bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sulfuric Acid Cleanup and KOH-Ethanol Treatment for Confirmation of Organochlorine Pesticides and Polychlorinated Biphenyls: Application to Wastewater Samples
Authors: HernÁndez Felix HernÁndez , Benet Francisco J.López , Escriche Julio Medina , Ubeda Juan C.Barberá 
Published: February 2020

Abstract
The efficacy of sulfuric acid cleanup and KOH-ethanol hydrolysis confirmation was studied for 22 organochlorine pesticides and 2 polychlorinated biphenyls (PCBs). Mean recoveries for different treatment times are given. The method was applied to analysis of several wastewater samples by gas chromatography with electron capture detection. Organochlorine compounds were extracted by using separatory funnels and 15% diethyl ether in hexane as extractant. All the compounds studied could be analyzed except trifluralin, dichloran, dieldrin, and endrin, which were destroyed after treatment with concentrated H2S04. The pesticides found most commonly in the samples analyzed were fenson, tetradifon, lindane, methoxychlor, and dicofol.
History of the Food and Drug Administration's Total Diet Study-1961 to 1987
Authors: Pennington Jean A T , Gunderson Ellis L 
Published: February 2020

Abstract
The Total Diet Study provides the Food and Drug Administration with baseline information on the levels of pesticide residues, contaminants, and nutrient elements in the food supply and in the diets of specific age-sex groups. The study also identifies trends and changes in the levels of these substances in the food supply and in diets over time and thereby assists in identifying potential public health problems. This paper describes the evolution of the Total Diet Study from 1961 to 1987. Food collections, sites of analysis, diets, food commodity groups, analytes, analytical methodologies, data transfer, publication of results, notable results, resources, and advantages of the study are discussed.
More Powerful Peroxide Kjeldahl Digestion Method
Authors: Hach Clifford C , Bowden Brian K , Kopelove Alan B , Brayton Scott V 
Published: February 2020

Abstract
Enhanced ammonia recovery and a simplified method are described for a rapid Kjeldahl digestion using sulfuric acid and hydrogen peroxide as the sole digestion reagents. This micro procedure uses a Vigreux fractionating head fitted to a 100 mL volumetric flask and a hot plate with a solid-state controller. Continuous-flow peroxide addition is controlled by a capillary funnel, and fumes are evacuated through a side-arm vent leading to a water aspirator. Complete recovery of nitrogen from the refractory compound, nicotinic acid, is obtained with less than 10 min digestion. The described method reduces digestion time by 25-50% over the open-manifold peroxy method. A digestibility index (DI), scaled 0-10, establishes the difficulty of digestion for each sample and assigns values to compounds. A useful tool for determining the minimal amount of reagent and digestion time required, the DI assigns zero for compounds not needing digestion and 10 for nicotinic acid. Digested samples obtained from the described method are suitable for direct colorimetric analysis of many elements in addition to Kjeldahl nitrogen. Distillation of the digested sample is not required
Liquid Chromatographic Determination and Stability of the Fusarium Mycotoxin
Moniliformin in Cereal Grains
Authors: Scott Peter M , Lawrence Guillaume A 
Published: February 2020

Abstract
Moniliformin is a mycotoxin produced by Fusarium subglutinans and other Fusarium species. A rapid, liquid chromatographic method for its determination in corn and wheat is described. Samples are extracted in acetonitrile-water (95 + 5); following defatting with n-hexane, an aliquot of the extract is evaporated and cleaned up on small C18 and neutral alumina columns successively. Reverse-phase liquid chromatography (LC) is conducted on a Ci8 column with 10 or 15% methanol or acetonitrile in aqueous ion-pair reagent as mobile phase, with detection by ultraviolet absorption at 229 and 254 nm. Average recoveries of moniliformin (potassium salt) added to ground corn and wheat at levels of 0.05-1.0 Mg/g were 80% (n = 20) and 85% {it = 12), respectively, and the limit of detection was ca 0.01- 0.18 Mg/g, depending on LC conditions. Analysis of 24 samples of wheat, 4 samples of rye, and 12 samples of corn showed moniliformin in only 2 corn samples (0.06 and 0.2 Mg/g)- Moniliformin was also detected in a sample of artificially damaged (slashed) corn (0.2 Mg/g) and selected kernels of corn that were field-inoculated with F. subglutinans and F. moniliforme (50 Mg/g and 0.5 Mg/g, respectively). In stability studies, moniliformin (potassium salt, 1 Mg/g) &gt;n ground corn and ground wheat heated at 50,100, and 150°C for 0.5-2 h decomposed moderately, e.g., 55% remained in corn after 0.5 h at 100°C
Improved Enzyme-Linked Immunosorbent Assay for Aflatoxin Bj in Agricultural Commodities
Authors: Chu Fun Sun , Fan Titan S L , Zhang Guang-Shi , Xu Yi-Chun , Faust Susan , Mcmahon Philip L 
Published: February 2020

