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LMA
Selected AbstractsThe development of "roughness" in the play fighting of rats: A Laban Movement Analysis perspectiveDEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2003Afra Foroud Abstract With increasing age, rats, when play fighting, become rougher. In part, this change can be accounted for by the increasing likelihood of using adult-typical fighting tactics. However, even when using the same tactics, adults appear rougher than juveniles in their play. In this study, videotaped sequences of play fighting in rats from the juvenile (30 days) to the post-pubertal (70 days) period were analyzed using Laban Movement Analysis (LMA). Movement qualities called Effort Factors in LMA captured the character of some of this change. Juveniles tended to use Indulging Efforts, whereas older rats tended to use Condensing Efforts. The latter are related to performing movements that are more controlled. This greater level of control was also evident in the way older rats maintained postural support during play fights. When standing over supine partners, juveniles are more likely to stand on the partner with all four paws, reducing their postural stability, and hence ability to control their partner's movements. Older rats are more likely to place their hind paws on the ground, thus providing a firmer anchor for movements with their upper bodies and forepaws. These age-related changes in behavior were found for both males and females. The findings lend support to a growing body of evidence that play fighting in the juvenile phase of rats is not just a more frequently occurring version of that present in adults, but rather, has unique organizational properties. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 42: 35,43, 2003. [source] CEC column behaviour of butyl and lauryl methacrylate monoliths prepared in non-aqueous mediaELECTROPHORESIS, Issue 4 2009Amparo Cantó-Mirapeix Abstract Polymeric monolithic stationary phases for capillary electrochromatography were prepared using two bulk monomers, butyl methacrylate (BMA) and lauryl methacrylate (LMA), by in situ polymerization in non-aqueous media. The effect of 1,4-butanediol/1-propanol ratio on porous properties was investigated separately for each monomer, keeping the proportion of monomers to pore-forming solvents fixed at 40:60,wt:wt. Also, mixtures of BMA and LMA at different 1,4-butanediol/1-propanol ratios were studied for tailoring the morphological features of the monolithic columns. The chromatographic performance of the different columns was evaluated by means of van Deemter plots of polycyclic aromatic hydrocarbons. Mercury-intrusion porosimetry, SEM, and nitrogen-adsorption measurements were also performed in order to understand their retention behaviour and porous properties. A comparison of these features was also performed for monoliths made with one bulk monomer (BMA or LMA) and with mixtures of both. These mixed monoliths showed satisfactory efficiencies and analysis times compared with those made with one bulk monomer; thus, the BMA,LMA monoliths constitute an attractive alternative to manipulate the electrochromatographic properties of methacrylate beds in CEC. [source] Changes In Rhesus Macaque ,Coo' Vocalizations during Early DevelopmentETHOLOGY, Issue 10 2000Kurt Hammerschmidt In order to test whether ,coo' calls of young rhesus macaques, Macaca mulatta, undergo some modifications during early development, and to explore which factors may influence these changes, we studied the ontogeny of their contact call, the ,coo' call. Vocalizations were recorded during brief periods of social separation. Infants were either raised with their mothers and other conspecifics, or separated from their mothers at birth and housed in a nursery with other infants. We recorded calls uttered in the separation context from 20 infants. We digitized the first 50 calls of a given series and subjected them to a Fourier transform. From each frequency,time spectrum, we extracted 65 acoustic parameters using a software program (LMA 5.9). We then used a cluster analysis to separate the ,coo' calls from other call types. With increasing age, the ,coos' dropped in pitch and became more even. The course of amplitude became more constant and the call duration increased slightly. Nevertheless, we found a high intra-individual variation throughout the 5 mo. Neither rearing condition nor sex had any apparent influence on age-related changes in ,coo' structure. With one exception, all parameters that correlated with age could be explained by variation in weight. Therefore, we conclude that growth is the main factor accounting for the observed changes. [source] Polymers from renewable resources: Bulk ATRP of fatty alcohol-derived methacrylatesEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 9 2008Gökhan Çayli Abstract Copper-mediated atom transfer radical polymerization (ATRP) of lauryl methacrylate (LMA) and other long-chain methacrylates was investigated in bulk at 35,°C by using CuCl/N,N,N,,N,,N,, -pentamethyldiethylenetriamine (PMDETA)/tricaprylylmethylammonium chloride (Aliquat®336) as the catalyst system and ethyl 2-bromoisobutyrate (EBIB) as the initiator. The investigated monomers can be derived from fatty alcohols and are therefore an important renewable resource for a sustainable development of our future. The amounts of ligand, Aliquat®336 