Higher NC Research Articles

Size regulation of the lateral organ initiation zone and its role in determining cotyledon number in conifers.

Unlike monocots and dicots, many conifers, particularly Pinaceae, form three or more cotyledons. These are arranged in a whorl, or ring, at a particular distance from the embryo tip, with cotyledons evenly spaced within the ring. The number of cotyledons, nc, varies substantially within species, both in clonal cultures and in seed embryos. nc variability reflects embryo size variability, with larger diameter embryos having higher nc. Correcting for growth during embryo development, we extract values for the whorl radius at each nc. This radius, corresponding to the spatial pattern of cotyledon differentiation factors, varies over three-fold for the naturally observed range of nc. The current work focuses on factors in the patterning mechanism that could produce such a broad variability in whorl radius. Molecularly, work in Arabidopsis has shown that the initiation zone for leaf primordia occurs at a minimum between inhibitor zones of HD-ZIP III at the shoot apical meristem (SAM) tip and KANADI (KAN) encircling this farther from the tip. PIN1-auxin dynamics within this uninhibited ring form auxin maxima, specifying primordia initiation sites. A similar mechanism is indicated in conifer embryos by effects on cotyledon formation with overexpression of HD-ZIP III inhibitors and by interference with PIN1-auxin patterning. We develop a mathematical model for HD-ZIP III/KAN spatial localization and use this to characterize the molecular regulation that could generate (a) the three-fold whorl radius variation (and associated nc variability) observed in conifer cotyledon development, and (b) the HD-ZIP III and KAN shifts induced experimentally in conifer embryos and in Arabidopsis. This quantitative framework indicates the sensitivity of mechanism components for positioning lateral organs closer to or farther from the tip. Positional shifting is most readily driven by changes to the extent of upstream (meristematic) patterning and changes in HD-ZIP III/KAN mutual inhibition, and less efficiently driven by changes in upstream dosage or the activation of HD-ZIP III. Sharper expression boundaries can also be more resistant to shifting than shallower expression boundaries. The strong variability seen in conifer nc (commonly from 2 to 10) may reflect a freer variation in regulatory interactions, whereas monocot (nc = 1) and dicot (nc = 2) development may require tighter control of such variation. These results provide direction for future quantitative experiments on the positional control of lateral organ initiation, and consequently on plant phyllotaxy and architecture.

Short-term outcomes in patients with lung cancer-associated acute ischemic stroke.

BackgroundTo investigate the independent risk factors of poor short‐term outcomes in patients with lung cancer‐associated acute ischemic stroke (LCAIS) and use them to develop an index of prognosis LCAIS (pLCAIS) which could help clinicians identify patients at high risk for poor short‐term outcomes.MethodsWe retrospectively enrolled patients with lung cancer‐associated acute ischemic stroke and employed the 90D modified Rankin cale (mRS) to divide them into two groups: good outcomes (score 0–2) and poor outcomes (score 3–6). Propensity score matching (PSM) was used to remove confounding factors, and multivariable logistic regression analysis was used to analyze the independent risk factors of pLCAIS. The receiver operating characteristic (ROC) and area under the ROC curve (AUC) developed a multiple model combining the independent risk factors of pLCAIS.ResultsA total of 172 patients were included: 67 (38.9%) with good outcomes and 105 (61.1%) with poor outcomes. After using PSM, there were 33 cases in each group. The results showed that patients with poor short‐term outcomes were significantly higher in D‐dimer (OR = 1.001, 95% CI: 1.000–1.002, p = 0.048), CRP (OR = 1.078, 95% CI: 1.008–1.153, p = 0.028), and neutrophil count (OR = 14.673, 95% CI: 1.802–19.500, p = 0.012). The ROC curve, used to assess the diagnostic ability of binary classifiers, showed that the product of these three independent risk factors showed high sensitivity and specificity.ConclusionIn this study, we have identified three independent risk factors associated with poor short‐term outcomes in pLCAIS: higher NC, CRP, and D‐dimer levels. These findings may be helpful for clinicians in identifying poor short‐term outcomes patients.

