Simpson's Diversity Index Research Articles

Spatial heterogeneity of fire and flooding patterns can support higher diversity of floral functional traits in an indigenous‐managed landscape

AbstractIn tropical wetlands, in addition to flooding, fire also contributes to the structure of biodiversity across environmental gradients. In fire‐prone ecosystems, flower‐rich fire refuges can be maintained by a seasonal patch‐burning mosaic. Here, we evaluate how a set of floral traits that influence and are related to the pollination systems of tree and non‐tree species varies in response to spatial patterns of fire frequency in a landscape with floodable and flood‐free areas. We classified the sampled species according to flower size, color, shape, symmetry, floral resource, type of pollination units, flowering duration, and anthesis time and compared them between floodable and flood‐free areas with high, moderate, or low fire frequency. We analyzed the functional richness in response to landscape metrics related to spatial patterns of fire frequency. The composition of floral traits of non‐tree species was stable, while tree species differed among fire frequency classes, especially in floodable areas. Many floral traits of tree species are ecological indicators, especially in floodable areas with high fire frequency. In contrast, among non‐tree species, only floral tissues as resources for pollinator were related to flood‐free areas with moderate/high fire frequency. The floral functional richness of the tree species positively linked with the modified Simpson diversity index, and for both trees and non‐trees, it negatively associated with the homogenization of the fire frequency (e.g., connectance based on probability that two adjacent sites belong to the same fire frequency class was negatively related to the functional richness of floral traits). These results demonstrate that homogenization of fire frequency in the landscape decreases the functional richness. Patches with different combinations of fire frequency and flood regime can support a shared set of floral traits besides those specifically related to a particular regime. The spatial heterogeneity of fire and flood patterns in wetlands needs to be preserved to support a higher diversity of pollination systems mediated by functional complementarity between the flowers of the tree and non‐tree species.

ORCHID DIVERSITY (Orchidaceae) IN TWO URBAN SITES IN THE STATE OF VERACRUZ, MEXICO

Knowledge of urban orchids and their phorophytes is essential for conservation and education initiatives in these areas. The objective of this study was to assess the diversity of epiphytic orchids and identify their phorophytes at Postgraduate College Campus Córdoba (CPCC) and Paso Coyol Ecological Park (PEPC) in order to better understand the differences in their composition. The hypothesis was that the diversity of naturally established orchids would be higher in the less urbanized area, while the phorophytes would be mostly introduced trees. Orchids growing on phorophytes of the garden area (12 000 m²) of both sites were quantified from November 2019 to December 2021. The origin (endemic, native, or exotic) of the orchids and their phorophytes were determined. Simpson and Shannon-Weaver diversity indices were applied, and Whittaker curves were developed. A total of 13 419 orchid individuals were recorded, divided into 31 species, with 26 species reported in the CPCC and 17 in the PEPC. The Simpson and Shannon-Weaver indices showed that the diversity of epiphytic orchids was higher in the CPCC (1-D = 0.78) than in the PEPC (1-D = 0.41). In contrast, species dominance was lower in the CPCC (H = 2.6) than in the PEPC (H = 1.16). Whittaker curves showed that Catasetum integerrimum was the most abundant species in the CPPC and Platystele stenostachya in the PEPC. The CPCC had a greater level of diversity. Fifteen species of phorophytes were recorded in the CPCC and 10 in the PEPC, with a predominance of exotic species, while introduced species accounted for 70 % of the phorophytes found.

