203 research outputs found
Emerging energy geographies : scaling and spatial divergence in European electricity generation capacity
This paper presents an evaluation of the impact of the related EU internal energy market and renewable energy policies by exploring the (sustainable) energy transition in the EUropean electricity sector and drawing on the emerging literatures on energy geographies. We use evidence aggregated from plant-level data on installed electricity generation capacity in the EUropean electric utilities sector over the period 1990â2013 to demonstrate how the unintended interaction between EU policies on energy market liberalization and climate change have led to new renewable energy entrants and more widely dispersed ownership of total generation capacity. Our empirical results suggest that six energy geography concepts enable deeper insights into the spatiality of the EUropean energy transition. Specifically, we find that territoriality and scaling are key lenses for interpreting the differentiated change processes occurring at EUropean, subregional and national levels. The EUropean energy transition is unlikely to converge onto a single trajectory any time soon, but particularly subregional approaches are argued to offer policy-makers with more spatially cognizant and effective levers
Emerging Energy Geographies: Scaling and Spatial Divergence in EUropean Electricity Generation Capacity
Metabarcoding of marine zooplankton: prospects, progress and pitfalls
Metabarcoding (large-scale taxonomic identification of complex samples via analysis of one or few orthologous DNA regions, called barcodes) is revolutionizing analysis of biodiversity of marine zooplankton assemblages. Metabarcoding relies on high-throughput DNA sequencing (HTS) technologies, which yield millions of DNA sequences in parallel and allow large-scale analysis of environmental samples. Metabarcoding studies of marine zooplankton have used various regions of nuclear small- (18S) and large-subunit (28S) rRNA, which allow accurate classification of novel sequences and reliable amplification with consensus primers, but- due to their relatively conserved nature- may underestimate species diversity in a community. To discriminate species, more variable genes are needed. A limited number of metabarcoding studies have used mitochondrial cytochrome oxidase I (COI), which ensures detection of species-level diversity, but may require group-specific primers and thus result in inconsistent amplification success rates. Reference databases with sequences for accurately-identified species are critically needed to allow taxonomic designation of molecular operational taxonomic units (MOTU) and comparison with previous studies of zooplankton diversity. Potential and promising applications of metabarcoding include rapid detection of impacts of climate change, monitoring and assessment of ecosystem health, calculation of biotic indices, characterization of food webs and detection of introduced, non-indigenous species
What goes in, must come out:combining scat-based molecular diet analysis and quantification of ingested microplastics in a marine top predator
Context: Microplastics (plastic particles <5 mm in size) are highly available for ingestion by a wide range of organisms, either through direct consumption or indirectly, via trophic transfer, from prey to predator. The latter is a poorly understood, but potentially major, route of microplastic ingestion for marine top predators.Approach: We developed a novel and effective methodology pipeline to investigate dietary exposure of wild top predators (grey seals; Halichoerus grypus) to microplastics, by combining scat-based molecular techniques with a microplastic isolation method. We employed DNA metabarcoding, a rapid method of biodiversity assessment, to garner detailed information on prey composition from scats, and investigated the potential relationship between diet and microplastic burden.Results: Outcomes of the method development process and results of both diet composition from metabarcoding analysis and detection of microplastics are presented. Importantly, the pipeline performed well and initial results suggest the frequency of microplastics detected in seal scats may be related to the type of prey consumed. Conclusions: Our non-invasive, data rich approach maximises time and resource-efficiency, while minimising costs and sample volumes required for analysis. This pipeline could be used to underpin a much-needed increase in understanding of the relationship between diet composition and rates of microplastic ingestion in high trophic-level species.<br/
A global review of marine turtle entanglement in anthropogenic debris: a baseline for further action
