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Segments
Kinds of Segments Terms modified by Segments Selected AbstractsTRAJECTORIES OF CRIME AT PLACES: A LONGITUDINAL STUDY OF STREET SEGMENTS IN THE CITY OF SEATTLE,CRIMINOLOGY, Issue 2 2004DAVID WEISBURD Studies of crime at micro places have generally relied on cross-sectional data and reported the distributions of crime statistics over short periods of time. In this paper we use official crime data to examine the distribution of crime at street segments in Seattle, Washington, over a 14-year period. We go beyond prior research in two ways. First, we view crime trends at places over a much longer period than other studies that have examined micro places. Second, we use group-based trajectory analysis to uncover distinctive developmental trends in our data. Our findings support the view that micro places generally have stable concentrations of crime events over time. However, we also find that a relatively small proportion of places belong to groups with steeply rising or declining crime trajectories and that these places are primarily responsible for overall city trends in crime. These findings are particularly important given the more general decline in crime rates observed in Seattle and many other American cities in the 1990s. Our study suggests that the crime drop can be understood not as a general process that occurred across the city landscape but one that was generated in a relatively small group of micro places with strong declining crime trajectories over time. [source] EFFECTS OF ENZYME-AIDED PEELING ON THE QUALITY OF LOCAL MANDARIN (CITRUS RETICULATA B.) SEGMENTSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 5 2004FANNY LIU ABSTRACT Pectinases are observed to selectively alter the albedo structure of citrus fruits and, hence, aid the removal of the peel and adhering albedo layer. This study was carried out to determine the optimum conditions needed to peel local mandarins using pectinases (Peelzym II, Novo Nordisk, Denmark). The experiment variables were enzyme concentration, vacuum pressure and vacuum infusion time. The mandarins were first scored from the stem end to the blossom end, followed by immersion in 1000 mL of enzyme solution at a set vacuum pressure and ambient temperature (27 ± 1C). Only one parameter was varied in any one experiment. Peelzym II at 0.4% v/w, 650 mm Hg vacuum and 16 min of vacuum time were optimal. The enzyme-peeled fruit segments were judged by the panelists using three different sensory tests to ascertain their appeal to consumers. A significant (P < 0.05) difference between enzyme-peeled and hand-peeled segments was found, with the panelists preferring the enzyme-peeled segments. [source] DIFFERENCES IN POLYSACCHARIDE STRUCTURE BETWEEN CALCIFIED AND UNCALCIFIED SEGMENTS IN THE CORALLINE CALLIARTHRON CHEILOSPORIOIDES (CORALLINALES, RHODOPHYTA),JOURNAL OF PHYCOLOGY, Issue 3 2010Patrick T. Martone The articulated coralline Calliarthron cheilosporioides Manza produces segmented fronds composed of calcified segments (intergenicula) separated by uncalcified joints (genicula), which allow fronds to bend and reorient under breaking waves in the wave-swept intertidal zone. Genicula are formed when calcified cells decalcify and restructure to create flexible tissue. The present study has identified important differences in the main agaran disaccharidic repeating units [,3)-,- d -Galp (1, 4)-,- l -Galp(1,] synthesized by genicular and intergenicular segments. Based on chemical and spectroscopical analyses, we report that genicular cells from C. cheilosporioides biosynthesize a highly methoxylated galactan at C-6 position with low levels of branching with xylose side stubs on C-6 of the [,3)-,- d -Galp (1,] units, whereas intergenicular segments produce xylogalactans with high levels of xylose and low levels of 6- O -methyl ,- d -Gal units. These data suggest that, during genicular development, xylosyl branched, 3-linked ,- d -Galp units present in the xylogalactan backbones from intergenicular walls are mostly replaced by 6- O -methyl -d- galactose units. We speculate that this structural shift is a consequence of a putative and specific methoxyl transferase that blocks the xylosylation on C-6 of the 3-linked ,- d -Galp units. Changes in galactan substitutions may contribute to the distinct mechanical properties of genicula and may lend insight into the calcification process in coralline algae. [source] Genomic imbalances in CML blast crisis: 8q24.12,q24.13 Segment identified as a common region of over-representationGENES, CHROMOSOMES AND CANCER, Issue 4 2003Susan M. Gribble The acute phase of chronic myeloid leukemia (CML) is accompanied by secondary chromosomal changes. The additional changes have a non-random pattern; however, highly abnormal (marker) chromosomes are reported in some 20% of abnormal karyotypes. These marker chromosomes have proved to be beyond the resolution of conventional G-banding analysis. We used molecular cytogenetic techniques to determine the structure of complex chromosome markers in 10 CML-derived cell lines after