Test Site Research Articles

Simulating Agricultural Water Recycling Using the APEX Model

Irrigation plays a vital role in many agricultural crop production regions. Drainage water recycling (DWR) is a popular irrigation water management system that collects excess water drained from cropland fields and stores it in on-site reservoirs for reuse. The efficacy of these systems varies by location, climate, irrigation frequency, and crop demands. Simulating this system would be beneficial for assessing the impact of water and land management practices on agriculture and natural resources. This study presents the development of computational algorithms for DWR simulation with the Agricultural Policy Environmental eXtender (APEX) model, along with the results for 39 testing sites where both reservoir and drainage systems are adopted. Simulating a DWR system with the revised reservoir module, the APEX model simulates irrigation water reuse ranging between 29% and 93%; sediment reduction of around 66%; nitrogen loss reduction of 23% and 73% for the mineral and organic forms, respectively; and phosphorus loss reduction of 22% and 79% for the soluble and sediment-transported forms, respectively. In conclusion, the results provided by the APEX model for sediment loss reduction align with field data, but discrepancies for nitrogen and phosphorus losses emerged from this test.

Multidisciplinary high resolution Geophysical Imaging of Pantano Ripa Rossa Segment of the Irpinia Fault (Southern Italy).

The Irpinia Fault, also known as the Monte Marzano Fault System, located in the Southern Apennines (Italy), is one of the most seismically active structures in the Mediterranean. It is the source of the 1980, Ms 6.9, multi-segment rupture earthquake that caused significant damage and nearly 3,000 casualties. Paleoseismological surveys indicate that this structure has generated at least four Mw ~ 7 surface-rupturing earthquakes in the past 2ka. This paper presents a comprehensive, high-resolution geophysical investigation focused on the southernmost fault segment of the Monte Marzano Fault System, i.e., the Pantano-Ripa Rossa Fault, outcropping within the Pantano di San Gregorio Magno intramontane basin. The project, named TEst Site IRpinia fAult (TESIRA), was supported by the University of Napoli Federico II to study the near-surface structure of this intra-basin fault splay that repeatedly ruptured co-seismically in the past thousands of years. Our imaging approach included 2D and 3D electrical and seismic surveys, gravimetry, 3D FullWaver electrical tomography, drone-borne GPR and magnetic surveys, and CO2 soil flux assessment across the surface rupture. This multidisciplinary investigation improved our understanding of the basin shallow structure, providing an image of a rather complex subsurface fault and basin geometry. Seismic data suggest that fault activity at the Pantano segment of MMFS is characterized by a near-surface cumulative displacement greater than previous estimations, calling into question earlier assumptions about the timing of its activation. Despite some challenges with our drone-mounted survey equipment, the integrated dataset provides a comprehensive and reliable image of the subsurface structure. This work demonstrates the utility of developing an integrated approach at high-resolution geophysical imaging and interpretation of fault zones with weak morphological expressions.

Mapping Soil Surface Moisture of an Agrophytocenosis via a Neural Network Based on Synchronized Radar and Multispectral Optoelectronic Data of SENTINEL-1,2—Case Study on Test Sites in the Lower Volga Region

In this article, the authors developed a novel method for the moisture mapping of the soil surface of agrophytocenosis using a neural network based on synchronized radar and multispectral optoelectronic data from Sentinel-1,2. The significance of this research lies in its potential to enhance precision farming practices, which are increasingly vital in addressing global agricultural challenges such as water scarcity and the need for sustainable resource management. To verify the developed method, data from two experimental plots were utilized. These plots were located on irrigated soybean crops, with the first plot situated on the right bank (plot No. 1) and the second on the left bank (plot No. 2) of the lower Volga River. Two experimental soil moisture geodatasets were created through measurements and geo-referencing points using the gravimetric method (for plot No. 1) and the proximal sensing method (for plot No. 2) employing the Soil Moisture Sensor ML3-KIT (THETAKIT, Delta). The soil moisture retrieval algorithm was based on the use of a neural network to predict the reflection coefficient of an electro-magnetic wave from the soil surface, followed by inversion into soil moisture using a dielectric model that takes into account the soil texture. The input parameter of the neural network was the ratio of the microwave radar vegetation index (calculated based on Sentinel-1 data) to the index (calculated based on the data of multispectral optoelectronic channels 8 and 11 of Sentinel-2). The retrieved soil moisture values were compared with in situ measurements, showing a determination coefficient of 0.44–0.65 and a standard deviation of 2.4–4.2% for plot No. 1 and similar metrics for plot No. 2. The conducted research laid the groundwork for developing a new technology for remote sensing of soil moisture content in agrophytocenosis, serving as a crucial component of precision farming systems and agroecology. The integration of this technology promotes sustainable agricultural practices by minimizing water consumption while maximizing crop productivity. This aligns with broader environmental goals of conserving natural resources and reducing agricultural runoff. On a larger scale, data derived from such studies can inform policy decisions related to water resource management, guiding regulations that promote efficient water use in agriculture.

