Home About us Contact
|
Home About us Contact | ||
|
|
||
Comparative
Terms modified by Comparative Selected AbstractsComparative in vitro study of the sealing efficiency of white vs grey ProRoot mineral trioxide aggregate formulas as apical barriersDENTAL TRAUMATOLOGY, Issue 2 2008Spyridon Stefopoulos Recently conventional grey MTA has been replaced by a new white MTA formula. The aim of this study was to compare the root canal adaptation of white MTA to that of grey MTA when used as an apical barrier in teeth with open apices. We also examined whether a previous calcium hydroxide intracanal medication affects MTA's sealing ability and investigated the ability to remove calcium hydroxide from the root canal walls. Forty-nine teeth were prepared in a manner to simulate a divergent open apex of immature teeth. Four teeth were used in a preliminary experiment to demonstrate the inefficacy of calcium hydroxide removal from the canal walls in teeth with open apices. Four groups of 10 teeth each were created: groups A and B were treated with calcium hydroxide intracanal medication and then received an apical plug of grey and white MTA respectively. Groups C and D received an apical plug of grey and white MTA respectively without previous intracanal medication. Four teeth served as negative and one as a positive control. The marginal adaptation and sealing ability of the apical barrier were tested by means of a dye tracer (basic fuchsine) after longitudinal sectioning. It was found that MTA apical barrier resisted displacement during gutta-percha condensation. Calcium hydroxide pretreatment, adversely affected white MTA sealing ability (P < 0.05). [source] Comparative and developmental study of the immune system in XenopusDEVELOPMENTAL DYNAMICS, Issue 6 2009Jacques Robert Abstract Xenopus laevis is the model of choice for evolutionary, comparative, and developmental studies of immunity, and invaluable research tools including MHC-defined clones, inbred strains, cell lines, and monoclonal antibodies are available for these studies. Recent efforts to use Silurana (Xenopus) tropicalis for genetic analyses have led to the sequencing of the whole genome. Ongoing genome mapping and mutagenesis studies will provide a new dimension to the study of immunity. Here we review what is known about the immune system of X. laevis integrated with available genomic information from S. tropicalis. This review provides compelling evidence for the high degree of similarity and evolutionary conservation between Xenopus and mammalian immune systems. We propose to build a powerful and innovative comparative biomedical model based on modern genetic technologies that takes take advantage of X. laevis and S. tropicalis, as well as the whole Xenopus genus. Developmental Dynamics 238:1249,1270, 2009. © 2009 Wiley-Liss, Inc. [source] Comparative in vitro and in vivo genotoxicities of 7H -benzo[c]fluorene, manufactured gas plant residue (MGP), and MGP fractionsENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 3 2004Leslie Cizmas Abstract Manufactured gas plant residue (MGP) is a complex mixture of polycyclic aromatic hydrocarbons (PAHs) that is tumorigenic in the lungs of mice. This study compared the relative genotoxicity of 7H -benzo[c]fluorene (BC), a PAH component of MGP, with MGP and MGP fractions in order to assess the contribution of BC to the genotoxicity of MGP. An MGP sample was separated into seven fractions (F1,F7) using silica gel column chromatography with petroleum ether (PE) followed by PE:acetone (99:1 v/v, then 98:2). PAHs were quantified using gas chromatography/mass spectrometry. An aliquot of F2, the fraction with the highest BC concentration and highest weighted mutagenic activity in Salmonella typhimurium strain TA98, was further separated using silica gel thin-layer chromatography with hexane. The first F2 subfraction, sF2-a, was enriched in BC and coeluting compounds and contained 35,000 ppm BC and 216,109 ppm carcinogenic PAHs (cPAHs, the sum of seven PAHs categorized by the U.S. EPA as class B2 carcinogens). The second F2 subfraction, sF2-b, contained a ninefold lower concentration of BC, with 3,900 ppm BC and 45,216 ppm cPAHs. Female ICR mice received topical application of crude MGP, crude MGP spiked with analytical-grade BC, F2, sF2-a, sF2-b, or analytical-grade BC. DNA adduct levels were analyzed by nuclease P1-enhanced 32P-postlabeling. In lung DNA of mice receiving 0.48 or 3.0 mg/mouse, net total RAL × 109 values were F2, 30.8 and 87.2; sF2-a, 24.8 and 106.7; and sF2-b, 19.6 and 151.0, respectively. Mice dosed with 0.10 mg analytical-grade BC (the mass of BC in 3.0 mg sF2-a) exhibited a net total RAL × 109 value of 7.03 in lung DNA. This was equal to approximately 7% of the total RAL × 109 value produced by 3.0 mg sF2-a. Thus, although BC appears to make an appreciable contribution to pulmonary adduct formation, the results suggest that MGP components other than BC play an important role in lung DNA adduct formation following topical MGP administration. Environ. Mol. Mutagen. 