Hasil untuk "Ecology"

V. Devictor, D. Mouillot, C. Meynard et al.

A. J. Fridlund

R. O'Neill

Ga-Eun Lee, Taeman Han, Tengteng Liu

Bucculatrix Zeller, 1839 is a large group of leaf miners in Bucculatricidae. The genus shows worldwide distribution with about 300 species, but taxonomic study has been rather limited in Korea. In this paper, we report four species of Bucculatrix for the first time in Korea: B. altera Seksjaeva, 1989, B. bisucla Seksjaeva, 1989, B. demaryella (Duponchel 1840), and B. tsurubamella Kobayashi, Hirowatari & Kuroko, 2010. Diagnoses, redescriptions, photographs of adults and genitalia, and DNA barcodes of each species are provided.

Basma M. Saleh, Osama Mere, Seham Elmrayed

BackgroundAntimicrobial resistance (AMR) is a pressing public health challenge in the Eastern Mediterranean Region (EMR), with Streptococcus pneumoniae being a major contributor due to its role in invasive pneumococcal disease (IPD). Pneumococcal conjugate vaccines (PCVs) have shown promise in reducing vaccine-type IPD and AMR, yet significant barriers persist.ObjectiveThis review examines the impact of PCVs on AMR, serotype distribution, and vaccine coverage in pediatric populations within the EMR, emphasizing the interplay between vaccination strategies and AMR trends.ContentThe introduction of PCVs, particularly PCV13, has led to reductions in vaccine-type IPD and AMR in several EMR countries. For example, post-PCV13 penicillin susceptibility in Saudi Arabia improved from 37 to 100% in invasive isolates, and Lebanon reported significant reductions in vaccine-type AMR. However, challenges such as inconsistent vaccination coverage (e.g., 76% in Yemen, absent in Egypt), socio-political instability, and the emergence of non-vaccine serotypes (NVTs) as per shown in the 73.5% of isolates in Omani children and the high multidrug resistance (MDR) rates (e.g., 85.7% in Yemen) undermine these benefits. Serotype replacement phenomena, driven by ecological shifts, are increasingly contributing to disease burden and AMR. While PCVs reduce the need for antibiotics and limit selective pressures driving resistance, high rates of MDR and inadequate antibiotic stewardship remain concerns. Strengthened vaccination programs, high-valency vaccines, and robust surveillance systems are critical to addressing these challenges.ConclusionPCVs play a pivotal role in mitigating AMR and reducing pneumococcal disease burden in the EMR. However, suboptimal vaccine coverage, NVT emergence, and persistent AMR highlight the need for comprehensive strategies, including enhanced coverage of higher valency vaccines, robust surveillance, targeted public health interventions, strengthened antibiotic stewardship, and improved regional collaboration. Addressing these issues can significantly reduce the AMR burden and improve health outcomes across the region.

Jiangxue Shi, Wenyan Zhang, Yi Dong et al.

The intertidal sediments of Sanya Haitang Bay, a tropical coast, harbor abundant multicellular magnetotactic prokaryotes (MMPs). Using light and electron microscopy, micromanipulation sorting, and whole-genome amplification, we examined their diversity from morphological, phylogenetic, and ecological perspectives. Two types of MMPs were identified: ellipsoidal (eMMPs) and spherical (sMMPs). Their average abundance was 1.37 × 10³ ind./dm³ in autumn and 0.27 × 10³ ind./dm³ in spring, indicating strong seasonal variation. eMMPs averaged 9.74 × 8.15 µm, consisting of 80–100 cells arranged in layers, whereas sMMPs averaged 5.64 µm in diameter with 40–50 cells organized radially or spirally. Electron microscopy revealed bullet-shaped magnetosomes in both types: those in eMMPs averaged 90.1 × 34.0 nm, while those in sMMPs averaged 97.2 × 36.3 nm. Interestingly, Cu was homogenously detected in the magnetosomes of sMMPs. 16S rRNA gene analysis identified nine OTUs, including three potential new species in the Desulfobacteraceae family within Thermodesulfobacteriota phylum. Of these, two may represent a new genus, and one is affiliated with <i>Candidatus</i> Magnetananas. Global distribution analysis suggests that eMMPs prefer stable, nutrient-rich environments, whereas sMMPs occupy broader ecological niches. Together, these findings expand understanding of tropical MMP diversity and distribution, and the discovery of Cu-containing magnetosomes provides new insight into biomineralization mechanisms.

