Search Results (2,999)

Ruminant livestock production plays a crucial role in the agricultural systems of Sub-Saharan Africa, significantly supporting rural livelihoods through income generation, improved nutrition, and employment opportunities. Despite its importance, the sector continues to face substantial challenges, such as low feed quality, seasonal feed shortages, and climate-related stresses, all of which limit productivity and sustainability. Considering these challenges, the adoption of natural feed additives has emerged as a promising strategy to enhance animal performance, optimise nutrient utilisation, and mitigate environmental impacts, including the reduction of enteric methane emissions. This review underscores the significant potential of natural feed additives such as plant extracts, essential oils, probiotics, and mineral-based supplements such as fossil shell flour as sustainable alternatives to conventional growth promoters in ruminant production systems across the region. All available documented evidence on the topic from 2000 to 2024 was collated and synthesised through standardised methods of systematic review protocol—PRISMA. Out of 319 research papers downloaded, six were included and analysed directly or indirectly in this study. The results show that the addition of feed additives to ruminant diets in all the studies reviewed significantly (p < 0.05) improved growth parameters such as average daily growth (ADG), feed intake, and feed conversion ratio (FCR) compared to the control group. However, no significant (p > 0.05) effect was found on cold carcass weight (CCW), meat percentage, fat percentage, bone percentage, or intramuscular fat (IMF%) compared to the control. The available evidence indicates that these additives can provide tangible benefits, including improved growth performance, better feed efficiency, enhanced immune responses, and superior meat quality, while also supporting environmental sustainability by reducing nitrogen excretion and decreasing dependence on antimicrobial agents. Full article

Quinoa (Chenopodium quinoa), a stress-tolerant pseudocereal ideal for studying abiotic stress responses, was used to systematically identify optimal reference genes for qPCR normalization under gradient stresses: low temperatures (LT group: −2 °C to −10 °C), heat (HT group: 39° C to 45 °C), and drought (DR group: 7 to 13 days). Through multi-algorithm evaluation (GeNorm, NormFinder, BestKeeper, the ΔCt method, and RefFinder) of eleven candidates, condition-specific optimal genes were established as ACT16 (Actin), SAL92 (IT4 phosphatase-associated protein), SSU32 (Ssu72-like family protein), and TSB05 (Tryptophan synthase beta-subunit 2) for the LT group; ACT16 and NRP13 (Asparagine-rich protein) for the HT group; and ACT16, SKP27 (S-phase kinase), and NRP13 for the DR group, with ACT16, NRP13, WLIM96 (LIM domain-containing protein), SSU32, SKP27, SAL92, and UBC22 (ubiquitin-conjugating enzyme E2) demonstrating cross-stress stability (global group). DHDPS96 (dihydrodipicolinate synthase) and EF03 (translation elongation factor) showed minimal stability. Validation using stress-responsive markers—COR72 (LT), HSP44 (HT), COR413-PM (LT), and DREB12 (DR)—confirmed reliability; COR72 and COR413-PM exhibited oscillatory cold response patterns, HSP44 peaked at 43 °C before declining, and DREB12 showed progressive drought-induced upregulation. Crucially, normalization with unstable genes (DHDPS96 and EF03) distorted expression profiles. This work provides validated reference standards for quinoa transcriptomics under abiotic stresses. Full article

Background: Standard room temperature housing (~22 °C) represents a stress for laboratory mice, resulting in an increased metabolic rate, calorie consumption, heart rate, and catecholamine levels compared to thermoneutral conditions (29–32 °C). Using a recently established two-hit model of heart failure with preserved ejection fraction (HFpEF) (Angiotensin II + High-fat diet for 28 days; MHS), we investigated how housing temperature modulates cardiac remodelling and function in male and female C57Bl/6J mice. Methods: Using the MHS mouse model, we investigated cardiac remodelling and function in 8-week-old C57BL/6J mice of both sexes housed at 10 °C, 22 °C, and 30 °C for four weeks. Control mice were analyzed in parallel. Before the MHS, the animals were allowed to acclimate for a week before the MHS started. Results: Mice housed at 10 °C consumed more food and had increased fat mass compared to those at 22 °C or 30 °C. This was accompanied by increased heart weight, stroke volume, heart rate, and cardiac output. Mice housed at 22 °C and 30 °C were similar for these cardiac parameters. Following MHS, mice at 10 °C and 22 °C developed marked cardiac hypertrophy, whereas thermoneutral housing attenuated this response and reduced left atrial enlargement. Cold-exposed females showed more diastolic dysfunction after MHS (increased E’ wave, E/E’, and isovolumetric relaxation time) than those at 22 °C or 30 °C. Ejection fraction and cardiac output declined significantly at 10 °C after MHS but were preserved at 22 °C and 30 °C in females. Conclusions: Cold housing exacerbates cardiac dysfunction in mice subjected to HFpEF-inducing stress, with pronounced effects in females. In contrast, thermoneutrality limits the cardiac hypertrophic response. Full article

