Laboratory Conditions Research Articles

Multiple-biomarker approach in the assessment of bisphenol A effect on the grooved carpet clam Ruditapes decussatus (Linnaeus, 1758)

BackgroundBisphenol A (BPA), a plastic additive monomer, is among the most highly produced chemicals worldwide, and is broadly used in many industries, such as food and beverage containers, milk bottles, and paper products. Previous studies demonstrated that BPA has potential toxicity to aquatic organisms, causing endocrine disturbance and behavioural disorders. The current work aimed to determine the toxic impacts of BPA on the edible marine clam Ruditapes decussatus considering a multi-biomarker approach (mortality, biochemical studies, DNA strand breaks using comet assay, and histopathological examinations with semi-quantitative and quantitative histopathological analyses). The clams were exposed under laboratory conditions to three concentrations of BPA (0 “control”, 1, and 5 µg/L) for a period of 21 days. After the exposure period, BPA impacts were assessed in the digestive gland as a versatile and environmentally relevant organ for ecotoxicological studies.ResultsIn BPA-treated clams, mortality (10%) occurred only at the highest BPA concentration (5 µg/L). Biochemical impairments were detected in a concentration-dependent manner as a consequence of BPA exposure. There were significant increases in malondialdehyde (MDA) and glutathione (GSH) levels, while catalase (CAT) activity was significantly reduced. Our results revealed that BPA induced neurotoxicity in R. decussatus, as evidenced by the inhibition of acetylcholinesterase (AChE) activity in a dose-dependent manner. Furthermore, DNA damage was strongly induced as BPA levels increased. Additionally, our results have been affirmed by alterations in digestive gland tissues at BPA treatments, which consequently can impair the clam’s ability for food absorption; these alterations included mainly atrophic and necrotic digestive tubules, epithelial cell vacuolization, hemocyte infiltration, and intertubular fibrosis. Based on the data obtained from the semi-quantitative and quantitative histopathological analyses, the exposure of the clam’s digestive gland to BPA with concentrations of 1 and 5 µg/L for 21 days showed significant histopathological alterations compared with the control clams.ConclusionThe multi-biomarker approach used in the current study proved to be a useful tool for assessing the impact of diphenylmethane compounds, such as BPA. Water-borne BPA causes oxidative stress, neurotoxicity, genotoxicity, and deleterious effects on the clam digestive gland; all of these could deteriorate clam performance and health, causing tissue dysfunction.

A thermal infrared imaging observation system for the measurement of overland flow velocities under controlled laboratory conditions

Flow velocity is an important physical parameter in characterizing the hydraulics of water flow. The accurate measurement of overland flow velocities has great significance for understanding and modeling sediment transport and soil erosion. In this study, a Thermal Infrared Imaging Observation System (TIIOS) based on thermal infrared imaging techniques and computer vision recognition technology was established to measure overland flow velocities under controlled laboratory conditions. TIIOS has three subsystems including thermal tracer control, image acquisition and transmission, and image storage and processing. It can be used to dynamically monitor changes in shallow flow velocity by means of automatic control of thermal tracer, instantaneous image acquisition, image correction, noise removal and centroid determination. The observation precision was high with a standard deviation of 0.004 m·s−1 for flow velocity, a temporal resolution of 1/9th s, and a spatial resolution of 2 mm. The new system achieved higher accuracy compared to the traditional dye tracing and salt tracing techniques in observing the dynamic transport process of thermal tracer movement. The relative errors of the centroid velocity measured by the TIIOS ranged from −9.83 % to 6.40 %; whereas the relative errors of centroid velocity measured by salt tracer ranged from −21.36 % to 17.22 %. Measurements by the established TIIOS under different hydraulic conditions demonstrate that the relative errors of the centroid velocity are all smaller than those of the leading-edge velocity. This observational system provided a reliable way to measure shallow flow velocity for better understanding the mechanisms of water erosion processes and showed its potential to be used in field experiments under natural conditions.

