Cold Conditions Research Articles

Large eddy simulation-based modeling of cold-air inhalation from nasal cavities to the distal lung: Insights for athlete health and performance

In cold environments, athletes are frequently susceptible to injuries from inhaling cold and dry air, posing significant health risks. Despite abundant prior research focusing on risk analysis and prevention, the existing body of literature has predominantly focused on heat transfer within lung airways while mainly overlooking the broader respiratory tract. This pioneering study introduces a comprehensive assessment of the entire respiratory system, spanning from the nasal and oral cavities to the larynx, then the trachea, and extending to the 13th generation of lung airways. Employing cutting-edge Computational Fluid Dynamics (CFD) techniques, the investigation operates Large Eddy Simulation (LES) integrated with an algebraic wall-modeled LES subgrid-scale model to simulate heat transfer within the human lung. This approach provides a detailed insight into the complex dynamics of respiratory thermoregulation in cold environments. By offering a comprehensive analysis of the temperature, heat flux, Nusselt number and static pressure profiles throughout the respiratory system, this study fundamentally advances our understanding of the physiological responses of the respiratory system to cold air exposure. These findings have paramount implications for athlete health and performance, shedding light on the complexities of cold-induced respiratory challenges. Moreover, this research lays a solid foundation for developing more effective preventive measures and strategies for optimizing athletic performance in cold weather conditions.

Laser-induced carbonization strategy for designing efficient dual-layer solar wastewater evaporator

Solar water evaporation technology is of great significance in alleviating the problem of clean water shortage. However, interface evaporation materials are crucial for solar evaporator and are hindered by high costs, complex processes, and environmental issues. In this work, a simple, fast, and environmentally friendly laser-induced carbonization strategy was used to convert commercial polypropylene into porous carbon materials in a one-step process, and assembled with natural bamboo to form an efficient dual-layer evaporator. The residual carbon nanotubes catalyst in the carbonized products further enhance its evaporation performance. The water evaporation rate of the evaporator under one sun is 1.93 kg·m−2·h−1. In addition, the evaporator has an evaporation rate of 1.62 to 1.85 kg·m−2·h−1 for wastewater containing methylene blue, carmine, CuCl2 and FeCl3. This strategy not only overcomes the limitations of traditional polymer carbonization methods but also allows for size adjustment based on the quantity of bamboo, and has been successfully applied to wastewater evaporation experiments under cold outdoor weather conditions. The proposed strategy not only elucidates the carbonization mechanism of polymers under laser irradiation, but also provides a new approach for the field of solar water evaporation.

The Effects of Weather Conditions on Hematological and Biochemical Parameters in Dogs: A Field Study

Although animals have adaptation abilities to different environmental conditions, various physiological changes may occur. The present research aimed to evaluate the effects of severe winter conditions on hematological and biochemical parameters in dogs kept outside all year. The research was carried out in the province of Kars, which is known for its severe cold conditions in Türkiye. Vital signs, hematological, and biochemical parameters of 12 adult dogs aged 1-8 years old (mixed breed, 8 males and 4 females) included in the study were compared in winter and summer seasons. The results indicated a significant effect of the winter season on the body temperature, respiration, and pulse rate of the dogs. In addition, it was observed that some hematological, including White blood cell (WBC), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) Hemoglobin (HB), and biochemical parameters (urea, TP, albumin, cholesterol, glucose, creatinine) of dogs differed in winter from those in summer. It should be considered that the vital values of dogs living outdoors in intense winter differed from those in mild winter or summer. It is also concluded that veterinarians should consider these differences in routine clinical examinations of these animals.

Do seasons impact the root microbiome of wild Poa annua populations?

