bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent Research Concerning the Freezing Point Value of Milk Produced in the Southeastern United States
Authors: Henningson R W
Published: February 2020

In 1953 Dahlberg, et al. published the first information indicating that the freezing point value of milk produced in the Southeastern United States might be higher than commonly accepted values. An extensive survey of retail milk marketed in South Carolina during 1957 produced an unweighted average freezing point value of –0.529°C, and disclosed that the unweighted average milk solids-not-fat content of retail milk marketed in South Carolina was 8.88%. Other surveys revealed such freezing point values as –0.537, –0.540, –-0.533, –0.528, and –0.532°C. Custer and Cardwell found freezing point depressions averaging 0.025—0.030°C less for reconstituted non-fat milks of southern origin than for similar milks of northern origin. The lactose and chloride contents of these milks were lower than those of the northern milks. Problems created by high freezing point values which are intensified by the effects of vacuum pasteurization, common in the Southeastern United States, on freezing point values will be discussed.
Rapid Tests for Protein in Milk
Authors: Kiddy Charles A , Plowman R D
Published: February 2020

A study of dye-binding methods for the rapid determination of the protein content of milk is being initiated. Preliminary studies are discussed; further study is recommended.
Composition Studies on Tobacco. XVI. Steam-Volatile Acids
Authors: Schmeltz Irwin , Stedman R L , Miller R L
Published: February 2020

The lower fatty acids of various types and grades of tobacco were studied by gas chromatography and identified by chromatographic and infrared spectral characteristics. Acids from C1 or C2 to C9 were found, including four (n-C4, n-C7, n-C8, and n-C9) not previously reported in tobacco leaf. Among the tobaccos investigated were bright (aromatic and aroma-deficient grades), burley, Maryland, and Turkish (Smyrna and Samsun). In general, all samples were qualitatively similar in volatile acid composition. Quantitatively the tobacco types differed as follows: Turkish (Samsun) contained a much higher level of β-methylvaleric acid (greater than four times) and a lower level of combined acetic and formic acids (less than one-half) than bright, and had a much higher proportion of isovaleric to n-valeric acid. Burley and Maryland contained lower levels of all identified acids than Turkish (Samsun) and bright. Among the grades of bright, the aromatic tobaccos contained more volatile acidic material than the aromadeficient tobaccos, and showed other differences in distributions of lower fatty acids compared to aroma-deficient samples.
Mycotoxins. I. Studies on Aflatoxin Derived from Contaminated Peanut Meal and Certain Strains of Aspergillus flavus
Authors: Armbrecht Bernard H , Hodges F Allen , Smith Howard R , Nelson Arthur A
Published: February 2020

Aspergillus flavus strains were obtained from British and domestic sources, and were cultured in our laboratories. Aflatoxin, the toxic derivative, was extracted from peanut meal by the method of Sargeant, et al. and from wheat by our method. The amounts of toxic substances present were estimated by paper chromatography. Concentrates were obtained by precipitation. One concentrate was reduced. Toxicity tests on ducklings confirmed British findings.
Use of Detergents in the Analysis of Fibrous Feeds. I. Preparation of Fiber Residues of Low Nitrogen Content
Authors: Soest P J Vax
Published: February 2020

Anionic, cationic, and nonionic detergents in different buffering media were examined for their capacity to dissolve nitrogenous constituents in forage dry matter, in the interest of preparing fiber of a low nitrogen content. Of the combinations examined, cetyl trimethyl ammonium bromide in strongly acid solution and sodium lauryl sulfate in slightly alkaline solutions appeared most effective.
Pesticide Residues in Commercial Animal Feeds
Authors: Minyard J P , Jackson E R
Published: February 2020

One hundred and one commercial feeds, of which 87 were dairy feeds or supplements, were analyzed for chlorinated organic pesticide residues by gas chromatography utilizing 5% SE-30 for the stationary phase and electron capture detection. A computation scheme for determining γ-BHC, aldrin, dieldrin, endrin, DDD, DDT, methoxychlor, heptachlor, heptachlor epoxide, chlordane, and toxaphene in combination with each other was developed, and values were tabulated for each in each feed. Contaminations ranged from low tens to hundreds (ppb). Most of the feeds contained residue amounts below those which would be expected to produce detectable residues in milk. Higher contamination levels were tentatively correlated with specific feed ingredients, as well as with protein and crude fiber content. Higher contaminations were observed with higher fiber content, lower feed protein value, and when grain screenings, rice bran, or rice mill by-product were ingredients. Much lower contaminations were associated with ground milo, wheat bran and middlings, ground and crimped oats, linseed oil meal, and various corn products.
Preparation of Electron Capturing Derivatives of Insensitive Pesticides
Authors: Gutenmann Walter H , Lisk Donald J
Published: February 2020

Many agricultural chemicals do not possess the proper structure or a sufficient number of electronegative functional groups for electron affinity determination. In the work reported, bromination coupled with other reactions is used to prepare sensitive derivatives of diphenyl, Guthion, MCP, and MCPB. Electron affinity gas chromatograms and standard curves representing nanogram quantities of these agricultural chemicals are illustrated.
Use of Starch-Gel Electrophoresis to Illustrate Inhibition of Tissue Esterases by Organophosphorus Pesticides. II. Comparison of Homogenates of Different Origin
Authors: Read Sheila I , Mckixley W P
Published: February 2020

