bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurements of voidage profiles in spouted beds
Authors: He Y.‐L. , Lim C. J. , Grace J. R. , Zhu J.‐X. , Qzn S.‐Z.
Published: March 2009

A fibre optic probe has been used to measure voidage profiles in the fountain, spout and annulus of spouted beds. The voidage in most of the annulus was found to be somewhat higher than the loose‐packed voidage and increased with increasing spouting gas flow rate, contrary to usual assumptions. There is a denser region in the annulus where the voidage was a little lower than the loose‐packed bed voidage. In the core of the fountain, the voidage decreased with height for low spouting gas flow rate, consistent with the model of Grace and Mathur (1978); however, at higher gas flow rate, it first increased with height and then decreased towards the fountain top. The radial profiles of local voidage were roughly parabolic in the lower portion of the spout and blunt in the upper portion.
Simulation of SO2 absorption by falling water drops
Authors: Hsu Chien‐T'Ai , Shih Shin‐Min , Chang Ching‐Yuang
Published: March 2009

The experimental data of Walcek et al. (1981) for SO2 absorption by falling water drops of 600 μm dia. at 13‐15°C and 1‐50 vol% SO2 in air can be well predicted by a model which ignores the effect of internal circulation and considers the diffusion of both SO2H2O and HSO3 and the accompanying equilibrium dissociation reaction of SO2.H2O within the drop. The data can also be described by the analytical solution obtained by simplifying the rigorous model with the assumption that the gas phase mass transfer resistance is negligible and that the difhtsivities of sulfur species are equal.
Preparation, characterization and activity of wet‐proofed Pt/silicalite catalysts
Authors: Rangwala H. A. , Wanke S. E. , Otto F. D.
Published: March 2009

A procedure for wet‐proofing Pt/silicalite catalysts with polytetrafluoroethylene fibres is described. The procedure yielded catalysts with stable and high activities for the exchange of hydrogen isotopes between liquid water and hydrogen gas. Characterization of the catalysts by hydrogen chemisorption and scanning electron microscopy showed that the wet‐proofing procedure can produce catalysts in which most of the Pt surface in the Pt/silicalite before wet‐proofing can remain accessible. Hydrogen chemisorption was found to be a valuable tool for prescreening of wet‐proofed catalysts.
Mise au point d'un absorbeur par voie semi‐sèche à base d'un venturi haute énergie
Authors: Kholi Nizar , Benachour Mohand , Zoulalian André
Published: March 2009

Afin de minimiser le volume de I'absorbeur, l'étude porte sur la mise au point d'un dispositif de traitement, par voie semi‐sèche, d'un effluent gazeux acide (SO2 dans l'air) à base d'un venturi hauteétnergie. Une comparaison expérimentale entre trois dispositifs permet, en fonction des paramètres opératoires étudiks, de choisir le dispositif, dénommé C, dont les capacités d'évaporation et d'absorption réactionnelles sont nettement supérieures aux deux autres. Pour le dispositif C, on prtcise ensuite les conditions opératoires et géométriques optimales. L'absorption de SO2 est effectuée soit dans une solution d'hydroxyde de sodium, soit dans une suspension d'hydroxyde de calcium. Dans ce dernier cas, les résultats obtenus sont supérieurs à ceux obtenus sur des dispositifs plus conventionnels à base de tours d'atomisation.
Identification and control of an industrial steam‐reforming plant
Authors: Meziou A. M. , Alatiqi I. M.
Published: March 2009

Reliable mathematical models for an industrial steam‐gas reformer and a steam‐boiler are simulated and used to study the dynamic behavior of the two coupled processes. Simulation results of the identified system are in good agreement with the nonlinear process operation.

Three control loops are considered for multivariable control system design. These are Hydrogen product temperature and quality, and boiler water level. A new multivariable control structure is obtained, which manipulates steam‐to‐carbon (S/C) ratio for the control of coil outlet temperature (COT), the fuel gas rate to control hydrogen product quality (conversion) and the boiler feed water to control drum level. The selected structure is then tuned using the Biggest‐Log modulus‐Tuning (BLT) method. Results show a very satisfactory response of the temperature and quality loops with the BLT based controllers. It is also found that the boiler water level loop is partially decoupled from the other two loops and hence does not need to be detuned according to BLT criterion.

The new multivariable control structure is compared with the conventional control utilising fuel gas rate to control COT. Closed‐loop simulation results show a better performance for the multivariable structure under continuous operation.
Multicomponent ion exchange column dynamics
Authors: Tan Henry K. S. , Spinner Irving H.
Published: March 2009

Simple model equations which consider different rate control mechanisms are formulated for fixed bed multicomponent ion exchange processes. Efficient and accurate numerical methods are developed for solving these equations for liquid phase, solid phase or combined phase control. The algorithms are applicable to both ion exchange and liquid adsorption and are shown to be extendable to a general form of isotherms. The accuracy of the numerical algorithm is evidenced by the fact that the asymptotic limiting equilibrium solutions are closely approached as the dimensionless length parameter is increased, regardless of the rate control mechanism.

