bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationship between the presence of periodontopathic bacteria and the expression of chemokine receptor mRNA in inflamed gingival tissues
Authors: Noda D. , Hamachi T. , Inoue K. , Maeda K.
Published: September 2007

Background and Objective:  Periodontal disease is a chronic disease characterized by the interaction between periodontopathic bacteria and the host immune response. The aim of this study was to investigate the correlation between periodontopathic bacteria and host immune cell infiltrates.

Material and Methods:  Twenty‐two patients with chronic periodontitis were included in this study. Gingival tissues were taken at the periodontal surgery after completion of initial therapy. Three types of periodontopathic bacteria were detected by polymerase chain reaction, and the prevalence of mRNA expression of chemokine receptors was examined by reverse‐transcription–polymerase chain reaction in the gingival tissues. The infiltration of T and B cells was determined by an immunohistochemical method.

Results:  In the patients, both Porphyromonas gingivalis and Tanerella forsythia were detected, and the mRNA expression of chemokine receptors CXCR1&2, CXCR4, CCR1, CCR2, CCR3 and CCR4 were more prevalent. The mean number of infiltrated B cells was significantly larger than that of T cells in the sites harboring both P. gingivalis and T. forsythia. Similarly, in the sites where P. gingivalis was detected but T. forsythia was not, the mean number of B cells was significantly larger than that of T cells. In the sites with mRNA expression of CCR2 and CCR3, the mean number of B cells was significantly larger.

Conclusion:  These results suggest that a high proportion of T helper 2‐associated chemokine receptor‐positive T cells may be associated with the predominance of B cells and may play an important role in the formation of chronic periodontitis in sites where both P. gingivalis and T. forsythia are detected.
Review of extracorporeal photopheresis in early‐stage (IA, IB, and IIA) cutaneous T‐cell lymphoma
Authors: Miller Janine D. , Kirkland Eugene B. , Domingo Diana Santo , Scull Heather , Jekutis Bernadette , Dallas Marcia , Cooper Kevin D. , Baron Elma D.
Published: September 2007

Background: Extracorporeal photopheresis (ECP) has been used for nearly 20 years for the treatment of cutaneous T‐cell lymphoma (CTCL). A substantial body of literature reports that this form of photoimmunotherapy improves or stabilizes the course of disease in a subset of patients across all stages. However, current clinical approach usually reserves ECP for patients who do not respond to other treatments or for patients with late‐stage disease or Sézary syndrome (SS).

Methods: A comprehensive Pubmed/Medline literature search was performed to identify studies reporting the use and efficacy of ECP in early stage (IA, IB, and IIA) CTCL. Information regarding prognostic factors and survival of early‐stage patients treated with ECP was also obtained and summarized.

Results: The heterogenous nature of the reports and lack of any prospective randomized trials made evaluation of response to treatment difficult. However, the current literature contains at least 124 early‐stage patients treated with ECP or ECP plus adjuvant therapy from 1987–2007 in 16 different reports. Response rates of treatment for this patient population with ECP and ECP plus adjuvant therapy varied from 33–88%.

Conclusions: Given the very low side effect profile of ECP compared with other therapies and its demonstrated efficacy, this treatment modality is possibly beneficial for patients with earlier stages of CTCL. Randomized prospective studies are needed to establish the role of ECP in this disease subset.
Lung function and bronchial hyper‐responsiveness 11 years after hospitalization for bronchiolitis
Authors: Hyvärinen MK , Kotaniemi‐Syrjänen A , Reijonen TM , Korhonen K , Korppi MO
Published: September 2007

Aim: Atopic infants hospitalized for wheezing not caused by respiratory syncytial virus (RSV) carry the highest risk for later asthma. In the present paper, early risk factors for later lung function abnormalities and for bronchial hyper‐responsiveness (BHR) were evaluated in 81 children, hospitalized for bronchiolitis in infancy, at the median age of 12.3 years.

Methods: The basic data, including data on atopy in children and viral aetiology of bronchiolitis, had been collected on entry to the study at less than 2 years of age. Lung function was studied by flow‐volume spirometry (FVS), and BHR by methacholine and exercise challenge tests 11.4 years after hospitalization during infancy.

Results: RSV aetiology of bronchiolitis was associated with reduced forced vital capacity (FVC; 93.65% of predicted ± 11.05 vs. 99.57%± 12.59, p = 0.009). Early sensitization to inhalant allergens (OR 12.59, 95% CI 2.30–68.77) and maternal smoking during pregnancy (OR 4.58, 95% CI 1.28–16.39) were associated with BHR to exercise, and early atopic dermatitis (OR 3.48, 95% CI 1.09–11.10) was associated with BHR to methacholine.

Conclusions: RSV bronchiolitis was associated with a restrictive pattern of lung function. Early atopy and maternal smoking during pregnancy may play a role in the development and persistence of BHR.
Effect of exocrine pancreatic function on resting energy expenditure in cystic fibrosis
Authors: Moudiou T , Galli‐Tsinopoulou A , Nousia‐Arvanitakis S
Published: September 2007

Aim: To prove the hypothesis that exocrine pancreatic function determines resting energy expenditure (REE) in cystic fibrosis (CF).

