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Invasive signal crayfish and native noble crayfish show trophic niche shrinkage in sympatry
No full textStudying the coexistence of native species and invasive species with similar functional traits, habitat usage, and feeding habits is crucial for understanding the dynamics of invasion and ecological changes in the invaded ecosystem. Due to competitive exclusion and often also dissemination of crayfish plague pathogen (Aphanomyces astaci, Schikora), North American crayfish represent a major threat to European native crayfish. Their co-occurrence is often only temporary, making studies investigating trophic ecology of native and non-native crayfish species rare. In this study, trophic niche and feeding ecology of European native noble crayfish Astacus astacus (Linnaeus, 1758) and North American signal crayfish Pacifastacus leniusculus (Dana, 1852) were compared between their sympatric and allopatric sites, in Křesánovský brook (Czech Republic), using carbon and nitrogen stable isotopes analysis. The results indicated a substantial change of trophic niche and diet of noble crayfish between allopatry and sympatry. In allopatry, both juvenile and adult noble crayfish exhibited a wider trophic niche width compared to juvenile and adult signal crayfish. However, in sympatry, where adult and juvenile noble crayfish coexisted with signal crayfish, their trophic niche width significantly narrowed and their diet shifted towards a more plant-based one. High degree of trophic niche overlap was observed between adults and juveniles in both species, particularly in sympatry rather than in allopatry. The substantial trophic niche overlap and dietary similarity between native noble crayfish and invasive signal crayfish in sympatry, make their long term coexistence on the invaded site unlikely
External mentoring as a talent attraction tool in the talent shortage context
No full textThe paper explores the role of external mentoring as a strategic talent attraction tool in the context of talent shortages and describes the ways in which it can help firms to find new candidates, especially among young graduates, at the same time developing its own employees. The authors conducted 21 in-depth interviews with experienced mentors from multinational companies in Russia and one expert interview. Content analysis was used to identify the key themes related to the effectiveness of external mentoring. External mentoring significantly enhances employer branding, knowledge exchange, learning and professional development. The critical components of success are voluntary participation, non-monetary recognition and long-term trust-based relationships between mentors and mentees. The paper also identifies the challenges that external mentoring may encounter and essential criteria for selecting mentors and mentees. The authors conceptualize external mentoring as a novel approach to talent attraction extending beyond internal employee development. The study provides fresh insights into resolving talent shortages and creating external talent pools, thus contributing to talent management and mentoring literature
Towards a monograph of membranaceous Vanillas: a nomenclatural revision of Vanilla subgen. Vanilla (Vanilloideae, Orchidaceae)
No full textBackground and aims – Vanilla subgenus Vanilla was established by Soto-Arenas and Cribb (2010) to include Neotropical species characterized by membranaceous leaves, a labellum without a penicillate callus, and a column attached solely at the base of the lip. Vanilla mexicana (= Epidendrum vanilla) was the first species attributed to this subgenus, and its nomenclature traces back to the Vanilla’s taxonomic origins, serving as the type species for the entire genus. Despite this, several biological aspects of membranaceous vanilla species remain poorly studied, including their taxonomy and nomenclature, which have not been thoroughly addressed. The lack of clarity regarding the circumscription of these fairly rare taxa has led to taxonomic confusion and neglect by botanists. This study aims to conduct a typological assessment of all names associated with Vanilla subgen. Vanilla. Material and methods – A comprehensive list of names attributable to Vanilla subgen. Vanilla was compiled from different sources. Protologues were studied for every name and type specimens were examined through direct visits or virtual herbaria. The International Code of Nomenclature of algae, fungi, and plants was followed for the type designation and nomenclatural notes. Key results – A comprehensive nomenclatural revision was carried out for 29 names. A total of eight lectotypes and one epitype are designated, with nomenclatural notes provided for most names within the subgenus
Investigations on the dysregulated genes in high-fat-fed mice infected with Prevotella intermedia and their possible role in the development of hepatocellular carcinoma