Numerical examples for ion exchange applications are presented. These examples included multicomponent elution and purification problems. The effect of mass transfer resistance was also examined. Other examples examine the validity of a model reduction assumption and the comparison of equilibrium theory with the results obtained using the present finite mass transfer rate model.
A proposed method for the calculation of theoretical plates in liquid‐liquid‐solid three‐phase extraction columns: Methanol, hexane and rapeseed meal system
Authors: Shi Meiren , Shen Shiquan , Liu Jian
Published: March 2009

A program is designed and tested to calculate the number of theoretical plates required in a LLS extraction column for the methanol, hexane, and rapeseed meal system. The calculation model takes into account the internal mixing effect of solid entrainment in the light phase. The concentration distribution along the column can also be obtained from the model by introducing the efficiency of real plates.
Experimental evaluation of molten caustic leaching of an oil sand coke residue
Authors: Ityokumbul Mku T.
Published: March 2009

An evaluation of molten caustic leaching, MCL, for the desulfurization and demineralization of Syncrude fluid coke has been carried out. The results obtained indicate that with the incorporation of an acid washing step, a treated coke product having sulfur and ash contents of less than 1 % may be obtained. Scanning electron microscopy confirm that vanadium is released during molten caustic leaching. At caustic to coke mass ratio in the range 1.8 ‐ 2.0, the dedlurization reaction was determined to be independent of particle size, thus suggesting chemical reaction control.
Characteristics of heavy‐oil‐in‐water emulsions containing produced sand
Authors: Jamaluddin A. K. M. , Bowen C. T. , Gillies R. , Small M. , Nazarko T. W.
Published: March 2009

Heavy‐oil‐in‐water (o/w) emulsions containing produced sand were prepared using commercially available emulsifiers. The emulsions were tested in beakers for emulsion type, quality, and sand‐retention characteristics. The apparent viscosities of the o/w emulsions were measured. The effects of polymer addition on the apparent viscosity and sand‐carrying capability of the emulsions were also studied.

The results of the breaker tests indicate that most emulsifier solutions water‐wet the beaker wall and temporarily improve heavy‐oil flow characteristics. However, most of the chemicals also water‐wet the sand particles and cause sand dropout. The Flothin F2 chemical alone showed stable oil dispersion and, in combination with the Flocon 4800C polymer, showed very good sand‐retention, viscosity‐reduction, and stable oil‐dispersion characteristics.
Oscillating grid turbulence and bulk mixing at high schmidt numbers
Authors: Kostazos A. E. , Apikides P. S. , Kastrinakis E. G. , Nychas S. G.
Published: March 2009

The mixing process of high Schmidt number (700‐35000) aqueous solutions was investigated in an oscillating grid mixing vessel. The influence of the following variables on the mixing time was studied: Schmidt number, initial solution concentration, volume ratio of the liquids to be mixed and oscillating grid frequency. The measurements were compared with Corrsin's isotropic turbulent mixing theory. The data were correlated in the form of dimensionless groups, involving the aforementioned variables.
Optimal periodic forcing of nonlinear chemical processes for performance improvements
Authors: Chen Chien‐Chong , Hwang Chyi , Yang Ray Y. K.
Published: March 2009

Unsteady‐state periodic operations can improve the optimal steady‐state performance of nonlinear chemical processes. To examine if the optimal periodic operation is proper and to obtain the optimal forcing functions subject to various control and state constraints it is suggested in this paper to convert the problems into a form which is suitable for constrained nonlinear programming. The adopted numerical optimization method is based on employing the control parametrization technique and is thus capable of dealing with the problem of multiple input forcings and obtaining optimal forcing functions and/or parameters while subject to general constraints. Besides, it provides information about to what extent the process performance can be improved by adopting the optimal periodic control.
Application of a fuzzy match inference strategy in synthesis of separation systems
Authors: Qian Yu , Lien Kristian M.
Published: March 2009

Symbolic representation and sequential processing of information in most expert systems have made it difficult to represent continuous variables and to model interactions among different parts of a large process system. This paper proposes a new approach, principally aimed at function oriented engineering design problems. Continuous variables and qualitative information are treated as fuzzy sets. A fuzzy match inference strategy is proposed to assess design schemes with rules in parallel. The fuzzy match inference strategy is then extended to multi‐step decision making in the synthesis of multicomponent separation sequences. The new concepts have been implemented in a prototype expert system, where the selection of separation technologies and sequencing of separators are approached in an integrated manner. It is shown from several examples that the inference strategy yields promising results in quantitative evaluation of process synthesis and combinatorial optimization.
Biodegradation of aromatic compounds in a self‐cycling fermenter (SCF)
Authors: Sarkis Bassam E. , Cooper David G.
Published: March 2009

The Self‐cycling fermentation (SCF) technique was applied to the biodegradation of several aromatic compounds by Pseudomonas putida and Pseudomonas fluorescens. The SCF technique was shown to have several advantages over the sequential batch reactor and other methods of biodegradation. The SCF technique allowed stable and repeatable performance over an extended period of time, with almost complete substrate consumption. The system was flexible and easily adapted to changes in concentration and/or type of substrate. The rates of consumption were considerably higher than reported for any other biodegradation technique.
Modeling and simulation of the drying of thin sheets in a continuous infrared dryer
Authors: Dhib R. , Broadbent A. D. , Thérien N.
Published: March 2009

The model gives the temperature and moisture distributions of the air, and of the moist sheet, as a function of time and distance in the dryer. The influence of the sheet's velocity and that of the radiant energy on the dryer performance as well as the effect of the moisture content of the entering sheet have been studied. A set of 27 experiments was carried out using the infrared dryer in order to calibrate the model. In these, the following three variables each had three operational levels: web velocity, initial web moisture and heating power. The model predictions agreed very well with the experimental data. Model predictions using arithmetic averages for the parameters, and parameters correlated with operational variables, are also presented and discussed.
Separation of monoclonal IgM antibodies using tangential flow ultrafiltration
Authors: Krishnan Mani , Kalogerakis Nicolas , Behie Leo A. , Mehrotra Anil K.
Published: March 2009