Method: Thirty‐eight CF individuals, 9–34 (19.98 ± 1.0) years, were divided into three groups:

Six pancreatic sufficient patients (PS; group A), 21 pancreatic insufficient patients (PI), whose pulmonary function was comparable to that of group A (group B1) and 11 PI patients, whose pulmonary function was significantly worse than that of group A (group B2). REE was estimated by indirect calorimetry. Predicted REE was based on Schofield equations. Measured REE was expressed as % of the predicted. BMI, BMI z‐scores, serum albumin, cholesterol and triglycerides levels were related to REE. Results were expressed as mean ± standard error.

Results: Groups B1 and B2 had significantly higher REE% (111.7 ± 2.75% and 119.94 ± 3.8, respectively) as opposed to group A (98.9 ± 3.81%; p = 0.022 and 0.035, respectively) whose REE% was similar to that predicted. REE% between group B1 and B2 was not statistically significant. In groups A, B1 and B, mean FEV1% was 86.33 ± 10.1%, 90.24 ± 4.39%, 44.54 ± 3.47%, respectively, mean BMI was 25.6 ± 2.06, 19.48 ± 0.64 and 20.09 ± 8.8, respectively, BMI z‐scores were 0.75 ± 0.51, –0.52 ± 0.24 and –1.07 ± 0.37, respectively. Significant correlation was demonstrated between REE%, BMI z‐scores and cholesterol levels in group A.

Conclusion: Clinically stable CF patients, who had comparable pulmonary function, exhibited increased REE% only in the presence of exocrine pancreatic insufficiency. REE% strongly correlated with BMI z‐scores in pancreatic sufficiency. These findings support the hypothesis that pancreatic rather than pulmonary function may determine nutritional status as well as REE in CF.
The Sustainability of Human Populations
Authors: Desvaux Martin
Published: September 2007

We live on an over-crowded Earth whose population is 6 billion and rising. How many people can the planet feed, clothe and water? Is there a limit to the number that the earth can sustain? And have we passed that limit already? Martin Desvaux looks at the weight of our numbers.
The Truth About Those Little Red Lights: A Tale of Power and Poppycock
Authors: Parris Matthew
Published: September 2007

Leaving your electrical appliances on standby wastes-how much? Up to 10% of the electricity supply. Everyone knows that. Or is it 8%? Or 3%? Anyway, it is a lot, and the statistic has acquired a life of its own. Matthew Parris's article from The Times of July 22nd, 2006, was runner-up in the 2007 Royal Statistical Society competition for journalists writing on a statistical theme. The Chancellor he refers to, one Gordon Brown, is now, of course, the Prime Minister.
Becoming Familiar with Multilevel Modeling
Authors: Goldstein Harvey
Published: September 2007

Items of data vary independently of one another—or so the textbooks would have us believe. But what do you do when the data do not behave like that? Real-life populations can vary in complex ways that are dependent on each other. Harvey Goldstein introduces the mysteries of multilevel modelling.
Seeing the Woods — Statistics for the Very Young
Authors: Du Feu Chris
Published: September 2007

If you go down to the woods today … you're sure of a big statistical experience. You might run into Chris Du Feu giving 9-year-olds their first lesson in statistics. Tasks for the teacher? One, clear nettles; two, make sure that leaves will stay firmly stuck in place on the bar-chart…
Emotion Refinement: A Theory Inspired by Chinese Poetics
Authors: Frijda Nico H. , Sundararajan Louise
Published: September 2007

William James made a distinction between coarse and noncoarse emotions. In the present article, we explore the nature of such noncoarse emotions, which we designate as emotions with refinement. We take our cue from the treatment of refined emotions in Chinese poetics and philosophy. The theory and description of savoring(in Chinese, p'in-wei) points to several features of emotion experiences and behavior that are usually absent in direct emotional responses to emotional events, such as self-reflexivity and higher level second-order awareness, detachment, and restraint. Emotions with those features can be found outside savoring and aesthetic contexts, for instance while dealing with actual life events. It appears both feasible and illuminating to analyze such emotion experiences and behavior in terms of current emotion theory, notably by means of the constructs of appraisal and action readiness. Emotions with refinement thus fit general emotion theory while also possessing distinctive character within the motion domain. Our analysis has implications for the structure of emotion experience and the study of consciousness.
Ideal Affect: Cultural Causes and Behavioral Consequences
Authors: Tsai Jeanne L.
Published: September 2007

Most research focuses on actual affect, or the affective states that people actually feel. In this article, I demonstrate the importance and utility of studying ideal affect, or the affective states that people ideally want to feel. First, I define ideal affect and describe the cultural causes and behavioral consequences of ideal affect. To illustrate these points, I compare American and East Asian cultures, which differ in their valuation of high-arousal positive affective states (e.g., excitement, enthusiasm) and low-arousal positive affective states (e.g., calm, peace-fulness). I then introduce affect valuation theory, which integrates ideal affect with current models of affect and emotion and, in doing so, provides a new framework for understanding how cultural and temperamental factors may shape affect and behavior.
Estimating the Relative Efficiency of Brazilian Publicly and Privately Owned Water Utilities: A Stochastic Cost Frontier Approach1
Authors: Da Silva e Souza Geraldo , De Faria Ricardo Coelho , Moreira Tito Belchior S.
Published: September 2007

