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• 2131. [Article] Preparation and properties of poly-L-tyrosyl acetamidinated ribonuclease

  Polypeptidyl derivatives of bovine pancreatic ribonuclease (RNase) containing two or three tyrosine chains with an average of two to three residues per chain have been prepared. The effects of various ...

  Citation × Citation Citation Abstract Copy Title: Preparation and properties of poly-L-tyrosyl acetamidinated ribonuclease Author: Lynn, Jackson Polypeptidyl derivatives of bovine pancreatic ribonuclease (RNase) containing two or three tyrosine chains with an average of two to three residues per chain have been prepared. The effects of various perturbants such as neutral salts, ethanol, urea and guanidine hydrochloride on the thermal transition of the derivatives have been studied. The forces responsible for maintaining the native conformation of RNase appear to be unaffected by chemical modification. In the association-dissociation reaction of the polypeptidyl derivatives of RNase, hydrophobic interactions are strongly implicated. Acetamidinated-RNase I was prepared by treating a RNase solution with excess acetimidate hydrochloride at pH 7.8 in 0.1 N NaHCO₃ buffer containing Na₂SO₄. After removal of reagents by dialysis, polypeptidylation was carried out under the same conditions by reacting the acetamidinated-RNase derivative with excess N-carboxy-L-tyrosine anhydride. There were then obtained a soluble fraction (IA) and an insoluble fraction (IB) of polytyrosyl-acetamidinated RNase (PT-Ac-RNase). IB could be dissolved in 0.0025 N HCl (IC). Fractions IA and IC were purified by gel filtration prior to experimental investigation. Another preparation (PT-Ac-RNase II) was carried out in phosphate buffer under comparable conditions as the preparation of PT-Ac-RNase I. Analysis for added amino acid residues and for the number of sites amidinated or peptidylated indicated that IA contained three peptide chains of average chain length slightly less than three tyrosines. The fraction IC had 17 moles of tyrosine per mole of protein, giving an average chain length of about six tyrosines. PT-Ac-RNase IIA had 4 moles of tyrosine per mole of protein attached to two sites. The enzymatic activities of the PT-Ac-RNase derivatives were shown to be about 5 percent of the unmodified enzyme by two methods of assay. The melting temperatures (Tm) as determined by difference spectra at 287 mμ and 237 mμ for RNase, acetamidinated RNase and PT-Ac-RNase in 0.05 M salt at pH 2.1 were very similar and varied between 33° and 35°. But calculations for Δε₂₈₇ mμ and Δε₂₃₇ revealed respective values of 1000 and 3000 for the PT-Ac-RNase derivatives. The Tm of PT-Ac-RNase IA was shown to be dependent on PH, urea, ethanol and guanidine trydrochloride. Lowering pH or increasing the concentration of perturbant would shift the Tm to lower temperature. However, the same observation has also been reported for native RNase. PT-Ac-RNase IC became insoluble between pH 5 and pH 9, but IA was soluble throughout this pH range. Although turbidity formation was enhanced by increasing concentration of KCI, addition of guanidine hydrochloride could prevent turbidity formation. Increasing concentration of KCI in the PT-Ac-RNase II solution at pH 2.1 shifted the Tm to higher temperatures and could induce turbidity formation at 1.2 M concentration. A similar effect of increasing the Tm of PT-Ac-RNase II was observed with CaCl₂, at pH 2.1. With 0.5 M KSCN precipitation of the protein derivative occurred. A higher enrichment of tyrosine as a result of peptidylation must account for these experimental observations. Spectrophotometric titration of PT-Ac-RNase II revealed seven normal and three abnormal tyrosines, indicating that the tyrosine residues covalently attached to the surface of the protein molecule are titrated normally. A thermodynamic treatment of the melting profiles of native RNase, Ac-RNase and PT-Ac-RNase derivatives in the presence of various concentrations of CaCl₂, was carried out. The approximation of two-state transition was employed to estimate the various thermodynamic parameters. The increase in heat capacity due to addition of extra tyrosine residues in the PT-Ac-RNase derivatives could probably account for the striking curvature at both low and high temperatures in the van't Hoff plots. However, the theory of gradual "unwinding" of the molecule cannot be excluded. Title: Preparation and properties of poly-L-tyrosyl acetamidinated ribonuclease Author: Lynn, Jackson Polypeptidyl derivatives of bovine pancreatic ribonuclease (RNase) containing two or three tyrosine chains with an average of two to three residues per chain have been prepared. The effects of various perturbants such as neutral salts, ethanol, urea and guanidine hydrochloride on the thermal transition of the derivatives have been studied. The forces responsible for maintaining the native conformation of RNase appear to be unaffected by chemical modification. In the association-dissociation reaction of the polypeptidyl derivatives of RNase, hydrophobic interactions are strongly implicated. Acetamidinated-RNase I was prepared by treating a RNase solution with excess acetimidate hydrochloride at pH 7.8 in 0.1 N NaHCO₃ buffer containing Na₂SO₄. After removal of reagents by dialysis, polypeptidylation was carried out under the same conditions by reacting the acetamidinated-RNase derivative with excess N-carboxy-L-tyrosine anhydride. There were then obtained a soluble fraction (IA) and an insoluble fraction (IB) of polytyrosyl-acetamidinated RNase (PT-Ac-RNase). IB could be dissolved in 0.0025 N HCl (IC). Fractions IA and IC were purified by gel filtration prior to experimental investigation. Another preparation (PT-Ac-RNase II) was carried out in phosphate buffer under comparable conditions as the preparation of PT-Ac-RNase I. Analysis for added amino acid residues and for the number of sites amidinated or peptidylated indicated that IA contained three peptide chains of average chain length slightly less than three tyrosines. The fraction IC had 17 moles of tyrosine per mole of protein, giving an average chain length of about six tyrosines. PT-Ac-RNase IIA had 4 moles of tyrosine per mole of protein attached to two sites. The enzymatic activities of the PT-Ac-RNase derivatives were shown to be about 5 percent of the unmodified enzyme by two methods of assay. The melting temperatures (Tm) as determined by difference spectra at 287 mμ and 237 mμ for RNase, acetamidinated RNase and PT-Ac-RNase in 0.05 M salt at pH 2.1 were very similar and varied between 33° and 35°. But calculations for Δε₂₈₇ mμ and Δε₂₃₇ revealed respective values of 1000 and 3000 for the PT-Ac-RNase derivatives. The Tm of PT-Ac-RNase IA was shown to be dependent on PH, urea, ethanol and guanidine trydrochloride. Lowering pH or increasing the concentration of perturbant would shift the Tm to lower temperature. However, the same observation has also been reported for native RNase. PT-Ac-RNase IC became insoluble between pH 5 and pH 9, but IA was soluble throughout this pH range. Although turbidity formation was enhanced by increasing concentration of KCI, addition of guanidine hydrochloride could prevent turbidity formation. Increasing concentration of KCI in the PT-Ac-RNase II solution at pH 2.1 shifted the Tm to higher temperatures and could induce turbidity formation at 1.2 M concentration. A similar effect of increasing the Tm of PT-Ac-RNase II was observed with CaCl₂, at pH 2.1. With 0.5 M KSCN precipitation of the protein derivative occurred. A higher enrichment of tyrosine as a result of peptidylation must account for these experimental observations. Spectrophotometric titration of PT-Ac-RNase II revealed seven normal and three abnormal tyrosines, indicating that the tyrosine residues covalently attached to the surface of the protein molecule are titrated normally. A thermodynamic treatment of the melting profiles of native RNase, Ac-RNase and PT-Ac-RNase derivatives in the presence of various concentrations of CaCl₂, was carried out. The approximation of two-state transition was employed to estimate the various thermodynamic parameters. The increase in heat capacity due to addition of extra tyrosine residues in the PT-Ac-RNase derivatives could probably account for the striking curvature at both low and high temperatures in the van't Hoff plots. However, the theory of gradual "unwinding" of the molecule cannot be excluded. Close

