bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the Influence of Coagulant on Phosphorus in Landscape Water Environment
Authors: Su Chunhong
Published: February 2020

This study selected three kinds of inorganic polymer coagulant: polyferric sulfate, polyaluminium chloride, polyaluminium ferric chloride, two inorganic low molecular coagulants: aluminum chloride and aluminum sulfate. The coagulation experiment of lake water without “water bloom” was carried out. The results were analyzed by multivariate linear regression and principal component regression analysis. It showed that the effects of the five coagulants on the phosphorus were the same when the landscape water was treated with different dosages of coagulants. The sequence was: total nitrogen (TN) > dosage > ammonia nitrogen > CODcr > turbidity > PH. Among them: the highest effect of total nitrogen on phosphorus was aluminum chloride (71.73%). The most obvious effect of dosage on phosphorus was polyaluminium chloride (34.68%). The most significant effect of ammonia nitrogen on phosphorus was polyaluminum chloride (16.98%).
Effects of Atrazine on the Growth of Suaeda Heteroptera
Authors: Huo Yujie , Wei Haifeng , Zhao Yumeng , He Jie , Zhang Mingliang
Published: February 2020

To explore the ecological degradation of Suaeda Heteroptera in Panjin Red Beach wetland, the effects of Atrazine on the growth and physiological effects of Suaeda Heteroptera seedlings were studied by indoor hydroponics. Experimental results show that the leaves and roots of the Suaeda Heteroptera seedlings are very sensitive to Atrazine. And the LD50 of the number of leaves of Suaeda Heteroptera seedlings were 34.2 μg/L. At low concentrations (3.8-11.4 μg/L), Atrazine promoted the growth of seedling leaves; at higher concentrations (22.8-34.8 μg/L), it inhibited leavse growth and had a significant dose-effect relationship Atrazine had different effects on height and root length of Suaeda Heteroptera, but had no effect on seedlings stem length. The formation of chlorophyll b in leaves of Suaeda Heteroptera treated by Atrazine was inhibited. Also, the main factor for the decrease of total chlorophyll consent is Atrazine.
Analysis of Changes in Ecological Patterns in the Upper Reaches of the Minjiang River One of Typical Disaster Prone Area of China
Authors: Ma Guangwen , Yu Yang , Wang Guang , Zhang Fenying , Liu Haijiang , He Lihuan , Wang Yeyao
Published: February 2020

Mountain torrents and debris flows are rapid transport processes for soil and water materials in small watersheds in mountainous areas. They have a strong destructive power and often result in devastating natural disasters. Natural ecosystems can regulate natural disasters, reduce the risk of damage, increase the stability of disaster-prone environments and reduce the vulnerability of downstream areas. The upper reaches of the Minjiang River (URM) in Sichuan Province, China is a typical area prone to flood and debris flow disasters. An established scientific model was used to analyze land cover change in the URM to discover the optimum land use pattern. Based on the analysis of the pattern of temporal and spatial changes of ecosystems in the URM, the results showed that the amount of ecosystem change in the URM was small, and the overall change rate of ecosystems was only 1.7%. There was an obvious trend of landscape fragmentation in the whole URM region, and the change of ecosystems had clear regional differences. Human economic activities were the main reason for the changes in the spatial pattern of ecosystems from 1985 to 2013.
Inherent Analysis on Feature and Mechanism of Renewable Energy System in ST-3E System
Authors: Diao Chunyan , Cui Bojun , Wu Yunjie , Li Jianfeng
Published: February 2020

Development of renewable energy is significant for energy security and also an important solution to cope with the climate change. Nowadays, due to its unique energy endowment, China’s energy security and sustainable development becomes a big issue. In this paper, in the ST-3E renewable energy system, the five features and five inherent mechanism are analyzed. In the area of sustainable development, this work can further promote the ST-3E renewable energy system model to help governments and international agencies to make energy strategies and policies.
Drainage and Total Nitrogen Loss of Cropland under Drip Irrigation and Subsurface Pipe Drainage
Authors: Zhang Shan , Tan Qian , Zhao Hang , Zhang Tong
Published: February 2020

Water saving irrigation as an effective measure to improve the utilization rate of water resources and alleviate water deficit has been widely practiced in arid and semi-arid regions. In this study, an integrated drip irrigation and subsurface pipe drainage system was developed to study the total nitrogen emission concentration of sunflowers during the whole growth period. The test and results show that total nitrogen concentration of farmland drainage in the spring irrigation period exceeded the standard V of “Surface Water Quality Standard”. In addition, prolonging the leaching time or reducing the irrigation quota can effectively reduce the concentration of total nitrogen in farmland drainage.
A proof of factorization for deep inelastic neutrino scattering
Authors: Ling R.
Published: February 2020

It is proven in this paper that the structure functions for the hadron quantity describing deep inelastic neutrino scattering factor into the product of a short-distance coefficient function, the non-perturbative parton distribution function which encompasses the underlying structure of the target, and the function for soft radiation which does not emerge in the case of electron scattering for which weak radiative corrections are usually practically ignored. This is shown to all orders of perturbative quantum chromodynamics and electroweak theory, and to leading order in the power expansion of the effective field theory used as a tool. It is based on the observation that there is no necessity to go into the partonic level of the physical process, for a generalized version of the operator product expansion affords a framework for the study of inclusive processes, where the momentum carried in by one current operator and out by the other is allowed to go to infinity. It is discovered following this line of argument that the objects entering the factorization theorem need not be SU(2) × U(1) gauge singlets, whether or not we perform the factorization in the symmetric phase. The factorization analysis provides initial conditions for evolution to arbitrary energies that allows for re-summation of large logarithms for loop calculations to the extent of accuracy requested.
On the Mordell-Weil ranks of supersingular abelian varieties in cyclotomic extensions
Authors: Lei Antonio , Ponsinet Gautier
Published: February 2020

