bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in the composition of phytate, phosphorus and other cations in soybean seeds with maturity
Authors: Saneoka Hirofumi , Hosokawa Takeshi , Yorizane Akihiro , Nakayama Nobuhiro , Itani Tomio , Fujita Kounosuke 
Published: October 2006

AbstractA field experiment was conducted to investigate the phytate, phosphorus (P), calcium (Ca), magnesium (Mg), potassium (K), iron (Fe), zinc (Zn) and manganese (Mn) contents during seed development and plant growth in soybean plants (Glycine max (L) Merr.). The amount of total P in plants increased with increasing plant dry weight. The seed P content increased sharply from anthesis, and the P distribution percentage in the seed reached 35% of the absorbed P at the full‐maturity stage. The P content in flowers was 5.62 g kg−1 dry matter, and that in the seed increased to 7.75 and 9.59 g kg−1 dry matter at 30 and 75 days after anthesis, respectively. The percentages of organic P and cellular P contents in the grain reached to 80–90% of the total P content at early immaturity stage, while it decreased with seed maturity. The percentage of phytic acid P in seeds to total P content was 68% at the full maturity stage. The phytate concentration negatively correlated with Ca, Mg, Zn, Mn and Fe concentrations in the seed; however, the total P concentrations in the seed correlated positively and the K concentration did not correlate with the phytate concentration. The Ca, Mg, Zn, Mn and Fe accumulated greatly at the early maturity stage of seeds; however, phytate accumulated with the increase in total P concentration with seed maturity.
Simple technique for estimating nitrate nitrogen concentration of Italian ryegrass (Lolium multiflorum Lam.) at the heading stage using a chlorophyll meter
Authors: Sunaga Yoshihito , Harada Hisatomi , Kawachi Tahei , Hatanaka Tetsuya , Ebato Munehiro 
Published: October 2006

AbstractA simple technique for estimating the nitrate nitrogen (NO3‐N) concentration of crop in a field was developed for diploid Italian ryegrass (Lolium multiflorum Lam.) at the heading stage, using a hand‐held chlorophyll meter (SPAD‐502). A rapid method for estimating the NO3‐N concentration in the crop is required in order to feed cattle safely, since high levels of NO3‐N in crops cause the nitrate poisoning of ruminants. The SPAD reading was determined as an average for the middle part of 10 flag leaves. SPAD readings for a variety of Nioudachi were correlated with reduced nitrogen concentrations with the following equation: reduced N concentration (g kg−1 DM) = 0.563 × SPAD reading −11.492 with a coefficient of determination of 0.715. SPAD readings also increased with NO3‐N concentrations. However, the relationship did not seem to fit a linear curve. A critical value for the SPAD reading was 47 for a NO3‐N concentration of 2.0 g kg−1 DM, a critical value for the acute nitrate poisoning of ruminants. The critical SPAD reading value was applicable for eight of 10 other varieties tested. Yields for Nioudachi were increased with the increase in SPAD readings and maximal yields within a year were obtained with SPAD readings over 45, which were less than the critical value for NO3‐N accumulation. Therefore, it is possible to manage nitrogen levels to obtain sufficient yields and prevent acute nitrate poisoning.
Constitutive Model for
Fiber-Reinforced Composite Laminates
Authors: Luccioni Bibiana
M. 
Published: October 2006

