bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring and Tracking Changes in Sensitivity to Azoxystrobin Fungicide in Alternaria solani in Wisconsin
Authors: Rosenzweig N. , Olaya G. , Atallah Z. K. , Cleere S. , Stanger C. , Stevenson W. R.
Published: March 2008

Azoxystrobin is a common fungicide used by farmers of Solanaceous crops against Alternaria solani, but there was growing concern about decreased sensitivity with repeated applications. In 2002 and 2003, monitoring of A. solani from commercial potato fields in Wisconsin indicated increased frequency and a statewide distribution of isolates with decreased in vitro sensitivity to azoxystrobin. Mean effective concentration in inhibiting spore germination by 50% values gathered in 2002 and 2003 were approximately 20-fold higher than baseline isolates of A. solani collected in 1998 from fields that had never been treated with azoxystrobin. This sensitivity decrease was correlated with site-specific mutations in the cytochrome b detected by quantitative real-time polymerase chain reaction. The F129L and the G143A substitution have been shown to cause a reduction in sensitivity or resistance, respectively, to quinone outside inhibitors. All of the recovered A. solani isolates collected in 2002 and 2003 were wild type at position 143. However, all three mutations responsible for the F129L substitution (TTA, CTC, and TTG) were detected in our samples. In addition, the frequency of this amino acid substitution in A. solani isolates was statistically different across sampling sites and years, indicating that sensitivity changes depended on specific disease management practices.
Postharvest Storage Losses Associated with Rhizomania in Sugar Beet
Authors: Campbell L. G. , Klotz K. L. , Smith L. J.
Published: March 2008

During storage of sugar beet, respiration and rots consume sucrose and produce invert sugar. Diseases that occur in the field can affect the magnitude of these losses. This research examines the storage of roots with rhizomania (caused by Beet necrotic yellow vein virus) and the effectiveness of rhizomania-resistant hybrids in reducing postharvest losses. Roots of susceptible hybrids from sites with rhizomania had respiration rates 30 days after harvest (DAH) that ranged from 0.68 to 2.79 mg of CO2 kg–1 h–1 higher than roots of the resistant hybrids. This difference ranged from 2.60 to 13.88 mg of CO2 kg–1 h–1 120 DAH. Roots of resistant hybrids from sites with rhizomania had 18 kg more sucrose per ton than roots from susceptible hybrids 30 DAH, with this difference increasing to 55 kg Mg–1 120 DAH. The invert sugar concentration of susceptible hybrids from sites with rhizomania ranged from 8.38 to 287 g per 100 g of sucrose higher than that for resistant hybrids 120 DAH. In contrast, differences between susceptible and resistant hybrids in respiration rate, sucrose loss, and invert sugar concentration in the absence of rhizomania were relatively small. Storage losses due to rhizomania can be minimized by planting resistant hybrids and processing roots from fields with rhizomania soon after harvest.
Serological and Molecular Assays for Rapid and Sensitive Detection of Iris yellow spot virus Infection of Bulb and Seed Onion Crops
Authors: Pappu H. R. , Rosales I. M. , Druffel K. L.
Published: March 2008

Iris yellow spot virus (IYSV) has spread rapidly in the United States and has become an important economic constraint to the production of both bulb and seed onion crops. Symptoms caused by IYSV may be confused with those caused by other fungal and bacterial pathogens and virus-specific, reliable, sensitive, and rapid detection methods would improve the diagnosis. Antiserum was produced to Escherichia coli-expressed nucleocapsid protein of IYSV and an indirect format of the enzyme-linked immunosorbent assay (ELISA) was developed. IYSV could be detected in onion tissue at dilutions of up to 1:1,000. An IYSV-specific primer pair was designed and used in a real-time reverse-transcription polymerase chain reaction (RT-PCR) assay for the rapid detection of IYSV. Compared with standard RT-PCR, real-time RT-PCR was more rapid and sensitive. A commercially available RNA extraction kit and a total nucleic acid extraction method were compared for the quality of the templates obtained for use in real-time RT-PCR and there was no difference in limits of detection. Availability of ELISA- and PCR-based rapid and sensitive detection methods would facilitate accurate virus diagnosis and aid in better understanding of the epidemiology of the disease and in development of management strategies.
Reassessment of Fungicide Synergism for Control of Dollar Spot
Authors: Burpee Lee , Latin Richard
Published: March 2008

Experiments were designed to assess reports of synergism between propiconazole and other fungicides to control dollar spot in creeping bentgrass. In 2004 and 2006, two field experiments were conducted near Griffin, GA, and repeated near West Lafayette, IN. A third experiment was conducted at the Griffin site in 2007. In each experiment, replicated treatments of commercial formulations of propiconazole, triadimefon, iprodione, vinclozolin, and chlorothalonil were applied to plots of creeping bentgrass at the sublabel rates of 0.12, 0.38, 0.57, 0.38, and 2.29 kg a.i. ha–1, respectively. In addition, each of the latter four fungicides was tank mixed with propiconazole at the rates given, and applied as treatments. Plots were treated once in experiments 1 and 3, and three times at a 21-day interval in experiment 2. Nontreated plots served as controls. Disease intensity was assessed visually by estimating the area of each plot that exhibited dollar spot symptoms. Synergism between tank-mixed fungicides was determined by comparing actual and expected values of the duration of disease control (experiment 1) or the percentage of disease control (experiments 2 and 3) in treated plots. No synergistic interactions were detected at Griffin or West Lafayette in experiments 1 or 2. In the first trial of experiment 3, synergism was observed between propiconazole and iprodione on one of five ratings dates and between propiconazole and vinclozolin on two of five rating dates. However, no synergistic interactions were detected in the second trial. Results suggest that there is a low probability for turfgrass managers to take advantage of fungicide synergism to control dollar spot with the products and rates tested.
Fairy Ring Disease of Cranberry: Assessment of Crop Losses and Impact on Cultivar Genotype
Authors: Oudemans Peter V. , Polashock James J. , Vinyard Bryan T.
Published: March 2008