Let

F
F

be a number field unramified at an odd prime

p
p

and let

F
∞

F_\infty

be the

Z

p

\mathbf {Z}_p

-cyclotomic extension of

F
F

. Let

A
A

be an abelian variety defined over

F
F

with good supersingular reduction at all primes of

F
F

above

p
p

. Büyükboduk and the first named author have defined modified Selmer groups associated to

A
A

over

F
∞

F_\infty

. Assuming that the Pontryagin dual of these Selmer groups is a torsion

Z

p

[
[

Gal

(

F
∞

/

F
)
]
]

\mathbf {Z}_p[[\textrm {Gal}(F_\infty /F)]]

-module, we give an explicit sufficient condition for the rank of the Mordell-Weil group

A
(

F
n

)

A(F_n)

to be bounded as

n
n

varies.
Membership in Sport or Exercise Groups Predicts Sustained Physical Activity and Longevity in Older Adults Compared to Physically Active Matched Controls
Authors: Stevens Mark , Cruwys Tegan
Published: February 2020

Background

Physical activity tends to decline in older age, despite being key to health and longevity. Previous investigations have focused on demographic and individual factors that predict sustained physical activity.

Purpose

To examine whether engaging in physical activity in the context of sport or exercise group membership can protect against age-related physical activity decline.

Methods

Drawn from the English Longitudinal Study of Ageing, participants were members of sport or exercise groups aged 50 and over (N = 2015) as well as nonmember controls, who were matched at baseline for age, sex, and physical activity levels (N = 1881). Longitudinal mixed effects models were used to assess the effect of sport or exercise group membership on physical activity and longevity across a 14-year follow-up.

Results

Members of sport or exercise groups experienced an attenuated decline in both moderate and vigorous physical activity over a 14-year follow-up compared to physically active matched controls. Sport or exercise group members were also less likely to have died at follow-up, an effect that was mediated through sustained physical activity.

Conclusions

Promoting membership in sport and exercise groups may be a beneficial strategy for supporting sustained physical activity and health among older people.
Visual Priming Influences Olfactomotor Response and Perceptual Experience of Smells
Authors: Manesse Cédric , Fournel Arnaud , Bensafi Moustafa , Ferdenzi Camille
Published: February 2020

Whereas contextual influences in the visual and auditory domains have been largely documented, little is known about how chemical senses might be affected by our multisensory environment. In the present study, we aimed to better understand how a visual context can affect the perception of a rather pleasant (floral) and a rather unpleasant (damp) odor. To this end, 19 healthy participants performed a series of tasks including odor detection followed by perceptual evaluations of odor intensity, pleasantness, flowery, and damp characters of both odors presented at 2 different concentrations. A visual context (either congruent or incongruent with the odor; or a neutral control context) preceded odor stimulations. Olfactomotor responses as well as response times were recorded during the detection task. Results showed an influence of the visual context on semantic and motor responses to the target odors. First, congruency between context and odor increased the saliency of the olfactory feature of the memory trace, for the pleasant floral odor only (higher perceived flowery note). Clinical applications of this finding for olfactory remediation in dysosmic patients are proposed. Second, the unpleasant odor remained unaffected by visual primes, whatever the condition. In addition, incongruency between context and odor (regardless of odor type) had a disruptive effect on odor sampling behavior, which was interpreted as a protective behavior in response to expectancy violation. Altogether, this second series of effects may serve an adaptive function, especially the avoidance of, or simply vigilance toward, aversive and unpredictable stimuli.
Identification of genome-wide single-nucleotide polymorphisms among geographically diverse radish accessions
Authors: Kobayashi Hiroto , Shirasawa Kenta , Fukino Nobuko , Hirakawa Hideki , Akanuma Takashi , Kitashiba Hiroyasu
Published: February 2020

Radish (Raphanus sativus L.) is cultivated around the world as a vegetable crop and exhibits diverse morphological and physiological features. DNA polymorphisms are responsible for differences in traits among cultivars. In this study, we determined genome-wide single-nucleotide polymorphisms (SNPs) among geographically diverse radish accessions using the double-digest restriction site-associated DNA sequencing (ddRAD-Seq) method. A total of 52,559 SNPs was identified in a collection of over 500 radish accessions (cultivated and wild) from East Asia, South and Southeast Asia, and the Occident and Near East. In addition, 2,624 SNP sites without missing data (referred to as common SNP sites) were identified among 510 accessions. Genetic diversity analyses, based on the common SNP sites, divided the cultivated radish accessions into four main groups, each derived from four geographical areas (Japan, East Asia, South and Southeast Asia, and the Occident and Near East). Furthermore, we discuss the origin of cultivated radish and its migration from the West to East Asia. SNP data generated in this work will facilitate further genetic studies on the radish breeding and production of DNA markers.
Paroxysmal and persistent atrial fibrillation ablation outcomes with the pulmonary vein ablation catheter GOLD duty-cycled phased radiofrequency ablation catheter: quality of life and 12-month efficacy results from the GOLD Atrial Fibrillation Registry
Authors: Boersma Lucas , Koźluk Edward , Maglia Giampiero , de Sousa João , Grebe Olaf , Eckardt Lars , Hokanson Robert B , Hemingway Lauren A , Ostern Ekaterina , Park Hyoung-Seob , Rovaris Giovanni , Arribas Fernando , Scharf Christoph , Csanádi Zoltán , Arenal Ángel , Laurenzi Francesco , Klaver Martijn , Goette Andreas
Published: February 2020

