bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of cocaine and heroin with their respective metabolites in meconium by gas chromatography‐mass spectrometry
Authors: López P. , Bermejo A. M. , Tabernero M. J. , Fernández P. , Álvarez I.
Published: February 2007

The analysis of meconium specimens is a relatively accurate method for the detection of fetal exposure to drugs. The purpose of this study was to develop and validate a method for meconium sample preparation for a gas chromatography‐mass spectrometry (GC‐MS) confirmation of meconium extracts for cocaine, benzoylecgonine, codeine, morphine and 6‐monoacetylmorphine. The analytes were initially extracted from the matrix by methanol. Subsequently a solid‐phase extraction with Waters Oasis® HLB cartridges was applied. Analytes were determined in GC‐MS single monitoring mode. The method was validated in the range 40–2000 ng g−1 using 0.5 g of meconium per assay. The detector response was linear over the studied range, and limits of quantitation and detection were found to be acceptable. Intra‐ and inter‐batch coefficients of variation oscillated between 2.54% and 20.5%, and mean relative errors were in the range 0.79%–19.9%. The recoveries were higher than 42.1% in all cases. Finally the method was applied to analysis of meconium in newborns to assess fetal exposure to cocaine and opiates. Copyright © 2007 John Wiley & Sons, Ltd.
Ab initio parametrized MM3 force field for the metal‐organic framework MOF‐5
Authors: Tafipolsky Maxim , Amirjalayer Saeed , Schmid Rochus
Published: February 2007

A new valence force field has been developed and validated for a particular class of coordination polymers known as nanoporous metal‐organic frameworks (MOFs), introduced recently by the group of Yaghi. The experimental, structural, and spectroscopic data in combination with density functional theory calculations on several model systems were used to parametrize the bonded terms of the force field, which explicitly treats the metal–oxygen interactions as partially covalent as well as distinguishes different types of oxygens in the framework. Both the experimental crystal structure of MOF‐5 and vibrational infrared spectrum are reproduced reasonably well. The proposed force field is believed to be useful in atomistic simulations of adsorption/diffusion of guest molecules inside the flexible pores of this important class of MOF materials. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Hic‐5 contributes to epithelial‐mesenchymal transformation through a RhoA/ROCK‐dependent pathway
Authors: Tumbarello David A. , Turner Christopher E.
Published: February 2007

Epithelial‐mesenchymal transformation (EMT) in response to TGFβ1 is a coordinated process of tissue morphogenesis that occurs during embryonic development as well as during certain pathologic events including kidney tubulointerstitial fibrosis. It is characterized by the disassembly of cell–cell junctions and dramatic alterations in the actin cytoskeleton that facilitates cell–matrix adhesion and stimulates migration. The focal adhesion adapter protein, Hic‐5, has previously been reported to be upregulated during TGFβ1‐induced EMT in mouse mammary epithelial cells and the current study recapitulates this result in both mouse kidney proximal tubule epithelial, MCT, cells and human mammary epithelial, MCF10A, cells. To evaluate a causative role for Hic‐5 in EMT, Hic‐5 RNA interference (siRNA) was used to prevent Hic‐5 expression in response to TGFβ1 stimulation and was shown to suppress cell migration and actin stress fiber formation. It also resulted in the retention of a robust epithelial cell morphology characterized by elevated E‐cadherin protein expression and well‐organized adherens junctions. In addition, Hic‐5 siRNA treatment led to the suppression of TGFβ1 induction of RhoA activation. In contrast, forced expression of Hic‐5 led to the formation of ROCK‐dependent actin stress fibers. Furthermore, the induction of Hic‐5 expression in response to TGFβ1 was shown to be a RhoA/ROCK I‐dependent process. Together, these data implicate Hic‐5 as a key regulator of EMT and suggest that RhoA stimulated Hic‐5 expression in response to TGFβ1 may be functioning in a feed forward mechanism whereby Hic‐5 maintains the mesenchymal phenotype through sustained RhoA activation and signaling. J. Cell. Physiol. 211: 736–747, 2007. © 2007 Wiley‐Liss, Inc.
Deterioration of iron archaeological artefacts: micro‐Raman investigation on Cl‐containing corrosion products
Authors: Réguer Solenn , Neff Delphine , Bellot‐Gurlet Ludovic , Dillmann Philippe
Published: February 2007

Deterioration after excavation of archaeological iron artefacts buried in soil is often associated with the presence of chlorinated phases in corrosion products, leading to serious problems for conservation of metallic objects of cultural heritage. Therefore, in order to better understand the corrosion process related to the presence of chlorine, some high‐resolution techniques of material characterisation are implemented. The analyses are realised on cross sections of corroded iron objects excavated from archaeological sites dated from the 12th to the 16th century A.D. Cl‐containing phases appear even when the Cl level in the water is low. In addition to the common oxy‐hydroxide‐containing chloride, akaganeite (β–FeOOH) often mentioned in the literature, a ferrous hydroxychloride β–Fe2(OH)3Cl was also found in the corrosion layers. Moreover, part of the study is based on the preparation and desalinisation of pure akaganeite powder in order to characterise the influence of the chloride content on its crystalline structure as characterised by Raman spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd.
Raman spectroscopy of covalently functionalized single‐wall carbon nanotubes
Authors: Graupner R.
Published: February 2007

