Provisional atlas of the freshwater leeches of the British Isles

Distribution maps were included in the second edition of the F.B.A. Scientific Publication on British freshwater leeches (Mann 1964). When that publication was extensively revised and enlarged to include a review of the literature on the ecology of leeches (Elliott & Mann 1979), it was decided that new maps should be published separately. The original maps were based on 1097 records whereas 4198 records were used for the new maps. The total British Isles list comprises sixteen species, thirteen genera and four families of leeches

A supplement to a bibliography of samplers for benthic invertebrates

A supplement to the earlier bibliography compiled by Elliott and Tullett 1978 (FBA Occas. Publ. No. 4) covering literature from December 1977 - December 1982 on samplers that could be used for the rapid removal of benthic intertebrates from the natural substrata of rivers and streams. In addition it includes papers on marine samplers that have been or could be used in freshwater

A bibliography of samplers for benthic invertebrates

This annotated bibliography covers literature to the end of November 1977, and includes references to samplers that could be used for the rapid removal of benthic invertebrates from natural substrata of rivers and streams. Marine samplers which have been, or could be, used in freshwater. Coverage of Russian literature is incomplete, although a selection of recent and important references are included. The references are arranged under the following headings, Reviews; Nets and quadrat samplers; Scoops, shovels and dredges; Grabs; Corers; Suction and air-lift samplers; Electroshocking samplers; Efficiencies and comparisons; and Samplers from catalogues. There is an index to samplers (by the common name) and an author index

The choice of a suitable sampler for benthic macroinvertebrates in deep rivers

Both chemical and biological methods are used to assess the water quality of rivers. Many standard physical and chemical methods are now established, but biological procedures of comparable accuracy and versatility are still lacking. This is unfortunate because the biological assessment of water quality has several advantages over physical and chemical analyses. Several groups of organisms have been used to assess water quality in rivers and these include Bacteria, Protozoa, Algae, macrophytes, macroinvertebrates and fish. Hellawell (1978) provides an excellent review of the advantages and disadvantages of these groups, and concludes that macroinvertebrates are the most useful for monitoring water quality. Although macroinvertebrates are relatively easy to sample in shallow water (depth 1m). The present paper first considers different types of samplers with emphasis on immediate samplers, and then discusses some problems in choosing a suitable sampler for benthic macroinvertebrates in deep rivers

ULF oscillations in the terrestrial magnetosphere

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

An Extensive Empirical Comparison of Probabilistic Hierarchical Classifiers in Datasets of Ageing-Related Genes

This study comprehensively evaluates the performance of 5 types of probabilistic hierarchical classification methods used for predicting Gene Ontology (GO) terms related to ageing. Of those tested, a new hybrid of a Local Hierarchical Classifier (LHC) and the Predictive Clustering Tree algorithm (LHC-PCT) had the best predictive accuracy results. We also tested the impact of two types of variations in most hierarchical classification algorithms, namely: (a) changing the base algorithm (we tested Naive Bayes and Support Vector Machines), and the impact of (b) using or not the Correlation based Feature Selection (CFS) algorithm in a pre-processing step. In total, we evaluated the predictive performance of 17 variations of hierarchical classifiers across 15 datasets of ageing and longevityrelated genes. We conclude that the LHC-PCT algorithm ranks better across several tests (7 out of 12). In addition, we interpreted the models generated by the PCT algorithm to show how hierarchical classification algorithms can be used to extract biological insights out of the ageing-related datasets that we compiled

Corrigendum: RNA Polymerase III, Ageing and Longevity

[This corrects the article DOI: 10.3389/fgene.2021.705122.]

Allosteric regulation of C. elegans AMP-activated protein kinase

AMP-activated protein kinase (AMPK) is a key metabolic regulator which responds to changes in the AMP:ATP ratio within cells. In response to high AMP levels, AMPK promotes a metabolic shift towards increased catabolism and autophagy to restore cellular energy and maintain homeostasis. In C. elegans, AMPK is important for controlling a multitude of functions including metabolism, reproductive health, and lifespan. AMPK is a heterotrimeric protein consisting of α catalytic, β linker, and γ regulatory subunits. Active AMPK is characterised by phosphorylation of the α subunit. It is also regulated allosterically by the nucleotide AMP binding within the γ subunit. C. elegans have five different AMPKγ subunits and their primary amino acid sequence implies two different modes of AMP-binding. Modifying the ability of AMPKγ to bind adenine nucleotides could directly impact how effectively AMPK manages energy homeostasis. Despite the importance of the γ subunit, most C. elegans AMPK research has focused on the catalytic α subunit. Here, we genetically dissect the functional role of the different γ subunits in relation to physiology and lifespan. We show that in normal animals, three of these γ subunits (aakg-1, aakg-2, and aakg-3) are required for normal responses to AMP, and contribute to normal fecundity and lifespan

Timing of TORC1 inhibition dictates Pol III involvement in Caenorhabditis elegans longevity

Organismal growth and lifespan are inextricably linked. Target of Rapamycin (TOR) signalling regulates protein production for growth and development, but if reduced, extends lifespan across species. Reduction in the enzyme RNA polymerase III, which transcribes tRNAs and 5S rRNA, also extends longevity. Here, we identify a temporal genetic relationship between TOR and Pol III in Caenorhabditis elegans, showing that they collaborate to regulate progeny production and lifespan. Interestingly, the lifespan interaction between Pol III and TOR is only revealed when TOR signaling is reduced, specifically in adulthood, demonstrating the importance of timing to control TOR regulated developmental versus adult programs. In addition, we show that Pol III acts in C. elegans muscle to promote both longevity and healthspan and that reducing Pol III even in late adulthood is sufficient to extend lifespan. This demonstrates the importance of Pol III for lifespan and age-related health in adult C. elegans

The SKN-1/Nrf2 transcription factor can protect against oxidative stress and increase lifespan in C. elegans by distinct mechanisms

In C. elegans the skn-1 gene encodes a transcription factor that resembles mammalian Nrf2 and activates a detoxification response. skn-1 promotes resistance to oxidative stress (Oxr) and also increases lifespan, and it has been suggested that the former causes the latter, consistent with the theory that oxidative damage causes aging. Here we report that effects of SKN-1 on Oxr and longevity can be dissociated. We also establish that skn-1 expression can be activated by the DAF-16/FoxO transcription factor, another central regulator of growth, metabolism and aging. Notably, skn-1 is required for Oxr but not increased lifespan resulting from over-expression of DAF-16; concomitantly, DAF-16 over-expression rescues the short lifespan of skn-1 mutants but not their hypersensitivity to oxidative stress. These results suggest that SKN-1 promotes longevity by a mechanism other than protection against oxidative damage