Low temperatures, one of the main characteristics of winters in temperate climates, are restrictive for agriculture, because they negatively affect plant growth and development. To alleviate cold stress, plants are able to establish a symbiosis with soil bacteria. Annual bluegrass (Poa annua) is adapted to low temperatures, has a global distribution, and colonizes a wide range of environments, including polar regions. Here, Poa annua plants were harvested randomly within a one square meter plot at five sites in Flanders, Belgium, during September (summer samples) and March (winter samples) over 2019 and 2020. For each time point, location and season, ten samples of bulk soil, rhizosphere soil and root endosphere were obtained, making a total of 570 samples. As specialized bacteria in the winter root microbiome may reduce the negative impact of cold, we wanted to unravel how winter temperatures affect the root microbiome. Amplicon sequencing of 16S rRNA genes revealed that location was the factor with the largest influence on the bacterial community composition, followed by compartment (root endosphere, rhizosphere, and bulk soil), season, and year. While season was not the main determining factor of the root endosphere, comparison of the summer and winter samples allowed the identification of cold-enriched root-colonizing bacterial families. Interestingly, one ASV corresponding to Massilia was enriched in all sites during the winter season and, thus, may represent an interesting taxonomic group for the development of biostimulants to help plants cope with cold conditions.

Elevation Regulates the Response of Climate Heterogeneity to Climate Change

AbstractClimate change represents a profound threat to the diversity and stability of global climate zones. However, the complex interplay between climate change and elevation in shaping climate heterogeneity is not yet fully understood. Here, we combine Shannon's diversity index (SHDI) with the Köppen‐Geiger climate classification to explore the altitudinal distributions of global climate heterogeneity; and their responses to climate change. The study reveals a distinctive pattern: SHDI, a proxy for climate heterogeneity tends to slow down or decline at lower elevations with increasing temperatures, while at higher elevations, it continues to rise due to continuing cold conditions. Examination of climate simulations, both with and without anthropogenic forcing, confirms that observed changes in climate heterogeneity are primarily attributable to anthropogenic climate change within these high‐elevation regions. This study underscores the importance of high‐elevation regions as not only custodians of diverse climate types but also potential refuges for species fleeing warmer climates.

Resistance to freezing conditions of endemic Antarctic polychaetes is enhanced by cryoprotective proteins produced by their microbiome.

The microbiome plays a key role in the health of all metazoans. Whether and how the microbiome favors the adaptation processes of organisms to extreme conditions, such as those of Antarctica, which are incompatible with most metazoans, is still unknown. We investigated the microbiome of three endemic and widespread species of Antarctic polychaetes: Leitoscoloplos geminus, Aphelochaeta palmeri, and Aglaophamus trissophyllus. We report here that these invertebrates contain a stable bacterial core dominated by Meiothermus and Anoxybacillus, equipped with a versatile genetic makeup and a unique portfolio of proteins useful for coping with extremely cold conditions as revealed by pangenomic and metaproteomic analyses. The close phylosymbiosis between Meiothermus and Anoxybacillus and these Antarctic polychaetes indicates a connection with their hosts that started in the past to support holobiont adaptation to the Antarctic Ocean. The wide suite of bacterial cryoprotective proteins found in Antarctic polychaetes may be useful for the development of nature-based biotechnological applications.

Transgenerational cross‐susceptibility to heat stress following cold and desiccation acclimation in the Angoumois grain moth

AbstractThe Angoumois grain moth, Sitotroga cerealella (Olivier), is a significant cosmopolitan primary pest of cereals worldwide and has thrived in divergent environments. However, the mechanisms underlying its survival in multiple contrasting environments are poorly understood. Here, we hypothesised that when facing diverse environmental stress, F1 generation exhibits transgenerational cross‐protection as a mechanism to persist under divergent stressful environments. Notably, F1 acclimation to cold or desiccation conditions could either enhance or lower heat tolerance in the F2 generation. Specifically, we tested whether typical diurnal fluctuations and/or winter rapid or chronic cold temperatures (18–22°C) as well as desiccation acclimation of F1 parental population yields transgenerational cross‐protection/susceptibility to heat stress on F2 offspring. F1 moths were exposed to cold hardening (2 h), chronic (72 h) and variable (fluctuating between 18 and 22°C for 72 h) temperature treatment groups. Desiccation treatment included incubation at 0%–1% relative humidity (24 h). F2 generation moths were then assessed for heat tolerance using critical thermal maxima (CTmax) at three different ramping rates (0.06, 0.25 and 0.5°C/min) as well as heat knockdown time (HKDT). Findings indicated that (i) desiccation, cold hardening and chronic low‐temperature acclimations in F1 reduced heat tolerance in F2 populations and (ii) ramping rate was crucial to decipher differences between treatment groups, with lower ramping rates associated with lower CTmax. Transgenerational cross‐susceptibility to heat stress indicates possible fitness costs of exposure to multiple contrasting stressors in the Angoumois grain moth and can be used in designing physical pest management strategies.

