Mean SW Research Articles

Early detection of cardiac dysfunction using shear wave imaging: insights into reduced cardiorespiratory fitness in childhood cancer survivors

Abstract Background Diastolic dysfunction is thought to be the earliest cardiotoxic sequel after cancer therapy among childhood cancer survivors. Despite many survivors do exhibit reduced cardiorespiratory fitness (CRF) potentially due to cardiotoxicity, current echocardiographic parameters fail to detect hidden diastolic dysfunction early after therapy (1). High frame rate (HFR) shear wave imaging (SWI) is a novel tool that could give insights about myocardial stiffness, which is a key determining factor of diastolic function. Purpose We aimed at testing the ability of SWI to detect early alterations in myocardial stiffness among childhood cancer survivors and its relation with the reduced CRF. Methods Fifty childhood cancer survivors (mean 20 ±3 years) who received chemo-and/or- radiotherapy (mean time after treatment: 4 ±3 years) and thirty-two matched healthy volunteers (HV) were recruited. Conventional as well as HFR echocardiographic images (ca. 1200 frames/second) were acquired at rest using a modified commercial echocardiography machine. All participants underwent an incremental, symptom-limited cardiopulmonary exercise test on a treadmill measuring peak oxygen consumption (VO2 peak). HFR data were analysed offline. An anatomical M mode was drawn along the ventricular septum, and tissue Doppler acceleration maps were extracted to measure SW velocities after mitral valve closure (MVC) (Figure 1). Results Among cancer survivors, left ventricular ejection fraction (LVEF) and global longitudinal strain were significantly lower compared to HV (56 % ±4 vs 59 % ±4, and 17.6 % ±1.6 vs 19.1 % ±1.2, respectively; p <0.001). However, both LVEF and GLS were within the normal range and none of them correlated with the peak VO2 (Figure 2A&B). None of the echocardiographic diastolic parameters (e.g. mitral E, E/e’, left atrial volume or TR jet velocity) showed significant difference between both groups (P > 0.05). The mean SW velocities were significantly higher in cancer survivors compared to HV (3.9 ±0.6 m/s vs 3.2 ±0.3 m/s respectively; p <0.001). Interestingly, SW velocities among cancer survivors showed moderate significant negative correlation with the VO2 peak (r= -0.590, p <0.001) indicating increasing myocardial stiffness as the cardiorespiratory fitness declined (Figure 2C). Conclusions Our data indicate that myocardial stiffness in cancer survivors is significantly increased. We hypothesize that this increased stiffness may at least in part explain the significantly reduced cardiorespiratory fitness in this population. Echocardiographic shear wave elastography appears as a promising non-invasive tool for early detection of diastolic dysfunction in follow-up of childhood cancer survivors.Figure 1.Figure 2.

Effects of different tillage and cropping systems on water repellency and hydraulic properties in a tropical Alfisol of southwestern Nigeria

This study examined the effects of growing intercrops (Sorghum, SOR (Sorghum bicolor L. Moench) in between rows of cowpea, COW (Vigna unguiculata) and soybean, SOY (Glyxine max L.Merr)) under different tillage systems on soil physico-chemical properties, soil water sorptivity (Sw), hydraulic conductivity (K), and soil hydrophobicity (R) in tropical Alfisol of Southwestern Nigeria. Results demonstrated cropping systems significantly impacted soil pH under each conventional tillage (CT), no tillage (NT), and compacted no till systems (NTC) tillage system in 2019, but not in the 2020 cropping season. Sorghum-cowpea SC) and sorghum-soybean (SS) intercropping systems under the three tillage systems had higher soil organic matter (SOM) contents than the corresponding sole sorghum (SOR) at the end of the study. Soil water sorptivity differed significantly (p < 0.001) among the cropping systems in 2019 and follows the order: SC > SS > SOY > SOR > COW while in 2020, averaged over three tillage systems, mean Sw values showed an increasing trend in the order: SOR (77.67 cm h-1/2) < COW (82.42 cm h-1/2) < SOY (88.00 cm h-1/2) < SS (88.73 cm h-1/2) < SC (98.29 cm h-1/2). In general, intercropping had a lower R than sole cropping. NTC soil was 46.48% and 56.39%; 32.47% and 41.67% more hydrophobic than soils under NT and CT in 2019 and 2020. Intercropping with legumes might have contributed to the higher K levels. Organic matter in soil improves conductivity by improving soil structure. The intercrop may have improved soil water conservation because of their shading and better soil protection. The study demonstrated that conservation tillage with intercropping could effectively enhance soil hydraulic properties.