Fairy ring is a disease of cultivated cranberry common in the eastern growing regions of the United States, especially New Jersey and Massachusetts. Rings may persist for many years, and current control recommendations are costly and largely ineffective. The goal of this study was to accurately assess the impact of this disease on cranberry, a long-lived, high-value, perennial crop. The rate of fairy ring expansion, rate of formation of new rings, and distribution of rings across three cultivars were determined using a geographical information system (GIS) database that incorporated aerial and satellite imagery. Ring growth rates, estimated from imagery collected over a 10-year period in cv. Ben Lear, averaged 0.455 m in radius per year. Rings were observed in ‘Ben Lear’ three times more frequently than in either ‘Early Black’ or ‘Stevens’ cultivars. Direct sampling showed that estimates for yield within rings were 22 to 68% less than unaffected areas of the field for cv. Ben Lear. These estimates included the effects of fruit rot, which was elevated within rings to 18 to 29% of the total harvest. The impact on yield of ‘Stevens’ and ‘Early Black’ was lower than in ‘Ben Lear’. Most cranberry cultivars are clonal and variation in fruit morphology within rings, particularly in ‘Ben Lear’, prompted an analysis of vine genotype. Areas affected by fairy ring in ‘Ben Lear’ showed an increase in genetic diversity at least 0.4 to 4 times that of unaffected areas. Therefore, it appears that fairy ring not only directly reduces yield but also can increase the host genetic diversity. This likely is due to increased seedling establishment resulting from seed drop when fruit decompose. Because seedlings typically yield less than the parental cultivar, the increase in genetic diversity also may contribute to long-term reduction of productivity in a cranberry field.
Region and Field Level Distributions of Aster Yellows Phytoplasma in Small Grain Crops
Authors: Hollingsworth C. R. , Atkinson L. M. , Samac D. A. , Larsen J. E. , Motteberg C. D. , Abrahamson M. D. , Glogoza P. , MacRae I. V.
Published: March 2008

Aster yellows (AY), a disease of small grain crops caused by aster yellows phytoplasma (AYp), produces disease symptoms similar to barley yellow dwarf (BYD). From 2003 to 2005, small grain production fields in Minnesota and North Dakota were surveyed to determine the incidences of AY and BYD. In-field spatial patterns of AY-infected plants also were investigated. Plants collected along a five-point transect line were tested for AYp using nested polymerase chain reaction (PCR) and quantitative real-time PCR assays, and extracted plant sap was tested for serotypes PAV and RPV of Barley yellow dwarf virus (BYDV) using enzyme-linked immunosorbent assays. During 2003, 2004, and 2005, AYp was detected in plants from 49, 15, and 7% of tested fields, respectively, whereas BYDV was found in plants from 2, 0, and 5% of fields, respectively. Average amplicon count number indicated an in-field spatial trend for greater incidence of AYp and increased populations of AYp in plants located near field edges, with comparably low copy numbers at transect point locations toward the direction of field center. AY is likely a common but largely undetected disease on small grain crops in the Upper Midwest.
Resistance in Peanut Cultivars and Breeding Lines to Three Root-Knot Nematode Species
Authors: Dong W. B. , Holbrook C. C. , Timper P. , Brenneman T. B. , Chu Y. , Ozias-Akins P.
Published: March 2008

Three major species of root-knot nematode infect peanut: Meloidogyne arenaria race 1, M. hapla, and M. javanica race 3. Sources of resistance to all three nematodes are needed for developing novel peanut cultivars with broad resistance to Meloidogyne spp. Cultivars and breeding lines of peanut were evaluated for resistance to M. arenaria, M. hapla, and M. javanica in the greenhouse and in the laboratory. Twenty-six genotypes with some resistance to M. arenaria, M. javanica, or M. hapla were identified from 60 accessions based on average eggs per gram of root and gall index relative to a susceptible control. Among these, 14 genotypes were moderately to highly resistant to all three species, 5 genotypes were resistant to M. arenaria and M. javanica, 2 genotypes were resistant to M. javanica and M. hapla, 1 genotype was resistant M. arenaria alone, and 4 genotypes were resistant to M. hapla alone. Reproduction of M. arenaria on lines NR 0817, C724-19-11, and D108 was highly variable, indicating that these genotypes likely were heterogeneous for resistance. COAN, NemaTAM, C724-25-8, and the M. arenaria-resistant plants of C724-19-11 contained the dominant sequence-characterized amplified region marker (197/909) for nematode resistance. Results with the molecular markers indicate that the high resistance to M. arenaria in GP-NC WS 6 may be different from the resistance in COAN, NemaTAM, and C724-25-8. Resistance to M. arenaria was correlated with resistance to M. javanica in peanut, whereas resistance to M. hapla was not correlated with the resistance to either M. arenaria or M. javanica. The resistant selections should be valuable sources for pyramiding resistance genes to develop new cultivars with broad and durable resistance to Meloidogyne spp.
Host Range Investigations of New, Undescribed, and Common Phytophthora spp. Isolated from Ornamental Nurseries in Minnesota
Authors: Schwingle B. W. , Blanchette R. A.
Published: March 2008