Raman spectroscopy is one of the most extensively employed methods for the characterization of carbon nanotubes. In this review article, an overview about Raman spectroscopy as a tool for the characterization of functionalized single‐walled carbon nanotubes (SWCNTs) is given. First, the relevant Raman modes in SWCNTs are introduced. Then, in a phenomenological approach, the effects that are observed for the individual modes in the Raman spectra are compiled and discussed. It is shown that special care has to be taken in order to separate the effects of functionalization, which are specific to a subset of the SWCNTs (metallic/semiconducting or diameter dependent), from changes in sample morphology or doping effects. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of common bean enrichment on nutritional quality of tortillas produced from nixtamalized regular and quality protein maize flours
Authors: Mora‐Avilés Alejandra , Lemus‐Flores Bibiana , Miranda‐López Rita , Hernández‐López David , Pons‐Hernández José L , Acosta‐Gallegos Jorge A , Guzmán‐Maldonado Salvador H
Published: February 2007

In Mexico the tortilla is most commonly eaten in the form of ‘taco’; this is normally accompanied with other food, in particular the common bean. Tortillas made of quality protein maize (QPM) fortified with common bean might be a strategy to improve their protein quality. In this study, amino acids and mineral changes that occur during nixtamalization and the chemical and nutritional characteristics of regular, commercial and QPM tortilla–bean combination were assessed. After nixtamalization, protein from QPM nixtamalized maize flour was reduced from 8.1% to 7.2% (w/w). Tryptophan was also reduced from 12.1 to 11.1 g kg−1 protein. QPM maize retained a higher amount (P < 0.05) of calcium (3180 mg kg−1) compared to regular maize (1820 mg kg−1). When nixtamalized maize flour of regular maize and commercial tortilla were combined with beans, protein content increased. The tryptophan and lysine contents in these tortillas were increased (P > 0.05) also, but were significantly lower (P > 0.05) than in tortilla made with QPM maize fortified with bean (22.7 and 69.9 g kg−1 protein, respectively). Mineral contents increased in tortilla–bean combination. The QPM and tortilla fortified with bean gave an improvement in protein quality and could contribute significantly towards human nutrition, especially in countries like Mexico where maize and beans are important components of the diet. Copyright © 2007 Society of Chemical Industry
Excimer Lasers Support Industrial Micromachining Diversity
Authors: Spiecker Gerd
Published: February 2007

The combination of high power, short wavelength and low cost per photon have made the excimer laser the tool of choice in a wide range of micromachining applications.
Cover Picture: Macromol. Mater. Eng. 2/2007
Authors: Karayannidis George P. , Achilias Dimitris S.
Published: February 2007

Cover: The picture on the cover shows the chemical recycling of poly(ethylene terephthalate) by glycolysis with diethylene glycol and the recovery of secondary value‐added materials such as unsaturated PET‐oligomer polyester resins or methacrylated PET‐oligomer monomers. These products after curing give new interesting alkyd or dimethacrylated crosslinked resins. Further details can be found in the article by G. P. Karayannidis* and D. S. Axilias on page 128.
Visible‐spectroscopy study of the low dimensional (C2H5NH3)2CuCl4 compound in the region of its low temperature phase transitions
Authors: Kapustianyk V. , Rudyk V. , Partyka M.
Published: February 2007

On the basis of absorption spectroscopy data the temperature evolution of Cu2+ ion environment in the layered compound (C2H5NH3)2CuCl4 was studied within the temperature range of 4.5–310 K. For the detailed analysis of the experimental data the specially created program package Crys Tool 1.0 based on the quantum mechanical models first of all on the model of normalised spherical harmonics (NSH) was used. It has been found that the crystal structure in the low temperature phases contains tetragonally distorted octahedral metal–halogen complexes. The parameters of crystal field, normalised spherical harmonics, angular overlap model as well as the metal–halogen distances show anomalous behaviour at the points of phase transitions: Tc = 10 K and T4 = 232 K (for heating). The changes of these parameters observed around T5 = 65 K also may be related to previously unknown phase transition. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ka‐band link optimization with rate adaptation for Mars and lunar communications
Authors: Sun Jun , Gao Jay , Shambayati Shervin , Modiano Eytan
Published: February 2007

On‐going development of Ka‐band capability for the Deep Space Networks (DSN) will radically increase the bandwidth available to support advanced mission concepts envisioned for future robotic as well as human exploration of Mars and beyond. While Ka‐band links can operate at much higher data rate than X‐band, they are much more susceptible to fluctuating weather conditions and manifest a significant trade‐off between throughput and availability. If the operating point is fixed, the maximum average throughput for deep space Ka‐band link is achieved at about 80% availability, i.e. weather‐related outages will occur about 20% of the time. Low availability increases the complexity of space mission operation, while higher availability would require additional link margins that lowers the overall throughput. To improve this fundamental throughput‐availability trade‐off, data rate adaptation based on real‐time observation of the channel condition is necessary.