43:159,168, 2004. © 2004 Wiley-Liss, Inc. [source] Comparative expressed sequence hybridization studies of high-hyperdiploid childhood acute lymphoblastic leukemiaGENES, CHROMOSOMES AND CANCER, Issue 3 2004Alicja M. Gruszka-Westwood The functional consequences of a high-hyperdiploid karyotype, found in up to one-third of cases of acute lymphoblastic leukemia (ALL), are unknown. Using the technique of comparative expressed sequence hybridization (CESH), we sought to address the question of whether increased chromosome copies in hyperdiploid ALL lead to increased gene expression. Relative expression of hyperdiploid ALL blasts versus peripheral blood mononuclear cells was analyzed in 18 patients. Common regions of overexpression corresponding to the presence of tri-/tetrasomies included: Xp22.1,22.2, 4q28, 6q14,15, 6q24, 10p13, 14q23,24, 17q21, 18q12, and 21q21, identified in 28,89% of cases. However, increased expression without underlying trisomy occurred at 3p21.3, 7q11.2, 8p21, and 8q24.1 in 39,90% of cases. High expression at 7q11.2, the most consistent change detected, was confirmed by quantitative PCR. Poor correlation between the presence of tri-/tetrasomy and overexpression was observed for chromosomes 14 and 17. Two cases were reanalyzed versus (i) B cells, (ii) transformed B cells, and (iii) CD34+19+ cells (the putative counterpart of the leukemic cell). A reduction in the number of relatively overexpressed regions was observed with CD34+19+ cells. In particular, the peak at 7q11.2 disappeared, suggesting up-regulation of genes from this region in the early ontology of normal B-cell development. In conclusion, we have shown that tri-/tetrasomies in hyperdiploid ALL lead to an increase in the expression of associated sequences. The choice of a biologically relevant reference is crucial for data interpretation. © 2004 Wiley-Liss, Inc. [source] Comparative genomics-guided loop-mediated isothermal amplification for characterization of Pseudomonas syringae pv. phaseolicolaJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2009X. Li Abstract Aims:, To design and evaluate a loop-mediated isothermal amplification (LAMP) protocol by combining comparative genomics and bioinformatics for characterization of Pseudomonas syringae pv. phaseolicola (PSP), the causal agent of halo blight disease of bean (Phaseolus vulgaris L.). Methods and Results:, Genomic sequences of Pseudomonas syringae pathovars, P. fluorescens and P. aeruginosa were analysed using multiple sequence alignment. A pathovar-specific region encoding pathogenicity-related secondary metabolites in the PSP genome was targeted for developing a LAMP assay. The final assay targeted a polyketide synthase gene, and readily differentiated PSP strains from other Pseudomonas syringae pathovars and other Pseudomonas species, as well as other plant pathogenic bacteria, e.g. species of Pectobacterium, Erwinia and Pantoea. Conclusion:, A LAMP assay has been developed for rapid and specific characterization and identification of PSP from other pathovars of P. syringae and other plant-associated bacteria. Significance and Impact of the Study:, This paper describes an approach combining a bioinformatic data mining strategy and comparative genomics with the LAMP technology for characterization and identification of a plant pathogenic bacterium. The LAMP assay could serve as a rapid protocol for microbial identification and detection with significant applications in agriculture and environmental sciences. [source] Skp2 and p27kip1 expression in melanocytic nevi and melanoma: an inverse relationship,JOURNAL OF CUTANEOUS PATHOLOGY, Issue 10 2004Qing Li Background:, S-phase kinase associated protein-2 (Skp2) ubiquitin ligase p45SKP2 is important in the degradation of p27kip1 (a cyclin dependent kinase inhibitor) and progression through the G1-S cell-cycle checkpoint. Low levels of p27 and high levels of Skp2 are related to poor prognosis in some cancers. Methods:, Clinicopathologic features and immunohistochemical expression of Skp2 and p27kip1 were investigated in 198 melanocytic proliferations: 21 melanocytic nevi, 23 melanoma in situ, 119 primary melanoma, and 35 metastatic melanoma samples. Comparative and survival analyses were performed. Results:, Progressive and significant increases and decreases in the nuclear expression of Skp2 and p27kip1, respectively, was identified moving from melanocytic nevi (0.05 ± 0.2/85 ± 15) to melanoma in situ (3 ± 2/45 ± 20) to primary cutaneous melanoma (12 ± 9/30 ± 25) to metastatic melanoma (25 ± 15/15 ± 20) (p , 0.006). Expression of these proteins also significantly correlated with increasing American Joint Committee on Cancer (AJCC) T (tumor) classification and AJCC stage (p , 0.01). Moreover, the level of these two proteins exhibited a significant inverse relationship (r = ,0.4, p = 0.0001). Skp2 cytoplasmic labeling index of >20% predicted worse 10-year overall survival (38% vs. 86%, p = 0.04) in primary melanoma. Neither p27 nor Skp2 nuclear expression impacted significantly on prognosis. Conclusions:, Gain of Skp2 and loss of p27kip1 protein expression are implicated in melanoma progression where the level of p27kip1 may be regulated by targeted proteolysis via Skp2. Cytoplasmic expression of Skp2 defines a subset of aggressive melanomas and could represent another pathway of deregulation of the cell cycle. [source] Validation of Tool Mark Comparisons Obtained Using a Quantitative, Comparative, Statistical AlgorithmJOURNAL OF FORENSIC SCIENCES, Issue 4 2010L. Scott Chumbley Ph.D. Abstract:, A statistical analysis and computational algorithm for comparing pairs of tool marks via profilometry data is described. Empirical validation of the method is established through experiments based on tool marks made at selected fixed angles from 50 sequentially manufactured screwdriver tips. Results obtained from three different comparison scenarios are presented and are in agreement with experiential knowledge possessed by practicing examiners. Further comparisons between scores produced by the algorithm and visual assessments of the same tool mark pairs by professional tool mark examiners in a blind study in general show good agreement between the algorithm and human experts. In specific instances where the algorithm had difficulty in assessing a particular comparison pair, results obtained during the collaborative study with professional examiners