bluuebunny/crossref_metadata_2025 huggingface dataset:
DATA ANALYTICAL METHODOLOGIES IN THE DEVELOPMENT OF A VOCABULARY FOR EVALUATION OF MEAT QUALITY
Authors: O'SULLIVAN M.G. , BYRNE D.V. , MARTENS H. , MARTENS M.
Published: May 2007

Pork patties from M. longissimus dorsi and M. psoas major were used by a sensory panel to develop a descriptive vocabulary to describe warmed‐over flavor development. The patties were made from meat from animals supplemented with one of four dietary treatments, (I) control diet, (II) supplemental iron (7 g iron (II) sulfate/kg feed), (III) supplemental vitamin E (200 mg dl‐α‐tocopherol acetate/kg of feed) and (IV) supplemental vitamin E + supplemental iron. The sample set used for training reflected the variation in muscle type and degree of warmed‐over flavor development (day 1 and 5). The sensory terms selected had to be relevant to the samples, discriminate between the samples, have cognitive clarity and be nonredundant. Based on these selection criteria an initial training list of 36 sensory terms consisting of odors, flavors, basic tastes and aftertastes was developed in a pretrial using experts with product knowledge. This list constituted the start of training the panel. Principle Component Analysis (PCA) and assessor suggestions were used for reducing the number of terms and after 5 days of training this list was reduced to 21 sensory terms. The discriminative ability of the sensory panel improved over the course of sensory training and was quantified by using the mean assessor signal to noise ratios (S/N) for the sensory terms for each training session. This signal to noise ratio is essentially the total initial variance divided by the residual cross‐validated variance. Subsequent detailed multivariate analysis found that the bilinear descriptor leverage was a particularly efficient method for term reduction.
THE EFFECT OF SOME BEVERAGES ON THE PERCEPTION OF SUCCEEDING BASIC TASTES
Authors: AHN NINA , FRØST MICHAEL BOM , FRANDSEN LISE WOLF , DIJKSTERHUIS GARMT , MARTENS MAGNI
Published: May 2007

The objective of this study was to investigate the effect beverages have on subsequently perceived basic tastes. Two types of milk, Cola and water were used to rinse the mouth prior to conducting a Time Intensity study with basic taste solutions. From this some effects of the prior beverage onto the TI parameters was found. Especially Cola showed an effect on the intensity of the subsequently tasted sweet taste, and whole milk showed a stronger effect than skim milk. The effects showed both in size and timing of the basic taste intensities.
USE OF SENSORY EVALUATION FOR MEASURING DEODORIZING EFFECTS OF AN AIR CONDITIONER
Authors: KIM SANG SOOK , RHYU MIE RA , LEE SUNG HWA
Published: May 2007

The application of sensory methodology for measuring deodorizing effect of an air conditioner equipped with electric plasma was introduced. Deodorizing effect was measured using chemical and sensory methods at different time (0, 30 and 60 min) and mode (control, blowing and cooling) of an air conditioner. Smoke from a roll of cigarette in a closed room was used as a source of odor and the concentrations of acetic acid and ammonia were measured as odorous chemical components. As one of the sensory methods triangle test was used and as a first step to obtain deodorizing effects by triangle test, the threshold of each panelist was obtained as the log dilution ratio of odor concentration at which the difference from odorless air was detected. The odor concentration at each time and mode was calculated using the threshold of the panel and the deodorizing effect was obtained on the basis of the odor concentration. In addition to a triangle test, scaling methods such as category scaling or magnitude estimation were used to measure deodorizing effect of an air conditioner. Deodorizing effects by scaling methods were calculated based on odor intensity with time at each mode. The regression analysis was done between the efficacy of deodorizing effect by sensory test and those by acetic acid and ammonia, the R2 values of the regression equations for triangle test, category scale, and magnitude estimation were 0.84, 0.72 and 0.69, respectively. Deodorizing effect by triangle test explained the decrease of acetic acid and ammonia better than those by category scaling or magnitude estimation while high cost and time consuming labor involved in triangle tests reduced the merit. The results of this study demonstrated that various sensory methods could be used to measure deodorizing effect of air conditioners and further researches on fast and reliable methods are needed to establish the official procedures.
AGREEMENT AND RELIABILITY ASSESSMENTS FOR PERFORMANCE OF SENSORY DESCRIPTIVE PANEL
Authors: BI JIAN
Published: May 2007

In the present paper, two indices, agreement coefficient and reliability coefficient, are introduced and proposed to measure quality of ratings data given by a sensory descriptive panel. Agreement coefficient describes variation of ratings for a single target (product), whereas reliability coefficient reflects discrimination ability of a descriptive panel for a sample of products. The two indices, which profoundly describe inherent characteristics of ratings data, are based on classical reliability theory and recent advances in psychological measurement. In the paper, estimates and tests for the two indices are provided. Confidence intervals for the indices are derived. A space with the two indices as dimensions, which is referred as rating quality space, gives visual presentation of performances of a descriptive panel or individual panelists. Numerical examples illustrate the use and interpretation of the indices.
USING ANDERSON'S STATISTIC TO COMPARE DISTRIBUTIONS OF CONSUMER PREFERENCE RANKINGS
Authors: BROCKHOFF P.B. , BEST D.J. , RAYNER J.C.W.
Published: May 2007