Evaluation of fatigue in young female adults due to repeated exposure to heat in summer and cold in winter.

The magnitude of fatigue (MF) from psychological and physiological responses during repeated exposure to heat in summer and during repeated exposure to cold in winter was evaluated to test two hypotheses on fatigue models. The first hypothesis is that exposure time (ET, min) would be a factor determining the MF and the second hypothesis is that the same fatigue models as a function of the number of exposure repetitions (NR) could be applied to both repeated exposure to heat in summer and cold in winter. In summer, eight young adult female subjects with clothing insulation (Icl, clo) of 0.3 clo first stayed in the control room at 26 ℃ for 15min, moved to the main testing room at 30 ℃ for 25min, 33°C for 15min, or 36 ℃ for 10min, and then returned to the control room. The product of air temperature difference (ΔTa, ℃) and ET was designed to be almost equal among these latter three conditions. The exposure was repeated five times. In winter, the same female subjects with Icl of 0.84 clo first stayed in the control room at 24 ℃ for 15min, moved to the main testing room at 18 ℃ for 30min, 15 ℃ for 20min, or 12 ℃ for 15min, and then returned to the control room. Again, the product of ΔTa and ET was designed to be equal among these latter three conditions. The exposure was repeated four times. The scores of subjective fatigue feeling (SFF) and salivary amylase value (SAV) were recorded when the subjects returned to the control room. Tympanic temperature, skin temperatures and local sweat rates (Sw, mg/cm2/min) at chest, forearm, front thigh, and front shin, and ECG were continuously monitored, except for Sw in the winter experiment. In the summer experiment, the SFF showed a threshold value at ΔTa = 4 ℃ but continuously increased with NR at ΔTa = 7 ℃ and 10 ℃. It was not correlated with ECG variables, but was positively correlated with SAV (R2 = 0.50) and the mean Sw (R2 = 0.76) at ΔTa = 7 ℃ and 10 ℃. In the winter experiment, the SFF showed a threshold value at ΔTa = - 6 ℃ but continuously increased with NR at ΔTa = - 9 ℃ and - 12 ℃. It was correlated with SAV at ΔTa = - 9 ℃ (R2 = 0.77) and score of LF: HF ratio at ΔTa = - 6 ℃ and - 9 ℃ (R2 = 0.49). It was confirmed that ET may be related to the MF and that different fatigue models may be applied dependent on ΔTa during repeated exposure to heat in summer and during repeated exposure to cold in winter. Thus, the two hypotheses were verified.

Genome-wide association mapping for component traits of drought tolerance in dry beans (Phaseolus vulgaris L.).

Understanding the genetic basis of traits of economic importance under drought stressed and well-watered conditions is important in enhancing genetic gains in dry beans (Phaseolus vulgaris L.). This research aims to: (i) identify markers associated with agronomic and physiological traits for drought tolerance and (ii) identify drought-related putative candidate genes within the mapped genomic regions. An andean and middle-american diversity panel (AMDP) comprising of 185 genotypes was screened in the field under drought stressed and well-watered conditions for two successive seasons. Agronomic and physiological traits, viz., days to 50% flowering (DFW), plant height (PH), days to physiological maturity (DPM), grain yield (GYD), 100-seed weight (SW), leaf temperature (LT), leaf chlorophyll content (LCC) and stomatal conductance (SC) were phenotyped. Principal component and association analysis were conducted using the filtered 9370 Diversity Arrays Technology sequencing (DArTseq) markers. The mean PH, GYD, SW, DPM, LCC and SC of the panel was reduced by 12.1, 29.6, 10.3, 12.6, 28.5 and 62.0%, respectively under drought stressed conditions. Population structure analysis revealed two sub-populations, which corresponded to the andean and middle-american gene pools. Markers explained 0.08-0.10, 0.22-0.23, 0.29-0.32, 0.43-0.44, 0.65-0.66 and 0.69-0.70 of the total phenotypic variability (R2) for SC, LT, PH, GYD, SW and DFW, respectively under drought stressed conditions. For well-watered conditions, R2 varied from 0.08 (LT) to 0.70 (DPM). Overall, 68 significant (p < 10-03) marker-trait associations (MTAs) and 22 putative candidate genes were identified across drought stressed and well-watered conditions. Most of the identified genes had known biological functions related to regulating the response to drought stress. The findings provide new insights into the genetic architecture of drought stress tolerance in common bean. The findings also provide potential candidate SNPs and putative genes that can be utilized in gene discovery and marker-assisted breeding for drought tolerance after validation.