In this paper, we model the Ka‐band channel using a Markov process to capture the impact of the temporal correlation in weather conditions. We then develop a rate adaptation algorithm to optimize the data rate based on real time feedback on the measured channel conditions. Our algorithm achieves both higher throughput and link availability as compared to the constant rate scheme presently in use. Copyright © 2007 John Wiley & Sons, Ltd.
Network layer performance of a satellite network with dynamic link‐layer resource allocation
Authors: Pandya Julee , Narula‐Tam Aradhana , Yao Huan , Wysocarski Jeff
Published: February 2007

Future packet switched military satellite communication networks are being designed with dynamic resource allocation on the up‐ and down‐links in order to efficiently utilize the limited Radio Frequency (RF) resources. The resource allocation algorithms must be designed to achieve good system efficiency and user performance in addition to optimizing link‐layer efficiency. An OPNET simulation environment is used to model and evaluate system performance for a satellite network with dynamically provisioned up‐ and down‐links under dynamic traffic and channel variations. Link‐layer resource allocation algorithms are developed and performance is evaluated in terms of application layer throughput, loss, delay, and jitter as well as system resource utilization. Copyright © 2007 John Wiley & Sons, Ltd.
RCP‐Planet: a rate control protocol for InterPlaNetary Internet
Authors: Fang Jian , Akyildiz Ian F.
Published: February 2007

UDP traffic is a part of the aggregate traffic over InterPlaNetary Internet backbone links, which includes planet images and multimedia data from some scientific observations. Existing rate control schemes cannot solve the rate control problem in InterPlaNetary Internet which is characterized byextremely long propagation delays,high link errors,asymmetrical bandwidth, andblackouts. In this paper, a rate control protocol, RCP‐Planet, is proposed to address all the above challenges. RCP‐Planet consists of two novel algorithms, i.e.Begin StateandOperational State. The protocol is based on a novel rate probing mechanism, i.e. sending probing sequences to capture the available bandwidth. A new rate control scheme is designed to update the transmission rate based on the observed rate for the probing sequence. Tornado codes are used for packet‐level FEC because of their fast encoding and decoding speed. Bandwidth asymmetry problem is addressed by FEC block‐level ACKs. Moreover, RCP‐Planet incorporates Blackout State into the protocol to improve performance in blackout conditions. Simulation results show that RCP‐Planet achieves high throughput performance, fairness, and is delay tolerant. Copyright © 2007 John Wiley & Sons, Ltd.
Water‐Soluble Germanium(0) Nanocrystals: Cell Recognition and Near‐Infrared Photothermal Conversion Properties
Authors: Lambert Timothy N. , Andrews Nicholas L. , Gerung Henry , Boyle Timothy J. , Oliver Janet M. , Wilson Bridget S. , Han Sang M.
Published: February 2007

Surfactant‐passivated germanium nanocrystals (Ge(0) NCs) 3–5 nm in diameter were synthesized and encapsulated with functionalized phospholipids to yield water‐soluble Ge(0) NCs. Upon encapsulation, the NCs retained their cubic crystalline phase and displayed good resistance to oxidation, as determined by transmission electron microscopy and X‐ray photoelectron spectroscopy. As a test of their cell compatibility, the ability of carboxyfluorescein (CF)‐labeled dinitrophenyl (DNP)‐functionalized Ge(0) NCs to crosslink dinitrophenol‐specific immunoglobulin E antibodies on the surface of mast cells (RBL‐2H3) was examined in vitro. Treatment with a multivalent DNP antigen (i.e., DNP‐Ge(0) NCs or CF‐DNP‐Ge(0) NCs) caused crosslinking of FcεRI receptors and cellular responses, which were evaluated with morphological and colorimetric assays and live‐cell fluorescence microscopy. Incubation of RBL‐2H3 cells with Ge(0) NCs for ≈24 h gave less than a 2 % increase in cell death as compared to DNP‐functionalized bovine serum albumin. When irradiated with near‐infrared (NIR) radiation (λexc=770 nm, 1.1 W cm−2) from a continuous‐wave Ti:sapphire laser, the bulk‐solution temperature of a toluene solution containing 20 mg mL−1 Ge(0) NCs increased by ≈35 °C within 5 min. Phospholipid‐encapsulated water‐soluble Ge(0) NCs at concentrations of 1.0 mg mL−1 also displayed stable photothermal behavior under repetitive and prolonged NIR laser exposures in water, to yield a temperature increase of ≈20 °C within 5 min (λexc=770 nm, 0.9 W cm−2). The photothermal efficiency of water‐soluble Ge(0) NCs compares favorably with a recent report for Au nanoshells.
Critically identifying stakeholders
Authors: Achterkamp Marjolein C. , Vos Janita F. J.
Published: February 2007

Although (the relevance of) stakeholder management receives considerable attention in literature, the problem of actual stakeholder identification is yet unresolved. This article analyses the potential contributions of critical systems thinking to solving this problem. Especially Ulrich's notion of boundary critique, by which he focuses on stakeholder roles and particularly the role of ‘the affected’, seems a fruitful contribution. By adapting the role definitions towards a project context, including project dynamics, and adding operating instructions, a method has been developed that can be used for actual stakeholder identification in organizational projects. This method is demonstrated on two projects. The results show that this adapted version of boundary critique, which in its original form mainly is used in the context of civil society, is also relevant in an organizational profit‐based context. Copyright © 2007 John Wiley & Sons, Ltd.
A critical systems perspective on the design of organizational space
Authors: Mobach Mark P.
Published: February 2007

