bluuebunny/crossref_metadata_2025 huggingface dataset:
Climate change? A comparison of language and literacy practices relating to the teaching of science across the Key Stage 2/3 interface in two school clusters
Authors: McCullagh John , Jarman Ruth
Published: October 2009

This paper reports the findings of a study of the literacy perceptions and practices of general primary teachers (Key Stage 2) and post‐primary science teachers (Key Stage 3) within two clusters of schools. The study also explores the possible impact on pupils of any difference in the language climate which may accompany them on their journey across this curricular interface. Interviews with science managers and teachers suggest a quite restricted view of literacy is taken in both phases of schooling with no evidence of any practices which may support the notion of curricular continuity. The different approaches to the introduction of scientific terminology, writing, reading and classroom discussion were reflected in pupils' accounts of their experience and clearly posed a problem for some. We suggest there would be merit in teachers adopting a much wider perspective on literacy which recognises the opportunities for developing the interrelated strands of “general literacy” and “the discourses of science” alongside “learning through language”. By addressing each of these domains, and sharing practice across the key stages, a more comprehensive and coherent approach to “language, literacy and science learning” may result, in turn helping minimise the adverse effects of “language climate change”.
Reading lessons: teacher–pupil interactions with text during three KS1 shared reading sessions
Authors: John Claire
Published: October 2009

Changes in the teaching of reading during the past decade include a shift away from a previous emphasis on ‘one‐to‐one’ learning experiences to a focus upon more communal forms of learning which place the teacher center stage. With the teacher's role thus highlighted, teacher–pupil interaction in practice has come under the spotlight, with a number of studies raising concerns about the quality of teaching taking place and suggesting this is featuring more traditional patterns of ‘IRF’ exchanges between teachers and pupils, which are limiting to children's learning. This article reports on a small‐scale study into teacher–pupil interaction styles during three Key Stage 1 ‘shared reading’ sessions – an activity in which teacher and children work together on an enlarged, illustrated text, with the teacher explicitly modeling components of the reading process to children. The article considers the more tacit modelling taking place during these sessions and how particular linguistic patterning used by teachers frames reading as an educational and cultural activity in ways that position children differentially in relation to it. In particular, it considers how variation in the use of the IRF exchange can mediate different cultural meanings about what it is to engage with text as a reader.
Operational Improvement: The Key to Value Creation in Private Equity
Authors: Matthews Gary , Bye Mark , Howland James
Published: October 2009

With credit tightening having reduced the availability of leverage and intensified the competition for new deals, the economic recession has caused many companies in private equity firm portfolios to under‐perform. These changes are forcing the private equity firms to depend even more on their ability to improve operating performance to achieve their investment goals and generate attractive returns. But few PE firms have proved capable of achieving such improvements in portfolio companies consistently over time.

In this paper, the authors discuss several ways that private equity firms use their operating expertise to drive value in their portfolio companies. They also examine the analytical framework used by some PE firms when assessing and prioritizing the many operational initiatives that could be undertaken within a newly acquired company. Part of that examination involves a detailed look at how private equity firms assemble an attractive mix of operational improvement projects in their initial 100‐day plans. Finally, the authors explore one of the challenges faced by private equity firms when attempting to implement operational enhancements in newly acquired companies: bringing about change without alienating company management.

The real‐world application of this approach is demonstrated with a case study that shows how one private equity buyer put its operational skills into practice to help create value within a mid‐sized portfolio company.
Bankruptcy as an Auction Process: Lessons from Sweden
Authors: Eckbo B. Espen , Thorburn Karin S.
Published: October 2009

The traditional U.S. Chapter 11 bankruptcy process in which financial claims are renegotiated under court protection and the firm continues to operate under existing management has long been criticized by economists as an inefficient way of dealing with financially distressed companies. In this paper, the authors make the case for a mandatory auction bankruptcy system of the kind now used in Sweden—one that requires all companies filing for Chapter 11 to be sold in open auctions soon after the filing.

After discussing the notable features of and differences between the U.S. and Swedish bankruptcy systems, the authors summarize recent research (much of it their own) on the benefits and possible drawbacks of the Swedish system. Among the most notable findings of this research, there is no evidence that mandatory bankruptcy auctions in Sweden lead to “fire‐sale” discounts in auction premiums. Moreover, the fact that three‐quarters of the Swedish companies that filed for bankruptcy survived as going concerns should allay concerns that an auction system will produce excessive liquidations. At the same time, the post‐bankruptcy operating profitability of the companies that emerge from Swedish auctions as going concerns tends to be on a par with that of their (non‐bankrupt) industry peers. Such post‐operating performance, when combined with a 75% rate of reorganization (versus liquidation), suggests that allowing auction investors—instead of the bankruptcy court—decide which companies survive and how they get capitalized and restructured has been quite effective in accomplishing the two aims of a bankruptcy system: (1) preserving intact all economically viable enterprises while (2) eliminating the excess capacity that results from prolonging the existence of companies that are never expected to earn high enough returns on capital to attract private investment.

