High Diversity Research Articles

Nitrogen fixation in the widely distributed marine γ-proteobacterial diazotroph Candidatus Thalassolituus haligoni.

The high diversity and global distribution of heterotrophic bacterial diazotrophs (HBDs) in the ocean has recently become apparent. However, understanding the role these largely uncultured microorganisms play in marine N2 fixation poses a challenge due to their undefined growth requirements and the complex regulation of the nitrogenase enzyme. We isolated and characterized Candidatus Thalassolituus haligoni, a member of a widely distributed clade of HBD belonging to the Oceanospirillales. Analysis of its nifH gene via amplicon sequencing revealed the extensive distribution of Cand. T. haligoni across the Pacific, Atlantic, and Arctic Oceans. Pangenome analysis indicates that the isolate shares >99% identity with an uncultured metagenome-assembled genome called Arc-Gamma-03, recently recovered from the Arctic Ocean. Through combined genomic, proteomic, and physiological approaches, we confirmed that the isolate fixes N2 gas. However, the mechanisms governing nitrogenase regulation in Cand. T. haligoni remain unclear. We propose Cand. T. haligoni as a globally distributed, cultured HBD model species within this understudied clade of Oceanospirillales.

Robust parameter determination approach based on red-tailed hawk optimization used for lithium-ion battery

Lithium-ion electrochemical batteries are being used more in a large number of applications, such as electric vehicles. However, increasing their efficiency lies in the accuracy of their model. For this, extracting the best values of parameters of the battery model is needed. A recent metaheuristic optimizer named the red-tail hawk (RTH) is used in the current research to extract the battery parameters. The idea of this algorithm is extracted from hunting techniques of red-tail hawks. The RTH algorithm is more likely to avoid entangled local optimums because of its high diversity, fast convergence rate, and appropriate exploitation-exploration balance. The RTH optimizer is compared with other algorithms to check and approve its performance. Using the proposed method, the root mean squared error (RMSE) between the model outputs and the measured voltage dataset was decreased to 8.12E-03, much better than all the other considered algorithms.

Iterated local search with ejection chains for the space-free multi-row facility layout problem

This paper presents an iterated local search algorithm based on ejection chains to solve the space-free multi-row facility layout problem. The aim of this problem is to find a non-overlapping layout of facilities on a given number of rows such that there is no space between two adjacent facilities. In addition, the left-most facility of the arrangement must have zero abscissa. Our algorithm looks for a local optimal solution by continuously alternating ejection moves and trial moves to form an ejection chain. Since the ejection chain can compound simple moves to create more complex and powerful moves, it has a greater chance to discover better solutions. Additionally, we propose a directional perturbation strategy to produce a solution of both high quality and good diversity. The idea is to calculate the score of each facility based on the location concentration of facilities in the elite solution set and the historical perturbation times of facilities in the search process, and to select the facility with the highest score for perturbation. Experimental results on four benchmark sets containing a total of 290 instances reveal that the proposed algorithm performs better for 131 (45.2%) instances in terms of best solution values and for 196 (80.0%) instances in terms of average solution values than a recently reported state-of-the-art algorithm.

Environmental regulation and marine economic resilience: An institutional synergy perspective

Growing economic and industrial activities have put a large strain on the marine environment and ecosystem, presenting the marine economy with a tradeoff between economic expansion and environmental conservation. Though the Porter hypothesis depicts a win-win situation, it is crucial to consider the conditions under which environmental regulations generate positive effects. This paper is to study how the synergy between market-based and government-based environmental regulations affects marine economic resilience, whereas maintaining economic resilience is a prerequisite for promoting innovation and productivity. The findings indicate that each 1 % increase in the synergistic level of environmental regulations resulted in a 0.234 % improvement in marine economic resilience. The heterogeneity tests indicate that the relationship is still significant if the marine economy characterizes high industrial diversity, high industrial upgrading, and large scale, while environmental regulation in coastal provinces that marine industrial structure is not advanced negatively affects marine economic resilience.

More diverse rhizobial communities can lead to higher symbiotic nitrogen fixation rates, even in nitrogen-rich soils.