The 4.2 ka event: A review of palaeoclimate literature and directions for future research

In recent years, much evidence has been presented on the 4.2 ka event. A review of 317 palaeoclimate papers shows that dry conditions were common during the event, especially from Eastern Mediterranean to India. The 4.2 ka event was not, however, a global drought event. Wet conditions were reported especially for central/northern Europe and sub-Saharan Africa. The 4.2 ka event is typically characterized either as short (4.2–4.0 ka) or long (4.4–3.8 ka) episode, possibly developing over an extended interval of time, in keeping with the North Atlantic forcing and correlating with the Bond 3 event of ice-rafted debris. This forcing is understood to drive a southward migration of the Inter-Tropical Convergence Zone (ITCZ), resulting in decreased rainfall over most of the Asian monsoon region, with possibility that an interplay of El Niño–Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) has modulated the global circulation. Cold conditions were also reported but less frequently, in comparison to other Bond events such as the 8.2 ka event, Dark Ages Cold Period and Little Ice Age. Some high-resolution records show a double peak structure of which two anomalies are tree-ring dated to 4.14–4.05 ka and 3.97 ka. Accurately and precisely dated high-resolution records indicative of various climatic variables, especially outside of the traditional study region (Mediterranean–Middle East–India–China), including reconstructions of the ENSO and NAO histories and ITCZ migrations, are crucially needed for rigorous examination of the global scale characteristics of the 4.2 ka event and its forcings. Such research seems to be just beginning.

Humidity-Responsive Liquid Metal Core-Shell Materials for Enduring Heat Retention and Insulation.

High humidity in extremely cold weather can undermine the insulation capability of the clothing, imposing serious life risks. Current clothing insulation technologies have inherent deficiencies in terms of insulation efficiency and humidity adaptability. Here, humidity-stimulated self-heating clothing using aluminum core-liquid metal shell microparticles (Al@LM-MPs) as the filler is reported. Al@LM-MPs exhibit a distinctive capability to react to water molecules in the air to generate heat, exhibiting remarkable sensitivity across a broad temperature range. This ability leads to the creation of intelligent clothing capable of autonomously responding to extreme cold and wet weather conditions, providing both enduring heat retention and insulation capabilities.

Stratigraphic and paleoceanographic alternations within a Mediterranean semi-enclosed, syn-rift basin during Marine Isotope Stage 5: The Gulf of Corinth, Greece

The Gulf of Corinth represents an ideal setting for studying the impact of sea level changes and regional climate on a semi-enclosed, syn-rift basin. Here we investigate the stratigraphic and paleoceanographic variability recorded in the sedimentary succession of the basin over the Marine Isotope Stage (MIS) 5 period when global sea level and climatic conditions along the eastern Mediterranean exhibited pronounced fluctuations. We used sedimentological (granulometry, composition), micropaleontological (planktic and benthic foraminifera), and isotopic (stable δ18O, δ13C, and clumped isotope) proxies on core samples from site M0079A (IODP Expedition 381) combined with additional data from the expedition overview and records from the surrounding area. The sedimentary succession comprises an alternating pattern of a) bioturbated, biogenic-rich deposits associated with increased hemipelagic sedimentation with b) partly bedded, detrital-rich sediments attributed to intercalated sediment gravity flows within the hemipelagic background under low oxic sea-surface conditions, and c) aragonite-rich laminated deposits, indicating either transitional conditions between marine and isolated environment or a highly stratified seawater column and low oxygen seafloor conditions. We find that the Gulf of Corinth lay under marine conditions for nearly the entire MIS 5 period, while the Rion sill would have been possibly shallower, even 10 m, than the current depth. Nevertheless, water exchange was restricted during the MIS 5a – MIS 4 transition when the sea level fluctuated very close to the sill height. The hydrological conditions within the Gulf during most of the highstands MIS 5a, 5c, and 5e reflect higher oxygen levels and/or increased nutrient availability compared to the Holocene and present-day regime. The combined effects of Ionian Sea inflows and enhanced riverine runoff led to increased water column stratification and low oxygen, eutrophic seafloor conditions in the Gulf of Corinth during times of high precipitation in southern Europe and deposition of sapropels S3, S4, and S5 throughout the eastern Mediterranean. In contrast, during periods of widespread cold and arid conditions in the eastern Mediterranean, water column mixing was intense within the Gulf. Prevalent marine conditions are also proposed during the MIS 5b and 5d lowstands, yet associated with predominately bedded-detrital sediments in the Gulf. A complementary investigation in the adjoining Patras Gulf is suggested to fully comprehend the dynamics of climate and sea level changes in complex rift systems.