Effect of neonicotinoid and fungicide strobilurin in neotropical solitary bee Centris analis

The indiscriminate use of pesticides is one of the factors directly impacting bee populations. However, limited information is available on the pesticide effects on solitary bees, especially in Neotropical countries. In this scenario, this study evaluated the survival and histopathological effects caused by the neonicotinoid insecticide acetamiprid (7 ng/μL) and the fungicide azoxystrobin (10 ng/μL) in the midgut and parietal fat body of the solitary bee Centris analis. Female and male newly-emerged bees were orally exposed for 48 h to the pesticides, or alone or in combination, under laboratory conditions. The exposure to the insecticide reduced the survival of males, while the mixture reduced survival in both sexes. Acetamiprid promoted a reduction in the number of regenerative nests in the midgut, alterations of fat body cells by increasing carbohydrates in trophocytes, and reduction of oenocyte size, and increased the frequency of pericardial cells in the advanced activity stage. Both pesticides caused changes in HSP70 immunolabelling of midgut from males at the end of pesticide exposure. Comparatively, the effects on males were stronger than in females exposed to the same pesticides. Therefore, acetamiprid alone and in mixture with fungicide azoxystrobin can be harmful to males and females of Neotropical solitary bee C. analis showing lethal and sublethal effects at a concentration likely to be found in the environment.

Toxicity evaluation of imidacloprid 17.8% SL against poplar defoliator Clostera cupreata (Butler) (Lepidoptera: Notodontidae)

Poplar (P. deltoides) is a major agroforestry species that plays a significant role in the socio-economic development of farmers in Northwestern India. The poplar leaf defoliator, Clostera cupreata, is a major insect pest of poplar, occurring in serious proportions and causing significant growth loss to the trees. In pursuit of chemical management for the poplar defoliator, Imidacloprid 17.8% SL was evaluated for its median lethal toxicity (LC50) against C. cupreata. The LC50 was calculated as 0.0017% at 72 hours after treatment (HAT) against third instar C. cupreata larvae under laboratory conditions. The screening process for the toxicity of Imidacloprid against C. cupreata may provide a crucial step for the development of novel insecticides for managing forestry insect pests.

Nucleation-assisted microthermometry: A novel application to fluid inclusions in halite

Halite deposits have long been utilized for interrogating past climate conditions. Microthermometry on halite fluid inclusions has been used to determine ancient water temperatures. One notable obstacle in performing microthermometric measurements, however, is the lack of a vapor bubble in the single-phase liquid inclusions at room temperature. (Pseudo-) isochoric cooling of the inclusions to high negative pressures, far below the homogenization temperature, has commonly been needed to provoke spontaneous vapor bubble nucleation in the liquid. High internal tensile stress in soft host minerals like halite, however, may induce plastic deformation of the inclusion walls, resulting in a wide scatter of measured homogenization temperatures. Nucleation-assisted (NA) microthermometry, in contrast, employs single ultra-short laser pulses provided by a femtosecond laser to stimulate vapor bubble nucleation in metastable liquid inclusions slightly below the expected homogenization temperature. This technique allows for repeated vapor bubble nucleation in selected fluid inclusions without affecting the volumetric properties of the inclusions, and yields highly precise and accurate homogenization temperatures.In this study, we apply, for the first time, NA microthermometry to fluid inclusions in halite and we evaluate the precision and accuracy of this thermometer utilizing (i) synthetic halite crystals precipitated under controlled laboratory conditions, (ii) modern natural halite that precipitated in the 1980s in the Dead Sea, and (iii) Late Pleistocene halite samples from a sediment core from Death Valley, CA. Our results demonstrate an unprecedented accuracy and precision of the method that provides a new opportunity to reconstruct reliable quantitative temperature records from evaporite archives.

