bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Tylenchulus semipenetrans Biotype in Zebediela and Champagne, Republic of South Africa
Authors: Kwaye R. G. , Mashela P. W. , Shimelis H. , Mapope N.
Published: March 2008

The biotype of the citrus nematode (Tylenchulus semipenetrans) from Zebediela and Champagne Citrus Estates, Republic of South Africa, was determined using 2-year-old differential hosts, namely, grape (Vitis vinifera cv. Richter 110), carrizo citrange (Citrus sinensis × Poncirus trifoliata), rough lemon (C. jambhiri), olive (Olea europaea cv. Misson), and trifoliate orange (P. trifoliata). The study was conducted under greenhouse conditions with 10 replicates. Nematodes from Zebediela and Champagne were extracted from roots through mechanical shaking, sieving, and incubation in Baermann trays and inoculated at 10,000 and 40,000 eggs and juveniles per plant, respectively. Results demonstrated that the citrus nematode from Zebediela had reproductive factors greater than one on grape, rough lemon, trifoliate orange, and carrizo citrange, but lower than one on olive. Reproductive factors were less than one for all differential hosts with the Champagne population, with olive having the lowest value. Differential-host tests using Zebediela and Champagne nematode populations suggested that the T. semipenetrans biotype is poncirus.
Detection of Cucurbit leaf crumple virus in Florida Cucurbits
Authors: Akad F. , Webb S. , Nyoike T. W. , Liburd O. E. , Turechek W. , Adkins S. , Polston J. E.
Published: March 2008

In October of 2006, yellow straightneck and zucchini squash plants (Cucurbita pepo L.) with crumpled, curled, thickened leaves were found in St. Johns and Marion counties in central Florida, respectively. Both locations had high populations of the whitefly, Bemisia tabaci. Incidences of symptomatic plants were greater than 95% in three squash fields (33 ha total) in St. Johns County and 35% in an experimental plot in Marion County. Twenty-three samples were collected from symptomatic plants (two from St. Johns County and 21 from Marion County). DNA was extracted for PCR and tested for the presence of begomoviruses using the following pairs of degenerate primers: AC1048/AV494, which amplifies a conserved region of the coat protein gene (2), PAR1c496/PAL1v1978, which amplifies a region of the begomovirus A component, and PBL1v2040/PCRc154, which amplifies a hypervariable region of the begomovirus B component (1). All squash samples yielded amplicons of sizes expected for a bipartite begomovirus: 1,159 nt with PAR1c496/PAL1v1978, 550 nt with AC1048/AV494, and 493 nt with PBL1v2040/PCRc154. The 1,159- and 493-nt amplicons obtained from two squash plants were cloned and sequenced. The 1,159 nt sequences from both plants shared 98% sequence identity with each other and 97% identity with equivalent regions of the A component of Cucurbit leaf crumple virus (CuLCrV) from Arizona and California (GenBank Accession Nos. AF256200 and AF224760, respectively). The 493-nt sequences amplified with PBL1v2040/PCRc154 were identical and shared a 96% identity with CuLCrV sequence (GenBank Accession No. AF327559) from Arizona and 97% identity with CuLCrV B component sequence (GenBank Accession No. AF224761) from California. Leaves were collected from eight symptomatic squash plants from Citra, FL and used for whitefly transmission assays. Approximately 100 adults of Bemisia tabaci biotype B were released onto each caged leaf and given a 24-h acquisition access period, after which a healthy squash seedling was introduced. Symptoms developed within 10 days on all test plants, and the presence of CuLCrV was confirmed by PCR assays, (primer pairs PAR1c496/PAL1v1978 and PBL1v2040/PCRc154) followed by sequencing. In 2007, similar symptoms were seen in several locations around the state. The same assays confirmed the presence of CuLCrV in watermelon (Citrullus lanatus L.) and squash in the following counties: Collier and Hendry in southwest Florida and Hillsborough, Manatee, and Sarasota in west-central Florida. To our knowledge, this is the first report of CuLCrV, and the first report of any begomovirus in cucurbits in Florida.

References: (1) M. R. Rojas et al. Plant Dis. 77:340, 1993. (2) S. D. Wyatt and J. K. Brown. Phytopathology 86:1288, 1996.
First Report of ‘Candidatus Phytoplasma trifolii’-Related Strain Associated with Safflower Phyllody Disease in Iran
Authors: Salehi M. , Izadpanah K. , Siampour M.
Published: March 2008