• 2132. [Article] Comparative values of liver nicotinamide nucleotide coenzymes, endocrine glands, and their relationships with production traits of diallel crossed beef bulls

  This investigation for the first time reports information on the correlation of various forms and ratios of nicotinamide nucleotide coenzymes in the liver tissue and endocrine glands weight with various ...

  Citation × Citation Citation Abstract Copy Title: Comparative values of liver nicotinamide nucleotide coenzymes, endocrine glands, and their relationships with production traits of diallel crossed beef bulls Author: Anwar-Afghan, Mohammad This investigation for the first time reports information on the correlation of various forms and ratios of nicotinamide nucleotide coenzymes in the liver tissue and endocrine glands weight with various production traits. Fifty-five inbred and line cross beef bulls raised under standard management conditions and slaughtered at 1000 lbs. body weight were used in the study. Fluorometeric determinations of the nicotinamide nucleotide coenzymes showed that NADH was present in lower concentration per gram of frozen liver tissue than NAD⁺ while the concentration of NADP⁺ was lower than NADPH per gram of frozen liver tissue. All forms of coenzymes showed a positive significant correlation with age (at 1000 lbs. body weight) and percent fat in the body. The coenzymes in the meantime also showed a significant negative correlation with percent lean in the carcass. Thyroid gland weight also showed a negative correlation with age, percent fat in the carcass and all the coenzymes which were positively associated with age and percent fat in the carcass. Thyroid gland weight was positively correlated with the NADP⁺/NADPH ratio since this ratio had a negative association with percent fat in the carcass. There was a positive correlation of thyroid weight with the NADP⁺/NADPH ratio. The latter ratio showed a significant positive association with feed per unit gain. Feed per unit gain, in the meantime, was positively associated with NADP⁺ and negatively associated with NAD⁺, percent lean in the carcass and gain per day. As age at 1000 lbs. body weight increases, the amount of thyroid tissue at 1000 lbs. body weight decreases and simultaneously feed per unit gain and percent fat in the carcass increases while percent lean and gain per day decreases. No significant correlation of any kind was observed between pituitary gland weight and production traits. This was attributed to the involvement of this gland with various hormones that may have antagonistic inducing action on these coenzymes. Evidence obtained, however, indicates both hormones (STH and TSH) increases percent lean, water content and gain per day and decreases percent fat in the carcass. Based on this evidence a model for the action of these hormones was presented. Inbreeding showed a negative significant correlation with percent lean in the carcass. In the meantime inbreeding was positively associated with total coenzymes (NAD⁺ + NADP⁺, NADH + NADPH). These coenzymes all have a significant negative correlation with percent lean in the carcass. Heterozygosity, therefore, seems to have a heterotic effect on growth as it increases percent lean in the carcass whereas it shows a negative heterotic effect on coenzyme concentration in liver tissue. This seems proper since the above coenzymes have a significant negative correlation with percent lean in the carcass. High percent lean and low coenzyme levels were characteristics associated with the line crosses while the opposite was true of inbred animals. Lines and line crosses showed statistically significant differences in coenzymes and production traits. This trend was also true for the average of parents compared with their offspring. Although statistically significant differences were not obtained when all inbreds of 17 and 21 percent inbreeding were compared with line crosses, a trend indicating higher gain per day, lower feed per unit gain and lower coenzyme levels, was noted in the line crosses. Diallel analysis showed no general combining ability for either the coenzymes or production traits. Specific combining ability and reciprocal effects were shown to exist for various coenzymes and production traits. Title: Comparative values of liver nicotinamide nucleotide coenzymes, endocrine glands, and their relationships with production traits of diallel crossed beef bulls Author: Anwar-Afghan, Mohammad This investigation for the first time reports information on the correlation of various forms and ratios of nicotinamide nucleotide coenzymes in the liver tissue and endocrine glands weight with various production traits. Fifty-five inbred and line cross beef bulls raised under standard management conditions and slaughtered at 1000 lbs. body weight were used in the study. Fluorometeric determinations of the nicotinamide nucleotide coenzymes showed that NADH was present in lower concentration per gram of frozen liver tissue than NAD⁺ while the concentration of NADP⁺ was lower than NADPH per gram of frozen liver tissue. All forms of coenzymes showed a positive significant correlation with age (at 1000 lbs. body weight) and percent fat in the body. The coenzymes in the meantime also showed a significant negative correlation with percent lean in the carcass. Thyroid gland weight also showed a negative correlation with age, percent fat in the carcass and all the coenzymes which were positively associated with age and percent fat in the carcass. Thyroid gland weight was positively correlated with the NADP⁺/NADPH ratio since this ratio had a negative association with percent fat in the carcass. There was a positive correlation of thyroid weight with the NADP⁺/NADPH ratio. The latter ratio showed a significant positive association with feed per unit gain. Feed per unit gain, in the meantime, was positively associated with NADP⁺ and negatively associated with NAD⁺, percent lean in the carcass and gain per day. As age at 1000 lbs. body weight increases, the amount of thyroid tissue at 1000 lbs. body weight decreases and simultaneously feed per unit gain and percent fat in the carcass increases while percent lean and gain per day decreases. No significant correlation of any kind was observed between pituitary gland weight and production traits. This was attributed to the involvement of this gland with various hormones that may have antagonistic inducing action on these coenzymes. Evidence obtained, however, indicates both hormones (STH and TSH) increases percent lean, water content and gain per day and decreases percent fat in the carcass. Based on this evidence a model for the action of these hormones was presented. Inbreeding showed a negative significant correlation with percent lean in the carcass. In the meantime inbreeding was positively associated with total coenzymes (NAD⁺ + NADP⁺, NADH + NADPH). These coenzymes all have a significant negative correlation with percent lean in the carcass. Heterozygosity, therefore, seems to have a heterotic effect on growth as it increases percent lean in the carcass whereas it shows a negative heterotic effect on coenzyme concentration in liver tissue. This seems proper since the above coenzymes have a significant negative correlation with percent lean in the carcass. High percent lean and low coenzyme levels were characteristics associated with the line crosses while the opposite was true of inbred animals. Lines and line crosses showed statistically significant differences in coenzymes and production traits. This trend was also true for the average of parents compared with their offspring. Although statistically significant differences were not obtained when all inbreds of 17 and 21 percent inbreeding were compared with line crosses, a trend indicating higher gain per day, lower feed per unit gain and lower coenzyme levels, was noted in the line crosses. Diallel analysis showed no general combining ability for either the coenzymes or production traits. Specific combining ability and reciprocal effects were shown to exist for various coenzymes and production traits. Close

