bluuebunny/crossref_metadata_2025_split huggingface dataset:
Making Sense of Computational Psychiatry
Authors: Mujica-Parodi Lilianne R , Strey Helmut H 
Published: February 2020

AbstractIn psychiatry we often speak of constructing “models.” Here we try to make sense of what such a claim might mean, starting with the most fundamental question: “What is (and isn’t) a model?” We then discuss, in a concrete measurable sense, what it means for a model to be useful. In so doing, we first identify the added value that a computational model can provide in the context of accuracy and power. We then present limitations of standard statistical methods and provide suggestions for how we can expand the explanatory power of our analyses by reconceptualizing statistical models as dynamical systems. Finally, we address the problem of model building—suggesting ways in which computational psychiatry can escape the potential for cognitive biases imposed by classical hypothesis-driven research, exploiting deep systems-level information contained within neuroimaging data to advance our understanding of psychiatric neuroscience.
Stylized Facts and Comparative Statics in (Social) Science Inquiry
Authors: Narang Neil , LeVeck Brad L 
Published: February 2020

Abstract
In a recent article, David Blagden (2019) critiques our research published in the International Studies Quarterly (LeVeck and Narang 2017a), in which we draw on the well-known “wisdom of crowds” phenomenon to argue that, because democracies typically include a larger number of decision makers in the foreign policy process, they may produce fewer decision-making errors in situations of crisis bargaining. As a result, bargaining may fail less often. Blagden's critique focuses on two supposed flaws: first, that “[d]emocracies may have a larger number of more diverse policymakers, of course, but this relationship is not necessary,” and second, that “weighing against the superior ability of large groups to average towards accurate answers, meanwhile, is a substantial drawback of larger groups: the diminishing ability to take and implement decisions” due to additional veto players. In this article, we demonstrate the ways in which we believe Blagden's critique to be misguided in its approach to social science inquiry. In particular, we argue that much of his critique requires that we reject two hallmarks of scientific inquiry: the use of stylized facts in theory building; and the use of comparative statics to generate testable hypotheses.
A New Technique for Determining Chemical Structure by Gas Chromatography
Authors: Beroza Morton , Acree Fred 
Published: February 2020

Abstract
A new technique that helps determine the chemical structure of organic compounds in microgram amounts utilizes a hot catalyst-containing tube that attaches to the injection port of a flameionization gas chromatograph. Hydrogen, the carrier gas, conducts the sample over the heated catalyst, and in this process saturates multiple bonds and removes halogen, oxygen, sulfur, and nitrogen atoms. The hydrocarbon products, which exit into the chromatographic column and separate in it, are the parent hydrocarbon and/or the next lower homolog. These data help determine the carbon skeleton of a wide variety of compounds, which may contain as many as 24 connected carbon atoms. The position of functional groups (e.g., ketones, alcohols, amines) may frequently be determined from the fragmentation pattern. A "neutral" catalyst composed of palladium on diatomaceous earth is the best catalyst found to date. Temperature programming of the analytical column has certain advantages in this procedure. Experimental data and discussion of different catalysts, flow rate, ring structures, operating parameters, comparison of this technique with pyrolysis and mass spectrometry, and limitations are included. Two apparatus designs permit collection of sufficient hydrocarbon product for characterization by another procedure. The technique is especially useful for identification of compounds available in only minute amounts, such as gas chromatographic fractions and degradation fragments of natural products.
Analysis of Radioactive Compounds by Gas Chromatography
Authors: Karmen Arthur 
Published: February 2020

Abstract
The use of radioactive tracers, analysis of the radioactive compounds by gas chromatography, and measurement of the radioactivity in the effluent of the GLC column represent a powerful combination of techniques that will facilitate the performance of many kinds of studies. The radioactivity can be measured in a number of ways, each of which has been studied, and the experimental conditions necessary for successful operation of each have been defined. Among other applications, this methodology can be used to study biosynthetic pathways in vivo and in vitro, as in fatty acid synthesis, to study relative rates of metabolism of groups of compounds, to determine traces of specific compounds in complex mixtures, and to calibrate the gas chromatograph.
Organic Arsenicals in Feeds
Authors: Hoffman Harold H 
Published: February 2020