During a survey in 2003, safflower plants (Carthamus tinctorius) with phyllody symptoms were observed in production fields in several districts of Fars and Yazd provinces in Iran. Affected plants showed floral virescence, phyllody, proliferation of axillary buds, and little leaf symptoms. Incidence of the disease was less than 10%. Direct and nested PCR assays were used to verify association of phytoplasma with the disease. Total DNA was extracted from fresh, fine roots of eight phyllody-affected safflower plants and one symptomless plant. With phytoplasma universal primer pair P1/P7 (5′-AAGAGTTTGATCCTGGCTCAGGATT-3′/5′-CGTCCTTCATCGGCTCTT-3′), target DNA fragments of approximately 1.8 kb were amplified by direct PCR from phyllody-affected plants and Iranian cabbage yellows (ICY) phytoplasma used as a positive control. Reamplification of P1/P7 products with 16S rRNA gene primer pair R16F2n/R16R2 (5′-GAAACGACTGCTAAGACTGG-3′/5′-TGACGGGCGGTGTGTACAAACCCCG-3′) yielded fragments of the expected size (1.2 kb) from all eight diseased plants and the ICY-positive control. No products were amplified from the symptomless plant by either assay. R16F2n/R16R2 products were subjected to restriction fragment length polymorphism (RFLP) analysis by separate digestion with AluI, HaeIII, HhaI, HinfI, HpaII, MseI, RsaI, Sau3AI, or TaqI endonuclease. Comparison of resulting RFLP patterns with published patterns of other phytoplasmas (2) tentatively identified safflower phyllody (SP) phytoplasma as a member of clover proliferation group 16SrVI, subgroup C. HhaI digests also differentiated SP from ICY phytoplasma, a previously reported subgroup 16SrVI-A strain (3). After sequencing of the 16S rDNA fragment (GenBank Accession No. DQ88948), a BLAST search determined that SP phytoplasma shared closest homology with 16SrVI group members (‘Candidatus Phytoplasma trifolii’) and related strains (4). Furthermore, phylogenetic analysis of 16S rDNA sequences revealed SP phytoplasma to be most similar (99.7%) to brinjal little leaf (BLL) phytoplasma (GenBank Accession No. X83431). Analysis of putative restriction sites in 16S rRNA gene sequences revealed that SP and BLL shared identical restriction profiles and that both differed from the ‘Ca. Phytoplasma trifolii’ reference strain (GenBank Accession No. AY390261) because of the absence of a single HhaI site and the presence of an additional MseI site. Although safflower phyllody disease has been previously reported in Israel, the associated phytoplasma was classified as a strain of the aster yellows subgroup 16SrI-B (1). To our knowledge, this is the first report of safflower as a host of a ‘Ca. Phytoplasma trifolii’-related strain.

References: (1) M. Klein. Plant Dis. Rep. 54:735, 1970. (2) I.-M. Lee et al. Int. J. Syst. Evol. Microbiol. 54:1037, 2004. (3) M. Salehi et al. Plant Dis. 91:625, 2007. (4) K. Wang and C. Hiruki, Phytopathology 91:546, 2001.
First Report of Beet mild curly top virus Infection of Chile Pepper in North-Central Mexico
Authors: Velásquez-Valle R. , Medina-Aguilar M. M. , Creamer R.
Published: March 2008

During the 2005 growing season, widespread virus-like symptoms were observed in pepper (Capsicum annuum) fields in north-central Mexico. Early in the season, plants were chlorotic and stunted with thickened, elongated leaves. From mid to late season, the affected plants showed severe yellowing, upwardly rolled, small leaves, and a few deformed fruits. Symptoms were similar to those described for curtoviruses in pepper (1). The leafhopper vector of curtoviruses, Circulifer tenellus, was first reported in the area in 1953 (3) (its presence was confirmed again in January 2008). Pepper fields were sampled in the states of Aguascalientes and Zacatecas, and five symptomatic plants from Zacatecas tested positive for the presence of curtoviruses by PCR using primers to the coat protein (CP) coding region (2). PCR amplicons from three samples of Ancho and Mirasol pepper types from Zacatecas, which also tested positive by PCR using the rep coding region (2), were sequenced and compared with reported curtoviruses. The samples showed 91% identity with the CP coding region and 93% identity with the rep coding region of Beet mild curly top virus (formerly the Worland strain). A survey of pepper fields from Aguascalientes and Zacatecas based on symptomatic plants was conducted from July to August of 2005. Forty-three fields of different types of pepper, including those growing under mulch and drip irrigation, were surveyed. Twenty-five plants in each of five contiguous rows were inspected for the symptoms described above. Disease symptoms were noted in Mirasol, Ancho, Pasilla, and Guajillo pepper types, and the average disease incidence was 9.87% (range: 1.6 to 48%), 15.2% (range: 6.4 to 25.6%), 7.85% (range: 2.4 to 15.2%), and 20.8% (range: 8 to 33.6%), respectively. To our knowledge, this is the first report of curtovirus infection of chile pepper in this region of Mexico. The moderate level of curtovirus infection found here suggests the need to initiate management strategies for this disease.

References: (1) L. L. Black et al. Page 98 in: Pepper Diseases. A Field Guide. AVRDC, Taiwan, 1991. (2) R. Creamer et al. Plant Dis. 89:480, 2005. (3) D. A. Young and N. W. Frazier. Hilgardia 23:25, 1954.
First Report of Stemphylium botryosum Causing Leaf Blight of Kiwi in the Province Imathia, Northern Greece
Authors: Thomidis T. , Michailides T. J.
Published: March 2008

In Greece, kiwi (Actinidia deliciosa) is mostly found in the northern part of the country where approximately 440,000 ha are grown. In the summer of 2006, a Stemphylium sp. was frequently isolated from leaves of kiwi (cv. Hayward) grown in the province of Imathia. Symptomatic leaves were covered with irregular, necrotic, brown areas. Lesions had a distinct margin that, in some cases, covered a wide part of the diseased leaves. Intense symptoms were frequently observed and associated with defoliation. This Stemphylium sp. was consistently isolated from diseased leaves onto potato dextrose agar (PDA) after surface sterilization with 0.1% chlorine solution. On the basis of morphological characteristics of mycelia, dimensions (length 20 to 29 μm and width 14 to 21 μm) and mean length/width ratio (1.42 μm) of conidia, and width and apical cell width of condiophores, the fungus was identified as Stemphylium botryosum (Wallr.) (2,3) Koch's postulates were completed in the laboratory by inoculating leaves of kiwi (cv. Hayward) with an isolate of S. botryosum originated from a symptomatic leaf of a Hayward kiwi. Twenty leaves were surface sterilized by dipping them into 0.1% chlorine solution for 2 to 3 min, washing in sterile distilled water, and allowing them to dry in a laminar flow hood. A leaf was then placed into a petri plate containing a wet, sterilized paper towel. Inoculation was made by transferring a 5-mm-diameter mycelial disc from the margins of a 7-day-old culture onto the center of each leaf surface. Petri plates were closed and incubated at 25°C with 12 h of light for 6 days. Koch's postulates were satisfied when the same S. botryosum was reisolated from 100% of inoculated leaves that developed symptoms similar to those observed in the vineyards. Leaves inoculated with a PDA plug alone (with no S. botryosum) did not develop any symptoms. Previously, Alternaria alternata was reported as the causal agent of a leaf spot pathogen of kiwi (1,4). To our knowledge, this is the first report of the occurrence of S. botryosum causing leaf blight of kiwi in Greece and worldwide. This pathogen can cause a high level of defoliation in diseased plants.

