Duration Of Saturation Research Articles

土壌中における炭酸塩岩の風化速度とその制約条件

The weathering of carbonate rocks in soil is an essential process in the evolution of karst landforms as well as in the global carbon cycle. Among the various methods for measuring the weathering rates of carbonate rocks, a field weathering experiment using rock tablets is a simple and relatively easy method to estimate the spatial distribution of weathering rates in karst terrains. This paper introduces some results of field experiments on the weathering of carbonate rocks. The results are summarized based on the following three factors: global climatic condition (annual temperature and precipitation), local environmental conditions (soil moisture), and duration of experiment. Annual precipitation is one of the major factors controlling the weathering rates of carbonate rocks. At a local scale, weathering rates are controlled by the duration of water saturation in soil, although some experiments also indicate the effects of soil water chemistry on weathering rates. Changes in the surface condition of tablets, as well as inter-annual climatic variations also affect weathering rates. Duration of experiment should be set carefully to reduce influences from the duration of the experiment.

The saturated impulse of fully clamped square plates subjected to linearly decaying pressure pulse

Saturated impulse refers to the critical value, beyond which the deflection of a beam or plate under pulse loading will no longer increase with further applied load. Previous studies have explored the saturated impulse for structures under rectangular pressure pulse loading. The present paper investigates the saturated impulse for fully clamped square plates subjected to linearly decaying pressure pulse, which is closer to the pulse produced by explosive loading. Both rigid-plastic model and elastic-plastic model are employed to study the saturated duration, saturated impulse, saturated deflection, etc. The results indicate that the saturated impulse exists if the decaying duration is greater than a certain value (i.e. the minimum decaying duration), and a saturation regime map is constructed accordingly. To facilitate engineering designs, an empirical expression for saturated duration is provided based on the elastic-plastic numerical results. In addition, a method is proposed to predict the deflection of fully clamped square plates, which replaces the linearly decaying pressure pulse with an equivalent rectangular pressure pulse. Inspired by Youngdahl's pioneering work, the proposed method has explicit physical meaning and wide range of application.

Editor's Highlight: Prospective Analyses of Volatile Organic Compounds in Obstructive Sleep Apnea Patients.

Various volatile organic compounds (VOCs) are known to be toxic. Although exhaled VOC patterns change in obstructive sleep apnea (OSA) patients, individual VOC profiles are not fully determined. The primary outcome was VOC characterizations; secondary outcomes included their relationships with sleep and clinical parameters in OSA patients. We prospectively examined 32 OSA patients with an apnea-hypopnea index (AHI) ≥ 15 by full polysomnography, and 33 age- and sex-matched controls without obvious OSA symptoms. Nine severe OSA patients were examined before and after continuous positive airway pressure (CPAP) treatment. By applying a method which eliminates environmental VOC influences, exhaled VOCs were identified by gas chromatography (GC)-mass spectrometry, and their concentrations were determined by GC. Exhaled aromatic hydrocarbon concentrations (toluene, ethylbenzene, p-xylene, and phenylacetic acid) in the severe OSA groups (AHI ≥ 30) and exhaled saturated hydrocarbon concentrations (hexane, heptane, octane, nonane, and decane) in the most severe OSA group (AHI ≥ 60) were higher than those in the control group. Exhaled isoprene concentrations were increased in all OSA groups (AHI ≥ 15); acetone concentration was increased in the most severe OSA group. Ethylbenzene, p-xylene, phenylacetic acid, and nonane concentrations were increased according to OSA severity, and correlated with AHI, arousal index, and duration of percutaneous oxygen saturation (SpO2) ≤ 90%. Multiple regression analyses revealed these 4 VOC levels were associated with the duration of SpO2 ≤ 90%. Isoprene and acetone decreased after CPAP treatment. OSA increased some toxic VOCs, and some correlated with OSA severity. CPAP treatment possibly ameliorates these productions.