and CuCl were optimized and the effect of their concentrations on the control of the polymerization and the observed conversions were investigated. It was found that a molar ratio of EBIB/CuCl/Ligand/Aliquat®336 of 1,:,1,:,3,:,1 provided the highest conversions of LMA and the best controlled polymerizations. These optimized conditions allowed for the synthesis of poly(lauryl methcarylate)s with different targeted DP (25, 50, 75, 100, 120, 240, and 500), including high-molecular-weight polymers with narrow molecular weight distributions. In addition, methacrylate monomers were prepared from fatty alcohols (capric, myristic, palmitic, stearic) and polymerized using the developed procedure to obtain polymers with the same DP and different chain lengths (C10, C12, C14, C16, and C18) of pending alkyl groups. Finally, the thermal properties of these polymers were examined by differential scanning calorimetry and thermogravimetric analysis. [source] Leaf dark respiration as a function of canopy position in Nothofagus fusca trees grown at ambient and elevated CO2 partial pressures for 5 yearsFUNCTIONAL ECOLOGY, Issue 4 2001K. L. Griffin Summary 1,Mass-based and area-based rates of respiration, leaf nitrogen content, leaf total protein content, non-structural carbohydrates and leaf mass per unit area (LMA) all decreased with depth in the canopy of Nothofagus fusca (Hook. F.) Oerst. (Red beech) trees grown for 5 years at ambient (36 Pa) or elevated (66 Pa) CO2 partial pressures. 2Elevated CO2 partial pressure had a strong effect on dark respiration, decreasing both mass-based and area-based rates at all canopy positions, but had little or no effect on leaf physical and biochemical properties. 3Leaf sugars, starch, protein, N and LMA were all correlated with respiration rate, and are therefore strong predictors of area-based dark respiration rates. The y axis intercept of regressions of respiration rate on mean leaf N, protein, starch and LMA was lower for plants grown at elevated compared to ambient CO2 partial pressures because of the differential effect of growth at elevated CO2 partial pressure on leaf gas-exchange, chemical and physical characteristics. 4,The lower respiration rates for leaves from trees grown at elevated CO2 partial pressure resulted in a significant increase in the ratio of light-saturated net photosynthesis to respiration, increasing the potential carbon-use efficiency of these leaves. [source] The effect of tree height and light availability on photosynthetic leaf traits of four neotropical species differing in shade toleranceFUNCTIONAL ECOLOGY, Issue 1 2000T. Rijkers Abstract 1.,Light-saturated rate of photosynthesis (Amax), nitrogen (N), chlorophyll (Chl) content and leaf mass per unit area (LMA) were measured in leaves of trees of different heights along a natural light gradient in a French Guiana rain forest. The following four species, arranged in order from most shade-tolerant to pioneer, were studied: Duguetia surinamensis, Vouacapoua americana, Dicorynia guianensis and Goupia glabra. Light availability of trees was estimated using hemispherical photography. 2.,The pioneer species Goupia had the lowest LMA and leaf N on both an area and mass basis, whereas Duguetia had the highest values. In general, leaf variables of Vouacapoua and Dicorynia tended to be intermediates. Because Amax/area was similar among species, Goupia showed both a much higher light-saturated photosynthetic nitrogen-use efficiency (PNUEmax) and Amax/mass. Leaves of Vouacapoua demonstrated the greatest plasticity in Amax/area, particularly in small saplings. 3.,A distinction could be made between the effect of tree height and light availability on the structural, i.e. LMA, and photosynthetic leaf characteristics of all four species. The direction and magnitude of the variation in variables were similar among species. 4.,LMA was the key variable that mainly determined variation in the other leaf variables along tree height and light availability gradients, with the exception of changes in chlorophyll concentration. Amax/area, N/area, LMA and stomatal conductance to water vapour (gs) increased, whereas Chl/mass decreased, with both increasing tree height and canopy openness. Amax/mass, PNUEmax and Amax/Chl increased with increasing openness only. N/mass and Chl/area were independent of tree height and openness, except for small saplings of Goupia which had a much lower Chl/area. [source] Exposure to anaesthetic trace gases during general anaesthesia: CobraPLA vs.ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2010LMA classic Background: To prospectively investigate the performance, sealing capacity and operating room (OR) staff exposure to waste anaesthetic gases during the use of the Cobra perilaryngeal airway (CobraPLA) compared with the laryngeal mask airway classic (LMA). Methods: Sixty patients were randomly assigned to the CobraPLA or the LMA group. Insertion time, number of insertion attempts and airway leak pressures were assessed after induction of anaesthesia. Occupational exposure to nitrous oxide (N2O) and Sevoflurane (SEV) was measured at the anaesthetists' breathing zone and the patients' mouth using a photoacoustic infrared spectrometer. Results: N2O waste gas concentrations differed significantly in the anaesthetist's breathing zone (11.7±7.2 p.p.m. in CobraPLA vs. 4.1±4.3 p.p.m. in LMA, P=0.03), whereas no difference could