Abstract
An improved enzyme-linked immunosorbent assay (ELISA) for aflatoxin B, in cornmeal and peanut butter was developed. Aflatoxin B, in cornmeal and peanut butter samples was extracted with 70% methanol in water containing 1% dimethylformamide diluted with assay buffer to a final concentration of 7.0% methanol, and directly subjected to an ELISA procedure that took less than 1 h for quantitative analysis and less than 30 min for screening tests. Analytical recoveries for 5-100 ppb B, added to the cornmeal and peanut butter were 91 and 95.4%, respectively. The interwell and interassay coefficient of variation was 10% or less at the 20 ppb level and above. Agreement for B, levels in more than 30 naturally contaminated corn, mixed feed, and peanut butter samples was excellent between the ELISA data and the data obtained from different independent laboratories using TLC or other analytical methods
Two Enzyme Immunoassays to Screen for 2,4-Dichlorophenoxyacetic Acid in Water
Authors: Fleeker James 
Published: February 2020

Abstract
Two solid-phase enzyme immunoassays were developed to measure 2,4-dichlorophenoxyacetic acid (2,4-D), using 2 sets of structurally distinct immunogens and enzyme ligands. The 2,4-D analog, 2-methyl- 4-chlorophenoxyacetic acid (MCPA), gave a similar response with both methods, whereas other phenoxy herbicides cross-reacted differently. In method A, the aromatic moiety of 2,4-D was distal from the carrier protein and labeled enzyme, whereas in method B, the acetic acid portion of the herbicide was distal. The use of both methods to screen for this herbicide in ground water and municipal and river water reduced the number of false-positive responses. Water sources having a low background response could be monitored with either method alone. When a concentration step, with disposable C18 extraction columns, was used, the limit of sensitivity was 5 ng/L,. Method A was the more sensitive of the 2 methods with a limit of detection of 10 j*g/L without the concentration step
Reverse-Phase Liquid Chromatographic Determination of Benzoic and Sorbic Acids in Foods
Authors: Bui Lap V , Cooper Chongchit 
Published: February 2020

Abstract
An isocratic liquid chromatographic (LC) technique is described for the determination of benzoic acid and sorbic acid in foods such as beverages, fruits, seafood, vegetables, sauces, and dairy, bakery, and confectionery products. A C1S column is used with methanol-phosphate buffer (5 + 95) as mobile phase and 4-hydroxyacetanilide or 3,5-dinitrobenzoic acid as internal standard. Sample preparation is simple, rapid, and produces a sample extract that has a minimum effect on the column performance and life. Specificity of the method was checked against common food additives such as i,-ascorbic acid, caffeine, artificial sweeteners (saccharin, cyclamate, aspartame), antioxidants (BHT, BHA) and artificial colors. Also described are 2 procedures for confirmation of the preservatives, using either redox reaction of sorbic acid with potassium permanganate or gas chromatography/ mass spectrometry. Mean recoveries of 90-105% were obtained with a precision of 1-6% and a detection limit of 20 mg/kg for the 2 preservatives
Determination of Phytosterols in Butter Samples by Using Capillary Column
Gas Chromatography
Authors: Smith Randall L , Sullivan Darryl M , Richter Earl F 
Published: February 2020

Abstract
A positive bias in the gas chromatographic (GC) analysis of butter for β-sitosterol was discovered when attempting to confirm values by gas chromatography/mass spectrometry (GC/MS). The source of the problem was traced to an interfering material that was not effectively separated by packed column GC. Because capillary columns are known to provide superior separation, they were substituted for packed columns in the assay, and instrument parameters were modified accordingly. A compound with a similar retention time, identified by GC/MS as lanosterol, was separated from β-sitosterol by the capillary column. The capillary column technique was applied to over 300 butter samples. The results indicate that the method can accurately quantitate β-sitosterol in butter with no known interferences. The limit of detection for this method is 1 mg/100 g. Recoveries at a level of 3 mg/100 g averaged 98% with a coefficient of variation of 3.45%
Comparison of Diethyl Ether and Ethyl Acetate as Extracting Agents for Recovery of Ascaris
spp. and Trichuris spp. Eggs
Authors: Rude Richard A , Peeler James T , Risty Norris G 
Published: February 2020