The Saturated Impulse for Fully Clamped Square Plates Subjected to Linear-Decay Pressure Pulse

Saturated impulse refers to the critical value beyond which the deflection of the beam or plate under pulse loading will no longer increase with further applied load. Previous effort has been made to study the saturate impulse for structures under rectangular pressure pulse loading. Through theoretical analysis, the present paper investigates the saturated impulse for fully clamped square plates subjected to linear-decay pressure pulse, which is closer to explosive loading pulse. The results indicate that the saturated impulse does exist if the decay duration is greater than a certain value (i.e. the minimum decay duration). The saturated impulse, saturated deflection and saturated duration all have nonlinearly relations with the dimensionless applied pressure, and grow with the increase of the decay duration.

Redox Dynamics and Oxygen Reduction Rates of Infiltrating Urban Stormwater beneath Low Impact Development (LID)

Low impact development (LID) best management practices (BMPs) collect, infiltrate, and treat stormwater runoff, and increase recharge to aquifers. Understanding the controls on reduction/oxidation (redox) conditions within LID BMPs is important for groundwater management because outflow from some LID BMPs can recharge aquifers and affect groundwater quality. Here we evaluate redox conditions of urban stormwater runoff in a LID infiltration trench in San Francisco, California, and quantify the relation between water saturation (%) and temperature (◦C) and resulting dissolved oxygen (DO) concentrations, redox dynamics, and O2 reduction rates. The DO fluctuations ha ve an inverse response to the duration of saturation of the trench. Anoxic (<0.5 mg/L) conditions often occurred within hours of stormwater events and persisted from a few hours to two days, which indicate that microbial respiration can be a limiting factor for DO. Temperature of stormwater runoff was not a statistically significant control on DO. The estimated O2 reduction rate is 0.003mg·L-1·min-1, which is two to five orders of magnitude higher than in groundwater from previous studies. Higher rates of O2 reduction are a function of the more toxic and organic-rich stormwater runoff that drives faster microbial O2 reduction. Our findings have important implications for the design of infiltration trenches and other LID BMPs to achieve desired redox conditions for infiltrating stormwater toward minimizing groundwater contamination.

Systematic Evaluation of Amide Proton Chemical Exchange Saturation Transfer at 3 T: Effects of Protein Concentration, pH, and Acquisition Parameters.

The goal of this work was to systematically evaluate the reproducibility of amide proton transfer chemical exchange saturation transfer (APT-CEST) at 3 T and its signal dependence on pH, protein concentration, and acquisition parameters. An in vitro system based on bovine serum albumin (BSA) was used, and its limitations were tested by comparing it to in vivo measurements. The contribution of small endogenous metabolites on the APT-CEST signal at 3 T was also investigated. In addition, the reliability of different z-spectrum interpolations as well as the use of only a few frequency offset data points instead of a whole z-spectrum were tested. We created both a BSA phantom at different concentrations and pH values and a metabolite phantom with different small molecules. Chemical exchange saturation transfer data were acquired using a 2-dimensional fast spoiled gradient-echo sequence with pulsed CEST preparation at different saturation durations and power levels. Healthy volunteer measurements were taken for comparison. Z-spectra were interpolated using a 24th-order polynomial (Poly), an eighth-order Fourier series (Fourier), and a smoothing Spline (sSpline) algorithm. To evaluate reduced data sets, only 6 to 14 frequency offsets of the z-spectrum were used and interpolated via a cubic Spline. Region of interest (ROI) evaluations were used to investigate the reproducibility of amide magnetization transfer ratio asymmetry [MTRasym(3.5 ppm)] and to analyze the MTRasym and z-spectra. Interscan standard deviations of MTRasym(3.5 ppm) were always below 0.3%. MTRasym(3.5 ppm) increased when the BSA concentrations increased and decreased when the pH increased. The amine MTRasym signal of small molecules was very small compared with BSA and was only detectable using short saturation times and higher power levels. The MTRasym(3.5 ppm) between BSA concentration steps and between nearly all pH steps was significantly different for all 3 fitting methods. The Fourier and sSpline methods showed no statistically significant differences; however, the results for the Poly method were significantly higher at some concentrations and pH values. Using only few frequency offsets resulted in less significant differences compared with fitting the complete z-spectrum. In general, MTRasym(3.5 ppm) of gray matter, white matter, and ventricle ROIs from volunteer scans increased with an increase in saturation power and partially decreased with an increase in saturation duration. Intra-ROI covariances of MTRasym(3.5 ppm) revealed the highest variations for Poly, whereas using reduced spectral data resulted in an increased signal variation. Amide proton transfer-CEST imaging is a highly reproducible method in which absolute signal differences of approximately 0.5% are detectable in principle. For in vivo applications, Fourier or sSpline interpolations of z-spectra are preferable. Using reduced data sets delivers similar results but with increased variation and therefore decreased (pH/concentration) differentiation capability. Differentiation capability increases with increases in the saturation duration and power level. The results from the in vitro BSA system cannot be directly transferred to the in vivo situation due to different chemical environments resulting in, for example, higher asymmetric macromolecular cMT effects in vivo. Amine signals from small molecules are unlikely to contribute to APT-CEST at 3 T (except for creatine); however, signals can be enhanced by using short saturation times and higher power levels.