be shown in SEV concentrations. Correct CobraPLA positioning was possible in 28 out of 30 patients (more than one attempt necessary in five patients). Correct positioning of the LMA classic was possible in all 30 patients (more than one attempt in three patients). Peak airway pressure was higher in the CobraPLA group (16±3 vs. 14±2 cmH2O, P=0.01). The average leak pressure of the CobraPLA was 24±4 cmH2O, compared with 20±4 cmH2O of the LMA classic (P<0.001; all values means±SD). Conclusion: Despite higher airway seal pressures, the CobraPLA caused higher intraoperative N2O trace concentrations in the anaesthetists' breathing zone. [source] Sparing the larynx during gynecological laparoscopy: a randomized trial comparing the LMA SupremeÔ and the ETTACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2010W. ABDI Background: We designed a prospective randomized single-blind study to compare efficiency and post-operative upper airway morbidity when the laryngeal mask airway (LMA) SupremeÔ is used as an alternative to the endotracheal tube (ETT). Methods: One hundred and thirty-eight elective pelvic laparoscopic ASA I,II female patients were assigned to receive either the LMA Supreme® or the ETT for airway management. Balanced anesthesia and ventilation techniques were standardized to control end-tidal CO2 and BIS value in the range 4.5,5 kPa and 40,50, respectively, and to maintain adequate hemodynamic stability. A single surgeon blinded to the airway management technique performed all surgical procedures. The ventilation efficiency of each airway was evaluated. Anesthesia- and surgery-related times were calculated and anesthesia details were recorded. Post-operative pain and pharyngolaryngeal morbidity were measured in a blind fashion using a numerical rating scale (NRS) (0,100). Results: Surgery duration was similar in both groups. Airway management duration was shorter with the LMA Supreme®. Post-operative pharyngolaryngeal morbidity incidence and all symptoms' intensity were significantly increased after ETT as compared with LMA Supreme® anesthesia. At the end of the PACU stage, the incidence and mean NRS of post-operative hoarseness were reduced when LMA Supreme® was used as an alternative to the ETT (16% vs. 47%; P<0.01 and 9 vs. 19, P<0.01, respectively). Conclusion: We demonstrated that choosing an LMA Supreme® was an efficient pharyngolaryngeal morbidity-sparing strategy. Moreover, we showed that the LMA Supreme® and the ETT were equally effective airways for a routine gynecological laparoscopy procedure. [source] Effects of adding liquid dl -methionine hydroxy analogue-free acid to drinking water on growth performance and small intestinal morphology of nursery pigsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3 2010C. Kaewtapee Summary This study was conducted to evaluate the effect of adding liquid dl -methionine hydroxy analogue free acid (LMA) to drinking water on growth performance, small intestinal morphology and volatile fatty acids in the caecum of nursery pigs. Twenty-four crossbred pigs (Large White × Landrace, BW ,18 kg) were divided into three groups with four replications of two piglets each. The piglets received drinking water without (control), with 0.05 or 0.10% LMA. The results indicated that adding LMA at 0.10% to drinking water significantly increased their weight gain, average daily feed intake (p < 0.05) and tended to improve the feed conversion ratio. Adding LMA to drinking water significantly increased their water intake and significantly reduced the pH of drinking water (p < 0.01), thus total plate count (p < 0.01) and Escherichia coli in drinking water was reduced (p < 0.05), while the total number of bacteria in the caecum was not significantly affected. Liquid dl -methionine hydroxy analogue free acid supplementation in drinking water tended to decrease pH in the stomach, duodenum, jejunum, colon and rectum. Furthermore, adding LMA at 0.10% significantly increased villous height in the duodenum, jejunum and ileum (p < 0.05), and the villous height:crypt depth ratio in the jejunum and ileum (p < 0.01) was higher, whereas acetic acid concentration in the caecum was significantly lower than in the control group. It could be concluded that adding LMA to drinking water improved growth performance of the nursery pigs because of high water quality and high nutrient utilization caused by an improvement of small intestinal morphology (not from nutritional effect of methionine source). [source] Chemical and physical plant defence across multiple ontogenetic stages in a tropical rain forest understorey treeJOURNAL OF ECOLOGY, Issue 4 2009Bruce L. Webber Summary 1Variation over plant ontogeny can play an important role in shaping trade-offs between investing resources in growth, reproduction and defence. Most previous ontogenetic studies on plant defence have compared two life stages, making it impossible to follow complete ontogenetic trajectories for plant defence traits. 2We used the highly defended rain forest understorey tree Ryparosa kurrangii to examine chemical (cyanogen concentrations; CNM) and physical (leaf mass per area; LMA) ontogenetic defence trajectories across multiple stages of development for the first time, using field and glasshouse plants. 