Consistent with these findings, the U.S. in recent years has seen a sharp increase in the use of auctions in Chapter 11 bankruptcies, though on a voluntary rather than a mandatory basis. Such a change reflects the growing recognition of the role of auction processes in reducing bankruptcy costs and preserving going‐concern values as U.S. capital market participants push harder for private workouts, “prepackaged” Chapter 11 filings, and auction sales in Chapter 11.
Historic Changes in the High Yield Bond Market
Authors: Reilly Frank K. , Wright David J. , Gentry James A.
Published: October 2009

In a history that now stretches about four decades, the high yield (HY) market has experienced growth in issuance and out‐standings that is remarkable both for its level (about 13% per annum, with HY bonds now accounting for about 25% of the total corporate bond market) and its cyclicality and sensitivity to the broad economy. The HY market has also experienced a notable shift away from B‐rated bonds and toward both lower‐risk Ba‐rated bonds and, to a lesser extent, more risky Caa‐rated bonds. Consistent with this development, studies of the performance of HY bonds show Ba‐rated bonds experiencing not only lower risk, but also higher returns than Caa‐rated bonds, which have produced surprisingly low average returns along with exceptionally high volatility. At the same time, studies of the correlation of HY bond returns with returns on other major asset classes report that all classes of HY bonds (but particularly the riskier B‐ and Caa‐rated bonds) have consistently stronger relationships with common stocks (especially small‐cap stocks) than with Treasuries and investment‐grade bonds.

Analysis of the volatility of HY bond returns over time shows that during periods of stability in the economy and financial markets, the volatility of HY bond returns has been very similar to that of investment‐grade bonds. But during periods of political or economic uncertainty, the volatility of HY bonds has become two or three times that of investment‐grade bonds, approaching the volatility of common stocks. The main driver of the significant increase in the risk of the aggregate HY bond market during periods of uncertainty has been Caa‐rated bonds, whose risk pattern has been remarkably similar to that of small‐cap common stocks.

Analysis of the credit risk spread (or CRS) series for both the composite HY bond market and each of its rating categories shows markedly non‐normal distributions with significant positive “skewness”—that is, periods of exceptionally high spreads (that are not counterbalanced by periods of exceptionally low spreads). The authors also report a consistently strong relationship of the CRS series with default rates and the general state of the economy, with major peaks occurring during or shortly after economic recessions.

Near the end of 2008, however, there was a clear break in this relationship when the CRS reached an historic peak of 2,000 basis points, or more than five standard deviations above its long‐term mean, while the default rate (at 4%) was below its long‐term average. The authors offer two explanations for this break in CRS‐default rate relationship: the jump in the CRS caused by the extreme flight to quality and drop in liquidity for all risky securities during the second half of 2008; and the use of covenant‐lite securities and other sources of financial flexibility that appear to have enabled many HY issuers to defer defaults (if not avoid them entirely).
New Insights into Rights Offerings as Signals of Firm Quality: Evidence from Australia*
Authors: Balachandran Balasingham , Faff Robert , Theobald Michael
Published: October 2009

Australian companies can choose among three different types of rights offerings: full standby (also known as “fully underwritten”); uninsured (or “non‐underwritten”); and partial standby (“partly underwritten”). At the same time, each of these three kinds of rights offerings can be either renounceable or non‐renounceable, with the former providing securities that can be sold while in the latter case the rights are forfeited if not exercised.

The main argument of this paper is that managers effectively signal the quality of their company through their choice of rights issue method. Consistent with this argument, the authors summarize the findings of their own research showing that high‐quality companies tend to choose full standby rights issues, with the full backing of an underwriter playing a “certifying” role for investors. By contrast, low‐quality firms tend to use partial standby issues with large subscription price discounts, while companies of intermediate‐quality choose uninsured rights issues. The authors also provide evidence that full standby rights issues are positively correlated with expected shareholder takeup, while both partial standby and uninsured issues have a negative correlation with takeup. Consistent with the above findings, the market response is most positive (or least negative) in the case of non‐renounceable, full standby rights issues with relatively low price discounts. The market reaction is most negative for non‐renounceable, partial standby issues with high price discounts.
Expression patterns of specific promyelocytic/retinoic acid receptor‐α transcripts in patients with acute promyelocytic leukemia
Authors: LIN J. , HAN L.‐X. , QIAN J. , WANG Y.‐L. , YAO D.‐M. , QIAN Z. , YANG X.‐F. , SHENG X.‐J.
Published: October 2009

Several additional promyelocytic/retinoic acid receptor‐α (PML/RARα) transcripts besides bcr1, bcr2, and bcr3 have been identified in patients with acute promyelocytic leukemia (APL). However, the expression levels of these specific isoforms and their clinical relevance have not been studied to date. The real‐time quantitative polymerase chain reaction was established to detect each specific isoform of PML/RARα transcripts (bcr1/2, P46R3, P4R3, bcr3, and P2R3) in 46 APL patients. Whereas P46R3 and P4R3 isoforms were concurrently expressed in both bcr1‐ and bcr2‐positive patients, P2R3 isoform was expressed only in bcr3‐positive patients. A total of 13 patients had lower expression of bcr1/2 (median 11.60%, 0.86–108.51%) than that of P46R3 (median 14.26%, 6.03–222.91%; P = 0.001). The expression level of P4R3 (median 19.10%, 0.71–266.19%) was lower than the sum of bcr1/2 and P46R3 (median 37.94%, 9.62–403.51%) in all cases (P < 0.001). All 16 cases with bcr3 had concurrent low expression of P2R3 (P < 0.001). Structural analysis revealed that both P4R3 and P2R3 splicing resulting in the generation of a premature termination codon, which was recognized by nonsense‐mediated decay (NMD). We suggest that alternative splicing of PML/RARα transcripts might be involved in NMD and each isoform should be quantified to further understand the pathogenesis of APL, stratify the risk of relapse, and monitor minimal residual disease.
Community‐Based Participatory Clinical Research in Obesity by Adolescents: Pipeline for Researchers of the Future
Authors: Branch Robert , Chester Ann
Published: October 2009

