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Selected AbstractsPreferential occurrence of diazotrophic endophytes, Azoarcus spp., in wild rice species and land races of Oryza sativa in comparison with modern racesENVIRONMENTAL MICROBIOLOGY, Issue 2 2000Margret Engelhard Several diazotrophic species of Azoarcus spp. occur as endophytes in the pioneer plant Kallar grass. The purpose of this study was to screen Asian wild rice and cultivated Oryza sativa varieties for natural association with these endophytes. Populations of culturable diazotrophs in surface-sterilized roots were characterized by 16S rDNA sequence analysis, and Azoarcus species were identified by genomic fingerprints. A. indigens and Azoarcus sp. group C were detected only rarely, whereas Azoarcus sp. group D occurred frequently in samples of flooded plants: in 75% of wild rice, 80% of land races of O. sativa from Nepal and 33% of modern cultivars from Nepal and Italy. The putatively endophytic populations of diazotrophs differed with the rice genotype. The diversity of cultured diazotrophs was significantly lower in wild rice species than in modern cultivars. In Oryza officinalis (from Nepal) and O. minuta (from the Philippines), Azoarcus sp. group D were the predominant diazotrophic putative endophytes in roots. In contrast, their number was significantly lower in modern cultivars of O. sativa, whereas numbers and diversity of other diazotrophs, such as Azospirillum spp., Klebsiella sp., Sphingomonas paucimobilis, Burkholderia sp. and Azorhizobium caulinodans, were increased. In land races of O. sativa, the diazotrophic diversity was equally high; however, Azoarcus sp. was found in high apparent numbers. Similar differences in populations were also observed in a culture-independent approach comparing a wild rice (O. officinalis) and a modern-type O. sativa plant: in clone libraries of root-associated nitrogenase (nifH,) gene fragments, the diazotrophic diversity was lower in the wild rice species. New lineages of nifH genes were detected, e.g. one deeply branching cluster within the anf (iron) nitrogenases. Our studies demonstrate that the natural host range of Azoarcus spp. extends to rice, wild rice species and old varieties being preferred over modern cultivars. [source] Combined use of selective inhibitors and fluorogenic substrates to study the specificity of somatic wild-type angiotensin-converting enzymeFEBS JOURNAL, Issue 8 2006Nicolas D. Jullien Somatic angiotensin-converting enzyme (ACE) contains two homologous domains, each bearing a functional active site. Studies on the selectivity of these ACE domains towards either substrates or inhibitors have mostly relied on the use of mutants or isolated domains of ACE. To determine directly the selectivity properties of each ACE domain, working with wild-type enzyme, we developed an approach based on the combined use of N-domain-selective and C-domain-selective ACE inhibitors and fluorogenic substrates. With this approach, marked differences in substrate selectivity were revealed between rat, mouse and human somatic ACE. In particular, the fluorogenic substrate Mca-Ala-Ser-Asp-Lys-DpaOH was shown to be a strict N-domain-selective substrate of mouse ACE, whereas with rat ACE it displayed marked C-domain selectivity. Similar differences in selectivity between these ACE species were also observed with a new fluorogenic substrate of ACE, Mca-Arg-Pro-Pro-Gly-Phe-Ser-Pro-DpaOH. In support of these results, changes in amino-acid composition in the binding site of these three ACE species were pinpointed. Together these data demonstrate that the substrate selectivity of the N-domain and C-domain depends on the ACE species. These results raise concerns about the interpretation of functional studies performed in animals using N-domain and C-domain substrate selectivity data derived only from human ACE. [source] Factors controlling the carbon isotope fractionation of tetra- and trichloroethene during reductive dechlorination by Sulfurospirillum ssp. and Desulfitobacterium sp. strain PCE-SFEMS MICROBIOLOGY ECOLOGY, Issue 1 2007Danuta Cichocka Abstract Carbon stable isotope fractionation of tetrachloroethene (PCE) and trichloroethene (TCE) was investigated during reductive dechlorination. Growing cells of Sulfurospirillum multivorans, Sulfurospirillum halorespirans, or Desulfitobacterium sp. strain PCE-S, the respective crude extracts and the abiotic reaction with cyanocobalamin (vitamin B12) were used. Fractionation of TCE (,C=1.0132,1.0187) by S. multivorans was more than one order of magnitude higher than values previously observed for tetrachloroethene (PCE) (,C=1.00042,1.0017). Similar differences in fractionation were observed during reductive dehalogenation by the close relative S. halorespirans with ,C=1.0046,1.032 and ,C=1.0187,1.0229 for PCE and TCE respectively. TCE carbon isotope fractionation (,C=1.0150) by the purified PCE-reductive dehalogenase from S. multivorans was more than one order of magnitude higher than fractionation of PCE (,C=1.0017). Carbon isotope fractionation of TCE by Desulfitobacterium sp. strain PCE-S (,C=1.0109,1.0122) as well as during the abiotic reaction with cyanocobalamin (,C=1.0154) was in a similar range to previously reported values for fractionation by mixed microbial cultures. In contrast with previous results with PCE, no effects due to rate limitations, uptake or transport of the substrate to the reactive site could be observed during TCE dechlorination. Our results show that prior to a mechanistic interpretation of stable isotope fractionation factors it has to be carefully verified how other factors such as uptake or transport affect the isotope fractionation during degradation experiments with microbial cultures. [source] Ecological implications of xylem cavitation for several Pinaceae in the Pacific Northern USAFUNCTIONAL ECOLOGY, Issue 5 2000J. Piñol Abstract 1.,Xylem hydraulic properties and vulnerability to cavitation (determined using the air-injection method) were studied in six Pinaceae of the northern Rocky Mountains: Pinus ponderosa, Pseudotsuga menziesii, Larix occidentalis, Pinus contorta, Pinus albicaulis and Abies lasiocarpa. We tested whether species extending into drier habitats exhibited increased resistance to water stress-induced cavitation, and whether there is a trade-off between xylem transport capacity and resistance to cavitation. 