Symbiotic nitrogen (N) fixation (SNF) by legumes and their rhizobial partners is one of the most important sources of bioavailable N to terrestrial ecosystems. While most work on the regulation of SNF has focussed on abiotic drivers such as light, water and soil nutrients, the diversity of rhizobia with which individual legume partners may play an important but under-recognized role in regulating N inputs from SNF. By experimentally manipulating the diversity of rhizobia available to legumes, we demonstrate that rhizobial diversity can increase average SNF rates by more than 90%, and that high rhizobial diversity can induce increased SNF even under conditions of high soil N fertilization. However, the effects of rhizobial diversity, the conditions under which diversity effects were the strongest, and the likely mechanisms driving these diversity effects differed between the two legume species we assessed. These results provide evidence that biodiversity-ecosystem function relationships can occur at the scales of an individual plant and that the effects of rhizobial diversity may be as important as long-established abiotic factors, such as N availability, in driving terrestrial N inputs via SNF.

The Unexpected Upside of High Language Diversity

The Unexpected Upside of High Language Diversity

The Unexpected Upside of High Language Diversity

The Unexpected Upside of High Language Diversity

Interspecific competition shapes bird species' distributions along tropical precipitation gradients.

The hypothesis that species' ranges are limited by interspecific competition has motivated decades of debate, but a general answer remains elusive. Here we test this hypothesis for lowland tropical birds by examining species' precipitation niche breadths. We focus on precipitation because it-not temperature-is the dominant climate variable that shapes the biota of the lowland tropics. We used 3.6 million fine-scale citizen science records from eBird to measure species' precipitation niche breadths in 19 different regions across the globe. Consistent with the predictions of the interspecific competition hypothesis, multiple lines of evidence show that species have narrower precipitation niches in regions with more species. This means species inhabit more specialized precipitation niches in species-rich regions. We predict this niche specialization should make tropical species in high diversity regions disproportionately vulnerable to changes in precipitation regimes; preliminary empirical evidence is consistent with this prediction.

The football world upside down: Traditional equities as an alternative for the new fan tokens? A portfolio optimization study

This study provides a comprehensive analysis of the relationship between fan tokens and equities as investment vehicles in football clubs. Using the GO-GARCH methodology to account for time-varying higher-order co-moments, we examine the risk-return characteristics of these assets in different portfolio contexts over the period November 2021-March 2023. Our results show high diversification opportunities between fan tokens and equities, especially with investments in different leagues. Portfolio analysis shows that equities generally outperform fan tokens as an investment vehicle, highlighting the importance of active portfolio management. The study also shows that equities have broader diversification potential than fan tokens when added to a portfolio. Furthermore, Turkish fan tokens have better characteristics than Italian fan tokens, possibly due to the nonfinancial benefits for investors. The results are relevant for both retail and institutional investors, regardless of their risk tolerance profiles.

Shared alleles and genetic structures in different Thai domestic cat breeds: the possible influence of common racial origins

Over hundreds of years, cats have been domesticated and selectively bred, resulting in numerous pedigreed breeds expedited by recent cat shows and breeding associations. Concerns have been raised about the limited breeding options and the genetic implications of inbreeding, indicating challenges in maintaining genetic diversity and accurate identification in purebred cats. In this study, genetic variability and structure were examined in 5 Thai domestic cat breeds using 15 microsatellite markers and mitochondrial DNA (mtDNA) D-loop sequencing. In total, 184 samples representing the Wichien Maat (WCM), Suphalak (SL), Khao-Manee (KM), Korat (KR), and Konja (KJ) breeds were analyzed. High genetic diversity (Ho and He > 0.5) was observed in all breeds, and mtDNA analysis revealed two primary haplogroups (A and B) that were shared among all domestic cat breeds in Thailand and globally. However, minor differences were observed between Thai domestic cat breeds based on clustering analyses, in which a distinct genetic structure was observed in the WCM breed. This suggests that allele fixation for distinctive morphological traits has occurred in Thai domestic cat breeds that emerged in isolated regions with shared racial origins. Analysis of relationships among individuals within the breed revealed high identification efficiency in Thai domestic cat breeds (P(ID)sibs < 10−4). Additionally, diverse and effective individual identification can be ensured by optimizing marker efficiency by using only nine loci. This comprehensive genetic characterization provides valuable insights into conservation strategies and breeding practices for Thai domestic cat breeds.