suggest ways in which algorithm performance may be improved. It is concluded that the addition of contextual information when inputting data into the algorithm should result in better performance. [source] Comparative and functional morphology of wing coupling structures in Trichoptera: AnnulipalpiaJOURNAL OF MORPHOLOGY, Issue 2 2010Ian C. StocksArticle first published online: 20 AUG 200 Abstract Several orders of morphologically four-winged insects have evolved mechanisms that enforce a union between the mesothoracic and metathoracic wings (forewings and hindwings) during the wing beat cycle. Such mechanisms result in a morphologically tetrapterous insect flying as if it were functionally dipterous, and these mechanisms have been described for several insect orders. The caddisfly suborders Annulipalpia and Integripalpia (Trichoptera) each have evolved a wing coupling apparatus, with at least three systems having evolved within the suborder Annulipalpia. The comparative and inferred functional morphology of the putative wing coupling mechanisms is described for the annulipalpian families Hydropsychidae (subfamilies Macronematinae and Hydropsychinae), Polycentropodidae and Ecnomidae, and a novel form-functional complex putatively involved with at-rest forewing-forewing coupling is described for Hydropsychidae: Smicrideinae. It is proposed that the morphology of the wing coupling apparatuses of Hydropsychinae and Macronematinae are apomorphies for those clades. J. Morphol. 2009. © 2009 Wiley-Liss, Inc. [source] Experimental investigation of the hydrodynamics in a liquid,solid riserAICHE JOURNAL, Issue 3 2005Shantanu Roy Abstract Liquid,solid fluid dynamics has been investigated in a 6-in. (0.15 m) "cold-flow" circulating fluidized bed riser using non-invasive flow monitoring methods. Gamma-ray computed tomography (CT) was used to measure the time-averaged cross-sectional solids volume fraction distributions at several elevations. The time-averaged mean and "fluctuating" solids velocity fields were quantified using the computer-automated radioactive particle tracking (CARPT) technique. The experimental equipment, protocol of implementation, and data analysis have been discussed briefly, with particular emphasis on the specific features in the use of these techniques for studying high-density turbulent flows as in a liquid,solid riser. The experimental study examines nine operating conditions, that is, three liquid superficial velocities and three solids flow rates. The solids holdup profile is found to be relatively uniform across the cross section of the riser, with marginal segregation near the walls. The time-averaged solids velocity profiles are found to have a negative component at the walls, indicating significant solids backmixing. Detailed characterization of the solids velocity fields in terms of RMS velocities, kinetic energies, Hurst exponents, residence time distributions, trajectory length distributions, dispersion coefficients, and so forth are presented. Comparative and symbiotic analyses of the results were used to develop a coherent picture of the solids flow field. In addition, the work also serves to demonstrate the power and versatility of these flow-imaging techniques in studying highly turbulent and opaque multiphase systems. © 2005 American Institute of Chemical Engineers AIChE J, 51: 802,835, 2005 [source] Comparative and functional morphology of the buccal cavity of Diplogastrina (Nematoda) and a first outline of the phylogeny of this taxon*JOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 1 2000A. Fürst Von Lieven The Diplogastrina include about 290 species of free living nematodes. Traditional classifications of this taxon are not based upon hypotheses of phylogenetic relationships. The highly variable structures of the buccal cavity were examined in 21 species using light microscopy and SEM. The function of the stomatal structures was studied with the aid of video recordings of living worms. The morphological data were used to reconstruct a first outline of the phylogenetic relationships of the Dipolgastrina. A rhabditoid gymnostomatal tube which is longer than wide, a short stegostom and a small dorsal tooth as in Pseudodiplogasteroides belong to the stem species pattern of Diplogastrina. Diplogastrina with a ,Rhabditis'-like gymnostomatal tube feed on bacteria and small fungal spores. A short and broad gymnostom as well as a right subventral tooth which forms a functional unit with the dorsal tooth were acquired step by step in the ancestral line leading to Mononchoides and Tylopharynx. The cuticularized cheilostom was divided into six plates connected by pliable regions twice independently within the Diplogastrina. The teeth-bearing posterior part of the buccal capsule can move forewards by pushing apart the plates of the cheilostom so that the teeth can get in contact with food items that are too big to be sucked into the buccal cavity. Diplogastrina with a divided cheilostom can feed not only on bacteria, but also on larger fungal spores, ciliates or other nematodes. Tylopharynx is specialized to rip apart the cell wall of fungal hyphae with the movements of a dorsal and a subventral tooth in order to suck out the contents of the fungus. This shows that the transformation of the buccal cavity in Diplogastrina is linked with an expansion of ecological niches. [source] Comparative and evolutionary dimensions of the energetics of human pregnancy and lactationAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 5 2002D.L. Dufour The purpose of this article is to compare the energetics of reproduction for human and other primates in order to evaluate the extent to which human reproductive energetics are distinct from