Interrelated structure of high altitude atmospheric profiles

A preliminary development of a mathematical model to compute probabilities of thermodynamic profiles is presented. The model assumes an exponential expression for pressure and utilizes the hydrostatic law and equation of state in the determination of density and temperature. It is shown that each thermodynamic variable can be factored into the produce of steady state and perturbation functions. The steady state functions have profiles similar to those of the 1962 standard atmosphere while the perturbation functions oscillate about 1. Limitations of the model and recommendations for future work are presented

High altitude Robin data-reduction program

Computer program for Robin data reductio

Effect of homogenisation conditions on recrystallisation in the Al-Mg-Mn alloy AA5454

The purpose of the present work is to understand the microstructure development and, particularly, to control the progress of recrystallisation in hot strip in the Al-Mg-Mn alloy AA 5454, which is typically used for the manufacture of structural automotive components. The chemical composition, together with the thermomechanical processing history of this material, has a strong influence on the microstructure of the product and the resulting properties as it is supplied to the customer. Electrical conductivity measurements, thermal analysis and electron microscopy have been carried out to characterise the evolution of precipitation state at various stages in the processing route. The conditions of the homogenisation heat treatment have been varied, and the effect on subsequent recrystallisation after hot rolling has been evaluated in both the as cast and rough rolled condition by optical microscopy techniques. Results indicate that the conditions of homogenisation heat treatment and roughing rolling are critical for the generation of a suitable recrystallised microstructure in AA 5454 hot strip. A new two stage homogenisation practice has been developed to expedite post-rolling recrystallisation in this alloy

Compendium of Applications Technology Satellite user experiments

The achievements of the user experiments performed with ATS satellites from 1967 to 1973 are summarized. Included are fixed and mobile point to point communications experiments involving voice, teletype and facsimile transmissions. Particular emphasis is given to the Alaska and Hawaii satellite communications experiments. The use of the ATS satellites for ranging and position fixing of ships and aircraft is also covered. The structure and operating characteristics of the various ATS satellite are briefly described

Implications of the structural change in dairy products trade on milk price paid to producers in Chile

Engler, A (reprint author), Univ Talca, Fac Ciencias Agr, Casilla 747, Talca, ChileSince 1990 row milk production has exhibited it rapid increase from 890 million liters in 1990 to 1818 million in 2006. The excess production has allowed for the expansion of the export sector, converting Chile in a net exporter in 2001. A relevant question in this new market scenario is how this Structural change can affect milk prices paid to producer,; in Chile. the consequences of this Structural change were explored in this study using a Vector Error Correction (VEC) model and cointegration analysis. The results indicated that the domestic, CIF (Cost. Insurance, Freight) and FOB (Free Oil Board) prices were cointegrated, implying that changes in the import and export prices are transmitted to the domestic market affecting the milk price paid to producers. Prior to 200 1, the import price (CIF) was the relevant reference dictating the movements of the domestic price. After 2001, the export price (FOB) became the reference, whereas the CIF price was no longer significant. the parameters of the VEC model SLIcroest that the conitegrating relation between CIF and domestic prices for the first period Under analysis ( 1990-2000) was clearer than that between FOB and domestic prices for the second period (2001-2007/3). the price elasticity for the FOB-domestic price vector had a large confidence interval, which is Why it IS difficult to draw strong conclusions regarding the impact Of future FOB fluctuations Oil the milk price paid to producers in Chile after 2001

Risk preferences estimation for small raspberry producers in the Bio-Bio Region, Chile

Toledo, R (reprint author), Ctr Reg Invest Quilamapu, Inst Invest Agropecuarias, Casilla 426, Chillan, ChileDecisions are strongly influenced by Ask and Ask preferences or decision makes; however, in Chile there are few studies in Me agricultural sector focused on this topic. The present paper analyzes the risk preferences of small producers or raspberries (Win idaeus L.) and the production function associated with their production system in the Bio-Bio Region of Chile. Under a mean-variance approach, the estimation procedure uses a flexible utility Function to incorporate a variety of risk preference alternatives. Three different estimation procedures were used: Least Squares Estimation, Seemingly Unrelated Regression and Full Information Maximum Likelihood, which revealed Me same Conclusions. Results showed that small farmers are risk averse (gamma=0.104) and present increasing relative and absolute aversion to risk (theta =0.099 < 1 and theta < gamma, respectively). The hypotheses of risk neutrality (gamma = 0) and constant absolute risk aversion (theta = 1) were rejected with 94% and 99% confidence, respectively. The chosen function of production is the Cobb Douglas type, because A presents a better adjustment, and the relevant factors are fertilizer quantity per hectare, the experience of the producer and the planted area. This Function presents decreasing returns to scale, then beta(2)+beta(3)+beta(4) is equal to 0.18. The hypothesis of constant returns to scale is rejected with 99%, confidence

Measure the Measure: the Impact of Differences in Pesticide MRLs on Chilean Fruit Exports to the EU

This paper advances the measurement of nontariff measures (NTMs) by discussing a framework for how to compare regulations. We argue that relative differences in SPS regulations trigger the impact on trade flows between trading partner countries and specifically look at maximum residue levels (MRLs) for pesticides in a case study on Chilean fruit exports to the EU. In order to capture the relative differences and stringency in tolerance levels of trading partners, a simple indicator is constructed and applied in an econometric analysis. In comparison to existing indices of regulatory heterogeneity, the depth of information generated by our indicator severely compromises its coverage. Further development of our heterogeneity index will need to aim at including elements of process standards and conformity assessment procedures

Survival Analysis with Large Dimensional Covariates: An Application in Microarray Studies

Use of microarray technology often leads to high-dimensional and low- sample size data settings. Over the past several years, a variety of novel approaches have been proposed for variable selection in this context. However, only a small number of these have been adapted for time-to-event data where censoring is present. Among standard variable selection methods shown both to have good predictive accuracy and to be computationally efficient is the elastic net penalization approach. In this paper, adaptation of the elastic net approach is presented for variable selection both under the Cox proportional hazards model and under an accelerated failure time (AFT) model. Assessment of the two methods is conducted through simulation studies and through analysis of microarray data obtained from a set of patients with diffuse large B-cell lymphoma where time to survival is of interest. The approaches are shown to match or exceed the predictive performance of a Cox-based and an AFT-based variable selection method. The methods are moreover shown to be much more computationally efficient than their respective Cox- and AFT- based counterparts

Genetic and serological heterogeneity of the supertypic HLA-B locus specificities Bw4 and Bw6

Gene cloning and sequencing of the HLA-B locus split antigens B38 (B16.1) and B39 (B16.2) allowed localization of their subtypic as well as their public specificities HLA-Bw4 or -Bw6 to the c~-helical region of the c~ 1 domain flanked by the amino acid positions 74-83. Comparison of their amino acid sequences with those of other HLA-B-locus alleles established HLA-Bw6 to be distinguished by Ser at residue 77 and Asn at residue 80. In contrast, HLA-Bw4 is characterized by at least seven different patterns of amino acid exchanges at positions 77 and 80-83. Reactivity patterns of Bw4- or Bw6-specific monoclonal antibodies reveal two alloantigenic epitopes contributing to the HLA-Bw4 or -Bw6 specificity residing next to the region of highest diversity of the cr domain

PLENARY PANEL: A 360-DEGREE VIEW OF SCIENCE AND AGRICULTURAL POLICY; EDITED TRANSCRIPT

Agricultural and Food Policy,