bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic diversity among Chinese landraces and cultivars of broomcorn millet (Panicum miliaceum) revealed by the polymerase chain reaction
Authors: Hu Y.G. , Zhu J. , Liu F. , Zhang Z. , Chai Y. , Weining S. 
Published: July 2008

AbstractBroomcorn millet is widely grown in Asia and Europe. This cereal is a very efficient user of soil water and is particularly adapted to sandy, dry soils and dry weather conditions. As one of the oldest crops in ancient China, it has played an important role in the formation and development of Chinese civilisation and culture. It is still one of the major grain crops in northern China where harsh climate conditions prevail. The genetic diversity and relationships among 32 accessions of broomcorn millet (Panicum miliaceum) from the major areas for broomcorn millet growing in China, in addition to six Indian landraces, were evaluated by PCR analysis with six introns splice junction or long random primers. A total of 56 DNA fragments across all materials were scored; among them, 42 (75%) were polymorphic as indicated by their absence in at least 1 of the 38 accessions tested, indicating a high variation at the DNA level among those accessions. Pair‐wise genetic dissimilarity (Dice’s coefficient) ranged from 0.0286 to 0.4737. The clustering largely corroborated with the geographical location of the origins of those accessions. The data indicated that the glutinous/non‐glutinous trait is also associated with the clustering. Majorities of the landraces from Yulin of Shaanxi were clustered into five groups, and majorities of the cultivars or breeding lines from Inner Mongolia were clustered into three groups. The results of this study suggest that the landraces from Yulin of Shaanxi were extensively utilised in the breeding programme of Shanxi, whereas this feature was not observed in the breeding programme of Inner Mongolia.
Naturalized Orchid Bee Pollinates Resin‐reward Flowers in Florida: Novel and Known Mutualisms
Authors: Pemberton Robert W. , Liu Hong 
Published: July 2008

ABSTRACTFemales of an orchid bee, Euglossa viridissima, recently naturalized in southern Florida, routinely collect resin to construct their brood cells from the flowers of two Clusia (Clusiaceae) and two Dalechampia (Euphorbiaceae) species. We demonstrated that the bee pollinates three of these species including: (1) the newly naturalized D. scandens, which it pollinates in Mexico; (2) the ornamental D. aristolochiifolia native to Peru; and (3) the ornamental C. lanceolata native to Brazil, but not the apomictic Clusia rosea native to Florida. Field observations indicated that the bee promotes outcrossing in a naturalized D. scandens population. Comparisons of fruit set between unmanipulated control flowers and flowers supplemented with additional pollen indicated that the presence of bee eliminates pollen limitation for cultivated C. lanceolata. The orchid bee's pollination of ornamental resin‐reward plants may promote their naturalization.
The Effect of Typhoons on the Diversity and Distribution Pattern of Aquatic Plants on Hainan Island, South China
Authors: Wang Qiang , Yu Dan , Li Zhongqiang , Wang Ligong 
Published: July 2008

ABSTRACTTyphoons are an important meteorological feature of the tropical southwest Pacific. However, little is known about their effects on aquatic plants. Here, we describe the potential influence of typhoons on the diversity and distribution of aquatic plants on Hainan Island, South China. Using a combination of field survey and published data, 266 species or sub‐species belonging to 115 genera in 57 families were found across typhoon impacted regions of the island. Multiple regression analysis indicated that species richness of aquatic plants was correlated with typhoon incidence rather than the area of aquatic habitat within each region. Heavy rainfall, flooding, and strong winds are likely to create suitable habitats and increase the diversity of aquatic habitats in regions frequently affected by typhoons, which may explain the higher species richness found in those regions. Beta diversity and cluster analyses showed that distinct aquatic floras occurred in regions that were impacted by different typhoon pathways. By comparing the aquatic floras of the Philippines and the typhoon‐affected regions of Hainan, we suggest that typhoons have the potential to transport aquatic plants long distances, although there are a number of other potential explanations for the patterns observed in the aquatic flora of Hainan Island.
Modelling Direct Radiation and Canopy Gap Regimes in Tropical Forests
Authors: Marthews Toby R. , Burslem David F. R. P. , Phillips Ruth T. , Mullins Christopher E. 
Published: July 2008

