bluuebunny/crossref_metadata_2025_split huggingface dataset:
On a symplectic generalization of Petrie’s conjecture
Authors: Tolman Susan 
Published: April 2010

Motivated by the Petrie conjecture, we consider the following questions: Let a circle act in a Hamiltonian fashion on a compact symplectic manifold

(
M
,
ω
)

(M,\omega )

which satisfies

H

2
i

(
M
;

R

)
=

H

2
i

(

C

P

n

,

R

)

H^{2i}(M;\mathbb {R}) = H^{2i}({\mathbb C}{\mathbb P}^n,\mathbb {R})

for all

i
i

. Is

H
j

(
M
;

Z

)
=

H
j

(

C

P

n

;

Z

)

H^j(M;\mathbb {Z}) = H^j({\mathbb C}{\mathbb P}^n;\mathbb {Z})

for all

j
j

? Is the total Chern class of

M
M

determined by the cohomology ring

H
∗

(
M
;

Z

)

H^*(M;\mathbb {Z})

? We answer these questions in the six-dimensional case by showing that

H
j

(
M
;

Z

)

H^j(M;\mathbb {Z})

is equal to

H
j

(

C

P

3

;

Z

)

H^j({\mathbb C}{\mathbb P}^3;\mathbb {Z})

for all

j
j

, by proving that only four cohomology rings can arise, and by computing the total Chern class in each case. We also prove that there are no exotic actions. More precisely, if

H
∗

(
M
;

Z

)

H^*(M;\mathbb {Z})

is isomorphic to

H
∗

(

C

P

3

;

Z

)

H^*({\mathbb C}{\mathbb P}^3;\mathbb {Z})

or

H
∗

(

G
~

2

(

R

5

)
;

Z

)

H^*(\widetilde {G}_2(\mathbb {R}^5);\mathbb {Z})

, then the representations at the fixed components are compatible with one of the standard actions; in the remaining two cases, the representation is strictly determined by the cohomology ring. Finally, our results suggest a natural question: Do the remaining two cohomology rings actually arise? This question is closely related to some interesting problems in symplectic topology, such as embeddings of ellipsoids.
First Report of Tomato chlorotic dwarf viroid in Tomato in France
Authors: Candresse T. , Marais A. , Tassus X. , Suhard P. , Renaudin I. , Leguay A. , Poliakoff F. , Blancard D. 
Published: April 2010

Tomato chlorotic dwarf viroid (TCDVd) is a pospiviroid found naturally infecting tomato (Solanum lycopersicum L.) (3) and several ornamentals such as Brugmansia, petunia (1), and trailing verbena (4). Initially identified in North America (3), it has been reported from India, Europe (the Netherlands and United Kingdom), and Japan. At the end of 2007, 20 to 25% of tomato plants within a group of greenhouses in the Brittany Region of France were observed with top bunching, leaf curling, and epinasty symptoms. Reverse transcription (RT)-PCR with a primer pair specific for several pospiviroids (5′GGGGAAACCTGGAGCGA3′ and 5′GGGGATCCCTGAAGCGC3′) amplified the correctly sized fragment (approximately 360 bp) from total nucleic acid extracts from three symptomatic plants. The sequence of the uncloned amplification product (GenBank Accession No. EU729744) was determined, together with that of five cloned cDNAs. All sequences were highly related with a total of three mutations in these six sequences and they showed 96.9% (GQ169709 and AY372399) to 99.4% (AF162131) identity with TCDVd sequences present in GenBank. Identification of TCDVd was confirmed from the same plant samples by molecular hybridization with a Potato spindle tuber viroid (PSTVd)-specific probe (which cross-hybridizes with TCDVd to a certain extent) and by PCR with the PSTVd/TCDVd-specific 2A-1S primer pair (3) and sequencing of the amplified fragment. The French isolate is most closely related to the original tomato isolate from Canada (GenBank Accession No. AF162131). In a grow-out test involving 2,500 seeds from the original seed lot from which the symptomatic plants were derived, 2 of the 250 pools of 10 plants tested positive for TCDVd infection with the 3H1-2H1 primer pair (2). The sequence of the amplified product proved identical to the isolate detected in the original greenhouse plants, indicating a low level of seed transmission. As with other pospiviroids, which appear to be more and more frequently reported in greenhouse tomatoes, possible sources of infection include contaminated seeds, as seem to be the case in this first outbreak, and also transfer to tomatoes from infected ornamental hosts. This is, to the best of our knowledge, the first report of TCDVd in tomato in France. References: (1) T. James et al. Plant Pathol. 57:400, 2008. (2) A. M. Shamloul et al. Can. J. Plant Pathol. 19:89, 1997. (3) R. P. Singh et al. J. Gen. Virol. 80:2823, 1999. 4) R. P. Singh et al. Plant Dis. 90:1457, 2006.
First Report of Papaya ringspot virus Infecting Zucchini Plants in Poland
Authors: Hasiów-Jaroszewska B. , Borodynko N. , Rymelska N. , Pospieszny H. 
Published: April 2010

