bluuebunny/crossref_metadata_2025 huggingface dataset:
Life style related to blood pressure and body weight in adolescence: Cross sectional data from the Young-HUNT study, Norway
Authors: Fasting Magnus H , Nilsen Tom IL , Holmen Turid L , Vik Torstein
Published: August 2009

Background

The associations between physical activity, unhealthy dietary habits and cigarette smoking and blood pressure, overweight and obesity are well established in adulthood. This is not the case for similar associations in adolescence. Thus, the purpose of this study is to examine how physical activity, smoking status and dietary habits were related to overweight, obesity and blood pressure in a population of Norwegian adolescents.

Methods

Weight, height, systolic (SBP) and diastolic blood pressure (DBP) were measured, and body mass index (BMI) was calculated among 8408 adolescents who participated in a population based study in 1995–97 in the county of Nord-Trøndelag. Internationally accepted cut-off values were used to determine if the adolescents were overweight or obese. The adolescents also completed a detailed questionnaire including dietary habits, physical activity and smoking habits. We calculated adjusted mean blood pressures and odds ratios for being overweight or obese for different exposure categories of life style variables.

Results

Low levels of physically activity were associated with increased odds of being overweight (odds ratio (OR), 1.4; 95% confidence interval (CI), 1.1–1.8 in girls and OR, 2.0; 95% CI, 1.6–2.5 in boys) or obese (girls: OR, 3.1; 95% CI, 1.6–6.0; boys: OR, 3.7; 95% CI, 2.1–6.4). In addition, the least physically active girls had a 1.5 mmHg higher mean DBP compared with the most active (p-trend <0.001), and among boys this difference was 1.0 mmHg (p-trend < 0.001). Smokers were more likely to be obese (OR, 1.6; 95% CI, 1.1–2.5 in girls and 1.4; 95% CI, 0.9–2.1 in boys) compared with non-smokers. Smokers also had lower mean SBP than non-smokers; however, this finding was restricted to smokers with the lowest smoking exposure. Associations between dietary habits and weight status largely disappeared after adjusting for weight losing behaviour.

Conclusion

In this population of adolescents low levels of physical activity were associated with higher mean DBP and higher odds of overweight or obesity. Smoking was also associated with higher odds of overweight and obesity. The paradoxical associations between healthy dietary habits and overweight and obesity are most likely an effect of reverse causality.
Bacterial artificial chromosomes improve recombinant protein production in mammalian cells
Authors: Blaas Leander , Musteanu Monica , Eferl Robert , Bauer Anton , Casanova Emilio
Published: August 2009

Background

The development of appropriate expression vectors for large scale protein production constitutes a critical step in recombinant protein production. The use of conventional expression vectors to obtain cell lines is a cumbersome procedure. Often, stable cell lines produce low protein yields and production is not stable over the time. These problems are due to silencing of randomly integrated expression vectors by the surrounding chromatin. To overcome these chromatin effects, we have employed a Bacterial Artificial Chromosome (BAC) as expression vector to obtain stable cell lines suitable for protein production.

Results

In this work, we explore the efficacy of a Bacterial Artificial Chromosome based vector applied to production of the constant region of the human IgG1. Direct comparison of bulk HEK 293 cell cultures generated with a "conventional" vector or with a BAC-based vector showed that the BAC-based vector improved the protein yield by a factor of 10. Further analysis of stable cell clones harboring the BAC-based vector showed that the protein production was directly proportional to the number of integrated BAC copies and that the protein production was stable for at least 30 passages.

Conclusion

Generation of stable cell clones for protein production using Bacterial Artificial Chromosomes offers a clear advantage over the use of conventional vectors. First, protein production is increased by a factor of 10; second, protein production is stable overtime and third, generation of BAC-based expression vectors does not imply a significant amount of work compare to a conventional vector. Therefore, BAC-based vectors may become an attractive tool for protein production.
Evolution of patients' complaints in a French university hospital: is there a contribution of a law regarding patients' rights?
Authors: Giugliani Camila , Gault Nathalie , Fares Valia , Jegu Jérémie , Trolli Sergio Eleni dit , Biga Julie , Vidal-Trecan Gwenaelle
Published: August 2009

Background

Legislative measures have been identified as one effective way of changing attitude or behaviour towards health care. The aim of this study was to describe trends in patients' complaints for medical issues; to evaluate the contribution of a law regarding patients' rights, and to identify factors associated to patients' perception of a medical error.

Methods

Patients with a complaint letter for medical issues in a French university hospital were included. Trends in complaint rates were analysed. Comparisons were made between a first (1998–2000) and a second (2001–2004) time period, before and after the diffusion of the law, and according to the perception of a medical error.

Results

Complaints for medical issues increased from 1998 to 2004. Of 164 complaints analysed, 66% were motivated by the perception of a medical error (47% during the first time period vs. 73% during the second time period; p = 0.001). Error or delay in diagnosis/treatment and surgical/medical complication were the main reasons for complaints. Surgical departments had the higher number of complaints. Second time period, substandard care, disability, and adverse effect of a health product were independently associated with the perception of a medical error, positively for the formers, and negatively for the latter.

