Mann-Kendall Trend Test Research Articles

Urbanization and hydrological dynamics: a 22-year assessment of impervious surface changes and runoff in an urban watershed

The frequency and intensity of flooding have been increasing in urban watersheds. Urbanization disrupts natural landscapes by replacing vegetated areas with impervious surfaces, reducing infiltration and increasing runoff. The objective of this study was to evaluate the relationship between change in impervious surface area and runoff amount of Mihang’o watershed located in the outskirts of Nairobi for the period 2000–2022. The specific objectives of this study were as follows: To determine the change in the impervious surface area of Mihang’o watershed, the trend of precipitation amount in the watershed, and the trend in runoff amount, a major source of flood water from the watershed. Supervised classification was performed on land satellite (Landsat) images to determine percentages of impervious surface cover for the study period, and linear regression analysis was used to establish the trend. Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) rainfall data were retrieved from Google Earth Engine, then processed to produce monthly and annual rainfall totals, and Mann–Kendall trend tests were used to establish the rainfall trend for the watershed. The Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS) model was used to simulate runoff from the watershed with the rainfall data and impervious surface area percentages as inputs; then, linear regression analysis was performed to establish the runoff trend. The impervious surface area increased by 87.03% from 2.88% (0.49 km2) of the total surface area of the watershed in 2000 to 22.21% (3.91 km2) in 2022, demonstrating an approximate increment of 3.96% (0.88 km2) each year. The Mann–Kendall trend test results (Sen’s slope results [β = 0.832], Kendall’s tau results [τb = 0.146], and p-value [0.625]) confirmed that there is no significant change in rainfall amounts. Runoff increased by 84.75% from 0.18 mm in 2000 to 1.18 mm in 2022; otherwise, an approximate increment of 3.85% (0.045 mm) was evident each year. Besides the impervious surface area, the HEC-HMS model factors in the length of slope, length of reach, soil type, size of subbasins, and longest flow path, thus producing accurate runoff estimations.

Dust Source Dynamics in Arid Iran: Examining the Relationship between MODIS AOD and Land Surface Characteristics in a Dried Catchment

Dust sources are expanding unprecedentedly across the arid parts of Iran. To quantify this trend in the Kaftar Catchment in SW Iran (5,600 km2), the MODIS AOD product “Optical_Depth_047”, accessible through Google Earth Engine was utilized, as one of the moderate-resolution (1km) aerosol data sources spanning from 2002 to 2023. The layers were preprocessed and averaged to derive annual mean data (AM-AOD), and its accuracy was verified using reference dust data collected from 24 stations in 2022 (correlation coefficient = 0.565; p-value < 0.01). The Mann-Kendall trend test confirmed a statistically significant upward trend in AOD values. A positive Sen’s slope predominated for the majority of the AM-AOD pixels. The Generalized Additive Model (mean R2 = 0.753) successfully predicted AM-AOD values at each pixel for the year 2035. According to the Landsat 8-derived LULC map of the region (Kappa = 83.56), the wetland area is projected to experience the highest increase in AM-AOD in 2035, reaching 0.43 ± 0.06, while rangelands are expected to observe the lowest increment at 0.17 ± 0.07. Our study underscores the urgency of rehabilitating the Kaftar Wetland, promoting low-water crops, and improving ecosystem resilience in rangelands.

Land use land cover change as a casual factor for climate variability and trends in the Bilate Watershed, Ethiopia