Assessment of Water Contamination at Municipal Solid Waste Disposal Site, Jawaharnagar, Hyderabad, Telangana, India

The impact of uncontrolled municipal solid waste disposal of 3800 tons per day on surface and groundwater downstream of the Jawaharnagar dumping site was studied. The un-engineered solid waste dumping yard site spreading over about 300 hectares (ha) is located on topographic high (hillock) and falls in Madyala stream and Dammaiguda watersheds of Musi sub-basin. Granites of the Archaean age underlie the area. Both surface and groundwater samples, collected covering hydrological cycles of 2011and 2012, were analyzed for major chemical constituents. Fifteen samples belonging to both seasons of 2012 were tested for BOD, COD, and TOC. The mean values of some tested chemical constituents of surface water samples (15) were - EC 13066 m S/cm, TH 753, Na+ 813, K+ 530, HCO3- 978, Cl- 1304, and NO3- 262 (all in mg/l), which prove that tanks and stream near the dump yard were pools of leachate. The average values of contaminated groundwater samples among the four sampled sessions (17) indicate EC was above 5000 m S/cm, TH 1624, Cl- 1502, and SO42- 284(all in mg/l), which were found much above the threshold values. Very high TOC (mean SW 241; GW 154 mg/l), BOD (5410; 117), and COD (6427; 176) content in both surface (SW) and groundwater (GW) samples indicate the presence of organic pollutants sourced from domestic waste dumps. Wide temporal and spatial variability in the concentration of many ion species could be due to rainfall deviation, point source changes, and heterogeneous fracture patterns. Low resistivity values (5 to 25 ohm.m) at a distance of 4 km from the dumping site and high infiltration rate (29 cm/hr) at the Madyala stream indicate hydrological features controlled the mass flux. The chloride-sulphate alkaline-earth water facies, K+:Mg2+ and BOD/COD ratios demonstrate apart from anthropogenic input water-rock interaction and evapotranspiration governed the evolution of water chemistry. The study supports the hypothesis that solid waste dumps, which attained the methanogenic phase, were a point source of pollution that generates leachate and dissipates contaminants to the aquatic environment through preferred pathways influenced by factors like soils, topography, aquifer hydraulics, and contaminant kinetics.

Repeatability of non-invasive break-up time measures with a new automated dry eye platform in healthy eyes.

To evaluate the intrasession repeatability for non-invasive break-up time (NIBUT) and tear meniscus height (TMH) measurements provided by a new multi-diagnostic platform, and to assess the interobserver reproducibility of TMH measures. Twenty-one healthy eyes of 21 patients (age, 23-65years) were enrolled. A complete eye examination was performed in all cases with the VX120+ device (Visionix-Luneau Technologies), including an analysis with the new Dry Eye module, performing three consecutive measurements. The within-subject standard deviation (Sw) and Bland-Altman plots were used to assess intersession repeatability. Differences between examiners for TMH were also analysed. No statistically significant differences were found between repeated measures of NIBUT (time associated with the first break) and TMH (p > 0.05). However, significant differences were found for NIBUT50% (time associated with half of breaks of the tear film) (p < 0.05). Mean Sw was 0.9s, 1.4s and 0.05mm for NIBUT, NIBUT50% and TMH, respectively. Ranges of agreement between consecutive measures were below 3.5s and 4.5s for NIBUT and NIBUT50%, respectively, and below 0.16mm for TMH. Furthermore, no significant differences were found between examiners in TMH measure, with an inter-examiner range of agreement of 0.12mm. The new dry eye platform of the VX120+ platform evaluated provides objective automated measures of NIBUT and TMH, with acceptable level of intrasession repeatability for clinical screening purposes.