Automated identification of earthen berms in Western US rangelands from LiDAR‐based digital elevation models

AbstractEarthworks such as earthen berms have been constructed across the western US since the late 1800s to mitigate erosion in landscapes where water is both the dominant driver of erosion and the limiting resource for biota. Berms alter hydrologic, geomorphic and ecologic processes by intercepting runoff and altering patterns of water availability in the landscape. Understanding site‐specific changes in process dynamics requires accurate mapping of berm locations and knowledge of their condition. This paper presents an automated, object‐based framework for identifying earthen berms from 1 m LiDAR‐derived digital elevation models in the western US rangelands. Geomorphon, a computer vision tool, was used to classify landforms and identify berm‐like landforms, including summits and ridges. Ten geomorphic and geometric attributes associated with each potential berm object were used to develop a machine‐learning model for distinguishing berms from natural summits and ridges. The model was trained and applied to independent test sites to identify and map berms. The mapped berms were compared with manually identified reference berms for accuracy assessment. The identification results achieved 79% to 87% recall, 82% to 92% precision and 81% to 89% F‐measure. We also explored the influence of training sample selection on model performance and conducted an analysis of attribute relative importance. The automated framework has the potential to be scaled up to larger areas in semi‐arid environments.

Space-time modeling of cascading hazards: Chaining wildfires, rainfall and landslide events through machine learning

The current study sets out to explore yearly landslide susceptibility dynamics on slopes regularly affected by fires. To do so, two yearly inventories have been generated, one for the landslides and one for the wildfires, for an area of approximately 2 km2 and for a period of 24 years. It is important to stress that space–time data-driven models employed for susceptibility assessment are relatively new, and their application so far has mostly linked landslide occurrences to the precipitation trigger and the standard morphometric characteristics of the landscape at hand. Here we also consider an additional element of disturbance to the slope equilibrium, in the form of burnt areas tested from one up to three years priors to the reference landslide occurrence time. The relevance of the wildfire spatiotemporal signal is tested as part of a multi-variate modeling procedure. The results highlight at least a 10 % performance increase when these wildfire-related predictors are featured (from an average AUC of 0.75 to 0.85 in a random forest modeling framework). The associated yearly variations in the landslide occurrence probability are translated into individual maps, stressing the extent to which the standard and static definition of susceptibility does not hold especially in the context of multiple hazards and in an urban setting such as the Camaldoli hills (Naples, Italy) we chose for our test site.

Exploring Experimental Tests concerning Liquid Hydrogen Releases

In recent years, the adoption of liquid hydrogen (LH2) has increased significantly in industrial and transport applications, driven by its low carbon footprint, thereby aiding the fight against global warming. Additionally, its high volumetric energy density, compared to gaseous or compressed hydrogen, enhances hydrogen storage capabilities. However, safety remains a major concern due to its physical-chemical properties and inherent hazardous characteristics, especially in the event of spillage scenarios. Therefore, to better understand the consequences of LH2 releases onto or into water, large-scale experimental tests were conducted by Bundesanstalt für Materialforschung und -prüfung (BAM) within the Safe Hydrogen Fuel Handling and Use for Efficient Implementation (SH2IFT) project at the Test Site Technical Safety of BAM, comprising 75 single spill events at varied release rates and orientations. While the rapid phase transition (RPT) phenomenon was not observed, self-ignition of the hydrogen-air cloud occurred, accompanied by blast wave overpressure and heat radiation, without a discernible ignition source. These findings emphasize the need for further investigation into LH2 safety. Leveraging experimental data for real-world applications provides insights into safe LH2 infrastructure implementation, laying foundational knowledge for addressing safety challenges and advancing LH2 technology.