Abstract
Two variations of the silver diethyldithiocarbamate color development for arsenic were compared with the molybdenum blue procedure, 33.005. Aliquots of common ash digests were used to insure that equal amounts of arsenic were present for each color development. On 3 feeds, each containing 145 ppm arsanilic acid, 15 collaborators reported recoveries averaging 98.8% for molybdenum blue and 94.7% for AgDDC. When the AgDDC method was modified by cooling the extracts to 5°C just prior to arsine evolution, recovery was increased to 96.6%. Since the arsenic source was arsanilic acid, collaborators were asked to also assay by the Bratton-Marshall color method, 33.007—33.009. Although the recovery was 100.6%, it is noteworthy that the collaborators also found an average of 11.7 ppm arsanilic acid in a base feed sample with no added arsenical.
Determination of Malathion in Formulations
Authors: Orloski E J 
Published: February 2020

Abstract
A second collaborative study was made of the Norris colorimetric method for malathion as modified by Upham to use acetonitrile as extraction solvent and by Ware to use a procedural standard instead of a standard curve. The following variables were evaluated: temperature change, levels of malathion, volume of alkali, shaking time, volume of ferric reagent, oxidizing time, deterioration of copper complex, interference of lubricant, effect of ultraviolet radiation, interference of other pesticides. The method was rewritten to take account of these variables. On the basis of collaborative results, the method is recommended for adoption as official, first action.
Total Dodine Residues in Fruits
Authors: Pasarela N Robert 
Published: February 2020

Abstract
A study was made of the method of Steller, et al., for determination of total dodine residues in fruits. The dodine is extracted with ethanol-chloroform and forms a complex with bromocresol purple, which is extracted into chloroform and hydrolyzed. Dodine is determined by spectrophotometric measurement of the absorbance of the hydrolysate at 590 mμ. Collaborative recoveries of added dodine from 0.1 to 10 ppm on apples, peaches, pears, strawberries, and pecans were satisfactory, and the method is recommended for adoption as official, first action.
Determination of Nicotine Residues on Foods
Authors: Martin Robert , Schwartzman George 
Published: February 2020

Abstract
A collaborative study was made of Schwartzman’s method for residues of nicotine in waxy crops and leafy crops. The nicotine is stripped from leafy crops with ammoniacal benzene-chloroform and from waxy crops with ammonium hydroxide, extracted with acid, and measured on an ultraviolet spectrophotometer. Average recoveries by five collaborators were 95.9% for waxy crops and 103.8% for leafy crops. It is recommended that the method be adopted as official, first action.
Separation and Measurement of Perthane, DDD (TDE), and DDT in Leafy Vegetables by Electron Capture Gas Chromatography
Authors: Klein A K , Watts J O 
Published: February 2020

Abstract
A column and a method are described by which mixtures of the olefins of Perthane, DDD, and DDT can be completely resolved and accurately measured by electron capture gas chromatography. The column consists of a 2.5% substrate coating composed of a 1:1 proportion of SF-96 and polyester 2,2-diethyl-1,3-propanediol-isophthalate on Celite.
Analysis of Acetone Peroxide Premixes for Bleaching and Maturing Flour
Authors: Taylor James T 
Published: February 2020

Abstract
A quantitative and a qualitative method for the determination of acetone peroxides were subjected to collaborative study. Quantitative analyses are based upon liberation and titration of hydrogen peroxide from acyclic peroxides and hydroperoxides by dilute sulfuric acid and standardized potassium permanganate, respectively. Single determination of 6 samples (varying in per cent levels of peroxide equivalent) each of baking premixes and milling premixes produced very good collaborative results. Qualitative analyses, achieved by comparing infrared spectra of acetone-extracted organic peroxides with acetone-extracted organic peroxides from a reference premix, gave peaks characteristic of the premixes. No interferences were seen from various starch blanks. Both the quantitative and the qualitative methods are recommended for adoption as official, first action.
Antihistamines Combined with Phenylephrine Hydrochloride and Codeine Phosphate or Dihydrocodeinone Bitartrate in Elixirs
Authors: Hyatt Rupert 
Published: February 2020

Abstract
A procedure has been developed for analysis of combinations of antihistamines with phenylephrine hydrochloride and codeine phosphate or dihydrocodeinone in cough sirup. The method involves separation by partition column chromatography and determination by spectrophotometric measurement, or by gas chromatography when more than one antihistamine is present. Recoveries from known mixtures were 99— 100.5% of the three ingredients.
A Rapid Procedure for Extraction of Extraneous Materials from Flour
Authors: Reed Garland L , Miller Mary T 
Published: February 2020