ABSTRACTSpatial and temporal variation in the below‐canopy light environment of tropical forests is not well known and its measurement is technically challenging. Distributions of gap and understory areas in forests are likewise little known because of the resource requirements of forest structural censuses and a lack of consensus over how gaps should be defined. A basic model of forest structure, based on tree allometries from the 50 ha Forest Dynamics Plot on Barro Colorado Island (BCI), Panama, and a solar positioning algorithm were used to predict spatial and temporal variation in the distribution of direct light at the forest floor. Predicted duration of direct sunlight was then compared with the distribution of gap and understory areas, delimited according to four standard gap definitions, giving predictions for the correspondence between direct light regimes and forest structure. At least 36 percent of the areas of gaps of all sizes was predicted to receive < 1 h of direct sunlight per day, and the understory to receive direct sunlight for ≥ 1 h per day in up to 15 percent of its area, even when not in proximity to gaps. The predicted distribution of light changed over the course of the year with the greatest spread of light throughout the forest floor coinciding with the months when maximum daily solar elevation peaked. These predictions suggest a partial decoupling of light regimes from canopy structure, with implications for gap definitions, patch models of forest development and current understanding of tree seedling recruitment patterns.
SAD2 in Arabidopsis Functions in Trichome Initiation through Mediating GL3 Function and Regulating GL1, TTG1 and GL2 Expression
Authors: Gao Ying , Gong Ximing , Cao Wanhong , Zhao Jinfeng , Fu Liqin , Wang Xuechen , Schumaker Karen S. , Guo Yan 
Published: July 2008

Abstract Most genes identified that control Arabidopsis trichome initiation and formation are transcription factors or regulatory components in transcriptional networks and include GLABROUS1 (GL1), GLABRA2 (GL2), GLABRA3 (GL3) and TRANSPARENT TESTA GLABRA1 (TTG1). Herein, we report that an importin β‐like protein, SENSITIVE TO ABA AND DROUGHT2 (SAD2), is required for trichome initiation. Mutations in SAD2 disrupted trichome initiation resulting in reduced trichome number, but had no effect on trichome development or root hair number and development. Expression levels of GL1, MYB23, GL2 and TTG1 were reduced in shoots of sad2 mutants while expression levels of GL3 and ENHANCER OF GLABRA3 (EGL3) were enhanced. Overexpression of GL3 increased trichome numbers in wild type but not in sad2 mutants, indicating that the function of the GL3 protein is altered in the sad2 mutants. In contrast, overexpression of GFP‐GL1 decreased trichome number in both wild type and sad2. Double mutant analysis of gl1 sad2 and gl3 sad2 indicated that SAD2 functions genetically, at least in part, in the same pathway with these two genes. Co‐immunoprecipitation indicated that the sad2 mutation does not disrupt formation of the TTG1‐GL3‐GL1 complex. Analysis of GFP fusions of GL1, GL2, GL3 and TTG1 suggested that these proteins are most likely not direct cargo of SAD2. Our data suggest that SAD2 is involved in trichome initiation by regulating these nuclear genes.
Signaling Components Involved in Plant Responses to Phosphate Starvation
Authors: Yuan Hui , Liu Dong 
Published: July 2008

Abstract Phosphorus is one of the macronutrients essential for plant growth and development. Many soils around the world are deficient in phosphate (Pi) which is the form of phosphorus that plants can absorb and utilize. To cope with the stress of Pi starvation, plants have evolved many elaborate strategies to enhance the acquisition and utilization of Pi from the environment. These strategies include morphological, biochemical and physiological responses which ultimately enable plants to better survive under low Pi conditions. Though these adaptive responses have been well described because of their ecological and agricultural importance, our studies on the molecular mechanisms underlying these responses are still in their infancy. In the last decade, significant progresses have been made towards the identification of the molecular components which are involved in the control of plant responses to Pi starvation. In this article, we first provide an overview of some major responses of plants to Pi starvation, then summarize what we have known so far about the signaling components involved in these responses, as well as the roles of sugar and phytohormones.
Floristics and Plant Biogeography in China
Authors: Li De‐Zhu 
Published: July 2008