Conclusion

This study revealed an increase with time in the number of complaints for medical issues in a university hospital, as well as an increase in the perception of a medical error after the passing of a law regarding patients' rights in France.
Longitudinal survey of malaria morbidity over 10 years in Saharevo (Madagascar): further lessons for strengthening malaria control
Authors: Rabarijaona Léon P , Randrianarivelojosia Milijaona , Raharimalala Lucie A , Ratsimbasoa Arsène , Randriamanantena Arthur , Randrianasolo Laurence , Ranarivelo Lanto A , Rakotomanana Fanja , Randremanana Rindra , Ratovonjato Jocelyn , Rason Marie-Ange , Duchemin Jean-Bernard , Tall Adama , Robert Vincent , Jambou Ronan , Ariey Frédéric , Domarle Olivier
Published: August 2009

Background

Madagascar has been known for having bio-geo-ecological diversity which is reflected by a complex malaria epidemiology ranging from hyperendemic to malaria-free areas. Malaria-related attacks and infection are frequently recorded both in children and adults living in areas of low malaria transmission. To integrate this variability in the national malaria control policy, extensive epidemiological studies are required to up-date previous records and adjust strategies.

Methods

A longitudinal malaria survey was conducted from July 1996 to June 2005 among an average cohort of 214 villagers in Saharevo, located at 900 m above the sea. Saharevo is a typical eastern foothill site at the junction between a costal wet tropical area (equatorial malaria pattern) and a drier high-altitude area (low malaria transmission).

Results

Passive and active malaria detection revealed that malaria transmission in Saharevo follows an abrupt seasonal variation. Interestingly, malaria was confirmed in 45% (1,271/2,794) of malaria-presumed fevers seen at the health centre. All four Plasmodia that infect humans were also found: Plasmodium falciparum; Plasmodium vivax, Plasmodium malariae and Plasmodium ovale. Half of the malaria-presumed fevers could be confirmed over the season with the highest malaria transmission level, although less than a quarter in lower transmission time, highlighting the importance of diagnosis prior to treatment intake. P. falciparum malaria has been predominant (98%). The high prevalence of P. falciparum malaria affects more particularly under 10 years old children in both symptomatic and asymptomatic contexts. Children between two and four years of age experienced an average of 2.6 malaria attacks with P. falciparum per annum. Moreover, estimated incidence of P. falciparum malaria tends to show that half of the attacks (15 attacks) risk to occur during the first 10 years of life for a 60-year-old adult who would have experienced 32 malaria attacks.

Conclusion

The incidence of malaria decreased slightly with age but remained important among children and adults in Saharevo. These results support that a premunition against malaria is slowly acquired until adolescence. However, this claims for a weak premunition among villagers in Saharevo and by extension in the whole eastern foothill area of Madagascar. While the Malagasy government turns towards malaria elimination plans nowadays, choices and expectations to up-date and adapt malaria control strategies in the foothill areas are discussed in this paper.
Induction of protein body formation in plant leaves by elastin-like polypeptide fusions
Authors: Conley Andrew J , Joensuu Jussi J , Menassa Rima , Brandle Jim E
Published: August 2009

Background

Elastin-like polypeptides are synthetic biopolymers composed of a repeating pentapeptide 'VPGXG' sequence that are valuable for the simple non-chromatographic purification of recombinant proteins. In addition, elastin-like polypeptide fusions have been shown to enhance the accumulation of a range of different recombinant proteins in plants, thus addressing the major limitation of plant-based expression systems, which is a low production yield. This study's main objectives were to determine the general utility of elastin-like polypeptide protein fusions in various intracellular compartments and to elucidate elastin-like polypeptide's mechanism of action for increasing recombinant protein accumulation in the endoplasmic reticulum of plants.

Results

The effect of elastin-like polypeptide fusions on the accumulation of green fluorescent protein targeted to the cytoplasm, chloroplasts, apoplast, and endoplasmic reticulum was evaluated. The endoplasmic reticulum was the only intracellular compartment in which an elastin-like polypeptide tag was shown to significantly enhance recombinant protein accumulation. Interestingly, endoplasmic reticulum-targeted elastin-like polypeptide fusions induced the formation of a novel type of protein body, which may be responsible for elastin-like polypeptide's positive effect on recombinant protein accumulation by excluding the heterologous protein from normal physiological turnover. Although expressed in the leaves of plants, these novel protein bodies appeared similar in size and morphology to the prolamin-based protein bodies naturally found in plant seeds. The elastin-like polypeptide-induced protein bodies were highly mobile organelles, exhibiting various dynamic patterns of movement throughout the cells, which were dependent on intact actin microfilaments and a functional actomyosin motility system.

