Long-term Variability Research Articles

Analysis of the Shoreline Changes using Geoinformatics in Ghoramara Island of Hugli Estuary, West Bengal in India

Conceptual FrameworkCoastal decrepitude is the loss of topographical resources along the coast as a result of silt, temperature fluctuations, tidal shifts, and wave breaking. Hydraulic activity, scraping, abrasion, and erosion are the major causes of erosion; other factors that affect it include the condition of the shore, rocks, joints, fissures, marine chemical reactions, and wave force. ObjectivesThe primary objectives of this study are to analyze the coastline changes between 1972 and 2022 utilizing remote sensing and GIS data and forecast the changes in the shoreline in 2032. MethodsThe study examined coastal areas from 1972 to 2022 using multi-temporal satellite data from Landsat TM and Landsat OLI/TIRS. Shoreline change and the calculations related to it were examined using the Digital Shoreline Analysis System using near-infrared bands and tasseled cap transformation, to determine the rate of change in the shoreline, the study also employed Shoreline Change Envelope and End Point Rate techniques. ResultsCoastal erosion caused substantial damage to the island between 1972 and 2022. The northern, southeastern, and western regions of the coast are seeing the highest levels of coastal erosion. The south coast experiences considerable erosion, whereas the west and southeast coasts experience the least. The EPR of Ghoramara Island has mean, minimum, and maximum changes of -10.59, -4.13, and -35.93, respectively. A notable inshore shift has occurred in the northern portion of Ghoramara, extending from 676 meters to 855 meters. The study also uses tidal gauge records and Revised Local Reference data from the Haldia Gauge Station to track long-term sea level variations. According to the study, Ghoramara Island's shoreline will change by 2032, with the greatest negative changes expected to occur around the island's western and southern borders. ConclusionThe study shows a significant decrease in Ghoramara's shoreline regions between 1972 and 2022, with a 3,000-population shifted from the place in 2016 due to Lohachara's submergence. Changes in the island's morphology and human activities have reduced cultivation. The study suggests increasing mangrove vegetation to combat coastal erosion and prevent further displacement of people to neighboring islands.

Millennial and orbital-scale variability in a 54 000-year record of total air content from the South Pole ice core

Abstract. The total air content (TAC) of polar ice cores has long been considered a potential proxy for past ice sheet elevation. Recent work, however, has shown that a variety of other factors also influence this parameter. In this paper we present a high-resolution TAC record from the South Pole ice core (SPC14) covering the last 54 000 years and discuss the implications of the data for interpreting TAC from ice cores. The SPC14 TAC record shows multiple features of interest, including (1) long-term orbital-scale variability, (2) millennial-scale variability in the Holocene and last glacial period, and (3) a period of stability from 35 to 25 ka. The longer, orbital-scale variations in TAC are highly correlated with integrated summer insolation (ISI), corroborating the potential of TAC to provide an independent dating tool via orbital tuning. Large millennial-scale variability in TAC during the last glacial period is positively correlated with past accumulation rate reconstructions as well as δ15N-N2, a firn thickness proxy. These TAC variations are too large to be controlled by direct effects of temperature and too rapid to be tied to elevation changes. We propose that grain size metamorphism near the firn surface explains these changes. We note, however, that at sites with different climate histories than the South Pole, TAC variations may be dominated by other processes. Our observations of millennial-scale variations in TAC show a different relationship with accumulation rate than observed at sites in Greenland.