Spatial variability of hydraulic parameters of a cropped soil using horizontal crosshole ground penetrating radar

AbstractSoil hydraulic parameters (SHP) play a crucial role controlling the spatiotemporal distribution of water in the soil–plant continuum and thus affect water availability for crops. To provide reliable information on the SHP at different scales, measurement techniques with a good spatial resolution and low labor costs are required. In this study, we used crosshole ground penetrating radar (GPR)‐derived soil water contents (SWCs) measured along horizontal rhizotubes under a controlled experimental test site cropped with winter wheat to estimate the unimodal and dual‐porosity soil hydraulic characteristics with different soil layer setups. Therefore, sequential inversion of the GPR‐derived SWCs was performed using the hydrological model HYDRUS‐1D, whereby the SWC data were either averaged prior inversion or used in a spatially distributed way. To analyze if the time‐lapse gathered GPR data contain enough information to estimate the SHP, additional synthetic studies were performed increasing the data resolution to daily GPR measurements. The results showed that the time‐lapse data contained enough information to estimate the SHP accurately. Additionally, spatially distributed soil hydraulic characteristics differed from the one estimated based on averaged SWCs derived from spatially distributed GPR data. Finally, we derived spatially resolved SHP, which can be used for 3D process rhizosphere processes and root–soil interaction modeling.

Condensate Banking Analysis Optimizes Reservoir Development in Permian Basin

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper URTeC 4044947, “Numerical Analysis of Condensate Banking and Development Optimization in the Deep Formation of the Permian Basin,” by Jichao Han, SPE, Sunil Lakshminarayanan, and Jiasen Tan, SPE, Oxy, et al. The paper has not been peer reviewed. _ In the context of unconventional reservoir development, the issue of condensate banking—a factor contributing to reduced productivity in gas condensate reservoirs when the reservoir pressure falls below the dewpoint pressure—poses a constant concern. Before implementation of any mitigation strategies, it is prudent to assess the potential of condensate banking in the future, based on the limited early production data. A specialized workflow was devised for a deep formation in the Permian Basin. This workflow aims to quantify the severity of condensate banking and subsequently optimize reservoir development strategies. Introduction Well A represents a single appraisal well situated within deep formations of the Permian Basin. With only 5 months of production data available, pressure/volume/temperature analysis and modeling identified it as a gas condensate reservoir, with the dewpoint very close to the critical point. This prompts two critical business inquiries: Are there any concerns regarding condensate banking for this well? And what are the optimal drawdown strategies tailored to this specific format surrounding the appraisal well? Model Setup and Calibration Modeling Workflow. This study uses the comprehensive simulation workflow derived from Hydraulic Fracturing Test Site 2, which can effectively handle integrated models to provide valuable insight for condensate banking analysis and reservoir development optimization (Fig. 1). Hydraulic fracture and reservoir simulations were conducted using GOHFER 3D and Navigator software, respectively. The integration of fracture and reservoir models poses a significant challenge in accurately transferring fracture geometry and conductivity information from fracture simulators to reservoir simulators. To address this challenge, an in‑house preprocessor was developed, designed to project results from the fracture simulator into the reservoir simulator seamlessly, ensuring the fidelity of complex fracture geometries. This preprocessor enables the extension or contraction of fracture geometries in proportion to reduce uncertainties imposed by production data. Additionally, fracture conductivity is determined through regional correlations among proppant concentration, net closure stress, and fracture conductivity. Model Introduction. The geological model has been simplified to enhance modeling efficiency while still meeting the project requirements. The 3D geological model adopts a layer-cake structure with a flat geostructure. To ensure accuracy, the well trajectory is adjusted to align with the desired formation. The reservoir model measures 4,000×10,000×330 ft, with a grid resolution of 200×25×10 ft. Fracture geometry is imported from the fracture simulator, while fracture conductivity is primarily determined based on proppant concentration data exported from the fracture simulator. Fracture height remains unaltered in the reservoir simulator, reflecting available geochemical measurements. A compositional simulation approach is adopted instead of a black-oil model. To improve the accuracy of pressure drop and condensate dropout predictions, the local grid refinement (LGR) approach is selected, resulting in denser grids. This approach proves superior to the dual-porosity, dual-permeability (DPDP) method.