• 2133. [Article] Fisher and logistic discriminant function estimation in the presence of collinearity

  The relative merits of the Fisher linear discriminant function (Efron, 1975) and logistic regression procedure (Press and Wilson, 1978; McLachlan and Byth, 1979), applied to the two group discrimination ...

  Citation × Citation Citation Abstract Copy Title: Fisher and logistic discriminant function estimation in the presence of collinearity Author: O'Donnell, Robert P. (Robert Paul) The relative merits of the Fisher linear discriminant function (Efron, 1975) and logistic regression procedure (Press and Wilson, 1978; McLachlan and Byth, 1979), applied to the two group discrimination problem under conditions of multivariate normality and common covariance, have been debated. In related research, DiPillo (1976, 1977, 1979) has argued that a biased Fisher linear discriminant function is preferable when one or more collinearities exist among the classifying variables. This paper proposes a generalized ridge logistic regression (GRL) estimator as a logistic analog to DiPillo's biased alternative estimator. Ridge and Principal Component logistic estimators proposed by Schaefer et al. (1984) for conventional logistic regression are shown to be special cases of this generalized ridge logistic estimator. Two Fisher estimators (Linear Discriminant Function (LDF) and Biased Linear Discriminant Function (BLDF)) and three logistic estimators (Linear Logistic Regression (LLR), Ridge Logistic Regression (RLR) and Principal Component Logistic Regression (PCLR)) are compared in a Monte Carlo simulation under varying conditions of distance between populations, training set s1ze and degree of collinearity. A new approach to the selection of the ridge parameter in the BLDF method is proposed and evaluated. The results of the simulation indicate that two of the biased estimators (BLDF, RLR) produce smaller MSE values and are more stable estimators (smaller standard deviations) than their unbiased counterparts. But the improved performance for MSE does not translate into equivalent improvement in error rates. The expected actual error rates are only marginally smaller for the biased estimators. The results suggest that small training set size, rather than strong collinearity, may produce the greatest classification advantage for the biased estimators. The unbiased estimators (LDF, LLR) produce smaller average apparent error rates. The relative advantage of the Fisher estimators over the logistic estimators is maintained. But, given that the comparison is made under conditions most favorable to the Fisher estimators, the absolute advantage of the Fisher estimators is small. The new ridge parameter selection method for the BLDF estimator performs as well as, but no better than, the method used by DiPillo. The PCLR estimator shows performance comparable to the other estimators when there is a high level of collinearity. However, the estimator gives up a significant degree of performance in conditions where collinearity is not a problem. Title: Fisher and logistic discriminant function estimation in the presence of collinearity Author: O'Donnell, Robert P. (Robert Paul) The relative merits of the Fisher linear discriminant function (Efron, 1975) and logistic regression procedure (Press and Wilson, 1978; McLachlan and Byth, 1979), applied to the two group discrimination problem under conditions of multivariate normality and common covariance, have been debated. In related research, DiPillo (1976, 1977, 1979) has argued that a biased Fisher linear discriminant function is preferable when one or more collinearities exist among the classifying variables. This paper proposes a generalized ridge logistic regression (GRL) estimator as a logistic analog to DiPillo's biased alternative estimator. Ridge and Principal Component logistic estimators proposed by Schaefer et al. (1984) for conventional logistic regression are shown to be special cases of this generalized ridge logistic estimator. Two Fisher estimators (Linear Discriminant Function (LDF) and Biased Linear Discriminant Function (BLDF)) and three logistic estimators (Linear Logistic Regression (LLR), Ridge Logistic Regression (RLR) and Principal Component Logistic Regression (PCLR)) are compared in a Monte Carlo simulation under varying conditions of distance between populations, training set s1ze and degree of collinearity. A new approach to the selection of the ridge parameter in the BLDF method is proposed and evaluated. The results of the simulation indicate that two of the biased estimators (BLDF, RLR) produce smaller MSE values and are more stable estimators (smaller standard deviations) than their unbiased counterparts. But the improved performance for MSE does not translate into equivalent improvement in error rates. The expected actual error rates are only marginally smaller for the biased estimators. The results suggest that small training set size, rather than strong collinearity, may produce the greatest classification advantage for the biased estimators. The unbiased estimators (LDF, LLR) produce smaller average apparent error rates. The relative advantage of the Fisher estimators over the logistic estimators is maintained. But, given that the comparison is made under conditions most favorable to the Fisher estimators, the absolute advantage of the Fisher estimators is small. The new ridge parameter selection method for the BLDF estimator performs as well as, but no better than, the method used by DiPillo. The PCLR estimator shows performance comparable to the other estimators when there is a high level of collinearity. However, the estimator gives up a significant degree of performance in conditions where collinearity is not a problem. Close