Eleven woody landscape plants commonly grown in the upper Midwestern United States were inoculated with up to three unnamed Phytophthora taxa (Phytophthora taxon Pgchlamydo, a Phytophthora alni-like isolate [Phytophthora MN14d], and Phytophthora sp. MN1) to explore their host ranges. In addition, P. cactorum, P. citricola, P. citrophthora, P. hedraiandra, and P. nicotianae were used to inoculate plants to further investigate the susceptibilities of plant genera previously found associated with these pathogens, to explore the susceptibility of important landscape plants (i.e., oak) to common ornamental Phytophthora spp., and to prove Koch's postulates. Koch's postulates were completed on fragrant sumac with P. citricola and P. nicotianae and on common lilac with P. citrophthora. A nonwound or wound inoculation technique were used to determine host susceptibility. Phytophthora sp. MN1 caused symptoms on American cranberrybush, bur and red oak, common lilac, fragrant sumac, Norway maple, and ‘P.J.M.’ rhododendron. The newly described organism P. hedraiandra caused disease on American cranberrybush, common lilac, red oak, and ‘Snowdrift’ crabapple. Fragrant sumac and common lilac generally were the most susceptible hosts to all Phytophthora spp. This study demonstrated that many ornamental Phytophthora pathogens have larger potential host ranges than previously known. The biology and ecology of P. hedraiandra and Phytophthora sp. MN1 must be further investigated, and methods for rapid identification should be developed.
First Report of Peach latent mosaic viroid Infecting Peach in Egypt
Authors: Hassan M. , Rysanek P. , Malfitano M. , Alioto D.
Published: March 2008

Peach latent mosaic viroid (PLMVd) is a widespread pathogen of stone fruit trees in some European and Mediterranean countries and also in North America. To access the presence of the viroid in Egypt, a survey was conducted that covered five commercial peach orchards in the El Khatatba Region in Al Minufiya Governorate. During 2003 and 2004, 73 peach trees (cv. Florida grafted on Nemagard rootstock) were visually inspected and sampled. No symptoms characteristic of PLMVd infection, such as mosaic, delayed growth, or fruit suture cracking, were observed. All samples were tested for the presence of PLMVd using dot-blot hybridization and reverse transcription (RT)-PCR. Aliquots (5 μl) of total nucleic acids extracted from approximately 2 mg of leaf tissue were spotted onto positively charged nylon membranes and hybridized under stringent conditions with a digoxigenin-labeled riboprobe (2). The extracts (1 μl) also were used in RT-PCR as described (1). Only 1 of the 73 peach trees was positive for PLMVd using these detection techniques. The RT-PCR product was of the size expected for PLVMd and was cloned and sequenced. The 339 nucleotide sequence was deposited in GenBank as Accession No. DQ839564. The sequence of this Egyptian PLMVd isolate was 94% identical to the reference PLMVd variant (GenBank Accession No. M83545) and most closely (95%) related to Canadian isolate variant 16 (GenBank Accession No. AJ550911). Such a low incidence compared with other countries may be because the survey was restricted to a limited number of samples, conducted on newly reclaimed lands where no sources of infection existed before, and material with relatively low PLMVd incidence might have been used for planting. Although the incidence of PLMVd was low in this survey, the occurrence represents a threat to the stone fruit tree industry in this country and regular screening of PLMVd in certification programs is suggested. To our knowledge, this is the first report of PLMVd on peach in Egypt.

References: (1) S. Loreti et al. EPPO Bull. 29:433, 1999. (2) A. M. Shamloul et al. Acta Hortic. 386:522, 1995.
Occurrence of Late Leaf Rust Caused by Pucciniastrum americanum in Red Raspberry (Rubus idaeus) in Buenos Aires, Córdoba, and Entre Ríos, Argentina
Authors: Lucero X. , Wright E. R. , Pérez B. A.
Published: March 2008

In the fall of 2003, severity of late leaf rust in leaves and fruits of red raspberry (Rubus idaeus L.) reached 50% in Buenos Aires (Azul, Baradero, Capilla del Señor, Gral. Rodríguez, Mar del Plata, and Tandil), Córdoba (Villa de Las Rosas), and Entre Ríos (Concordia). The south of Argentina, Río Negro (El Bolsón), and Chubut (El Hoyo, Lago Puelo) remained rust free. The abaxial side of the field infected leaves had pustules filled with masses of yellow spores. Chlorotic areas corresponded in the adaxial side. Urediospores were vacuum harvested from field infected leaves collected in the Tandil area and placed onto a healthy 1-year-old greenhouse-grown plant (cv. Heritage). Spores from a single pustule were increased on plants of the same cultivar. Spores were studied with optic and electronic microscopy. Uredial ostiolar cells were warted, laterally free, and constricted in the middle. The obovoid, echinulate urediospores, from infected leaves averaged 24 × 16 μm (16 to 30 × 11 to 21 μm). Morphological characteristics and spore measurements agreed with those reported for Pucciniastrum americanum (1). Urediniospores were suspended in mineral oil and sprayed onto three raspberry cultivars that were maintained in a darkened mist chamber at 20°C for 48 h and the transferred to a 20°C and 12-h light cycle chamber. Control plants were inoculated with sterile water. There were three replicate plants of each treatment. After 11 days, large sporulating uredia (0.5 mm) were produced on inoculated leaves of cv. Autumn Bliss and smaller uredia (0.1 to 0.3 mm) were produced on cv. Heritage. There were necrotic flecks and the least and smallest uredia were produced on cv. Himbo Queen. No symptoms were present in control plants. To our knowledge, this is the first report of P. americanum causing disease on raspberry in Argentina.