3In glasshouse seedlings, total plant cyanide and CNM decreased between cotyledon-bearing and recently autonomous seedlings. In field populations, foliar CNM decreased in a nonlinear fashion and showed a trade-off with LMA through the ontogenetic progression from small seedlings to large mature trees. 4Cyanogenesis was ubiquitous in all individuals tested, with considerable quantitative plasticity in constitutive expression. Environmental influences on defence traits, as measured by foliar nitrogen and potential light availability in the field, had no detectable effect on CNM. Non-cyanide nitrogen (N , NCN)M was negatively correlated with CNM, and NCN was negatively correlated with plant height; therefore, at constant plant height there was no relationship between (N , NCN)M and CNM. LMA was positively correlated with increasing light availability. 5Our results suggest that light and nitrogen availability have no detectable effect on CNM in R. kurrangii and that most of the observed population-level CNM plasticity may be due to underlying genetic and ontogenetic influences. These findings are related to a theoretical model recently proposed for resistance trajectories during plant ontogeny, taking into account the life-history traits of rain forest understorey trees. 6Synthesis. The nonlinear ontogenetic trajectory of plant defence expression observed in this study suggests that ontogenetic defence changes may be strongly influenced by plant life-history traits, the defence(s) examined and the environmental niche the plant occupies. [source] Prey availability directly affects physiology, growth, nutrient allocation and scaling relationships among leaf traits in 10 carnivorous plant speciesJOURNAL OF ECOLOGY, Issue 1 2008Elizabeth J. Farnsworth Summary 1Scaling relationships among photosynthetic rates, leaf mass per unit area (LMA), and foliar nitrogen (N) and phosphorus (P) content hold across a diverse spectrum of plant species. Carnivorous plants depart from this spectrum because they dedicate substantial leaf area to capturing prey, from which they derive N and P. We conducted a manipulative feeding experiment to test whether scaling relationships of carnivorous plant leaf traits become more similar to those of non-carnivorous taxa when nutrients are not limiting. 2We examined the effects of prey availability on mass-based maximum photosynthetic rate (Amass), chlorophyll fluorescence, foliar nutrient and chlorophyll content, and relative growth rate of 10 Sarracenia species. We hypothesized that increased prey intake would stimulate Amass, reduce stress-related chlorophyll fluorescence, increase photosynthetic nutrient-use efficiencies (PNUEN, PNUEP), and increase relative biomass allocation to photosynthetically efficient, non-carnivorous phyllodes. 3Two plants per species were assigned in a regression design to one of six weekly feedings of finely ground wasps: 0,0.25 g for small plant species; 0,0.5 g for intermediate-sized species; and 0,1.0 g for large species. The first two leaves emerging on each plant were fed. 4Increased prey availability increased photosystem efficiency (Fv/Fm ratio) in the first two leaves, and chlorophyll content and Amass in younger leaves as older leaves rapidly translocated nutrients to growing tissues. Higher prey inputs also led to lower N : P ratios and a shift from P- to N-limitation in younger leaves. PNUEP was significantly enhanced whilst PNUEN was not. Better-fed plants grew faster and produced a significantly higher proportion of phyllodes than controls. 5Feeding shifted scaling relationships of P relative to Amass, N and LMA from outside the third bivariate quartile to within the 50th bivariate percentile of the universal spectrum of leaf traits; other scaling relationships were unaffected. Carnivorous plants can rapidly reallocate P when nutrients are plentiful, but appear to be less flexible in terms of N allocation. 6Synthesis. Our results support the general hypothesis put forward by Shipley et al. (2006) that observed scaling relationships amongst leaf traits derive from trade-offs in allocation to structural tissues vs. liquid-phase (e.g. photosynthetic) processes. These trade-offs appear to be especially constraining for plants growing in extremely nutrient-poor habitats such as bogs and other wetlands. [source] Convergence towards higher leaf mass per area in dry and nutrient-poor habitats has different consequences for leaf life spanJOURNAL OF ECOLOGY, Issue 3 2002Ian J. Wright Summary 1,Leaf life span (LL) and leaf mass per area (LMA) are fundamental traits in the carbon economy of plants, representing the investment required per unit leaf area (LMA) and the duration of the resulting benefit (LL). Species on dry and infertile soils converge towards higher LMA. It has been generally assumed that this allows species from low-resource habitats to achieve longer average leaf life spans, as LMA and LL are often correlated. 2,Leaf life span and LMA were measured for 75 perennial species from eastern Australia. Species were sampled from nutrient-rich and nutrient-poor sites within high and low rainfall regions. LL and LMA were positively correlated across species within each site. In addition, evolutionary divergences in LL and LMA were correlated within each site, indicating that cross-species relationships were not simply driven by differences between higher taxonomic groups. 3,Within a rainfall zone, LL,LMA combinations shifted as expected along common axes of variation such that species on poorer soils had higher LMA and longer LL, but significantly so only at high rainfall. 