This paper is the first to introduce critical systems thinking into a new emerging research strand: the design of organizational space. The study revealed two things. First, critical systems thinking provides a thorough framework to understand the possibilities to connect organization and building; both in a conceptual understanding of the mutual relations and with regard to the practical implications that such connections have. Second, an application of critical systems thinking in an immersive virtual environment resulted in an inspiring debate around all sorts of facts and values of the current and expected future states of organizational space. It raised the awareness about a true interdisciplinary design in organization and architecture and allowed significant improvements to be made. This paper may be also regarded as an introduction to an application of critical systems thinking in other design processes where human and technical systems designs are interwoven. Copyright © 2007 John Wiley & Sons, Ltd.
Knowledge About Genetics Among African Americans
Authors: Kessler Lisa , Collier Aliya , Halbert Chanita Hughes
Published: February 2007

Although knowledge about genetic concepts is important for individuals to be active participants in medical technologies that use genetic science, limited information is available on knowledge about basic genetic concepts and terminology in African Americans. The purpose of this study was to evaluate knowledge about general genetic concepts and medical genetics terminology among African Americans and to identify factors having independent associations with knowledge. Participants were 109 adult African Americans enrolled in a study on attitudes about race, genetics, and smoking. The majority of respondents were knowledgeable about general genetic concepts, but were less knowledgeable about medical genetics terminology. Education was the only factor independently associated with knowledge about sporadic disorders in multivariate logistic regression analysis. Respondents with at least some college education were most likely to be knowledgeable about sporadic disorders (OR=2.70, 95% CI=1.10, 6.67, p=.03). The results of this study suggest that genetics education targeted to African Americans may need to focus on increasing understanding about technical concepts related to genetics.
Effect of phylloquinone supplementation on biochemical markers of vitamin K status and bone turnover in postmenopausal women
Authors: Bügel Susanne , Sørensen A. Dorthe , Hels Ole , Kristensen Mette , Vermeer Cees , Jakobsen Jette , Flynn Albert , Mølgaard Christian , Cashman Kevin D.
Published: February 2007

While current intakes of phylloquinone (vitamin K1) in many populations are believed to be sufficient to maintain normal blood coagulation, these may be insufficient to cover the requirements for optimal bone metabolism. Therefore, the objective of the present study was to investigate the effect of increasing phylloquinone intakes above the usual dietary intake for 6 weeks on biochemical markers of vitamin K status and bone turnover in postmenopausal women. Thirty-one postmenopausal women completed this 3 × 6-week randomised cross-over study, in which volunteers were supplemented with 0 (placebo), 200, and 500 μg phylloquinone/d. In addition, the volunteers were given 10 μg vitamin D3/d throughout the study period. With increasing phylloquinone intake, the concentration of serum γ-carboxylated and under-γ-carboxylated osteocalcin was significantly increased and decreased, respectively, in a dose-dependent manner (P < 0·001). Mean serum phylloquinone concentration was significantly (P < 0·001) higher with daily supplementation with 500 μg phylloquinone/d compared with that during either of the placebo or 200 μg phylloquinone/d supplementation periods, which did not differ (P = 0·15). Serum total osteocalcin was significantly (P < 0·001) increased in response to daily supplementation with 500 (but not 200) μg phylloquinone compared with placebo. Serum bone-specific alkaline phosphatase as well as the urinary markers of bone resorption (N-telopeptide cross-links of collagen, pyridinoline and deoxypyridinoline) and urinary γ-carboxyglutamate were unaffected by phylloquinone supplementation. In conclusion, while daily supplementation with 200 and 500 μg phylloquinone/d for 6 weeks increased vitamin K status in postmenopausal women, it had no effect on bone turnover.
Vitamin A deficiency modifies lipid metabolism in rat liver
Authors: Oliveros Liliana B. , Domeniconi María A. , Vega Verónica A. , Gatica Laura V. , Brigada Ana M. , Gimenez María S.
Published: February 2007

Liver fatty acid metabolism of male rats fed on a vitamin A-deficient diet for 3 months from 21 d of age was evaluated. Vitamin A restriction produced subclinical plasma and negligible liver retinol concentrations, compared with the control group receiving the same diet with 4000 IU vitamin A (8 mg retinol as retinyl palmitate)/kg diet. Vitamin A deficiency induced a hypolipidaemic effect by decreasing serum triacylglycerol, cholesterol and HDL-cholesterol levels. The decrease of liver total phospholipid was associated with low phosphatidylcholine synthesis observed by lower [14C]choline incorporation into phosphatidylcholine, compared with control. Also, liver fatty acid synthesis decreased, as was indicated by activity and mRNA expression of acetyl-CoA carboxylase (ACC), and incorporation of [14C]acetate into saponified lipids. A decrease of the PPARα mRNA expression was observed. Liver mitochondria of vitamin A-deficient rats showed a lower total phospholipid concentration coinciding with a decrease of the cardiolipin proportion, without changes in the other phospholipid fractions determined. The mitochondria fatty acid oxidation increased by 30 % of the control value and it was attributed to a high activity and mRNA expression of carnitine palmitoyltransferase-I (CPT-I). An increase in serum β-hydroxybutyrate levels was observed in vitamin A-deficient rats. Vitamin A deficiency alters the mitochondria lipid composition and also enhances fatty acid oxidation by modifiying the production of malonyl-CoA, the endogenous inhibitor of CPT-I, due to decreased activity of liver ACC. The incorporation of vitamin A into the diet of vitamin A-deficient rats reverted all the changes observed.
Daily intake of conjugated linoleic acid-enriched yoghurts: effects on energy metabolism and adipose tissue gene expression in healthy subjects
Authors: Nazare Julie-Anne , Perrière Aude Brac de la , Bonnet Fabrice , Desage Michel , Peyrat Jocelyne , Maitrepierre Christine , Louche-Pelissier Corinne , Bruzeau Joëlle , Goudable Joëlle , Lassel Taous , Vidal Hubert , Laville Martine
Published: February 2007

