bluuebunny/crossref_metadata_2025 huggingface dataset:
Bet-hedging and epigenetic inheritance in bacterial cell development
Authors: Veening Jan-Willem , Stewart Eric J. , Berngruber Thomas W. , Taddei François , Kuipers Oscar P. , Hamoen Leendert W.
Published: March 2008

Upon nutritional limitation, the bacterium
Bacillus subtilis
has the capability to enter the irreversible process of sporulation. This developmental process is bistable, and only a subpopulation of cells actually differentiates into endospores. Why a cell decides to sporulate or not to do so is poorly understood. Here, through the use of time-lapse microscopy, we follow the growth, division, and differentiation of individual cells to identify elements of cell history and ancestry that could affect this decision process. These analyses show that during microcolony development,
B. subtilis
uses a bet-hedging strategy whereby some cells sporulate while others use alternative metabolites to continue growth, providing the latter subpopulation with a reproductive advantage. We demonstrate that
B. subtilis
is subject to aging. Nevertheless, the age of the cell plays no role in the decision of its fate. However, the physiological state of the cell's ancestor (more than two generations removed) does affect the outcome of cellular differentiation. We show that this epigenetic inheritance is based on positive feedback within the sporulation phosphorelay. The extended intergenerational “memory” caused by this autostimulatory network may be important for the development of multicellular structures such as fruiting bodies and biofilms.
Identification and Characterization of the Huanglongbing Bacterium in Pummelo from Multiple Locations in Guangdong, P. R. China
Authors: Deng X. , Chen J. , Feng Z. , Shan Z. , Guo H. , Zhu J. , Li H. , Civerolo E. L.
Published: March 2008

Huanglongbing (HLB, yellow shoot disease, ex. citrus greening disease), caused by Candidatus Liberibacter spp., is highly destructive to citrus production in Asia, Africa, and South America. Although primarily affecting sweet orange and mandarin, HLB has long been observed in pummelo in Guangdong Province, People's Republic of China; however, the disease in pummelo has received little research attention. Accordingly, it remains unclear how closely related the strains of Ca. Liberibacter in pummelo are to those in other citrus species. In this study, the loci of 16S rDNA, rplAJ (β-operon of ribosomal protein), and an outer membrane protein (omp) gene were analyzed and characterized among strains of Ca. Liberibacter in pummelo samples from six different locations in Guangdong. Sequence comparisons indicated that ‘Candidatus Liberibacter asiaticus’, but not ‘Ca. Liberibacter africanus’ or ‘Ca. Liberibacter americanus’, was exclusively associated with HLB symptoms in pummelo. The pummelo strains of ‘Ca. Liberibacter asiaticus’ from Guangdong were highly homogeneous. Analyses of single-nucleotide polymorphisms in the omp locus showed that the Guangdong pummelo strains grouped with ‘Ca. Liberibacter asiaticus’ strains from Thailand, Nepal, and an unspecified location in China but differed from the Philippine and China-Behai strains. Based on the sequence homogeneity at the omp locus, the history of pummelo culture and the means by which HLB is known to be spread, we believe that, likely, the pummelo strain of ‘Ca. Liberibacter asiaticus’ recently was spread to pummelo in the study areas from infected sweet orange or mandarin trees by insect vectors or by propagation of pummelo infected elsewhere.
Limiting Effects of Low Temperature on Growth and Spore Germination in Gibberella circinata, the Cause of Pitch Canker in Pine Species
Authors: Inman A. R. , Kirkpatrick S. C. , Gordon T. R. , Shaw D. V.
Published: March 2008

Pitch canker, caused by Gibberella circinata (anamorph = Fusarium circinatum), causes canopy dieback and mortality in susceptible pine species in many parts of the world. Pitch canker is most problematic in areas with a relatively warm climate, suggesting a possible limitation on disease development imposed by low temperatures. To test this hypothesis, the effect of temperature on radial growth was examined in isolates of G. circinata of diverse geographic origin. All isolates grew most rapidly at 25°C and progressively more slowly at 20, 15, and 10°C. Spore germination occurred most rapidly at 20°C and was slowest at 10°C. To determine if the time required for spore germination might influence the likelihood of infection, the duration of wound susceptibility was examined by inoculating branches of susceptible Monterey pines (Pinus radiata). In each of six field trials, branches were wounded and then inoculated immediately or at 2, 6, or 9 days after wounding. The results indicated that wounds inoculated immediately became infected at a significantly higher rate than those inoculated 2 days later. Thus, if low temperatures extend the time required for germination beyond this period, a reduced infection frequency would be expected. Such a limiting effect of temperature could help to explain the current distribution of pitch canker.
Differential Pathogenicity ofXanthomonas campestrispv.phaseoliandX. fuscanssubsp.fuscansStrains on Bean Genotypes with Common Blight Resistance
Authors: Mutlu N. , Vidaver A. K. , Coyne D. P. , Steadman J. R. , Lambrecht P. A. , Reiser J.
Published: March 2008