We propose a novel, untapped opportunity, challenging cultural and man‐power barriers to transferring advances in biomedical science knowledge that will improve community health care (Type II Clinical Translational Research) in a medically underserved community. We describe a pilot model in which adolescents apply principles of Community‐Based Participatory Research (CBPR) at the epicenter of the obesity diabetes epidemic in rural Appalachia in West Virginia. The model invites minority, financially disadvantaged, and educationally disadvantaged adolescents to become educated on ethics, then provides infrastructure to support study design and conduct of CBPR. This experience demonstrates that these adolescents can effi ciently, with quality and integrity, reach into the most vulnerable of communities and their own families to show that the prevalence of obesity is at 50% and diabetes 10.4% (n= 989). Our experience illustrates the infrastructure requirements for this strategy to be successful and emphasizes the substantial benefit that could accrue if the model is successfully sustained. The benefit includes not only the translation of knowledge to influence community lifestyle behavior but also the creation of a pipeline of new biomedical scientists for the future.
Enhanced healing of diabetic foot ulcers using local heat and electrical stimulation for 30 min three times per week
Authors: PETROFSKY Jerrold Scott , LAWSON Daryl , BERK Lee , SUH Hyejin
Published: October 2009

Background:  Electrical stimulation (ES) with heating is effective in healing chronic wounds. However, it this effect due to ES alone or both heating and ES? The aim of the present study was to deduce the individual roles of heat and ES in the healing of chronic wounds.

Methods:  The study was performed on 20 patients (mean age 48.4 ± 14.6 years) with non‐healing diabetic foot ulcers (mean duration 38.9 ± 23.7 months) who received local dry heat (37°C; n = 10) or local dry heat + ES (n = 10) three times a week for 4 weeks. Patients were given ES using biphasic sine wave stimulation (30 Hz, pulse width 250 μs, current approximately 20 mA).

Results:  Skin blood flow in and around the wound was measured with a laser Doppler flow imager. In the ES + heat group, the average wound area and volume decreased significantly by 68.4 ± 28.6% and 69.3 ± 27.1%, respectively (both P < 0.05), over the 1‐month period. During the average session, blood flow increased to 102.3 ± 25.3% with local heat and to 152.3 ± 23.4% with ES + heat. In the group receiving treatment with local heat only, wounds that had not healed for at least 2 months showed 30.1 ± 22.6% healing (i.e. a decrease in wound area) after 1 month. Although this level of healing was significant, it was less than that observed in the ES + heat group (P < 0.05).

Conclusions:  Local dry heat and ES work well together to heal chronic diabetic foot wounds; however, local heat would appear to be a relevant part of this therapy because ES alone has produced little healing in previous studies.
The Age of Knowledge Design: A View from Japan
Authors: Konno Noboru
Published: October 2009

Everyone talks about innovation; but these days, even that concept has changed. Essentially, companies need to make a shift from an analytical to a creative model—from the pursuit of innovation as basically a product‐driven concept, to the idea of innovation as the day‐to‐day practice of all members of an organization.
Phage Therapy To Reduce PreprocessingSalmonellaInfections in Market-Weight Swine
Authors: Wall Samantha K. , Zhang Jiayi , Rostagno Marcos H. , Ebner Paul D.
Published: October 2009

Contamination of meat products with food-borne pathogens usually results from the carcass coming in contact with the feces of an infected animal during processing. In the case ofSalmonella, pigs can become colonized with the organism during transport and lairage from contaminated trailers and holding pens, resulting in increased pathogen shedding just prior to processing. Increased shedding, in turn, amplifies the likelihood of carcass contamination by magnifying the amount of bacteria that enters the processing facility. We conducted a series of experiments to test whether phage therapy could limitSalmonellainfections at this crucial period. In a preliminary experiment done with small pigs (3 to 4 weeks old; 30 to 40 lb), administration of an anti-Salmonellaphage cocktail at the time of inoculation withSalmonella entericaserovar Typhimurium reducedSalmonellacolonization by 99.0 to 99.9% (2- to 3-log reduction) in the tonsils, ileum, and cecum. To test the efficacy of phage therapy in a production-like setting, we inoculated four market-weight pigs (in three replicates) withSalmonella entericaserovar Typhimurium and allowed the challenged pigs to contaminate a holding pen for 48 h. Sixteen naïve pigs were randomly split into two groups which received either the anti-Salmonellaphage cocktail or a mock treatment. Both groups of pigs were comingled with the challenged pigs in the contaminated pen. Treatment with the anti-Salmonellaphage cocktail significantly reduced cecalSalmonellaconcentrations (95%;P< 0.05) while also reducing (numerically) ilealSalmonellaconcentrations (90%;P= 0.06). Additionalin vitrostudies showed that the phage cocktail was also lytic against several non-Typhimurium serovars.
Genomic Characterization of the Intron-Containing T7-Like Phage phiL7 ofXanthomonas campestris
Authors: Lee Chia-Ni , Lin Juey-Wen , Weng Shu-Fen , Tseng Yi-Hsiung
Published: October 2009