Experimental results are presented for the separation of monoclonal IgM antibodies from hybridoma cell cultures using tangential flow ultrafiltration with total recycle of the retentate. IgM antibodies are pentameric immunoglobulin molecules with a molar mass of 900 kDa and a tip‐to‐tip distance of 38 nm. The major impurity (foulant) in the supernatant sample was albumin, whose molar mass and diameter are 67 kDa and 7 nm, respectively. The antibody (product) recovery rate, variations in the permeation velocity and the time for a 90%‐reduction in feed volume were investigated using 100 and 300 kDa NMWCO membranes at three transmembrane pressures and two tangential velocities. A model is also presented, in which the ultrafiltration process is divided into two regimes: the surface fouling regime (characterized by the adsorption of antibody molecules on the membrane surface) and the internal fouling regime (characterized by pore‐blockage due to deposition of foulant protein molecules). Approximately 16% of the effective membrane area was blocked in the surface fouling regime. The model predictions are in satisfactory agreement with the experimental results.
Solvent effects on liquefaction: Solubilization profiles of a canadian prototype wood, populus deltoides, in the presence of different solvents
Authors: Heitz Michèle , Brown Anthony , Chornet Esteban
Published: March 2009

Populus deltoides was treated with straight chain alcohols from methanol to n‐hexanol, mono and triethanolamine, water, ethyleneglycol, acetone, cyclohexane and lactic acid. A batch reactor was used in all the runs and the temperature range used was from 100 to 320°C. A reaction ordinate concept was used to evaluate the treatment severities. The results of these experiments showed a significant influence of the solvent on the extent of liquefaction of wood as well as on the holocellulose and lignin contents of the residues. An attempt to relate the liquefaction profiles to the solubility parameters of the solvents is discussed.
Investigation on the flocculation of asphaltenes and the colloidal stability of the crude oil fraction (> 210°C)
Authors: Chaala A. , Benallal B. , Hachelef S.
Published: March 2009

Several problems are encountered with asphaltenes during the exploitation, transportation, storage and treatment of crude oil. The purpose of the present work was to study the behaviour of the crude oil fraction (<210°C) by varying the temperature and doping with some hydrocarbons including solid paraffin and aromatic concentrate. The effect of flooding water was investigated. A preliminary characterization study on asphaltenes removed from the crude oil using two different solvents was performed. The state of the oil was determined by the stability factor which indicates the susceptibility of asphaltenes to agglomerate or to disperse in the continuous phase.
Entry and exit flows of casson fluids
Authors: Pham T. V. , Mitsoulis E.
Published: March 2009

Entry and exit flows through abrupt contractions are studied numerically for Casson fluids exhibiting a yield stress. The Casson constitutive equation recommended for describing blood flow is used with an appropriate modification proposed by Papanastasiou, which applies everywhere in the flow field in both yielded and practically unyielded regions. The emphasis is on determining the extent and shape of unyielded/yielded regions along with the swelling ratio of the free stream for planar and axisymmetric contraction flows for the whole range of Casson numbers. The results for pressure are used to determine the excess pressure losses that give rise to entrance, exit, and the total end correction.
Zeolites grown on wire gauze: A new structured catalyst packing for dustproof, low pressure drop denox processes
Authors: Calis H. P. , Gerritsen A. W. , Bleek C. M. Van Den , Legein C. H. , Jansen J. C. , Van Bekkum H.
Published: March 2009

To prove the applicability of zeolite crystals as a catalyst in dustproof low pressure drop reactors, a novel structured catalyst packing has been developed consisting of ZSM‐5 crystals in situ grown on metal wire gauze. Using this technique, mechanically strong catalyst packings of any required shape can be produced that give an extremely low pressure drop across the packing and that trap almost no dust particles. These features make the packing especially suitable for end‐of‐pipe processes, such as the catalytic removal of NOx from large flows of dust containing flue gas. To demonstrate the feasibility of the packing as a catalyst, it was tested — after incorporation copper into the zeolites by ion exchange — on its activity for Selective Catalytic Reduction of nitric oxide with ammonia at 350°C. Both the activity and selectivity of the catalyst packing proved to be superior to conventional vanadia/titania catalysts.
Experimental study of residence time, particle movement and bed depth profile in rotary kilns
Authors: Lebas E. , Hanrot F. , Ablitzer D. , Houzelot J.‐L.
Published: March 2009

Experiments were performed in a pilot scale rotary kiln with coal and coke particles to study their mean residence time, residence time distribution, bed depth profile and time spent at the bed surface. The influence of filling ratio on residence time was studied with a uniform bed depth in the kiln. Residence time distribution and bed depth profile measurements were performed in a kiln without end constriction, at different rotational speeds and different solid inputs. The residence time fraction corresponding to the passage of the particles at the bed surface was measured with a photographic study of the movement of a coloured particle.

