bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface-directed differentiation of embryonic stem cells
Authors: Hanley E. , Lauer J. L. , Micales B. K. , Lyons G. E. , Shohet J. L.
Published: May 2008

Here, we explore how embryonic stem-cell (ESC) differentiation patterns on surfaces are affected by changes in the processing parameters of plasma-polymerized materials. Mouse ESCs were plated on plasma-polymerized tetraethylene glycol dimethyl ether (tetraglyme) surfaces on glass. Depending on the processing conditions, the plated ESCs precociously express the platelet endothelial cell adhesion molecule and von Willebrand Factor genetic markers which indicate directed differentiation of some ESCs into endothelial cells. The surface properties show that a larger fraction of directed differentiation takes place when the plasma-induced surface chemistry includes a branched ether bond and higher carbon-to-oxygen ratios.
Thermal conductivity reduction in oxygen-deficient strontium titanates
Authors: Yu Choongho , Scullin Matthew L. , Huijben Mark , Ramesh Ramamoorthy , Majumdar Arun
Published: May 2008

We report significant thermal conductivity reduction in oxygen-deficient lanthanum-doped strontium titanate (Sr1−xLaxTiO3−δ) films as compared to unreduced strontium titanates. Our experimental results suggest that the oxygen vacancies could have played an important role in the reduction. This could be due to the nature of randomly distributed and clustered vacancies, which would be very effective to scatter phonons. Our results could provide a pathway for tailoring the thermal conductivity of complex oxides, which is very beneficial to various applications including thermoelectrics.
Interband cascade laser emitting at λ=3.75μm in continuous wave above room temperature
Authors: Kim M. , Canedy C. L. , Bewley W. W. , Kim C. S. , Lindle J. R. , Abell J. , Vurgaftman I. , Meyer J. R.
Published: May 2008

We report a five-stage interband cascade laser that operates at λ=3.75μm in cw mode up to a maximum temperature of 319K. With gold electroplating, epitaxial-side-up mounting, and one facet coated for high reflectivity, a 3mm×9.2μm ridge emits over 10mW of cw power at 300K.
Microalgal sediment biostabilisation along a salinity gradient in the Eden Estuary, Scotland: unravelling a paradox
Authors: Spears Bryan M. , Saunders James E. , Davidson Irvine , Paterson David M.
Published: May 2008

Microalgal biostabilisation of cohesive sediments via the production of extracellular polymeric substances (EPS) has been well documented in intertidal ecosystems and represents a key ecosystem service with respect to the regulation of sediment transport. However, recent ecosystem comparison studies have uncovered a paradox in which sediment stability is commonly observed to be lower in freshwater ecosystems (compared with estuarine ecosystems) even though sediment EPS concentrations and microalgal biomass are high. Using a combination of freshwater and estuarine field and mesocosm techniques, the relative and interactive roles of salinity and the production of EPS (carbohydrate concentration) by benthic microalgae in the mediation of sediment stability in the Eden River catchment (river, mudflat and saltmarsh) were assessed. Sediment stability apparently increased with salinity from river (42.43 N m–2 surface stagnation pressure; salinity 0) to mudflat (98.65 N m–2; salinity 25) to saltmarsh (135.48 N m–2; salinity 46). The opposite trend was observed in sediment chlorophyll a and carbohydrate concentrations, indicating that salinity is the main variable driving sediment stability across the ecosystems under moderate EPS concentrations. Observations from mesocosm experiments highlighted the individual and combined importance of salinity and EPS in biostabilisation, with the largest increase in sediment stability observed following combined additions (25-fold increase compared with the control). The biogeochemical processes responsible, and their role in buffering phosphorus transport across the freshwater–saltwater transitional zone, are discussed.
Multi-year validation of photographic identification of grey nurse sharks, Carcharias taurus, and applications for non-invasive conservation research
Authors: Bansemer Carley S. , Bennett Mike B.
Published: May 2008

Captive and wild Carcharias taurus were used to assess whether spots present on their flanks were suitable as natural tags for individual shark recognition. Photographic images of seven captive sharks taken at monthly intervals for 14 months and at 3 years after the start of the study indicated that spot numbers, positions and sizes did not change. Eighty-nine wild sharks were photographically re-captured at least once subsequent to their initial image-capture; fourteen were re-photographed at least 23 months subsequent to their initial image-capture and a single individual after 14 years. Unique physical marks (e.g. partial fin loss) on six wild sharks were used to validate the pattern recognition process by providing unambiguous identification of individuals independently of their spots. Preliminary visual identification data on the eastern Australian C. taurus population show how spatial and temporal information on individual sharks can be collected without recourse to conventional tagging to address key questions about this species’ ecology and population biology.
Phylogeography of the freshwater catfish Tandanus tandanus (Plotosidae): a model species to understand evolution of the eastern Australian freshwater fish fauna
Authors: Jerry Dean R.
Published: May 2008

