Cumulative Curves Research Articles

The Prognostic Value of Red Cell Distribution Width in Critically Ill Cerebral Infarction Patients: A Retrospective Cohort Study

Objective: Red blood cell distribution width (RDW) has been utilized as a prognostic indicator for mortality risk assessment in cardiovascular and cerebrovascular patients. Nevertheless, the prognostic significance of RDW in critically ill patients with cerebral infarction is yet to be investigated. The objective of this study is to examine the association between RDW and the risk of all-cause mortality in cerebral infarction patients admitted to the intensive care unit (ICU). Method: A retrospective cohort study was conducted using the Medical Information Mart for Intensive Care IV 2.2 (MIMIC-IV) intensive care dataset for data analysis. The main results were the all-cause mortality rates at 3 and 12 months of follow-up. Cumulative curves were plotted using the Kaplan-Meier method, and Cox proportional hazards analysis was used to examine the relationship between RDW and mortality rates in critically ill cerebral infarction patients. Results: The findings indicate that RDW serves as a significant prognostic factor for mortality risk in critically ill stroke patients, specifically at the 3 and 12-month follow-up periods. The observed correlation between increasing RDW levels and higher mortality rates among cerebral infarction patients further supports the potential utility of RDW as a predictive indicator. Conclusion: RDW emerges as an independent predictor of mortality risk during the 3 and 12-month follow-up periods for critically ill patients with cerebral infarction.

Acoustic emission and fractal characteristics of red beds soft rock under water-force coupling

Groundwater has a significant influence on the mechanical properties of surrounding rock. Aiming at the large deformation of surrounding rock of red layer soft rock tunnel affected by groundwater, the uniaxial graded loading tests were carried out on red beds soft rock with different water content. The failure process of the specimen was monitored by acoustic emission (AE) and the crack evolution law was analyzed, and the scanning electron microscopy (SEM) was used to compare the microstructure of the specimens before and after immersion. Combined with fractal theory, the monofractal and multifractal characteristics of AE ringing count during the loading process of red beds soft rock were analyzed. The results show that, with the gradual increase of water content, the AE ringing count before the yield stage gradually decreased, and the corresponding cumulative ringing count at the same time gradually decreased, and the decrease was large in the early stage of immersion, and decreased in the later stage. The cumulative ringing curve gradually slowed down, the internal crack appeared earlier, the cumulative ringing curve stepped significantly, the AE signal amplitude gradually weakened, and the bandwidth of each frequency band gradually decreased. The failure of red beds soft rock with different water content is dominated by shear crack, and with the gradual increase of water content, the proportion of shear crack increases gradually, and the AE b value decreases gradually. With the gradual increase of the relative peak strength, the correlation dimension D of red beds soft rock with different water content increases first and then decreases. At 80% of the relative peak strength, the correlation dimension D reaches its maximum value and then drops sharply until it is maintained at a relatively low level, and the correlation dimension D gradually decreases with the water content. The fitting correlation coefficients of different water content (lnC(r), lnr) are all above 0.9, indicating that the AE ringing count of water-bearing red beds soft rock has fractal characteristics, and the higher the correlation coefficient, the higher the self-similarity of AE ringing count sequence. As the weight q gradually increases, the generalized fractal dimension D(q) gradually decreases. When q ≠ 0, under the condition of the same q, D(q) presents a trend of first increasing and then decreasing. The multifractal characteristics of AE ringing count of red beds soft rock with different water content is inverted ‘U’ shape. From the natural state to immerse 1 d, the ∆α gradually increases, and from 1 to 7 d, the ∆α gradually decreases, where Δα = αmax − αmin represents the spectral width of the multifractal spectrum. When saturation is not reached, ∆f < 0 indicates that the number of cracks in the specimen is small, when saturation is reached, ∆f > 0 indicates that a large number of cracks are generated inside the specimen and macro cracks are formed, where Δf = f (αmax) − f (αmin) represents the frequency relationship between different signals of different sizes. This research can provide a reliable theoretical basis for the construction and maintenance of large deformation of water-rich soft rock tunnel excavation, and have certain engineering significance.