Numerical modeling of hydro-mechanical processes during hydraulic testing of pre-existing fractures at the Grimsel Test Site, Switzerland

This study presents a fully coupled hydro-mechanical framework for modeling hydraulic shearing in a mesoscale reservoir located at the Grimsel Test Site, Switzerland. The experiment was conducted on a ductile–brittle fault embedded in low-permeable granite. We observe that normal fracture opening increases flow channel recoverably, while fracture sliding locks asperities leading to a non-recoverable increase in flow. To couple these processes, we use a poro-elasto-plastic constitutive framework and employ a permeability function that depends on several parameters, such as dilation angle, in-situ stresses, residual aperture and maximum aperture. Our results capture the recorded pressure responses well, and indicate that the permeability changes by one order of magnitude during the experiment.

Heart Shape to Fracture Distance: Characterizing Hydraulic Fracture Propagation before Hits

Summary Estimating the distance from the hydraulic fracture tip to the monitor well can be useful for fracture characterization, well spacing optimization, and preventing parent-child well interference. A heart-shaped signal is referred to as the extensional precursor of a fracture hit recorded by crosswell strain measurements and can serve as a vital tool for such estimation. This study incorporates the 3D displacement discontinuity method (DDM) to understand the impact of fracture geometry and monitor well offset on the heart-shaped signal’s characteristics. Results from numerical simulation and analytical solutions reveal a strong linear correlation between the spatial extent of the heart-shaped signal and the fracture tip distance. This relationship was further developed to predict tip distance using field data from the Hydraulic Fracture Test Site 2 (HFTS2). A reasonable approximation result from field data further validates the methodology. In addition, it is worth noting that the estimation accuracy depends on the ratio between fracture dimension and tip distance. The findings of this study offer a novel approach for real-time monitoring and characterizing hydraulic fracture propagation, which can be further used for well spacing optimization in unconventional and enhanced geothermal system reservoir development, as well as caprock integrity monitoring for carbon sequestration projects.

Estimation of Undrained Shear Strength of Soil from CPTu Data

The estimation of undrained shear strength ( ) from Cone Penetration Test with pore pressure measurement (CPTu) for two sites was investigated in this research. The CPTu cone parameters: net cone resistance ( ), excess pore pressure ( ) and effective cone resistance ( ) were used to estimate the for the two sites and the values obtained were compared with the undrained shear strength in triaxial compression ( calculated from Anisotropically Consolidated Undrained Compression (CAUC) triaxial test results. For the clayey silt site, the undrained shear strength from the CAUC tests are higher compared to the values obtained from the CPTu, and the highest correlation was obtained from the effective cone resistance parameter . For the quick clay test site, the value and were relatively the same and showed stronger correlation as compared to the clayey silt site. The measured from the cone parameter had the highest correlation. It was concluded that and yields good correlation with the CAUC results for the clayey silt and quick clay test sites respectively as compared to the other con parameters.

Analysis of the Heat Transfer Performance of a Buried Pipe in the Heating Season Based on Field Testing

Ground source heat pump (GSHP) systems have been widely used in the field of shallow geothermal heating and cooling because of their high thermal efficiency and environmental friendliness. A borehole heat exchanger (BHE) is the key part of a ground source heat pump system, and its performance and investment cost have a direct and significant impact on the performance and cost of the whole system. The ground temperature gradient, air temperature, seepage flow rate, and injection flow rate affect the heat exchange performance of BHEs, but most of the research on BHEs lacks field test verification. Therefore, this study relied on the results of a field thermal response test (TRT) based on a distributed optical fiber temperature sensor (DOFTS) and site hydrological, geological, and geothermal data to establish a corrected numerical model of buried pipe heat transfer and carry out the heat transfer performance analysis of a buried pipe in the heating season. The results showed that the ground temperature gradient of the test site was about 3.0 °C/100 m, and the temperature of the constant-temperature layer was about 9.17 °C. Increasing the air temperature could improve the heat transfer performance. The temperature of the surrounding rock and soil mass of the single pipe spread uniformly, and the closer it was to the buried pipe, the lower the temperature. When there is groundwater seepage, the seepage carries the cold energy generated by a buried pipe’s heat transfer through heat convection to form a plume zone, which can effectively alleviate the phenomenon of cold accumulation. With an increase in seepage velocity, the heat transfer of the buried pipe increases nonlinearly. The heat transfer performance can be improved by appropriately reducing the temperature and velocity of the injected fluid. Selecting a backfill material with higher thermal conductivity than the ground body can improve the heat transfer performance. These research results can provide support for the optimization of the heat transfer performance of a buried tube heat exchanger.