Enteroaggregative Escherichia coli (EAEC) isolates obtained from non-diarrheic children carry virulence factor-encoding genes from Extraintestinal Pathogenic E. Coli (ExPEC).

Enteroaggregative E. coli (EAEC) is one of the most frequent pathogens isolated from diarrheal patients as well as from healthy individuals in Brazil and has recently also been implicated as an extraintestinal pathogenic E. coli (ExPEC) associated with bloodstream and urinary tract infections. In this study, 37 EAEC isolates, obtained from fecal samples of non-diarrheic children, were molecularly and phenotypically characterized to access the pathogenic features of these isolates. The EAEC isolates were assigned into the phylogroups A (54.1%), D (29.7%), B1 (13.5%) and B2 (2.7%); and harbored genes responsible for encoding the major pilin subunit of the aggregative adherence fimbriae (AAFs) or aggregate-forming pili (AFP) adhesins as follows: aggA (24.3%), agg3A (5.4%), agg4A (27.0%), agg5A (32.4%) and afpA (10.8%). The most frequent O:H serotypes were O15:H2 (8.1%), O38:H25 (5.4%) and O86:H2 (5.4%). Twenty-one isolates (56.8%) produce the aggregative adherence (AA) pattern on HeLa cells, and biofilm formation was more efficient among EAEC isolates harboring the aggA and agg5A genes. PFGE analysis showed that 31 (83.8%) of the isolates were classified into 10 distinct clusters, which reinforces the high diversity found among the isolates studied. Of note, 40.5% (15/37) of the EAEC isolates have a genetic profile compatible with E. coli isolates with intrinsic potential to cause extraintestinal infections in healthy individuals, and therefore, classified as EAEC/ExPEC hybrids. In conclusion, we showed the presence of EAEC/ExPEC hybrids in the intestinal microbiota of non-diarrheic children, possibly representing the source of some endogenous extraintestinal infections.

Factors affecting nutritional status among children aged below five years in Rwanda’s Western and Southern Provinces

BackgroundThe state of a child’s nutrition is a critical indicator of their overall health and wellbeing. Public health still faces challenges from undernutrition, especially in developing nations across the globe. In Rwanda, around 33% of children aged under five years suffer from chronic undernutrition. Many factors, such as poverty, illiteracy, poor WASH practices, improper child feeding practices, and insufficient healthcare, are the leading causes of undernutrition. The study aims to assess infant and young child feeding practices, WASH, food security, and their association with the nutritional status of children under five years in Rwanda’s Western and Southern provinces.MethodsA community-based cross-sectional study design was applied to study factors affecting the nutritional status of children under five years in 439 households in the Karongi, Nyabihu, and Nyamagabe districts of Rwanda. The study assessed anemia, stunting, underweight, and wasting indicators, and collected data was analyzed using SPSS version 25.ResultsThe study findings indicate that among the children surveyed, 29.2% (128) were identified as stunted, 5.9% (26) were underweight, 2.3% (10) suffered from wasting, and 20.9% (31) had anemia. Factors associated with these conditions included larger household size [AOR = 2.108; 95% CI (1.016–4.371)], positively associated with stunting. Additionally, children from households where the head was above 60 years old were more likely to exhibit stunting [AOR = 4.809; 95% CI (1.513, 15.283)]. Furthermore, a high household dietary diversity score was positively linked to being underweight [AOR = 6.061; 95% CI (1.535,23.942)].ConclusionHousehold characteristics like size, dietary diversity, and the age of the household head affect children’s nutritional status. Improving these conditions would enhance children’s nutritional status.

Mechanisms of coexistence: Exploring species sorting and character displacement in woody plants to alleviate belowground competition.

