Search Results (265)

In a warming world, mechanisms, such as the heat shock response, which plays a role in the recovery from or tolerance towards heat stress, are of increasing importance. Certain heat shock protein genes (hsps) have previously been shown to be highly inducible in several paper wasp species during high temperature stress under laboratory conditions. Here, we sought to investigate how hsps are expressed under natural daily temperature fluctuations by collecting broods from wild nests of two species of paper wasps (Polistes dominula, P. nimpha). We collected them at 06:00 and 16:00, the expected low and high points in daily hsp expression, and measured the expression of three hsps (hsp70, hsp83, hsc70). We found that the nest temperature in July could reach temperatures that result in a large upregulation of hsp expression in the laboratory. Under natural conditions, however, we found that the induction response was much more moderate and limited to the larvae. The pupae showed no response to the daily fluctuating temperature and had a constant expression similar to that of larvae in the afternoon. The similarities and differences between natural and laboratory hsp expressions highlight the importance of field studies, as they add valuable context when interpreting laboratory results. Full article

Sin Nombre virus (SNV) is the main causative agent of hantavirus cardiopulmonary syndrome (HCPS) in North America. SNV is transmitted via environmental biological aerosols (bioaerosols) produced by infected deer mice (Peromyscus maniculatus). It is similar to other viruses that have environmental transmission routes rather than a person-to-person transmission route, such as avian influenza (e.g., H5N1) and Lassa fever. Despite the lack of person-to-person transmission, these viruses cause a significant public health and economic burden. However, due to the lack of targeted pharmaceutical preventatives and therapeutics, the recommended approach to prevent SNV infections is to avoid locations that have a combination of low foot traffic, receive minimal natural sunlight, and where P. maniculatus may be found nesting. Consequently, gaining insight into the SNV bioaerosol decay profile is fundamental to the prevention of SNV infections. The Biological Aerosol Reaction Chamber (Bio-ARC) is a flow-through system designed to rapidly expose bioaerosols to environmental conditions (ozone, simulated solar radiation (SSR), humidity, and other gas phase species at stable temperatures) and determine the sensitivity of those particles to simulated ambient conditions. Using this system, we examined the bioaerosol stability of SNV. The virus was found to be susceptible to both simulated solar radiation and ozone under the tested conditions. Comparisons of decay between the virus aerosolized in residual media and in a mouse bedding matrix showed similar results. This study indicates that SNV aerosol particles are susceptible to inactivation by solar radiation and ozone, both of which could be implemented as effective control measures to prevent disease in locations where SNV is endemic. Full article

The reliance on imported seeds for grassland rehabilitation in Mexico has led to increased costs and other difficulties in implementing grassland rehabilitation programs. Varieties need to be generated from local ecotypes that are outstanding in forage production and their response to rehabilitation programs. However, the scarcity of occurrence records is often a deterrent to niche and distribution modeling, hence the need for an approach that overcomes such limitations. The objectives of this study were (1) to develop a geographic information system (GIS)-based approach to determining the population distribution of a promising ecotype of Bouteloua curtipendula (Michx.) Torr. for grassland rehabilitation in the Chihuahuan Desert, Mexico; (2) to identify the edaphoclimatic variables that define the ecotype’s distribution; and (3) to develop models to determine the potential area for the use of the ecotype in grassland rehabilitation. The challenge for the present study was that only one georeferenced collection site of the ecotype in Chihuahua was available for use in the construction and calibration of the models. GIS software 10.3 was used to develop two potential distribution models: Model A, with variables obtained directly from a vector climate dataset, and Model B, with derived variables. A field work methodology was developed for the validation process using a georeferenced digital mesh and the nested sampling method modified by Whittaker. The information was analyzed with 10 non-parametric statistical tests. The two models had an overall accuracy and sensitivity level greater than 70% and a positive predictive power greater than 80%. The predicted population distribution areas in Chihuahua (18,158 ha) in the form of discontinuous patches cohered with those in previous reports on the distribution form of B. curtipendula. The edaphoclimatic variables influencing ecotype distribution were soil type, average minimum and maximum temperature in January, average maximum temperature in June, average minimum temperature in July, and average precipitation in August. The sensitivity analysis showed soil type as an important variable in defining the ecotype’s distribution. Considering soil as the main predictor variable, the potential rehabilitation area where the ecotype may be used was estimated at 7,181,735 ha in the Chihuahuan Desert region. The study developed and validated an approach to modeling the ecological niche of an ecotype of commercial interest, despite severe limitations in the number of georeferenced sites available for modeling. Further study is needed to explore its applicability to grassland rehabilitation in the Chihuahuan Desert and the study of rare and understudied ecotypes or species in other settings. Full article