other primates and other large-bodied placental mammals. The article also evaluates the energetics of human and primate gestation and lactation using data from a variety of different populations living under different environmental circumstances. Energetics refers to energy intake and expenditure, and changes in body fat stores. Human and nonhuman primates have longer periods of gestation and lactation and slower prenatal and postnatal growth than other mammals of similar size. This reduces daily maternal energy costs. The development of sizable fat stores is not unique to humans, but fat stores are typically greater in human females and may play a greater role in reproduction. The strategies used to meet the energy costs of pregnancy vary among populations of humans and nonhuman primates and among humans interindividual variability is high. In pregnancy, some increase energy intake but others apparently do not. Increases in metabolic efficiency are evident in some human populations, whereas decreases in physical activity occur, but are not seen in all human or primate populations. Lactation is more energetically costly on a daily basis among humans and nonhuman primates, but has not been as well studied. It appears that both nonhuman and human primates tend to increase energy intake to meet in part the cost of lactation. They also use other strategies such as relying on body tissue stores, reductions in physical activity, and/or increases in metabolic efficiency to meet the remainder of the cost. It is also clear that human females in different populations and different women in the same population use a different combination of strategies to meet the cost of lactation. Am. J. Hum. Biol. 14:584,602, 2002. © 2002 Wiley-Liss, Inc. [source] Comparative whitefly transmission of Tomato chlorosis virus and Tomato infectious chlorosis virus from single or mixed infectionsPLANT PATHOLOGY, Issue 2 2009A. Dalmon Tomato chlorosis virus (ToCV) and Tomato infectious chlorosis virus (TICV) are two criniviruses that are emerging worldwide, and induce similar yellowing diseases in tomato crops. While TICV is transmitted only by Trialeurodes vaporariorum, ToCV is transmitted by three whitefly species in two genera Trialeurodes vaporariorum, T. abutilonea and Bemisia tabaci. The efficiency of transmission by T. vaporariorum from plants infected by one virus or by both was compared, and the probability of virus transmission by a single whitefly was derived from group testing experiments. The estimated transmission probabilities ranged from 0·01 to 0·13, and were not significantly different between ToCV and TICV, or between single and mixed infections. Experiments using B. tabaci as a vector and source plants infected by TICV and ToCV did not reveal any functional trans-complementation for transmission of TICV by ToCV, suggesting that if this phenomenon occurs in nature, it is at a very low frequency. Possible reasons why TICV did not establish in southern France while ToCV is now endemic are discussed. [source] Nicotine, acetanilide and urea multi-level 2H-, 13C- and 15N-abundance reference materials for continuous-flow isotope ratio mass spectrometry,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 22 2009Arndt Schimmelmann Accurate determinations of stable isotope ratios require a calibration using at least two reference materials with different isotopic compositions to anchor the isotopic scale and compensate for differences in machine slope. Ideally, the , values of these reference materials should bracket the isotopic range of samples with unknown , values. While the practice of analyzing two isotopically distinct reference materials is common for water (VSMOW-SLAP) and carbonates (NBS 19 and L-SVEC), the lack of widely available organic reference materials with distinct isotopic composition has hindered the practice when analyzing organic materials by elemental analysis/isotope ratio mass spectrometry (EA-IRMS). At present only L-glutamic acids USGS40 and USGS41 satisfy these requirements for ,13C and ,15N, with the limitation that L-glutamic acid is not suitable for analysis by gas chromatography (GC). We describe the development and quality testing of (i) four nicotine laboratory reference materials for on-line (i.e. continuous flow) hydrogen reductive gas chromatography-isotope ratio mass-spectrometry (GC-IRMS), (ii) five nicotines for oxidative C, N gas chromatography-combustion-isotope ratio mass-spectrometry (GC-C-IRMS, or GC-IRMS), and (iii) also three acetanilide and three urea reference materials for on-line oxidative EA-IRMS for C and N. Isotopic off-line calibration against international stable isotope measurement standards at Indiana University adhered to the ,principle of identical treatment'. The new reference materials cover the following isotopic ranges: ,2Hnicotine ,162 to ,45,, ,13Cnicotine ,30.05 to +7.72,, ,15Nnicotine ,6.03 to +33.62,; ,15Nacetanilide +1.18 to +40.57,; ,13Curea ,34.13 to +11.71,, ,15Nurea +0.26 to +40.61, (recommended , values refer to calibration with NBS 19, L-SVEC, IAEA-N-1, and IAEA-N-2). Nicotines fill a gap as the first organic nitrogen stable isotope reference materials for GC-IRMS that are available with different ,15N values. Comparative ,13C and ,15N on-line EA-IRMS data from 14 volunteering laboratories document the usefulness and reliability of acetanilides and ureas as EA-IRMS reference materials. Published in 2009 by John Wiley & Sons, Ltd. [source] Comparative morphometrics of embryonic facial morphogenesis: Implications for cleft-lip etiologyTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 1 2007Nathan M. Young Abstract Cleft lip (CL) with or without cleft palate (CL[P]) has a complex etiology but