Rarely do we observe competitive exclusion within plant communities, even though plants compete for a limited pool of resources. Thus, our understanding of the mechanisms sustaining plant biodiversity might be limited. In this study, we explore two common ecological strategies, species sorting and character displacement, that promote coexistence by reducing competition. We assess the degree to which woody plants may implement these two strategies to lower belowground competition for nutrients which occurs via nutritional (mostly mycorrhizal) mutualisms. First, we compile data on plant traits and the mycorrhizal association state of woody angiosperms using a global inventory of indigenous flora. Our analysis reveals that species in locations with high mycorrhizal diversity exhibit distinct mean values in leaf area and wood density based on their mycorrhizal type, indicating species sorting. Second, we reanalyse a large dataset on leaf area to demonstrate that in areas with high mycorrhizal diversity, trees maintain divergent leaf area values, showcasing character displacement. Character displacement among plants is considered rare, making our observation significant. In summary, our study uncovers a rare occurrence of character displacement and identifies a common mechanism employed by plants to alleviate competition, shedding light on the complexities of plant coexistence in diverse ecosystems.

Climate cycling did not affect haplotype distribution in an abundant Southern African avian habitat generalist species, the familiar chat (Oenanthe familiaris).

Avian species diversity in Southern Africa is remarkably high, yet the mechanisms responsible for that diversity are poorly understood. While this is particularly true with respect to species endemic to the subregion, it is unclear as to how more broadly distributed African species may have colonized southern Africa. One process that may in part account for the high bird species diversity in southern Africa is a "species pump" model, wherein the region was repeatedly colonized by lineages from areas further north: a pattern related to climate cycling and the eastern African arid corridor. Once occupying southern Africa, with its many varied biomes, it is possible that climate cycling further affected lineages by generating genetic diversity in multiple refugia, a pattern recently shown for several southern African bird species. Here, we used mtDNA to address these questions in a widespread, sedentary habitat generalist bird species, the familiar chat (Oenanthe familiaris). The phylogenetic structure suggests a north-to-south colonization pattern, supporting the "species pump" model. Haplotype diversity was partitioned into two distinct clusters: southern Africa and Malawi (East Africa). Southern African haplotypes were not geographically partitioned, and we hypothesize that this pattern has arisen because this species is a habitat generalist, and as such resilient to habitat-altering climate perturbations. Based on our phylogenetic results, we discuss the validity of currently recognized subspecies.

Understanding the influence of environmental factors on forest composition along the vertical gradient of Northwestern Himalaya

Temperate and alpine ecosystems are considered the most sensitive and vulnerable region towards climate change in the Indian Himalayan region. The current study investigates forest composition in relation to environmental and edaphic factors, which is critical for determining plant community patterns. The impact of climatic and soil properties was studied to better understand species diversity and composition over an elevational gradient (2500–4800 m) in Beas Valley, Northwestern Himalaya. A total of 181 species from 15 community types, representing 122 genera and 53 families (9 Trees, 13 shrubs, and 142 herbs) were recorded from the valley. Non-metric multidimensional scaling (NMDS) analysis revealed significant compositional dissimilarity (PseudoF = 10.16, R2 = 0.48, p < 0.001) among vegetation types. Structural equation modeling (SEM) results indicated that tree species diversity was significantly influenced by solar radiation (β=0.17, p = 0.001) and winter temperature (β=41.95, p = 0.017). It was observed that solar radiation and winter temperature shape the community types in high elevation temperate regions. In contrast, precipitation, solar radiation along with summer temperature determine the composition of sub-alpine communities, whereas solar radiation, winter temperature and soil pH determine the composition of alpine communities. This indicated that multiple environmental factors are responsible for this diversity. The research findings shed light on crucial factors influencing high elevation plant diversity, emphasizing the significance of understanding environmental correlations for effective conservation. This is pioneer study, which will act as a reference for future studies in Beas valley. This scientific foundation allows for prioritized conservation efforts, focusing on areas with specific environmental conditions influencing forest composition and plant diversity, ultimately contributing to better management and preservation of high elevation plant communities.

Exploring the phylogeny and depth evolution of cusk eels and their relatives (Ophidiiformes: Ophidioidei).