Abstract
Preliminary studies were conducted to determine the effect of viscosity and specific gravity of the extracting solvent on the recovery of extraneous materials from flour. Results showed no statistical differences, and studies were initiated to develop a more rapid procedure. The unpublished procedure of Cory, which uses a household detergent and eliminates the need for the Wildman trap flask, was modified and studied. Compared with the official procedure, the modified procedure is less time consuming, eliminates the long digestion period, requires less special technique, and results in filter papers that are clean and easy to examine.
Determination of Vanillin by Ultraviolet Absorption
Authors: Feexy Fraxk J 
Published: February 2020

Abstract
Because the official chromatographic method for vanillin, ethyl vanillin, and coumarin in vanilla extracts is timeconsuming, a sorting procedure based on ultraviolet absorption was developed for rapid determination of vanillin in the absence of the other two components. Small amounts of coumarin are detected by its green fluorescence under alkaline conditions. Thirteen collaborators analyzed four samples for vanillin by the official and the proposed methods; seven checked for the presence of coumarin. On the basis of results, the method is recommended for adoption as official, first action.
Determination of Vanillin and Ethyl Vanillin by Gas-Liquid Chromatography
Authors: Marten Glenn E , Feeny Frank J , Scaringelli Frank P 
Published: February 2020

Abstract
A rapid method has been developed in which gas-liquid chromatography is used to separate vanillin and ethyl vanillin in vanilla samples and determine them quantitatively. A flame ionization detector is used for the vanillin determination. 2-Phenoxyethanol is used as internal standard. The presence of any other substances is eliminated.
Rapid Determination of Furazolidone in Feed
Authors: Stone Loyal R 
Published: February 2020

Abstract
Furazolidone is extracted from feed into dimethylformamide-carbon tetrachloride solution and isolated by chromatography on an alumina column. After extraction into water the absorbance of furazolidone itself is measured without color development. The procedure requires much less laboratory time than method 33.025 and has the additional advantage of being specific for furazolidone. Accuracy is at least equal to that of the official method over the range 0.0055% to 0.033% furazolidone.
Separate Determination of Furazolidone and Nitrofurazone in Feeds
Authors: Stone Loyal R 
Published: February 2020

Abstract
Furazolidone is separated from nitrofurazone by chromatography on an alumina column from dimethylformamide- carbon tetrachloride solution. The drugs are extracted into water with interferences remaining in the carbon tetrachloride phase. Each drug is then converted to 5-nitrofurfural phenylhydrazone and determined colorimetrically
Effect of Atmospheric Pressure on Reichert-Meissl and Polenske Values of Butterfat
Authors: Dunn Thomas C , Weiss Louis C 
Published: February 2020

Abstract
Three samples of butter were tested at four atmospheric pressures to determine the effect of pressure on the Reichert- Meissl and Polenske values. The effect is not of great significance. In view of improved methods for determining the adulteration of butter with vegetable oil, it is recommended that the study be dropped.
One-step Cleanup of Chlorinated Insecticide Residues by Chromatography on Carbon-Celite Mixtures
Authors: Moats William A 
Published: February 2020

Abstract
one-step chromatographic cleanup technique for chlorinated insecticides has been developed in which carbon (Nuchar)-Celite mixtures are used. Insecticides are selectively eluted from the adsorbent with 20% (v/v) acetone in ethyl ether. Procedures are described for cleanup of residues in fat up to 0.8 g of fat and for cleanup of extracts of green leafy plant materials. Cleanup is satisfactory for paper chromatography. Aldrin, chlordane, DDD, DDE, DDT, dieldrin, endrin, heptachlor, heptachlor epoxide, Kelthane, lindane, Thiodan, and thiodandiol were recovered quantitatively or nearly so. Methoxychlor and toxaphene were partially recovered.
Summary of Results of the Collaborative Tests on the Rhodamine B Colorimetric Method for Antimony
Authors: Bartlet J C , Monkman J L 
Published: February 2020