Conclusion

An endoplasmic reticulum-targeted elastin-like polypeptide fusion approach provides an effective strategy for depositing large amounts of concentrated heterologous protein within the limited space of the cell via storage in stable protein bodies. Furthermore, encapsulation of recombinant proteins into physiologically inert organelles can function to insulate the protein from normal cellular mechanisms, thus limiting unnecessary stress to the host cell. Since elastin-like polypeptide is a mammalian-derived protein, this study demonstrates that plant seed-specific factors are not required for the formation of protein bodies in vegetative plant tissues, suggesting that the endoplasmic reticulum possesses an intrinsic ability to form protein body-like accretions in eukaryotic cells when overexpressing particular proteins.
The Endogenous Hydrogen Sulfide Producing Enzyme Cystathionine-β Synthase Contributes to Visceral Hypersensitivity in a Rat Model of Irritable Bowel Syndrome
Authors: Xu Guang-Yin , Winston John H , Shenoy Mohan , Zhou Shufang , Chen Jiande DZ , Pasricha Pankaj J
Published: August 2009

Background

The pathogenesis of visceral hypersensitivity, a characteristic pathophysiological feature of irritable bowel syndrome (IBS), remains elusive. Recent studies suggest a role for hydrogen sulfide (H2S) in pain signaling but this has not been well studied in visceral models of hyperalgesia. We therefore determined the role for the endogenous H2S producing enzyme cystathionine-β-synthetase (CBS) in a validated rat model of IBS-like chronic visceral hyperalgesia (CVH). CVH was induced by colonic injection of 0.5% acetic acid (AA) in 10-day-old rats and experiments were performed at 8–10 weeks of age. Dorsal root ganglion (DRG) neurons innervating the colon were labeled by injection of DiI (1,1'-dioleyl-3,3,3',3-tetramethylindocarbocyanine methanesulfonate) into the colon wall.

Results

In rat DRG, CBS-immunoreactivity was observed in approximately 85% of predominantly small- and medium-sized neurons. Colon specific DRG neurons revealed by retrograde labeling Dil were all CBS-positive. CBS-positive colon neurons co-expressed TRPV1 or P2X3 receptors. Western blotting analysis showed that CBS expression was significantly increased in colon DRGs 8 weeks after neonatal AA-treatment. Furthermore, the CBS inhibitor hydroxylamine markedly attenuated the abdominal withdrawal reflex scores in response to colorectal distention in rats with CVH. By contrast, the H2S donor NaHS significantly enhanced the frequency of action potentials of colon specific DRG neurons evoked by 2 times rheobase electrical stimulation.

Conclusion

Our results suggest that upregulation of CBS expression in colonic DRG neurons and H2S signaling may play an important role in developing CVH, thus identifying a specific neurobiological target for the treatment of CVH in functional bowel syndromes.
Descending Serotonergic Facilitation and the Antinociceptive Effects of Pregabalin in a Rat Model of Osteoarthritic Pain
Authors: Rahman Wahida , Bauer Claudia S , Bannister Kirsty , Vonsy Jean-Laurent , Dolphin Annette C , Dickenson Anthony H
Published: August 2009

Background

Descending facilitation, from the brainstem, promotes spinal neuronal hyperexcitability and behavioural hypersensitivity in many chronic pain states. We have previously demonstrated enhanced descending facilitation onto dorsal horn neurones in a neuropathic pain model, and shown this to enable the analgesic effectiveness of gabapentin. Here we have tested if this hypothesis applies to other pain states by using a combination of approaches in a rat model of osteoarthritis (OA) to ascertain if 1) a role for descending 5HT mediated facilitation exists, and 2) if pregabalin (a newer analogue of gabapentin) is an effective antinociceptive agent in this model. Further, quantitative-PCR experiments were undertaken to analyse the α2δ-1 and 5-HT3A subunit mRNA levels in L3–6 DRG in order to assess whether changes in these molecular substrates have a bearing on the pharmacological effects of ondansetron and pregabalin in OA.

Results

Osteoarthritis was induced via intra-articular injection of monosodium iodoacetate (MIA) into the knee joint. Control animals were injected with 0.9% saline. Two weeks later in vivo electrophysiology was performed, comparing the effects of spinal ondansetron (10–100 μg/50 μl) or systemic pregabalin (0.3 – 10 mg/kg) on evoked responses of dorsal horn neurones to electrical, mechanical and thermal stimuli in MIA or control rats. In MIA rats, ondansetron significantly inhibited the evoked responses to both innocuous and noxious natural evoked neuronal responses, whereas only inhibition of noxious evoked responses was seen in controls. Pregabalin significantly inhibited neuronal responses in the MIA rats only; this effect was blocked by a pre-administration of spinal ondansetron. Analysis of α2δ-1 and 5-HT3A subunit mRNA levels in L3–6 DRG revealed a significant increase in α2δ-1 levels in ipsilateral L3&4 DRG in MIA rats. 5-HT3A subunit mRNA levels were unchanged.

Conclusion

These data suggest descending serotonergic facilitation plays a role in mediating the brush and innocuous mechanical punctate evoked neuronal responses in MIA rats, suggesting an adaptive change in the excitatory serotonergic drive modulating low threshold evoked neuronal responses in MIA-induced OA pain. This alteration in excitatory serotonergic drive, alongside an increase in α2δ-1 mRNA levels, may underlie pregabalin's state dependent effects in this model of chronic pain.
Phenotype and functional evaluation of ex vivo generated antigen-specific immune effector cells with potential for therapeutic applications
Authors: Han Shuhong , Huang Yuju , Liang Yin , Ho Yuchin , Wang Yichen , Chang Lung-Ji
Published: August 2009