Spatial Distribution of Arsenic in the Aksu River Basin, Xinjiang, China: The Cumulative Frequency Curve and Geostatistical Analysis

The quality of drinking water is crucial for human health and the sustainable development of societies. The Aksu River Basin, a typical inland river system, has areas where groundwater arsenic levels exceed safe drinking water standards (i.e., arsenic concentrations greater than 10 μg/L). Identifying the causes of high arsenic levels in the basin’s groundwater requires further study. Analyzing the hydrogeochemical composition of the Aksu River basin helps us to understand the spatial distribution of groundwater environments and locate areas with dangerously high arsenic levels. In this research, we collected 196 groundwater samples from along the river. Out of these, 38 samples had arsenic levels above 10 μg/L, which represents 19.4% of the total samples collected. By examining the slope changes in the cumulative frequency curves of major ion ratios and employing geostatistics (specifically, the Kriging interpolation), and taking into account the environmental characteristics of the entire basin, we divided the study area into five sub-regions (Zone I through Zone V). The geostatistical analysis showed a significant spatial variability in groundwater arsenic levels, with a clear spatial correlation. Our findings demonstrate that arsenic concentrations in the Aksu River basin’s groundwater vary widely, with Zones II and III—mainly located in the northeastern part of the basin and in Awat County—being hotspots for high-arsenic water. Factors such as a weak reducing environment, intense evaporation, strong cation exchange, and the low-permeability recharge of surface water contribute to the accumulation of arsenic in the basin’s groundwater. The results of this study are vital for assessing the risk of arsenic contamination in groundwater in similar basins and for identifying critical areas for further investigation and research.

&lt;i&gt;Diospyros&lt;/i&gt; &lt;i&gt;crassiflora&lt;/i&gt; (HIERN) surface and subsoil leaf litter decomposition pattern along a time gradient in a humid rainforest

Litter decomposition is a crucial bedrock of nutrient recycling, organic matter accumulation, soil physicochemical properties, biodiversity and life support of forest and agroforestry systems. We therefore investigated &lt;i&gt;Diospyros&lt;/i&gt; &lt;i&gt;crassiflora&lt;/i&gt; surface and subsoil leaf litter decomposition pattern along a duration gradient in a humid rainforest. The study was conducted in the nursery of the humid forest research station of the Forestry Research Institute of Nigeria (FRIN) in Umuahia, Abia State. One gram (1g) of &lt;i&gt;D.&lt;/i&gt; &lt;i&gt;crassiflora&lt;/i&gt; fresh leaf litter was placed on the surface and subsoil of 4kg of topsoil contained in 32cm x 20cm polyethene bags; there were a total of 108 bags in a completely randomized experimental design layout and the treatments were the duration gradient of litter decomposition which were: 2, 4, 6, 8, 10, 12, and 14 weeks; on each of the duration, litter was collected from nine of the polyethene bags for laboratory analysis and estimate of decomposition rate. The results showed a significantly high initial decomposition rate (3.19±0.13 %day-1; 4.28±0.03 %day-1) in the 2 week duration followed by significant continuous decline until the lowest (0.04±0.00%day-1; 0.28±0.02%day-1) in the 14 week in the surface and subsoil respectively. There was a positive correlation (r=0.80) in decomposition rate between the surface and subsoil leaf litter, which yielded a model with a significant R2 (0.64), for site-specific estimates of decomposition rate &lt;i&gt;D.&lt;/i&gt; &lt;i&gt;crassiflora&lt;/i&gt; leaf litter. A steeper and smoother subsoil cumulative percentage decomposition curve showed that leaf litter decomposition was significantly faster in the subsoil than surface soil.&#x0D;

Automatic detection and characterization of discontinuity traces and rock fragment size distribution using a digital image processing method

