86 research outputs found
Revealing the stygobiotic and crenobiotic molluscan biodiversity hotspot in Caucasus : part I : the phylogeny of stygobiotic Sadlerianinae Szarowska, 2006 (Mollusca, Gastropoda, Hydrobiidae) from Georgia with descriptions of five new genera and twenty-one new species
The position of the southwestern Caucasus as a stygobiotic Mollusca hotspot is confirmed. Molecular data of stygobiotic gastropods revealed the diversity of subfamily Sadlerianinae Szarowska, 2006, inhabiting the subterranean environment of Georgia. In addition to the well-known endemic genera Pontohoratia Vinarski, Palatov & Glöer, 2014 and Motsametia Vinarski, Palatov & Glöer, 2014, five more genera were identified in northwestern Georgia as new to the science: Kartvelobia gen. nov., Imeretiopsis gen. nov., Caucasopsis gen. nov., Caucasogeyeria gen. nov., and Hausdorfenia gen. nov. Additionally, 21 new species were found to inhabit the studied area (Samegrelo, Imereti, Racha regions in Georgia)
Comparison of Earthworm (Lumbricidae) and Oribatid Mite (Acari, Oribatida) Communities in Natural and Urban Ecosystems
This study investigates earthworm and oribatid mite communities in urban, semi-natural and natural ecosystems of Tbilisi (Georgia). Ten species of earthworms and 100 species of oribatid mites were registered in 45 soil samples. Two species of oribatid mites, Microzetes auxilaris Grandjean, 1936 and Multioppia laniseta Moritz, 1966, are new for the Caucasian fauna. We hypothesized that species number and abundance of invertebrate animals tend to decrease from natural to urban ecosystems. The hypothesis was supported only partially. Number of species of oribatid mites and earthworms decreased together with increase of urbanization, whereas abundance showed no significant changes due to high density of stress tolerant and ubiquitous species in urban sites. Accordingly, species abundance is considered to have minor indicatory value. Our studies support ecological “time-hypothesis” in a way that older (natural) sites were presented with more diverse fauna than recent (urban) ones. Statistical analyses showed that studied ecosystems should be grouped in two rather than three categories: in urban and natural ones.В статье предоставлены результаты исследования сообществ дождевых червей и панцирных клещей в урбанизированных, полуприродных и природных экосистемах г. Тбилиси (Грузия). В 45 почвенных пробах были найдены 10 видов дождевых червей и 100 видов панцирных клещей. Два вида клещей Microzetes auxilaris Grandjean, 1936 и Multioppia laniseta Moritz, 1966 являются новымы для фауны Кавказа. Мы предположили, что количество и плотность населения безпозвоночных должны уменьшаться от природных к урбанизированным экосистемам. Наша гипотеза подтвердилась частично. Количество видов дождевых червей и панцирных клещей сократилось с увеличением степени урбанизированности среды, тогда, как плотность населения существенно не менялась из-за высокой плотности отдельных убиквистовых и толерантных к стрессам видов. Соответственно считаем, что плотность населения не имеет большого индикационного значения. Наши результаты подтверждают экологическую «гипотезу времени» тем, что более старые (природные) участки были представлены более разнообразной фауной, чем более новые (урбанизированные). Статистический анализ показал, что изученные экосистемы должны быть сгруппированны по двум, а не по трем категориям: по природным и урбанизированным
Comment on “Relict basin closure and crustal shortening budgets during continental collision: an example from Caucasus sediment provenance” by cowgill et al. (2016)
A global agenda for advancing freshwater biodiversity research
This manuscript is a contribution of the Alliance for Freshwater Life (www.allianceforfreshwaterlife.org). We thank Nick Bond, Lisa Bossenbroek, Lekima Copeland, Dean Jacobsen, Maria Cecilia Londo?o, David Lopez, Jaime Ricardo Garcia Marquez, Ketlhatlogile Mosepele, Nunia Thomas-Moko, Qiwei Wei and the authors of Living Waters: A Research Agenda for the Biodiversity of Inland and Coastal Waters for their contributions. We also thank Peter Thrall, Ian Harrison and two anonymous referees for their valuable comments that helped improve the manuscript. Open access funding enabled and organised by Projekt DEAL
A global agenda for advancing freshwater biodiversity research
Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation
A global agenda for advancing freshwater biodiversity research
Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation.Peer reviewe
Integrative phylogenetic, phylogeographic and morphological characterisation of the Unio crassus species complex reveals cryptic diversity with important conservation implications
The global decline of freshwater mussels and their crucial ecological services highlight the need to understand their phylogeny, phylogeography and patterns of genetic diversity to guide conservation efforts. Such knowledge is urgently needed for Unio crassus, a highly imperilled species originally widespread throughout Europe and southwest Asia. Recent studies have resurrected several species from synonymy based on mitochondrial data, revealing U. crassus to be a complex of cryptic species. To address long-standing taxonomic uncertainties hindering effective conservation, we integrate morphometric, phylogenetic, and phylogeographic analyses to examine species diversity within the U. crassus complex across its entire range. Phylogenetic analyses were performed using cytochrome c oxidase subunit I (815 specimens from 182 populations) and, for selected specimens, whole mitogenome sequences and Anchored Hybrid Enrichment (AHE) data on ∼600 nuclear loci. Mito-nuclear discordance was detected, consistent with mitochondrial DNA gene flow between some species during the Pliocene and Pleistocene. Fossil-calibrated phylogenies based on AHE data support a Mediterranean origin for the U. crassus complex in the Early Miocene. The results of our integrative approach support 12 species in the group: the previously recognised Unio bruguierianus, Unio carneus, Unio crassus, Unio damascensis, Unio ionicus, Unio sesirmensis, and Unio tumidiformis, and the reinstatement of five nominal taxa: Unio desectus stat. rev., Unio gontierii stat. rev., Unio mardinensis stat. rev., Unio nanus stat. rev., and Unio vicarius stat. rev. Morphometric analyses of shell contours reveal important morphospace overlaps among these species, highlighting cryptic, but geographically structured, diversity. The distribution, taxonomy, phylogeography, and conservation of each species are succinctly described
Linear criteria for hypotheses testing
In the present paper we prove necessary and sufficient conditions for the existence of linear consistent criteria. Keywords: Statistical structure, Linear consistent criteria, Weakly and strongly linear criteri
The consistent criteria of hypotheses
In this paper we define the consistent criteria of hypotheses such as the probability of any kind of errors is zero for given criteria. We prove necessary and sufficient conditions for the existence of such criteria
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An Information-Theoretic Method for Identifying Effective Treatments and Policies at the Beginning of a Pandemic
Background: Identifying effective treatments and policies early in a pandemic is challenging because only limited and noisy data are available, and biological processes are unknown or uncertain. Consequently, classical statistical procedures may not work or require strong structural assumptions. An information-theoretic approach can overcome these problems and identify effective treatments and policies. The efficacy of this approach is illustrated using a study conducted at the beginning of the COVID-19 pandemic.Methods: An information-theoretic inferential approach with and without prior information was applied to the limited data available in the second month (April 24, 2020) of the COVID-19 pandemic. For comparison, a second statistical analysis used a large sample with millions of observations available at the end of the pandemic’s pre-vaccination period (mid-December 2020).Results: Even with limited data, the information-theoretic estimates performed well in identifying influential factors and helped explain why death rates varied across nations. Later experiments and statistical analyses based on more recent, richer data confirm that these factors contribute to survival.Conclusions: An information-theoretic statistical technique is a robust method that can overcome the challenges of under-identified estimation problems in the early stages of medical emergencies. It can easily incorporate prior information from theory, logic, or previously observed emergencies
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