bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Various Types of Vacuum Packages and Length of Storage on the Microbial Flora of Wholesale and Retail Cuts of Beef
Authors: SEIDEMAN S. C. , VANDERZANT C. , HANNA M. O. , CARPENTER Z. L. , SMITH G. C.
Published: December 2016

Wholesale cuts of beef (knuckles, ribs, chucks) were vacuum packaged in three types of packages with oxygen transmission rates (cc/100 in.2/24 h) of 0.41–0.75, 1.09, and 2.28. One type of package was sealed with a clip; the others were heat sealed. Wholesale cuts were stored for 0–35 days at 1–3 C and retail cuts from ribs and knuckles were observed under retail conditions for 5 days. Differences in psychrotrophic, mesophilic, and lactobacillus counts of knuckles and ribs resulting from differences in type of package usually were not statistically significant. Differences in psychrotrophic counts of retail steaks of knuckles and ribs resulting from differences in type of package used for the primal cuts were not significant. Psychrotrophic and mesophilic counts of cuts in defective packages (leakers) increased faster than those of cuts in intact packages. The initial microbial flora of knuckles, ribs, and chucks consisted primarily of Moraxella-Acinetobacter spp. and coryneform bacteria. During the first few weeks of storage at 1–3 C Lactobacillus spp. already were dominant on knuckles and Microbacterium and Lactobacillus spp. predominated on ribs. After 28–35 days of storage Lactobacillus spp. were dominant on both knuckles and ribs. The microbial population on chucks after 21 days of storage consisted of Lactobacillus, Microbacterium, Enterobacteriaceae. Pseudomonas, Moraxella-Acinetobacter spp. and coryneform bacteria. The microflora of cuts from defective packages was comprised of species of Pseudomonas, Microbacterium, Lactobacillus, and Moraxella-Acinetobacter.
Bacterial Spoilage of Citrus Products at pH Lower than 3.51
Authors: JUVEN B. J.
Published: December 2016

A strain of Lactobacillus brevis, L-3, was isolated from a blown can of grapefruit segments in sugar syrup; it caused spoilage of citrus products having pH values lower than 3.5. When inoculated into orange (pH 3.38) and grapefruit (pH 2.99) juices, after 5 h at 30 C L-3 produced 15 and 22 μg diacetyl/ml, respectively, and off-flavor was detectable. L-3 grew in APT broth acidified to pH 3.0 with citric, hydrochloric, phosphoric, or tartaric acid. However, its growth was inhibited at pH 3.6 if the acidulant was lactic acid, while with acetic acid inhibition occurred at a pH between 3.7 and 4.0. The thermal resistance of L-3 in orange serum (pH 3.4) was studied in the temperature range of 52 to 60 C: a z value of 8.3 was obtained. A simple and reliable capillary technique for studying the thermal resistance of gas-producing organisms in liquid foods and media is presented.
Mathematical Model Describing the Relationship of Fat, Protein, and Lactose to the Total Solids—Its Application in Milk Testing
Authors: CERVINKA V. , ROLF B. W. , LOCKHART L. H. , GIBSON T. J.
Published: December 2016

California dairy farmers producing and selling Grade A milk for pasteurization receive payment based on milkfat and solids-not-fat content of raw milk. In 1970, the concept of using electronic methods for testing of milk and its components was accepted by the California Department of Food and Agriculture. The InfraRed Milk Analyzer (IRMA) with its ability to measure fat, protein, and lactose, using a predetermined factor for the unmeasured solids, appeared to fill the need for a rapid, accurate, and economical method. After comparing IRMA results with chemical tests of known accuracy for several seasons, it appeared the ash factor could vary seasonally and geographically, as well as with individual dairy herds. It was decided to study the accuracy and calibration stability of InfraRed Milk Analyzers (IRMA), as well as the use of a constant value for the ash factor. By applying a multiple regression technique to milk sample data, it was possible to generate a model describing the relationship of fat, protein, and lactose to total solids (and solids-not-fat).
Experimental Anisakiasis: Cultivation and Temperature Tolerance Determinations1
Authors: BIER JEFFREY W.
Published: December 2016

All stages of the anisakine life cycle—egg, larva, and adult—have been used to initiate cultures. Eggs develop to hatching larvae at different temperatures depending on the species or strain. Newly hatched larvae of Phocanema decipiens and Contracaecum osculatum grow to an average 31.1 mm in 52 weeks and 6.5 mm in 32 weeks, respectively. Larvae from fish or those previously cultivated will molt at 35 C in a complex culture medium. P. decipiens and Anisakis marina have produced eggs in vitro. A. marina eggs from cultured females produced viable larvae. Freshness of the larvae used to initiate cultures is considered a major factor in success.

The histochemistry of the composition and structure of P. decipiens cuticle in larvae from fish and cultures has been defined; experiments have demonstrated that the processes of cuticular deposition and ecdysis are independent. It has been postulated and evidence provided that a neurosecretory mechanism controls ecdysis; it has also been shown that this system can be stimulated by an insect hormone and a synthetic analog.