Rock materials naturally contain cracks and fractures, which may produce rock fragments or grains under geological and engineering conditions. Identification and characterization of the spatial extent of discontinuity traces and size distribution of fragments/grains are prerequisites for accurate geomechanical assessments of the stability of rocks containing natural or artificial discontinuities. This study introduces an advanced image processing methodology that leverages color gradient analysis and multi-threshold criteria to effectively detect and delineate fracture traces or boundary outlines. Furthermore, this approach facilitates the acquisition of precise fragment or grain size distribution statistics. To comprehensively characterize these discontinuity traces, the methodology employs the calculation of fractal dimensions alongside the use of an equivalent diameter conversion technique. These tools enable the quantification of the complexity and size distribution of the fragments or grains. The efficacy of this approach has been demonstrated through a series of case studies, encompassing a wide range of applications including digital images from numerical simulations, experimental tests, field observations, and micrographic analyses of rock structures. In these studies, the method proved capable of satisfactorily calculating the fractal dimensions of fractures, cracks, and contacts. Simultaneously, it accurately and efficiently determined the size distribution, as evidenced by frequency histograms and cumulative distribution curves obtained from the images. In essence, the proposed approach provides an automatic quantitative methodology to identify and characterize macroscopic and microscopic rock structures containing discontinuity traces or comprised of fragments/grains. This advancement holds significant potential for enhancing the precision and efficiency of geological and geomechanical assessments.

A242 EPIDEMIOLOGICAL ASPECTS, RISK FACTORS, AND CUMULATIVE PREVALENCE OF EXTRAINTESTINAL MANIFESTATIONS IN INFLAMMATORY BOWEL DISEASE: RESULTS FROM A 7,150 PATIENTS’ COHORT IN A TERTIARY CARE CENTER

Abstract Background Canada is among the countries with a high burden of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Extraintestinal manifestations (EIMs) incorporate a spectrum of systemic IBD-accompanying conditions that are associated with a poorer quality of life, higher disease activity, and increased need for IBD-related surgery and treatment escalation. Aims We aimed to establish the all-time and cumulative prevalence of EIMs in a large cohort of IBD patients and assess the risk factors associated with EIMs in IBD. Methods We conducted a retrospective cohort study of 7,150 IBD patients followed at the Division of Gastroenterology, University of Alberta, diagnosed between 1954–2022, with 159,026 person-years follow-up. Data were obtained via manual chart review, from electronic medical records and administrative reporting systems. The EIMs included ophthalmological, musculoskeletal, urogenital, hepatobiliary, dermatological, and pulmonary. Univariate and multivariate logistic regression models and cumulative prevalence curves with the Kaplan-Meier analysis were used. Results Data of 3,910 CD and 3,240 UC patients (50.3% females, median age 48.0 (range 17-98 y.o.)) were analyzed. Over one-third of IBD patients (34.0%) had at least one EIM. The EIMs prevalence did not differ significantly between CD and UC (34.8% vs. 33.0%; p=0.112). In CD patients, the most common EIM was scleritis/episcleritis (10.9%), followed by nephrolithiasis (10.1%) and axial spondyloarthritis (7.3%). The UC patients most frequently had scleritis/episcleritis (10.3%), primary sclerosing cholangitis (8.4%) and nephrolithiasis (7.8%). In CD patients, age at diagnosis ≥40 y.o. (OR 1.77, 95%CI 1.33-2.37), disease duration ≥20 years (OR 2.28, 95%CI 1.62-3.21) and C-reactive protein≥8.0 mg/L (OR 1.46, 95%CI 1.01-2.12) were independent risk factors for EIMs (Fig.1a). Among UC patients, the following EIM risk factors were identified: disease duration ≥20 years (OR 1.63, 95%CI 1.19-2.22), obesity (OR 1.40, 95%CI 1.04-1.89), vitamin B12 deficiency (OR 1.64, 95%CI 1.12-2.40), and need for IBD surgery (OR 1.63, 95%CI 1.13-2.34) (Fig.1b). Cumulative probability of EIMs in CD vs. UC was 8% vs. 12%, at 10 years, 27% vs. 38% at 20 years, and 51% vs. 59% at 30 years since diagnosis (Log-rank, pampersand:003C0.001) (Fig.1c). Conclusions Over one-third of IBD patients have at least one EIM and their pattern and cumulative prevalence varies substantially between CD and UC. It is important to be aware of the EIMs’ risk factors to recognize them early and provide adequate management aiming to decrease morbidity and mortality and improve the quality of life of IBD patients. Fig. 1a. Associations between demographic, phenotypic and clinical IBD features and EIMs among CD patients - results of the multivariate logistic regression analysis. Fig. 1b. Associations between demographic, phenotypic and clinical IBD features and EIMs among UC patients - results of the multivariate logistic regression analysis. Fig 1c. Cumulative prevalence of EIMs in CD (grey line) vs. UC (pink line). Funding Agencies None