The geologically complex eastern Australian coastal margin supports the highest taxonomic diversity of freshwater fishes on the continent. However, mechanisms leading to coastal biogeographic patterns are poorly understood. A 399-bp fragment of the hypervariable mtDNA control region was sequenced from populations of eel-tailed catfish (Tandanus tandanus) to determine their phylogeographic structure and to relate this to proposed biogeographic mechanisms and landform evolution. Genetic structure in Tandanus is complex, with haplotypes clustering into three lineages: a phylogenetically distant, northern Queensland clade that is probably a new species; a mid-northern New South Wales clade corresponding to the recently discovered ‘Bellinger’ Tandanus cryptic species; and a third ‘derived’ clade T. tandanus. Phylogenetic analyses suggest that eastern Australian Tandanus originally invaded freshwaters from the coast where volcanic activity in the north and increasing aridity from the Paleocene reduced inter-fluvial connections, causing genetic divergence of northern Queensland and mid-northern New South Wales populations. The haplotypes represented by Murray–Darling drainage T. tandanus were the most derived, indicating that this species originally evolved on the coast and subsequently colonised the Murray–Darling basin. Tandanus in eastern Australia is phylogenetically structured and possibly comprises three species in this region; a pattern potentially shared by other eastern Australian freshwater fishes.
Paired β-sheet structure of an Aβ(1-40) amyloid fibril revealed by electron microscopy
Authors: Sachse Carsten , Fändrich Marcus , Grigorieff Nikolaus
Published: May 2008

Alzheimer's disease is a neurodegenerative disorder that is characterized by the cerebral deposition of amyloid fibrils formed by Aβ peptide. Despite their prevalence in Alzheimer's and other neurodegenerative diseases, important details of the structure of amyloid fibrils remain unknown. Here, we present a three-dimensional structure of a mature amyloid fibril formed by Aβ(1-40) peptide, determined by electron cryomicroscopy at ≈8-Å resolution. The fibril consists of two protofilaments, each containing ≈5-nm-long regions of β-sheet structure. A local twofold symmetry within each region suggests that pairs of β-sheets are formed from equivalent parts of two Aβ(1-40) peptides contained in each protofilament. The pairing occurs via tightly packed interfaces, reminiscent of recently reported steric zipper structures. However, unlike these previous structures, the β-sheet pairing is observed within an amyloid fibril and includes significantly longer amino acid sequences.
Structural basis for tropomyosin overlap in thin (actin) filaments and the generation of a molecular swivel by troponin-T
Authors: Murakami Kenji , Stewart Murray , Nozawa Kayo , Tomii Kumiko , Kudou Norio , Igarashi Noriyuki , Shirakihara Yasuo , Wakatsuki Soichi , Yasunaga Takuo , Wakabayashi Takeyuki
Published: May 2008

Head-to-tail polymerization of tropomyosin is crucial for its actin binding, function in actin filament assembly, and the regulation of actin-myosin contraction. Here, we describe the 2.1 Å resolution structure of crystals containing overlapping tropomyosin N and C termini (TM-N and TM-C) and the 2.9 Å resolution structure of crystals containing TM-N and TM-C together with a fragment of troponin-T (TnT). At each junction, the N-terminal helices of TM-N were splayed, with only one of them packing against TM-C. In the C-terminal region of TM-C, a crucial water in the coiled-coil core broke the local 2-fold symmetry and helps generate a kink on one helix. In the presence of a TnT fragment, the asymmetry in TM-C facilitates formation of a 4-helix bundle containing two TM-C chains and one chain each of TM-N and TnT. Mutating the residues that generate the asymmetry in TM-C caused a marked decrease in the affinity of troponin for actin-tropomyosin filaments. The highly conserved region of TnT, in which most cardiomyopathy mutations reside, is crucial for interacting with tropomyosin. The structure of the ternary complex also explains why the skeletal- and cardiac-muscle specific C-terminal region is required to bind TnT and why tropomyosin homodimers bind only a single TnT. On actin filaments, the head-to-tail junction can function as a molecular swivel to accommodate irregularities in the coiled-coil path between successive tropomyosins enabling each to interact equivalently with the actin helix.
Improvement of detection of hypoattenuation in acute ischemic stroke in unenhanced computed tomography using an adaptive smoothing filter
Authors: Takahashi N. , Lee Y. , Tsai D.-Y. , Ishii K. , Kinoshita T. , Tamura H. , Kimura M.
Published: May 2008

Background: Much attention has been directed toward identifying early signs of cerebral ischemia on computed tomography (CT) images. Hypoattenuation of ischemic brain parenchyma has been found to be the most frequent early sign.

Purpose: To evaluate the effect of a previously proposed adaptive smoothing filter for improving detection of parenchymal hypoattenuation of acute ischemic stroke on unenhanced CT images.

Material and Methods: Twenty-six patients with parenchymal hypoattenuation and 49 control subjects without hypoattenuation were retrospectively selected in this study. The adaptive partial median filter (APMF) designed for improving detectability of hypoattenuation areas on unenhanced CT images was applied. Seven radiologists, including four certified radiologists and three radiology residents, indicated their confidence level regarding the presence (or absence) of hypoattenuation on CT images, first without and then with the APMF processed images. Their performances without and with the APMF processed images were evaluated by receiver operating characteristic (ROC) analysis.

Results: The mean areas under the ROC curves (AUC) for all observers increased from 0.875 to 0.929 ( P=0.002) when the radiologists observed with the APMF processed images. The mean sensitivity in the detection of hypoattenuation significantly improved, from 69% (126 of 182 observations) to 89% (151 of 182 observations), when employing the APMF ( P=0.012). The specificity, however, was unaffected by the APMF ( P=0.41).