No full textIntroduction: Hepatocellular carcinoma (HCC) is a leading global cancer, often linked to various factors, including viral infections and metabolic disorders. Recent studies suggest that microbial infections, particularly from oral pathogens like Prevotella intermedia (Pi), may elevate the progression of HCC through dysbiosis and chronic inflammation. Aim: In view of this, the study aimed to identify candidate genes in high-fat diet-fed mice infected with Pi and to assess the relevance of these orthologous genes in the development of human HCC. Materials and methods: The GEO dataset, GSE136937, was employed to identify the differentially expressed genes across two datasets viz., regular chow-fed and high-fat diet-fed mice infected with Pi. A comparison was made between normal vs. high-fat diet-fed mice infected with Pi to demonstrate the influence of the microbial factor on the development of metabolic disorders and cancer. The identified DEGs were subjected to protein-protein interaction (PPI) analysis and gene ontology (GO) assessments. Human orthologs were evaluated for gene expression status and survival using the TCGA dataset. Results: The analysis revealed numerous DEGs between infected and uninfected groups. The top 20 DEGs (16 upregulated, 4 downregulated) were further investigated in liver hepatocellular carcinoma patients (TCGA). Notably, genes RMND1 and CYP3A43 displayed similar expression patterns in both mouse and human datasets. High RMND1 expression was associated with poor prognosis, while low CYP3A43 expression indicated a poor survival outcome in HCC patients. Conclusion: Metabolic disorders in conjunction with microbial dysbiosis together could support the malignant phenotype by modifying the expression profiles of key genes involved in carcinogenesis. More intense experimental and in vivo studies are needed to further confirm the association of these candidate genes with HCC
Morphological and phylogenetic analyses reveal new species and records of Fusarium (Nectriaceae, Hypocreales) from China
No full textSpecies of Fusarium are important phytopathogens, saprobes, and endophytes around the world. Some species can affect plant health and cause yield loss of economic plants. Fusarium species are widely distributed in China, and many species were found from different plant hosts. The Fusarium incarnatum-equiseti species complex (FIESC) is one of the most significant species complexes within the genus. Based on morphological and three-gene (cal, rpb2, and tef1) phylogenetic analyses, two new species are in the Incarnatum clade, and two new host records are identified and described, viz. Fusarium fici sp. nov., Fusarium xylosmatis sp. nov., Fusarium fecundum, and Fusarium weifangense
Long delays in identification and publication of naturalized species: a case study of introduced grasses in Hawai‘i
No full textAs introduced plants spread across the world, botanists have documented their naturalizations through herbarium specimens and published reports that serve as primary sources for the study and management of biological invasions. Invasion lag time, attracting much attention from both theoretical and applied perspectives, is typically defined as the time between introduction and first reported naturalization. Delays in identifying naturalized specimens in herbaria and publication delays may be a major cause of long reported lag times, but such delays have rarely been quantified. The Hawaiian naturalized grass flora serves as a case study to examine these delays among 269 species introduced after European colonization. From herbarium data, we found the collection date of the fist naturalized specimen, when it was correctly identified, and compared these to the date of the first published naturalization report. There was an average delay of 27 years (median of 17 years) between the first naturalized herbarium specimen and its publication, although this delay has decreased among more recent naturalizations. Among this delay is the time needed for correct identification of specimens, which was an average of 18 years, but a median of 4 years, indicating that most grasses are quickly identified but some identifications required decades. These delays, when not accounted for, obscure actual temporal trends in invasions. It is also important to understand and account for these delays in order to better characterize the phenomena that contribute to reported lag times for biological invasions. Minimizing identification and publication delays in the future will be important for successful management and control of new invasions. Expanded investment in and support of taxonomic experts at biodiversity institutions is needed to reduce reporting delays for new naturalizations
Sinosasa damingshanensis (Poaceae, Bambusoideae), a new combination supported by morphological and molecular evidence