Microstructural, mechanical and qualitative phase identification of durable mullite-based ceramics obtained by utilization of waste clay–diatomite has been studied. Mullite-based ceramics were fabricated using waste clay–diatomite from the Baroševac open-cast coal mine, Kolubara (Serbia). The raw material consists mainly of SiO₂ (70.5 wt%) and a moderately high content of Al₂O₃ (13.8 wt%). In order to achieve the stoichiometric mullite composition (3Al₂O₃-2SiO₂), the raw material was mixed with an appropriate amount of Al(NO₃)₃·9H₂O. After preparing the precursor powder, the green compacts were sintered at 1300, 1400 and 1500 °C for 2 h. During the process, rod-shaped mullite grains were formed, measuring approximately 5 µm in length and a diameter of 500 nm (aspect ratio 10:1). The microstructure of the sample sintered at 1500 °C resulted in a well-developed, porous, nest-like morphology. According to the X-ray diffraction analysis, the sample at 1400 °C consisted of mullite, cristobalite and corundum phases, while the sample sintered at 1500 °C contained mullite (63.24 wt%) and an amorphous phase that reached 36.7 wt%. Both samples exhibited exceptional compressive strength—up to 188 MPa at 1400 °C. However, the decrease in compressive strength to 136 MPa at 1500 °C is attributed to changes in the phase composition, the disappearance of the corundum phase and alterations in the microstructure. This occurred despite an increase in bulk density to 2.36 g/cm³ (approximately 82% of theoretical density) and a complete reduction in open porosity. The residual glassy phase (36.7 wt% at 1500 °C) is probably the key factor influencing the mechanical properties at room temperature in these ceramics produced from waste clay–diatomite. However, the excellent mechanical stability of the samples sintered at 1400 and 1500 °C, achieved without binders or additives and using mined diatomaceous earth, supports further research into mullite-based insulating materials. Mullite-based materials obtained from mining waste might be successfully used in the field of energy-efficient refractory materials and thermal insulators. for high-temperature applications Full article

The main goal of this study is to present future changes in various precipitation indices at a kilometer-scale resolution for Bulgaria on an annual and seasonal basis. Numerical simulations were conducted using the Non-Hydrostatic Regional Climate Model version 4 (RegCM4-NH) following the Coordinated Regional Climate Downscaling Experiment Flagship Pilot Study protocol for three 10-year periods (1995–2004, 2041–2050, and 2090–2099), with horizontal grid resolutions of 15 km and 3 km, on the petascale supercomputer HPC Discoverer at Sofia Tech Park. Data from the Hadley Centre Global Environment Model version 2 (HadGEM2-ES), based on the Representative Concentration Pathway 8.5 (RCP8.5) scenario, were used as boundary conditions for the regional climate model (RCM) simulations, which were subsequently downscaled to the kilometer-scale (3 km) simulations using a one-way nesting approach. High-resolution model data were compared with high-resolution observational datasets as well as lower-resolution (15 km) data. Future changes in precipitation indices were analyzed on both annual and seasonal scales, including mean daily and hourly precipitation, the frequency and intensity of wet days (>1 mm/day) and wet hours (>0.1 mm/hour), extreme daily precipitation (99th percentile, p99), and extreme hourly precipitation (99.9th percentile, p99.9) for both future periods. Additionally, changes in near-surface (2 m) temperature and surface snow amount were also presented. There is no substantial difference in projected temperature change between the resolutions. A positive trend in annual mean precipitation is expected in the near future. Extreme precipitation (p99 and p99.9) is projected to increase in spring and winter, accompanied by a rise in daily and hourly precipitation intensity across both future periods. An increase in surface snow amount is observed in the central Danubian Plain, Thracian Lowland, and parts of the Rila and Pirin mountains for the near-future period. However, surface snow amount is expected to decrease by the end of the century. Full article