References: (1) L. Corazza et al. Plant Dis. 83:487, 1999. (2) M. B. Ellis. Dematiaceous Hyphomycetes. Mycology Institute. London, England, 1971. (3) E. G. Simmons. Mycologia 61:1, 1969. (4) C. Tsahouridou and C. C. Thanassoulopoulos. Plant Dis. 84:371, 2000
First Report of Leaf Smut on Fescue (Festuca rubra) Caused by Urocystis agropyri in Interior Alaska
Authors: McBeath J. H. , Cheng M. , Gay P. A. , Yokogi T.
Published: March 2008

In June and early July of 2003 and July of 2007, a smut disease was found on fescue (Festuca rubra L.) at the Fairbanks Golf and Country Club and vicinities, Interior Alaska. Diseased plants were pale green-to-slightly yellow and stunted. The lesions were long, narrow, yellowish green streaks parallel to the veins of leaves and sheaths. At a later stage, sori developed under the epidermis and the leaves and sheaths turned silvery gray. Rupture of the epidermis resulted in the release of masses of black spores that covered the leaves, especially along and within infected sheaths. Microscopic observation showed spore balls consisting of one-to-four, dark reddish brown teliospores surrounded by small, hyaline-to-light brown sterile cells. The spore balls were globose to elongate and 16 to 32 × 18 to 38 μm. The teliospores were globose, dark reddish brown, and 7.5 to 20 μm in diameter. Urocystis agropyri is recognized by R. W. Smiley et al. (2) and J. D. Smith et al. (3) as occurring on turf grasses; K. Vánky (4) restricts this species to Elymus spp. and recognizes U. ulei as the valid species infecting Festuca spp, including F. rubra. On the basis of host symptoms and morphology of spores, the smut found on F. rubra in Alaska fits better with published descriptions of U. agropyri (Preuss) Schrot (2,3), however, it likely is not conspecific with flag smut of wheat. For molecular verification of this identification, DNA was isolated from teliospores with a DNeasy Plant Mini Kit (Qiagen, Valencia, CA). Primers were designed for amplification of the large subunit ribosomal gene based on the only two published sequences of U. ranunculi (Lib.) Moesz (GenBank Accession No. AF009879) and U. colchici (Schltdl.) Rabenh (GenBank Accession No. AF009878) (1). A 400-bp PCR product was amplified by the forward primer 3′-GCATTGTAAACTCAGAAGTGTTATCCG-5′ and reverse primer 5′-TTCCCTAAACCTATATCCGGCG-3′. Nucleotide sequence of the PCR product (GenBank Accession No. AY547283) shared 97.7% homology with U. ranunculi and 98.2% with U. colchici. Comparison of nucleotide sequences will be more meaningful in the identification of species of Urocystis when additional sequences are published. To our knowledge, this is the first report of U. agropyri from turfgrass in Alaska.

References: (1) D. Begerow et al. Can. J. Bot. 75:2045, 1997. (2) R. W. Smiley et al. Compendium of Turfgrass Diseases. 3rd ed. The American Phytopathological Society, St Paul, MN, 2005. (3) J. D. Smith et al. Page 189 in: Fungal Diseases of Amenity Turf Grassess. E. & F. N. Spon, London, 1989. (4) K. Vánky. Page 308 in: European Smut Fungi. Gustav Fischer Verlag, NY. 1994.
First Report of Purple Coneflower Phyllody Associated with a 16SrI-B Phytoplasma in Maryland
Authors: Lee I.-M. , Bottner K. D. , Dally E. L. , Davis R. E.
Published: March 2008

Purple coneflower (Echinacea purpurea (L.) Moench) is a flowering perennial plant native to North America and is widely grown as an ornamental flower. It is also grown commercially to make herbal teas and extracts purported to help strengthen the immune system. Propagation is by seed or root cuttings. Aster yellows phytoplasmas (strains belonging to group 16SrI) have been reported to be associated with purple coneflower exhibiting virescence and phyllody symptoms in the northern United States and Canada. A subgroup 16SrI-A phytoplasma was identified to be associated with symptomatic purple coneflower in Wisconsin (2). During the summers of 1994 and 2007, purple coneflower plants in Maryland sporadically exhibited symptoms resembling those caused by phytoplasma infection. Symptoms included stunting, virescence, phyllody, and abnormal flower bud proliferation from the cone. Samples from four symptomatic and two asymptomatic purple coneflower plants were collected. Total nucleic acid was extracted from leaf tissue. To assess the etiology of the disease, nested PCR with universal phytoplasma primer pair P1/P7 followed by R16F2n/R16R2 was employed for the detection of phytoplasmas (1). An amplicon of approximately 1.2 kb was amplified from all four symptomatic purple coneflower plants but not from the two asymptomatic plants. Restriction fragment length polymorphism (RFLP) patterns of 16S rDNA digested singly with restriction enzymes AluI, KpnI, HpaI, MseI, HhaI, and RsaI indicated that affected purple coneflower plants were infected by a phytoplasma belonging to aster yellows group 16SrI (‘Candidatus Phytoplasma asteris’-related strains), subgroup 16SrI-B (1). Nucleotide sequence analysis of cloned 16S rDNA (GenBank Accession Nos. EU333394 and EU333395) confirmed the results from RFLP analyses. To our knowledge, this is the first report of a 16SrI-B phytoplasma infecting an Echinacea sp. in Maryland.