Freezing and thawing cycles significantly affect the mechanical and hydraulic behavior of soils, posing detrimental challenges for infrastructures in cold climates. This study develops and validates a coupled Thermal–Hydraulic–Mechanical (THM) model using COMSOL Multiphysics (Version 6.3) to demonstrate the complexities of vapor and water flux, heat transport, frost heave, and vertical stress build-up in unsaturated soils. The analysis focuses on fine sand, sandy clay, and silty clay by examining their varying susceptibilities to frost action. Silty clay generated the highest amount of frost heave and steepest vertical stress gradients due to its high-water retention and strong capillary forces. Fine sand, on the other hand, produced a minimal amount of frost heave and a polarized vertical stress distribution. The study also revealed that vapor flux is more noticeable in freezing fine sand, while silty clay produces the greatest water flux between the frozen and unfrozen zones. The study also assesses the impact of soil properties including the saturated hydraulic conductivity, the particle thermal conductivity, and particle heat capacity on the frost-induced phenomena. Findings show that reducing the saturated hydraulic conductivity has a greater impact on mitigating frost heave than other variations in thermal properties. Silty clay is most affected by these changes, particularly near the soil surface, while fine sand shows less noticeable responses. Full article

Late-spring frost events severely damage low-chill peach blossoms, causing significant yield losses. Although 5-aminolevulinic acid (ALA) enhances cold tolerance through the PpC3H37-PpWRKY18 module, the regulatory mechanism of ALA on PpC3H37 remains to be elucidated. Using yeast one-hybrid screening with the PpC3H37 promoter as bait, we identified PpDof9 as a key interacting transcription factor. A genome-wide analysis revealed 25 PpDof genes in peaches (Prunus persica). These genes exhibited variable physicochemical properties, with most proteins predicted as nuclear-localized. Subcellular localization experiments in tobacco revealed that PpDof9 was localized to the nucleus, consistent with predictions. A synteny analysis indicated nine segmental duplication pairs and tandem duplications on chromosomes 5 and 6, suggesting duplication events drove family expansion. A conserved motif analysis confirmed universal presence of the Dof domain (Motif 1). Promoter cis-element screening identified low-temperature responsive (LTR) elements in 12 PpDofs, including PpDof1, PpDof8, PpDof9, and PpDof25. The quantitative real-time PCR (qRT-PCR) results showed that PpDof1, PpDof8, PpDof9, PpDof15, PpDof16, and PpDof25 were significantly upregulated under low-temperature stress, and this upregulation was further enhanced by ALA pretreatment. Our findings demonstrate ALA-mediated modulation of specific PpDof TFs in cold response and provide candidates (PpDof1, PpDof9, PpDof8, PpDof25) for enhancing floral frost tolerance in peaches. Full article

Cucumbers (Cucumis sativus L.) are highly sensitive to cold, but grafting onto cold-tolerant rootstocks can enhance their low-temperature resilience. This study investigates the physiological and molecular mechanisms by which exogenous vitamin C (Vc) mitigates cold stress in grafted cucumber seedlings. Using cucumber ‘Chiyu 505’ as the scion and pumpkin ‘Chuangfan No.1’ as the rootstock, seedlings were grafted using the whip grafting method. In the third true leaf expansion stage, seedlings were foliar sprayed with Vc at concentrations of 50, 100, 150, and 200 mg L⁻¹. Three days after initial spraying, seedlings were subjected to cold stress (8 °C) for 3 days, with continued spraying. After that, morphological and physiological parameters were assessed. Results showed that 150 mg L⁻¹ Vc treatment was most impactive, significantly reducing the cold damage index while increasing the root-to-shoot ratio, root vitality, chlorophyll content, and activities of antioxidant enzymes (SOD, POD, CAT). Moreover, this treatment enhanced levels of soluble sugars, soluble proteins, and proline compared to control. However, 200 mg L⁻¹ treatment elevated malondialdehyde (MDA) content, indicating potential oxidative stress. For transcriptomic analysis, leaves from the 150 mg L⁻¹ Vc and CK treatments were sampled at 0, 1, 2, and 3 days of cold stress. Differential gene expression revealed that genes associated with photosynthesis (LHCA1), stress signal transduction (MYC2-1, MYC2-2, WRKY22, WRKY2), and antioxidant defense (SOD-1, SOD-2) were initially up-regulated and subsequently down-regulated, as validated by qRT-PCR. Overall, we found that the application of 150 mg L⁻¹ Vc enhanced cold tolerance in grafted cucumber seedlings by modulating gene expression networks related to photosynthesis, stress response, and the antioxidant defense system. This study provides a way for developing Vc biostimulants to enhance cold tolerance in grafted cucumbers, improving sustainable cultivation in low-temperature regions. Full article