Converging forms: an examination of sub-Arctic, circumarctic, and Central Asian Ranunculus auricomus agg. populations.

Phenotypic complexity in species complexes and recently radiated lineages has resulted in a diversity of forms that have historically been classified into separate taxa. Increasingly, with the proliferation of high-throughput sequencing methods, additional layers of complexity have been recognized, such as frequent hybridization and reticulation, which may call into question the previous morphological groupings of closely related organisms. We investigated Northern European, Asian, and Beringian populations of Ranunculus auricomus agg. with phylogenomic analysis of 736 genes and 27,586 SNPs in order to deduce the interrelatedness and hybrid origin of this phenotypically and taxonomically complicated group from Europe characterized by a history of hybridization, polyploidy, apomixis, and recent radiation. The ploidy levels and the reproductive mode of the Northern European populations were assessed via flow cytometric seed screening. In addition, in order to examine the phenotypic plasticity of the dwarf forms previously described as species and summarized as the Ranunculus monophyllus group, we conductedclimate chamber experiments under cold (northern) and warm (temperate) conditions. The Northern European populations are tetra- to hexaploid and propagate primarily through apomixis. The complex is characterized by highly reticulate relationships. Genetic differentiation of the main clusters has occurred between the above-mentioned geographical regions. We find evidence for the hybrid origin of the taxa in these areas with differing genomic contributions from the geographically nearest European sexual progenitor species. Furthermore, polyphyly in the taxa of the R. monophyllus group is supported. Experiments show low lability in the traits associated with the R. monophyllus group. We conclude that multiple adaptations of hybrids to colder climates and shorter vegetation periods have shaped the phenotypes of the R. monophyllus group, and we suggest a formal classification as nothotaxa within the R. auricomus group.

Late Pleistocene depositional processes of coastal aeolian deposits and their relationship with environment change on the Changxing Island of Liaodong Peninsula, northeastern China

Coastal aeolian deposits are product of the coupling between aerodynamics and coastal hydrodynamics, which is of great significance for reconstructing aeolian activities and the coastal environmental change. Here, we investigated the coastal aeolian deposits on Changxing Island, northeastern China, using geochemistry and microscopy of the minerals together with the published sedimentological data. The results showed that aeolian deposits are mainly derived from beach sands reworked by wind. Previously published Optically Stimulated Luminescence (OSL) dating results show that the deposition ages of the aeolian deposits are 41 ka, 49 ka, and 67 ka, respectively. The sedimentologic and geochemistry of aeolian deposits are sensitive to climate change. Notably, the micromorphology structure of the surface of quartz sand particles reveals the process of the coastal environment evolution. ∼41 ka, the surface of the grains is characterized by significant subaqueous environments, showing subangular with high relief, large conchoidal fracture, and V-shaped pits. These features correspond to the early sub-interstadial stage of MIS3, characterized by a warm and humid climate and sea level highstand. Under the relative sea level rise, the high rate of sand supply produced by coastal erosion contribute to aeolian deposit formation. In contrast, at 49 ka and 67 ka, the quartz grain exhibits typical aeolian environment features that exhibits subrounded with low relief, upturned plates, and dish-shaped pits, which respond to glacial periods of cold and windy conditions and sea level lowstand. The exposure of abundant sandy material, coupled with lower vegetation cover and strong East Asian winter monsoon (EAWM) contribute to higher sediment availability and sand accumulation. We therefore propose that sediment supply control by sea-level change is the primary reason for coastal aeolian sand deposition under different climatic backgrounds.