With 289 known species in 51 genera, the ophidiiform family Ophidiidae together with their relatives from the Carapidae (36 species in eight genera) of the same suborder Ophidioidei dominate the deep sea, but some occur also in shallow water habitats. Despite their high species diversity in the deep sea and wide bathymetric distributions, their phylogenetic relationships and evolution remain unexplored due in part to sampling difficulties. Thanks to the biodiversity exploratory program entitled "Tropical Deep-Sea Benthos" and joint efforts between Taiwan and French teams for sampling from different localities across the Indo-West Pacific over the last two decades, we are able to compile comprehensive datasets for investigations. In this study, 59 samples representing 36 of 59 known ophidioid genera are selected and used to construct a multi-gene dataset to infer the phylogenetic relationships of ophidioid fishes and their relatives. Our results reveal that the Ophidiidae forms a paraphyletic group with respect to the Carapidae. The four main clades of Ophidioidei resolved are the (1) clade comprising species from the subfamily Brotulinae; (2) clade that includes species in the genera Acanthonus and Xyelacyba; (3) clade grouping Hypopleuron caninum with species from the family Carapidae; and (4) clade containing the species in the subfamily Brotulotaenilinae, Neobythitinae (in part), and Ophidiinae. Accordingly, we suggest the following new revisions based on our results and proposed morphological diagnoses. The subfamily Brotulinae should be elevated to the family level. The genera Xyelacyba and probably Tauredophidium (unsampled in this study) should be included in the newly established family Acanthonidae with Acanthonus. The families Carapidae and Ophidiidae are re-defined. Our time-calibrated phylogenetic and ancestral depth reconstructions enable us to clarify the evolutionary history of ophidiiform fishes and infer past patterns of species distributions at different depths. While Ophidiiformes is inferred to have originated in shallow waters around 96.25 million years ago (Mya), the common ancestor to the Ophidioidei is inferred to have invaded the deep sea around 90.22 Mya, the dates coinciding with the global anoxic event of the OAE2. The observed bathymetric distribution patterns in Ophidioidei most likely point to the mesopelagic zone as the center of origin and diversification. This was followed by multiple events of depth transitions or range expansions towards either shallower waters or greater depth zones, which were likely triggered by past climate changes during the Paleogene-Neogene.

Light-averse behaviour of attic-dwelling bats when commuting through urban areas

Light pollution is spreading around the world, causing a variety of problems, particularly for nocturnal animals such as bats. As urban areas expand, attic-dwelling bats face the problem of being exposed to more and more artificial light as they move to their dark foraging areas. Avoiding street lights could force bats to make energetically costly detours, which could eventually lead to the collapse of urban colonies. We therefore investigated the response of attic-dwelling bats to street lighting, using the brown long-eared bat (Plecotus auritus) as an example. Using radio-tracking, we followed 17 bats during their commutes through two urban areas: a small town and a village in rural Germany. After a conservative filtering process to ensure a high spatial accuracy of the tracking data, we analysed the data of nine bats in detail, using a use-versus-availability approach for the small town and a descriptive approach for the smaller dataset obtained from the village. The best-fitting model confirmed that the bats responded to artificial light at night. Close to the roost (∼10 m), bats preferred areas with low light intensities, but seemed to tolerate some light levels. We speculate that this pattern was caused by bats being forced to leave the roost into an illuminated area. At medium distances from roosts (∼400 m), most bats avoided street lights. In fact, all bats avoided being in close proximity to street lights, even when the lanterns produced only low levels of light. We conclude that brown long-eared bats avoid street lights when moving through urban areas. We recommend the establishment of dark corridors in urban areas to support high bat diversity, including all species along the continuum of light-opportunistic and light-sensitive species.

Prevalence and genetic diversity of Bartonella spp. in wild small mammals from South Africa.

