Search Results (168)

The Fernald Feed Materials Production Center (FMPC), located in Fernald, Ohio, USA, released radon (Rn) as a byproduct of the processing of uranium materials during the years from 1951 to 1989. Rn is a colorless, odorless gas that emits charged alpha radiation that interacts with cells in the lung and trachea-bronchial tree, leading to DNA damage, mutations, and tumor initiation. The purpose of this project was to use evidence collected by the Fernald Dosimetry Reconstruction Project and other sources to estimate the outdoor Rn exposure to individuals in the community immediately surrounding the FMPC during the years of plant operation. Using previously tabulated source terms, diffusion and meteorological data, and self-reported detailed residential histories, we estimated radon exposure for approximately 9300 persons who lived at more than 14,000 addresses. The results indicated that a portion of the population cohort experiences mean annual Rn exposure exceeding the U.S. Environmental Protection Agency (EPA) action limit of 4 pCiL⁻¹. These exposure estimates support the analysis of the incidence of lung cancer in the Fernald Community Cohort (FCC). Full article

Studying the nutritional ecology of Neoseiulus cucumeris (Oudemans) at different temperatures is a fundamental tool for improving mass production for use in biological control of pest mites. The current research studied the impact of both food types and temperatures on the life history and demographic parameters of the predator mite N. cucumeris. Mite cultures in the laboratory were developed using Tetranychus urticae Koch, and N. cucumeris was collected from field plants. The developmental stages of N. cucumeris fed on date palm pollen and the immature stages of T. urticae were investigated in a laboratory setting at different temperatures. Our research revealed that N. cucumeris readily accepted both food types at all the tested temperatures. The developmental stages and adult longevity of N. cucumeris, both female and male, decreased dramatically when the temperature increased from 18 °C to 34 °C. The net reproductive rate (R₀) reached its greatest values of 22.52 and 9.72 offspring/individual at 26 °C, and the intrinsic rate of increase (r_m) reached its maximum values of 0.17 and 0.13 day⁻¹ at 34 °C and minimum of 0.12 and 0.10 day⁻¹ at 18 °C, when fed on date palm pollen and immature stages of T. urticae, respectively. Conversely, the average generation time (T) showed a notable reduction from 22.48 to 16.48 and 20.88 to 16.76 days, accompanied by an upsurge in temperature from 18 °C to 34 °C, when fed on date palm pollen and immature stages of T. urticae, respectively. The finite rate of growth (λ) exhibited distinct variations, reaching its highest value at 34 °C, 26 °C, and 18 °C when fed on date palm pollen and immature stages of T. urticae, respectively. From these results, we can conclude that N. cucumeris was successfully fed date palm pollen as an alternate source of nourishment. In addition, the immature stages of T. urticae are suitable as food sources for N. cucumeris because they shorten the mean generation time. Therefore, the success of mass-rearing the predator mite N. cucumeris on a different, less expensive diet, such as date palm pollen, and determining the most suitable temperature for it has increased its spread as a biocontrol agent. Full article

Agroecological transitions in collective urban gardens in Toulouse region were studied through the prism of global health (2011–2022). The specific meaning of “global health” in the context of urban gardens concerns the health of gardeners (well-being and physical health), plants, soil, and animals, as well as the interactions between humans and non-humans, which are crucial for gardeners. A sociotechnical research project was developed on four different collective gardening sites, consisting of the following: 1. surveys issued to 100 garden stakeholders to highlight issues and practices, participation in meetings with the social centers in charge of events, and focus groups; 2. participative agronomic and environmental measurements and field observations, including soil quality analyses; and 3. analysis of the available documentary corpus. In order to produce the results, these three research methods (surveys, agronomy, document analysis) were combined through a transdisciplinary approach, in that both the field experimentation outcomes and retrieved scientific publications and technical documents informed the discussions with gardeners. Consideration of the four different sites enabled the exploration of various contextual factors—such as soil or air quality—affecting the production of vegetables. A rise in the concerns of gardeners about the impacts of their activities on global health was observed, including aspects such as creating and enjoying landscapes, taking care of the soil and biodiversity, developing social connections through the transmission of practices, and regular outside physical activity and healthier eating. The increased consideration for global health issues by all stakeholders promotes the implementation of agroecological practices in gardens to improve biodiversity and adherence to circular economy principles. Four concepts emerged from the interviews: health, production of vegetables, living soil, and social interactions. Notably, nuances between the studied sites were observed, according to their history, environment, and organization. These collective gardens can thus be considered as accessible laboratories for social and agroecological experimentation, being areas that can strongly contribute to urban ecosystem services. Full article

