bluuebunny/crossref_metadata_2025 huggingface dataset:
Montelukast as add-on therapy to β-agonists and late airway response
Authors: Rosewich M. , Rose M. A. , Eickmeier O. , Travaci M. , Kitz R. , Zielen S.
Published: February 2007

The present study investigated whether single-dose oral leukotriene receptor antagonists as add-on therapy to short-acting β-agonists, immediately after allergen challenge, block the late-phase airway response.

In total, 35 mild asthmatics (mean age 24 yrs, 19 males) sensitised for house dust mites underwent two courses of bronchial allergen challenge. After the early allergic response (EAR), subjects received salbutamol once and were randomly assigned to either 10 mg of montelukast or placebo (double-blind crossover). To identify a late allergic response, forced expiratory volume in one second (FEV1) was monitored over the following 8 h. Baseline exhaled nitric oxide (NO) was determined ahead of each allergen challenge.

Baseline NO levels differed significantly depending on the reaction to allergen challenge. In total, 12 subjects showed no significant response, 11 only showed an EAR, and 12 had a dual response and underwent further analysis. The area under the FEV1time–response curve 3–8 h after bronchial allergen challenge was -0.77±1.68 from the pre-challenge values on montelukast compared with -2.47±1.32 on placebo. The baseline exhaled NO fraction of subjects without an EAR was significantly lower than of those presenting a dual response.

The results of the present study demonstrate that single-dose leukotriene receptor antagonists given orally right after the early allergic response can significantly inhibit the late allergic response after bronchial allergen challenge.
Characterisation of asthma among adults with and without childhood farm contact
Authors: Schulze A. , van Strien R. T. , Praml G. , Nowak D. , Radon K.
Published: February 2007

Childhood farm contact is associated with a lower prevalence of sensitisation and allergic rhinitis. Findings have been contradictory for asthma. The aim of the present study was to investigate the differences between farm and nonfarm subjects using objective measurements.

A cross-sectional questionnaire study was performed among rural adults aged 18–44 yrs, of which 37% lived on a farm during the first 3 yrs of life and were thus referred to as “farm subjects”. Lung function, bronchial hyperresponsiveness (BHR) to methacholine and sensitisation were measured in a random sample. A total of 1,595 subjects were included in the analyses.

Among farm subjects, sensitisation against inhalant allergens (odds ratio (OR) 0.7; 95% confidence interval 0.6–0.9), allergic rhinitis (0.5 (0.4–0.8)) and asthma diagnosis (0.7(0.4–1.1)) were less common than among nonfarm subjects. For BHR and lung function, no statistically significant differences were found between the two groups. Stratifying for sensitisation, farm subjects had a lower OR of asthma diagnosis (0.5 (0.3–1.0)) and a nonsignificantly reduced OR of BHR with sensitisation (0.8 (0.5–1.1)).

The present study confirmed, using objective measurements, that farm subjects have a lower prevalence of symptoms and asthma diagnosis, while the prevalence of bronchial hyperresponsiveness does not differ.
Prognostic value of blood gas analyses in patients with idiopathic pulmonary arterial hypertension
Authors: Hoeper M. M. , Pletz M. W. , Golpon H. , Welte T.
Published: February 2007

Blood gas abnormalities in patients with idiopathic pulmonary arterial hypertension (IPAH) may be related to disease severity and prognosis.

The present authors performed a 12-yr retrospective analysis assessing arterialised capillary blood gases, haemodynamics, exercise variables and survival in 101 patients with IPAH.

At baseline, arterial oxygen tension (Pa,O2) and carbon dioxide arterial tension (Pa,CO2) were 9.17±1.86 and 4.25±0.532 kPa, respectively. WhilePa,O2was not associated with survival, a lowPa,CO2was a strong and independent prognostic marker. When patients were divided according to a baselinePa,CO2value above or below 4.25 kPa, a cut-off value determined by receiver operating characteristics analysis, survival rates were 98 and 86% at 1 yr, 82 and 69% at 2 years, 80 and 51% at 3 yrs, 77 and 41% at 5 yrs, and 65 and 12% at 8 yrs, respectively.Pa,CO2after 3 months of medical therapy was strongly associated with survival. Hypocapnia at rest and during exercise correlated with low cardiac output, low peak oxygen uptake and reduced ventilatory efficacy. Multiple regression analysis revealed that 6-min walking distance, right atrial pressure andPa,CO2were independently associated with survival.

In patients with idiopathic pulmonary arterial hypertension, hypocapnia (carbon dioxide arterial tension <4.25 kPa) is an independent marker of mortality.
Eosinophilic airway inflammation and exacerbations of COPD: a randomised controlled trial
Authors: Siva R. , Green R. H. , Brightling C. E. , Shelley M. , Hargadon B. , McKenna S. , Monteiro W. , Berry M. , Parker D. , Wardlaw A. J. , Pavord I. D.
Published: February 2007

Evidence suggests that eosinophilic airway inflammation is important in the pathogenesis of severe chronic obstructive pulmonary disease (COPD) exacerbations. The present authors tested the hypothesis that a management strategy that aims to reduce sputum eosinophil counts is associated with a reduction in exacerbations of COPD.