Conclusion: The APMF has the potential to improve the detection of parenchymal hypoattenuation of acute ischemic stroke on unenhanced CT images.
Use of Resistant Cultivars and Reduced Fungicide Programs to Manage Peanut Diseases in Irrigated and Nonirrigated Fields
Authors: Woodward J. E. , Brenneman T. B. , Kemerait R. C. , Smith N. B. , Culbreath A. K. , Stevenson K. L.
Published: May 2008

Field experiments were conducted in 2004 and 2005 to evaluate the response of several peanut cultivars to standard and reduced-input fungicide programs under production systems which differed in the duration of crop rotation, disease history within a field, or in the presence or absence of irrigation. Effects on early leaf spot (caused by Cercospora arachidicola), late leaf spot (caused by Cercosporidium personatum), and southern stem rot (caused by Sclerotium rolfsii), pod yields, and economic returns were assessed. Standard fungicide programs were similar for both sets of experiments and included applications of pyraclostrobin, tebuconazole, azoxystrobin, or chlorothalonil. Reduced-fungicide programs, comprising combinations of the aforementioned fungicides, resulted in two and four applications for the cultivar and irrigation experiment, respectively. Two additional programs (a seven-spray chlorothalonil and a nontreated control) were included in the cultivar experiment. Fungicide programs provided adequate levels of leaf spot suppression, and stem rot incidence was similar among fungicide programs within the two management systems. In the cultivar experiment, returns were significantly lower for the reduced program compared with the full program and seven-spray chlorothalonil program; however, they were significantly higher than the nontreated control. Significant differences in leaf spot, stem rot, and yield were observed among cultivars in both experiments. Overall, leaf spot intensity was lowest for the cvs. Georgia-03L and Georgia-01R and greatest for Georgia Green and Georgia-02C. Georgia-03L, Georgia-02C, and AP-3 consistently had lower incidence of stem rot than the other cultivars. Pod yields for all cultivars were equivalent to or greater than Georgia Green in both experiments; however, the performance of reduced-fungicide programs was inconsistent.
Evaluation of Soybean Germplasm for Resistance to Soybean Rust (Phakopsora pachyrhizi) in Nigeria
Authors: Twizeyimana M. , Ojiambo P. S. , Ikotun T. , Ladipo J. L. , Hartman G. L. , Bandyopadhyay R.
Published: May 2008

Soybean rust, caused by Phakopsora pachyrhizi, is one of the most important constraints to soybean production worldwide. The absence of high levels of host resistance to the pathogen has necessitated the continued search and identification of sources of resistance. In one set of experiments, 178 soybean breeding lines from the International Institute of Tropical Agriculture were rated for rust severity in the field in 2002 and 2003 at Ile-Ife, Yandev, and Ibadan, Nigeria. Thirty-six lines with disease severity ≤3 (based on a 0-to-5 scale) were selected for a second round of evaluation in 2004 at Ibadan. In the third round of evaluation under inoculated field conditions, 11 breeding lines with disease severity ≤2 were further evaluated for rust resistance at Ibadan in 2005 and 2006. The breeding lines TGx 1835-10E, TGx 1895-50F, and TGx 1903-3F consistently had the lowest level of disease severity across years and locations. In another set of experiments, 101 accessions from the United States Department of Agriculture–Agricultural Research Service and National Agriculture Research Organization (Uganda) were evaluated in the first round in 2005 under inoculated conditions in the screenhouse; 12 accessions with disease severity ≤20% leaf area infected were selected for evaluation in the second round in 2005 and 2006 under inoculated field conditions at Ibadan. Highly significant differences (P < 0.0001) in disease severity were observed among the 101 accessions during this first round of rust evaluation. Significant (P < 0.0001) differences in rust severity and sporulation also were observed among the 12 selected accessions. Accessions PI 594538A, PI 417089A, and UG-5 had significantly (P < 0.05) lower disease severity than all other selected accessions in both years of evaluation, with rust severities ranging from 0.1 to 2.4%. These results indicate that some of the breeding lines (TGx 1835-10E, TGx 1895-50F, and TGx 1903-3F) and accessions (PI 594538A, PI 417089A, and UG-5) would be useful sources of soybean rust resistance genes for incorporation into high-yielding and adapted cultivars.
Activity of Fungicides AgainstMonilinia vaccinii-corymbosiin Blueberry Flowers Treated at Different Phenological Stages
Authors: Tarnowski T. L. B. , Savelle A. T. , Scherm H.
Published: May 2008

The activity of fenbuconazole and azoxystrobin applied to blueberry flowers at different phenological stages against subsequent gynoecial infection by the mummy berry fungus Monilinia vaccinii-corymbosi was evaluated. In the greenhouse, potted blueberry plants having flower clusters at five distinct stages (from bud scale separation to anthesis) were treated with the two fungicides. One day after anthesis (between 1 and 15 days after fungicide treatment), individual flowers were detached and inoculated with conidia of M. vaccinii-corymbosi in the laboratory. Four days after inoculation, hyphal ingress into the style was determined microscopically as a measure of fungicide efficacy. Results revealed a significant flower stage effect (P < 0.0001), whereby only fungicide application at anthesis but not at the four preanthesis stages reduced subsequent fungal ingress into the style. There was no significant difference between the two fungicides (P > 0.50) nor was there a significant fungicide–flower stage interaction (P > 0.30). In the field during 2 years, mature blueberry plants were treated with the two fungicides and exposed to natural pathogen inoculum. At the time of application, flower clusters at anthesis and at three preanthesis stages were selected and tagged. Mummy berry incidence in fruit developing from the tagged clusters was assessed to determine treatment effects. Whereas fenbuconazole lowered disease incidence for all preanthesis stages, azoxystrobin was effective only at the latest preanthesis stage. The discrepancy between these results and those of the greenhouse study (where there was no preanthesis activity of either fungicide) indirectly suggests post-infection fungicidal activity in the ovary, the base of which was exposed to the fungicide spray at the time of treatment for all flower phenology stages. Thus, although there appears to be insufficient translocation of the two fungicides in flowers treated at preanthesis stages to prevent stylar ingress by the pathogen, fungicidal activity in the ovary may be sufficient to halt subsequent fungal colonization, especially for fenbuconazole. To prescribe the most effective management program for flower-infecting fungi, translocation and post-infection activity of fungicides in floral tissues must be better understood.
First Report of Powdery Mildew Caused by Golovinomyces cichoracearum on Orange Coneflower (Rudbeckia fulgida) in Italy
Authors: Garibaldi A. , Bertetti D. , Frati S. , Gullino M. L.
Published: May 2008