The lytic phage phiL7, which morphologically belongs to theSiphoviridaefamily, infectsXanthomonas campestrispv. campestris. Nucleotide sequence analysis has revealed that phiL7 contains a linear double-stranded DNA genome (44,080 bp, 56% G+C) with a 3′-protrudingcossite (5′-TTACCGGAC-3′) and 59 possible genes. Among the deduced proteins, 32 have homologs with known functions and 18 show no database similarities; moreover, the genes encoding these 18 proteins mostly have varying G+C contents and form clusters dispersed along the genome. Only 39 genes have sequences related (27% to 78%) to those of sequenced genes ofX. oryzaepv. oryzae phages, although the genome size and architecture of theseXanthomonasphages are similar. These findings suggest that phiL7 acquired genes by horizontal transfer, followed by evolution via various types of mutations. Major differences were found between phiL7 and theX. oryzaepv. oryzae phages: (i) phiL7 has a group I intron inserted in the DNA polymerase gene, the first such intron observed inXanthomonasphages; (ii) although infection of phiL7 exerted inhibition to the host RNA polymerase, similar to the situations inX. oryzaepv. oryzae phages Xp10 and Xop411, sequence analysis did not identify a homologue of the Xp10 p7 that controls the shift from host RNA polymerase (RNAP) to viral RNAP during transcription; and (iii) phiL7 lacks the tail fiber protein gene that exhibits domain duplications thought to be important for host range determination in OP1, and sequence analysis suggested that p20 (tail protein III) instead has the potential to play this role.
Influence of Species Specificity and Other Factors on Bacteria Associated with the Coral
Stylophora pistillata
in Taiwan
Authors: Hong Mei-Jhu , Yu Yi-Ting , Chen Chaolun A. , Chiang Pei-Wen , Tang Sen-Lin
Published: October 2009

Species of bacteria associated with
Stylophora pistillata
were determined by analyses of 16S ribosomal genes. Coral samples were taken from two distinct sites at Kenting, in the far south of Taiwan; three coral colonies at each site were tagged and sampled in the winter and summer of 2007. Six hundred 16S rRNA gene clones were selected and sequenced for diversity analysis and community comparison. LIBSHUFF and nonparametric multiple dimensional scaling analyses showed variations in the composition of the coral-associated bacteria in the different samples, suggesting that seasonal and geographic factors and variations in individual coral colonies were all vital drivers of the structure of the
S. pistillata
-associated bacterial community. To examine the association between species specificity and environmental impacts on the structure of the coral-associated bacterial community, we conducted an integrated, comparative analysis of 44 coral-associated bacterial data sets, including the present study's data. The clustering analysis suggests that the influence of spatial and temporal factors on the coral-associated bacteria population structure is considerable; nonetheless, the effect of species specificity is still detectable in some coral species, especially those from the Caribbean Sea.
The Siderophore Pyoverdine of
Pseudomonas syringae
pv. tabaci 6605 Is an Intrinsic Virulence Factor in Host Tobacco Infection
Authors: Taguchi Fumiko , Suzuki Tomoko , Inagaki Yoshishige , Toyoda Kazuhiro , Shiraishi Tomonori , Ichinose Yuki
Published: October 2009

To investigate the role of iron uptake mediated by the siderophore pyoverdine in the virulence of the plant pathogen
Pseudomonas syringae
pv. tabaci 6605, three predicted pyoverdine synthesis-related genes,
pvdJ
,
pvdL
, and
fpvA
, were mutated. The
pvdJ
,
pvdL
, and
fpvA
genes encode the pyoverdine side chain peptide synthetase III
l
-Thr-
l
-Ser component, the pyoverdine chromophore synthetase, and the TonB-dependent ferripyoverdine receptor, respectively. The Δ
pvdJ
and Δ
pvdL
mutants were unable to produce pyoverdine in mineral salts-glucose medium, which was used for the iron-depleted condition. Furthermore, the Δ
pvdJ
and Δ
pvdL
mutants showed lower abilities to produce tabtoxin, extracellular polysaccharide, and acyl homoserine lactones (AHLs), which are quorum-sensing molecules, and consequently had reduced virulence on host tobacco plants. In contrast, all of the mutants had accelerated swarming ability and increased biosurfactant production, suggesting that swarming motility and biosurfactant production might be negatively controlled by pyoverdine. Scanning electron micrographs of the surfaces of tobacco leaves inoculated with the mutant strains revealed only small amounts of extracellular polymeric matrix around these mutants, indicating disruption of the mature biofilm. Tolerance to antibiotics was drastically increased for the Δ
pvdL
mutant, as for the Δ
psyI
mutant, which is defective in AHL production. These results demonstrated that pyoverdine synthesis and the quorum-sensing system of
Pseudomonas syringae
pv. tabaci 6605 are indispensable for virulence in host tobacco infection and that AHL may negatively regulate tolerance to antibiotics.
Cytoplasmic Histidine Kinase (HP0244)-Regulated Assembly of Urease with UreI, a Channel for Urea and Its Metabolites, CO
2
, NH
3
, and NH
4
+
, Is Necessary for Acid Survival of
Helicobacter pylori
Authors: Scott David R. , Marcus Elizabeth A. , Wen Yi , Singh Siddarth , Feng Jing , Sachs George
Published: October 2009

Helicobacter pylori
colonizes the normal human stomach by maintaining both periplasmic and cytoplasmic pH close to neutral in the presence of gastric acidity. Urease activity, urea flux through the pH-gated urea channel, UreI, and periplasmic α-carbonic anhydrase are essential for colonization. Exposure to pH 4.5 for up to 180 min activates total bacterial urease threefold. Within 30 min at pH 4.5, the urease structural subunits, UreA and UreB, and the Ni
2+
insertion protein, UreE, are recruited to UreI at the inner membrane. Formation of this complex and urease activation depend on expression of the cytoplasmic sensor histidine kinase, HP0244. Its deletion abolishes urease activation and assembly, impairs cytoplasmic and periplasmic pH homeostasis, and depolarizes the cells, with an ∼7-log loss of survival at pH 2.5, even in 10 mM urea. Associated with this assembly, UreI is able to transport NH
3
, NH
4
+
, and CO
2
, as shown by changes in cytoplasmic pH following exposure to NH
4
Cl or CO
2
. To be able to colonize cells in the presence of the highly variable pH of the stomach, the organism expresses two pH-sensor histidine kinases, one, HP0165, responding to a moderate fall in periplasmic pH and the other, HP0244, responding to cytoplasmic acidification at a more acidic medium pH. Assembly of a pH-regulatory complex of active urease with UreI provides an advantage for periplasmic buffering.
Combined Genomic and Proteomic Approaches Identify Gene Clusters Involved in Anaerobic 2-Methylnaphthalene Degradation in the Sulfate-Reducing Enrichment Culture N47
Authors: Selesi Draženka , Jehmlich Nico , von Bergen Martin , Schmidt Frank , Rattei Thomas , Tischler Patrick , Lueders Tillmann , Meckenstock Rainer U.
Published: October 2009