Determining the daytime Earth radiative flux from National Institute of Standards and Technology Advanced Radiometer (NISTAR) measurements

Abstract. The National Institute of Standards and Technology Advanced Radiometer (NISTAR) onboard the Deep Space Climate Observatory (DSCOVR) provides continuous full-disk global broadband irradiance measurements over most of the sunlit side of the Earth. The three active cavity radiometers measure the total radiant energy from the sunlit side of the Earth in shortwave (SW; 0.2–4 µm), total (0.4–100 µm), and near-infrared (NIR; 0.7–4 µm) channels. The Level 1 NISTAR dataset provides the filtered radiances (the ratio between irradiance and solid angle). To determine the daytime top-of-atmosphere (TOA) shortwave and longwave radiative fluxes, the NISTAR-measured shortwave radiances must be unfiltered first. An unfiltering algorithm was developed for the NISTAR SW and NIR channels using a spectral radiance database calculated for typical Earth scenes. The resulting unfiltered NISTAR radiances are then converted to full-disk daytime SW and LW flux by accounting for the anisotropic characteristics of the Earth-reflected and emitted radiances. The anisotropy factors are determined using scene identifications determined from multiple low-Earth orbit and geostationary satellites as well as the angular distribution models (ADMs) developed using data collected by the Clouds and the Earth's Radiant Energy System (CERES). Global annual daytime mean SW fluxes from NISTAR are about 6 % greater than those from CERES, and both show strong diurnal variations with daily maximum–minimum differences as great as 20 Wm−2 depending on the conditions of the sunlit portion of the Earth. They are also highly correlated, having correlation coefficients of 0.89, indicating that they both capture the diurnal variation. Global annual daytime mean LW fluxes from NISTAR are 3 % greater than those from CERES, but the correlation between them is only about 0.38.

Validation of corneal topographic and aberrometric measurements obtained by color light-emitting diode reflection topography in healthy eyes.

To evaluate the intrasession repeatability of anterior corneal topographic and aberrometric measurements provided by a color-LED topographer as well as their interchangeability with those provided by a Scheimpflug-based system in healthy eyes. Thirty-five healthy eyes of 35 patients (age, 16-66years) were enrolled. A complete eye examination was performed in all cases including a complete corneal analysis with the Scheimpflug-based system Pentacam (Oculus Optikgeräte) (one measurement) and the Cassini system (i-Optics) (three consecutive measurements). Intrasession repeatability of the Cassini measurements was assessed with the within-subject standard deviation (Sw) and the intraclass correlation coefficient (ICC). The Bland-Altman analysis was used to evaluate the agreement between both devices. Mean Sw for keratometric readings was 0.02mm (ICC ≥ 0.992), ranging between 0.16 and 0.05D (ICC 0.930-0.978) for anterior and total astigmatic measurements. Mean Sw for asphericity and corneal diameter were 0.06 (ICC 0.926) and 0.03mm (IC 0.997), respectively. Aberrometric parameters showed ICCs ≥ 0.816, except for Z42 (ICC 0.741) and Z44 (ICC 0.544). When comparing devices, statistically significant differences were found for most of topographic and aberrometric data (p ≤ 0.044). Likewise, ranges of agreement between devices were clinically relevant (keratometry > 0.06mm; total astigmatic components > 0.69D; asphericity 0.35; second-, third-, and fourth-order Zernike terms, more than 0.20, 0.13, and 0.01μm, respectively). Consistent anterior corneal topographic, total corneal astigmatic, and aberrometric measurements are obtained with color-LED topography in healthy eyes, which are not interchangeable with those provided by the Scheimpflug-based topography.

Validation of keratometric measurements obtained with an intraoperative image‐guided system: intra‐session repeatability and interchangeability with an optical biometer