José Edson Fontes Figueiredo, Gisele de Fátima Dias Diniz, Mikaely Sousa Marins et al.

IntroductionBacillus velezensis is a ubiquitous bacterium with potent antifungal activity and a plant growth promoter. This study investigated the potential of B. velezensis CNPMS-22 as a biocontrol agent against phytopathogenic fungi under diverse experimental conditions and its potential as a plant growth promoter. Genome sequencing and analysis revealed putative genes involved in these traits.MethodsThis research performed in vitro experiments to evaluate the CNPMS-22 antagonistic activity against 10 phytopathogenic fungi using dual culture in plate (DCP) and inverted sealed plate assay (ISP). Greenhouse and field tests evaluated the ability of CNPMS-22 to control Fusarium verticillioides in maize plants in vivo. The CNPMS-22 genome was sequenced using the Illumina HiSeq 4,000 platform, and genomic analysis also included manual procedures to identify genes of interest accurately.ResultsCNPMS-22 showed antifungal activity in vitro against all fungi tested, with notable reductions in mycelial growth in both DCP and ISP experiments. In the ISP, volatile organic compounds (VOCs) produced by CNPMS-22 also altered the mycelium coloration of some fungi. Scanning electron microscopy revealed morphological alterations in the hyphae of F. verticillioides in contact with CNPMS-22, including twisted, wrinkled, and ruptured hyphae. Eight cluster candidates for synthesizing non-ribosomal lipopeptides and ribosomal genes for extracellular lytic enzymes, biofilm, VOCs, and other secondary metabolites with antifungal activity and plant growth promoters were identified by genomic analysis. The greenhouse and field experiments showed that seed treatment with CNPMS-22 reduced Fusarium symptoms in plants and increased maize productivity.ConclusionOur findings highlight the CNPMS-22’s potential as bioinoculant for fungal disease control and plant growth with valuable implications for a sustainable crop productivity.

Toshkov Nesho, Kodinova Siyka, Simitchiev Apostol et al.

Watermelon (Citrullus vulgaris) seeds which are considered as waste have a high nutritional value due to the high content of proteins, minerals and unsaturated fatty acids and for that reason they are suitable for production of functional extruded products. Therefore the focus of this experiment is to investigate the effect of watermelon seed flour content, temperature of the matrix and moisture content on the density and expansion ratio of extrudates from corn grits. A single screw extruder Brabender 20 DN was used for the extrusion cooking. A full factorial experiment 23 with independent parameters watermelon seed flour content (3 % and 10 %), temperature of the matrix (160 °C and 180 °C) and moisture content (14 % and 18 %) was applied. The expansion ratio varies between 1.76 and 2.56 while the density change from 0.103 g/cm3 to 0.159 g/cm3 respectively. The statistical analysis showed that the expansion ratio decrease with the increase of the moisture content and watermelon seed flour content while the density increase.

Masoumeh Panahi, Rasool Rezaei, Habiballah Charehgani

Meloidogyne javanica and Ralstonia solanacearum are the highly specialized soil-born plant parasites with economic importance causing root-knot and bacterial wilt diseases in tomatoes, respectively. The occurrence and intensity of the bacterial wilt escalated in the presence of root-knot nematodes and R. solanacearum concurrently detected in different vegetable crops. Sampling and preparation of leaf extract were done to investigate the activity of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POX) enzymes at 24, 48, 72, and 120 hours post-inoculation (hpi) of tomato plants with R. solanacearum and M. javanica. The enzyme activity was measured at each time interval. The CAT and SOD enzymes exhibited maximum activity levels at 120 and 48 hpi in the nematode treatment, respectively. Meanwhile, the levels of POX enzyme peaked at 48 and 72 hpi in the nematode and nematode-bacterium treatments, respectively. Pathogen stress eventually led to a decrease in the SOD and POX enzymes 120 hours after inoculation and a significant increase in CAT during nematode-bacterium treatment. The results revealed apparent enzyme activity variations in tomato plants infected with both pathogens at different time intervals after inoculation.

Yue Zhang, Hongqi Wu, Yiliang Kang et al.

