702 research outputs found

    CTCF May Not Directly Regulate ERĪ± mRNA Expression in the ER+ MCF7 Breast Cancer Cell Line

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    Introduction: CTCF is an evolutionally conserved 11-zinc finger protein factor involved in an array of processes whose deregulation could lead to cellular transformation. Through interactions with ERĪ± binding regions and ERregulated genes, CTCF was shown to compartmentalize the cellular genome into domains. It also colocalized with ERĪ± in MCF7 cells and had interactions with ERĪ± during histone deacetylase recruitment and fork-head activity. A fast-running isoform was previously shown to be expressed in breast cancer tissue but not in normal breast tissue. It is not clear whether there is a regulatory relationship between CTCF and ERĪ± in breast cancer. Aim: To determine whether CTCF expression regulated ERĪ± expression in the ER+ MCF7 breast cancer cell line. Methods: MCF7 breast cancer cells were transfected with either CTCF expression vectors or siRNA against CTCF. Following CTCF over-expression and knock-down, changes in endogenous expression of ERĪ± gene and protein expression were monitored by quantitative polymerase chain reaction (using MIQE guidelines) and western blot analysis respectively. Results: CTCF plasmid overexpression and siRNA knockdown was associated with cell rounding but with 96.4% and 95.7% cell viability respectively. Increase in CTCF mRNA on over-expression was associated with a rise in CTCF protein expression. siRNA knockdown of CTCF mRNA was accompanied by a corresponding decrease in CTCF protein expression. CTCF over-expression and knockdown appeared to inhibit the ability to detect ERĪ± protein expression by western blotting. Neither the over-expression nor knockdown of CTCF altered ERĪ± mRNA expression as detected by QPCR. Conclusion: Alterations in CTCF mRNA expression did not affect ERĪ± gene expression in MCF7 cells suggesting that CTCF interactions with the estrogen receptor in breast cancer may not be mediated via direct regulation of ERĪ± mRNA expression

    A taxonomic and ecological review of Pseudocloeon glaucum (Agnew)(Ephemeroptera: Baetidae)

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    Pseudocloeon masai (Lugo-Ortiz and McCafferty), P. nadineae (Lugo-Ortiz and McCafferty) and P. quintum (Agnew) are junior subjective synonyms of P. glaucum (Agnew). Larvae of P. glaucum manifest a wide range of variation in mouthpart morphology, particularly with respect to the development of the distomedial process of segment 2 of the labial palps, body size, general body colour and abdominal colour pattern. Such variation is observed in different cohorts and populations, and explains why several names have been applied to the same species. Larvae of P. glaucum also have considerable ecological tolerance, accounting for the abundance and widespread distribution of the species in the Afrotropical Region. New records from Kenya, Lesotho, Namibia and Zimbabwe are provided

    A non-paraphyletic classification of the afrotropical genus Acanthiops Waltz & McCafferty (Ephemeroptera: Baetidae)

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    Acanthiops Waltz & McCafferty (Ephemeroptera: Baetidae) is shown to be a monophyletic grouping defined by an anteromedially emarginate and laterally expanded and flattened pronotum in the larva. Attempts to restrict the concept of Acanthiops to Ac. marlieri (Demoulin) and re-erect Afroptiloides Gillies, syn. n., for Ac. elgonensis Lugo-Ortiz & McCafferty, Ac. griffithsi Lugo-Ortiz & McCafferty, Ac. tsitsa Barber-James & McCafferty, Ac. variegatus (Gillies), Ac. varius (Crass) and Ac. zomba Lugo-Ortiz & McCafferty, are shown to be based on inconsistent and inadequate morphological features that result in a paraphyletic taxonomy. The unofficial separate treatment of Ac. cooperi (Gillies & Wuillot) and Ac. erepens (Gillies) under Platycloeon Gillies & Wuillot is also shown to be paraphyletic. Acanthiops faro Barber-James & McCafferty, sp. n., is described from larvae from Guinea, and is distinguished by the combination of a papillate projection on labial palp segment 2, small tubercles on terga 1-8 and abdominal colour pattern. Acanthiops io Lugo-Ortiz & McCafferty, sp. n., is described from larvae from the Democratic Republic of Congo, and is distinguished by the combination of a papillate projection on palp segment 2, elongate tubercles on terga 1-9 and abdominal colour pattern. The larva of Ac. erepens (Gillies) is redescribed to incorporate morphological features and variability previously not accounted for, and larvae originally assigned to Baetis cataractae Crass are shown to be equivalent to Ac. erepens. New locality data or emendations on locality data are provided for Ac. griffithsi, Ac. tsitsa Barber-James & McCafferty and Ac. varius (Crass)

    Building pondscapes for amphibian metapopulations

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    The success of ponds constructed to restore ecological infrastructure for pondā€breeding amphibians and benefit aquatic biodiversity depends on where and how they are built. We studied effects of pond and landscape characteristics, including connectivity, on metapopulation dynamics of 12 amphibian species in Switzerland. To understand the determinants of longā€term occupancy (here summarized as incidence), environmental effects on both colonization and persistence should be considered. We fitted dynamic occupancy models to 20Ā years of monitoring data on a pond construction program to quantify effects of pond and landscape characteristics and different connectivity metrics on colonization and persistence probabilities in constructed ponds. Connectivity to existing populations explained dynamics better than structural connectivity metrics, and simple metrics (distance to the nearest neighbor population, population density) were useful surrogates for dispersal kernelā€weighted metrics commonly used in metapopulation theory. Population connectivity mediated the persistence of conservation target species in new ponds, suggesting sourceā€“sink dynamics in newly established populations. Population density captured this effect well and could be used by practitioners for site selection. Ponds created where there were 2ā€“4 occupied ponds within a radius of āˆ¼0.5Ā km had >3.5 times higher incidence of target species (median) than isolated ponds. Species had individual preferences regarding pond characteristics, but breeding sites with larger (ā‰„100Ā m2^{2}) total water surface area, that temporarily dried, and that were in surroundings with maximally 50% forest benefitted multiple target species. Pond diversity will foster amphibian diversity at the landscape scale