A clinical study to determine the efficacy of 7 ppm dexmedetomidine as an adjuvant to 2% lignocaine in infraorbital nerve block

Dexmedetomidine is a selective alpha-2-adrenoceptor agonist used as an adjuvant for regional anaesthesia. We studied its efficacy as an adjuvant to lidocaine in infraorbital nerve block in 90 patients divided equally into three groups. The first group (control) was given 2% lidocaine 2ml only, the second, 2% lidocaine 2ml with dexmedetomidine 14μg peripherally (peripheral group), and the third, 2% lidocaine 2ml peripherally with dexmedetomidine 14μg systemically (systemic group). Onset of anaesthesia, duration of action, blood pressure, oxygen saturation, and heart rate were evaluated. The mean (SD) onset of action was faster in the peripheral group (185 (39.02) seconds) than in the others (control: 261.67 (67.02); systemic: 217.37 (34.86) seconds). The duration of action was longer in the peripheral group (124.87 (19.75) minutes) than in the others (control: 70.43 (13.62); systemic: 88.83 (20.63) minutes). Differences in blood pressure, oxygen saturation, and heart rate measured at different intervals were not significant. The addition of 7mg/L dexmedetomidine to lidocaine perineurally speeds up the onset of action and prolongs the duration of anaesthesia.

Characterization of viscosupplementation formulations using chemical exchange saturation transfer (ViscoCEST).

BackgroundOsteoarthritis (OA) is characterized by progressive loss of cartilage in joints, and is a major cause of pain and disability, and imposes significant health care expense. New therapies are being developed to treat the symptomatic effect of OA, one of which is intra-articular injection of viscosupplementations of different forms of hyaluronic acid (HA). The current study evaluates the chemical exchange saturation transfer (CEST) effect from two popular viscosupplementations [Hylan gf-20 (Synvisc) and hyaluronan (Orthovisc)] by targeting the exchangeable hydroxyl protons present on these molecules (ViscoCEST).MethodsViscoCEST imaging from two viscosupplementations (Synvisc and Orthovisc) was performed on a 7T Siemens whole body MRI scanner. ViscoCEST images were collected with different combination of saturation pulse power and saturation duration. Z spectra were acquired at B1rms of 3.6 μT and 1 s saturation duration by varying the frequency from −4 to +4 ppm in step size of 0.1 ppm. Field inhomogeneity (B0) and radiofrequency (B1) maps were also acquired to correct ViscoCEST contrast map for any inhomogeneity.ResultsBoth viscosupplementations showed broad CEST effect (ViscoCEST), which peaked ~0.8 ppm from down field of water resonance. Orthovisc showed 20 % higher ViscoCEST contrast than Synvisc suggestive of more HA component in Orthovisc. Increased ViscoCEST contrast was observed from both viscosupplementations with increase in B1rms and saturation pulse duration.ConclusionViscoCEST has a potential to image the spatial distribution of viscosupplements in vivo in patients’ intra-articular space as well as temporal variation in their spatial distribution.