Larvae in vitro, in fish flesh, and in fried fish fingers, do not survive heating to 60 C for 1 min. The recommended time and temperature found in Japanese and European literature for freezing fish to kill anisakine larvae is −20 C for 24 h; however, some North American species survive after 52 h at this temperature.
Tyrosine and Histidine Decarboxylase Activities of Pediococcus cerevisiae and Lactobacillus Species and the Production of Tyramine in Fermented Sausages
Authors: RICE S. L. , KOEHLER P. E.
Published: December 2016

In investigating formation of tyramine and histamine in a model system, it was found that four commercial sausage starter cultures did not exhibit appreciable tyrosine or histidine decarboxylase activity. In addition, other species of Pediococcus cerevisiae and Lactobacillus did not display appreciable decarboxylase activity. Mixtures of P. cerevisiae and Lactobacillus plantarum were also unable to produce significant levels of these amines. One species of Streptococcus tested was able to produce 34.5 μg of tyramine/hour under the assay conditions. When P. cerevisiae and L. plantarum were used as starter cultures to prepare sausages, it was found that this treatment resulted in lower tyramine levels (approximately 200 μ/g) than when the Streptococcus sp. was used as a starter culture (approximately 300 μ/g). However, the use of P. cerevisiae and L. plantarum did not result in a significantly lower tyramine level than when no starter culture was used.
Food Safety in the Seventies
Authors: MORRISON A. B.
Published: December 2016

There is presently more concern about food safety than ever more, even though our foods are now much safer than they have ever been. As a regulatory agency, the Health Protection Branch wishes to ensure that all foods are safe for all Canadians all the time. The presence in foods of potentially hazardous chemicals, microorganisms, or products of microbial metabolism constitute some of the major hazards associated with foods. The acceptability to society of a given hazard (risk) and the cost to eliminate it must be considered when regulatory programs are developed.
Stability of Thiamine and Riboflavin During Extrusion Processing of Triticale
Authors: BEETNER G. , TSAO T. , FREY A. , LORENZ K.
Published: December 2016

Triticale kernels were extruded using a Brabender Plasticorder extruder with ¾-inch rifled barrel and 1:1 flight depth ratio screw. Whole grain samples were extruded at initial moisture contents of 15, 20, and 25%. Debranned samples were extruded at an initial moisture content of 22%. Barrel temperatures of 350, 400, and 450 F and nozzle openings of 1/8 inch and 1/16 inch were used. The products were analyzed for thiamine and riboflavin content. Results were corrected for final moisture content and expressed as fraction retained. A multiple regression was done to determine the relationship between independent and derived variables, and the retention. Riboflavin retention was correlated simply as a function of barrel temperature. Thiamine retention of the debranned material was correlated as a function of nozzle size and barrel temperature. Thiamine retention of the whole grain samples was correlated for nozzle size, first and second order temperature effects, and confounding between nozzle size and temperature.
The National Sanitation Training Program: Canadian Restaurant Association's Answer to Safe and Sanitary Foodservice
Authors: DAVIES RICHARD J.
Published: December 2016

There are an estimated 120,000 cases of bacterial food poisoning occuring in the Canadian foodservice industry each year. The Canadian Restaurant Association in co-operation with all Provincial departments of health and Health and Welfare Canada, developed a sanitation code to help the foodservice operator understand every essential sanitation requirement. In conjunction with the code, a national sanitation training program was developed to assist in the total education in foodservice sanitation of all personnel in the Canadian foodservice industry. To date, 3,200 personnel have successfully completed one of the national sanitation training programs and gained a more responsible level of foodservice sanitation awareness. The program as well as being accepted by all Provincial departments of health and Health and Welfare Canada, has officially been endorsed by the Canadian Public Health Association and the Consumers Association of Canada.
Antibiotic-Resistant Bacteria in Raw Meat from Retail Markets
Authors: HANKIN LESTER , ANAGNOSTAKIS SANDRA L. , REDYS JOHN J.
Published: December 2016

Raw meat samples from retail markets were examined for bacteria resistant to chloramphenicol and neomycin sulfate. Total numbers of bacteria ranged from 17,000 to 30,000,000 per gram and resistant bacteria from < 100 to 450,000 per gram. Twelve isolates resistant to both antibiotics were identified as either Pseudomonas aeruginosa, Pseudomonas putida. or Pseudomonas fluorescens.
Thermal Inactivation and Subsequent Reactivation of Staphylococcal Enterotoxin B in Selected Liquid Foods
Authors: REICHERT CHARLOTTE A. , FUNG DANIEL Y. C.
Published: December 2016

Thermal inactivation and reactivation kinetics of staphylococcal enterotoxin B (SEB) were studied in buffer and certain liquid food systems using three serological techniques (single-gel diffusion method, radioimmunoassay, and microslide). Heating temperatures were 80–100 C and times were 0–5 min. Initial toxin concentrations employed were 0.008–5 μg/ml. Inactivation of SEB was faster in the earlier stages of heating and was much slower during continued heating. With the exception of phosphate buffered saline, reactivation of heated SEB was observed even when with small initial quantities of SEB. Reactivation (% activity) was greater when the heating time was shorter at any temperature.
Factors Related to the Occurrence of Trimethylamine in Milk1
Authors: VON GUNTEN R. L. , BUSH L. J. , ODELL G. V. , WELLS M. E. , ADAMS G. D.
Published: December 2016