References: (1) I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998. (2) G. R. Stanosz et al. Plant Dis. 81:424, 1997.
First Report of Cercospora concors Causing Cercospora Leaf Blotch of Potato in Inner Mongolia, North China
Authors: Tian S. M. , Ma P. , Liu D. Q. , Zou M. Q.
Published: March 2008

Cercospora leaf blotch disease of potato (Solanum tuberosum L.) caused by Cercospora concors (Casp.) Sacc (synonym Mycovellosiella concors (Casp.) Deighton) occurs worldwide but mainly has been reported in the cool and temperate climates of Europe, Asia, North America, and eastern Africa. Cercospora leaf blotch is usually a minor disease and may go unnoticed since it commonly occurs simultaneously with other potato leaf diseases such as late blight (caused by Phytophthora infestans) and early blight (caused by Alternaria solani) (2). Symptoms of Cercospora leaf blotch first appear on lower leaves as small, yellowish green, irregular blotches and later may appear on middle and upper leaves. As the leaves expand, the blotches enlarge and become purplish brown or black. Conidiophores and conidia form on the underside of the lesions, giving the lesions a mildewed appearance similar to late blight. Necrotic lesions are distinguished from those caused by the early blight pathogen A. solani by the lack of concentric rings (1). In more severe epidemics of Cercospora leaf blotch, potato leaves may be killed, stem lesions become dark and entire plants die, but no resulting yield loss from the disease has been documented. Potato tubers are not infected. From August to September of 2005, yellow-brown lesions appeared on the upper side of potato leaves (cv. Zihuabai, certified virus free) and gray mildew developed on the underside of leaves in potato field trials conducted in Jining County, 41°N, 113°E of Inner Mongolia, North China. The infections were observed mostly on lower and middle leaves of plants; 20 to 30% of plants were infected. In the laboratory, the mildew was scraped with a sterile scalpel and examined microscopically. The conidiophores were irregular in width, grayish, and highly branched. The conidia were numerous, light to dark, straight or slightly bent, cylindrical or obclavate, with conspicuous scars, and zero to six septa. The mature spores were from 16 to 59 μm long and 4 to 6 μm wide. The teleomorph of the fungus was not found. On the basis of the morphological characters, the causal agent was identified as C. concors. C. concors has been previously identified from potato leaves in the Engshi District of Hubei Province, China (3), but to our knowledge, this is the first report of the fungus causing Cercospora leaf blotch of potato in Inner Mongolia, North China.

References: (1) G. D. Franc and B. I. Christ. Page 22 in: Compendium of Potato Diseases. 2nd ed. W. R. Stevenson et al., eds. American Phytopathological Society, St. Paul, MN, 2001. (2) E. R. French. Page 19 in: Compendium of Potato Diseases. 2nd ed. W. R. Stevenson et al., eds. American Phytopathological Society, St. Paul, MN, 2001. (3) S. M. Tian et al. China Potato J. 1:13, 1997.
Fusarium Wilt of Gerbera Caused by a Fusarium sp. in Brazil
Authors: Garibaldi A. , Minuto A. , Uchimura M. Shiniti , Gullino M. L.
Published: March 2008

In 2006, gerbera (Gerbera jamesonii) plants, cvs. Basic, Xena, and Olimpia grown for cut flower production in two greenhouse farms in the region of Guarapuava, Paraná, Brazil, exhibited symptoms of a wilt disease. Affected plants (approximately 20, 60, and 50% on cvs. Basic, Xena, and Olimpia, respectively) were stunted and developed yellow leaves unilaterally with initially brown and eventually black streaks in the vascular system. The first symptoms occurred 2 months after transplanting during the hottest period of the summer with an average air temperature of 27°C. Vascular streaks in the yellow leaves were continuous with a brown discoloration in the vascular system of the crown and upper taproot. Occasionally, the leaves of affected plants turned red. A Fusarium sp. was consistently and readily isolated onto a Fusarium-selective medium from symptomatic vascular tissue sampled from the crown of infected plants. Colonies were identified as Fusarium oxysporum on the basis of colony and conidia morphology (1) after subculturing on potato dextrose agar. Since F. oxysporum f. sp. chrysanthemi has been previously reported on Chrysanthemum morifolium, Argyranthemum frutescens, and gerbera (4), pathogenicity tests were carried out by using one monoconidial isolate obtained from wilted plants and one Italian isolate (F. oxysporum f. sp. chrysanthemi MASS 6). The isolates of F. oxysporum were grown in casein hydrolysate in shake culture (90 rpm) for 10 days at 25°C with 12 h of fluorescent light per day. Healthy rooted plants of 30-, 20-, and 45-day-old C. morifolium (cv. Captiva), A. frutescens (cv. Stella 2000), and gerbera (cvs. Jaska, Dalma, and Excellence), respectively, were inoculated by separately dipping roots into a conidial suspension (5 × 107 conidia/ml) of the two isolates of F. oxysporum. Plants were transplanted (one plant per pot) into pots (3.5 liter vol). Noninoculated plants served as control treatments. Plants (15 per treatment) were grown in a glasshouse at an average day temperature of 32°C and night temperature of 23°C (minimum 21°C and maximum 43°C). Wilt symptoms and discoloration of the vascular system in roots, crown, and petioles developed within 29 days on C. morifolium, 26 days on A. frutescens, and 14 days on gerbera. Noninoculated plants remained healthy. F. oxysporum was consistently reisolated from infected plants. The pathogenicity test was carried out twice. Gerbera wilt caused by F. oxysporum f. sp. chrysanthemi was recently reported in Italy (2) and Spain (3). Currently, the wilt of gerbera in the area of Paraná is limited to two farms. To our knowledge, this is the first report of the disease in Brazil as well as in South America.