Conjugated linoleic acid (CLA) is a group of positional and geometric isomers of conjugated dienoic derivatives of linoleic acid. The present study was designed to determine whether 14-week CLA supplementation as triacylglycerols (3·76 g) with a 50 : 50 combination of the two main isomers (35 %cis-9,trans-11 and 35 %trans-10,cis-12) added to flavoured yoghurt-like products was able to alter body composition in healthy subjects and to alter the expression of several key adipose tissue genes (PPAR γ, lipoprotein lipase (LPL), hormone-sensitive lipase (HSL) and uncoupling protein 2 (UCP-2)). Forty-four healthy subjects were randomly assigned to consume daily either a CLA-supplemented yoghurt-like product or a placebo yoghurt for 98 d. There were no significant effects of CLA supplementation on body weight, fat mass or free fat mass. Basal energy expenditure expressed as kg free fat mass increased significantly in the CLA group (123·3 (sem2·5) kJ/kg free fat mass per d on day 98v.118·7 (sem2·3) kJ/kg free fat mass per d on day 0,P = 0·03). PPAR γ mRNA gene expression increased significantly with CLA supplementation (53 (sem20) %,P < 0·01) and a significant reduction in mRNA levels of HSL was observed ( − 42 (sem7) %,P = 0·01). The levels of UCP-2 and LPL mRNA were not affected. The present results suggest that a 98 d supplementation diet with a 50 : 50 mixture of the two CLA isomerscis-9,trans-11 andtrans-10,cis-12 in a dairy product was unable to alter body composition, although a significant increase in the RMR has been induced. Moreover, changes in mRNA PPAR γ and HSL in adipose tissue were recorded.
The effect of marine oil-derivedn-3 fatty acids on transepithelial calcium transport in Caco-2 cell models of healthy and inflamed intestines
Authors: Gilman Jennifer , Cashman Kevin D.
Published: February 2007

Marine oil-derivedn-3 fatty acids have been shown to stimulate intestinal Ca absorption in animal studies, but the effects of such fatty acids on Ca absorption in human subjects are relatively unknown. In particular,n-3 fatty acids may be of therapeutic value for some Crohn's disease patients who experience Ca malabsorption. Therefore, the aim of the present study was to investigate the effect of 20 : 5n-3 and 22 : 6n-3 on transepithelial Ca transport across monolayers of healthy Caco-2 cells as well as of TNF-α-treated Caco-2 cells (anin vitromodel of Crohn's disease). Caco-2 cells were seeded onto permeable filter supports and allowed to differentiate into monolayers, which were treated with 80 μm-20 : 5n-3, 80 μm-22 : 6n-3, or 40 μm-20 : 5n-3+40 μm-22 : 6n-3 for 6 or 8 d, with or without co-treatment with TNF-α (10 ng/ml) (n11–15 monolayers per treatment). On day 16, transepithelial and transcellular transport of45Ca and fluorescein transport (a marker of paracellular diffusion) were measured. Treatment of healthy and inflamed Caco-2 cells with 20 : 5n-3, 22 : 6n-3 and both fatty acids combined for 8 d significantly (P < 0·005–0·01) increased total transepithelial Ca transport compared with that in control, effects which were mediated by an enhanced rate of transcellular Ca transport. The effects ofn-3 fatty acids on Ca absorption after 6 d were less clear-cut. In conclusion, the presentin vitrofindings highlight the need to investigate the effect of marine oil-basedn-3 fatty acids on Ca absorptionin vivoin studies of healthy human subjects as well as of Crohn's disease patients.
Eicosapentaenoic acid actions on adiposity and insulin resistance in control and high-fat-fed rats: role of apoptosis, adiponectin and tumour necrosis factor-α
Authors: Pérez-Matute Patricia , Pérez-Echarri Nerea , Martínez J. Alfredo , Marti Amelia , Moreno-Aliaga María J.
Published: February 2007

n-3 PUFA have shown potential anti-obesity and insulin-sensitising properties. However, the mechanisms involved are not clearly established. The aim of the present study was to assess the effects of EPA administration, one of then-3 PUFA, on body-weight gain and adiposity in rats fed on a standard or a high-fat (cafeteria) diet. The actions on white adipose tissue lipolysis, apoptosis and on several genes related to obesity and insulin resistance were also studied. Control and cafeteria-induced overweight male Wistar rats were assigned into two subgroups, one of them daily received EPA ethyl ester (1 g/kg) for 5 weeks by oral administration. The high-fat diet induced a very significant increase in both body weight and fat mass. Rats fed with the cafeteria diet and orally treated with EPA showed a marginally lower body-weight gain (P = 0·09), a decrease in food intake (P < 0·01) and an increase in leptin production (P < 0·05). EPA administration reduced retroperitoneal adipose tissue weight (P < 0·05) which could be secondary to the inhibition of the adipogenic transcription factor PPARγ gene expression (P < 0·001), and also to the increase in apoptosis (P < 0·05) found in rats fed with a control diet. TNFα gene expression was significantly increased (P < 0·05) by the cafeteria diet, while EPA treatment was able to prevent (P < 0·01) the rise in this inflammatory cytokine. Adiposity-corrected adiponectin plasma levels were increased by EPA. These actions on both TNFα and adiponectin could explain the beneficial effects of EPA on insulin resistance induced by the cafeteria diet.
Growth and body composition in children with chronic kidney disease
Authors: Rashid R. , Neill E. , Maxwell H. , Ahmed S. F.
Published: February 2007