The highly enriched deltaproteobacterial culture N47 anaerobically oxidizes the polycyclic aromatic hydrocarbons naphthalene and 2-methylnaphthalene, with sulfate as the electron acceptor. Combined genome sequencing and liquid chromatography-tandem mass spectrometry-based shotgun proteome analyses were performed to identify genes and proteins involved in anaerobic aromatic catabolism. Proteome analysis of 2-methylnaphthalene-grown N47 cells resulted in the identification of putative enzymes catalyzing the anaerobic conversion of 2-methylnaphthalene to 2-naphthoyl coenzyme A (2-naphthoyl-CoA), as well as the reductive ring cleavage of 2-naphthoyl-CoA, leading to the formation of acetyl-CoA and CO
2
. The glycyl radical-catalyzed fumarate addition to the methyl group of 2-methylnaphthalene is catalyzed by naphthyl-2-methyl-succinate synthase (Nms), composed of α-, β-, and γ-subunits that are encoded by the genes
nmsABC
. Located upstream of
nmsABC
is
nmsD
, encoding the Nms-activating enzyme, which harbors the characteristic [Fe
4
S
4
] cluster sequence motifs of
S
-adenosylmethionine radical enzymes. The
bns
gene cluster, coding for enzymes involved in beta-oxidation reactions converting naphthyl-2-methyl-succinate to 2-naphthoyl-CoA, was found four intervening open reading frames further downstream. This cluster consists of eight genes (
bnsABCDEFGH
) corresponding to 8.1 kb, which are closely related to genes for enzymes involved in anaerobic toluene degradation within the denitrifiers “
Aromatoleum aromaticum
” EbN1,
Azoarcus
sp. strain T, and
Thauera aromatica
. Another contiguous DNA sequence harbors the gene for 2-naphthoyl-CoA reductase (
ncr
) and 16 additional genes that were found to be expressed in 2-methylnaphthalene-grown cells. These genes code for enzymes that were supposed to catalyze the dearomatization and ring cleavage reactions converting 2-naphthoyl-CoA to acetyl-CoA and CO
2
. Comparative sequence analysis of the four encoding subunits (
ncrABCD
) showed the gene product to have the closest similarity to the
Azoarcus
type of benzoyl-CoA reductase. The present work provides the first insight into the genetic basis of anaerobic 2-methylnaphthalene metabolism and delivers implications for understanding contaminant degradation.
Benzo[a]pyrene-induced neurobehavioral function and neurotransmitter alterations in coke oven workers
Authors: Niu Qiao , Zhang Hongmei , Li Xin , Li Meiqin
Published: October 2009

Objective

To study alterations in neurobehavioral function and neurotransmitter levels in coke oven workers occupationally exposed to benzo[a]pyrene (B[a]P) and explore possible biomarkers of B[a]P neurotoxicity.

Methods

176 coke oven workers occupationally exposed to B[a]P and 48 warehouse workers (controls) were investigated by questionnaire. Emotional and cognitive function was investigated using the WHO/NCTB. B[a]P concentrations in the working environment, concentrations of monoamine and amino acid neurotransmitters, and levels of urinary 1-hydroxypyrene (1-OH-Py) were assayed by HPLC. Spectrophotometry was used to determine choline neurotransmitter concentrations.

Results

Airborne B[a]P concentrations were higher in the coke oven plant than in the controls' workplace, and 1-OH-Py levels were significantly increased in coke workers compared to controls (p=0.000). Digital span and order digital span scores indicated that learning and memory were significantly decreased in coke oven workers (p=0.006). Concentrations of norepinephrine (NE), dopamine, 5-hydroxytryptamine and homovanillic acid were lower, while levels of 5-hydroxyindoleacetic acid were higher in the exposed group compared to controls; the difference in NE was significant (p=0.000). Aspartic acid and gamma-aminobutyric acid levels were significantly decreased in coke oven workers compared to controls (p=0.004 and p=0.004). Acetylcholine (Ach) concentration was four- to fivefold greater in coke oven workers than in controls, while acetylcholine esterase (AchE) activity was significantly decreased (p=0.000 and p=0.012). Statistical analysis showed that digital span and order digital span scores were negatively correlated to Ach and positively correlated to AchE.