Old vineyards in production in the Pampa biome have high levels of metals, such as copper (Cu), zinc (Zn), and manganese (Mn). The high metal contents in the soil can damage the growth and development of the cover plant species that cohabit the vineyards. However, it is possible to define the critical toxicity level (CTL) of metals in soil and tissue in order to monitor and define possible strategies for reducing metal inputs and selecting more tolerant species. This study aimed to define the CTL of Cu, Zn, and Mn in the soil and plant tissue of plants present between the rows of vineyards with different cultivation histories in the Pampa biome in South America. For this purpose, soil and plant tissue samples were collected in a native field area (NF), without agricultural cultivation and in two vineyards, vineyard 1 (V1) and vineyard 2 (V2), both with a history of fungicide application. To define the CTL, the foliar concentrations and soil contents of Cu, Zn, and Mn were correlated with the dry mass production of the shoot. The CTLs for Cu, Zn, and Mn in the soil were set at 15, 3.0, and 35 mg kg⁻¹, respectively. In the tissue, CTLs for Cu, Zn, and Mn were estimated at 75, 77, and 380 mg kg⁻¹, respectively. The contents of Cu, Mn, and Zn in the soil of the vineyards are above the CTL. The concentrations of the metals in the tissue varied, with samples above the CTL for Cu and Zn in the vineyards. The values of Cu, Zn, and Mn in NF are below the CTL in soil and tissue. The high contents of Cu, Zn, and Mn in the soil and tissue limited the dry mass production of the plants between the rows of vineyards. Full article

Muehlenbeckia tuggeranong is an endangered subshrub with an estimated seven individuals remaining in its native habitat, and twelve held in an ex situ living collection in the Australian National Botanic Gardens, Canberra. We conducted a genetic analysis on all known individuals of the species both in situ and ex situ to inform the conservation management of one of the rarest plants in Australia, certainly the rarest in the Australian Capital Territory. We found recent seedlings did not result from hybridisation with M. axillaris but resulted from sexual reproduction within the ex situ collection, leading to greater genetic diversity ex situ than in situ. However, low genetic diversity across the species indicates a high risk of extinction. Through simulations we identified the optimal breeding pairs to minimise further genetic diversity loss and increase the number of available genotypes for future reintroduction. Our work highlights the need to incorporate genetically informed breeding programs into living collections management of endangered plant species, particular those with unique life history traits. Full article

The diverse topography and mild monsoon climate in East Asia are considered to be important drivers for the long-term ecological success of the Tertiary relict ‘living fossil’ plants during the glacial/interglacial cycles. Here we investigated the phylogeographic pattern and demographic history of a hamamelidaceous Tertiary relict ‘living fossil’ tree (Parrotia subaequalis) endemic to the subtropical forests of eastern China, employing molecular data and ecological niche modeling. In the long evolutionary history, P. subaequalis has accumulated a high haplotype diversity. Weak gene flow by seeds, geographical isolation, and heterogeneous habitats have led to a relatively high level of genetic differentiation in this species. The divergence time of two cpDNA lineages of P. subaequalis was dated to the late Miocene of the Tertiary period, and the diversification of haplotypes occurred in the Quaternary period. Paleo-distribution modeling suggested that P. subaequalis followed the pattern of ‘glacial expansion-interglacial compression’. The Dabie Mountain and Yellow Mountain in Anhui Province and the Tianmu Mountain and Simin Mountain in Zhejiang Province were inferred to be multiple glacial refugia of P. subaequalis in East Asia and have been proposed to be protected as ‘Management Units’. Collectively, our study offers insights into the plant evolution and adaptation of P. subaequalis and other Tertiary relict ‘living fossil’ trees endemic to East Asia refugia. Full article