Study on electric vehicle thermal management system using phase change materials and CO2 heat pump waste heat recovery under cold conditions

The thermal management system plays a pivotal role in electric vehicle. The CO2 heat pump technology, which performs well at low temperatures and environmentally friendly, has emerged as one of the most promising solutions for optimizing the thermal management system of electric vehicles. However, at −30 ℃ to −15 ℃, the CO2 heat pump faces issues with excessively high discharge temperatures and limited Gas Cooler heat exchange area, thereby there is potential of waste heat recovery and utilization. This paper proposes a thermal management system that utilizes PCM heat storage to recover waste heat from the CO2 heat pump. The system aims to insulate the battery during winter parking, reducing the battery’s preheating energy consumption and enhancing the vehicle’s overall energy utilization efficiency. This paper explored the waste heat characteristics of CO2 heat pump under various conditions. Subsequently, Numerical structural optimization analysis of the PCM heat storage was conducted. Finally, an economic analysis of the PCM heat storage is performed, considering the boundary condition of the urban climate. The result showed that Under the heat production control strategy, the PCM heat storage has a high heat storage rate at −30 ∼ -20 ℃ ambient temperature, reaching 1470 W ∼ 2709 W, and the heat storage time is less than 1 h. At −15 ℃, where the energy saving is maximized, the system battery coupled with the PCM heat heat storage consumes only 0.88 kWh for preheating, saving 44 % compared to the 1.58 kWh consumed by the baseline. The PCM heat storage demonstrates a better energy-saving effect in colder areas.

Comparative study of the thermo‐catalytic reforming of agricultural and forest residue and advanced characterization of final products in a cold climate

AbstractGlobal agricultural and forest residues hold promise for renewable fuel production through thermo‐catalytic reforming (TCR). Limited data exists on TCR outcomes for regions known for cold conditions like Canada. This study used a 2 kg h−1 TCR unit for the intermediate pyrolysis/reforming of agricultural (wheat straw pellet, WSP) and forest (softwood pellet, SWP) residues. Maximum bio‐oil yields were 8.43% for wheat straw pellets and 7.99% for softwood pellets at 400 and 500°C reactor and reformer temperatures. Feedstock, bio‐oil, and biochar properties were analyzed through proximate and ultimate analysis. At 550°C reactor and 700°C reforming temperatures, 70.73% of the wheat straw pellet‐based gas yield contained 36.11 vol.% H2 and 11.08 vol.% CH4, giving a higher heating value (HHV) of 12.54 MJ kg−1. A high concentration of CH4 (22.02 vol.%) in the softwood pellet‐based gas gave an HHV of 17.94 MJ kg−1. The low viscosity (3.9 mPa · s−1) and total acid number (7.3 mg KOH g−1) wheat straw pellet‐based bio‐oil had an O/C molar ratio of 0.09 and an HHV of 35.80 MJ kg−1. The 400/600°C reactor/reformer temperatures gave the lowest area percentage of mono‐aromatic (16 vol.%) and polycyclic aromatic (11.20 vol.%) compounds in the softwood pellet bio‐oil. The O/C molar ratio (0.5–0.6) in softwood pellet biochar elevated the higher heating value from 32.37 to 34.57 MJ kg−1. The study results guide optimal TCR unit operation in cold climates like Canada with local feedstocks, emphasizing its notable hydrogen production over bio‐oil and biochar.

Why does the courtyard spaces of same ethnic group present diverse characteristics in different regions： evidence based on ENVI-met climate modeling

The rapid urbanization in developing countries like China has led to a heightened challenge of climate degradation and the erosion of traditional ecological knowledge worldwide. The widespread distribution of Yi traditional settlements across various climatic zones in southwest China offers a unique opportunity to investigate the diverse courtyard spaces within the same ethnic group, influenced by distinct climatic environments. Through comprehensive field investigation, meticulous field measurement, and rigorous ENVI-met simulation, this study conducts a comparative analysis of microclimates in Yi typical courtyards across diverse climatic conditions. The results show that: 1) Courtyard plays a pivotal role in regulating microclimate dynamics across cold, temperate, and hot climatic conditions. 2) The microclimate regulation mechanism of a courtyard varies across different climatic environments. 3) The climate regulation efficacy of courtyards will diminish as the climate environment undergoes changes. 4) The aspect ratio (AR) is a key spatial factor which plays a crucial role in determining the efficiency of regulating courtyard microclimate. Concluded this study, the research findings not only provide valuable guidance for the protection planning and design of traditional Yi settlements in southwest China, but also offer significant insights for courtyard construction in other regions with extreme climates worldwide. In addition, this study constructs a new research framework for traditional settlements, which is of great significance for scientifically and accurately identifying the spatial value of traditional settlements and improving the theoretical system of traditional settlement protection and activation.