4,Low rainfall species were expected to have shorter LL at a given LMA or, equally, require higher LMA to achieve a given LL, i.e. shift to a parallel axis of variation, and this was observed on both nutrient-rich and nutrient-poor soils. On average, 30% higher LMA was seemingly required at dry sites to achieve a given LL. Thus, convergence towards higher LMA has different consequences for leaf life span in dry and nutrient-poor habitats. 5,The broad shifts in LL,LMA combinations between site types were also seen when comparing closely related species-pairs (phylogenetically independent contrasts) occurring on nutrient-rich and nutrient-poor soils (within each rainfall zone), and at high- and low-rainfall sites (at each soil nutrient level). [source] Failure to inflate Ambu® AuraFlexÔ single-use LMA after insertionACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2009M. Tavakkolizadeh No abstract is available for this article. [source] LMA: a big choiceACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2009A. LARSSON No abstract is available for this article. [source] Comparison between intubation and the laryngeal mask airway in moderately obese adultsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2009M. ZOREMBA Background: Obesity is a well-established risk factor for perioperative pulmonary complications. Anaesthetic drugs and the effect of obesity on respiratory mechanics are responsible for these pathophysiological changes, but tracheal intubation with muscle relaxation may also contribute. This study evaluates the influence of airway management, i.e. intubation vs. laryngeal mask airway (LMA), on postoperative lung volumes and arterial oxygen saturation in the early postoperative period. Methods: We prospectively studied 134 moderately obese patients (BMI 30) undergoing minor peripheral surgery. They were randomly assigned to orotracheal intubation or LMA during general anaesthesia with mechanical ventilation. Premedication, general anaesthesia and respiratory settings were standardized. While breathing air, we measured arterial oxygen saturation by pulse oximetry. Inspiratory and expiratory lung function was measured preoperatively (baseline) and at 10 min, 0.5, 2 and 24 h after extubation, with the patient supine, in a 30° head-up position. The two groups were compared using repeated-measure analysis of variance (ANOVA) and t -test analysis. Statistical significance was considered to be P<0.05. Results: Postoperative pulmonary mechanical function was significantly reduced in both groups compared with preoperative values. However, within the first 24 h, lung function tests and oxygen saturation were significantly better in the LMA group (P<0.001; ANOVA). Conclusions: In moderately obese patients undergoing minor surgery, use of the LMA may be preferable to orotracheal intubation with respect to postoperative saturation and lung function. [source] Safety of laryngeal mask airway and short-stay practice in office-based adenotonsillectomyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2009R. GRAVNINGSBRÅTEN Background: It is still disputed whether laryngeal mask airway (LMA) is safe and convenient for adenotonsillectomy, and whether these procedures can be safely undertaken in an office-based short-stay ambulatory setting. We report the result of this practice in 1126 consecutive children <16 years of age. Methods: The patients received general anaesthesia with propofol and remifentanil. For analgesic prophylaxis, they received paracetamol, fentanyl and local anaesthetic administration. NSAIDs were given to patients weighing above 15 kgs. A surgical technique with elevation, scissors and electrocoagulation was used. Post-operatively, the tonsillectomies were observed in the unit for at least 1.5 h and the adenoidectomies for at least 15,20 min. Results: Conversion from LMA to an endotracheal tube was carried out in six patients (0.5%), mostly due to airway leakage during ventilation. One patient had a pulmonary atelectasis and was re-intubated. No re-operation was needed in the clinic after surgery, and all patients, except for the one with atelectasis (0.1%), were discharged home as planned. In 122 patients answering a questionnaire, after discharge, two patients (1.6%) were admitted to hospital and re-operated due to bleeding; a further six patients (4.9%) were admitted for observation. In 25% of the patients, nausea and vomiting occurred after discharge, including 21% vomiting of swallowed blood during home travel. Only 5.6% reported significant post-discharge pain. Conclusion: With a well-trained team, adenotonsillectomy on children can be carried out safely in an office-based setting with LMA and a short post-operative stay. [source] Positive pressure ventilation with the LMA: inspiratory leaks and effect on the adequacy of ventilationACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2007S. K. Ramachandran No abstract is available for this article. [source] A hybrid approach to Web forum interactional coherence analysisJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 8 2008Tianjun Fu Despite the rapid growth of text-based computer-mediated communication (CMC), its limitations have rendered the media highly incoherent. This poses problems for content analysis of online discourse archives. Interactional coherence analysis (ICA) attempts to accurately