Anderson's statistic, which compares distributions of ranks, is generalized to cope with tied rankings. A simple example is given to illustrate the calculations involved. In market research work it is often important to compare distributions as well as mean values. Comparison of distributions can indicate either market segmentation or product variability.
MONITORING TASTE PANEL EFFICIENCY DURING EVALUATION OF THE SENSORY QUALITY OF RONCAL CHEESE
Authors: MENDÍA C. , LARRÁYOZ P. , ORDÓÑEZ A.I. , IBÁÑEZ F.C. , TORRE P.
Published: May 2007

A statistical study was performed on the scores awarded by a taste panel over a full Roncal cheese manufacturing season. The panel evaluations were part of a quality control program carried out on that cheese under the auspices of the Appellation of Origin for Roncal cheese by panelists previously trained and qualified as proficient. Analysis of variance and factor analysis were performed to examine variability for the different attributes and the influence of such factors as cheesemaking plant and the manufacturing season and also to monitor panel reliability. The results indicated that the attributes associated with the descriptor “characteristic” had the highest variability; these attributes were characteristic odor, characteristic aroma, characteristic texture, characteristic flavor, and characteristic aftertaste. Cheesemaking plant was the factor that had the greatest effect on variability. Factor analysis and exploratory box plot data analysis were used to detect discrepancies between individual assessors and the rest of the panelists.
EFFECT OF HEALTH CONCERN AND CONSUMPTION PATTERNS ON MEASURES OF SWEETNESS BY HEDONIC AND JUST‐ABOUT‐RIGHT SCALES
Authors: BOWER JOHN A. , BOYD RACHEL
Published: May 2007

An established disparity between hedonic scales and just‐about‐right (JAR) measures, important for product development procedures, was examined for sweetness in lemonade by consumer groups divided on the basis of health concern level and consumption patterns related to sweet foods, regular and diet drinks and ‘healthy eating’. The disparity was demonstrated by all subgroups in that the JAR scale identified a lower sucrose concentration as nearest ‘just right’compared to that identified as ‘most liked’by the hedonic scale. Regression analysis predicted lower optimum sweetness for the JAR than the hedonic scale. For subjects who completed both tests the disparity was significantly different from zero. Trends of differences in response on both scales and for the disparity according to health concern and consumption patterns were demonstrated graphically. Few of these effects were statistically significant, but the differences in disparity level could justify market segmentation of drink products with different sucrose levels.
TEXTURE‐FLAVOR INTERACTIONS IN LOW FAT STIRRED YOGURT: HOW MECHANICAL TREATMENT, THICKENER CONCENTRATION AND AROMA CONCENTRATION AFFECT PERCEIVED TEXTURE AND FLAVOR
Authors: KORA ENKELEJDA PAÇI , LATRILLE ERIC , SOUCHON ISABELLE , MARTIN NATHALIE
Published: May 2007

The influence of thickening agent (0 and 7g/L), mechanical treatment (low and high) and flavoring agent concentration (2.2 to 63.2 μL/kg) on texture, taste and aroma of low fat stirred yogurts was investigated through sensory profiling by a panel of ten subjects trained on 13 attributes. Two assessment conditions were used: either in the presence or in the absence of olfactory perception (nostrils closed with nose clips). Sensory differences were greater for texture than for the other perception modalities. Olfactory perception enhanced yogurt astringency. If both thickener addition and mechanical treatment influenced texture attributes and rheology, the second factor had the strongest effect. Texture attributes were highly correlated with rheological parameters. Increasing flavoring agent concentration tended to decrease thickness and the addition of thickening agent depressed green apple notes and sweet taste, suggesting texture/flavor interactions.
An Interwoven Learning Exchange: Transforming Research‐Teaching Relationships in the Top End, Northern Australia
Authors: WRIGHT SARAH , SUCHET‐PEARSON SANDIE , LLOYD KATE
Published: May 2007

In this paper, we explore processes of learning through a focus on relationships. Situated within the context of our research on educational tourism with Indigenous tour operators in the Northern Territory, we examine the relationships built between three groups: ourselves, Indigenous tour operators and undergraduate university students. We develop a conceptualisation of teaching and research as an interwoven learning exchange characterised by multi‐directional learning experiences within which all collaborators teach, research and learn. By viewing all contributors, including ourselves, as active and multiple situated co‐learners, we begin a process of recognising and reconfiguring power relationships. We reflect on how an interwoven learning exchange may bring new subjectivities into being through transformed research‐teaching relationships.
Age‐related physiological and morphological changes of muscle spindles in rats
Authors: Kim Gee Hee , Suzuki Shuji , Kanda Kenro
Published: May 2007

Age‐related physiological and morphological changes of muscle spindles were examined in rats (male Fischer 344/DuCrj: young, 4–13 months; middle‐aged, 20–22 months; old, 28–31 months). Single afferent discharges of the muscle spindles in gastrocnemius muscles were recorded from a finely split dorsal root during ramp‐and‐hold (amplitude, 2.0 mm; velocity, 2–20 mm s−1) or sinusoidal stretch (amplitude, 0.05–1.0 mm; frequency, 0.5–2 Hz). Respective conduction velocities (CVs) were then measured. After electrophysiological experimentation, the muscles were dissected. The silver‐impregnated muscle spindles were teased and then analysed using a light microscope. The CV and dynamic response to ramp‐and‐hold stretch of many endings were widely overlapped in old rats because of the decreased CV and dynamic response of primary endings. Many units in old rats showed slowing of discharge during the release phase under ramp‐and‐hold stretch and continuous discharge under sinusoidal stretch, similarly to secondary endings in young and middle‐aged rats. Morphological studies revealed that primary endings of aged rat muscle spindles were less spiral or non‐spiral in appearance, but secondary endings appeared unchanged. These results suggest first that primary muscle spindles in old rats are indistinguishable from secondary endings when determined solely by previously used physiological criteria. Secondly, these physiological results reflect drastic age‐related morphological changes in spindle primary endings.
Prenatal stress in the rat results in increased blood pressure responsiveness to stress and enhanced arterial reactivity to neuropeptide Y in adulthood
Authors: Igosheva Natalia , Taylor Paul D. , Poston Lucilla , Glover Vivette
Published: May 2007