A total of 82 patients with COPD were randomised into two groups. One group was treated according to traditional guidelines (British Thoracic Society (BTS) group) and the other (sputum group) was treated with the additional aim of minimising eosinophilic airway inflammation, assessed using the induced sputum eosinophil count. The primary outcome was exacerbations, which were categorised as mild, moderate or severe.

The frequency of severe exacerbations per patient per year was 0.5 and 0.2 in the BTS and sputum groups, respectively (mean reduction 62%). The majority of this benefit was confined to patients with eosinophilic airway inflammation. There was no difference in the frequency of mild and moderate exacerbations. The average daily dose of inhaled or oral corticosteroids during the trial did not differ between the groups. Out of 42 patients in the sputum group, 17 required regular oral corticosteroids to minimise eosinophilic airway inflammation.

A management strategy that aims to minimise eosinophilic airway inflammation, as well as symptoms, is associated with a reduction in severe exacerbations of chronic obstructive pulmonary disease.
Effect of anti-PcrV antibody in a murine chronic airwayPseudomonas aeruginosainfection model
Authors: Imamura Y. , Yanagihara K. , Fukuda Y. , Kaneko Y. , Seki M. , Izumikawa K. , Miyazaki Y. , Hirakata Y. , Sawa T. , Wiener-Kronish J. P. , Kohno S.
Published: February 2007

Pseudomonas aeruginosais one of the most important pathogens in patients with chronic airway conditions, such as cystic fibrosis and diffuse panbronchiolitis. Type III secretion system-mediated virulence factors contribute to the lung damage in chronicP. aeruginosainfection.

The effects of the anti-PcrV immunoglobulin (Ig)G, which blocks the type III secretion system, were evaluated in a mouse model of chronicP. aeruginosainfection. On bacteriological examination, anti-PcrV IgG showed no bactericidal effects. On bronchoalveolar lavage fluid (BALF) analysis, total cell number and neutrophil ratios in the anti-PcrV IgG-treated groups were lower than those in the control group. In addition, macrophage inflammatory protein-2, tumour necrosis factor-α, and interleukin-β concentrations in BALF were lower in the anti-PcrV IgG-treated groups when compared with controls. Plasma anti-PcrV IgG titre was elevated after administration of anti-PcrV IgG. Although plasma titre decreased gradually, a significant concentration was maintained during the experimental period.

These data suggest that anti-PcrV immunoglobulin G reduces the inflammatory reaction caused by chronicPseudomonas aeruginosarespiratory infection and may be useful in treating respiratory diseases.
Use of different exhaled nitric oxide multiple flow rate models in COPD
Authors: Roy K. , Borrill Z. L. , Starkey C. , Hazel A. L. , Morris J. , Vestbo J. , Singh D.
Published: February 2007

Multiple flow rates of exhaled nitric oxide (eNO) fraction (Fe,NO) data can be modelled to estimate airway wall concentration of nitric oxide (Caw,NO), diffusing capacity of nitric oxide (Daw,NO), alveolar nitric oxide concentration (Calv,NO) and total maximal flux of nitric oxide in the airway compartment (J′aw,NO).

Fe,NOat 10, 30, 50, 100 and 200 mL·s−1from 50 chronic obstructive pulmonary disease (COPD) patients and 35 healthy controls (smokers and nonsmokers) modelled using five different methods was compared and the effect of the number of flow rates was investigated.

All methods showed that current smoking reducedC&SetFont Italic="0";aw,NOin COPD patients, with some methods showing that smoking reducedJ′aw,NO. Smoking did not affectCalv,NOorDaw,NO. The methods gave similar results forCaw,NObut there was variability between methods forJ′aw,NO,Calv,NOandDaw,NO&SetFont Italic="0";. The median error by least squares fitting between modelled and actual data was significantly lower for the nonlinear method (1.96) compared with the mixed methods (3.31 and 3.62). Parameters calculated using the nonlinear method using five and four flow rates were significantly different. The ratio (95% confidence interval) ofCaw,NOwas 2.02 (1.45–2.83).

Nitric oxide models give different results, although airway conductance of nitric oxide is relatively model independent. Nonlinear modelling has the least error, suggesting it is the best method. The number of flow rates should be standardised.
Rapid evolution in response to introduced predators I: rates and patterns of morphological and life-history trait divergence
Authors: Fisk Debra L , Latta Leigh C , Knapp Roland A , Pfrender Michael E
Published: February 2007

Background

Introduced species can have profound effects on native species, communities, and ecosystems, and have caused extinctions or declines in native species globally. We examined the evolutionary response of native zooplankton populations to the introduction of non-native salmonids in alpine lakes in the Sierra Nevada of California, USA. We compared morphological and life-history traits in populations of Daphnia with a known history of introduced salmonids and populations that have no history of salmonid introductions.

Results

Our results show that Daphnia populations co-existing with fish have undergone rapid adaptive reductions in body size and in the timing of reproduction. Size-related traits decreased by up to 13 percent in response to introduced fish. Rates of evolutionary change are as high as 4,238 darwins (0.036 haldanes).