Sustainable forest development in the face of global warming: Optimizing Robinia pseudoacacia L. stands to alleviate soil moisture depletion

To foster sustainable forest development amid global warming, it is imperative to enhance the quality of existing forest stands while avoiding excessive depletion of soil moisture. This study established 24 Robinia pseudoacacia L. standard plots (40 × 40 m2) in the Caijiachuan watershed, located in the gully region of the Loess Plateau, Shanxi Province, China, to monitor soil moisture content from 2007 to 2021. Additionally, the study examined the influence of 19 ecological factors, including climate, topography, and stand characteristics, on soil moisture. The findings indicated a sustained decline in soil moisture storage across the 0–200 cm soil profile, with significant depletion at 0–140 cm. The soil moisture content at depths of 80–200 cm was critically low, resulting in a “dry soil layer” during years with low precipitation. Climatic factors (average annual temperature and annual precipitation) and stand factors (uniform angle index, stand density, litter thickness, and Simpson diversity index of the shrubs) emerged as dominant factors impacting soil moisture variations. An increase in average annual temperature due to global warming, compounded by suboptimal stand density, primarily drove soil moisture depletion. Using a multivariate optimization equation to model the relationship between dominant factors and soil moisture storage, this study recommends a dynamic stand management strategy. This strategy involves selective thinning or replanting of Robinia pseudoacacia L. trees, targeting a gradual reduction in optimal stand density from 1500 to 1000 plants·ha−1 over the next two decades. Additionally, transitioning stand spatial arrangements from uniform or clustered to random distributions, maintaining ideal litter thickness (2.43–2.47 cm), and enhancing shrub diversity are advisable. Such measures can alleviate soil moisture deficits in Robinia pseudoacacia L. stands attributable to global warming, thereby promoting the Loess Plateau's sustainable forestry advancement.

Analysis of the decision to convert croplands into E. Camaldulensis woodlot and its impact on income diversification in Mecha district, Northwest Ethiopia

Financial benefits from Eucalyptus woodlot growing can surpass staple crop production; nevertheless, the reasons for this shift and its potential impacts on income diversification remain largely unknown in the highlands of Ethiopia. Using a binary logistic regression model, the study aimed to evaluate the factors influencing the conversion of cropland to Eucalyptus camaldulensis woodlots. The independent t-test and the Simpson Diversity Index were used to evaluate the impact of transition on income diversification. Quantitative data gathered from 337 randomly chosen household heads were used in the analysis. Results revealed that market demand for E. camaldulensis woodlot, plot accessibility to a transportation route, declining cropland productivity, more saving potential, and total land holding size significantly influenced the decisions of farmers to convert their croplands into E. camaldulensis woodlot. Woodlot adopters diversified their source of income by 49.4 % compared to non-adopters, implying that eucalyptus woodlot plantings can be more preferred to income improvement than crop production. Policy makers must pay attention to important factors that significantly influence the decisions that farmers make about the conversion of croplands into E. camaldulensis woodlots. Increased growth in woodlots with balanced cropland output through a sustainable land management approach is required to increase the diversification of income among farmers.

Geographical distribution, disease association and diversity of Klebsiella pneumoniae K/L and O antigens in India: roadmap for vaccine development.

Klebsiella pneumoniae poses a significant healthcare challenge due to its multidrug resistance and diverse serotype landscape. This study aimed to explore the serotype diversity of 1072 K. pneumoniae and its association with geographical distribution, disease severity and antimicrobial/virulence patterns in India. Whole-genome sequencing was performed on the Illumina platform, and genomic analysis was carried out using the Kleborate tool. The analysis revealed a total of 78 different KL types, among which KL64 (n=274/1072, 26 %), KL51 (n=249/1072, 24 %), and KL2 (n=88/1072, 8 %) were the most prevalent. In contrast, only 13 distinct O types were identified, with O1/O2v1 (n=471/1072, 44 %), O1/O2v2 (n=353/1072, 33 %), and OL101 (n=66/1072, 6 %) being the predominant serotypes. The study identified 114 different sequence types (STs) with varying serotypes, with ST231 being the most predominant. O serotypes were strongly linked with STs, with O1/O2v1 predominantly associated with ST231. Simpson's diversity index and Fisher's exact test revealed higher serotype diversity in the north and east regions, along with intriguing associations between specific serotypes and resistance profiles. No significant association between KL or O types and disease severity was observed. Furthermore, we found the specific association of virulence factors yersiniabactin and aerobactin (P<0.05) with KL types but no association with O antigen types (P>0.05). Conventionally described hypervirulent clones (i.e. KL1 and KL2) in India lacked typical virulent markers (i.e. aerobactin), contrasting with other regional serotypes (KL51). The cumulative distribution of KL and O serotypes suggests that future vaccines may have to include either ~20 KL or four O types to cover >85 % of the carbapenemase-producing Indian K. pneumoniae population. The results highlight the necessity for comprehensive strategies to manage the diverse landscape of K. pneumoniae strains across different regions in India. Understanding regional serotype dynamics is pivotal for targeted surveillance, interventions, and tailored vaccine strategies to tackle the diverse landscape of K. pneumoniae infections across India. This article contains data hosted by Microreact.