Entanglement in anthropogenic debris poses a threat to marine wildlife. Although this is recognised as a cause of marine turtle mortality, there remain quantitative knowledge gaps on entanglement rates and population implications. We provide a global summary of this issue in this taxon using a mixed methods approach, including a literature review and expert opinions from conservation scientists and practitioners worldwide. The literature review yielded 23 reports of marine turtle entanglement in anthropogenic debris, which included records for 6 species, in all ocean basins. Our experts reported the occurrence of marine turtles found entangled across all species, life stages and ocean basins, with suggestions of particular vulnerability in pelagic juvenile life stages. Numbers of stranded turtles encountered by our 106 respondents were in the thousands per year, with 5.5% of turtles encountered entangled; 90.6% of these dead. Of our experts questioned, 84% consider that this issue could be causing population level effects in some areas. Lost or discarded fishing materials, known as âghost gearâ, contributed to the majority of reported entanglements with debris from land-based sources in the distinct minority. Surveyed experts rated entanglement a greater threat to marine turtles than oil pollution, climate change and direct exploitation but less of a threat than plastic ingestion and fisheries bycatch. The challenges, research needs and priority actions facing marine turtle entanglement are discussed as pathways to begin to resolve and further understand the issue. Collaboration among stakeholder groups such as strandings networks, the fisheries sector and the scientific community will facilitate the development of mitigating actions
Micromanipulation at an infertility centre
Aim. Human in vitro fertilisation (IVF) and gamete intrafallopian transfer have been used in the management of various forms of infertility. In cases of severe male-factor infertility, fertilisation can be a factor. In this study micromanipulation was used to increase fertilisation in such cases.Methods. Two micromanipulation techniques, subzonal sperm injection (SUZI) and partial zona dissection (PZD), were used to assist fertilisation in patients with abnorTl)al semen parameters. Ten couples with severe oligo-, teratoand asthenozoospermia participated in the SUZI programme. Seventy-three oocytes were obtained from these 10 patients. PZD was used on day 1 oocytes in cases of male infertility as well as a rescue attempt on day 2 oocytes when fertilisation had failed after routine insemination.Results. The SUZI technique had a fertilisation rate of 37,7%. In this group, a biochemical pregnancy was achieved. Differences between the fertilisation rate of conventionallVF (33,3%) and PZD (56,3%) in cases of male infertility, were not statistically significant although a clinical difference could be detected. PZD was statistically effective in facilitating fertilisation (37,5% v. 8,3%) in couples where this procedure was introduced to reinseminate 24-hour-old unfertilised oocytes. Four patients received PZD reinseminated embryos. An average of 1,45 PZD embryos were replaced and 1 implantation pregnancy was confirmed.Conclusion. The micromanipulation results are encouraging arid seemed to increase the efficiency of IVF in humans. Furthermore, our data support the conclusion that micromanipulation procedures can bring about pregnancies
De novo transcriptome assembly and gene expression profiling of the copepod Calanus helgolandicus feeding on the PUA-producing diatom Skeletonema marinoi
Diatoms are the dominant component of the marine phytoplankton. Several diatoms produce secondary metabolites, namely oxylipins, with teratogenic effects on their main predators, crustacean copepods. Our study reports the de novo assembled transcriptome of the calanoid copepod Calanus helgolandicus feeding on the oxylipin-producing diatom Skeletonema marinoi. Differential expression analysis was also performed between copepod females exposed to the diatom and the control flagellate Prorocentrum minimum, which does not produce oxylipins. Our results showed that transcripts involved in carbohydrate, amino acid, folate and methionine metabolism, embryogenesis, and response to stimulus were differentially expressed in the two conditions. Expression of 27 selected genes belonging to these functional categories was also analyzed by RT-qPCR in C. helgolandicus females exposed to a mixed solution of the oxylipins heptadienal and octadienal at the concentration of 10 \ub5M, 15 \ub5M, and 20 \ub5M. The results confirmed differential expression analysis, with up-regulation of genes involved in stress response and down-regulation of genes associated with folate and methionine metabolism, embryogenesis, and signaling. Overall, we offer new insights on the mechanism of action of oxylipins on maternally-induced embryo abnormality. Our results may also help identify biomarker genes associated with diatom-related reproductive failure in the natural copepod population at sea