Factors affecting precipitation formation and precipitation susceptibility of marine stratocumulus with variable above- and below-cloud aerosol concentrations over the Southeast Atlantic

Abstract. Aerosol–cloud–precipitation interactions (ACIs) provide the greatest source of uncertainties in predicting changes in Earth's energy budget due to poor representation of marine stratocumulus and the associated ACIs in climate models. Using in situ data from 329 cloud profiles across 24 research flights from the NASA ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) field campaign in September 2016, August 2017, and October 2018, it is shown that contact between above-cloud biomass burning aerosols and marine stratocumulus over the Southeast Atlantic Ocean was associated with precipitation suppression and a decrease in the precipitation susceptibility (So) to aerosols. The 173 “contact” profiles with aerosol concentration (Na) greater than 500 cm−3 within 100 m above cloud tops had a 50 % lower precipitation rate (Rp) and a 20 % lower So, on average, compared to 156 “separated” profiles with Na less than 500 cm−3 up to at least 100 m above cloud tops. Contact and separated profiles had statistically significant differences in droplet concentration (Nc) and effective radius (Re) (95 % confidence intervals from a two-sample t test are reported). Contact profiles had 84 to 90 cm−3 higher Nc and 1.4 to 1.6 µm lower Re compared to separated profiles. In clean boundary layers (below-cloud Na less than 350 cm−3), contact profiles had 25 to 31 cm−3 higher Nc and 0.2 to 0.5 µm lower Re. In polluted boundary layers (below-cloud Na exceeding 350 cm−3), contact profiles had 98 to 108 cm−3 higher Nc and 1.6 to 1.8 µm lower Re. On the other hand, contact and separated profiles had statistically insignificant differences between the average liquid water path, cloud thickness, and meteorological parameters like surface temperature, lower tropospheric stability, and estimated inversion strength. These results suggest the changes in cloud microphysical properties were driven by ACIs rather than meteorological effects, and adjustments to existing relationships between Rp and Nc in model parameterizations should be considered to account for the role of ACIs.

Environmental effects on aerosol–cloud interaction in non-precipitating marine boundary layer (MBL) clouds over the eastern North Atlantic

Abstract. Over the eastern North Atlantic (ENA) ocean, a total of 20 non-precipitating single-layer marine boundary layer (MBL) stratus and stratocumulus cloud cases are selected to investigate the impacts of the environmental variables on the aerosol–cloud interaction (ACIr) using the ground-based measurements from the Department of Energy Atmospheric Radiation Measurement (ARM) facility at the ENA site during 2016–2018. The ACIr represents the relative change in cloud droplet effective radius re with respect to the relative change in cloud condensation nuclei (CCN) number concentration at 0.2 % supersaturation (NCCN,0.2 %) in the stratified water vapor environment. The ACIr values vary from −0.01 to 0.22 with increasing sub-cloud boundary layer precipitable water vapor (PWVBL) conditions, indicating that re is more sensitive to the CCN loading under sufficient water vapor supply, owing to the combined effect of enhanced condensational growth and coalescence processes associated with higher Nc and PWVBL. The principal component analysis shows that the most pronounced pattern during the selected cases is the co-variations in the MBL conditions characterized by the vertical component of turbulence kinetic energy (TKEw), the decoupling index (Di), and PWVBL. The environmental effects on ACIr emerge after the data are stratified into different TKEw regimes. The ACIr values, under both lower and higher PWVBL conditions, more than double from the low-TKEw to high-TKEw regime. This can be explained by the fact that stronger boundary layer turbulence maintains a well-mixed MBL, strengthening the connection between cloud microphysical properties and the below-cloud CCN and moisture sources. With sufficient water vapor and low CCN loading, the active coalescence process broadens the cloud droplet size spectra and consequently results in an enlargement of re. The enhanced activation of CCN and the cloud droplet condensational growth induced by the higher below-cloud CCN loading can effectively decrease re, which jointly presents as the increased ACIr. This study examines the importance of environmental effects on the ACIr assessments and provides observational constraints to future model evaluations of aerosol–cloud interactions.

P0782PROGNOSTIC IMPACT OF NECK CIRCUMFERENCE ON CARDIVASCULAR OUTCOMES AND MORTALITY IN PATIENTS WITH MODERATE CHRONIC KIDNEY DISEASE: AN ANALYSIS FROM THE GERMAN CHRONIC KIDNEY DISEASE (GCKD) STUDY