Atmospheric pollen concentrations and chronic obstructive pulmonary disease (COPD) patients visits in Beijing: time series analysis using a generalized additive model

To investigate the correlation between the daily visits of chronic obstructive pulmonary disease (COPD) patients in hospital clinic and pollen concentrations in Beijing. We collected daily visits of COPD patients of Beijing Shijitan Hospital from April 1st, 2019 to September 30th, 2019. The relationship between pollen concentrations and COPD patient number was analyzed with meteorological factors, time trend, day of the week effect and holiday effect being controlled by the generalized additive model of time series analysis. R4.1.2 software was applied to generate Spearman correlation coefficient, specific and incremental cumulative effect curves of relative risks as well as the response and three-dimensional diagrams for the exposure lag effect prediction. The fitting models were used to predict the lag relative risk and 95% confidence intervals for specific and incremental cumulative effects of specific pollen concentrations. The number of COPD patients was positively correlated with pollen concentration. When pollen concentration increased by 10 grains/1000 mm2, the peak value of the specific cumulative effect appeared on day0, with the effect gone on day4 and a lag time of 4 days observed, whereas the incremental cumulative effect’s peak value was shown on day17, and the effect disappeared on day18, with a lag time of 18 days. The results showed that pollen concentration was not only positively correlated with the number of COPD patients, but also had a bimodal lag effect on COPD visits in the hospital at Beijing.

High incidence of gallstones after Roux-en-Y reconstruction gastrectomy in gastric cancer: a multicenter, long-term cohort study.

Roux-en-Y reconstruction is a common anastomosis technique during gastrectomy in gastric cancer. There is a lack of studies on gallstones after Roux-en-Y reconstruction gastrectomy. This study investigated the incidence and potential risk factors associated with gallstones after Roux-en-Y reconstructive gastrectomy in gastric cancer. The study analyzed data from gastric cancer who underwent radical gastrectomy and Roux-en-Y reconstruction at two hospitals between January 2014 and December 2020. The patients fall into distal and total gastrectomy groups based on the extent of gastrectomy. The cumulative event probability curve was plotted using the Kaplan-Meier, and differences in gallstone between groups were evaluated using the Log-Rank. Propensity score matching was applied to construct a balanced total versus distal gastrectomies cohort. A Cox regression was employed to analyze the risk factors for gallstones after Roux-en-Y reconstructive gastrectomy in gastric cancer. Further subgroup analysis was performed. Five hundred thirty-one patients were included in this study, 201 in the distal gastrectomy group and 330 in the total gastrectomy. During the follow-up, gallstones occurred in 170 cases after gastrectomy, of which 145 cases accounted for 85.29% of all stones in the first two years after surgery. Then, to reduce the impact of bias, a 1:1 propensity score matching analysis was performed on the two groups of patients. A total of 344 patients were evaluated, with each subgroup comprising 172 patients. In the matched population, the Cox regression analysis revealed that females, BMI ≥23kg/m 2 , total gastrectomy, No.12 lymph node dissection, and adjuvant chemotherapy were risk factors for gallstones after Roux-en-Y reconstructive gastrectomy. Subgroup analysis showed that open surgery further increased the risk of gallstones after total gastrectomy. The incidence of gallstones increased significantly within 2years after Roux-en-Y reconstructive gastrectomy for gastric cancer. Patients with these risk factors should be followed closely after gastrectomy to avoid symptomatic gallstones.