The Impact of Obstructive Sleep Apnea and Tobacco Smoking on Endothelial Function

Background: Endothelial dysfunction has been recognized to occur in the context of obstructive sleep apnea (OSA) or tobacco smoking. However, the deleterious effect on vascular function with concurrence of both conditions is largely unknown. Objective: To investigate whether the concurrence of OSA and smoking poses an additive detriment to endothelial dysfunction. Methods: Chinese men without a history of chronic medical illness were invited to complete a questionnaire including smoking pack-year exposure, polysomnography and peripheral arterial tonometry (PAT) for endothelial function. Serum 8-isoprostane, advanced oxidation protein products (AOPP) and monocyte chemo-attractant protein-1 (MCP-1) were measured. Results: 114 men were successfully enrolled. PAT ratio, adjusted for age and body mass index, correlated inversely with overall severity of OSA: apnea-hypopnea index (AHI), r = -0.160 (p = 0.092); oxygen desaturation index, r = -0.214 (p = 0.024); duration of oxygen saturation <90%, r = -0.219 (p = 0.020); and minimum oxygen saturation, r = 0.250 (p = 0.008). The PAT ratio decreased with increasing pack-year group (p = 0.018). It was lower with concurrent smoking history and moderate-severe OSA (AHI ≥15/h) compared to having one or neither factor (p = 0.011). Serum levels of 8-isoprostane and AOPP were positively related to severity of OSA, while MCP-1 correlated with smoking quantity. Multiple linear regression analyses showed that severity of intermittent hypoxia, MCP-1 and pack-year exposure were independent predictors of PAT ratio. Conclusion: While OSA, in particular intermittent hypoxemia, and tobacco smoking were independent risk factors, the concurrence of moderate-severe OSA and smoking was associated with the most severe impairment in endothelial function.

Clinical predictors of chest radiographic abnormalities in young children hospitalized with bronchiolitis: a single center study.

PurposeChest radiography is often performed on patients hospitalized with typical clinical manifestations of bronchiolitis. We aimed to determine the proportion of subjects with pathologic chest radiographic findings and the clinical predictors associated with pathologic chest radiographic findings in young children admitted with the typical presentation of bronchiolitis.MethodsWe obtained the following data at admission: sex, age, neonatal history, past history of hospitalization for respiratory illnesses, heart rate, respiratory rate, the presence of fever, total duration of fever, oxygen saturation, laboratory parameters (i.e., complete blood cell count, high-sensitivity C-reactive protein [hs-CRP], etc.), and chest radiography.ResultsThe study comprised 279 young children. Of these, 26 had a chest radiograph revealing opacity (n=24) or atelectasis (n=2). Multivariate logistic regression analysis showed that after adjustment for confounding factors, the clinical predictors associated with pathologic chest radiographic findings in young children admitted with bronchiolitis were elevated hs-CRP level (>0.3 mg/dL) and past history of hospitalization for respiratory illnesses (all P<0.05).ConclusionThe current study suggests that chest radiographs in young children with typical clinical manifestations of bronchiolitis have limited value. Nonetheless, young children with clinical factors such as high hs-CRP levels at admission or past history of hospitalization for respiratory illnesses may be more likely to have pathologic chest radiographic findings.

Chemical and pedological features of subaqueous and hydromorphic soils along a hydrosequence within a coastal system (San Vitale Park, Northern Italy)

Transitional systems are complex and fragile ecosystems where the water table oscillation plays a fundamental role in soil and landscape development. Due to global climate change, by the end of the next century a large part of these environments will be affected by water flooding, causing deep changes to soil properties and functionality. Increasing the knowledge on the genesis and properties of these soils can be fundamental for providing useful tools for the correct management of this natural resource. The transition from wetland to hydromorphic interdune system in the coastal area of the S. Vitale park (Northern Italy) represents a unique soil hydrosequence characterized by soils which undergo continuous or partial, permanent or periodic saturation and reduction. These hydrosequences offer a great opportunity to investigate how soil properties change in the transition from subaqueous to hydromorphic soils and to understand which pedogenetic processes mostly characterize the soil development under different water saturation conditions. In this study, the soil transition through the hydrosequence was recognized by the evaluation of some morphological (e.g. Munsell color) and chemical (organic carbon, sulfur ratio, CaCO3 content) soil properties that could trace the extent of sulfidization and decarbonation processes along the soil sequences. The presence of salts of marine origin characterized the subaqueous pedons, while nutrients accumulation (i.e., phosphorous) increased with soil emersion.These hydrosequences represent a soil continuum where the duration of water saturation and the oscillation of the water table along the soil profiles strongly affect some specific soil-forming processes that involve S redox transformation, P accumulation, CaCO3 depletion and salt accumulation.