We have shown previously that stress in the pregnant rat leads to a heightened cardiovascular response to restraint in adult offspring. The present study was undertaken to explore further the persistent cardiovascular effects of prenatal stress, with a focus on peripheral vascular function. Sprague–Dawley female rats were exposed to restraint/bright light three times daily in the last week of pregnancy. Litters from stressed and control females were cross‐fostered to control dams to eliminate possible effects of maternal stress on nursing behaviour. At 120 days, offspring cardiovascular variables were measured by radiotelemetry. Reactivity of mesenteric small arteries was assessed by myography, and responses to electrical field stimulation determined. Resting cardiovascular parameters in prenatally stressed (PS) offspring were similar to controls but PS rats showed a greater increase in systolic blood pressure following restraint stress (P < 0.05). Recovery was also prolonged in PS animals compared with controls and was of longer duration in PS females than in PS males (P < 0.05). Adult PS females, but not males, also had elevated basal plasma corticosterone levels in comparison with controls (P < 0.05). Vascular reactivity to neuropeptide Y (P < 0.05) and electrical field stimulation (P < 0.05) in mesenteric arteries was also significantly increased in PS animals. Vascular responses to adrenergic agonists as well as endothelial dilator function did not differ between PS and controls. We conclude that prenatal stress during late gestation has long‐lasting effects on cardiovascular responsiveness and vascular reactivity to neuropeptide Y in the offspring.
Time-Variant Reliability Assessment of FPSO Hull Girder With Long Cracks
Authors: Ayala-Uraga Efrén , Moan Torgeir
Published: May 2007

An efficient time-variant reliability formulation for the safety assessment of an aging floating production storage and offloading (FPSO) vessels with the presence of through-thickness cracks (i.e., long cracks), is presented in this paper. Often in ship structures, cracks are detected by means of close visual inspection when they have already propagated through the thickness. The propagation of long cracks in stiffened panels is therefore considered, as they may be present in critical details of the deck and/or bottom plating of the vessel. Although it has been found that stiffened panels are tolerant to fatigue cracking, the safety of such structural components with the presence of long cracks may be threatened when exposed to overload extreme conditions, i.e., brittle or ductile fracture may occur. The probability of brittle fracture of an aging hull structure, i.e., a stiffened panel at the bottom plating with the presence of long cracks is studied in this paper. The mean stress effect due to the continuously varying still-water loading as well as residual stresses is explicitly accounted for in the crack growth calculation procedure presented herein. An analytical model is established for determining the equivalent long-term stress range including the mean stress effect. The continuously varying still-water load effects due to the operational nature of FPSOs introduce additional uncertainties in the estimation of fatigue damage as well as in the likelihood of fracture failure mode. In the present case study it is found that the time-invariant approach is a good approximation when dealing with the time-variant reliability problem. One of the main conclusions drawn from this study is that the still-water mean stress has a significant effect on the failure probabilities of stiffened panels with long cracks under brittle fracture mode.
Dynamic Response Interaction of Vibrating Offshore Pipeline on Moving Seabed
Authors: Olunloyo Vincent O. S. , Osheku Charles A. , Oyediran Ayo A.
Published: May 2007

The dynamic response interaction of a vibrating offshore pipeline on a moving seabed is herein investigated where the pipeline is idealized as a beam vibrating on an elastic foundation. This problem is of relevance in offshore exploration where pipelines are laid either on or buried in the seabed. When such pipes carry oil and gas, the undulating topography of the sea floor and the internal motion of the fluid subject the entire structure to vibration due to bending forces and form the subject of our study. Our analysis revealed that in general, the seabed acts either as a damper or as a spring and in particular when we have sedimentation, the seabed geology permits the geomechanical property of the sediment cover to act only as a damper. As expected, external excitation will increase the response of these pipes for which an amplification factor has been derived. For soft beds, high transverse vibrations were dampened by increasing the internal fluid velocity whereas they became amplified for hard beds. These results are of contemporary interest in the oil/gas industry where deep sea exploration is now receiving significant attention.
A classroom experiment to measure the speed-dependent coefficient of rolling friction
Authors: Xu Y. , Yung K. L. , Ko S. M.
Published: May 2007

To help students understand one of the most basic mechanical phenomena, rolling friction, a simple laboratory setup for measuring the rotational speed-dependent coefficient of rolling friction was developed. Equipment and apparatus used in the measurement are simple and easy to acquire, yet the phenomena and the mechanisms behind it are intriguing. The air drag force, which is caused by air friction, is used in the measurement to reduce the cost of the apparatus.
The electric dipole moment of the electron: An intuitive explanation for the evasion of Schiff’s theorem
Authors: Commins Eugene D. , Jackson J. D. , DeMille David P.
Published: May 2007

In most experimental searches for the electron electric dipole moment, one searches for a linear Stark effect in a paramagnetic atom or molecule and interprets the result in terms of the electric dipole moment of the unpaired valence electron(s). Schiff’s theorem states that in the limit of nonrelativistic quantum mechanics, there can be no linear Stark effect to first order in the electric dipole moment. Sandars has shown that Schiff’s theorem is not applicable when special relativity is taken into account. We give a heuristic explanation for this relativistic effect, which corrects a widespread misconception in the literature.
Two variational variations on a problem in electrostatics
Authors: Garg Anupam
Published: May 2007