Prediction of complete regression in fertility-sparing patients with endometrial cancer and apical hyperplasia: the GLOBAL model in a large Chinese cohort

BackgroundFertility preservation treatment is increasingly essential for patients with apical endometrial hyperplasia (AEH) and early endometrial cancer (EEC) worldwide. Complete regression (CR) is the main endpoint of this treatment. Accurately predicting CR and implementing appropriate interventions during treatment are crucial for these patients.MethodsWe conducted a retrospective study involving 193 patients diagnosed with atypical AEH or EEC, enrolled from January 2012 to March 2022 at our center. We evaluated 24 clinical parameters as candidate predictors and employed LASSO regression to develop a prediction model for CR. Subsequently, a nomogram was constructed to predict CR after the treatment. We evaluated the performance of the nomogram using receiver operator characteristic (ROC) curve and decision curve analysis (DCA) to assess its predictive accuracy. Additionally, we employed cumulative curves to determine the CR rate among patients.ResultsOut of the 193 patients, 173 achieved CR after undergoing fertility preservation treatment. We categorized features with similar properties and provided a list of formulas based on their coefficients. The final model, named GLOBAL (including basic information, characteristics, blood pressure, glucose metabolism, lipid metabolism, immunohistochemistry, histological type, and medication), comprised eight variables identified using LASSO regression. A nomogram incorporating these eight risk factors was developed to predict CR. The GLOBAL model exhibited an AUC of 0.907 (95% CI 0.828–0.969). Calibration plots demonstrated a favorable agreement between the predicted probability by the GLOBAL model and actual observations in the cohort. The cumulative curve analysis revealed varying cumulative CR rates among patients in the eight subgroups. Categorized analysis demonstrated significant diversity in the effects of the GLOBAL model on CR among patients with different total points (p < 0.05).ConclusionWe have developed and validated a model that significantly enhances the predictive accuracy of CR in AEH and EEC patients seeking fertility preservation treatment.

Comparison of nonlinear functions to describe lactation curves for cumulative milk production in buffalo.

The aim of this study was to examine the suitability of different growth functions (linear, sinusoidal, Gompertz, Schumacher and Richards) to fit cumulative milk production data from buffalo cows. Cumulative milk production at each day in milk was calculated from two published datasets reporting (i) fortnightly test-day milk yield records of the first lactation of Murrah buffalo that had calved during 1977-2012 and (ii) the first lactation records of Jaffarabadi buffalo collected from history-cum-pedigree registers for each quinquennium between 1991 and 2010. Each function was fitted to the lactation curves using nonlinear regression procedures. The Richards and sinusoidal equations provided the smallest root mean square error values, Akaike's and Bayesian information criteria and, therefore, the best fit for the cumulative lactation curves for milk yield. The Richards equation appeared to provide the most accurate estimate of the cumulative milk production at peak milk yield. Sinusoidal and flexible classical growth functions are appropriate to describe cumulative milk production curves and estimate lactation traits in buffalo.

Differences between Italians and immigrants in COVID-19 vaccination coverage in the Reggio Emilia resident population (Emilia-Romagna Region, Northern Italy)

The present work describes the cumulative coverage curves by country of birth, sex, age, and area of residence of the adult population residing in the province of Reggio Emilia (Emilia-Romagna Region, Northern Italy).The analyses are stratified by country of birth into HDC (Highly Developed Country), mostly Italians, and HMPC (Highly Migration Pressure Country), as a proxy of migrant status, excluding deaths. Vaccinations carried out up to September 2022 and recorded in the information system were considered, including vaccinations performed outside the province. Vaccinations done abroad are not included when the information is incomplete or the type of vaccine is different from those administered in Italy.Vaccination coverage (%) by number of doses and estimated Hazard Ratio (HR) and related 95% confidence intervals (95%CI) are calculated using Cox models, adjusted for age and stratified by sex.A lower vaccination coverage was detected, delayed by a few weeks, among HMPC, but the differences in vaccination coverage are reversed when the different age structure of the two populations is taken into account. From the estimates of the Cox models, a higher propensity to vaccinate was noted among immigrants, in particular among women (women HR: 1.65; CI95% 1.52-1.78; men HR: 1.39; CI95% 1.28-1.52). Women were vaccinated first, but, at the end of the observation period, there were no particular differences in coverage between the two sexes, either among Italians or immigrants. Focusing on the area of origin, a strong propensity for vaccination was noted, particularly among who came from North Africa. In the mountain areas of the province, a lower propensity for vaccination was observed, perhaps explained by the greater distance of the vaccination centers or by a lower acceptability of the vaccine.