Ex vivoactivation and expansion of lymphocytes for adoptive cell therapy has demonstrated great success. To improve safety and therapeutic efficacy, increased antigen specificity and reduced non-specific response of theex vivogenerated immune cells are necessary. Here, using a complete protein-spanning pool of pentadecapeptides of the latent membrane protein 2A (LMP2A) of Epstein-Barr virus (EBV), a weak viral antigen which is associated with EBV lymphoproliferative diseases, we investigated the phenotype and function of immune effector cells generated based on IFN-γ or CD137 activation marker selection and dendritic cell (DC) activation. Theseex vivoprepared immune cells exhibited a donor- and antigen-dependent T cell response; the IFN-γ-selected immune cells displayed a donor-related CD4- or CD8-dominant T cell phenotype; however, the CD137-enriched cells showed an increased ratio of CD4 T cells. Importantly, the pentadecapeptide antigens accessed both class II and class I MHC antigen processing machineries and effectively activated EBV-specific CD4 and CD8 T cells. Phenotype and kinetic analyses revealed that the IFN-γ and the CD137 selections enriched more central memory T (Tcm) cells than did the DC-activation approach, and after expansion, the IFN-γ-selected effector cells showed the highest level of antigen-specificity and effector activities. While all three approaches generated immune cells with comparable antigen-specific activities, the IFN-γ selection followed byex vivoexpansion produced high quality and quantity of antigen-specific effector cells. Our studies presented the optimal approach for generating therapeutic immune cells with potential for emergency and routine clinical applications.
Clinician performed resuscitative ultrasonography for the initial evaluation and resuscitation of trauma
Authors: Gillman Lawrence M , Ball Chad G , Panebianco Nova , Al-Kadi Azzam , Kirkpatrick Andrew W
Published: August 2009

Background

Traumatic injury is a leading cause of morbidity and mortality in developed countries worldwide. Recent studies suggest that many deaths are preventable if injuries are recognized and treated in an expeditious manner – the so called 'golden hour' of trauma. Ultrasound revolutionized the care of the trauma patient with the introduction of the FAST (Focused Assessment with Sonography for Trauma) examination; a rapid assessment of the hemodynamically unstable patient to identify the presence of peritoneal and/or pericardial fluid. Since that time the use of ultrasound has expanded to include a rapid assessment of almost every facet of the trauma patient. As a result, ultrasound is not only viewed as a diagnostic test, but actually as an extension of the physical exam.

Methods

A review of the medical literature was performed and articles pertaining to ultrasound-assisted assessment of the trauma patient were obtained. The literature selected was based on the preference and clinical expertise of authors.

Discussion

In this review we explore the benefits and pitfalls of applying resuscitative ultrasound to every aspect of the initial assessment of the critically injured trauma patient.
Combating HIV stigma in health care settings: what works?
Authors: Nyblade Laura , Stangl Anne , Weiss Ellen , Ashburn Kim
Published: August 2009

The purpose of this review paper is to provide information and guidance to those in the health care setting about why it is important to combat HIV‐related stigma and how to successfully address its causes and consequences within health facilities. Research shows that stigma and discrimination in the health care setting and elsewhere contributes to keeping people, including health workers, from accessing HIV prevention, care and treatment services and adopting key preventive behaviours.

Studies from different parts of the world reveal that there are three main immediately actionable causes of HIV‐related stigma in health facilities: lack of awareness among health workers of what stigma looks like and why it is damaging; fear of casual contact stemming from incomplete knowledge about HIV transmission; and the association of HIV with improper or immoral behaviour.

To combat stigma in health facilities, interventions must focus on the individual, environmental and policy levels. The paper argues that reducing stigma by working at all three levels is feasible and will likely result in long‐lasting benefits for both health workers and HIV‐positive patients. The existence of tested stigma‐reduction tools and approaches has moved the field forward. What is needed now is the political will and resources to support and scale up stigma‐reduction activities throughout health care settings globally.
Lung disease assessment in primary ciliary dyskinesia: a comparison between chest high-field magnetic resonance imaging and high-resolution computed tomography findings
Authors: Montella Silvia , Santamaria Francesca , Salvatore Marco , Maglione Marco , Iacotucci Paola , De Santi Maria Margherita , Mollica Carmine
Published: August 2009

Background

Primary ciliary dyskinesia (PCD) is associated with pulmonary involvement that requires periodical assessment. Chest high-resolution computed tomography (HRCT) has become the method of choice to evaluate chronic lung disease, but entails exposure to ionizing radiation. Magnetic resonance imaging (MRI) has been proposed as a potential radiation-free technique in several chest disorders. Aim of our study is to evaluate whether high-field MRI is as effective as HRCT in identifying PCD pulmonary abnormalities. We also analyzed the relationships between the severity and extension of lung disease, and functional data.

Methods

Thirteen PCD patients (8 children/5 adults; median age, 15.2 yrs) underwent chest HRCT and high-field 3T MRI, spirometry, and deep throat or sputum culture. Images were scored using a modified version of the Helbich system.

Results

HRCT and MRI total scores were 12 (range, 6–20) and 12 (range, 5–17), respectively. Agreement between HRCT and MRI scores was good or excellent (r > 0.8). HRCT and MRI total scores were significantly related to forced vital capacity (r = -0.5, p = 0.05; and r = -0.7, p = 0.009, respectively) and forced expiratory volume at 1 second (r = -0.6, p = 0.03; and r = -0.7, p = 0.009, respectively).