Effects of different obesity evaluation indexes on long-term blood pressure variability in adults

Abstract Background In recent years, people have a new understanding of the treatment of hypertension. Even at the optimal blood pressure levels recommended by the guidelines, further attention to blood pressure variability is warranted. Obesity and overweight are associated with blood pressure variability, but existing studies mainly focus on the effect of traditional obesity indicators on blood pressure variability (BPV). Objectives To explore the correlation between the new obesity assessment indicators LAP, BRI, CVAI and blood pressure variability. Methods A total of 7092 subjects who had regular physical examination in a community health center, were included for analysis. We used new measures to assess obesity, including LAP, BRI, CVAI. Subjects were grouped according to the baseline CVAI quartile. We used variation independent of mean(VIM) to assess long-term variations in blood pressure. Variance analysis was used to analyze the differences among different blood pressure variables and their baseline characteristics. Stepwise multivariate linear regression and multiple logistic regression analyses were used to assess the impact of CVAI/LAP/BRI on VIM. Results The average age of the subjects was 60.7±6.8 years old. With the increase of CVAI and BRI, the mean blood pressure variability increased gradually. In contrast, the mean blood pressure variability decreases with increasing LAP. After adjusting for other confounding factors, multiple linear regression analysis showed that VIMSBP increased by 0.007 and 0.216 for each unit increase in CVAI and BRI, respectively. LAP found no correlation. Multiple logistic regression analysis showed that increased CVAI and BRI were risk factors for increased VIMSBP, and increased LAP was protective factor for increased VIMSBP. Conclusion Compared with traditional indicators, the novel obesity indicators were also associated with blood pressure variability. And it has a stronger correlation than traditional indicators.

Metabolic syndrome and long-term heart rate variability: a systematic review and meta-analysis

Abstract Introduction Metabolic syndrome (MS) is defined as the convergence over time of a group of non-communicable chronic diseases (hypertension, diabetes, dyslipidemia, obesity). There is agreement that MS is related to pathological changes in the behavior of the autonomic nervous system (ANS). Heart rate variability (HRV) is a very useful tool for assessing autonomous behavior, widely used and that could be useful for the diagnosis and monitoring of MS. However, to date, there are no quantitative analyses using meta-analysis (MA) that have addressed the changes that MS causes on the ANS. Therefore, the objective of this systematic review and MA is to evaluate changes in long-term HRV in patients with MS, in order to characterize the cardiac autonomic dysfunction induced by this pathological condition and the most frequently reported explanatory variables. Methods We searched PubMed, Web of Science and Scopus electronic databases for original works with long-term HRV recordings (24-h holter) that compared people with MS (MS+) versus healthy people as a control group (MS-). The search was carried out between June 25th, 2022 and September 1st, 2022. In the databases selected, the terms used were "metabolic syndrome" linked to "heart rate variability" (HRV), "cardiac autonomic control", "cardiac autonomic function", or "cardiac autonomic modulation". This systematic review and MA was performed according with PRISMA guidelines and registered at the International Prospective Register of Systematic Reviews (CRD42022358975). Results are reported as standard mean difference [95% CI]. Results Thirteen articles were included in the qualitative synthesis and seven of them met required criteria to be included in the MA. MS decreased SDNN (-0.33 [-0.57, -0.09], p=0.008), LF (-0.40 [-0.51, -0.28], p<0.0001), VLF (-0.35 [-0.50, -0.21], p p<0.0001)) and TP (-0.24 [-0.43, -0.05], p=0.01). The MA did not find significant differences in rMSSD (-0.09 [-0.31, 0.13], p=0.41), HF (-0.29 [-0.61, 0.03], p=0.07) and LF/HF (-0.04 [-0.45, 0.36], p=0.84). No article reported information by gender. In the case of the non-linear variables, the information reported was not enough to carry out the MA, but the qualitative analyses showed no change in SD1 of the Poincare plot and a decrease in the multiscale entropy. For the SD2 of the Poincare plot and alfa-1 of the detrended fluctuation analyses, the results are not conclusive. Conclusions The analysis of HRV (time-domain) in long recording periods showed that patients with MS have lower values in the SDNN and no significant changes in rMSSD. Regarding the frequency domain analysis, we found that MS induced a significant decrease in LF, VLF and TP. The MA did not show changes in HF and LF/HF, and quantitative analyses of non-linear parameters could not be performed.