Overall survival of homebound patients without cancer receiving inpatient respite care in a hospital ward in Japan: a retrospective observational study

ObjectivesThis study aimed to investigate the relationship between the use of inpatient respite care and the overall survival of homebound patients without cancer admitted to a hospital ward in order...

Functional outcomes of robot-assisted radical prostatectomy with preservation of pelvic stabilized structure and early elevated retrograde liberation of neurovascular bundle

Objectives: To examine the functional outcomes of robot-assisted radical prostatectomy (RARP) with preservation of pelvic floor stabilized structure and early elevated retrograde liberation of the neurovascular bundle (PEEL). Methods: This study was a retrospective cohort study. Between June 1, 2022, and March 20, 2023, 27 cases of RARP with PEEL and 153 cases of RARP with preservation of pelvic floor stabilized structure (PPSS) were included in this study. All patients were males, aged (62.5±5.2) years (range: 50 to 73 years). There were 18 cases of ≤T2b stage and 9 cases of T2c stage. After 1∶1 propensity score matching, the postoperative functional outcomes of 27 cases of RARP with PEEL and 27 cases of RARP with PPSS were compared. All surgeries were performed by a single surgeon and included patients were clinically staged as cT1-2N0M0 without preoperative urinary incontinence or erectile dysfunction. In RARP with PEEL, the prostate was cut near the midline at the front when dissecting the neurovascular bundle, dissection was performed between the visceral layer of the pelvic fascia and the prostatic fascia, preserving the parietal layer and the visceral layer of the pelvic fascia, and the neurovascular bundle was retrogradely released from the apex. The cumulative probability curve was plotted using the Kaplan-Meier method and the Log-rank test was used to compare the differences in functional outcomes between the two groups. Univariate and multivariate analysis with the Cox proportional hazards model was used to compare postoperative urinary continence and sexual function. Results: The recovery time of continence and potency was significantly longer in the PPSS group than in the PEEL group (all P<0.05). The continence rate of the PEEL group was significantly higher than that of the PPSS group (92.59% vs. 68.10%, P=0.026) at 3 months after surgery. The potency rate of the PEEL group was also significantly higher than that of the PPSS group (40.70% vs. 15.10%, P=0.037) at 3 months after surgery. In the univariate analysis, compared to the PPSS technique, the PEEL technique was associated with a shorter recovery time of continence (HR=1.94, 95%CI: 1.08 to 3.48, P=0.027) and a shorter recovery time of potency (HR=2.06, 95%CI: 1.03 to 4.13, P=0.042). In the multivariate analysis, the PEEL technique was an independent prognosis factor for postoperative recovery of continence (HR=2.05, 95%CI: 1.01 to 4.17, P=0.047) and potency (HR=3.57, 95%CI: 1.43 to 8.92, P=0.007). All the cases of the PPSS group and the PEEL group were performed successfully with negative surgical margins. Conclusion: Compared with PPSS, PEEL may be more conducive to the recovery of urinary continence and sexual function after RARP.

P1133 Relative survival and cause-specific mortality of a Chilean Inflammatory Bowel Disease cohort