2.,At lower elevations the more drought-tolerant P. ponderosa was much less resistant to cavitation than the codominant P. menziesii. Greater vulnerability to cavitation in P. ponderosa was compensated for, at least in part, by increased stomatal control of water loss (inferred from carbon isotope discrimination) and by increased sapwood to leaf area ratios. Similar differences, but less pronounced, were found in codominant species at higher elevations. 3.,Leaf specific hydraulic conductivity was negatively correlated with mean cavitation pressure. When species were separated into pines and non-pines, sapwood specific conductivity and mean cavitation pressure were also negatively correlated within each of the two groups. 4.,Our results indicate that within the evergreen conifers examined, greater resistance to water stress-induced cavitation is not required for survival in more xeric habitats, and that there is a trade-off between xylem conductance and resistance to cavitation. [source] Respiratory changes in human red cellsINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 6 2001G. Aliberti To investigate physiological respiratory changes in human red cells, we measured automated red cell parameters in samples from the pulmonary and radial arteries of 86 patients undergoing aorto-coronary bypass and from the pulmonary artery and the aorta in 23 patients. Our results showed higher mean corpuscular volume (88.53 ± 5.06 fl vs. 88.12 ± 4.94 fl, P < 0.000001), haematocrit (0.369 ± 0.039 vs. 0.367 ± 0.038, P < 0.0005), red cell distribution width (43.38 ± 4.16 vs. 43.04 ± 4.05 fl, P < 0.000001) and a lower mean corpuscular haemoglobin concentration (338.3 ± 15.9 vs. 339.9 ± 16.8 g/l, P < 0.005) in pulmonary arterial as compared to radial arterial blood. There were no differences with respect to haemoglobin concentration, red blood cell count, or mean corpuscular haemoglobin. Similar differences were observed between pulmonary arterial and aortic blood. Our results suggest cyclic respiratory modifications of red cell parameters attributable to the CO2 Jacobs,Stewart cycle. [source] The detection of elements in larval otoliths from Atlantic herring using laser ablation ICP-MSJOURNAL OF FISH BIOLOGY, Issue 4 2003D. Brophy Trace element concentrations of otoliths from larval herring Clupea harengus collected from known spawning beds in the Celtic and Irish Seas, were investigated using laser ablation ICP-MS and compared with concentrations in the larval cores of juvenile otoliths from the same populations and year class. A range of elements (Mg, Zn, Sr, Ba and Pb) was detectable in early larval otoliths (20,40 µm diameter). Larval otolith concentrations exceeded the larval core concentrations of juvenile otoliths and also the concentrations reported in the literature, for Mg, Zn, Ba and Pb, indicating that the measurement of elements in larval otoliths was severely affected by post-mortem contamination, most likely due to adherence of tissue and endolymph residue on the otolith surface. Comparison of otolith composition between larvae from two freezing treatments showed that contamination from Mg and Zn was more serious in otoliths that had remained in frozen larvae for prolonged periods. Larval populations from the two seas showed significant differences in otolith Sr concentrations, which were consistent over two sampling years. Similar differences were seen in the corresponding juvenile populations. The results show that while early larval otoliths are extremely susceptible post-mortem contamination, Sr concentrations can be reliably measured using laser ablation ICP-MS and for this element, the detection of region specific differences is possible. [source] Early Detection Of Diminished Baroreflex Sensitivity In Diabetic Patients Without Evidence Of Cardiovascular Autonomic NeuropathyJOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 3 2000D Ziegler Diabetic cardiovascular autonomic neuropathy (CAN) carries an increased risk of mortality. Decreased baroreflex sensitivity (BRS) has been identified as a predictor of increased mortality following myocardial infarction. We evaluated spontaneous BRS in 39 healthy control subjects (C: age (mean ± SEM): 41.5 ± 1.9 years) and 116 diabetic patients (64% Type 1, 36% Type 2; age: 45.8 ± 1.4 years; diabetes duration: 16.9 ± 1.0 years; HbA1c: 9.2 ± 0.2%) using cross-spectral analysis between systolic blood pressure and heart rate in the low-frequency (LF) and high-frequency (HF) bands as well as time domain (sequence) analysis in the supine and standing positions over 10 min. According to previously suggested definitions based on autonomic function tests (AFTs), 36 patients had definite CAN (CAN+: 3 of 7 indices abnormal), 13 had borderline CAN (CAN[+]: 2 of 7 indices abnormal), and 64 had no evidence of CAN (CAN,: 1 of 7 indices abnormal). Maximum gain in cross-spectral LF band (standing) was significantly reduced in CAN, as compared with C (5.2 ± 0.4 vs. 7.2 ± 0.8 ms/mmHg, p < 0.05). Moreover, maximum gain in cross-spectral HF band was significantly lower in CAN, than in C (supine: 12.0 ± 1.2 vs. 17.9 ± 2.5 ms/mmHg, p < 0.05; standing: 4.9 ± 0.5 vs. 8.7 ± 1.0 ms/mmHg, p < 0.05). The slope of the regression line between defined increases or reductions in systolic blood pressure and R-R intervals was significantly reduced in CAN, compared to C (supine: 10.6 ± 0.7 vs. 14.2 ± 1.6 ms/mmHg, p < 0.05; standing: 5.6 ± 0.4 vs. 8.1 ± 0.7 ms/mmHg, p < 0.05). Similar differences were obtained when comparing the CAN, and CAN[+] groups, the latter showing significantly reduced BRS by both techniques (p < 0.05). In contrast, no such differences were noted when comparing the CAN[+] and CAN+ groups. In conclusion, reduced spontaneous baroreflex sensitivity is an early marker of autonomic dysfunction at a stage when autonomic function tests do not yet indicate the presence of CAN, while cases with borderline CAN show a degree of BRS abnormality that is comparable to the level seen in definite CAN. Prospective studies are needed to evaluate whether reduced BRS is a predictor of mortality in diabetic patients. [source] Injury Deaths of US Citizens Abroad: New Data Source, Old Travel ProblemJOURNAL OF TRAVEL MEDICINE, Issue 5 2009Daniel J Tonellato BA Candidate Background Global