Vertical distribution of microplastics in sediment columns along the coastline of China

At present, there has been relatively less coverage of microplastics (MPs) pollution in sediment columns, especially across a large geographical span. This study collected sediment columns across 11 provinces along the coastline of China for MPs pollution investigation. The study found higher MPs diversity (Simpson diversity index) in sediment columns than in surface sediments, mostly comprising fiber MPs with dominant transparent and blue colors. Lower MPs pollution was noted in mangrove reserves, while estuarine and coastal areas showed higher pollution levels. Spearman correlation analysis shows that vertical of MPs abundance significantly decreased with depth at 6 of 11 sites. Large-sized MPs with diverse colors in deeper sediments (>40 cm) suggests that burial processes may render MPs more resistant to degradation. Our research highlights varied MPs distribution in coastal sediment, aiding future marine MPs pollution prediction and assessment.

Emergence of genetic diversity and multi-drug resistant Clostridium perfringens from wild birds

BackgroundClostridium perfringens (C. perfringens) is an important zoonotic microorganism that can cause animal and human infections, however information about the prevalence status in wild birds of this pathogenic bacterium is currently limited.ResultIn this study, 57 strains of C. perfringens were isolated from 328 fecal samples of wild birds. All the isolates were identified as type A and 70.18% of the isolates carried the cpb2 gene. Antimicrobial susceptibility testing showed that and 22.80% of the isolates were classified as multidrug-resistant strains. The MLST analysis of the 57 isolates from wild birds was categorized into 55 different sequence types (STs) and clustered into eight clonal complexes (CCs) with an average of 20.1 alleles and the Simpson Diversity index (Ds) of 0.9812, and revealed a high level of genetic diversity within the C. perfringens populations. Interestingly, the isolates from swan goose were clustered in the same CC while isolates from other bird species were more scattered suggesting that a potential difference in genetic diversity among the C. perfringens populations associated with different bird species.ConclusionC. perfringens exhibits a wide range of host adaptations, varying degrees of antimicrobial resistance, and a high degree of genetic diversity in wild birds. Understanding the prevalence, toxin type, antimicrobial resistance, and genetic diversity of C. perfringens in wildlife populations is essential for developing effective strategies for disease control and management.

Effects of Organic Farming on Soil Probiotics of Double Rice Cropping System in South China

Organic management practices of double rice cropping can contribute to soil health and crop productivity. However, the impact of organic versus conventional farming practices (CK) on the diversity and functionality of soil probiotics remains poorly understood, despite growing interest in sustainable agricultural methods. To this end, this study evaluated the effects of these farming systems in double rice production on soil microbial communities using metagenomic sequencing and the PROBIO database. Our study accessed the Shannon and Simpson diversity indices of soil probiotics between the two farming systems. Specifically, the Shannon index values were 93.82 for CK and 93.51 for organic farming, showing no statistically significant difference. Similarly, the Simpson index values were 6.18 for CK and 6.46 for organic farming, also demonstrating no significant variance. However, distinct variations in microbial community compositions were observed. Organic farming significantly increased (P &amp;lt; 0.05) the abundance of probiotics that benefit plant growth and nitrogen supply, but reduced those associated with plant nutrient supply and yield. The results show that while organic farming can positively influence certain microbial functions beneficial for sustainable agriculture, it also presents challenges that may affect crop productivity and ecosystem services. These findings suggest that organic farming practices need to be carefully managed to harness the benefits of enhanced microbial functions without compromising crop yields.