References: (1) C. Booth. Fusarium. CMI, Kew, UK, 1977. (2) A. Garibaldi et al. Plant Dis. 88:311, 2004. (3) A. Garibaldi et al. Plant Dis. 91:638, 2007. (4) A. Minuto et al. J. Phytopathol. 155:373, 2007.
First Report of Orobanche crenata Parasitism on Ornamental Anemone (Anemone coronaria) in Israel
Authors: Dor E. , Eizenberg H. , Joel D. M. , Levitin E. , Hershenhorn J.
Published: March 2008

Broomrapes (Orobanche spp.) are obligatory parasitic weeds that infect roots of vegetables and field crops worldwide, resulting in severe damage. Orobanche crenata Forsk is common in agricultural fields in the Mediterranean Basin, Southern Europe, and the Middle East and is known as an important scourge of grain and forage legumes and of some Apiaceous crops such as carrot (Daucus carota L.) and celery (Apium graveolens L.) (3,4). To our knowledge, in this note, we report for the first time on Anemone coronaria L. (Ranunculaceae) as a new host for O. crenata and this is also the first report of Orobanche parasitism on a geophytic crop. Anemone (Anemone coronaria L.) is a high-value ornamental crop, which is commercially grown for cut flowers. Four anemone cultivars (Meron Red, Galil White, Jerusalem Blue, and Jerusalem Pink) were planted in September 2006 in a 2-ha field in Israel. The previous crop, broad bean (Vicia faba L.), was heavily infected during 2005 by O. crenata. In February 2007, O. crenata parasitized the anemone plants and developed numerous fertile flowering stalks throughout the field. The four anemone cultivars were equally infected by the parasite. Additional flowering stalks were still emerging on anemone plants during July 2007. Washing the root system clearly verified direct connection between the parasite and anemone roots. The parasite species was identified morphologically after Flora Europea (1) and Flora Palaestina (2). In addition, the stem had the fragrance typical of O. crenata. Neither symptoms nor visible qualitative or quantitative damage could be detected on infected anemone plants compared with noninfected plants. However, anemone appears to be an alternate host on which O. crenata can produce additional seed for the parasite seed bank.

References: (1) A. O. Chater and D. A. Webb. Orobanche. Page 285 in: Flora Europaea. T. G. Tutin et al., eds. Vol. 3. University Press, Cambridge, 1972. (2) N. Feinbrun-Dothan. Page 210 in: Flora Palaestina. Vol. 3. Israel Academy of Sciences and Humanities, Jerusalem, 1978. (3) D. M. Joel et al. Hortic. Rev. 33:267, 2007. (4) C. Parker and C. R. Riches. Page 111 in: Parasitic Weeds of the World: Biology and Control. CAB International, Wallingford, Great Britain, 1993.
Critical role of the 65-kDa isoform of glutamic acid decarboxylase in consolidation and generalization of Pavlovian fear memory
Authors: Bergado-Acosta Jorge R. , Sangha Susan , Narayanan Rajeevan T. , Obata Kunihiko , Pape Hans-Christian , Stork Oliver
Published: March 2008

Evidence suggests that plasticity of the amygdalar and hippocampal GABAergic system is critical for fear memory formation. In this study we investigated in wild-type and genetically manipulated mice the role of the activity-dependent 65-kDa isozyme of glutamic acid decarboxylase (GAD65) in the consolidation and generalization of conditioned fear. First, we demonstrate a transient reduction of GAD65 gene expression in the dorsal hippocampus (6 h post training) and in the basolateral complex of the amygdala (24 h post training) during distinct phases of fear memory consolidation. Second, we show that targeted ablation of the GAD65 gene in Gad65−/− mice results in a pronounced context-independent, intramodal generalization of auditory fear memory during long-term (24 h or 14 d) but not short-term (30 min) memory retrieval. The temporal specificity of both gene regulation and memory deficits in Gad65 mutant mice suggests that GAD65-mediated GABA synthesis is critical for the consolidation of stimulus-specific fear memory. This function appears to involve a modulation of neural activity patterns in the amygdalo-hippocampal pathway as indicated by a reduction in theta frequency synchronization between the amygdala and hippocampus of Gad65−/− mice during the expression of generalized fear memory.
Activation of CB1 specifically located on GABAergic interneurons inhibits LTD in the lateral amygdala
Authors: Azad Shahnaz Christina , Kurz Jörg , Marsicano Giovanni , Lutz Beat , Zieglgänsberger Walter , Rammes Gerhard
Published: March 2008