Aims

The GOLD AF Registry has been designed to prospectively assess the population, indications, and outcomes using second-generation phased radiofrequency (RF) ablation (pulmonary vein ablation catheter GOLD) in a global examination of standard-of-care use for the treatment of paroxysmal and persistent atrial fibrillation (AF).

Methods and results

GOLD AF (NCT02433613) is a prospective, observational, multi-centre registry designed to characterize efficacy and safety of phased RF ablation in patients with AF. The primary endpoint was freedom from AF recurrence at 12-month follow-up after a 90-day blanking period. Ancillary objectives include safety, procedural efficiency, and quality of life (QoL). The QoL assessment using the Atrial Fibrillation Effect on QualiTy-of-Life (AFEQT) and the European Heart Rhythm Association (EHRA) Score of AF-related symptoms was collected at baseline and 12 months. In total, 1054 patients were included in this analysis (age 60.6, 67.6% male, 26.5% PersAF). Kaplan–Meier estimate of freedom from AF recurrence was 77.7% at 12 months. Peri-procedural device or procedure-related complications were observed in 26 (2.5%) patients, with a low stroke rate of 0.3%. One-year post-ablation, the EHRA AF Symptom score decreased in 68% of patients. The AFEQT score improvement was observed in 88.4% and 90.4% of patients who completed the questionnaire in-person or interviewed by phone at 12 month follow-up, respectively.

Conclusion

Phased RF ablation for the treatment of paroxysmal and persistent AF demonstrated a 77.7% freedom from AF recurrence at 12 months in addition to a significant reduction in arrhythmia symptoms and clinically meaningful improved QoL. Low peri-procedural complication rate of <3% was reported.
Current trends in access to treatment for hepatitis B in immigrants vs non-immigrants
Authors: Miquel Mireia , Pardo Albert , Forné Montse , Martínez-Alpin Gemma , Rodríguez-Castellano Adrià , Casas Meritxell , Rosinach Mercè , Roget Mercè , Dalmau Blai , Temiño Rocío , Quer Joan Carlos , Sanchez-Delgado Jordi , Ortiz Jordi , Vergara Mercedes
Published: February 2020

Background

Universal vaccination for hepatitis B virus (HBV) and migratory movements have changed the demographic characteristics of this disease in Spain and in Europe. Therefore, we evaluated the characteristics of the disease and the possible differences according to origin (immigrants vs non-immigrants) and access to treatment.

Methods

This is a multicenter cross-sectional study (June 2014 to May 2015) in which outpatients with a positive HBsAg were seen and followed in four Hepatology units. Demographic and clinical data and indication and access to treatment were collected in two different regions of Catalonia (Spain) where there are no barriers to treatment due to a comprehensive coverage under the National Health System.

Results

A total of 951 patients were evaluated (48.1% men). Of these, 46.6% were immigrants (58.7% of them were born in Africa) and were significantly younger compared to non-immigrants. The proportions of patients with alcohol consumption, being overweight, and other indicators of metabolic co-morbidities were significantly higher in non-immigrants. Among the 937 patients receiving HBeAg examination, 91.7% were HBeAg-negative. Chronic HBeAg-positive infection was significantly higher in immigrants (3.9% vs 0.6%, P = 0.001) and chronic HBeAg-negative hepatitis was higher non-immigrants (31.7% vs 21.4%, P < 0.001). Not only was the proportion of patients who met treatment criteria significantly higher among non-immigrants (38.4% vs 29.2%, P = 0.003), but also the proportion of those with indication of effectively receiving therapy at the time of data collection (83.2% vs 57.8 %, P < 0.001).

Conclusions

The immigrant population with HBV is younger and has a lower prevalence of metabolic co-morbidities and a higher frequency of chronic HBeAg infection. Despite having access to care and an indication for treatment, some do not get adequately treated due to several factors including local adaptation that precludes access to treatment.
Generativity and Social Well-Being in Older Women: Expectations Regarding Aging Matter
Authors: Moieni Mona , Seeman Teresa E , Robles Theodore F , Lieberman Matthew D , Okimoto Stephanie , Lengacher Clara , Irwin Michael R , Eisenberger Naomi I
Published: February 2020

Objectives

Beliefs about aging can contribute to health and well-being in older adults. Feeling generative, or that one is caring for and contributing to the well-being of others, can also impact health and well-being. In this study, we hypothesized that those with more positive expectations regarding aging (ERA) in the mental health domain would report greater levels of perceived social support (PSS) and lower levels of loneliness in response to a generativity intervention (vs control condition).

Method

Participants in this study (n = 73, 100% female) were randomly assigned to a 6-week generativity condition, which involved writing about life experiences and sharing advice with others, or to a control condition, which involved writing about neutral topics. Pre- and postintervention, PSS, and feelings of loneliness were measured.

Results

Those in the generativity condition with more positive ERA in the mental health domain reported greater PSS and lower loneliness postintervention.