Reference: (1) G. F. Laundon and A. F. Rainbow. Pucciniastrum americanum. No. 210 in: Descriptions of Pathogenic Fungi and Bacteria. CMI, Kew, Surrey, England, 1969.
First Report of Rhizoctonia Blight of a Coastal Redwood Tissue-Culture-Derived Saplings Caused by Rhizoctonia solani AG-IV in Taiwan
Authors: Hsiao W. W. , Wu Y. S. , Wang Y. N. , Huang B. L. , Huang L. C.
Published: March 2008

Coastal redwood (Sequoia sempervirens (D. Don) Endl.) is native to North America. This tall tree species is used for forestation and lumber; its wood is also used for furniture, its burls for art ware, and its bark for fuel, insulation, and mulch. In August 2005, an instance of wilt was observed among 2-year-old tissue-culture-cloned plants (2) in the Sitou Forest of central Taiwan. Essentially, all plants were infected. The leaves or stems near the ground were affected first, but the wilt soon spread over the entire plant with the leaves becoming grayish brown and water soaked, and then wilting, drying, and finally defoliation occurred. Aerial hyphae were present over the affected areas, aerial mycelium was cob-web-like, hyaline, later becoming slightly brown. Hyphae were 6.5 to 10.4 μm wide with right-angle branching and septal constriction at their bases. Sclerotia were hemispherical, subglobose, to irregular in shape, 1 to 2 mm, and brown. The perfect stage of the fungus was not found. The fungus was identified as Rhizoctonia solani Kühn (3). Vegetative cells were stained with alkaline safranin solution and identified as multinucleate (1). Portions of the stem that displayed symptoms, together with adjacent healthy tissue, were disinfested for 1 min in 0.5% NaOCl and plated on to potato-dextrose agar (PDA) (Merck, Darmstadt, Germany) supplemented with 100 mg/L of ampicillin (Sigma, St. Louis, MO). Single hyphal tips were transferred to PDA and two isolates were established as pure cultures. On the basis of hyphal anastomosis with AG-IV tester isolates (exfop234, exfop241, and exfop250) (1), the fungus was identifed as R. solani AG-IV. Pathogenicity of the fungal isolates was confirmed by inoculating 2-month-old tissue-culture-derived S. sempervirens plants that were grown in pots and incubated in a growth chamber maintained at 28°C with a relative humidity above 95%. Inoculum consisted of a single mycelial 5-day-old 0.5-cm disc grown on PDA of the pathogen placed on the soil surface touching the base of each plant. Four plants were inoculated with mycelium and the four control plants were noninoculated. Inoculated plants wilted gradually over 4 days and all plants developed severe stem rot and were dead in 6 days, whereas control plants remained symptomless. The Rhizoctonia solani AG-IV was reisolated from all inoculated plants. This fungus has been observed to cause disease in many species of plants (4), but to our knowledge, this is the first report of Rhizoctonia blight of coastal redwood tissue-culture-derived saplings caused by Rhizoctonia solani AG-IV in Taiwan.

References: (1) T. T. Chang. Taiwan J. For. Sci. 12:47, 1997. (2) L. C. Huang et al. Plant Physiol. 98:166, 1992. (3) B. Sneh et al. Identification of Rhizoctonia species. The American Phytopathological Society, St. Paul, MN, 1991. (4) S. T. Su et al. List of Plant Diseases in Taiwan. The Phytopathological Society of the Republic of China, 2002.
Detecting polymorphic regions inArabidopsis thalianawith resequencing microarrays
Authors: Zeller Georg , Clark Richard M. , Schneeberger Korbinian , Bohlen Anja , Weigel Detlef , Rätsch Gunnar
Published: March 2008

Whole-genome oligonucleotide resequencing arrays have allowed the comprehensive discovery of single nucleotide polymorphisms (SNPs) in eukaryotic genomes of moderate to large size. With this technology, the detection rate for isolated SNPs is typically high. However, it is greatly reduced when other polymorphisms are located near a SNP as multiple mismatches inhibit hybridization to arrayed oligonucleotides. Contiguous tracts of suppressed hybridization therefore typify polymorphic regions (PRs) such as clusters of SNPs or deletions. We developed a machine learning method, designated margin-based prediction of polymorphic regions (mPPR), to predict PRs from resequencing array data. Conceptually similar to hidden Markov models, the method is trained with discriminative learning techniques related to support vector machines, and accurately identifies even very short polymorphic tracts (<10 bp). We applied this method to resequencing array data previously generated for the euchromatic genomes of 20 strains (accessions) of the best-characterized plant,Arabidopsis thaliana. Nonredundantly, 27% of the genome was included within the boundaries of PRs predicted at high specificity (≈97%). The resulting data set provides a fine-scale view of polymorphic sequences inA. thaliana; patterns of polymorphism not apparent in SNP data were readily detected, especially for noncoding regions. Our predictions provide a valuable resource for evolutionary genetic and functional studies inA. thaliana, and our method is applicable to similar data sets in other species. More broadly, our computational approach can be applied to other segmentation tasks related to the analysis of genomic variation.
Comparative analysis of the small RNA transcriptomes of Pinus contorta and Oryza sativa
Authors: Morin Ryan D. , Aksay Gozde , Dolgosheina Elena , Ebhardt H. Alexander , Magrini Vincent , Mardis Elaine R. , Sahinalp S. Cenk , Unrau Peter J.
Published: March 2008