Abstract Background In the past two decades, multiple studies have shown an improvement in outcomes of inflammatory bowel disease (IBD) patients including a decreasing mortality associated with new treatments, surveillance, and healthcare support. There are no large studies in Latin-American countries addressing survival and death causes in IBD patients. We aimed to assess relative survival (RS) and causes of death in Chilean IBD patients. Methods IBD patients treated in a tertiary reference centre (Pontificia Universidad Católica of Chile, Santiago, Chile) since January 1990 were included in a local database. Death certificates were analysed to obtain the date and specific cause of death. The recorded time started on the date of definitive diagnosis and lasted until death or censoring on December 31st, 2020. The survival of IBD patients was compared with the life expectancy of the Chilean general population based on official life tables collected in the Human Mortality Database (www.mortality.org). The RS was computed using the Ederer II method implemented in the RELSURV package of the R software. A RS greater than 1.0 indicates that the analysed cohort has a higher survival than the expected survival of the reference population for the same age, sex and date at which age was coded. Inclusion of 1.0 within 95% CI indicates no difference between observed and expected survival. Data were also expressed graphically as the observed cumulative survival curves over time and the 95% confidence interval (CI) and compared to the reference population. Results We included 1,289 IBD patients with a media age at diagnosis of 35.9±14 years, 40.9% males and a follow-up of 22,525 patients-year. Ulcerative Colitis, Crohn’s disease and IBD unclassified patients comprised 50.2%, 43.1% and 6.7% of the cohort, respectively. A total of 106 patients (8.9%) died during the study period. Compared with the general population, the survival of IBD patients was higher (RS = 1.04; 95% CI: 1.02-1.07) at 20 years of follow-up (Table and Figure). This higher RS in IBD patients was observed in males and females, as well as CD patients and IBD patients older than 40-year-old (Table). The main causes of death in IBD patients were cancer (34%), infections (27.7%) and cardiovascular diseases (21.3%). Conclusion Compared to the general population, a higher long-term survival was observed in this large cohort of Chilean IBD patients. These findings may be due to a closer surveillance of this group of patients. Causes of death mirrored those in previously reported cohorts; therefore, a special care should be pay on their prevention in Latin-American countries as well.

A First Approach on the Impact of Distributed Generation on Voltage Sags

An analysis of the distributed generation (DG) impact on studies of voltage sags caused by system faults is presented. The simulation of 62 case studies of phase-to-ground faults on 13.8, 69, 138 and 230 kV transmission lines were performed and the voltage of a 380 V sensitive industrial busbar client was monitored. These lines are part of the electrical system of the city of Goiania, Brazil. For each case study, different fault positions were simulated by considering different DG levels connected to the consumer busbar. Long-term simulation scenarios were obtained by the Monte Carlo method and analyzed based on their cumulative distribution functions and probability density curves of voltage sags. This is one major contribution of this work.

A First Approach on the Impact of Distributed Generation and network topology on Studies of Voltage Sags

An analysis of the distributed generation (DG) and network topology impact on studies of voltage sags caused by system faults is presented. The simulation of 62 case studies of phase-to-ground faults on 13.8, 69, 138 and 230 kV transmission lines were performed and the voltage of a 380 V sensitive industrial busbar client was monitored. These lines are part of the electrical system of the city of Goiania, Brazil. For each case study, different fault positions were simulated by considering different DG levels connected to the consumer busbar. Long-term simulation scenarios were obtained by the Monte Carlo method and analyzed based on their cumulative distribution functions and probability density curves of voltage sags. This is one major contribution of this work.

Evaluation of Subdaily Hydrological Regime Alteration Characteristics for Hydro–Photovoltaic Complementary Operation in the Upper Yellow River

The complementary operation of hydropower and photovoltaic power, aimed at meeting real-time demand, has led to frequent adjustments in power generation, causing significant fluctuations in hydrological systems and adversely affecting fish reproduction. The traditional hydrological regime alteration assessment index is based on index of hydrologic alternation (IHA) and mostly focuses on annual and daily runoff alterations. This study proposes a new set of indicators considering the characteristics of subdaily hydrological regime alterations, including magnitude, rate of change, duration, frequency, and timing. Using the hourly outflow from Longyangxia, an analysis of indicator redundancy was conducted. The alteration of the indicators before and after hydropower and photovoltaic operation was then analyzed using the cumulative probability distribution curve. Additionally, a concentration index was introduced to analyze the variations in hydrological impacts during different months. The results show that the hydro–photovoltaic complementary operation changed the subdaily natural flow regime, significantly increasing the rate of flow increase or decrease and the duration, with most indexes increasing by more than 100% compared with the natural flow regime. Furthermore, the concentration values of the indexes for the hydro–photovoltaic complementary operation were less than 10, indicating a more significant impact on the subdaily flow regime throughout the year. This research provides crucial data for mitigating ecological impacts under multi-source complementary scheduling.