Both the common bacterial blight (CBB) pathogen (Xanthomonas campestris pv. phaseoli) and X. fuscans subsp. fuscans, agent of fuscous blight, cause indistinguishable symptoms in common bean, Phaseolus vulgaris. Yield losses can exceed 40%. Lack of information about the specificity between X. campestris pv. phaseoli strains and major quantitative trait loci (QTL) or alleles conferring resistance makes the task of identifying genetic changes in host–pathogen interactions and the grouping of bacterial strains difficult. This, in turn, affects the choice of pathogen isolates used for germplasm screening and complicates breeding for CBB resistance. Common bean host genotypes carrying various sources and levels of resistance to CBB were screened with 69 X. campestris pv. phaseoli and 15 X. fuscans subsp. fuscans strains from around the world. Differential pathogenicity of the CBB pathogen was identified on the 12 selected bean genotypes. The X. fuscans subsp. fuscans strains showed greater pathogenicity than X. campestris pv. phaseoli strains having the same origin. African strains were most pathogenic. The largest variation in pathogenicity came from X. campestris pv. phaseoli strains that originated in Caribbean and South American countries. Pathogenic variation was greater within X. campestris pv. phaseoli than within X. fuscans subsp. fuscans strains. Implications for breeding for CBB resistance are discussed.
Evaluation of QoI Fungicide Application Strategies for Managing Fungicide Resistance and Potato Early Blight Epidemics in Wisconsin
Authors: Rosenzweig N. , Atallah Z. K. , Olaya G. , Stevenson W. R.
Published: March 2008

Potato early blight (Alternaria solani) is a yield-limiting disease and control depends primarily on multiple fungicide applications. Azoxystrobin, registered in the United States in 1999, initially provided outstanding early blight control. Within 3 years, approximately 80% of the total potato acreage was being treated with azoxystrobin and other quinone outside inhibitor (QoI), fungicides registered subsequently. Alternaria solani isolates with decreased in vitro sensitivity to azoxystrobin were detected in Wisconsin during 2001. Field experiments were conducted in 2001 to 2003 to evaluate season-long fungicide programs and test fungicide resistance management strategies. The fungicide program recommended to growers at that time, which consisted of three applications of azoxystrobin for weeks 1, 3, and 5 alternated with applications of chlorothalonil at label recommended rates, was effective in controlling early blight when conditions were conducive to disease development. Mean sensitivity in vitro of A. solani isolates from fungicide efficacy field experiments in 2001 to 2003 was numerically highest for isolates from the untreated control plots, chlorothalonil-alone plots, or plots treated with three applications of azoxystrobin alternated with chlorothalonil compared with other treatments tested. Three single-nucleotide polymorphisms (SNPs) can cause the F129L substitution (TTC to TTA, CTC, or TTG) that results in decreased sensitivity to azoxystrobin of A. solani. The TTA mutant was the most frequently recovered mutant type in the field experiments. The frequency of recovery of wild-type isolates in experiments was 22% in 2001, 4% in 2002, and 22% in 2003.
Preemergence Infection of Potato Sprouts by Phytophthora infestans in the Highland Tropics of Ecuador
Authors: Kromann Peter , Taipe Arturo , Andrade-Piedra Jorge L. , Munk Lisa , Forbes Gregory A.
Published: March 2008

Experiments were conducted to determine whether preemergence infection of potato sprouts by Phytophthora infestans occurs in the highland tropics of Ecuador. In three separate experiments in the field, P. infestans was identified on the preemerged sprouts of 49, 5, and 43% of tubers, respectively, which had been removed from soil prior to emergence. Tubers had been planted within 10 m of approximately 300-m2 plots with mature potato plants severely infected with late blight. Infection potential of potato sprouts also was evaluated in the greenhouse by applying 10-ml sporangial suspensions (50 and 250 sporangia/ml) daily for 10 days to the soil surface of pots planted with sprouted seed potato tubers. The daily inoculation rate of 50 sporangia/ml (15.9 × 103 sporangia/m2) resulted in sprout infection in 100% of inoculated pots and roughly corresponded to the sporangial deposition accumulated over 24 h in the field. Deposition had been measured at 1 m from a severely infected potato plot. Our study demonstrated the potential for preemergence infection of potato sprouts by P. infestans in the highlands of Ecuador, where year-round aerial inoculum is present. Preemergence infection is consistent with high levels of disease sometimes seen in recently emerged potato fields. These experiments indicate a need to reconsider disease management approaches.
Influence of Beet necrotic yellow vein virus on Sugar Beet Storability
Authors: Strausbaugh Carl A. , Rearick Eugene , Camp Stacey , Gallian John J. , Dyer Alan T.
Published: March 2008

Rhizomania caused by Beet necrotic yellow vein virus (BNYVV) and storage losses are serious sugar beet production problems. To investigate the influence of BNYVV on storability, six sugar beet cultivars varying for resistance to BNYVV were grown in 2005 and 2006 in southern Idaho fields with and without BNYVV-infested soil. At harvest, samples from each cultivar were placed in an outdoor ventilated pile in Twin Falls, ID and were removed at 40-day intervals starting at the end of October. After 144 and 142 days in storage, sugar reduction across cultivars averaged 20 and 13% without and 68 and 21% with BNYVV for the 2005 and 2006 roots, respectively. In the December samplings, frozen root area was 1 and 2% without and 25 and 41% with BNYVV for the 2005 and 2006 roots, respectively. Root rot was always worse with stored roots from BYNVV-infested soil in December, January, and February samplings. Root weight loss was variable in 2005; however, in 2006, an increase in weight reduction always was associated with BNYVV-infested roots. In order to prevent losses in rhizomania-infested areas, cultivars should be selected for storability as well as rhizomania resistance.
Effect of Cauliflower Residue Amendments and Soil Solarization on Verticillium Wilt Control in Artichoke
Authors: Berbegal M. , García-Jiménez J. , Armengol J.
Published: March 2008