our investigations of CML patients in blast crisis. Multicolor fluorescence in situ hybridization identified a multitude of structural chromosome aberrations. In addition, genomic gains identified by comparative genomic hybridization (CGH) were mapped to highly complex marker chromosomes in more than one cell line. The most common genomic loss detected by CGH affected chromosome 9, whereas the most common genomic gains affected, in order of frequency, the sequences of 8q, 6, and 13q. The smallest discrete amplification on 8q was identified in cell line MEG-01. This amplicon contains sequences represented by the marker D8S263/RMC08P029 but did not contain the proximal MYC gene or a more distal marker, D8S256/RMC08P025. We determined the size of the amplicon to be less than the chromosome segment 8q24.12,q24.13. The use of region- and locus-specific probes to analyze the organization of highly complex marker structures aided the identification of preferentially amplified genomic regions. The resultant amplifications could harbor gene(s) driving disease progression. © 2003 Wiley-Liss, Inc. [source] Effect of Left Ventricular Lead Concordance to the Delayed Contraction Segment on Echocardiographic and Clinical Outcomes after Cardiac Resynchronization TherapyJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 5 2009JEFFREY W.H. FUNG M.D. Introduction: The optimal left ventricular (LV) pacing site for cardiac resynchronization therapy (CRT) is unclear. The current study aims to explore the clinical significance of LV lead concordance to delayed contraction segment in CRT. Methods and Results: Concordant LV lead position was defined as the lead tip located by fluoroscopy at or immediately adjacent to the LV segment with latest contraction determined by tissue Doppler imaging. Echocardiographic and clinical outcomes among 101 consecutive patients with or without concordant LV lead positions were compared. There was no significant difference in changes in LV volumes and clinical parameters between patients with concordant (n = 46) or nonconcordant (n = 55) LV lead positions at 3 and 6 months. In multivariate analysis, the baseline asynchrony index (,= 1.092, 95% CI: 1.050,1.114; P < 0.001), but not LV lead concordance, was the only independent predictor of LV reverse remodeling. By Cox regression analysis, ischemic etiology, and LV reverse remodeling, but not LV lead concordance, were independent predictors of mortality (,= 2.475, 95% CI: 1.183,5.178; P = 0.016, and ,= 0.272, 95% CI: 0.130,0.567; P < 0.001, respectively), cardiovascular hospitalization (,= 1.551, 95% CI: 1.032,2.333; P = 0.035, and ,= 0.460, 95% CI: 0.298,0.708; P < 0.001, respectively), and heart failure hospitalization (,= 0.486, 95% CI: 0.320,0.738; P = 0.001 for LV reverse remodeling). Conclusion: LV lead concordance to the delayed contraction segment may not be a major determining factor for favorable echocardiographic and clinical outcomes after CRT. [source] Left Ventricular Lead Proximity to an Akinetic Segment and Impact on Outcome of Cardiac Resynchronization TherapyJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2006DANIEL ARZOLA-CASTANER M.D. Background: Previous studies report that the optimal pacing site for cardiac resynchronization therapy (CRT) is along the left ventricular (LV) lateral and postero-lateral (PL) wall. However, little is known regarding whether pacing over an akinetic site impacts the contractile response and long-term outcome from CRT. Methods and Results: A total of 38 patients with ischemic cardiomyopathy were studied for their acute hemodynamic and 12-month clinical response to CRT. The intraindividual percentage change in dP/dt (%,dP/dt), over baseline, was derived from the mitral regurgitation (MR) Doppler profile with CRT on versus off. Two-dimensional echocardiography was used for myocardial segmentation and determinination of akinetic sites. LV lead implant site was determined using angiographic and radiographic data and categorized as being "on" (group 1) or "off" (group 2) an akinetic site. Long-term response was measured as a combined endpoint of hospitalization for heart failure and/or all cause mortality at 12 months. Time to primary endpoint was estimated by the Kaplan-Meier method. Clinical characteristics and acute hemodynamic response was similar in both (group 1 [n = 14]; %,dP/dt 48.8 ± 67.4% vs group 2 [n = 24]; %,dP/dt 32.2 ± 40.1%, P = 0.92). No difference in long-term outcome was observed (P = 0.59). In contrast, lead placement in PL or mid-lateral (ML) positions was associated with a better acute hemodynamic response when compared to antero-lateral (AL) positions (PL, %,dP/dt 45.7 ± 50.7% and ML, %,dP/dt 45.1 ± 58.8% vs AL, %,dP/dt 2.9 ± 30.9%, respectively, P = 0.014). Conclusion: LV lead proximity to an akinetic segment does not impact acute hemodynamic or 12-month clinical response to CRT. [source] ST Segment and T Wave Alternans in a Patient with Brugada SyndromePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2000HIROSHI TADA We describe a patient with Brugada syndrome in whom J point and ST-segment elevation