Various equations were tested to represent the experimental results. The equations of Kramers and Croockewit (1952) and Ronco (1965) were adequate to calculate mean residence times, while only the former could represent correctly the bed depth profile. An equation is proposed which turns out to be quite accurate in predicting the fraction of the residence time spent in the upper layer of the bed.
Fluidized bed gasification of coal
Authors: Chatterjee P. K. , Datta A. B. , Kundu K. M.
Published: March 2009

Gasification of high ash India coal has been studied in a laboratory‐scale, atmospheric fluidized bed gasifier using steam and air as fluidizing media. A one‐dimensional analysis of the gasification process has been presented incorporating a two‐phase theory of fluidization, char gasification, volatile release and an overall system energy balance. Results are presented on the variation of product gas composiiton, bed temperature, calorific value and carbon conversion with oxygen and steam feed. Comparison between predicted and experimental data has been presented, and the predictions show similar trends as in the experiments.
Restoration of Runx1 Expression in the Tie2 Cell Compartment Rescues Definitive Hematopoietic Stem Cells and Extends Life of Runx1 Knockout Animals Until Birth
Authors: Liakhovitskaia Anna , Gribi Ruby , Stamateris Evangelos , Villain Gaelle , Jaffredo Thierry , Wilkie Ron , Gilchrist Derek , Yang Jian , Ure Janice , Medvinsky Alexander
Published: March 2009

Mice deficient in the runt homology domain transcription factor Runx1/AML1 fail to generate functional clonogenic hematopoietic cells and die in utero by embryonic day 12.5. We previously generated Runx1 reversible knockout mice, in which the Runx1 locus can be restored by Cre-mediated recombination. We show here that selective restoration of the Runx1 locus in the Tie2 cell compartment rescues clonogenic hematopoietic progenitors in early Runx1-null embryos and rescues lymphoid and myeloid lineages during fetal development. Furthermore, fetal liver cells isolated from reactivated Runx1 embryos are capable of long-term multilineage lymphomyeloid reconstitution of adult irradiated recipients, demonstrating the rescue of definitive hematopoietic stem cells. However, this rescue of the definitive hematopoietic hierarchy is not sufficient to rescue the viability of animals beyond birth, pointing to an essential role for Runx1 in other vital developmental processes.

Disclosure of potential conflicts of interest is found at the end of this article.
Isolation of heterothallic haploid and auxotrophic mutants of Schizosaccharomyces japonicus
Authors: Furuya Kanji , Niki Hironori
Published: March 2009

The fission yeast Schizosaccharomyces japonicus var. japonicus belong to the genus Schizosaccharomyces, together with Schizosaccharomyces pombe, which has been well studied as a model organism. In contrast, Sz. japonicus is poorly characterized and genetic tools were yet to be developed. We here report the isolation of the heterothallic haploids NIG2017, NIG2025 and NIG2028, which were derivatives of a Sz. japonicus homothallic strain (NIG2008). Based on the genomic sequence of Sz. japonicus, released by the Broad Institute, we found that Sz. japonicus also possesses orthologues of the mating‐type genes of Sz. pombe; two mat‐M (−) and two mat‐P (+) genes. As expected, heterothallic strains were defective in one of the Sz. japonicus mat genes (matsj). We confirmed that NIG2017 and NIG2025 strains only expressed mRNA from the matsj‐P genes, while homothallic strains expressed both matsj‐M and matsj‐P. Although the NIG2028 strain expressed both gene products, matsj‐P was found mutated, which may have conferred the heterothallic phenotype of the mutant. Thus, we concluded that these were stable heterothallic strains. We designated NIG2017 and NIG2025 as h+ and NIG 2028 as h−, respectively. We also found additional h− strains (NIG5872 and NIG5873) that arose from the cross between NIG2017 and NIG2028 derivatives. In addition to that, we have constructed a ura4sj‐deleted strain and an ade6sj‐mutated strain. We used these heterothallic strains and the auxotroph strains to perform spore dissection analysis to determine the genetic distances between several loci, and found that the mating type loci and ade6sj locus were linked to centromeres. Copyright © 2009 John Wiley & Sons, Ltd.
Stabilin‐2 mediates homophilic cell–cell interactions via its FAS1 domains
Authors: Park Seung-Yoon , Jung Mi-Yeon , Kim In-San
Published: March 2009

Stabilin‐2 was recently shown to mediate a heterophilic interaction with integrin alphaMbeta2 via its FAS1 domain. Here, we demonstrate that stabilin‐2 also mediates homophilic cell–cell interactions. L cells expressing stabilin‐2 mediate a significant level of cell aggregation, and this aggregation is significantly inhibited by anti‐stabilin‐2 antibody. Stabilin‐2‐mediated aggregation is mediated by homophilic interactions and enhanced in the presence of Ca2+ and Mg2+. Interestingly, exogenous addition of FAS1 domains but not EGF‐like domains enhances stabilin‐2‐mediated cell aggregation, suggesting that exogenous FAS1 domains may form polymeric structure with FAS1 domains of stabilin‐2. Together, these data show the participation of stabilin‐2 in homophilic cell adhesion and role of FAS1 domains.
Commentary on “A roadmap for the prevention of dementia II. Leon Thal Symposium 2008.” The Multidomain Alzheimer Preventive Trial (MAPT): A new approach to the prevention of Alzheimer's disease
Authors: Gillette‐Guyonnet Sophie , Andrieu Sandrine , Dantoine Thierry , Dartigues Jean‐François , Touchon Jacques , Vellas B. ,   MAPT Study Group
Published: March 2009

Background

Because no effective curative approaches are available, preventive approaches in the field of Alzheimer's disease (AD) are needed. We present the design of the ongoing Multidomain Alzheimer Preventive Trial (MAPT) Study. Several previous studies suggested that many factors may be involved in the occurrence of AD at late ages. Because of the probable multifactorial nature of AD, it seems logical to initiate multidomain interventions to examine their potential synergistic effects. The MAPT Study aims to evaluate the efficacy of a multidomain intervention (nutritional, physical, and cognitive training) and omega 3 treatment in the prevention of cognitive decline in frail elderly persons aged 70 years or over. The study also collects imaging and biological data that could be used in future AD prevention and treatment trials.