Abstract Background and Aims Neck circumference (NC) is an approximator of upper body subcutaneous fat tissue and a marker of obesity. It has been shown to be associated with cardiovascular risk factors and incident chronic kidney disease (CKD). In CKD patients, the impact on cardiovascular events and all cause death has not been fully elucidated yet. The prognostic impact on these outcomes in a representative cohort of adult patients with moderate CKD of Caucasian origin was investigated here. Method We used data from the GCKD study, a German multi-centric prospective observational cohort study of 5217 adults with moderate chronic kidney disease, defined as eGFR 30–60 mL/min/1.73 m2 or eGFR >60 mL/min/1.73 m2 and significant proteinuria (albuminuria >300 mg/g creatinine or proteinuria >500 mg/g creatinine). Exclusion criteria were active malignancy, heart failure NYHA class IV, organ transplantation, and non-Caucasian origin. NC was measured repeatedly (annually, except at first year of follow-up) during the study, therefore, the mean value was analyzed. We report data from the 4-year follow-up visit regarding 1) a combined endpoint of non-fatal myocardial infarction, non-fatal stroke, cardiovascular death, and peripheral artery disease event (amputation or revascularization) and 2) all-cause death as another endpoint. Cox proportional hazard regression was used to calculate hazard ratios (HR) with 95% CIs. In univariate analysis, ordinal regression with quintiles of NC was applied. Results NC was accrued in 4453 participants and analyzed. NC overall was 40±5 cm (43±4 cm in men and 37±4 cm in women, p<0.001), mean age 60±12 years, 41% were female, 96% had hypertension, 35% were diabetic, 58% had ever smoked, eGFR was 50±18 ml/min/1.73 m (CKD-EPI), BMI 28±6 kg/m, LDL-cholesterol 119±43 mg/dl. Higher quintiles of NC were associated increased risk of the cardiovascular outcome in univariate analysis: highest (44 cm) vs. lowest (36.5 cm), HR 2.34 (1.63–3.36; p<0.001). In multivariable analysis adjusted for age, sex, and BMI, this effect was reduced but still apparent: HR 1.04 (1.01–1.08, p=0.025). Age (HR per year 1.05, 1.04–1.07, p<0.001), and female sex (HR 0.69, 0.50–0.95, p=0.023), showed also significant effects, whereas BMI did not (p=0.831). The effect of higher quintiles of NC on the risk of all-cause death in univariate analysis was even stronger: highest vs. lowest, HR 3.2 (1.72–5.81, p=0.006). However, after adjustment this effect was abolished: HR 0.99 (0.95–1.04; p=0.85). Only age (HR 1.07, 1.04–1.09, p<0.001), and female sex (HR 0.45, 0.27-0.74, p=0.002), remained significant predictors of all-cause death in this model. Conclusion In patients with chronic kidney disease, we found higher NC to be associated with increased cardiovascular event risk, but not all-cause death, after adjustment for age, sex and BMI. The risk of cardiovascular outcomes and overall mortality was consistently lower in women. Our analysis supports evidence, that upper body subcutaneous adipose tissue might be an independent contributor to cardiovascular event risk.

Robust Watermarking through Dual Band IWT and Chinese Remainder Theorem

CRT was a widely used algorithm in the development of watermarking methods. The algorithm produced good image quality but it had low robustness against compression and filtering. This paper proposed a new watermarking scheme through dual band IWT to improve the robustness and preserving the image quality. The high frequency sub band was used to index the embedding location on the low frequency sub band. In robustness test, the CRT method resulted average NC value of 0.7129, 0.4846, and 0.6768 while the proposed method had higher NC value of 0.7902, 0.7473, and 0.8163 in corresponding Gaussian filter, JPEG, and JPEG2000 compression test. Meanwhile the both CRT and proposed method had similar average SSIM value of 0.9979 and 0.9960 respectively in term of image quality. The result showed that the proposed method was able to improve the robustness and maintaining the image quality.

Microphysical characteristics of convective clouds over ocean and land from aircraft observations

The Cloud Aerosol Interaction and Precipitation Enhancement EXperiment (CAIPEEX) is a field campaign conducted in India with an instrumented research aircraft. On 29 October 2010, a cyclonic circulation over the Bay of Bengal persisted throughout the day. A special mission was conducted over the Bay of Bengal on this day with the objective of characterizing marine and continental clouds on the same day and finding contrasting/similar signatures of their microphysical properties. The research aircraft sampled growing convective clouds over the ocean and over land. High concentrations of aerosol and cloud condensation nuclei (CCN) were observed over land compared to ocean. Over ocean, higher liquid water content (LWC) and lower cloud droplet number concentrations (Nc) were observed, and droplets reached the threshold of precipitation initiation at lower cloud depths. Over land, clouds contained lower LWC and higher Nc, hence droplets did not reach the threshold of precipitation initiation at a warm temperature as in ocean clouds. Over the ocean larger droplets or drizzle were observed at lower cloud depth than over land. The maximum LWC was found to be very similar at higher altitudes. The convective clouds over land were modified by pollution aerosol with contrasting microphysical properties to those over the ocean.