Climate change and land use dynamics are critical issues facing many regions worldwide, particularly in developing countries. This study examines the spatiotemporal changes in land use and land cover (LULC) and their impact on climate variability in the Bilate Watershed, Ethiopia, from 1994 to 2024. Utilizing multispectral satellite imagery from Landsat 5, 7, and 8, along with meteorological data from five weather stations, LULC classification was performed using the Random Forest algorithm on the Google Earth Engine platform. To analyze climatic variability and trends, the Mann–Kendall trend test, the Standardized Precipitation Index (SPI), and the Standardized Temperature Index (STI) were employed. The findings indicate a significant decline in forest cover, with an accelerated annual loss of approximately 4681.2 hectares between 2014 and 2024. Concurrently, agricultural land expanded by about 1141 hectares annually, and urban areas grew by 24.3 hectares per year in recent years. Seasonal mean rainfall variation showed significant declines in the upper catchment, with Bega (p = 0.004, Sen’s slope = − 3.819 mm), Belg (p = 0.006, Sen’s slope = − 7.972 mm), and Kiremt (p = 0.005, Sen’s slope = − 7.117 mm), while the lower catchment experienced a notable increase during the Belg season (p = 0.025, Sen’s slope = 6.424 mm), highlighting uneven water availability across the watershed. Furthermore, pronounced warming trends were observed in the upper catchment (Bega: p = 0.002, Sen’s slope = 0.029; Belg: p = 0.001, Sen’s slope = 0.030; Kiremt: p = 0.004, Sen’s slope = 0.018), with moderate warming noted in the middle catchment during the Kiremt season (p = 0.020, Sen’s slope = 0.016). These LULC changes have significantly impacted climate variability, emphasizing the critical influence of human activities on regional climate dynamics. This study underscores the urgent need for sustainable land management and conservation strategies to mitigate the challenges posed by deforestation, urbanization, and agricultural expansion.

A method for evaluating ecological quality levels and trends using natural evolution time series.

Ecological quality assessment serves as a valuable tool for impartially measuring the effects of development and utilization activities on ecosystems, forming the bedrock of ecological governance. The ecological quality evaluation method, relying on a reference frame, takes into consideration the comparability of ecological quality, thus guaranteeing the presence of external benchmarks for the assessment results. However, present research on absolute assessment of ecological quality is limited, as the majority of existing studies focus on large-scale regions, and overlooking regional differences in smaller-scale regions to a certain extent. Therefore, to achieve a comprehensive, convenient, objective, and accurate ecological quality evaluation, this study established a model for regional ecological quality assessment through remote sensing. This model was based on the analysis of natural evolutionary features and was applied to assess the ecological quality in the largest ecosystem within the arid area of the Ningxia Hui Autonomous Region (NHAR) - the grassland ecosystem. For this assessment, the Modified soil-adjusted vegetation index (MSAVI), the wetness components of tasseled cap transformations (WET), and net primary productivity (NPP) were selected as indicators of soil and water conservation capacity, water source conservation capacity, and carbon sequestration capacity, respectively. The evaluation units were established according to the geomorphic types, and the improved derivative dynamic time warping (DDTW) algorithm was used to compare the conformity between the time series of evaluation units and natural evolution time series, pixel by pixel. The ecological quality was classified into five levels (levels 1, 2, 3, 4, and 5) using the natural breaks (Jenks) classification method. The Mann-Kendall trend test and the Sen's slope are used to analyze the trend of the conformity measurement results of the ecological quality each year at a significance level of 95%. The main results are as follows: (1) The indicators selected in the study are mostly independent of each other within each evaluation unit, with a correlation (0.552) observed only between MSAVI and WET in plain areas. (2) Spatial heterogeneity exists in the natural evolution characteristics, with significant variations in the similarity between the reference frames of different evaluation units. There is no strict rule linking the similarity results to the elevation of the terrain. (3) From the perspective of the evolutionary process and intensity, the soil and water conservation capacity, water source conservation capacity, and carbon sequestration capacity in the study area primarily fell within level 2. The advantageous level of each evaluation unit was also primarily at level 2. The overall trend of these three capacities demonstrated stability and remained constant. In summary, our assessment indicated that the overall quality of grassland ecosystems in the arid areas of the NHAR was relatively stable and superior. This method we employed has broad applicability and can serve as a general framework for ecological quality assessments. It can be adapted for ecological restoration assessments in other regions by fine-tuning regional parameters, offering valuable insights for regional ecological management.

BN O04 - Trends in the management of bile duct stones in the United Kingdom: Are we following the evidence?