Understory flowering plants often face limitations in pollinator availability. This necessitates an investigation of pollination mechanisms and reproductive traits to understand their survival strategies. Floral syndromes, which are critical determinants of plant–pollinator coevolution, significantly impact the reproductive success and diversification dynamics of angiosperms. The genus Impatiens is known for its remarkable floral diversity and varied pollination systems and it is also serves as an exemplary model for examining plant–pollinator interactions. Therefore, this study was performed to elucidate the pollination characteristics and breeding systems of three sympatric species, Impatiens davidii, Impatiens jinggangensis, and Impatiens commelinoides. The results indicated all the Impatiens species exhibited similar individual flower longevity (4–5 days). However, I. commelinoides and I. jinggangensis peaked in July-August, whereas I. davidii primarily flowered in August-September. These species shared a self-compatible breeding system that requires pollinators for facultative outcrossing, with bumblebees (Bombus) and polyester bees (Amegilla) identified as the primary pollinators. The presence of wing petals had a significant impact on fruit set in both I. davidii and I. commelinoides. The three Impatiens species demonstrated notable interspecific differences in their floral scent profiles, accompanied by distinct variations in floral morphology and scent characteristics. These differences collectively represent pollination strategies and life-history tactics that highlight pronounced interspecific divergence. The variation in pollination strategies is attributed to the synergistic interaction between floral morphology and scent chemistry. Thus, these findings offer valuable insights for the investigation of forest understory plant conservation, resource utilization, and co-evolutionary relationships with primary pollinators. Full article

Hemp (Cannabis sativa L.) is one of the oldest annual fiber crops cultivated throughout human history. Addressing the challenges encountered during the harvesting of hemp for seed and fiber purposes requires further investigation. Studies are also needed to determine plant characteristics in terms of both variety and gender. This study aimed to determine the physico-mechanical properties of hemp plants. The stems of male and female hemp plants were divided into three sections along their length: lower, middle, and upper regions. Samples measuring 25.4 mm in length were collected from each section, and measurements of thickness and inner and outer diameter were conducted. The same samples were subjected to axial and lateral compression tests to determine load, elongation, and energy values. According to the results, the thickness of hemp ranged from 2.347 mm to 2.628 mm, the inner diameter varied between 3.986 mm and 4.452 mm, while the outer diameter ranged from 8.861 mm to 9.708 mm. The results showed that male hemp plants have an increase in thickness and inner and outer diameter values from the lower to the upper region compared to female hemp plants. The compressive loads in the axial and lateral directions were found to be higher in male hemp plants compared to female hemp plants. Moreover, elongation and energy requirements during axial and lateral compressions showed trends consistent with the load values across the stem samples. This study determined that the results of axial and lateral compression applied at three different positions (lower, middle, and upper) on male and female hemp stalks varied significantly based on both sex and position. Full article

The Ascomycete genus Cordyceps affects plant crops significantly, filling an important ecological niche. Cordyceps militaris (L.) Fr. presents many health benefits for humans, but its population history has not been reported. The objective of this research was to report the collection, population structure, demographic history, diversity, and cytosine deaminases of 43 wild strains of C. militaris in China through resequencing using an Illumina HiseqTM platform. All strains were assigned to the warm, subtropical, and middle temperate zone populations, confirmed by ADMIXTURE-1.3.0, PCA, and phylogenic analysis. Their population sizes declined historically, suggesting that this species suffered from bottlenecks in the wild. LD decays (r²) revealed a north-to-south migration pattern of wild C. militaris, consistent with the MSMC2-v2.1.4 analysis. The regions of high Pi were aggregating at the chromosomes CP023325.1 (51) and CP023323.1 (9), playing a key role in adaptation, especially for the sites on cytosine deaminase. Within the species, genetic differentiation was relatively high among the three populations (F_st = 0.083, 0.092, and even 0.109). According to the artificial intelligence-assisted (RoseTTAFold) predicted structures of the cytosine deaminases, they were classified into eight clades with unique, distinct, and structurally conserved domains, offering a potential suite of single- and double-stranded deaminases of great promise as tunable base editors for therapeutic and agricultural breeding applications. These provided new insights for mining novel proteins from macrofungi, structurally and functionally. Full article