• 2134. [Article] The Roles of Large Top Predators in Coastal Ecosystems: New Insights from long Term Ecological Research

  To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by The Oceanography ...

  Citation × Citation Citation Abstract Copy Title: The Roles of Large Top Predators in Coastal Ecosystems: New Insights from long Term Ecological Research Author: Matich, Philip, Silliman, Brian R., Heithaus, Michael R., Mather, Martha E., Ripple, William J., Nifong, James C., Rosenblatt, Adam E. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by The Oceanography Society, and can be found at: http://www.tos.org/oceanography/. Title: The Roles of Large Top Predators in Coastal Ecosystems: New Insights from long Term Ecological Research Author: Matich, Philip, Silliman, Brian R., Heithaus, Michael R., Mather, Martha E., Ripple, William J., Nifong, James C., Rosenblatt, Adam E. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by The Oceanography Society, and can be found at: http://www.tos.org/oceanography/. Close

• 2135. [Article] Commercial Fishing License Limitation in the State of Alaska: A Controversial System of Grandfather Rights

  After two failed attempts to establish limited entry in its salmon fisheries,iii pursuant to legislation adopted by the Alaska Legislature in 1973, Alaska placed its primary salmon fisheries under limitation ...

  Citation × Citation Citation Abstract Copy Title: Commercial Fishing License Limitation in the State of Alaska: A Controversial System of Grandfather Rights Author: Twomley, Bruce Year: 2001 After two failed attempts to establish limited entry in its salmon fisheries,iii pursuant to legislation adopted by the Alaska Legislature in 1973, Alaska placed its primary salmon fisheries under limitation by 1975. Alaska persisted in seeking limited entry largely in response to declining salmon resources coupled with increasing levels of participation. Alaska’s system limited the number of gear licenses to a maximum number which must be equal to or greater than the highest number of units of gear present in a particular fishery during the four years prior to limitation. With all prior participants eligible to apply, the number of eligible applicants was generally far greater than the maximum number. Under an elaborate system of grandfather rights, permanent entry permits have been awarded to those fishers who demonstrated the most dependence upon a particular fishery, as measured by their past participation and economic dependence. Eligible fishers may continue to fish until there is a final determination on their applications. Permanent entry permits are, for the most part, freely transferable and inheritable, subject to some restriction (for example, permits may neither be leased nor pledged as security for a debt). Salmon fishers helped design Alaska’s program for Alaska’s salmon fleet, which consisted largely of individual fishers who owned and operated their own vessels. The program achieved a moratorium on new entrants and a gradual reduction of units of gear toward the maximum number as individual claims to permits were resolved. Alaska’s license limitation program contributes to limiting fishing capacity, because it is coupled with other limitations on effort such as vessel size and gear restriction. Taken together, Alaska’s license limitation and other management tools allow managers to calculate with some assurance the power of the fishing fleets they seek to control. Although the program is neutral as to residency, the percentages of permits held by Alaskans have tended to remain stable from the time of initial limitation. Alaska’s program has always been controversial. The allocation system is complicated, expensive, and requires years to complete. While the program has survived all major legal challenges, courts have modified the program. Although the percentage of permits held by Alaskan residents has remained stable, in some areas, the number of permits held by local, rural Alaska residents has declined. Additionally, the high cost of permits in valuable fisheries has made initial entry into some fisheries difficult. Alaska’s license limitation program is most useful in fisheries that resemble Alaska salmon fisheries. The more a fishery departs from the Alaska salmon fishery model (as a fleet of individual owner-operators), the less likely it is that Alaska’s form of license limitation would be of value. Title: Commercial Fishing License Limitation in the State of Alaska: A Controversial System of Grandfather Rights Author: Twomley, Bruce Year: 2001 After two failed attempts to establish limited entry in its salmon fisheries,iii pursuant to legislation adopted by the Alaska Legislature in 1973, Alaska placed its primary salmon fisheries under limitation by 1975. Alaska persisted in seeking limited entry largely in response to declining salmon resources coupled with increasing levels of participation. Alaska’s system limited the number of gear licenses to a maximum number which must be equal to or greater than the highest number of units of gear present in a particular fishery during the four years prior to limitation. With all prior participants eligible to apply, the number of eligible applicants was generally far greater than the maximum number. Under an elaborate system of grandfather rights, permanent entry permits have been awarded to those fishers who demonstrated the most dependence upon a particular fishery, as measured by their past participation and economic dependence. Eligible fishers may continue to fish until there is a final determination on their applications. Permanent entry permits are, for the most part, freely transferable and inheritable, subject to some restriction (for example, permits may neither be leased nor pledged as security for a debt). Salmon fishers helped design Alaska’s program for Alaska’s salmon fleet, which consisted largely of individual fishers who owned and operated their own vessels. The program achieved a moratorium on new entrants and a gradual reduction of units of gear toward the maximum number as individual claims to permits were resolved. Alaska’s license limitation program contributes to limiting fishing capacity, because it is coupled with other limitations on effort such as vessel size and gear restriction. Taken together, Alaska’s license limitation and other management tools allow managers to calculate with some assurance the power of the fishing fleets they seek to control. Although the program is neutral as to residency, the percentages of permits held by Alaskans have tended to remain stable from the time of initial limitation. Alaska’s program has always been controversial. The allocation system is complicated, expensive, and requires years to complete. While the program has survived all major legal challenges, courts have modified the program. Although the percentage of permits held by Alaskan residents has remained stable, in some areas, the number of permits held by local, rural Alaska residents has declined. Additionally, the high cost of permits in valuable fisheries has made initial entry into some fisheries difficult. Alaska’s license limitation program is most useful in fisheries that resemble Alaska salmon fisheries. The more a fishery departs from the Alaska salmon fishery model (as a fleet of individual owner-operators), the less likely it is that Alaska’s form of license limitation would be of value. Close