Abstract:  This paper assesses cost efficiencies of Brazilian public and private companies of water supply. To measure the efficiency, we used a stochastic frontier model derived from the translog family – a specification similar to a Cobb‐Douglas including a quadratic term in log output. The model parameters are estimated by maximum likelihood using Brazilian data for the year 2002. Statistical inference leads to the conclusion that there is no evidence that private firms and public firms are significantly different in terms of efficiency measurements.
Linear Superposition in Total Maximum Daily Loads Applications: The Steady‐State Response Matrix Revisited1
Authors: Martin James L.
Published: September 2007

Abstract:  The steady‐state response matrix has historically proved a valuable tool in computing the water quality response to loadings and in providing insight into the relative impact of individual loading sources. The insight obtained may be is particularly useful in modern applications of increasingly complex water quality models to problems involving multiple point and nonpoint sources, such as in the assessment of total maximum daily loads (TMDLs). Where appropriate and the underlying equations linear, the steady‐state response matrix can be used to synthesize the results of more complicated models and present them in a way easily understood by policy makers. A straightforward method is presented for generating the response matrix using complex models, and example applications discussed. Example applications include a simple demonstration; incorporation of the method into the Mississippi Department of Environmental Quality’s STREAM model used in TMDL development; a TMDL modeling study of the Grand Calumet River and Indiana Harbor Canal, Indiana, using CE‐QUAL‐ICM; and a TMDL modeling study of the Big Sunflower River, Mississippi, using the Water Analysis Simulation Program model.
Femoropopliteal artery centerline interpolation using contralateral shape
Authors: Tran David N. , Fleischmann Dominik , Rakshe Tejas , Roos Justus E. , Rosenberg Jarrett , Straka Matus , Napel Sandy
Published: September 2007

Curved planar reformation allows comprehensive visualization of arterial flow channels, providing information about calcified and noncalcified plaques and degrees of stenoses. Existing semiautomated centerline‐extraction algorithms for curved planar reformation generation fail in severely diseased and occluded arteries. We explored whether contralateral shape information could be used to reconstruct centerlines through femoropopliteal occlusions. We obtained CT angiography data sets of 29 subjects (16m/13f, 19–86yo) without peripheral arterial occlusive disease and five consecutive subjects (1m/4f, 54–85yo) with unilateral femoropopliteal arterial occlusions. A gradient‐based method was used to extract the femoropopliteal centerlines in nondiseased segments. Centerlines of the five occluded segments were manually determined by four experts, two times each. We interpolated missing centerlines in 2475 simulated occlusions of various occlusion lengths in nondiseased subjects. We used different curve registration methods (reflection, similarity, affine, and global polynomial) to align the nonoccluded segments, matched the end points of the occluded segments to the corresponding patent end points, and recorded maximum Euclidean distances to the known centerlines. We also compared our algorithm to an existing knowledge‐based PCA interpolation algorithm using the nondiseased subjects. In the five subjects with real femoropopliteal occlusions, we measured the maximum Euclidean distance and the percentage of the interpolation that remained within a typical 3 mm radius vessel. In the nondiseased subjects, we found that the rigid registration methods were not significantly different among themselves but were more accurate than the nonrigid methods . In simulations using nondiseased subjects, our method produced centerlines that stayed within 3 mm of a semiautomatically tracked centerline in occlusions up to 100 mm in length; however, the PCA method was significantly more accurate for all occlusions lengths. In the actual clinical cases, we found the following [occlusion length (mm):error (mm)]: , , , , and , which were almost always more accurate than the PCA algorithm. We conclude that the use of contralateral shape information, when available, is a promising method for the interpolation of centerlines through arterial occlusions.
Feasibility of transrib focused ultrasound thermal ablation for liver tumors using a spherically curved 2D array: A numerical study
Authors: Liu Hao‐Li , Chang Hsu , Chen Wen‐Shiang , Shih Tzu‐Ching , Hsiao Jong‐Kai , Lin Win‐Li
Published: September 2007

The use of focused ultrasound thermal ablation to treat hepatocarcinoma and other liver tumors produces promising clinical results. However, one of the major drawbacks is the high absorption of ultrasonic energy by the rib, making partial rib removal necessary in many cases. This study numerically investigated the feasibility of using a spherical ultrasound phased array for transrib liver‐tumor thermal ablation. An independently array‐element activitation scheme, which switches off the transducer elements obstructed by the ribs based on feedback anatomical medical imaging, was proposed to reduce the rib‐overheating problem. The numerical results showed that the proposed treatment planning strategy can effectively reduce the specific energy absorbed by the rib while maintaining the energy at the target position, which both reduces the rib‐overheating problem and increases the possibility of treating a target lesion under an intact rib. The analysis also demonstrated that the target position and the ultrasound frequency play key roles in the treatment. Patients with diverse characteristics were also tested to show the generality of the proposed strategy. The proposed treatment planning strategy also provides useful information for evaluating the treatment effectiveness prior to clinically performing transrib ultrasound liver‐tumor thermal ablation.
Radiologic validation of a fast neutron multileaf collimator
Authors: Farr J. B. , Maughan R. L. , Yudelev M. , Blosser E. , Brandon J. , Horste T. , Forman J. D.
Published: September 2007