Conclusion

Occupational B[a]P exposure may reduce coke oven workers' neurobehavioral function and monoamine, amino acid and choline neurotransmitter levels. Moreover, Ach and AchE correlated with neurobehavioral function; AchE has poor specificity, but Ach is a potential biomarker of B[a]P neurotoxicity in coke oven workers.
THE ENHANCEMENT OF ZHOU et al.'s QUANTUM SECRET SHARING PROTOCOL
Authors: CHEN JIA-HAO , LEE KUO-CHANG , HWANG TZONELIH
Published: October 2009

Recently, Zhou et al. proposed a quantum secret sharing (QSS) protocol, which provides only 25% qubit efficiency after the processes of the random sampling discussion and the secret derivation. This work proposes an enhancement of Zhou et al.'s protocol. With the technique of the Bell measurement, the improved QSS protocol has 50% qubit efficiency.
STUDIES OF OPINION STABILITY FOR SMALL DYNAMIC NETWORKS WITH OPPORTUNISTIC AGENTS
Authors: SOBKOWICZ PAWEL
Published: October 2009

There are numerous examples of societies with extremely stable mix of contrasting opinions. We argue that this stability is a result of an interplay between society network topology adjustment and opinion changing processes. To support this position we present a computer model of opinion formation based on some novel assumptions, designed to bring the model closer to social reality. In our model, the agents, in addition to changing their opinions due to influence of the rest of society and external propaganda, have the ability to modify their social network, forming links with agents sharing the same opinions and cutting the links with those they disagree with. To improve the model further we divide the agents into "fanatics" and "opportunists," depending on how easy it is to change their opinions. The simulations show significant differences compared to traditional models, where network links are static. In particular, for the dynamical model where inter-agent links are adjustable, the final network structure and opinion distribution is shown to resemble real world observations, such as social structures and persistence of minority groups even when most of the society is against them and the propaganda is strong.
Yam (Dioscorea pseudojaponicaYamamoto) Ameliorates Cognition Deficit and Attenuates Oxidative Damage in Senescent Mice Induced by D-Galactose
Authors: Chiu Chuan-Sung , Deng Jeng-Shyan , Hsieh Ming-Tsuen , Fan Ming-Jen , Lee Min-Min , Chueh Fu-Shin , Han Chien-Kuo , Lin Ying-Chih , Peng Wen-Huang
Published: October 2009

This study attempted to access the neuroprotective effect of yam (Dioscorea pseudojaponica Yamamoto) on the senescent mice induced by D-gal. The mice in the experiments were administered orally with yam (20, 100 or 500 mg/kg for 4 weeks, from the sixth week). The learning and memory abilities of the mice in Morris water maze test and the mechanisms involved in the neuroprotective effect of yam on the mice brain tissue were investigated. The content of diosgenin in the yam was also detected by using HPLC.

Mice treated with yam were found to significantly improve their learning and memory abilities in Morris water maze test compared to those treated with D-gal (200 mg/kg for 10 weeks). In addition, yam was also found to increase the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx) and decrease the malondialdehyde (MDA) level on the brains of D-gal treated mice. Finally, the amount of diosgenin in the yam was 5.49 mg/g extract.

To sum up, these results indicate that yam had the potential to be a useful treatment for cognitive impairment in TCM. Its beneficial effect may be partly mediated via enhancing endogenous antioxidant enzymatic activities.
Gingko biloba Extract (EGb 761) Prevents Increase of Bad-Bcl-XL Interaction Following Cerebral Ischemia
Authors: Koh Phil-Ok
Published: October 2009

A standardized extract of Gingko biloba, EGb 761, has been shown to exert a neuroprotective effect against permanent and transient focal cerebral ischemia. This study investigated whether EGb 761 modulates Bcl-2 family proteins in ischemic brain injury. Male adult rats were treated with EGb 761 (100 mg/kg) or vehicle prior to middle cerebral artery occlusion (MCAO), brain tissues were collected 24 hours after MCAO. EGb761 administration significantly decreased the number of TUNEL-positive cells in the cerebral cortex. Ischemic brain injury induced decrease of Bcl-2 and Bcl- X L levels. EGb 761 prevented not only the injury-induced decrease of Bcl-2 and Bcl- X L levels, but also the injury-induced increase of Bax. Moreover, in the presence of EGb 761, the interaction of Bad and Bcl- X L decreased compared to that of vehicle-treated animals. In addition, EGb 761 prevented the injury-induced increase of cleaved PARP. The finding suggests that EGb 761 prevents cell death against ischemic brain injury and EGb 761 neuroprotection is affected by preventing the injury-induced increase of Bad and Bcl- X L interaction.
The Proliferation and Migration Effects of Huangqi on RSC96 Schwann Cells
Authors: Fang Wen-Kuei , Ko Fu-Yang , Wang Hwai Lee , Kuo Chia-Hua , Chen Li-Mien , Tsai Fuu-Jen , Tsai Chang-Hai , Chen Yueh-Sheng , Kuo Wei-Wen , Huang Chih-Yang
Published: October 2009

This study evaluated the proliferation effects of huangqi on neuron regeneration. We investigated the molecular mechanisms, which include: (1) cyclin D1, A, E-cell cycle factors and MAPK signaling proliferation (2) FGF-2-UPA-MMPs migration signaling. After treatment with various Huanqi concentrations (1.25, 12.5, 125, 250 and 500 μg/ml,), we observed that Huanqi can increase Rsc 96 cell proliferation at 12.5 μg/ml ( p < 0.01) concentration determined by the MTT and wound healing tests. Examination by RT-PCR and Western blotting assay showed that Huangqi is able to stimulate the mRNA and protein expressions of cyclin D1, A, E, cell cycle controlling proteins and excite ERK and P38 MAPK signaling pathways to promote cell proliferation. Huangqi stimulates the FGF-2-UPA-MMP 9 migration pathway and enhances RSC 96 Schwann cells migration. Using MAPK chemical inhibitors, U0126, SB203580 and SP600125, the proliferative effects of Huangqi on RSC 96 cells were ERK and P38 signaling-dependent. Based on these results, applying an appropriate dose of Huangqi with biomedical materials would be a potential approach to enhancing neuron regeneration.
Rhein Lysinate Suppresses the Growth of Tumor Cells and Increases the Anti-Tumor Activity of Taxol in Mice
Authors: Lin Ya-Jun , Zhen Yong-Zhan , Shang Bo-Yang , Zhen Yong-Su
Published: October 2009