Probiotics and Antibiotic-Induced Microbial Aberrations in Children

Probiotics are often considered in children to prevent antibiotic-associated diarrhea. However, the underlying mechanistic effects and impact of probiotics on antibiotic-induced microbiota changes are not well understood. To investigate the effects of a multispecies probiotic on the gut microbiota composition in children receiving antibiotics. This is a secondary analysis of a randomized, quadruple-blind, placebo-controlled clinical trial from February 1, 2018, to May 31, 2021, including 350 children receiving broad-spectrum antibiotics in the inpatient and outpatient settings. Patients were followed up until 1 month after the intervention period. Fecal samples and data were analyzed between September 1, 2022, and February 28, 2023. Eligibility criteria included 3 months to 18 years of age and recruitment within 24 hours following initiation of broad-spectrum systemic antibiotics. In total, 646 eligible patients were approached and 350 participated in the trial. Participants were randomly assigned to receive daily placebo or a multispecies probiotic formulation consisting of 8 strains from 5 different genera during antibiotic treatment and for 7 days afterward. Fecal stool samples were collected at 4 predefined times: (1) inclusion, (2) last day of antibiotic use, (3) last day of the study intervention, and (4) 1 month after intervention. Microbiota analysis was performed by 16S ribosomal RNA gene sequencing. A total of 350 children were randomized and collected stool samples from 88 were eligible for the microbiota analysis (54 boys and 34 girls; mean [SD] age, 47.09 [55.64] months). Alpha diversity did not significantly differ between groups at the first 3 times. Shannon diversity (mean [SD], 3.56 [0.75] vs 3.09 [1.00]; P = .02) and inverse Simpson diversity (mean [SD], 3.75 [95% CI, 1.66-5.82] vs -1.31 [95% CI, -3.17 to 0.53]; P = 1 × 10-4) indices were higher in the placebo group compared with the probiotic group 1 month after intervention. Beta diversity was not significantly different at any of the times. Three of 5 supplemented genera had higher relative abundance during probiotic supplementation, but this difference had disappeared after 1 month. The studied probiotic mixture had minor and transient effects on the microbiota composition during and after antibiotic treatment. Further research is needed to understand their working mechanisms in manipulating the microbiome and preventing antibiotic-associated dysbiosis and adverse effects such as antibiotic-associated diarrhea. ClinicalTrials.gov Identifier: NCT03334604.

Seasonal variation and diversity of endophytic fungi isolated from different parts of Andrographis paniculata (Burm. f.) Wall. ex Nees

A total of 18 species of endophytic fungi were isolated from Andrographis paniculata plant. The fungi were: Aspergillus flavus, A. niger, A. terreus, Cladosporium sp., Colletotrichum sp., Curvularia chonburiensis, Curvularia lycopersici, Fusarium solani, Fusarium udum, Fusarium sp. 1, Lasiodiplodia theobromae, Monodictys paradoxa, P. chrysogenum, P. oxalicum, Penicillium sp. 1, Penicillium sp. 2, Penicillium sp. 3, and Scytalidium lignicola. In summer, 18 species of fungi were isolated from A. paniculata while 13 fungal species were isolated in winter season. The highest value of Shannon and Simpson diversity index was found in the leaf in summer season and the lowest value in the stem in winter season. Maximum species richness of endophytic fungi was recorded in leaf in Margalef‘s index and Menhinick index in winter season. Minimum species richness of endophytic fungi was recorded in stem in Margalef’s index and Menhinick index in summer season. Biodivers. Conserv. Bioresour. Manag. 2024, 10(1): 29-34

Unravelling the paradox of spatial homogeneity: An analysis of land use planning and monofunctional development in Wroclaw, Poland