Papaya ringspot virus (PRSV), a member of the aphid-transmitted genus Potyvirus, is the cause of a destructive disease and a major limiting factor for papaya and cucurbit cultivation worldwide. The virus occurs in China, France, Germany, India, Italy, Mexico, Taiwan, and the United States. Its P biotype is a devastating pathogen of papaya crops and its W biotype is a pathogen of cucurbits (4). In 2009, zucchini plants with leaf mosaic and marbled fruit were collected from the Kujawsko-Pomorskie Region of Poland. Samples came from the same region where Zucchini yellow mosaic virus (ZYMV) (3) and Watermelon mosaic virus (WMV) (1) have been found previously. Forty leaf and ten fruit samples of zucchini (Cucurbita pepo cv. giromontina) were tested by double-antibody sandwich (DAS)-ELISA with commercial antisera against WMV, ZYMV, and PRSV (DSMZ, Braunschweig, Germany). PRSV was found in two samples tested. Leaf extracts from infected plants were mechanically inoculated onto Carborundum-dusted leaves of the following indicator plants: Cucumis sativus, Chenopodium quinoa, Cucurbita pepo, Nicotiana benthamiana, and N. tabacum cv. Xanthi. After 2 weeks, symptoms of leaf chlorosis on cucumber and chlorotic lesions on zucchini were observed. Total RNA was extracted from infected leaves with a phenol-chloroform based extraction procedure. The presence of PRSV was confirmed by reverse transcription (RT)-PCR reaction using primers 04-02 and 04-04, which amplify the coat protein gene (2). Amplified DNA was gel purified with a Qiaex Kit (Qiagen, Valencia, CA) and cloned into pGEM-T easy (Promega, Madison, WI). Overlapping sequences were obtained using universal M13F and M13R primers. BioEdit software ( http://www.mbio.ncsu.edu/BioEdit/bioedit.html ) was used to assemble the nucleotide consensus sequence. The obtained sequence (861 bp encoding 287 amino acids) was deposited in the GenBank database under Accession No. GQ927328. The comparison with PRSV sequences retrieved from the GenBank database were carried out to investigate the genetic diversity between Polish PRSV isolates and establish their molecular relationships to the previously characterized PRSV isolates from different parts of the world. The sequences of PRSV Polish isolates obtained from two infected plant samples were identical. Comparisons revealed that the Polish isolate designated PRSV-BON shared the highest identity (97%) with three Australian isolates (U14739, U14740, and U14744). To our knowledge, this is the first report of PRSV infecting zucchini plants in Poland. The occurrence of subtropic viruses like PRSV in Poland indicated the introduction of new pathogens that likely affect cucurbit production in this country and beyond. References: (1) N. Borodynko et al. Plant Pathol. 58:783, 2009. (2) M. Chin et al. Arch. Virol. 152:2101, 2007. (3) H. Pospieszny et al. Plant Dis. 91:639, 2007. (4) D. J. Purcifull et al. CMI/AAB Descriptions of Plant Viruses. No. 292, 1984.
First Report of a Branch Dieback of Olive Trees in Tunisia Caused by a Phoma sp.
Authors: Rhouma A. , Triki M. A. , Krid S. , Tuset J. J. , Msallem M. 
Published: April 2010