Teletherapy with high linear energy transfer radiations (LET), perhaps more than with low LET types, requires careful beam collimation to limit effects to normal structures. Intensity modulated techniques may also hold promise in this regard. Accordingly, a remote computer‐controlled, high‐resolution multileaf collimator (MLC) is placed into service at the Gershenson Radiation Oncology Center's fast neutron therapy center of the Karmanos Cancer Institute, Detroit, Michigan. Prior to clinical application the basic radiological properties of the fast neutron MLC are studied. Complicating the evaluation is the mixed neutron and gamma radiation field environment encountered with fast neutron beams. As a reference the MLC performance is compared to an existing multirod collimator (MRC) used at the facility for more than ten years. The MLC aggregate transmission is found to be about 4%, slightly outperforming the MRC. The measured gamma component for a closed collimator is 1.5 times higher for the MLC, compared with the MRC. The different materials used for attenuation, steel and tungsten, respectively account for the difference. The geometry for the MRC is double focused whereas that for the MLC is single focused. The resulting penumbrae agree between the focused axis of the MLC and both axes of the MRC. Penumbra differences between the focused and unfocused axes were not observable at small field sizes and a maximum of about for a field at depth in water. For a field the focused penumbra is , and the unfocused is . The many benefits of the fully automatic MLC over the semimanual MRC are considered to justify this compromise.
IMRT optimization including random and systematic geometric errors based on the expectation of TCP and NTCP
Authors: Witte Marnix G. , van der Geer Joris , Schneider Christoph , Lebesque Joos V. , Alber Markus , van Herk Marcel
Published: September 2007

The purpose of this work was the development of a probabilistic planning method with biological cost functions that does not require the definition of margins. Geometrical uncertainties were integrated in tumor control probability (TCP) and normal tissue complication probability (NTCP) objective functions for inverse planning. For efficiency reasons random errors were included by blurring the dose distribution and systematic errors by shifting structures with respect to the dose. Treatment plans were made for 19 prostate patients following four inverse strategies: Conformal with homogeneous dose to the planning target volume (PTV), a simultaneous integrated boost using a second PTV, optimization using TCP and NTCP functions together with a PTV, and probabilistic TCP and NTCP optimization for the clinical target volume without PTV. The resulting plans were evaluated by independent Monte Carlo simulation of many possible treatment histories including geometrical uncertainties. The results showed that the probabilistic optimization technique reduced the rectal wall volume receiving high dose, while at the same time increasing the dose to the clinical target volume. Without sacrificing the expected local control rate, the expected rectum toxicity could be reduced by 50% relative to the boost technique. The improvement over the conformal technique was larger yet. The margin based biological technique led to toxicity in between the boost and probabilistic techniques, but its control rates were very variable and relatively low. During evaluations, the sensitivity of the local control probability to variations in biological parameters appeared similar for all four strategies. The sensitivity to variations of the geometrical error distributions was strongest for the probabilistic technique. It is concluded that probabilistic optimization based on tumor control probability and normal tissue complication probability is feasible. It results in robust prostate treatment plans with an improved balance between local control and rectum toxicity, compared to conventional techniques.
Two‐dimensional extrapolation methods for texture analysis on CT scans
Authors: Sensakovic William F. , Starkey Adam , Armato Samuel G.
Published: September 2007

The application of texture analysis to medical images may require the calculation of texture descriptors on regions of interest (ROIs) that are not completely filled by the tissue under analysis. If a texture descriptor is calculated using such “deficient” ROIs, the accuracy and computational speed may be adversely affected. This study applied 198 texture descriptors from five texture classes (first‐order statistical, second‐order statistical, Fourier, fractal, and Laws’ filtered) to lung parenchyma ROIs automatically extracted from the thoracic CT scans of ten patients. Statistically significant differences in the values of 138 of these texture descriptors were demonstrated when calculated on deficient ROIs. Three extrapolation methods (mean fill, tiled fill, and CLEAN deconvolution) then were applied to correct the deficient ROIs. Texture descriptor values were calculated and compared for the original, deficient, and corrected ROIs (based on the three extrapolation methods). Each extrapolation method induced statistically significant improvements in texture descriptor accuracy for some subset of texture descriptors. CLEAN deconvolution improved the greatest number of descriptors, demonstrated the best overall accuracy, and created ROIs that were visually most similar to the original ROIs.
Enhanced 4D cone‐beam CT with inter‐phase motion model
Authors: Li Tianfang , Koong Albert , Xing Lei
Published: September 2007

Four‐dimensional (4D) cone‐beam CT (CBCT) is commonly obtained by respiratory phase binning of the projections, followed by independent reconstructions of the rebinned data in each phase bin. Due to the significantly reduced number of projections per reconstruction, the quality of the 4DCBCT images is often degraded by view‐aliasing artifacts easily seen in the axial view. Acquisitions using multiple gantry rotations or slow gantry rotation can increase the number of projections and substantially improve the 4D images. However, the extra cost of the scan time may set fundamental limits to their applications in clinics. Improving the trade‐off between image quality and scan time is the key to making 4D onboard imaging practical and more useful. In this article, we present a novel technique toward high‐quality 4DCBCT imaging without prolonging the acquisition time, referred to as the “enhanced 4DCBCT”. The method correlates the data in different phase bins and integrates the internal motion into the 4DCBCT image formulation. Several strategies of the motion derivation are discussed, and the resultant images are assessed with numerical simulations as well as a clinical case.
Microdosimetric study for secondary neutrons in phantom produced by a carbon beam
Authors: Endo Satoru , Tanaka Kenichi , Takada Masashi , Onizuka Yoshihiko , Miyahara Nobuyuki , Sato Tatsuhiko , Ishikawa Masayori , Maeda Naoko , Hayabuchi Naofumi , Shizuma Kiyoshi , Hoshi Masaharu
Published: September 2007