Abstract In 1998, a revolutionary system of angiosperm classification, the Angiosperm Phylogeny Group system was published. Meanwhile, another new system of classification of angiosperms, the eight‐class system was proposed by C. Y. Wu and colleagues based on long term work on the flora of China. The Flora Reipublicae Popularis Sinicae project was initiated in 1959 and completed by 2004. It is the largest Flora so far completed in the world, including 31 228 species of vascular plants, or one‐eighth of the global plant diversity. The English‐language and updated Flora of China (FOC) is an international joint effort initiated in 1988 and accelerated in 1998. Up to now, 15 of the 24 volumes of the FOC have been published. Based on the floristic data, the composition, characteristics, floristic divisions and affinities of the flora of China have been studied by Wu and colleagues since 1965. In the past 10 years, analyses of the available floristic data have been very productive. The East Asiatic Floristic Kingdom was proposed in 1998. All 346 families of angiosperms in China, according to the eight‐class system of classification, were comprehensively discussed by using knowledge of current and historical distribution of seed plants in the world, together with some morphological and molecular data. A scheme of distribution patterns or areal‐types of families and genera of seed plants in China was modified and elucidated, together with a proposed scheme of areal‐types of the world. Molecular phylogenetic and biogeographical studies of angiosperms in China in the past 10 years also witnessed a progressive development. Integration of morphological and molecular data and fossil evidence revealed some significant results. Eastern Asia, which used to be regarded as an important center of survival during the ice age, is likely an important center of diversification of angiosperms.
Simplified Categorization of Outdoor Activities for Male and Female U.S. Indoor Workers—A Feasibility Study to Improve Assessment of Ultraviolet Radiation Exposures in Epidemiologic Study Questionnaires
Authors: Kwok Richard K. , Linet Martha S. , Chodick Gabriel , Kleinerman Ruth A. , Freedman Daryl M. , Fears Tom , Johnson Ruby E. , Alexander Bruce H. 
Published: July 2008

AbstractSkin cancer studies depend on questionnaires to estimate exposure to ultraviolet light and subsequent risk but are limited by recall bias. We investigate the feasibility of developing a short checklist of categories comprising outdoor activities that can improve sun exposure questionnaires for use in epidemiologic studies. We recruited 124 working and retired U.S. radiologic technologists (52% women). Each subject was instructed to complete a daily activity diary, listing main indoor and outdoor activities between 9:00 A.M. and 5:00 P.M. during a 7 day period. A total of 4697 entries were associated with 1408 h (21.1%) of the total 6944 h spent outdoors. We were able to classify the activities into seven main activity categories: driving, yard work, home‐maintenance, walking or performing errands, water activities, other recreational or sports activities and leisure activities or relaxing outside. These activities accounted for more than 94% of time spent outdoors both for working and retired men and women. Our data document the feasibility and guidance for developing a short checklist of outdoor activities for use in epidemiologic questionnaires for estimating sunlight exposures of working and retired indoor workers.
Crayfish Procambarus clarkii Retina and Nervous System Exhibit Antioxidant Circadian Rhythms Coupled with Metabolic and Luminous Daily Cycles
Authors: Fanjul‐Moles María Luisa , Prieto‐Sagredo Julio , López Dario Santiago , Bartolo‐Orozco Ramón , Cruz‐Rosas Hugo 
Published: July 2008

AbstractBased on previous work in which we proposed midgut as a putative peripheral oscillator responsible for circadian reduced glutathione (GSH) crayfish status, herein we investigated the retina and optic lobe‐brain (OL‐B) circadian GSH system and its ability to deal with reactive oxygen species (ROS) produced as a consequence of metabolic rhythms and light variations. We characterized daily and antioxidant circadian variations of the different parameters of the glutathione system, including GSH, oxidized glutathione (GSSG), glutathione reductase (GR) and glutathione peroxidase (GPx), as well as metabolic and lipoperoxidative circadian oscillations in retina and OL‐B, determining internal and external GSH‐system synchrony. The results demonstrate statistically significant bi‐ and unimodal daily and circadian rhythms in all GSH‐cycle parameters, substrates and enzymes in OL‐B and retina, as well as an apparent direct effect of light on these rhythms, especially in the retina. The luminous condition appears to stimulate the GSH system to antagonize ROS and lipid peroxidation (LPO) daily and circadian rhythms occurring in both structures, oscillating with higher LPO under dark conditions. We suggest that the difference in the effect of light on GSH rhythmic mechanisms of both structures for antagonizing ROS could be due to differences in glutathione‐system coupling strength with the circadian clock.
Flavodoxin Relaxes in Microseconds Upon Excitation of the Flavin Chromophore: Detection of a UV–Visible Silent Intermediate by Laser Photocalorimetry
Authors: Martínez‐Junza Víctor , Rizzi Alberto C. , Alagaratnam Sharmini , Bell Toby D. M. , Canters Gerard W. , Braslavsky Silvia E. 
Published: July 2008