Comparison of the VersaTREK blood culture system against the Bactec9240 system in patients with suspected bloodstream infections
BACKGROUND: To evaluate the VersaTREK (TREK Diagnostic Systems, Cleveland, Ohio) blood culture system against the Bactec9240 (BD Microbiology, Cockeysville, MD), for the recovery of bloodstream pathogens. METHODS: Venous blood from patients with suspected bacterial sepsis was evenly distributed into bottles of each system. Positive signals were recorded and bottles processed onto standard media for organism recovery. False positive signals were regarded if no organisms were seen on Gram stain and no growth was observed. RESULTS: 177 bottles were available for analysis; the Bactec9240 system yielded 43 positive, 134 negative results and no false positive signals. The VersaTREK system had 58 positive signals with 14 being false positives. CONCLUSIONS: In our setting with high background burden of immuno-compromised patients, the VersaTREK system compared favourably with the Bactec9240 in recovering blood stream aerobic and facultative anaerobic pathogens from patients with suspected bacterial sepsis. A concern is the high false positivity rate. Due to its versatility to accommodate small and large workloads as well as using smaller volumes of blood, this system may establish itself as a useful alternative for the recovery of bloodstream pathogens
Elucidating the Antimycobacterial Mechanism of Action of Decoquinate Derivative RMB041 Using Metabolomics
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), still remains one of the leading causes of death from a single infectious agent worldwide. The high prevalence of this disease is mostly ascribed to the rapid development of drug resistance to the current anti-TB drugs, exacerbated by lack of patient adherence due to drug toxicity. The aforementioned highlights the urgent need for new anti-TB compounds with different antimycobacterial mechanisms of action to those currently being used. An N-alkyl quinolone; decoquinate derivative RMB041, has recently shown promising antimicrobial activity against Mtb, while also exhibiting low cytotoxicity and excellent pharmacokinetic characteristics. Its exact mechanism of action, however, is still unknown. Considering this, we used GCxGC-TOFMS and well described metabolomic approaches to analyze and compare the metabolic alterations of Mtb treated with decoquinate derivative RMB041 by comparison to non-treated Mtb controls. The most significantly altered pathways in Mtb treated with this drug include fatty acid metabolism, amino acid metabolism, glycerol metabolism, and the urea cycle. These changes support previous findings suggesting this drug acts primarily on the cell wall and secondarily on the DNA metabolism of Mtb. Additionally, we identified metabolic changes suggesting inhibition of protein synthesis and a state of dormancy
Integrating conventional microscopy and molecular analysis to analyse the abundance and distribution of four Calanus congeners in the North Atlantic
Analysis of the demographic structure of Calanus species in the North Atlantic presents particular difficulties due to the overlapping spatial distributions of four main congeneric species (Calanus finmarchicus, Calanus helgolandicus, Calanus glacialis and Calanus hyperboreus). These species have similar morphologies, making microscopic discrimination only possible between some of the species at late copepodite or adult stages. However, molecular techniques now offer the possibility of screening significant numbers of specimens and unambiguously identifying them to species, regardless of developmental stage. Unfortunately, the processing rate of specimens by molecular methods is still too low to offer a realistic alternative to microscopy for analysis of samples from large field surveys. Here, we outline and test an approach involving the use of molecular methodology in conjunction with conventional microscopy to assess the species assignment of developmental stage abundances of Calanus congeners. Our study has highlighted many important methodological issues. First, it cannot be assumed that the species composition is homogeneous across the development stages; applying proportional species composition of adults to morphologically undistinguishable earlier development stages can result in error. The second important conclusion is that prosome length may be a highly unreliable discriminator of C. finmarchicus and C. glaciali
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