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Combined Presence (combined + presence)
Selected AbstractsThe musculature of three species of gastrotrichs surveyed with confocal laser scanning microscopy (CLSM)ACTA ZOOLOGICA, Issue 3 2006Francesca Leasi Abstract The muscular system of gastrotrichs consists of circular, longitudinal and helicoidal bands that when analysed with confocal laser scanning microscopy, provide new insights into their functional organization and phylogenetic importance. We therefore undertook a comparative study of the muscle organization in three species of Gastrotricha from the orders Macrodasyida (Paradasys sp., Lepidodasyidae; Turbanella sp., Turbanellidae) and Chaetonotida (Polymerurus nodicaudus, Chaetonotidae). The general muscle organization of the marine interstitial macrodasyidans, Paradasys and Turbanella, not only confirms earlier observation on other species but also adds new details concerning the organization and number of helicoidal, longitudinal and other muscle bands (e.g. semicircular band). The freshwater, epibenthic,epiphytic chaetonotid, Polymerurus nodicaudus, has a similar muscular organization to other species of Chaetonotidae, especially species of Chaetonotus, Halichaetonotus and Lepidodermella. Perhaps unique to Polymerurus is the combined presence of an unbranched Rückenhautmuskel (also in Halichaetonotus and Lepidodermella) and a specialized dorsoventral caudal muscle, which flank the splanchnic component of the longitudinal muscles (only in Chaetonotus and Lepidodermella). This combination, together with the presence of splanchnic dorsoventral muscles, known only in Xenotrichulidae, implies a unique phylogenetic position for Polymerurus, and indicates a potential basal position of this taxon among the Chaetonotidae studied so far (i.e. Aspidiophorus, Chaetonotus, Halichaetonotus and Lepidodermella). [source] Toxicity assessment of reference and natural freshwater sediments with the LuminoTox assayENVIRONMENTAL TOXICOLOGY, Issue 4 2006P. M. Dellamatrice Abstract We examined the possibility of adapting the LuminoTox, a recently-commercialized bioanalytical testing procedure initially developed for aqueous samples, to assess the toxic potential of sediments. This portable fluorescent biosensor uses photosynthetic enzyme complexes (PECs) to rapidly measure photosynthetic efficiency. LuminoTox testing of 14 CRM (Certified Reference Material) sediments was first undertaken with (1) a "solid phase assay" (Lum-SPA) in which PECs are in intimate contact with sediment slurries for a 15 min exposure period and (2) an elutriate assay (Lum-ELU) in which PECs are exposed for 15 min to sediment water elutriates. CRM sediment toxicity data were then compared with those generated with the Microtox Solid Phase Assay (Mic-SPA). A significant correlation (P < 0.05) was shown to exist between Lum-SPA and Mic-SPA, indicating that both tests display a similar toxicity response pattern for CRM sediments having differing contaminant profiles. The sediment elutriate Lum-ELU assay displayed toxicity responses (i.e. measurable IC20s) for eight of the 14 CRM sediments, suggesting that it is capable of determining the presence of sediment contaminants that are readily soluble in an aqueous elutriate. Lum-SPA and Mic-SPA bioassays were further conducted on 12 natural freshwater sediments and their toxicity responses were more weakly, yet significantly, correlated. Finally, Lum-SPA testing undertaken with increasing mixtures of kaolin clay confirmed that its toxicity responses, in a manner similar to those reported for the Mic-SPA assay, are also subject to the influence of grain size. While further studies will be required to more fully understand the relationship between Lum-SPA assay responses and the physicochemical makeup of sediments (e.g., grain size, combined presence of natural and anthropogenic contaminants), these preliminary results suggest that LuminoTox testing could be a useful screen to assess the toxic potential of solid media. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 395,402, 2006. [source] Assessing household health expenditure with Box,Cox censoring modelsHEALTH ECONOMICS, Issue 9 2005Jean-Paul Chaze Abstract In order to assess the combined presence of zero expenditures and a heavily skewed distribution of positive expenditures, the Box,Cox transformation with location parameter is used to define a set of models generalising the standard Tobit, Heckman selection and double-hurdle models. Extended flexibility with respect to previous specifications is introduced, notably regarding negative transformation parameters, which may prove necessary for medical expenditures, and corner-solution outcomes. An illustration is provided by the analysis of household health expenditure in Switzerland. Copyright © 2005 John Wiley & Sons, Ltd. [source] Regional Inequalities and Civil Conflict in Sub-Saharan Africa,INTERNATIONAL