in leads V1 and V2 were augmented by atrial pacing and intravenous administration of propranolol or cibenzoline. Significant T wave alternans with a 2:1 appearance of terminal negative T wave was observed in the absence and presence of atrial pacing after the administration of cibenzoline. The cellular mechanism responsible for T wave alternans. beat-to-beat appearance of terminal negative T wave and augmented J point and ST-segment elevation is discussed [source] The Presence of Megamitochondria in the Ellipsoid of Photoreceptor Inner Segment of the Zebrafish RetinaANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 6 2005J. Kim Summary Although the megamitochondria (MM) were localized in various pathological conditions, normal retina of some mammalian species was reported to include MM for various physiological roles. However, it was not clearly confirmed whether the MM is present in the retina of lower vertebrate as well. In this study, we tried to show the presence of the MM in the zebrafish retina using electron microscopic technique. In all the photoreceptors including rods, cones and double cones of the zebrafish retina, MM were observed in the ellipsoid of inner segment. In the photoreceptor epllipsoid of the zebrafish retina, the mitochondria located in the central portion of the ellipsoid had a highly electron-dense matrix, which were accompanied by the mitochondria with electron-lucent matrix in the apical portion of the ellipsoid. The presence of MM was more clearly discernable in the rods, which were localized under the double cones. This finding is somewhat different from those observed in the previous studies because MM were localized in the inner segment of cones, but were not in those of rods in the case of mammalian retina. Although the exact physiological meaning for the presence of MM in some vertebrate species should be further studied, the present study could show that the MM in the ellipsoid of the retinal photoreceptors was not only restricted in some mammalian species. [source] Early Embryonic Development of the Camel Lumbar Spinal Cord SegmentANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2005M. E. Abd Elmonem The lumbar spinal cord segment of the camel embryo at CVRL 2.4 to 28 cm was examined. Major changes are occurring in the organization of the lumbar spinal cord segments during this early developmental period. At the CVRL 2.4, 2.7 and 3.6 cm the three primary layers, ependymal cells layer, mantle cells layer, marginal cells layer in the developing lumber spinal cord segment were demonstrated. The mantle layer is the first to show striking differentiation, while the marginal layer is represented by thin outer rim. Proliferation and differentiation of the neuroepithelial cells in the developing spinal cord produce the thick lateral walls, thin roof and floor plates. The spinal ganglion and dorsal root of the spinal nerve are differentiated. At 2.7 cm CVRL differential thickening of the lateral walls produces a shallow longitudinal groove called sulcus limitans, which separates the dorsal part (alar plate) from ventral part (basal plate). The ventral root of the spinal nerve, the spinal cord and ganglion are embedded in loose mesenchyme, which tends to differentiate into spinal meninges. At 3.6 cm CVRL the basal plate, which is the future ventral gray horn, seem to be quite voluminous and the dorsal and ventral roots unite to form the beginning of the spinal nerve. At 5.5 cm CVRL the alar plates enlarge forming the dorsal septum. At 8.4 cm to 10.5 cm CVRL the basal plates enlarge, and bulge ventrally on each side of the midline producing the future ventral medium fissure, and the white and gray matters can be recognized. At 28 cm CVRL the lumen of the spinal cord is differentiated into the central canal bounded dorsally and ventrally by dorsal and ventral gray commissures, and therefore the gray matter takes the appearance of a butterfly. The lumber spinal nerve and their roots are well distinguished. [source] Innentitelbild: 1,1,8,8-Tetramethyl[8](2,11)teropyrenophane: Half of an Aromatic Belt and a Segment of an (8,8) Single-Walled Carbon Nanotube (Angew. Chem.ANGEWANDTE CHEMIE, Issue 30 200930/2009) Große, nichtplanare PAHs (polycyclische aromatische Kohlenwasserstoffe) können als diskrete Teilstrukturen der neueren Allotrope von Kohlenstoffnanoröhren betrachtet werden. G.,J. Bodwell et,al. beschreiben in ihrer Zuschrift auf S.,5595,ff. eine kurze Syntheseroute zu einem (2,11)Teropyrenophan mit einem mehrkernigen aromatischen System aus 36 Kohlenstoffatomen, dessen Struktur einem Segment einer einwandigen (8,8)-Kohlenstoffnanoröhre ähnelt. [source] Mantle Branch Structure in the South-Central Segment of the Da Hinggan Mts., Inner Mongolia and Its Ore-controlling RoleACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 6 2009NIU Shuyin Abstract: Mantle branch structure is the third tectonic unit of multiple evolution of a mantle branch. It is not only the main mechanism of intercontinental orogeny, but also an important ore-forming and ore-control structure. Studies on geotectonic evolution, regional