Growth failure is a common yet complex problem of childhood chronic kidney disease caused by multiple factors encountered due to the primary disease or secondary to the renal impairment. This review seeks to describe the various patho-physiological mechanisms contributing to growth failure in the various stages of childhood with particular emphasis on nutritional problems and endocrine dysfunction encountered whilst managing these children. In addition, we shall examine the role of body composition in chronic kidney disease, their relationship with growth and nutrition and the potential effect of abnormalities in fat mass and lean mass on long-term morbidity and mortality.
Supplementation with vitamin A reduces watery diarrhoea and respiratory infections in Mexican children
Authors: Long Kurt Z. , Rosado Jorge L. , DuPont Herbert L. , Hertzmark Ellen , Santos Jose Ignacio
Published: February 2007

Previous clinical vitamin A trials have found no consistent effect on diarrhoeal disease and respiratory tract infection. These inconsistent results may be due to the distinct effects vitamin A supplementation has among children stratified by factors related to socio-economic status, nutritional status and season. We evaluated the effect of supplementation on the overall incidence of diarrhoeal disease and respiratory tract infections and on the incidence among children stratified by these factors. A total of 188 children, aged 6–15 months, from periurban, marginalized communities of Mexico City were assigned to receive vitamin A ( < 12 months of age, 20 000 IU retinol; ≥ 12 months, 45 000 IU retinol) or a placebo every 2 months, and were followed for up to 15 months. Project personnel visited households twice a week to determine the onset and duration of diarrhoeal disease and respiratory tract infections. Vitamin A supplementation had no significant effect on risk of overall diarrhoeal disease but reduced mild watery diarrhoea (incidence rate ratio (RR) 0·69; 95 % CI 0·50, 0·93) and cough with fever (RR 0·69; 95 % CI 0·48, 0·98). Vitamin A supplementation decreased diarrhoeal disease during the summer (RR 0·74; 95 % CI 0·57, 0·94), among non-stunted children (RR 0·69; 95 % CI 0·52, 0·93) and among children from households with better socio-economic measures. Heterogeneity in the response to vitamin A supplementation may reflect heterogeneity in the aetiology and epidemiology of diarrhoeal disease and respiratory tract infections and the impact that supplementation has on the immune response.
Comparison of the absorption efficiency of α- and β-cryptoxanthin in female Wistar rats
Authors: Breithaupt Dietmar E. , Yahia Elhadi M. , Velázquez Francisco J. Valdés
Published: February 2007

Xanthophylls, such as lutein and zeaxanthin, have received increasing interest in recent years because of positive correlations between their consumption and the prevention of eye diseases. Numerous human intervention studies have been conducted with lutein to estimate the bioavailability from different formulations. The present study was designed to obtain basic data on the absorbance efficiency of the monohydroxylated counterparts of lutein and zeaxanthin: α- and β-cryptoxanthin. A corn-oil-based diet comprising ß-cryptoxanthin from papaya purée and α-cryptoxanthin from green carrot leaves was fed to five female Wistar rats for 8 consecutive days at a rate of 17·3 nmol/d and 9·2 nmol/d, respectively. The identity of the xanthophylls in the supplement was ascertained by LC-(APCI)MS analyses, and xanthophylls present in liver and plasma samples were determined by HPLC/diode array detector (DAD). The β-cryptoxanthin concentrations of rat livers in the treatment group were statistically distinguishable (P < 0·01) from those present in the livers of the control group that were fed a basic diet. α-Cryptoxanthin, the second xanthophyll present in the supplement, was not found in rat livers in the treatment group. Plasma samples were free of xanthophylls. This is the first report proving that β-cryptoxanthin has a higher absorption efficiency than α-cryptoxanthin in rats, at least from a minimally processed oil-based xanthophyll supplement.
Conjugated linoleic acid in diets for large-size rainbow trout (Oncorhynchus mykiss): effects on growth, chemical composition and sensory attributes
Authors: Valente L. M. P. , Bandarra N. M. , Figueiredo-Silva A. C. , Rema P. , Vaz-Pires P. , Martins S. , Prates J. A. M. , Nunes M. L.
Published: February 2007