Discussion

These results highlight the importance of psychological factors, such as ERA, in moderating the efficacy of interventions to promote social well-being in older adults.
Hearing Impairment and Mental Health Among Married Couples
Authors: West Jessica S
Published: February 2020

Objectives

Disablement is a significant health problem and chronic stressor for older adults and is associated with negative mental health outcomes. Although some research has explored how disability extends beyond individuals to influence the mental health of their support networks, less population-based research has assessed the consequences of hearing impairment, a growing public health concern that affects 72.4% of people aged 65 and older. Moreover, although much research has examined the negative individual impact of hearing impairment, less population-based research has assessed its consequences on spouses. To fill this gap, the current study builds on gender, marriage, and stress proliferation research to examine (a) the association between own hearing impairment and spouses’ depressive symptoms, and (b) whether this association varies by the gender of the spouse.

Method

Fixed-effects regression models were conducted using data from 5,485 couples (10,970 individuals) from 10 waves of the Health and Retirement Study (1998–2016).

Results

Wives’ fair or poor hearing is significantly associated with an increase in husbands’ depressive symptoms, net of controls. However, husbands’ fair or poor hearing is not associated with an increase in wives’ depressive symptoms.

Discussion

These findings suggest that hearing impairment can proliferate from one spouse to the other, but that this proliferation depends on gender. Health care providers need to be aware of the implications for husbands when treating women with hearing impairment.
The exponentiated phase measurement, and objective-function hybridization for adjoint waveform tomography
Authors: Yuan Yanhua O , Bozdağ Ebru , Ciardelli Caio , Gao Fuchun , Simons F J
Published: February 2020

Seismic tomography has arrived at the threshold of the era of big data. However, how to extract information optimally from every available time-series remains a challenge; one that is directly related to the objective function chosen as a distance metric between observed and synthetic data. Time-domain cross-correlation and frequency-dependent multitaper traveltime measurements are generally tied to window selection algorithms in order to balance the amplitude differences between seismic phases. Even then, such measurements naturally favour the dominant signals within the chosen windows. Hence, it is difficult to select all usable portions of seismograms with any sort of optimality. As a consequence, information ends up being lost, in particular from scattered waves. In contrast, measurements based on instantaneous phase allow extracting information uniformly over the seismic records without requiring their segmentation. And yet, measuring instantaneous phase, like any other phase measurement, is impeded by phase wrapping. In this paper, we address this limitation by using a complex-valued phase representation that we call ‘exponentiated phase’. We demonstrate that the exponentiated phase is a good substitute for instantaneous-phase measurements. To assimilate as much information as possible from every seismogram while tackling the non-linearity of inversion problems, we discuss a flexible hybrid approach to combine various objective functions in adjoint seismic tomography. We focus on those based on the exponentiated phase, to take into account relatively small-magnitude scattered waves; on multitaper measurements of selected surface waves; and on cross-correlation measurements on specific windows to select distinct body-wave arrivals. Guided by synthetic experiments, we discuss how exponentiated-phase, multitaper and cross-correlation measurements, and their hybridization, affect tomographic results. Despite their use of multiple measurements, the computational cost to evaluate gradient kernels for the objective functions is scarcely affected, allowing for issues with data quality and measurement challenges to be simultaneously addressed efficiently.
Probabilistic estimation of structure coefficients and their uncertainties, for inner-core sensitive modes, using matrix autoregression
Authors: Pachhai S , Masters G , Laske G
Published: February 2020

Normal-mode structure coefficients are crucial observations to infer the velocity, density and attenuation structure of the deep Earth interior, but estimating these coefficients from Earth's normal mode spectra is a non-linear inverse problem. Additionally, complete source information is typically unknown for large earthquakes, and there is a trade-off between the earthquake source and attenuation. Therefore, proper estimation of elastic and anelastic structure coefficients with their uncertainties becomes challenging. Here, we combine a matrix autoregression and a fully non-linear probabilistic sampling to address existing limitations. After successful feasibility experiments using synthetic data with noise, we apply this combined approach to the data for 19 inner-core sensitive spheroidal (S) modes measured for earthquakes from 1994 to 2016. We further implement a model selection criterion to assess whether anelastic structure is significant. Our model selection criterion indicates that anelastic structure coefficients are required only for modes with strong shear-wave energy in the inner core. Inversion results also show a strong correlation between elastic and anelastic splitting functions for these modes. This indicates that the seismic waves travel faster and strongly attenuate along polar paths such that the m = 0 singlet remains poorly observed for these modes.
Orthogonal structure on a quadratic curve
Authors: Olver Sheehan , Xu Yuan
Published: February 2020

Orthogonal polynomials on quadratic curves in the plane are studied. These include orthogonal polynomials on ellipses, parabolas, hyperbolas and two lines. For an integral with respect to an appropriate weight function defined on any quadratic curve, an explicit basis of orthogonal polynomials is constructed in terms of two families of orthogonal polynomials in one variable. Convergence of the Fourier orthogonal expansions is also studied in each case. We discuss applications to the Fourier extension problem, interpolation of functions with singularities or near singularities and the solution of Schrödinger’s equation with nondifferentiable or nearly nondifferentiable potentials.
Antibody Fc Glycosylation Discriminates Between Latent and Active Tuberculosis
Authors: Lu Lenette L , Das Jishnu , Grace Patricia S , Fortune Sarah M , Restrepo Blanca I , Alter Galit
Published: February 2020

Background

Mycobacterium tuberculosis remains a global health problem and clinical management is complicated by difficulty in discriminating between latent infection and active disease. While M. tuberculosis-reactive antibody levels are heterogeneous, studies suggest that levels of IgG glycosylation differ between disease states. Here we extend this observation across antibody domains and M. tuberculosis specificities to define changes with the greatest resolving power.