STUDIES QUARTERLY, Issue 2 2009Gudrun ØStby The case study literature is ripe with examples of a positive association between inequality and civil war, but systematic country-level studies have largely failed to find a significant relationship. One reason for this discrepancy may be that large-N studies tend to ignore spatial variations in group welfare within countries, although civil wars often take place within limited areas. We address this gap in the literature by applying GIS operations to Demographic and Health Surveys to construct new disaggregated data on welfare and socioeconomic inequalities between and within subnational regions in 22 countries in Sub-Saharan Africa. These measures are coupled with geographical data on the location of conflict zones for the period 1986,2004. We find that conflict onsets are more likely in regions with (1) low levels of education; (2) strong relative deprivation regarding household assets; (3) strong intraregional inequalities; and (4) combined presence of natural resources and relative deprivation. [source] Adrenergic-Cholinergic Interaction that Modulates Repolarization in the Atrium is Altered with AgingJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 4 2002EUGENE A. SOSUNOV Ph.D. Autonomic Modulation of Atrial Repolarization.Introduction: Aging is associated with involution of both limbs of the autonomic nervous system, and the prejunctional and postjunctional effects of adrenergic and cholinergic stimulation are altered with senescence. Hence, postjunctional age-related changes in adrenergic-cholinergic interaction are a likely occurrence and may contribute to an altered substrate for arrhythmias. Methods and Results: Microelectrode techniques were used to record action potentials from epicardial slices of Bachmann's bundles of dogs aged 3 to 5 years (adult) and 8 to 12 years (old) in the absence or presence of acetylcholine and isoproterenol (separately and in combination). In control, action potential duration to 90% repolarization (APD) was longer in old atria. Acetylcholine (10,8 to 10,5 mol/L) in a concentration-dependent manner hyperpolarized and shortened APD in both tissues, with more prominent effects in the old. The effects of isoproterenol (10,9 to 10,6 mol/L) to elevate the plateau and shorten APD were about the same in both adult and old tissues. In adults, low concentrations of isoproterenol (10,9 and 10,8 mol/L) significantly prolonged APD, which had been first shortened by acetylcholine. This effect of isoproterenol was decreased in old atrial tissue, resulting in shorter APD in old than adult atria in the combined presence of beta-adrenergic and muscarinic agonists. Conclusion: In adult Bachmann's bundle, beta-adrenergic stimulation effectively operates as a "brake" to decrease the extent of cholinergic-induced APD shortening. The action of beta-adrenergic stimulation to antagonize acetylcholine-induced acceleration of repolarization declines with age, which may contribute to an altered arrhythmogenic substrate. [source] ANTIMONATE OPAQUE GLAZE COLOURS FROM THE FAIENCE MANUFACTURE OF LE BOIS D'ÉPENSE (19TH CENTURY, NORTHEASTERN FRANCE)*ARCHAEOMETRY, Issue 5 2009M. MAGGETTI Three types of antimony-based, opaque ceramic colours were used in the faience workshop of Le Bois d'Épense during the first decades of the 19th century; that is, yellow, tawny and green. Yellow is generated by lead antimonate crystals (Naples Yellow), which are incorporated into an uncoloured glass matrix. According to SEM,EDS measurements, these pigments contain iron. The tawny colour is the optical result of the combined presence of similar yellow, iron-bearing lead antimonate particles in a Fe-rich, brownish glass matrix. The green opaque colour is produced by the combination of a blue cobalt glass and yellow Pb,Sn,Fe-antimonate crystals. Cores of zoned pigments lighten the recipes, according to which the pigments were produced. First, they were synthesized by calcination, ground and then mixed with a colourless, brown or blue glass powder. The resulting powder mixture was added to a liquid agent and used as high-temperature ceramic colour. [source] Structural implications of a G170R mutation of alanine:glyoxylate aminotransferase that is associated with peroxisome-to-mitochondrion mistargetingACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2010Snezana Djordjevic In a subset of patients with the hereditary kidney-stone disease primary hyperoxaluria type 1 (PH1), the liver-specific enzyme alanine:glyoxylate aminotransferase (AGT) is mistargeted from peroxisomes to mitochondria. This is a consequence of the combined presence of the common P11L polymorphism and a disease-specific G170R mutation. In this paper, the crystal structure of mutant human AGT containing the G170R replacement determined at a resolution of 2.6,Å is reported. The crystal structure of AGT consists of an intimate dimer in which an extended