PREDICTION OF BOD AND COD OF A REFINERY WASTEWATER USING MULTILAYER ARTIFICIAL NEURAL NETWORKS

In the recent past, artificial neural networks (ANNs) have shown the ability to learn and capture non-linear static or dynamic behaviour among variables based on the given set of data. Since the knowledge of internal procedure is not necessary, the modelling can take place with minimum previous knowledge about the process through proper training of the network. In the present study, 12 ANN based models were proposed to predict the Biochemical Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) concentrations of wastewater generated from the effluent treatment plant of a petrochemical industry. By employing the standard back error propagation (BEP) algorithm, the network was trained with 103 data points for water quality indices such as Total Suspended Solids (TSS), Total Dissolved Solids (TDS), Phenol concentration, Ammoniacal Nitrogen (AMN), Total Organic Carbon (TOC) and Kjeldahl’s Nitrogen (KJN) to predict BOD and COD. After appropriate training, the network was tested with a separate test data and the best model was chosen based on the sum square error (training) and percentage average relative error (% ARE for testing). The results from this study reveal that ANNs can be accurate and efficacious in predicting unknown concentrations of water quality parameters through its versatile training process

A TRANSLOG COST FUNCTION ANALYSIS OF U.S. AGRICULTURE: A DYNAMIC SPECIFICATION

This study has used an empirical approach developed by Urga and Walters (2003) to examine the implications of the short-run specification of the standard translog cost specification along with the possible implications of non-stationarity. We have estimated a dynamic translog cost specification complete with dynamic share equations for U.S. agriculture and compared it to the static, long-run specification. We found that the dynamic translog specification yielded more significant parameter estimates, and yielded results that are consistent with economic theory. In particular, the coefficient m (the adjustment cost parameter) determines the overall autoregressive structure of the model. The fact that its estimated value (0.36) is statistically different from zero at any conventional level of confidence indicates that the dynamic structure of the model is important. This finding illustrates the superiority of the short-run, dynamic specification over the static, long-run model.Agribusiness,

A Translog Cost Function Analysis of U.S. Agriculture: 1948-1999

This study examines the implications of the short-run specification of the standard, static translog cost function along with the possible implications of non-stationarity by estimating a dynamic translog cost specification complete with dynamic share equations for the U.S. using an empirical approach developed by Urga and Walters (2003). We compare the results of the static, long-run model with those of a dynamic, short-run error-correction model in terms of 1) significance of the parameter estimates, and 2) consistency with economic theory.Research Methods/ Statistical Methods,

Inhibition of RNA polymerase II transcription in human cells by synthetic DNA-binding ligands

Sequence-specific DNA-binding small molecules that can permeate human cells potentially could regulate transcription of specific genes. Multiple cellular DNA-binding transcription factors are required by HIV type 1 for RNA synthesis. Two pyrrole-imidazole polyamides were designed to bind DNA sequences immediately adjacent to binding sites for the transcription factors Ets-l, lymphoid-enhancer binding factor 1, and TATA-box binding protein. These synthetic ligands specifically inhibit DNA-binding of each transcription factor and HIV type 1 transcription in cell-free assays. When used in combination, the polyamides inhibit virus replication by >99% in isolated human peripheral blood lymphocytes, with no detectable cell toxicity, The ability of small molecules to target predetermined DNA sequences located within RNA polymerase II promoters suggests a general approach for regulation of gene expression, as well as a mechanism for the inhibition of viral replication

Fmoc solid phase synthesis of polyamides containing pyrrole and imidazole amino acids

Polyamides containing N-methylimidazole (Im) and N-methylpyrrole (Py) amino acids are synthetic ligands that have an affinity and specificity for DNA comparable to those of many naturally occurring DNA binding proteins. A machine-assisted Fmoc solid phase synthesis of polyamides has been optimized to afford high stepwise coupling yields (>99%). Two monomer building blocks, Fmoc-Py acid and Fmoc-Im acid, were prepared in multigram scale. Cleavage by aminolysis followed by HPLC purification affords up to 200 mg quantities of polyamide with purities and yields greater than or equal to those reported using Boc chemistry. A broader set of reaction conditions will increase the number and complexity of minor groove binding polyamides which may be prepared and help ensure compatibility with many commercially available peptide synthesizers

Aliphatic/aromatic amino acid pairings for polyamide recognition in the minor groove of DNA