Methods

Capillary electrophoretic glycan analysis was performed on bulk non-antigen–specific IgG, bulk Fc domain, bulk Fab domain, and purified protein derivative (PPD)- and Ag85A-specific IgG from subjects with latent (n = 10) and active (n = 20) tuberculosis. PPD-specific isotype/subclass, PPD-specific antibody-dependent phagocytosis, cellular cytotoxicity, and natural killer cell activation were assessed. Discriminatory potentials of antibody features were evaluated individually and by multivariate analysis.

Results

Parallel profiling of whole, Fc, and Fab domain-specific IgG glycosylation pointed to enhanced differential glycosylation on the Fc domain. Differential glycosylation was observed across antigen-specific antibody populations. Multivariate modeling highlighted Fc domain glycan species as the top discriminatory features, with combined PPD IgG titers and Fc domain glycans providing the highest classification accuracy.

Conclusions

Differential glycosylation occurs preferentially on the Fc domain, providing significant discriminatory power between different states of M. tuberculosis infection and disease.
Antibiotic Use in Food Animals: Controlling the Human Health Impact
Authors: Tollefson Linda , Miller Margaret Ann
Published: February 2020

Resistance to antimicrobial drugs has compromised control of many bacterial pathogens. For foodborne pathogens, the most likely source of resistance is use of antimicrobials in food-producing animals. To control the human health impact from use of antimicrobials in animals, the U.S. Food and Drug Administration (FDA) recently announced plans to assess the microbial safety of all antimicrobials intended for use in food-producing animals. This paper describes the history of antimicrobial use and regulation in animals, the public health concern, the current animal drug approval process in the United States, the international perspective, and FDA's proposed procedures to evaluate the human health impact of the antimicrobial effects associated with animal drugs intended for use in food-producing animals. The primary public health goal of the improved regulatory paradigm is to ensure that significant human antimicrobial therapies are not lost due to use of antimicrobials in food animals.
Liquid Chromatographic Determination of Residual Nitrite/Nitrate in Foods: NMKL Collaborative Study
Authors: Merino Leonardo , Edberg Ulla , Fuchs Georg , Åman Per ,   Collaborators:, Corbari G , Dahlberg L , Da-Riz V , Eerola S , Gerard R , Grancher D , Jensen S , Kangro A , Kjolby A , Lundberg L , Marin M , Meland S , Muriel B , Nicolas M , Ravn T , Tuhkanen M , Vartiala T , Zieprath G
Published: February 2020

Nitrite and nitrate are used as additives in the food industry to provide color and taste and to control undesirable gas and flavor production by anaerobic bacteria by virtue of their antimicrobial properties. The analytical method that has been widely used to determine nitrite and nitrate involves the use of toxic cadmium. In response to a request from the Nordic Committee on Food Analysis, a study was performed to obtain an alternative chromatographic method to determine residual nitrite and nitrate in meat products. The study was done in 3 stages: (1) comparative evaluation of the performance of 3 liquid chromatographic methods, (2) internal validation of the selected ion chromatographic method, and (3) a collaborative study in which 17 laboratories from European countries participated. Furthermore, the applicability of the method to matrixes other than meat and meat products was demonstrated. The results of the collaborative study show that the European Prestandard prENV 12014-4 is well suited for the determination of nitrite and nitrate in different foods (e.g., meat products, vegetables, baby food, and cheese). The limits of detection for nitrite and nitrate ions are 1 and 10 mg/kg, respectively. Recoveries of residual nitrite/nitrate ranged from 96 to 108%. Repeatability and reproducibility were satisfactory.
Averaging the Closest Two out of Three Observations
Authors: Blodgett Robert J
Published: February 2020

The average of 3 observations is the standard method of estimating the location of their distribution. The average of the closest 2 out of 3 observations, although often used, has more variability than the average of all 3 observations for a standard normal distribution. One statistic uses a threshold to decide when to use the average of all 3 observations rather than the closest 2. With the standard normal, this statistic still has more variability than the average of all 3 observations.
Validation of an Immunoassay for Detection and Quantitation of a Genetically Modified Soybean in Food and Food Fractions Using Reference Materials: Interlaboratory Study
Authors: Lipp Markus , Anklam Elke , Stave James W ,   Collaborators:, Bahrs-Windsberger J , Barreto Crespo M T , Benvenuto E , Berben G , Brignon P , Busch U , Cordes C , Eklund E , El Jaziri M , Engel K H , Eriksen F , Eriksson S , Felinger A , Fogher C , Folch I , Garrett S , Hischenhuber C , Hörtner H , Jany K D , Krska R , Kruse L , Kuiper H A , Lobre C , Miraglia M , Mhller W , Nunes Costa J M , Oliveira L , Patel P , Pietsch K , Pöpping B , Remler P , Rentsch J , Schulze M , Sutton M , van Duijn G , van Kan F , Wurz A
Published: February 2020