Processes of urban development progressing across Europe, with built-up areas expanding at a faster rate than the population, especially in the Central and Eastern Europe region. The importance of ensuring a high quality of urban life and effective environmental planning is widely acknowledged for the sustainable development of functional urban areas. While the literature extensively covers the implementation stage of monofunctional development in Polish suburban zones, the origins of spatial homogeneity in planning have received limited attention in research. This paper aims to assess local zoning plans and examine the diversity of urban planning in the subregion of Wroclaw, Poland. Employing exploratory experts interviews and landscape metrics such as Patch Richness Density and Simpson Diversity Index, along with spatial statistics as the Hot Spot tool and Cluster and Outlier analysis, the findings reveal that monofunctional residential development in Polish functional urban areas may result from a complex interplay of various economic, institutional, educational, professional responsibility, and political, social, as well as historical factors on the urban planning stage. These results contribute to a deeper understanding of the extent and spatial distribution of planning diversity, opening paths for further discussions on the professional requirements of urban planners.

Diversity and distribution of birds in a Congo Basin wetland: the upstream part of the Nyong River valley in Cameroon along two regions (Centre and East)

Several studies have recently been carried out on the avifauna of Cameroon and have made it possible to update the data for certain regions; however, no recent study has been carried out on the upper valley of the Nyong River, which is a wetland, and therefore the data remains quite old. We carried out a study on the avifauna of this valley and birds were sampled over a period of one year using the mist-netting method. The collected data were analyzed using PAST bio statistical software for the diversity and distribution of the avifauna. A total of 268 individuals belonging to 69 bird species were captured, with a high proportion of passerines (73%) compared with non-passerines. The high diversity of the avifauna is supported by estimated values of diversity indexes which show an absence of supremacy of one species (H’=3.64) and an equal distribution of individuals in their environment (J’=0.86). With the value of the Simpson diversity index of 0.96, our result confirms high diversity within the upper valley of the Nyong River avifauna but it also reveals the abundance of this avifauna. In addition, the Kruskal-Wallis test value of 0.04 showed a significant difference in the distribution of relative abundances of taxa at the areas investigated and that different could be justified by a difference in the physiognomy of their vegetation. This study confirms that the composition as well as the structure of the upper valley of the Nyong River as observed in the field play a main role in the diversity of bird species due to the presence of feeding, resting and nesting areas. Based on our distribution and diversity analysis, the pattern of variation in distribution of birds in this wetland appears to lean on environmental factors and particularly the vegetation, which played the main role with a mixture of poor and good dispersers, migratory and vagrant due to presence of lush vegetation all year round.

Antibiotyping, RAPD- and ERIC-PCR fingerprinting of Klebsiella pneumoniae clinical isolates at a tertiary reference hospital in Denpasar, Bali, Indonesia.

Klebsiella pneumoniae is a healthcare-associated infections agent and could be an extended spectrum β-lactamase (ESBL) producer. Understanding the transmission of this bacterium in a hospital setting needs accurate typing methods. An antibiogram is used to detect the resistance pattern of the isolates. Random Amplified Polymorphic DNA (RAPD) and Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR are rapid, technically simple, and easy-to-interpret DNA typing methods. This study aimed to evaluate the use of antibiotyping, RAPD-, and ERIC-PCR to investigate the heterogeneity of K. pneumoniae isolated from clinical specimens. The antibiograms of 46 K. pneumoniae clinical isolates were determined by Vitek® 2 Compact. All isolates underwent RAPD-PCR using AP4 primer and ERIC-PCR using ERIC-2 primer. The dendrogram was generated using the GelJ software and analyzed to determine its similarity. The analysis of antibiogram and the molecular typing diversity index was calculated using the formula of the Simpson's diversity index. About 71.7% of the isolates were ESBL-producers, and more than 80% of isolates were susceptible to amikacin, ertapenem, and meropenem. The antibiotyping produced 32 diverse types with DI = 0.964. In addition, the RAPD-PCR produced 47 different types with DI = 1, while ERIC-PCR was 46 (DI=0.999). Antibiotyping, RAPD- and ERIC-PCR showed powerful discrimination power among the isolates, supported the diversity of K. pneumoniae isolates in current study. These combination could be promising tools for clonal relationship determination, including in tracking the transmission of the outbreak's agent in hospital setting.