PurposeTo evaluate the intra‐session repeatability of keratometric measurements obtained in healthy eyes with the Verion image‐guided system (Alcon Laboratories Inc, Fort Worth, Texas, USA) as well as the interchangeability of such measurements with those obtained with an optical biometer (Aladdin, Topcon, Tokyo, Japan).MethodsA total of 53 eyes of 53 patients (age 31–67 years) were enrolled in the study. All eyes received a comprehensive ophthalmologic examination including an analysis with the Verion image‐guided and Aladdin systems. Three consecutive measurements of keratometry were obtained with the Verion system to assess the intra‐session repeatability. Within‐subject standard deviation (Sw) and intraobserver precision (± 1.96 × Sw) were calculated. Bland–Altman analysis was used for the interchangeability analysis.ResultsMean Sw was 0.26, 0.24 and 0.10 D for the keratometric power in the flattest meridian (K1), keratometric power in the steepest meridian (K2) and astigmatism, respectively. Mean Sw was 4.29° for the axis of the flattest corneal meridian (AX1). Statistically significant but clinically acceptable differences were found in K1, K2 and keratometric astigmatism among systems (p < 0.01). In contrast, differences among systems in AX1 were not statistically significant (p = 0.385) but clinically relevant (mean difference: 15.74°; limits of agreement: −30.93 to 62.41°).ConclusionsThe Verion system provides consistent measurements of keratometric parameters, with measurements of AX1 that are not interchangeable with that provided by the optical biometer Aladdin, especially in cases of low and oblique astigmatism.

Acoustic Radiation Force Impulse Quantification in the Evaluation of Renal Parenchyma Elasticity in Pediatric Patients With Chronic Kidney Disease: Preliminary Results.

To evaluate renal parenchymal elasticity with acoustic radiation force impulse imaging in pediatric patients with chronic kidney disease (CKD) and compare with healthy volunteers. Thirty-eight healthy volunteers and 30 pediatric CKD patients were enrolled in this prospective study. The shear wave velocity (SW) values of both kidneys in CKD patients and healthy volunteers were evaluated. The mean SW in healthy volunteers was 2.21 ± 0.34 m/s, whereas the same value was 1.81 ± 0.49, 1.72 ± 0.63, 1.66 ± 0.29, 1.48 ± 0.37, and 1.23 ± 0.27 for stages 1, 2, 3, 4, and 5 in CKD patients, respectively. The SW was significantly lower for each stage in the CKD patients compared with healthy volunteers. Acoustic radiation force impulse could not predict the different stages of CKD, with the exception of stage 5. The cut-off value for predicting CKD was 1.81 m/s; at this threshold, sensitivity was 76.5% and specificity was 92.1% (area under the curve = 0.870 [95% confidence interval: 0.750-0.990]; P < .001). Interobserver agreement expressed as intraclass coefficient correlation was 0.65 (95% confidence interval: 0.34 to 0.83; P < .001). Acoustic radiation force impulse may be a potentially useful tool in detecting CKD in pediatric patients.

Control of radiation and evaporation on temperature variability in a WRF regional climate simulation: comparison with colocated long term ground based observations near Paris

The objective of this paper is to understand how large-scale processes, cloud cover and surface fluxes affect the temperature variability over the SIRTA site, near Paris, and in a regional climate simulation performed in the frame of HyMeX/Med-CORDEX programs. This site is located in a climatic transitional area where models usually show strong dispersions despite the significant influence of large scale on interannual variability due to its western location. At seasonal time scale, the temperature is mainly controlled by surface fluxes. In the model, the transition from radiation to soil moisture limited regime occurs earlier than in observations leading to an overestimate of summertime temperature. An overestimate of shortwave radiation (SW), consistent with a lack of low clouds, enhances the soil dryness. A simulation with a wet soil is used to better analyse the relationship between dry soil and clouds but while the wetter soil leads to colder temperature, the cloud cover during daytime is not increased due to the atmospheric stability. At shorter time scales, the control of surface radiation becomes higher. In the simulation, higher temperatures are associated with higher SW. A wet soil mitigates the effect of radiation due to modulation by evaporation. In observations, the variability of clouds and their effect on SW is stronger leading to a nearly constant mean SW when sorted by temperature quantile but a stronger impact of cloud cover on day-to-day temperature variability. Impact of cloud albedo effect on precipitation is also compared.

Intra-session repeatability of iridocorneal angle measurements provided by a Scheimpflug photography-based system in healthy eyes.