Pedogenesis and landscape relationships of a Holocene age barrier island

Soil characteristics and pedogenic processes are relatively unstudied on Holocene age barrier islands in the Mid-Atlantic region of the United States. The objective of this study was to assess how landform stability and hydrologic conditions (water availability) influenced pedogenesis in barrier island soils. Ten topographic transects were established on different barrier island landforms (i.e., washover fan, back-barrier flat, barrier flat, and dune field) which ranged in age from 1 to 228years. The topographic transects spanned drainage conditions, ranging from very poorly to excessively drained. The primary evidence for pedogenesis across the chronosequence was in the accumulation of organic matter, expressed in the formation of A and O horizons. Pedogenic development was restricted by the young age and weathering resistant nature of the soil parent material. The close proximity of the water table to the soil surface was associated with greater organic matter inputs from vegetation and slower decomposition under anaerobic conditions, which together led to increased accumulation of organic carbon in lower, wetter landscape positions. Frequency and duration of saturation also impacted subsoil development, producing subtle, but noticeable color differences between oxidized and reduced horizons.

Effect of gantacurium on evoked laryngospasm and duration of apnea in anesthetized healthy cats.

To evaluate whether the ultrashort-acting neuromuscular blocking agent gantacurium can be used to blunt evoked laryngospasm in anesthetized cats and to determine the duration of apnea without hemoglobin desaturation. 8 healthy adult domestic shorthair cats. Each cat was anesthetized with dexmedetomidine and propofol, instrumented with a laryngeal mask, and allowed to breathe spontaneously (fraction of inspired oxygen, 1.0). The larynx was stimulated by spraying sterile water (0.3 mL) at the rima glottidis; a fiberscope placed in the laryngeal mask airway was used to detect evoked laryngospasm. Laryngeal stimulation was performed at baseline; after IV administration of gantacurium at doses of 0.1, 0.3, and 0.5 mg/kg; and after the effects of the last dose of gantacurium had terminated. Duration of apnea and hemoglobin oxygen saturation (measured by means of pulse oximetry) after each laryngeal stimulation were recorded. Neuromuscular block was monitored throughout the experiment by means of acceleromyography on a pelvic limb. Laryngospasm was elicited in all cats at baseline, after administration of 0.1mg of gantacurium/kg, and after the effects of the last dose of gantacurium had terminated. The 0.3 and 0.5 mg/kg doses of gantacurium abolished laryngospasm in 3 and 8 cats, respectively, and induced complete neuromuscular block measured at the pelvic limb; the mean ± SE duration of apnea was 2 ± 1 minutes and 3 ± 1.5 minutes, respectively. Hemoglobin oxygen saturation did not decrease significantly after administration of any dose of gantacurium. Gantacurium may reduce tracheal intubation-associated morbidity in cats breathing oxygen.

Obstructive sleep apnea rather than diabetes or obesity associated with proteinuria in late mid-aged male workers: a decision tree analysis.

Both proteinuria and obstructive sleep apnea (OSA) are associated with cardiovascular events and consequent mortality. To examine whether age, OSA, diabetes, and obesity are potential predictors of proteinuria, a data-driven analysis was performed to delineate a potential categorical classification algorithm. In this cross-sectional community-based cohort study, demographic data, blood pressure, serum biochemical analyses, proteinuria via single dipstick urinalysis, and overnight polysomnographies were measured in 300 males with sedentary work styles. Sixty-one (20.3%) of all these participants had proteinuria. Logistic regression analysis showed that glycated hemoglobin (HbA1c), duration of arterial oxygen saturation <90%, age, and log high-sensitivity C-reactive protein, but not apnea-hypopnea index (AHI), were responsible for 16.7% of the variance of proteinuria's presence. A decision tree analysis showed that subjects over 49years old had a higher risk for proteinuria than those subjects of 49years old, or less. In the over 49-year-old group, subjects with an AHI >21 events/h had a higher risk for proteinuria; whereas in the 49-year-old and less group, subjects with HbA1c >7%, or with HbA1c ≤7, and body mass index (BMI) >27.4kg/m(2) had a higher risk for proteinuria than their counterparts. AHI was the major determinant responsible for the presence of proteinuria in late mid-aged male workers, while HbA1c and BMI were found in the junior subgroup. By algorithmic analysis, this study provides a comprehensive hierarchical model for better understanding of the correlates of proteinuria and sleep apnea.

