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Combined Results (combined + result)
Selected AbstractsHerbivory and plant growth rate determine the success of El Niño Southern Oscillation-driven tree establishment in semiarid South AmericaGLOBAL CHANGE BIOLOGY, Issue 12 2006MILENA HOLMGREN Abstract While climatic extremes are predicted to increase with global warming, we know little about the effect of climatic variability on biome distribution. Here, we show that rainy El Niño Southern Oscillation (ENSO) events can enhance tree recruitment in the arid and semiarid ecosystems of north-central Chile and northwest Peru. Tree-ring studies in natural populations revealed that rainy El Niño episodes have triggered forest regeneration in Peru. Field experiments indicate that tree seedling recruitment in Chile is much less successful than in Peru due mostly to larger mortality caused by herbivores. The dramatic impact of herbivores in Chile was derived from the combined result of slower plant growth and the presence of exotic herbivores (European rabbits and hares). The interplay of herbivory and climatic effects we demonstrated implies that rainy ENSO events may represent ,windows of opportunity' for forest recovery if herbivore pressure is minimized at the right moment. [source] Differential Signaling Circuits in Regulation of Ultraviolet C Light-induced Early- and Late-phase Activation of NF-,BPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2010Shiyong Wu Ultraviolet C light (UVC) induces nuclear factor-kappa B (NF-,B) activation via a complex network. In the early phase (4,12 h) of irradiation, NF-,B activation is accompanied with I,B, reduction via a translation inhibition pathway. In the late phase of UVC-induced NF-,B activation (16,24 h), the I,B, depletion is a combined result of regulation at both transcriptional and translational levels. However, the NF-,B activation appears to be independent of the level of I,B,. In this review, we will discuss the multiple signaling circuits that regulate NF-,B activation during the early and late phases of UVC irradiation. [source] Why Are Fewer Women than Men Elected?POLITICAL STUDIES REVIEW, Issue 2 2010Gender, the Dynamics of Candidate Selection Why are fewer women than men elected? Research suggests that this is the combined result of: (1) the supply of female aspirants, or the qualifications of women as a group to run for political office; and (2) the demand for female aspirants, or the preference of political elites for male over female candidates. The aim of this article is to reassess this explanation through the lens of recent case studies of female representation in four regions of the world: Africa, Latin America, North America and Western Europe. On their own, each contribution lends support to arguments about either supply or demand, leading their authors to offer distinct recommendations for change: an increase in the number of women who come forward, which is likely to be a slow and difficult process, or the adoption of gender quotas, which are quick but may produce mixed results. Yet juxtaposing these studies also exposes the limits of the traditional supply and demand model of candidate selection. On the one hand, the ,political market' does not operate efficiently towards an equilibrium solution of supply and demand. Rather, ideologies of gender introduce important distortions to the process: the fact that women are under-represented in all countries around the world suggests that both the supply of and demand for female candidates is artificially repressed, leading to low numbers of women in elective office. On the other hand, important variations exist in women's descriptive representation across countries and across political parties. These differences suggest that dynamics of supply and demand are shaped in crucial ways by features of the broader political context, which may include structural conditions but also the emergence of new and sometimes unanticipated opportunities. [source] Experimentally generated footprints in sand: Analysis and consequences for the interpretation of fossil and forensic footprintsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2010K. D'Août Abstract Fossilized footprints contain information about the dynamics of gait, but their interpretation is difficult, as they are the combined result of foot anatomy, gait dynamics, and substrate properties. We explore how footprints are generated in modern humans. Sixteen healthy subjects walked on a solid surface and in a layer of fine-grained sand. In each condition, 3D kinematics of the leg and foot were analyzed for three trials at preferred speed, using an infrared camera system. Additionally, calibrated plantar pressures were recorded. After each trial in sand, the depth of the imprint was measured under specific sites. When walking in sand, subjects showed greater toe clearance during swing and a 7° higher knee yield during stance. Maximal pressure was the most influential factor for footprint depth under the heel. For other foot zones, a combination of factors correlates with imprint depth, with pressure impulse (the pressure-time integral) gaining importance distally, at the metatarsal heads and the hallux. We conclude that footprint topology cannot be related to a single variable, but that different zones of the footprint reflect different aspects of the kinesiology of walking. Therefore, an integrated approach, combining anatomical, kinesiological, and substrate-mechanical insights, is necessary for a correct interpretation. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source] Synthesis,Structure,Property Relationships for Hyperbranched Aminosilica CO2 AdsorbentsADVANCED FUNCTIONAL MATERIALS, Issue 23 2009Jeffrey H. Drese Abstract Hyperbranched aminosilica (HAS) adsorbents are prepared via the ring-opening polymerization of aziridine in the presence of mesoporous silica SBA-15 support. The aminopolymers are covalently bound to the silica support and capture CO2 reversibly in a temperature swing process. Here, a range of HAS materials are prepared with different organic loadings. The effects of organic loading on the structural properties and CO2 adsorption properties of the resultant hybrid materials are examined. The residual porosity in the HAS adsorbents after organic loading, as well as the molecular weights and degrees of branching for the separated aminopolymers, are determined to draw a relationship between adsorbent structure and performance. Humid adsorption working capacities and apparent adsorption kinetics are determined from experiments in a packed-bed flow system monitored by mass spectrometry. Dry adsorption isotherms are presented for one HAS adsorbent with a high amine loading at 35 and 75,°C. These combined results establish the relationships between adsorbent synthesis, structure, and CO2 adsorption properties of the family of HAS materials. [source] Perovskite oxide absorbents for oxygen separationAICHE JOURNAL, Issue 12 2009Yufeng He Abstract The fixed-bed oxygen absorption processes of the series of Ba1,xSrxCo0.8Fe0.2O3,, oxides were studied by oxygen partial pressure swing absorption in the temperature range of 300,850°C. The results show that SrCo0.8Fe0.2O3,,, with the smallest A-site ion radius, has the largest oxygen absorption capacity (0.402 mmol/g) at 500°C. The oxygen absorption and desorption kinetics fit well with the pseudo-second-order kinetics model. Comparing the modeling absorption rate coefficient k2 with the desorption rate coefficient k2,, all the oxides studied had higher oxygen absorption rates than oxygen desorption ones. In addition, the combined results of X-ray diffraction analysis, O2 -TPD, room temperature iodometric titration, and thermogravimetric analysis explained the relationship between the oxygen absorption capacities and the average radii of the A-site ions for this series of Ba1,xSrxCo0.8Fe0.2O3,, in the temperature range of 300,600°C. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Confirmation of Correlations and Common Quantitative Trait Loci Between Neurotensin Receptor Density and Hypnotic Sensitivity to EthanolALCOHOLISM, Issue 12 2001V. Gene Erwin Background: In previous studies, genetic correlations were observed between hypnotic sensitivity to ethanol and high-affinity neurotensin receptor (NTS1) binding. Provisional quantitative trait loci (QTLs) were identified for these traits, and some of these QTLs were found on common chromosomal regions. In continued efforts to examine the relationship between NTS1 binding capacity and hypnotic sensitivity to ethanol, studies were designed to confirm correlations between NTS1 densities in the brain, duration of ethanol-induced loss of righting reflex (LORR), and blood ethanol concentrations at regain of righting reflex (BECRR). Another purpose of the study was to confirm QTLs for these traits. Methods: ILS X ISS F 2 mice and HAS X LAS F 2 rats as well as the progenitors were tested for LORR, BECRR, and NTS1 densities. Phenotypic correlations were calculated between LORR and BECRR and between these measures and NTS1 densities in striatum from both mice and rats. The F 2 mice were genotyped by using polymorphic markers for five previously reported QTLs for LORR to confirm QTLs for BECRR and NTS1 densities in striatum, ventral midbrain, and frontal cortex. Results: Phenotypic correlations were found between LORR and BECRR (r=,0.66 to ,0.74, p < 10,9) and between these measures and NTS1 densities in striatum (r= 0.28,0.38, p < 10,2) from both mice and rats. QTLs for LORR and BECRR (lod score = 2,6) were found in common regions of chromosomes 1, 2, and 15. By using the combined results from a previous LSXSS RI study and the current results, a suggestive QTL (lod score = 3.1) for striatal NTS1 receptor densities was found on chromosome 15 at approximately 60 cM, in the same region as the chromosome 15 LORR/BECRR QTL. Conclusions: The results are in agreement with previously reported correlations and QTLs for NTS1 receptor densities and measures of hypnotic sensitivity to ethanol in mice and extend those correlations to another species, the rat. These findings support a role for NTS1 in genetically mediated differences in hypnotic sensitivity to ethanol. [source] Ethanol-Induced Up-Regulation of the Urokinase Receptor In Cultured Human Endothelial CellsALCOHOLISM, Issue 2 2001Edlue M. Tabengwa Background: Moderate alcohol consumption has