The overall objectives of this research were to (a) identify the odor threshold for trimethylamine (TMA) in milk and determine how precisely different concentrations are delineated by taste, and (b) investigate the relationship of different factors to the occurrence of TMA flavor in milk of cows grazed on wheat pasture. The odor threshold for TMA in milk, defined as detection by 50% of a panel untrained in milk judging, was determined to be 1 ppm. Trained milk judges detected 5 ppm TMA in milk in every instance, but were not able to distinguish between 5 and 10 ppm TMA. There appeared to be a positive relationship between the amount of TMA administered orally to cows and its intensity in milk 2 h later. There was a linear relationship between amount of wheat forage consumed as well as stage of maturity of the forage and TMA flavor in milk. Feeding of grain or silage plus grain either before or after grazing wheat pasture had little influence on TMA milk scores. Feeding of alfalfa hay between grazing wheat pasture and milking tended to increase TMA milk scores. There was significant variation among cows in TMA milk flavor scores in all trials.
Characteristics of Yeasts Isolated From Bread Doughs of Bakeries in Shiraz, Iran
Authors: TADAYON R. A.
Published: December 2016

Iranian bakers use portions of sour doughs saved from the previous day for leavening. In the present study dough samples from 43 different bakeries in Shiraz, Iran were examined for the presence of yeasts. On the basis of colonial characteristics, 92 different yeast cultures were isolated. Eighty-one of the yeast cultures were examined for their cell morphology, pellicle formation on liquid medium, ability to form ascospores on nine different sporulating media, and their ability to ferment and assimilate glucose, galactose, raffinose, sucrose, maltose, and lactose. Results showed that 15 of the yeast cultures formed pellicles, 17 cultures did not sporulate, and 33 of the sporulating cultures differed biochemically from the genus Saccharomyces. Based on cultural, cell morphology, and biochemical characteristics, 29 of the remaining 31 sporulating yeasts were similar to Saccharomyces cerevisiae and the remaining two probably belonged to the genus Saccharomyces. Yeast cultures were also examined for their baking strength; 11 of the cultures had baking strengths comparable to those of commercial bakers' yeast.
Prediction of Microbial Death During Drying of a Macaroni Product
Authors: HSIEH FU-HUNG , ACOTT KAREN , LABUZA THEODORE P.
Published: December 2016

Death of Staphylococcus aureus 196E in a semolina-egg dough was studied during a variable temperature simulated drying test. Data for the death rate constant of the organism collected under steady state conditions of constant temperature and water activity were used to predict the amount of death occurring in the unsteady state test. Very good agreement was found. Utilizing the steady state information it was predicted that over 5-log cycles of kill would occur for S. aureus 196E and Salmonellae anatum NF3 during the pasta drying process. This indicates that kill caused by the process itself may not be enough if high levels of these pathogens occur initially in the dough.
Counting Somatic Cells in Milk with a Rapid Flow-Through Cytophotometer
Authors: BREER C. , LUTZ H. , SUPER B. S.
Published: December 2016

Somatic cells are differentially counted in the presence of fat globules by detecting fluorescence of nuclear DNA in somatic cells after staining with acridine orange. Milk is diluted and stained in one step and passed through a new instrument, the Cytofluorograf, a rapid flow-through cytophotometer, which illuminates each particle with 4880Å light from an argon ion laser. A pulse of green fluorescence is emitted by each somatic cell nucleus. These pulses are used by the instrument to tally the cells. Damaged cells are clearly distinguished from fat globules. There is no difficulty in setting the threshold for the differential count, even in samples with damaged cells, and additional information of potential diagnostic value is available.
Operational Practices Associated with Foodborne Disease Outbreaks in the Catering Industry in England and Wales
Authors: JONES SARAH L. , PARRY SHARON M. , O'BRIEN SARAH J. , PALMER STEPHEN R.
Published: December 2016

Catering businesses continue to be the most common setting for foodborne disease outbreaks. In a study of catering businesses in England and Wales, operational practices relating to the supply, preparation, and service of food in 88 businesses associated with outbreaks were compared with those practices at 88 control businesses. Operational practices did not differ significantly between case and control businesses but larger small medium-size enterprise (SME) businesses were more likely to be associated with foodborne disease outbreaks than were micro-SME businesses. Businesses associated with outbreaks of Salmonella infection were less likely to use local or national suppliers but instead used regional suppliers, especially for eggs. This practice was the only significantly independent operational practice associated with outbreaks of Salmonella infection. Regional egg suppliers also were more likely to be used by businesses associated with outbreaks attributed to food vehicles containing eggs. Businesses associated with egg-associated outbreaks were less likely to use eggs produced under an approved quality assurance scheme, suggesting that the underlying risk associated with using regional suppliers may relate to the use of contaminated eggs.
Prevalence and Characterization of Salmonella in Bovine Lymph Nodes Potentially Destined for Use in Ground Beef†
Authors: ARTHUR TERRANCE M. , BRICHTA-HARHAY DAYNA M. , BOSILEVAC JOSEPH M. , GUERINI MICHAEL N. , KALCHAYANAND NORASAK , WELLS JAMES E. , SHACKELFORD STEVEN D. , WHEELER TOMMY L. , KOOHMARAIE MOHAMMAD
Published: December 2016