Selective placement of an aliphatic β-alanine (β) residue paired side-by-side with either a pyrrole (Py) or imidazole (Im) aromatic amino acid is found to compensate for sequence composition effects for recognition of the minor groove of DNA by hairpin pyrrole−imidazole polyamides. A series of polyamides were prepared which contain pyrrole and imidazole aromatic amino acids, as well as γ-aminobutyric acid (γ) “turn” and β-alanine “spring” aliphatic amino acid residues. The binding affinities and specificities of these polyamides are regulated by the placement of paired β/β, Py/β, and Im/β residues. Quantitative footprint titrations demonstrate that replacing two Py/Py pairings in a 12-ring hairpin (6-γ-6) with two Py/β pairings affords 10-fold enhanced affinity and similar sequence specificity for an 8-bp target sequence. The 6-γ-6 hairpin ImPyImPyPyPy-γ-ImPyPyPyPyPy-β-Dp, which contains six consecutive amino acid pairings, is unable to discriminate a single-base-pair mismatch site 5‘-TGTTAACA-3‘ from a 5‘-TGTGAACA-3‘ match site. The hairpin polyamide Im-β-ImPyPyPy-γ-ImPyPyPy-β-Py-β-Dp binds to the 8-bp match sequence 5‘-TGTGAACA-3‘ with an equilibrium association constant of Ka = 2.4 × 1010 M-1 and ≥48-fold specificity versus the 5‘-TGTTAACA-3‘ single-base-pair mismatch site. Modeling indicates that the β-alanine residue relaxes ligand curvature, providing for optimal hydrogen bond formation between the floor of the minor groove and both Im residues within the Im-β-Im polyamide subunit. This observation provided the basis for design of a hairpin polyamide, Im-β-ImPy-γ-Im-β-ImPy-β-Dp, which incorporates Im/β pairings to recognize a “problematic” 5‘-GCGC-3‘ sequence at subnanomolar concentrations. These results identify Im/β and β/Im pairings that respectively discriminate G·C and C·G from A·T/T·A as well as Py/β and β/Py pairings that discriminate A·T/T·A from G·C/C·G. These aliphatic/aromatic amino acid pairings will facilitate the design of hairpin polyamides which recognize both a larger binding site size as well as a more diverse sequence repertoire

Stereochemical control of the DNA binding affinity, sequence specificity, and orientation preference of chiral hairpin polyamides in the minor groove

Three-ring polyamides containing pyrrole (Py) and imidazole (Im) amino acids covalently coupled by γ-aminobutyric acid (γ) form six-ring hairpins that recognize five-base-pair sequences in the minor groove of DNA. Selective chiral substitution of the ``gamma-turn'' enhances the properties of polyamide hairpins with regard to DNA affinity and sequence specificity. Polyamides of core sequence composition ImPyPy-γ-PyPyPy which differ by selective stereochemical substitution of the prochiral alpha-position in the γ-turn were prepared. The DNA binding properties of two enantiomeric polyamides were analyzed by footprinting and affinity cleavage on a DNA fragment containing two match sites (5'-TGTTA-3' and 5'-ACATT-3') and one 5'-TGTCA-3' mismatch site. Quantitative footprint titrations demonstrate that replacement of γ-aminobutyric acid by (R)-2,4-diaminobutyric acid enhances DNA binding affinity for the 5'-TGTTA-3' match site 13-fold (K_a = 3.8 x 10^9 M-1). The enhanced affinity is achieved without a compromise in sequence selectivity, which in fact increases and is found to be 100-fold higher relative to binding at a single base pair mismatch sequence, 5'-TGTCA-3'. An (S)-2,4-diaminobutyric acid linked hairpin binds with 170-fold reduced affinity relative to the R-enantiomer and only 5-fold sequence specificity versus a 5'-ACATT-3' reversed orientation site. These effects are modulated by acetylation of the chiral amine substituents. This study identifies structural elements which should facilitate the design of new hairpin polyamides with improved DNA binding affinity, sequence specificity, and orientational selectivity

Anatomy of the porcine thyroid

Digitized 2007 AES.Includes bibliographical references (page 10)

Economic Evaluation of Parasite Control in Swine A Case of Ivomec

Economic losses, increased cost and/or decreased revenue, associated with disease outbreaks or parasites in swine are significant [2, 3 and 4]. Knowledge of economic implications of disease presence is needed in making hog production health management decisions. The adverse economic and production effi^ts of internal and external parasitism. in swine are well-recognized. In the. past, data limitations have made it difficult to quantify the effect of parasite control on grow-finish and reproduction performance in swine. Average daily gain decreases from 5-15% from mange infestations have been reported by several, researchers. Similarly, internal parasitism has been demonstrated to cause substantial economic losses without precipitating significant clinical disease or death of affected swine. These insidious losses cause millions of dollars in losses to the United States and world swine industry each year