Automated detection of physical fatigue in transportation maintenance workers through physiological and motion data

Lifting bags of dry concrete mix has caused significant physical fatigue and work-related musculoskeletal disorders (WMSDs) in transportation maintenance workers. Detection of physical fatigue can effectively prevent developing WMSDs. However, there lacks studies exploring the automated detection of physical fatigue in transportation activities. Additionally, previous efforts on physical fatigue detection, primarily focused in the construction sector, may not be directly applicable to transportation activities, due to different activity duration, intensity, and frequency. Also, prior detection methodologies have been examined under laboratory conditions, and their efficacy in real-world environments remains unverified. Therefore, this study explored physical fatigue detection methods by conducting field experiments with 29 transportation maintenance workers lifting bags of dry concrete mix in a highway maintenance facility. Participants’ physical fatigue levels were measured using electromyography (EMG), electrodermal activity, and/or heart rate (HR) and motion data with different machine learning algorithms. Results indicated that the Fully Connected Neural Networks algorithm can achieve the highest accuracy (87.84%) with EMG, HR, and motion data for classifying physical fatigue levels in transportation maintenance workers. This study demonstrated the feasibility of automated physical fatigue detection, which can be implemented as a monitoring tool of physical fatigue for enhancing health of transportation practitioners.

Electrochemical and Photoelectrochemical Reduction of Carbon Dioxide on Ruthenium-Cultured Bacterial Biofilms

Most of the bacterial species form biofilms, in which microorganisms are attached to a surface and they are held together by extracellular polymeric substances that they produce. They tend to grow almost everywhere both on living or non-living surfaces. Biofilms are able to propagate charge within their structures and to transfer effectively electrons at interfaces, as well as they could exhibit electrocatalytic properties (e.g. in Microbial Fuels Cells). The application of microbes provides better flexibility: experiments with fuel cells can be operated at normal conditions (temperatures and pressures). Wide variety of microbial metabolic pathways gives the possibility to use aggregates of bacteria in diverse processes. Proposed electrochemical studies using bacterial biofilms (in the form of thin coatings on the glassy carbon electrodes) can be considered as an attempt to find efficient methods of using the energy produced by microorganisms and converting it to electricity.The ultimate goal of the present research has been to determine whether it is possible under laboratory conditions to perform electrocatalytic processes using the hybrid (composite) layers composed of aggregates of bacteria in pristine or modified forms. A biofilm formed by a strain of Yersinia enterocolitica (Y. enterocolitica) is characterized by a high physicochemical stability over a wide pH range (4-10) and temperatures (0-40°C).The subject of interest is a fairly complex reaction, electroreduction of carbon dioxide. There has been growing interest in the search of electrocatalytic anf photoelectrochemical systems capable of efficient conversion of carbon dioxide into fuels and utility chemicals. Our previously performed studies have clearly shown that the Y. enterocolitica biofilm itself has no activity with respect to reduction of CO2, however it acts as a good matrix for the catalytic (e.g. noble metal or metaloorganic) centers, because it affects the reaction mechanism and appears to decrease overpotential of the electroreduction processes. The conducted research shows that the composite materials containing bacterial biofilms can be successfully used to construct systems that have an electrocatalytic reactivity in the reduction of carbon dioxide. We will also address the possibility of dispersing the organometallic ruthenium (II) complex in the biological layer (biofilm). Indeed, the ruthenium (II) complex has been immobilized in the biofilm matrix by successive modification of the liquid medium (Luria-Bertani medium) for culturing bacteria with a solution of the complex compound. In addition, the biological matrix was used (along with the ruthenium (II) complex molecules dispersed in its layer) as a protective coating, stabilizing the unstable p-type semiconductor - copper (I) oxide. The proposed hybrid co-catalytic system showed activity during the photoelectrochemical reduction of carbon dioxide and stability under semi-neutral experimental conditions. Finally, we are going to address the design of the above-mentioned catalytically active systems emphasizing the need to control the structure of the studied hybrid materials (in addition to their stability). Among important issues is the viability of bacteria in the biological membrane as well as elucidation of the role of the bacterial biofilm during the carbon dioxide reduction.