Comparison of starch-gel electrophoresis patterns of ali-esterases of rabbit spleen, lung, brain, heart, and kidney showed that liver contained the most esterase, kidney the next greatest amount; patterns were generally similar, although amounts of esterase differed in different parts of the gel. Similar studies on various species of mammals, fowl, and fish showed that, in general, patterns of the same organ differed among species. Various enzymes appeared to be somewhat specific with respect to inhibitors but not to substrates, under the conditions used. Bromine treatment increased the inhibitory effect of Schradan, Dibrom and Ruelene, and EPN and parathion, in decreasing order.
Determination of Mercury in Pink Wheat
Authors: Jones Lawrence , Schwartzman George
Published: February 2020

A dithizone method for determining Hg in pink wheat, in which the sample size is limited to 250 mg, has been designed to measure 0—20 μg of μg, although larger amounts can probably be measured by adjusting conditions. In the 1.0—2.0 μg range of Hg, the recovery is about 14% low. An analysis may be completed in 2 hours after the initial kernel has been picked out under ultraviolet light.
Cleanup for Residue Analysis of Some 2,4-D Esters in Potatoes
Authors: Bevexue Arthur , Zweig Gunter , Nash Nancy L
Published: February 2020

A cleanup procedure was devised for analysis of 2,4-D esters in potatoes which eliminated the interference of a halogen-containing material in the potatoes. Recoveries on fortified samples were 82-84%.
Thin-Layer Chromatography for Chlorinated Pesticide Residue Analysis
Authors: Kovacs Martin F
Published: February 2020

A rapid sensitive method for the application of thin-layer chromatography to the detection and estimation of chlorinated organic pesticide residues has been developed. Compared to paper chromatography the method is faster, more sensitive, and in most cases more specific. Chlorinated pesticide residues were identified in extracts of various food products at concentrations as low as 1 part per billion; these results were verified by gas-liquid chromatography.

Because of its simplicity, speed, and sensitivity, thin-layer chromatography is suitable as a rapid screening method or as a confirmatory method in conjunction with gas-liquid chromatography or other analytical methods for chlorinated pesticide residue analysis.
Adaptation of a Twin-Beam Ultraviolet Spectrophotometer for Spectrophotometric Neutralization Analysis
Authors: Wilkie John B
Published: February 2020

Spectrophotome trie neutralization may be used to evaluate absorbing compounds in the presence of interference. The procedure has been expedited by new apparatus and technique, which eliminate the use of large volumes and pumping. The adaptation does not require extensive machine work, and conversion to ordinary spectrophotometric operation from optical neutralization operation is rapid.
Rapid Method for Determination of Moisture in Freeze-Dehydrated Shrimp
Authors: Despaul John E , Ezerski Donald W
Published: February 2020

Difficulties in determining moisture in freeze-dehydrated shrimp by the toluene distillation method were overcome by drying several whole shrimp directly in a vacuum oven. This procedure is faster and more reliable than several other methods tried, and results of a limited collaborative study show that it compares well with the toluene distillation method.
Determination of Certifiable FD&C Color Additives in Foods and Drugs
Authors: Graichen Charles , Molitor John C
Published: February 2020

Dolinsky and Stein described the use of a liquid anion exchange resin in butanol to extract FD&C colors from baked goods. The experience gained in our laboratory from analysis of over 450 food samples and more than 250 drug and vitamin samples by this procedure led to the development of several modifications of the original method. Solutions of the resin in hexane are employed to separate the azo colors from the triphenylmethane colors. For certain colors, a buffered resin solution is employed to minimize decomposition. The modification of the procedure to be employed depends primarily upon the color or colors present rather than upon the product to be analyzed. The applications of these procedures and their limitations in the analysis of foods and drugs for certifiable colors are discussed.
Determination of Piperazine in Formulations by Nonaqueous Titration
Authors: Maybury R B , Payfer R
Published: February 2020

A new method is presented for the nonaqueous titration of piperazine in formulations in which the piperazine base is first brought into aqueous solution, and the solution is made strongly alkaline and extracted with chloroform. The chloroform solution of piperazine is then titrated with acetous perchloric acid to alpha-naphthol benzein indicator. The procedure is rapid, shows good agreement with other methods, and is applicable to most kinds of piperazine formulations.

An alternative procedure for piperazine adipate, citrate, or tartrate in powders is given, in which the compound is dissolved and titrated directly in glacial acetic acid.
Quantitative Determination of Benzaldehyde in Flavors by Gas-Liquid Chromatography
Authors: Brunelle Richard L , Martin Glenn E
Published: February 2020

A rapid and specific method is given for determination of benzaldehyde in the presence of interfering substances by gas-liquid chromatography. Separation is effected on a ¼ column containing 2 5% Apiezon M as the liquid phase on a solid support of Chromoport XXX (60—80 mesh) at isothermal conditions, 100°C. The determination can be performed in the presence of benzoic acid and other interfering substances. Results are compared with those obtained by ultraviolet spectrophotometry on a variety of almond and cherry flavors.
The Analysis of Micro Amounts of Binapacryl, EPN, Methyl Parathion, and Parathion
Authors: George Donald A
Published: February 2020