The effect of fresh cauliflower residue amendment alone and with a low dose of metham sodium (MS) combined with soil solarization was investigated for the control of Verticillium wilt of artichoke in two commercial fields under artichoke–cauliflower rotation. Treatments were a factorial combination of three main plots (an unamended control, soil amended with cauliflower residue, and a combination of cauliflower residue and a low dose of MS) and two subplots (application of a plastic cover or uncovered). Inoculum densities of Verticillium dahliae were measured before and after soil treatments as well as disease incidence, symptom severity, and yield. Although soil solarization reduced inoculum of V. dahliae and the incidence of Verticillium wilt of artichoke, no added benefit was obtained when solarization was used with cauliflower residue amendments. In addition to toxic volatile compounds, other mechanisms could be involved in disease suppression because the effects of incorporating cauliflower residue were not enhanced by the plastic covering. The effect of cauliflower residues on populations of V. dahliae microsclerotia in soil was inconsistent, possibly due to varying pretreatment inoculum levels. Treatments with cauliflower residue amendments and low doses of MS maintained low inoculum densities in the fields until the end of the growing season and significantly reduced the percentage of infected plants.
First Report of Rhizoctonia solani Subgroup AG 1-ID Causing Leaf Blight on Durian in Vietnam
Authors: Thuan T. T. M. , Tho N. , Tuyen B. C.
Published: March 2008

During the rainy season in Vietnam, leaf blight disease caused by Rhizoctonia solani often occurs on 3- to 5-year-old durian (Durio zibethinus). Symptoms appear as large, pale brown, blighted lesions with an irregular border. In excessive moisture conditions, yellowish white hyphae appear on the lesions, and the affected leaves turn dark brown and wilt. There are no reports describing the anastomosis groups (AG) and subgroups of Rhizoctonia solani occurring in durian. In June of 2004, two isolates of R. solani were obtained from leaf blight lesions on durian growing in Binh Duong and Dong Nai provinces. The durian isolates were identified as AG 1 based on hyphal anastomosis. In pathogenicity tests, the durian isolates infected cucumber, mung bean, and leaf mustard seedlings grown on water agar in petri dishes. The rDNA-ITS sequence of the durian isolates was determined (GenBank Accession Nos. EF197797 and EF197798) and aligned with those of AG 1-IA, AG 1-IB, AG 1-IC, and AG 1-ID available in the GenBank database. The sequence similarity of the total rDNA-ITS region (including 5.8S) within the durian isolates was 99.9%. The sequence similarity of the durian isolates and AG 1-ID isolates was 99.1 to 100%, but similarity with other AG 1 subgroups was 89.1 to 94.0%. The results suggest that the two Vietnam durian isolates of R. solani are members of AG 1-ID. AG 1-ID has only been reported causing necrotic leaf spots on coffees in the Philippines (1). To our knowledge, this is the first report of R. solani AG 1-ID on durian and the first report of the presence of R. solani AG 1-ID in Vietnam.

Reference: (1) A. Priyatmojo et al. Phytopathology 91:1054, 2001.
First Report of Angelonia flower break virus in Nemesia spp. and Other Ornamental Plants in California
Authors: Mathews D. M. , Dodds J. A.
Published: March 2008

Between June 2006 and July 2007, ornamental plant samples were collected from four counties in California (Riverside, Sacramento, San Diego, and Santa Barbara) and tested for the presence of Angelonia flower break virus (AnFBV) using ELISA (Agdia, Inc., Elkhart, IN). Tissue samples were from propagation facilities or wholesale outlets except those from Riverside County, which were from retail stores. Thirteen positive samples were found in three varieties each of Angelonia and Nemesia spp. and seven varieties of Verbena spp., with at least one positive from each county. Foliar symptoms ranged from asymptomatic to a mild mosaic with distinct flower breaking in the Angelonia spp. Results were confirmed by reverse transcription (RT)-PCR of the coat protein gene (1) and the 1,172-bp amplicons were sequenced. Viral isolates from the three varieties of the Angelonia spp. had 98 to 99% nucleotide similarity and 99 to 100% amino acid identity to the Maryland strain of AnFBV (1; GenBank Accession No. DQ221212), with 91 to 92% nucleotide similarity and 96 to 97% amino acid identity to the Israel and Florida strains (GenBank Accession Nos. DQ223771 and DQ219415). All viral isolates from the Nemesia and Verbena spp. plants had nucleotide similarities of 96 to 98% and 98% amino acid identity to the Israel and Florida strains, with 91 to 92% nucleotide similarity to the Maryland strain. AnFBV has been previously reported in Angelonia and Verbena spp. among other hosts (1,2), but not in Nemesia spp. and not in California. This recently described carmovirus appears to be well established in the state in a variety of ornamental plant species.

References: (1) S. Adkins et al. Phytopathology 96:460, 2006. (2) F. Assis-Filho et al. Plant Dis. 90:1115, 2006.
First Report of Stemphylium vesicarium as Causal Agent of Wilting and Root Rotting of Radish Sprouts in Italy
Authors: Belisario A. , Vitale S. , Luongo L. , Nardi S. , Talevi S. , Corvi F.
Published: March 2008