The purpose of this study was to evaluate intra-session repeatability of measurements of the iridocorneal angle at different meridians in the nasal and temporal areas in healthy eyes using the Sirius Scheimpflug photography-based system in glaucoma analysis mode. A total of 43 eyes of 43 patients ranging in age from 36 to 79 years were enrolled in the study. All eyes received a comprehensive ophthalmologic examination including a complete anterior segment analysis with the Costruzione Strumenti Oftalmici [CSO] Sirius system. Three consecutive measurements of nasal and temporal angles at 0°, ±10°, ±20°, and ±30° meridians were obtained in order to assess the intra-session repeatability of iridocorneal angle measurements provided by the device using the glaucoma analysis mode. Within-subject standard deviation (Sw), coefficient of variation (CV), and intraclass correlation coefficient (ICC) values were calculated. The mean Sw was 1.07 ± 1.09°, 1.22 ± 1.53°, 0.66 ± 0.51°, 0.86 ± 0.57°, 0.68 ± 0.65°, 0.84 ± 0.68°, and 0.91 ± 0.70° at the temporal 30°, 20°, 10°, 0°, -10°, -20°, and -30° positions, respectively. Mean Sw was 3.13 ± 3.15°, 3.43 ± 3.63°, 2.75 ± 2.29°, 2.19 ± 1.55°, 1.90 ± 1.49°, 2.14 ± 1.74°, and 2.24 ± 2.06° at the temporal -30°, -20°, -10°, 0°, 10°, 20°, and 30° positions, respectively. Mean CV ranged from 1.36 ± 1.05 % (nasal 0° position) to 10.92 ± 13.95 % (nasal -20° position). ICC values ranged from 0.778 to 0.972. The glaucoma analysis mode of the Sirius system provides consistent measurements of the iridocorneal angle at different meridians in healthy eyes, with slightly less consistency for nasal measurements. It may be considered a clinically useful non-invasive technique for the detection of potentially occludable angles.

Sinus Width Analysis and New Classification with Clinical Implications for Augmentation

To measure the distances between the medial and lateral sinus wall (sinus width [SW]) at different levels on cone beam computed tomography (CBCT) and apply those SW values to formulate a new sinus classification. Edentulous sites adjacent to maxillary sinuses with inadequate residual bone height (RBH) were included from the CBCT database. SW was measured at the heights of 1, 3, 5, 7, and 9 mm from the sinus floor. Mean SW was stratified into different groups by RBH, study sites (first and second premolars and molars), and measurement levels. Statistical analyses were conducted with commercially available software (IBM SPSS Statistics 19, SPSS Inc., Chicago, IL, USA). A total 186 patients (mean age 50.4 years) with 267 edentulous sites were included. Mean SW was wider at molar sites, higher measurement levels, and sites with less RBH. Narrow, average, or wide sinuses were classified based on the 33rd and 67th percentile SW values at 1-, 5-, and 9-mm measurement levels, respectively. SW at different levels relating to sinus floor elevation was measured. The proposed classification could contribute to estimate the difficulty of sinus augmentation, useful for the selection of surgical approaches. Further studies are required to testify its clinical implications.

Evaluation of maxillary sinus width on cone‐beam computed tomography for sinus augmentation and new sinus classification based on sinus width

The degree of difficulty in performing lateral window sinus augmentation may depend on the morphology of the maxillary sinus. The aim of this was to measure the distances between the medial and lateral sinus wall (sinus width [SW]) at different levels and apply those SW values to formulate a new sinus classification. Edentulous sites adjacent to maxillary sinuses with inadequate ridge height (RH; <10 mm) were included from cone-beam computed tomography database in the University of Michigan. SW was measured at the heights of 5, 7, 10, 13, and 15 mm from alveolar crest at the edentulous sites. Mean SW was stratified by residual RH into three different groups (group 1: <4 mm, group 2: ≥4 and <7, and group 3: ≥7 and <10), study sites (first and second premolars and molars), and measurement levels. Three hundred and twenty subjects (mean 50.1 years old) with 422 edentulous sites were included. Mean SW was wider at molar sites, higher measurement levels, and sites with shorter residual RH. Mean SW at the lower (average 2.3 mm from sinus floor) and higher boundary (15 mm from the alveolar crest) of lateral window osteotomy was 9.0 (2.8) and 16.0 (4.4) mm, respectively. Narrow, average, or wide sinuses were classified when the SW was <8, 8-10 and >10 mm at the lower boundary or <14, 14-17 and >17 mm at the upper boundary, respectively. SW at levels that were relevant to lateral window sinus augmentation was measured. The proposed sinus classification could facilitate communication between health providers and determine the degree of easiness of sinus augmentation. It might be particularly useful for the selection of grafting materials and surgical approaches. Further studies are required to test its clinical implications.