Two nonstandard variational approximations are developed for a problem in electrostatics. The results are compared with a numerical solution based on the relaxation method. Suggestions for further study are made.
Quantum mechanical versus semiclassical tunneling and decay times
Authors: Shegelski Mark R. A. , Kavka Jeremy , Hnybida Jeff
Published: May 2007

We present a method for calculating lifetimes without using semiclassical approximations by using a heuristic expression for the lifetime. The details are given for tunneling past a centrifugal barrier. We compare the fully quantum mechanical results to the well-known WKB tunneling times. We show that bound states play a major role in determining lifetimes.
Visualizing flat spacetime: Viewing optical versus special relativistic effects
Authors: Black Don V. , Gopi M. , Wessel Frank , Pajarola Renato , Kuester Falko
Published: May 2007

A visual representation of Minkowski spacetime appropriate for a student with a background in geometry and algebra is presented. Minkowski spacetime can be modeled with a Euclidean four-space to yield accurate visualizations as predicted by special relativity. The contributions of relativistic aberration as compared to classical prerelativistic aberration to the geometry are discussed in the context of its visual representation.
Chemical modification results in hyperactivation and thermostabilization ofFusarium solaniglucoamylase
Authors: Bhatti Haq Nawaz , Rashid M. Hamid , Asgher Muhammad , Nawaz Rakhshanda , Khalid A.M. , Perveen Raheela
Published: May 2007

Chemical modification of carboxyl groups of glucoamylase from a mesophilic fungus, Fusarium solani , was carried out using ethylenediamine as nucleophile in the presence of water-soluble 1-ethyl-3(3-dimethylaminopropyl)carbodiimide. Modification brought about a dramatic enhancement of catalytic activity and thermal stability of glucoamylase. Temperature and pH optima of ethylenediamine-coupled glucoamylase (ECG) increased as compared with those of native enzyme. The specificity constant (kcat/Km) of native, ECG-2, ECG-11, and ECG-17 was 136, 173, 225, and 170, respectively, at 55 °C. The enthalpy of activation (ΔH*) and free energy of activation (ΔG*) for soluble starch hydrolysis were lower for the chemically modified forms. All of the modified forms werestable at higher temperatures and possessed high ΔG* against thermal unfolding. The effects of α-chymotrypsin and subtilisin on the modified forms were activating as compared with native. Moreover, denaturation of ECG-2, ECG-11, and ECG-17 in urea at 4 mol·L–1also showed an activation trend. A possible explanation for the thermal denaturation of native and increased thermal stability of ECG-2, ECG-11, and ECG-17 at higher temperatures is also discussed.
Heterogeneity between 16S ribosomal RNA gene copies borne by oneDesulfitobacteriumstrain is caused by different 100-200 bp insertions in the 5´ region
Authors: Villemur Richard , Constant Philippe , Gauthier Annie , Shareck Martine , Beaudet Réjean
Published: May 2007

Strains of Desulfitobacterium hafniense, such as strains PCP-1, DP7, TCE1, and TCP-A, have unusual long 16S ribosomal RNA (rRNA) genes due to an insertion of approximately 100 bp in the 5' region. In this report, we analyzed the 16S rRNA genes of different Desulfitobacterium strains to determine if such an insertion is a common feature of desulfitobacteria. We amplified this region by polymerase chain reaction (PCR) from eight Desulfitobacterium strains (D. hafniense strains PCP-1, DP7, TCP-A, TCE1, and DCB-2; D. dehalogenans; D. chlororespirans; and Desulfitobacterium sp. PCE1) and resolved each PCR product by denaturing gradient gel electrophoresis (DGGE). All strains had from two to seven DGGE- migrating bands, suggesting heterogeneity in their 16S rRNA gene copies. For each strain, the 5' region of the 16S rRNA genes was amplified and a clone library was derived. Clones corresponding to most PCR–DGGE migration bands were isolated. Sequencing of representative clones revealed that the heterogeneity was generated by insertions of 100–200 bp. An insertion was found in at least one copy of the 16S rRNA gene in all examined strains. In total, we found eight different types of insertions (INS1–INS8) that varied from 123 to 193 nt in length. Two-dimensional structural analyses of transcribed sequences predicted that all insertions would form an energetically stable loop. Reverse transcriptase – PCR experiments revealed that most of the observed insertions in the Desulfitobacterium strains were excised from the mature 16S rRNA transcripts. Insertions were not commonly found in bacterial 16S rRNA genes, and having a different insertion in several 16S rRNA gene copies borne by a single bacterial species was rarely observed. The function of these insertions is not known, but their occurrence can have an important impact in deriving 16S rRNA oligonucleotidic fluorescence in situ hybridization probes, as these insertions can be excised from 16S rRNA transcripts.Key words: Desulfitobacterium, 16S ribosomal RNA genes, heterogeneity, gene insertions, fluorescence in situ hybridization.
Exploring the diversity of marine-derived fungal polyketide synthases
Authors: Mayer Kimberly M. , Ford Jermaine , Macpherson Gordon R. , Padgett David , Volkmann-Kohlmeyer Brigitte , Kohlmeyer Jan , Murphy Colleen , Douglas Susan E. , Wright Jonathan M. , Wright Jeffrey L.C.
Published: May 2007