Conclusion

Chest high-field 3T MRI appears to be as effective as HRCT in assessing the extent and severity of lung abnormalities in PCD. MRI scores might be used for longitudinal assessment and be an outcome surrogate in future studies.
Treatment with ephrin B2 positively impacts the abnormal metabolism of human osteoarthritic chondrocytes
Authors: Kwan Tat Steeve , Pelletier Jean-Pierre , Amiable Nathalie , Boileau Christelle , Lavigne Martin , Martel-Pelletier Johanne
Published: August 2009

Introduction

Members of the ephrin system, the ephrin receptor erythropoietin-producing hepatocellular B4 (EphB4) and its specific ligand, ephrin B2, appear to be involved in the bone remodelling process. We recently showed that their interaction inhibits the resorptive activity of human osteoarthritic (OA) subchondral bone osteoblasts. Hence, we further investigated the possible implication of these ephrin members on the catabolic/anabolic activities of human OA chondrocytes.

Methods

EphB4 receptor and ephrin B2 levels were determined by quantitative PCR and immunohistochemistry, and the effects of ephrin B2 on the expression/production of factors involved in the OA process.

Results

EphB4 receptors and ephrin B2 ligands are expressed and produced by human normal and OA chondrocytes. Ephrin B2 protein was found at similar levels in both cartilage types, whereas EphB4 receptor expression (P < 0.0001) and production (P < 0.01) levels were significantly increased in OA chondrocytes/cartilage. Ephrin B2 treatment significantly inhibited the interleukin (IL)-1beta, IL-6, matrix metalloproteinase-1 (MMP-1), MMP-9, MMP-13, and proteinase-activated receptor-2 (PAR-2) gene expression levels, whereas MMP-2 was unaffected, and significantly increased collagen type II, a cartilage specific macromolecule. It also inhibited the IL-1beta stimulated protein production of IL-6, MMP-1 and MMP-13.

Conclusions

Our study is the first to provide data on the presence and role of ephrin B2/EphB4 receptors in human chondrocytes/cartilage. Data showed that ephrin B2 treatment positively impacts the abnormal metabolism of OA cartilage by inhibiting important catabolic factors involved in this disease at the same time as increasing anabolic activity.
Cracking an Open Safe: More HAZUS Vulnerability Functions in Terms of Structure-Independent Intensity
Authors: Porter Keith
Published: August 2009

In another work, the “open safe” of the HAZUS-MH methodology was cracked to create seismic vulnerability functions that honor all HAZUS-MH methodologies and data, yet that appear in the form of tables of mean casualty rates (indoor deaths and injuries as four fractions of total occupancy) versus a structure-independent intensity measure, in particular, [Formula: see text] or [Formula: see text]. In this work, mean repair cost is tabulated against both these intensity measures, for various combinations of model building type, code design level, occupancy class, seismic environment, NEHRP site soil class, magnitude range and distance range.
Pitfalls of Deterministic Application of Nonlinear Site Factors in Probabilistic Assessment of Ground Motions
Authors: Goulet Christine A. , Stewart Jonathan P.
Published: August 2009

It is common for ground motions to be estimated using a combination of probabilistic and deterministic procedures. Probabilistic seismic hazard analyses (PSHA) are performed to estimate intensity measures ( IMs) for reference site conditions (usually rock). This is followed by a deterministic modification of the rock IMs to account for site effects, typically using site factors from the literature or seismic codes. We demonstrate for two California sites and three site conditions that the deterministic application of nonlinear site factors underestimates ground motions evaluated probabilistically for return periods of engineering interest. Reasons for this misfit include different standard deviation terms for rock and soil sites, different controlling earthquakes, and overestimation of the nonlinear component of the site response in the deterministic procedure. This problem is solved using site-specific PSHA with appropriate consideration of nonlinear site response, within the hazard integral.
Constructing City Models to Estimate Losses Due to Earthquakes Worldwide: Application to Bucharest, Romania
Authors: Trendafiloski Goran , Wyss Max , Rosset Philippe , Marmureanu Gheorghe
Published: August 2009

We propose a method to calculate damage and human losses for cities in the developing world by averaging over an entire city, or its administrative districts. Bucharest, Romania, serves as an example. First, we modeled this city as located at a single coordinate point. We transformed the census information on building types, ages and height into EMS-98 vulnerability classes and distribute the population into them. We assumed a seismic load of MSK [Formula: see text] (M7.4 1977 Vrancea earthquake). Validating our model by comparison with casualties reported in 1977, we find differences of 20% to 30%. We reduced these errors to about 4%, by adjusting the distribution of building types into vulnerability classes, based on their performance in the 1977 earthquake. Calibrations of this type will be necessary for most developing countries. In a second step, we modeled Bucharest with six districts, in which the distribution of people into building types and the average soil conditions are known. This is our preferred model. We also calculated the soil properties that would be estimated from topography, if microzonation would not be available. The agreement was satisfactory. We propose this method to model important cities in earthquake prone areas of the developing world.
Coupling the cell cycle to development
Authors: Budirahardja Yemima , Gönczy Pierre
Published: August 2009