travel continues to increase, including among US citizens. The global burden of injuries and violence, accounting for approximately 5 million deaths worldwide in 2000, is also growing. Travelers often experience heightened risk for this biosocial disease burden. This study seeks to further describe and improve our understanding of the variable risk of travel-related injury and death. Methods Information on US civilian citizen deaths from injury while abroad was obtained from the US Department of State Web site. This information was categorized into regional and causal groupings. The groupings were compared to each other and to injury deaths among citizens in their native countries. Results From 2004 to 2006, there were 2,361 deaths of US citizens overseas due to injury. Of these US citizen injury deaths, 50.4% occurred in the Americas region. Almost 40% (37.8%) of US citizen injury deaths in the low- to middle-income Americas were due to vehicle crashes compared to about half that (18.9%) (proportional mortality ratio [PMR] = 1.72, 95% confidence interval [CI] 1.59,1.62) for low- to middle-income Americas citizen injury deaths. Similar differences between US citizen injury death abroad and the in-country distributions were also found for vehicle crashes in Europe (35.9% vs 16.5%, PMR = 2.17, 95% CI 1.78,2.64; p < 0.0005), for drowning deaths in the Americas (13.1% vs 4.6%, PMR = 2.67, 95% CI 2.29,3.11) and many island nations (63.5% vs 3.5%, PMR = 11.38, 95% CI 8.17,15.84), and for homicides in the low- to middle-income European countries (16.9% vs 10.5%, PMR = 1.52, 95% CI .90,2.57). Conclusions US citizens should be aware of regional variation of injury deaths in foreign countries, especially for motor vehicle crashes, drowning, and violence. Improved knowledge of regional variations of injury death and risk for travelers can further inform travelers and the development of evidence-based prevention programs and policies. The State Department Web site is a new data source that furthers our understanding of this challenging travel-related health issue. [source] Analyses of GA20ox - and GID1 -over-expressing aspen suggest that gibberellins play two distinct roles in wood formationTHE PLANT JOURNAL, Issue 6 2009Mélanie Mauriat Summary Gibberellins (GAs) are involved in many aspects of plant development, including shoot growth, flowering and wood formation. Increased levels of bioactive GAs are known to induce xylogenesis and xylem fiber elongation in aspen. However, there is currently little information on the response pathway(s) that mediate GA effects on wood formation. Here we characterize an important element of the GA pathway in hybrid aspen: the GA receptor, GID1. Four orthologs of GID1 were identified in Populus tremula × P. tremuloides (PttGID1.1,1.4). These were functional when expressed in Arabidopsis thaliana, and appear to present a degree of sub-functionalization in hybrid aspen. PttGID1.1 and PttGID1.3 were over-expressed in independent lines of hybrid aspen using either the 35S promoter or a xylem-specific promoter (LMX5). The 35S:PttGID1 over-expressors shared several phenotypic traits previously described in 35S:AtGA20ox1 over-expressors, including rapid growth, increased elongation, and increased xylogenesis. However, their xylem fibers were not elongated, unlike those of 35S:AtGA20ox1 plants. Similar differences in the xylem fiber phenotype were observed when PttGID1.1, PttGID1.3 or AtGA20ox1 were expressed under the control of the LMX5 promoter, suggesting either that PttGID1.1 and PttGID1.3 play no role in fiber elongation or that GA homeostasis is strongly controlled when GA signaling is altered. Our data suggest that GAs are required in two distinct wood-formation processes that have tissue-specific signaling pathways: xylogenesis, as mediated by GA signaling in the cambium, and fiber elongation in the developing xylem. [source] Validation Study of Genetic Associations with Coronary Artery Disease on Chromosome 3q13-21 and Potential Effect Modification by SmokingANNALS OF HUMAN GENETICS, Issue 6 2009Benjamin D. Horne Summary The CATHGEN study reported associations of chromosome 3q13-21 genes (KALRN, MYLK, CDGAP, and GATA2) with early-onset coronary artery disease (CAD). This study attempted to independently validate those associations. Eleven single nucleotide polymorphisms (SNPs) were examined (rs10934490, rs16834817, rs6810298, rs9289231, rs12637456, rs1444768, rs1444754, rs4234218, rs2335052, rs3803, rs2713604) in patients (N = 1618) from the Intermountain Heart Collaborative Study (IHCS). Given the higher smoking prevalence in CATHGEN than IHCS (41% vs. 11% in controls, 74% vs. 29% in cases), smoking stratification and genotype-smoking interactions were evaluated. Suggestive association was found for GATA2 (rs2713604, p = 0.057, OR = 1.2). Among smokers, associations were found in CDGAP (rs10934490, p = 0.019, OR = 1.6) and KALRN (rs12637456, p = 0.011, OR = 2.0) and suggestive association was found in MYLK (rs16834871, p = 0.051, OR = 1.8, adjusting for gender). No SNP association was found among non-smokers, but smoking/SNP interactions were detected for CDGAP (rs10934491, p = 0.017) and KALRN (rs12637456, p = 0.010). Similar differences in SNP effects by smoking status were observed on re-analysis of CATHGEN. CAD associations were suggestive for GATA2 and among smokers significant post hoc associations were found in KALRN, MYLK, and CDGAP. Genetic risk conferred by some of these genes may be modified by smoking. Future CAD association studies of these and other genes should evaluate effect modification by smoking. [source] Influence of CYP2C9 and CYP2C19 genetic polymorphisms on pharmacokinetics of gliclazide MR in Chinese subjectsBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 1 2007Yifan Zhang What is already known about this subject ,,Gliclazide has been considered metabolized by CYP2C9. ,,Its modified release formulation, gliclazide MR, shows low pharmacokinetic variability in Whites but high variability in Chinese. What this study adds ,,The results of this study show that the pharmacokinetics of gliclazide MR are affected mainly by CYP2C19 genetic polymorphism instead of CYP2C9 genetic polymorphism. ,,CYP2C19 genetic polymorphism might be responsible for the high pharmacokinetic variability of gliclazide MR in