AbstractA small contraction concomitant with the relaxation of the protein in ca. 3 μs is observed upon ns‐laser excitation at 455 nm of the Cys69Ala (C69A) mutant of flavodoxin II from Azotobacter vinelandii. This constitutes another example of detection of a UV–vis silent transient species through a photocalorimetric technique. The contraction is attributed to reorganization of protein dihedral bonds and of water molecules at relatively long distances from the flavin chromophore, after the protein has received the heat shock from the relaxing photoproduced charge transfer state. This study constitutes a preliminary step towards the understanding of the origin of protein movements taking place upon electron transfer reactions, e.g. between a photoinduced electron donor (or acceptor) and an accepting (or donating) cofactor in a protein.
Characterization of the bone marrow immunofluorescence test in childhood autoimmune neutropenia
Authors: LANE S. W. , HASSELL P. , KENNEDY G. A. , FUNG Y. L. , WILLIAMS B. A. 
Published: July 2008

SummaryThe bone marrow immunofluorescenece test (BMIFT) demonstrates autoantibodies to granulocytes and their precursors on fresh‐frozen bone marrow slides. It may be used to differentiate childhood autoimmune neutropenia (AIN) from other causes of childhood neutropenia, even when circulating neutrophil counts are low. We sought to characterize the diagnostic utility of the BMIFT in childhood AIN. All BMIFT requests for investigation of children with neutropenia between January 1998 and May 2007 were reviewed. Patients were classified as AIN or nonautoimmune causes. Baseline demographic data, results of BMIFT, granulocyte immunofluorescence testing and bone marrow findings were collected from clinical records and the institutional laboratory database. Seventy‐six children had BMIFT performed for investigation of neutropenia. There were 45 patients diagnosed with AIN, 28 with nonimmune neutropenia and three failed tests. The median age of children with AIN was 1.2 years (range 0.3–15.3), compared with 3.6 years (range 0.1–15.7) in the nonautoimmune group. The median neutrophil count in AIN was 0.3 × 109/l (0.9 × 109/l in nonautoimmune). BMIFT was positive in 24 of 45 patients with AIN and 0 of 28 with nonautoimmune neutropenia (sensitivity 53%, specificity 100%, positive predictive value (PPV) 100%, negative predictive value 57%). Ten patients had other autoimmune diatheses at diagnosis. The BMIFT is a simple, highly specific test with excellent PPV and thus is a clinically useful test to confirm AIN in children.
Genetic and Structural Insights into the Dissemination Potential of the Extremely Broad-Spectrum Class A β-Lactamase KPC-2 Identified in an
Escherichia coli
Strain and an
Enterobacter cloacae
Strain Isolated from the Same Patient in France
Authors: Petrella Stephanie , Ziental-Gelus Nathalie , Mayer Claudine , Renard Murielle , Jarlier Vincent , Sougakoff Wladimir 
Published: July 2008

ABSTRACT

Two clinical strains of
Escherichia coli
(2138) and
Enterobacter cloacae
(7506) isolated from the same patient in France and showing resistance to extended-spectrum cephalosporins and low susceptibility to imipenem were investigated. Both strains harbored the plasmid-contained
bla
TEM-1
and
bla
KPC-2
genes.
bla
KLUC-2
, encoding a mutant of the chromosomal β-lactamase of
Kluyvera cryocrescens
, was also identified at a plasmid location in
E. cloacae
7506, suggesting the IS
Ecp1
-assisted escape of
bla
KLUC
from the chromosome. Determination of the KPC-2 structure at 1.6 Å revealed that the binding site was occupied by the C-terminal (C-ter) residues coming from a symmetric KPC-2 monomer, with the ultimate C-ter Glu interacting with Ser130, Lys234, Thr235, and Thr237 in the active site. This mode of binding can be paralleled to the inhibition of the TEM-1 β-lactamase by the inhibitory protein BLIP. Determination of the 1.23-Å structure of a KPC-2 mutant in which the five C-ter residues were deleted revealed that the catalytic site was filled by a citrate molecule. Structure analysis and docking simulations with cefotaxime and imipenem provided further insights into the molecular basis of the extremely broad spectrum of KPC-2, which behaves as a cefotaximase with significant activity against carbapenems. In particular, residues 104, 105, 132, and 167 draw a binding cavity capable of accommodating both the aminothiazole moiety of cefotaxime and the 6α-hydroxyethyl group of imipenem, with the binding of the former drug being also favored by a significant degree of freedom at the level of the loop at positions 96 to 105 and by an enlargement of the binding site at the end of strand β3.
Mechanism of Action of the Antibiotic NXL101, a Novel Nonfluoroquinolone Inhibitor of Bacterial Type II Topoisomerases
Authors: Black Michael T. , Stachyra Thérèse , Platel Denis , Girard Anne-Marie , Claudon Monique , Bruneau Jean-Michel , Miossec Christine 
Published: July 2008