geological characteristics and oreforming and ore-control structures have shown that since the Mesozoic the Da Hinggan Mts. region has entered a typical intercontinental orogenic stage, and it is closely related to mantle branch activities. The south-central segment of the Da Hinggan Mts. is a typical mantle branch structure and possesses obvious magmatic-metamorphic complexes in the core, detachment slip beds in the periphery and overlapped fault depression basins. Moreover, all of these are the principal factors leading to ore formation and ore control in the region. This paper also further explores the mechanism of mineralization in the south-central segment of the Da Hinggan, summaries the rules of mineralization, puts forward the models of mineralization and points out future ore-exploring orientation. [source] Phase 1 pharmacokinetic and drug-interaction study of dasatinib in patients with advanced solid tumorsCANCER, Issue 6 2010Faye M. Johnson MD Abstract BACKGROUND: The recently developed the Src and Abelson (Abl) kinase inhibitor dasatinib has antitumor effects in epithelial and mesenchymal tumors. Preclinical data have indicated that dasatinib is metabolized primarily through cytochrome P450 3A4 (CYP3A4) and may cause QT prolongation. In light of its improved tolerability, the authors were interested in the safety of a once-daily dasatinib regimen. METHODS: The authors conducted a phase 1 trial of dasatinib in 29 patients with advanced solid tumors. Segment 1 of the trial was short term and sequential and was designed to determine whether the coadministration of the potent CYP3A4 inhibitor ketoconazole had an effect on the pharmacokinetics of dasatinib. Segment 2 was designed to evaluate the safety of dasatinib as dosing was increased. QT intervals were monitored closely in both segments. Efficacy was assessed in Segment 2 using both positron emission tomography and computed tomography. RESULTS: Hematologic toxicities were markedly less than those observed in patients with leukemia, whereas nonhematologic toxicities were similar. The authors determined that the maximum recommended dose was 180 mg once daily based on the incidence of pleural effusion. Coadministration of ketoconazole led to a marked increase in dasatinib exposure, which was correlated with an increase in corrected QT (QTc) values of approximately 6 msec. No adverse cardiac events were observed. CONCLUSIONS: The dose-limiting toxic effect for dasatinib was pleural effusion. The pharmacokinetic and cardiac studies indicated that coadministration of dasatinib with potent CYP3A4 inhibitors or agents that prolong the QTc interval should be avoided if possible. Close monitoring for toxicity and dose reduction should be considered if the coadministration of such agents cannot be avoided. Cancer 2010. © 2010 American Cancer Society. [source] Synthesis of the C1,C17 Segment (I) of Phorboxazole B.CHEMINFORM, Issue 50 2004Brian S. Lucas No abstract is available for this article. [source] Rigid,Flexible Block Molecules Based on a Laterally Extended Aromatic Segment: Hierarchical Assembly into Single Fibers, Flat Ribbons, and Twisted RibbonsCHEMISTRY - A EUROPEAN JOURNAL, Issue 23 2008Eunji Lee Abstract Self-assembling rigid,flexible block molecules consisting of a laterally extended aromatic segment and different lengths of hydrophilic coils were synthesized and characterized. The block molecule based on a long poly(ethylene oxide) coil (1), in the melt state, shows an unidentified columnar structure, whereas the molecule with a shorter poly(ethylene oxide) coil (2) self-organizes into an oblique columnar structure. Further decrease in the poly(ethylene oxide) coil length as in the case of 3, on heating, induces a rectangular columnar structure in addition to an oblique columnar mesophase. In diethyl ether, 1 and 2 were observed to self-assemble into uniform nanofibers with bilayer packing. Remarkably, these elementary fibers were observed to further aggregate in a lateral way to form well-defined flat ribbons (1) and twisted ribbons (2) with solvent exchange of diethyl ether into methanol. Furthermore, the ribbons formed in methanol dissociated into elementary fibers in response to the addition of aromatic guest molecules. This transformation between ribbons and single fibers in response to the addition of guest molecules is attributed to the intercalation of aromatic substrates within the rigid segments and subsequent loosening of the aromatic stacking interactions. These results demonstrate that the introduction of a laterally extended aromatic segment into an amphiphilic molecular architecture can lead to the hierarchical formation from elementary fibers of nanoribbons with a tunable twist through controlled lateral interactions between aromatic segments. [source] Algorithm for Spatial Clustering of Pavement SegmentsCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 2 2009Chientai Yang This article formulates a new spatial search model for determining appropriate pavement preservation project termini. A spatial clustering algorithm using fuzzy c-mean clustering