Bartonella spp. are intracellular bacteria associated with several re-emerging human diseases. Small mammals play a significant role in the maintenance and spread of Bartonella spp. Despite the high small mammal biodiversity in South Africa, there is limited epidemiological information regarding Bartonella spp. in these mammals. The main aim of this study was to determine the prevalence and genetic diversity of Bartonella spp. from wild small mammals from 15 localities in 8 provinces of South Africa. Small mammals (n = 183) were trapped in the Eastern Cape, Free State, Gauteng, Limpopo, Mpumalanga, Northern Cape, North West, and Western Cape provinces of South Africa between 2010 and 2018. Heart, kidney, liver, lung, and spleen were harvested for Bartonella DNA screening, and prevalence was determined based on the PCR amplification of partial fragments of the 16S-23S rRNA intergenic spacer (ITS) region, gltA, and rpoB genes. Bartonella DNA was detected in Aethomys chrysophilus, Aethomys ineptus, Gerbillurus spp., Lemniscomys rosalia, Mastomys coucha, Micaelamys namaquensis, Rhabdomys pumilio, and Thallomys paedulcus. An overall prevalence of 16.9% (31/183, 95% CI: 12.2%-23%) was observed. Bartonella elizabethae, Bartonella grahamii, and Bartonella tribocorum were the zoonotic species identified, while the remaining sequences were aligned to uncultured Bartonella spp. with unknown zoonotic potential. Phylogenetic analyses confirmed five distinct Bartonella lineages (I-V), with lineage IV displaying strong M. coucha host specificity. Our results confirm that South African wild small mammals are natural reservoirs of a diverse assemblage of Bartonella spp., including some zoonotic species with high genetic diversity, although prevalence was relatively low.IMPORTANCESmall mammals play a significant role in the maintenance and spread of zoonotic pathogens such as Bartonella spp. Despite the high small mammal biodiversity in southern Africa including South Africa, there is limited epidemiological information regarding Bartonella spp. in these mammals across the country. Results from our study showed the liver and spleen had the highest positive cases for Bartonella spp. DNA among the tested organs. Bartonella elizabethae, B. grahamii, and B. tribocorum were the three zoonotic species identified and five distinct Bartonella lineages (I-V) were confirmed through phylogenetic analyses. To the best of our knowledge, this study presents the first extensive nuclear diversity investigation of Bartonella spp. in South African small mammals in South Africa.

Community Composition and Functional Characterization of Microorganisms in Surface Sediment of the New Britain Trench.

The deep-sea harbors abundant prokaryotic biomass is a major site of organic carbon remineralization and long-term carbon burial in the ocean. Deep-sea trenches are the deepest part of the ocean, and their special geological and morphological features promoting the accumulation of organic matter and active organic carbon turnover. Despite the expanding reports about the organic matter inputs, limited information is known regarding microbial processes in deep-sea trenches. In this study, we investigated the species composition and metabolic potential in surface sediment of the New Britain Trench (NBT), using a metagenomic approach. The predominant microbial taxa in NBT sediment include Proteobacteria, Acidobacteria, Planctomycetes, Actinobacteria and Chloroflexota. The microbial communities showed highly diverse metabolic potentials. Particularly, genes encoding enzymes for degradation of aromatic compounds, as well as those encoding haloalkane dehalogenase and haloacetate dehalogenase were annotated in the NBT surface sediment, which indicate the potential of microorganisms to degrade different types of refractory organic matter. The functional genes encoding enzymes for dissimilatory nitrate reduction, denitrification, and nitrification were also represented in the NBT metagenome. Overall, the microbial communities show high diversity of heterotrophic lineages and metabolic features, supporting their potential contributions in organic carbon metabolism. Meanwhile, Nitrosopumilus, a dominant genus in the surface sediment of the NBT, is a typical ammonia-oxidizing archaea (AOA), with autotrophic CO2 fixation pathways including the 3-hydroxypropionate/4-hydroxybutylate (3HP/4HB) cycle, the reductive TCA (rTCA) cycle. The results demonstrate that autotrophic metabolic processes also play an important role in the surface sediment, by providing newly synthesized organic matter.

Comprehensive Qualitative and Quantitative Analysis of Flavonoids in Dandelion (Taraxacum officinale) Flowers and Food Products.

Taraxacum officinale, a cosmopolitan perennial, is widely used as an edible, fodder, honey, and medicinal plant. Interestingly, detailed LC-QTOF-MS profiling of the flower extract revealed the presence of several flavonoid signals, most likely lacking literature confirmation. Targeted isolation, including extraction based on DoE planning, led to the isolation of 11 flavonoids, three of which were new (16, 18, and 33). Their structures were determined by the NMR technique. Both biflavones (16 and 18) were structured by two luteolin molecules, linked by a C-C bond through IB (C-6') and IIA (C-6″ or C-8″) rings. Novel flavonolignan (33) was composed of tricin and an unusual carboxyl function containing a lignan moiety. The content of 28 flavonoids (glycosides, aglycones, biflavones, and flavonolignans) was determined by the LC-MS/MS method in raw flowers and dandelion syrups and tincture. Multivariate analyses showed the separation of spring and autumn flowers and a high diversity of food products and helped to identify metabolites correlated with the samples.