Chinese. Aims To investigate the influence of CYP2C9 and CYP2C19 genetic polymorphisms on the pharmacokinetics of gliclazide modified release (MR) in healthy Chinese subjects. Methods In a single-dose pharmacokinetic study, 24 healthy male subjects with various CYP2C9 and CYP2C19 genotypes received an oral dose of 30 mg gliclazide MR and plasma was sampled for 72 h postdose. In a multiple-dose pharmacokinetic study, 17 other CYP2C9*1 homozygotes with various CYP2C19 genotypes received 30 mg gliclazide MR once daily for 6 days and plasma was sampled after the last dose. The plasma concentrations of gliclazide were measured using a validated LC/MS/MS method. CYP2C9 and CYP2C19 genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism analysis. Results In the single-dose study, no significant difference in any pharmacokinetic parameters was found in CYP2C9*1/*1, *1/*3 and *1/*13 subjects. In contrast, the AUC0,, of gliclazide was significantly increased by 3.4-fold [95% confidence interval (CI) 2.5, 4.7; P < 0.01] in CYP2C19 poor metabolizer (PM) subjects compared with CYP2C19*1 homozygotes. The half-life (t1/2) was prolonged from 15.1 to 44.5 h (P < 0.01). Similar differences were found in the multiple-dose study. The parameters of gliclazide AUCss, AUC0,, and Cmax were 3.4-fold (95% CI 2.9, 4.0), 4.5-fold (95% CI 3.8, 5.4) and 2.9-fold (95% CI 2.4, 3.4) increased (P < 0.01) in CYP2C19 PM subjects, respectively, compared with CYP2C19*1 homozygotes, and t1/2 was increased from 13.5 to 24.6 h (P < 0.01). Conclusions The pharmacokinetics of gliclazide MR are affected mainly by CYP2C19 genetic polymorphism instead of CYP2C9 genetic polymorphism. [source] Interactions among peripheral perfusion, cardiac activity, oxygen saturation, thermal profile and body position in growing low birth weight infantsACTA PAEDIATRICA, Issue 1 2010R Sahni Abstract Aims:, To investigate the correlation between the ,perfusion index' (PI) and other commonly used estimates of cutaneous blood flow [heart rate (HR), surface temperatures (ST) and central-to-peripheral thermal gradients (C-P grad)] and to use this new non-invasive tool to compare differences between prone and supine sleep position in low birth weight (LBW) infants. Methods:, Six-hour continuous recordings of pulse oximetry, cardiac activity and absolute ST from three sites (flank, forearm and leg), along with minute-to-minute assessment of behavioural states were performed in 31 LBW infants. Infants were randomly assigned to the prone or supine position for the first 3 h and then reversed for the second 3 h. PI data were correlated with HR and C-P grad, and compared across sleep positions during quiet sleep (QS) and active sleep (AS). Results:, Perfusion index correlated significantly with HR (r2 = 0.40) and flank-to-forearm thermal gradient (r2 = 0.28). In the prone position during QS, infants exhibited higher PI (3.7 ± 0.9 vs. 3.1 ± 0.7), HR (158.4 ± 8.9 vs. 154.1 ± 8.8 bpm), SpO2 (95.8 ± 2.6 vs. 95.2 ± 2.6%), flank (36.7 ± 0.4 vs. 36.5 ± 0.4°C), forearm (36.1 ± 0.6 vs. 35.5 ± 0.4°C) and leg (35.4 ± 0.7 vs. 34.7 ± 0.7°C) temperatures and narrower flank-to-forearm (0.6 ± 0.4 vs. 0.9 ± 0.3°C) and flank-to-leg (1.3 ± 0.6 vs. 1.8 ± 0.7°C) gradients, compared to those of the supine position. Similar differences were observed during AS. Conclusion:, Perfusion index is a good non-invasive estimate of tissue perfusion. Prone sleeping position is associated with a higher PI, possibly reflecting thermoregulatory adjustments in cardiovascular control. The effects of these position-related changes may have important implications for the increased risk for sudden infant death syndrome in prone position. [source] How fantasy benefits young children's understanding of pretenseDEVELOPMENTAL SCIENCE, Issue 1 2006David M. Sobel Sobel and Lillard (2001) demonstrated that 4-year-olds' understanding of the role that the mind plays in pretending improved when children were asked questions in a fantasy context. The present study investigated whether this fantasy effect was motivated by children recognizing that fantasy contains violations of real-world causal structure. In Experiment 1, 4-year-olds were shown a fantasy character engaged in ordinary actions or actions that violated causal knowledge. Children were more likely to say that a troll doll who was acting like but ignorant of the character was not pretending to be that character when read the violation story. Experiment 2 suggested that this difference was not caused by a greater interest in the violation story. Experiment 3 demonstrated a similar difference for characters engaged in social and functional violations that were possible in the real world. These data are consistent with the hypothesis that preschoolers use actions and appearance more than mental states to make judgments about pretense, but that those judgments can be influenced by the context in which the questions are presented. [source] Daily and hourly movement of male desert-dwelling elephantsAFRICAN JOURNAL OF ECOLOGY, Issue 1 2010Keith Leggett Abstract The daily and hourly movements of eight male desert-dwelling elephants of various ages (12,45 years old) were determined hourly by global positioning system (GPS)/telemetry collars during the wet, cold dry and hot dry seasons of 2006 in northwest Namibia. The average daily movement in the wet season was greater than that observed during either the cold dry or the hot dry seasons. A similar difference was also observed for the movement rates, with the highest average rate of hourly movement recorded during the wet season. The diurnal movements (both distance and rate) were greater than those in the nocturnal hours during the wet season, whilst during the cold dry and hot dry season the reverse was true. The daily cycle of movement also changed seasonally, with greatest movement rates observed during the wet season between 11.00,20.00 hours, during the cold dry season between 14.00,21.00 hours; and between 04.00,11.00 hours during the hot dry season. Periods of decreased movement rates were observed between 09.00,10.00 and 02.00,03.00 hours in the wet season; 03.00,06.00 and 11.00,13.00 hours in the cold dry season; and 01.00,03.00 and 12.00,14.00 hours during the hot dry season. Résumé On a suivi heure par heure les déplacements quotidiens de huit éléphants du désert mâles, d'âge