Toward Optimal Closure of the Earth's Top-of-Atmosphere Radiation Budget

Abstract Despite recent improvements in satellite instrument calibration and the algorithms used to determine reflected solar (SW) and emitted thermal (LW) top-of-atmosphere (TOA) radiative fluxes, a sizeable imbalance persists in the average global net radiation at the TOA from satellite observations. This imbalance is problematic in applications that use earth radiation budget (ERB) data for climate model evaluation, estimate the earth’s annual global mean energy budget, and in studies that infer meridional heat transports. This study provides a detailed error analysis of TOA fluxes based on the latest generation of Clouds and the Earth’s Radiant Energy System (CERES) gridded monthly mean data products [the monthly TOA/surface averages geostationary (SRBAVG-GEO)] and uses an objective constrainment algorithm to adjust SW and LW TOA fluxes within their range of uncertainty to remove the inconsistency between average global net TOA flux and heat storage in the earth–atmosphere system. The 5-yr global mean CERES net flux from the standard CERES product is 6.5 W m−2, much larger than the best estimate of 0.85 W m−2 based on observed ocean heat content data and model simulations. The major sources of uncertainty in the CERES estimate are from instrument calibration (4.2 W m−2) and the assumed value for total solar irradiance (1 W m−2). After adjustment, the global mean CERES SW TOA flux is 99.5 W m−2, corresponding to an albedo of 0.293, and the global mean LW TOA flux is 239.6 W m−2. These values differ markedly from previously published adjusted global means based on the ERB Experiment in which the global mean SW TOA flux is 107 W m−2 and the LW TOA flux is 234 W m−2.

Radiative Effects of Various Cloud Types as Classified by the Split Window Technique over the Eastern Sub-tropical Pacific Derived from Collocated ERBE and AVHRR Data.

The radiative effects of several cloud types as classified by the split window (11 and 12 μm) technique were studied using coincident and collocated Earth Radiation Budget Experiment (ERBE) S-8 data and Advanced Very High Resolution Radiometer (AVHRR) data from NOAA-9. The parameter investigated was cloud radiative forcing (CRF), the difference between clear and cloudy shortwave flux (SW) and longwave flux (OLR) at the top of the atmosphere. In computing the CRF, the accuracy of clear SW and OLR is essential. Clear scene IDs in the ERBE dataset were evaluated using coincident and collocated AVHRR image data. The mean visible reflectance and SW for clear footprints defined by the ERBE are reasonably small and are 3.2% and 89.0 Wm-2, respectively. However, the values computed using our technique are smaller, 2.7% and 83.9 Wm-2, respectively. The use of collocated AVHRR image data improves clear footprint definition and implies that care should be taken when computing CRF from ERBE data alone. The CRF from several cloud types classified by the split window were compared. Cumulonimbus clouds show the largest impact on top of the atmosphere radiation for both SW and OLR. Cirrus and lowlevel cumulus clouds have similar effects on OLR, but large differences between them are seen for SW. The impact of low-level cumulus clouds on SW is much larger than that of cirrus clouds. Some optically thin cirrus clouds show positive cloud radiative forcing (warming effect). The relationships between OLR and cloud types (including cloud-free) as classified by the split window technique were investigated. By using brightness temperature differences between the split window channels, OLR estimation is improved for cloud-free and low-level cumulus clouds when compared with OLR estimated by the National Oceanic and Atmospheric Administration (NOAA) operational algorithm.

Scale-dependent soil and climate variability effects on watershed water balance of the SWAT model