Absorbed doses from main charged‐particle beams and charged‐particle fragments have been measured with high accuracy for particle therapy, but there are few reports for doses from neutron components produced as fragments. This study describes the measurements on neutron doses produced by carbon beams; microdosimetric distributions of secondary neutrons produced by carbon beams have been measured by using a tissue equivalent proportional counter at the Heavy Ion Medical Accelerator in Chiba, Japan at the National Institute of Radiological Sciences. The microdosimetric distributions of the secondary neutron were measured on the distal and lateral faces of a body‐simulated acrylic phantom . To confirm the dose measurements, the neutron energy spectra produced by incident carbon beams in the acrylic phantom were simulated by the particle and heavy ion transport code system. The absorbed doses obtained by multiplying the simulated neutron energy spectra with the kerma factor calculated by MCNPX agree with the corresponding experimental data fairly well. Downstream of the Bragg peak, the ratio of the neutron dose to the carbon dose at the Bragg peak was found to be a maximum of and the ratio of neutron dose was a maximum of at a lateral face of the acrylic phantom. The ratios of neutrons to charged particle fragments were 11% to 89% in the absorbed doses at the lateral and the distal faces of the acrylic phantom. We can conclude that the treatment dose will not induce serious secondary neutron effects at distances greater than from the Bragg peak in carbon particle therapy.
Resistance Mechanisms of Multiresistant
Pseudomonas aeruginosa
Strains from Germany and Correlation with Hypermutation
Authors: Henrichfreise B. , Wiegand I. , Pfister W. , Wiedemann B.
Published: September 2007

In this study, we analyzed the mechanisms of multiresistance for 22 clinical multiresistant and clonally different
Pseudomonas aeruginosa
strains from Germany. Twelve and 10 strains originated from cystic fibrosis (CF) and non-CF patients, respectively. Overproduction of the efflux systems MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY-OprM was studied. Furthermore, loss of OprD, alterations in type II topoisomerases, AmpC overproduction, and the presence of 25 acquired resistance determinants were investigated. The presence of a hypermutation phenotype was also taken into account. Besides modifications in GyrA (91%), the most frequent mechanisms of resistance were MexXY-OprM overproduction (82%), OprD loss (82%), and AmpC overproduction (73%). Clear differences between strains from CF and non-CF patients were found: numerous genes coding for aminoglycoside-modifying enzymes and located, partially in combination with β-lactamase genes, in class 1 integrons were found only in strains from non-CF patients. Furthermore, multiple modifications in type II topoisomerases conferring high quinolone resistance levels and overexpression of MexAB-OprM were exclusively detected in multiresistant strains from non-CF patients. Correlations of the detected phenotypes and resistance mechanisms revealed a great impact of efflux pump overproduction on multiresistance in
P. aeruginosa
. Confirming previous studies, we found that additional, unknown chromosomally mediated resistance mechanisms remain to be determined. In our study, 11 out of 12 strains and 3 out of 10 strains from CF patients and non-CF patients, respectively, were hypermutable. This extremely high proportion of mutator strains should be taken into consideration for the treatment of multiresistant
P. aeruginosa
.
Effect of Zinc in Enteropathogenic
Escherichia coli
Infection
Authors: Crane John K. , Naeher Tonniele M. , Shulgina Irina , Zhu Chengru , Boedeker Edgar C.
Published: September 2007

Enteropathogenic
Escherichia coli
(EPEC) infection triggers the release of ATP from host intestinal cells, and the ATP is broken down to ADP, AMP, and adenosine in the lumen of the intestine. Ecto-5′-nucleotidase (CD73) is the main enzyme responsible for the conversion of 5′-AMP to adenosine, which triggers fluid secretion from host intestinal cells and also has growth-promoting effects on EPEC bacteria. In a recent study, we examined the role of the host enzyme CD73 in EPEC infection by testing the effect of ecto-5′-nucleotidase inhibitors. Zinc was a less potent inhibitor of ecto-5′-nucleotidase in vitro than the nucleotide analog α,β-methylene-ADP, but in vivo, zinc was much more efficacious in preventing EPEC-induced fluid secretion in rabbit ileal loops than α,β-methylene-ADP. This discrepancy between the in vitro and in vivo potencies of the two inhibitors prompted us to search for potential targets of zinc other than ecto-5′-nucleotidase. Zinc, at concentrations that produced little or no inhibition of EPEC growth, caused a decrease in the expression of EPEC protein virulence factors, such as bundle-forming pilus (BFP), EPEC secreted protein A, and other EPEC secreted proteins, and reduced EPEC adherence to cells in tissue culture. The effects of zinc were not mimicked by other transition metals, such as manganese, iron, copper, or nickel, and the effects were not reversed by an excess of iron. Quantitative real-time PCR showed that zinc reduced the abundance of the RNAs encoded by the
bfp
gene, by the plasmid-encoded regulator (
per
) gene, by the locus for the enterocyte effacement (LEE)-encoded regulator (
ler
) gene, and by several of the
esp
genes. In vivo, zinc reduced EPEC-induced fluid secretion into ligated rabbit ileal loops, decreased the adherence of EPEC to rabbit ileum, and reduced histopathological damage such as villus blunting. Some of the beneficial effects of zinc on EPEC infection appear to be due to the action of the metal on EPEC bacteria as well as on the host.
SOME PROPERTIES OF WHEAT STRIATE MOSAIC VIRUS
Authors: Lee Peter E. , Bell W.
Published: September 2007