Methods

The MAPT Study is a 3‐year, randomized, controlled trial conducted by university hospital practitioners specializing in memory disorders in four French cities (Bordeaux, Limoges, Montpellier, and Toulouse). The study plans to enroll 1200 frail elderly subjects on the basis of at least one of the following criteria: subjective memory complaint spontaneously expressed to a general practitioner, limitation in one instrumental activity of daily living (IADL), and slow walking speed. To demonstrate the protective effect of interventions, subjects are randomized into one of the following four groups: omega 3 alone, multidomain intervention alone, omega 3 plus multidomain intervention, or placebo (n = 300 each). The principal outcome measure is a change in cognitive function at 3 years, as determined by the Grober and Buschke Test.

Conclusions

The MAPT Study is the first preventive trial involving multidomain interventions. Final results should be available in 2013.
Commentary on “A roadmap for the prevention of dementia II: Leon Thal symposium 2008.” The megacommunity approach to Alzheimer's disease
Authors: Van Lee Reggie , Meagher Beth , Fritz Patrick , Penfield Susan
Published: March 2009

There are many groups and organizations across the government, private, and nonprofit sectors that are passionately engaged in the fight against Alzheimer's disease (AD), but they have constraints on their funding and scope and, therefore, cannot tackle the problem holistically. Addressing the complexities of this epidemic strategically will require the collective efforts of committed stakeholders. Individuals and organizations must work together to identify mutual interests and forge new relationships and partnerships. Through this network of stakeholders, known as a megacommunity, individual members can support and expand their objectives and impact through the combined knowledge and resources in the megacommunity network. Leaders Engaged on Alzheimer's Disease (LEAD) is an example of a megacommunity tackling the toughest issues facing AD patients and their families. LEAD is currently comprised of more that thirty individuals and organizations committed to sharing information and coordinating action across organizational boundaries.
Article Commentary: Clinical implications of a damaged cochlea: Pure tone thresholds vs information‐carrying capacity
Authors: Halpin Chris , Rauch Steven D.
Published: March 2009

The pure tone audiogram is an accurate measure of auditory threshold as a function of stimulus frequency. However, it does not provide the complete picture in patients with sensorineural hearing loss (SNHL) because it is not a direct measure of damage to the cochlear epithelium or of the associated limits on information‐carrying capacity that restrict word recognition. Diagnostic use of the audiogram leads to the error of viewing SNHL as “dB of hearing loss,” which may seem reversible by gain. Cochlear disorders, on the other hand, often give rise to abnormal thresholds because regions are damaged and may best be thought of more in terms of intractable sensory limitations, comparable to vision loss in retinal disease. We argue that word recognition testing at low vs high presentation levels provides a quantification of the cochlea's information‐carrying capacity and is a useful predictor of word recognition limits with hearing aids.
Relationship between vascular endothelial growth factor and Notch1 expression and lymphatic metastasis in tongue cancer
Authors: Joo Young‐Hoon , Jung Chan‐Kwon , Kim Min‐Sik , Sun Dong‐Il
Published: March 2009

Objective

To determine the role of angiogenesis in lymph node metastasis and the depth of invasion in early tongue cancer.

Study Design

Retrospective analysis.

Subjects and Methods

The study included 51 subjects with tongue cancer. Immunohistochemical staining for vascular endothelial growth factor, Notch1, and Notch3 was performed. Microvessel density was evaluated by counting the number of CD34‐stained microvessels in each pathologic specimen.

Results

Significant correlations were found between vascular endothelial growth factor and Notch1 expression and cervical lymph node metastasis (P = 0.020 and P < 0.009, respectively), tumor depth of invasion (P = 0.001 and P < 0.001, respectively), and microvessel density indicated by CD34 staining (P = 0.001 and P < 0.001, respectively). Nodal metastasis (P = 0.022), T stage (P = 0.002), and positive VEGF expression (P = 0.044) were statistically significant prognostic factors for disease‐specific survival.

Conclusion

Vascular endothelial growth factor and Notch1 expression are significantly related to cervical lymph node metastasis and depth of invasion in tongue cancer patients.
Could intervention by clinics such as Primeros Pasos affect the prevalence of childhood malnutrition in the developing world?
Authors: Seccombe Adam , Hughes Elizabeth
Published: March 2009

Objective

Guatemala is a country severely affected by malnutrition, particularly in its child population. The present study aimed to assess the impact of recognised aetiological factors on the prevalence of malnutrition and to establish the efficacy of a Guatemalan malnutrition clinic by examining the changes in the prevalence of malnutrition in the ten surrounding communities served by the clinic.

Design

Records of children (n 7681) aged 5–16 years seen by the clinic between 2004 and 2006 were examined. Anthropometric data for each child were taken from these records and used as an indicator for their nutritional status to estimate the change in rates of malnutrition during this period.

