STRUCTURE OF SOUTH CENTRAL AGRICULTURAL PRODUCTION

Using a dual economic specification of a multiproduct technology, the structure of agricultural production was tested for five South Central states (Texas, Oklahoma, Arkansas, Mississippi, and Louisiana). A comprehensive set of output supplies and input demands comprised the estimation equations in each state. Evidence of nonjoint production in a subset of commodities was detected in four of the five states. Several commodities also satisfied sufficient conditions for consistent aggregations. However, the specific outputs satisfying each structural property varied by state. Sufficient conditions for consistent geographic aggregation across the states were not satisfied. These results provide empirical guidance and important cautions for legitimately simplifying state-level model specifications of southern agricultural production.Industrial Organization,

Optimization of a Diagnostic Platform for Oxidation-Reduction Potential (ORP) Measurement in Human Plasma and Exploration of ORP after Trauma

Oxidation-reduction potential (ORP) measurement has demonstrated oxidative stress in patients with severe illness/injury. A new ORP diagnostic platform using disposable sensors (Supplemental Figure 1) has been validated by comparison to mass spectrometry, but the response of ORP to experimental positive and negative control conditions has not been determined. Furthermore, optimal methods of sample handling for ORP measurement have not been studied. We sought to optimize ORP measurement in human plasma, under controlled conditions. We hypothesized that freeze-thawing of the sample, storage of the sample for up to one month, and the method of sample anticoagulation would influence ORP levels. Furthermore, we hypothesized that ORP can detect incremental experimental changes that either increase or decrease redox state. Finally, we hypothesized that trauma injuries cause increased levels of reactive oxygen species (ROS) in the circulating bloodstream, and therefore would reflect higher ORP signals in plasma measurements in both human and mouse subjects. We enrolled healthy human volunteers in a prospective observational study and measured ORP in plasma prepared with heparin or citrate anticoagulants directly after blood draw and up to 28 days later. Additionally, we evaluated the platform’s ability to detect an exogenous increase and decrease in ORP by performing both positive and negative control titrations using six different concentrations of hydrogen peroxide (H2O2) and two different concentrations of ascorbic acid respectively. Lastly, we compared human trauma plasma samples in an uncontrolled emergency room setting with healthy human plasma and then mimicked this experiment in a more controlled mouse model experiment. We found that fresh plasma better retains the ORP signal as compared to freeze-thaw samples measured on subsequent days. We also found that the platform can detect exogenous, concentration-dependent oxidations with H2O2 and reductions with ascorbic acid. Furthermore, plasma prepared with heparin is more sensitive than using citrate anticoagulant when measuring ORP. Also, human trauma patients’ plasma (of varying degrees of trauma) samples were characterized by significantly higher ORP signals than healthy controls when measured in heparin anticoagulant, whereas mouse ORP signals did not change following a controlled, moderate traumatic brain injury. These data indicate that the diagnostic platform is capable of detecting exogenous increases and decreases in ORP signal from plasma samples with validity and is sensitive to different concentrations of positive and negative controls. We also show that plasma should be collected and centrifuged in heparin anticoagulant tubes and can be analyzed fresh or frozen for optimal results

Particle Learning for General Mixtures

This paper develops particle learning (PL) methods for the estimation of general mixture models. The approach is distinguished from alternative particle filtering methods in two major ways. First, each iteration begins by resampling particles according to posterior predictive probability, leading to a more efficient set for propagation. Second, each particle tracks only the "essential state vector" thus leading to reduced dimensional inference. In addition, we describe how the approach will apply to more general mixture models of current interest in the literature; it is hoped that this will inspire a greater number of researchers to adopt sequential Monte Carlo methods for fitting their sophisticated mixture based models. Finally, we show that PL leads to straight forward tools for marginal likelihood calculation and posterior cluster allocation.Business Administratio

Equilibrium behaviour of two cavity-confined polymers: Effects of polymer width and system asymmetries