A consistent contamination from a Stemphylium sp. was detected on radish (Raphanus sativus) seeds by a seed blotter test. Twenty-five percent of seed lots were contaminated. Stemphylium vesicarium (teleomorph Pleospora allii) was identified on the basis of morphological characters of conidia and conidiophores (4). Conidia were golden brown to dark drown, oblong to oval with one to four transverse and one to three longitudinal septa, constricted at one to three of the major transverse septa. Conidia dimensions ranged from 12 to 22 × 30 to 40 μm. Conidiophores were straight or occasionally one-branched with a swollen apex and one to four septate. Pseudothecia with asci and ascopores were observed on radish seeds. Asci were cylindrical to clavate with eight ascospores with up to six transverse septa and numerous longitudinal septa. Species identification was also confirmed after comparing the sequences of the internal transcribed spacer (ITS) region of rDNA and gpd (glyceraldehyde-3-phosphate dehydrogenase) (3) of four isolates with those of Stemphylium species already present in the NCBI database. Accessions Nos. AM 746020 to AM746023 and AM883174 to AM883177 were deposited for ITS and gpd, respectively. Artificial inoculations were carried out on radish seeds previously disinfected with 1% sodium hypochlorite for 10 min and then plated on S. vesicarium sporulating colonies grown on potato dextrose agar (PDA). The four sequenced isolates were tested for pathogenicity. Disinfected seeds were plated onto PDA only and used as a control. After 48 h of incubation, seeds were sown in sterilized soil in plastic plates. The emerging and the eventually dead plants were counted. Stem necrosis and root rotting developed on sprouts within the first week after sowing. On the surviving infected plantlets, wilting and death occurred on more than 70% of the plants within 4 weeks after sowing. Control plantlets obtained from disinfected seeds remained healthy. The fungus reisolated from wilted and dead plants was morphologically identical to the original isolates, thus confirming S. vesicarium as the causal agent. In Italy, this pathogen is common on asparagus (1), but it has also been reported on Allium spp., tomato, and pear. On European pear it is the causal agent of brown spot (2), a destructive disease in the Mediterranean area but also in the Netherlands and other continental European countries. On the basis of these results, seed contamination with S. vesicarium can represent a threat for the production of radish for sprout consumption. To our knowledge, this is the first report of S. vesicarium on radish plantlets in Italy.

References: (1) F. Del Zan et al. L'informatore Agrario 11:95, 1989. (2) I. Llorente and E. Montesinos. Plant Dis. 90:1368, 2006. (3) B. M. Pryor and D. M. Bigelow. Mycologia 95:1141, 2003. (4) E. G. Simmons. Sydowia 38:284, 1985.
Resistance to Citrus Canker Caused by Xanthomonas axonopodis pv. citri in an Accession of Citrus sp. Similar to Grapefruit
Authors: Gochez A. M. , Canteros B. I.
Published: March 2008

Citrus canker is caused by Xanthomonas axonopodis pv. citri. All grapefruit (Citrus paradisi Macf.) cultivars are highly susceptible to the A-group strains of Xanthomonas axonopodis pv. citri. A type of grapefruit (Citrus sp.) called Dalan Dan (DD) has shown high resistance in the field in Misiones, Argentina where it is widely planted. The DD is Accession No. NC678 in the Campinas Citrus Germplasm Collection (Centro APTA Citrus Sylvio Moreira, Cordeiropolis, SP, Brazil) and Accession No. CCC-618 Dalan Dan in the Argentina Citrus Germplasm Collection at INTA (Concordia, Entre Ríos). Molecular studies completed in Brazil have shown high similarities among grapefruit varieties and DD (1). We report here the characterization of quantitative resistance to citrus canker in DD. Quantitative resistance in citrus is expressed as lower number of lesions per leaf area (3). Lesions per square centimeter were calculated after 3 to 4 weeks of two sets of inoculation of three inoculum levels (5 × 102, 2.5 × 103, and 5 × 103 cells per ml) in leaves of developing leaf flushes. The period of greatest susceptibility in DD was 15 to 23 days for the three inoculum levels; 1.35 ± 0.34 to 0.01 ± 0.01, 4.98 ± 0.91 to 0.91 ± 0.48, and 9.85 ± 2.17 to 1.91 ± 1.37 lesions per cm2, respectively. By contrast, the period of greatest susceptibility in grapefruit cv. Duncan was 15 to 29 days for the same three inoculum levels; 2.78 ± 0.46 to 1.22 ± 0.39, 17.29 ± 2.79 to 5.55 ± 0.93, and 22.87 ± 3.27 to 11.95 ± 3.55 lesions per cm2, respectively. The results shown here suggest that the DD citrus accession is susceptible to citrus canker for a very short time during the development of leaf flushes, which results in very high resistance in the field. This citrus germplasm material could be valuable as a source of resistance to improve other varieties or as a replacement of grapefruit due to the similar fruit and juice qualities.

References: (1) M. J. Corazza-Nunes et al. Euphytica 126:169, 2002. (2) M. J. Corazza-Nunes et al. Summa Phytopathol. 32:322, 2006. (3) R. E. Stall et al. Phytopathology 72:1097, 1982.
First Report of Ascochyta Leaf Spot Caused by Phoma exigua var. exigua on Common Bean in Greece
Authors: Bardas G. A. , Tziros G. T. , Tzavella-Klonari K.
Published: March 2008

Common bean (Phaseolus vulgaris L.) is cultivated extensively in Greece for dry and fresh bean production. During 2005 and 2006, a disease with typical blight symptoms was observed occasionally on dark red kidney, brown kidney, and black bean plants in most bean-producing areas of Greece. It rarely was destructive unless the crop had been weakened by some unfavorable environmental conditions. Infected leaves had brown-to-black lesions that developed concentric zones 10 to 30 mm in diameter and also contained small, black pycnidia. Concentric dark gray-to-black lesions also appeared on branches, stems, nodes, and pods. Infected seeds turned brown to black. Plants sometimes showed defoliation and pod drop. The fungus was consistently isolated on potato dextrose agar from diseased leaves and pods and identified as Phoma exigua var. exigua Sutton and Waterstone on the basis of morphological characteristics of conidia and pycnidia (1,2). Spores were massed in pycnidia from which they were forced in long, pink tendrils under moist weather conditions. Conidia were cylindrical to oval, allantoid, hyaline, pale yellow to brown, usually one-celled, and 2 to 3 × 5 to 10 μm. To satisfy Koch's postulates, a conidial suspension (1 × 106 conidia per ml) of the fungus was sprayed onto leaves and stems of bean seedlings (first-leaf stage) (cv. Zargana Hrisoupolis). Both inoculated and control seedlings (inoculated with sterile water) were covered with plastic bags for 72 h in a greenhouse at 23°C. Inoculated plants showed characteristic symptoms of Ascochyta leaf spot 12 to 15 days after inoculation. The fungus was reisolated from lesions that developed on the leaves and stems of all inoculated plants. The pathogen is present worldwide on bean. To our knowledge, this is the first report of P. exigua var. exigua on common bean in Greece.