Associations of long-term visit-to-visit blood pressure variability with subclinical kidney damage and albuminuria in adulthood: a 30-year prospective cohort study

Abstract Background Recent evidence indicates that long-term visit-to-visit blood pressure variability (BPV) may be associated with the risk of cardiovascular disease. We therefore aimed to determine the potential associations of long-term BPV from childhood to middle age with subclinical kidney damage (SKD) and albuminuria in adulthood. Methods Using data from the ongoing cohort of Hanzhong Adolescent Hypertension study, which recruited children and adolescents aged 6 to 18 years at baseline, we assessed BP variability by standard deviation (SD) and average real variability (ARV) for 30 years (6 visits). Presence of SKD was defined as estimated glomerular filtration rate (eGFR) between 30 and 60 ml/min/ 1.73 m2 or elevated urinary albumin-to creatinine ratio (uACR) at least 30 mg/g. Albuminuria was defined as uACR ≥ 30 mg/g. Results During a follow-up of 30 years, of the 1771 participants, 204 SKD events occurred. After adjustment for demographic, clinical characteristics and mean BP during 30 years, higher SDSBP, ARVSBP, SDDBP, ARVDBP, SDMAP, ARVMAP and ARVPP were significantly associated with higher risk of SKD [ORs (95% CIs) were 1.14(1.06-1.23), 1.15(1.08-1.21), 1.12(1.06-1.17), 1.16(1.08-1.25), 1.12(1.07-1.17), 1.18(1.10-1.27) and 1.11(1.03-1.21), respectively]. When we used cumulative exposure to BP from childhood to adulthood instead of mean BP as adjustment factors, results were similar. In addition, greater long-term BPV was also associated with the risk of albuminuria [ORs (95% CIs) were 1.07(1.03-1.10) for SDSBP, 1.13(1.06-1.20) for ARVSBP, 1.11(1.06-1.17) for SDDBP, 1.14(1.06-1.23) for ARVDBP, 1.18(1.09-1.27) for ARVMAP and 1.08(1.01-1.17) for ARVPP]. Long-term BP variability for 30 years from childhood to middle age was associated with higher risk of SKD and albuminuria in adulthood, independent of mean BP or cumulative exposure to BP during follow-up.The example of SBP across 6 visits

Exploring biochar addition impacts on soil erosion under natural rainfall: A study based on four years of field observations on the Loess Plateau

Biochar’s potential impact on soil erosion has gained attention, but remained inconsistent, particularly lacks the results from continuous field monitoring under diverse rainfall conditions. This study aimed to explore the long-term variation in soil erosion induced by biochar addition under distinct natural rainfalls. Six runoff plots, treated with different amounts of biochar derived from apple tree branches (0, 1%, 2.5%, 4%, 5.5% and 7%), were established. Over a four-year period from 2017 to 2020, runoff and soil loss from these plots were continuously monitored and analyzed. Among 215 recorded rainfall events, 27 events resulted in runoff and sediment production were classified into three rainfall patterns (RI, RII and RIII) using K-means clustering. RIII characterized by high mean rainfall depth (138.80 mm), duration (3443 min), and erosivity (879 MJ.mm (ha. h)−1), but infrequent occurrence, followed by RII and RI with moderate and low mean depth, duration and erosivity, but higher frequency. Biochar addition, relative to control, resulted in an average annual runoff reduction, ranging from 9% to 36%, with a mean reduction of 28%, and reduced runoff for each rainfall, ranging from 4% to 28%, with a mean reduction of 12%. Similarly, biochar addition also reduced average annual soil loss, ranging from 43% to 79%, with a mean reduction of 61%, and reduced soil loss for each rainfall, ranging from 29% to 74%, with a mean reduction of 52%. The reduction of runoff and soil loss was positively correlated with biochar addition rates. Notably, the soil loss reduction was exceeded that of runoff. Soil erosion was negatively linked to surface area of soil particles (p < 0.05), total carbon, and total organic carbon (p < 0.01), but positively correlated with sand content (p < 0.01) and bulk density (BD) (p < 0.05) under biochar addition. Comparison of the mean reduction of runoff and soil loss among three rainfall patterns, the order was as follows: RII>RI>RIII. The optimal controlling of soil erosion was observed in 7% biochar addition under RII. Runoff-soil loss relationships well-fitted by power equation, showed soil incorporated with biochar treatments exhibited heightened susceptibility to erosion under RIII with high intensity compared to RII and RI with moderate or low rainfall intensity. Thus, the findings indicate biochar is a potential soil amendment to improve a degraded or degrading sloping farmland, however, the rainfall characteristics need to be considered when it is applied to the sloping farmland prone to erosion.