• 2136. [Article] CO₂ reduction in aqueous-ionic liquid solution in microscale-based corona reactor

  Global warming problem is becoming an increasingly important environmental concern and CO₂ is considered as the major cause of global warming. Among various methods of CO₂ utilization, conversion of CO₂ ...

  Citation × Citation Citation Abstract Copy Title: CO₂ reduction in aqueous-ionic liquid solution in microscale-based corona reactor Author: Miao, Yu Global warming problem is becoming an increasingly important environmental concern and CO₂ is considered as the major cause of global warming. Among various methods of CO₂ utilization, conversion of CO₂ to value added chemical products is the most attractive. In this study, a microscale-based corona reactor is introduced for reduction of CO₂. Two kinds of solvent were used in this study for absorbing CO₂: DI-water and ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]). The latter one has a much higher solubility of CO₂. After saturated with CO₂, solution was introduced into the microreactor built around the concept of corona discharge. The corona was created through a significant potential difference between two graphite electrodes. The current that passed through two electrodes acted as a catalytic agent for the reduction of CO₂. The experiments were conducted at room temperature and at steady state. The ranges of the operating conditions were: mean residence time 5 to 100 (sec), thickness of spacer 200 and 500 (μm), and voltage applied across the reactor 20 and 22.5 (V). Reactions happened in the bulk of the reactor and five main products were detected at the outlet stream: i) formic acid (HCOOH), ii) formaldehyde (HCHO), iii) methanol (CH₃OH), iv) methane (CH₄) and v) hydrogen (H₂). Among these compounds, formic acid, formaldehyde and methanol are intermediate products. The conversion of CO₂ in aqueous solution can reach as high as 94.8% at mean residence time of 100 sec. Although in ionic liquid solution the conversion of CO₂ is much lower (19.3% at mean residence time of 100 sec), consumption of CO₂ in ionic liquid is 6-7 times larger than that in water when generating same volume of products. A mathematical model reflecting geometry and flow conditions inside the microreactor was developed to simulate the process of CO₂ reduction. The model was solved numerically using COMSOL Multiphysics software package. The simulated results were optimized to fit the experimental data using COMSOL-Matlab LiveLink software package. Primary reaction rate constants for CO₂ reduction were predicted. The mathematical model was found to explain the experimental data pretty well. Title: CO₂ reduction in aqueous-ionic liquid solution in microscale-based corona reactor Author: Miao, Yu Global warming problem is becoming an increasingly important environmental concern and CO₂ is considered as the major cause of global warming. Among various methods of CO₂ utilization, conversion of CO₂ to value added chemical products is the most attractive. In this study, a microscale-based corona reactor is introduced for reduction of CO₂. Two kinds of solvent were used in this study for absorbing CO₂: DI-water and ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]). The latter one has a much higher solubility of CO₂. After saturated with CO₂, solution was introduced into the microreactor built around the concept of corona discharge. The corona was created through a significant potential difference between two graphite electrodes. The current that passed through two electrodes acted as a catalytic agent for the reduction of CO₂. The experiments were conducted at room temperature and at steady state. The ranges of the operating conditions were: mean residence time 5 to 100 (sec), thickness of spacer 200 and 500 (μm), and voltage applied across the reactor 20 and 22.5 (V). Reactions happened in the bulk of the reactor and five main products were detected at the outlet stream: i) formic acid (HCOOH), ii) formaldehyde (HCHO), iii) methanol (CH₃OH), iv) methane (CH₄) and v) hydrogen (H₂). Among these compounds, formic acid, formaldehyde and methanol are intermediate products. The conversion of CO₂ in aqueous solution can reach as high as 94.8% at mean residence time of 100 sec. Although in ionic liquid solution the conversion of CO₂ is much lower (19.3% at mean residence time of 100 sec), consumption of CO₂ in ionic liquid is 6-7 times larger than that in water when generating same volume of products. A mathematical model reflecting geometry and flow conditions inside the microreactor was developed to simulate the process of CO₂ reduction. The model was solved numerically using COMSOL Multiphysics software package. The simulated results were optimized to fit the experimental data using COMSOL-Matlab LiveLink software package. Primary reaction rate constants for CO₂ reduction were predicted. The mathematical model was found to explain the experimental data pretty well. Close

• 2137. [Article] Intraethnic diversity : an exploratory study of ethnic identity of Chinese American adolescents

  The purpose of the study was to explore the ethnic identity of Chinese American adolescents through the investigation of relationships between ethnic identity and selected demographic, sociocultural, and ...