Abstract
Ethyl acetate and diethyl ether were compared for their ability to recover Ascaris spp. and Trichuris spp. eggs from seeded milorganite, liquid sludge, and cabbage. Concentrations of 10,100, and 1000 eggs/ 10 g test sample were prepared for 20 replicates of each product. The use of diethyl ether yielded fewer eggs/10 g than did ethyl acetate in 5 of 6 sets of data. For Ascaris spp., recovery from cabbage was 10 times higher with ethyl acetate at the higher concentration than with diethyl ether. For Trichuris spp., recovery from liquid sludge was slightly higher with diethyl ether for all egg concentrations. The other results ranged from 0 to 23% difference in recovery for the 2 agents. Depending on the parasites in question and the products to be screened, the substitution of ethyl acetate for diethyl ether may be significant.
Comparison of LECO FP-228 "Nitrogen Determinator" with AOAC Copper Catalyst Kjeldahl Method for Crude Protein
Authors: Sweeney Rose A , Rexroad Paul R 
Published: February 2020

Abstract
The LECO FP-228 "Nitrogen Determinator" was compared with the AOAC copper catalyst Kjeldahl method, 7.033-7.037, for the determination of crude protein in feed materials. The completely microprocessor- controlled instrument determines nitrogen by measuring the nitrogen gas following combustion of the sample; it was easy to operate and broadly applicable. A wide variety of feed materials of various nitrogen levels were analyzed in one mixed sequence. Results were precise, accurate, and rapid. Analysis time for one sample was approximately 3 min. Fourteen samples containing 2.5-15.5% N were selected for study and consisted of meals, grains, forages, and standard organic materials. The overall mean for the 14 samples by the LECO combustion method was 8.61% N compared with an overall mean of 8.58% N for the AOAC Kjeldahl method. Within-sample standard deviations for the LECO combustion method ranged from 0.013 to 0.052% N with a pooled standard deviation (SD) of 0.033% N for the 14 samples. Standard deviations for the AOAC Kjeldahl method ranged from 0.006 to 0.035% N with a pooled SD of 0.022% N. Combined average recovery of nitrogen from tryptophan, lysine- HC1, and EDTA determined by the LECO combustion method was 99.94% compared to 99.88% determined by the AOAC Kjeldahl method.
Colorimetric Determination of a Polymeric Quaternary Ammonium Antimicrobial Preservative in an Ophthalmic Solution
Authors: Good Ralph M , Liao John C , Hook Joan M , Punko Cathy L 
Published: February 2020

Abstract
A simple colorimetric method is presented for the determination of Polyquad®, a polymeric quaternary ammonium antimicrobial preservative, in an ophthalmic solution. Polyquad and magnesium are coprecipitated by ion pairing with Ponceau S, a highly colored sulfonate dye, at an acidic pH. The sample is centrifuged and the supernate analyzed spectrophotometrically. The concentration of Polyquad is determined by the decrease in dye concentration. Formulation excipients such as disodium edetate, dextran, and hydroxypropylraethylcellulose did not interfere with the quantitation. The method is specific, accurate, precise, and stability-indicating for the quantitation of 10 ppm Polyquad.
Enumeration of Clostridium perfringens Spores in Human Feces: Comparison of Four Culture Media
Authors: Harmon Stanley M , Kautter Donald A 
Published: February 2020

Abstract
Enumeration of Clostridium perfringens spores was compared using 4 culture media. Duplicate 1 g portions of 35 stools (25 from C. perfringens food poisoning outbreaks and 10 from normal stools) were heat treated 20 min at 75°C and tested on tryptose-sulfite-cycloserine (TSC) agar, tr ypticase-soy-blood (TSB) agar, lactose-sulfite (LS) medium, and iron milk (IM) medium. Dilutions were plated directly onto TSB and TSC, and a 3-tube most probable number determination was made with each specimen in LS and IM incubated at 45°C. TSB was easiest to use and nonhemolytic food poisoning strains were readily differentiated from the normal hemolytic biotype on this medium. Confirmed counts on TSC and TSB were similar for all specimens, but counts of 8 of 25 outbreak specimens were 2-4 log units lower in LS and IM than on plating media; spores in specimens associated with 2 of 5 outbreaks were intolerant of the elevated temperatures. Results showed that elevated temperature MPN methods in LS and IM are inappropriate for the examination of outbreak stools.
First Report of Sex Chromosomes in Night Lizards (Scincoidea: Xantusiidae)
Authors: Nielsen Stuart V , Pinto Brendan J , Guzmán-Méndez Irán Andira , Gamble Tony 
Published: February 2020