is developed to minimize the rating variation in each cluster (project) of pavement segments while considering minimal project scope (i.e., length) and cost, initial setup cost, and barriers, such as bridges. A case study using the actual roadway and pavement condition data in fiscal year 2005 on Georgia State Route 10 shows that the proposed algorithm can identify more appropriate segment clustering scheme, than the historical project termini. The benefits of using the developed algorithm are summarized, and recommendations for future research are discussed. [source] Distinct Population Segments and Congressional Intent: Reply to WaplesCONSERVATION BIOLOGY, Issue 2 2000David S. Pennock No abstract is available for this article. [source] Uncoupling proteins 2 and 3 interact with members of the 14.3.3 familyFEBS JOURNAL, Issue 9 2000Benoit Pierrat Uncoupling proteins (UCPs) are members of the superfamily of the mitochondrial anion carrier proteins (MATP). Localized in the inner membrane of the organelle, they are postulated to be regulators of mitochondrial uncoupling. UCP2 and 3 may play an important role in the regulation of thermogenesis and, thus, on the resting metabolic rate in humans. To identify interacting proteins that may be involved in the regulation of the activity of UCPs, the yeast two-hybrid system was applied. Segments of hUCP2 containing the hydrophilic loops facing the intermembrane space, or combinations of these, were used to screen an adipocyte activation domain (AD) fusion library. The 14.3.3 protein isoforms ,, ,, , were identified as possible interacting partners of hUCP2. Screening of a human skeletal muscle AD fusion library, on the other hand, yielded several clones all of them encoding the , isoform of the 14.3.3 family. Mapping experiments further revealed that all these 14.3.3 proteins interact specifically with the C-terminal intermembrane space domain of both hUCP2 and hUCP3 whereas no interactions could be detected with the C-terminal part of hUCP1. Direct interaction between UCP3 and 14.3.3 , could be demonstrated after in vitro translation by coimmunoprecipitation. When coexpressed in a heterologous yeast system, 14.3.3 proteins potentiated the inhibitory effect of UCP3 overexpression on cell growth. These findings suggest that 14.3.3 proteins could be involved in the targeting of UCPs to the mitochondria. [source] Precision Polymers: Monodisperse, Monomer-Sequence-Defined Segments to Target Future Demands of Polymers in MedicineADVANCED MATERIALS, Issue 32-33 2009L. Hartmann Abstract The established technology platforms of solid-phase-supported oligopeptide and oligonucleotide synthesis can be expanded to access fully synthetic macromolecules, preserving both the monodisperse character and the defined monomer sequence. Precision polymers are sequentially assembled from a library of functional building blocks, enabling one to program interaction capabilities or generate functions by sequence-specific positioning of functionalities. Examples are provided, showing that these monodisperse macromolecules can be conjugated to oligonucleotides, oligopeptides, or poly(ethylene glycol)s. The resulting model systems can contribute to the understanding of complex biomedical-related processes. Due to the absence of chemical and molecular-weight distributions in these multifunctional segments, exact correlation of the monomer sequence and (bio)properties is attainable. This is demonstrated by the design of carrier systems that exhibit fine-tuned interactions with plasmid DNA, actively controlling important steps in DNA delivery and transfection, such as polyplex formation, DNA compression, and release of the cargo. [source] In Vitro Selection of Self-Interacting Transmembrane Segments--Membrane Proteins Approached from a Different PerspectiveIUBMB LIFE, Issue 3 2002Dieter Langosch Abstract The principles underlying the folding of integral membrane proteins are uncovered in an increasingly detailed way. Experimental determination of high-resolution structures followed by analysis of packing reveal structural similarities as well as differences to soluble globular proteins. At the same time, protein/protein interactions at the level of membrane-embedded domains have been investigated for different model proteins. More recently, self-interacting transmembrane helices have been selected from combinatorial libraries in vitro to study the mechanistic basis of protein/protein interaction in membranes in a systematic way. With an emphasis on the latter approach, this review discusses insights emerging from an integrated view on the recent advances. [source] Clinical Application of PET/CT Fusion Imaging for Three-Dimensional Myocardial Scar and Left Ventricular Anatomy during Ventricular Tachycardia AblationJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 6 2009JING TIAN M.D., Ph.D. Background: Image integration has the potential to display three-dimensional (3D) scar anatomy and facilitate substrate characterization for ventricular tachycardia (VT) ablation. However, the current generation of clinical mapping systems