Abstract
In acid solution, pentavalent antimony forms a colored complex with Rhodamine B that can be extracted with an organic solvent such as benzene or toluene. The method was tested by ten collaborators on three samples. The average recovery was 105% with a coefficient of variation of about 10%. The method has been recommended for adoption as official, first action.
Oxidative Metabolism and Persistence of Trithion on Field-Sprayed Lettuce
Authors: Coffin D E 
Published: February 2020

Abstract
Trithion was applied to field-growing lettuce, and samples were removed at various times after spraying and analyzed for Trithion and its oxidative metabolites. Trithion persisted in growing lettuce for 21 days. Five oxidation products of Trithion appeared within 4 hours of spraying and persisted for up to 21 days. The results indicate that the principal route of oxidation of Trithion involves thioether oxidation to form the sulfoxide and then the sulfone, followed by phosphorothionate oxidation to form the thiolphosphate sulfone.
Determination of Polysorbate 80 in Bakery Products and Frozen Desserts
Authors: Hall Martha J 
Published: February 2020

Abstract
A gravimetric method has been developed for determining polysorbate 80 at levels of 0.05 and 0.1% in bread, ice cream, and cake mix. The sample is hydrolyzed and saponified with hydrochloric acid and potassium hydroxide, respectively, and the liberated glycol is extracted with chloroform. The residue from the chloroform extracts is dissolved in water, and the fatty acids are extracted with petroleum ether. The glycol is then re-extracted from the aqueous solution into chloroform. The chloroform extract is evaporated to dryness, and the residue is dissolved in water and precipitated with phosphomolybdic acid. Recoveries at the 0.05% level ranged between 75 and 105%, and at the 0.1% level, between 85 and 107%.
Chromatographic Separation of Malathion Prior to Infrared Spectrophotometry Estimation
Authors: Double R C 
Published: February 2020

Abstract
Column chromatography was used to separate malathion from other pesticide formulations prior to spectrophotometric measurement. Malathion is separated by a petroleum ether-acetone system on a Florisil column. The chromatographic procedure is applicable to technical preparations, emulsifiable concentrates, dusts, and water-based fruit fly bait.
Hydrolysis of Proteins for Amino Acid Analysis. II. Acid Hydrolysis in Sealed Tubes of Mixtures of β-Lactoglobulin and Starch
Authors: Gordon William G , Basch Jay J 
Published: February 2020

Abstract
Experiments with a mixture of β-Iactoglobulin and starch, simulating the composition of carbohydrate-rich foods and feeds, have been carried out to determine conditions for acid hydrolysis that will permit maximal recovery of amino acids in hydrolysates of such materials. When a large excess of 6N HC1 is used for hydrolysis, good recoveries of most amino acids are obtained. However, about one-quarter of the tyrosine present is destroyed under the conditions investigated. Some destruction of methionine and cystine may also be attributed to the presence of carbohydrate, but a special method for the determination of these amino acids is available.
Potentiometric Determination of Vitamin C in Highly Colored Products
Authors: Hardesty William S 
Published: February 2020

Abstract
The method of Barakat and co-workers for determination of vitamin C in colored products has been modified for potentiometric use. The procedure is simple and rapid: An aliquot of sample containing 1—3 nig of ascorbic acid is titrated in a 3% acetic acid medium in the presence of KI with previously standardized 0.01% N-bromosuccinimide. The potentiometric titration uses two Pt electrodes with a polarizing current. Results were compared with the USP XVI method and the AOAC 2,6-dichlorophenol indophenol method. Recoveries, obtained from seven commercial products, four of which were vitamin C-enriched, ranged from 96 to 101%. The method also works well on drug mixtures containing ascorbic acid. It is recommended that the method be studied collaboratively.
Assay of Oil-Soluble Vitamins. Part II. Vitamin A and Vitamin D Assays from a Common Saponification and Extraction
Authors: Deutsch M J , Duffy D , Weeks C E 
Published: February 2020

Abstract
Combining the assays of vitamin A and vitamin D facilitates the completion of analyses of products containing both vitamins. Methods are given for typical pharmaceuticals, feeds, and oils. Samples not containing vitamin A or similar compounds may be assayed for vitamin D without chromatography.
Chemical Assay of Chick Edema Factor in Fats and Fatty Acids
Authors: Higginbotham G R 
Published: February 2020