The diversity of microRNAs and small-interfering RNAs has been extensively explored within angiosperms by focusing on a few key organisms such as Oryza sativa and Arabidopsis thaliana. A deeper division of the plants is defined by the radiation of the angiosperms and gymnosperms, with the latter comprising the commercially important conifers. The conifers are expected to provide important information regarding the evolution of highly conserved small regulatory RNAs. Deep sequencing provides the means to characterize and quantitatively profile small RNAs in understudied organisms such as these. Pyrosequencing of small RNAs from O. sativa revealed, as expected, ∼21- and ∼24-nt RNAs. The former contained known microRNAs, and the latter largely comprised intergenic-derived sequences likely representing heterochromatin siRNAs. In contrast, sequences from Pinus contorta were dominated by 21-nt small RNAs. Using a novel sequence-based clustering algorithm, we identified sequences belonging to 18 highly conserved microRNA families in P. contorta as well as numerous clusters of conserved small RNAs of unknown function. Using multiple methods, including expressed sequence folding and machine learning algorithms, we found a further 53 candidate novel microRNA families, 51 appearing specific to the P. contorta library. In addition, alignment of small RNA sequences to the O. sativa genome revealed six perfectly conserved classes of small RNA that included chloroplast transcripts and specific types of genomic repeats. The conservation of microRNAs and other small RNAs between the conifers and the angiosperms indicates that important RNA silencing processes were highly developed in the earliest spermatophytes. Genomic mapping of all sequences to the O. sativa genome can be viewed at http://microrna.bcgsc.ca/cgi-bin/gbrowse/rice_build_3/.
Prenatal choline supplementation alters the timing, emotion, and memory performance (TEMP) of adult male and female rats as indexed by differential reinforcement of low-rate schedule behavior
Authors: Cheng Ruey-Kuang , MacDonald Christopher J. , Williams Christina L. , Meck Warren H.
Published: March 2008

Choline availability in the maternal diet has a lasting effect on brain and behavior of the offspring. To further delineate the impact of early nutritional status, we examined effects of prenatal-choline supplementation on timing, emotion, and memory performance of adult male and female rats. Rats that were given sufficient choline (CON: 1.1 g/kg) or supplemental choline (SUP: 5.0 g/kg) during embryonic days (ED) 12–17 were trained with a differential reinforcement of low-rate (DRL) schedule that was gradually transitioned through 5-, 10-, 18-, 36-, and 72-sec criterion times. We observed that SUP-females emitted more reinforced responses than CON-females, which were more efficient than both groups of males. In addition, SUP-males and SUP-females exhibited a reduction in burst responding (response latencies <2 sec) compared with both groups of CON rats. Furthermore, despite a reduced level of burst responding, the SUP-males made more nonreinforced responses prior to the DRL criterion as a result of maintaining the previous DRL criterion following transition to a new criterion. In summary, long-lasting effects of prenatal-choline supplementation were exhibited by reduced frustrative DRL responding in conjunction with the persistence of temporal memory in SUP-males and enhanced temporal exploration and response efficiency in SUP-females.
Effect of water activity on the inactivation kinetics of Escherichia coli O157:H7 by electron beam in ground beef, chicken breast meat, and trout fillets
Authors: Black Jennifer Leah , Jaczynski Jacek
Published: March 2008

Water activity (aw) of ground beef, chicken breast meat, and trout fillets was modified to intermediate (aw 0.98–0.99) and lowest (aw 0.94–0.96) levels. The meat samples with modified and unaltered (native, aw 1.00) aw were inoculated with Escherichia coli O157:H7 and subjected to electron beam (e‐beam). Survivor curves were plotted and the D10‐values were calculated. The D10‐values ranged from 0.22 kGy for trout at native aw to 0.33 kGy for beef at intermediate, and chicken and trout at lowest aw. Regardless of the species, aw reduction increased E. coli resistance to e‐beam, suggesting that even small depletion of unbound water from food increases survival. The difference of the D10‐values between the samples at intermediate and lowest aw was insignificant. E‐beam could be used before aw‐reducing techniques are applied to food products. However, this would require stringent microbial control following e‐beam processing. The ‘tailing’ of survivors was observed for some samples with reduced aw.
Optimisation of hydrophilic antioxidant extraction from Hizikiafusiformis by integrating treatments of enzymes, heat and pH control
Authors: Siriwardhana Nalin , Kim Kil‐Nam , Lee Ki‐Wan , Kim Soo‐Hyun , Ha Jin‐Hwan , Song Choon Bok , Lee Joon‐Bak , Jeon You‐Jin
Published: March 2008

Effective extraction of algal bioactive compounds can be achieved by treatments such as pH control, heat and enzymatic hydrolysis. Hizikia fusiformis antioxidants were extracted with those treatments individually and extraction efficacies were compared by measuring yield, total phenolic content and antioxidant activities. Increased pH could successfully improve the extraction, and incubation at pH 12.0 for 12 h was the most effective pH treatment. Incubation at 100 °C for 45 min was significantly (P < 0.05) more effective than the other heat treatments. Optimum condition for enzymatic treatment was combination of 2% Alcalase (alkaline endopeptidase/protease) and 3% Ultraflo (β‐glucanase/carbohydrase) at pH 8.0 and 54–58 °C for 24 h. Integration of those optimised treatments in the extraction sequence of heat (H), enzymatic hydrolysis (E) and pH control (P) was the most effective sequence. Compared with other extraction sequences, HEP sequence indicated significantly higher phenolic content and antioxidative activities in 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and hydrogen peroxide scavenging assays.
Changes in vegetable microbiological quality introduced by processing methods
Authors: Kokkinakis Emmanuel , Boskou Georgios , Fragkiadakis Georgios A. , Kokkinaki Aikaterini
Published: March 2008