No full textMorphological characteristics and phylogenetic analyses clearly revealed that Chimonobambusa damingshanensis should be a member of the genus Sinosasa, rather than Chimonobambusa, and is a distinct species close to Sinosasa huapingensis and S. mingyueshanensis. Morphologically, it differs from all the other known Sinosasa species by internodes initially with white pubescent, culm leaf auricles absent and triangularly subulate sheath blades, characteristics that are unusual in this genus. And this morphological distinction warrants recognition of Ch. damingshanensis as a new combination of Sinosasa
Discovering diversity of Central Asian and Himalayan Epeorus (Caucasiron) mayflies (Ephemeroptera, Heptageniidae) using DNA barcoding and morphology
No full textThe mayflies of the genus Epeorus Eaton, 1881 subgenus Caucasiron Kluge, 1997 are distributed from the eastern Mediterranean to the mountains of south-west China. In contrast to the Caucasus, the Mediterranean and Irano-Anatolian regions, where E. (Caucasiron) represents one of the most extensively studied mayfly taxa, the species diversity in the more eastern mountains of Asia has been studied only sporadically. In this study, the species diversity of E. (Caucasiron) from the mountains of Central Asia (Pamir, Tian Shan) and the western part of the Himalayas was analysed using DNA barcoding and the morphology of larvae and adults. The distance- and phylogenetic tree-based molecular species delimitation analyses revealed five E. (Caucasiron) species occurring in the study area. Three of them did not correspond morphologically to any known species of the genus Epeorus. These species were described herein as E. (C.) himalayensis Hrivniak & Sroka, sp. nov., E. (C.) lanceolatus Hrivniak & Sroka, sp. nov. and E. (C.) lineatus Hrivniak & Sroka, sp. nov. All new species were compared with other representatives of the subgenus and other related species of the genus Epeorus, and appropriate morphological diagnostic characters were provided. Morphological revision, main diagnostic characters, and information on the distribution of E. (C.) guttatus Braasch & Soldán, 1979 and two other potentially related Epeorus species from the area, E. psi Eaton, 1885 and E. suspicatus (Braasch, 2006), are also given
Four new species of Beltraniella (Amphisphaeriales, Beltraniaceae) revealed by morphology and phylogenetic analyses from China
No full textBeltraniella is a widely-distributed genus on Earth, although its abundance is relatively limited in relation to other dematiaceous hyphomycetes. In the present study, diseased leaves of Myristica fragrans and decaying leaves were collected from Hainan and Sichuan Province. Fungal DNA was amplified and sequenced using two barcodes, the internal transcribed spacer (ITS) and large subunit of ribosomal RNA (LSU), and phylogenetic analyses were conducted through maximum likelihood (ML) and Bayesian inference (BI) algorithms. Four new species of Beltraniella, B. dujiangyanensis, B. jianfengensis, B. myristicae, and B. xinglongensis are identified through phylogenetic analyses and morphological comparison during a survey of fungal diversity in Hainan and Sichuan Provinces, China. Detailed descriptions of the morphological characteristics of these four new species are provided and illustrated with figures
Antarctica and psychobiotic effects of Lactobacillus bulgaricus under stress
No full textThe maritime profession is an extreme test of the crew’s mental health. Psychobiotics are live bacteria that improve the gut microbiome and benefit the host’s mental health. The study aims to establish the effect of a probiotic containing Lactobacillus bulgaricus DWT1 on the mental resilience of the crew of the St. St. Cyril and Methodius research ship during the First Bulgarian Military Antarctic Expedition during the 127-day journey to Antarctica. The crew was divided into two groups: the first took the probiotic, and the second did not. Zung questionnaires were used to test anxiety and depression levels in everyone before departure and after return. We used the Wilcoxon test to analyze data from sleep quality assessments. The individuals taking the probiotic showed no statistically significant differences in anxiety and depression levels before and after the journey and maintained sleep quality under the expedition’s extreme conditions. The ones not taking the probiotic had a significant increase in anxiety and depression levels, which correlatively worsened physiological sleep. The journey of the military ship crew to Antarctica is a model for studying the effects of probiotics containing Lactobacillus bulgaricus DWT1 on the mental health of people subjected to extreme stress. The probiotic’s formula is psychobiotic, maintains the gut-brain axis, protects against depression and anxiety and improves physiological sleep under stress