Soil salinization has a significant impact on agricultural production and ecology. There is an urgent demand to establish an effective method that monitors the spatial and temporal distribution of soil salinity. In this study, a multi-indicator soil salinity monitoring model was proposed for monitoring soil salinity in Bachu County, Kashgar Region, Xinjiang, from 2002 to 2022. The model was established by combining multiple predictors (spectral, salinity, and composite indices and topographic factors) and the accuracy of the four models (Random Forest [RF], Partial Least Squares [PLS], Classification Regression Tree [CART], and Support Vector Machine [SVM]) was compared. The results reveal the high accuracy of the optimized prediction model, and the order of the accuracy is observed as RF > PLS > CART > SVM. The most accurate model, RF, exhibited an R² of 0.723, a root mean square error (RMSE) of 2.604 g·kg⁻¹, and a mean absolute error (MAE) of 1.95 g·kg⁻¹ at a 0–20 cm depth. At a 20–40 cm depth, RF had an R² value of 0.64, an RMSE of 3.62 g·kg⁻¹, and an MAE of 2.728 g·kg⁻¹. Spatial changes in soil salinity were observed throughout the study period, particularly increased salinization from 2002 to 2012 in the agricultural and mountainous areas within the central and western regions of the country. However, salinization declined from 2012 to 2022, with a decreasing trend in salinity observed in the top 0–20 cm of soil, followed by an increasing trend in salinity at a 20–40 cm depth. The proposed method can effectively extract large-scale soil salinity and provide a practical basis for simplifying the remote sensing monitoring and management of soil salinity. This study also provides constructive suggestions for the protection of agricultural areas and farmlands.

John R. Lewis

R. Smith

Carlos J. Dommar, Leonardo López, Richard Paul et al.

In 2013, the Caribbean underwent an unprecedented epidemic of Chikungunya that affected 29 islands and mainland territories throughout the Caribbean in the first six months. Analysing the spread of the epidemic among the Caribbean islands, we show that the initial patterns of the epidemic can be explained by a network model based on the flight connections among islands. The network does not follow a random graph model and its topology is likely the product of geo-political relationships that generate increased connectedness among locations sharing the same language. Therefore, the infection propagated preferentially among islands that belong to the same cultural domain, irrespective of their human and vector population densities. Importantly, the flight network topology was also a more important determinant of the disease dynamics than the actual volume of traffic. Finally, the severity of the epidemic was found to depend, in the first instance, on which island was initially infected. This investigation shows how a simple epidemic model coupled with an appropriate human mobility model can reproduce the observed epidemiological dynamics. Also, it sheds light on the design of interventions in the face of the emergence of infections in similar settings of naive subpopulations loosely interconnected by host movement. This study delves into the feasibility of developing models to anticipate the emergence of vector-borne infections, showing the importance of network topology, bringing valuable methods for public health officials when planning control policies. Significance statement: The study shows how a simple epidemic model associated with an appropriate human mobility model can reproduce the observed epidemiological dynamics of the 2014 Chikungunya epidemic in the Caribbean region. This model sheds light on the design of interventions in the face of the emergence of infections in similar settings of naive subpopulations loosely interconnected by the host.

F. Waterhouse

Ruimin Qin, Jingjing Wei, Li Ma et al.

<i>Pedicularis kansuensis</i> is an indicator species of grassland degradation. Its population expansion dramatically impacts the production and service function of the grassland ecosystem, but the effects and mechanisms of the expansion are still unclear. In order to understand the ecological effects of <i>P. kansuensis</i>, three <i>P. kansuensis</i> patches of different densities were selected in an alpine grassland, and species diversity indexes, biomasses, soil physicochemical properties, and the mechanism among them were analyzed. The results showed that <i>P. kansuensis</i> expansion increased the richness index, the Shannon–Wiener index significantly, and the aboveground biomass ratio (ABR) of the Weed group (<i>p</i> < 0.05), but reduced the total biomass of the community and the ABR of the Gramineae and Cyperaceae decreased insignificantly (<i>p</i> > 0.05); soil moisture, soil AOC, and NO₃⁻·N decreased significantly (<i>p</i> < 0.05), while soil pH and total soil nutrients did not change significantly, and available phosphorus (AP) decreased at first and then increased (<i>p</i> < 0.05). The structural equation model (SEM) showed that <i>P. kansuensis</i> expansion had a significant positive effect on the community richness index, and a significant negative effect followed on the soil AOC from the increase of the index; the increase of pH had a significant negative effect on the soil AOC, NO₃⁻·N, and AP. It indicated that <i>P. kansuensis</i> expansion resulted in the increase of species richness, the ABR of the Weed group, and the community’s water demand, which promoted the over-utilization of soil available nutrients in turn, and finally caused the decline of soil quality. This study elucidated a possible mechanism of poisonous weeds expansion, and provided a scientific and theoretical basis for grassland management.