been correlated to reduced coronary artery disease (CAD) risk and mortality. This alcohol effect may be mediated in part by an increased endothelial cell (EC) fibrinolysis. ECs synthesize fibrinolytic proteins, tissue plasminogen activator (t-PA), urokinase type plasminogen activator (u-PA), and plasminogen activator inhibitor type-1(PAI-1). In addition, they synthesize and regulate receptors for fibrinolytic proteins, namely (t-PA and plasminogen receptor) Annexin II and u-PA receptor (u-PAR). These receptors play an important role in the regulated expression of receptor-bound plasminogen activator conversion of receptor-bound plasminogen to receptor-bound plasmin on the EC surface (surface-localized fibrinolytic activity). Therefore, systemic factors, such as ethanol, that affect the level, or activity or interaction of one or more of these components, resulting in the increased expression of surface-localized EC fibrinolytic activity, will be expected to reduce the risk for thrombosis, CAD, and myocardial infarction (MI). We have previously shown that low ethanol up-regulates t-PA and u-PA gene transcription, while it down-regulates PAI-1, hence resulting in increased (sustained, 24 hr) surface-localized EC fibrinolytic activity. The current studies were carried out to determine whether low ethanol increased u-PAR expression in cultured human umbilical cord vein ECs (HUVECs). Methods: Cultured HUVECs were preincubated (1 hr) in the absence/presence of ethanol (0.025,0.2%, v/v); u-PAR mRNA (RT-PCR), antigen (western blot), and activity (125I-u-PA ligand binding/Scatchard analysis) levels were then measured after 0,24 hr. To determine whether the ethanol-induced changes in the u-PAR expression were transcriptional, transient transfection studies were carried out using a u-PAR/luciferase promoter construct (pu-PAR120/luc [1.2-kb u-PAR promoter fragment ligated to a promoterless luciferase vector]). Results: uPAR mRNA levels increased 2- to 3-fold and antigen levels (western blot) increased 2- to 4-fold while u-PA binding activity increased 36% (1.25 vs. 1.7 , 105 sites/cell, Bmax) without significantly affecting the Kd (1,2 nM). Transient transfection of cultured HUVECs with a pu-PAR120/luc construct resulted in a 2- to 3-fold increase in promoter activity in ethanol-induced cultures, compared with controls. Conclusion: These combined results demonstrate that low ethanol (,0.1%, v/v) induces the up-regulation of u-PAR gene transcription, resulting in increased u-PAR ligand binding activity. These results also further identify/define the contribution and role of another fibrinolytic protein in the overall ethanol-induced increase in surface-localized EC fibrinolysis that may underlie and contribute, in part, to the cardioprotection attributed to moderate alcohol consumption. [source] Long-term monitoring in IC4665: fast rotation and weak variability in very low mass objectsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2009Alexander Scholz ABSTRACT We present the combined results of three photometric monitoring campaigns targeting very low mass (VLM) stars and brown dwarfs in the young open cluster IC4665 (age ,40 Myr). Each of our observing runs covers time-scales of ,5 d in the seasons 1999, 2001 and 2002, respectively. In all three runs, we observe ,100 cluster members, allowing us for the first time to put limits on the evolution of spots and magnetic activity in fully convective objects on time-scales of a few years. For 20 objects covering masses from 0.05 to 0.5 M,, we detect a periodic flux modulation, indicating the presence of magnetic spots co-rotating with the objects. The detection rate of photometric periods (,20 per cent) is significantly lower than in solar-mass stars at the same age, which points to a mass dependence in the spot properties. With two exceptions, none of the objects exhibits variability and thus spot activity in more than one season. This is contrary to what is seen in solar-mass stars and indicates that spot configurations capable of producing photometric modulations occur relatively rarely and are transient in VLM objects. The rotation periods derived in this paper range from 3 to 30 h, arguing for a lack of slow rotators among VLM objects. The periods fit into a rotational evolution scenario with pre-main sequence contraction and moderate (40,50 per cent) angular momentum losses due to wind braking. By combining our findings with literature results, we identify two regimes of rotational and magnetic properties, called C- and I-sequence. Main properties on the C-sequence are fast rotation, weak wind braking, H, emission and saturated activity levels, while the I-sequence is characterized by slow rotation, strong wind braking, no H, emission and linear activity-rotation relationship. Rotation rate and stellar mass are the primary parameters that determine in which regime an object is found. We outline a general scheme to understand rotational evolution for low-mass objects in the context of these two regimes and discuss the potential as well as the problems of this picture. [source] Age-standardisation when target setting and auditing performance of Down syndrome screening programmesPRENATAL DIAGNOSIS, Issue 11 2004Howard