A potential source of pathogenic bacteria in ground beef is the lymphatic system, specifically the lymph nodes. Bacteria have been isolated from the lymph nodes of cattle at slaughter; however, most studies have dealt with mesenteric lymph nodes, which are not normally incorporated into ground beef. The objective of the current study was to determine the prevalence and multidrug-resistance status of Salmonella in bovine lymph nodes associated with lean and fat trimmings that might be utilized in ground beef production. Bovine lymph nodes (n = 1,140) were collected from commercial beef processing plants. Half of the lymph nodes sampled were obtained from cull cow and bull processing plants, and the remainder were obtained from fed beef processing plants. Lymph nodes located in chuck and flank adipose tissue were collected for this study. Salmonella prevalence in the lymph node samples was low, with an overall prevalence of 1.6% and a 95% confidence interval of 0.85 to 2.3%. Lymph nodes from cull cattle carcasses had a higher prevalence of Salmonella than did those from fed cattle carcasses. Lymph nodes from the flanks of cow and bull carcasses had the highest prevalence at 3.86%, whereas lymph nodes from the chuck region of fed cattle carcasses had the lowest prevalence at 0.35%. Three of the 18 Salmonella-positive lymph node samples contained multidrug-resistant Salmonella, and all 3 samples were from cull cattle.
Production of Mycotoxins by Penicillium expansum Inoculated into Apples
Authors: WATANABE MITSURU
Published: December 2016

We investigated the production of mycotoxins in apple fruits inoculated with spores of 40 strains of apple blue mold, Penicillium expansum. Patulin and citrinin contents in the extracts from apples stored at 25°C for 12 days after inoculation were determined by high-performance liquid chromatography (HPLC) analysis with UV and fluorescence detection. Patulin and citrinin were produced by 90% (36) and 80% (32) of the 40 strains, indicating that P. expansum is a consistent producer of these mycotoxins. The patulin content in the extracts was substantially higher than the citrinin content. Other mycotoxins whose production in pure culture has been reported were simultaneously detected with high-resolution liquid chromatography–mass spectrometry (LC-MS) analysis with the positive ion mode of electrospray ionization. Along with patulin and citrinin, expansolides A and B were identified based on the HPLC and LC-MS spectral data and detected in 88% (35) of the extracts. The results indicate that P. expansum is a consistent producer of expansolides A and B in rotten areas of apple fruits. The findings raise the possibility that products from decayed apples might contain expansolides A and B in addition to patulin and citrinin.
Safety Aspects and Implications of Regulation of Probiotic Bacteria in Food and Food Supplements
Authors: WASSENAAR TRUDY M. , KLEIN GÜNTER
Published: December 2016

The application of living bacteria as probiotics in food or food supplements requires a careful safety assessment. This review summarizes key issues concerning the safety aspects of bacteria added to particular products marketed for improvement of general health or treatment of (post)infectious symptoms. The bacteria used in such products should be completely safe; however, it can be challenging to provide evidence for absence of all virulence properties. In some cases, virulence factors have been detected in probiotic bacterial strains, and the implications of these traits for safety assessments are discussed. Horizontal gene transfer can result in acquisition of virulence genes or antimicrobial resistance in probiotic bacteria. Antimicrobial resistance in these bacteria can possibly aid the spread of undesired resistance in intestinal bacterial populations. The relative risk of such gene transfers is considered. The generation of complete bacterial genome sequences can both resolve and create safety issues. Current practices of safety assessment procedures in the United States and the European Union are briefly reviewed and a future outlook is provided.
Drug Residues Recovered in Feed after Various Feedlot Mixer Truck Cleanout Procedures
Authors: VAN DONKERSGOED JOYCE , SIT DAN , GIBBONS NICOLE , RAMOGIDA CATERINA , HENDRICK STEVE
Published: December 2016

A study was conducted to determine the effectiveness of two methods of equipment cleanout, sequencing or flushing, for reducing drug carryover in feedlot mixer trucks. Feed samples were collected from total mixed rations before and after various feed mixer equipment cleanout procedures. Medicated rations contained either 11 ppm of tylosin or 166 or 331 ppm of chlortetracycline. There were no differences between sequencing and flushing or between flushing with dry barley and flushing with barley silage in the median proportion of drug recovered in the next ration. A larger drug reduction was achieved using flush material at a volume of 10 versus 5% of the mixer capacity and mixing the flush material for 3 versus 4 min. Regardless of the drug or prescription concentrations in the total mixed rations or the equipment cleanout procedure used, concentrations of chlortetracycline and tylosin recovered were very low.
Characteristics of Shiga Toxin–Producing Escherichia coli Isolated from Swiss Raw Milk Cheese within a 3-Year Monitoring Program
Authors: ZWEIFEL C. , GIEZENDANNER N. , CORTI S. , KRAUSE G. , BEUTIN L. , DANUSER J. , STEPHAN R.
Published: December 2016