Increased Blood Pressure Variability Over a 16-Year Period Is Associated With Left Ventricular Diastolic Dysfunction in a Population-Based Cohort.

Left ventricular diastolic dysfunction (LVDD) is often associated with elevated blood pressure (BP). It is prevalent among hypertensive patients. Additionally, increased BP variability has been linked to LVDD. However, the precise connection between LVDD and BP variability within the general population remains unclear. Thus, this study aimed to evaluate this association in a general population. A total of 2,578 participants(1,311 females) with a mean age of 47.8 ± 6.7 years who had echocardiographic data from the Korean Genome and Epidemiology study with 16 years of follow-up were analyzed. LVDD was identified through the last echocardiography during the follow-up period. BP variability was assessed using mean, standard deviation (SD), and coefficient of variance (CV). LVDD was detected in 249 individuals. The cohort was divided into an LVDD group and a normal LV diastolic function group. The LVDD group had a higher percentage of females, more advanced age, higher body mass index (BMI), higher BP and BUN levels, lower heart rate, lower hemoglobin, and lower serum creatinine than the normal LV diastolic function group. Remarkably, LVDD was associated with higher BP variability. In the multivariate analysis, LVDD was associated with increased age, female sex, increased BMI, hypertension, and increased BUN. Elevated mean systolic and diastolic BPs, SD of systolic BP, mean pulse pressure (PP), SD of PP, and CV of PP were significantly linked to LVDD even after adjusting for other significant variables in the multivariate analysis. LVDD was identified in 249 (9.7%) participants. Increased long-term BP variability was significantly associated with LVDD in this population-based cohort.

Altered Trends in Light Use Efficiency of Grassland Ecosystem in Northern China

Light use efficiency (LUE) is a crucial indicator used to reflect the ability of terrestrial ecosystems to transform light energy. Understanding the long-term trends in LUE and its influencing factors are essential for determining the future carbon sink and carbon sequestration potential of terrestrial ecosystems. However, the long-term interannual variability of LUE in grasslands in northern China at the ecosystem scale is poorly understood due to the limitations of the year length and the coverage of the site data. In this study, we assessed the long-term LUE trends in the grasslands of northern China from 1982 to 2018 and then revealed the relationships between interannual variability in LUE and climate factors. Our study showed a substantial rising trend for LUE from 1982 to 2018 in the grasslands of northern China (3.42 × 10−3 g C/MJ/yr). Regarding the different grassland types, alpine meadow had the highest growth rate (4.85 × 10−3 g C/MJ/yr), while temperate steppe had the lowest growth rate (1.58 × 10−3 g C/MJ/yr). The climate factors driving LUE dynamics were spatially heterogeneous in grasslands. Increasing precipitation accelerated the interannual growth rate of LUE in temperate steppe, and increasing temperature accelerated the interannual growth rate of LUE in other types. In addition, the temporal dynamic of LUE showed different trends in relation to time scales, and the growth trend slowed down after 1998. Our results should be considered in developing future grassland management measures and predicting carbon cycle–climate interactions.

The strength, position, and width changes of the intertropical convergence zone since the Last Glacial Maximum.