Nanopix-v1: A compact miniaturized coded-aperture gamma imager

This article explores the complex challenges associated with detecting and identifying radioactive hotspots in the nuclear industry using gamma cameras. Gamma cameras facilitate the localization of radioactive hotspots by overlaying a visualization of radioactivity onto a visible image. In the nuclear industry, gamma rays are observed in an energy range spanning from 59.5 keV (Am-241) to 1.3 MeV (Co-60).The motivation for this exploration stems from a specific challenge: characterizing hot-cells inaccessible to human operators. At the ORANO La Hague radioactive waste reprocessing plant, access to these restricted regions is possible through apertures with diameters ranging from 8 to 10 cm. In collaboration, the Nanopix-v1, characterized by its compact form as a coded mask gamma imaging system, with dimensions of 8 × 5.1 × 4.3 cm³ and a mass of 268 g, was developed through the synergistic efforts of CEA List and X-ray Imaging Europe (XIE) in partnership with ORANO.This article conducts a detailed examination of the laboratory and in situ performance of the Nanopix-v1, carried out within the challenging operational environment of the La Hague radioactive waste reprocessing plant. The focal point of the article is a comprehensive exploration of the technological components supporting the Nanopix-v1, along with an explanation of the coded mask imaging localization methodologies that underpinned the rigorous evaluation process. The performance of the gamma camera is evaluated through a series of carefully conducted trials, aimed at evaluating the angular resolution and minimum measurement time, including laboratory conditions, experimentation within a metrological Cs-137 irradiator, and practical implementation at the ORANO La Hague site.

Cryopreserved apoptotic mesenchymal stromal cells retain functional efficacy in suppressing an allergic inflammation in a murine model.

Mesenchymal stromal cell (MSC) apoptosis is required for in vivo immunosuppression. However, the induction of apoptosis is heavily dependent on the recipient's immune system. In graft-versus-host disease (GvHD), patients who fail to respond to MSCs are in fact those whose immune cells are unable to induce MSC apoptosis ex vivo. The information is critical to explain why responses in clinical trials vary even though the same sources of MSC products are infused. More importantly, it highlights the need for an alternative MSC treatment for the nonresponders. By using a mouse model of ovalbumin (OVA)-induced allergic inflammation, we demonstrated that we could generate apoptotic MSCs (ApoMSCs) in vitro and use them to successfully reduce allergic airway inflammation. In order to address the logistics of their potential future clinical application, we have shown that ApoMSCs could be cryopreserved without impairing efficacy compared to freshly generated ApoMSCs. We have also highlighted that MSCs need to undergo complete apoptosis before cryopreservation to retain their immunosuppressive activity. The cryopreserved ApoMSCs could serve as a potential future off-the-shelf cellular product, in particular for patients who suffer from inflammatory conditions yet do not harbor the immune capacity to induce MSC apoptosis in vivo. Our data provide proof-of-concept that under laboratory conditions, ApoMSCs can be successfully frozen and thawed without affecting their anti-inflammatory activity, as tested in a murine model of allergic inflammation.

Phosphorus and selenium compounding mitigates Cr stress in peanut seedlings by enhancing growth homeostasis and antioxidant properties.

Peanut is an economically important crop, but it is susceptible to Cr contamination. In this study, we used peanut as experimental material to investigate the effects of exogenous P, Se interacting with Cr on the nutrient growth and antioxidant system of peanut seedlings by simulating Cr (0μM, 50μM, and 100μM) stress environment. The results showed that exogenous P, Se supply could mitigate irreversible damage to peanut seedlings by altering the distribution of Cr in roots and aboveground, changing root conformation, and repairing damaged cells to promote growth. When the Cr concentration is 100μM, it exhibits the highest toxicity. Compared to the control group P and Se (0 MM), the treatment with simultaneous addition of P + Se (0.5 + 6.0) resulted in a significant increase in root length and root tip number by 248.7% and 127.4%, respectively. Additionally, there was a 46.9% increase in chlorophyll content, a 190.2% increase in total surface area of the seedlings, and a respective increase of 149.1% and 180.3% in soluble protein content in the shoot and roots. In addition, by restricting the absorption of Cr and reducing the synthesis of superoxide dismutase SOD (Superoxide dismutase), CAT (Catalase), POD (Peroxidase), and MDA (Malonaldehyde), it effectively alleviates the oxidative stress on the antioxidant system. Therefore, the exogenous addition of P (0.5 MM) and Se (6.0 MM) prevented the optimal concentration of chromium toxicity to peanuts. Our research provides strong evidence that the exogenous combination of P and Se reduces the risk of peanut poisoning by Cr, while also exploring the optimal concentration of exogenous P and Se under laboratory conditions, providing a basis for further field experiments.