Species-specific differences in bumblebee worker body size between different elevations: Implications for pollinator community structure under climate change

Pollinator populations face growing threats from global climate change, particularly in alpine environments with rapidly rising temperatures. Understanding how bumblebees, critical alpine pollinators, respond to these temperature changes is therefore an important goal. Predicting species’ responses to climate change requires several different approaches, one of which is to compare processes at different elevations, which experience different temperature regimes. Bumblebee body size is linked to fitness through its influence on nutritional requirements and foraging capacity. It is also a highly plastic trait that depends on ecological factors such as temperature. Thus, understanding how body size varies at different elevations may help predict bumblebee fitness under climate change. We collected bumblebee workers from five species in a single growing season, at two distinct elevations in the Swiss Alps. Our study aimed to examine whether body size responses differed among species and across functional traits related to foraging and nesting. Larger body size is thought to confer an advantage under cold conditions; we therefore expected greater body size with elevation, but with species-specific relationships. Contrary to our expectation, not all species were larger at high elevations. Specifically, while two species were significantly larger at high elevation, one (Bombus terrestris) was significantly smaller at high elevation, and two showed no size differences with elevation. Additionally, interspecific variation in body size was greater at low elevations. This suggests a divergence of body size with warming, although local factors may also play a role in shaping functional traits.

Middle to late Holocene human societies on the eastern margin of the Eurasian Steppe, and their adaptation to environmental changes

The impact of environmental changes on the development of human societies in the Eurasian Steppe is not well understood over the Holocene timescale. In this study, we have reported the phytoliths, grain size, and weight loss on ignition for an aeolian soil profile in the Liao River Basin at the eastern margin of the Eurasian Steppe. The profiles spanned the middle and late Holocene based on AMS 14C dating. By employing the summed radiocarbon probability distribution of archaeological sites and kernel density analysis, the spatial and temporal distributions of human populations and settlements were investigated in order to analyze the rise and fall of ancient cultures. Our findings indicated that the environment in the Liao River Basin underwent three stages of change. From 6700 to 5400 cal yr BP, the climate was warm and humid. The climate suddenly became cold and dry from 5400 to 4900 cal yr BP. The climate fluctuated, with a general tendency towards cold and dry conditions, from 4900 cal yr BP to 1700 cal yr BP. In addition, human societies in the region underwent significant changes, with rapid agricultural development and population growth in the warm and humid environment of the Middle Neolithic (6700–5000 yr BP). However, during the Late Neolithic (5000–4000 yr BP), the living environment suddenly became cold and dry, which limited the development of human society and drastically reduced its population. Nevertheless, the resilience of human societies continued to increase, and in the Bronze Age (4000–2000 yr BP), even in an overall cold and dry living environment, human societies still developed and their population increased sharply. Changes in the East Asia Summer Monsoon were an important driver of cultural change, and our study emphasizes the complex human-environment interactions that shaped societal development on the Eurasian Steppe.

Effects of Packaging Material and Moisture Contents on Pulse Beetle Infestation under Different Storage Conditions in Chickpea