An immunoassay for detection of a specific genetically modified soybean (Roundup-Ready®) was validated on dried soybean powder in an interlaboratory study. Different percentages of genetically modified soybeans in nonmodified soybean matrix were evaluated in a blind study. Thirty-eight laboratories from 13 countries participated. The immunoassay was evaluated for 2 endpoints: (1) To give a semiquantitative result, i.e., determination of a given sample above or below a given threshold, or (2) to compute a quantitative result, i.e., percentage of genetically modified soybeans in the sample. Semiquantitative results showed that a given sample which contained <2% genetically modified soybeans was identified as below 2% with a 99% confidence level. Quantitative use of the assay resulted in a repeatability (r) and reproducibility (R) that were computed to be RSDr = 7% and RSDR = 10%, respectively, for a sample containing 2% genetically modified soybeans. Application of this method depends on availability of appropriate reference materials for a specific food matrix. Only matrix-matched reference materials can be used for analysis of food or food fractions.
Evaluation of a Dry, Rehydratable Film Method for Rapid Enumeration of Staphylococcus aureus
Authors: Mach Patrick A , Lindberg Kathryn G , Lund Marlys E
Published: February 2020

Results with the new 3M™ Petrifilm™ Rapid S. aureus Count (RSA) Plate method were compared with those of the classical Baird-Parker agar (BPA) method for detection and enumeration of Staphylococcus aureus. Studies on 219 bacterial strains demonstrated that the Petrifilm RSA plate is more sensitive than and as specific as the classical BPA method for confirmed identification of S. aureus. Counts of colonies from 71 pure cultures, 61 naturally contaminated food samples, and more than 750 artificially inoculated food samples showed that the Petrifilm RSA method was as effective as the classical BPA method for identification and enumeration of S. aureus. The Petrifilm RSA method gave results in one-third the time required for the classical method.
Flow Injection Spectrophotometric Determination of Copper, Iron, Manganese, and Zinc in Animal Feeds Using a Common Manifold
Authors: Liu Jing-Fu , Jiang Gui-Bin , Feng Ying-Di
Published: February 2020

A rapid and simple procedure was developed for the determination of copper, iron, manganese, and zinc in animal feeds using an identical flow injection spectrophotometric manifold but different chromogenic reagents and different detection wavelengths. Bis(cyclohexanone)oxalydihydrazone, formaldoxime, 1,10-phenanthroline, and xylenol orange were adopted as chromogenic reagents for Cu, Mn, Fe, and Zn, respectively. Detection conditions such as manifold parameters, buffer pH, reagent concentration, temperature, and acidity of sample solution were optimized. Analytical characteristics of the method and interference of metal ions commonly present in feeds were studied. By changing the reagents and detection wavelengths, which can be done quickly, the proposed low cost flow injection system can determine Cu, Fe, Mn, or Zn in the range of 0.5–10 mg/L with a sampling throughput of 120/h.
Spectrophotometric Determination of Ritodrine and Isoxsuprine Hydrochlorides Using 4-Aminoantipyrine
Authors: Revanasiddappa Hosakere D , Manju Bochhe Gowda
Published: February 2020

A simple, accurate, and rapid method for the quantitative determination of ritodrine hydrochloride (RTH) and isoxsuprine hydrochloride (ISH) in both pure and dosage forms, is described. The method is based on the development of pink colored product as a result of the condensation of 4-aminoantipyrine with phenols in the presence of an alkaline oxidizing agent. The resulting products are measured at 510 nm for both drugs, with molar absorptivities of 0.98 × 104 and 1.20 × 104 L/mol·cm for RTH and ISH, respectively. A study of the effect of commonly associated excipients revealed that they did not cause interference.
Confirmation of Moxidectin Residues in Cattle Fat by Liquid Chromatography/Mass Spectrometry
Authors: Stout Steven J , Wickremesinhe Enaksha , daCunha Adrian R , Khunachak Alisa
Published: February 2020

Moxidectin, a potent new endo- and ectoparasitic agent, is determined in cattle tissues by liquid chromatography (LC) with fluorescence detection. The original confirmatory method for moxidectin in cattle fat, the target tissue for regulatory purposes, was LC with mass spectrometry (MS) using thermospray (TSP) ionization and selected ion monitoring. As newer ionization techniques for LC/MS made TSP obsolete and with the availability of a new generation of benchtop LC/MS instrumentation, the confirmation of moxidectin in cattle fat was re-evaluated. The ionization techniques of atmospheric pressure chemical ionization versus electrospray ionization, the detection techniques of single-stage MS versus tandem MS, and the instrumentation of ion trap versus quadrupole were investigated. The final confirmatory method was based on full-scan single-stage MS. Even with full-scan detection, the analysis required at least 10-fold less extract than the original TSP method. The applicability of this new confirmatory method was demonstrated on both ion trap and quadrupole instruments.
Survey of Residual Tetracyclines in Kidneys of Diseased Animals in Aichi Prefecture, Japan (1985–1997)
Authors: Oka Hisao , Ito Yoko , Ikai Yashitomo , Matsumoto Hiroshi , Kato Keiichi , Yamamoto Isao , Shimizu Michihiko , Kawamura Norihisa , Miyazaki Yutaka , Nojiri Takayasu , Okumura Masanao , Ohmi Shin , Sato Takeo , Mori Giichiro
Published: February 2020