Using an approach based on polymerase chain reaction (PCR), we examined the diversity of polyketide synthase (PKS) genes present in 160 marine fungal isolates, representing 142 species. We obtained ketosynthase (KS) domain PCR products from 99 fungal isolates, representing Dothideomycetes, Sordariomycetes, Eurotiomycetes, and incertae sedis. Sequence similarity searches and phylogenetic analysis of 29 marine partial-KS-encoding sequences revealed domains predicted to encode reducing, nonreducing, and 6-methylsalicylic acid PKSs. Bioinformatic analysis of an alignment of the KS sequences from marine-derived fungi revealed no unique motifs in this region. However, several specificity-determining positions were apparent between fungal 6-methylsalicylic acid PKSs as compared with either reducing or nonreducing PKSs. Evaluation of these positions in the context of a modelled three-dimensional protein structure highlighted their potential use as PKS classification markers. Evaluating primer-binding sites was necessary to obtain KS domain fragments from putative PKSs while maintaining a level of sequence information adequate to properly classify and characterize them.
HIGH PRESSURE ELECTRICAL RESISTIVITY STUDY ON NONLINEAR SINGLE CRYSTAL ZINC THIOUREA CHLORIDE
Authors: ARIPONNAMMAL S. , SELVA VENNILA R. , RADHIKA S. , USHASREE P. M.
Published: May 2007

Zinc thiourea chloride (ZTC) crystals were crystallized by slow evaporation technique. The lattice parameters of the grown crystals were determined by angle dispersive X-ray powder diffraction technique (XRD) and the structure was confirmed. High pressure electrical resistivity study was carried out on this crystal and the results are reported here.
A NEW LOOP ALGEBRA AND TWO NEW LIOUVILLE INTEGRABLE HIERARCHY
Authors: DONG HUAN-HE
Published: May 2007

A new loop algebra containing four arbitrary constants is presented, and the corresponding computing formula of constant γ in the quadratic-form identity is obtained in this paper, which can be reduced to a computing formula of constant γ in the trace identity. As application, two new Liouville integrable hierarchy and Hamiltonian structures are derived.
Leptin modulates the expression of secreted and membrane-associated mucins in colonic epithelial cells by targeting PKC, PI3K, and MAPK pathways
Authors: Homsi Mahmoud El , Ducroc Robert , Claustre Jean , Jourdan Gérard , Gertler Arieh , Estienne Monique , Bado André , Scoazec Jean-Yves , Plaisancié Pascale
Published: May 2007

Mucins play an essential role in the protection and repair of gastrointestinal mucosa. We recently showed that luminal leptin strongly stimulated mucin secretion in vivo in rat colon. In the present study, we challenged the hypothesis that leptin may act directly on goblet cells to induce mucin expression in rat and human intestinal mucin-producing cells (DHE and HT29-MTX). The endoluminal effect of leptin was also studied in vivo in rat perfused colon model. The presence of leptin receptors was demonstrated in the two cell lines by Western blot and RT-PCR. In rat DHE cells, leptin (0.01–10 nmol/l, 60 min) dose dependently increased the secretion of mucins (210 ± 3% of controls) and the expression of Muc2, Muc3, and Muc4 (twofold basal level) but not of Muc1 and Muc5AC. Luminal perfusion of leptin (60 min, 0.1–100 nmol/l) in rat colon also increased the mRNA level of Muc2, Muc3, and Muc4 but not of Muc1. In human HT29-MTX cells, leptin (0.01–10 nmol/l, 60 min) dose dependently enhanced MUC2, MUC5AC, and MUC4 mRNA levels. These effects were prevented by pretreatment of cells with the leptin mutein L39A/D40A/F41A, which acts as a receptor antagonist. Finally, pathway inhibition experiments suggest that leptin increased mucin expression by activating PKC-, phosphatidyl inositol 3-kinase-, and MAPK-dependent pathways but not the JAK/STAT pathway. In conclusion, leptin may contribute significantly to membrane-associated and secreted mucin production via a direct stimulation of colonic epithelial cells and the activation of leptin receptors. These data are consistent with a role for leptin in regulation of the intestinal barrier function.
Development and Physiological Regulation of Intestinal Lipid Absorption. I. Development of intestinal lipid absorption: cellular events in chylomicron assembly and secretion
Authors: Black Dennis D.
Published: May 2007

The newborn mammal must efficiently absorb dietary fat, predominantly as triacylglycerol, and produce chylomicrons to deliver this lipid to peripheral tissues. The cellular mechanisms involved in enterocyte chylomicron assembly have recently been elucidated, and data on their regulation in the immature gut are beginning to emerge. This review focuses on key proteins involved in chylomicron assembly: apolipoprotein B-48, microsomal triglyceride transfer protein, and apolipoproten A-IV. Recent studies support a role for apolipoprotein A-IV in enhancing chylomicron secretion by promoting production of larger particles. These proteins are regulated in a manner to maximize the lipid absorptive capacity of the newborn intestine.
Phosphatidylinositol 3-kinase is involved in prostaglandin E2-mediated murine duodenal bicarbonate secretion
Authors: Tuo Bi-Guang , Wen Guo-Rong , Seidler Ursula
Published: May 2007