Experiments using nanofluidic devices have proven effective in characterizing the physical properties of polymers confined to small cavities. Two recent studies using such methods examined the organization and dynamics of two DNA molecules in box-like cavities with strong confinement in one direction and with square and elliptical cross sections in the lateral plane. Motivated by these experiments, we employ Monte Carlo and Brownian dynamics simulations to study the physical behaviour of two polymers confined to small cavities with shapes comparable to those used in the experiments. We quantify the effects of varying the following polymer properties and confinement dimensions on the organization and dynamics of the polymers: the polymer width, the polymer contour length ratio, the cavity cross-sectional area, and the degree of cavity elongation for cavities with rectangular and elliptical cross sections. We find that the tendency for polymers to segregate is enhanced by increasing polymer width. For sufficiently small cavities, increasing cavity elongation promotes segregation and localization of identical polymers to opposite sides of the cavity along its long axis. A free-energy barrier controls the rate of polymers swapping positions, and the observed dynamics are roughly in accord with predictions of a simple theoretical model. Increasing the contour length difference between polymers significantly affects their organization in the cavity. In the case of a large linear polymer co-trapped with a small ring polymer in an elliptical cavity, the small polymer tends to lie near the lateral confining walls, and especially at the cavity poles for highly elongated ellipses.Comment: 19 pages, 15 figures, 4 pages of supplemental inf

An electrophoresis apparatus for the rapid routine analysis of sera and other protein solutions

An electrophoresis apparatus is described which was found suitable for the rapid analysis of sera and other protein mixtures. A method for identification of protein components in the migrating column is given.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The particle size of bluetongue virus as determined by ultrafiltration and ultracentrifugation

1. The particle diameter of bluetongue virus (sheep virulent and egg adapted virus) was determined by gradocol membrane filtration. 2. Details of the technique for clarifying infective emulsions by aluminium hydroxide adsorption and trypsin digestion are given. 3. The density of the egg adapted virus was calculated from data obtained from centrifugation in media of low and high specific gravity and was found to be 1.147.gm./cm.³ in strong cane sugar and 1.106 gm/cm.³ in serum albumin. 4. The particle diameter of the sheep virulent virus was determined approximately, and of the egg adapted virus accurately by centrifugation.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The particle size of African horsesickness virus as determined by ultrafiltration and ultracentrifugation

(1) Details of the technique employed for the preparation of gradocol membranes are given together with the technique employed in the filtration of neurotropic horsesickness virus. (2) From data collected from the filtration of 6 strains of virus it is found that the limiting membrane is one with a porosity of 100 mµ. Hence the diameter of the virus particles is from 40-60 mµ with a mean of 50 mµ. (3) Details of the technique used for determinations by the inverted capillary method of centrifugation are given. (4) The method used for determining the density of the virus particles is given. By this method a density of 1.25 gm. per c.c. was calculated. (5) By the centrifugation method a mean value of 45.4 mµ for the particle diameter was calculated. (6) The particle diameter determined by both methods agree closely. (7) There was no significant difference in the size of the virus particles of 6 strains of different antigenic structure.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Comparative electrophoretic studies of bovine and human colostrum in relation to neonatal immunity

Since there is no reason to doubt the generally accepted conception that the concentration of ƴ globulins is an accurate index of humoral immunity, it may be concluded that in bovines there is no transplacental transmission of specific immunity and that the acquired passive immunity of the calf results from the ingestion and absorption of the globulins present in high concentration in the colostrum. The human acquires its transmitted passive immunity exclusively in utero to a degree correlated with the immunity of its mother. This immunity is not influenced by the ingestion of colostrum from which the ƴ globulin component is absent.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

The diffusion constant and molecular weight and shape of neurotropic horsesickness virus

(1) A new method for the analytical determination of the diffusion constant of a virus is described. (2) This method is based upon the amount of virus which diffuses across the interface formed between an infective emulsion and the dispersion medium and the method of calculation is detailed. (3) From the experimental data collected the diffusion constant is calculated as 0.87 x 10-7 cm²/sec. (4) From the diffusion constant the size is calculated as 48.8 m.µ, a figure which corresponds closely to that obtained from ultrafiltration and ultracentrifugation experiments. (5) By combining the diffusion constant with the sedimentation and partial specific volume data the molecular weight is calculated to be of the order or 41,000,000. (6) From the above data it is shown that horsesickness virus particles are essentially globular in shape and not threadlike or elongated.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format