Unbiased estimation of sampling variance for Simpson's diversity index.

Quantification of measurement uncertainty is crucial for robust scientific inference, yet accurate estimates of this uncertainty remain elusive for ecological measures of diversity. Here, we address this longstanding challenge by deriving a closed-form unbiased estimator for the sampling variance of Simpson's diversity index. In numerical tests the estimator consistently outperforms existing approaches, particularly for applications in which species richness exceeds sample size. We apply the estimator to quantify biodiversity loss in marine ecosystems and to demonstrate ligand-dependent contributions of T-cell-receptor chains to specificity, illustrating its versatility across fields. The novel estimator provides researchers with a reliable method for comparing diversity between samples, essential for quantifying biodiversity trends and making informed conservation decisions.

Charting heterogeneity and spatial landscape of consensus molecular subtypes in colorectal cancer.

e15647 Background: High inter-patient heterogeneity and spatial diversity within tumors represent significant challenges to improving outcomes in colorectal cancer (CRC). Despite elucidation of consensus molecular subtypes (CMS), little progress has been made in translating this knowledge into clinical gain. Intratumoral CMS heterogeneity remains a relatively unexplored area and understanding of the interplay between subtypes holds promise for improving prognostication. We leverage spatial transcriptomics (ST) to enhance understanding of CMS heterogeneity and spatial distribution, with the goal of advancing personalized therapy through high resolution molecular sub-typing. Methods: ST using the 10x Genomics Visium platform was performed on paraffin-embedded CRC specimens for which comprehensive clinicopathological and long-term clinical outcome data were available. ST data were deconvoluted with respect to CMS single-cell RNA sequencing (scRNA-seq) data, yielding maps of CMS landscapes at a resolution of 55 microns. A pre-trained deep learning model was used to identify distinct CRC tissue classes (tumor epithelium, stroma, etc.) within H&amp;E images, enabling spatial correlation of histomorphology with CMS. Cellular composition within these CMS maps was quantified through deconvolution of six major cell types using reference scRNA-seq data. Pseudo-bulk samples were generated from the ST data to evaluate CMS behaviors and compute pathway activities. Results: 40 CRC patients were assayed using ST and H&amp;E profiling (13, 8, 14, and 5 from stages 1-4, respectively). Median follow-up was 112 months (Range 1–192). Intratumoral CMS heterogeneity was evident in all patients, with diverse CMS compositions. Using Simpson diversity index to quantify this heterogeneity, we observed significant correlation of heterogeneity with disease specific survival (DSS) (p = .03). CMS landscapes displayed spatial patterns that were distinct among tissue categories (average F1-score: testing = .92, validation = .89. Tissue categories based on deep learning from H&amp;E images). Tumors with higher levels of CMS1 or 4 were associated with worse outcome. Stratification by the composite CMS biomarker (CMS1+CMS4)/(CMS2+CMS3) yielded significant separation of the Kaplan-Meier curve for DSS (p = .018). Conclusions: This study demonstrates that CRC tumors contain significant intratumoral CMS heterogeneity that is not detectable using bulk classification methods. Spatial patterns in CMS transcriptional topographies correlate with H&amp;E-derived morphology, suggesting the potential for estimating CMS composition from histopathological features. Importantly, we show that spatially composite CMS-derived biomarkers possess strong prognostic potential. The capacity to decode CMS topographic patterns and associate these with clinical outcome offers great potential to advance personalized therapy for CRC.