Previously, we found that in the lateral amygdala (LA) of the mouse, WIN55,212-2 decreases both glutamatergic and GABAergic synaptic transmission via activation of the cannabinoid receptor type 1 (CB1), yet produces an overall reduction of neuronal excitability. This suggests that the effects on excitatory transmission override those on inhibitory transmission. Here we show that CB1 activation by WIN55,212-2 and Δ9-THC inhibits long-term depression (LTD) of basal synaptic transmission in the LA, induced by low-frequency stimulation (LFS; 900 pulses/1 Hz). The CB1 agonist WIN55,212-2 blocked LTD via Gi/o proteins, activation of inwardly rectifying K+ channels (Kirs), inhibition of the adenylate cyclase-protein kinase A (PKA) pathway, and PKA-dependent inhibition of voltage-gated N-type Ca2+ channels (N-type VGCCs). Interestingly, WIN55,212-2 effects on LTD were abolished in CB1 knock-out mice (CB1-KO), and in conditional mutants lacking CB1 expression only in GABAergic interneurons, but were still present in mutants lacking CB1 in principal forebrain neurons. LTD induction per se was unaffected by the CB1 antagonist SR141716A and was normally expressed in CB1-KO as well as in both conditional CB1 mutants. Our data demonstrate that activation of CB1 specifically located on GABAergic interneurons inhibits LTD in the LA. These findings suggest that CB1 expressed on either glutamatergic or GABAergic neurons play a differential role in the control of synaptic transmission and plasticity.
Combining Non-Linear Regressions that have Unequal Error Variances and Some Parameters in Common
Authors: Hamilton David C. , Knop O.
Published: March 2008

Methods of estimation and inference are presented for the situation where two non-linear regression models with unequal error variances contain some parameters in common. Such a situation arises in structural chemistry, when bond lengths are available for three nearly collinear atoms in crystals and a model is required to quantify the extent and form of the relationship between the longer and the shorter bond. Some atomic triples are symmetric and require a different model and error variance from those required by the asymmetric triples. The profile likelihood for the regression parameters is a weighted sum of the logarithms of the sums-of-squares functions from each model, and the estimates can be obtained by using a simple modification to a standard non-linear least squares program. A likelihood ratio test for assessing whether the parameters in common are equal is described. When these techniques are applied to two data sets consisting of bond lengths for bromine–tellurium–bromine and sulphur–tellurium–sulphur triples, there is no evidence against the equality hypothesis. An extension to the model to allow for a non-constant variance is required for proper analysis of the sulphur–tellurium–sulphur data.
Grouped Data Exponentially Weighted Moving Average Control Charts
Authors: Steiner Stefan H.
Published: March 2008

In the manufacture of metal fasteners in a progressive die operation, and other industrial situations, important quality dimensions cannot be measured on a continuous scale, and manufactured parts are classified into groups by using a step gauge. This paper proposes a version of exponentially weighted moving average (EWMA) control charts that are applicable to monitoring the grouped data for process shifts. The run length properties of this new grouped data EWMA chart are compared with similar results previously obtained for EWMA charts for variables data and with those for cumulative sum (CUSUM) schemes based on grouped data. Grouped data EWMA charts are shown to be nearly as efficient as variables-based EWMA charts and are thus an attractive alternative when the collection of variables data is not feasible. In addition, grouped data EWMA charts are less affected by the discreteness that is inherent in grouped data than are grouped data CUSUM charts. In the metal fasteners application, grouped data EWMA charts were simple to implement and allowed the rapid detection of undesirable process shifts.
Variation of phenolic content in coconut oil extracted by two conventional methods
Authors: Seneviratne Kapila N. , Sudarshana Dissanayake Dissanayake M.
Published: March 2008

Phenolic compounds present in the nonsaponifiable fraction of coconut oil were analysed by high‐performance liquid chromatography with florescence detection. Mass spectra of the phenolic compounds were also obtained separately by LC–MS to confirm the presence of the phenolic compounds. Caffeic acid, p‐coumaric acid, ferulic acid and (+/−) catechin were observed in coconut oil. Phenolic acid fraction of the coconut oil prepared by boiling coconut milk (traditional coconut oil) was more complex compared with that of coconut oil prepared by pressing copra (commercial coconut oil). Total phenol content of traditional coconut oil was nearly seven times higher than that of commercial coconut oil (618 ± 46 vs. 91 ± 11 mg kg−1), suggesting that the phenol content varies with the extraction method.
Chemical compositions and functional properties of gelatin from pre‐cooked tuna fin
Authors: Aewsiri Tanong , Benjakul Soottawat , Visessanguan Wonnop , Tanaka Munehiko
Published: March 2008

Gelatin was extracted from pre‐cooked tuna caudal fin with the yield of 1.99%. Tuna fin gelatin (TFG) contained high protein content (89.54%) with hydroxyproline content of 14.12 mg g−1. TFG comprised a lower content of high‐molecular‐weight cross‐links and hydroxyproline content than porcine skin gelatin (PSG). However, proline content in TFG was twofold higher than that of PSG. The highest bloom strength and turbidity of TFG were observed at pH 6, while the lowest solubility was noticeable at the same pH. The bloom strength of TFG gel was lower than that of PSG gel at all pHs. TFG exhibited the lower emulsifying activity but greater emulsifying stability than PSG (P < 0.05). TFG showed poor foaming properties than PSG. The tensile strength, elongation at break, water vapour permeability of film from PSG was greater than those of TFG (P < 0.05). The study revealed that gelatin of good quality can be prepared from tuna processing discards.
Effect of heat treatment on antinutrients and precaecal crude protein digestibility in broilers of four tropical crop seeds
Authors: Iyayi Eustace A. , Kluth Holger , Rodehutscord Markus
Published: March 2008