In previous studies, rhein, one of the major bioactive constituents in the rhizome of rhubarb, inhibited the proliferation of various human cancer cells. However, because of its water insolubility, the anti-tumor efficacy of rhein was limited in vivo. In this study, we observed the anti-tumor activity of rhein lysinate (the salt of rhein and lysine easily dissolves in water) in vivo and investigated its mechanism. Inhibition of ovarian cancer SKOV-3 cell proliferation was determined by MTT assay and the mechanism of action of rhein lysinate was investigated by Western blot analysis. The therapeutic efficacy of rhein lysinate was evaluated by intragastric and intraperitoneal administrations in H22 hepatocellular carcinoma mice. Rhein lysinate inhibited the proliferation of SKOV-3 cells and the IC50 value was 80 μM. Rhein lysinate inhibited the phosphorylation of MEK and ERK and increased the anti-tumor activity of Taxol in vitro. It inhibited tumor growth by both intragastric and intraperitoneal administrations and improved the therapeutic effect of Taxol in H22 hepatocellular carcinoma mice. In conclusion, rhein lysinate offers an anti-tumor activity in vivo and is hopeful to be a chemotherapeutic drug.
Anti-Tumor Activity of Polysaccharides Isolated from Patrinia scabra Bunge on U14 Cervical Carcinoma Bearing Mice
Authors: Lu Wen-Zong , Geng Guo-Xia , Li Qing-Wang , Li Jian , Liu Fu-Zhu , Han Zeng-Sheng , Gao Da-Wei , Yan Xin , Yang Xiao-Lei
Published: October 2009

The aim of our study was to investigate the effect of Patrinia scabra Bunge polysaccharide (PSB-P2) on cervical cancer cell (U14)-bearing mice. The tumor weight of mice treated with PSB-P2 (40, 80 mg/kg b.w.) was significantly lower than that of the control group and serum lactate dehydrogenase (LDH) activity was decreased, while serum alkaline phosphatase (AKP) level was only changed slightly. Meanwhile, the number of apoptotic tumor cells was significantly increased in the mice by the treatment of PSB-P2 (40, 80 mg/kg b.w.). At the same time, cell cycle analysis showed the accumulation of tumor cells in the G0/G1 phase and a relative decrease in the S phase. On the other hand, using the reverse transcription-polymerase chain reaction (RT-PCR) assay, PSB-P2 (40, 80 mg/kg b.w.) showed the up-regulation of p53 and Bax, and significant inhibition of Bcl-2 in tumor tissues. It suggests a possible mechanism of the inhibitory effect of PSB-P2 on tumor growth.
The Anti-Hyperglycemic Effect of Plants in Genus Gynura Cass.
Authors: Li Wei-Lin , Ren Bing-Ru , Min-Zhuo  , Hu Yong , Lu Chang-Gen , Wu Ju-Lan , Chen Jian , Sun Shi
Published: October 2009

Gynura divaricata (L.) DC and G. bicolor DC are used as secret recipes to treat diabetes mellitus in some parts of China. Pharmacological tests were performed to prove the anti-hyperglycemic effect of these two plants of genus Gynura Cass. in this study. Both water and 95% ethanol extracts of fresh G. divaricata had significant effects on lowering blood glucose level in normal mice, in which the dose of 0.4 g (crude drug)/kg of 95% ethanol extract was more effective than 50 mg/kg glyburide. The ethyl acetate and n-butanol extracts of dried G. divaricata had significant effects on lowering blood glucose level in normal and alloxan diabetic mice too. Both ethyl acetate and n-butanol extracts of dried G. bicolor showed very significant effect on lowering blood glucose level to normal and alloxan-diabetic mice, and the dose 4.0 g (crude drug)/kg had a more hypoglycemic effect than 50 mg/kg glyburide in normal mice.
DEVELOPMENT OF THE NONLINEAR DYNAMICAL SYSTEMS THEORY FROM RADIO ENGINEERING TO ELECTRONICS
Authors: LETELLIER CHRISTOPHE , GINOUX JEAN-MARC
Published: October 2009

Although initial results that contributed to the emergence of the nonlinear dynamical system theory arose from astronomy (the three-body problem), many subsequent developments were related to radio engineering and electronics. The path between the van der Pol equation and the Chua circuit is thus reviewed through main historical contributions.
AN ANALYTICAL PREDICTION OF PERIODIC FLOWS IN THE CHUA CIRCUIT SYSTEM
Authors: LUO ALBERT C. J. , XUE BING
Published: October 2009

In this paper, periodic and chaotic behaviors in the Chua circuit system are investigated, and the analytical prediction of periodic flows in such a system is carried out. The solutions of the system in different regions with different parameters are first obtained. The switching boundaries are introduced for systems switching because of different system parameters in different domains. In the vicinity of the switching boundaries, the normal vector-field product is introduced to measure flow switching on the separation boundary, and the conditions for grazing and passable flows to the discontinuous boundary are presented. The basic mappings are defined and periodic responses of such a system are predicted analytically from mapping structures. The local stability and bifurcation analysis are carried out.
IDENTIFICATION OF THE TRANSITION RULE IN A MODIFIED CELLULAR AUTOMATA MODEL: THE CASE OF DENDRITIC NH4Br CRYSTAL GROWTH
Authors: ZHAO Y. , BILLINGS S. A. , COCA D. , RISTIC R. I. , DEMATOS L.
Published: October 2009