The main objective of this research was to investigate the effect in microbial quality of vegetables, because of the chain of buyers and sellers involved in the collection, processing and selling of vegetables, from the primary production sector up to the consumer level (from farm to table). Two processing plants and six hotels were selected and 240 vegetables, 30 vegetable containers, 18 water samples used for sanitation purposes and samples of 18 personnel's hands, were microbiologically analysed. Based on actual results and processing plants auditing, we conclude that initial vegetable microbial quality is critical. The storage, separation and packaging processes, cleaning procedures and retention time at processing plants can influence vegetable microbial quality. Buyers–sellers involved between vegetable production in primary sector and final consumer can offer a dramatic decrease in vegetable quality. The use of ISO 9001:2000 can improve product quality through techniques such as product traceability and resources management.
Influence of natural and controlled fermentations on α‐galactosides, antinutrients and protein digestibility of beans (Phaseolus vulgaris L.)
Authors: Shimelis Emire Admassu , Rakshit Sudip Kumar
Published: March 2008

The influence of natural fermentation (NF) and controlled fermentation (CF) in diminishing the content of antinutrients, α‐galactosides and increments in in vitro protein digestibility was investigated. The dry bean (Phaseolus vulgaris) flour was the substrate used in this research study. A decrease in raffinose oligosaccharide, antinutritional components and pH was observed in both types of fermentation. The natural lactic fermentation of ground beans produced significant increase (P < 0.05) in protein digestibility. For all varieties of beans, raffinose concentration reduced significantly to an undetectable level after 96 h of NF. CF did not have any significant effect on the reduction of the α‐galactosides content of the flours during fermentation. NF is an inexpensive method by which consumers can obtain good‐quality protein. Both types of fermentation diminish antinutrients and improve the nutritional value of the bean flour, and indicate the potential to use bean flour as an ingredient for fabricated foods.
Antioxidant activities and composition of extracts from chilli
Authors: Li‐E Jin , Qing Cao , Ke‐Chang Xie
Published: March 2008

The extract yields obtained by three methods in different solvents from chilli were compared. The antioxidant activities of chilli extracts vs. butylated hydroxytoluene (BHT) was determined through the peroxide value (POV), the beta‐carotene bleaching assay and the 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging method. The results showed that the extract yields by three extract methods, namely, Soxhlet, ultrasonic wave and saturation, were 16.32%, 15.78% and 11.62%, respectively, when 85% ethanol acted as solvent. The extracting efficiency of solvent from high to low was 95% ethanol > ethyl acetate > anhydrous ethanol > distilled water. The total phenol content of chilli extracts from ultrasonic wave with 85% ethanol as solvent was 73.91 mg gallic acid equivalents (GAE) per gram extracts and the value of inhibitory capacity IC50 on free radical (DPPH) was 38.99 mg mL−1. The POV of chilli extracts was close to that of BHT. The ultrasonic wave was more helpful for the extraction of antioxidant substance from chilli than other methods. In addition, the composition of chilli extracts was analysed by gas chromatography‐mass spectrum (GC‐MS).
Modelling of cooking‐cooling processes for meat and poultry products
Authors: Marcotte Michèle , Chen Cuiren R. , Grabowski Stefan , Ramaswamy Hosahalli S. , Piette Jean‐Paul Gabriel
Published: March 2008

Traditional cooking‐cooling of processed meat and poultry products is industrially carried out in smokehouses or autoclaves. A mathematical model was developed to simulate these operations. Equations, describing heat transfer and thermal destruction of micro‐organisms and quality characteristics, were solved numerically. The model was validated experimentally for heat transfer and energy consumption and was used to perform a sensitivity analysis. Input variables were: process time (PT), smokehouse temperature (TSH), bologna size (diameter, D and height, H), surface heat transfer coefficients (hheat and hcool), product thermal diffusivity (αheat and αcool). Output variables were: product core temperature (Tc), core and volume‐average lethality (Pcm and Pvm) and cook (Cc and Cv) values as well as surface (Qs) and volume‐average (Qv) quality retention, total specific energy consumption (En) and energy efficiency (Ce). Multiple linear regression models were developed to predict Cc and Cv from five inputs and used to obtain acceptable deviation ranges.
Fish industry waste: treatments, environmental impacts, current and potential uses
Authors: Arvanitoyannis Ioannis S. , Kassaveti Aikaterini
Published: March 2008

Fish waste management has been one of the problems having the greatest impact on the environment. Fish farming detrimental effects on the marine environment in particular have become an issue of public concern. In European Union, numerous Directives, Decisions and Regulations were voted in an attempt to minimise the environmental impact of fisheries within the frame of Integrated Coastal Management. Treated fish waste has found many applications among which the most important are animal feed, biodiesel/biogas, dietic products (chitosan), natural pigments (after extraction), food‐packaging applications (chitosan), cosmetics (collagen), enzyme isolation, Cr immobilisation, soil fertiliser and moisture maintenance in foods (hydrolysates). In this review, an update of both environmental impact (inputs and outputs) and treated fish waste uses is provided by means of six comprehensive tables and seven figures.
Comparison of composition and antioxidant capacity of some cereals and pseudocereals
Authors: Gorinstein Shela , Lojek Antonin , Číž Milan , Pawelzik Elke , Delgado‐Licon Efren , Medina Oscar J. , Moreno Marlén , Salas Ines Arnao , Goshev Ivan
Published: March 2008