N-terminal segment of 21 amino acids from one subunit wraps as an elongated irregular coil around the outside of the crystallographic symmetry-related subunit. In addition to the N-terminal segment, the monomer structure contains a large domain of 261 amino acids and a small C-terminal domain of 110 amino acids. Comparison of the mutant AGT structure and that of wild-type normal AGT shows that the two structures are almost identical, with a backbone-atom r.m.s. deviation of 0.34,Å. However, evidence of significant local structural changes in the vicinity of the G170R mutation might be linked to the apparent decrease in protein stability. [source] Filaggrin null mutations increase the risk and persistence of hand eczema in subjects with atopic dermatitis: results from a general population studyBRITISH JOURNAL OF DERMATOLOGY, Issue 1 2010J.P. Thyssen Summary Background, Hand eczema is prevalent in the general population. It remains unclear whether or not filaggrin gene (FLG) null mutations increase the overall risk of hand eczema or only increase the risk of hand eczema in subjects with atopic dermatitis. Objectives, To investigate the association between FLG null mutations and hand eczema. Methods, A random sample of 3335 adults from the general population in Denmark was patch tested, FLG genotyped for R501X and 2282del4 null mutations and questioned about hand eczema. Results, Participants with combined presence of atopic dermatitis and FLG null mutation status had a significantly higher prevalence of hand eczema, an earlier onset of hand eczema and a higher persistence of hand eczema compared with subjects with normal FLG status and absence of atopic dermatitis. Logistic regression analyses revealed positive associations between hand eczema within the past 12 months and FLG null mutation status in participants with a history of atopic dermatitis [odds ratio (OR) 2·98; 95% confidence interval (CI) 1·27,7·01], but not in subjects without atopic dermatitis (OR 0·82; 95% CI 0·41,1·67). Conclusions,FLG null mutations were significantly associated with hand eczema (< 12 months) in subjects with atopic dermatitis. Combined atopic dermatitis and filaggrin null mutation status was strongly associated with early onset of hand eczema and hand eczema persistence. [source] Nitric oxide (NO) modulation of PAF-induced cardiopulmonary action: interaction between NO synthase and cyclo-oxygenase-2 pathwaysBRITISH JOURNAL OF PHARMACOLOGY, Issue 4 2001Fulvia Fabi To further investigate into the mechanisms of PAF-induced cardiopulmonary actions, we examined the effects of the nitric oxide synthase (NOS) inhibitor L -N, -nitro- L -arginine (L -NNA), of the specific cyclooxygenase-2 (COX-2) inhibitor NS 398, and of the combined presence of both COX and NOS inhibitors on the PAF responses in the heart lung preparation of guinea-pig (HLP). In HLPs perfused with homologous blood, dose-response curves for the haemodynamic and bronchial effects of PAF (1 , 32 ng) were carried out in the absence or presence of L -NNA (200 ,M). L -NNA caused an increase in the resting pulmonary arterial pressure (PAP) without affecting the other basal values, and strongly potentiated the bronchoconstriction and pulmonary hypertension elicited by PAF. An enhancement of the PAF-induced actions on right atrial pressure (RAP) and cardiac output (CO) was also observed. All the effects of L -NNA were antagonized by L -arginine (2 mM). The presence of L -NNA in the perfusing blood of HLPs failed to affect the pulmonary hypertensive and bronchoconstrictor responses induced by the thromboxane A2 mimetic U46619 (0.05 , 1.6 ,g), 5-hydroxytryptamine (0.1 , 1.6 ,g), and histamine (0.1 , 1.6 ,g), thus suggesting that these PAF secondary mediators are not responsible for the hyper-responsiveness to PAF induced by L -NNA. Blocking COX-2 pathway with NS 398 (15 , 30 ,M) did not alter the cardiopulmonary resting variables. However, a reduction of the PAF-mediated pulmonary hypertension, but not of bronchoconstriction, was observed. When L -NNA was added to the perfusing medium of HLPs pre-treated with NS 398 or with indomethacin (15 ,M), the basal PAP values were enhanced. However, in the combined presence of COX and NOS inhibitors, only a slight increase in the hypertensive responses to the highest doses of PAF was observed, whereas the PAF mediated actions at bronchial and cardiac level were unaffected. This study indicates that (i) the cardiopulmonary actions induced by PAF are specifically modulated by endogenous NO through the NOS pathway, and (ii) COX-2 isoform is involved in the pulmonary hypertensive, but not bronchoconstrictor, effects of PAF. Furthermore, an interaction between PAF stimulated COX, particularly COX-2, and NOS pathways appears to take a functional role at both bronchial and cardiovascular level. British Journal of Pharmacology (2001) 134, 777,788; doi:10.1038/sj.bjp.0704311 [source] | |||||||||||||