the myoplasm and the evolution of direct development.
Risk Management strategies for maintaining student performance in large classes are discussed. Risk management theory is discussed and used to describe student behavior. Results of risk management experiments in which students are exposed to alternative levels of grading are reported along with other factors which influence student behavior. Class performance was not found to decline under a system involving only a 50 percent chance of assignments being graded. Procedures for implementing and limitations of chance grading systems in large classes are discussed.
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