  Citation × Citation Citation Abstract Copy Title: Intraethnic diversity : an exploratory study of ethnic identity of Chinese American adolescents Author: Lee, Phyllis S. The purpose of the study was to explore the ethnic identity of Chinese American adolescents through the investigation of relationships between ethnic identity and selected demographic, sociocultural, and psychological characteristics. Data were obtained from 106 Chinese American youth between the ages of 14 and 21 through the use of two instruments designed for the study. Three dimensions of ethnic identity were measured by subscales of the Sinoethnic Identity Scale. Demographic, sociocultural, and psychological data were obtained from the Background Information Survey. The strongest ethnic identities were found in the traditional, or core, dimension which was comprised of fundamental values, customs, and traditions. Weaker ethnic identities were exhibited in the intermediate, or familial, dimension which was responsible for the transmission of the ethnic culture as well as the preparations for interfacing the larger society. It was suspected that this dimension held the greatest potential for intercultural and intragenerational conflicts for Chinese American adolescents. The neutral stance taken in the societal dimension suggested two divergent interpretations: students may be exhibiting ambivalent feelings toward their ethnic identities within the scheme of life, or students may have come to terms with the notion of bicultural identities. Step-wise multiple regression was used to analyze the data. School achievement emerged as the most significant variable in the traditional dimension, suggesting that a Chinese heritage may not ensure school success, but school success contributed to the definition of being Chinese. In the familial dimension it was found that the gender of the subject was the most important variable. Subjects appeared to be highly socialized into ethnically appropriate sex roles, although there were indications of disagreement with the actual practice of these roles. Church attendance was identified as the most significant variable of the societal dimension. Those who attended church exhibited stronger agreement with ethnically appropriate social behaviors and expressed preferences for social activities and relationships within the ethnic community. The findings indicated that ethnic identity was a multidimensional aspect in the lives of Chinese American youth. The three dimensions that comprised Chinese ethnic identity appeared to be differentially affected by demographic, sociocultural, and psychological phenomena. It was also speculated that there was a relationship between the acknowledgement and expression of ethnic identity and historical and contemporary social , economic, and political conditions of society. The range of intraethnic diversity expressed by Chinese American adolescents suggested the need for reexamination of assumptions and expectations currently held by educational personnel. Recommendations for future research which might lead to the provision of educational policies and practices appropriate to Chinese American youth, a more informed understanding of the Chinese experience in the United States, and a greater understanding of the impact of ethnic identity in the lives of minority youth were presented. Title: Intraethnic diversity : an exploratory study of ethnic identity of Chinese American adolescents Author: Lee, Phyllis S. The purpose of the study was to explore the ethnic identity of Chinese American adolescents through the investigation of relationships between ethnic identity and selected demographic, sociocultural, and psychological characteristics. Data were obtained from 106 Chinese American youth between the ages of 14 and 21 through the use of two instruments designed for the study. Three dimensions of ethnic identity were measured by subscales of the Sinoethnic Identity Scale. Demographic, sociocultural, and psychological data were obtained from the Background Information Survey. The strongest ethnic identities were found in the traditional, or core, dimension which was comprised of fundamental values, customs, and traditions. Weaker ethnic identities were exhibited in the intermediate, or familial, dimension which was responsible for the transmission of the ethnic culture as well as the preparations for interfacing the larger society. It was suspected that this dimension held the greatest potential for intercultural and intragenerational conflicts for Chinese American adolescents. The neutral stance taken in the societal dimension suggested two divergent interpretations: students may be exhibiting ambivalent feelings toward their ethnic identities within the scheme of life, or students may have come to terms with the notion of bicultural identities. Step-wise multiple regression was used to analyze the data. School achievement emerged as the most significant variable in the traditional dimension, suggesting that a Chinese heritage may not ensure school success, but school success contributed to the definition of being Chinese. In the familial dimension it was found that the gender of the subject was the most important variable. Subjects appeared to be highly socialized into ethnically appropriate sex roles, although there were indications of disagreement with the actual practice of these roles. Church attendance was identified as the most significant variable of the societal dimension. Those who attended church exhibited stronger agreement with ethnically appropriate social behaviors and expressed preferences for social activities and relationships within the ethnic community. The findings indicated that ethnic identity was a multidimensional aspect in the lives of Chinese American youth. The three dimensions that comprised Chinese ethnic identity appeared to be differentially affected by demographic, sociocultural, and psychological phenomena. It was also speculated that there was a relationship between the acknowledgement and expression of ethnic identity and historical and contemporary social , economic, and political conditions of society. The range of intraethnic diversity expressed by Chinese American adolescents suggested the need for reexamination of assumptions and expectations currently held by educational personnel. Recommendations for future research which might lead to the provision of educational policies and practices appropriate to Chinese American youth, a more informed understanding of the Chinese experience in the United States, and a greater understanding of the impact of ethnic identity in the lives of minority youth were presented. Close

• 2138. [Article] The acute effects of moderate intensity circuit weight training on lipid-lipoprotein profiles

  Few studies have examined the acute effects of resistive-type exercise on lipid-lipoprotein profiles. This study examined the acute effects of a single session of circuit weight training (CWT) on plasma ...