Biodiversity Analysis of Protected Forests in Central Kalimantan: Implications for Conservation and Sustainable Management

Protected forests in Central Kalimantan are vital reservoirs of biodiversity, housing diverse flora and fauna crucial for local and global ecosystems. Despite their ecological significance, these forests face imminent threats from deforestation, illegal encroachment, and climate change, jeopardizing their biodiversity and ecological integrity. This study aims to assess the biodiversity of Central Kalimantan's protected forests and explore its implications for conservation and sustainable management. The research methodology employs a comprehensive approach, integrating field surveys, laboratory analysis, and community engagement. Field surveys involve transect walks, camera traps, and direct observations to inventory flora and fauna. Soil and water analyses assess habitat conditions, while participatory approaches engage local communities in forest management. Findings reveal a rich diversity of flora and fauna, including rare and endemic species such as Shorea stenoptera and Dipterocarpus grandiflorus. High Shannon-Wiener and Simpson diversity indices indicate a healthy ecosystem, but deforestation and illegal encroachment pose significant threats, fragmenting habitats and disrupting species survival. Climate change exacerbates these challenges, necessitating adaptation strategies for ecosystem resilience. Community participation emerges as pivotal in conservation efforts, leveraging traditional knowledge and fostering sustainable livelihoods. Collaboration among stakeholders is essential for effective forest management, emphasizing the need for holistic conservation strategies. In conclusion, this study underscores the urgent need for conservation action to safeguard the biodiversity of Central Kalimantan's protected forests. By integrating scientific research with community engagement, policymakers and stakeholders can develop effective strategies to conserve these invaluable ecosystems, ensuring their sustainability for future generations.

Effects of Organic Fertilizer Addition to Vegetation and Soil Bacterial Communities in Saline-Alkali-Degraded Grassland with Photovoltaic Panels.

The Songnen grassland is an important resource for livestock production in China. Due to the intensification of anthropogenic activities in recent years, vegetation degradation has worsened, and the salinization of grassland has become increasingly serious, which severely affects the sustainable development of grassland animal husbandry. In this study, organic fertilizer addition was carried out at saline-and-alkaline-degraded Songnen grassland sites with photovoltaic panels, and we investigated the effects of organic fertilizer treatments on the vegetation and soil bacteria in these areas. The results showed that both organic fertilizer treatments increased the community composition and diversity indices of plants (p < 0.05); they also had significant effects on soil electrical conductivity and rapidly available potassium (p < 0.05). In the dominant phylum of bacteria, the relative abundance of Firmicutes increased without adding organic fertilizer under the photovoltaic panel; the addition of organic fertilizer had a significant effect on the relative abundance of Firmicutes and Desulfobacterota (p < 0.05), reducing their relative abundance, respectively. There were differences in the number of bacteria at the genus level under different treatments compared to the control, with the highest enrichment of bacteria occurring at the OFE position, and a significant difference (p < 0.05) being found between the control and the other four groups at the genus level of g_norank_f_norank_o_Actinomarinales. Organic fertilizer had a significant effect on the bacterial Simpson diversity index, with the most significant increasing trend found in OFE (the front eaves of the photovoltaic panel in fertilization area). The results of a correlation analysis showed that pH, electrical conductivity, and total nitrogen were the main factors affecting the soil bacterial community.

Microplastic pollution in surface sediments of Coromandel coastline, South-East Coast, India: Diversity index, carbonyl index, pollution load index, risk fraction and MPs inventory