divers (12 à 45 ans), grâce à des colliers GPS (système de positionnement mondial) et télémétriques, au cours des saisons des pluies, sèche chaude et sèche froide de 2006, dans le nord-ouest de la Namibie. Le déplacement quotidien moyen durant la saison des pluies était supérieur à ceux observés en saison sèche froide ou en saison sèche chaude. Une différence semblable fut aussi observée pour le taux de déplacement, le taux moyen le plus élevé par l'heure étant enregistré pendant la saison des pluies. Les mouvements diurnes (aussi bien leur distance que leur rythme) étaient plus grands que les mouvements nocturnes en saison des pluies, alors que pendant la saison sèche froide et la saison sèche chaude, c'était l'inverse. Le cycle quotidien des déplacements changeait aussi avec les saisons, le rythme étant plus élevé en saison des pluies entre 11h00 et 20h00; en saison sèche froide entre 14h00 et 21h00; et en saison sèche chaude entre 04h00 et 11h00. On a observé des périodes de rythme ralenti entre 21h00 et 04h00 en saison des pluies; entre 03h00 et 05h00 et entre 11h00 et 13h00 en saison sèche froide; et entre 01h00 et 03h00 et entre 12h00 et 14h00 en saison sèche chaude. [source] The diapause decision as a cascade switch for adaptive developmental plasticity in body mass in a butterflyJOURNAL OF EVOLUTIONARY BIOLOGY, Issue 6 2010K. GOTTHARD Abstract Switch-induced developmental plasticity, such as the diapause decision in insects, is a major form of adaptation to variable environments. As individuals that follow alternative developmental pathways will experience different selective environments the diapause decision may evolve to a cascade switch that induces additional adaptive developmental differences downstream of the diapause decision. Here, we show that individuals following alternative developmental pathways in a Swedish population of the butterfly, Pararge aegeria, display differential optimization of adult body mass as a likely response to predictable differences in thermal conditions during reproduction. In a more northern population where this type of selection is absent no similar difference in adult mass among pathways was found. We conclude that the diapause decision in the southern population appears to act as a cascade switch, coordinating development downstream of the diapause decision, to produce adult phenotypes adapted to the typical thermal conditions of their expected reproductive period. [source] Leaf vascular dimensions associated with freeze tolerance in bahiagrass (Paspalum notatum)ANNALS OF APPLIED BIOLOGY, Issue 2 2009J.W. Breman Abstract Foliage damage as a result of individual freeze events is a major limitation to the expansion of bahiagrass (Paspalum notatum) pastures and hay production in Southeastern USA. Greater tolerance to such freeze events would allow production deeper into the fall and winter and allow expansion of this species into colder regions. While it has been reported that small cells are more tolerant to freeze damage, this possibility has not been explored in bahiagrass. Specifically, the hypothesis was examined that xylem vessels with smaller diameter in the midrib of leaves are associated with freeze tolerance among bahiagrass genotypes. Vascular bundle diameter was also measured as a possible index of xylem cell size. A total of eight bahiagrass genotypes were eventually studied representing four freeze-sensitive and four freeze-tolerant lines. There was a clear distinction in xylem cell size between the freeze-sensitive and the freeze-tolerant lines. The freeze-tolerant genotypes had xylem element cells that were significantly smaller than the freeze-sensitive genotypes. Averaged across three leaf positions and all genotypes, the xylem element diameter for the freeze-sensitive lines was 222 ,m and for the freeze-tolerant lines was only 164 ,m. A similar difference was observed in overall vascular bundle diameter with freeze-sensitive lines having a mean of 1168 ,m and the freeze-tolerant lines a mean of 917 ,m. These results indicated that the diameter of the xylem cells in the vascular midrib of bahiagrass may be an important variable influencing the sensitivity among genotypes to freeze damage. [source] Circadian and Gender Effects on Repolarization in Healthy Adults: A Study Using Harmonic Regression AnalysisANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 1 2010Kenneth A. Mayuga M.D. Background: Sudden cardiac death and myocardial infarction have a circadian variation with a peak incidence in the early morning hours. Increased dispersion of repolarization facilitates the development of conduction delay necessary to induce sustained arrhythmia. Both QT-dispersion and T-wave peak to T-wave end (TpTe) have been proposed as markers of dispersion of myocardial repolarization. Methods: Forty healthy adults (20 women), age 35,67 years old, with normal EKGs, echocardiograms, stress tests, and tilt-table tests were analyzed during a 27-hour hospital stay. EKGs were done at eight different time points. QT-intervals, QT-dispersion, and TpTe were measured at each time point. Harmonic regression was used to model circadian periodicity, P < 0.05 was considered significant. Results: The composite QT-interval was longer in women than in men (416 ± 17 msec vs 411 ± 20 msec, respectively, P = 0.006). The QT-dispersion among all leads was greater in men than women (37 ± 13 msec vs 30 ± 11 msec, respectively, P < 0.0001); a similar difference was found in the precordial leads. Harmonic regression showed that QT-dispersion had a significant circadian variation, primarily in men. In men, the maximum QT-dispersion occurred at 6 AM (45 ± 15 msec). TpTe also had a significant circadian variation that was not affected by gender in the majority of leads. Conclusions: A circadian variation exists in the dispersion of myocardial repolarization, as measured by both TpTe and QT-dispersion. Men and women have a different circadian variation pattern. Further studies regarding the mechanisms and clinical implications are needed. Ann Noninvasive Electrocardiol 2010;15(1):3,10 [source] Effects of tibolone and continuous combined hormone replacement therapy on bleeding rates, quality of life and tolerability in postmenopausal womenBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 8 2002J. Huber Objective To compare the