Aromatic nitrated insecticides can be determined by a microchemical method based on the Averell-Norris procedure. The method is more sensitive than other known methods, and interference from plant extracts is low.
Fluorescence Determination of Gibberellic Acid in Cherries
Authors: Parker K G , John L E S T , Lisk D J
Published: February 2020

A method has been developed for determination of gibberellic acid in cherries based on a charcoal column cleanup followed by fluorescence measurement. Sensitivity of the method is about 0.02 ppm.
Resistance of Pseudomonas to Various Chemical Germicides
Authors: Beloian A , Koski T
Published: February 2020

Studies were conducted to determine the range of susceptibility of Pseudomonas to seven samples of commercial contact germicides. Tests were made by the official phenol coefficient method, 5.001-5.009. Ranges of resistance for Pseudomonas strains varied with the germicides tested and the concentration of germicide used. Chlorine in water supply systems showed a resistance range of 45-150 ppm to Pseudomonas organisms. Comparative studies were also conducted, using the dilution test method, on various strains of Pseudomonas to determine the effectiveness of disinfectants; strain PRD-10 proved to be the test strain of choice for determining the validity of Pseudomonicidal claims.
Aflatoxin: Effect on Mitotic Division in Cultured Embryonic Lung Cells
Authors: Legator Marvin S , Withrow Alida
Published: February 2020

Crude aflatoxin mixtures as well as crystallized B1 aflatoxin suppressed mitotic division in heteroploid and diploid human embryonic lung cells. This inhibition occurred 4 hours after exposure of the cells to the toxicant and reached a maximum in 8—12 hours. A concentration of 0.01 μg of the toxicant could be detected by this method. A sample of 2 μg of TLC pure B1 (determined by chemical assay) derived from contaminated peanuts was submitted for assay. A concentration of 0.03 μg produced a 51% reduction in mitosis.
Application of 4-(p-Nitrobenzyl) pyridine as a Rapid Quantitative Reagent for Organophosphate Pesticides
Authors: Getz Melvin E , Watts Randall R
Published: February 2020

A rapid colorimetric determination for organophosphate pesticides is reported. The basis for this method is the reaction between nitrobenzyl pyridine and phosphate pesticide in a slightly basic solution at 175-180°C. The method reported is rapid and has a sensitivity of approximately 2 μg of an organophosphate pesticide. Recoveries are presented for several crops fortified at 1 ppm. Interferences were noted for some types of crops, and the need for further cleanup work was indicated.
The Mass Spectra of Some Carbamate Pesticides
Authors: Damico Joseph N , Benson Walter R
Published: February 2020

The mass spectra of fourteen carbamate pesticides have been tabulated. The carbamates are divided into three classes: N-methyl, N-phenyl, and N,N-dimethyl. The significant fragmentation ions for these three classes are noted, and ions are postulated for the eight N-methylcarbamates rearrangement. The data can be utilized to characterize these classes of compounds.
Extraction and Assay Methods for Sugars in Apples and Carrots
Authors: Eheart James F , Mason Blanche S
Published: February 2020

Results of a statistically planned study are presented which show the extraction effectiveness of four different ethanol concentrations, and also whether it is necessary to reflux, add CaCO3, and use sample replicates, duplicate ethanol extract aliquots, and duplicate colorimeter tubes for the determination of total and reducing sugars, sucrose, glucose, and fructose in fresh apples and carrots. The copper sulfate-arsenomolybdate and the ferric ferricyanide-arsenomolybdate colorimetric methods for the determination of total and redvicing sugars and sucrose were also compared. Based on result obtained from this study, the addition of CaCO3, and refluxing the ethanol extracts, and the use of duplicate aliquots of ethanol extract and duplicate colorimeter tubes were unnecessary; at least two replicate samples should be vised. Differences in the results by assay method (Cu and Fe reduction) were not consistent enough to justify recommending one method over the other for the determination of total and reducing sugars and sucrose. The most effective ethanol concentration for extracting sugars from apples was 85% (v/v); for extraction from carrots, 75% was best.
Analysis of Pesticide Residues by Polarography
Authors: Gajan Raymond J
Published: February 2020

Polarography is a rapid, sensitive, and relatively specific technique that can be applied to pesticide residue analysis. The technique should also prove a valuable tool in overall pesticide research, such as monitoring new columns, studying kinetics, identifying and determining metabolites, assaying primary pesticide standards, and conducting stability studies.
Quantitative Determination of Blood Added to Hamburger
Authors: Hankin Lester
Published: February 2020

A quantitative method is proposed for determining blood deceptively added to ground beef (hamburger) to conceal excess fat. Blood is eluted from the sample with water, oxidized with hydrogen peroxide to liberate iron from the hemoglobin, and then treated with sodium tungstate to precipitate proteins. Iron content is then measured. Samples of hamburger to which blood was added were analyzed to provide a standard formula for the calculation of excess blood in unknown samples. The amount of iron in unadulterated or blank samples is taken into account in these calculations. Tolerance limits for the method are given.
Methods for Evaluating Vitamin A Isomers
Authors: Ames Stanley R
Published: February 2020