Food is an important vehicle for transmission of Shiga toxin–producing Escherichia coli (STEC). To assess the potential public health impact of STEC in Swiss raw milk cheese produced from cow's, goat's, and ewe's milk, 1,422 samples from semihard or hard cheese and 80 samples from soft cheese were examined for STEC, and isolated strains were further characterized. By PCR, STEC was detected after enrichment in 5.7% of the 1,502 raw milk cheese samples collected at the producer level. STEC-positive samples comprised 76 semihard, 8 soft, and 1 hard cheese. By colony hybridization, 29 STEC strains were isolated from 24 semihard and 5 soft cheeses. Thirteen of the 24 strains typeable with O antisera belonged to the serogroups O2, O22, and O91. More than half (58.6%) of the 29 strains belonged to O:H serotypes previously isolated from humans, and STEC O22:H8, O91:H10, O91:H21, and O174:H21 have also been identified as agents of hemolytic uremic syndrome. Typing of Shiga toxin genes showed that stx1 was only found in 2 strains, whereas 27 strains carried genes encoding for the Stx2 group, mainly stx2 and stx2vh-a/b. Production of Stx2 and Stx2vh-a/b subtypes might be an indicator for a severe outcome in patients. Nine strains harbored hlyA (enterohemorrhagic E. coli hemolysin), whereas none tested positive for eae (intimin). Consequently, semihard and hard raw milk cheese may be a potential source of STEC, and a notable proportion of the isolated non-O157 STEC strains belonged to serotypes or harbored Shiga toxin gene variants associated with human infections.
Molecular Screening, Isolation, and Characterization of Enterohemorrhagic Escherichia coli O157:H7 from Retail Shrimp
Authors: SURENDRARAJ ALAGARSAMY , THAMPURAN NIRMALA , JOSEPH TOMS C.
Published: December 2016

Foodborne outbreaks attributed to the contamination of foods with enterohemorrhagic Escherichia coli (EHEC) O157:H7 are a growing global concern. Fish and shrimp samples obtained from different retail fish markets in Cochin, India, were screened by direct PCR assays targeting three important virulence markers of EHEC, the intimin protein (eaeA gene), enterohemolysin (hlyA gene), and Shiga toxin (stx gene). One shrimp (Fenneropenaeus indicus) sample was positive for all these virulence markers, and seven typical E. coli O157:H7 isolates were recovered from the marker-positive shrimp sample. This is the first report of recovery of typical E. coli O157:H7 from fish or shellfish in India. All the typical EHEC isolates had a characteristic reaction in eosin methylene blue agar and belonged to IMViC (indole, methyl red, Voges Proskauer, Simmons citrate reactions) biotype I. These isolates also were negative for sorbitol and methylumbelliferyl-β -glucuronide and exhibited β-hemolytic activity. One isolate showed self-agglutination for E. coli O157 antisera and produced a false-positive reaction with CHROMagar O157. These typical EHEC isolates belonged to a restricted biotype group and had a very low multiple antibiotic resistance index. Isolation of E. coli O157:H7 in fish and shellfish indicates that strict adherence to hygienic handling methods and proper cooking or processing is needed before consumption of these products.
Prevalence, Characterization, and Genotypic Analysis of Escherichia coli O157:H7/NM fromSelected Beef Exporting Abattoirs of Argentina
Authors: MASANA M. O. , LEOTTA G. A. , DEL CASTILLO L. L. , D'ASTEK B. A. , PALLADINO P. M. , GALLI L. , VILACOBA E. , CARBONARI C. , RODRÍGUEZ H. R. , RIVAS M.
Published: December 2016

In Argentina, Escherichia coli O157:H7/NM (STEC O157) is the prevalent serotype associated with hemolytic uremic syndrome (HUS), which is endemic in the country with more than 400 cases per year. In order to estimate the prevalence and characteristics of STEC O157 in beef cattle at slaughter, a survey of 1,622 fecal and carcass samples was conducted in nine beef exporting abattoirs from November 2006 to April 2008. A total of 54 samples were found positive for STEC O157, with an average prevalence of 4.1% in fecal content and 2.6% in carcasses. Calves and heifers presented higher percentages of prevalence in feces, 10.5 and 8.5%, respectively. All STEC O157 isolates harbored stx2 (Shiga toxin 2), eae (intimin), ehxA (enterohemolysin), and fliCH7 (H7 flagellin) genes, while stx1 (Shiga toxin 1) was present in 16.7% of the strains. The prevalent (56%) stx genotype identified was stx2 combined with variant stx2c (vh-a), the combination of which is also prevalent (>90%) in STEC O157 post–enteric HUS cases in Argentina. The clonal relatedness of STEC O157 strains was established by phage typing and pulsed-field gel electrophoresis (PFGE). The 54 STEC isolates were categorized into 12 different phage types and in 29 XbaI-PFGE patterns distributed in 27 different lots. STEC O157 strains isolated from 5 of 21 carcasses were identical by PFGE (100% similarity) to strains of the fecal content of the same or a contiguous bovine in the lot. Five phage type–PFGE–stx profiles of 10 strains isolated in this study matched with the profiles of the strains recovered from 18 of 122 HUS cases that occurred in the same period.
Design of a New Universal Real-Time PCR System Targeting the tuf Gene for the Enumeration of Bacterial Counts in Food
Authors: TANAKA YUICHIRO , TAKAHASHI HAJIME , SIMIDU USIO , KIMURA BON
Published: December 2016