A survey was conducted to determine the incidence of tetracycline antibiotic (TCAs) residues in the kidneys of slaughtered animals that did not pass inspection for human consumption by the Japanese Food Sanitation Law and the Meat Inspection Law at the slaughterhouses in Aichi Prefecture, Japan, from April 1985 to March 1998. The kidneys were analyzed by the AOAC Official Method 995.09. Among 424 animals (147 cattle and 277 pigs), 131 (30.9%) were contaminated with TCAs, including 69 (16.3%) with chlortetracycline (CTC), 61 (14.4%) with oxytetracycline (OTC), 3 (0.7%) with tetracycline (TC), and 1 (0.2%) with doxycycline (DC). One sample (cattle kidney) was contaminated with both OTC and DC. The frequencies of OTC and TC residues were significantly higher ( p< 0.05) in cattle than in pigs, whereas, the frequency of CTC was significantly higher ( p< 0.01) in pigs. Pig kidney samples collected in 1991–1997 had significantly higher incidences of TCAs and CTC ( p< 0.01) residues than those in 1985–1986.
Selective Separation and Simultaneous Determination of Trace Levels of Five Types of Fluorinated Quinolone Drugs by Thin-Layer Chromatography/Fluorescence Densitometry
Authors: Wang Pei-Lan , Chen Liang , Fan Ying-Fang
Published: February 2020

This paper reports the determination of trace levels of 5 types of fluorinated quinolone drugs, i.e., ciprofloxacin, norfloxacin, enoxacin, pefloxacin, and ofloxacin, by thin-layer chromatography (TLC)/fluorescence densitometry. The new analytical method uses 2-step TLC development, selective separation, and simultaneous determination of the 5 drugs. The method was also applied to the determination of recoveries of standards of the 5 drugs in plasma and urine samples. The results show that the method has a wide linear range, high repeatability, and good stability.
Rapid Determination of Nineteen Chlorophenols in Wood, Paper, Cardboard, Fruits, and Fruit Juices by Gas Chromatography/Mass Spectrometry
Authors: Diserens Jean-Marc
Published: February 2020

Although the use of pentachlorophenol (PCP) is prohibited in most countries, it is still widely found in the wood of pallets, containers, crates and in cardboard, paper, etc. Such material may contain not only PCP but other chlorophenols as well. Wooden crates and cardboard boxes are often used to store and transport fresh fruits. Consequently, chlorophenols present in the wood may contaminate the stored fruits by migration. To ascertain that packaging, storage material, and fruit raw materials are free from chlorophenol residues, we developed a rapid and sensitive method for the detection of 19 chlorophenols by gas chromatography/mass spectrometry (GC/MS). The test portions are directly extracted and acetylated in a solution of sodium carbonate in the presence of acetic anhydride and hexane. The hexane layer is analyzed, without further purification, by GC/MS in the selective-ion monitoring mode. The method allows the analysis of >40 samples/day with detection limits of <20 μg/kg for chlorophenols in wood, cardboard, and paper, and <2 μg/kg for chlorophenols in fruits. Typical recoveries of all chlorophenols were 94% from paper, 115% from cardboard, 51% from wood (depending on the size of the chips or shavings), and 93% from fruit puree.
Spectrophotometric Determination of Sulfur Dioxide in Air, Using Thymol Blue
Authors: Gayathri Nagasundaram , Balasubramanian Natesan
Published: February 2020

A simple and sensitive spectrophotometric method was developed for the determination of trace amounts of sulfur dioxide. The method is based on the reaction of SO2 with a known excess of ICl as the oxidant. The unreacted ICl iodinates thymol blue under acidic conditions. The λmax of thymol blue is at 545 nm under acidic conditions, and on iodination λmax shifts to 430 nm. This shift results in a decrease in the absorbance at 545 nm. The amount of uniodinated thymol blue present depends on the concentration of unreacted ICl, which in turn depends on the SO2 concentration. The system obeys Beer's law in the range 0–30 μg SO2 in a final volume of 25 mL, having a molar absorptivity of 3.2 × 104 L/mol-cm with a relative standard deviation (RSD) of 2% at 24 μg SO2 (n = 10). The uniodinated dye can be extracted into 5 mL isoamyl alcohol under acidic conditions for measurement of absorbance. The extraction method obeys Beer's law in the range 0–5 mg SO2, having a molar absorpitivity of 4.16 × 104 L/mol-cm with an RSD of 1.9% at 4 μg SO2 (n = 10). The method has been successfully applied to the determination of atmospheric SO2.
Quantitative Determination of Paralytic Shellfish Poisoning Toxins in Shellfish by Using Prechromatographic Oxidation and Liquid Chromatography with Fluorescence Detection
Authors: Lawrence James F , Niedzwiadek Barbara
Published: February 2020