The core machinery that drives the eukaryotic cell cycle has been thoroughly investigated over the course of the past three decades. It is only more recently, however, that light has been shed on the mechanisms by which elements of this core machinery are modulated to alter cell cycle progression during development. It has also become increasingly clear that, conversely,core cell cycle regulators can play a crucial role in developmental processes. Here, focusing on findings from Drosophila melanogaster and Caenorhabditis elegans, we review the importance of modulating the cell cycle during development and discuss how core cell cycle regulators participate in determining cell fates.
A highly conserved retinoic acid responsive element controlswt1aexpression in the zebrafish pronephros
Authors: Bollig Frank , Perner Birgit , Besenbeck Birgit , Köthe Susanne , Ebert Christina , Taudien Stefan , Englert Christoph
Published: August 2009

The Wilms' tumor suppressor gene Wt1 encodes a zinc-finger transcription factor that plays an essential role in organ development, most notably of the kidney. Despite its importance for organogenesis, knowledge of the regulation of Wt1 expression is scarce. Here, we have used transgenesis in zebrafish harboring two wt1 genes, wt1a and wt1b, in order to define regulatory elements that drive wt1expression in the kidney. Stable transgenic lines with approximately 30 kb of the upstream genomic regions of wt1a or wt1b almost exactly recapitulated endogenous expression of the wt1 paralogs. In the case of wt1b, we have identified an enhancer that is located in the far upstream region that is necessary and sufficient for reporter gene expression in the pronephric glomeruli. Regarding wt1a, we could also identify an enhancer that is located approximately 4 kb upstream of the transcriptional start site that is required for expression in the intermediate mesoderm. Interestingly, this intermediate mesoderm enhancer is highly conserved between fish and mammals, is bound by members of the retinoic acid receptor family of transcription factors in gel shift experiments and mediates responsiveness to retinoic acid both in vivo and in cell culture. To our knowledge, this is the first functional demonstration of defined regulatory elements controlling Wt1 expression in vivo. The identification of kidney-specific enhancer elements will help us to better understand the integration of extracellular signals into intracellular networks in nephrogenesis.
Auxin patternsSolanum lycopersicumleaf morphogenesis
Authors: Koenig Daniel , Bayer Emmanuelle , Kang Julie , Kuhlemeier Cris , Sinha Neelima
Published: August 2009

One of the most striking aspects of plant diversity is variation in leaf shape. Much of this diversity is achieved by the modulation of leaf blade dissection to form lobes or leaflets. Here, we show that the phytohormone auxin is a crucial signal regulating the partitioned outgrowth necessary to develop a dissected leaf. In developing leaves, the asymmetric distribution of auxin, driven by active transport, delineates the initiation of lobes and leaflets and specifies differential laminar outgrowth. Furthermore, homologous members of the AUX/indole-3-acetic acid (IAA) gene family mediate the action of auxin in determining leaf shape by repressing outgrowth in areas of low auxin concentration during both simple and compound leaf development. These results provide molecular evidence that leaflets initiate in a process reminiscent of organogenesis at the shoot apical meristem, but that compound and simple leaves regulate marginal growth through an evolutionarily conserved mechanism, thus shedding light on the homology of compound and simple leaves.
MARCKS modulates radial progenitor placement, proliferation and organization in the developing cerebral cortex
Authors: Weimer Jill M. , Yokota Yukako , Stanco Amelia , Stumpo Deborah J. , Blackshear Perry J. , Anton E.S.
Published: August 2009

The radial glial cells serve as neural progenitors and as a migratory guide for newborn neurons in the developing cerebral cortex. These functions require appropriate organization and proliferation of the polarized radial glial scaffold. Here, we demonstrate in mice that the myristoylated alanine-rich C-kinase substrate protein (MARCKS), a prominent cellular substrate for PKC,modulates radial glial placement and expansion. Loss of MARCKS results in ectopic collection of mitotically active radial progenitors away from the ventricular zone (VZ) in the upper cerebral wall. Apical restriction of key polarity complexes [CDC42, β-catenin (CTNNB1), N-cadherin (CDH2), myosin IIB (MYOIIB), aPKCζ, LGL, PAR3, pericentrin, PROM1] is lost. Furthermore,the radial glial scaffold in Marcks null cortex is compromised, with discontinuous, non-radial processes apparent throughout the cerebral wall and deformed, bulbous, unbranched end-feet at the basal ends. Further, the density of radial processes within the cerebral cortex is reduced. These deficits in radial glial development culminate in aberrant positioning of neurons and disrupted cortical lamination. Genetic rescue experiments demonstrate,surprisingly, that phosphorylation of MARCKS by PKC is not essential for the role of MARCKS in radial glial cell development. By contrast, the myristoylation domain of MARCKS needed for membrane association is essential for MARCKS function in radial glia. The membrane-associated targeting of MARCKS and the resultant polarized distribution of signaling complexes essential for apicobasal polarity may constitute a critical event in the appropriate placement, proliferation and organization of polarized radial glial scaffold in the developing cerebral cortex.
Islet-to-LMO stoichiometries control the function of transcription complexes that specify motor neuron and V2a interneuron identity
Authors: Song Mi-Ryoung , Sun Yunfu , Bryson Ami , Gill Gordon N. , Evans Sylvia M. , Pfaff Samuel L.
Published: August 2009