identify and construct CMC interaction networks. In this study, we propose the Hybrid Interactional Coherence (HIC) algorithm for identification of web forum interaction. HIC utilizes a bevy of system and linguistic features, including message header information, quotations, direct address, and lexical relations. Furthermore, several similarity-based methods including a Lexical Match Algorithm (LMA) and a sliding window method are utilized to account for interactional idiosyncrasies. Experiments results on two web forums revealed that the proposed HIC algorithm significantly outperformed comparison techniques in terms of precision, recall, and F-measure at both the forum and thread levels. Additionally, an example was used to illustrate how the improved ICA results can facilitate enhanced social network and role analysis capabilities. [source] A c-cut Nd:GdVO4 solid-state laser passively Q-switched with Co2+:LaMgAl11O19 lasing at 1.34 µmLASER PHYSICS LETTERS, Issue 8 2007H.-J. Qi Abstract We investigated a high power diode-laser pumped passively Q-switched c-cut Nd:GdVO4 solid-state laser, lasing at 1.34 µm, with a Co2+:LaMgAl11O19 saturable absorber. With the optimum output coupler transmission T = 5.5% and pump power of 11.5 W, the static output power of 3.01 W was obtained. The passively Q-switching operation with Co:LMA (initial transmission T0 = 90%) as saturable absorber, shows that the shortest output pulse width, the highest output power, the highest pulse repetition and the highest pulse peak power were 32 ns, 266 mW, 277 kHz, and 187 W, respectively. (© 2007 by Astro Ltd., Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] Resistive load of laryngeal mask airway and proseal laryngeal mask airway in mechanically ventilated patientsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 6 2003G. Natalini Background:, The ProSeal Laryngeal Mask Airway (PLMA) ventilation tube is narrower and shorter than the standard Laryngeal Mask Airway (LMA) and is without the vertical bars at the end of the tube. In this randomized, crossover study, PLMA and LMA resistances were compared. Methods:, Respiratory mechanics was calculated in 26 anesthetized, mechanically ventilated patients with both LMA and PLMA. The laryngeal mask positioning was fiberoptically evaluated. Differences in the respiratory mechanics of the LMA and the PLMA were attributed to the differences between the laryngeal masks. Results:, In the total study population the airway resistance was 1.5 ± 2.6 hPa.l,1.s,1 (P = 0.005) higher with the PLMA than with the LMA. During the PLMA use, the peak expiratory flow reduced by 0.02 ± 0.05 l min,1 (P = 0.046), the expiratory resistance increased by 0.6 ± 1.3 hPa.l,1.s,1 (P = 0.022), and the time constant of respiratory system lengthened by 0.09 ± 0.18 s (P = 0.023). These differences doubled when the LMA was better positioned than the PLMA, whereas they disappeared when the PLMA was positioned better than the LMA. Conclusions:, The standard LMA offers a lower resistive load than the PLMA. Moreover, the fitting between the laryngeal masks and the larynx, as fiberoptically evaluated, plays a major role in determining the resistive properties of these devices. [source] Submergence-induced leaf acclimation in terrestrial species varying in flooding toleranceNEW PHYTOLOGIST, Issue 2 2007Liesje Mommer Summary ,,Earlier work on the submergence-tolerant species Rumex palustris revealed that leaf anatomical and morphological changes induced by submergence enhance underwater gas exchange considerably. Here, the hypothesis is tested that these plastic responses are typical properties of submergence-tolerant species. ,,Submergence-induced plasticity in leaf mass area (LMA) and leaf, cell wall and cuticle thickness was investigated in nine plant species differing considerably in tolerance to complete submergence. The functionality of the responses for underwater gas exchange was evaluated by recording oxygen partial pressures inside the petioles when plants were submerged. ,,Acclimation to submergence resulted in a decrease in all leaf parameters, including cuticle thickness, in all species irrespective of flooding tolerance. Consequently, internal oxygen partial pressures (pO2) increased significantly in all species until values were close to air saturation. Only in nonacclimated leaves in darkness did intolerant species have a significantly lower pO2 than tolerant species. ,,These results suggest that submergence-induced leaf plasticity, albeit a prerequisite for underwater survival, does not discriminate tolerant from intolerant species. It is hypothesized that these plastic leaf responses may be induced in all species by several signals present during submergence; for example, low LMA may be a response to low photosynthate concentrations and a thin cuticle may be a response to high relative humidity. [source] A test of the generality of leaf trait relationships on the Tibetan PlateauNEW PHYTOLOGIST, Issue 4 2006Jin-Sheng He Summary ,,Leaf mass per area (LMA), nitrogen concentration (on mass and area bases, Nmass and Narea, respectively), photosynthetic capacity (Amass and Aarea) and photosynthetic nitrogen use efficiency (PNUE) are key foliar traits, but few data are available from cold, high-altitude environments. ,,Here, we systematically measured these leaf traits in 74 species at 49 research sites on the Tibetan Plateau to examine how