A novel universal real-time PCR, consisting of newly designed oligonucleotide subsets, was designed for a bacterial housekeeping gene encoding the peptide elongation factor Tu. Specificity and universality were confirmed in 66 bacterial strains, including 51 genera and 63 species. The amplification kinetics of tuf gene–targeted real-time quantitative PCR were consistent in a wide range of bacterial species tested. A calibration curve (r2 = 0.97) was produced for the estimation of bacterial counts, based on measurements of representative inoculations with 10-fold serial dilutions of the cells of representative bacterial species. Linear regression analysis of the real-time PCR–derived bacterial counts and aerobic plate counts, in a total 149 samples consisting of 25 minced meat, 34 fresh-cut vegetables, and 90 fish, exhibited a high correlation (r2 = 0.84, 0.87, and 0.95, respectively) over the range of 3.0 to 9.0 log CFU/g. In total, the difference between the two methods was less than 0.5 log in 75 of these samples, and in the remaining 74 samples, the difference was 0.5 to 1.0 log. Presently, our tuf gene–targeted real-time quantitative PCR assay achieves a rapid (within 2 h) estimation of bacterial counts of 3.0 to 9.0 log CFU/g, in a practical manner.
Perspectives for Geographically Oriented Management of Fusarium Mycotoxins in the Cereal Supply Chain
Authors: van der FELS-KLERX H. J. , BOOIJ C. J. H.
Published: December 2016

This article provides an overview of available systems for management of Fusarium mycotoxins in the cereal grain supply chain, with an emphasis on the use of predictive mathematical modeling. From the state of the art, it proposes future developments in modeling and management and their challenges. Mycotoxin contamination in cereal grain–based feed and food products is currently managed and controlled by good agricultural practices, good manufacturing practices, hazard analysis critical control points, and by checking and more recently by notification systems and predictive mathematical models. Most of the predictive models for Fusarium mycotoxins in cereal grains focus on deoxynivalenol in wheat and aim to help growers make decisions about the application of fungicides during cultivation. Future developments in managing Fusarium mycotoxins should include the linkage between predictive mathematical models and geographical information systems, resulting into region-specific predictions for mycotoxin occurrence. The envisioned geographically oriented decision support system may incorporate various underlying models for specific users' demands and regions and various related databases to feed the particular models with (geographically oriented) input data. Depending on the user requirements, the system selects the best fitting model and available input information. Future research areas include organizing data management in the cereal grain supply chain, developing predictive models for other stakeholders (taking into account the period up to harvest), other Fusarium mycotoxins, and cereal grain types, and understanding the underlying effects of the regional component in the models.
From "Ethnocracity" to Urban Apartheid: A View from Jerusalem\al-Quds
Authors: Yacobi Haim
Published: December 2016

In the core of this article stands an argument that while ethnocracy was a relevant analytical framework for understanding the urban dynamics of Jerusalem\al-Quds up until two decades ago, this is no longer the case. As this article demonstrates, ver the past twenty years or so, the city’s geopolitical balance and its means of demographic control, as well as an intensifying militarization and a growing use of state violence, have transformed the city from an ethnocracity into an urban apartheid.  Theoretically, this article aims to go beyond the specific analogy with South African apartheid, the most notorious case of such a regime. Rather I would suggest that in our current market-driven, neo-liberal era, an apartheid city should be taken as a distinct urban regime based on urban trends such as privatization of space, gentrification, urban design, infrastructure development and touristic planning. I would propose that these practices substitute for explicit apartheid legislation (of a sort introduced in the South African case), bringing to the fore new participants in the apartheidization of the city, such as real estate developers and various interest groups.
Extending the Concept of Ethnocracy: Exploring the Debate in the Baltic Context
Authors: Agarin Timofey
Published: December 2016

The advance of liberal understanding of democracy with its interest in and constrained ability to interfere with citizens’ identities made cases of ethnocracy rare over the past decades. Over the past 25 years, Baltic politics and societies have experienced considerable change, however, as I demonstrate, considerable debate persists around the issues central to the argument about ethnocracy in the region. In the context, when discussing the central role played by state institutions in negotiating conflicts between groups over access to scarce resources of the state, it is central to see minorities as being in both the inferior numerical position as well as in symbolically more disadvantageous place: If we see democratic politics for what they are as majoritarian politics, and if we see these as taking place in the context of state institutions designed to uphold the ethnic majority dominance, then any kind of liberal democratic politics would be a good candidate for ethnocracy.
Extending Ethnocracy: Reflections and Suggestions
Authors: Yiftachel Oren
Published: December 2016

As prelude to the special issue, this short piece reflects on the scholarly origins of the 'ethnocracy' concept, and comments on the arguments made by James Anderson's insightful opening article. It then outlines several concepts developed in the author's own work in later years as 'offsprings' of ethnocracy. Finally, it answers the challenge raised by Anderson by suggesting future theoretical, conceptual and empirical directions for research into ethnocratic dynamics on urban, state and global scales.
Derivation of the reduced reaction mechanisms of ozone depletion events in the Arctic spring by using concentration sensitivity analysis and principal component analysis
Authors: Cao Le , Wang Chenggang , Mao Mao , Grosshans Holger , Cao Nianwen
Published: December 2016