cannot display 3D left ventricle (LV) anatomy with embedded 3D scar reconstructions or allow display of border zone and high-resolution anatomic scar features. Objective: This study reports the first clinical experience with a mapping system allowing an integrated display of 3D LV anatomy with detailed 2D/3D scar and border zone reconstruction. Methods: Ten patients scheduled for VT ablation underwent contrast-enhanced computed tomography (CT) and Rubidium-82 perfusion/F-18 Fluorodeoxyglucose metabolic Positron Emission Tomography (PET) imaging to reconstruct 3D LV and scar anatomy. LV and scar models were co-registered using a 3D mapping system and analyzed with a 17-segment model. Metabolic thresholding was used to reconstruct the 3D border zone. Real-time display of CT images was performed during ablation. Results: Co-registration (error 4.3 ± 0.7 mm) allowed simultaneous visualization of 3D LV anatomy and embedded scar and guided additional voltage mapping. Segments containing homogenous or partial scar correlated in 94.4% and 85.7% between voltage maps and 3D PET scar reconstructions, respectively. Voltage-defined scar and normal myocardium had relative FDG uptakes of 40 ± 13% and 89 ± 30% (P < 0.05). The 3D border zone correlated best with a 46% metabolic threshold. Real-time display of registered high-resolution CT images allowed the simultaneous characterization of scar-related anatomic changes. Conclusion: Integration of PET/CT reconstruction allows simultaneous 3D display of myocardial scar and border zone embedded into the LV anatomy as well as the display of detailed scar anatomy. Multimodality imaging may enable a new image-guided approach to substrate-guided VT ablation. [source] Close relation of arterial ICC-like cells to the contractile phenotype of vascular smooth muscle cellJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 4 2007Vladimír Pucovský Abstract This work aimed to establish the lineage of cells similar to the interstitial cells of Cajal (ICC), the arterial ICC-like (AIL) cells, which have recently been described in resistance arteries, and to study their location in the artery wall. Segments of guinea-pig mesenteric arteries and single AIL cells freshly isolated from them were used. Confocal imaging of immunostained cells or segments and electron microscopy of artery segments were used to test for the presence and cellular localization of selected markers, and to localize AIL cells in intact artery segments. AIL cells were negative for PGP9.5, a neural marker, and for von Willebrand factor (vWF), an endothelial cell marker. They were positive for smooth muscle ,-actin and smooth muscle myosin heavy chain (SM-MHC), but expressed only a small amount of smoothelin, a marker of contractile smooth muscle cells (SMC), and of myosin light chain kinase (MLCK), a critical enzyme in the regulation of smooth muscle contraction. Cell isolation in the presence of latrunculin B, an actin polymerization inhibitor, did not cause the disappearance of AIL cells from cell suspension. The fluorescence of basal lamina protein collagen IV was comparable between the AIL cells and the vascular SMCs and the fluorescence of laminin was higher in AIL cells compared to vascular SMCs. Moreover, cells with thin processes were found in the tunica media of small resistance arteries using transmis-sion electron microscopy. The results suggest that AIL cells are immature or phenotypically modulated vascular SMCs constitutively present in resistance arteries. [source] Consumer preference for production-derived quality: analyzing perceptions of premium chicken production methodsAGRIBUSINESS : AN INTERNATIONAL JOURNAL, Issue 3 2009Brian Innes The authors assess consumer interest in a food product containing production-derived attributes. They use the French Label Rouge system in the Ontario chicken market as an example of a producer-controlled quality system. Conjoint analysis reveals a significant proportion of respondents value nonprice attributes; medication and housing had the highest importance scores, followed by price and brand ownership. Cluster analysis of the part-worth utilities revealed three consumer segments: price conscious consumers; consumers focused on naturalness; and those focused on animal health. Segments do not appear to differ on the basis of socioeconomic and demographic profile of respondents. However, multiitem scales reflecting attitudes towards production systems vary significantly across segments. Price-conscious respondents show agreement with use of medication and express concern over quality. Respondents in the naturalness segment express concern over quality, locality of production and impact of production methods on own health. Animal-health-conscious respondents show agreement with the use of medications, concern over quality, locality and impact of production methods on own health, but neutrality towards byproducts and traditional production methods. [EconLit citations: D120, Q130]. © 2009 Wiley Periodicals, Inc. [source] Phototropism of Thalli and Rhizoids Developed from the Thallus Segments of Bryopsis