these traits, measured near the extremes of plant tolerance, compare with global patterns. ,,Overall, Tibetan species had higher leaf nitrogen concentrations and photosynthetic capacities compared with a global dataset, but they had a slightly lower Amass at a given Nmass. These leaf trait relationships were consistent with those reported from the global dataset, with slopes of the standardized major axes Amass,LMA, Nmass,LMA and Amass,Nmass identical to those from the global dataset. Climate only weakly modulated leaf traits. ,,Our data indicate that covarying sets of leaf traits are consistent across environments and biogeographic regions. Our results demonstrate functional convergence of leaf trait relationships in an extreme environment. [source] Phosphorus nutrition-mediated effects of arbuscular mycorrhiza on leaf morphology and carbon allocation in perennial ryegrassNEW PHYTOLOGIST, Issue 2 2005Agustín A. Grimoldi Summary ,,The aim of this work was to disentangle phosphorus status-dependent and -independent effects of arbuscular mycorrhizal fungus (AMF) on leaf morphology and carbon allocation in perennial ryegrass (Lolium perenne). ,,To this end, we assessed the P-response function of morphological components in mycorrhizal and nonmycorrhizal plants of similar size. ,,AMF (Glomus hoi) stimulated relative P-uptake rate, decreased leaf mass per area (LMA), and increased shoot mass ratio at low P supply. Lower LMA was caused by both decreased tissue density and thickness. Variation in tissue density was almost entirely caused by variations in soluble C, while that in thickness involved structural changes. ,,All effects of AMF were indistinguishable from those mediated by increases in relative P-uptake rate through higher P-supply rates. Thus the relationships between relative P-uptake rate, leaf morphology and C allocation were identical in mycorrhizal and nonmycorrhizal plants. No evidence was found for AMF effects not mediated by changes in plant P status. [source] Anesthetic experience of 100 pediatric tracheostomiesPEDIATRIC ANESTHESIA, Issue 7 2009FIONA WRIGHTSON MB ChB FRCA Summary Background:, Tracheostomy is more hazardous in the pediatric population than in adults (Paediatr Nurs, 17, 2005, 38; Int J Pediatr Otorhinolaryngol, 67, 2003, 7; J R Soc Med, 89, 1996, 188). Airway management in these children and infants is potentially challenging. Previous case series of pediatric tracheostomy published in the surgical journals make little mention of anesthetic techniques used and do not describe airway management. The aim of this study was to review the anesthetic, and in particular the airway management of children undergoing tracheostomy at Great Ormond Street Hospital (GOSH). Methods:, Between September 2004 and December 2007, the ENT surgical database showed that 109 children had a surgical tracheostomy performed at GOSH. We were only able to locate the notes of 100 of these cases. The anesthetic records of these 100 patients undergoing tracheostomy were analyzed retrospectively. Results:, Ninety-four percent (94/100) of tracheostomies were elective, and 6% (6/100) were emergency. In this study, 26% (26/100) of children were recorded as difficult to intubate. These difficult airways were managed as follows: 10/26 used a laryngeal mask airway (LMA), 5/26 were managed with facemask alone, 3/26 had fiber-optic intubation, 5/26 had surgical intubation and 2/26 were intubated with the aid of a bougie and cricoid pressure. Conclusions:, This case series demonstrates that intubation is difficult in up to 26% of children presenting for tracheostomy. While intubation of the trachea remains the preferred option when anesthetizing children for tracheostomy, the LMA or facemask can provide a successful airway where intubation is not possible. The use of the LMA or facemask may therefore be life saving in the unintubatable child. [source] Insertion characteristics, sealing pressure and fiberoptic positioning of CobraPLA in childrenPEDIATRIC ANESTHESIA, Issue 10 2007MAURIZIO PASSARIELLO MD Summary Background:, The CobraPLATM is a new supraglottic airway device designed for the use in spontaneously breathing and mechanically ventilated patients. In adults it has been found as effective as the LMA, but with better sealing qualities. The aim of the present study was to evaluate fit and sealing characteristics of CobraPLA size 1.5 and 2 in mechanically ventilated children. Methods:, Forty children, ASA I/II, aged 1,10 years, weighing 10,35 kg were scheduled for minor surgical procedures. The number of attempts for insertion and fiberoptic positioning of the CobraPLA was assessed. After muscle relaxation had been achieved, airway sealing pressure was measured by gradually increasing maximum inspiratory pressure to a maximum of 30 cmH2O. Results:, Insertion of CobraPLA was successful at the first attempt in 90% of patients. The vocal cords were visualized in 90% of patients (grade 0: 2.5%, grade 1: 7.5%, grade 2: 30%, grade 3: 15%, grade 4: 45%). Median sealing pressure was 20.0 ± 6.0 cmH2O. In 21% of patients gastric insufflation was observed at a peak inspiratory pressure of 20 cmH2O or below. Conclusions:, The CobraPLA was found to have easy insertion characteristics and good anatomical fitting in children between 10 and 35 kg. If positive pressure ventilation with CobraPLA size 1.5 and 2.0 is required, peak inspiratory pressure should be kept