Suspensions of wheat striate mosaic virus prepared with the sediments from high-speed centrifugation (105,000 g) of liquid extracts from viruliferous leafhoppers (Endria inimica Say), infected 63%, 46%, 33%, 5.5%, 3.5%, and 1.6% of the leafhoppers into which they were injected after dilution to 10−0.7, 10−1, 10−2, 10−3, 10−4, and 10−5 respectively. Suspensions of the virus were still infective after they were heated for 10 minutes at 45 °C, but not at 55 °C. Suspensions stored at 4 °C were highly infective after 3 days, but were toxic to the injected insects by the fourth day. Most infectivity was lost after 3 days at −10 °C. Wheat plants did not become infected when mechanically inoculated with suspensions which were infectious to leafhoppers. A specific particle was not correlated with infectivity when suspensions from viruliferous and healthy insects were compared in the electron microscope.
REACTION OF STRAWBERRY TO A RINGSPOT VIRUS FROM RASPBERRY
Authors: Mellor Frances C. , Stace-Smith Richard
Published: September 2007

A ringspot virus that occurs in raspberry was graft-transmitted to 5 strains of Fragaria vesca and to 11 commercial varieties of strawberry. Shock symptoms on F. vesca were similar to those of the strawberry viruses, mottle, and vein-banding, but were followed by mild chronic symptoms that were diagnostic. Most of the commercial varieties were killed by the virus but British Sovereign and Sparta appeared to be immune. The virus was transmitted through a large proportion of the seed from infected plants but not through the pollen.
MASSOSPORA LEVISPORA, A NEW SPECIES OF FUNGUS PATHOGENIC TO THE CICADA, OKANAGANA RIMOSA
Authors: Soper R. S.
Published: September 2007

Massospora levispora Soper pathogenic to the cicada, Okatiagana. rimosa (Say), is described. This species and M. cicadina Peck, the only species currently referred to this genus, differ chiefly in size and shape of the conidia but there are also morphological differences between the resting spores of the two species. It was found that the symptoms expressed by infected cicadas were similar to those reported for hosts of M. cicadina.
EVIDENCE OF A REQUIREMENT FOR PHYTOCHROME-Pfr IN THE FLORAL INITIATION OF CHENOPODIUM RUBRUM
Authors: Cumming Bruce G.
Published: September 2007

Floral initiation of four Chenopodium rubrum selections was studied in daily photoperiods between 2 hours and continuous light.At 15 °C, decreasing or increasing the photoperiod from optimum to sub- or supra-optimal lengths resulted in progressively later floral initiation. The optimum photoperiod was shorter if the ratio of the red to far-red spectral energies was increased during the terminal portion or the whole of each photoperiod. A given photoperiod that was optimal with an intermediate R/FR ratio was sub- and supra-optimal with low and high R/FR ratios, respectively.A working hypothesis is presented in which the concentration of a floral hormone is postulated to be dependent on the formation of phytochrome-Pfr so that its level would be greatest in extreme long photoperiods and least in continuous darkness. Sub- and supra-optimal amounts of Pfr-dependent floral hormone would be produced in sub- and supra-optimal photoperiods, respectively, which result in later than optimal floral initiation. This concept provides a correlative scheme for optimal initiation in either short or long photoperiods.At 30 °C, ambiphotoperiodism was shown. Floral initiation in both short and extreme long photoperiods was earlier than in extreme short or intermediate photoperiods. In one selection, the earliest floral initiation was in intermediate photoperiods at 15 °C, but in extreme long photoperiods at 30 °C with a secondary optimum in intermediate photoperiods. Ambiphotoperiodism may be indicative of endogenously controlled rhythms interacting with the phytochrome system.Ability of the C. rubrum selections to flower in a wide range of photoperiods, including extremely long ones, is correlated with latitudinal origin, viz. 62°46′ N. > 60°47′ N. > 50°10′ N. > 34°20′ N. These differences demonstrate a role of phytochrome in ecotypic differentiation.
STUDIES ON THE MORPHOLOGY OF SYNNEMATA OF HIRSUTELLA GIGANTEA PETCH
Authors: Loughheed T. C.
Published: September 2007

The morphology of the synnemata produced by Hirsulella gigantea has been investigated using histological techniques. Dark-colored initials are formed within the aerial mycelium by a proliferation of differentiated hyphae. Development of the synnemata continues by an elongation in a direction away from the nutrient agar. As the synnemata grow, the hyphae become oriented in a longitudinal direction. At maturity only the outer coat consists of differentiated hyphae; the bulk of the structure is formed of normal mycelium. Sporogenous cells form on the outer coat and bear conidia, commonly in pairs, within a drop of mucus. The synnemata formed by H. gigantea are compared with those produced by Isaria cretacea and Penicillium claviforme. Some similarities are found, especially during the early stages of development.Three other forms of fruiting bodies were observed in cultures of H. gigantea grown under unusual conditions. Two of these forms were sterile.
MODELING OF ADSORPTION IN PORES BY MEANS OF THIRD ORDER + SECOND ORDER PERTURBATION DENSITY FUNCTIONAL THEORY AND MONTE CARLO SIMULATION
Authors: JAMNIK A. , LUO F.
Published: September 2007