A Comprehensive Study on the Synthesis and Micellization of Disymmetric Gemini Imidazolium Surfactants

AbstractTwo groups of disymmetric Gemini imidazolium surfactants, [C14C4Cmim]Br2 (m = 10, 12, 14) and [CmC4Cnim]Br2 (m + n = 24, m = 12, 14, 16, 18) surfactants, were synthesized and their structures were confirmed by 1H NMR and ESI–MS spectroscopy. Their adsorption at the air/water interface, thermodynamic parameters and aggregation behavior were explored by means of surface tension, electrical conductivity and steady‐state fluorescence. A series of surface activity parameters, including cmc, γcmc, πcmc, pC20, cmc/C20, Γmax and Amin, were obtained from surface tension measurements. The results revealed that the overall hydrophobic chain length (Nc) for [C14C4Cmim]Br2 and the disymmetry (m/n) for [CmC4Cnim]Br2 had a significant effect on the surface activity. The cmc values decreased with an increase of Nc or m/n. The thermodynamic parameters of micellization (ΔGmθ, ΔHmθ, ΔSmθ) derived from the electrical conductivity indicated that the micellization process of [C14C4Cmim]Br2 and [CmC4Cnim]Br2 was entropy‐driven at different temperatures, but the contribution of ΔHmθ to ΔGmθ was enhanced by increasing Nc or m/n. The micropolarity and micellar aggregation number (Nagg) were estimated by steady‐state fluorescence measurements. The results showed that the surfactant with higher Nc or m/n can form larger micelles, due to a tighter micellar structure.

Low‐altitude summer/winter microphysics, dynamics, and CCN spectra of northeastern Caribbean small cumuli, and comparisons with stratus

AbstractLow‐altitude cloud microphysics and cloud condensation nuclei (CCN) spectra are presented and analyzed from two cumulus cloud aircraft field campaigns, Ice in Clouds Experiment‐Tropical (ICE‐T) and Rain in Cumulus over the Ocean (RICO), in the same eastern Caribbean location at opposite seasons. These are further compared with two previously analyzed stratus cloud aircraft campaigns off the central California coast, Physics of Stratocumulus Tops (POST) and Marine Stratus/Stratocumulus Experiment (MASE). Multiple regression analysis predictions of cloud droplet concentrations (Nc) based on CCN spectra, NCCN(S) where S is supersaturation, compared much better with measured Nc than single NCCN‐Nc regressions in both cumulus projects. The addition of vertical velocity (W) to the single and multiple regressions showed small improvements. For RICO the multiple regression correlations were also superior to previous adiabatic model predictions of Nc also based on NCCN(S) and mean W. More adiabatic cloud parcels with considerably higher Nc, liquid water contents, and W showed only slightly better correlations than flight‐averaged Nc of all low clouds. Results show the value of more extensive CCN spectra and the relative unimportance of W variations for determining Nc, in these Caribbean cumuli. The fact that flight‐averaged Nc of all low cloud data was almost as well correlated with NCCN(S) as were Nc of more adiabatic cloud parcels indicates that entrainment did not significantly perturb CCN‐Nc relationships. As should be expected higher cloud S were determined for the cumulus clouds than for the stratus clouds. Suppression of cloud S by higher NCCN that had previously been observed in stratus was observed in ICE‐T but not in RICO where the NCCN range may have been too low for cloud S suppression. But ICE‐T and POST even showed this S suppression over the same limited NCCN range as RICO (< 200 cm−3).

Effect of Interfacial Tension on Water/Oil Relative Permeability on the Basis of History Matching to Coreflood Data