Cryptosporidiosis is a gastrointestinal disease affecting terrestrial and aquatic vertebrates worldwide. This study investigated molecularly and microscopically the prevalence and the diversity of Cryptosporidium spp. in goats across the Bouira communes, Algeria. A total of 559 fecal samples were collected from 70 farms, representing 16.6% of the regional goat population. Samples were analyzed using microscopy (modified Ziehl-Neelsen staining) and molecular methods (i.e., qPCR and nested PCR targeting the 18S rRNA gene, followed by sequencing). Microscopy detected Cryptosporidium in 6.1% of samples, while qPCR revealed a significantly higher prevalence of 13.6% (p < 0.00001), confirming the superior sensitivity of molecular diagnostics. Spatial analysis identified significant clustering (Moran’s I = 0.330, p = 0.0003), with communes-level prevalence ranging from 6.7% to 45.7%. Infection rates correlated positively with humidity and rainfall but negatively with temperature. Phylogenetic analysis confirmed Cryptosporidium xiaoi as the sole species circulating, showing 100% genetic similarity to global caprine isolates. Despite C. xiaoi’s host adaptation, a GenBank review highlighted six other zoonotic species infecting goats worldwide, underscoring potential cross-species transmission risks. The study emphasizes the need for PCR-based surveillance to assess true prevalence and zoonotic threats, while climatic findings support targeted interventions in high-risk areas. Full article

Earth’s energy imbalance (EEI) is a major indicator of climate change. Its metrics are top of the atmosphere radiation imbalance (EEI TOA) and net internal heat uptake. Both EEI and temperature are expected to respond gradually to forcing on annual timescales. This expectation was tested by analyzing regime changes in the inputs to EEI TOA along with increasing ocean heat content (OHC). Outward longwave radiation (OLR) displayed rapid shifts in three observational and two reanalysis records. The reanalysis records also contained shifts in surface fluxes and temperature. OLR, outward shortwave radiation (OSR) and TOA net radiation (Net) from the CERES Energy Balanced and Filled Ed-4.2.1 (2001–2023) record and from 27 CMIP5 historical and RCP4.5 forced simulations 1861–2100, were also analyzed. All variables from CERES contained shifts but the record was too short to confirm regime changes. Contributions of OLR and OSR to net showed high complementarity over space and time. EEI TOA was −0.47 ± 0.11 W m⁻² in 2001–2011 and −1.09 ± 0.11 W m⁻² in 2012–2023. Reduced OSR due to cloud feedback was a major contributor, coinciding with rapid increases in sea surface temperatures in 2014. Despite widely varying OLR and OSR, 26/27 climate models produced stable regimes for net radiation. EEI TOA was neutral from 1861, shifting downward in the 26 reliable records between 1963 and 1995, with 25 records showing it stabilizing by 2039. To investigate heat uptake, temperature and OHC 1955/57–2023 was analyzed for regime change in the 100 m, 700 m and 2000 m layers. The 100 m layer, about one third of total heat content, was dominated by regimes. Increases became more gradual with depth. Annual changes between the 700 m layer and 1300 m beneath were negatively correlated (−0.67), with delayed oscillations during lag years 2–9. Heat uptake at depth is dynamic. These changes reveal a complex thermodynamic response to gradual forcing. We outline a complex arrangement of naturally evolved heat engines, dominated by a dissipative heat engine nested within a radiative engine. EEI is a property of the dissipative heat engine. This far-from-equilibrium natural engine has evolved to take the path of least resistance while being constrained by its maximum power limit (~2 W m⁻²). It is open to the radiative engine, receiving solar radiation and emitting scattered shortwave and longwave radiation. Steady states maximize entropy within the dissipative engine by regulating spatial patterns in surface variables that influence outgoing OLR and OSR. Regime shifts to warmer climates balance the cost of greater irreversibility with increased energy rate density. The result is the regulation of EEI TOA through a form of thermodynamic metabolism. Full article

The red imported fire ant (Solenopsis invicta, RIFA) is a globally invasive species with strong sensitivity to environmental conditions. This study investigated the seasonal dynamics and colony structure of RIFA over the course of one year across two typical habitats in South China: Camellia oleifera plantations and fishponds. The results revealed clear seasonal patterns in caste composition. Worker abundance peaked during winter (December–January), while reproductive individuals (queens, males, and alates) emerged primarily in spring and early summer (March–May). Colony biomass, worker number, and individual dry weight were significantly higher in C. oleifera plantations, whereas fishpond habitats exhibited greater numbers of larvae and male alates, suggesting different reproductive allocation strategies across habitats. An analysis of caste composition indicated that adult workers were dominant in both habitats, but the proportion of pupae was notably higher in fishpond colonies, especially in spring. Significant correlations were found between colony metrics and nest characteristics, including a negative relationship between worker body length and colony biomass. Environmental factor analysis showed that air pressure positively influenced worker numbers, while temperature was negatively associated with them. Precipitation and humidity played key roles in regulating larval and pupal populations. Overall, RIFA exhibited strong seasonal patterns and ecological plasticity in response to habitat differences and environmental variables. These findings provide insights into the species’ invasion biology and inform habitat-specific monitoring and management strategies. Full article