Conclusion

Species introductions into aquatic habitats can dramatically alter the selective environment of native species leading to a rapid evolutionary response. Knowledge of the rates and limits of adaptation is an important component of understanding the long-term effects of alterations in the species composition of communities. We discuss the evolutionary consequences of species introductions and compare the rate of evolution observed in the Sierra Nevada Daphnia to published estimates of evolutionary change in ecological timescales.
Epidemiology and clinical findings associated with enteroviral acute flaccid paralysis in Pakistan
Authors: Saeed Mohsan , Zaidi Sohail Z , Naeem Asif , Masroor Muhammad , Sharif Salmaan , Shaukat Shahzad , Angez Mehar , Khan Anis
Published: February 2007

Background

Enteroviruses are among the most common viruses infecting humans worldwide and they are associated with diverse clinical syndromes. Acute flaccid paralysis (AFP) is a clinical manifestation of enteroviral neuropathy, transverse myelitis, Guillian-Barre Syndrome, Traumatic neuritis and many other nervous system disorders. The objective of this study was to understand the role of Non-Polio Enteroviruses (NPEV) towards this crippling disorder.

Methods

Stool specimens of 1775 children, aged less than 15 years, suffering from acute flaccid paralysis were collected after informed consent within 14 days of onset of symptoms during January 2003 to September 2003. The specimens were inoculated on RD and L20B cells using conventional tube cell culture while micro-neutralization test was used to identify the non-polio enterovirus (NPEV) serotypes. Detailed clinical information and 60-days follow-up reports were analyzed for NPEV-associated AFP cases.

Results

NPEV were isolated from 474 samples. The male to female ratio was 1.4:1. The isolation of NPEV decreased significantly with the increase in age. Cases associated with fever at the onset of NPEV-associated AFP were found to be 62%. The paralysis was found asymmetrical in 67% cases, the progression of paralysis to peak within 4 days was found in 72% cases and residual paralysis after 60 days of paralysis onset was observed in 39% cases associated with NPEV. A clinical diagnosis of Guillian-Barre syndrome was made in 32% cases. On Microneutralization assay, echo-6 (13%) and coxsackievirus B (13%) were the most commonly isolated serotypes of NPEV along with E-7, E-13, E-11, E-4 and E-30. The isolates (n = 181) found untypable by the antiserum pools were confirmed as NPEV by PCR using Pan-Enterovirus primers.

Conclusion

The present study suggests that NPEV are a dominant cause of AFP and different serotypes of NPEV are randomly distributed in Pakistan. The untypable isolates need further characterization and analysis in order to determine their association with clinical presentation of a case.
An adenovirus prime/plasmid boost strategy for induction of equipotent immune responses to two dengue virus serotypes
Authors: Khanam Saima , Rajendra Pilankatta , Khanna Navin , Swaminathan Sathyamangalam
Published: February 2007

Background

Dengue is a public health problem of global significance for which there is neither an effective antiviral therapy nor a preventive vaccine. It is a mosquito-borne viral disease, caused by dengue (DEN) viruses, which are members of the Flaviviridae family. There are four closely related serotypes, DEN-1, DEN-2, DEN-3 and DEN-4, each of which is capable of causing disease. As immunity to any one serotype can potentially sensitize an individual to severe disease during exposure to a heterologous serotype, the general consensus is that an effective vaccine should be tetravalent, that is, it must be capable of affording protection against all four serotypes. The current strategy of creating tetravalent vaccine formulations by mixing together four monovalent live attenuated vaccine viruses has revealed the phenomenon of viral interference leading to the manifestation of immune responses biased towards a single serotype.

Results

This work stems from the emergence of (i) the DEN virus envelope (E) domain III (EDIII) as the most important region of the molecule from a vaccine perspective and (ii) the adenovirus (Ad) as a promising vaccine vector platform. We describe the construction of a recombinant, replication-defective Ad (rAd) vector encoding a chimeric antigen made of in-frame linked EDIIIs of DEN virus serotypes 2 and 4. Using this rAd vector, in conjunction with a plasmid vector encoding the same chimeric bivalent antigen, in a prime-boost strategy, we show that it is possible to elicit equipotent neutralizing and T cell responses specific to both DEN serotypes 2 and 4.

Conclusion

Our data support the hypothesis that a DEN vaccine targeting more than one serotype may be based on a single DNA-based vector to circumvent viral interference. This work lays the foundation for developing a single Ad vector encoding EDIIIs of all four DEN serotypes to evoke a balanced immune response against each one of them. Thus, this work has implications for the development of safe and effective tetravalent dengue vaccines.
Evaluating antibiotics for use in medicine using a poloxamer biofilm model
Authors: Clutterbuck Abi L , Cochrane Christine A , Dolman Jayne , Percival Steven L
Published: February 2007

Background

Wound infections, due to biofilms, are a constant problem because of their recalcitrant nature towards antibiotics. Appropriate antibiotic selection for the treatment of these biofilm infections is important. The traditional in vitro disc diffusion method for antibiotic selection uses bacterial cultures grown on agar plates. However, the form of bacterial growth on agar is not representative of how bacteria grow in wounds and other tissue sites as here bacteria grow naturally in a biofilm. The aim of this research was to test a more appropriate method for testing antimicrobial efficacy on biofilms and compare with the standard methods used for antibiotic sensitivity testing.