Chickpea (Cicer arietinum L.) is an important pulse crop grown globally for its nutritional richness and versatility which offers a significant source for both carbohydrates and protein. Chickpea seeds face a significant threat from various insect pests among these pulse beetles or bruchids (Callosobruchus spp.) stand out as the most destructive, inflicting damage ranging from 50% to 60% during storage. Bruchids are considered minor pests in the field, but they pose a serious threat during storage, leading to both quantitative and qualitative losses. The present investigation was carried out with the objective of studying the influence of ambient and cold storage conditions on storability and to assess the pest infestation (pulse beetle) under ambient and cold storage conditions in two chickpea varieties viz., JG-11 (desi) and NBeG-119 (kabuli). The seed was thoroughly sun dried to two moisture levels of seven and nine percent and stored in gunny and grain pro bags (hermetic bags). Gunny bags were kept at ambient storage as well as in the cold storage, while grain pro bags were stored at ambient storage conditions only as these are the hermetic bags and the dry chain technology concept holds good for storage at ambient conditions only. Highest % seed damage (12.11 % in JG-11 and 13.00 % in NBeG-119) was noticed in seeds stored with nine per cent moisture content while, the lowest % seed damage (9.50 % in JG-11 and 9.83 % in NBeG 119) was recorded in seeds with seven per cent moisture content. After 8 months of storage highest per cent fecundity (151.66 and 144.66 in JG-11 and 145.00 and 138.50 in NBeG-119) was recorded in seeds stored in gunny bags kept at ambient storage with nine and seven per cent moisture respectively, followed by the seed stored in grain pro bags at ambient storage with nine percent seed moisture (9.667 in JG-11 and 7.833 in NBeG-119) and no fecundity was recorded in seeds stored in gunny bag at cold storage. At the end of storage period highest adult emergence was recorded in seeds stored in gunny bag at ambient storage with nine (196.83 in JG-11 and 217.17 in NBeG-119) and seven (187.83 in JG-11 and 207.83 in NBeG-119) per cent seed moisture followed by the seed stored in grain pro bags at ambient storage with nine percent seed moisture (11.67 in JG-11 and 13.00 in NBeG-119) and no adult emergence was recorded in seeds stored in gunny bag at cold storage (0.00 in JG-11 and 0.00 in NBeG-119 ) with seven and nine percent moisture at the end of the storage. Highest weight loss % (2.019% in JG-11 and 1.866% in NBeG-119) was recorded in seeds stored with nine per cent moisture content. While, the lowest weight loss % (1.679% in JG-11 and 1.772% in NBeG-119) was noticed in seeds stored with seven per cent moisture at the end of storage period.

Extreme coastal El Niño events are tightly linked to the development of the Pacific Meridional Modes

Coastal El Niño events—marine heatwaves instances in the far eastern Tropical Pacific during otherwise basin-scale neutral or cold conditions—can have severe societal impacts for countries along the west coast of South America, as exemplified by the 2017 and 2023 Peru-Ecuador floods. Due to the brevity of the observational record, it is not well understood whether these events are driven by local or large-scale processes. Here, to overcome this limitation we use a data-driven modeling approach to address their return period and forcing mechanisms. It is shown that extreme coastal El Niño events are a local manifestation in the eastern tropical Pacific of the constructive interactions of the Pacific Meridional Modes (PMM). Specifically, the North PMM yields a dipole-like anomaly SST pattern along the equator that favors its development, while the positive phase of the South PMM reinforces it. A smaller group of more moderate coastal events are remotely driven by zonal wind anomalies in the western tropical Pacific without the PMMs’ influence. The role of PMMs in the development of extreme coastal El Niño suggests that they may be more predictable than previously thought.

Differential responses of SARS-CoV-2 variants to environmental drivers during their selective sweeps

Previous work has shown that environmental variables affect SARS-CoV-2 transmission, but it is unclear whether different strains show similar environmental responses. Here we leverage genetic data on the transmission of three (Alpha, Delta and Omicron BA.1) variants of SARS-CoV-2 throughout England, to unpick the roles that climate and public-health interventions play in the circulation of this virus. We find evidence for enhanced transmission of the virus in colder conditions in the first variant selective sweep (of Alpha, in winter), but limited evidence of an impact of climate in either the second (of Delta, in the summer, when vaccines were prevalent) or third sweep (of Omicron, in the winter, during a successful booster-vaccination campaign). We argue that the results for Alpha are to be expected if the impact of climate is non-linear: we find evidence of an asymptotic impact of temperature on the alpha variant transmission rate. That is, at lower temperatures, the influence of temperature on transmission is much higher than at warmer temperatures. As with the initial spread of SARS-CoV-2, however, the overwhelming majority of variation in disease transmission is explained by the intrinsic biology of the virus and public-health mitigation measures. Specifically, when vaccination rates are high, a major driver of the spread of a new variant is it’s ability to evade immunity, and any climate effects are secondary (as evidenced for Delta and Omicron). Climate alone cannot describe the transmission dynamics of emerging SARS-CoV-2 variants.