Abstract Background Common bile duct stones (CBDS) are typically managed in two stages: Endoscopic Retrograde Cholangiopancreatography (ERCP) followed by laparoscopic cholecystectomy (LC). However, access to ERCP can be limited or require referral, has a high failure rate, often necessitates additional imaging, and may involve multiple procedures. Increasing evidence suggests that single-stage management, involving LC with intraoperative imaging and bile duct exploration when indicated, is cheaper, more effective, and reduces overall length of stay. British Society of Gastroenterology guidance states that it is a valid alternative to ERCP. This study aimed to determine whether clinical practice aligns with this evidence. Method National Health Service (NHS) Admitted Patient Care publications summarise Hospital Episode Statistics by financial year and are openly accessible. OPCS4 Procedure Codes were screened by two authors and categorised as “operative” or “endoscopic.” Codes detailing the management of CBDS or bile duct exploration were included, while ambiguous codes or those for non-stone indications were excluded. Data pertaining to these codes were extracted from the Admitted Patient Care publications for 2012 to 2022 and summarised in a Microsoft Excel spreadsheet. Trends were analysed using a Non-Seasonal Mann-Kendall Trend Test Results A total of 249,475 procedures for CBDS were performed over the ten-year period, with a mean patient age of 67. Annually, the total number of procedures increased from 21,365 to 27,668 (p=0.002). Endoscopic procedures increased from 19,716 to 25,976 (p=0.002), while operative procedures remained stable (1,649 to 1,692, p=0.431). Consequently, the proportion of endoscopic management rose from 92.3% to 93.9% (p&amp;lt;0.001). The mean age of patients undergoing operative procedures was ten years younger than those undergoing endoscopic procedures (57 vs. 67 years) Conclusion Despite evidence and guidance supporting single-stage procedures, there is a trend towards endoscopic management of CBDS in the UK. This may be due to operational pressures on the NHS, including the sequelae of the COVID-19 pandemic, or reflect challenges within hospital culture, skill mix, or equipment availability.

Spatial benefit assessment and marine climate response of coastal zone in Fujian Province under cross-system influence.

To gain a scientific understanding of the cross-system impact of coastal zones and promote the sustainable development and protection of coastal areas, we constructed a spatial benefit evaluation system that encompassed both terrestrial and marine systems, focusing on the ecological, economic, and social dimensions. We employed the entropy method, moving average method, and Mann-Kendall trend test to quantitatively characterize the spatial benefits of the coastal zone in Fujian Province, China, and the evolution of the marine climate from 2005 to 2020. Building on this, the grey relational analysis method was applied to investigate the correlation between spatial benefits and marine climate and to explore the trends and magnitude of the impact of marine climate on spatial benefits. During the study period, the spatial benefits of the coastal zone in Fujian Province exhibited a fluctuating pattern of an initial increase followed by a decrease, with spatial benefits varying among cities. The role of the economic system in enhancing spatial benefits was not considerable. Changes in the marine climate aligned with the global warming trend, with the most considerable changes observed in sea level and tropical cyclone frequency and intensity, which are sensitive to human activities. There was a high degree of correlation between coastal zone spatial benefits and marine climate, with seawater salinity being most closely related to spatial benefits, while tropical cyclones showed the weakest correlation. The results of this study support sustainable development efforts in coastal zones.

Quantification of streamflow response to climate change and human activities within upstream mountainous areas of the Daqing River Basin, Northern China

The Daqinghe River Basin is located in the North China Plain. In recent years, however, climate warming, drying, and intense human activities have led to declining ecosystem functions and shrinking wetlands in the region. Understanding streamflow changes in the upstream mountainous areas of the Daqinghe River Basin in this changing environment and identifying the driving factors can provide a scientific basis for water resources management and optimization in these areas. This study focuses on the Beihedian River watershed, the Xidayang Reservoir watershed, and the Wangkuai Reservoir watershed in the upstream mountainous areas of the Daqinghe River. It is based on hydro-meteorological data collected between 1963 and 2019. The methods used in the study include the linear tendency estimation method, the non-parametric Mann-Kendall trend test, the elasticity coefficient method, and hydrological simulation methods. The results of this study suggest that the streamflow, precipitation, and potential evapotranspiration (PET) in the three watersheds showed an overall decreasing trend. The minimum precipitation decrease rate ranged from −1.09 to −0.55 mm/a, and the minimum streamflow decreasing rate at the Beihedian Hydrological Station was −1.32 mm/a, with a minimum range of 0–176.03 mm. Change-point analysis revealed that the streamflow in the Beihedian River and Xidayang Reservoir watersheds experienced a significant change point around 1999, with a significant level of α=0.05. As for the Wangkuai Reservoir watershed, a significant change point was observed around 1980, which is likely attributable to land system reforms and protective forest projects. The attribution analysis which combined both climate change and human activities using the elasticity coefficient method and hydrological simulation methods indicated that climate change contributed an average of 32.93%, 34.50%, and 35.12% to the reduction in streamflow in the three watersheds, respectively. Human activities accounted for an average contribution of 67.07%, 65.50%, and 64.88%, respectively. Water conservancy projects, afforestation, and other human activities were identified as the primary factors contributing to streamflow decreases.