is thought to be due to either genetic or environmentally induced disruptions of developmental processes affecting the shape and size of the facial prominences (medial nasal, lateral nasal, and maxilla). Recent advances in landmark-based morphometrics enable a rigorous reanalysis of phenotypic shape variation associated with facial clefting. Here we use geometric morphometric (GM) tools to characterize embryonic shape variation in the midface and head of six strains of mice that are both cleft-liable (A, A/WySn, CL/Fr) and normal (BALB/cBy, C57BL, CD1). Data were comprised of two-dimensional landmarks taken from frontal and lateral photographs of embryos spanning the time period in which the facial prominences fuse (GD10-12). Results indicate that A/- strain mice, and particularly A/WySn, have overall smaller midfaces compared to other strains. The A/WySn strain also has significant differences in facial shape related to retarded development. Overall, CL/Fr strain mice are normal-sized, but tend to have undersized maxillary prominences that do not project anteriorly and have a small nasal contact area. These results suggest that the etiology of clefting differs in A/WySn and CL/Fr strains, with the former strain suffering disruptions to developmental processes affecting overall size (e.g., neural crest migration deficiencies and lower mitotic activity), while the latter strain has defects restricted to the shape and size of the maxilla. A combination of molecular experimentation and phenotypic analysis of shape is required to test these hypotheses further. Anat Rec, 290:123,139, 2007. © 2006 Wiley-Liss, Inc. [source] Comparative studies of oncostatin M expression in the tissues of adult rodentsTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 1 2005Iya Znoyko Oncostatin M (OSM), a member of the interleukin-6 family of cytokines, is thought to be expressed mostly by activated T-lymphocytes and monocytes in adult animals. However, here we report specific constitutive tissue expression of OSM in the pancreas, kidney, testes, spleen, stomach, and brain, but not liver or lung, of three adult rodent species. © 2005 Wiley-Liss, Inc. [source] Citizenship Tests: A Comparative, Communitarian PerspectiveTHE POLITICAL QUARTERLY, Issue 3 2007AMITAI ETZIONI The history, nature and scope of citizen naturalisation tests are briefly examined in this article, as well as their political and social applications. A comparison of tests from the United States, the United Kingdom, the Netherlands and Germany highlights the ways in which these tests are used as immigration controls rather than as a way to establish preparation for citizenship. The difference in the content of the tests also reveal alternative conceptions of citizenship including authoritarian, liberal and neo-communitarian. [source] Using Visual Stimuli in EthnographyANTHROPOLOGY & EDUCATION QUARTERLY, Issue 2 2008George Spindler In this article, the work of George and Louise Spindler is reviewed with visual stimuli ranging from the Rorschach technique and Thematic Apperception Technique to inventions of their own, the Cross-Cultural Sensitization Technique, the Instrumental Activities Inventory, and the Cross-Cultural, Comparative, Reflective Interview Technique. The sites of the various researches, the methods of application, and a brief analysis of the results are included.,[interview techniques, culture and personality, ethnography and education] [source] Comparative in vitro degradation of the human hemorphin LVV-H7 in mammalian plasma analysed by capillary zone electrophoresis and mass spectrometryBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 2 2007Harald John Abstract The human hemorphin LVV-H7 (L32VVYPWTQRF41) is a hemoglobin-,, -,, -, or -, chain derived cationic decapeptide of the µ-opioid receptor binding family. It exhibits potential pharmacological value relevant, for example, for blood pressure regulation, learning performance and Alzheimer's disease. The regulatory potency is strictly dependent on the length of the amino acid sequence which is sensitive towards proteinases from tissues and plasma. To analyse LVV-H7 in vitro degradation in mammalian plasma, a novel multi-component quantitative capillary zone electrophoretic (CZE) procedure was applied, combined with qualitative metabolite profiling by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In all types of plasma, LVV-H7 was N -terminally truncated generating four metabolites (M1,M4) with an intact C -terminus: M1 (V33VYPWTQRF41), M2 (V34YPWTQRF41), M3 (Y35PWTQRF41) and M4 (W37TQRF41). In EDTA plasma these degradation products were detected exclusively, whereas in citrate and heparin plasma four further metabolites appeared resulting from additional C -terminal cleavage of the dipeptide R40F41: M5 (L32VVYPWTQ39), M6 (V33VYPWTQ39), M7 (V34YPWTQ39) and M8 (Y35PWTQ39). In the presence of selective proteinase inhibitors aminopeptidase M and angiotensin-converting enzyme (for N - and C -terminal truncation, respectively) were identified as plasma enzymes responsible for hemorphin degradation. Furthermore, striking inter-mammalian species distinctions were detected revealing strongly differing degradation velocities but similar metabolite patterns. Copyright © 2007 John Wiley & Sons, Ltd. [source] Comments on papers reporting IR-spectra and other data of alleged L-alanine alaninium nitrate and L-alanine sodium nitrate crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 7 2009M. Fleck Abstract We argue that the IR- and Raman-spectra of "L-alanine alaninium nitrate" given in "Investigation on the growth, optical behaviour and factor group of an NLO crystal: L-Alanine Alaninium nitrate" by Aravindan et al., Cryst. Res. Technol. 