From 2007 to 2008, a new dieback of branches of olive trees was observed in several orchards in central and southern Tunisia. The appearance of this new syndrome coincided with warm temperatures and frequent rainfall from February to April 2007. Affected trees were observed in seven commercial orchards; disease incidence ranged from 1 to 9% and affected trees were randomly distributed in each orchard. Symptoms included abundant dead branches and wilted leaves remained attached. Distinct brown areas appeared on the bark of current-year shoots as well as on larger branches. Cankers on branches that were >2 years old were difficult to detect but were conspicuous in current-year shoots. To determine the etiology of this new syndrome, a study was carried out on samples of affected branches collected from 2007 to 2008 from different areas of the country. Unidentified species of Chaetomium and Phoma were isolated from the margins of the cankers. Koch's postulates were performed with one isolate each of a Chaetomium sp. and a Phoma sp on 2-year-old olive trees, cv. Chemlali, grown in 13-cm-diameter pots containing a sand/lime/peat mixture. Stems were inoculated by placing 10 μl of conidial suspension (106 conidia/ml) on 1-cm-long longitudinal stem wounds that had been made with a sterile scalpel. Control plants were wounded, but inoculum was replaced with sterile distilled water. Three sets of 10 plants each were wound inoculated with each of the fungi on the same day. Inoculated plants were covered with a polyethylene plastic bag to retain moisture and incubated for 2 months at 30°C with a 12-h photoperiod. After 45 days, only branches inoculated with the Phoma isolate showed brown discoloration areas at the inoculation sites. A Phoma sp. was recovered from necrotic bark from each of the 10 inoculated plants. Conidia were hyaline, unicellular, slightly ellipsoidal, and 4.8 to 6.3 × 1.8 to 2.2 μm. To confirm the identification, DNA extraction was done with hyphae collected from a 7-day-old culture on PDA after incubation at 25°C (1). Fungal primers ITS1 and ITS4 (3) were used for amplification. Purified amplicons were directly sequenced using the ITS1 and ITS4 primers for the internal transcribed spacer region of rDNA. A BLAST search of the GenBank database revealed 96% homology with Phoma sp. isolate (AJ972865.1) and 98% homology with Phoma medicaginis isolate (DQ026014.1). P. incompta has been reported as responsible for branch dieback of olive tree in Italy (2). To our knowledge, this is the first report of a canker disease of olive caused by a Phoma sp. in Tunisia. References: (1) S. R. Tendulkar et al. Biotechnol. Lett. 22:1941, 2003. (2) L. Tosi and A. Zazzerini. Petria 4:161, 1994. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.
First Report of Beet necrotic yellow vein virus Infecting Spinach in California
Authors: Liu H.-Y. , Mou B. , Richardson K. , Koike S. T. 
Published: April 2010