Four tropical crop seeds, namely Vigna unguiculata (Cowpea), Mucuna pruriens, Manihot esculenta and Centrosema pubescens were thermally processed for 1 h at 100 °C and analysed for their antinutritional factors (ANF). Four hundred and forty‐eight 1‐day‐old broilers were used to determine the effect of heating the seeds on their precaecal crude protein (CP) digestibility. Total phenols, protein precipitable tannins and l‐dopa were higher in the mucuna and centrosema seeds and diets than in the vigna and manihot seeds and diets. Phytic acid was of similar occurrence in all the raw seeds. Heat treatment resulted in reduction in all the ANF in the seeds. Precaecal CP digestibility, feed intake and growth rate were significantly (P < 0.01) increased in the heat‐treated mucuna and centrosema diets. There was no significant effect on the digestibility of CP, feed intake and growth rate in birds on the vigna and manihot diets owing to heat treatment of the seeds. The results showed that heating improved the nutritive quality of mucuna and centrosema seeds but was not of significant advantage with vigna and manihot seeds when used at levels of up to 150 g kg−1 in diets.
Determination of clenbuterol in UHT milk in Turkey
Authors: Unusan Nurhan
Published: March 2008

Clenbuterol use is linked to its ability to induce weight gain and a greater proportion of muscle to fat. Clenbuterol residues can affect lung and heart function in persons who have eaten liver or meat of animals which were given the drug. Any residue of clenbuterol is regarded unacceptable in the EU. The purpose of the study was to determine the occurrence of clenbuterol in UHT milk samples in Turkey. The occurrence of hormone residues in Ultra Heat Treatment (UHT) milk samples was investigated by semi‐quantitative enzyme‐linked immunoassay technique. There was a high incidence rate of clenbuterol, with forty‐one (68.3%) milk samples being contaminated. 21.7% of the samples were over the permissible level for clenbuterol as accepted by the EU. Clenbuterol levels in the samples purchased in Central Anatolia Region appear to be serious public health problem at the moment.
Modelling the enzymatic softening of apples in relation to cultivar, growing system, picking date and season
Authors: Róth Erika , Hertog Maarten L.A.T.M. , Kovács Etelka , Nicolaï Bart
Published: March 2008

The postharvest softening of four apple cultivars cv. Idared, Liberty, Pilot and Pinova coming from an organic and an integrated experimental orchard was studied to compare the effects of cultivar, growing system, picking date and season. The stiffness of apples was examined monthly by acoustic impulse‐response technique. The activity of β‐galactosidase (β‐Gal) and polygalacturonase (PG) causing cell wall breakdown was investigated at harvest and during storage. A mechanistic model approach was developed to interpret the integral set of data on softening as a function of the measured enzyme activities. No consistent differences were observed in β‐Gal or PG activity during storage of apples coming from either organic or integrated orchards, whereas their stiffness behaved comparably. In general, the effect of cultivar and season was higher than the effect of production system. Using the developed model, postharvest stiffness changes were described in relation to the observed changes in β‐Gal and PG activity during storage.
Characterisation of wines and distilled spirits from melon (Cucumis melo L.)
Authors: Gómez Luis Fernando Hernández , Úbeda Juan , Briones Ana
Published: March 2008

Melon fermentation and distillation was studied with a view to produce melon spirits. Three different substrates were obtained from melon (Cucumis melo L.). Sugar concentration was around 60–70 g L−1 and the pH between 4.6 and 5.2. The substrates were clarified and then fermented at one of two pH levels at 20 °C. A commercial Saccharomyces cerevisiae starter culture was used to obtain melon wines with an alcohol concentration of 3.8–5.8% (v/v). The melon wines were distilled in a distillation column to yield distillates with an alcohol content of 33–60% (v/v). The major volatiles in the melon wines and in the distillates were analysed by gas chromatography (GC). The results demonstrated that melon could be a good substrate of fermentation and distillation but also yielded significant differences in the volatiles analysed in the different melon wines and distillates obtained from the different substrates in the different conditions of the experiment. Fermentation pH greatly affected the methanol, acetaldehyde, and butanol contents and thus the final quality of the spirits produced.
Composition, chemical and microbiological properties of Jordanian ovine organ meats
Authors: Abdullah Basem Mohd
Published: March 2008

Sheep livers, spleens, kidneys and hearts were taken from fifteen carcasses at a local slaughterhouse to study proximate composition, energy value, minerals content and chemical and microbiological characteristics. A wide range of weights was identified between organs and within one type of organ. Kidneys had the highest mean moisture and fat contents, while liver had the highest protein content, nitrogen‐free extract value, energy (kcal) values and the lowest pH value. The thiobarbituric acid value was highest in kidneys and lowest in livers. There was considerable variability of mineral content within and between organs. The aerobic plate counts were similar for all organs and numbers of Staphylococcus aureus were low, with little difference in number between organs.
Local excitation and interference of surface phonon polaritons studied by near‐field infrared microscopy
Authors: HUBER A.J. , OCELIC N. , HILLENBRAND R.
Published: March 2008

We demonstrate that mid‐infrared surface phonon polariton excitation, propagation and interference can be studied by scattering‐type near‐field optical microscopy (s‐SNOM). In our experiments we image surface phonon polaritons (SPPs) propagating on flat SiC crystals. They are excited by weakly focused illumination of single or closely spaced metal disks we fabricated on the SiC surface by conventional photolithography. SPP imaging is performed by pseudo‐heterodyne interferometric detection of infrared light scattered by the metal tip of our s‐SNOM. The pseudo‐heterodyne technique simultaneously yields optical amplitude and phase images which allows us to measure the SPP wave vector – including its sign – and the propagation length and further to study SPP interference. High resolution imaging of SPPs could be applied to investigate for example SPP focusing or heat transfer by SPPs in low dimensional nanostructures.
Plasmonic devices with controllable resonances – an avenue towards high‐speed and mass fabrication of optical meta‐materials
Authors: KURIHARA K. , ROCKSTUHL C. , PETIT S. , YAMAKAWA Y. , TOMINAGA J.
Published: March 2008