Abstract
Nowadays, conventional materials have been progressively replaced by composite materials in a wide variety of applications. Particularly, fiber reinforced composite laminates are widely used. The appropriate design of elements made of this type of material requires the use of constitutive models capable of estimating their stiffness and strength. A general constitutive model for fiber reinforced laminated composites is presented in this paper. The model is obtained as a generalization of classical mixture theory taking into account the relations among the strains and stresses in the components and the composite in principal symmetry directions of the material. The constitutive equations for the laminated composite result from the combination of lamina constitutive equations that also result from the combination of fibers and matrix. It is assumed that each one of the components are orthotropic and elastoplastic. Basic assumptions of the proposed model and the resulting equations are first presented in the paper. The numerical algorithm developed for the implementation in a three-dimensional (3D) finite element nonlinear program is also described. The paper is completed with application examples and comparison with experimental results. The comparison shows the capacity of the proposed model for the simulation of stiffness and strength of different composite laminates.
BdlA, a Chemotaxis Regulator Essential for Biofilm Dispersion in
Pseudomonas aeruginosa
Authors: Morgan Ryan , Kohn Steven , Hwang Sung-Hei , Hassett Daniel J. , Sauer Karin 
Published: October 2006

ABSTRACT

Multiple environmental cues have been shown to trigger biofilm detachment, the transition from surface-attached, highly organized communities known as biofilms to the motile lifestyle. The goal of this study was to identify a gene product involved in sensing environmental cues that trigger biofilm dispersion in
Pseudomonas aeruginosa
. To do so, we focused on novel putative chemotaxis transducer proteins that could potentially be involved in environmental sensing. We identified a locus encoding such a protein that played a role in detachment, as indicated by the observation that an isogenic mutant biofilm could not disperse in response to a variety of environmental cues. The locus was termed
bdlA
for
b
iofilm
d
ispersion
l
ocus. The BdlA protein harbors an MCP (
m
ethyl-accepting
c
hemotaxis
p
rotein) domain and two PAS (
P
er-
A
rnt-
S
int) domains that have been shown to be essential for responding to environmental signals in other proteins. The dispersion-deficient phenotype of the
bdlA
mutant was confirmed by treatment with the biocide H
2
O
2
and by microscopic observations. The dispersion response was independent of motility.
bdlA
mutant biofilms were found to have increased adherent properties and increased intracellular levels of cyclic di-GMP (c-di-GMP). Our findings suggest that BdlA may be a link between sensing environmental cues, c-di-GMP levels, and detachment. Based on our findings, a possible involvement of BdlA in a signaling cascade resulting in biofilm dispersion is discussed.
Isocitrate Dehydrogenase of
Bradyrhizobium japonicum
Is Not Required for Symbiotic Nitrogen Fixation with Soybean
Authors: Shah Ritu , Emerich David W. 
Published: October 2006

ABSTRACT

A mutant strain of
Bradyrhizobium japonicum
USDA110 lacking isocitrate dehydrogenase activity was created to determine whether this enzyme was required for symbiotic nitrogen fixation with soybean (
Glycine max
cv. Williams 82). The isocitrate dehydrogenase mutant, strain 5051, was constructed by insertion of a streptomycin resistance gene cassette. The mutant was devoid of isocitrate dehydrogenase activity and of immunologically detectable protein, indicating there is only one copy in the genome. Strain 5051 grew well on a variety of carbon sources, including arabinose, pyruvate, succinate, and malate, but, unlike many microorganisms, was a glutamate auxotroph. Although the formation of nodules was slightly delayed, the mutant was able to form nodules on soybean and reduce atmospheric dinitrogen as well as the wild type, indicating that the plant was able to supply sufficient glutamate to permit infection. Combined with the results of other citric acid cycle mutants, these results suggest a role for the citric acid cycle in the infection and colonization stage of nodule development but not in the actual fixation of atmospheric dinitrogen.
Reciprocal Transcriptional and Posttranscriptional Growth-Phase-Dependent Expression of
sfh
, a Gene That Encodes a Paralogue of the Nucleoid-Associated Protein H-NS
Authors: Doyle Marie , Dorman Charles J. 
Published: October 2006