AbstractSquamate reptiles (lizards, snakes, and amphibians) are an outstanding group for studying sex chromosome evolution—they are old, speciose, geographically widespread, and exhibit myriad sex-determining modes. Yet, the vast majority of squamate species lack heteromorphic sex chromosomes. Cataloging the sex chromosome systems of species lacking easily identifiable, heteromorphic sex chromosomes, therefore, is essential before we are to fully understand the evolution of vertebrate sex chromosomes. Here, we use restriction site-associated DNA sequencing (RADseq) to classify the sex chromosome system of the granite night lizard, Xantusia henshawi. RADseq is an effective alternative to traditional cytogenetic methods for determining a species’ sex chromosome system (i.e., XX/XY or ZZ/ZW), particularly in taxa with non-differentiated sex chromosomes. Although many xantusiid lineages have been karyotyped, none possess heteromorphic sex chromosomes. We identified a ZZ/ZW sex chromosome system in X. henshawi—the first such data for this family. Furthermore, we report that the X. henshawi sex chromosome contains fragments of genes found on Gallus gallus chromosomes 7, 12, and 18 (which are homologous to Anolis carolinensis chromosome 2), the first vertebrate sex chromosomes to utilize this linkage group.
Emotional Legacies, Transitional Justice and Alethic Truth
Authors: Clark Janine Natalya 
Published: February 2020

Abstract
Transitional justice processes seek to address the legacy of past human rights abuses. This article focuses on the emotional dimensions of legacy. It argues that war crimes and human rights abuses leave important emotional legacies that have not received sufficient attention within transitional justice theory or practice, and underscores that any process of ‘dealing with the past’ is necessarily incomplete if powerful emotions connected to that past are overlooked. Drawing on the author’s fieldwork in the Bosnian village of Ahmići, the article aims to demonstrate that the neglect of emotional legacies — which it links to the concept of therapeutic jurisprudence — represents a missed opportunity to explore how the meta emotions that people share constitute potential new bases for building reconciliation in post-conflict societies such as Bosnia-Herzegovina. Reflecting more broadly on the relationship between truth and reconciliation, it emphasizes the utility of alethic truth as a concept that accommodates and draws attention to common emotions — and thus points to unexplored dimensions of the relationship between truth and reconciliation.
Subversive Invisibility during the Cold War: Paule Marshall’s “Brooklyn”
Authors: Parry Shirley 
Published: February 2020

AbstractThis essay explores how Paule Marshall engages issues of leftist politics and homosexuality in “Brooklyn,” her only fiction set during the Cold War. On the surface, this novella, the second in Marshall’s 1961 collection Soul Clap Hands and Sing, is a story of sexual harassment that, she has explained, was based on an experience she had at Brooklyn College. Marshall’s boldness in confronting the sexual and racial politics of the 1950s in the story’s depiction of an African American woman’s sexual harassment by her white professor has been noted by many. But less remarked is the fact that beneath the surface narrative of this story, Marshall has incorporated transgressive subtexts that address leftist politics and homosexuality, two issues that were deeply contested during the McCarthy years. A close examination of “Brooklyn” highlights the previously unrecognized narrative strategies that Marshall employs to both produce and conceal these subversive subtexts, thus creating a story that seems to reject communism at the same time that it incorporates a pro-communist political statement, and that seems to reflect the dominant culture’s assumption of heteronormativity while simultaneously endorsing the necessity of existential choice in the area of sexuality. In addition, Marshall shapes her characters so as to make existential choice more broadly the core theme of the story. This essay also situates the narrative in the context of Marshall’s own political activism as well as in the context of the negative impact that the Cold War political tensions had on African American writers during the 1950s.
Are long-term N-body simulations reliable?
Authors: Hernandez David M , Hadden Sam , Makino Junichiro 
Published: February 2020

ABSTRACT
N-body integrations are used to model a wide range of astrophysical dynamics, but they suffer from errors which make their orbits diverge exponentially in time from the correct orbits. Over long time-scales, their reliability needs to be established. We address this reliability by running a three-body planetary system over about 200 e-folding times. Using nearby initial conditions, we can construct statistics of the long-term phase-space structure and compare to rough estimates of resonant widths of the system. We compared statistics for a wide range of numerical methods, including a Runge–Kutta method, Wisdom–Holman method, symplectic corrector methods, and a method by Laskar and Robutel. ‘Improving’ an integrator did not increase the phase-space accuracy, but simply increasing the number of initial conditions did. In fact, the statistics of a higher order symplectic corrector method were inconsistent with the other methods in one test.
A slow-down time-transformed symplectic integrator for solving the few-body problem
Authors: Wang Long , Nitadori Keigo , Makino Junichiro 
Published: February 2020