Polyphenols, phenolic acids, fibres and antioxidant capacity were determined in water, acetone and methanol extracts of buckwheat, rice, soybean, quinoa and 3 amaranth cultivars. Their antioxidant activities were comparatively assessed by total radical‐trapping antioxidative potential (TRAP), ferric ion‐reducing antioxidant power (FRAP), cupric‐reducing antioxidant capacity (CUPRAC) and nitric oxide (NO•) assays, which comprised of contributions from polyphenols and phenolic acids (especially from the most abundant ferulic acid). The correlation coefficients between polyphenols and antioxidant activities of cereal and pseudocereal methanol extracts with FRAP, NO•, CUPRAC and TRAP were 0.99, 0.97, 0.96 and 0.77, respectively. The weakest correlation was with dietary fibres, an average one exhibited with tannins and marked correlation was shown with the phenolics. All the applied methods have shown that pseudocereals have higher antioxidant activity than some cereals (rice and buckwheat) and can be successfully replaced by cereals in case of allergy.
Effect of cream treatment on phospholipids and protein recovery in butter‐making process
Authors: Britten Michel , Lamothe Sophie , Robitaille Gilles
Published: March 2008

A simple approach is proposed to recover native protein and phospholipid fractions from butter‐making process using equipments available in dairy‐processing plant. A washing treatment was used to remove protein from the cream and increase the phospholipids purity in buttermilk. Cream from a first separation was diluted with milk ultrafitration permeate and separated a second time. A 10X dilution factor reduced protein concentration in the cream from 1.6 ± 0.2 to 0.52 ± 0.03%. As a result, the phospholipids to protein ratio in buttermilk increased from 53 ± 10 to 172 ± 7 mg g−1. In butter‐making process, an important portion of total phospholipids (∼26%) is retained in butter. Butter serum made from washed cream could then be used to produce phospholipid concentrates with phospholipids to protein ratio of 473 ± 3 mg g−1. Interestingly, the extracts from butter serum are characterised by a higher proportion of sphingomyelin compared with those from buttermilk.
Fracture properties of potato crisps
Authors: Rojo F. J. , Vincent J. F. V.
Published: March 2008

The Weibull modulus of potato crisps is about 4, comparable with ceramic materials, with a characteristic strength of about 1.5 MPa. This combination of brittleness and weakness gives crispness. The critical stress intensity factor (KIC) and the energy of fracture (R) are around 0.12 MPa and 45 J m–2, respectively. There was no significant difference between the material values obtained for the fracture properties of crisps of a range of subjective ‘crispness’ as measured by a trained organoleptic panel. Crispness is ranked by the structural bending strength. Centrally loaded plate tests give qualitative evaluation of crispness. Both these tests could be used in quality control, with advantage over organoleptic tests such as cost, the time required, objectivity, consistency of results, the relation of the measured parameters to standard materials tests and the relatively small amount of material that is needed by comparison.
Influence of chopped laser light onto the electronic transport through atomic‐sized contacts
Authors: GUHR D.C. , RETTINGER D. , BONEBERG J. , ERBE A. , LEIDERER P. , SCHEER E.
Published: March 2008

This paper reports on the influence of laser irradiation onto the electrical conductance of gold nanocontacts established with the mechanically controllable breakjunction technique. We concentrate here on the study of reversible conductance changes which can be as high as 200%. We investigate the dependence on the initial conductance of the contacts, the wavelength, the intensity and position of the laser spot with respect to the sample. Under most conditions an enhancement of the conductance is observed. We discuss several physical mechanisms which might contribute to the observed effect including thermal expansion, rectification and photon‐assisted transport. We conclude that thermal expansion is not the dominating one.
Modelling of the near‐field of metallic nanoparticle gratings: localized surface plasmon resonance and SERS applications
Authors: GRIMAULT A.‐S. , VIAL A. , GRAND J. , LAMY DE LA CHAPELLE M.
Published: March 2008

We numerically study the influence of the shape of gold nanostructures on the spectral position of their localized surface plasmon resonance and on Surface Enhanced Raman Scattering efficiency. Calculations are performed using a Finite‐Difference Time‐Domain (FDTD) method, whose accuracy for dispersive media is enhanced through the use of a Drude‐Lorentz model. The relevance of this method is then pointed out by comparing the calculations with experimental data for both the plasmon resonance and the Raman signal enhancement. The influence of a thin layer of water is also investigated.
Implementation of a bimorph‐based aperture tapping‐SNOM with an incubator to study the evolution of cultured living cells
Authors: LONGO G. , GIRASOLE M. , CRICENTI A.
Published: March 2008