Results

An overall reduction was seen in all forms of malnutrition over the 3-year period, although over 50 % of the study population remained malnourished in 2006. A consistent reduction was also seen in rates of moderate and severe malnutrition, but not in rates of mild malnutrition.

Conclusions

The results demonstrate that clinics such as Primeros Pasos can have a beneficial effect on schoolchildren, particularly those who are severely malnourished. A need has been highlighted for more research in this area, particularly how clinics such as Primeros Pasos can be best used in the fight against malnutrition.
Mothers’ infant feeding experiences: constraints and supports for optimal feeding in an HIV-impacted urban community in South Africa
Authors: Sibeko Lindiwe , Coutsoudis Anna , Nzuza S’phindile , Gray-Donald Katherine
Published: March 2009

Objective

To better understand the enabling and challenging factors impacting on infant feeding practices in communities with a high HIV prevalence.

Design

Qualitative study, with data collected through in-depth interviews and observations of mothers, in addition to discussions with health-service providers.

Setting

Urban settlement in the province of KwaZulu-Natal, South Africa.

Subjects

Mothers recruited from an HIV clinic and from within the community.

Results

Emerging from discussions with mothers on the acceptability of alternative feeding methods were the challenges they encountered in feeding their infants. Mothers readily identified feeding in the context of HIV infection as an issue of great concern, encompassing three central themes: (i) stigma and disclosure of HIV; (ii) confusion and coercion; and (iii) diarrhoea, sickness and free formula. It became evident that mothers rarely received quality infant feeding counselling and consequently mixed feeding, a widespread practice but one that is highly risky for HIV transmission, remained a common feeding practice. Exclusive breast-feeding (EBF) was best practised with support, following disclosure of HIV status. Availability of free formula did not guarantee exclusive formula feeding but instead led to inappropriate feeding practices.

Conclusions

In addition to providing accurate information, health-care workers must be empowered to counsel mothers effectively, addressing issues of disclosure and thereby facilitating mobilization of maternal support networks. These findings illustrate the challenges that exist in policy translation within the context of quality of training for health-care workers on optimizing maternal infant feeding practices, particularly in HIV-prevalent, resource-poor settings.
Social class-related gradient in the association of skeletal growth with blood pressure among adolescent boys in India
Authors: Rao Shobha , Apte Priti
Published: March 2009

Objective

In view of the fact that height differences between socio-economic groups are apparent early in childhood, it is of interest to examine whether skeletal growth is reflective of the social class gradient in CVD risk. The present study examined blood pressure levels, adiposity and growth of adolescent boys from high and low social classes.

Design

In a cross-sectional study, skeletal growth (height and sitting height), adiposity (weight, BMI and body fat) and blood pressure levels of the adolescents were measured.

Setting

Pune, India.

Subjects

Adolescent schoolboys (9–16 years) from high socio-economic (HSE; n 1146) and low socio-economic (LSE; n 932) class.

Results

LSE boys were thin, short and undernourished (mean BMI: 15·5 kg/m2v. 19·3 kg/m2 in HSE boys, P = 0·00). Social gradient was revealed in differing health risks. The prevalence of high systolic blood pressure (HSBP) was high in HSE class (10·5 % v. 2·7 % in LSE class, P = 0·00) and was associated with adiposity, while the prevalence of high diastolic blood pressure (HDBP) was high in LSE class (9·8 % v. 7·0 % in HSE class, P = 0·00) and had only a weak association with adiposity. Despite this, lower ratio of leg length to height was associated with significantly higher respective health risks, i.e. for HDBP in LSE class (OR = 1·99, 95 % CI 1·14, 3·47) and for HSBP in HSE class (OR = 1·69, 95 % CI 1·02, 2·77).

Conclusions

As stunting in childhood is a major problem in India and Asia, the leg length to height indicator needs to be validated in different populations to understand CVD risks.
Weight loss by mobile phone: a 1-year effectiveness study
Authors: Haapala Irja , Barengo Noël C , Biggs Simon , Surakka Leena , Manninen Pirjo
Published: March 2009

Objective

To investigate the short- and long-term effectiveness and the predictors of weight loss in a mobile phone weight-loss programme among healthy overweight adults.

Design

One hundred and twenty-five healthy, overweight (BMI = 26–36 kg/m2), 25–44-year-old, screened volunteers were randomized to an experimental group (n 62) to use a mobile phone-operated weight-loss programme or to a control group (n 63) with no intervention. Via text messaging, the programme instructed a staggered reduction of food intake and daily weight reporting with immediate tailored feedback. Assessments were at 0, 3, 6, 9 and 12 months for the experimental group; at 0 and 12 months for the control group. Main outcome variables were changes in body weight and waist circumference.

Results

By 12 months the experimental group had lost significantly more weight than the control group (4·5 (sd 5·0) v. 1·1 (sd 5·8) kg; F(1,80) = 8·0, P = 0·006) and had a greater reduction in waist circumference (6·3 (sd 5·3) v. 2·4 (sd 5·4) cm; F(1,80) = 55·2, P = 0·0001). Early weight loss, self-efficacy, contact frequency, attitudes towards the medium, changes in work and family life and changes made in dietary habits were the strongest predictors of weight loss.

Conclusions

This mobile phone weight-loss programme was effective in short- and long-term weight loss. As a minimum-advice, maximal-contact programme, it offers ideas for future weight-loss programmes.
Unhealthy dietary patterns are associated with weight gain during pregnancy among Finnish women
Authors: Uusitalo Ulla , Arkkola Tuula , Ovaskainen Marja-Leena , Kronberg-Kippilä Carina , Kenward Mike G , Veijola Riitta , Simell Olli , Knip Mikael , Virtanen Suvi M
Published: March 2009

Objective

To study whether the dietary patterns of Finnish pregnant women are associated with their weight gain rate during pregnancy.