  Citation × Citation Citation Abstract Copy Title: The acute effects of moderate intensity circuit weight training on lipid-lipoprotein profiles Author: Lee, Young-soo Few studies have examined the acute effects of resistive-type exercise on lipid-lipoprotein profiles. This study examined the acute effects of a single session of circuit weight training (CWT) on plasma lipid-lipoprotein profiles: triglycerides (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and the ratio of TC to HDL-C. The subjects in the study were 17 healthy, nonsmoking male university students, ages of 18-25 years, enrolled in weight lifting classes. Subjects were required to fast overnight (at least 12 hours) before CWT. Subjects repeated a four-station weight training circuit three times, with a resistance determined by their individual 3 repetition maximum (3-RM). The stations were bench press, parallel squat, leg extension, and seated row. Blood samples were drawn from the antecubital vein at pre-CWT, completion of the 1st and 3rd circuits, and 15 min post-CWT. All concentrations of plasma lipid and lipoprotein cholesterol were corrected for plasma volume changes. A repeated measures ANOVA was used to determine if significant differences existed among mean values for the dependent variables (i.e., levels of TG, TC, HDL-C, LDL-C, and TC/HDL-C ratio at specified time points). Results of the study indicated that plasma TC and HDL-C levels were changed significantly during and following CWT. However, the change was not in the anticipated direction: Plasma TC and HDL-C levels were lower at completion of the 1st circuit of CWT (p<0.05). The ratios of TC to HDL-C were changed significantly, reflecting a decrease in HDL-C during CWT and a slight increase in HDL-C at 15 min post-CWT. Plasma TG and LDL-C levels were not changed significantly during CWT or 15 min post-CWT. It was concluded that apparent changes in lipoprotein patterns occur during short-term moderate intensity CWT and return to pre-CWT levels in a relatively short time. Title: The acute effects of moderate intensity circuit weight training on lipid-lipoprotein profiles Author: Lee, Young-soo Few studies have examined the acute effects of resistive-type exercise on lipid-lipoprotein profiles. This study examined the acute effects of a single session of circuit weight training (CWT) on plasma lipid-lipoprotein profiles: triglycerides (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and the ratio of TC to HDL-C. The subjects in the study were 17 healthy, nonsmoking male university students, ages of 18-25 years, enrolled in weight lifting classes. Subjects were required to fast overnight (at least 12 hours) before CWT. Subjects repeated a four-station weight training circuit three times, with a resistance determined by their individual 3 repetition maximum (3-RM). The stations were bench press, parallel squat, leg extension, and seated row. Blood samples were drawn from the antecubital vein at pre-CWT, completion of the 1st and 3rd circuits, and 15 min post-CWT. All concentrations of plasma lipid and lipoprotein cholesterol were corrected for plasma volume changes. A repeated measures ANOVA was used to determine if significant differences existed among mean values for the dependent variables (i.e., levels of TG, TC, HDL-C, LDL-C, and TC/HDL-C ratio at specified time points). Results of the study indicated that plasma TC and HDL-C levels were changed significantly during and following CWT. However, the change was not in the anticipated direction: Plasma TC and HDL-C levels were lower at completion of the 1st circuit of CWT (p<0.05). The ratios of TC to HDL-C were changed significantly, reflecting a decrease in HDL-C during CWT and a slight increase in HDL-C at 15 min post-CWT. Plasma TG and LDL-C levels were not changed significantly during CWT or 15 min post-CWT. It was concluded that apparent changes in lipoprotein patterns occur during short-term moderate intensity CWT and return to pre-CWT levels in a relatively short time. Close

• 2139. [Article] Geographic factors as retardants to the development of Alaska's mineral industries

  The various elements of physical geography are commonly entertained as factors retarding the mineral industries of Alaska. It has been shown by numerous writers that the mineral industries of Alaska are, ...

  Citation × Citation Citation Abstract Copy Title: Geographic factors as retardants to the development of Alaska's mineral industries Author: Francis, Karl Earvil The various elements of physical geography are commonly entertained as factors retarding the mineral industries of Alaska. It has been shown by numerous writers that the mineral industries of Alaska are, indeed, in a difficult situation. Only the petroleum industry and sand and gravel for construction are of much significance to the Alaskan economy. Alaska's location makes it difficult to use domestic markets and turns the attention of all the resource-based primary industry toward the Orient. Though close to Europe, Alaskan trade across the Arctic Ocean yet awaits future transportation developments. The strategic position of Alaska has very significantly affected Alaska's primary industries by imposing stifling inflation on the state through emergency military activity little concerned with economics. Statehood and increased concern with the economy of Alaska by the Federal government promises to improve Alaska's locational problems. Alaska's size to some extent limits accessibility to the interior, but it also provides Alaska with a high mineral resource potential of great diversity and a very diverse landscape. The diversity of the land is a retardant to the extent that complexity of environment is a characteristic of Alaskan operations requiring a wide range of field experience and field equipment. Experience in all Alaskan terrain is quite rare. The topography of Alaska limits the development of new transportational routes to the interior from the south coast. It does not appreciably affect operational costs on existing roads and rails. Low terrain subject to frost action is a greater operational problem. As an underdeveloped land, Alaska is not unusually disadvantaged by topography; it does, in fact, have some advantages. A great hydroelectric potential exists in Alaska, but there is little chance that it will be of any great value to the mineral industries at this stage. Alaska has many diverse climates. South coastal Alaska has a climate similar enough to southern climates to be considered insignificant as a retardant to the mineral industries. In providing frozen coasts to western and northern Alaska, climate seriously retards development in these areas. Permafrost is a climatic resultant offering some considerable but yet largely undetermined effect on the mineral industries. The colder parts of Alaska have their biggest effect on the mineral industries in being different and, consequently, foreign and discouraging to southern people. The inherent disadvantage of cold is still largely obscured by blundering and inefficiency. Alaska has a considerable and diverse mineral resource that can, at this time, only be inferred. The unknown of Alaskan geology is its most striking feature. Exploration in all aspects is seriously discouraged by the economy and the obscuration of bed rock. Geophysical and geochemical prospecting has met with little success. It is felt that the lack of knowledge of and experience with the land is the biggest retardant to Alaska's mineral industries. The land is not inherently hostile, but rather it is different from that familiar to most of the people on it. A two-pronged attack on ignorance of the land is suggested, one to disseminate present knowledge and the other to seek out the unknown. When Alaska acquires a people familiar with and fully oriented toward the land, the effect of the geographic factors presently retarding the mineral industries will be greatly reduced. Title: Geographic factors as retardants to the development of Alaska's mineral industries Author: Francis, Karl Earvil The various elements of physical geography are commonly entertained as factors retarding the mineral industries of Alaska. It has been shown by numerous writers that the mineral industries of Alaska are, indeed, in a difficult situation. Only the petroleum industry and sand and gravel for construction are of much significance to the Alaskan economy. Alaska's location makes it difficult to use domestic markets and turns the attention of all the resource-based primary industry toward the Orient. Though close to Europe, Alaskan trade across the Arctic Ocean yet awaits future transportation developments. The strategic position of Alaska has very significantly affected Alaska's primary industries by imposing stifling inflation on the state through emergency military activity little concerned with economics. Statehood and increased concern with the economy of Alaska by the Federal government promises to improve Alaska's locational problems. Alaska's size to some extent limits accessibility to the interior, but it also provides Alaska with a high mineral resource potential of great diversity and a very diverse landscape. The diversity of the land is a retardant to the extent that complexity of environment is a characteristic of Alaskan operations requiring a wide range of field experience and field equipment. Experience in all Alaskan terrain is quite rare. The topography of Alaska limits the development of new transportational routes to the interior from the south coast. It does not appreciably affect operational costs on existing roads and rails. Low terrain subject to frost action is a greater operational problem. As an underdeveloped land, Alaska is not unusually disadvantaged by topography; it does, in fact, have some advantages. A great hydroelectric potential exists in Alaska, but there is little chance that it will be of any great value to the mineral industries at this stage. Alaska has many diverse climates. South coastal Alaska has a climate similar enough to southern climates to be considered insignificant as a retardant to the mineral industries. In providing frozen coasts to western and northern Alaska, climate seriously retards development in these areas. Permafrost is a climatic resultant offering some considerable but yet largely undetermined effect on the mineral industries. The colder parts of Alaska have their biggest effect on the mineral industries in being different and, consequently, foreign and discouraging to southern people. The inherent disadvantage of cold is still largely obscured by blundering and inefficiency. Alaska has a considerable and diverse mineral resource that can, at this time, only be inferred. The unknown of Alaskan geology is its most striking feature. Exploration in all aspects is seriously discouraged by the economy and the obscuration of bed rock. Geophysical and geochemical prospecting has met with little success. It is felt that the lack of knowledge of and experience with the land is the biggest retardant to Alaska's mineral industries. The land is not inherently hostile, but rather it is different from that familiar to most of the people on it. A two-pronged attack on ignorance of the land is suggested, one to disseminate present knowledge and the other to seek out the unknown. When Alaska acquires a people familiar with and fully oriented toward the land, the effect of the geographic factors presently retarding the mineral industries will be greatly reduced. Close