Detection of spatial and temporal variation characteristics of vegetation cover in the Lower Mekong region and the influencing factors

As the main component of terrestrial ecosystem, vegetation plays a very important role in regional ecosystem environmental change, global carbon cycle and climate regulation. The Lower Mekong region (LMR) is at the core of Southeast Asia, its vegetation changes will affect the regional ecosystem and climate. Five countries of LMR were selected as the study area, based on MODIS (Moderate-Resolution Imaging Spectroradiometer) NDVI(Normal Difference Vegetation Index) data from 2000 to 2022, using the Sen’s slope estimator, Mann–Kendall trend test and geographic detector to study the spatial and temporal variation trends and driving forces of vegetation coverage. The results showed that:(1) From 2000 to 2022,the vegetation coverage in the LMR showed an overall fluctuating upward trend, the annual average Fractional Vegetation Cover(FVC) value was 0.70, mainly with high vegetation coverage and relatively high vegetation coverage. Vegetation distribution had obviously spatial heterogeneity, and the vegetation of Myanmar, Laos and Vietnam was significantly larger than Thailand and Cambodia.(2) The variation trend analysis of Sen_MK showed that the proportion of improved and degraded vegetation coverage areas in the LMR were 56.33% and 37.55% respectively. The vegetation improvement area was much larger than the vegetation degradation area during 2000–2022. According to the variation trend analysis of different countries, the vegetation coverage improvement area in Vietnam, Myanmar and Thailand were larger than the degraded , the overall vegetation coverage variation trend were good. However, in Laos and Cambodia, the degraded areas were larger than the improved, the overall variation trends of coverage were not good.(3) The results of geographic detector showed that the Land Use and Land Cover(LULC) had the greatest influence on vegetation coverage in the study area.The influencing factors of vegetation coverage were different in the LMR. For Vietnam, Thailand and Laos,elevation and slope factors were second only to LULC, for Myanmar and Cambodia, the influence of precipitation factor was second only to LULC. The results provide scientific data support for understanding the ecological environment status and future changes in the research area.

Testing of UV fluorescence marking with daily recaptures of a low-mobile bush-cricket species

The primary goal of developing new mark–release–recapture (MRR) methods is to make MMR more cost-effective and able to provide more information. To test the effectiveness of UV fluorescence marking, a case study was carried out on an Isophya costata population occurring in a mown grassland with a heterogeneous vegetation pattern. The marked individuals were examined daily, from the emergence of imagos until the mowing of the habitat. The 40 marked insects (20 males and 20 females) were recaptured in 206 cases over 16 days (32.2% of the potential maximal recaptures). The finding of males was 26.2% successful, and the finding of females was 38.1% successful. Females released in shorter and sparse vegetation were recaptured more than those released in dense vegetation or than males. Recaptures showed a significant decrease during the study period in almost all groups based on Mann–Kendall trend tests. Detections were made on the upper third of the vertical structure of the vegetation in 88% of cases. In most of the detections (males: 70%, females: 62%), the axis of the insect’s body was more likely to be located vertically. The results showed that the chance of detection is significantly reduced when the position of the insect’s body is facing the axis of UV illumination. Thus, the visibility of individuals can be greatly increased by marking all sides of the body.

Quantification Analysis of Sports Momentum Based on a Multi-Index Approach and TOPSIS

This study quantifies the concept of momentum in sports, inspired by Novak Djokovic's unexpected loss in 2023, and evaluates its impact on game outcomes. Utilizing a structured multi-index approach, we categorized performance into fourteen primary and three secondary indexes. The TOPSIS model enhanced by entropy weighting, along with the Delphi model, was applied for weight assessments of these indexes. Our analysis, incorporating the Mann-Kendall trend test and Spearman correlation coefficient, revealed a significant correlation of 0.51 between momentum and match results, underscoring its pivotal role. The results contribute to a deeper understanding of momentum, enabling coaches to refine strategies and optimize performance based on dynamic changes in momentum. This study provides a comprehensive framework for quantifying momentum, with potential applications extending beyond tennis to other sports where strategic momentum management could influence outcomes.