hypnoides LamourouxJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 6 2006Nai-Hao Ye Abstract Newly regenerated thalli were used to study the phototropism of Bryopsis hypnoides Lamouroux under different qualities of light. Positive phototropism in the thalli and negative phototropism in the rhizoids of B. hypnoides were investigated and analyzed in terms of bending. Both thalli and rhizoids developed from thallus segments exhibited typical tip growth, and their photoreceptive sites for phototropism were also restricted to the apical hemisphere. The bending curvature of rhizoids and thalli were determined with unilateral lights at various wavelengths and different fluence rates after a fixed duration of illumination. The trends of bending from the rhizoid and thallus were coincident, which showed that the action spectrum had a large range, from ultraviolet radiation (366.5 nm) to green light (524 nm). Based on the bending curvatures, blue light had the highest efficiency, while the efficiency of longer wavelengths (>500 nm) was significantly lower. External Ca2+ had no effect on the bending curvature of thalli and rhizoids. Blue light (440 nm) induced thallus branching from rhizoids, while red light (650 nm) had no such effect. Fast-occurring chloroplast accumulation in the outermost cytoplasmic layer of the blue light (440 nm)-irradiated region in the rhizoid was observed, from which protrusions (new thalli) arose after 4 h of the onset of illumination, and this action was thought to be driven by the dynamics of actin microfilaments. (Managing editor: Wei Wang) [source] Effect of gutta-percha solvents at different temperatures on the calcium, phosphorus and magnesium levels of human root dentinJOURNAL OF ORAL REHABILITATION, Issue 8 2001H. Do The aim of this study in vitro investigation was to evaluate the alterations caused by warmed gutta-percha solvents on the calcium, phosphorus and magnesium levels of root dentin. Extracted human anterior teeth, whose crowns and apical root thirds had been removed were used as root dentin specimens. The roots were sectioned longitudinally into two segments, cleaned and dried. Segments were divided into 12 groups (n=12). In 6 groups, the specimens received treatment with the following solvents at room temperature (22 °C): Chloroform, xylene, eucalyptol, orange oil, halothane and saline (control). Within each group, the specimens were further subgrouped into two to be incubated (100% humidity at 37 °C) for 5 and 10 min, respectively, following treatment with the solvents. The remaining six groups were treated with the same solvents which had been previously warmed to body temperature (37 °C) and received the same experimental procedures. The levels of calcium, phosphorus and magnesium in each specimen were analysed using energy dispersive spectrometric microanalysis. Statistical analysis of the readings showed that neither warming of the solvents nor prolonged incubation (treatment) time was capable of altering the histochemical composition of cut root dentin surfaces. [source] 94 An obligate(?) heterokont biflagellate parasite in codium fragileJOURNAL OF PHYCOLOGY, Issue 2003T. F. Lee Specimens of Codium fragile (Suringar) Hariot ssp. tomentosoides were collected from 9 sites in New England, and Long Island, New York at intervals throughout the years 1999-2003. Segments were removed from the thalli and chopped into fine fragments, mostly individual utricles and medullary filaments. Fragments were incubated in enriched seawater in dim light at 15C, 12:12 LD. Within 2,3 days, in almost all cases (more than 300) motile cells formed in many of the utricles and filaments. These were 10,15 micrometer elongated biflagellate heterokont cells. They appeared to consume the chloroplasts, and within 24 hours were reduced to colorless cells, about 5 micrometers long. These cells are unable to grow in Codium chloroplast suspensions. They appear to be always associated with Codium thalli, despite attempts to clean the thalli, and were never seen in utricles or filaments of intact plants. Their ultrastructure is under investigation and will be reported on here. [source] Bonus-Malus Scales in Segmented Tariffs With Stochastic Migration Between SegmentsJOURNAL OF RISK AND INSURANCE, Issue 4 2003Natacha Brouhns This article proposes a computer-intensive methodology to build bonus-malus scales in automobile insurance. The claim frequency model is taken from Pinquet, Guillén, and Bolancé (2001). It accounts for overdispersion, heteroskedasticity, and dependence among repeated observations. Explanatory variables are taken into account in the determination of the relativities, yielding an integrated automobile ratemaking scheme. In that respect, it complements the study of Taylor (1997). [source] Generalization Across Segments in Second Language Consonant IdentificationLANGUAGE LEARNING, Issue 1 2009Kenneth J. De Jong This article examines the extent of differences between second language (L2) learners in their abilities to identify L2 consonants and provides evidence for linguistic generalization from one consonant