Abstract. The ozone depletion events (ODEs) in the springtime Arctic have been investigated since the 1980s. It is found that the depletion of ozone is highly associated with an auto-catalytic reaction cycle, which involves mostly the bromine-containing compounds. Moreover, bromide stored in various substrates in the Arctic such as the underlying surface covered by ice and snow can be also activated by the absorbed HOBr. Subsequently, this leads to an explosive increase of the bromine amount in the troposphere, which is called the “bromine explosion mechanism”. In the present study, a reaction scheme representing the chemistry of ozone depletion and halogen release is processed with two different mechanism reduction approaches, namely, the concentration sensitivity analysis and the principal component analysis. In the concentration sensitivity analysis, the interdependence of the mixing ratios of ozone and principal bromine species on the rate of each reaction in the ODE mechanism is identified. Furthermore, the most influential reactions in different time periods of ODEs are also revealed. By removing 11 reactions with the maximum absolute values of sensitivities lower than 10 %, a reduced reaction mechanism of ODEs is derived. The onsets of each time period of ODEs in simulations using the original reaction mechanism and the reduced reaction mechanism are identical while the maximum deviation of the mixing ratio of principal bromine species between different mechanisms is found to be less than 1 %. By performing the principal component analysis on an array of the sensitivity matrices, the dependence of a particular species concentration on a combination of the reaction rates in the mechanism is revealed. Redundant reactions are indicated by principal components corresponding to small eigenvalues and insignificant elements in principal components with large eigenvalues. Through this investigation, aside from the 11 reactions identified as unimportant in the concentration sensitivity analysis, additionally nine reactions were indicated to contribute only little to the total response of the system. Thus, they can be eliminated from the original reaction scheme. The results computed by applying the reduced reaction mechanism derived after the principal component analysis agree well with those by using the original reaction scheme. The maximum deviation of the mixing ratio of principal bromine species is found to be less than 10 %, which is guaranteed by the selection criterion adopted in the simplification process. Moreover, it is shown in the principal component analysis that O(1D) in the mechanism of ODEs is in quasi-steady state, which enables a following simplification of the reduced reaction mechanism obtained in the present study.
Impacts of heterogeneous uptake of dinitrogen pentoxide and chlorine activation on ozone and reactive nitrogen partitioning: improvement and application of the WRF-Chem model in southern China
Authors: Li Qinyi , Zhang Li , Wang Tao , Tham Yee Jun , Ahmadov Ravan , Xue Likun , Zhang Qiang , Zheng Junyu
Published: December 2016

Abstract. The uptake of dinitrogen pentoxide (N2O5) on aerosol surfaces and the subsequent production of nitryl chloride (ClNO2) can have a significant impact on the oxidising capability and thus on secondary pollutants such as ozone. The range of such an impact, however, has not been well quantified in different geographical regions. In this study, we applied the Weather Research and Forecasting coupled with Chemistry (WRF-Chem) model to investigate the impact of the N2O5 uptake processes in the Hong Kong–Pearl River Delta (HK–PRD) region, where the highest ever reported N2O5 and ClNO2 concentrations were observed in our recent field study. We first incorporated into the WRF-Chem an aerosol thermodynamics model (ISORROPIA II), recent parameterisations for N2O5 heterogeneous uptake and ClNO2 production and gas-phase chlorine chemistry. The revised model was then used to simulate the spatiotemporal distribution of N2O5 and ClNO2 over the HK–PRD region and the impact of N2O5 uptake and Cl activation on ozone and reactive nitrogen in the planetary boundary layer (PBL). The updated model can generally capture the temporal variation of N2O5 and ClNO2 observed at a mountaintop site in Hong Kong, but it overestimates N2O5 uptake and ClNO2 production. The model results suggest that under average conditions, elevated levels of ClNO2 (> 0.25 ppb within the PBL) are present in the south-western PRD, with the highest values (> 1.00 ppb) predicted near the ground surface (0–200 m above ground level; a.g.l.). In contrast, during the night when very high levels of ClNO2 and N2O5 were measured in well-processed plumes from the PRD, ClNO2 is mostly concentrated within the residual layer ( ∼  300 m a.g.l.). The addition of N2O5 heterogeneous uptake and Cl activation reduces the NO and NO2 levels by as much as 1.93 ppb ( ∼  7.4 %) and 4.73 ppb ( ∼  16.2 %), respectively, and it increases the total nitrate and ozone concentrations by up to 13.45 µg m−3 ( ∼  57.4 %) and 7.23 ppb ( ∼  16.3 %), respectively, in the PBL. Sensitivity tests show that the simulated chloride and ClNO2 concentrations are highly sensitive to chlorine emission. Our study suggests the need to measure the vertical profiles of N2O5 ∕ ClNO2 under various meteorological conditions, to consider the chemistry of N2O5 ∕ ClNO2 in the chemical transport model and to develop an updated chlorine emission inventory over China.
Statistical atmospheric inversion of small-scale gas emissions by
coupling the tracer release technique and Gaussian plume modeling: a test case with controlled methane emissions
Authors: Ars Sébastien , Broquet Grégoire , Yver Kwok Camille , Roustan Yelva , Wu Lin , Arzoumanian Emmanuel , Bousquet Philippe
Published: December 2016