The effects of graded levels (0 %, 0·5 %, 0·75 and 1 %) of dietary conjugated linoleic acid (CLA) were assessed on 97 g rainbow trout. Fish were fed to satiation twice a day for 12 weeks. At the end of the experiment, all groups of fish weighed more than 250 g and no significant differences were detected in growth performance, feed conversion, nutrient or energy utilisation or body composition between treatments. A decrease in liver lipid content resulted from including CLA and was accompanied by a reduction in malic enzyme activity. The muscle saturated acid and PUFA content did not vary between dietary treatments, despite the increasing concentration of stearic acid and CLA. In the liver, however, both fractions increased significantly with dietary CLA. Moreover, the MUFA decreased significantly in both muscle and liver. CLA was incorporated into tissue lipids, with levels in flesh (2·1–4·2 %) being 2-fold higher than in liver (0·8–1·9 %). In muscle, the percentage of cis-9, trans-11 isomer ranged from 39·5 % to 41·8 % and that of trans-10, cis-12 isomer from 31·4 % to 33·4 % of total CLA. The incorporation of CLA isomers in the liver varied with dietary treatment, and the cis-9, trans-11 isomer seemed to be more efficiently incorporated than trans-10, cis-12. Sensory data indicated slight-to-moderate differences between the trout fed with and without CLA. The present results suggest that 250 g rainbow trout can incorporate CLA in both muscle and liver, contributing to the production of a functional food.
Inbreeding depression in two seed-feeding beetles, Callosobruchus maculatus and Stator limbatus (Coleoptera: Chrysomelidae)
Authors: Fox C.W. , Scheibly K.L. , Smith B.P. , Wallin W.G.
Published: February 2007

Inbreeding depression is well documented in insects but the degree to which inbreeding depression varies among populations within species, and among traits within populations, is poorly studied in insects other than Drosophila. Inbreeding depression was examined in two long-term laboratory colonies of the seed beetle, Callosobruchus maculatus (Fabricius), which are used frequently as models for experiments in ecology, evolution and behaviour. Inbreeding depression in these laboratory colonies are compared with one recently field-collected population of a different seed beetle, Stator limbatus Horn. Inbreeding reduced embryogenesis, egg hatch and larval survival in both species, such that eggs produced by sib matings were >17% less likely to produce an adult offspring. Inbred larvae also took 4–6% longer to develop to emergence in both species. Inbreeding depression varied among the measured traits but did not differ between the two populations of C. maculatus for any trait, despite the large geographic distance between source populations (western Africa vs. southern India). Inbreeding depression was similar in magnitude between C. maculatus and S. limbatus. This study demonstrates that these laboratory populations of C. maculatus harbour substantial genetic loads, similar to the genetic load of populations of S. limbatus recently collected from the field.
Feeding and foraging behaviour of a generalist caterpillar: are third instars just bigger versions of firsts?
Authors: Johnson M.-L. , Zalucki M.P.
Published: February 2007

Similarities and differences in foraging behaviour between first and third instar Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) on Vigna radiata (L.) R. Wilczek (Fabaceae) (mung bean) were determined by frequent, repeated observation of insects on whole plants. The time apportioned to feeding, resting and searching by these two larval instars differed. Third instars were often found feeding on exposed areas of the plant and, if in the terminal parts, would leave these areas more frequently than first instars. Third instars fed at fewer sites and spent less time searching and resting, fed in longer bouts and spent 20% more time feeding than first instars. Although both instars tended to move upwards to the top of the plant, this applied to approximately half of the third instars observed compared to all of the first instars. First instars were found to have a higher relative growth rate than third instars. The results show that it cannot be assumed that first instars are just smaller versions of late instars.
Evo Morales, the ‘Two Bolivias’ and the Third Bolivian Revolution
Authors: DUNKERLEY JAMES
Published: February 2007

This essay, written in September 2006, considers the first months of the MAS government headed by Evo Morales in the light of the virtually constant political crisis in Bolivia since 2000. The first part asks why the turbulent course of public life in Bolivia has proved so difficult to explain. It seeks to show that the recent period has been depicted in rather narrow interpretations that stress institutional failings, poverty and oppression, or civic heroism, but do not try to find the linkages between these phenomena. The second section proposes an alternative approach, treating the recent experience of conflict as a revolutionary episode in which the idea of ‘Two Bolivias’ needs to be qualified by appreciation of past revolutionary experiences. The final sections suggest that the ardour and complexities of the current conflict might seem more comprehensible if the MAS and its supporters are viewed as essentially plebeian in both condition and ideological disposition. Such a classical and early modern allusion provides a fuller analytical palate for understanding the current conjuncture and the socio-political propositions being made in a ‘semi-modern’ environment.
Kinematic and dynamic model-based control of wheeled mobile manipulators: a unified framework for reactive approaches
Authors: Padois V. , Fourquet J.-Y. , Chiron P.
Published: February 2007

The work presented in this paper aims at providing a unified modelling framework for the reactive control of wheeled mobile manipulators (WMM). Where most work in the literature often provides models, sometimes simplified, of a given type of WMM, an extensive description of obtaining explicit kinematic and dynamic models of those systems is given. This modelling framework is particularly well suited for reactive control approaches, which, in the case of mobile manipulation missions, are often necessary to handle the complexity of the tasks to be fulfilled, the dynamic aspect of the extended workspace and the uncertainties on the knowledge of the environment. A flexible reactive framework is thus also provided, allowing the sequencing of operational tasks (in our case, tasks described in the end-effector frame) whose natures are different but also an on-line switching mechanism between constraints that are to be satisfied using the system redundancy. This framework has been successfully implemented in simulation and on a real robot. Some of the obtained results are presented.
Long-term trends in food habits of a relict brown bear population in northern Spain: the influence of climate and local factors
Authors: RODRÍGUEZ C. , NAVES J. , FERNÁNDEZ-GIL A. , OBESO J.R. , DELIBES M.
Published: February 2007