An Adaptive Unmixing Method Based on Iterative Multi-Objective Optimization for Surface Water Fraction Mapping (IMOSWFM) Using Zhuhai-1 Hyperspectral Images

Surface water fraction mapping is an essential preprocessing step for the subpixel mapping (SPM) of surface water, providing valuable prior knowledge about surface water distribution at the subpixel level. In recent years, spectral mixture analysis (SMA) has been extensively applied to estimate surface water fractions in multispectral images by decomposing each mixed pixel into endmembers and their corresponding fractions using linear or nonlinear spectral mixture models. However, challenges emerge when introducing existing surface water fraction mapping methods to hyperspectral images (HSIs) due to insufficient exploration of spectral information. Additionally, inaccurate extraction of endmembers can result in unsatisfactory water fraction estimations. To address these issues, this paper proposes an adaptive unmixing method based on iterative multi-objective optimization for surface water fraction mapping (IMOSWFM) using Zhuhai-1 HSIs. In IMOSWFM, a modified normalized difference water fraction index (MNDWFI) was developed to fully exploit the spectral information. Furthermore, an iterative unmixing framework was adopted to dynamically extract high-quality endmembers and estimate their corresponding water fractions. Experimental results on the Zhuhai-1 HSIs from three test sites around Nanyi Lake indicate that water fraction maps obtained by IMOSWFM are closest to the reference maps compared with the other three SMA-based surface water fraction estimation methods, with the highest overall accuracy (OA) of 91.74%, 93.12%, and 89.73% in terms of pure water extraction and the lowest root-mean-square errors (RMSE) of 0.2506, 0.2403, and 0.2265 in terms of water fraction estimation. This research provides a reference for adapting existing surface water fraction mapping methods to HSIs.

Geographical Access to Point-of-care diagnostic tests for diabetes, anaemia, Hepatitis B, and human immunodeficiency virus in the Bono Region, Ghana

BackgroundDiabetes mellitus, human immunodeficiency virus (HIV), hepatitis B and anaemia are major global public health issues according to the World Health Organization (WHO). Access to diagnostic testing is essential for their prompt detection and treatment. The WHO has recommended a list of essential in-vitro diagnostics for testing at all levels of care. However, a survey preceding this study showed limited availability of point-of-care (POC) tests for these conditions in the Bono Region (BR) of Ghana. This study assessed the geographical access to diabetes, anaemia, hepatitis B, and HIV POC testing in the BR, Ghana for targeted improvement.MethodsWe gathered the geolocated data of 137 facilities (CHPS, Clinics, healthcare centres, and hospitals) in the BR that were providing glucose, haemoglobin (Hb), Hepatitis B Surface Antigen (Hep B), and HIV POC testing services in July 2022. We used ArcGIS 10.1 to quantify the geographical access (distance and travel time) to the nearest available testing site for each test and show places with inadequate access, for targeted improvement. The journey time was calculated assuming a speed of 20 kilometres (km)/h. ArcMap 10.1 was employed to run spatial autocorrelation (Moran Index (MI)) to determine the spatial distribution of the facilities providing the tests investigated.ResultsOf the 137 facilities, the glucose test was available in 67 (49%), the Hb test in 55 (40%), the Hep B test in 44 (32%), and the HIV test in 73 (53%). The mean (standard deviation (SD)) for obtaining glucose tests in the region was 7.4 ± 3.7 km, Hb was 8.1 ± 4.06 km, Hep B was 8.2 ± 4.1 km, and HIV test was 7.3 ± 3.7 km by a motorised cycle. The mean SD travel time in the region to obtain the glucose test was 94.4 ± 47.2 min compared to 95.7 ± 47.8 min for Hb, 95.9 ± 47.93 min for Hep B, and 92.7 ± 46.3 min for the HIV test. Three districts (Berekum East, Dormaa East, and Jaman North) recorded shorter distances (< 10 km) and a shorter travel time to the glucose, Hb, Hep B, and HIV tests compared to the Banda district, which recorded more than 10 km for all tests investigated. Positive IM values were recorded for all the POC tests, suggesting that the health facilities providing the glucose, Hb, Hep B, and HIV tests in the BR were spatially distributed at random.ConclusionsThe findings revealed moderate access to all the tests in districts across the region. However, geographical access to glucose, Hb, Hep B, and HIV POC testing was poor (distance ≥ 10 km and travel time of ≥ 93 min), in the Banda district. This study showed the need to prioritise the Banda district for targeted improvement for all the tests. A further study is recommended to identify potential solutions to addressing the POC testing implementation in the BR, as demonstrated by this study.