Precise estimation of the biological activity of the vitamin A in various products is complicated if cis isomers are present because they have lower biopotencies than alltrans isomer. Two general types of vitamin A sources contain cis isomers; the trans-neo type contains all-trans and 13-cis isomers, and the trans-cis type (including fish liver oils) contains, in addition, the 9-cis and 9,13-di-cis isomers of very low biopotency. The trans-neo type cannot be satisfactorily assayed by the SbCl3 blue color procedure, but the USP assay gives a satisfactory estimate of biopotency. No colorimetric or spectrophotometric procedure alone can be used to estimate the biopotency of the transcis type. Two empirical equations involving biopotency, maleic value, and either blue color or USP analyses satisfactorily estimate the biopotency of the trans-cis type of vitamin A product.
Extraneous Materials in Mushrooms
Authors: Brown Robert F
Published: February 2020

Studies were continued on the official, first action method for extraction and microscopic examination of maggots in canned mushrooms, 36.085(a). A No. 10 and a No. 16 sieve were added to the nested sieve combination used in the method, and a widefield stereoscopic microscope equipped with an ocular micrometer was used for maggot measurement. Results indicate that changes should be made in method 36.085 (a) to permit analyses of mushroom samples containing larger and various sized maggots
Separation, Determination, and Identification of Antipyrine and Benzocaine in Glycerol and Propylene Glycol Bases
Authors: Krause Richard T
Published: February 2020

Antipyrine and benzocaine are separated by column partition chromatography on three columns arranged serially with the sample-Celite mixture (top), a ferric chloride-Celite mixture (middle), and 22V HCl-Celite mixture (bottom). Antipyrine is retained on the ferric chloride column, and benzocaine is retained on the HC1 column. Maximum absorbances are determined on chloroform eluates at 272 and 283 mμ for antipyrine and benzocaine, respectively. Infrared spectra of the residues are determined in potassium bromide. Recoveries from 6 simulated commercial preparations averaged 100.4 ± 0.4% for antipyrine and 99.2 ± 0.5% for benzocaine. Six commercial products were also analyzed and per cent of declared ranged from 96.0 to 107.0 for antipyrine and from 92.4 to 106.0 for benzocaine. Infrared spectra of sample residues produced spectra with the same absorption peaks as that of the respective standards. It is recommended that additional work be done to verify recoveries of the urea-acetic acid preparation and that the method then be studied collaboratively.
Lysine and Methionine Availability in Heated Casein-Glucose Mixtures
Authors: Rao M Narayana , McLaughlan J M
Published: February 2020

Mixtures of casein, glucose, and water (2:2:1) were autoclaved at 15 p.s.i. for 5, 10, 20, and 40 minutes and then freeze dried. The available lysine and methionine in the casein-glucose (C-G) mixtures were determined by chemical and bioassay techniques. There was a considerable decrease in the amount of available lysine (65—68%) and methionine (39—47%) in the samples antoclaved for 20 and 40 minutes. The gross protein values of C-G mixtures combined with basal diets deficient in lysine or methionine gave values for available lysine and methionine which agreed closely with those obtained by chemical and microbiological assays. Plasma lysine levels correlated well with the gross protein values (r = 0.99; n = 4) and dinitrofluorobenzene available lysine; however, the correlation between the plasma methionine levels and gross protein values was not as significant (r=0.75; n = 5). The results presented here show that it is possible to use plasma amino acid levels as an index of the nutritional availability of certain amino acids in foodstuffs.
updating Analytical Constants for Egg Content of Food
Authors: Stauffer Leonard J
Published: February 2020

Significant changes were found in analytical indices for calculating egg content by the digitonin method, 13.131. It is recommended that the reported values be adopted for use in deriving a general formula for estimating egg content of noodles.
The Dumas Method for Nitrogen in Feeds
Authors: Ebeling Melvin E
Published: February 2020

A second collaborative study was made to compare Dumas with Kjeldahl methods for nitrogen determination in agricultural feed materials. The Dumas method used was the Nitrogen Analyzer II, Coleman Model 29A. The two methods were compared by ten participating laboratories on seven feed materials and one organic standard compound. Results for the Dumas procedure were in good agreement with the AOAC Kjeldahl method, and a high order of precision was achieved. It is recommended that the Dumas method be adopted as official, first action.
Infrared, Ultraviolet, and Visible Spectrophotometric Determination of Imidan in Animal Dips and Sprays
Authors: Czech Fred P , Mack Marvin D , Evans George
Published: February 2020

Procedures utilizing certain regions of spectral energy for the analysis of Imidan in emulsifiable and wettable powder concentrates, aqueous livestock dips, spray dips, and sprays are presented and compared. The UV method is recommended for rapid analysis of proprietary concentrates. Ill and colorimetric methods are advised for filth-laden animal dips and sprays. The IR method can be gen-r erally applied, is entirely specific for Imidan, and is quite precise. The other procedures are particularly useful for determination of low levels of Imidan.
Collaborative Study of an Acid Autoclave Method for Mineral Oil Extraction of Light Filth from Spaghetti and Macaroni
Authors: Thrasher Joel J
Published: February 2020

A method for the extraction of light filth from alimentary pastes based on rapid autoclaving of acidified samples, wet sieving on a No. 230 plain weave sieve, and heating the sieve retainings in an acidic mineral oil mixture is described. This new method is faster and results in higher and more reproducible recoveries than method 36.025. Recoveries were equal or better than those achieved by the official method, and the filter papers were cleaner.
Gas Chromatographic Determination of Methylene Chloride, Ethylene Dichloride, and Trichloroethylene Residues in Spice Oleoresins
Authors: Roberts Laura A
Published: February 2020