We present the implementation of a tapping‐mode aperture scanning near‐field optical microscope (Tapping‐SNOM) to a Binder CB incubator (Istituto di Struttura della Materia, Rome, Italy). The microscope operates in the intermittent contact mode using a nonbent optical fibre allowing to reduce the perturbation exerted on the sample, while the incubator maintains a constant temperature, humidity and CO2 level. This instrument can maintain and analyse in a controlled environment different samples, both organic and nonorganic. In particular, the Tapping‐SNOM can study different cell lines at nanometric resolution and in physiological buffer, following the evolution of the living cells almost indefinitely. We will present several examples of the capabilities of the tapping scanning near‐field optical microscope in the study of different lines of living cells, showing corresponding topographical, optical or phase‐lag images of the live samples, evidencing the excellent stability, versatility and resolution of the system.
Molecular ordering in self‐organized dye particles: polarized evanescent‐field studies
Authors: KINOSHITA S. , FUJIMOTO A. , TOMIOKA A.
Published: March 2008

Self‐organized rhodamine 6G particles prepared by wetting/dewetting process of an ethanol solution on a hydrophilic glass surface did show fluorescence without quenching. Polarized evanescent‐field excitation showed that the molecule's transition moment within dye particles was oriented unidirectionally and parallel to the substrate surface. The deduced dye orientation showed correlation between adjacent particles, which implies a simultaneous aggregate growth from a common crystal seed grown in a possible ‘arm’ region connecting the adjacent droplets just before these droplets were disconnected upon solvent evaporation. The dye orientation of most particles pointed about 45° off the dewetting direction. By contrast, the particles of another π‐conjugated NK1420 dye, J‐aggregates of which grow easily from an oversaturated solution, showed dye orientation along the dewetting direction preferably, still indicating the effect of self‐organization, however based on a different mechanism.
Influence of the light‐scattering form factor on the Bragg diffraction patterns of arrays of metallic nanoparticles
Authors: GONÇALVES M. R. , SIEGEL A. , MARTI O.
Published: March 2008

Accurate models for the light‐scattering form factors of nanoparticles are of crucial importance to characterize the optical properties of the particles and to develop new photonic devices. Analytical or semi‐empirical models exist for particles of spherical and cylindrical shape. The angular spectrum of scattering for particles of more complex shape is very complex and can only be obtained by numerical simulations. Moreover, the light scattering of metallic particles depends on many parameters as size, shape, optical constants, substrate and polarization of light. Experimental verification of the differential scattering cross‐sections obtained from different calculation methods is always necessary. Measurements done on single nanoparticles are very sensitive to their local properties and the sinal‐to‐noise ratio may be very poor. Arrays of identical particles illuminated by a planes waves produce Bragg diffraction and the resultant patterns depend on the averaged values of the form factors of the particles.

 In order to test the validity of models for the scattering form factor, we present an experimental setup capable of measuring Bragg diffraction patterns of arrays of nanoparticles in the visible and near‐infrared regions of the spectrum. The approach is similar to that of X‐ray diffraction of crystals.
Experimental research on the performance of a very‐small‐aperture laser
Authors: HONGFENG GAI , WANG JIA , TIAN QIAN , XIA WEI , XIANGANG XU , HAN SHUO , HAO ZHIBIAO
Published: March 2008

Very‐small‐aperture lasers (VSALs) with different aperture shapes are fabricated. Their far‐field and near‐field performance is analyzed experimentally. The far‐field performance, including the threshold current, the slope efficiency, the lasing ability and the linear frequency modulation property, is found to be influenced by the front facet reflectivity. A new factor is tentatively proposed to analyze the lasing abilities of VSALs with different aperture shapes. This factor can diminish the discrepancies among the same type laser diodes. The near‐field performance focusses on the confinement effect of the VSAL aperture. A near‐field scanning optical microscopy is used to measure the near‐field intensity distribution from a VSAL. The experimental results indicate that the near‐field performance is affected by the aperture shape. A 100‐nm C‐aperture is proved to be superior to a 100 × 300 nm2 rectangular aperture on both power throughput and peak intensity. These two apertures are fabricated on the same VSAL facet for the fairness of comparison. An optical spot beyond the diffraction limit is also obtained by fabricating a 70‐nm C‐aperture on a VSAL facet.
Focussed ion beam machined cantilever aperture probes for near‐field optical imaging
Authors: JIN E.X. , XU X.
Published: March 2008

Near‐field optical probe is the key element of a near‐field scanning optical microscopy (NSOM) system. The key innovation in the first two NSOM experiments (Pohl et al., 1984; Lewis et al., 1984) is the fabrications of a sub‐wavelength optical aperture at the apex of a sharply pointed transparent probe tip with a thin metal coating. This paper discusses the routine use of focussed ion beam (FIB) to micro‐machine NSOM aperture probes from the commercial silicon nitride cantilevered atomic force microscopy probes. Two FIB micro‐machining approaches are used to form a nanoaperture of controllable size and shape at the apex of the tip. The FIB side slicing produces a silicon nitride aperture on the flat‐end tips with controllable sizes varying from 120 nm to 30 nm. The FIB head‐on drilling creates holes on the aluminium‐coated tips with sizes down to 50 nm. Nanoapertures in C and bow tie shapes can also be patterned using the FIB head‐on milling method to possibly enhance the optical transmission. A transmission‐collection NSOM system is constructed from a commercial atomic force microscopy to characterize the optical resolution of FIB‐micro‐machined aperture tips. The optical resolution of 78 nm is demonstrated by an aperture probe fabricated by FIB head‐on drilling. Simultaneous topography imaging can also be realized using the same probe. By mapping the optical near‐field from a bow‐tie aperture, optical resolution as small as 59 nm is achieved by an aperture probe fabricated by the FIB side slicing method. Overall, high resolution and reliable optical imaging of routinely FIB‐micro‐machined aperture probes are demonstrated.