Reduction of Multipath Effect in GNSS Positioning by Applying Pseudorange Acceleration as Weight

A novel approach is proposed to mitigate the multipath effect, considered a major source of error in global navigation satellite system (GNSS) positioning in urban areas. We utilize code pseudorange acceleration measurements as a weight in a least squares estimation process. If GNSS signals are reflected off a surrounding surface, they cause large variations in the recorded pseudorange measurement. Accelerations computed at each epoch with three consecutive pseudoranges exhibit significant fluctuations in a multipath signal. As a result, positioning accuracy improved by 75% horizontally and 79% vertically compared to not applying any weight. Even when multipath errors exist, the range acceleration (RA) value is sometimes low at many epochs. When a threshold value for the signal-to-noise ratio was additionally applied besides RA, the positioning accuracy at two test sites (including a deep urban environment) improved by more than 80% in both horizontal and vertical directions.

Tracking modifications to implementation strategies: a case study from SNaP - a hybrid type III randomized controlled trial to scale up integrated systems navigation and psychosocial counseling for PWID with HIV in Vietnam

IntroductionEvaluation of implementation strategies is core to implementation trials, but implementation strategies often deviate from the original plan to adjust to the real-world conditions. The optimal approach to track modifications to implementation strategies is unclear, especially in low-resource settings. Using data from an implementation trial for people who inject drugs (PWID) with HIV in Vietnam, we describe the tracking of implementation strategy modifications and present findings of this process.MethodsSNaP (Systems Navigation and Psychosocial Counseling) is a hybrid type-III effectiveness-implementation randomized controlled trial aiming to scale up the evidence-based intervention, integrated systems navigation and psychosocial counseling, for PWID with HIV in Vietnam. Forty-two HIV testing sites were randomized 1:1 to a standard or tailored arm. While the standard arm (SA) received a uniform package of strategies, implementation strategies for the tailored arm (TA) were tailored to address specific needs of each site. The central research team also met monthly with the TA to document how their tailored strategies were implemented over time. Five components were involved in the tracking process: describing the planned strategies; tracking strategy use; monitoring barriers and solutions; describing modifications; and identifying and describing any additional strategies.ResultsOur approach allowed us to closely track the modifications to implementation strategies in the tailored arms every month. TA sites originally identified 27 implementation strategies prior to implementation. During implementation, five strategies were dropped by four sites and two new strategies were added to twelve sites. Modifications of five strategies occurred at four sites to accommodate their changing needs and resources. Difficulties related to the COVID-19 pandemic, low number of participants recruited, high workload at the clinic, lack of resources for HIV testing and high staff turnover were among barriers of implementing the strategies. A few challenges to tracking modifications were noted, including the considerable amount of time and efforts needed as well as the lack of motivation from site staff to track and keep written documentations of modifications.ConclusionsWe demonstrated the feasibility of a systematic approach to tracking implementation strategies for a large-scale implementation trial in a low-resource setting. This process could be further enhanced and replicated in similar settings to balance the rigor and feasibility of implementation strategy tracking. Our findings can serve as additional guidelines for future researchers planning to report and track modifications to implementation strategies in large, complex trials.Trial registration: clinicaltrials.gov ID: NCT03952520 (first posted 2019-05-16).