A method of identifying the transition rule, encapsulated in a modified cellular automata (CA) model, is demonstrated using experimentally observed data of the evolution of dendritic crystal growth patterns in NH4Br crystals. The influence of the factors, such as experimental set-up and image preprocessing, color and size calibrations, on the method of identification are discussed in detail. A noise reduction parameter and the diffusion velocity of the crystal boundary are also considered. The results show that the proposed method can in principle provide a good representation of the dendritic growth anisotropy.
HOPF BIFURCATION FOR NONSMOOTH LIÉNARD SYSTEMS
Authors: LIU XIA , HAN MAOAN
Published: October 2009

The Hopf cyclicity of nonsmooth Liénard systems on the plane is studied and an algebraic method to find the Hopf cyclicity is presented. A sufficient and necessary condition which ensures the origin being a center is obtained. Some new and interesting applications are presented.
RESONANT BIFURCATIONS OF PERIODIC ORBITS IN HIGH DIMENSIONAL SYSTEMS
Authors: XIANG GUANGHUI , HU ZHAOPING
Published: October 2009

We study resonant bifurcations of periodic orbits of six-dimensional systems associated with three pairs of conjugate pure imaginary eigenvalues. Bifurcation functions can be obtained by Liapunov–Schmidt methods and we can use these functions for a detailed analysis of six-dimensional systems about their resonant bifurcations of periodic orbits.
DYNAMICAL SYNTHESIS OF QUASI-MINIMAL SETS
Authors: AKHMET M. U.
Published: October 2009

We address a nonautonomous differential equation with a pulse function, whose moments of discontinuity depend on the initial moment. Existence of a quasi-minimal set is proved. An appropriate simulation of a chaotic attractor is presented.
VASOMOTION SPECTRA AND PRINCIPAL COMPONENTS OF POOLED MEASURES PREDICT DIABETES IN MONKEYS
Authors: TIGNO X. T. , HANSEN B. C. , ALBANO A. M.
Published: October 2009

Diabetic neuropathy may be a result of disturbed vasomotion, the spontaneous rhythmic oscillations of vessel diameter, flow, or pressure in the microcirculation. To examine the differences in vasomotion prior to overt diabetes and with diagnosed diabetes, metabolic and blood flow measurements were obtained from three metabolically distinct groups of nonhuman primates: normoglycemic, metabolic syndrome/prediabetic, and overtly diabetic. Three of these indices characterize spectral properties of microcirculatory vasomotion: (1) the fraction of spectral power in a band around 2.0 Hz, (2) the ratio of spectral power in a band around 1.0 Hz to that around 2.0 Hz, (3) the Hurst exponent. The rest were more traditional measures including (4) fasting plasma Glucose (FPG), (5) glycosylated hemoglobin level (HbA1c), (6) fasting insulin levels (IRI), (7) average systolic blood pressure, and (8) average diastolic blood pressure.

We found that the mean fraction of the spectral power of the vasomotion in the 2 Hz band is significantly greater in the nondiabetic than in the diabetic group. Similarly, the ratio of the spectral power in the 1.0 Hz band to that in the 2.0 Hz band was significantly higher among the diabetic subjects than in the nondiabetic and prediabetic subjects.

Principal component analysis (PCA) of the ensemble of eight measures revealed that values of the first principal component in the diabetic group were highly and significantly different from those of the normal and prediabetic groups, which are also significantly different from each other. Furthermore, the spectral measures of vasomotion offered a distinct advantage over the traditional physiological variables in distinguishing the normal subjects from the prediabetic group, and are likely to reflect very early autonomic dysfunction.
SYNCHRONY IN SLOW–FAST METACOMMUNITIES
Authors: RINALDI SERGIO
Published: October 2009

The synchronization of metacommunities due to dispersal among patches is analyzed in the case of slow–fast populations. The analysis is performed by studying a standard model with the fast population dispersing when special meteorological conditions are present. This assumption fits very well with the peculiar nature of slow–fast systems and implies that metacommunities synchronize if the slow population accelerates during the outbreak of the fast population. This result shows great potential in the study of marine and fresh-water plankton communities as well as in the study of synchronization of insect-pest outbreaks in forests.
EXPONENTIAL CONVERGENCE BEHAVIOR OF FUZZY CELLULAR NEURAL NETWORKS WITH DISTRIBUTED DELAYS AND TIME-VARYING COEFFICIENTS
Authors: TAN MAN-CHUN
Published: October 2009

In this paper, a class of fuzzy cellular neural networks (FCNNs) with distributed delays and time-varying coefficients is studied. By employing the mathematical analysis method, some sufficient conditions are derived for ensuring that all solutions of such FCNNs converge exponentially to zero. Both the Lipschitz continuous condition on activation functions and the differentiability of time-varying delays are not required in this study.
IMPROVED IMAGE COMPRESSION BASED ON FEED-FORWARD ADAPTIVE DOWNSAMPLING ALGORITHM
Authors: SINGH SATISH KUMAR , KUMAR SHISHIR
Published: October 2009

All the visual signals used in internet, mobile and multimedia applications are needed to be coded at very low bit rates, without affecting much the quality of image or video data. To achieve a very low bit rate and very high compression ratio the image can be downsampled prior to compression and the full resolution image can be obtained by estimating the missing portion after decompression with reward of better PSNR. In this paper an attempt has been made to design an improved image compression system based on the feed forward adaptive downsampling algorithm considering the visual significance of the image. The mathematical basis has been established for visual significance and downsampling parameters, the mathematical formulation has also been established to get the PSNR value reconstructed image, without the actual reconstruction on the downsampled image in terms of known pixel values, remained after downsampling. Through this paper a fast image compression method is proposed which is having high compression ratio, feed-forward nature, acceptable signal-to-noise ratio and is application oriented. This method can also be used further for variable bit rate application.