References: (1) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory. Online publication. ARS, USDA, 2007. (2) B. C. Sutton and J. M. Waterstone. Ascochyta phaseolorum. No. 81 in: Descriptions of Pathogenic Fungi and Bacteria. CMI/AAB, Kew, Surrey, England, 1966.
First Report of Cactodera milleri in Wisconsin
Authors: Schroeder N. E. , Gerhardt D. J. , Phibbs A. , MacGuidwin A. E.
Published: March 2008

During the summer of 2005, lemon-shaped cysts and second-stage juveniles of a cyst nematode were recovered from soil at the University of Wisconsin Agricultural Research Station in Hancock, WI. Samples were collected on multiple dates from a plot (61 × 12 m) in continuous potato production for 20 years with significant weed pressure. PCR-restriction fragment length polymorphism profiles of the internal transcribed spacer (ITS) 1 region using restriction enzyme HhaI indicated Cactodera spp. (2). Morphological observations and morphometrics made on cysts, males, J2s, and eggs were consistent with Cactodera milleri Graney and Bird, 1990 (1). Host range studies were conducted in a growth chamber. Soybean, potato, and beet did not support nematode development and reproduction. Common lambsquarters (Chenopodium album), a known host of C. milleri, was an excellent host. No obvious aboveground disease symptoms were evident on lambsquarters in the growth chamber assay. This detection represents the first record of C. milleri in Wisconsin. Unless detailed morphological or molecular measurements are made, C. milleri may be easily confused with the soybean cyst nematode, Heterodera glycines. The presence of lambsquarters in fields planted with glyphosate-resistant soybeans makes the recovery of both nematode species in a single soil sample possible.

References: (1) L. S. O. Graney and G. W. Bird. J. Nematol. 22:457, 1990. (2) A. L. Szalanski et al. J. Nematol. 29:255, 1997.
Immediate memory consequences of the effect of emotion on attention to pictures
Authors: Talmi Deborah , Anderson Adam K. , Riggs Lily , Caplan Jeremy B. , Moscovitch Morris
Published: March 2008

Emotionally arousing stimuli are at once both highly attention grabbing and memorable. We examined whether emotional enhancement of memory (EEM) reflects an indirect effect of emotion on memory, mediated by enhanced attention to emotional items during encoding. We tested a critical prediction of the mediation hypothesis—that regions conjointly activated by emotion and attention would correlate with subsequent EEM. Participants were scanned with fMRI while they watched emotional or neutral pictures under instructions to attend to them a lot or a little, and were then given an immediate recognition test. A region in the left fusiform gyrus was activated by emotion, voluntary attention, and subsequent EEM. A functional network, different for each attention condition, connected this region and the amygdala, which was associated with emotion and EEM, but not with voluntary attention. These findings support an indirect cortical mediation account of immediate EEM that may complement a direct modulation model.
Comparison of two basophil activation markers CD63 and CD203c in the diagnosis of amoxicillin allergy
Authors: Abuaf N. , Rostane H. , Rajoely B. , Gaouar H. , Autegarden J. E. , Leynadier F. , Girot R.
Published: March 2008

Background
To confirm allergy to β‐lactam (BL), a basophil activation test in flow cytometry based on CD63 up‐regulation was described. CD203c is a more recent basophil activation marker and up to day there is no consensus about which marker is the more sensitive one. CD203c has not yet been evaluated in the diagnosis of BL allergy.

Objective
The aim of the study was to compare the reliability of CD203c to CD63 for the diagnosis of amoxicillin (AX) allergy, which is nowadays the most frequent BL allergy.

Methods
Twenty‐seven patients with an immediate positive skin test (ST) to AX, 20 had had anaphylaxis with AX and 7 had urticaria and/or angioedema, were compared with 14 controls with no allergy to BL and to six patients with delayed positive ST to AX.

Results
In the anaphylaxis group, AX induced up‐regulation of CD203c in the basophils of 12 patients out of 20 (60%) and of CD63 in four patients (20%) (P<0.02). Two patients out of seven with urticaria or angioedema had a positive result with CD203c and CD63. In patients who had anaphylaxis, ampicillin (AMP) induced CD203c up‐regulation in eight out of 12 (67%) patients tested, and CD63 up‐regulation in 4 out of 12 (33%) (all patients who had anaphylaxis could not be tested with AMP). False‐positive results were observed with CD203c as well as CD63, and for 10 patients indeed this was confirmed by a negative drug provocation test. The origin of conflicting results between CD63 and CD203c might be at least the targeting of basophils based on anti‐IgE labelling. Among IgE+ gated cells, by means of CD33, a marker of monocytes, a contamination up to 50% by monocytes was detected. In contrast to CD63, CD203c is an activation marker specific of basophils with a basal low‐level expression in resting basophils. Thus, IgE and CD203c double targeting of basophils avoids the contamination by monocytes.