In 2009, plants from two spinach (Spinacia oleracea) experimental fields in Monterey County and one commercial spinach field in Ventura County of California exhibited vein-clearing, mottling, interveinal yellowing, and stunting symptoms. For experimental fields, up to 44% of spinach plants have symptoms. With a transmission electron microscope, rigid rod-shaped particles with central canals were observed from plant sap of the symptomatic spinach. Analysis with a double-antibody sandwich-ELISA assay for Beet necrotic yellow vein virus (BNYVV) showed that all 10 symptomatic plants we tested were positive and 5 asymptomatic plants were negative. Symptomatic spinach from both counties was used for mechanical transmission experiments. Chenopodium quinoa, Tetragonia expansa, and Beta vulgaris (sugar beet) showed chlorotic local lesions and B. macrocarpa and spinach showed vein-clearing, mottling, and systemic infections. To further confirm the presence of BNYVV, reverse transcription (RT)-PCR was conducted. Total RNA was extracted from field- and mechanically inoculated symptomatic spinach plants using an RNeasy Plant Kit (Qiagen Inc., Valencia, CA) and used as a template in RT-PCR. Forward and reverse primers specific to the BNYVV RNA-3 P25 protein gene from the beet isolate were used (2). Amplicons of the expected size (approximately 860 bp) were obtained. Four RT-PCR products were sequenced and the sequences were identical (GenBank Accession No. GU135626). Sequences from the spinach plants had 97 to 99% nucleotide and 94 to 100% amino acid identity with BNYVV RNA-3 P25 protein sequences available in the GenBank. On the basis of the data from electron microscopy, indicator plants, serology, and cDNA sequencing, the virus was identified as BNYVV. BNYVV has been reported from spinach fields in Italy (1). To our knowledge, this is the first report of BNYVV occurring naturally on spinach in California. Since BNYVV is transmitted by the zoospores of the soil-inhabiting plasmodiophorid Polymyxa betae, it could be a new threat to spinach production in the state. References: (1) C. R. Autonell et al. Inf. Fitopatol. 45:43, 1995. (2) H.-Y. Liu and R. T. Lewellen, Plant Dis. 91:847, 2007.
Preparation of Trojan Horse Liposomes (THLs) for Gene Transfer across the Blood-Brain Barrier
Authors: Pardridge William M. 
Published: April 2010

INTRODUCTIONNonviral plasmid DNA is delivered to the brain via a transvascular route across the blood-brain barrier (BBB) following intravenous administration of DNA encapsulated within Trojan horse liposomes (THLs), also called PEGylated immunoliposomes (PILs). The liposome surface is covered with several thousand strands of polymer (e.g., polyethylene glycol [PEG]), and the tips of 1%-2% of the polymer strands are conjugated with a targeting monoclonal antibody that acts as a molecular Trojan horse (MTH). The MTH binds to a receptor (e.g., for transferrin or insulin) on the BBB and brain cell membrane, triggering receptor-mediated transcytosis of the THL across the BBB in vivo, and receptor-mediated endocytosis into brain cells beyond the BBB. The persistence of transgene expression in the brain is inversely related to the rate of degradation of the episomal plasmid DNA. THL technology enables an exogenous gene to be widely expressed in the majority of cells in adult brain (or other organs) within 1 d of a single intravenous administration. Applications of the THLs include tissue-specific gene expression with tissue-specific promoters, complete normalization of striatal tyrosine hydroxylase in experimental Parkinson’s disease following intravenous tyrosine hydroxylase gene therapy, a 100% increase in survival time of mice with brain tumors following weekly intravenous antisense gene therapy using THLs, and a 90% increase in survival time with weekly intravenous RNA interference (RNAi) gene therapy in mice with intracranial brain tumors. This protocol describes the preparation of THLs for use in gene transfer in vitro or in vivo.
Optimized DNA Preparation from Mycobacteria
Authors: Käser Michael , Ruf Marie-Thérèse , Hauser Julia , Pluschke Gerd 
Published: April 2010