Methods

Outer Membrane Protein analysis was performed on E.coli, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis and Acinetobacter juni when grown on Mueller Hinton agar ('quasi-biofilm state') and 30% Poloxamer hydrogel ('true- biofilm state). Susceptibility to antibiotics on 28 clinical isolates was determined using the modified Kirby Bauer disc diffusion method, on agar and 30% Poloxamer.

Results

Similar outer membrane proteins [OMPs] were identified in bacteria grown in a biofilm state and on a 30% poloxamer hydrogel, which were very different to the OMPs identified in bacteria grown on Mueller-Hinton agar and broth. There was a significant difference between the means of the clearance zones around the antibiotic discs on standard agar and poloxamer gels [P < 0.05]. The zones of clearance were generally smaller for poloxamer-grown bacteria than those grown on standard agar. Diffusion distances of various antibiotics through agar and 30% poloxamer showed no significant difference [P > 0.05].

Conclusion

The findings of this experiment suggest that poloxamer gel could be used as an appropriate medium on which to conduct biofilm antibiotic susceptibility tests as it enables bacteria to be grown in a state representative of the infected surface from which the culture was taken.
Determining client need in a multi-state fetal alcohol syndrome consortium: from training to practice
Authors: Christopher Suzanne , Dunnagan Tim , Haynes George , Stiff Lili
Published: February 2007

Background

A multi-state consortium was developed in the US to conduct baseline data collection and intervention research on fetal alcohol syndrome. Each state employed support specialists whose job it was to reduce or eliminate alcohol consumption in women who were at high risk for drinking alcohol during their pregnancy. The purpose of this paper is to report how support specialists in three primarily rural/frontier states were trained to assess client need and how client need was actually assessed in the field.

Methods

A qualitative process evaluation was conducted using semi-structured interviews. Interviews were conducted with state staff involved in support specialist training and consortium activities and the support specialists themselves. Inductive analyses were conducted with interview data.

Results

Need determination varied by state and for one state within the state. How support specialists were trained to assess need and how need was assessed in the field was mostly congruent.

Conclusion

Process evaluation is an effective method for providing practical and useful answers to questions that cannot be answered by outcome evaluation alone.
On the performances of different IMRT treatment planning systems for selected paediatric cases
Authors: Fogliata Antonella , Nicolini Giorgia , Alber Markus , Åsell Mats , Clivio Alessandro , Dobler Barbara , Larsson Malin , Lohr Frank , Lorenz Friedlieb , Muzik Jan , Polednik Martin , Vanetti Eugenio , Wolff Dirk , Wyttenbach Rolf , Cozzi Luca
Published: February 2007

Background

To evaluate the performance of seven different TPS (Treatment Planning Systems: Corvus, Eclipse, Hyperion, KonRad, Oncentra Masterplan, Pinnacle and PrecisePLAN) when intensity modulated (IMRT) plans are designed for paediatric tumours.

Methods

Datasets (CT images and volumes of interest) of four patients were used to design IMRT plans. The tumour types were: one extraosseous, intrathoracic Ewing Sarcoma; one mediastinal Rhabdomyosarcoma; one metastatic Rhabdomyosarcoma of the anus; one Wilm's tumour of the left kidney with multiple liver metastases. Prescribed doses ranged from 18 to 54.4 Gy. To minimise variability, the same beam geometry and clinical goals were imposed on all systems for every patient. Results were analysed in terms of dose distributions and dose volume histograms.

Results

For all patients, IMRT plans lead to acceptable treatments in terms of conformal avoidance since most of the dose objectives for Organs At Risk (OARs) were met, and the Conformity Index (averaged over all TPS and patients) ranged from 1.14 to 1.58 on primary target volumes and from 1.07 to 1.37 on boost volumes. The healthy tissue involvement was measured in terms of several parameters, and the average mean dose ranged from 4.6 to 13.7 Gy. A global scoring method was developed to evaluate plans according to their degree of success in meeting dose objectives (lower scores are better than higher ones). For OARs the range of scores was between 0.75 ± 0.15 (Eclipse) to 0.92 ± 0.18 (Pinnacle3 with physical optimisation). For target volumes, the score ranged from 0.05 ± 0.05 (Pinnacle3 with physical optimisation) to 0.16 ± 0.07 (Corvus).

Conclusion

A set of complex paediatric cases presented a variety of individual treatment planning challenges. Despite the large spread of results, inverse planning systems offer promising results for IMRT delivery, hence widening the treatment strategies for this very sensitive class of patients.
Genome display tool: visualizing features in complex data sets
Authors: Viswanath Lalitha , Lu Yue , Fox George E
Published: February 2007

Background

The enormity of the information contained in large data sets makes it difficult to develop intuitive understanding. It would be useful to have software that allows visualization of possible correlations between properties that can be associated with a core data set. In the case of bacterial genomes, existing visualization tools focus on either global properties such as variations in composition or detailed local displays of the features that comprise the annotation. It is not easy to visualize other information in the context of this core information.