Relict endangered populations may be especially vulnerable to the effects of climate change. A data series for the period 1974–2003 was used to examine shifts in brown bear Ursus arctos food habits in its south-westernmost European population. This focused on the hyperphagic season, when bears gain the fat that is essential for winter dormancy and reproduction. General climatic indicators were predictors of diet trends. Other variables potentially able to modify brown bear food habits at the local scale were accounted for by considering two areas where local conditions changed in different ways during the study period. General climatic indicators such as temperature and the winter North Atlantic Oscillation index were good predictors of some diet trends, although local factors seemed to modulate the potential response of food habits to recent climate change. Boreal and temperate food items decreasingly contributed to brown bear diet, replaced by increasing contributions of southern foods, which suggested that warmer temperatures might determine the occurrence of some food items in the diet of Cantabrian brown bears through effects on plant distribution and phenology. At the local scale, high cattle density in one of the study areas limited food sources available for brown bears. Important food sources for brown bears, such as heath-like Vaccinium formations and old-growth oak forest in the Cantabrian Mountains, require increased levels of protection.
The consistency of UK pension fund trustee decision-making
Authors: CLARK GORDON L. , CAERLEWY-SMITH EMIKO , MARSHALL JOHN C.
Published: February 2007

An important research programme in the social sciences concerns the theory and practice of individual decision-making under conditions of risk and uncertainty. At the same time, it is apparent that western governments increasingly rely upon individuals to plan and maintain savings programmes to meet their income aspirations: the long-term retirement income of those outside of the welfare state depends a great deal on the competence and consistency of individual decision-making. In this paper, we use a set of problems requiring the same techniques of judgement to test the consistency of trustee decision-making. Respondents were a group of trustees drawn from select UK defined benefit pension plans compared with a larger group of Oxford undergraduates. It was found that many respondents were inconsistent across related problems requiring the application of probabilistic judgement. It is also shown that trustees were more consistent than many undergraduates and it appears that trustee education and professional qualifications can make a positive difference to consistent decision-making. A more challenging test that depends upon understanding the relationship between demographic ageing, immigration, and the financing of pay-as-you-go social security suggests that substantive knowledge and consistency of judgement are crucial components of expertise. Implications are drawn for the trustee institution and the wider debate over the role and significance of individual decision-making with respect to income aspirations.
Junger Mann mit gürtelförmigen Abdominal-Schmerzen von kolikartigem Charakter
Authors: Hashagen  , Niemann  , Degen  , Ott
Published: February 2007

Wir berichten über einen Patienten mittleren Alters mit gürtelförmigen Oberbauchschmerzen, bei welchem nebst einer chronischen zusätzlich eine subakute Thrombose der kavernös transformierten und stark verkalkten Portalvene duplexsonographisch und computertomographisch nachgewiesen wurde. Eine Vollliqueminisierung und anschliessende Marcoumarisierung führte zur Besserung der Symptomatik.
Turbulent transfer mechanism in sediment‐laden flow
Authors: Yang Shu‐Qing
Published: February 2007

Characteristics of turbulent flows in rivers can be significantly modified because of the presence of sediment particles and secondary currents/nonuniformity. This paper investigates why the measured vertical distributions of velocity deviate from the log law. In contrast to previous research that attributed the deviation to Richardson number only, this study demonstrates that like Reynolds shear stress (−), momentum flux (uv) caused by the nonzero wall‐normal velocity v is also responsible for these deviations. Starting from Reynolds equations, this paper shows that the classical log law can be obtained only when v = 0; otherwise the velocity v results in the deviation. On the basis of experimental data available in the literature, this study shows that in an open channel, v is nonzero because of the coexistence of secondary currents and sediment and, subsequently, the Reynolds shear stress and streamwise velocity are affected. Equations for these interactions are obtained and solved numerically. The validity of the proposed model has been verified using experimental data, and good agreement between the predicted and observed profiles has been achieved.
Explicit tidal forcing in an ocean general circulation model
Authors: Schiller A. , Fiedler R.
Published: February 2007

The eight dominant constituents of the semi‐diurnal and diurnal tides plus accurate phase information have been implemented in a global version of the Modular Ocean Model (version 4), developed by the Geophysical Fluid Dynamics Laboratory. The simulated tidal signal in the Southeast Asian region has been validated with observations, indicating that the amplitudes and phases are reasonably well reproduced by the model. Tidal currents play an essential role in transport and mixing processes in the Indonesian Seas and off the Australian Northwest Shelf. Vertical tidal mixing introduces a distinct signal in the surface mixed‐layer and upper ocean temperature. The results suggest that application of explicit tidal forcing in operational Ocean General Circulation Models (OGCMs) should become feasible in the near‐term future.
A modified method for detecting incipient bifurcations in a dynamical system
Authors: Livina V. N. , Lenton T. M.
Published: February 2007

We assess the proximity of a system to a bifurcation point using a degenerate fingerprinting method that estimates the declining decay rate of fluctuations in a time series as an indicator of approaching a critical state. The method is modified by employing Detrended Fluctuation Analysis (DFA) which improves the estimation of short‐term decay, especially in climate records which generally possess power‐law correlations. When the modified method is applied to GENIE‐1 model output that simulates collapse of the Atlantic thermohaline circulation, the bifurcation point is correctly anticipated. In Greenland ice core paleotemperature data, for which the conventional degenerate fingerprinting is not applicable due to the short length of the series, the modified method detects the transition from glacial to interglacial conditions. The technique could in principle be used to anticipate future bifurcations in the climate system, but this will require high‐resolution time series of the relevant data.