The intertropical convergence zone (ITCZ) plays a key role in regulating tropical hydroclimate and global water cycle through changes in its convection strength, latitudinal position, and width. The long-term variability of the ITCZ, along with the corresponding driving mechanisms, however, remains obscure, mainly because it is difficult to separate different ITCZ variables in paleoclimate proxy records. Here, we report a speleothem oxygen isotope (δ18O) record from southwestern Sulawesi, Indonesia, and compile it with other speleothem records from the Maritime Continent. Using the spatial gradient of speleothem δ18O along a transect across the ITCZ, we constrain ITCZ variabilities over the Maritime Continent during the past 30,000 y. We find that ITCZ convection strength overall intensified from the last glacial period to the Holocene, following changes in climate boundary conditions. The mean position of the regional ITCZ has moved latitudinally no more than 3° in the past 30,000 y, consistent with the deduction from the atmospheric energy framework. However, different from modern observations and model simulations for future warming, the ITCZ appeared narrower during both the late Holocene and most part of the last glacial period, and its expansion occurred during Heinrich stadials and the early-to-mid Holocene. We also find that during the last glacial and deglacial period, prominent millennial-scale ITCZ changes were closely tied to the variability of the Atlantic meridional overturning circulation (AMOC), whereas during the Holocene, they were predominantly modulated by the long-term variability of the Walker circulation.

Distinguishing the main climatic drivers to the variability of gross primary productivity at global FLUXNET sites

Climate exerts both short-term and long-term impacts on the ecosystem carbon assimilation. However, the main climatic drivers for the variability of gross primary productivity (GPP) remain unclear across various timescales and vegetation types. Here, we combine the state-of-the-art machine learning algorithms with a well-established explanatory method to explore the impacts of climatic factors on long-term GPP variability at global FLUXNET sites across four timescales and six plant functional types. Results show that diffuse shortwave radiation (SWdif) dominates GPP variability at the sub-daily (half-hourly to three hourly) timescales especially for the tree species, and acts as the secondary contributor after air temperature at the daily or longer timescales. Attribution analyses further showed that the main effects of SWdif are much higher than their interactive effects with other climatic factors in regulating the GPP variability. By identifying the main climatic drivers, this study improves the understanding of the climate-driven GPP variability and provides important implications for the future projection of ecosystem carbon assimilation under global climate change.

Spatio-temporal variability of surface chlorophyll and pCO2 over the tropical Indian Ocean and its long-term trend using CMIP6 models

Under the global climate change scenario, ever-increasing ocean temperatures and elevated carbon dioxide (CO2) concentration levels in the ocean and atmosphere significantly affect ocean biogeochemistry. The spatiotemporal distribution of chlorophyll and partial pressure of CO2 (pCO2) over the Indian Ocean (IO) are investigated using satellite, in-situ, and simulations from eleven Coupled Model Inter-comparison Project phase 6 models. All the models show negative bias near the Somali region over the Arabian Sea (AS) during the southwest monsoon season. The CESMs and CanESM5 models show relatively less bias over the tropical IO except for the AS in all seasons compared to other models. The annual cycle of pCO2 shows a bimodal characteristic, with the first peak in May and the other in October over the northern IO, which the CanESM5, IPSL, and MPIs models reasonably well capture. All the models produce the phase of the annual cycle of pCO2 reasonably well for the southern IO. The pCO2 distribution and its trend decomposition are estimated using the multimodel mean from the CanESM5, IPSL-CM6A-LR, and MPIs models, suggesting that the increase in dissolved inorganic carbon is the dominant factor that contributes to about 70 % of the rise in the total pCO2 trend, and the total alkalinity and sea surface temperature have a secondary role. Region-wise analysis manifests that the southern IO and AS exhibit maximum susceptibility to the long-term variations in the pCO2 trend caused by the changes in dissolved inorganic carbon levels in the ocean. The study discusses substantive factors leading to the variability in the biogeochemical properties of the IO as simulated by these models and, thus, the possibilities for future improvements.