• 2140. [Article] Evaluation of secondary homemaking education in Bend, Oregon

  Concern over the low enrollment in homemaking classes prompted this study of the homemaking program in secondary schools in Bend, Oregon. Two questionnaires were constructed to obtain the opinions and ...

  Citation × Citation Citation Abstract Copy Title: Evaluation of secondary homemaking education in Bend, Oregon Author: Park, Ruth Stermer Concern over the low enrollment in homemaking classes prompted this study of the homemaking program in secondary schools in Bend, Oregon. Two questionnaires were constructed to obtain the opinions and beliefs of ninth, tenth, and eleventh-grade girls in Bend, Oregon, and their parents about the following: 1. What factors influence girls to enroll or not enroll in homemaking classes. 2. What factors parents consider in encouraging their daughters to enroll or not enroll in homemaking. 3. What girls and their parents believe should be taught in homemaking classes. 4. What types of homemaking classes and scheduling of those classes should be offered. The questionnaires were administered to the girls in Grade 9, 10, and 11 during a glass period. All girls who were present that day completed a questionnaire then took a parent questionnaire home for their parents to fill out. After the questionnaires were constructed they were pretested to determine if they would obtain the desired information. The data from the questionnaires were tabulated and organized into tables so that it could be analyzed and evaluated to try to determine ways to improve the program of homemaking education at the secondary level. The analysis of the data was organized into three sections. One deals with the girls' evaluations of homemaking education in Bend, Oregon; another deals with the parents' evaluations and the third draws together the similar and contrasting opinions and beliefs of the girls and their parents. In view of the beliefs and attitudes of the girls and their parents as shown in the study the following suggestions were made as possible next steps toward an improved homemaking education program in the Bend secondary schools. 1. Include different types of scheduling and different types of classes in the curriculum. 2. Reevaluate what is now being taught and try to place more emphasis on the areas of home management and relationships. 3. Carry out a better public relations program to inform the administration, other faculty, the community and the students in the school of the goals of the homemaking program. In light of the findings of the study, trends in education, and trends in high school education in Bend, Oregon, the writer proposes a new class to be offered on an experimental basis during the fall semester of 1962. The class would be scheduled to meet two or three times a week and would be a selected group or eleventh and twelfth-grade girls who were not planning to take any other homemaking. The center of emphasis of this class for young women would be upon development of attitudes, goals, and values to meet the problems of the changing times and upon the preparation for being a homemaker as well as a person employed outside the home. Title: Evaluation of secondary homemaking education in Bend, Oregon Author: Park, Ruth Stermer Concern over the low enrollment in homemaking classes prompted this study of the homemaking program in secondary schools in Bend, Oregon. Two questionnaires were constructed to obtain the opinions and beliefs of ninth, tenth, and eleventh-grade girls in Bend, Oregon, and their parents about the following: 1. What factors influence girls to enroll or not enroll in homemaking classes. 2. What factors parents consider in encouraging their daughters to enroll or not enroll in homemaking. 3. What girls and their parents believe should be taught in homemaking classes. 4. What types of homemaking classes and scheduling of those classes should be offered. The questionnaires were administered to the girls in Grade 9, 10, and 11 during a glass period. All girls who were present that day completed a questionnaire then took a parent questionnaire home for their parents to fill out. After the questionnaires were constructed they were pretested to determine if they would obtain the desired information. The data from the questionnaires were tabulated and organized into tables so that it could be analyzed and evaluated to try to determine ways to improve the program of homemaking education at the secondary level. The analysis of the data was organized into three sections. One deals with the girls' evaluations of homemaking education in Bend, Oregon; another deals with the parents' evaluations and the third draws together the similar and contrasting opinions and beliefs of the girls and their parents. In view of the beliefs and attitudes of the girls and their parents as shown in the study the following suggestions were made as possible next steps toward an improved homemaking education program in the Bend secondary schools. 1. Include different types of scheduling and different types of classes in the curriculum. 2. Reevaluate what is now being taught and try to place more emphasis on the areas of home management and relationships. 3. Carry out a better public relations program to inform the administration, other faculty, the community and the students in the school of the goals of the homemaking program. In light of the findings of the study, trends in education, and trends in high school education in Bend, Oregon, the writer proposes a new class to be offered on an experimental basis during the fall semester of 1962. The class would be scheduled to meet two or three times a week and would be a selected group or eleventh and twelfth-grade girls who were not planning to take any other homemaking. The center of emphasis of this class for young women would be upon development of attitudes, goals, and values to meet the problems of the changing times and upon the preparation for being a homemaker as well as a person employed outside the home. Close