Prevalence, clinical characteristics, and predictors of obesity hypoventilation syndrome in a large sample of Saudi patients with obstructive sleep apnea.

Objectives:To assess the prevalence, clinical characteristics, and predictors of obesity hypoventilation syndrome (OHS) in a large sample of Saudi patients with obstructive sleep apnea (OSA).Methods:This prospective observational study consisted of 1693 patients who were diagnosed to have sleep-disordered breathing using type I attended polysomnography (PSG) between January 2002 and December 2012 in the University Sleep Disorders Center (USDC) at King Saud University Hospital, Riyadh, Kingdom of Saudi Arabia.Results:Out of 1693 OSA patients, OHS was identified in 144 (8.5%) (women 66.7%). Compared with the pure OSA patients, the OHS patients were significantly older (57.4±13.4 years versus 46.8±13.7 years), had a higher body mass index (44.6±10.8 versus 35.7±9.2 kg/m2), a higher daytime partial pressure of carbon dioxide (PaCO2) (56.5±12.7 versus 41.6±6.7 mmHg), a longer duration of nocturnal oxygen saturation (nSaO2) <90% (71.0±34.3 versus 10.5±20.5 minutes), and a higher apnea hypopnea index (68.2±47.1 versus 46.5±34.1 events/hour). A multivariate logistic regression analysis showed that serum bicarbonate (odds ratio [OR]=1.17, p=0.0001, confidence interval [CI]=1.10-1.25), and duration of nSaO2 <90% (OR=1.05, p=0.0001, CI=1.04-1.06) were predictors of OHS.Conclusion:Obesity hypoventilation syndrome is common among Saudi OSA patients referred to the Sleep Disorders Center. Serum bicarbonate and duration of nSaO2 <90% are independent predictors of OHS among patients with OSA.

Effect of Timing and Duration of Soil Saturation on Soilborne Pythium Diseases of Common Bean (Phaseolus vulgaris)

Understanding combined abiotic (waterlogging) and biotic (Pythium spp.) stress resistance remains an important challenge to improving common bean (Phaseolus vulgaris) productivity in disease-prone regions with irregular but intensive rainfall patterns. This study documented the effects of timing (1, 3, 5, 7, and 9 days after sowing) and duration (3, 6, 12, and 24 h) of soil saturation (waterlogging) on damping-off, as well as hypocotyl and root diseases of common bean caused by Pythium irregulare. There were significant effects of timing of waterlogging as well as the presence or absence of the pathogen on emergence of the three bean varieties tested; namely, 'Gourmet Delight', 'Brown Beauty', and 'Pioneer'. The interaction between time of waterlogging and variety was significant for both root and hypocotyl disease severities. In the presence of P. irregulare, waterlogging 1 day after sowing resulted in the least emergence (55.2 ± 5.6%), although plants that survived after 5 weeks had less hypocotyl and root disease (percent hypocotyl disease index [%HDI] ± standard deviation [SD] = 42.0 ± 2.1% and percent root disease index [%RDI] ± SD = 42.4 ± 2.1%, respectively) than nonwaterlogged plants (%HDI = 50.8 ± 2.1% and %RDI = 48.0 ± 2.1%, respectively). The most severe disease assessed 5 weeks after sowing occurred when plants were subjected to waterlogging 9 days after sowing (%HDI = 61.3 ± 2.1% and %RDI = 56.0 ± 2.1%). In general, both hypocotyl and root disease severity increased as the duration of waterlogging increased from 1 to 24 h, with %HDI increasing from 53.9 ± 3.2% to 70.9 ± 3.2%, while %RDI increased from 57.2 ± 1.5% to 73.7 ± 1.5%. Varieties responded differentially in terms of disease development after waterlogging, with the least hypocotyl and root disease on Gourmet Delight (%HDI = 51.4 ± 3.2 and %RDI = 60.1 ± 1.5, respectively) and greatest on Pioneer (%HDI = 66.2 ± 3.2 and %RDI = 64.9 ± 1.5, respectively). Despite being susceptible to hypocotyl and root disease, Pioneer had the greatest emergence and shoot dry weight overall among the three varieties, suggesting that this variety has a degree of tolerance to waterlogging, P. irregulare infection, and the combination of these two stresses. Although the resistance of Gourmet Delight could be exploited to breed bean varieties that exhibit less hypocotyl and root disease when waterlogging occurs, the tolerance to both P. irregulare infection and waterlogging observed for Pioneer could also be exploited to breed varieties that incur less damage from hypocotyl or root disease or waterlogging. Furthermore, this study demonstrated what appears to be independent resistance to hypocotyl versus root infection by P. irregulare, which offers an opportunity to combine resistance to both stresses to reduce the impact of damping-off and root rot in conditions conducive for P. irregulare.