Results

A Java based software known as the Genome Display Tool (GDT), allows the user to simultaneously view the distribution of multiple attributes pertaining to genes and intragenic regions in a single bacterial genome using different colours and shapes on a single screen. The display represents each gene by small boxes that correlate with physical position in the genome. The size of the boxes is dynamically allocated based on the number of genes and a zoom feature allows close-up inspection of regions of interest. The display is interfaced with a MS-Access relational database and can display any feature in the database that can be represented by discrete values. Data is readily added to the database from an MS-Excel spread sheet. The functionality of GDT is demonstrated by comparing the results of two predictions of recent horizontal transfer events in the genome of Synechocystis PCC-6803. The resulting display allows the user to immediately see how much agreement exists between the two methods and also visualize how genes in various categories (e.g. predicted in both methods, one method etc) are distributed in the genome.

Conclusion

The GDT software provides the user with a powerful tool that allows development of an intuitive understanding of the relative distribution of features in a large data set. As additional features are added to the data set, the number of possible correlations that can be visualized grows rapidly. Although described here for use in bacterial genomics, the principle is general and similar software might be useful in other contexts such as patient studies.
Bioinformatics strategies for lipidomics analysis: characterization of obesity related hepatic steatosis
Authors: Yetukuri Laxman , Katajamaa Mikko , Medina-Gomez Gema , Seppänen-Laakso Tuulikki , Vidal-Puig Antonio , Orešič Matej
Published: February 2007

Background

Lipids are an important and highly diverse class of molecules having structural, energy storage and signaling roles. Modern analytical technologies afford screening of many lipid molecular species in parallel. One of the biggest challenges of lipidomics is elucidation of important pathobiological phenomena from the integration of the large amounts of new data becoming available.

Results

We present computational and informatics approaches to study lipid molecular profiles in the context of known metabolic pathways and established pathophysiological responses, utilizing information obtained from modern analytical technologies. In order to facilitate identification of lipids, we compute the scaffold of theoretically possible lipids based on known lipid building blocks such as polar head groups and fatty acids. Each compound entry is linked to the available information on lipid pathways and contains the information that can be utilized for its automated identification from high-throughput UPLC/MS-based lipidomics experiments. The utility of our approach is demonstrated by its application to the lipidomic characterization of the fatty liver of the genetically obese insulin resistant ob/ob mouse model. We investigate the changes of correlation structure of the lipidome using multivariate analysis, as well as reconstruct the pathways for specific molecular species of interest using available lipidomic and gene expression data.

Conclusion

The methodology presented herein facilitates identification and interpretation of high-throughput lipidomics data. In the context of the ob/ob mouse liver profiling, we have identified the parallel associations between the elevated triacylglycerol levels and the ceramides, as well as the putative activated ceramide-synthesis pathways.
Ptf1ais essential for the differentiation of GABAergic and glycinergic amacrine cells and horizontal cells in the mouse retina
Authors: Nakhai Hassan , Sel Saadettin , Favor Jack , Mendoza-Torres Lidia , Paulsen Friedrich , Duncker Gernot I. W. , Schmid Roland M.
Published: February 2007

Basic helix-loop-helix (bHLH) transcription factors are important regulators of retinal neurogenesis. In the developing retina, proneural bHLH genes have highly defined expressions, which are influenced by pattern formation and cell-specification pathways. We report here that the tissue-specific bHLH transcription factor Ptf1a (also known as PTF1-p48) is expressed from embryonic day 12.5 of gestation (E12.5)to postnatal day 3 (P3) during retinogenesis in the mouse. Using recombination-based lineage tracing, we provide evidence that Ptf1ais expressed in precursors of amacrine and horizontal cells. Inactivation of Ptf1a in the developing retina led to differentiation arrest of amacrine and horizontal precursor cells in addition to partial transdifferentiation of Ptf1a-expressing precursor cells to ganglion cells. Analysis of late cell-type-specific markers revealed the presence of a small population of differentiated amacrine cells, whereas GABAergic and glycinergic amacrine cells, as well as horizontal cells, were completely missing in Ptf1a-knockout retinal explants. We conclude that Ptf1a contributes to the differentiation of horizontal cells and types of amacrine cells during mouse retinogenesis.
A homeo-paired domain-binding motif directs Myf5 expression in progenitor cells of limb muscle
Authors: Buchberger Astrid , Freitag Diana , Arnold Hans-Henning
Published: February 2007