The water balance of large watersheds in Texas was studied using a process level watershed model called the soil and water assessment tool (SWAT). The major components of the SWAT watershed model are evapo-transpiration (ET), soil water storage (SW), and water yield (WYLD), which is the sum of surface runoff and subsurface flow. Important input variables controlling the water balance in watersheds are the soils and climate. In this paper, changes in mean and variance of water balance components due to variability in soils and climate were assessed for six different watersheds (Hydrologic Cataloging Units, HCUs) in Texas covering wet to semi-arid regions using 1:250,000 scale data. Bulk density, soil available water capacity, and moist soil albedo were selected as soil parameters. Soil heterogeneity in watersheds was defined in terms of textural classes in the soil textural triangle. Spatial variability of precipitation between neighboring weather stations was quantified using power spectra. The impact of geographic scales on changes to the mean of the water balance components was determined by studying the Seco Creek sub-watershed within the Hondo HCU using 1:24,000 scale data. Results from scales of observation show that changes to mean SW was high as a function of increasing scale from 1:250,000 to 1:24,000, while mean ET sensitivity remained about the same. The direct influence of soil properties such as bulk density, available water capacity, on the variance of ET, SW, and WYLD was about equal when using 1:24,000 scale data. For watersheds in wet climate composed of heterogeneous soils (loam fine sands and fine sandy loams), the means of the water components were relatively sensitive to climate and soils variability, and soil heterogeneity. Watersheds composed of shallow soils in semi-arid climate showed sensitivity of mean water balance components due to moist albedo and available water capacity. Changes to mean and variance of water balance components as a function of geographic scale suggest the presence of scale-dependent water balance ‘uncertainty’ laws.

Regional left ventricular wall motion abnormalities in myocardial infarction and mitral annular descent velocities studied with pulsed tissue Doppler imaging

We evaluated global left ventricular (LV) systolic function from mitral annular systolic motion velocities measured by pulsed tissue Doppler imaging in patients with previous myocardial infarction (MI) and LV regional wall motion abnormalities. The subject group consisted of 45 patients with wall asynergies, 3 with ischemic cardiomyopathy, 8 with dilated cardiomyopathy, and 15 healthy control subjects. The peak systolic descent velocity (Sw) and the time from the electrocardiographic Q wave to the peak of the systolic wave (Q-Sw) were measured at 6 mitral annular sites obtained from 2-dimensional apical long-axis, 4-chamber, and 2-chamber echocardiograms; these variables were compared with the LV ejection fraction (EF) calculated from the left ventriculogram. The mean Sw at the sites corresponding to the infarct regions was significantly lower and the mean Q-Sw was significantly longer in the MI groups than in the control group. The mean Sw and Q-Sw at all 6 sites in the ischemic and dilated cardiomyopathy groups were significantly lower and longer, respectively, than those of the control group. There were significant correlations between the EF and the means of the Sw and Q-Sw values at the sites corresponding to the infarct regions in the MI groups. In the ischemic and dilated cardiomyopathy groups, significant correlations existed between the EF and the means of the Sw and Q-Sw values at all 6 sites. Thus the parameters obtained from mitral annular systolic motion velocities with pulsed tissue Doppler imaging reflect LV asynergy corresponding to the infarct regions in patients with MI, and global LV systolic function may be evaluated with these parameters. (J Am Soc Echocardiogr 1998;11:841-8.)

Inbreeding Effects for Selected Agronomic Characters in Eastern Gamagrass

Information on the consequences of inbreeding in naturally crosspollinated plants is useful in determining strategies for genetic manipulation. Research was conducted in 1982 and 1983 to determine the effects of inbreeding in eastern gamagrass [Tripsacum dactyloides (L.) L.) on plant height (PH), plant weight (PW), 100‐spikelet weight (SW), and fertility measured by the percent of spikelets containing pure live seed (PLS). Plant materials consisted of 20 randomly chosen parents from a diploid (2n = 2x = 36) panmictic population and S1 and S2 progeny derivatives. Twenty ramets of each parent, 822 S1 seedlings, and 593 S2 seedlings were field grown using a completely randomized design. Parental plants had higher mean PH, PW, and SW than S1 or S2 progeny populations (P &lt; 0.01). No consistent differences for these traits were detected between the S1 and S2 generations. More than two‐thirds of the parents had significantly higher PH and PW than their S, or S2 progenies. In 1982. SW did not differ between generations; in 1983, however, 80% of the parents had significantly greater SW than their respective S1 or S2 generation progenies. Inbreeding had little detrimental effect on PLS. Less than one‐half of the parents had a greater percentage of spikelets containing PLS than their corresponding S1 and S2 generation progenies in 1982, and even fewer differences were found in 1983. Plants with reduced vigor but normal color, yellow and albino plants, and plants with altered floral morphology were found in selfed progeny populations. Inbreeding eastern gamagrass should have value in exposing recessive alleles existing at low frequencies and in the development of inbred lines.