ABSTRACT

The IncHI1 self-transmissible plasmid pSf-R27 from
Shigella flexneri
2a strain 2457T harbors
sfh
, a gene that codes for a protein with strong amino acid sequence homology to the global transcription regulator and nucleoid-associated protein H-NS and to its paralogue, StpA. Previously, we discovered that the expression of
sfh
mRNA is growth phase dependent such that in cultures growing in Lennox broth at 37°C, the transcript is readily detectable in the early stages of exponential growth but is not detectable at the onset of stationary phase. In contrast, the Sfh protein is poorly expressed in early-exponential growth when
sfh
mRNA is abundant whereas it is expressed to a high level in early stationary phase, when
sfh
transcript expression is low (P. Deighan, C. Beloin, and C. J. Dorman, Mol. Microbiol. 48:1401-1416, 2003). This unusual pattern of reciprocal mRNA and protein expression is not due to growth phase-dependent effects on either mRNA or protein stability, nor is it due to the known abilities of the Sfh, StpA, and H-NS proteins to influence
sfh
gene expression. Instead, our data point to a blockade of
sfh
mRNA translation in early-exponential growth that is relieved as the culture enters the stationary phase of growth. Replacing the 5′ end and translation initiation signals of the
sfh
mRNA with heterologous sequences did not alter the growth phase-dependent expression of the Sfh protein, suggesting that growth phase control of translation is intrinsic to another component of the message.
Neisseria gonorrhoeae
DNA Recombination and Repair Enzymes Protect against Oxidative Damage Caused by Hydrogen Peroxide
Authors: Stohl Elizabeth A. , Seifert H. Steven 
Published: October 2006

ABSTRACT

The strict human pathogen
Neisseria gonorrhoeae
is exposed to oxidative damage during infection.
N. gonorrhoeae
has many defenses that have been demonstrated to counteract oxidative damage. However,
recN
is the only DNA repair and recombination gene upregulated in response to hydrogen peroxide (H
2
O
2
) by microarray analysis and subsequently shown to be important for oxidative damage protection. We therefore tested the importance of RecA and DNA recombination and repair enzymes in conferring resistance to H
2
O
2
damage.
recA
mutants, as well as RecBCD (
recB
,
recC
, and
recD
) and RecF-like pathway mutants (
recJ
,
recO
, and
recQ
), all showed decreased resistance to H
2
O
2
. Holliday junction processing mutants (
ruvA
,
ruvC
, and
recG
) showed decreased resistance to H
2
O
2
resistance as well. Finally, we show that RecA protein levels did not increase as a result of H
2
O
2
treatment. We propose that RecA, recombinational DNA repair, and branch migration are all important for H
2
O
2
resistance in
N. gonorrhoeae
but that constitutive levels of these enzymes are sufficient for providing protection against oxidative damage by H
2
O
2
.
Mutations in Four Regulatory Genes Have Interrelated Effects on Heterocyst Maturation in
Anabaena
sp. Strain PCC 7120
Authors: Lechno-Yossef Sigal , Fan Qing , Ehira Shigeki , Sato Naoki , Wolk C. Peter 
Published: October 2006

ABSTRACT

Regulatory genes
hepK
,
hepN
,
henR
, and
hepS
are required for heterocyst maturation in
Anabaena
sp. strain PCC 7120. They presumptively encode two histidine kinases, a response regulator, and a serine/threonine kinase, respectively. To identify relationships between those genes, we compared global patterns of gene expression, at 14 h after nitrogen step-down, in corresponding mutants and in the wild-type strain. Heterocyst envelopes of mutants affected in any of those genes lack a homogeneous, polysaccharide layer. Those of a
henR
mutant also lack a glycolipid layer.
patA
, which encodes a positive effector of heterocyst differentiation, was up-regulated in all mutants except the
hepK
mutant, suggesting that
patA
expression may be inhibited by products related to heterocyst development.
hepS
and
hepK
were up-regulated if mutated and so appear to be negatively autoregulated. HepS and HenR regulated a common set of genes and so appear to belong to one regulatory system. Some nontranscriptional mechanism may account for the observation that
henR
mutants lack, and
hepS
mutants possess, a glycolipid layer, even though both mutations down-regulated genes involved in formation of the glycolipid layer. HepK and HepN also affected transcription of a common set of genes and therefore appear to share a regulatory pathway. However, the transcript abundance of other genes differed very significantly from expression in the wild-type strain in either the
hepK
or
hepN
mutant while differing very little from wild-type expression in the other of those two mutants. Therefore,
hepK
and
hepN
appear to participate also in separate pathways.
Requirement for the Cell Division Protein DivIB in Polar Cell Division and Engulfment during Sporulation inBacillus subtilis
Authors: Thompson L. S. , Beech P. L. , Real G. , Henriques A. O. , Harry E. J. 
Published: October 2006