ABSTRACT

NXL101 is one of a new class of quinoline antibacterial DNA gyrase and topoisomerase IV inhibitors showing potent activity against gram-positive bacteria, including methicillin- and fluoroquinolone-resistant strains. NXL101 inhibited topoisomerase IV more effectively than gyrase from
Escherichia coli
, whereas the converse is true of enzymes from
Staphylococcus aureus
. This apparent target preference is opposite to that which is associated with most fluoroquinolone antibiotics. In vitro isolation of
S. aureus
mutants resistant to NXL101 followed by cloning and sequencing of the genes encoding gyrase and topoisomerase IV led to the identification of several different point mutations within, or close to, the quinolone resistance-determining region (QRDR) of GyrA. However, the mutations were not those that are most frequently associated with decreased sensitivity to quinolones. A fluoroquinolone-resistant mutant variant of gyrase generated in vitro was highly resistant to inhibition by the fluoroquinolones ciprofloxacin and moxifloxacin but remained fully susceptible to inhibition by NXL101. Two mutant gyrases constructed in vitro, with mutations in
gyrA
engineered according to those most frequently found in
S. aureus
strains resistant to NXL101, were insensitive to inhibition by NXL101 and had a diminished sensitivity to ciprofloxacin and moxifloxacin. Certain combinations of mutations giving rise to NXL101 resistance and those giving rise to fluoroquinolone resistance may be mutually exclusive.
Recombination and Selection Can RemoveblaTEMAlleles from Bacterial Populations
Authors: Mroczkowska Joanna E. , Barlow Miriam 
Published: July 2008

ABSTRACTWe passaged cells expressing TEM-1 and TEM-12 from a single plasmid through either ampicillin or ceftazidime. We found that the combined effects of recombination and selection removed theblaTEM-1allele from the bacterial population when it was passaged through ceftazidime or theblaTEM-12allele when cultures were passaged through ampicillin.
Evaluation of a Multiplex Flow Immunoassay for Detection of Epstein-Barr Virus-Specific Antibodies
Authors: Binnicker M. J. , Jespersen D. J. , Harring J. A. , Rollins L. O. , Beito E. M. 
Published: July 2008

ABSTRACTConventional methods for the detection of Epstein-Barr virus (EBV)-specific antibodies include the immunofluorescence assay (IFA) and enzyme immunoassay (EIA). While sensitive and specific, these methods are labor-intensive and require separate assays for each analyte. This study evaluated the performance of a multiplex bead assay (BioPlex 2200; Bio-Rad Laboratories, Hercules, CA) for the simultaneous detection of immunoglobulin G (IgG) and IgM class antibodies to the EBV viral capsid antigen (VCA) and IgG class antibodies to Epstein-Barr virus nuclear antigen-1 (EBNA-1). Serum specimens (n= 1,315) submitted for routine EBV-specific antibody testing by EIA (Grifols-Quest, Inc., Miami, FL) were also tested by the multiplex bead assay using the BioPlex 2200 automated analyzer. Specimens showing discordant results were tested by IFA. Following IFA resolution, the BioPlex VCA IgM, VCA IgG, and EBNA-1 IgG assays demonstrated 97.9%, 91.4%, and 96.9% agreement, respectively, with the results obtained by EIA. Furthermore, the BioPlex assays showed an overall agreement of 94.1% with the EIA when the specimens were categorized by disease state (susceptible, acute, or past infection) based on the EBV-specific antibody profiles. These findings indicate that the BioPlex EBV assays demonstrate a performance comparable to that of the conventional EIA, while allowing for a more rapid (2.3 h for 100 samples versus 4.5 h by the EIA) and higher-throughput (∼400 samples per 9 h versus 200 samples by the EIA) analysis of the EBV-specific antibody response.