Rudbeckia fulgida (orange coneflower), a flowering plant belonging to the Asteraceae, is increasingly used as a border in parks and gardens. In September 2007, severe outbreaks of a previously unknown powdery mildew were observed on plants in a public park in Torino (northern Italy). More than 90% of the plants were affected by the disease. Both surfaces of leaves of affected plants were covered with white mycelia and conidia. As the disease progressed, infected leaves turned yellow and wilted. Mycelia and conidia also were observed on stems and flower calyxes. Conidia were hyaline, ellipsoid, borne in chains (as many as three to four conidia per chain) and measured 34 × 23 (30 to 39 × 21 to 25) μm. Conidiophores measured 129 × 12 (89 to 181 × 11 to 13) μm and showed a foot cell measuring 88 × 12 (48 to 129 × 11 to 13) μm followed by two shorter cells. Fibrosin bodies were absent. Chasmothecia were not observed in the collected samples. The internal transcribed spacer (ITS) region of rDNA was amplified using the primers ITS4/ITS6 and sequenced. BLASTn analysis (1) of the 619 bp showed a 100% homology with the sequence of Golovinomyces cichoracearum (3). The nucleotide sequence has been assigned GenBank Accession No. EU 233820. Pathogenicity was confirmed through inoculations by gently pressing diseased leaves onto leaves of healthy R. fulgida plants. Twenty plants were inoculated. Fifteen noninoculated plants served as the control. Plants were maintained in a greenhouse at temperatures ranging from 18 to 22°C. Eight days after inoculation, typical symptoms of powdery mildew developed on inoculated plants. The fungus observed on inoculated plants was morphologically identical to that originally observed. Noninoculated plants did not show symptoms. The pathogenicity test was carried out twice. To our knowledge, this is the first report of powdery mildew on R. fulgida in Italy. Powdery mildew on Rudbeckia spp. was previously reported in the United States (4), Poland, and more recently, India and Switzerland. Particularly, in Switzerland the disease has been observed on R. laciniata and R. nitida (2). The economic importance of this disease is currently limited. Voucher specimens are available at the AGROINNOVA Collection, University of Torino.

References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) A. Bolay. Cryptogam. Helv. 20:1, 2005. (3) U. Braun and S. Takamatsu. Schlechtendalia 4:1, 2000. (4) D. F. Farr et al. Page 82 in: Fungi on Plants and Plants Products in the United States. The American Phytopathological Society, St Paul, MN, 1989.
First Report of Soybean Rust Caused by Phakopsora pachyrhizi in Iowa and its Statewide Occurrence
Authors: Li X. , Engelbrecht C. J. , Mueller D. S. , Yang X. B.
Published: May 2008

On 25 September 2007, soybean leaves with lesions typical of soybean rust were found in two commercial fields located in Dallas County, Iowa. Growth stage of the infected soybean plants was near physiological maturity. Diagnosis of Phakopsora pachyrhizi on leaves was confirmed by morphological observation of uredinia and urediniospores and conventional PCR conducted by the Iowa State University Plant and Insect Diagnostic Clinic using P. pachyrhizi-specific primers Ppm1 and Ppa2 as described (1). Water blanks were used as negative controls in PCR testing. Leaves were collected from additional counties throughout Iowa and examined microscopically. Soybean rust was identified on leaves from 14 counties, almost all the counties sampled, ranging from far western to far eastern Iowa. The northernmost detection was at 42.9°N in Hancock County, which also is the northernmost detection of soybean rust in the continental United States so far. In a commercial field in Fremont County, in the southwestern corner of Iowa along the Missouri River, disease incidence was approximately 20% and disease severity was 5%. Observed disease incidence was 1 to 2% and severity was less than 1% from all other samples. Most uredinia were scattered on the leaves as single pustules or clustered in groups of three to five pustules. Pustules on some leaf samples were sporulating, depending on weather conditions at the time when samples were collected. Fresh urediniospores collected from the leaf samples were placed on glass slides with free water on the surface and incubated in a dew chamber under darkness for 8 h to test for germination. Germination rates ranged from 80 to 90%. Rust spores also were used to inoculate detached soybean trifoliate leaves, which were kept in a dew chamber under darkness for 12 h with water-soaked cotton wrapped around the petioles. Typical soybean rust pustules developed within 10 to 14 days after incubation. The detections of soybean rust in Iowa were consistent with the predictions of an aerobiological spore dispersal model, which predicted spore showers in central to western Iowa in August. Above normal wet weather in the Great Plains and Iowa may have favored the statewide disease occurrence. To our knowledge, this is the first report of soybean rust in Iowa.