Recruitment of multipotent mesodermal cells to the myogenic lineage is mediated by the transcription factor Myf5, the first of the myogenic regulatory factors to be expressed in most sites of myogenesis in the mouse embryo. Among numerous elements controlling the spatiotemporal pattern of Myf5 expression, the -58/-56 kb distal Myf5 enhancer directs expression in myogenic progenitor cells in limbs and in somites. Here, we show by site-directed mutagenesis within this enhancer that a predicted homeobox adjacent to a putative paired domain-binding site is required for the activity in muscle precursor cells in limbs and strongly contributes to expression in somites. By contrast, predicted binding sites for Tcf/Lef, Mef3 and Smad transcription factors play no apparent role for the expression in limbs but might participate in the control in somites. A 30mer oligonucleotide sequence containing and surrounding the homeo and paired domain-binding motifs directs faithful expression in myogenic cells in limbs and also enhances myotomal expression in somites. Pax3 and Meox2 transcription factors can bind to these consensus sites in vitro and therefore constitute potential regulators. However, genetic evidence in the Meox2-deficient mouse mutant argues against a role for Meox2 in the regulation of Myf5 expression. The data presented here demonstrate that a composite homeo and paired domain-binding motif within the-58/-56 enhancer is required and sufficient for activation of the Myf5 gene in muscle progenitor cells in the limb. Although Pax3 constitutes a potential cognate transcription factor for the enhancer, it fails to transactivate the site in transfection experiments.
Transcriptional regulation of epidermal cell fate in theArabidopsisembryo
Authors: Takada Shinobu , Jürgens Gerd
Published: February 2007

How distinct cell fates are specified at correct positions within the plant embryo is unknown. In Arabidopsis, different cell fates are generated early on, starting with the two daughter cells of the zygote. To address mechanisms of position-dependent gene activation and cell fate specification,we analyzed the regulatory region of the Arabidopsis thaliana MERISTEM LAYER 1 (ATML1) gene, which is already expressed at the one-cell stage and whose expression is later restricted to the outermost, epidermal cell layer from its inception. A sensitive, multiple GFP reporter revealed a modular organization to the ATML1 promoter. Each region contributes positively to specific spatial and temporal aspects of the overall expression pattern, including position-dependent but auxin-independent regulation along the apical-basal axis of the embryo. A 101 bp fragment that conferred all aspects of ATML1 expression contained known binding sites for homeodomain transcription factors and other regulatory sequences. Our results suggest that expression patterns associated with cell fate determination in the plant embryo result from positional signals targeting different regulatory sequences in complex promoters.
Head regeneration in wild-type hydra requires de novo neurogenesis
Authors: Miljkovic-Licina Marijana , Chera Simona , Ghila Luiza , Galliot Brigitte
Published: February 2007

Because head regeneration occurs in nerve-free hydra mutants, neurogenesis was regarded as dispensable for this process. Here, in wild-type hydra, we tested the function of the ParaHox gsx homolog gene, cnox-2,which is a specific marker for bipotent neuronal progenitors, expressed in cycling interstitial cells that give rise to apical neurons and gastric nematoblasts (i.e. sensory mechanoreceptor precursors). cnox-2 RNAi silencing leads to a dramatic downregulation of hyZic, prdl-a, gscand cnASH, whereas hyCOUP-TF is upregulated. cnox-2indeed acts as an upstream regulator of the neuronal and nematocyte differentiation pathways, as cnox-2(-) hydra display a drastic reduction in apical neurons and gastric nematoblasts, a disorganized apical nervous system and a decreased body size. During head regeneration, the locally restricted de novo neurogenesis that precedes head formation is cnox-2 dependent: cnox-2 expression is induced in neuronal precursors and differentiating neurons that appear in the regenerating tip; cnox-2 RNAi silencing reduces this de novo neurogenesis and delays head formation. Similarly, the disappearance of cnox-2+cells in sf-1 mutants also correlates with head regeneration blockade. Hence in wild-type hydra, head regeneration requires the cnox-2 neurogenic function. When neurogenesis is missing, an alternative, slower and less efficient, head developmental program is possibly activated.
PSA-NCAM in postnatally generated immature neurons of the olfactory bulb:a crucial role in regulating p75 expression and cell survival
Authors: Gascon Eduardo , Vutskits Laszlo , Jenny Benoit , Durbec Pascale , Kiss Jozsef Zoltan
Published: February 2007

In the mammalian brain, ongoing neurogenesis via the rostral migratory stream (RMS) maintains neuronal replacement in the olfactory bulb throughout life. Mechanisms that regulate the final number of new neurons in this system include proliferation, migration and apoptosis. Here we show that the polysialylated isoforms of the neural cell adhesion molecule (PSA-NCAM) act as a pro-survival molecule in immature newborn neurons. Confocal microscopic analysis revealed a threefold increase in TUNEL-positive cells in the subventricular zone (SVZ) and the RMS of transgenic animals lacking the gene encoding NCAM (NCAM-/-), as compared with wild types. The enhanced apoptotic cell death occurred specifically in the population of mCD24-positive newborn neurons, but not in GFAP-positive astrocytes. Using in vitro cultures of purified SVZ-derived neurons, we demonstrate that the loss or inactivation of PSA on NCAM, as well as the deletion of NCAM, lead to reduced survival in response to neurotrophins including BDNF and NGF. These changes in cell survival are accompanied by an upregulation of p75 neurotrophin receptor expression in vitro as well as in vivo. Furthermore, the negative effects of PSA-NCAM inactivation on cell survival could be prevented by the pharmacological blockade of the p75 receptor-signaling pathway. We propose that PSA-NCAM may promote survival by controlling the expression of the p75 receptor in developing neurons.
Design of a minimum variance multiple input-multiple output neuro self-tuning proportional-integral-derivative controller for non-linear dynamic systems
Authors: Guo L. Z. , Zhu Q. M. , Warwick K
Published: February 2007