Shifting cold regions streamflow regimes in North America affect flood frequency analysis

ABSTRACT Over threshold flood events in seventy years of data from 202 reference hydrometric stations in Canada and the United States were separated into nival, mixed, and pluvial flood types. While Mann-Kendall trend tests showed few significant trends in flood magnitude, significant changes in flood type fraction were found over time, with annual mean temperature, and with annual precipitation. Nival events decreased in frequency over the seventy-year period in 16% of sites, while mixed and pluvial events increased (5%, 12%). These changes indicate a shift from nival events towards more pluvial dominated systems. Fewer significant changes in flood type fraction were found with analysis against four climate indices. Flood frequency analysis using a combined distribution approach with the three flood types resulted in larger magnitude design flow estimates (median increase of 20 – 30 %) in comparison with the results from considering the data to be a single population.

Establishing Climate Change on Rainfall Trend, Variation and Change Point Pattern in Umuahia, Nigeria

This study investigates the prevailing conditions of changing climatic trends and change point dates in Umuahia, Nigeria, using daily annual maximum series (AMS) rainfall data spanning 31 years. The Indian Meteorological Department (IMD) was employed to downscale the time series data into durations ranging from 5 minutes to 24 hours. Mann-Kendall (MK) trend and Sen's Slope Estimator (SSE) tests revealed a statistically significant increasing trend across all durations. The Sen's Slope magnitude ranged from 0.1373 mm/year for 5-minute duration to 0.9045 mm/year for 24-hour duration, corresponding to a variation rate of 9.05 mm/decade for the 24-hour duration. Trend change-point analysis, utilizing Distribution-free CUSUM and Sequential Mann-Kendall tests, identified 2002 as the initial rainfall change-point date. These results provide robust evidence of positive changing climatic conditions for rainfall in Umuahia, indicating that non-stationary Intensity-Duration-Frequency (IDF) modelling may be more appropriate for flood risk management and urban planning in this area.

Trends in areas of Oncomelania hupensis snail habitats in Anhui Province from 2004 to 2023 based on the Mann-Kendall test

To investigate the trends in areas of Oncomelania hupensis snail habitats in Anhui Province from 2004 to 2023, so as to provide insights into facilitating the progress of schistosomiasis elimination in the province. Areas of O. hupensis snail habitats in Anhui Province from 2004 to 2023 were collected, and the trends in and mutations of O. hupensis snail habitats in Anhui Province, and the trends in O. hupensis snail habitats in different types of schistosomiasis-endemic foci and in different cities of Anhui Province from 2004 to 2023 were analyzed using Mann-Kendall test. The areas of O. hupensis snail habitats reduced by 12.62% in Anhui Province in 2023 relative to in 2004. Mann-Kendall trend test showed that the areas of O. hupensis snail habitats appeared a tendency towards a decline in Anhui Province from 2004 to 2023 (Z = -3.926, P < 0.001, β = -215.66), with an annual average reduction of 215.66 hm2. Mann-Kendall mutation test showed that the areas of O. hupensis snail habitats appeared a tendency towards a decline in Anhui Province since 2015 (|Z| > U0.05, P < 0.05). The areas of O. hupensis snail habitats appeared a tendency towards a decline in marshland and lake regions (Z = -4.899, P < 0.001, β = -260.13), and a tendency towards a rise in hilly regions of Anhui Province from 2004 to 2023 (Z = 2.758, P < 0.01, β = 44.55). Among 9 cities endemic for schistosomiasis in Anhui Province, the areas of O. hupensis snail habitats appeared a tendency towards a decline in 5 cities of Ma'anshan, Tongling, Anqing, Huangshan and Chizhou (Z = -4.056 to -2.109, all P values < 0.05, β = -92.12 to -0.45). The average constituent ratios of areas of O. hupensis snail habitats were 88.19% and 11.81% in marshland and lake regions and hilly regions of Anhui Province from 2004 to 2023, respectively, and the ratio of areas of O. hupensis snail habitats in marshland and lake regions to areas of snail habitats in hilly regions reduced from 9.23∶1 in 2004 to 5.74∶1 in 2023 in Anhui Province, with the ratio appearing a tendency towards a decline (Z = -4.477, P < 0.001, β = -0.16). The areas of O. hupensis snail habitats appeared a tendency towards a decline in Anhui Province from 2004 to 2023, with a reduction in areas of O. hupensis snail habitats in marshland and lake regions and a rise in hilly regions. Targeted O. hupensis snail control interventions are required tailored to real snail status.