LIM transcription factors bind to nuclear LIM interactor (Ldb/NLI/Clim) in specific ratios to form higher-order complexes that regulate gene expression. Here we examined how the dosage of LIM homeodomain proteins Isl1 and Isl2 and LIM-only protein Lmo4 influences the assembly and function of complexes involved in the generation of spinal motor neurons (MNs) and V2a interneurons(INs). Reducing the levels of Islet proteins using a graded series of mutations favored V2a IN differentiation at the expense of MN formation. Although LIM-only proteins (LMOs) are predicted to antagonize the function of Islet proteins, we found that the presence or absence of Lmo4 had little influence on MN or V2a IN specification. We did find, however, that the loss of MNs resulting from reduced Islet levels was rescued by eliminating Lmo4,unmasking a functional interaction between these proteins. Our findings demonstrate that MN and V2a IN fates are specified by distinct complexes that are sensitive to the relative stoichiometries of the constituent factors and we present a model to explain how LIM domain proteins modulate these complexes and, thereby, this binary-cell-fate decision.
Characterization of the aluminium coating layer in the hot press forming of boron steel
Authors: Jang J H , Joo B D , Van Tyne C J , Moon Y H
Published: August 2009

Hot press forming allows geometrically complex parts to be easily formed from boron steel blanks. The rapid cooling after forming produces a product with extremely high strength. To prevent the blanks from oxidizing and decarburizing during heating, forming, and subsequent press cooling, the boron steel is supplied with an aluminium-based coating. This surface coating influences the formability of the component and the quality of the final product. The main purpose of the present research is to characterize the changes in the aluminium-coated layer on a boron steel during hot press forming. To characterize the evolution of the coated layer, experiments for hot press forming were conducted under various conditions that simulated a production process. Test specimens were heated to temperatures between 810 and 930 °C and were then press hardened. The aluminium-coated layer develops four distinct microstructural regions: (a) a diffusion zone; (b) an aluminium—iron (Al—Fe) zone I; (c) a low-aluminium zone (LAZ); and (d) an Al—Fe zone II. The band-like LAZ is clearly observable in the temperature range of 810 to 870 °C and becomes sparsely dispersed at temperatures above 900 °C. The microcracking behaviour of the aluminium-coated layer during forming was also analysed with both bending and deep-drawing tests. The strain concentration in the softer LAZ is found to be closely connected to both microcracking and exfoliation of the coated layer during the press forming.
Analysis of surface generation in the ultraprecision polishing of freeform surfaces
Authors: Cheung C F , Ho L T , Charlton P , Kong L B , To S , Lee W B
Published: August 2009

The use of freeform designs in engineering surfaces has become increasingly popular over the last decade. Applications of freeform shapes range from aesthetics of components to the bending of light rays through advanced optic designs. The fabrication of the components for these applications requires submicrometre form accuracy, in some cases with surface roughness at nanometric levels. Ultraprecision polishing is an emerging technology for the fabrication of high-precision and high-quality freeform surfaces. However, the factors affecting nanosurface generation in ultraprecision polishing have received relatively little attention. Moreover, the quality of the polished surface relies heavily on appropriate selection of process conditions and polishing strategies. This paper presents an analytical study of the factors affecting surface generation in ultraprecision polishing. A series of polishing experiments have been designed and undertaken, allowing the relationships between various factors and the surface quality of the workpiece to be determined. The results of the study provide a better understanding of nanosurface generation, as well as the strategy for optimizing surface quality, in the ultraprecision polishing of freeform surfaces.
Matrix perturbation method for predicting dynamic modal shapes of the workpiece in high-speed machining
Authors: Zhang X-M , Zhu L-M , Ding H
Published: August 2009

Machining is a material removal process that changes the dynamic properties during machining operations. The variations in the dynamic properties of the workpiece have an important effect on the integrated machining system dynamics which determines the stability of the system. This paper presents the matrix perturbation method for analytical prediction of the dynamic modal shape of the workpiece in high-speed machining. A finite element model of the workpiece is developed first. Based on the finite element model, the matrix perturbation method is adopted to compute the modal shapes of the workpiece at different machining stages, which are reasonable-approximation modal shapes of the real workpiece. In order to validate the proposed method, numerical simulation and hammer impact experiments of thin-walled workpieces at different machining stages are conducted, and the experimentally measured modal frequencies are compared with the present analytical method.
Engine idle-speed system modelling and control optimization using artificial intelligence
Authors: Wong P K , Tam L M , Li K , Vong C M
Published: August 2009

This paper proposes a novel modelling and optimization approach for steady state and transient performance tune-up of an engine at idle speed. In terms of modelling, Latin hypercube sampling and multiple-input and multiple-output (MIMO) least-squares support vector machines (LS-SVMs) are proposed to build an engine idle-speed model based on experimental sample data. Then, a genetic algorithm (GA) and particle swarm optimization (PSO) are applied to obtain an optimal electronic control unit setting automatically, under various user-defined constraints. All of the above techniques mentioned are artificial intelligence techniques. To illustrate the advantages of the MIMO LS-SVM, a traditional multilayer feedforward neural network (MFN) is also applied to build the engine idle-speed model. The modelling accuracies of the MIMO LS-SVM and MFN are also compared. This study shows that the predicted results using the estimated model from the LS-SVM are in good agreement with the actual test results. Moreover, both the GA and PSO optimization results show an impressive improvement on idle-speed performance in a test engine. The optimization results also indicate that PSO is more efficient than the GA in an idle-speed control optimization problem based on the LS-SVM model. As the proposed methodology is generic, it can be applied to different engine modelling and control optimization problems.
Electromagnetic design of a novel microwave internal combustion engine ignition source, the quarter wave coaxial cavity igniter
Authors: Pertl F A , Smith J E
Published: August 2009