Prostaglandin E2(PGE2) plays an important role in the regulation of duodenal bicarbonate (HCO3−) secretion, but its signaling pathway(s) are not fully understood. In the present study, we investigated the signaling pathways involved in PGE2-mediated duodenal HCO3−secretion. Murine duodenal mucosal HCO3−secretion was examined in vitro in Ussing chambers by pH-stat titration in the presence of a variety of signal transduction modulators. Phosphatidylinositol 3-kinase (PI3K) activity was measured by immunoprecipitation of PI3K and ELISA, and Akt phosphorylation was measured by Western analysis with anti-phospho-Akt and anti-Akt antibodies. PGE2-stimulated duodenal HCO3−secretion was reduced by the cAMP-dependent signaling pathway inhibitors MDL-12330A and KT-5720 by 23% and 20%, respectively; the Ca2+-influx inhibitor verapamil by 26%; and the calmodulin antagonist W-13 by 24%; whereas the PI3K inhibitors wortmannin and LY-294002 reduced PGE2-stimulated HCO3−secretion by 51% and 47%, respectively. Neither the MAPK inhibitor PD-98059 nor the tyrosine kinase inhibitor genistein altered PGE2-stimulated HCO3−secretion. PGE2application caused a rapid and concentration-dependent increase in duodenal mucosal PI3K activity and Akt phosphorylation. These results demonstrated that PGE2activates PI3K in duodenal mucosa and stimulates duodenal HCO3−secretion via cAMP-, Ca2+-, and PI3K-dependent signaling pathways.
Dose effects of modified alternate-day fasting regimens on in vivo cell proliferation and plasma insulin-like growth factor-1 in mice
Authors: Varady Krista A. , Roohk D. J. , Hellerstein Marc K.
Published: May 2007

Reduced cell proliferation is associated with lower cancer risk. Alternate-day fasting (ADF), defined as alternating 24-h periods of ad libitum feeding and fasting, decreases cell proliferation. The effect of modified regimens of ADF on cell proliferation, however, has not been examined. This study measured the effects of modified ADF regimens on prostate and splenic T-cell proliferation and circulating insulin-like growth factor-1 (IGF-1) levels in mice. In a 4-wk study, 24 male C57BL/6J mice were randomized to one of four interventions: 1) ADF-25% [25% calorie restriction (CR) on fast day], 2) ADF-50% (50% CR on fast day), 3) ADF-100% (100% CR on fast day), and 4) control. Body weight of the ADF-100% group was less ( P < 0.005) than that of the ADF-25% and ADF-50% groups posttreatment. On the feast day, the ADF-100% and ADF-50% groups ate 85% and 45% more food, respectively, than controls, indicating a hyperphagic response to fasting. Proliferation rates of T-cells were 6% and 30% lower ( P < 0.05) in the ADF-50% and ADF-100% groups, respectively, relative to controls. Prostate cell proliferation was reduced ( P < 0.05) by 49% in the ADF-100% group, relative to controls, but did not change in the other groups. IGF-1 levels were reduced ( P < 0.05) by 40%, relative to controls, in the ADF-100% group. These findings confirm the beneficial effects of ADF-100% on cancer risk by decreasing cell proliferation and IGF-1 levels and suggest that modified ADF regimens comprising 25–50% CR on the fast day do not replicate these effects.
A Three-Kilobase Fragment of the Human Robo4 Promoter Directs Cell Type–Specific Expression in Endothelium
Authors: Okada Yoshiaki , Yano Kiichiro , Jin Enjing , Funahashi Nobuaki , Kitayama Mie , Doi Takefumi , Spokes Katherine , Beeler David L. , Shih Shu-Ching , Okada Hitomi , Danilov Tatyana A. , Maynard Elizabeth , Minami Takashi , Oettgen Peter , Aird William C.
Published: May 2007

Robo4, a member of the roundabout family, is expressed exclusively in endothelial cells and has been implicated in endothelial cell migration and angiogenesis. Here we report the cloning and characterization of the human Robo4 promoter. The 3-kb 5′-flanking region directs endothelial cell–specific expression in vitro. Deletion and mutation analyses revealed the functional importance of two 12-bp palindromic DNA sequences at −2528 and −2941, 2 SP1 consensus motifs at −42 and −153, and an ETS consensus motif at −119. In electrophoretic mobility shift assays using supershifting antibodies, the SP1 motifs bound SP1 protein, whereas the ETS site bound a heterodimeric member of the ETS family, GA binding protein (GABP). These DNA–protein interactions were confirmed by chromatin immunoprecipitation assays. Transfection of primary human endothelial cells with small interfering RNA against GABP and SP1 resulted in a significant (≈50%) reduction in endogenous Robo4 mRNA expression. The 3-kb Robo4 promoter was coupled to LacZ, and the resulting cassette was introduced into the Hprt locus of mice by homologous recombination. Reporter gene activity was observed in the vasculature of adult organs (particularly in microvessels), tumor xenografts, and embryos, where it colocalized with the endothelial cell–specific marker CD31. LacZ mRNA levels in adult tissues and tumors correlated with mRNA levels for endogenous Robo4, CD31, and vascular endothelial cadherin. Moreover, the pattern of reporter gene expression was similar to that observed in mice in which LacZ was knocked into the endogenous Robo4 locus. Together, these data suggest that 3-kb upstream promoter of human Robo4 contains information for cell type–specific expression in the intact endothelium.
Elevated Cholesterol Levels in the Plasma Membranes of Macrophages Inhibit Migration by Disrupting RhoA Regulation
Authors: Nagao Tomokazu , Qin Chunbo , Grosheva Inna , Maxfield Frederick R. , Pierini Lynda M.
Published: May 2007

Objective—

Atherogenesis begins as small subendothelial accumulations of foam cells that develop through unregulated uptake of modified and aggregated low-density lipoprotein (LDL). The reason why foam cells remain in the atherosclerotic plaque rather than migrating out of the area is unclear. We tested the hypothesis that elevated membrane cholesterol levels, which may result from interactions with aggregated LDL, affect macrophage migration.