Light intensity, CO₂ concentration, and temperature are three primary environmental factors with high temporal variability, nonlinearity, and strong coupling, which directly influence the photosynthetic rate of plants. To investigate the combined influence of these factors on the photosynthetic rate of chili pepper plants, a predictive model was developed for their net photosynthetic rate (Pn) during the peak fruiting period. A multifactorial nested experimental design with irregular sampling intervals was used to systematically examine the interacting effects of light intensity, CO₂ concentration, and temperature on photosynthesis. Based on the collected data, a support vector regression (SVR) algorithm was trained and its performance was compared with that of a backpropagation (BP) neural network, a radial basis function (RBF) neural network, and a random forest (RF) algorithm. To optimize performance, a grid search with five-fold cross-validation was conducted to identify optimal hyperparameters; this process yielded a cost parameter (C) of 38 and a gamma parameter (γ) of 8, which minimized the root mean square error (RMSE) on the training set. On the test set, the SVR model achieved a coefficient of determination (R²) of 0.9941 and an RMSE of 0.6988 μmol m⁻² s⁻¹ (relative to the full Pn range of −4.19 to 39.2 μmol m⁻² s⁻¹). A linear fit between measured and predicted Pn values yielded a slope of 0.992 and an intercept of 0.07, indicating near-perfect agreement and surpassing the performance of the BP, RBF, and RF models. These results demonstrate that the SVR-based model outperformed the other approaches and exhibited superior predictive ability, establishing it as a robust theoretical foundation and a practical tool for dynamic environmental optimization in controlled-environment agriculture. Full article

Due to late-stage diagnoses and limited treatment options, pancreatic cancer is predicted to be the second leading cause of cancer deaths by 2030. Many different murine models were developed over the past decades to test new therapies for this tumor entity. The laws and regulations demand the continuous refinement of animal experiments in order to improve animal welfare sustainably. A key aspect here is the definition of early humane endpoint criteria to avoid severe and lasting suffering of the animals through timely euthanasia. The present study analyzed the welfare of mice in different pancreatic cancer models, various mouse strains, and under different therapeutic interventions in preclinical testing. Their welfare was monitored before any intervention, during tumor progression, and on the days before the individual humane endpoint for each mouse by assessing body weight change, distress score, perianal temperature, burrowing behavior, nesting activity, and mouse grimace scale. The data was retrospectively analyzed via receiver operating characteristic curve analysis to quantify the predictability of each parameter for humane endpoint determination. Burrowing behavior proved to be a robust predictor of the humane endpoint two days in advance under various conditions, including diverse pancreatic cancer models and different therapeutic approaches. Full article

Ants have long been regarded as ubiquitous insects that are indicators of environmental change and ecosystems. Understanding the patterns of ant species richness along elevational gradients is crucial for elucidating their ecological functions within ecosystems. However, there is currently no comprehensive consensus on the pattern. In this study, we explored the pattern of ant species richness along an elevational gradient in the Mt. Daliang region (Sichuan, China), a biodiversity conservation hotspot in China. The ant species richness was investigated using 115 plots 50 × 50 m in size, distributed across 12 elevation bands of 250 m interval between 750 to 3500 m a.s.l. We identified 157 ant species from 51 genera and seven subfamilies. Myrmicinae was the most diverse subfamily, consisting of 20 genera and 84 species, followed by Formicinae, Dolichoderinae, Ponerinae, Dorylinae, Amblyoponinae, and Proceratiinae. We found a unimodal distribution pattern of ant species richness along the elevational gradient, with the highest ant species richness occurring at mid-elevations. This hump-shaped pattern of ant species richness was presented alongside the temperature variation. Furthermore, our results indicated that ground-foraging ant species were the most abundant in this region and that ants prefer to nest in the soil. Our findings highlight the importance of elevation in influencing ant species richness in Daliang Mountain, Sichuan, China, and provide novel insights into the potential drivers of elevational gradients in ant species communities. Full article