Summary The effect of interfacial tension (IFT) on the displacement of the nonwetting and wetting phases has been investigated by the use of simulations/history matching of flooding experiments. In surfactant flooding, a conventional assumption is to neglect the effect of capillary pressure (Pc) on measured two-phase properties. The methodology applied in this paper allows improved interpretation of experimental results by correcting for the influence of capillary end effects on the measured capillary desaturation curve (CDC) and on the estimated relative permeability (kr). Three fluid systems of different IFTs were prepared by use of a solvent system (CaCl2 brine/iso-octane/isopropanol) rather than a surfactant system with the assumption that both systems have similar flood behavior at reduced IFT. Three coreflood cycles, including multirate oil injection (drainage) followed by multirate water injection (imbibition), were carried out at each IFT in water-wet Berea cores. The kr functions corrected for capillary end effects were derived by numerically history matching the experimental production and pressure-drop (PD) history. A typical CDC is observed for the nonwetting phase oil, with a roughly constant plateau in residual oil saturation (ROS), Sor, below a critical capillary number (Ncc) and a declining slope above Ncc toward zero Sor. No influence of Pc was found for the nonwetting-phase CDC. The results from the displacement of the wetting phase formed an apparent CDC with a declining slope and no Ncc. Analyzing the wetting-phase results, we find that the wetting-phase CDC is not a true CDC. First, it is a plot of the average remaining water saturation (Sw) in the core which, in all the experiments, is higher than residual water saturation, Swr, obtained from Pc measurements. Second, we find that the remaining Sw is only partly a function of Nc. At low Nc, the water production (WP) is limited by capillary end effects. Rate-dependent WP observed with the high-IFT system is fully reproduced in simulations by use of constant kr and Pc. The remaining wetting-phase saturation at a low capillary number (Nc) is a result of the core-scale balance between viscous and capillary forces and would, for example, depend on the core length. At a higher Nc, the WP is found to be limited by the low kr tail, typical for wetting phases. However, we find that the kr functions become rate dependent at a higher Nc, and we assume that this rate dependency can be modeled as a function of Nc. The remaining wetting-phase saturation at a higher Nc would then be a function of Nc and the number of pore volumes (PVs) injected. The observed Nc dependency in the flow functions indicates a potential for the accelerated production of the wetting phase by use of surfactant. Assuming that the results obtained here for the wetting phase also apply to oil in a mixed-wet system, it is strongly recommended to evaluate the effect of both Pc and Ncc when designing a surfactant model for a mixed-wet field.

Acid soap formation of oleic acid and catanionic complex formation in the alkyldimethylamine oxide/sodium oleate equimolar mixtures

The influence of adding alkyldimethylamine oxide (CnDMAO) with varying alkyl chain lengths (nc) on the acid soap formation of oleic acid was investigated. The solutions of equimolar mixtures of CnDMAO and sodium oleate (Na+Ol−), each 25 mmol kg−1, became turbid at a certain critical pH (pHc) on decreasing pH. Values of the pHc depended on nc and showed the minimum at C10DMAO/NaOl mixture. The presence of the minimum was interpreted in terms of two different kinds of the complex formed in the micelles depending on nc: the catanionic complex (CnDMAOH+/Ol−) in the mixed micelles of nc=16, 14, 12 and 10, and the acid soap of oleic acid for C6DMAO/NaOl and C8DMAO/NaOl mixtures. At pHc where the amounts of these complexes of double-chain nature reached certain critical values in the mixed micelles, a phase separation (most probably lamella formation) took place. It was expected that the critical amount of the catanionic complex was smaller for the mixtures of higher nc values and hence pHc increased with nc for the mixtures nc≥10. For the mixtures of nc<10, it was expected that the amount of the acid soap in the mixed micelles increased with decreasing nc at a given pH and the pHc increased with decreasing nc. Micelle compositions at cmc were evaluated on the basis of the regular solution theory coupled with the pseudo phase approximation. The micelle compositions at 100 mmol kg−1 were examined with 13C-NMR. The results showed the mixed micelle formation for nc=16–10, while the micelles mostly consisting of oleic acid for the mixtures of nc=8 and 6. The assumption of two different complexes for the two groups of the mixture was thus supported. The cmc range of mixed micelles was evaluated and it was well correlated with the observed concentration range of pyrene fluorescence change.

Molecular Structure and Some Physicochemical Properties of High‐Amylose Barley Starches

ABSTRACTThe molecular structure and some physicochemical properties of starches from two high‐amylose cultivars of barley, high‐amylose Glacier A (HAG‐A) and N (HAG‐N), were examined and compared with those of a normal cultivar, Normal Glacier (NG). The true amylose contents of HAG‐A, HAG‐N, and NG were 41.0, 33.4, and 23.0%, respectively. Iodine affinities before and after defatting of starch, and thermograms of differential scanning calorimetry, indicated that HAG‐A and HAG‐N starches had a higher proportion of amylose‐lipid complex than did NG starch. The amylopectins from HAG‐A and HAG‐N were similar to NG amylopectin in average chain length (18–19), β‐amylolysis limit (β‐AL 56–57%), number‐average degrees of polymerization (DPn 6,000–7,500) and chain length distribution. Very long chains (1–2%) were found in amylopectins from all cultivars. HAG‐A amylopectin had a larger amount of phosphorus (214 ppm) than the others. The amyloses from HAG‐A and HAG‐N resembled NG amylose in DPn (950–1,080) and β‐AL (70–74%). However, HAG‐A and HAG‐N had a larger number of chains per molecule (NC 2.4–2.7) than NG amylose (1.8) and contained the branched amylose with a higher NC (9.5–10.6) than that of NG amylose (5.8), although molar fractions of the branched amylose (15–20%) were similar.