In this study a minimum variance neuro self-tuning proportional-integral-derivative (PID) controller is designed for complex multiple input-multiple output (MIMO) dynamic systems. An approximation model is constructed, which consists of two functional blocks. The first block uses a linear submodel to approximate dominant system dynamics around a selected number of operating points. The second block is used as an error agent, implemented by a neural network, to accommodate the inaccuracy possibly introduced by the linear submodel approximation, various complexities/uncertainties, and complicated coupling effects frequently exhibited in non-linear MIMO dynamic systems. With the proposed model structure, controller design of an MIMO plant with n inputs and n outputs could be, for example, decomposed into n independent single input-single output (SISO) subsystem designs. The effectiveness of the controller design procedure is initially verified through simulations of industrial examples.
Design of a fuzzy-based controller for electric vehicles on Indian roads
Authors: Poorani S , Kumar K Udaya , Renganarayanan S
Published: February 2007

This paper presents a novel approach with a rule-based acceleration control strategy for electric vehicles. This proposal has a straightforward goal for minimizing the complexities of the existing controllers used in vehicles. The use of fuzzy logic enables the heuristic rule-based technique to be used, as an efficient solution. The fuzzy logic controller designed here is a combination of fuzzy decision maker and fuzzy speed controller. The fuzzy decision maker is designed in such a way that it takes into account the battery's state of charge, speed, type of terrain, road load, brake, acceleration, and gear as input parameters, which gives the reference speed to the fuzzy speed controller according to the changing situations. The fuzzy speed controller is designed for the d.c. chopper-fed drive for the seperately excited motor. The fuzzy logic controller determines the vehicle speed according to the scenarios in Indian road conditions. Simulation results would specify the performance of the new proposed fuzzy controller. The results have been compared with the conventional controller proportional integral. From the results it has been inferred that the range of the vehicle has been increased, with less error in speed, with the fuzzy logic controller, than with the classical proportional integral controller. This controller has also been implemented in the embedded chip, field programmable gate array (FPGA) and results shown experimentally, which is the future vehicle.
Machine tool condition monitoring using sweeping filter techniques
Authors: Amer W , Grosvenor R , Prickett P
Published: February 2007

This paper presents an approach to milling process monitoring utilizing sweeping filter frequency analysis techniques. The paper demonstrates how critical information retrieved via the new technique may be used to ascertain the tool condition. This information can be used to suggest remedial actions, to increase the quality of work, and to reduce overall machining costs. The deployed system does not require any additional sensors to be attached to the machine. It consists of three front-end nodes based upon embedded controllers which are linked on a controller area network bus. These nodes acquire and analyse data dynamically from the spindle load, spindle speed, and cutting axis current signals as are typically available on milling machines. These nodes are controlled by a bridge node, which is interfaced to the internet for remote information display. The front-end nodes contain the implementation of the sweeping filter technique. Potential faults from the signature of the acquired signal are identified at this level and can be further verified by the bridge node. The overall system allows dynamic decision making based on a health index measure of the process. The system has the flexibility for any number of required front-end nodes to be deployed depending upon the monitoring requirements.
On the design of adaptive autopilots for a launch vehicle
Authors: Roshanian J , Saleh A. R. , Jahed-Motlagh M. R.
Published: February 2007

Three efficient and practical approaches for the design of an adaptive autopilot for a launch vehicle (LV) attitude control system during atmospheric flight are presented. The proposed adaptive control schemes are developed on the basis of different combinations of gain scheduling, decoupling, and the model reference adaptive technique. A new adaptation mechanism based on hyperstability theory is developed. Every scheme contains some degree of adaptation, corresponding to its complexity and cost of realization. A six-degree-of-freedom non-linear simulation was used to compare the adaptation characteristics of the proposed schemes in the presence of different disturbances during atmospheric flight of the vehicle.
A minimal set of dynamic equations in systems modelled with bond graphs
Authors: Romero G , Felez J , Maroto J , Cabanellas J. M.
Published: February 2007

The current paper presents a procedure for converting to a minimal set the dynamic equations of a system modelled with bond graphs starting from a large set of differential-algebraic equations including any type of topological loops and zero-order causal paths (ZCPs). This minimal set is composed only of differential equations expressed in terms of the degrees of freedom of the system. These equations are suitable for use in real-time simulations.

Initially, flows corresponding to inertances and displacements associated with compliances are used to establish the dynamic equations and to find the ZCPs of the system. Two different methods are used to solve the ZCPs. With the first method, Lagrange multipliers are introduced by means of new flows and efforts as break variables of causal paths, adding constraint equations. With the second method, break variables are used directly to open the ZCPs.