ABSTRACTDuring spore formation inBacillus subtilis, cell division occurs at the cell pole and is believed to require essentially the same division machinery as vegetative division. Intriguingly, although the cell division protein DivIB is not required for vegetative division at low temperatures, it is essential for efficient sporulation under these conditions. We show here that at low temperatures in the absence of DivIB, formation of the polar septum during sporulation is delayed and less efficient. Furthermore, the polar septa that are complete are abnormally thick, containing more peptidoglycan than a normal polar septum. These results show that DivIB is specifically required for the efficient and correct formation of a polar septum. This suggests that DivIB is required for the modification of sporulation septal peptidoglycan, raising the possibility that DivIB either regulates hydrolysis of polar septal peptidoglycan or is a hydrolase itself. We also show that, despite the significant number of completed polar septa that form in this mutant, it is unable to undergo engulfment. Instead, hydrolysis of the peptidoglycan within the polar septum, which occurs during the early stages of engulfment, is incomplete, producing a similar phenotype to that of mutants defective in the production of sporulation-specific septal peptidoglycan hydrolases. We propose a role for DivIB in sporulation-specific peptidoglycan remodelling or its regulation during polar septation and engulfment.
COST SIMULATION AND PERFORMANCE OPTIMIZATION OF WEB-BASED APPLICATIONS ON MOBILE CHANNELS
Authors: BOOK MATTHIAS , GRUHN VOLKER , HÜLDER MALTE , KÖHLER ANDRÉ , KRIEGEL ANDREAS 
Published: October 2006

When considering the addition of a mobile presentation channel to an existing web-based application, a key question that has to be answered even before development begins is how the mobile channel's characteristics will impact the user experience and the cost of using the application. If either of these factors is outside acceptable limits, economical considerations may forbid adding the channels, even if it would be feasible from a purely technical perspective. Both of these factors depend considerably on two metrics: The time required to transmit data over the mobile network, and the volume transmitted. The PETTICOAT method presented in this paper uses the dialog flow model and web server log files of an existing application to identify typical interaction sequences and to compile volume statistics, which are then run through a tool that simulates the volume and time that would be incurred by executing the interaction sequences on a mobile channel. From the simulated volume and time data, we can then calculate the cost of accessing the application on a mobile channel, and derive suitable approaches for optimizing cost and response times.
Decreased Chicken Ovalbumin Upstream Promoter Transcription Factor II Expression in Tamoxifen-Resistant Breast Cancer Cells
Authors: Riggs Krista A. , Wickramasinghe Nalinie S. , Cochrum Renate K. , Watts Mary Beth , Klinge Carolyn M. 
Published: October 2006