A gas chromatographic method has been developed for determining methylene chloride, ethylene dichloride, and trichloroethylene residues in spice oleoresins. The proposed method employs a Porapak Q column and a microcoulometric gas chromatograph. It is based on the volatility of the solvent residues, their relative retention times on a polyaromatic bead chromatographic column, and their detectability using a halide-specific microcoulometric method. The system is linear for all three solvents. Six collaborators obtained recoveries ranging front 72.8 to 91.4% The lower recoveries are attributed primarily to the volatility of the solvents, delay in analysis, and titration cell disruption by solvent front. It is recommended that the method be adopted as official first action for ethylene dichloride and trichloroethylene and that methylene chloride be subjected to further study.
Effect of Deproteinating Agents (Picric Acid and Sulfosalicylic Acid) on Analysis for Free Amino Acids in Swine Blood and Tissue
Authors: Knipfel J E , Christensen D A , Owen B D
Published: February 2020

Amino acid analyses were performed on samples of blood, liver tissue, loin muscle, and ham muscle by ion exchange chromatography after deproteination of the samples with picric acid or sulfosalicylic acid (SSA). Resolution of threonine and serine from the ion exchange column was poor when SSA was used as the deproteinating agent. Twelve of sixteen amino acids were higher (P < 0.05) in serum deproteinated with picric acid as compared to concentrations determined after SSA deproteination. Amino acid values for ham muscle tended to be higher after deproteination with picric acid; however, with liver and loin muscle samples, the values were somewhat higher after SSA deproteination. In both serum and tissue analyses, coefficients of variation were lower for niGSt amino acids when picric acid was utilized as the deproteinating agent. The latter observation, in particular, suggests that picric acid is preferable to SSA as a deproteinating agent before amino acid analyses of biological fluids. Standardization of methods of deproteination is needed to allow meaningful comparisons of data.
Effects of different sources and levels of dietary iron and selenium on the postprandial net portal appearance of these minerals in growing pigs
Authors: Dalto Danyel Bueno , Matte J Jacques
Published: February 2020

The present study compares the net portal appearance of dietary iron (Fe) and selenium (Se) after meals containing different sources and levels of these minerals. Twelve pigs (55.1 ± 3.7 kg) were used in a cross-over design to assess the 11-h net portal-drained viscera (PDV) flux of serum Fe and Se after ingestion of boluses containing inorganic (I) or organic (O) dietary Fe and Se at industry average (A; 200 and 0.6 mg, respectively) or high (H; 400 and 1.2 mg, respectively) levels. Arterial serum Fe concentrations increased by an average of 158% within 6 h post-meal and gradually decreased thereafter (P < 0.001). Values were greater (P < 0.001) for I than for O until 6 h post-meal and greater (P ≤ 0.001) for A than for H from 4 to 8 h post-meal. For the whole post-prandial period (11 h), arterial serum Fe concentrations tended (P = 0.06) to be greater for I than for O and were lowest for HO (P ≤ 0.03). Net PDV flux of Fe tended to be greater for AI than for AO (P ≥ 0.07). Cumulative appearance of Fe in PDV serum (% of dietary intake) was greater for I than for O (2.43 vs. −0.76%; P = 0.02) and A tended to be greater than H (1.96 vs. −0.29 %; P = 0.09) until 3 h post-meal, but these effects further faded out (P ≥ 0.43). Arterial serum Se concentration decreased for all treatments (average of 7%) from premeal values (P < 0.001), and this was more pronounced for O than for I (P = 0.03). Irrespective of treatment, net PDV flux of Se was positive (different from 0, P ≤ 0.03) during the first 90 min post-meal, decreased to negative minimum values (different from 0, P = 0.03) at 5 h post-meal, and was not different from 0 thereafter (P ≥ 0.11). Cumulative appearance of Se in PDV serum (% of dietary intake) was greater for I than for O (20.0 vs. −3.8%; P = 0.04) only at 45 min post-meal. In conclusion, both dietary Fe and Se absorption are limited to the early post-meal period. Whereas for Fe, the level effect is in accordance with the known negative correlation between its dietary concentration and percentage of intestinal absorption, this was not the case for dietary Se. The postabsorptive availability of dietary I was greater than O for both minerals and, particularly for Fe, at low levels.
Cavity Tightness Preferences of Overwintering Halyomorpha halys (Hemiptera: Pentatomidae)
Authors: Chambers Benjamin D , Leskey Tracy C , Cullum John P , Pearce Annie R , Kuhar Thomas P
Published: February 2020