The investigation along the Coromandel coastline of South-east India focused on assessing microplastics abundance using Simpson's diversity index (DIMP), Degradation-carbonyl index (DgCIMP), Pollution load index (PLIMP) and Ecological risk fraction (RfMP). These indices evaluated the dissemination and transportation of MPs across a 1076 km stretch divided into five zones from Chennai to Kanyakumari. During the wet season, average microplastics abundance (101 ± 36.6 items/kg dw) was lower compared to the dry season (143 ± 56.2 items/kg dw). Notably, 54% and 45% of microplastics were found in the 0.1–0.5 mm size range, with 45% and 64% being colored microplastics, and 80% and 71% being fibers during the wet and dry seasons respectively. Micro-Fourier-transform infrared spectroscopy (μFTIR) analysis showed rayon (34%) and PE (64%) dominance in ports and estuaries during both seasons. Kottaipattinam Port exhibited higher diversity indices (DIMPsh=0.56,DIMPsz=0.66,DIMPco=0.50andDIMPpo=0.65) compared to other zones, with an overall diversity index IDIMP of 0.57. Notably, among the DgCIMP values (n = 96), only 12 fell within the moderate photo-chemical oxidation range (0.16–0.35), while the majority (n = 60) surpassed 0.35 indicating higher oxidation levels, with some (n = 24) exceeding 0.50, signifying extreme oxidation. PLIMP revealed that 42% of sampling stations had very low to negligible MP contamination levels in ports and estuaries. However, ecological risk fraction RfMP values ranged from 10.2 to 13,670, with 27% of values exceeding 1500, indicating higher coastal ecological risk in 13 sampling stations.

Association among polydisperse aerodynamic size of bioaerosols, biodiversity and urbanization in kindergartens

The aerodynamic sizes of bioaerosols may significantly affect their behaviors, respiratory deposition and biodiversity. The respirable bacterial size, biodiversity, and human-associated bacteria (HAB) related bioaerosols were evaluated at three kindergartens in Taiwan. Kindergartens A, B, and C were in urban, semi-urban, and rural areas, respectively. A six-stage viable Andersen cascade impactor was used to collect bioaerosols and to determine their size distributions. The geometric mean diameter (GMD), geometric standard deviation (GSD), heat maps, and uniformity were used to evaluate the association of bacteria characteristics. A BD Phoenix-100 automated interpretation system was used to identify the airborne bacteria species.The results revealed that 1425 colonies of the sampled airborne bacteria contained 63 species in 29 genera, and overall, 63.0% were HABs. The most abundant phylum was Actinobacteria (56.6 ± 22.2%) and Firmicutes (31.6 ± 22.3%), and from the taxonomic analysis, both airborne Micrococcus and the Staphylococcus aureus are the dominant genus. All the bacteria aerodynamic particle size distributions were polydisperse distributions. The heat map and uniformity analysis had revealed most of the sampled bioaerosols distributed between 1.1–3.3 μm, and most of the polydisperse airborne Streptococcus spp. had a size in the respirable range, due to urbanization, they have potentially contributed to respiratory risk in the kindergartens. The Shannon diversity index (H) and inverse Simpson diversity index (D) of the bioaerosols in urban kindergarten were negatively correlated with GMD and GSD. The Pearson correlations revealed that the kindergarten in the rural area, with a higher temperature, a lower relative humidity, and a lower CO2 concentration than the others, tended to have the largest H and D values (P < 0.05). Multiple and stepwise regression revealed that bioaerosol aerodynamic size was statistically significantly correlated with H (P = 0.001) and D values (P = 0.002). This study sheds light on the characteristics of bioaerosols and their associations with microbiome.

Ecology of multispecies biofilm formed in refrigerated raw milk in the presence of nisin and the quorum quenching furanone

SummaryCharacterisation of bacterial communities in multispecies biofilm can aid the search for prevention and control strategies. This study evaluated the influence of nisin and quorum quenching compound furanone on the diversity of biofilm formed from raw milk. Stainless steel coupons were immersed in raw milk containing either nisin or furanone. Biofilm DNA was extracted, followed by metataxonomic analyses. Chao‐1 richness, Simpson, and Shannon diversity indexes fluctuated over the 10‐day period in the control biofilm. However, both nisin and furanone led to a decrease in the Chao‐1 index of the biofilm microbiota and small fluctuation in the Simpson and Shannon diversity indexes without altering the number of sessile cells. Gammaproteobacteria, recognised contaminants of significance in milk, was the dominant class in all biofilms. Addition of nisin or furanone to the raw milk altered the microbial community of the biofilm, resulting particularly in the abundance of the genera Acinetobacter, Lactococcus, and Serratia.