Abstract
Tamoxifen (TAM) is successfully used for the treatment and prevention of breast cancer. However, many patients that are initially TAM responsive develop tumors that are antiestrogen/TAM resistant (TAM-R). The mechanism behind TAM resistance in estrogen receptor α (ERα)–positive tumors is not understood. The orphan nuclear receptor chicken ovalbumin upstream promoter transcription factor (COUP-TF)-I interacts directly with 4-hydroxytamoxifen (4-OHT)- and estradiol (E2)-occupied ERα, corepressors NCoR and SMRT, and inhibit E2-induced gene transcription in breast cancer cells. Here we tested the hypothesis that reduced COUP-TFI and COUP-TFII correlate with TAM resistance. We report for the first time that COUP-TFII, but not COUP-TFI, is reduced in three antiestrogen/TAM-R cell lines derived from TAM-sensitive (TAM-S) MCF-7 human breast cancer cells and in MDA-MB-231 cells compared with MCF-7. ERα and ERβ protein expression was not different between TAM-S and TAM-R cells, but progesterone receptor (PR) was decreased in TAM-R cells. Further, E2 increased COUP-TFII transcription in MCF-7, but not TAM-R, cells. Importantly, reexpression of COUP-TFII in TAM-S cells to levels comparable to those in MCF-7 was shown to increase 4-OHT-mediated growth inhibition and increased apoptosis. Conversely, knockdown of COUP-TFII in TAM-S MCF-7 cells blocked growth inhibitory activity and increased 4-OHT agonist activity. 4-OHT increased COUP-TFII-ERα interaction ∼2-fold in MCF-7 cells. COUP-TFII expression in TAM-R cells also inhibited 4-OHT-induced endogenous PR and pS2 mRNA expression. These data indicate that reduced COUP-TFII expression correlates with acquired TAM resistance in human breast cancer cell lines and that COUP-TFII plays a role in regulating the growth inhibitory activity of TAM in breast cancer cells. (Cancer Res 2006; 66(20): 10188-98)
High-risk Melanoma Susceptibility Genes and Pancreatic Cancer, Neural System Tumors, and Uveal Melanoma across GenoMEL
Authors: Goldstein Alisa M. , Chan May , Harland Mark , Gillanders Elizabeth M. , Hayward Nicholas K. , Avril Marie-Francoise , Azizi Esther , Bianchi-Scarra Giovanna , Bishop D. Timothy , Bressac-de Paillerets Brigitte , Bruno William , Calista Donato , Cannon Albright Lisa A. , Demenais Florence , Elder David E. , Ghiorzo Paola , Gruis Nelleke A. , Hansson Johan , Hogg David , Holland Elizabeth A. , Kanetsky Peter A. , Kefford Richard F. , Landi Maria Teresa , Lang Julie , Leachman Sancy A. , MacKie Rona M. , Magnusson Veronica , Mann Graham J. , Niendorf Kristin , Newton Bishop Julia , Palmer Jane M. , Puig Susana , Puig-Butille Joan A. , de Snoo Femke A. , Stark Mitchell , Tsao Hensin , Tucker Margaret A. , Whitaker Linda , Yakobson Emanuel ,   The Lund Melanoma Study Group,   the Melanoma Genetics Consortium (GenoMEL)
Published: October 2006

Abstract
GenoMEL, comprising major familial melanoma research groups from North America, Europe, Asia, and Australia has created the largest familial melanoma sample yet available to characterize mutations in the high-risk melanoma susceptibility genes CDKN2A/alternate reading frames (ARF), which encodes p16 and p14ARF, and CDK4 and to evaluate their relationship with pancreatic cancer (PC), neural system tumors (NST), and uveal melanoma (UM). This study included 466 families (2,137 patients) with at least three melanoma patients from 17 GenoMEL centers. Overall, 41% (n = 190) of families had mutations; most involved p16 (n = 178). Mutations in CDK4 (n = 5) and ARF (n = 7) occurred at similar frequencies (2-3%). There were striking differences in mutations across geographic locales. The proportion of families with the most frequent founder mutation(s) of each locale differed significantly across the seven regions (P = 0.0009). Single founder CDKN2A mutations were predominant in Sweden (p.R112_L113insR, 92% of family's mutations) and the Netherlands (c.225_243del19, 90% of family's mutations). France, Spain, and Italy had the same most frequent mutation (p.G101W). Similarly, Australia and United Kingdom had the same most common mutations (p.M53I, c.IVS2-105A&gt;G, p.R24P, and p.L32P). As reported previously, there was a strong association between PC and CDKN2A mutations (P &lt; 0.0001). This relationship differed by mutation. In contrast, there was little evidence for an association between CDKN2A mutations and NST (P = 0.52) or UM (P = 0.25). There was a marginally significant association between NST and ARF (P = 0.05). However, this particular evaluation had low power and requires confirmation. This GenoMEL study provides the most extensive characterization of mutations in high-risk melanoma susceptibility genes in families with three or more melanoma patients yet available. (Cancer Res 2006; 66(20): 9818-28)
Attenuation of CD8+ T-Cell Function by CD4+CD25+ Regulatory T Cells in B-Cell Non-Hodgkin's Lymphoma
Authors: Yang Zhi-Zhang , Novak Anne J. , Ziesmer Steven C. , Witzig Thomas E. , Ansell Stephen M. 
Published: October 2006