Assessment of Climate Change Effects on the Hydrological Regime of Bagmati River Basin using SWAT Model

Developing economies have been particularly vulnerable to the consequences of climate change due to their quickly growing populations and underdeveloped social and economic infrastructure. The Bagmati River Basin (BRB) belonging to such an economy is susceptible to the effects of climate change, including droughts and floods brought upon by changes in discharge. This study assessed the potential effects of climate change on discharge in BRB using the Soil and Water Assessment Tool (SWAT). The model was calibrated and validated based on observed flow data from 2000-2010 at two outlets: Khokana and Padhera Dovan. Using R2, NSE, PBIAS, RSR, and p-factor, the goodness of fit between the final simulated values and the observed values were evaluated. Historical data from three meteorological stations and bias-corrected global climate model (GCM) outputs from the ACCESS-CM2 model were used to drive the calibrated SWAT model under two scenarios (SSP 2-4.5 and SSP 5-8.5) from the IPCC Sixth Assessment Report (AR6). The study demonstrated long-term spatial and temporal variations in hydrologic responses to future climate changes, providing insights for water resources managers and those involved in mitigating natural hazards in the region.

Analysis of Supply Chain Management Performance in the Community Coffee Production System in Bajawa, Ngada Regency

Research on Supply Flow Performance Management in the Bajawa People's Coffee Production System was carried out in Ngada Regency, with the aim of finding out the relationship between cooperation and the performance of the Bajawa coffee supply flow, knowing the relationship between information sharing and the supply flow performance of Bajawa coffee and knowing the long-term relationship with Bajawa coffee supply flow performance. Many factors can influence the performance of supply flow management in companies, including information sharing, long term relationships, and cooperation. The method used in this research is to analyze the relationship between the dependent variable (cooperation, information sharing and long-term relationships) and the independent variable (Bajawa coffee supply flow performance). From the results of the multiple linear regression analysis carried out, it shows that: the long-term relationship variable has the greatest influence on the Bajawa coffee SCM performance variable (dependent) with a coefficient value of (0.047), then the cooperation variable with a value of ( 0.019 ), and which has a The smallest influence is the information sharing variable (0.018). This means that the three independent variables have a positive and significant effect on the dependent variable.

ЦИФРОВЫЕ РЕСУРСЫ В ПРЕДИКЦИИ ПРЕЭКЛАМПСИИ И ЗАДЕРЖКИ РОСТА ПЛОДА

Abstact. Introduction. Preeclampsia and fetal growth restriction are pregnancy complications related to Great Obstetrical Syndromes and having a similar pathogenesis. No antipathogenetic therapy methods have been found for both pathologies, but there is a means of prevention: Acetylsalicylic acid. The drug is effective only in high-risk pregnant women; therefore, various models are being developed to predict preeclampsia and fetal growth restriction, including digital models. They aim to help select patients who need that prophylaxis. Aim. This study is aiming to create a digital model for the early prediction of preeclampsia, based on the patient’s electronic medical card. Materials and Methods. The investigation involved 231 pregnant women. An algorithm was developed for the early prediction of preeclampsia and fetal growth restriction, based on detecting a combination of systemic and local hemodynamic markers: High variability of blood pressure between visits (long-term variability) and high resistance of blood flow in uterine arteries. Long-term (intervisit) variability of blood pressure is calculated for each trimester: First, the arithmetic mean is calculated among the values of systolic blood pressure at successive visits; second, the standard deviation is computed based on the result. Uterine arteries are checked using Doppler ultrasound technology at 11-13 weeks of gestation: Resistivity of blood flow (peripheral resistivity) in the right and left uterine arteries is assessed. Results and Discussion. For this new prediction algorithm, a digital model was developed, the ECAPP program (registration certificate No. 2018660666 – Electronic Prenatal Record with assessing the risk of developing preeclampsia based on blood pressure variability and uterine blood flow resistance). Conclusions. The IT resource presented has a potential for the effective early prediction of preeclampsia, as well as for predicting fetal growth restriction. Keywords: preeclampsia, fetal growth restriction, prognosis, digital model.