Comparision between bupivacaine and ropivacaine in patients undergoing forearm surgeries under axillary brachial plexus block: a prospective randomized study.

Brachial plexus block is a suitable alternative to general anaesthesia for patient undergoing upper extremity surgery. Ropivacaine the S-enantiomer emerged as a possible replacement of Bupivacaine without undesirable toxic effects. It provides similar duration of sensory analgesia with early recovery of motor block. Comparision of onset, duration of sensory- motor block and any adverse effects between 0.5% Bupivacaine and 0.5% Ropivacaine in axillary brachial plexus block. Prospective randomized study. This study was carried out in 50 patients between 18-55 y, comparable in demographic variables was randomly allocated to two groups of 25 each. Group I received 30ml 0.5% Bupivacaine, Group II received 30 ml 0.5% Ropivacaine in axillary brachial plexus block for forearm surgeries. Onset, Duration of sensory-motor block, Heart rate, Blood pressure, Oxygen saturation and Respiratory rate were recorded. Statistical analysis used was Statistical Package for Social Sciences version 15.0, Chi-square test was used to evaluate the proportional data. Odds ratio/risk ratios have been calculated wherever necessary. Parametric data has been evaluated using Student t-test while non-parametric data has been evaluated using Mann-Whitney U-test. Onset of motor blockade was earlier in ropivacaine group (5 min) as compared to bupivacaine group (20 min), Higher levels of motor blockade, Mean onset time for motor block was significantly shorter in ropivacaine group (14.88±3.35 min) as compared to bupivacaine group (22.92±3.79 min), Mean duration of block was significantly longer in bupivacaine group (408.40±50.39 min) as compared to ropivacaine group (365.60±34.29 min) (p=0.001), Onset of sensory block was observed from 5 min itself in ropivacaine group as compared to bupivacaine group (10 min), Duration of sensory block was significantly longer in bupivacaine group (450.40±54.50 min) as compared to ropivacaine group (421.20±38.33 min) . On the basis of present study, conclusions were drawn that onset of action of sensory, motor block was early in Ropivacaine group with faster recovery of motor functions as compared to Bupivacaine group. No adverse effects were noted in either groups. This study suggests that Ropivacaine is a suitable alternative to Bupivacaine for forearm surgeries under Brachial Plexus Block.

Using ancient and recent soil properties to design a conceptual hydrological response model

Morphology (ancient) and chemistry (recent) were used as indicators of hydrological response and used to construct a conceptual hydrological response model with new insights into hydropedological interpretations of easily accessible soil data. Soil chemistry is hypothesised to be equilibrated with the recent water regime. Profiles of three soil types on the soilscape with descriptions, analyses, long-term soil water content and water tension data are discussed and 15 auger observations with descriptions and MIR data are used to develop a conceptual response model. Morphology was able to identify the primary response of soils. The deep interflow Cambisol on the midslope has a vertical flowpath through the first subsoil, indicated by the red apedal morphology, which combines with interflow in the second subsoil, indicated by stagnic colour patterns. The responsive Gleysol on the footslope is a storage mechanism, indicating permanently saturated conditions. The responsive Luvisol at the toeslope has interflow in the Albic horizon while the subsoils act as a storage mechanism. pH and base saturation were used to indicate leaching (flowpath), ferrolysis (fluctuating watertable), acid weathering and accumulation (water saturation). Iron and Mn were used as indicators of reducing conditions to infer the duration of saturation. Soil response was verified by water contents and tension data. Pedological processes were correlated to horizons and hydrological response. Chemistry was more sensitive to water regime change than soil morphology. Therefore soil chemistry was successfully used in designing a conceptual hydrological response model and improved identification of hydrological processes.