Conclusion
CD203c seems to be a more sensitive activation marker of basophils than CD63 for the diagnosis of amoxicillin allergy.
The use of peepers to sample pore water in acid sulphate soils
Authors: VanOploo P. , White I. , Macdonald B. C. T. , Ford P. , Melville M. D.
Published: March 2008

Serious environmental impacts of acidic drainage from acid sulphate soils in coastal areas are the result of the interactions between the hydrologic cycle, land use and drainage management, and pore water chemistry. In this study, in situ, diffusion‐controlled dialysis profile samplers, or peepers, were used to examine pore water chemistry of acid sulphate soils in a coastal, sugarcane‐producing area in Eastern Australia. The peepers sampled pore water at 20‐mm intervals over a 1.0‐m length, permitting excellent resolution of the sharp transitions in pore water chemistry that occur around a soil profile’s iron sulphide oxidation front. Comparison of peeper profiles with soil water profiles extracted from soil samples by centrifuging, illustrated the advantages of peepers over conventional soil water sampling techniques in unconsolidated, sulphidic soils. For conventional sampling, the low permeability, gel‐like, unoxidized soil samples had to be frozen then thawed before water could be extracted by centrifuging. Peeper profiles of species not involved in redox reactions agreed well with those from centrifuged soil extracts. Redox sensitive species, however, were in poorer agreement because of the lengthy soil sample preparation and extraction procedures required for extraction by centrifuging. The approximately 6‐day equilibration time required for peeper sampling allows them to follow monthly or seasonal changes in pore water chemistry in acid sulphate soils due to variations in climate, and land use and management.
Specific Fab fragments recovered by phage display technique recognizing human spermatozoa
Authors: Fiszer Dorota , Pupecka Małgorzata , Schmidt Katarzyna , Rozwadowska Natalia , Kamieniczna Marzena , Grygielska Beata , Kurpisz Maciej
Published: March 2008

Human hybridoma cell lines are often unstable and loose ability for antibody production. Sometimes, they show low and varying levels of heavy and light chains synthesis. Therefore it is reasonable to preserve generated specificities of light and heavy chains by cloning them to phagemid vector and creating phage display library. The aim of this study was to construct phage display library of Fab fragments recognizing sperm surface antigens. The source of mRNA constituted seven hybridoma cell lines producing antisperm antibodies which was proved by ELISA, and agglutination test as well as by inhibition of sperm to penetrate hamster oocytes. Fragments of cDNA encoding κ/λ and γ chains were cloned into pComb3HSS phagemid vector and amplified in XL‐1Blue. The library was panned against whole unfixed sperm cells. Three positive clones selected after fourth round of panning showed heavy chain belonging to VH4 family, two of them (G28, K61) possessed lambda chain from VL2 family and one (H43) kappa chain from VK1 family. As these Fabs revealed similarities to antibodies against some proteins involved in sperm motility and cell fusion it can be suggested that these Fabs may be a cause of infertility. Finally, we proved that it is feasible to preserve specificities produced by human hybridomas using phage display technique and we recovered some Fabs which may be of diagnostic and research value, and may also have some value for contraceptive vaccine.
Some artefacts of the approaches with the discretization in near‐field optics calculations
Authors: BORTCHAGOVSKY E.G.
Published: March 2008

This article is devoted to an observation artefact arising in near‐field optical calculations by methods with the discretization of a scattering object and the substitution of separated dipoles instead of discretizing meshes. It is discussed that such an artificial discretization gives within the object a non‐monotonously changing field on the scale of the discretizing mesh size, which propagates from the object to a distance of the same order of magnitude as the mesh size in contrast to the real situation where such a non‐monotonously changing fields exist on the scale of a real atomic lattice. If such a non‐monotonously changing field exists in the observation plane where the picture is calculated, the choice of the observation points can change the obtained picture remarkably.
Nano‐Raman mapping of a porous glass‐ceramic SERS substrate in collection mode
Authors: ZAVALIN A. , CRICENTI A. , GENEROSI R. , LUCE M. , MORGAN S. , PISTON D.
Published: March 2008

Porous glass‐ceramics is an extremely important material to be used in combination with metallic nanolayers as a Surface‐Enhanced Raman Scattering (SERS) substrate for biological and chemical analysis, demonstrating excellent biocompatibility and chemical inertness. These materials show their own Raman background signal lateral distribution, mostly from crystalline skeleton, which has to be considered. A nano‐Raman setup using the optical fibre of a Scanning Near‐Field Optical Microscope (SNOM), working in collection mode, is described and applied for mapping of such glass‐ceramic. The collected Raman signal of Ti and P containing phase distribution in this near‐field geometry reaches spatial resolution around 50 nm.
Study of surface plasmon polaritons near the photonic‐bandgap edge for interphotonic band switching devices
Authors: ONUKI T. , OHTERA Y. , TOKIZAKI T.
Published: March 2008

The photonic energy band structures near the bandgap edges of surface plasmon polariton in dielectric lattice structures on a smooth silver film were studied. At the bandgap edges, sharp changes of the surface plasmon polariton's transmittance arise owing to small changes in the refractive index around the lattice structure, which results in the band transition between the pass band and the stop band. On the analogy of ‘the phase transition’ between the surface plasmon polariton's conductive phase and the insulation phase, the surface plasmon polariton's phase diagram of the 1D lattice structure at a single frequency (λ≈ 780 nm) with parameters of the pitch and the refractive index of lattice were investigated. At the boundary, the most sensitive transition was found between the second pass band and the first stop band, with the ∼0.5 lattice filling factor. The surface plasmon polariton's phase state has been determined by far‐field observation using an optical microscope.
Caustics in a field negatively refracted at a plane interface
Authors: SHENDELEVA M. L.
Published: March 2008