Reference: (1) R. D. Frederick et al. Phytopathology 92:217, 2002.
Occurrence of Four Citrus Viroids in Chongqing, China
Authors: Wang X. F. , Zhou C. Y. , Tang K. Z. , Li Z. A.
Published: May 2008

Chongqing Municipality, located in the superior citrus belt of the upper-middle Yangtze River, is one of the most important citrus-producing areas in China. A survey was performed to evaluate the occurrence and distribution of citrus viroids in this area, where Poncirus trifoliata is the main rootstock. From 2002 to 2006, 72 samples of sweet oranges (Citrus sinensis), lemons (C. jambhiri), mandarins (C. reticulata), and mandarin hybrids, which showed stunting, bark scaling, and cracking symptoms on the rootstock, were collected and graft inoculated into Arizona 861-S1 Etrog citron (C. medica) on rough lemon rootstock and maintained in a greenhouse at 28 to 32°C. Fifty-one of the seventy-two samples were cultivars imported from abroad, and the remaining samples were all local cultivars. Sixty samples induced symptoms typical of citrus viroids on the Etrog indicator plants. To identify the causal agent(s), a one-step reverse transcription (RT)-PCR protocol, using five primer pairs (1) targeting the complete genome sequences, was used to detect Citrus exocortis viroid (CEVd), Citrus bent leaf viroid (CBLVd), Hop stunt viroid (HSVd), Citrus viroid III (CVd-III), and Citrus viroid IV (CVd-IV) (2). All 72 samples were infected by citrus viroids. Sixty-five and thirty-five of the seventy-two samples were positive for HSVd and CVd-III, respectively. CEVd and CBLVd were found, respectively, in 20 and 11 of 72 samples, whereas CVd-IV was not detected. Of 72 samples, 12 without typical symptoms on Etrog citrons were infected by HSVd and CBLVd. Nearly all (70 of 72) infected citrus plants harbored more than one viroid species, and two plants were both infected by CEVd, CBLVd, HSVd, and CVd-III. RT-PCR products were purified and ligated into pGEM T-Easy Vector (Promega, Madison, WI) and three clones for each of the four viroid species were sequenced and deposited in GenBank: CEVd (Accession Nos. EU382202, U382203, and EU382204); CBLVd (Accession Nos. EU382211, EU382212, and EU382213); HSVd (Accession Nos. EU382208, EU382209, and EU382210); and CVd-III (Accession Nos. EU382205, EU382206, and EU382207). BLAST analysis showed that these nucleotide sequences had greater than 94% nucleotide identity to the most similar genome sequences in GenBank. Sweet orange was more frequently infected by viroids than the other citrus cultivars. To our knowledge, this is the first report of CBLVd, HSVd, and CVd-III in Chongqing and the first report of CBLVd in China. The high incidence of citrus viroids in Chongqing necessitates rapid development of a system of propagation and testing to reduce the incidence of viroids and the associated loss of citrus production.

References: (1) L. Bernard and N. Duran-Vila. Mol. Cell. Probes 20:105, 2006. (2) K. Z. Tang et al. Acta Hortic. Sin. 32:408, 2005.
First Report of Sclerotinia sclerotiorum on African Daisy (Osteospermum sp.) in Italy
Authors: Garibaldi A. , Pensa P. , Minuto A. , Gullino M. L.
Published: May 2008

African daisy (Osteospermum sp.) is an ornamental plant grown in the winter as a potted plant in Liguria (northern Italy) and is generally marketed in early-to-late spring in Italy and central and northern Europe. In the winter of 2006, stem lesions, general chlorosis, wilt, and plant death occurred in a greenhouse nursery. Affected plants were characterized by the presence of soft, watery tissues. Necrotic tissues were covered with a white, cottony mycelium. During periods of high humidity, black sclerotia differentiated within the mycelium. To recover the pathogen, diseased stem tissue was surface sterilized for 1 min in 1% NaOCl and plated on potato dextrose agar (PDA) amended with 100 mg/l of streptomycin sulfate. Sclerotinia sclerotiorum (Lib.) de Bary (2) was consistently isolated from affected tissue. Sclerotia produced on PDA measured 1.3 to 3.1 × 1.5 to 3.5 mm in diameter. The internal transcribed spacer (ITS) region of rDNA was amplified using primers ITS4/ITS6 and then sequenced. BLASTn analysis (1) of the 633 bp showed a 100% identity with S. sclerotiorum. The nucleotide sequence was assigned GenBank Accession No. EU 556701. Pathogenicity of two isolates obtained from infected plants was confirmed by inoculating 10 80-day-old plants grown in 14-cm-diameter pots. Inoculum consisted of 1 cm2 of mycelium excised from a 10-day-old PDA culture of each isolate and placed on the soil surface around the base of each plant. Ten plants were inoculated with each isolate and 10 noninoculated plants served as controls. Plants were maintained in a greenhouse under shade at temperatures of 10 to 22°C (average 19°C), in high relative humidity (>90%), and were watered as needed. The trial was conducted twice. All inoculated plants developed leaf yellowing within 12 days of inoculation. White, cottony mycelium and black sclerotia developed on stems and at the base of all inoculated plants, which eventually wilted. Control plants remained symptomless. S. sclerotiorum was reisolated from the stems of inoculated plants. This disease has been reported on an Osteospermum sp. in the United States (3) and Argentina (4). To our knowledge, this is the first report of white mold on an Osteospermum sp. in Italy as well as in Europe. Currently, the economic importance of this disease is limited.