Immune system dysfunction in personnel of chemical hazard facilities: purpose and effectiveness of immunotherapeutic drugs

Clinical signs of the presence of immune dysfunction/insufficiency, identified by questioning workers at the landfill for the storage and destruction of industrial toxic waste, were the basis for performing a screening study of immune status. This included a clinical blood test with determination of the leukocyte formula, assessment of the phenotypic status of lymphocytes for the main subpopulations, determination of the concentration in serum immunoglobulins of various classes, assessment of the migration activity of leukocytes, assessment of the microbicidal capacity of neutrophils and their ability to phagocytosis. When the examined employees were found to have more than 20% changes in the normative range of immune status parameters and the presence of combined disorders in different parts of immunoreactivity, in particular combined disorders in the cellular part of the immune system, it was the basis for conducting an in-depth stage of immunoepidemiological examination. This included determination of functional activity cellular elements of the adaptive component of immunity, assessment of the severity of autosensitization, assessment of the severity and specificity of atopic hypersensitization, assessment of cytokine status in normal conditions and in response to mitogen. When assessing the phenotypic status of immunoreactivity cells, it turned out that the absolute number of T lymphocytes (CD3+ phenotype), helper T lymphocytes (CD3+CD4+ phenotype) and killer T lymphocytes (CD3+CD8+ phenotype) was significantly reduced in the peripheral blood of test site employees (p ≤ 0.05, compared with similar indicators in the control group). On the contrary, the content of NK cells (CD3-CD56+ phenotype) tended to increase (both the absolute number and the proportion among other lymphocyte populations). Dysfunction of the cellular component of humoral immunoreactivity (a significant decrease in the absolute number of lymphocytes with the CD3-CD20+ phenotype [B lymphocytes] in the peripheral blood), as well as a significant increase in the concentration of serum IgA-class immunoglobulin and pronounced disimmunoglobulinemia in the serum of the examined individuals (compared to individuals in the control group ) indicated a predominantly inhalation method of exposure to immunotoxic industrial toxicants from the landfill on the immune system. Pathogenetically targeted immune-oriented therapy for the personnel of the test site was carried out with drugs that have thymomimetic activity (cytovir-3, thymogen) and are a means of replacement immunocorrection with a cytokine drug (genetically engineered recombinant yeast IL-2 [roncoleukin]). The established effectiveness of the immunotherapy, in particular the reduction in the incidence rate of various nosological forms of immune-related pathology among the site employees who received immunotherapy and the presence of an immunocorrective effect in the immunoactive drugs used for therapy, indicate the advisability of carrying out preventive medical measures in persons professionally exposed to xenobiotic influences as a component of improving medical provision.

Spatial and temporal characterization of Aedes albopictus oviposition activity in candidate urban settings for sterile insect technique testing in La Reunion Island

BackgroundUnderstanding of mosquito spatiotemporal dynamics is central to characterize candidate field sites for the sterile insect technique (SIT) testing, and is critical to the effective implementation and evaluation of pilot sterile male release programs. Here, we present a detailed description of Aedes albopictus (Skuse) egg-laying activity over a 6-year period in urban areas identified as potential SIT testing sites on Reunion Island.MethodWeekly entomological collections using ovitraps were carried out in residential and adjacent uninhabited habitats in two urban areas, Duparc and Bois Rouge, in the municipality of Sainte Marie, Reunion Island. Time-series data incorporating the frequency of positive ovitraps and the total number of eggs/ovitrap recorded each time at each locality during the study period from May 2013 to December 2018 were analyzed with multifaceted statistical approaches including descriptive statistics and spatiotemporal analyses incorporating the role of climatic factors on overall ovitrap productivity.ResultsDuring the ovitrap survey, the proportion of egg-positive ovitraps differed among study sites (χ2 = 50.21, df = 2, P < 0.001), being relatively lower in Duparc (89.5%) than in Bois-Rouges (95.3%) and the adjacent buffer zone (91.2%). Within each neighborhood, Ae. albopictus egg abundance varied by month in a roughly seasonal pattern marked by a single peak occurring more regularly February each year, a decline at the onset of the austral winter in July, followed by a period of lower ovitrap productivity in August and September. Fluctuation in both positivity rate and eggs densities per ovitraps were related to annual and seasonal variations in local temperature and rainfall (P < 0.001 in all cases). The spatial analysis also captured substantial between- and within-habitats heterogeneity, whereby the overall ovitrap productivity was higher in residential areas than in the buffer zone.ConclusionsCollectively, these results reveal that the distribution of Ae. albopictus oviposition activity is shaped by local habitat heterogeneity and seasonal climatic factors. Overall, this study provides baseline insights into the reproductive dynamics of Ae. albopictus, which would assist in planning locally tailored SIT interventions, while addressing concerns related to focal areas of high egg-laying intensity and potential immigration of females from natural areas.