INTRODUCTIONExtraction of genomic DNA from mycobacteria requires special consideration because (i) many mycobacterial species exhibit extremely slow growth, and thus produce only small amounts of starting material, and (ii) a robust and waxy cell wall renders mycobacteria difficult to lyse. Hence, mycobacterial DNA extraction often results in low DNA yields of unsuitable quality. Published protocols for mycobacterial DNA preparations and commercially available extraction kits are mainly designed for the isolation of small amounts of genomic material suitable for polymerase chain reaction (PCR)-based applications like species identification. However, such DNA quantities and qualities are usually not sufficient for contemporary genomic analyses such as whole genome sequence analysis, single nucleotide polymorphism (SNP) detection, or DNA microarrays, or for investigations of bacterial evolution, virulence, or epidemiology on a world-wide population level. Moreover, most protocols that achieve a high standard in DNA recovery typically employ large reaction volumes and thus require milliliter-scale plasticware and centrifugal equipment as well as large amounts of chemicals, all of which are costly both in purchase and disposal. The DNA extraction method described here was established to address the challenges that result from the slow growth and distinct cell wall composition of mycobacteria, and to greatly enhance both yield and purity of mycobacterial DNA preparations in a small extraction volume. Designed to be performed using 1.5-mL reaction tubes and the corresponding equipment, the method is economical and practical, and reliably yields large amounts of pure genomic DNA--increases of at least 10-fold as compared to earlier protocols.
Calcium Imaging of Neuronal Circuits In Vivo Using a Circuit-Tracing Pseudorabies Virus: Figure 1.
Authors: Granstedt Andrea E. , Kuhn Bernd , Wang Samuel S.-H. , Enquist Lynn W. 
Published: April 2010

INTRODUCTIONPseudorabies virus (PRV) is a neuroinvasive virus of the herpes family that has a broad host range but does not infect higher-order primates. PRV characteristically travels along chains of synaptically connected neurons and has been used extensively for elucidating neural circuits in the peripheral and central nervous system in vivo. The recombinant virus PRV369 is an attenuated retrograde tracer that encodes G-CaMP2, a fluorescent calcium sensor protein that is stable at physiological pH and mammalian temperature. This protocol describes the use of PRV369 to express G-CaMP2 in a neuronal circuit and to monitor its activity in a living animal, specifically in the submandibular ganglia (SMG), the peripheral parasympathetic ganglia that innervate the salivary glands. The procedure describes the delivery of PRV369 to the glands and shows how SMG neurons can then be imaged post-inoculation to explore connectivity and activity.
Live Cell Imaging inDrosophila melanogaster
Authors: Parton Richard M. , Vallés Ana Maria , Dobbie Ian M. , Davis Ilan 
Published: April 2010

INTRODUCTIONAlthough many of the techniques of live cell imaging inDrosophila melanogasterare also used by the greater community of cell biologists working on other model systems, studying living fly tissues presents unique difficulties with regard to keeping the cells alive, introducing fluorescent probes, and imaging through thick, hazy cytoplasm. This article outlines the major tissue types amenable to study by time-lapse cinematography and different methods for keeping the cells alive. It describes various imaging and associated techniques best suited to following changes in the distribution of fluorescently labeled molecules in real time in these tissues. Imaging, in general, is a rapidly developing discipline, and recent advances in imaging technology are able to greatly extend what can be achieved with live cell imaging ofDrosophilatissues. As far as possible, this article includes the latest technical developments and discusses likely future developments in imaging methods that could have an impact on research usingDrosophila.
Green Fluorescent Proteins (GFPs) for Measuring Voltage
Authors: Siegel Micah S. , Isacoff Ehud Y. 
Published: April 2010

INTRODUCTIONMeasuring signal transduction in large numbers of cells, with high spatial and temporal resolution, is a fundamental problem for studying information processing in the nervous system. To address this problem, a family of detectors that are chimeras between signal transduction proteins and fluorescent proteins has been designed. The prototype sensor is a genetically encoded probe that can be used to measure transmembrane voltage in single cells. This article describes a modified green fluorescent protein (GFP), fused to a voltage-sensitive K+ channel, so that voltage-dependent rearrangements in the K+ channel induce changes in the fluorescence of GFP. The probe has a maximal fractional fluorescence change of 5.1%, making it comparable to some of the best organic voltage-sensitive dyes. Moreover, the fluorescent signal is expanded in time in a manner that makes the signal 30-fold easier to detect than a traditional linear dye. DNA-encoded sensors have the advantage that they may be introduced into an organism noninvasively and targeted to specific brain regions, cell types, and subcellular compartments.
Regulation of Microbe-Associated Molecular Pattern-Induced Hypersensitive Cell Death, Phytoalexin Production, and Defense Gene Expression by Calcineurin B-Like Protein-Interacting Protein Kinases, OsCIPK14/15, in Rice Cultured Cells
Authors: Kurusu Takamitsu , Hamada Jumpei , Nokajima Hiroshi , Kitagawa Youichiro , Kiyoduka Masahiro , Takahashi Akira , Hanamata Shigeru , Ohno Ryoko , Hayashi Teruyuki , Okada Kazunori , Koga Jinichiro , Hirochika Hirohiko , Yamane Hisakazu , Kuchitsu Kazuyuki 
Published: April 2010