Impact of climatic trends on the water demand and irrigation planning for annual crops in the São Francisco River basin, Brazil

This study evaluated the spatial distribution of precipitation (P) and Peman-Monteith reference ET (ETo) in Brazil's São Francisco River basin (1961–2022). The analysis included Mann-Kendall trend tests and future IPCC projections on P and ETo to assess the need for supplemental irrigation (SI) of maize crop over twelve hypothetical growing seasons. The average annual P in the basin was 1300 mm year−1, decreasing from the Upper to the Lower section. Annual ETo averaged 1670 mm year−1, with higher depths in the Middle and Lower-middle sections. Trends for both P and ETo were significant(p < 0.05) in 58% of the basin. The overall trend magnitude in P was positive (average of about 0.5 mm year−2). Trend was decreasing in 56% of the sites (3.2 mm year−2) and increasing in 44% of them (5.3 mm year−2). For ETo, the overall trend was also positive (average of 3.0 mm year−2), with increasing trend in 79% of the sites (4.6 mm year−2) and a decreasing trend of 3.8 mm year−2 in 21% of the area. The need of SI varied both over the year with peaks in the May–August period and over the basin with higher depths in the Middle and Lower-middle sections. Large SI values (>800 mm) were associated with the dry season and areas with persistent trends in decreasing P and increasing ETo. Future IPCC projections indicate increased SI depths in most of the basin by 2081–2100, with the Middle and Lower-middle sections facing potentially unsustainable level for crop production.

Analysis of Diurnal Air Temperature Trends and Pattern Similarities in Highland and Lowland Stations of Italy and UK

ABSTRACTIn this study, an analysis of hourly air temperatures in four groups of 32 stations from the UK highland (5 stations), UK lowland (4 stations), Italian highland (11 stations), and Italian lowland (12 stations) at different altitudes was carried out over the period from 2002 to 2021. The study aimed to examine the trends of each hour of the day during this period, over different averaging time windows (10‐day, 30‐day, and 60‐day). The trends were computed using the Mann–Kendall trend test and Sen's slope estimator. The similarity of trends within and across the groups of stations was assessed using the hierarchical clustering with dynamic time warping technique. An additional analysis was conducted to show the correlation of trends among the group of stations using the correlation distance matrix. Hierarchical clustering and distance correlation analysis show trend similarities and correlations, also indicating dissimilarities among different groups. Using 30‐day averages, significant warming trends in specific months at the Italian stations are evident, especially in February, July, August, and December. The UK highland stations did not show statistically significant trends, but clear pattern similarities were found within the groups, especially in certain months. The ultimate goal of this article is to provide insights into temperature dynamics and climate change characteristics on regional and diurnal scales.

Aerosol loading in the guinea coast climate region of Nigeria: comparison of MODIS and AERONET data sources

This study compares aerosol optical depth (AOD) measurements from satellite data with that from a ground-based station. It aims at validating monthly AOD data from the Moderate Resolution Imaging Spectroradiometer (MODIS) Deep Blue (DB) collection 6.1 (Aqua and Terra) at 550 nm against AOD data from the Aerosol Robotic Network (AERONET) station at 500 nm in Ilorin over the period 2003–2022. The analysis focuses on eight selected cities/locations within the Guinea Coast region of Nigeria. Descriptive and inferential statistical methods, including correlation, regression, standard deviation, coefficient of variation, the Mann–Kendall trend test, root mean square error (RMSE), mean absolute error (MAE), and relative mean bias (RMB), were employed. The results indicate a positive correlation in most locations, with correlation values ranging from 0.3 to 0.7. The correlation between the datasets in Ilorin showed a positive and significant relationship while the other seven locations presented a weak and insignificant relationship. Additionally, the period from 2013–2022 showed better correlation compared to 2003–2012. AOD levels were highest during the harmattan season (DJF), exceeding 0.8, and lowest during the monsoon (JJA) and post-monsoon (SON) seasons, with values below 0.5, reflecting the effects of wet scavenging. The highest agreement between MODIS Aqua and AERONET data was observed during the harmattan season. The study also found that MODIS tends to overestimate AOD compared to AERONET and that MODIS-AOD exhibits greater spread and variability than AERONET-AOD.