Pinna nobilis, an ecologically significant and critically endangered bivalve endemic to the Mediterranean Sea, has been classified as “Critically Endangered” by IUCN due to habitat degradation, climate change, and mass mortality events caused by the protozoan parasite Haplosporidium pinnae. Effective conservation efforts require robust molecular tools for species identification and genetic monitoring, necessitating the development of optimized DNA extraction and amplification protocols for a non-invasive sampling protocol. In this study, we evaluated multiple DNA extraction methods—Chelex-100, the sodium chloride (NaCl) method, a modified CTAB protocol, and a commercial kit, NucleoSpin Tissue Kit—using minute shell fragments from both ethanol-preserved and air-dried (dead) samples. We optimized key parameters, including incubation times, temperatures, and sample preparation, to determine the most effective protocol for obtaining high-quality DNA suitable for downstream applications. Additionally, we assessed different PCR strategies, including nested and semi-nested approaches targeting the COI gene marker, to enhance species identification. To further refine the methodology, we evaluated novel specific primers for nested PCR, improving sensitivity and specificity in detecting P. nobilis DNA from minute and degraded samples. Our results provide an optimized, cost-effective, and time-efficient workflow for non-invasive molecular identification of P. nobilis, with broad implications for conservation genetics, biodiversity monitoring, and species recovery programs. Full article

Sustainable strategies are required to mitigate elevated atmospheric CO₂ levels. Achieving that by adsorption, especially by using clay-based adsorbents, drew attention. These are even more promising when these adsorbents are obtained by low-cost modifications. This study evaluates the effect of ball milling on the carbon capture performance of Australian halloysite nanotube (HNT)-rich kaolin samples: one without iron impurities (Hal) and the other with iron impurities (HalFe). The iron was mainly nested within illite/mica minerals in HalFe. Samples were ball-milled for 30 and 60 min, and their CO₂ sorption was assessed at various pressures and temperatures. Crystallography, electronic microscopy, and surface area and charge characterization revealed reduced length and increased width of tubular structure following ball milling, leading to higher specific surface area without compromising crystallinity. CO₂ sorption of Hal increased 14% at 20 bar and 15 °C after 60 min milling, with a ~300% rise at near-atmospheric pressures. Conversely, milling negatively affected CO₂ sorption of HalFe, likely due to iron/illite-mica-related damage during milling. Crystallography, infrared, and thermographic analyses revealed physisorption as the primary sorption mechanism. Since direct disposal of CO₂-laden materials is against sustainability principles, these materials were tested for methylene blue removal from aqueous solutions, achieving ~83% (Hal) and ~91% (HalFe) removal efficiencies. This highlights HNTs-rich kaolin clays’ valorization potential for carbon capture and utilization (CCU). Full article

The new eco-friendly flammable refrigerant in air conditioners has resulted in an annual increase in fire incidents associated with these units. Fire investigators face significant challenges in identifying the causes of these fires. In this study, copper tube samples were extracted from various locations of air conditioner condenser debris post fire. The morphology characteristics of the ruptured copper tubes formed by a high-temperature flame in fire and that formed by corrosion were analyzed, respectively. The findings indicate that the ruptures in the copper tubes of air conditioners may be classified into two types based on their origins: ruptures resulting from fire and ruptures resulting from corrosion. The ruptures in the copper tubes resulting from fire are associated with the presence of aluminum alloy fins. At elevated temperatures, the copper and aluminum atoms persist in diffusing and fracturing. A significant quantity of silver-white aluminum is present surrounding the ruptures, and distinct elemental layers may be seen in the cross-section. The corrosion-induced ruptures in the copper tubes are associated with ant nest corrosion. Despite the influence of high-temperature flame melting on surface corrosion pits, they will not entirely obscure the pits and the cross-section continues to exhibit the bifurcated structure characteristic of ant nest corrosion. This investigation demonstrates that corrosion of ant nests is the root cause of copper tube breakage obscured by flames. An investigation method for the refrigerant leakage air conditioning fire is proposed. The above findings can provide proof and method for air conditioning fire investigation. Full article

On the beach of Linosa Island (Italy), 43 loggerhead sea turtle (Caretta caretta) unhatched eggs were recovered from nests, formalin-fixed and necropsied. The tissue samples were stained with hematoxylin-eosin (HE), Grocott, von Kossa, periodic acid-Schiff (PAS), and Movat pentachrome stains. Histologically, vacuolar degeneration (100.0%) and increased numbers of melanomacrophages (18.6%) in the liver, and edema (14.0%) in the lungs were observed. Twenty-five kidneys (58.1%) showed deposition of blue amorphous material with HE staining, which also appeared PAS-positive and black with von Kossa staining, allowing a diagnosis of calcium oxalate, confirmed by transmission electron microscopy (TEM). The hepatic lesions may be indicative of toxicosis, infection, or a defense mechanism. A statistically significant association between the nest position and renal oxalosis (renal calcium oxalate deposition) was observed. Renal oxalosis was probably due to the exceptionally high summer temperatures, which were statistically higher compared to the temperatures recorded in the previous two years. Full article