Design

A validated 181-item FFQ was applied retrospectively to assess the diet during the eighth month of pregnancy, and maternal height and maternal weight at first and last antenatal visits were recalled. Information on sociodemographic characteristics, parity and smoking of the pregnant women was obtained by a structured questionnaire and from the Finnish Birth Registry. Principal components analysis was used to identify dietary patterns that described the diet of pregnant women based on their food consumption profile.

Setting

Finland.

Subjects

Subjects consisted of 3360 women who had newly delivered in 1997–2002 and whose baby carried human leucocyte antigen-conferred susceptibility to type 1 diabetes in two university hospital regions, Oulu and Tampere, in Finland.

Results

Out of seven dietary patterns identified, the ‘fast food’ pattern was positively associated (β= 0·010,se= 0·003,P= 0·004) and the ‘alcohol and butter’ pattern was inversely associated (β= –0·010,se= 0·003,P< 0·0001) with weight gain rate (kg/week) during pregnancy after adjusting for potential dietary, perinatal and sociodemographic confounding factors. Both of the dietary pattern associations demonstrated dose dependency.

Conclusions

Pregnant women should be guided to have a well-planned, balanced, healthy diet during pregnancy in order to avoid rapid gestational weight gain. The association between diet, health and maternal weight gain of the women who consumed alcohol during pregnancy should be studied further.
α-Linolenic Acid-Rich Flaxseed Oil Ingestion Increases Plasma Adiponectin Level in Rats
Authors: Sekine Seiji , Sasanuki Shiho , Murano Yoshihiro , Aoyama Toshiaki , Takeuchi Hiroyuki
Published: March 2009

Adiponectin, an adipose-specific secretory protein, exhibits antidiabetic and antiatherogenic properties. The effect of α-linolenic acid (ALA) on adiponectin has not been revealed. ALA is included abundantly in vegetable oils such as flaxseed oil. In this study, we attempted to clarify the effect of ALA-rich flaxseed oil (FSO) intake on the adiponectin level in rats. Seven-week-old male Sprague-Dawley rats were fed test diets containing high oleic safflower oil (HOSO) or FSO for 4 weeks. After the experimental period, the plasma adiponectin concentration in the FSO-fed group was higher than that in the HOSO-fed group. The adiponectin content of perirenal adipose tissue in the FSO-fed group was also significantly higher than that in the HOSO-fed group. However, the adiponectin mRNA level in the perirenal adipose tissue did not differ significantly between the HOSO-fed and FSO-fed groups. In this study, we clarified the effect of the ALA-rich FSO ingestion on the plasma adiponectin concentration in rats. It was suggested that the ALA-rich FSO intake might exhibit beneficial effects through an increase of the adiponectin level.
Carotenoid Micellarization Varies Greatly Between Individual and Mixed Vegetables With or Without the Addition of Fat or Fiber
Authors: O'Conell Orla , Ryan Lisa , O'Sullivan Laurie , Aherne-Bruce S. Aisling , O'Brien Nora M.
Published: March 2009

Carotenoid bioavailability is influenced by a number of factors, including the type of food matrix and the presence of fat, fiber, and other carotenoids. Therefore, the objectives of the present study were: first, to assess the effects of mixing raw vegetables on the micellarization of β-carotene, lycopene, β-cryptoxanthin, and lutein compared with individual vegetables; second, to investigate the effects of adding different oils on carotenoid transfer to the micelles; and third, and to a minor extent, to determine carotenoid micellarization following the addition of fiber. The two mixed vegetable meals were TRS (tomato, red pepper, and spinach) and CRS (courgette/zucchini, red pepper, and spinach). Similar trends in carotenoid micellarization were seen between individual vegetables and the TRS meal but not with the CRS meal. In general, the addition of olive, peanut, or rapeseed oil to the CRS meal significantly enhanced carotenoid micellarization but this effect was not concentrationdependent. In relation to the TRS meal, adding either vegetable oils or fiber (oat bran, wheat bran, and pectin) significantly decreased the micellarization of carotenoids to varying degrees. The results from this study indicate that changes to a combination of raw vegetables, with or without the addition of dietary fat or fiber, can have varying results on carotenoid bioavailability.
RBX1/ROC1 disruption results in early embryonic lethality due to proliferation failure, partially rescued by simultaneous loss of p27
Authors: Tan Mingjia , Davis Shannon W. , Saunders Thomas L. , Zhu Yuan , Sun Yi
Published: March 2009

RBX1 (RING box protein-1) or ROC1 (regulator of cullins-1) is the RING component of SCF (Skp1, Cullins, F-box proteins) E3 ubiquitin ligases, which regulate diverse cellular processes by targeting various substrates for degradation. However, the in vivo physiological function of RBX1 remains uncharacterized. Here, we show that a gene trap disruption of mouse
Rbx1
causes embryonic lethality at embryonic day (E)7.5, mainly due to a failure in proliferation; p27, a cyclin dependent kinase inhibitor, normally undetectable in the early embryos, accumulates at high levels in the absence of
Rbx1
. Although mice heterozygous for the
Rbx1
gene trap appear viable and fertile without obvious abnormalities, the
Rbx1