Results for the inhomogeneous structure of the hard-core repulsive Yukawa (HCRY) fluid and of the hard-core attractive Yukawa (HCAY) fluid in planar and in spherical micropores are presented. The density profiles are obtained by the recently proposed third order + second order perturbation density functional approximation (DFA) and compared with the results of open ensemble Monte Carlo simulation. As known from other recent studies, the reliability of the DFA theory considered in this work is very sensitive to the accuracy of the required bulk direct correlation function (DCF) obtained by the solution of the Ornstein–Zernike (OZ) equation combined by a suitable closure relation. Comparison between the DFA results and simulation data shows that for the HCRY fluid, the DFA theory utilizing the DCF obtained by the OZ equation supplemented by Malijevsky–Labik approximation satisfies the required accuracy for a broad range of conditions. The results for the nonuniform HCAY fluid obtained in our previous work via the mean spherical approximation (MSA)/OZ DCF showed larger disagreement in some cases. In addition, the MSA/OZ equation for the HCAY model failed to have a physical solution at subcritical temperatures when approaching the vapor–liquid coexistence curve. For this reason, an improved version of the theory incorporating nonlinear optimized random phase approximation (ORPA) in the OZ equation for the RDF calculation of the HCAY fluid is applied. This leads to much better agreement of the DFA predictions with the simulation data. In addition, the calculations can also be performed at the conditions at which the MSA/OZ equation has no physical solution.
ACTIVE TRACKING CONTROL OF THE HYPERCHAOTIC LC OSCILLATOR SYSTEM
Authors: WANG XINGYUAN , JIA BIN , WANG MINGJUN
Published: September 2007

This paper presents an active tracking control strategy of the four-dimensional hyperchaotic LC oscillator system based on the theory of stability of the linear system. This strategy can track all kinds of reference signals. It is also proved that the strategy can make the system converge to any desired smooth orbit exponentially in theory. Numerical simulations have shown that the proposed strategy can not only trace the given reference signals, but the response system can also be in different-structure synchronization with the drive system.
MAGNETIZATION PLATEAUS ON THE ZIGZAG LADDER WITH TWO-, AND THREE-SITE EXCHANGES
Authors: HOVHANNISYAN V. V. , ANANIKYAN L. N. , ANANIKIAN N. S.
Published: September 2007

We consider the Heisenberg model with two-, and three-spin exchange interactions on a zigzag ladder in a strong magnetic field. Using the recursion method for the partition function in Ising approximation we have found exact results for the magnetization. We have shown the existence of magnetization plateaus in the case of mutual two-, and three-spin exchanges at low temperatures and different exchange parameters. The system exhibits different magnetic behaviors, depending on the values of the exchange parameters.
PROPERTY SIMULATION FOR NANO-SCALE INTERFACIAL FRICTION BETWEEN TWO KINDS OF MATERIAL IN MEMS BASED ON AN ATOMISTIC SIMPLIFIED MODEL
Authors: YANG PING , LIAO NINGBO , YANG DAOGUO
Published: September 2007

The objective of this research work is to provide a systematic method to perform molecular dynamics simulation or evaluation for nano-scale interfacial friction between different materials in MEMS. A simplified model to simulate surface sliding between different kinds of material by molecular dynamics [MD] is proposed because the surface property is a dominant factor for the performance between two kinds of material in MEMS. The Newton's equations of motion are established by using the Morse potential function. An improved Verlet algorithm is employed to solve atom trajectories. Comparing the results of the computer simulation with experimental results in Ref. 1, the validity of the model is confirmed. The simulation results show that the preliminary stage and the last stage, when no interface is formed, the friction force fluctuates periodly and its peak value is smaller relatively, while at the intermediate stage, where the interface is formed, the friction force fluctuates periodly and its peak value is relatively bigger. The friction force is approximately proportional to the contact area. In the meantime, Cu sliding along Al with uniform speed and accelerated motion was also investigated, the mechanical properties between two surfaces were analyzed and a tentative computational simulation on the effect of the driving force was developed. The results lay a basis for future work.
FUZZY PREDICTIVE CONTROLLER FOR UNKNOWN DISCRETE CHAOTIC SYSTEMS
Authors: BOUKABOU ABDELKRIM , MANSOURI NOURA
Published: September 2007

In this paper, a fuzzy logic-based approach is taken for modeling and prediction-based control of unknown chaotic system using measured input–output data obtained from the underlying system. Under this framework, a Takagi–Sugeno (TS) fuzzy system is used with a general structure of a linear combination of Gaussian basis function in conjunction with the Levenberg–Marquardt algorithm for the optimization of model parameters. A real-time one-pass learning algorithm is developed for identifying the unknown chaotic system. Based on the fuzzy model above, a predictive controller is achieved for the stabilization of the fuzzy model on unknown unstable fixed points. Several simulation examples are included to illustrate the effectiveness and the feasibility of the proposed method for both fuzzy modeling and predictive control phases.
A GALLERY OF CHUA ATTRACTORS PART VI
Authors: BILOTTA ELEONORA , DI BLASI GIANPIERO , STRANGES FAUSTO , PANTANO PIETRO
Published: September 2007

In this article, we conclude our series of papers on the analysis and visualization of Chua attractors and their generalizations. We present a gallery of 144 n-scroll, 15 hyperchaotic and 37 synchronized systems. Along with time series and FFT we provide 3D visualizations; for some attractors we also supply Lyapunov coefficients and fractal dimensions.