Brown marmorated stink bug (Halyomorpha halys) (Stål) is a household nuisance pest that seeks shelter in buildings during the winter months. It has been found in a variety of cavities and spaces between building elements, as well as in the objects stored within buildings. This experiment examined the cavity tightness preferences for these insects as they settled in winter refugia. Adult overwintering H. halys were placed in two types of simulated refugia made from rigid material. Each type had a cavity of constant width, while one had a flat lid and constant tightness, and the other had a sloped lid that became tighter as insects moved inside. Adults were allowed to enter and settle, then their locations were recorded. In sloped lid cavities, H. halys tended to settle where the cavity tightness was between 4.5 and 5.5 mm. In the flat lid cavity boxes, H. halys tended to move all the way back. In both configurations, H. halys had a significant tendency to orient their heads towards the cavity entrance. A field comparison of cavity tightness in refugia with less rigid cardboard substrates was also performed, with spacers consisting of one or two layers of 3-mm cardboard. This comparison found differences in cavity selection by sex, with males more likely to pick single-spaced layers, and females more likely to select double-spaced layers. Understanding these preferences could be useful for collection, pest management, trap design, and study of impacts on structures.
The Arabidopsis TRM61/TRM6 complex is a bona fide tRNA N1-methyladenosine methyltransferase
Authors: Tang Jun , Jia Pengfei , Xin Peiyong , Chu Jinfang , Shi Dong-Qiao , Yang Wei-Cai
Published: February 2020

tRNA molecules, which contain the most abundant post-transcriptional modifications, are crucial for proper gene expression and protein biosynthesis. Methylation at N1 of adenosine 58 (A58) is critical for maintaining the stability of initiator methionyl-tRNA (tRNAiMet) in bacterial, archaeal, and eukaryotic tRNAs. However, although research has been conducted in yeast and mammals, it remains unclear how A58 in plant tRNAs is modified and involved in development. In this study, we identify the nucleus-localized complex AtTRM61/AtTRM6 in Arabidopsis as tRNA m1A58 methyltransferase. Deficiency or a lack of either AtTRM61 or AtTRM6 leads to embryo arrest and seed abortion. The tRNA m1A level decreases in conditionally complemented Attrm61/LEC1pro::AtTRM61 plants and this is accompanied by reduced levels of tRNAiMet, indicating the importance of the tRNA m1A modification for tRNAiMet stability. Taken together, our results demonstrate that tRNA m1A58 modification is necessary for tRNAiMet stability and is required for embryo development in Arabidopsis.
High Burden of Staphylococcus aureus Among Native American Individuals on the White Mountain Apache Tribal Lands
Authors: Sutcliffe Catherine G , Grant Lindsay R , Reid Angelina , Douglass Grace , Brown Laura B , Kellywood Kamellia , Weatherholtz Robert C , Hubler Robin , Quintana Alvaro , Close Ryan , McAuley James B , Santosham Mathuram , O’Brien Katherine L , Hammitt Laura L
Published: February 2020

Background

This study was done to determine the burden of invasive Staphylococcus aureus on the White Mountain Apache Tribal lands.

Methods

Active population and laboratory-based surveillance for invasive S aureus infections was conducted from May 2016 to April 2018. A case was defined as a Native American individual living on or around the White Mountain Apache Tribal lands with S aureus isolated from a normally sterile body site.

Results

Fifty-three cases were identified. Most cases were adults (90.6%) and had ≥1 underlying medical condition (86.8%), the most common of which were diabetes (49.1%) and obesity (41.5%). A total of 26.4% cases were categorized as community acquired. Most infections were methicillin-resistant (75.5%). A total of 7.5% of cases required amputation, and 7.7% of cases died within 30 days of initial culture. The incidence of invasive S aureus was 156.3 per 100 000 persons. The age-adjusted incidence of invasive methicillin-resistant S aureus was 138.2 per 100 000 persons.

Conclusions

This community has a disproportionately high burden of invasive methicillin-resistant S aureus compared with the general US population. Interventions are urgently needed to reduce the morbidity and mortality associated with these infections.
A Multitype Birth–Death Model for Bayesian Inference of Lineage-Specific Birth and Death Rates
Authors: Barido-Sottani Joëlle , Vaughan Timothy G , Stadler Tanja
Published: February 2020

Heterogeneous populations can lead to important differences in birth and death rates across a phylogeny. Taking this heterogeneity into account is necessary to obtain accurate estimates of the underlying population dynamics. We present a new multitype birth–death model (MTBD) that can estimate lineage-specific birth and death rates. This corresponds to estimating lineage-dependent speciation and extinction rates for species phylogenies, and lineage-dependent transmission and recovery rates for pathogen transmission trees. In contrast with previous models, we do not presume to know the trait driving the rate differences, nor do we prohibit the same rates from appearing in different parts of the phylogeny. Using simulated data sets, we show that the MTBD model can reliably infer the presence of multiple evolutionary regimes, their positions in the tree, and the birth and death rates associated with each. We also present a reanalysis of two empirical data sets and compare the results obtained by MTBD and by the existing software BAMM. We compare two implementations of the model, one exact and one approximate (assuming that no rate changes occur in the extinct parts of the tree), and show that the approximation only slightly affects results. The MTBD model is implemented as a package in the Bayesian inference software BEAST 2 and allows joint inference of the phylogeny and the model parameters.[Birth–death; lineage specific rates, multi-type model.]
Light-Emitting Diode–Based Photodynamic Therapy for Photoaging, Scars, and Dyspigmentation: A Systematic Review
Authors: Huang Alisen , Nguyen Julie K. , Jagdeo Jared
Published: February 2020

BACKGROUND

Light-emitting diodes (LEDs) may be used as an activating light source for photosensitizers in photodynamic therapy (PDT), a form of noninvasive phototherapy. Photodynamic therapy for aesthetic dermatologic conditions has demonstrated skin rejuvenating effects.