42, 1097 (2007), actually concern L-Alanine. Correspondingly, the data presented in "A comparative study on the growth and characterization of nonlinear optical amino acid crystals: L-Alanine (LA) and L-alanine alaninium nitrate (LAAN)" by Aravindan et al., Spectrochim. Acta A 71, 297 (2008), seems to be erroneous, as is "Synthesis, Growth, and Characterization of a New Semiorganic Nonlinear Optical Crystal: L-Alanine Sodium Nitrate (LASN)", Sethuraman, et al., Cryst. Growth Des. 8, 1863 (2008). In these papers properties and data were reported for L-Alanine compounds that actually are L-Alanine crystals and, in addition, unit cell parameters were given that seem to have been copied from other papers. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Writing the "Show,Me" Standards: Teacher Professionalism and Political Control in U.S. State Curriculum PolicyCURRICULUM INQUIRY, Issue 3 2002Margaret Placier This qualitative case study analyzes the process of writing academic standards in one U.S. state, Missouri. The researchers took a critical pragmatic approach, which entailed close examination of the intentions and interactions of various participants in the writing process (teachers, politicians, business leaders, the public), in order to understand the text that was finally produced. School reform legislation delegated responsibility for writing the standards to a teacher work group, but the teachers found that their "professional" status and their intention to write standards that reflected a "constructivist" view of knowledge would meet with opposition. Politicians, who held different assumptions about the audience, organization, and content of the standards, exercised their greater power to control the outcome of the process. As the researchers analyzed public records and documents generated during the writing process, they constructed a chronological narrative detailing points of tension among political actors. From the narrative, they identified four conflicts that significantly influenced the final wording of the standards. They argue that as a consequence of these conflicts, Missouri's standards are characterized by a dichotomous view of content and process; bland, seemingly value,neutral language; and lack of specificity. Such conflicts and outcomes are not limited to this context. A comparative, international perspective shows that they seem to occur when groups in societies marked by political conflicts over education attempt to codify what "all students should know." [source] Gene transfer into chicken embryos as an effective system of analysis in developmental biologyDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 3 2000Sadao Yasugi Chicken embryos have been used as a model animal in developmental biology since the time of comparative and experimental embryology. Recent application of gene transfer techniques to the chicken embryo increases their value as an experimental animal. Today, gene transfer into chicken cells is performed by three major systems, lipofection, electroporation and the virus-mediated method. Each system has its own features and applicability. In this overview and the associated four minireviews, the methods and application of each system will be presented. [source] Comparative and developmental study of the immune system in XenopusDEVELOPMENTAL DYNAMICS, Issue 6 2009Jacques Robert Abstract Xenopus laevis is the model of choice for evolutionary, comparative, and developmental studies of immunity, and invaluable research tools including MHC-defined clones, inbred strains, cell lines, and monoclonal antibodies are available for these studies. Recent efforts to use Silurana (Xenopus) tropicalis for genetic analyses have led to the sequencing of the whole genome. Ongoing genome mapping and mutagenesis studies will provide a new dimension to the study of immunity. Here we review what is known about the immune system of X. laevis integrated with available genomic information from S. tropicalis. This review provides compelling evidence for the high degree of similarity and evolutionary conservation between Xenopus and mammalian immune systems. We propose to build a powerful and innovative comparative biomedical model based on modern genetic technologies that takes take advantage of X. laevis and S. tropicalis, as well as the whole Xenopus genus. Developmental Dynamics 238:1249,1270, 2009. © 2009 Wiley-Liss, Inc. [source] Agnathan brain anatomy and craniate phylogenyACTA ZOOLOGICA, Issue 2009Roman Hossein Khonsari Abstract The central nervous system of hagfishes displays unique characteristics that are distinct from any other craniate neuroanatomic features. Whether these hagfish characters are general for all craniates, autapomorphies of hagfishes, or merely a derived state of the general cyclostome condition is still a matter of debate that relates to the question of the monophyly or paraphyly of the cyclostomes. The present cladistic study includes 123 neuroanatomical characters of nine chordate species and supports cyclostome paraphyly, in contrast to most current molecular sequence-based phylogenies, which support cyclostome monophyly. An understanding of the unique neural characters in hagfishes is critical to inspiring further comparative and developmental studies with regards to these two conflicting results and the very deep divergence between craniates and their presumed sister groups. The recent access to hagfish developmental data may provide exciting perspectives in the understanding and characterization of the basalmost craniate node and the interpretation of hagfish brain structure. [source] Techniques to measure the dry aeolian deposition of dust in arid and semi-arid landscapes: a comparative