effects of tibolone and conjugated equine oestrogens continuously combined with medroxyprogesterone acetate on bleeding rates, quality of life (QoL) and tolerability. Design A double-blind, randomised comparative trial. Setting Thirty-seven centres in six European countries. Population Five hundred and one postmenopausal women, under 65 years of age with an intact uterus. Interventions For 12 months, women received daily treatment with tibolone 2.5 mg (n= 250), or conjugated equine oestrogens 0.625 mg continuously combined with medroxyprogesterone acetate 5 mg (CEE,MPA, n= 251). Main outcome measures The primary outcome was vaginal bleeding rate during cycles 4,6. The secondary outcomes were vaginal bleeding rate during cycles 1,3, 7,9 and 10,13, cumulative bleeding rate, QoL, wellbeing, climacteric symptoms, urogenital complaints and tolerability. Results Treatment with tibolone led to a significantly lower bleeding rate during cycles 4,6 compared with CEE,MPA (15.0%vs 26.9%; P= 0.004); there was a similar difference during cycles 1,3. Both treatments improved QoL, wellbeing, climacteric symptoms and urogenital complaints. By intent-to-treat analysis, tibolone significantly improved sexual drive, interest and/or performance, compared with CEE,MPA at 12 months (P= 0.017). Although both treatments were well tolerated, there was a significantly lower incidence of breast tenderness with tibolone than CEE,MPA (2.4%vs 17.1%; P < 0.001). Conclusion The vaginal bleeding rate during cycles 4,6 was significantly lower in women using tibolone. Both treatments improved QoL, wellbeing, climacteric symptoms and urogenital symptoms. Breast tenderness was significantly less frequent with tibolone. [source] Risk factors predisposing to fetal loss following a second trimester amniocentesisBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 10 2001Nikolaos E. Papantoniou Objective To examine the influence of possible risk factors on fetal loss rate following amniocentesis. Design Retrospective analysis of case records between 1993 and 1998. Setting Fetal medicine unit of a large teaching hospital. Population One thousand and six women with singleton pregnancies formed the study group. Seven hundred and eight of them had bleeding during the current pregnancy before the procedure, while 298 had a history of three or more first trimester abortions and/or a second trimester miscarriage or termination of pregnancy. Four thousand and twenty-four women who had amniocentesis and had no risk factors served as controls. Both groups were also classified according to maternal age. Group 1: 1610 women aged 20,34 years; Group 2: 2850 women aged 35,39 years; Group 3; 570 women > 40 years. Methods Women of both groups underwent a second trimester amniocentesis between 16 and 21 weeks of gestation. Fetal losses following amniocentesis were examined in three time intervals: 1. in the first two weeks after the procedure; 2. up to the 28th week; 3. from the 28th week to term. Results There was a statistically significant difference in the fetal loss rate between women aged 20,34 years (2.54%) and those > 40 years (5.1%). Women with a history of vaginal bleeding during the current pregnancy had a higher fetal loss rate compared with controls (6.5%vs 2.8%), which corresponds to an odds ratio of 2.4 (95% CI 1.69,3.42). A similar difference was found between the group of women with a history of previous abortions/terminations and the controls (8%vs 2.8%): OR 3.03 (95% CI 1.92,4.79). Conclusions There is a higher risk of fetal loss following amniocentesis in women > 40 years of age compared with those aged 20,34 years. Bleeding in the current pregnancy, a history of three or more first trimester abortions, a second trimester miscarriage or termination of pregnancy seem to be significant predisposing factors for fetal loss after an amniocentesis. [source] Inappropriate Use of Antibiotics for Acute Asthma in United States Emergency DepartmentsACADEMIC EMERGENCY MEDICINE, Issue 8 2008Stefan G. Vanderweil BA Abstract Objectives:, The aim was to examine the use of antibiotics to treat asthma patients in U.S. emergency departments (EDs). The authors sought to investigate inappropriate antibiotic prescriptions by identifying the frequency and predictors of antibiotics prescribed for asthma exacerbations using data from two sources, the National Hospital Ambulatory Medical Care Survey (NHAMCS) and the National Emergency Department Safety Study (NEDSS). Methods:, The authors used data from NHAMCS and NEDSS to identify the proportion of ED visits for asthma exacerbations that resulted in the prescription of an antibiotic. NHAMCS provided national data from 1993 through 2004, while NEDSS provided data from 63 primarily academic EDs from 2003 through 2006. Univariate analysis and multivariate logistic regression modeling were used to identify variables associated with antibiotic administration. Results:, Analysis of NHAMCS data revealed that 22% (95% confidence interval [CI] = 20% to 24%) of acute asthma visits resulted in an antibiotic prescription from 1993 through 2004, with no significant change in prescribing frequency over the 12-year period. NEDSS data from 2003 through 2006 showed that 18% (95% CI = 17% to 19%) of acute asthma cases in academic EDs received an antibiotic. Multivariate modeling of NHAMCS data revealed that African American patients (odds ratio [OR] = 0.8; 95% CI = 0.6 to 0.97) and patients in urban EDs (OR = 0.5; 95% CI = 0.4 to 0.7) were less likely to receive antibiotics for asthma exacerbations than white patients and patients in nonurban EDs, respectively. NHAMCS analysis also found that patients in the South were more likely to receive antibiotics than those in the Northeast (OR = 1.4; 95% CI = 1.1 to 1.9). A NEDSS multivariate model found a similar difference, with African Americans (OR = 0.6; 95% CI = 0.4 to 0.8) and Hispanics (OR = 0.6; 95% CI = 0.4 to 0.8) being less likely than whites to receive an antibiotic. Conclusions:, ED treatment of acute asthma with unnecessary antibiotics is likely to contribute to bacterial antibiotic resistance. Interventions are needed to reduce inappropriate antibiotic prescriptions and to address disparities in asthma care. [source] The impact of impaired insulin release and insulin resistance on glucose intolerance after renal transplantation,CLINICAL