Biology of Major Insect Pests of Carnation

Caranations are among the most popular commercial cut flowers. Among the insect pests attacking carnation, two spotted spider mite Tetranychus urticae Koch and bud borer Helicoverpa armigera (Hübner) were studied under laboratory conditions at the Department of Entomology, Dr Y S Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh, India during 2021. Total developmental/ period of T. urticae lasted for 12.10 days. The growth parameters revealed that the gross reproductive rate, net reproductive rate (R0 ), true generation time (T) and finite rate of natural increase (λ) was 91.24 eggs/ individual, 81.20 eggs/ individual, 18.73 days and 1.26 females/ day, respectively for T. urticae. The intrinsic rate of increase (r) was 0.23 females/ female/ day. Total developmental/ period for H. armigera was 32.12 days; its growth parameters revealed that the net reproductive rate (R0 ) was 37.40 offsprings/ individual, intrinsic rate of increase (r) was 0.10 females/ female/ day and finite rate of natural increase (λ) was 1.10 females/ with generation time (T) being 37.94 days.

The influence of abiotic factors on the development of caterpillars of the chestnut transient moth (Cameraria ohridella Deschka & Dimic) in laboratory conditions

Goal. To investigate the effect of abiotic factors on the duration of development of the caterpillars of the chestnut transient moth, and the ability of the caterpillars to penetrate another leaf of bitter chestnut in laboratory conditions. Methods. In laboratory conditions, experiments were conducted to determine the duration of development of moth caterpillars at temperatures of 15, 20, 25, 30°C, with and without illumination. Chestnut moth caterpillars of different ages were previously selected in natural conditions. In the laboratory, they were placed in thermostats according to their age (10 specimens each), and kept at the appropriate temperature until pupation. To test their ability to re-penetrate the leaves, caterpillars of different ages were removed from the primary leaf and planted on another. Artificial lighting was applied (round the clock) using 4 fluorescent lamps PHILIPS TLD18W/54-765 with a power of 18 W. The experiment was repeated 10 times. Accounting was carried out daily. Statistical processing of data was carried out according to generally accepted methods. Results. During the experiment, it was determined that moth caterpillars are not able to re-enter another chestnut leaf. During the study of the influence of abiotic factors on the duration of the development of caterpillars, it became known that under a temperature regime of 15°C and without lighting, their survival is significantly lower than with lighting. In conditions of complete darkness, 24.4% of the pest was frightened, and with lighting — 58.8%. At the same time, the results of the experiment also showed the importance of the effect of the temperature regime on the maintenance of these insects. Thus, the greatest death of caterpillars was recorded at a temperature of 15°C, when the temperature increased to 20—25°C, this indicator gradually decreased, but when the holding temperature increased to 30°C, the death rate increased again. Thus, we came to the conclusion that it is possible to keep the chestnut moth in laboratory conditions only during the period of its seasonal activity in nature. It is at this time that it becomes possible to study it more thoroughly, and to search for ecological means to reduce the number of chestnuts. Conclusions. Chestnut moth caterpillars are not able to re-enter another chestnut leaf, and their full development is possible only inside mines, where there are optimal conditions for this. The greatest mortality of young caterpillars in laboratory conditions was observed at storage temperatures of 15 and 30°С. The optimal temperature regime for this stage of pest development is 20—25°C. Therefore, keeping these caterpillars in laboratory conditions is effective only during the period of their seasonal activity in nature.