An electromagnetic field radiated by a line source situated near a plane interface between a medium with positive refractive index and a medium with negative refractive index is considered by using the geometrical optics approach. Rays and wave fronts of the refracted field are constructed using Fermat's principle. It is shown that the negatively refracted rays intersecting in pairs create 2‐fold caustics that meet at a cusp point. The cusp of the caustic is directed towards the interface for |n| > 1 and away from the interface for |n| < 1, where n is the relative refractive index. It is also shown that wave fronts of the refracted field propagate towards the interface, in the direction from negative to positive optical path lengths.
Numerical study of optical nanolithography using nanoscale bow‐tie–shaped nano‐apertures
Authors: WANG L. , XU X.
Published: March 2008

Contact lithography using bow‐tie–shaped nano‐apertures was recently demonstrated to achieve nanometer scale resolution. In this work, the detailed field distributions in contact nanolithography are analyzed using finite difference time domain simulations. It was found that the high imaging contrast, which is necessary for successful lithography, is achieved close to the mask exit plane and decays quickly with the increase of the distance from the mask exit plane. Simulations are also performed for comparable regular‐shaped apertures and different shape bow‐tie apertures. Design rules are proposed to optimize the bow‐tie aperture for producing a sub‐wavelength, high transmission field with high imaging contrast.
SNOM images of X‐ray radiographs at nano‐scale stored in a thin layer of lithium fluoride
Authors: OLIVA C. , USTIONE A. , ALMAVIVA S. , BALDACCHINI G. , BONFIGLI F. , FLORA F. , LAI A. , MONTEREALI R.M. , FAENOV A.YA. , PIKUZ T. A. , FRANCUCCI M. , GAUDIO P. , MARTELLUCCI S. , RICHETTA M. , REALE L. , CRICENTI A.
Published: March 2008

In this work, we report a method to observe soft X‐ray radiographs at nanoscale of various kind of samples, biological and metallic, stored in a thin layer of lithium fluoride, employing scanning near‐field optical microscopy with an optical resolution that reaches 50 nm. lithium fluoride material works as a novel image detector for X‐ray nano‐radiographs, due to the fact that extreme ultraviolet radiation and soft X‐rays efficiently produce stable point defects emitting optically stimulated visible luminescence in a thin surface layer. The bi‐dimensional distribution of the so‐created defects depends on the local nanostructure of the investigated sample.
Fluorescent two‐photon nanolithography
Authors: KUNIK D. , LUDUEÑA S.J. , COSTANTINO S. , MARTÍNEZ O.E.
Published: March 2008

Improving the excitation conditions in two‐photon fluorescent lithography reduces the size of the fabricated structures to nanometre scales. We demonstrate that a precise control of the illumination profile and the scanning speed of the laser beam is enough to decrease the photo‐polymerization volume of resins by orders of magnitude. This work also shows experimental evidence of surface effects that yield a different polymerization intensity threshold compared with bulk. Such phenomenon enables to perform a non‐linear optical nanolithography in a simple way, allowing fast‐prototyping procedures. We present a detailed study of the polymer growth process using fluorescence and atomic force microscopy.
Studies of house‐entering habits of mosquitoes in The Gambia, West Africa: experiments with prefabricated huts with varied wall apertures
Authors: SNOW W. F.
Published: March 2008

ABSTRACT. The house‐entering behaviour of nocturnal mosquitoes was studied in The Gambia. Mosquitoes were captured as they attacked man in the open and in experimental huts which comprised 1.8 m cube frames with corrugated iron roofs and plywood walls of various heights. Catches of all species were similar in the open and in a roofed, but unwalled, hut frame. The mosquitoes taken in catches in unwalled huts and others with wall heights of 0.6,1.2 and 1.7 m (giving an 8 cm eaves‐level entry slit) fell into two categories. The first group, which included the endophilic species Anopheles gambiae Giles s. I., An.melas Theobald and Mansonia spp. were only slightly affected by increasing wall height, but the second group, including the exophilic mosquitoes Aedes spp., An.pharoensis Theobald, Cx poicilipes (Theobald) and Cx thalassius Theobald showed a very marked progressive exclusion. In comparisons of catches in two huts with 8 cm entry slits at eaves or ground level, large numbers of An.pharoensis found access through the ground level entry but not at eaves level. No consistent difference could be demonstrated for other species. It is concluded that the house‐entering behaviour which distinguishes endophagic mosquito species includes at least two distinct responses: flight upwards to eaves level and the passage from outside to indoors. It is also suggested that house entry as a component in host‐seeking behaviour and indoor resting are distinct, but not necessarily exclusive, behavioural traits.
The Beffa form of Simulium soubrense of the S.damnosum complex in Togo and Benin
Authors: CHEKE R. A. , GARMS R. , OUEDRAOGO J. , SOMÉ A. , SOWAH S.
Published: March 2008

ABSTRACT. The Beffa form of Simulium soubrense Vajime & Dunbar, a member of the S.sanctipauli sub‐complex of the S.damnosum complex, was found breeding throughout rivers in the Togo‐Benin Gap, as far north as 9o30'N. Its distribution changed with the season. In southern Togo there were seasonal fluctuations in the relative abundancies of the Beffa form and of S.damnosumlS.sirbanum. There was considerable temporal and regional variation in the frequencies of different colour morphs of adult flies. The flies in Benin tended to be darker. Infections with Onchocerca volvulus (Leuckart) appeared to be independent of the host's colour morph category. Larger flies harboured significantly more first stage Onchocerca larvae but no significant relations with fly size were found for second and third stage larvae.
The relative efficacy of repellents against mosquito vectors of disease
Authors: CURTIS C. F. , LINES J. D. , IJUMBA J. , CALLAGHAN A. , HILL N. , KARIMZAD M. A.
Published: March 2008