TRANSPLANTATION, Issue 6 2002Jøran Hjelmesæth Abstract: The current knowledge of the pathogenesis of post-transplant glucose intolerance is sparse. This study was undertaken to assess the relative importance of insulin secretion (ISec) and insulin sensitivity (IS) in the pathogenesis of post-transplant diabetes mellitus (PTDM), impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) after renal transplantation. An oral glucose tolerance test (OGTT) was performed in 167 non-diabetic recipients 10 wk after renal transplantation. Fasting, 1-h and 2-h insulin and glucose levels were used to estimate the insulin secretory response and IS. One year after transplantation 89 patients were re-examined with an OGTT including measurements of fasting and 2 h glucose. Ten weeks after transplantation the PTDM-patients had significantly lower ISec and IS than patients with IGT/IFG, who again had lower ISec and IS than those with normal glucose tolerance (NGT). One year later, a similar difference in baseline ISec was observed between the three groups, whereas baseline IS did not differ significantly. Patients who improved their glucose tolerance during the first year, were mainly characterized by a significantly greater baseline ISec, and they received a significantly higher median prednisolone dose at baseline with a subsequent larger dose reduction during the first year, than the patients who had their glucose tolerance unchanged or worsened. In conclusion, both impaired ISec and IS characterize patients with PTDM and IGT/IFG in the early course after renal transplantation. The presence of defects in insulin release, rather than insulin action, indicates a poor prognosis regarding later normalization of glucose tolerance. [source] Hyperphagia and obesity of OLETF rats lacking CCK1 receptors: Developmental aspectsDEVELOPMENTAL PSYCHOBIOLOGY, Issue 5 2006Timothy H. Moran Abstract Otsuka Long Evans Tokushima Fatty (OLETF) rats have a deletion in the gene encoding the cholecystokinin,1 (CCK1) receptor. This deletion prevents protein expression, making the OLETF rat a CCK1 receptor knockout model. Consistent with the absence of CCK1 receptors, OLETF rats do not reduce their food intake in response to exogenously administered CCK and consume larger than normal meals. This deficit in within-meal feedback signaling is evident in liquid as well as solid meals. Neonatal OLETF rats show similar differences in independent ingestion tests. Intake is higher and is reflected in greater licking behavior. Neonatal OLETF rats also have diminished latencies to consume and higher initial ingestion rats. Adult OLETF rats are hyperphagic and obese. Although arcuate nucleus peptide gene expression is apparently normal in OLETF rats, when obesity is prevented through pair-feeding to amounts consumed by control Long Evans Tokushima Otsuka (LETO) rats, dorsomedial hypothalamic NPY mRNA expression is significantly elevated in OLETF rats. NPY overexpression is also evident in preobese, juvenile OLETF rats suggesting a causal role for this overexpression in the hyperphagia and obesity. Running wheel exercise normalizes food intake and body weight in OLETF rats. When access to exercise is provided at a time when OLETF rats are obese, the effects are limited to the period of exercise. When running wheel access is available to younger, preobese OLETF rats, exercise results in long lasting reductions in food intake and body weight and improved glucose regulation. These lasting metabolic effects of exercise may be secondary to an exercise induced reduction in DMH NPY mRNA expression. © 2006 Wiley Periodicals, Inc. Dev Psychobiol 48: 360,367, 2006. [source] The impact of grassland management on archaeal community structure in upland pasture rhizosphere soilENVIRONMENTAL MICROBIOLOGY, Issue 3 2003Graeme W. Nicol Summary The community structure of rhizosphere soil Archaea from three grassland types, associated with different management practices, was examined at a site in the Borders region of Scotland, by analysis of 16S rRNA gene fragments amplified from 16S rDNA and from rRNA. Denaturing gradient gel electrophoresis (DGGE) and sequence analysis of amplified products indicated high relative abundance within the archaeal community of two distinct lineages of non-thermophilic (group 1) Crenarchaeota. Grassland management practices influenced archaeal community structure, as characterized by both 16S rRNA- and 16S rDNA-derived DGGE profiles. One band dominated DGGE profiles in all three grassland types examined, and reproducible differences in the presence and intensity of bands were observed between profiles from managed and natural grassland sites. Analysis of 16S rRNA-derived amplicons from managed and natural grasslands at sites in the north of England and the north of Wales also indicated high relative abundance of non-thermophilic crenarchaeotes within the archaeal community. The band dominating the Scottish grassland site also dominated DGGE profiles from the English and Welsh sites, and similar differences were seen between profiles derived from soils subjected to different management regimes. The study indicates that grassland archaeal communities are dominated by Crenarchaeota, with closely related members of this lineage ubiquitous in distribution in UK upland pasture, and indicate that management practices influence the nature of the crenarchaeotal community. [source] Depressive symptoms in intellectual disability: does gender play a role?JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 6 2003Y. Lunsky Abstract Background Gender issues remain largely unaddressed in the dual diagnosis arena, even in the area of depression where there is a 2,:,1 female to male ratio in the general population. This paper argues that women with intellectual disability (ID) report higher levels of depressive symptoms than men with ID and that risk factors for depression identified for women in the general population are relevant to this group. Method Findings are based on structured interviews with 99 men and women with ID, with corroborative information provided from caregivers and casebook reviews. Results Overall, women reported higher levels of depression than men. Individuals with higher depression scores were more lonely and had higher stress levels than individuals with lower scores. Women with