study in West NigerEARTH SURFACE PROCESSES AND LANDFORMS, Issue 2 2008Dirk Goossens Abstract Seven techniques designed to measure the dry aeolian deposition of dust on a desert surface were tested during field experiments in Niger, central-west Africa. Deposition fluxes were measured during eight periods of 3,4 days each. Experimental techniques tested were the MDCO (marble dust collector) method, the Frisbee method, the glass plate method (optical analysis of dust deposited on glass surfaces using particle imaging software), the soil surface method (deposition on a simulated desert floor) and the CAPYR (capteur pyramidal) method. Theoretical techniques tested were the inferential method and the combination method (gradient method extended with a deposition term for coarse dust particles). The results obtained by the MDCO, Frisbee, inferential and combination methods could be directly compared by converting the data to identical standard conditions (deposition on a water surface producing no resuspension). The results obtained by the other methods (glass plate, soil surface, CAPYR) were compared relatively. The study shows that the crude (unconverted) deposition fluxes of the five experimental techniques were similar, while the crude deposition fluxes calculated by the two theoretical techniques were substantially higher, of the order of four to five times as high as for the experimental techniques. Recalculation of the data to identical environmental conditions (the standard water surface) resulted in nearly identical deposition fluxes for the MDCO, Frisbee, inferential and combination techniques, although the latter two still had slightly higher values (but the differences remained small). The measurements illustrate the need to include a grain shape factor in theoretical dust deposition models. Without such a factor, theoretical models overestimate the deposition. The paper also discusses the advantages and disadvantages of the techniques tested. Copyright © 2007 John Wiley & Sons, Ltd. [source] Variation in gene content among geographically diverse Sulfolobus isolatesENVIRONMENTAL MICROBIOLOGY, Issue 1 2008Dennis W. Grogan Summary The ability of competitive (i.e., comparative) genomic hybridization (CGH) to assess similarity across entire microbial genomes suggests that it should reveal diversification within and between natural populations of free-living prokaryotes. We used CGH to measure relatedness of genomes drawn from Sulfolobus populations that had been shown in a previous study to be diversified along geographical lines. Eight isolates representing a wide range of spatial separation were compared with respect to gene-specific tags based on a closely related reference strain (Sulfolobus solfataricus P2). For the purpose of assessing genetic divergence, 232 loci identified as polymorphic were assigned one of two alleles based on the corresponding fluorescence intensities from the arrays. Clustering of these binary genotypes was stable with respect to changes in the threshold and similarity criteria, and most of the groupings were consistent with an isolation-by-distance model of diversification. These results indicate that increasing spatial separation of geothermal sites correlates not only with minor sequence polymorphisms in conserved genes of Sulfolobus (demonstrated in the previous study), but also with the regions of difference (RDs) that occur between genomes of conspecifics. In view of the abundance of RDs in prokaryotic genomes and the relevance that some RDs may have for ecological adaptation, the results further suggest that CGH on microarrays may have advantages for investigating patterns of diversification in other free-living archaea and bacteria. [source] Application of toxicity identification evaluation procedures for characterizing produced water using the tropical mysid, Metamysidopsis insularisENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2004Najila Elias-Samlalsingh Abstract Toxicity identification evaluations (TIEs) were performed on seven produced water (PW) effluents from inland discharge facilities operated in Trinidad and Tobago, a Caribbean tropical country with one of the oldest commercial oil industries in the world. The research was performed to determine the presence and magnitude of toxicity and characterize which toxicants are responsible for observed effects. Marine effluent toxicity characterizations with Metamysidopsis insularis revealed high whole acute toxic-unit response for produced water ranged from 8.1 to >17.0 acute toxic-unit (initial toxicity test) and 5.7 to 1,111 acute toxic-unit (baseline toxicity test). Toxicity test results for all sites except one, which had the highest toxicity, are comparative with similar studies on produced water. The toxicological causality of this complex mixture differed for each PW with nonpolar organics being consistently toxic in all samples. Other potential toxicants contributing to overall toxicity to a much lesser extent were metals, ammonia, and volatile organic compounds. With the use of sodium thiosulfate and filtration manipulations for only PW6 sample, there was very slight reduction in toxicity; therefore, oxidants and filterable materials were not a great contributing factor. Whole effluent toxicity also can be attributed to ionic imbalance and the very stable oil-in-water emulsion that consists of fine oil droplets (less than 0.1,10 ,m with an average diameter of 2.5 ,m). This investigation is the first of its type in Trinidad and demonstrates clearly the applicability of this test method and local test species for evaluating complex effluents in tropical environments. [source] Efficacy and Tolerability of the New Antiepileptic Drugs, I: Treatment