We report on the fabrication of plasmonic devices with adjustable resonances in the visible portion employing a thermal lithography method. The genuine approach enables the fabrication of nanostructured pattern at a spatial resolution comparable to other nanofabrication techniques, but at significantly larger speeds and over extended spatial domains. The fabricated structures consisted in periodically arranged nanoholes in a silver thin film and supported localized plasmon resonance (LPR) in the vicinity of 370 nm. Results from measured spectral properties were in good agreement with simulations based on rigorous diffraction theory. The method was evaluated towards a potential application to realize large‐scale meta‐materials with effective negative refractive index in the visible.
Controlling the plasmon resonance of single metal nanoparticles by near‐field anisotropic nanoscale photopolymerization
Authors: IBN‐EL‐AHRACH H. , BACHELOT R. , LÉRONDEL G. , VIAL A. , GRIMAULT A.‐S. , PLAIN J. , ROYER P. , SOPPERA O.
Published: March 2008

We propose a new approach for tuning the Surface Plasmon (SP) resonance wavelength using hybrid nanoparticles. Our approach is based on nanoscale photopolymerization around metal nanoparticles. The enhanced optical near‐field of silver nanoparticles triggers local photopolymerization. As a result, atomic force microscopy reveals two nanoscale polymerized lobes around nanoparticles, with a controlled effective index distribution. A spectral breaking degeneracy of surface plasmon resonance of the nanoparticles has been demonstrated by polarized extinction spectroscopy.
Near‐field investigation of porous silicon photoluminescence modification after oxidation in water
Authors: JUAN M. , BOUILLARD J.‐S. , PLAIN J. , LERONDEL G. , ADAM P. M. , BACHELOT R. , ROYER P.
Published: March 2008

We report on local photo‐induced oxidation of porous silicon in water at room temperature. Starting from a nonluminescent sample, the oxidation process induces luminescence which was found to first increase and then decrease as a function of the oxidation time. A clear blue shift is also observed. This effect is believed to be owing to size modification of silicon nanocrystallites and thus is explained in terms of quantum confinement. Optical near‐field images and spectrum are used to monitor the photoluminescence modifications after oxidation. As the photoluminescence can be widely tuned in wavelength and intensity, this method offers a way to pattern the emission properties of the sample.
A Poincaré's approach for plasmonics: the plasmon localization
Authors: BARCHIESI D. , KREMER E. , MAI V.P. , GROSGES T.
Published: March 2008

A Poincaré's approach is employed to characterize the excitation of a plasmon, which in essence corresponds to a zero of a complex S‐matrix. Throughout this work we study the plasmonic behaviour of gold, as this metal not only is frequently used in experimental arrays, but also requires an accurate dispersion model to properly excite plasmons. We investigate the plasmonic behaviour of gold nanogratings by means of Born's approximation and the Finite‐Elements Method. Also, a method based on the Poincaré's approach is proposed to optimize this kind of structures.
Cell wall investigations utilizing tip‐enhanced Raman scattering
Authors: BUDICH C. , NEUGEBAUER U. , POPP J. , DECKERT V.
Published: March 2008

Tip‐enhanced Raman scattering is used to investigate the surface structure of the cell wall of Staphylococcus epidermidis with high lateral resolution and chemical specificity. For most biological samples, the transmission tip‐enhanced Raman scattering set‐up is ideally suited because it allows the specimen to be kept under specific environmental conditions, whereas it most efficiently collects the signal created at the field‐enhancing probe. Special emphasis is given here to the parameters required to reproducibly set up the instrument, such that field‐enhancement factors can be estimated properly. Also the importance of control experiments to avoid misinterpretation of signals will be emphasized by an example.
Total internal reflection fluorescence microscopy study of spiral Ca2+ waves in single heart cell
Authors: BAI Y. , TANG A. , WANG S. , ZHU X.
Published: March 2008

Spiral wave phenomena exist in many scales of nature and have attracted the attention of scientists from different fields. Although much work has been done on qualitative analysis of spiral waves, the mechanism of spiral waves' spontaneous formation and termination in living systems is still not clear. Here, by using total internal reflection fluorescence microscopy, we show the spiral waves of calcium signals in single rat cardiac myocytes and the simulation of the waves comprising calcium sparks. The mechanism of the formation and termination of spiral waves is attributable to the calcium release channels' refractory resulting from their stochastic release. We suggest that this mechanism can be adapted to other living systems.
Study of the optical response of phase‐change recording layer with zinc oxide nanostructured thin film
Authors: KAO T. S. , FU Y. H. , HSU H. W. , TSAI D. P.
Published: March 2008

Recently, use of nanostructured materials as a near‐field optical active layer has attracted a lot of interest. The non‐linear optical properties and strong enhancements of metallic oxide nanostructured thin films are key functions in applications of promising nanophotonics. For the importance of ultra‐high density optical data storage, we continue investigating the ultra‐high density recording property of near‐field optical disk consisting of zinc oxide (ZnOx) nanostructured thin film. A carrier‐to‐noise ratio above 38 dB at a recording mark size of 100 nm can be obtained in the ZnOx near‐field optical disk by a DVD driver tester directly. In this article, we use an optical pump‐probe system (static media tester) to measure the optical response of a phase‐change recording layer (Ge2Sb2Te5) and demonstrate the high contrast of optical recording with a ZnOx nanostructured thin film in short pulse durations. Also, we investigate the dependence of writing power and the optical response in conventional re‐writable recording layers and the phase‐change material with ZnOx nanostructured thin film.