Разработка технологии получения безлактозного молока методом диафильтрации

Abstract. The purpose. The research is aimed at solving the problem related to the development of technology for producing an environmentally friendly product of animal origin – lactose-free milk. This will solve the problem of consumption of milk and dairy products by people who do not tolerate milk sugar for physiological reasons. Analyzing, on the basis of a literary review, the current state of the issue of lactose-free milk production, it can be concluded that existing technologies have certain disadvantages due to changes in the composition of the initial product, or the significant complexity of the technological chain. The proposed development is based on a method of milk diafiltration consisting of several repetitive cycles. The cycle consists in the separation of milk by the ultrafiltration process into permeate (aqueous lactose solution) and concentrate (proteins, fat, lactose residues). Then pure water is added to the concentrate in a volume equal to the volume of the discharged permeate. For a scientifically based approach to the development of the proposed technology, it is necessary to conduct a study of ultrafiltration separation of milk, obtain optimal operating parameters of the process, determine the change in permeability and selectivity of membranes from lactose concentration, consider the possibility of obtaining lactose-free milk with different mass fraction of fat, determine the number of cycles of the membrane diafiltration process. Research methods. The study of the process of ultrafiltration separation of milk was carried out in laboratory conditions on a membrane installation using organic and inorganic membranes. The experiments determined the main characteristics of ultrafiltration membranes – permeability and selectivity, with varying parameters (parameter range: P = 0.15…0.5 MPa, t = 35…65 °C). Results. Based on the experimental data obtained, by processing them and optimizing the parameters, optimal modes of the milk separation process by ultrafiltration were obtained. The following parameters are defined: the velocity of the product in the supramembrane space, the operating pressure of the separation process, its temperature. The preferred ultrafiltration membranes for the membrane-milk system have been selected. Scientific novelty. To develop a technology for producing lactose-free milk, for the first time a number of studies and experiments were carried out, such as changing the permeability and selectivity of membranes from the concentration of lactose, obtaining lactose-free milk with mass fraction of fat the number of cycles of the membrane diafiltration process was determined.

Эффективность лактулозусодержащей добавки при выращивании баранчиков

Purpose. To study lactulose-containing prebiotic feed additives in feeding Kalmyk fat-tailed rams, evaluate their effect on growth and development indicators, and determine the physiological state of animals when they are used. Materials and Methods. LLC "Baska" of Yustinsky district of the Republic of Kalmykia was chosen for the experiment. The experimental part of the work was conducted on 45 rams of Kalmyk fat-tailed breed, selected according to the principle of pair-analogs in three groups of 15 animals each. The animals in the first group (control group) received general economic ration (OR); the second group – OR + feed additive "Lactumin-1" at a dose of 0.6% of the weight of concentrates; the third group – OR + feed additive "LactuSuper" at a dose of 0.5% of the weight of concentrates. The conditions of the experimental young animals were the same for all experimental groups and corresponded to the generally accepted zootechnical and veterinary norm. The study of blood parameters was carried out in the conditions of Complex Analytical Laboratory of VRIMMP (Volgograd) using analyzers URiT-3020 Vet Plus (China) and URiT-800 Vet (China), lysozyme, bactericidal and phagocytic activity – using the methods of Dorofeychuk V.G. and Fedyuk V.V. In order to study the effect of lactulose-containing feed additives on the live weight of experimental animals, the rams were individually weighed every 30-31 days. The results obtained during the experiment and laboratory conditions were processed using mathematical and statistical methods by calculating the reliability criterion (Student-Fisher method) in the Statistica 10.0 program. Results. Addition of lactulose-containing additives to the diet had a positive effect on blood parameters, contributed to the improvement of the natural immunity of animals and an increase in live weight: at the age of 4 months the content of total protein in the rams blood of I and II groups increased by 1.63% (P≥0.95) compared to the control group, lysozyme activity – by 1.4 and 2.7% (P≥0.95), bactericidal – by 0.37 and 1.24%, phagocytic – by 3.39% (P≥0.95) and 4.7% (P≥0.99), live weight – by 4.93% (P≥0 .99) 7.56% (P≥0.999); at the age of 6 months the amount of total protein was greater by 1.63 and 3.29% (P≥0.95), lysozyme activity – by 1.88 and 2.84% (P≥0.95), bactericidal activity – by 0.59 and 1 .42%, phagocytic – by 1.54% (P≥0.95) and 3.98% (P≥0.99), live weight – by 2.39% (P≥0.95) 4.36% (P≥0.99), respectively. Conclusion. Lactulose-containing feed additives had a beneficial effect on blood biochemical parameters, increased the level of natural immunity of animals, and contributed to an increase in meat productivity of rams.