The Effect of Flame Sterilization on the Microorganisms in Continuously Cultivated Soil and the Yield and Quality of Tobacco Leaves

Flame disinfection is a new technology that uses high temperatures to kill pathogens and control soil-borne diseases. In order to determine the feasibility of applying flame disinfection technology to flue-cured tobacco, a field experiment was conducted in Pianpo Village (test site I) and Lühuai Village (test site II), Luquan County, Yunnan Province. The effects of flame disinfection on soil-borne disease control, flue-cured tobacco growth agronomic traits, the tobacco yield and quality, and the soil microbial community in the flue-cured tobacco field were investigated. The results were as follows. (1) After flame disinfection, the control rates of the four main soil-borne diseases—black root rot, root rot, wilt, and root knot nematodes—were all over 70%. (2) Samples were taken from the experimental site of Pianpo Village at 0 and 114 days after disinfection (tobacco boom period) to study the effects of soil microbial communities by high-throughput sequencing. Compared with the control group, after 0 days of flame disinfection, the abundance of bacterial actinobacteria, Nocardia, Streptomyces, and fungal ascomycetes decreased, while the abundance of bacterial Proteobacteria, Bacteroidetes, Arthrobacter, and mycospora increased. After 114 days of disinfection, the abundance of bacterial actinobacteria, Proteobacteria, chloromyces, and fungal ascomycetes decreased. The abundance of Mortierella was recovered, the abundance of Gibberella and Fusarium increased, and the abundance of Trichospora and Basidiomycetes decreased in both periods. (3) After flame disinfection treatment, the tobacco yield in the two experimental areas was increased by 50.80% and 54.70%, respectively, and the proportion of high-quality tobacco was also increased. In conclusion, flame disinfection before tobacco planting can improve the soil conditions, effectively control soil-borne tobacco diseases, and improve the quality and yield of tobacco leaves.

Microbiota of spring wheat seeds grown within the contrasting agroclimatic conditions of the Tyumen region

Relevance. Pathogenic microbiota of seed grain can cause death of seedlings, root rot, weakening of plants and a decrease in yield. Monitoring of seed grains pathogens infection rate is always relevant because the composition of the microbiota is dynamic due to the influence of natural and anthropogenic factors.Methods. Phytopathological analysis of spring wheat seeds grown at the state variety testing sites of the Tyumen region was carried out in contrasting years: cool and excessively moist in July 2015 and hot with moderate rainfall in 2016. We used the “wet chamber” method. 144 samples were analyzed.Results. Fungus of the genus Alternaria were the most abundant representatives of the grain microbial community. Average infection rate of seed samples with fungi Alternaria spp. was 49.5%. No differences were found by year of the study. In 2015 compared to 2016, higher prevalence of fungus of the genus Fusarium (4.8% vs. 1.6%) and bacteria (5.7% vs. 0.7%) was observed in the seed material. The maximum indicators of Fusarium infestation were observed in samples from Nizhnetavda variety testing site located in the subtaiga zone – up to 30% (variety Ikar). In 2016 compared to 2015, higher infection of seed material with helminthosporiose (7.1% vs. 2.6%) and mold fungi (2.3% vs. 0.2%) was observed. The prevalence of Bipolaris sorokiniana fungi was the highest in wheat samples grown in the northern forest-steppe zone, especially samples from the Yalutorovsky variety testing site — the limit value was 27% (variety SKENT-3). Harmfulness fungus of the genus Alternaria was significantly lower compared to other key representatives of grain microbiota. The average score of seedling damage was 1.4 vs. 2.2–2.6, seed germination indices — 94.1% vs. 53.2–67.4%.