New ignition sources are needed to operate the next generation of lean high-efficiency internal combustion engines. A significant environmental and economic benefit could be obtained from these lean engines. Towards this goal, the quarter wave coaxial cavity resonator (QWCCR), igniter was examined. A brief overview of the QWCCR's history is presented, followed by an electromagnetic analysis of the resonator. Microwave and radio-frequency gas breakdown at atmospheric and higher conditions are reviewed briefly. The presented analysis focuses on geometric and material parameter relations compared with performance characteristics, such as resonator quality factor and developed tip electric field which initiates a single-electrode high-pressure microwave gas breakdown. Conductor surface losses, dielectric losses, and radiation losses of the device are considered in the analysis, for which parameters of a prototype QWCCR were chosen for construction and evaluation of a resonator. Improved designs allowed successful integration of a QWCCR into a Briggs and Stratton engine. Given the capability of precise control, high power, and high energy delivery, and the opportunity for further optimization, the QWCCR has the potential to deliver more energy per ignition than a conventional spark plug and thus should be considered for application as a lean ignition source.
Real-time estimation of combustion variability for model-based control and optimal calibration of spark ignition engines
Authors: Lee T-K , Prucka R G , Filipi Z S
Published: August 2009

A method for indirect real-time estimation of combustion variability by substitutive measurements is investigated in this paper. An impetus for improving combustion stability, particularly at near-idle conditions, is provided by increasing driver sensitivity to engine noise, vibration, and harshness. The combustion stability is generally quantified by the cycle-by-cycle variations, and represented by the coefficient of variation in the indicated mean effective pressure (COVIMEP). Since the COVIMEP is calculated from a set of IMEP data obtained by experiments, prediction of the COVIMEP in real time from measurements of IMEP is impossible. Instead, an indirect prediction methodology of combustion variability is proposed on the basis of statistical analysis of substitutive measurements. A set of relevant exploratory variables is determined first. Then, trends of the COVIMEP are investigated to determine the regression model, and an exponential form proved to be the best. A systematic regression analysis procedure based on statistical analysis enables the simplest equations to be found while maintaining accuracy. The results demonstrate that the COVIMEP behaviour can be captured as a function of 10–90 per cent burn duration and manifold absolute pressure. The implementation can utilize real-time pressure measurements if the engine is equipped with pressure transducers, or virtual sensing of 10–90 per cent burned using a neural network trained a priori on measured or predicted data. The resulting regression equations derived with and without the charge motion valve enable the estimation of the combustion variability for optimal calibration or model-based control.
Karanja oil utilization in a direct-injection engine by preheating. Part 2: experimental investigations of engine durability and lubricating oil properties
Authors: Agarwal A K , Dhar A
Published: August 2009

Straight vegetable oil utilization as a diesel engine fuel has the advantages of eliminating the energy, time, and cost involved in biodiesel production. Since straight vegetable oils have quite high viscosity compared with mineral diesel, they have to be modified to bring their combustion-related properties closer to mineral diesel. In this experimental study, a heat exchanger was designed and used to utilize the waste heat of exhaust gases for reducing the viscosity of Karanja oil by preheating. Carbon deposits, wear of vital engine components, and various effects of utilizing preheated Karanja oil on lubricating oil were analysed during a long-term endurance test executed for 512h. Carbon deposits on various critical parts of the power cell were analysed by visual inspection. For pistons, the piston merit rating was determined. The effect on a lubricating oil because of heated Karanja oil vis-à-vis mineral diesel was evaluated by comparing the densities, viscosities, flash points, carbon residues, ash contents, copper corrosion effect and pentane, benzene insolubility measurements at intervals of every 128h for 512h. The wear of the cylinder liner, piston rings, gudgeon pin, and small- and big-end bearings for a Karanja-oil-fuelled engine were also measured and compared vis-à-vis mineral diesel-fuelled engine.
Fuzzy modelling, control, and bifurcation-based stability analysis of a gasoline direct injection engine
Authors: Boverie S , Heredia G , Gonzalez-Cantos A , Ollero A , Passaquay D , Titli A , Aracil J , Gordillo F
Published: August 2009

This paper presents an advanced model and control structure of a non-linear hybrid system: a gasoline direct injection (GDI) engine. The engine management system proposed in the paper is based on a hierarchical structure that uses Takagi—Sugeno fuzzy models of the engine to define piecewise linear controllers. Thanks to the hierarchical controller structure, engine idle speed regulation is tackled as a high-level requirement and therefore no specific low-level controller is needed. Moreover, the two combustion modes are correctly handled to optimize the engine efficiency. A global stability analysis of the GDI engine working either in homogeneous mode or in stratified mode is also presented, based on bifurcation analysis. Bifurcation analysis can be applied to a wide range of different controllers (even close-to-production), and therefore it can be of significant practical value.