Abstract
A microcoulometric gas chromatographic method for detecting chick edema factor in fats was studied collaboratively by six laboratories. The method involved extracting unsaponifiable material from fat and fractionating it on an activated alumina column, then examining the third alumina fraction by microcoulometric gas chromatography. Results did not warrant adoption of the method. Initial studies with electron capture gas chromatography for this determination showed promise. A better cleanup procedure needs to be developed. It is planned to continue the study, and to combine acetonitrile extraction and cleanup on an acid- Celite column with electron capture determination.
Aluminum and Iron in Plants
Authors: Lixden Elizabeth I 
Published: February 2020

Abstract
A review of literature discloses nun erous methods applicable to determination of Al and Fe in plants. A comparison of results for Fe by a colorimetric method using 2,2’-bipyridine as chelating agent with those by the colorimetric o-phenanthroline and the TiCl3 titrimetric methods in Official Methods of Analysis showed that the 2,2’-bipyridine was simpler, less time-consuming, and equally as accurate as the o-phenanthroline procedure, and free of the Cu interference encountered in the TiCl3 method. Further study is recommended for accurate and efficient methods for Al and Fe.
Confirmatory Tests for Aflatoxin B1
Authors: Andrellos Peter John , Reid George R 
Published: February 2020

Abstract
Three confirmatory tests have been devised to identify aflatoxin B±. Portions of the isolated toxin are treated with formic acid-thionyl chloride, acetic acid-thionyl chloride, and trifluoroacetic acid, respectively, and aliquots of the three fluorescent reaction products are spotted on thin-layer chromatography plates. Standards treated with each of the three reagents, plus an untreated standard, are spotted on the same plate, and after development the spots are compared under ultraviolet light.
Pyridoxine Determined Fluorometrically as Pyridoxal Cyanide Compound
Authors: Polansky Marilyn Macarthur , Camarra Ricpiard T , Toepfer Edward W 
Published: February 2020

Abstract
Pyridoxine was oxidized with manganese dioxide to pyridoxal, which was converted to pyridoxal cyanohydrin by a reaction with potassium cyanide. Fluorescence readings were linearly related over a range of 0.005 to 0.5 μg of pyridoxine/ml. Recoveries of pyridoxine as pyridoxal were good and offered a method for the fluorometric determination of pyridoxine in aqueous solution.
Gas Chromatographic Analysis of Insect Attractants: Trimedlure, Medlure, Siglure, Butyl Sorbate, Cue-lure, Methyleugenol
Authors: Beroza Morton , Sarmiento Rafael 
Published: February 2020

Abstract
Means of analyzing trimedlure, medlure, siglure, butyl sorbate, cue-lure, and methyleugenol by gas chromatography have been devised to ensure the procurement of high quality attractants needed for the detection of insect pests, especially those invading noninfested areas. The methods permit the estimation of the 4 trans isomers present in commercially produced trimedlure and medlure, and of the cis and trans isomers of siglure. Commercially available butyl sorbate gives a single sharp peak and is supposed to be the trans, trans isomer. Cue-lure and methyleugenol each give a single peak.
Cleanup Processes for Pesticide Residue Analysis
Authors: Mckinley W P , Coffin D E , Mccully K A 
Published: February 2020

Abstract
At least six cleanup procedures developed for the isolation of chlorinated hydrocarbon pesticides are described. Four procedures for organophosphate pesticide cleanup in plant extracts are also given. A combination of methods is suggested for a broad scope organophosphate pesticide cleanup technique.
Application of Thin-Layer Chromatography to the Quantitative Estimation of Antioxidants: BHA, BHT, PG, and NDGA
Authors: Sahasrabudhe Madhu R 
Published: February 2020

Abstract
A procedure is described for the quantitative estimation of BHA, BHT, PG, and NDGA in lard. The antioxidants are extracted from n-hexane solutions of the fat with 80% ethyl alcohol and acetonitrile, separated by two-dimensional thin-layer chromatography using benzene and acetonitrile, and estimated quantitatively by colorimetric methods after extraction of the spots. A special flask for concentration and a suction tube assembly for spot pickup are described. Recoveries of the antioxidants from lard were in the following ranges: BHA, 98-101%; BHT, 96-101%; PG, 90-101%; NDGA, 82-98%. The advantages of the method over others in use are that (I) all four antioxidants can be estimated in one aliquot of fat, (2) PG and NDGA can be estimated when present together in mixtures, and (3) the isomers of BHA can be effectively separated.