Biology of fall armyworm (Spodoptera frugiperda) infesting sugarbeet (Beta vulgaris)

The potential for damage caused by the maize fall armyworm (FAW) varies considerably, ranging from 9.0–62.5% across different seasons and regions in India. This poses a significant threat to the food and nutritional security of numerous farmers in the country. Notably, the FAW has been identified as a new host for sugarbeet, marking the first instance of such an occurrence. A comprehensive examination of the fall armyworm's behaviour in this new host was conducted. The infestation of the FAW in sugarbeet commenced during the seedling stage and persisted until the harvesting phase. During the initial seedling stage, larvae within the rhizosphere region induced defoliation of leaves and inflicted damage to the collar region. This led to the drying of the central shoot, mirroring the symptoms of dead heart, although no scraping symptoms were observed. As the plants entered the vegetative stage, they experienced further defoliation and wilting. In terms of its life cycle, the FAW exhibited distinct stages. The egg stage lasted around 3.2 ± 0.17 days. Larvae generally underwent 6 instars, with durations of 3.8 ± 0.65 days, 3.2 ± 0.90 days, 2.9 ± 0.14 days, 3.1 ± 0.36 days, 3.6 ± 0.24 days, and 6.8 ± 0.74 days for the first to sixth instars, respectively. The overall larval period ranged from 19 to 25 days, with an average of 23.4 ± 3.20 days. The pupal and adult stages lasted approximately 9.3 ± 1.80 days and 11.1 ± 1.94 days, respectively. Consequently, the complete life cycle of the fall armyworm in the sugarbeet, as observed under laboratory conditions, spanned approximately 43.8 ± 6.94 days.

Эффективность протравливания семян тритикале препаратами защитного действия в Приамурье

Abstract. The purpose is to establish a productive seed disinfectant for spring triticale varieties with a protective and stimulating effect. During field experiments methods were used that tested pesticides and determined the economic efficiency of using research results in agriculture. The relevance and national and economic significance of the development is determined by farmers’ demand in the extreme conditions of the Far East to increase the efficiency of treating triticale seeds, identifying protective agrochemicals against a complex of diseases that help to improve biological and economic indicators when cultivating triticale. The scientific novelty of research is associated with the establishment of effective agrochemicals to protect seedlings from pathogens of the genus Fusarium and reduce grain losses of spring triticale varieties in years of different meteorological conditions. Results. Biological effectiveness of agrochemicals against fungal diseases Fusarium spp., Alternaria spp. and B. sorokiniana was revealed in laboratory conditions. High biological effectiveness was reveled for “Maxim”, average – for “Kinto Duo” and low – for “Inshur Perform”. The greatest effect from treating seeds with agrochemicals was in Ukro variety, followed by Karmen and Yarilo. Significantly high effectiveness of agrochemicals “Maxim” and “Kinto Duo” against strains of fungi from the genus Fusarium in field conditions was revealed on seedlings of Ukro and Yarilo varieties. The prevalence of diseases in triticale seedlings depended by 24.1 % on year conditions, by 7.7 % on genotype and by 42.3 % on agrochemicals. Fungicidal seed disinfectants “Kinto Duo” and “Maxim” (2 l/t) confirmed the effect declared by the manufacturers and statistically significantly surpassed the seed disinfectant “Inshur Perform” (0.5 l/t) in biological effectiveness and positive effect on grain yield of triticale varieties. They contributed to obtain grain yields that significantly exceeded the control level by 0.3 and 0.33 t/ha. Their conditionally net income in comparison with the option without a fungicides reached +3298.8 and +2314.1 rubles/ha, respectively.

Tunnel System Made by the Long-Clawed Shrew in a Laboratory Condition

Tunnel System Made by the Long-Clawed Shrew in a Laboratory Condition

One Genome, Multiple Phenotypes: Would Rhodnius milesi Carcavallo, Rocha, Galvão & Jurberg, 2001 (Hemiptera, Triatominae) Be a Valid Species or a Phenotypic Polymorphism of R. neglectus Lent, 1954?