Efficacy of a burn prevention educational program to diminish the incidence of burn injuries in the pediatric population

BackgroundPediatric burn injuries are a significant public health issue in low- and middle-income countries, leading to substantial morbidity and mortality. This study aimed to evaluate the efficacy of the No+Quema2 educational program, implemented in Aguascalientes, Mexico, in preventing burn injuries among children under nine years old. MethodsThe No+Quema2 program, initiated in 2014, included educational courses for children, training for health workers, and specialized care for children with burn sequelae. Epidemiological data on burn injuries from 2014 to 2022 were retrieved from the National System of Epidemiological Surveillance of the Health Ministry of Mexico. Monthly incidence rates per 100,000 inhabitants were analyzed using the Mann-Kendall trend test and segmentation analysis to detect trends and changes. ResultsThe program trained over 25,000 scholars from 1750 elementary schools and distributed medical kits for immediate burn care. Additionally, 200 children with burn sequelae received scheduled treatment. The analysis showed a significant decrease in the state incidence rate of burn injuries compared to the national mean post-implementation. The estimated number of burn injuries prevented during the study period was approximately 3839, or 604 per year. ConclusionThe No+Quema2 program has made a significant impact on burn prevention among children in Aguascalientes, Mexico. Despite the limitations of relying on government-reported data, the correlation between the program's activities and the observed decrease in burn injuries is promising. These findings underscore the critical importance of the No+Quema2 program's activities in achieving sustained, targeted educational interventions and long-term reductions in burn injury incidence. They also highlight the need for more robust study designs to validate these outcomes, emphasizing the importance of evidence-based strategies in future burn prevention efforts.

Variability of seasonal temperature from 1990 to 2020 within Oum Er Rbia hydraulic basin (Morocco): Study of trends and anomalies

Abstract The fifth report of the Intergovernmental Panel on Climate Change (IPCC) indicates that global temperatures have increased during the 20th century. In Morocco, numerous studies have unveiled that the nation has been contending with the effects of global warming for several decades, attributed to its geographical location. The studies have mainly focused on the evolution of rainfall and the recurrence of droughts. Nevertheless, temperature variations remain less addressed, especially at large spatial scales. This paper aims to study the seasonal temperature variability in the large hydraulic basin of Oum Er Rbia, focusing on its anomalies and trends as well as identifying their impacts on the basin’s territory. Indeed, the large basin of Oum Er Rbia occupies more than 48,.000 km2 and is characterized by an arid to semi-arid climate. Its water resources are important and play an essential role in the country’s socio-economic development. This basin is well-known for its agricultural activity. Although its water and economic potential are significant, the great basin is considered vulnerable to climatic variations, which strongly condition its development. Considering the significance of temperature trends within the framework of global warming, this current study delves into the topic of seasonal temperature variability within the expansive hydraulic basin of Oum Er Rbia. Based on statistical analysis using the temperature anomaly index and the Mann-Kendall trend test, this study reveals that strong interannual variability marked the evolution of seasonal temperatures during the period of 1990-2020, with a remarkable upward trend during the autumn and spring. When the temperature increase, the temperature increases in turn: thus, the negative impacts affect both water resources and the agriculture sector, which suffers from the combined effect of increased evapotranspiration and reduction of irrigation water.