Optimization of 7-T chemical exchange saturation transfer parameters for validation of glycosaminoglycan and amide proton transfer of fibroglandular breast tissue.

To (a) implement simulation-optimized chemical exchange saturation transfer (CEST) measurements sensitive to amide proton transfer (APT) and glycosaminoglycan (GAG) hydroxyl proton transfer effects in the human breast at 7 T and (b) determine the reliability of these techniques for evaluation of fibroglandular tissue in the healthy breast as a benchmark for future studies of pathologic findings. All human studies were institutional review board approved, were HIPAA compliant, and included informed consent. The CEST parameters of saturation duration (25 msec) and amplitude (1 μT) were chosen on the basis of simulation-driven optimization for APT contrast enhancement with the CEST effect quantified by using residuals of a Lorentzian fit. Optimized parameters were implemented at 7 T in 10 healthy women in two separate examinations to evaluate the reliability of CEST magnetic resonance (MR) imaging measurements in the breast. CEST z-spectra were acquired over saturation offset frequencies ranging between ±40 ppm by using a quadrature unilateral breast coil. The imaging-repeat imaging reliability was assessed in terms of the intraclass correlation coefficient, which indicates the ratio of between-subject variation to total variation. Simulations were performed of the Bloch equations with chemical exchange-guided selection of optimal values for pulse duration and amplitude, 25 msec and 1 μT, respectively. Reliability was evaluated by using intraclass correlation coefficients (95% confidence intervals), with acceptable results: 0.963 (95% confidence interval: 0.852, 0.991) and 0.903 (95% confidence interval: 0.609, 0.976) for APT and GAG, respectively. Simulations were used to derive optimal CEST preparation parameters to elicit maximal CEST contrast enhancement in healthy fibroglandular breast tissue due to APT at 7 T. By using these parameters, reproducible values were obtained for both the amide and hydroxyl protons from CEST MR imaging at 7 T and are feasible in the human breast.

Validating a spatially distributed hydrological model with soil morphology data

Abstract. Spatially distributed models are popular tools in hydrology claimed to be useful to support management decisions. Despite the high spatial resolution of the computed variables, calibration and validation is often carried out only on discharge time series at specific locations due to the lack of spatially distributed reference data. Because of this restriction, the predictive power of these models, with regard to predicted spatial patterns, can usually not be judged. An example of spatial predictions in hydrology is the prediction of saturated areas in agricultural catchments. These areas can be important source areas for inputs of agrochemicals to the stream. We set up a spatially distributed model to predict saturated areas in a 1.2 km2 catchment in Switzerland with moderate topography and artificial drainage. We translated soil morphological data available from soil maps into an estimate of the duration of soil saturation in the soil horizons. This resulted in a data set with high spatial coverage on which the model predictions were validated. In general, these saturation estimates corresponded well to the measured groundwater levels. We worked with a model that would be applicable for management decisions because of its fast calculation speed and rather low data requirements. We simultaneously calibrated the model to observed groundwater levels and discharge. The model was able to reproduce the general hydrological behavior of the catchment in terms of discharge and absolute groundwater levels. However, the the groundwater level predictions were not accurate enough to be used for the prediction of saturated areas. Groundwater level dynamics were not adequately reproduced and the predicted spatial saturation patterns did not correspond to those estimated from the soil map. Our results indicate that an accurate prediction of the groundwater level dynamics of the shallow groundwater in our catchment that is subject to artificial drainage would require a model that better represents processes at the boundary between the unsaturated and the saturated zone. However, data needed for such a more detailed model are not generally available. This severely hampers the practical use of such models despite their usefulness for scientific purposes.