The goal in constructing our Gallery has been to make the general public aware of the enormous variety of chaotic phenomena and to change the widespread impression that they are isolated rarities. The Gallery provides a valuable collection of images and technical data which can be used to analyze these phenomena and to reproduce them in future studies.

From a scientific point of view, we have tried to identify new methodological approaches to the study of chaos, opening nontraditional perspectives on the complexity of this domain. In our papers, we have discussed a broad range of topics, ranging from techniques for visualizing Chua attractors to computational methods allowing us to make a statistical classification of attractors' positions in phase space and to describe the evolutionary processes through which their shapes change over time. We see these processes as analogous to population dynamics in artificial environments. Within these environments, we use experimental methods to identify the models which guide morphogenetic change and which organize genetic landscapes in parameter space.

This paper is organized as follows. First, we provide formal descriptions of the attractors generated by n-scroll, hyperchaotic and synchronized systems. The next section describes a Gallery of Chua attractors, generated by gradually varying the parameters and analyzing the resulting bifurcation maps. We then describe software tools allowing us to perform statistical analyses on selected sets of attractors, to visualize them, to explore their organization in phase space, and to conduct experimental investigations of the morphogenetic processes through which a small set of base attractors can generate a broad range of different forms. In the last section, we describe the creation of a Virtual 3D Gallery displaying some of the attractors we have presented in our six papers. The attractors are organized by theme, as they might be in a museum. The environment allows users to explore the attractors, interact with shapes, listen to music and sounds generated by the attractors, change their spatial organization, and create new shapes. To complete the paper — and the series — we propose a number of general conclusions.
EXACT APPROXIMATIONS OF OMEGA NUMBERS
Authors: CALUDE CRISTIAN S. , DINNEEN MICHAEL J.
Published: September 2007

A Chaitin Omega number is the halting probability of a universal prefix-free Turing machine. Every Omega number is simultaneously computably enumerable (the limit of a computable, increasing, converging sequence of rationals), and algorithmically random (its binary expansion is an algorithmic random sequence), hence uncomputable. The value of an Omega number is highly machine-dependent. In general, no more than finitely many scattered bits of the binary expansion of an Omega number can be exactly computed; but, in some cases, it is possible to prove that no bit can be computed.

In this paper, we will simplify and improve both the method and correctness of the proof proposed in an earlier paper, and we will compute the exact approximations of two Omega numbers of the same prefix-free Turing machine, which is universal when used with data in base 16 or base 2: we compute 43 exact bits for the base 16 machine and 40 exact bits for the base 2 machine.
MULTICENTER NETWORK AND SYNCHRONIZATION
Authors: LIU ZENGRONG , DONG CHENGDONG , FAN QINGDUAN
Published: September 2007

This paper proposes a new complex network: multicenter network. Coupled maps on two different types of network, coupled map lattices with nearest neighbors and multicenter network, are investigated. Both theoretical analysis and numerical simulation show that the synchronization of coupled map is much easier than that on the regular network.
HYPERBOLIC PERIODIC ORBITS FROM THE BIFURCATION OF A FOUR-DIMENSIONAL NONLINEAR CENTER
Authors: FERRAGUT ANTONI , LLIBRE JAUME , TEIXEIRA MARCO ANTONIO
Published: September 2007

We study the bifurcation of hyperbolic periodic orbits from a four-dimensional nonlinear center in a class of differential systems. The tool for proving these results is the averaging theory.
LIMIT CYCLES IN TWO TYPES OF SYMMETRIC LIÉNARD SYSTEMS
Authors: JIANG J. , HAN M. , YU P. , LYNCH S.
Published: September 2007

Liénard systems and their generalized forms are classical and important models of nonlinear oscillators, and have been widely studied by mathematicians and scientists. The main problem considered is the maximal number of limit cycles that the system can have. In this paper, two types of symmetric polynomial Liénard systems are investigated and the maximal number of limit cycles bifurcating from Hopf singularity is obtained. A global result is also presented.
PERIODIC ORBITS NEAR A HETEROCLINIC LOOP FORMED BY ONE-DIMENSIONAL ORBIT AND A TWO-DIMENSIONAL MANIFOLD: APPLICATION TO THE CHARGED COLLINEAR THREE-BODY PROBLEM
Authors: LLIBRE JAUME , PAŞCA DANIEL
Published: September 2007

This paper is devoted to the study of a type of differential systems which appear usually in the study of the Hamiltonian systems with two degrees of freedom. We prove the existence of infinitely many periodic orbits on each negative energy level. All these periodic orbits pass near to the total collision. Finally we apply these results to study the existence of periodic orbits in the charged collinear three-body problem.