below the leak pressure and the abdomen closely monitored for signs of gastric insufflation. [source] Airway management in two of newborns with Pierre Robin Sequence: the use of disposable vs multiple use LMA for fiberoptic intubationPEDIATRIC ANESTHESIA, Issue 12 2006JUDI M. CAIN Summary In this article, we discuss the use of LMAs as a conduit to intubate the trachea of two Pierre Robin Sequence infants. Multiple use LMAs will admit larger diameter tracheal tubes (TT) than their disposable counterparts. Increased friction with the surface of the TT makes passing even small diameter tubes through the lumen of the disposable LMA difficult. [source] Continuous sciatic block for leg and foot surgery in 160 childrenPEDIATRIC ANESTHESIA, Issue 11 2005LAKSHMI VAS MD Summary Background:, The aim of this study was to assess the safety and efficacy of continuous sciatic block for lower limb surgery in children. Methods:, A total of 160 pediatric patients aged 4 months to 12 years weighing 3.5,50 kg, were given continuous sciatic block plus single shot 3-in-1 block for leg and foot surgery. After general anesthesia, the sciatic nerve was located by using loss of resistance to saline by the mid-thigh approach. An 18 gauge epidural needle was introduced at the junction of the proximal two-third with the distal one-third of a line extending from the apex of popliteal triangle to the midpoint of the line joining the greater trochanter and the ischial tuberosity. A 20 g catheter was threaded through the needle for 5,10 cm and 0.25% bupivacaine 0.75 ml·kg,1 was injected. A single shot 3-in-1 block was also given to facilitate the use of a tourniquet with 0.25% bupivacaine 0.25 ml. In 20 patients a nerve stimulator was used in addition to loss of resistance. The intraoperative sedation comprised propofol and ketamine infusions and 50% nitrous oxide in oxygen by LMA. Results:, Eight-two percent of patients showed no response to surgery; 14% patients showed some response to the medial incision over the ankle and needed additional bolus doses of ketamine and propofol. Block was considered to have failed in 4% who required an increase in propofol and ketamine infusions. A total of 154 patients had good postoperative pain relief for 72 h with continuous infusion of 0.05% bupivacaine. The other six were given oral codeine and diclofenac. There were no complications attributable to sciatic block in any patient. Conclusions:, Sciatic block with a single shot 3-in-1 block for tourniquet pain and light general anesthesia provides good intraoperative conditions for leg and foot surgery and adequate postoperative pain relief. Additional sedation to minimize the discomfort of a cast may be a consideration in the first 24 h. [source] Manikin training for neonatal resuscitation with the laryngeal mask airwayPEDIATRIC ANESTHESIA, Issue 6 2004Donna Gandini MB BS Summary Background :,We describe our experience of brief (,15 min) manikin-only training with the laryngeal mask airway (LMATM) for neonatal resuscitation in 80 health care workers. Methods :,Prior to training, 31% had not heard of the LMA, 57% did not know the LMA could be used for neonatal resuscitation and 88% thought it was a disposable device. Results :,The mean (sd) range time to insert the LMA after training was 5 (2, 5,16) s and there were no failed insertions. The preferred technique for neonatal resuscitation, before vs after training, changed from 72 to 14% for the face mask (P < 0.00001), from 6 to 80% for the LMA (P < 0.00001), from 5 to 0% for laryngoscope-guided tracheal intubation (P = 0.04) and from 16 to 5% for unknown (P = 0.02). All considered that training was adequate and the LMA should be available on neonatal resuscitation carts. Confidence in using the LMA increased from 8 to 97% (P < 0.0001). Conclusions :,We conclude that LMA insertion success rates are high and confidence increases after brief manikin-only training. [source] Incidence of postoperative nausea and vomitingin paediatric ambulatory surgeryPEDIATRIC ANESTHESIA, Issue 8 2002I. Villeret SummaryBackground: We performed a prospective descriptive study over a 5-month period to determine the incidence of postoperative nausea and vomiting (PONV) during the first 24 h following elective ambulatory paediatric surgery, excluding head and neck procedures. Methods: Four hundred and seven patients, aged 15 days to 16 years, were analysed prospectively. Results: The incidence of PONV was 9.4%, occurring most frequently during the first 3 h after anaesthesia and in hospital but rarely during the journey home. It was associated with age, previous history of PONV, tracheal intubation or use of the laryngeal mask airway (LMAÔ), controlled or manual ventilation, opioids and absence of oral intake of liquids or solids. Conversely, type of surgery, premedication, induction mode, association of regional anaesthesia, inhaled nitrous oxide, duration of anaesthesia, stay in the postanaesthesia care unit and duration of journey after discharge were not significantly associated with PONV. Conclusions: PONV never induced complications or delayed patient discharge and curative treatment was rapidly effective. [source] Modification of the LMA no. 1 for diode laser photocoagulation in ex-premature infantsPEDIATRIC ANESTHESIA, Issue 3 2000Article first published online: 9 OCT 200 No abstract is available for this article. [source] | ||||||||||||||||||||||