higher depression scores were more likely to report coming from abusive situations, to have poor social support from family and to be unemployed when compared to women with lower scores, but similar differences were not found when comparing men with higher and lower depression scores. Conclusion Men and women who report experiencing these psychosocial correlates of depression should be a target group for future prevention efforts, taking gender specific concerns into consideration. [source] Androgen Receptor Expression in the Levator Ani Muscle of Male MiceJOURNAL OF NEUROENDOCRINOLOGY, Issue 10 2007J. A. Johansen The spinal nucleus of the bulbocavernosus (SNB) is a sexually dimorphic group of motoneurones that innervates the bulbocavernosus (BC) and levator ani (LA), skeletal muscles that attach to the base of the penis. In many species, including mice, rats and hamsters, the LA and BC have been found to be highly responsive to androgen and, in rats, these muscles mediate several effects of androgen on the SNB system. However, characterising the SNB system in mice is important because of the availability of genetic models in this species. In the present study, we examined AR expression in skeletal muscles of C57/BlJ6 adult male mice using immunoblotting and immunocytochemistry, comparing the BC/LA to the androgen-unresponsive extensor digitorum longus (EDL). We found similar differences in AR expression for these muscles in the mouse as previously reported for rats. In mice, the BC/LA contains more AR protein than does the EDL. At the cellular level, the LA contains a higher percentage of AR positive myonuclei and fibroblasts than does the EDL. Finally, AR expression is enriched at the neuromuscular junction of mouse LA fibres. The increased expression of AR in the LA compared to the EDL in both muscle fibres and fibroblasts indicates that each cell type may critically mediate androgen action on the SNB system in mice. [source] Extremely interesting, very interesting, or only quite interesting?JOURNAL OF SOCIOLINGUISTICS, Issue 3 2002Adverbs, social class An earlier study, based on interviews with a socially stratified sample showed a difference in the use of adverbs, with the middle,class speakers using derived adverbs in ,ly more than twice as frequently as the working,class speakers. An examination of interactions in peer,group same,sex dyads shows a similar socially stratified pattern in both adults and adolescents. There are similar differences in the use of some other adverbs and certain adjectives. The consistency of the results suggests that there is a stable difference in speech styles between the two social classes and that this difference reflects a different attitude on the part of the speakers to their audience. [source] Comparison of oxidative capacity among leg muscles in humans using gated 31P 2-D chemical shift imagingNMR IN BIOMEDICINE, Issue 10 2009Sean C. Forbes Abstract In many small animals there are distinct differences in fiber-type composition among limb muscles, and these differences typically correspond to marked disparities in the oxidative capacities. However, whether there are similar differences in the oxidative capacity among leg muscles in humans is less clear. The purpose of this study was to compare the rate of phosphocreatine (PCr) recovery, a functional in vivo marker of oxidative capacity, in the lateral and medial gastrocnemius, soleus, and the anterior compartment of the leg (primarily the tibialis anterior) of humans. Subjects performed plantar flexion and dorsiflexion gated exercise protocols consisting of 70 sets of three rapid dynamic contractions (<2.86,s) at 20,s intervals (total: 23.3,min). Starting after the sixth set of contractions, 31P 2-D CSI (8,×,8 matrix, 14,16,cm FOV, 3,cm slice, TR 2.86,s) were acquired via a linear transmit/receive surface coil using a GE 3T Excite System. The CSI data were zero-filled (32,×,32) and a single FID was produced for each time point in the lateral and medial gastrocnemius, soleus, and anterior compartment. The time constant for PCr recovery was calculated from ,,=,-,t/ln[D/(D,+,Q)], where Q is the percentage change in PCr due to contraction during the steady-state portion of the protocol, D the additional drop in PCr from rest, and ,t is the interval between contractions. The , of PCr recovery was longer (p,<,0.05) in the anterior compartment (32,±,3,s) than in the lateral (23,±,2,s) and medial gastrocnemius muscles (24,±,3,s) and the soleus (22,±,3,s) muscles. These findings suggest that the oxidative capacity is lower in the anterior compartment than in the triceps surae muscles and is consistent with the notion that fiber-type phenotypes vary among the leg muscles of humans. Copyright © 2009 John Wiley & Sons, Ltd. [source] Proteomic and SAGE profiling of murine melanoma progression indicates the reduction of proteins responsible for ROS degradationPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 5 2006Gustavo A. de Souza Abstract Using 2-DE of total cell protein extracts, we compared soluble proteins from murine melanoma lines Tm1 and Tm5 with proteins from the nontumoral cell melan-a from which they were derived. Seventy-one of the 452 spots (average) detected with CBB were differentially accumulated, i.e., increased or decreased twofold. Forty-four spots were identified by PMF/MALDI-TOF, 15 with increased and 29 with decreased protein levels. SAGE showed that 17/34 (50%) of the differentially accumulated proteins, pI range 4,7, presented similar differences at the mRNA level. Major reductions in protein were observed in tumor cells of proteins that degrade reactive oxygen species (ROS). Decreases of , twofold in GST, superoxide dismutase, aldehyde dehydrogenase, thioredoxin, peroxiredoxin 2, and peroxiredoxin 6 protein were observed. SAGE indicated the reduction of other proteins involved in ROS degradation. As expected, the accumulation of exogenous peroxides was significantly higher in the tumor cells while the levels of glutathionylation were two times lower in the tumor cells compared to melan-a. The differential accumulation of proteins involved in oncogene/tumor suppressor pathways was observed. Melanoma cells can favor survival pathways activated by ROS by inhibiting p53 pathways and activation of Ras and c-myc pathways. [source] | ||||||||||||||||||||||