Jianbo Qing, Jianbo Qing, Changqun Li et al.

BackgroundIgA nephropathy (IgAN) is the most frequent glomerulonephritis in inflammatory bowel disease (IBD). However, the inter-relational mechanisms between them are still unclear. This study aimed to explore the shared gene effects and potential immune mechanisms in IgAN and IBD.MethodsThe microarray data of IgAN and IBD in the Gene Expression Omnibus (GEO) database were downloaded. The differential expression analysis was used to identify the shared differentially expressed genes (SDEGs). Besides, the shared transcription factors (TFs) and microRNAs (miRNAs) in IgAN and IBD were screened using humanTFDB, HMDD, ENCODE, JASPAR, and ChEA databases. Moreover, weighted gene co-expression network analysis (WGCNA) was used to identify the shared immune-related genes (SIRGs) related to IgAN and IBD, and R software package org.hs.eg.db (Version3.1.0) were used to identify common immune pathways in IgAN and IBD.ResultsIn this study, 64 SDEGs and 28 SIRGs were identified, and the area under the receiver operating characteristic curve (ROC) of 64 SDEGs was calculated and two genes (MVP, PDXK) with high area under the curve (AUC) in both IgAN and IBD were screened out as potential diagnostic biomarkers. We then screened 3 shared TFs (SRY, MEF2D and SREBF1) and 3 miRNAs (hsa-miR-146, hsa-miR-21 and hsa-miR-320), and further found that the immune pathways of 64SDEGs, 28SIRGs and 3miRNAs were mainly including B cell receptor signaling pathway, FcγR-mediated phagocytosis, IL-17 signaling pathway, toll-like receptor signaling pathway, TNF signaling pathway, TRP channels, T cell receptor signaling pathway, Th17 cell differentiation, and cytokine-cytokine receptor interaction.ConclusionOur work revealed the differentiation of Th17 cells may mediate the abnormal humoral immunity in IgAN and IBD patients and identified novel gene candidates that could be used as biomarkers or potential therapeutic targets.

T. Smith, R. Smith

Katie M. Moriarty, Joel Thompson, Matthew Delheimer et al.

Background Many mammalian species have experienced range contractions. Following a reduction in distribution that has resulted in apparently small and disjunct populations, the Humboldt marten (Martes caurina humboldtensis) was recently designated as federally Threatened and state Endangered. This subspecies of Pacific marten occurring in coastal Oregon and northern California, also known as coastal martens, appear unlike martens that occur in snow-associated regions in that vegetation associations appear to differ widely between Humboldt marten populations. We expected current distributions represent realized niches, but estimating factors associated with long-term occurrence was challenging for this rare and little-known species. Here, we assessed the predicted contemporary distribution of Humboldt martens and interpret our findings as hypotheses correlated with the subspecies’ niche to inform strategic conservation actions. Methods We modeled Humboldt marten distribution using a maximum entropy (Maxent) approach. We spatially-thinned 10,229 marten locations collected from 1996–2020 by applying a minimum distance of 500-m between locations, resulting in 384 locations used to assess correlations of marten occurrence with biotic and abiotic variables. We independently optimized the spatial scale of each variable and focused development of model variables on biotic associations (e.g., hypothesized relationships with forest conditions), given that abiotic factors such as precipitation are largely static and not alterable within a management context. Results Humboldt marten locations were positively associated with increased shrub cover (salal (Gautheria shallon)), mast producing trees (e.g., tanoak, Notholithocarpus densiflorus), increased pine (Pinus sp.) proportion of total basal area, annual precipitation at home-range spatial scales, low and high amounts of canopy cover and slope, and cooler August temperatures. Unlike other recent literature, we found little evidence that Humboldt martens were associated with old-growth structural indices. This case study provides an example of how limited information on rare or lesser-known species can lead to differing interpretations, emphasizing the need for study-level replication in ecology. Humboldt marten conservation would benefit from continued survey effort to clarify range extent, population sizes, and fine-scale habitat use.

R. Daubenmire