The use of herbal medicines containing Petasites hybridus extracts has a long history in the treatment of various ailments. The observed effects are primarily due to pharmacologically active compounds such as petasin, isopetasin, and neopetasin. In evidence-based phytotherapy, extracts from leaves and rhizomes are applied for different indications. While leaf extracts are administered to treat allergic rhinitis symptoms, rhizome extracts are utilized among others in the management of gastrointestinal spasms and migraines. The quality and source of plants are critical for producing authorized herbal medicinal products. Although the preparation of P. hybridus leaf extracts from cultivated plant material is already established, the rhizomes used for preparing extracts are still derived from commercial wild collections. However, switching to cultivation is desirable to ensure consistent quality and availability. For regulatory purposes, comparative pharmacological studies are needed to assess the bioactivity of plant material from different sources. Therefore, this study analyzed rhizome extracts from wild harvesting and cultivation for their petasin composition (i.e., isopetasin, neopetasin, petasin) and spasmolytic effects on Ca²⁺-dependent precontracted guinea pig ileum ex vivo. The results confirm petasins as active compounds of P. hybridus rhizome extracts. Moreover, they demonstrate that the total content of petasins determines the spasmolytic effects, regardless of the individual composition of the different petasins. No significant differences in efficacy were found between cultivated and wild-collected rhizomes, demonstrating that cultivated material is a reliable, consistent, and sustainable alternative for P. hybridus rhizome extract production. Full article

Tanacetum balsamita is a perennial medicinal plant belonging to the Asteraceae family. The species bears a long history as a valuable traditional drug in different cultures, while it is an essential component in the traditional cuisine of several countries. In this context, our literature review aims at providing a comprehensive overview of T. balsamita, covering its traditional uses, phytochemistry, biological activities, and toxicity from 1983 to 2024. Methods: Various databases were used to collect the information, including Scopus, Science Direct, Google Scholar, PubMed, and Web of Science. Results and conclusions: Although many of its traditional uses have gradually faded into obscurity over the centuries, recent decades have rekindled the interest in this species. Recent ethnobotanical surveys have reported the use of this species against various health-related conditions, while current pharmacological studies have corroborated several health benefits of the species, such as antioxidant, antidiabetic, anti-hyperpigmentation, anticancer, and antimicrobial activities. The validated properties are mainly attributed to the presence of multiple phytoconstituents belonging to flavonoids, phenolic acids, terpenes, and fatty acids, which could also indicate potential uses for T. balsamita in the food industry as a natural preservative and flavoring agent of food products. Full article

Phyllotreta striolata (Fabricius) (Coleoptera: Chrysomelidae) is one of the most damaging pests affecting vegetables. This pest feeds on the leaves and roots of Brassicaceae plants during their adult and larval stages, respectively, resulting in substantial economic losses. The laboratory-rearing methods for P. striolata and its life-history parameters have not been fully studied. This study developed a laboratory method for the generational rearing of P. striolata, including techniques for egg collection and rearing immature individuals, which allows for the continuous observation and collection of individuals at various developmental stages. This method established five F1 populations and three consecutive generations of P. striolata from various field-collected parent populations. During the rearing process, developmental durations and survival rates at four stages of P. striolata were acquired, confirming the method’s effectiveness. The female ratio, tibia length of the hind leg, and fluctuating asymmetry of adults in three of the five F1 populations were measured to assess P. striolata’s adaptability to the rearing conditions. The established laboratory-rearing method and life-history parameters of P. striolata could potentially contribute to research in its ecology, population dynamics prediction, and pest management. Full article