of New-Onset Epilepsy: Report of the TTA and QSS Subcommittees of the American Academy of Neurology and the American Epilepsy SocietyEPILEPSIA, Issue 5 2004Jacqueline A. French Summary: Purpose: To assess the evidence demonstrating efficacy, tolerability, and safety of seven new antiepileptic drugs [AEDs; gabapentin (GBP), lamotrigine (LTG), topiramate (TPM), tiagabine (TGB), oxcarbazepine (OXC), levetiracetam (LEV), and zonisamide (ZNS), reviewed in the order in which these agents received approval by the U.S. Food and Drug Administration] in the treatment of children and adults with newly diagnosed partial and generalized epilepsies. Methods: A 23-member committee, including general neurologists, pediatric neurologists, epileptologists, and doctors in pharmacy, evaluated the available evidence based on a structured literature review including MEDLINE, Current Contents, and Cochrane Library for relevant articles from 1987 until September 2002, with selected manual searches up to 2003. Results: Evidence exists, either from comparative or dose-controlled trials, that GBP, LTG, TPM, and OXC have efficacy as monotherapy in newly diagnosed adolescents and adults with either partial or mixed seizure disorders. Evidence also shows that LTG is effective for newly diagnosed absence seizures in children. Evidence for effectiveness of the new AEDs in newly diagnosed patients with other generalized epilepsy syndromes is lacking. Conclusions: The results of this evidence-based assessment provide guidelines for the prescription of AEDs for patients with newly diagnosed epilepsy and identify those seizure types and syndromes for which more evidence is necessary. [source] Governmental participation and the organizational adaptation of Green parties: On access, slack, overload and distressEUROPEAN JOURNAL OF POLITICAL RESEARCH, Issue 2006BENOÎT RIHOUX On the one hand, a series of hypotheses with regards to the possible link between prior organizational adaptation and eventual access to governmental participation are examined. On the other, the opposite question is addressed: that of the potential impact of governmental participation , and, more recently, exit from government , on further organizational adaptation. Following both a qualitative and a qualitative comparative (QCA) analysis, one ultimately identifies a link between prior organizational adaptation and eventual access to government, but a much more indirect and contrasted link between governmental participation (and exit from government) and further organizational adaptation. [source] UNDERSTANDING THE EVOLUTION AND STABILITY OF THE G-MATRIXEVOLUTION, Issue 10 2008Stevan J. Arnold The G -matrix summarizes the inheritance of multiple, phenotypic traits. The stability and evolution of this matrix are important issues because they affect our ability to predict how the phenotypic traits evolve by selection and drift. Despite the centrality of these issues, comparative, experimental, and analytical approaches to understanding the stability and evolution of the G -matrix have met with limited success. Nevertheless, empirical studies often find that certain structural features of the matrix are remarkably constant, suggesting that persistent selection regimes or other factors promote stability. On the theoretical side, no one has been able to derive equations that would relate stability of the G -matrix to selection regimes, population size, migration, or to the details of genetic architecture. Recent simulation studies of evolving G -matrices offer solutions to some of these problems, as well as a deeper, synthetic understanding of both the G -matrix and adaptive radiations. [source] The origin of the endothelial cells: an evo-devo approach for the invertebrate/vertebrate transition of the circulatory systemEVOLUTION AND DEVELOPMENT, Issue 4 2005R. Muńoz-Chápuli Summary Circulatory systems of vertebrate and invertebrate metazoans are very different. Large vessels of invertebrates are constituted of spaces and lacunae located between the basement membranes of endodermal and mesodermal epithelia, and they lack an endothelial lining. Myoepithelial differentation of the coelomic cells covering hemal spaces is a frequent event, and myoepithelial cells often form microvessels in some large invertebrates. There is no phylogenetic theory about the origin of the endothelial cells in vertebrates. We herein propose that endothelial cells originated from a type of specialized blood cells, called amoebocytes, that adhere to the vascular basement membrane. The transition between amoebocytes and endothelium involved the acquisition of an epithelial phenotype. We suggest that immunological cooperation was the earliest function of these protoendothelial cells. Furthermore, their ability to transiently recover the migratory, invasive phenotype of amoebocytes (i.e., the angiogenic phenotype) allowed for vascular growth from the original visceral areas to the well-developed somatic areas of vertebrates (especially the tail, head, and neural tube). We also hypothesize that pericytes and smooth muscle cells derived from myoepithelial cells detached from the coelomic lining. As the origin of blood cells in invertebrates is probably coelomic, our hypothesis relates the origin of all the elements of the circulatory system with the coelomic wall. We have collected from the literature a number of comparative and developmental data supporting our hypothesis, for example the localization of the vascular endothelial growth factor receptor-2 ortholog in hemocytes of Drosophila or the fact that circulating progenitors can differentiate into endothelial cells even in adult vertebrates. [source] | ||||||||||||||||||||||||||||||||||||||||||||||