Global warming and anthropogenic climate change are projected to expand the geographic distribution and population abundance of ectothermic species and exacerbate the biological invasion of exotic species. DNA methylation, as a reversible epigenetic modification, could provide a putative link between the phenotypic plasticity of invasive species and environmental temperature variations. We assessed and interpreted the epigenetic mechanisms of invasive and indigenous species’ differential tolerance to thermal stress through the invasive species Bemisia tabaci Mediterranean (MED) and the indigenous species Bemisia tabaci AsiaII3. We examine their thermal tolerance following exposure to heat and cold stress. We found that MED exhibits higher thermal resistance than AsiaII3 under heat stress. The fluorescence-labeled methylation-sensitive amplified polymorphism (F-MSAP) results proved that the increased thermal tolerance in MED is closely related to DNA methylation changes, other than genetic variation. Furthermore, the quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting analysis of DNA methyltransferases (Dnmts) suggested that increased expression of Dnmt3 regulates the higher thermal tolerance of female MED adults. A mechanism is revealed whereby DNA methylation enhances thermal tolerance in invasive species. Our results show that the Dnmt-mediated regulation mechanism is particularly significant for understanding invasive species’ successful invasion and rapid adaptation under global warming, providing new potential targets for controlling invasive species worldwide. Full article

This study investigated into how different current input levels during cold metal transfer (CMT) welding affected the characteristics of the weld bead. For the current variation, three input values were taken: 80 A, 90 A, and 100 A. Weld beads fabricated from all three current inputs were compared by analysing their microstructure, microhardness, tensile strength, and residual stress. The microhardness of the weld bead decreased when the current parameter was increased from 80 A to 100 A. The average tensile strength increased from 80 A to 90 A. The lowest residual stress calculated was −135 MPa with 100 A current. Full article

Understanding the impacts of climate change on species’ geographic distributions is fundamental for biodiversity conservation and resource management. As a key plant group for ecological restoration and windbreak and sand fixation in arid and semi-arid ares in China’s Three Northern Regions (Northeast, North, and Northwest China), Caragana spp. exhibit distribution patterns whose regulatory mechanisms by environmental factors remain unclear, with a long-term lack of climatic explanations influencing their spatial distribution. This study integrated 2373 occurrence records of 44 Caragana species in China’s Three Northern Regions with four major environmental variable categories. Using the Biomod2 ensemble model, current and future climate scenario-based suitable habitats for Caragana spp. were predicted. This study innovatively combined quantitative analyses with Kira’s thermal indexes (warmth index, coldness index) and Wenduo Xu’s humidity index (HI) to elucidate species-specific relationships between distribution patterns and hydrothermal climatic constraints. The main results showed that (1) compared to other environmental factors, climate is the key factor affecting the distribution of Caragana spp. (2) The current distribution centroid of Caragana spp. is located in Alxa Left Banner, Inner Mongolia. In future scenarios, the majority of centroids will shift toward lower latitudes. (3) The suitable habitats for Caragana spp. will expand overall under future climate scenarios. High-stress scenarios exhibit greater spatial changes than low-stress scenarios. (4) Hydrothermal requirements varied significantly among species in China’s Three Northern Regions, and 44 Caragana species can be classified into five distinct types based on warmth index (WI) and humidity index (HI). The research findings will provide critical practical guidance for ecological initiatives such as the Three-North Shelterbelt Program and the restoration and management of degraded ecosystems in arid and semi-arid regions under global climate change. Full article