Munition disposal practices have significant effects on microbial composition and overall soil health. Explosive soil contamination can disrupt microbial communities, leading to microbial abundance and richness changes. This study investigates the microbial diversity of soils and roots from sites with a history of ammunition disposal, aiming to identify organisms that may play a role in bioremediation. Soil and root samples were collected from two types of ammunition disposal (through open burning and open detonation) and unpolluted sites in Machachi, Ecuador, over two years (2022 and 2023). High-throughput sequencing of the 16S rRNA gene (for bacteria) and the ITS region (for fungi and plants) was conducted to obtain taxonomic profiles. There were significant variations in the composition of bacteria, fungi, and plant communities between polluted and unpolluted sites. Bacterial genera such as Pseudarthrobacter, Pseudomonas, and Rhizobium were more abundant in roots, while Candidatus Udaeobacter dominated unpolluted soils. Fungal classes Dothideomycetes and Sordariomycetes were prevalent across most samples, while Leotiomycetes and Agaricomycetes were also highly abundant in unpolluted samples. Plant-associated reads showed a higher abundance of Poa and Trifolium in root samples, particularly at contaminated sites, and Alchemilla, Vaccinium, and Hypericum were abundant in unpolluted sites. Alpha diversity analysis indicated that bacterial diversity was significantly higher in unpolluted root and soil samples, whereas fungal diversity was not significantly different among sites. Redundancy analysis of beta diversity showed that site, year, and sample type significantly influenced microbial community structure, with the site being the most influential factor. Differentially abundant microbial taxa, including bacteria such as Pseudarthrobacter and fungi such as Paraleptosphaeria and Talaromyces, may contribute to natural attenuation processes in explosive-contaminated soils. This research highlights the potential of certain microbial taxa to restore environments contaminated by explosives. Full article

In recent decades, a large number of houses from the Late Yangshao period have been excavated in Zhengzhou. They are basically single-level buildings with wood skeletons and mud walls and use a huge amount of timber resources. Nevertheless, there are still a lot of questions about the uncertain relationship between plants, architecture, and human activities. In this study, we complete the reconstruction of a Holocene vegetation community around the Dahecun site via pollen analysis of the Z2 core. We take house F1 in Dahecun as an example to estimate the wood consumption of a single house and collect the published data of all houses from the Late Yangshao period in the study area to estimate the wood consumption of houses built in Zhengzhou during this period. Combining the above two approaches, this study explores the relationship between plants, architecture, and human activities in Zhengzhou in the Late Yangshao period, as well as the history of land use. The results are as follows: (1) After 4.9 ka BP, the number of trees and shrubs such as Pinus (falling from 58.8% to 46.9%) decreased rapidly, and the number of herbaceous plants increased. (2) Excluding the influence of the Holocene climate change, the large-scale decline in trees and shrubs in the region is likely to have been human-driven. The number of excavated houses in 11 of the 236 Late Yangshao sites in the Zhengzhou area reached 362, while the minimum wood consumption reached 1270.62 m³. In addition, the rapid expansion of the population size and the large-scale development of new arable land and forest clearance in the Late Yangshao period show that humans had a strong influence on the surrounding vegetation and land cover/use. The trend of regional deforestation was so obvious and irreversible that the inhabitants had to adopt techniques using less wood or no wood to build houses during the subsequent Longshan culture period. Full article

Viola philippica, a medicinal herbaceous plant documented in the Chinese Pharmacopoeia, is a promising candidate for research into plant-derived pharmaceuticals. However, the study of newly emerging viruses that threaten the cultivation of V. philippica remains limited. In this study, V. philippica plants exhibiting symptoms such as leaf yellowing, mottled leaves, and vein chlorosis were collected and subjected to RNA sequencing to identify potential viral pathogens. A novel polerovirus, named Viola Philippica Polerovirus (VPPV), was identified in V. philippica. VPPV possesses a linear, positive-sense, single-stranded RNA genome consisting of 5535 nucleotides (nt) and encodes seven highly overlapping open reading frames (ORFs). Two potential recombination events were identified within ORF2, ORF3a, and ORF3, providing insights into the genetic diversity and evolution history of this novel polerovirus. An infectious cDNA clone of VPPV was successfully constructed and shown to infect Nicotiana benthamiana. Using a PVX-based heterologous expression system, the VPPV P0 protein was shown to trigger a systemic hypersensitive response (HR)-like reaction in N. benthamiana, indicating that P0 functions as the main pathogenicity determinant. These findings contributed to the detection and understanding of pathogenic mechanisms and control strategies for VPPV in V. philippica. Full article