Search results for " Fragment."
showing 10 items of 1142 documents
How to support energy policy coordination? Findings from the Brazilian wind industry
2019
Abstract Despite a growing sense of urgency, the deployment of clean technologies has been affected by fragmentation of energy policy design and implementation. In some case, wicked policy issues around renewable energy infrastructure have delayed or even halted the uptake of renewables. To find possible answer to consistent policy design that involves public/private institutions of the electricity sector, the authors propose the adoption of a dynamic performance management approach to support the energy policy coordination.
Pollution exposure and high DNA fragmentation index in human sperms: a case-control study
2016
Study question: Could pollution exposure play a key role on sperm quality, in terms of DNA fragmentation index (DFI)? Summary answer: Patients exposed to high level of pollution show an higher percentage of sperm DNA fragmentation index in contrast with patient from control group. What is known already: Taranto area is characterized by a number of steel factories and petrochemical industries. Data about the detrimental effects of environmental pollution are alarming. Pollution coming from the industrial plants causes health and fertility risks, mainly due to the exposure to several pollutant (PM10, heavy metals, etc). Toxic substances can affect DNA directly or indirectly, through oxidative…
Impact of landscape on spatial genetic structure and diversity ofCoenagrion mercuriale(Zygoptera:Coenagrionidae) in northern France
2015
AbstractLoss and fragmentation of habitat is a current main cause of biodiversity loss in freshwater habitats. Odonates (dragonflies and damselflies) depend on these habitats to complete their development. Fragmentation may be a particular threat for odonates because it generates a network of small habitat patches within which populations could suffer from isolation and loss of genetic diversity. The southern damselfly Coenagrion mercuriale is categorized on the IUCN red list as Near Threatened, largely because of population fragmentation and demographic declines associated with changes in land use. Small populations at the margin of this species’ range are of particular concern because the…
Phylogeographical structure in the coastal speciesSenecio rodriguezii(Asteraceae), a narrowly distributed endemic Mediterranean plant
2009
Aim Our goals were (1) to assess the levels of chloroplast DNA variation in a narrowly distributed plant restricted to continental islands, (2) to ascertain whether a phylogeographical structure is present in plants restricted to coastal linear systems, and (3) to interpret the results in the light of the known palaeogeography of these islands. Location The Eastern Balearic Islands (Majorca and Minorca) in the Western Mediterranean Basin. Methods Sampling included 134 individuals from 28 populations of Senecio rodriguezii covering the entire range of the species. Sequences of the chloroplast genome (trnT-trnL spacer) were obtained and parameters of population genetic diversity and substruct…
Evolution of fitness in experimental populations of vesicular stomatitis virus
1996
Abstract The evolution of fitness in experimental clonal populations of vesicular stomatitis virus (VSV) has been compared under different genetic (fitness of initial clone) and demographic (population dynamics) regimes. In spite of the high genetic heterogeneity among replicates within experiments, there is a clear effect of population dynamics on the evolution of fitness. Those populations that went through strong periodic bottlenecks showed a decreased fitness in competition experiments with wild type. Conversely, mutant populations that were transferred under the dynamics of continuous population expansions increased their fitness when compared with the same wild type. The magnitude of …
CD8+CD45RA+CD27-CD28-T-cell subset in PBL of cervical cancer patients representing CD8+T-cells being able to recognize cervical cancer associated ant…
2003
Objective In response to antigenic stimulation, naive MHC-class I restricted and antigen-specific CD8+CD45RA+CD28+T-cells undergo clonal expansion and differentiate into CD8+CD45RO+ memory T-cells. Upon re- encounter with the nominal antigen, CD45RO+ T-cells are able to convert to CD8+CD45RA+CD28-T-cells displaying potent immune effector functions, including TNF-alpha production. This T-cell subpopulation constitutes a minor population in healthy individuals. In the present study we are currently evaluating whether this particular T-cell subset in PBL represents CD8+T-cells which may be able to recognize cervical cancer associated antigens provided by HPV 16 E7. Material and methods Flow-cy…
Cytoprotective effect of NMDA receptor antagonists on prion protein (PrionSc)-induced toxicity in rat cortical cell cultures
1993
Rat cortical cells were incubated with the Scrapie prion protein, PrionSc. At concentrations of 3 ng/ml of PrionSc and higher, the viability of the cells decreased significantly after a 12-h incubation period. Simultaneously, the degree of DNA fragmentation increased. In control experiments with antibodies against PrionSc, PrionSc lost its deleterious effect on neurons. PrionSc did not affect the viability of astrocytes. Drugs known to block NMDA receptor channels, such as memantine (1-amino-3,5-dimethyl-adamantane) (Mem), its analogue 1-N-methylamino-3,5-dimethyl-adamantane as well as (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate (MK-801) prevented the effect of …
Effect of flupirtine on Bcl-2 and glutathione level in neuronal cells treated in vitro with the prion protein fragment (PrP106-126).
1997
Flupirtine, trade name Katadolon, is a centrally acting nonopioid analgesic that has recently been found to display cytoprotective activity in vitro and in vivo on neurons induced to undergo apoptosis. This report shows that the PrP106-126 fragment of the prion protein, which is the likely etiological agent for a series of encephalopathies, is toxic to cortical neurons in vitro. Simultaneously, PrP106-126 influences the molecular GSH content and the bcl-2 expression in neurons. Significant toxicity (32% reduction in cell viability) was observed at a concentration of 50 microM of the peptide after 9 days of incubation, while at higher concentrations toxicity increased to 70%. Neurotoxicity w…
Functional characterization of two melanocortin (MC) receptors in lamprey showing orthology to the MC1 and MC4 receptor subtypes
2007
Abstract Background The melanocortin (MC) receptors have a key role in regulating body weight and pigmentation. They belong to the rhodopsin family of G protein-coupled receptors (GPCRs). The purpose of this study was to identify ancestral MC receptors in agnathan, river lamprey. Results We report cloning of two MC receptors from river lamprey. The lamprey receptors, designated MCa and MCb, showed orthology to the MC1 and MC4 receptor subtypes, respectively. The molecular clock analysis suggested that lamprey MC receptor genes were not duplicated recently and diverged from each other more than 400 MYR ago. Expression and pharmacological characterization showed that the lamprey MCa receptor …
Cytocidal effects of Escherichia coli hemolysin on human T lymphocytes.
1993
Escherichia coli hemolysin is the prototype of a large family of pore-forming toxins produced by gram-negative organisms. Besides its known cytotoxic activities against granulocytes, monocytes, endothelial cells, and renal epithelial cells, we now demonstrate that the toxin potently kills human T lymphocytes. Evidence based on different and independent approaches indicates that lymphocidal activity is due to formation of transmembrane pores. Additionally, cells prestimulated with phytohemagglutinin respond to low doses of E. coli hemolysin with DNA fragmentation similar to that observed in cells undergoing programmed cell death. Kinetic considerations lead us to conclude that DNA degradatio…