to other consonants. It distinguishes among different sorts of models of the relationship between segments: (a) segmentally specific models in which each segment is treated separately and (b) generalized featural models in which segments that share features are treated as a group. It also examines (c) ordered models in which one segment might rely on another previously existing one. The article presents the results of an experiment with 40 Korean learners of English identifying English obstruents in different prosodic locations, and it examines the pattern of variation in perceptual accuracy across the listeners. Results indicate that manner perception varies from person to person as a unit, regardless of the segment, suggesting a single generalized featural skill. Voicing identification, however, does not vary as a unit across the different prosodic positions, suggesting different skills that are applicable to different prosodic positions and are acquired separately. There is also evidence for an implicational relationship between pairs of segments that differ in markedness, providing some evidence for an ordered model; however, such patterns are not pervasive across different contrasts. [source] AB-polymer Networks with Cooligoester and Poly(n -butyl acrylate) Segments as a Multifunctional Matrix for Controlled Drug ReleaseMACROMOLECULAR BIOSCIENCE, Issue 9 2010Christian Wischke Abstract Semi-crystalline AB-copolymer networks from oligo[(, -caprolactone)- co -glycolide]dimethacrylates and n -butylacrylate have recently been shown to exhibit a shape-memory functionality, which may be used for self-deploying and anchoring of implants. In this study, a family of such materials differing in their molar glycolide contents ,G was investigated to determine structure,property functional relationships of unloaded and drug loaded specimens. Drug loading and release were evaluated, as well as their degradation behavior in vitro and in vivo. Higher ,G resulted in higher loading levels by swelling and a faster release of ethacridine lactate, lower melting temperature of polymer crystallites, and a decrease in shape fixity ratio of the programmed temporary shape. For unloaded networks, the material behavior in vivo was independent of the mechanical load associated with different implantation sites and agreed well with data from in vitro degradation studies. Thus, AB networks could be used as novel matrices for biofunctional implants, e.g., for urogenital applications, which can self-anchor in vivo and provide mechanical support, release drugs, and finally degrade in the body to excretable fragments. [source] Segmented Block Copolymers with Terephthalic-Extended Poly(ethylene oxide) SegmentsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 5 2008Debby Husken Abstract Segmented block copolymers comprised of flexible PEO segments and monodisperse crystallizable bisestertetraamide segments have been synthesized. The influence of the terephthalic units in the soft phase on the transitions and the thermal mechanical and elastic properties are studied. The presence of terephthalic units in the copolymer increases the glass transition temperature of the soft phase by ,5,°C. The low-temperature flexibility of the copolymers is improved because of the lower crystallinity and melting temperature of PEO. With the use of terephthalic-extended PEO segments, segmented block copolymers with low moduli (G',<,15 MPa) and good elastic properties could be obtained. [source] Polyamides X.34: A New Class of Polyamides with Long Alkane SegmentsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 13 2003Moritz Ehrenstein Abstract A new series of semi-crystalline polyamides (PA), which comprise extended aliphatic segments between the amide moieties and which display an interesting amphiphilic character has been synthesized and characterized. The polymers PA-2.34, PA-4.34, PA-8.34, PA-10.34, and PA-12.34 were prepared by melt-polycondensation of salts of tetratriacontanedioic acid and the respective short-chain diamine. The thermal properties of these polymers were investigated by differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical thermal analysis. The new polyamides exhibit melting temperatures that depend on the length of the diamine and range between 166 (PA-12.34) and 190,°C (PA-2.34). Solid transitions were observed between 38 and 57,°C. The materials displayed a rather limited solubility in common polyamide solvents, but readily dissolved in alkylsulfonic acids. All members of the series formed thermo-reversible gels in the highly polar sulfuric acid and 1,2,3,4-tetrahydronaphthalene, reflecting their interesting amphiphilic character. Young's moduli and tensile strengths of melt-processed, isotropic films of the polyamides investigated were in the range of 0.5,0.7 GPa and 20.30 MPa, respectively, independent of the length of the diamine used. Melting temperatures of polyamides PA-X.34 (x) and 1,2,3,4-tetrahydronaphthalene/PA-X.34 gels (37.5 wt.-% polyamide, determined from the second DSC heating scans) (+). [source] | ||||||||||||||||||||||||||||||||||