Methods and Results—

Cholesterol loading by incubation with cholesterol-chelated methyl-β-cyclodextrin decreased migration of J774A.1 macrophages toward complement 5a (C5a) in transwell migration assays, even though cholesterol-loaded macrophages responded to a bath application of C5a. In a micropipette polarization assay, cholesterol-loaded cells polarized toward a C5a gradient. In a transwell migration assay, cholesterol-loaded cells extended lamellae through the filter pores but were unable to translocate their cell bodies. Cholesterol loading decreased both the cellular levels of GTP-bound active RhoA and the phosphorylation of myosin light chain. Expression of constitutively active RhoA largely prevented the inhibition of cell migration by cholesterol loading.

Conclusions—

These results suggest that increases in plasma membrane cholesterol content alter RhoA activation, resulting in inhibition of cell migration. These findings provide one possible explanation for the retention of foam cells in atherosclerotic lesions.
Cooperation of SRC-1 and p300 With NF-κB and CREB in Angiotensin II-Induced IL-6 Expression in Vascular Smooth Muscle Cells
Authors: Sahar Saurabh , Reddy Marpadga A. , Wong Cynthie , Meng Li , Wang Mei , Natarajan Rama
Published: May 2007

Objective—

The purpose of this study was to evaluate the role of coactivator histone acetyltransferases (HATs) p300 and SRC-1 in angiotensin II (Ang II)–induced interleukin-6 (IL-6) gene expression in vascular smooth muscle cells (VSMCs).

Methods and Results—

Ang II increased IL-6 mRNA expression via NF-κB and CREB in an extracellular signal-regulated kinase (ERK)–dependent manner in rat VSMCs. It was also significantly enhanced by the histone deacetylase inhibitor, Trichostatin A. Chromatin immunoprecipitation (ChIP) assays showed that Ang II increased Histone H3 Lysine (K9/14) acetylation on the IL-6 promoter. Ang II-induced IL-6 promoter transactivation was significantly enhanced by p300 and SRC-1, with maximal activation in cells cotransfected with NF-κB (p65) and SRC-1. Nucleofection of VSMCs with either an ERK phosphorylation site mutant of SRC-1 or p300/CBP HAT deficient mutants significantly blocked Ang II-induced IL-6 expression. ChIP assays revealed that Ang II enhanced coordinate occupancy of p65, CREB, p300, and SRC-1 at the IL-6 promoter. An ERK pathway inhibitor blocked Ang-induced IL-6 promoter SRC-1 occupancy and histone acetylation.

Conclusions—

Ang II-induced IL-6 expression requires NF-κB and CREB as well as ERK-dependent histone acetylation mediated by p300 and SRC-1. These results provide new insights into nuclear chromatin mechanisms by which Ang II regulates inflammatory gene expression.
Gene Transfer of Connexin43 Mutants Attenuates Coupling in Cardiomyocytes
Authors: Kizana Eddy , Chang Connie Y. , Cingolani Eugenio , Ramirez-Correa Genaro A. , Sekar Rajesh B. , Abraham M. Roselle , Ginn Samantha L. , Tung Leslie , Alexander Ian E. , Marbán Eduardo
Published: May 2007

Modification of electrical conduction would be a useful principle to recruit in preventing or treating certain arrhythmias, notably ventricular tachycardia (VT). Here we pursue a novel gene transfer approach to modulate electrical conduction by reducing gap junctional intercellular communication (GJIC) and hence potentially modify the arrhythmia substrate. The ultimate goal is to develop a nondestructive approach to uncouple zones of slow conduction by focal gene transfer. Lentiviral vectors encoding connexin43 (Cx43) internal loop mutants were produced and studied in vitro. Transduction of neonatal rat ventricular myocytes (NRVMs) revealed the expected subcellular localization of the mutant gene product. Fluorescent dye transfer studies showed a significant reduction of GJIC in NRVMs that had been genetically modified. Additionally, adjacent mutant gene-modified NRVMs displayed delayed calcium transients, indicative of electrical uncoupling. Multi-site optical mapping of action potential (AP) propagation in gene-modified NRVM monolayers revealed a 3-fold slowing of conduction velocity (CV) relative to nontransduced NRVMs. In conclusion, lentiviral vector–mediated gene transfer of Cx43 mutants reduced GJIC in NRVMs. Electrical charge transfer was also reduced as evidenced by delayed calcium transients in adjacent NRVMs and reduced CV in NRVM monolayers. These data validate a molecular tool that opens the prospect for gene transfer targeting gap junctions as an approach to modulate cardiac conduction.
Inhibition of Progression and Stabilization of Plaques by Postnatal Interferon-γ Function Blocking in ApoE-Knockout Mice
Authors: Koga Mitsuhisa , Kai Hisashi , Yasukawa Hideo , Yamamoto Tomoka , Kawai Yumiko , Kato Seiya , Kusaba Ken , Kai Mamiko , Egashira Kensuke , Kataoka Yasufumi , Imaizumi Tsutomu
Published: May 2007