References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) N. F. Buchwald. Den. Kgl. Veterin.er-og Landbohojskoles Aarsskrift. 75, 1949. (3) H. S. Gill. Plant Dis. Rep. 59:82, 1975. (4) E. R. Wright et al. Plant Dis. 89:1014, 2005.
Emergence of a Novel Population of Puccinia striiformis f. sp. tritici in Eastern United States
Authors: Markell S. G. , Milus E. A.
Published: May 2008

The geographic range of stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici, has increased dramatically since 2000 in the United States. Yield losses to the disease have been most severe in the eastern United States, where measurable yield loss had been rare prior to 2000. The objective of this study was to examine the phenotypic and genotypic variation among isolates of P. striiformis f. sp. tritici collected from populations in the eastern United States before and since 2000. Virulence phenotype and amplified fragment length polymorphism (AFLP) markers were used to examine 42 isolates collected between 1960 and 2004. In addition, the genetic structure of 59 isolates collected in 2005 using a hierarchical sampling strategy was examined. The data indicated that the contemporary isolates (collected since 2000) were very distinct from older isolates (collected before 2000) based on virulence and AFLP markers, and that the old population prevalent before 2000 may have been replaced by the contemporary population. The old and new populations appear to be genetically distinct and may represent an exotic introduction rather than a mutation in isolates of the old population.
Duplex Real-Time Polymerase Chain Reaction Reveals Competition Between Erwinia amylovora and E. pyrifoliae on Pear Blossoms
Authors: Lehman Susan M. , Kim Won-Sik , Castle Alan J. , Svircev Antonet M.
Published: May 2008

Erwinia amylovora and E. pyrifoliae are the causative agents of fire blight and Asian pear blight, respectively. The pathogens are closely related, with overlapping host ranges. Data are unavailable on the current distribution of E. pyrifoliae and on the interaction between the two species when they are present together on the same host. In this study, a duplex real-time polymerase chain reaction (PCR) protocol was developed to monitor the population dynamics of E. amylovora and E. pyrifoliae on the surface of Bartlett pear blossoms. Bacterial cells washed from blossoms were used directly as the PCR template without DNA extraction. Primers and a probe based on the E. amylovora levansucrase gene detected all E. amylovora strains. All E. pyrifoliae strains, including the Japanese Erwinia strains previously described as E. amylovora, were detected with a primer and probe combination based on the E. pyrifoliae hrpW gene. Disease development and severity were not significantly different in blossoms inoculated with individual Erwinia species or with a mixture of the two species. However, E. amylovora grew to greater population sizes than did E. pyrifoliae in both single species inoculations and in mixtures, suggesting that E. amylovora has a greater competitive fitness on Bartlett pear blossoms than E. pyrifoliae.
An Antibiotic Complex from Lysobacter enzymogenes Strain C3: Antimicrobial Activity and Role in Plant Disease Control
Authors: Li S. , Jochum C. C. , Yu F. , Zaleta-Rivera K. , Du L. , Harris S. D. , Yuen G. Y.
Published: May 2008

Lysobacter enzymogenes C3 is a bacterial biological control agent that exhibits antagonism against multiple fungal pathogens. Its antifungal activity was attributed in part to lytic enzymes. In this study, a heat-stable antifungal factor (HSAF), an antibiotic complex consisting of dihydromaltophilin and structurally related macrocyclic lactams, was found to be responsible for antagonism by C3 against fungi and oomycetes in culture. HSAF in purified form exhibited inhibitory activity against a wide range of fungal and oomycetes species in vitro, inhibiting spore germination, and disrupting hyphal polarity in sensitive fungi. When applied to tall fescue leaves as a partially-purified extract, HSAF at 25 μg/ml and higher inhibited germination of conidia of Bipolaris sorokiniana compared with the control. Although application of HSAF at 12.5 μg/ml did not reduce the incidence of conidial germination, it inhibited appressorium formation and suppressed Bipolaris leaf spot development. Two mutant strains of C3 (K19 and ΔNRPS) that were disrupted in different domains in the hybrid polyketide synthase-nonribosomal peptide synthetase gene for HSAF biosynthesis and had lost the ability to produce HSAF were compared with the wild-type strain for biological control efficacy against Bipolaris leaf spot on tall fescue and Fusarium head blight, caused by Fusarium graminearum, on wheat. Both mutant strains exhibited decreased capacity to reduce the incidence and severity of Bipolaris leaf spot compared with C3. In contrast, the mutant strains were as efficacious as the wild-type strain in reducing the severity of Fusarium head blight. Thus, HSAF appears to be a mechanism for biological control by strain C3 against some, but not all, plant pathogenic fungi.
Genetic Analysis of Resistance to Pyrenophora tritici-repentis Races 1 and 5 in Tetraploid and Hexaploid Wheat
Authors: Singh P. K. , Mergoum M. , Ali S. , Adhikari T. B. , Hughes G. R.
Published: May 2008

Tan spot of wheat, caused by the fungus Pyrenophora tritici-repentis, is a destructive disease worldwide that can lead to serious losses in quality and quantity of wheat grain production. Resistance to multiple races of P. tritici-repentis was identified in a wide range of genetically diverse genotypes, including three different species Triticum aestivum (AABBDD), T. spelta (AABBDD), and T. turgidum (AABB). The major objectives of this study were to determine the genetic control of resistance to P. tritici-repentis races 1 and 5 in 12 newly identified sources of resistance. The parents, F1, F2, and F2:3 or F2:5 families of each cross were analyzed for the allelism tests and/or inheritance studies. Plants were inoculated at the two-leaf stage under controlled environmental conditions and disease reaction was assessed based on lesion-type rating scale. A single recessive gene controlled resistance to necrosis caused by P. tritici-repentis race 1 in both tetraploid and hexaploid resistant genotypes. The lack of segregation in the inter- and intra-specific crosses between the resistant tetraploid and hexaploid genotypes indicated that they possess the same genes for resistance to tan necrosis and chlorosis induced by P. tritici-repentis race 1. A single dominant gene for chlorosis in hexaploid wheat and a single recessive gene for necrosis in tetraploid wheat, controlled resistance to P. tritici-repentis race 5.
Modeling the Rejection Probability in Plant Imports
Authors: Surkov I. V. , van der Werf W. , van Kooten O. , Lansink A. G. J. M. Oude
Published: May 2008