AbstractThe underlying mechanisms by which tumor cells are resistant to CTL-mediated apoptosis are not clear. Using a human model of B-cell non-Hodgkin's lymphoma (B-cell NHL), we show that intratumoral Treg cells inhibit the proliferation and granule production of activated autologous infiltrating CD8+ T cells. Our results also show that degranulation and subsequent cytotoxic activity of infiltrating CD8+ T cells exposed to lymphoma B cells is completely attenuated by the presence of intratumoral Treg cells. Furthermore, we show that increased numbers of intratumoral Treg cells correlates with the number of CD8+ T cells in biopsy specimens from patients with B-cell NHL, supporting the in vitro findings that intratumoral Treg cells inhibit proliferation of infiltrating CD8+ T cells. Taken together, these data indicate that human lymphoma B cells are sensitive to autologous CTL-mediated cell death but are protected by the inhibitory function of intratumoral Treg cells. (Cancer Res 2006; 66(20): 10145-52)
A Prospective Nested Case-Control Study of Vitamin D Status and Pancreatic Cancer Risk in Male Smokers
Authors: Stolzenberg-Solomon Rachael Z. , Vieth Reinhold , Azad Azar , Pietinen Pirjo , Taylor Philip R. , Virtamo Jarmo , Albanes Demetrius 
Published: October 2006

Abstract
Sun exposure is associated with lower death rates for pancreatic cancer in some ecological studies. Skin exposure to UVB light induces cutaneous production of precursors to 25-hydroxyvitamin D [25(OH)D]. Pancreatic islet and duct cells express 25(OH)D3-1α-hydroxylase that generates the biologically active 1,25(OH)2 vitamin D form. Thus, 25(OH)D concentrations could affect pancreatic function and possibly pancreatic cancer etiology. We conducted a prospective nested case-control study in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention cohort of male Finnish smokers, ages 50 to 69 years at baseline, to test whether more adequate vitamin D status, as determined by prediagnostic serum 25(OH)D concentrations, was associated with lower pancreatic cancer risk. Two hundred incident exocrine pancreatic cancer cases that occurred between 1985 and 2001 (up to 16.7 years of follow-up) were matched by age and date of blood draw to 400 controls who were alive and free of cancer at the time the case was diagnosed. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated using conditional logistic regression. Higher vitamin D concentrations were associated with a 3-fold increased risk for pancreatic cancer (highest versus lowest quintile, &gt;65.5 versus &lt;32.0 nmol/L: OR, 2.92; 95% CI, 1.56-5.48, Ptrend = 0.001) that remained after excluding cases diagnosed early during follow-up. Contrary to expectations, subjects with higher prediagnostic vitamin D status had an increased pancreatic cancer risk compared with those with lower status. Our findings need to be replicated in other populations and caution is warranted in their interpretation and implication. Our results are intriguing and may provide clues that further the understanding of the etiology of this highly fatal cancer. (Cancer Res 2006; 66(20): 10213-9)