Cuckle Abstract Objective To describe and illustrate a method of setting Down syndrome screening targets and auditing performance that allows for differences in the maternal age distribution. Methods A reference population was determined from a Gaussian model of maternal age. Target detection and false-positive rates were determined by standard statistical modelling techniques, except that the reference population rather than an observed population was used. Second-trimester marker parameters were obtained for Down syndrome from a large meta-analysis, and for unaffected pregnancies from the combined results of more than 600 000 screens in five centres. Audited detection and false-positive rates were the weighted average of the rates in five broad age groups corrected for viability bias. Weights were based on the age distributions in the reference population. Results Maternal age was found to approximate reasonably well to a Gaussian distribution with mean 27 years and standard deviation 5.5 years. Depending on marker combination, the target detection rates were 59 to 64% and false-positive rate 4.2 to 5.4% for a 1 in 250 term cut-off; 65 to 68% and 6.1 to 7.3% for 1 in 270 at mid-trimester. Among the five centres, the audited detection rate ranged from 7% below target to 10% above target, with audited false-positive rates better than the target by 0.3 to 1.5%. Conclusion Age-standardisation should help to improve screening quality by allowing for intrinsic differences between programmes, so that valid comparisons can be made. Copyright © 2004 John Wiley & Sons, Ltd. [source] Different Ca2+ signalling cascades manifested by mastoparan in the prothoracic glands of the tobacco hornworm, Manduca sexta, and the silkworm, Bombyx moriARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 2 2007Skarlatos G. Dedos Abstract Application of the tetradecapeptide mastoparan to the prothoracic glands (PGs) of the tobacco hornworm, Manduca sexta, and the silkworm, Bombyx mori, resulted in increases in intracellular Ca2+ ([Ca2+]i). In M. sexta, Gi proteins are involved in the mastoparan-stimulated increase in [Ca2+]i. However, there is no involvement of Gi proteins in the mastoparan-stimulated increase in [Ca2+]i in prothoracic gland cells from B. mori. Unlike in M. sexta prothoracic glands, in B. mori prothoracic glands mastoparan increases [Ca2+]i even in the absence of extracellular Ca2+. Pharmacological manipulation of the Ca2+ signalling cascades in the prothoracic glands of both insect species suggests that in M. sexta prothoracic glands, mastoparan's first site of action is influx of Ca2+ through plasma membrane Ca2+ channels while in B. mori prothoracic glands, mastoparan's first site of action is mobilization of Ca2+ from intracellular stores. In M. sexta, the combined results indicate the presence of mastoparan-sensitive plasma membrane Ca2+ channels, distinct from those activated by prothoracicotropic hormone or the IP3 signalling cascade, that coordinate spatial increases in [Ca2+]i in prothoracic gland cells. We propose that in B. mori, mastoparan stimulates Ca2+ mobilization from ryanodine-sensitive intracellular Ca2+ stores in prothoracic gland cells. Arch. Insect Biochem. Physiol. 65:52,64, 2007. © 2007 Wiley-Liss, Inc. [source] Electrical stimulation as an adjunct to spinal fusion: A meta-analysis of controlled clinical trialsBIOELECTROMAGNETICS, Issue 7 2002Masami Akai Abstract This study was a meta-analysis to examine whether electrical stimulation has a specific effect on spinal fusion. Little evidence exists on the efficacy of electrical stimulation for improving fusion rate of spinal fusion surgery. Using MEDLINE (1966,2000) and EMBASE (1985,1999), a search for articles was carried out using the Medical Subject Headings: (1) electric stimulation or electromagnetic fields, (2) spinal fusion, (3) controlled or clinical trial, and (4) human. Data were extracted from all the hit articles and additionally collected from appropriate journal lists. A total of five randomized controlled trials (RCT) on bones assessing healing of spinal fusion were identified and scored on methodological quality. All the identified studies reported positive findings, but the quality score of each trial showed wide flaws. Because of relatively homogenous subjects who had spine fusion and radiographic assessment from these studies, pooling of the data was able to be performed. Excluding one trial with the lowest score, the combined results of four trials, whose major endpoints were the success rate of the fusion, revealed a statistically significant effect of electrical stimulation with various techniques, but the selected trials still showed wide variation in view of stimulation modalities and treatment protocol. The pooled result of the studies in this review revealed the efficacy of electrical stimulation based on proved methodological quality. As problems on therapeutic modality and protocol remain, there is a further need for improvement in design to constitute acceptable proof and to establish treatment programs that better demonstrate electrical stimulation effects on spinal fusion. Bioelectromagnetics 23:496,504, 2002. © 2002 Wiley-Liss, Inc. [source] | |||||||||||||