A role of interferon-γ is suggested in early development of atherosclerosis. However, the role of interferon-γ in progression and destabilization of advanced atherosclerotic plaques remains unknown. Thus, the aim of this study was to determine whether postnatal inhibition of interferon-γ signaling could inhibit progression of atherosclerotic plaques and stabilize the lipid- and macrophage-rich advanced plaques. Atherosclerotic plaques were induced in ApoE-knockout (KO) mice by feeding high-fat diet from 8 weeks old (w). Interferon-γ function was postnatally inhibited by repeated gene transfers of a soluble mutant of interferon-γ receptors (sIFNγR), an interferon-γ inhibitory protein, into the thigh muscle every 2 weeks. When sIFNγR treatment was started at 12 w (atherosclerotic stage), sIFNγR not only prevented plaque progression but also stabilized advanced plaques at 16 w: sIFNγR decreased accumulations of the lipid and macrophages and increased fibrotic area with more smooth muscle cells. Moreover, sIFNγR downregulated expressions of proinflammatory cytokines, chemokines, adhesion molecules, and matrix metalloproteinases but upregulated procollagen type I. sIFNγR did not affect serum cholesterol levels. In conclusion, postnatal blocking of interferon-γ function by sIFNγR treatment would be a new strategy to inhibit plaque progression and to stabilize advanced plaques through the antiinflammatory effects.
Nitrite Reductase Function of Deoxymyoglobin
Authors: Rassaf Tienush , Flögel Ulrich , Drexhage Christine , Hendgen-Cotta Ulrike , Kelm Malte , Schrader Jürgen
Published: May 2007

Although the primary function of myoglobin (Mb) has been considered to be cellular oxygen storage and supply, recent studies have suggested to classify Mb as a multifunctional allosteric enzyme. In the heart, Mb acts as a potent scavenger of nitric oxide (NO) and contributes to the attenuation of oxidative damage. Here we report that a dynamic cycle exists in which a decrease in tissue oxygen tension drives the conversion of Mb from being an NO scavenger in normoxia to an NO producer in hypoxia. The NO generated by reaction of deoxygenated Mb with nitrite is functionally relevant and leads to a downregulation of cardiac energy status, which was not observed in mice lacking Mb. As a consequence, myocardial oxygen consumption is reduced and cardiac contractility is dampened in wild-type mice. We propose that this pathway represents a novel homeostatic mechanism by which a mismatch between oxygen supply and demand in muscle is translated into the fractional increase of deoxygenated Mb exhibiting enhanced nitrite reductase activity. Thus, Mb may act as an oxygen sensor which through NO can adjust muscle energetics to limited oxygen supply.
Management into the Development Strategies of Urbanizing Regions in Asia: Implications of Urban Function, Form, and Role
Authors: Lebel Louis , Garden Po , Banaticla Ma. Regina N. , Lasco Rodel D. , Contreras Antonio , Mitra A. P. , Sharma Chhemendra , Nguyen Hoang Tri , Ooi Giok Ling , Sari Agus
Published: May 2007

The way urbanization unfolds over the next few decades in the developing countries of Asia will have profound implications for sustainability. One of the more important opportunities is to guide urbanization along pathways that begin to uncouple these gains in well‐being from rising levels of energy use. Increasing energy use for transport, construction, climate control in houses and offices, and industrial processes is often accompanied by increasing levels of atmospheric emissions that impact human health, ecosystem functions, and the climate system. Agriculture, forestry, and animal husbandry alter carbon stocks and fluxes as carbon dioxide, methane, and black carbon. In this article we explore how carbon management could be integrated into the development strategies of cities and urbanizing regions. In particular, we explore how changes in urban form, functions, and roles might alter the timing, aggregation, spatial distribution, and composition of carbon emissions. Our emphasis is on identifying system linkages and points of leverage. The study draws primarily on emission inventories and regional development histories carried out in the regions around the cities of Manila, Jakarta, Ho Chi Minh City, New Delhi, and Chiang Mai. We find that how urban functions, such as mobility, shelter, and food, are provided has major implications for carbon emissions, and that each function is influenced by urban form and role in distinct ways. Our case studies highlight the need for major “U‐turns” in urban policy.
Multiscale Variability of the Flow during the North American Monsoon Experiment
Authors: Johnson Richard H. , Ciesielski Paul E. , McNoldy Brian D. , Rogers Peter J. , Taft Richard K.
Published: May 2007

The 2004 North American Monsoon Experiment (NAME) provided an unprecedented observing network for studying the structure and evolution of the North American monsoon. This paper focuses on multiscale characteristics of the flow during NAME from the large scale to the mesoscale using atmospheric sounding data from the enhanced observing network.

The onset of the 2004 summer monsoon over the NAME region accompanied the typical northward shift of the upper-level anticyclone or monsoon high over northern Mexico into the southwestern United States, but in 2004 this shift occurred slightly later than normal and the monsoon high did not extend as far north as usual. Consequently, precipitation over the southwestern United States was slightly below normal, although increased troughiness over the Great Plains contributed to increased rainfall over eastern New Mexico and western Texas. The first major pulse of moisture into the Southwest occurred around 13 July in association with a strong Gulf of California surge. This surge was linked to the westward passages of Tropical Storm Blas to the south and an upper-level inverted trough over northern Texas. The development of Blas appeared to be favored as an easterly wave moved into the eastern Pacific during the active phase of a Madden–Julian oscillation.

On the regional scale, sounding data reveal a prominent sea breeze along the east shore of the Gulf of California, with a deep return flow as a consequence of the elevated Sierra Madre Occidental (SMO) immediately to the east. Subsidence produced a dry layer over the gulf, whereas a deep moist layer existed over the west slopes of the SMO. A prominent nocturnal low-level jet was present on most days over the northern gulf. The diurnal cycle of heating and moistening (Q1 and Q2) over the SMO was characterized by deep convective profiles in the mid- to upper troposphere at 1800 LT, followed by stratiform-like profiles at midnight, consistent with the observed diurnal evolution of precipitation over this coastal mountainous region. The analyses in the core NAME domain are based on a gridded dataset derived from atmospheric soundings only and, therefore, should prove useful in validating reanalyses and regional models.