OBJECTIVE

To evaluate the safety and efficacy of PDT using LEDs to treat aesthetic dermatologic conditions including photoaged skin, scarring, and dyspigmentation.

MATERIALS AND METHODS

A search of PubMed and EMBASE databases was conducted through May 31, 2019, to identify studies that used LEDs as a light source for PDT and evaluated cosmetic improvements as the primary outcome measure.

RESULTS

A total of 24 original articles were included in the authors' systematic review. The available evidence supports methyl aminolevulinate or 5-aminolevulinic acid incubation followed by LED treatment for global improvement of skin quality, including smoother texture, reduction of rhytides, and improvement of scars. Histologic analysis for global skin improvement demonstrated increased collagen fibers and decreased elastin fibers after LED-mediated PDT.

CONCLUSION

Light-emitting diode–based PDT seems to have beneficial effects for photoaging, scars and dyspigmentation. A paucity of high-quality studies using LED-based PDT for aesthetic outcomes was found, highlighting the need for well-designed randomized control trials on this topic.
Comparison of Positive Inotropic Agents in the Management of Acute Decompensated Heart Failure
Authors: Kelly Julie , Cheng Judy , Malloy Rhynn , Lupi Kenneth
Published: February 2020

Current guidelines recommend the consideration of positive inotropes in patients with acute decompensated heart failure (ADHF) who have low cardiac index and evidence of systemic hypoperfusion or congestion. However, there is no evidence detailing the first line agent for the management of ADHF. The purpose of this study was to compare the safety and efficacy of dobutamine to milrinone for the treatment of ADHF. This was a single-center, retrospective study at a tertiary academic medical center, approved by Partner's Health Care Institutional Review Board. Patients included in this study were those admitted with ADHF who received dobutamine or milrinone from June 2015 to July 2017. A total of 95 dobutamine and 40 milrinone patients were included in the analysis. Median hospital length of stay was 12 days in the dobutamine group versus 10 days in the milrinone group (P = 0.34). Rehospitalization within 30 days occurred in 29.5% of patients in the dobutamine group versus 17.5% of patients in the milrinone group (P = 0.15). Median intensive care unit length of stay was 4.5 days in the dobutamine group versus 10 days in the milrinone group (P < 0.01). All other minor end points including all-cause mortality, progression to renal failure within 72 hours, rehospitalization in 90 days, and urine output within 72 hours of therapy were not found to be statistically significant. In addition, a post hoc analysis compared major and minor outcomes between milrinone and dobutamine using linear and logistic regression with adjustment for baseline characteristics. There were not any statistically significant findings in the post hoc analysis. Overall, there were no statistically significant differences in outcomes between the 2 groups other than longer intensive care unit length of stay in the milrinone group.
Primitive Myxoid Mesenchymal Tumor of Infancy in the Orbit: A New Location for a Rare Tumor
Authors: Hayes Rylan A. , Nicholls Wayne , Davies Janene , Sullivan Timothy J.
Published: February 2020

Primitive myxoid mesenchymal tumor of infancy is a rare subtype of sarcoma. With the advent of relevant immunohistochemical and genetic analysis, it was defined by Alaggio et al. in a 2006 case series. Since then, 25 further cases are described in the literature—arising variably from the neck, chest, scalp, abdomen, back, or limbs. Here it is described for the first time arising in the orbit, confirmed by identification of BCOR immunopositivity with internal tandem duplication. All specialties involved in the management of orbital masses should be aware of the subtypes of sarcomas found in the orbit as approaches to their management may change depending on the diagnosis. As more cases are identified, a better understanding of this tumor’s clinical behavior and appropriate management can be established.
Influence of angle κ on visual and refractive outcomes after implantation of a diffractive trifocal intraocular lens
Authors: Garzón Nuria , García-Montero María , López-Artero Esther , Albarrán-Diego César , Pérez-Cambrodí Rafael , Illarramendi Igor , Poyales Francisco
Published: February 2020

Purpose:

To evaluate changes in angle κ after the implantation of a trifocal intraocular lens (IOL) and to assess the postoperative outcomes of patients with different angle κ values.

Setting:

IOA Madrid Innova Ocular, Madrid, Spain.

Design:

Prospective trial.

Methods:

Sixty-three eyes from 63 patients who had bilateral implantation of a diffractive trifocal IOL (POD F, PhysIOL) were included. Pupil offset was used as the best estimate of angle κ and was measured using Pentacam (Oculus) preoperatively and at 3 months postoperatively. Postoperative refractive outcomes (sphere, cylinder, and manifest refraction spherical equivalent) and visual outcomes at far, intermediate, and near distance were assessed and compared between eyes with small pupil offset and eyes with large pupil offset. Quality of vision was assessed using a subjective questionnaire.

Results:

There was a significant decrease in pupil offset values postoperatively (mean: 0.197 ± 0.12 mm) compared with those preoperatively (mean: 0.239 ± 0.12 mm), with a mean decrease of −0.042 mm (P = .0002). The same significant decrease was found for both right and left eyes, when analyzed separately. No statistically significant difference was found in any of the refractive and visual acuity outcomes between eyes with small pupil offset and eyes with large pupil offset. The majority of patients (14 of 16) complaining of significant halos had eyes with small pupil offset.