Fentanyl, Heroin, Methamphetamine, and Cocaine Analyte Concentrations in Urine Drug Testing Specimens

The US is experiencing a protracted drug overdose crisis primarily associated with exposure to illicitly manufactured fentanyl (IMF), methamphetamine, and cocaine. Overdose risk and treatment responses may be directly affected by absolute drug exposure concentrations and drug use prevalence. To quantify changes in absolute drug exposure concentrations from 2013 to 2023. This cross-sectional study analyzed urine drug testing (UDT) results from urine specimens collected between January 1, 2013, and August 22, 2023, in 49 states and the District of Columbia. Urine specimens were obtained from patients aged 18 years or older who presented to substance use disorder treatment clinics. The UDT was ordered by clinicians based on medical necessity. Urine specimens were analyzed for the following drugs or metabolites (analytes tested in parentheses): fentanyl (fentanyl), heroin (6-monoacetylmorphine), cocaine (benzoylecgonine), and methamphetamine (methamphetamine) using liquid chromatography with tandem mass spectrometry. Relative concentrations of fentanyl, heroin, cocaine, and methamphetamine. Creatinine-normalized drug concentration values were log-transformed prior to visualization and statistical analyses. The Mann-Kendall trend test was performed to examine trends over time. To estimate the geospatial and temporal patterns of drug concentration, a second series of models (1 for each drug) with an interaction effect for clinic location and collection year were fit. A total of 921 931 unique UDT samples were collected from patients (549 042 males [59.6%]; median [IQR] age, 34 [27-44] years). The adjusted fentanyl concentration in urine specimens was 38.23 (95% CI, 35.93-40.67) ng/mg creatinine in 2023 and 4.61 (95% CI, 3.59-5.91) ng/mg creatinine in 2013. The adjusted methamphetamine concentration was 3461.59 (95% CI, 3271.88-3662.30) ng/mg creatinine in 2023 and 665.27 (95% CI, 608.51-727.32) ng/mg creatinine in 2013. The adjusted cocaine concentration was 1122.23 (95% CI, 1032.41-1219.87) ng/mg creatinine in 2023 and 559.71 (95% CI, 524.69-597.06) ng/mg creatinine in 2013. The adjusted heroin concentration was 58.36 (95% CI, 48.26-70.58) ng/mg creatinine in 2023 and 146.59 (95% CI, 136.06-157.92) ng/mg creatinine in 2013. Drug concentrations varied across US Census divisions. This cross-sectional study found that absolute concentrations of fentanyl, methamphetamine, and cocaine in urine specimens increased from 2013 to 2023, with a decrease in heroin concentration during that period. The findings suggest that exposure to these substances, as well as the illicit drug supply, has fundamentally changed in many parts of the US, highlighting the need to reinforce surveillance initiatives and accelerate efforts to treat individuals with IMF and/or stimulant exposure.

Trends and Outcomes in Elective Pediatric Surgery During Weekends

PurposeLimited operating room availability constrains hospital scheduling capacity for elective surgical cases. Leveraging weekends for elective surgical cases could increase operative capacity but must be balanced with practical considerations. Our study aimed to characterize trends and outcomes for elective pediatric surgeries performed during weekends. MethodsThis retrospective cohort study used the Pediatric Health Information System database from 2016 to 2019 to identify surgeries in children <18 years of age from 38 hospitals. Six elective surgeries, commonly performed on the weekend, were selected for analysis. Trends in elective surgeries during weekends (Saturday or Sunday) were evaluated using the Mann-Kendall trend test. Multivariable regression models were used to compare complications and costs between weekend and weekday surgeries. ResultsOf the 233,266 elective surgeries evaluated, 357 (0.15%) were performed during weekend hours. The proportion of surgeries performed on weekends was stable over time (p = 0.65). Following adjustment for clinicodemographic and hospital-level factors, no differences were observed when comparing weekend to weekday surgeries in terms of surgical complications [adjusted Odds Ratio: 1.59; 95% Confidence Interval (CI): 0.65–3.90; p = 0.32] or mortality (n = 1 in cohort). Weekend surgeries were associated a small additional cost compared to weekday surgeries (β-coefficient $312; 95% CI: $152 to $473; p < 0.01). ConclusionElective pediatric surgeries performed during weekends were uncommon, stable in occurrence, and not associated with substantial increases in complications or costs compared to weekday surgeries. Increasing surgical capacity by extending into weekend scheduling merits further assessment of patient and provider satisfaction, unexpected human resource costs, and thoughtful case selection to ensure patient safety. Level of EvidenceIII. Type of StudyRetrospective Cohort Study.