Species of the Rhodnius genus have a complex taxonomy because the events of phenotypic plasticity and cryptic speciation make it difficult to correctly classify these vectors. During the taxonomic history of the genus, five synonymization events occurred. Additionally, some authors suggest that R. milesi possibly represent only phenotypic polymorphisms of R. neglectus. Thus, we analyzed the specific status of R. milesi in relation to R. neglectus using phylogenetic studies with the mitochondrial gene cytochrome B and the study of reproductive barriers. The phylogenetic reconstruction grouped R. milesi together with R. neglectus from different localities, demonstrating that these taxa represent the same species based on the phylogenetic species concept. Experimental crosses demonstrate the absence of pre- and postzygotic barriers under laboratory conditions. Additionally, when the hatch rates of crosses are compared to intraspecific crosses, it can be noted that they are high and very similar. Finally, the mortality rate of the hybrids does not indicate hybrid inviability, the absence of chromosome pairing errors does not indicate hybrid sterility, and the proportion between male and female hybrids demonstrates that Haldane’s rule was not acting. Therefore, we perform the formal synonymization of R. milesi with R. neglectus.

Field laboratory comparison of STANDARD Q Filariasis Antigen Test (QFAT) with Bioline Filariasis Test Strip (FTS) for the detection of Lymphatic Filariasis in Samoa, 2023.

To monitor the progress of lymphatic filariasis (LF) elimination programmes, field surveys to assess filarial antigen (Ag) prevalence require access to reliable, user-friendly rapid diagnostic tests. We aimed to evaluate the performance of the new Q Filariasis Antigen Test (QFAT) with the currently recommended Filariasis Test Strip (FTS) for detecting the Ag of Wuchereria bancrofti, the causative agent of LF, under field laboratory conditions. During an LF survey in Samoa, 344 finger-prick blood samples were tested using FTS and QFAT. Microfilariae (Mf) status was determined from blood slides prepared from any sample that reported Ag-positive by either Ag-test. Each test was re-read at 1 hour and the next day to determine the stability of results over time. Overall Ag-positivity by FTS was 29.0% and 30.2% by QFAT. Concordance between the two tests was 93.6% (kappa = 0.85). Of the 101 Mf slides available, 39.6% were Mf-positive, and all were Ag-positive by both tests. Darker test line intensities from Ag-positive FTS were found to predict Mf-positivity (compared to same/lighter line intensities). QFAT had significantly higher reported test result changes than FTS, mostly reported the next day, but fewer changes were reported between 10 minutes to 1-hour. The field laboratory team preferred QFAT over FTS due to the smaller blood volume required, better usability, and easier readability. QFAT could be a suitable and user-friendly diagnostic alternative for use in the monitoring and surveillance of LF in field surveys based on its similar performance to FTS under field laboratory conditions.

Seed mass affects emergence but not germination in native grassland forage species

For ecological restoration of degraded grasslands, species selection and knowledge of the species biology are essential. Seed germination and seedling establishment, as well as seed regenerative traits, can partially determine direct seeding success in this context. The objectives of this study are (1) to characterize the seeds of 29 native forage species of the Pampa Austral grasslands, (2) to evaluate their germination and emergence, and (3) to evaluate the relationship between germination and emergence and seed traits (mass, length, width, and length/width ratio), to test the usefulness of these traits for rapid species selection. We studied the germination percentage of untreated (UG) and treated (TG) seeds under laboratory conditions of 29 native forage species (four legumes, nine cool season, and 16 warm‐season grasses) and the percentage of field emergence (FE) for 17 of those species, selected based on their UG. Additionally, all species were characterized, including thousand‐seed mass, length, width, and length/width ratio. Average UG was 53.30 ± 3.17% for Poaceae and 25.63 ± 5.73% for Fabaceae. Four cool season and eight warm‐season grasses had UG greater than 60%. Mean FE was 35.18 ± 0.66% 2 months after sowing. FE has a direct relationship with seed mass (r2 = 0.69; p < 0.001), while this relationship was not observed for UG under laboratory conditions (r2 = 0.15; p = 0.7174). In Pampa Austral grasslands, seed mass proved to be a relevant trait for species selection given its strong relationship with FE.