+/
Gt

MEFs do show retarded growth with G1 arrest and p27 accumulation. Simultaneous loss of p27 extended the life span of

Rbx1
Gt/Gt

embryos from E6.5 to E9.5, indicating that p27-mediated cell cycle inhibition contributes to the early embryonic lethality in the
Rbx1
-deficient embryos. Our study demonstrates that the in vivo physiological function of RBX1 is to ensure cell proliferation by preventing p27 accumulation during the early stage of embryonic development.
Mechanistic role of movement and strain sensitivity in muscle contraction
Authors: Davis Julien S. , Epstein Neal D.
Published: March 2009

Tension generation can be studied by applying step perturbations to contracting muscle fibers and subdividing the mechanical response into exponential phases. The de novo tension-generating isomerization is associated with one of these phases. Earlier work has shown that a temperature jump perturbs the equilibrium constant directly to increase tension. Here, we show that a length jump functions quite differently. A step release (relative movement of thick and thin filaments) appears to release a steric constraint on an ensemble of noncompetent postphosphate release actomyosin cross-bridges, enabling them to generate tension, a concentration jump in effect. Structural studies [Taylor KA, et al. (1999) Tomographic 3D reconstruction of quick-frozen, Ca
2+
-activated contracting insect flight muscle.
Cell
99:421–431] that map to these kinetics indicate that both catalytic and lever arm domains of noncompetent myosin heads change angle on actin, whereas lever arm movement alone mediates the power stroke. Together, these kinetic and structural observations show a 13-nm overall interaction distance of myosin with actin, including a final 4- to 6-nm power stroke when the catalytic domain is fixed on actin. Raising fiber temperature with both perturbation techniques accelerates the forward, but slows the reverse rate constant of tension generation, kinetics akin to the unfolding/folding of small proteins. Decreasing strain, however, causes both forward and reverse rate constants to increase. Despite these changes in rate, the equilibrium constant is strain-insensitive. Activation enthalpy and entropy data show this invariance to be the result of enthalpy–entropy compensation. Reaction amplitudes confirm a strain-invariant equilibrium constant and thus a strain-insensitive ratio of pretension- to tension-generating states as work is done.
Jagged1 is the pathological link between Wnt and Notch pathways in colorectal cancer
Authors: Rodilla Verónica , Villanueva Alberto , Obrador-Hevia Antonia , Robert-Moreno Àlex , Fernández-Majada Vanessa , Grilli Andrea , López-Bigas Nuria , Bellora Nicolás , Albà M. Mar , Torres Ferran , Duñach Mireia , Sanjuan Xavier , Gonzalez Sara , Gridley Thomas , Capella Gabriel , Bigas Anna , Espinosa Lluís
Published: March 2009

Notch has been linked to β-catenin-dependent tumorigenesis; however, the mechanisms leading to Notch activation and the contribution of the Notch pathway to colorectal cancer is not yet understood. By microarray analysis, we have identified a group of genes downstream of Wnt/β-catenin (down-regulated when blocking Wnt/β-catenin) that are directly regulated by Notch (repressed by γ-secretase inhibitors and up-regulated by active Notch1 in the absence of β-catenin signaling). We demonstrate that Notch is downstream of Wnt in colorectal cancer cells through β-catenin-mediated transcriptional activation of the Notch-ligand Jagged1. Consistently, expression of activated Notch1 partially reverts the effects of blocking Wnt/β-catenin pathway in tumors implanted s.c. in nude mice. Crossing
APC

Min
/+

with
Jagged1
+/Δ
mice is sufficient to significantly reduce the size of the polyps arising in the APC mutant background indicating that Notch is an essential modulator of tumorigenesis induced by nuclear β-catenin. We show that this mechanism is operating in human tumors from Familial Adenomatous Polyposis patients. We conclude that Notch activation, accomplished by β-catenin-mediated up-regulation of Jagged1, is required for tumorigenesis in the intestine. The Notch-specific genetic signature is sufficient to block differentiation and promote vasculogenesis in tumors whereas proliferation depends on both pathways.
Plants with double genomes might have had a better chance to survive the Cretaceous–Tertiary extinction event
Authors: Fawcett Jeffrey A. , Maere Steven , Van de Peer Yves
Published: March 2009

Most flowering plants have been shown to be ancient polyploids that have undergone one or more whole genome duplications early in their evolution. Furthermore, many different plant lineages seem to have experienced an additional, more recent genome duplication. Starting from paralogous genes lying in duplicated segments or identified in large expressed sequence tag collections, we dated these youngest duplication events through penalized likelihood phylogenetic tree inference. We show that a majority of these independent genome duplications are clustered in time and seem to coincide with the Cretaceous–Tertiary (KT) boundary. The KT extinction event is the most recent mass extinction caused by one or more catastrophic events such as a massive asteroid impact and/or increased volcanic activity. These events are believed to have generated global wildfires and dust clouds that cut off sunlight during long periods of time resulting in the extinction of ≈60% of plant species, as well as a majority of animals, including dinosaurs. Recent studies suggest that polyploid species can have a higher adaptability and increased tolerance to different environmental conditions. We propose that polyploidization may have contributed to the survival and propagation of several plant lineages during or following the KT extinction event. Due to advantages such as altered gene expression leading to hybrid vigor and an increased set of genes and alleles available for selection, polyploid plants might have been better able to adapt to the drastically changed environment 65 million years ago.