Low-temperature stress severely limits plant growth and reduces agricultural productivity. Calmodulin-like (CML) proteins are crucial calcium sensors in plant cold responses. Transcriptome analysis of cold-stressed Saussurea involucrata identified seven differentially expressed CML genes. qRT-PCR confirmed that SiCML6 was strongly induced at 4 °C and −2 °C. Bioinformatics analysis showed that SiCML6 encodes a transmembrane protein containing an EF-hand domain. This protein carries a signal peptide and shows the closest phylogenetic relationship to Helianthus annuus CML3. Its promoter contains ABA, methyl jasmonate (MeJA), and cold-response elements. Arabidopsis plants overexpressing SiCML6 showed significantly higher survival rates at −2 °C than wild-type plants. Under freezing stress, SiCML6-overexpressing lines exhibited reduced malondialdehyde content, relative electrolyte leakage, and ROS accumulation (H₂O₂ and O₂⁻), along with increased proline, soluble sugars, soluble proteins, and total antioxidant capacity (T-AOC). SiCML6 elevated the expression of cold-responsive genes CBF3 and COR15a under normal conditions and further upregulated CBF1/2/3 and COR15a at 4 °C. Thus, low temperatures induced SiCML6 expression, which was potentially regulated by ABA/MeJA. SiCML6 enhances freezing tolerance by mitigating oxidative damage through boosted T-AOC and osmoprotectant accumulation while activating the CBF-COR signaling pathway. This gene is a novel target for improving crop cold resistance. Full article

Molecular chaperones, especially heat shock proteins (HSPs) have vital functions in cells’ responses to stress. Here, we cloned and sequenced the complete complementary DNA encoding HSP90 (MjHSP90) from the shrimp Marsupenaeus japonicus. The MjHSP90 cDNA comprised 3162 bp, including a 2172 bp coding region encoding a 724 amino acid-protein (predicted molecular mass = 83.12 kDa). Homology and phylogenetic analyses showed that MjHSP90 was highly conserved and most homologous to Litopenaeus vannamei HSP90. MjHSP90 is expressed in all tested tissues, with high expression in gill tissue and the hepatopancreas. Cold stress significantly upregulated MjHSP90 expression in the gill and hepatopancreas (p < 0.05). Following RNA interference knockdown of MjHSP90, the cold stress-related death rate of the shrimp increased significantly, accompanied by significantly upregulated expression of apoptosis-related genes Mjcaspase-3 and Mjbcl-2 (p < 0.05) and an increase in the number of apoptotic cells. The results indicated that MjHSP90 might play a pivotal role in the shrimp’s immune response to cold stress. Full article

Global climate change is causing increasing fluctuations in winter temperatures, including episodes of warm conditions above 9 °C. Such events disrupt cold acclimation in plants and can induce deacclimation, reducing frost tolerance and altering, among other things, hormonal regulation. This study investigated hormonal and molecular changes associated with cold acclimation and deacclimation in oilseed rape (Brassica napus L.) cultivars Kuga and Thure. Plants were grown under different conditions: non-acclimated (17 °C for three weeks), cold-acclimated (4 °C for three weeks), and deacclimated (16/9 °C day/night for one week). Detailed hormone analysis included auxins, gibberellins, cytokinins, stress-related hormones, and the expression of hormone-related genes (BnABF2, BnAOS, BnARF1, BnARR6, BnICS1, BnRGA, and BnWRKY57). Hormone concentrations in leaves changed dynamically in response to deacclimation with increased amounts of growth-promoting hormones and decreased amounts of stress hormones. Additionally, alterations in gene expression during deacclimation, such as in BnABF2 and BnICS1, may function as protective mechanisms to help maintain or regain frost tolerance during reacclimation when temperatures decline again after the warm period. These findings improve the understanding of hormonal and molecular responses involved in the deacclimation of oilseed rape. Full article