ABSTRACTAn accurate and efficient method dealing with the few-body dynamics is important for simulating collisional N-body systems like star clusters and to follow the formation and evolution of compact binaries. We describe such a method which combines the time-transformed explicit symplectic integrator and the slow-down method. The former conserves the Hamiltonian and the angular momentum for a long-term evolution, while the latter significantly reduces the computational cost for a weakly perturbed binary. In this work, the Hamilton equations of this algorithm are analysed in detail. We mathematically and numerically show that it can correctly reproduce the secular evolution like the orbit averaged method and also well conserve the angular momentum. For a weakly perturbed binary, the method is possible to provide a few orders of magnitude faster performance than the classical algorithm. A publicly available code written in the c++ language, sdar, is available on github. It can be used either as a standalone tool or a library to be plugged in other N-body codes. The high precision of the floating point to 62 digits is also supported.
The ASAS-SN catalogue of variable stars VI: an all-sky sample of δ Scuti stars
Authors: Jayasinghe T , Stanek K Z , Kochanek C S , Vallely P J , Shappee B J , Holoien T W-S , Thompson Todd A , Prieto J L , Pejcha O , Fausnaugh M , Otero S , Hurst N , Will D 
Published: February 2020

ABSTRACT
We characterize an all-sky catalogue of ∼8400 δ Scuti variables in ASAS-SN, which includes ∼3300 new discoveries. Using distances from Gaia DR2, we derive period–luminosity relationships for both the fundamental mode and overtone pulsators in the WJK, V, Gaia DR2 G, J, H, Ks, and W1 bands. We find that the overtone pulsators have a dominant overtone mode, with many sources pulsating in the second overtone or higher order modes. The fundamental mode pulsators have metallicity-dependent periods, with log10(P) ∼ −1.1 for $\rm [Fe/H]\lt -0.3$ and log10(P) ∼ −0.9 for $\rm [Fe/H]\gt 0$, which leads to a period-dependent scale height. Stars with $P\gt 0.100\, \rm d$ are predominantly located close to the Galactic disc ($\rm |\mathit{ Z}|\lt 0.5\, kpc$). The median period at a scale height of $Z\sim 0\, \rm kpc$ also increases with the Galactocentric radius R, from log10(P) ∼ −0.94 for sources with $R\gt 9\, \rm kpc$ to log10(P) ∼ −0.85 for sources with $R\lt 7\, \rm kpc$, which is indicative of a radial metallicity gradient. To illustrate potential applications of this all-sky catalogue, we obtained 30 min cadence, image subtraction TESS light curves for a sample of 10 fundamental mode and 10 overtone δ Scuti stars discovered by ASAS-SN. From this sample, we identified two new δ Scuti eclipsing binaries, ASASSN-V J071855.62−434247.3 and ASASSN-V J170344.20−615941.2 with short orbital periods of Porb = 2.6096 and 2.5347 d, respectively.
Interactive Effects of Light Quality and Temperature on Arabidopsis Growth and Immunity
Authors: Liu Xiaoying , Xue Chunmei , Kong Le , Li Ruining , Xu Zhigang , Hua Jian 
Published: February 2020

Abstract
We report here the interactive effects of three light qualities (white, red and blue) and three growth temperatures (16�C, 22�C and 28�C) on rosette growth, hypocotyl elongation and disease resistance in Arabidopsis thaliana. While an increase in temperature promotes hypocotyl elongation irrespective of light quality, the effects of temperature on rosette growth and disease resistance are dependent on light quality. Maximum rosette growth rate under white, red and blue light are observed at 28�C, 16�C and 22�C, respectively. The highest disease resistance is observed at 16�C under all three light conditions, but the highest susceptibility is observed at 28�C for white light and 22�C for red and blue light. Interestingly, rosette growth is inhibited by phytochrome B (PHYB) under blue light at 28�C and by cryptochromes (CRYs) under red light at 16�C. In addition, disease resistance is inhibited by PHYB under blue light and promoted by CRYs under red light. Therefore, this study reveals a complex interaction between light and temperature in modulating rosette growth and disease resistance as well as the contribution of PHYB and CRY to disease resistance.