Phytosanitary inspection of imported plants and flowers is a major means for preventing pest invasions through international trade, but in a majority of countries availability of resources prevents inspection of all imports. Prediction of the likelihood of pest infestation in imported shipments could help maximize the efficiency of inspection by targeting inspection on shipments with the highest likelihood of infestation. This paper applies a multinomial logistic (MNL) regression model to data on import inspections of ornamental plant commodities in the Netherlands from 1998 to 2001 to investigate whether it is possible to predict the probability that a shipment will be (i) accepted for import, (ii) rejected for import because of detected pests, or (iii) rejected due to other reasons. Four models were estimated: (i) an all-species model, including all plant imports (136,251 shipments) in the data set, (ii) a four-species model, including records on the four ornamental commodities that accounted for 28.9% of inspected and 49.5% of rejected shipments, and two models for single commodities with large import volumes and percentages of rejections, (iii) Dianthus (16.9% of inspected and 46.3% of rejected shipments), and (iv) Chrysanthemum (6.9 and 8.6%, respectively). All models were highly significant (P < 0.001). The models for Dianthus and Chrysanthemum and for the set of four ornamental commodities showed a better fit to data than the model for all ornamental commodities. Variables that characterized the imported shipment's region of origin, the shipment's size, the company that imported the shipment, and season and year of import, were significant in most of the estimated models. The combined results of this study suggest that the MNL model can be a useful tool for modeling the probability of rejecting imported commodities even with a small set of explanatory variables. The MNL model can be helpful in better targeting of resources for import inspection. The inspecting agencies could enable development of these models by appropriately recording inspection results.
Mortality and utilisation of critical care resources amongst high‐risk surgical patients in a large NHS trust*
Authors: Jhanji S. , Thomas B. , Ely A. , Watson D. , Hinds C. J. , Pearse R. M.
Published: May 2008

Previous reports describe a population of non‐cardiac surgical patients at high risk of complications and death. Outcomes are sub‐optimal for such patients, perhaps in part related to inadequate provision or ineffective utilisation of critical care resources. In this study, data describing 26 051 in‐patient non‐cardiac surgical procedures performed in a large NHS Trust between April 2002 and March 2005 were extracted from local databases. Of these procedures, 2 414 (9.3%) were high risk with an overall mortality rate of 12.2% and a prolonged hospital stay (high‐risk population median (IQR) 16 (9–30) days vs standard risk 3 (2–6) days). Mortality rates for specific procedures were consistent with UK averages. However, only 852 (35.3%) high‐risk patients were admitted to a critical care unit at any stage after surgery. Of 294 high‐risk patients who died, only 144 (49.0%) were admitted to a critical care unit at any time and only 75 (25.6%) of these deaths occurred within a critical care area. Mortality rates were high amongst patients discharged and readmitted to critical care (37.7%) and amongst those admitted to critical care following initial postoperative care on a standard ward (29.9%). These data suggest that the outcome of high‐risk general surgical patients could be improved by adequate provision and more effective utilisation of critical care resources.
Serum IGF‐I measured by four different immunoassays in patients with adult GH deficiency or acromegaly and in a control population
Authors: Granada Maria Luisa , Ulied Angels , Casanueva Felipe F. , Pico Antonio , Lucas Tomas , Torres Elena , Sanmartí Anna
Published: May 2008

Background  IGF‐I is a useful tool in GH disorders diagnosis, however, the use of commercially available kits needs to be validated.

Objective  To validate the use of serum IGF‐I concentrations measured by four immunoassays in the diagnosis of adult GH deficiency and acromegaly.

Design  Cross‐sectional study.

Patients  Fifty GH‐deficient (GHD) patients, 41 acromegaly patients and 405 controls.

Measurements  Serum IGF‐I concentrations were measured by four commercial immunoassays: (1) RIA‐NICHOLS; (2) ICMA‐IMMULITE; (3) IRMA‐IMMUNOTECH; and (4) non‐extraction‐IRMA‐DSL. Reference values were established from the control population in six age groups. Individual results were transformed to standard deviation score (SD score) from the age‐related reference population and reference data provided by each assay manufacturer. Diagnostic sensitivity for GH deficiency was calculated.

Results  IGF‐I measured by the four assays differed significantly. In controls, assay 2 yielded the lowest results, followed by assays 1, 3 and 4 (P < 0·0001 for all comparisons). IGF‐I declined with age, but no sex‐related differences were observed. When IGF‐I was standardized with respect to reference data obtained from the manufacturers, it showed better sensitivity in assays 1 and 2, than with our controls (65%vs. 77·5% and 58%vs. 70%, respectively) for GHD diagnosis. With assays 3 and 4, higher sensitivity was obtained when standardized with our controls (62%vs. 52% and 56%vs. 36%, respectively). In acromegaly, IGF‐I was > 2 SD score with all assays.

Conclusions  IGF‐I SD score for GHD diagnosis differed according to the normative data used. All assays proved to be useful for active acromegaly diagnosis.
Effects of light to moderate alcohol consumption on thyroid volume and thyroid function
Authors: Valeix Pierre , Faure Patrice , Bertrais Sandrine , Vergnaud Anne‐Claire , Dauchet Luc , Hercberg Serge
Published: May 2008

Objective  To examine a possible relationship between alcohol consumption and thyroid volume and function.