The procedure developed in the present paper solves the problem originated by the use of Lagrange multipliers with the introduction of break variables that imply the presence of new variables and constraint equations. This procedure, before numerical integration of the dynamic equations, converts the equations to a minimal set in order to gain computational efficiency. Several examples are also provided to illustrate the conversion steps.
Tracking control of a piezoceramic actuator system using a combined self-tuning regulator and phase-lead compensator
Authors: Yan Mu-Tian , Chen Yil , Yen Ping-Lang
Published: February 2007

This paper presents the modelling and control of a piezoceramic actuator system. To compensate for the hysteresis effect of the piezoceramic actuator, a self-tuning regulator combined with a feedforward phase-lead compensator is proposed. A dynamic model of the piezoceramic actuator system is derived and analysed using the recursive least-squares method. The self-tuning regulator is designed to achieve the desired tracking performance as well as to deal with system parameter variation based on an identified model. The phase-lead compensator is employed to compensate the phase lag of a tracking response due to the hysteresis effect. Experimental results not only show that the maximum tracking error is significantly reduced if the phase-lead compensator is added in the feedforward loop but they also demonstrate that the proposed controller can obtain a faster transient response and a smaller tracking error than a proportional-integral-derivative (PID) controller.
Design of discrete-time adaptive repetitive controllers and application to feed drive systems
Authors: Uchiyama N , Takagi S , Sano S
Published: February 2007

Although repetitive control is well known to be useful for controlling systems required to perform periodic motions with high accuracy, the repetitive control system is generally a high-order system and has undesirable high-frequency characteristics. Hence, there has been much research on the robustness improvement of repetitive controllers. Although adaptive control is useful when the plant dynamics is unknown, little effort has been made to apply adaptive control to the repetitive control system. Since the repetitive control system is generally a high-order system, many controller parameters need to be estimated online, especially if adaptive pole-placement control, which enables arbitrary pole placement of the control system, is applied. This paper presents a discrete-time design of adaptive poleplacement repetitive controllers for plants with unknown transfer function coefficients (orders of the plants are assumed to be known) and disturbances by assuming that a non-minimum phase continuous-time plant is controlled with a small sampling period. From this assumption, plant unstable zeros appearing by discretization can be approximated by known ones (limiting zeros). By employing the idea of limiting zeros, the repetitive controller can be realized as a feedforward controller without knowing the plant transfer function coefficients. Since the repetitive controller is placed out of the feedback loop by this design, the adaptive pollplacement controller can be realized without updating a large number of controller parameters. Experimental results with the application of a feed drive system, which is often used in computer numerical control (CNC) machine tool systems with repetitive motion, demonstrate the effectiveness of the proposed method. Design methods with and without the limiting zeros are compared in the experiment. It is then shown that using the limiting zeros reduces the control input variance and improves the control performance.
New global asymptotic stability criterion for neural networks with discrete and distributed delays
Authors: Shi Peng , Zhang Jinhui , Qiu Jiqing , Xing Li'nan
Published: February 2007

This paper investigates the problem of global asymptotic stability for a class of neural networks with time-varying and distributed delays. By the Lyapunov-Krasovskii functional approach, a new delay-dependent stability criterion is derived in terms of linear matrix inequalities (LMIs). The new stability condition does not require the time delay function to be continuously differentiable and its derivative to be less than 1, and it allows the time delay to be a fast time-varying function. Simulation examples are given to demonstrate the effectiveness of the developed techniques.
A vision-based method for localization of mobile robots
Authors: Wang Shi-Min , Lai Li-Chun , Wu Chia-Ju , Wu Hsien-Huang P
Published: February 2007

The ability to determine its positions and orientations accurately is very important for a mobile robot when performing tasks such as free-range path tracking and navigation. In this paper, a cost-effective method is proposed for localization of a mobile robot, where a low-resolution charge-coupled device (CCD) camera, a stepping motor, and three artificial landmarks are used. The CCD camera is mounted on the robot and its rotation is controlled by the stepping motor. Then, from the images captured by the CCD camera, image-processing techniques are used to determine the distances between the CCD camera and the three landmarks. On the basis of these distances, it can be proved that the position of the robot is determined uniquely provided that the three artificial landmarks observed are not installed in a line. Moreover, the heading angle of the robot is determined from the rotation angle of the stepping motor. To account for possible installation errors, a non-linear programming method is proposed. Meanwhile, a least-squares method is also used to increase the accuracy of localization. To show the feasibility of the proposed method, experimental results are included for illustration.
Design of a high-temperature thermal ballast water treatment system
Authors: Mesbahi E , Norman R A , Vourdachas A , Quilez-Badia G
Published: February 2007

The introduction of non-indigenous marine species to foreign environments through the medium of ballast water has led to a research focus on the design of onboard ballast water treatment systems. Such systems must be capable of meeting new International Maritime Organization (IMO) standards while also having minimal effect on the environment and on the operational costs and safety of the vessel. Thermal treatment of ballast water appears to be a promising solution, although the application of low-temperature treatment methods may be limited by the time required for the process. A thermodynamic model is presented for a two-stage heat exchanger system to be used for high-temperature treatment of ballast water during discharge. The model may be used for estimation of ballast water treatment requirements during the design phase for a vessel. It was also used to size a pilot-scale, high-temperature treatment system that has been tested onboard ship with regard to the biological effectiveness of the treatment method.