Contribution of Deep Vertical Velocity to Deficiency of Sverdrup Transport in the Low-Latitude North Pacific

Abstract Deep vertical velocity is a critical factor causing deficiencies in Sverdrup theory. However, few studies have focused on its influence in the low-latitude western Pacific. Through multiple analyses of observational, reanalysis, and simulation data, this study explored the contribution of deep nonzero vertical velocity to the Sverdrup transport inaccuracy in the low-latitude North Pacific. The vertical velocities inducing relatively small non-Sverdrup transport exist within 1500–2500 m, which exhibit similar patterns with opposite values to the south and north of 13°N. The zonally integrated meridional volume transport associated with these vertical velocities displays nonnegligible dipolar zonal bands west of approximately 150°W. The positive and negative transport bands, centered at 11° and 17°N, can reach an amplitude of approximately 8.0 Sv (1 Sv ≡ 106 m3 s−1) when integrated from the eastern boundary to 140°E. On average, such integrated meridional transport makes up roughly half of the prominent Sverdrup transport discrepancies in the central-western Pacific. Further investigation indicated that the spatial pattern of these vertical velocities is modulated by ocean topography and deep meridional currents. Moreover, a near-global test suggested that the meridional non-Sverdrup transport related to deep vertical velocity is widespread and undergoes remarkable multidecadal variation. This study reveals the disruptive role of deep vertical velocity in disturbing the Sverdrup balance and emphasizes the consideration of its long-term variation when diagnosing wind-driven circulation changes using Sverdrup theory.

Changes in Water Balance Elements in the Basins of the Largest Tributaries of Lake Baikal in the Late XX–Early XXI Century

Long-term variations in the water balance were analyzed in the basins of 20 largest tributaries of the Baikal. The values of river runoff were derived from actual data on the period from 1976 to 2019, and those of evaporation, precipitation, and potential evaporation, from ERA5-Land reanalysis since 1976 to 2020. Data were obtained to show an increase in the potential evaporation in all analyzed drainage basins by values from 0.39 to 0.62% per year since 1976 to 2020. A moderate or statistically insignificant decrease is typical of precipitation (0.25 to 0.59% per year) and water discharges, mostly due to a decrease in the summer runoff at a rate of 5.6%/10 years. The possible role of changes in vegetation cover in these processes was studied by evaluating NDVI parameter in 2019 compared with 2002 by data of space surveys MOD13A3 and MYD13A3 with MODIS spectroradiometer of Terra and Aqua satellites. A conclusion was made about the key role of precipitation in the decrease in the maximal runoff in Lake Baikal basin.

Increasing Salt Marsh Elevation Using Sediment Augmentation: Critical Insights from Surface Sediments and Sediment Cores

Sea-level rise is particularly concerning for tidal wetlands that reside within an area with steep topography or are constrained by human development and alteration of sedimentation. Sediment augmentation to increase wetland elevations has been considered as a potential strategy for such areas to prevent wetland loss over the coming decades. However, there is little information on the best approaches and whether adaptive management actions can mimic natural processes to build sea-level rise resilience. In addition, the lack of information on long-term marsh characteristics, processes, and variability can hamper development of effective augmentation strategies. Here, we assess a case study in a southern California marsh to determine the nature of the pre-existing sediments and variability of the site in relation to sediments applied during an augmentation experiment. Although sediment cores revealed natural variations in the grain size and organic content of sediments deposited at the site over the past 1500 years, the applied sediments were markedly coarser in grain size than prehistoric sediments at the site (100% maximum sand versus 76% maximum sand). The rate of the experimental sediment application (25.1 ± 1.09 cm in ~2 months) was also much more rapid than natural accretion rates measured for the site historically. In contrast, post-augmentation sediment accretion rates on the augmentation site have been markedly slower than pre-augmentation rates or current rates on a nearby control site. The mismatch between the characteristics of the applied sediment and thickness of application and the historic conditions are likely strong contributors to the slow initial recovery of vegetation. Sediment augmentation has been shown to be a useful strategy in some marshes, but this case study illustrates that vegetation recovery may be slow if applied sediments are not similar or at a thickness similar to historic conditions. However, testing adaptation strategies to build wetland elevations is important given the long-term risk of habitat loss with sea-level rise. Lessons learned in the case study could be applied elsewhere.