Subjects  A total of 1493 subjects (599 males aged 45–60 years and 894 females aged 35–60 years) with no known thyroid disorders who were participating in the SUpplémentation en VItamines et Minéraux AntioXydants (SU.VI.MAX) study.

Measures  Daily dietary intakes and alcohol consumption in grams per day were based on five 24‐h dietary records. Thyroid volume and structure were measured by ultrasonography. At baseline, TSH and free T4 (FT4) were measured.

Results  Male and female drinkers consumed (mean ± SD), respectively, 30·6 ± 23·3 and 14·2 ± 13·4 g of ethanol per day. There was a decrease in carbohydrate intake with higher alcohol consumption among both male (P = 0·0001) and female drinkers (P = 0·06). Alcohol intake was associated with higher thyroid volume in males and females independently of iodine status. Multivariate odds ratios (ORs, with 95% confidence intervals) of thyroid enlargement (sex‐specific 85th percentile values of ≥ 20 ml for males, ≥ 14 ml for females) in males and females who drank ≥ 45 and ≥ 20 g/day, respectively, were 2·22 (1·10–4·47) and 2·11 (1·15–3·90) compared with low drinkers, and 11·75 (2·15–64·12) and 2·03 (1·04–3·96) compared with abstainers. ORs were slightly increased when smokers were excluded. Alcohol intake was associated with low FT4 levels in male drinkers independently of TSH.

Conclusions  An increasing dose–response relationship was found between alcohol intake levels and ORs for thyroid enlargement in both males and females. Alcohol consumption was strongly associated with a higher risk in females.
Induction of hepatic 11β‐hydroxysteroid dehydrogenase type 1 in patients with alcoholic liver disease
Authors: Ahmed Adeeba , Saksena Sushma , Sherlock Mark , Olliff Simon P. , Elias Elwyn , Stewart Paul M.
Published: May 2008

Background and aim  The alcohol‐induced pseudo‐Cushing's syndrome is an important differential diagnosis of hypercortisolism that is poorly understood. Two isozymes of 11β‐hydroxysteroid dehydrogenase (11β‐HSD) interconvert hormonally active cortisol (F) and inactive cortisone (E). Previously we have shown higher urinary F : E metabolite ratios (a reflection of global 11β‐HSD activity) in patients with alcoholic liver disease (ALD) compared to patients with chronic liver disease (CLD) of other aetiologies, suggesting that the phenotype of alcoholic pseudo‐Cushing's may relate to altered metabolism of F.

Subjects and methods  We performed selective venous sampling of the hepatic, renal and peripheral veins measuring F and E concentrations (using in‐house radioimmunoassay) in 20 patients with histologically confirmed ALD and 19 patients with CLD. Six patients who also had selective venous sampling for investigation of suspected hyperaldosteronism were used as ‘normal’ controls.

Results  There was a significant difference in the hepatic F gradient (mean ± SEM) between groups, indicating increased F production in the liver in patients with ALD (34·5 ± 21·7 nmol/l) compared to those with CLD (–21·0 ± 18·5 nmol/l) (P < 0·05) and normals (–19·7 ± 17·2 nmol/l) (P < 0·05). 11β‐HSD1 mRNA expression was increased fivefold in the ALD group compared with normal controls (P < 0·01).

Conclusions  These results indicate significant induction of HSD11B1 gene expression and activity in patients with ALD during short‐ and long‐term abstinence from alcohol. The mechanism is unknown but might be explained on the basis of alcohol‐induced changes in intracellular redox potential or as a protective mechanism to limit liver inflammation and injury. Selective 11β‐HSD1 inhibitors may offer a novel therapeutic approach to treat alcoholic pseudo‐Cushing's.
Mental and motor development before and during growth hormone treatment in infants and toddlers with Prader–Willi syndrome
Authors: Festen D. A. M. , Wevers M. , Lindgren A. C. , Böhm B. , Otten B. J. , Wit J. M. , Duivenvoorden H. J. , Hokken‐Koelega A. C. S.
Published: May 2008

Background  Prader–Willi syndrome (PWS) is a neurogenetic disorder characterized by muscular hypotonia, psychomotor delay, feeding difficulties and failure to thrive in infancy. GH treatment improves growth velocity and body composition. Research on the effects of GH on psychomotor development in infants with PWS is limited.

Objective  To evaluate psychomotor development in PWS infants and toddlers during GH treatment compared to randomized controls.

Design/patients  Forty‐three PWS infants were evaluated at baseline. Twenty‐nine of them were randomized into a GH group (n = 15) receiving 1 mg/m2/day GH or a non‐GH‐treated control group (n = 14). At baseline and after 12 months of follow‐up, analysis with Bayley Scales of Infant Development II (BSID‐II) was performed. Data were converted to percentage of expected development for age (%ed), and changes during follow‐up were calculated.

Results  Infants in the GH group had a median age of 2·3 years [interquartile range (IQR) 1·7–3·0] and in the control group of 1·5 years (IQR 1·2–2·7) (P = 0·17). Both mental and motor development improved significantly during the first year of study in the GH group vs. the control group: median (IQR) change was +9·3% (–5·3 to 13·3) vs.–2·9% (–8·1 to 4·9) (P < 0·05) in mental development and +11·2% (–4·9 to 22·5) vs.–18·5% (–27·9 to 1·8) (P < 0·05) in motor development, respectively.

Conclusion  One year of GH treatment significantly improved mental and motor development in PWS infants compared to randomized controls.