Abstract. This study presents a new method for estimating the pollutant emission rates of a site and its main facilities using a series of atmospheric measurements across the pollutant plumes. This approach is based on a combination of the tracer release method, a Gaussian atmospheric transport model and a statistical atmospheric inversion approach. The conversion between the tracer controlled emission and the measured atmospheric concentrations across the plume provides knowledge on the atmospheric transport. The concept of the method consists of using this knowledge to optimize the configuration of the Gaussian model parameters and the model uncertainty statistics in the inversion system. The pollutant rates of each source are inverted to optimize the match between the concentrations simulated with the Gaussian model and the pollutants' measured atmospheric concentrations, accounting for the Gaussian model uncertainty. This new approach is evaluated with a series of inversions of controlled methane point sources using acetylene as a tracer gas. In these experiments, different configurations of methane and acetylene point source locations are tested to assess the efficiency of this method in comparison with the classic tracer release technique to cope with the distances between the different methane and acetylene sources. The results from these controlled experiments demonstrate that when the targeted and tracer gases are not well collocated, this new approach provides a better estimate of the emission rates than the tracer release technique. As an example, the relative error between the estimated and actual emission rates is reduced from 29 % with the tracer release technique to 8 % with the combined approach in the case of a tracer located 60 metres upwind of a methane source. This method also enables an estimate of different sources within the same site to be provided.
Measuring OVOCs and VOCs by PTR-MS in an urban roadside microenvironment of Hong Kong: relative humidity and temperature dependence, and field intercomparisons
Authors: Cui Long , Zhang Zhou , Huang Yu , Lee Shun Cheng , Blake Donald Ray , Ho Kin Fai , Wang Bei , Gao Yuan , Wang Xin Ming , Louie Peter Kwok Keung
Published: December 2016

Abstract. Volatile organic compound (VOC) control is an important issue of air quality management in Hong Kong because ozone formation is generally VOC limited. Several oxygenated volatile organic compound (OVOC) and VOC measurement techniques – namely, (1) offline 2,4-dinitrophenylhydrazine (DNPH) cartridge sampling followed by high-performance liquid chromatography (HPLC) analysis; (2) online gas chromatography (GC) with flame ionization detection (FID); and (3) offline canister sampling followed by GC with mass spectrometer detection (MSD), FID, and electron capture detection (ECD) – were applied during this study. For the first time, the proton transfer reaction–mass spectrometry (PTR-MS) technique was also introduced to measured OVOCs and VOCs in an urban roadside area of Hong Kong. The integrated effect of ambient relative humidity (RH) and temperature (T) on formaldehyde measurements by PTR-MS was explored in this study. A Poly 2-D regression was found to be the best nonlinear surface simulation (r  =  0.97) of the experimental reaction rate coefficient ratio, ambient RH, and T for formaldehyde measurement. This correction method was found to be better than correcting formaldehyde concentrations directly via the absolute humidity of inlet sample, based on a 2-year field sampling campaign at Mong Kok (MK) in Hong Kong. For OVOC species, formaldehyde, acetaldehyde, acetone, and MEK showed good agreements between PTR-MS and DNPH-HPLC with slopes of 1.00, 1.10, 0.76, and 0.88, respectively, and correlation coefficients of 0.79, 0.75, 0.60, and 0.93, respectively. Overall, fair agreements were found between PTR-MS and online GC-FID for benzene (slope  =  1.23, r  =  0.95), toluene (slope  =  1.01, r  =  0.96) and C2-benzenes (slope  =  1.02, r  =  0.96) after correcting benzene and C2-benzenes levels which could be affected by fragments formed from ethylbenzene. For the intercomparisons between PTR-MS and offline canister measurements by GC-MSD/FID/ECD, benzene showed good agreement, with a slope of 1.05 (r  =  0.62), though PTR-MS had lower values for toluene and C2-benzenes with slopes of 0.78 (r  =  0.96) and 0.67 (r  =  0.92), respectively. All in all, the PTR-MS instrument is suitable for OVOC and VOC measurements in urban roadside areas.
Modelling Holocene peatland dynamics with an individual-based dynamic vegetation model
Authors: Chaudhary Nitin , Miller Paul A. , Smith Benjamin
Published: December 2016

Abstract. Dynamic global vegetation models (DGVMs) are designed for the study of past, present and future vegetation patterns together with associated biogeochemical cycles and climate feedbacks. However, current DGVMs lack functionality for the representation of peatlands, an important store of carbon at high latitudes. We demonstrate a new implementation of peatland dynamics in a customised "Arctic" version of the dynamic vegetation model LPJ-GUESS, simulating the long-term evolution of selected northern peatland ecosystems and assessing the effect of changing climate on peatland carbon balance. Our approach employs a dynamic multi-layer soil with representation of freeze-thaw processes and litter inputs from a dynamically-varying mixture of the main peatland plant functional types; mosses, dwarf shrubs and graminoids. The model was calibrated and tested for a sub-arctic mire in Stordalen, Sweden, and validated at a temperate bog site in Mer Bleue, Canada. A regional evaluation of simulated carbon fluxes, hydrology and vegetation dynamics encompassed additional locations spread across Scandinavia. Simulated peat accumulation was found to be generally consistent with published data and the model was able to capture reported long-term vegetation dynamics, water table position and carbon fluxes. A series of sensitivity experiments were carried out to investigate the vulnerability of high latitude peatlands to climate change. We found that the Stordalen mire may be expected to sequester more carbon in the first half of the 21st century due to milder and wetter climate conditions, a longer growing season, and CO2 fertilization effect, turning into a carbon source after mid-century because of higher decomposition rates in response to warming soils.