Conclusions:

Large pupil offset did not negatively affect visual and refractive outcomes. The tolerance to larger pupil offset might be due to the IOL optical design, with the first diffractive ring being larger than other commonly used multifocal IOLs. More studies comparing various diffractive IOL models would be useful to confirm such hypothesis.
Measuring Choroid Thickness as a Marker of Systemic Inflammation in Patients With Ankylosing Spondylitis
Authors: Steiner Martina , del Mar Esteban-Ortega Maria , Thuissard-Vasallo Israel , García-Lozano Isabel , Moriche-Carretero Manuel , García-González Alejandro Javier , Pérez-Blázquez Eugenio , Sambricio Javier , García-Aparicio Ángel , Casco-Silva Bruno Francisco , Sanz-Sanz Jesús , Valdés-Sanz Nuria , Fernández-Espartero Cruz , Díaz-Valle Teresa , Gurrea-Almela María , Fernández-Melón Julia , Gómez-Resa María , Pato-Cour Esperanza , Díaz-Valle David , Méndez-Fernández Rosalía , Navío Marco Teresa , Almodóvar Raquel , García-Saenz María Carmen , del-Prado-Sánchez Cristina , Muñoz-Fernández Santiago ,   on behalf of the Choroidal Thickness in Spondylitis (COnTEST) Study Group
Published: February 2020

Background and Objective

Ankylosing spondylitis (AS) is an inflammatory disease, and choroidal thickness (CT) has been proposed and evaluated as a potential marker of systemic inflammation associated with AS and other inflammatory diseases. This study compared CT measurements taken from patients with severe AS disease activity without eye inflammation with those taken from healthy subjects.

Methods

This cross-sectional, multicenter study compared CT in 44 patients with high AS disease activity, and no history of eye inflammation with CT in 44 matched healthy subjects aged between 18 and 65 years. In the AS group, the correlation between CT and C-reactive protein, human leukocyte antigen (HLA) B27 positivity, disease duration, and disease activity was calculated.

Results

Mean CT values of patients with AS were significantly higher in the right eye, the left eye, and the thickest choroid eye. The right eye mean CT was 338.3 ± 82.8 μm among patients with AS and 290.5 ± 71.2 μm among healthy subjects (p = 0.005). The left eye mean CT was 339.5 ± 84.7 μm for patients with AS and 298.4 ± 68.9 μm for healthy subjects (P = 0.015). The thickest choroid eye CT was 358.4 ± 82.1 μm among patients with AS and 314.1 ± 65.2 μm among healthy subjects (P = 0.006). We did not find a significant correlation between CT and disease activity, C-reactive protein, human leukocyte antigen B27 positivity, or disease duration.

Conclusions

Patients with active AS but without a history of eye inflammation had a thicker choroid than healthy subjects. This finding suggests that CT is a marker of systemic inflammation in patients with inflammatory disease, regardless of known eye symptoms.
Network explanations and explanatory directionality
Authors: Jansson Lina
Published: February 2020

Network explanations raise foundational questions about the nature of scientific explanation. The challenge discussed in this article comes from the fact that network explanations are often thought to be non-causal, i.e. they do not describe the dynamical or mechanistic interactions responsible for some behaviour, instead they appeal to topological properties of network models describing the system. These non-causal features are often thought to be valuable precisely because they do not invoke mechanistic or dynamical interactions and provide insights that are not available through causal explanations. Here, I address a central difficulty facing attempts to move away from causal models of explanation; namely, how to recover the directionality of explanation. Within causal models, the directionality of explanation is identified with the direction of causation. This solution is no longer available once we move to non-causal accounts of explanation. I will suggest a solution to this problem that emphasizes the role of conditions of application. In doing so, I will challenge the idea thatsui generismathematical dependencies are the key to understand non-causal explanations. The upshot is a conceptual account of explanation that accommodates the possibility of non-causal network explanations. It also provides guidance for how to evaluate such explanations.

This article is part of the theme issue ‘Unifying the essential concepts of biological networks: biological insights and philosophical foundations’.
Evolving complexity: how tinkering shapes cells, software and ecological networks
Authors: Solé Ricard , Valverde Sergi
Published: February 2020

A common trait of complex systems is that they can be represented by means of a network of interacting parts. It is, in fact, the network organization (more than the parts) that largely conditions most higher-level properties, which are not reducible to the properties of the individual parts. Can the topological organization of these webs provide some insight into their evolutionary origins? Both biological and artificial networks share some common architectural traits. They are often heterogeneous and sparse, and most exhibit different types of correlations, such as nestedness, modularity or hierarchical patterns. These properties have often been attributed to the selection of functionally meaningful traits. However, a proper formulation of generative network models suggests a rather different picture. Against the standard selection–optimization argument, some networks reveal the inevitable generation of complex patterns resulting from reuse and can be modelled using duplication–rewiring rules lacking functionality. These give rise to the observed heterogeneous, scale-free and modular architectures. Here, we examine the evidence for tinkering in cellular, technological and ecological webs and its impact in shaping their architecture. Our analysis suggests a serious consideration of the role played by selection as the origin of network topology. Instead, we suggest that the amplification processes associated with reuse might shape these graphs at the topological level. In biological systems, selection forces would take advantage of emergent patterns.

This article is part of the theme issue ‘Unifying the essential concepts of biological networks: biological insights and philosophical foundations’.