The prechromatographic oxidation LC method developed by Lawrence [J. Assoc. Off. Anal. Chem. 74, 404–409(1991)] for the determination of paralytic shellfish poisoning (PSP) toxins has been tested for the quantitative determination of PSP toxins in shellfish. All aspects of the method were studied and modified as necessary to improve its performance for routine regulatory purposes. The chromatographic conditions were changed to shorten analysis time. The oxidation reaction was tested for repeatability and the influence of the s ample matrix on quantitation. An important part of the study was to quantitatively evaluate an ion exchange (-COOH) cleanup step using disposable solid-phase extraction cartridges that separated the PSP toxins into 3 distinct groups for quantitation, namely the C toxins, the GTX toxins, and the saxitoxin group. The cleanup step was very simple and used increasing concentrations of aqueous NaCl for elution of the toxins. The C toxins were not retained by the cartridges and thus were eluted unretained with water. The GTX toxins (GTX1 to GTX6 as well as dcGTX2 and dcGTX3) eluted from the cartridges with 0.05M NaCl while the saxitoxin group (saxitoxin, neosaxitoxin, and dcsaxitoxin) required 0.3M NaCl for elution. Each fraction was analyzed by LC after oxidation with periodate or peroxide. All of the compounds could be separated and quantitatively determined in spiked samples of mussels, clams, and oysters. The nonhydroxylated toxins could be quantitated at concentrations as low as about 0.02 μg/g (2 μg/100 g) of tissue while the hydroxylated toxins could be quantitated at concentrations as low as about 0.1 μg/g (10 μg/100 g). Average recoveries of the toxins through the complete cleanup procedure were 85%or greater for spiked extracts of oysters and clams and greater than 73%for mussels.
Immunoassay Methods for Paralytic Shellfish Poisoning Toxins
Authors: Usleber Ewald , Dietrich Richard , Bürk Christine , Schneider Elisabeth , Märtlbauer Erwin
Published: February 2020

The current status of immunochemical techniques for analysis of paralytic shellfish poisoning (PSP) toxins is summarized. Important aspects regarding production of the biological reagents necessary for immunochemical methods, the characteristics of polyclonal and monoclonal antibodies against saxitoxin and neosaxitoxin, and the importance of test sensitivity and specificity are discussed. Applications of immunochemical techniques for PSP toxins include microtiter plate enzyme immunoasays and enzyme-linked immunofiltration assays for toxin detection, and immunoaffinity chromatography (IAC) for sample extract cleanup. A major advantage of enzyme immunoassay (EIA) is simplicity and rapidity of the test procedure, and higher sensitivity than other methods. However, quantitative agreement between EIA and mouse bioassay is dependent on antibody specificity and the toxin profile in the shellfish; thus, both over- and underestimation of total toxicity may occur. For screening purposes, however, EIAs offer major advantages over the mouse bioassay, which is criticized in Europe because of animal welfare. A major application of antibodies against PSP toxins is their use for extract cleanup by IAC, which gives highly purified extracts, thereby enhancing determination of PSP toxins by conventional physicochemical methods such as liquid chromatography. IAC can also be used to isolate PSP toxins for preparation of analytical standard solutions.
Atomic Absorption Spectrometric Determination of Chromium, Copper, Lead, Mercury, and Zinc in Sediments Collected in Bayou d'Inde, Southwestern Louisiana
Authors: Hardaway Carey , Gauthreaux Kermit , Sneddon Joseph , Beck James N
Published: February 2020

The concentrations of the metals chromium (Cr), copper (Cu), lead (Pb), mercury (Hg), and zinc (Zn) were determined in sediment cores taken from Bayou d'Inde in southwestern Louisiana. Previous studies had reported elevated concentrations of these trace metals in sediments along this waterway. The current study, conducted more than a decade later, was designed to determine if these metals had migrated from the areas of highest concentrations. Concentrations as high as 400 mg/kg for Cr, 1100 mg/kg for Cu, 10 mg/kg for Hg, and 600 mg/kg for Pb and Zn were found. Areas of high concentrations of metals were isolated within a distance of about 1 km from the most highly contaminated areas in the bayou. Low concentrations of metals were found at the mouth of the bayou. Estimated sedimentation rates of 0.67–1.2 cm/yr were based on the burial of the sediments originally studied. The concentrations of the metals studied remained high and were also highly localized, both spatially and temporally.
Determination of Water (Moisture) and Dry Matter in Animal Feed, Grain, and Forage (Plant Tissue) by Karl Fischer Titration: Collaborative Study
Authors: Thiex Nancy J , Erem Terri van ,   Collaborators:, Amundson D , Boucher J , Clark A , Clark D , Coco P , Dow D , Fahey P , Hoffmann H , Mertens D , Morris H , Rittenhouse T , Wohla M
Published: February 2020

A Karl Fischer method for determining water (dry matter) in animal feed and forages was collaboratively studied. Water was extracted from animal feed or forage material into methanol–formamide (1 + 1) directly in the Karl Fischer titration vessel by high-speed homogenization. The water was titrated at 50°C with one-component Karl Fischer reagent based on imidazole. Ten blind samples were sent to 9 collaborators in the United States, Canada, and Germany. The within-laboratory relative standard deviation (repeatability) ranged from 1.14 to 6.99% for water or from 0.09 to 0.56% for dry matter. Among-laboratory (including within-) relative standard deviation (reproducibility) ranged from 5.35 to 10.73%, or from 0.44 to 0.77% for dry matter. The authors recommend that the method be adopted as Official First Action by AOAC INTERNATIONAL. A comparable alternative extraction procedure using boiling methanol is also recommended for Official First Action.
Measurement of Resistant Starch
Authors: McCleary Barry V , Monaghan Dympna A
Published: February 2020

A robust and reliable method was developed to measure resistant starch (RS), i.e., starch that enters the large intestine. In vivo conditions were reflected as much as possible while a user-friendly format was maintained. Parameters investigated included α-amylase concentration, pH of incubation, maltose inhibition of α-amylase, the need for amyloglucosidase inclusion, the effect of shaking and stirring on determined values, and problems in recovering and analyzing the RS-containing pellet. The RS values obtained were in good agreement with published in vivo data. An interlaboratory evaluation of the method has been completed (First Action Method 2002.02).