Climate Monitoring of Wind in the Free Atmosphere of the Northern Hemisphere: Long-Term Characteristics and Variability Trends

Climate Monitoring of Wind in the Free Atmosphere of the Northern Hemisphere: Long-Term Characteristics and Variability Trends

Multiyear Trends of the Ion Composition and Temperature of the Mid-Latitude Lower Thermosphere

Experimental data on measurements of the nitric oxide NO content in the mid-latitude lower thermosphere demonstrate its significant dependence on solar (and correspondingly) geomagnetic activity, which varies from undisturbed to strongly disturbed conditions up to three or four times or more. Such a dependence of [NO] on heliogeophysical factors cannot but affect the content of NO+ ions, which predominate (together with O+2 ions) at heights of 105–120 km. The analysis in the present work has confirmed this assumption: the φ+ = [NO+]/[O+2] ratio in the mid-latitude E layer of the ionosphere is indeed intricately correlated with solar activity. At the same time, data from vertical sounding of the ionosphere for 86 years of observations indicates a systematic multiyear increase of the critical frequency of the E layer (foE) at a fixed level of solar activity. Taking into account these circumstances made it possible to estimate the long-term variations of the neutral atmosphere temperature near the peak height of the E layer (hmE = 110–115 km). The calculations showed that between1931 and 2017, the annual mean temperature of the mid-latitude lower thermosphere increased at a linear rate exceeding 0.3–0.5 K/yr.

Valve-sparing aortic root replacement: Long-term variables significantly associated with mortality and morbidity

ObjectivesIn aortic root surgery, valve-sparing aortic root replacement is an attractive alternative by mitigating the risks inherent to prosthetic valves; however, little is known about the variables that impact its durability. We review our mid- to long-term outcomes after valve-sparing aortic root replacement and describe factors that impact survival and valve reintervention and insufficiency. MethodsA retrospective review of 284 consecutive patients undergoing valve-sparing aortic root replacement between November 1999 and January 2022 at Austin Health, Melbourne, Australia, was undertaken, with a median follow-up of 6.43 ± 4.83 years, but up to 22.0 years. Freedom from mortality, aortic reintervention, and insufficiency was analyzed using Kaplan–Meier methods, Cox proportional hazard models, and Fine-Gray analysis. ResultsThe median age of patients at intervention was 60.0 years (interquartile range, 48.0-67.0), of whom 68 (23.9%) had bicuspid aortic valve disease, 27 (9.5%) had Marfan syndrome, 119 (41.9%) had severe aortic root dilation (>50 mm), and 155 had (54.6%) severe aortic insufficiency at the time of intervention. The 30-day mortality was 1.8%, with freedom from mortality of 96.0% (95% CI, 92.6-97.8) at 5 years and 88.2% (95% CI, 81.4-92.6) at 10 years. Freedom from aortic reintervention was 92.2% (95% CI, 87.7-95.2) at 5 years and 79.8% (95% CI, 71.8-85.8) at 10 years. Factors associated with reintervention were concomitant leaflet repair (hazard ratio, 8.13, 95% CI, 1.07-61.7) and bicuspid valvulopathy (hazard ratio, 2.23, 95% CI, 1.07-4.68), with reintervention in the bicuspid aortic valve being more likely due to aortic stenosis and in the tricuspid aortic valve due to aortic insufficiency (chi-square P = .05). The freedom from aortic insufficiency was 89.1% (95% CI, 83.5-92.9), 84.9% (95% CI, 77.8-89.9) at 5 and 10 years, respectively, and 80.7% (95% CI, 71.0-87.4). ConclusionsValve-sparing aortic root replacement has excellent long-term outcomes, with low mortality and reintervention rates. Concomitant leaflet repair and bicuspid valve disease are the only long-term factors associated with reintervention.