Abstract. Laboratory tests of insect repellents by various different methods showed that An.stephensi Liston was consistently more susceptible than An.gambiae Giles, An.albimanus Wiedemann or An.pulcher‐rimus Theobald. The six repellents tested were di‐ethyl toluamide (deet), di‐methyl phthalate (DMP), ethyl‐hexanediol, permethrin, citronella and cedarwood oil. Testing systems in which the mosquitoes were presented with a choice gave consistently lower ED50 values than when there was no choice, i.e. the standards of tolerance are not absolute but depend on the options available. In field tests in an experimental hut a curtain with a high dose of di‐ethyl toluamide (deet) reduced biting in the hut but had to be re‐impregnated frequently. Deet‐impregnated anklets gave about 84% protection against Culex quinquefasciatus Say for 80 days after one impregnation, in a trial in which the anklets were brought out of sealed storage and tested for 2 h nightly. Similar protection was found against An.funestus Giles but the protection against An.gambiae s.L, An.coustani Laveran and Mansonia spp. was not as good. There were highly significant differences between the four collectors' mosquito attractiveness but this varied highly significantly between the mosquito species.
Microdistribution of immature African blackflies resulting from water velocity and turbulence preferences
Authors: ROBERTS D. M. , OKAFOR B. C.
Published: March 2008

Abstract. 1. The velocity preferences of larval and pupal blackflies were studied experimentally by comparing the colonization of plastic strings placed in different velocity ranges; and also by investigating the simuliid microdistribution under natural conditions in the river. This required a novel method described for taking spot measurements of water velocity.

2. Simulium mcmahoni de Meillon, S.hirsutum Pomeroy and S.cervicor‐nutum Pomeroy were most abundant in slow velocities (0.3‐1.0 m s_1), S.colasbelcouri Grenier & Ovazza and S.hargreavesi Gibbins preferred 1.1‐1.8 m s_1, S.squamosum Enderlein and S.vorax Pomeroy 1.9‐2.2 m s_1.

3. The larvae of S.hargreavesi and S.cervicornutum preferred a higher velocity range compared with their pupae.

4. In moderate velocities (1.1‐1.4 m s_1), the abundance of S.hargreavesi was greater under turbulent conditions than in smooth‐flowing water, but this was reversed at very high velocities (2.3‐2.6 m s_1).

5. Velocity had no apparent effect on substrate preference when substrates of different flexibilities were compared for three blackfly species. All avoided the most flexible substrates and preferred ones consisting of rigid articulating plates. Anisopteran predators were found to have a similar substrate choice.
Induction of salivation in biting midges and mosquitoes, and demonstration of virus in the saliva of infected insects
Authors: BOORMAN J.
Published: March 2008

Abstract. Culicoides biting midges and Aedes aegypti (Linnaeus) mosquitoes were induced to salivate by the topical application of pilocarpine, neostigmine, malathion and dimethoate; of these, malathion was the most effective. Drops of saliva produced by virus‐infected midges and mosquitoes were shown to contain virus. The method could be used to demonstrate transmission in insects infected with a variety of pathogens.
Proteolytic activity in the ectoperitrophic fluid of blood‐fed Culex nigripalpus
Authors: HANDEL EMILE VAN , ROMOSER WILLIAM S.
Published: March 2008

Abstract. In blood‐fed Culex nigripalpus Theobald, proteolytic activity appeared in the ectoperitrophic fluid after 3 h, but only after 6 h in a homogenate of the blood‐filled midgut. The activity continued to be higher in ectoperitrophic fluid than in whole gut homogenate until about 40 h after the meal, when most of the intact clot had disappeared. Apparently, undigested blood inhibits proteolytic activity. The blood clot lacked activity and the inhibitor could not be removed by washing. The results are compatible with a hypothesis that the peritrophic membrane separates the digestion from the ingestion compartment.
Tsetse ecology in a Liberian rain‐forest focus of Gambian sleeping sickness
Authors: KAMINSKY RONALD
Published: March 2008

Abstract. Investigations on tsetse ecology were undertaken in Bong County of Liberia during the dry season, October 1981 to February 1982, around villages where the human infection rate with Trypanosoma brucei gambiense Dutton was about 2%. Most tsetse captured in biconical traps were Glossina palpalis Robineau‐Desvoidy and G.pallicera Bigot, with relatively few G.fusca Walker and G.nigrofusca Newstead.

Swamps and water‐gathering places were predominant habitats of all four species, but tsetse were also found in coffee and cocoa plantations.

Breeding‐places of G.palpalis were found in the leaf axils of oilpalm trees (Elaeis guineensis Jacquin), especially beside paths where people would risk being bitten. Bloodmeals of twenty‐nine wild‐caught G.palpalis were identified as mostly from man (fifteen) and bushbuck (Tragelaphus scriptus (Pallas)) or other wild ruminants (eleven), plus three from reptiles. It is concluded that man may be the principal host of tsetse in the area, while man or bushbuck could be the main reservoir to T. b.gambiense infection.

Most of the activity of G.palpalis occurs in the early afternoon from noon to 16.00 hours. Mean life‐span of G.palpalis and G.pallicera, estimated from wing‐fray age‐groups, was consistent with the females, and to a lesser degree the males, having vector potential.