AbstractAlthough cytosolic free Ca2+ mobilization induced by microbe/pathogen-associated molecular patterns is postulated to play a pivotal role in innate immunity in plants, the molecular links between Ca2+ and downstream defense responses still remain largely unknown. Calcineurin B-like proteins (CBLs) act as Ca2+ sensors to activate specific protein kinases, CBL-interacting protein kinases (CIPKs). We here identified two CIPKs, OsCIPK14 and OsCIPK15, rapidly induced by microbe-associated molecular patterns, including chitooligosaccharides and xylanase (Trichoderma viride/ethylene-inducing xylanase [TvX/EIX]), in rice (Oryza sativa). Although they are located on different chromosomes, they have over 95% nucleotide sequence identity, including the surrounding genomic region, suggesting that they are duplicated genes. OsCIPK14/15 interacted with several OsCBLs through the FISL/NAF motif in yeast cells and showed the strongest interaction with OsCBL4. The recombinant OsCIPK14/15 proteins showed Mn2+-dependent protein kinase activity, which was enhanced both by deletion of their FISL/NAF motifs and by combination with OsCBL4. OsCIPK14/15-RNAi transgenic cell lines showed reduced sensitivity to TvX/EIX for the induction of a wide range of defense responses, including hypersensitive cell death, mitochondrial dysfunction, phytoalexin biosynthesis, and pathogenesis-related gene expression. On the other hand, TvX/EIX-induced cell death was enhanced in OsCIPK15-overexpressing lines. Our results suggest that OsCIPK14/15 play a crucial role in the microbe-associated molecular pattern-induced defense signaling pathway in rice cultured cells.
PLANT HOMOLOGOUS TO PARAFIBROMIN Is a Component of the PAF1 Complex and Assists in Regulating Expression of Genes within H3K27ME3-Enriched Chromatin
Authors: Park Sunchung , Oh Sookyung , Ek-Ramos Julissa , van Nocker Steven 
Published: April 2010

Abstract
The human Paf1 complex (Paf1C) subunit Parafibromin assists in mediating output from the Wingless/Int signaling pathway, and dysfunction of the encoding gene HRPT2 conditions specific cancer-related disease phenotypes. Here, we characterize the organismal and molecular roles of PLANT HOMOLOGOUS TO PARAFIBROMIN (PHP), the Arabidopsis (Arabidopsis thaliana) homolog of Parafibromin. PHP resides in an approximately 670-kD protein complex in nuclear extracts, and physically interacts with other known Paf1C-related proteins in vivo. In striking contrast to the developmental pleiotropy conferred by mutation in other plant Paf1C component genes in Arabidopsis, loss of PHP specifically conditioned accelerated phase transition from vegetative growth to flowering and resulted in misregulation of a very limited subset of genes that included the flowering repressor FLOWERING LOCUS C. Those genes targeted by PHP were distinguished from the bulk of Arabidopsis genes and other plant Paf1C targets by strong enrichment for trimethylation of lysine-27 on histone H3 (H3K27me3) within chromatin. These findings suggest that PHP is a component of a plant Paf1C protein in Arabidopsis, but has a more specialized role in modulating expression of a subset of Paf1C targets.