To address the freezing damage to tunnel lining caused by frost heaving of the surrounding rock in water-rich tunnels in cold regions, a numerical thermo-mechanical coupling model for tunnel-surrounding rock that considers the anisotropy of frost heave deformation was established by examining overall frost heaves in a freeze–thaw cycle. Using a COMSOL Multiphysics 6.0 platform and the sequential coupling method, the temperature field evolution of tunnel-surrounding rock, freezing cycle development, and distribution characteristics of the frost heaving force of a tunnel lining under different minimum temperatures, numbers of negative temperature days, frost heave ratios, and anisotropy coefficients of frost heave deformation were systematically simulated. The results revealed that the response of the temperature field of tunnel-surrounding rock to the external temperature varies spatially with time lags, the shallow surface temperatures and the area around the lining fluctuate with the climate, and the temperature of the deep surrounding rock is dominated by the geothermal gradient. The extent of the freezing cycle and the frost heaving force increase significantly when lowering the minimum temperature. The maximum frost heaving force usually occurs in the region of the side wall and the spring line, and tensile stress is prone to be generated at the spring line; the influence of slight fluctuations in the minimum temperature or the short shift in the coldest day on the frost heaving force is limited. A substantial increase in frost heaving force is observed with higher frost heave ratios; for example, an increase from 0.25% to 2.0% results in a 116% rise at the sidewall. Although the increase in the anisotropy coefficient of frost heave deformation does not change the overall distribution pattern of frost heaving force, it can exacerbate the directional concentration of frost heave strain, which can increase the frost heaving force at the periphery of the top arch of the lining. This study revealed the distribution pattern and key influencing factors of the freezing cycle and frost heaving force for tunnels, providing a theoretical basis and data reference for the frost resistance design of tunnels in cold regions. Full article

We present a model that integrates the mapping of the phenology and climatic suitability for the spotted lanternfly (SLF), Lycorma delicatula (White, 1845) (Hemiptera: Fulgoridae), to provide guidance on when and where to conduct surveillance and management of this highly invasive pest. The model was designed for use in the Degree-Day, Establishment Risk, and Phenological Event Maps (DDRP) platform, which is an open-source decision support tool to help to detect, monitor, and manage invasive threats. We validated the model using presence records and phenological observations derived from monitoring studies and the iNaturalist database. The model performed well, with more than >99.9% of the presence records included in the potential distribution for North America, a large proportion of the iNaturalist observations correctly predicted, and a low error rate for dates of the first appearance of adults. Cold and heat stresses were insufficient to exclude the SLF from most areas of the conterminous United States (CONUS), but an inability for the pest to complete its life cycle in cold areas may hinder establishment. The appearance of adults occurred several months earlier in warmer regions of North America and Europe, which suggests that host plants in these areas may experience stronger feeding pressure. The near-real-time forecasts produced by the model are available at USPest.org and the USA National Phenology Network to support decision making for the CONUS. Forecasts of egg hatch and the appearance of adults are particularly relevant for surveillance to prevent new establishments and for managing existing populations. Full article

Temperature fluctuations caused by climate change and global warming pose a threat to fish. The burbot (lota lota) population is particularly sensitive to increased water temperature, but the systematic impacts of high-temperature exposure on their liver and intestinal health remain unclear. In January of 2025, we collected wild adult burbot individuals from the Ussuri River (water temperature: about 2 °C), China. The burbot were exposed to 2 °C, 7 °C, 12 °C, 17 °C, and 22 °C environments for 96 h; then, the liver and intestinal contents were subsequently collected for histopathology observation, immunohistochemistry, biochemical index assessment, and transcriptome/16S rDNA sequencing analysis. There was obvious liver damage including hepatocyte necrosis, fat vacuoles, and cellular peripheral nuclei. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were elevated and subsequently decreased. Additionally, the malondialdehyde (MDA) level significantly increased with increasing temperature. These results indicate that 7 °C (heat stress temperature), 12 °C (tipping point for normal physiological metabolism status), 17 °C (tipping point for individual deaths), and 22 °C (thermal limit) are critical temperatures in terms of the physiological response of burbot during their breeding period. In the hepatic transcriptome profiling, 6538 differentially expressed genes (DEGs) were identified, while KEGG enrichment analysis showed that high-temperature stress could affect normal liver function by regulating energy metabolism, immune, and apoptosis-related pathways. Microbiomics also revealed that acute heat stress could change the intestinal microbe community structure. Additionally, correlation analysis suggested potential regulatory relationships between intestinal microbe taxa and immune/apoptosis-related DEGs in the liver. This study revealed the potential impact of environmental water temperature changes in cold habitats in winter on the physiological adaptability of burbot during the breeding period and provides new insights for the ecological protection of burbot in the context of global climate change and habitat warming. Full article