    Bending the curve: Simple but massive conservation action leads to landscape-scale recovery of amphibians

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    Success stories are rare in conservation science, hindered also by the research-implementation gap, where scientific insights rarely inform practice and practical implementation is rarely evaluated scientifically. Amphibian population declines, driven by multiple stressors, are emblematic of the freshwater biodiversity crisis. Habitat creation is a straightforward conservation action that has been shown to locally benefit amphibians, as well as other taxa, but does it benefit entire amphibian communities at large spatial scales? Here, we evaluate a landscape-scale pond-construction program by fitting dynamic occupancy models to 20 y of monitoring data for 12 pond-breeding amphibian species in the Swiss state Aargau, a densely populated area of the Swiss lowlands with intensive land use. After decades of population declines, the number of occupied ponds increased statewide for 10 out of 12 species, while one species remained stable and one species further declined between 1999 and 2019. Despite regional differences, in 77% of all 43 regional metapopulations, the colonization and subsequent occupation of new ponds stabilized (14%) or increased (63%) metapopulation size. Likely mechanisms include increased habitat availability, restoration of habitat dynamics, and increased connectivity between ponds. Colonization probabilities reflected species-specific preferences for characteristics of ponds and their surroundings, which provides evidence-based information for future pond construction targeting specific species. The relatively simple but landscape-scale and persistent conservation action of constructing hundreds of new ponds halted declines and stabilized or increased the state-wide population size of all but one species, despite ongoing pressures from other stressors in a human-dominated landscape

    Towards assessing impacts of alien plant infestations on river systems in the Southern Cape using cost-benefit analyses

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    Ecosystem resilience is key to the provision of dependable ecosystem goods and services, and it is generally accepted that ecosystem diversity helps to maintain sys-tem resilience. It is therefore reasonable to postulate that changes to the variables that drive species patterns will result in changes to ecosystem community structure and consequently negatively impact on system resilience. Alien vegetation in the riparian zone can impact on water temperatures, flow patterns, degree of shading, channel modification, and changes to natural sediment loads. Climate change is likely to exacerbate the problem both directly through its amplification of thermal extremes in aquatic systems, and indirectly through its impacts on dispersal patterns of alien invasive vegetation

    More future synergies and less trade-offs between forest ecosystem services with natural climate solutions instead of bioeconomy solutions

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    To reach the Paris Agreement, societies need to increase the global terrestrial carbon sink. There are many climate change mitigation solutions (CCMS) for forests, including increasing bioenergy, bioeconomy, and protection. Bioenergy and bioeconomy solutions use climate-smart, intensive management to generate high quantities of bioenergy and bioproducts. Protection of (semi-)natural forests is a major component of "natural climate solution" (NCS) since forests store carbon in standing biomass and soil. Furthermore, protected forests provide more habitat for biodiversity and non-wood ecosystem services (ES). We investigated the impacts of different CCMS and climate scenarios, jointly or in isolation, on future wood ES, non-wood ES, and regulating ES for a major wood provider for the international market. Specifically, we projected future ES given by three CCMS scenarios for Sweden 2020-2100. In the long term, fulfilling the increasing wood demand through bioenergy and bioeconomy solutions will decrease ES multifunctionality, but the increased stand age and wood stocks induced by rising greenhouse gas (GHG) concentrations will partially offset these negative effects. Adopting bioenergy and bioeconomy solutions will have a greater negative impact on ES supply than adopting NCS. Bioenergy or bioeconomy solutions, as well as increasing GHG emissions, will reduce synergies and increase trade-offs in ES. NCS, by contrast, increases the supply of multiple ES in synergy, even transforming current ES trade-offs into future synergies. Moreover, NCS can be considered an adaptation measure to offset negative climate change effects on the future supplies of non-wood ES. In boreal countries around the world, forestry strategies that integrate NCS more deeply are crucial to ensure a synergistic supply of multiple ES

    A molecular analysis of the Afrotropical Baetidae

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    Recent work on the Afrotropical Baetidae has resulted in a number of important taxonomic changes: several polyphyletic genera have been split and more than 30 new Afrotropical genera have been established. In order to test their phylogenetic relevance and to clarify the suprageneric relationships, we reconstructed the first comprehensive molecular phylogeny of the Afrotropical Baetidae. We sequenced a total of ca. 2300 bp from nuclear (18S) and mitochondrial (12S and 16S) gene regions from 65 species belonging to 26 genera. We used three different approaches of phylogeny reconstruction: direct optimization, maximum parsimony and maximum likelihood. The molecular reconstruction indicates the Afrotropical Baetidae require a global revision at a generic as well as suprageneric level. Only four of the 12 genera were monophyletic when represented by more than one species in the analysis. Historically, two conflicting concepts of the suprageneric classification of Afrotropical Baetidae were proposed. One was based on the gathering of sister genera into complexes and the other on the division of the family into a restricted number of subfamilies. According to our reconstruction, neither is completely satisfactory: the major complexes of genera present in Africa are either paraphyletic or polyphyletic and the division of the Afrotropical Baetidae into two subfamilies is probably too simplified
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