Analysis of biogas production from sewage sludge combining BMP experimental assays and the ADM1 model.

The Anaerobic Digestion Model No. 1 (ADM1) was employed to simulate methane (CH4) production in an anaerobic reactor (AR), and the associated bench-scale biochemical methane potential (BMP) assay, having sewage sludge (SWS) from a municipal wastewater treatment plant (WWTP) as feedstock. The SWS presented the following physical-chemical characteristics: pH (7.4-7.6), alkalinity (2,382±100mg CaCO3 L-1), tCOD (21,903±1,000 mg L-1), TOC (895±100 mg L-1), TS, TVS, and VSS (2.0%, 1.1%, and 0.8%, respectively). The BMP assay was conducted in six replicates under anaerobic mesophilic conditions (37±0.1°C) for 11 days with a CH4 yield registered of 137.6±6.39 NmL CH4 or 124±6.72 CH4 g-1 VS-1. When the results obtained with the BMP bench-scale reactors were compared to the output generated with computational data by the ADM1 model having as input data the same initial sewage tCOD, similar cumulative CH4 production curves were obtained, indicating the accuracy of the ADM1 model. This approach allowed the characterization of the sludge and estimation of its biogas production potential. The combination of BMP assays, experimental data, and ADM1 model simulations provided a framework for studying anaerobic digestion (AD) processes.

Investigating paleoseismicity using high-resolution airborne LiDAR data - A case study of the Huangxianggou fault in the northeastern Tibetan plateau

Fault-offset landforms have long been recognized as holding important information about paleoseismic slip. Constructing an along-strike fault slip distribution could help reveal a fault's long-term rupture patterns and facilitate a more precise assessment of its future behavior. In this study, we documented the paleoseismic history of the Huangxianggou Fault, an oblique sinistral-thrust segment of the West Qingling Fault in the northeastern region of the Tibetan Plateau, using LiDAR-derived high-resolution DEM (0.1 m/pixel) and measurement of offset landforms. A total of 46 well-preserved and well-shaped landforms were chosen for horizontal and vertical displacement measurements, and the dense measurement data allow us to generate the cumulative offset probability distribution curves of horizontal and vertical displacements. Statistical analysis revealed at least seven surface-rupturing events, each with similar coseismic horizontal displacements of ∼7.0 m and vertical displacements of ∼0.7 m, in agreement with previous paleoseismic trench results. Using empirical relationships between moment magnitude and horizontal displacement, a plausible moment magnitude range of Mw7.3–7.7 was determined for these paleoearthquakes. Furthermore, by evaluating rupture parameters and fault slip rate, we determined a recurrence interval of 2.7–3.4 kyr for significant surface-rupturing events on this fault. The elapsed time since the last earthquake closely approaches this interval, suggesting a potential seismic risk for the Huangxianggou Fault. Our results emphasizes the importance of high-resolution topographic data in paleoseismic investigations, enabling the identification of numerous offset landforms and precise displacement measurements across faults. Paleoearthquake counts derived from horizontal and vertical displacement analyses were found to be consistent, highlighting the significance of vertical displacements in quantifying paleoearthquakes for strike-slip faults with a thrust component.

A First Approach on the Impact of Distributed Generation and Fault Impedance on Studies of Voltage Sags

An analysis of the distributed generation (DG) and fault impedance on studies of voltage sags caused by system faults is presented. The simulation of 62 case studies of phase-to-ground faults on 13.8, 69, 138 and 230 kV transmission lines were performed and the voltage of a 380 V sensitive industrial busbar client was monitored. These lines are part of the electrical system of the city of Goiania, Brazil. For each case study, different fault positions and impedance fault were simulated by considering different DG levels connected to the consumer busbar. Long-term simulation scenarios were obtained by the Monte Carlo method and analyzed based on their cumulative distribution functions and probability density curves of voltage sags. This is one major contribution of this work.