181 research outputs found
Alien species of <i>Bugula</i> (Bryozoa) along the Atlantic coasts of Europe
Three apparently non-native species of Bugula occur in marinas and harbours in Atlantic Europe. The most common, B. neritina, was known from a few sites in southern Britain and northern France during the 20th century, following its discovery at Plymouth by 1911. During the 1950-60s it was abundant in a dock heated by power station effluent at Swansea, south Wales, where it flourished until the late 1960s, while water temperatures were 7-10°C above ambient. It disappeared after power generation ceased, when summer temperatures probably became insufficient to support breeding. Details of disappearances have not been recorded but B. neritina was not seen in Britain between c1970 and 1999. Since 2000, it has been recorded along the south coast of England, and subsequently in marinas in the southern North Sea, Ireland and southern Scotland, well to the north of its former range, as well as along the Atlantic coast from Spain to The Netherlands. It has also been introduced to outlying localities such as the Azores and Tristan da Cunha. We report that this rapidly spreading form has the same COI haplotype as B. neritina currently invasive elsewhere in the world. B. simplex has been reported less, with 1950s records from settlement panels in some Welsh docks. It has not been targeted in most recent marina surveys but has been observed in southwest England, Belgium and The Netherlands. There are almost no recent records of B. stolonifera, though it was probably introduced to a few British and Irish ports prior to the 1950s. Its current status in most of western Europe is unknown but it has been reported as expanding throughout most of the world during the last 60 years. Having poorly known distributions, B. simplex and B. stolonifera should be recorded during future monitoring of alien species in Atlantic Europe. Illustrations to aid identification are included for all three species
Zinc Oxide Nanoparticles (ZnO-NPs) Suppress Fertility by Activating Autophagy, Apoptosis, and Oxidative Stress in the Developing Oocytes of Female Zebrafish
In vertebrates, the core mechanisms that control gametogenesis are largely multiple,
complex, successive, and orchestrated by intrinsic and extrinsic factors. However, age, health status, and hormonal activity are important factors for good fertility; other intangible intracellular molecular mechanisms that manage oocyte development are still unclear. The present study was designed to elucidate the ultrastructure changes in the ovary in response to its exposure to zinc oxide nanoparticles (ZnO-NPs) and to explore the role of autophagy and apoptosis during egg maturation and ovulation on the fertility of female zebrafish. In our study, ZnO-NPs could induce cytotoxicity in the maturing oocyte by activating autophagy and apoptosis in a caspase-dependent manner and could induce oxidative stress by generating reactive oxygen species (ROS) that elevated the mutated ovarian tP53 protein. Simultaneously, necroptosis developed, mimicking the features of apoptosis and necrosis. Collectively, ZnO-NPs created a suitable necrotic environment that led to follicular developmental retardation that altered oocyte ovulation and reduced fecundity of female zebrafish
Poly ionic liquid nanovesicles via polymerization induced self assembly and their stabilization of Cu nanoparticles for tailored CO2 electroreduction
Herein, we report a straightforward, scalable synthetic route towards poly ionic liquid PIL homopolymer nanovesicles NVs with a tunable particle size of 50 to 120 nm and a shell thickness of 15 to 60 nm via one step free radical polymerization induced self assembly. By increasing monomer concentration for polymerization, their nanoscopic morphology can evolve from hollow NVs to dense spheres, and finally to directional worms, in which a multilamellar packing of PIL chains occurred in all samples. The transformation mechanism of NVs internal morphology is studied in detail by coarse grained simulations, revealing a correlation between the PIL chain length and the shell thickness of NVs. To explore their potential applications, PIL NVs with varied shell thickness are in situ functionalized with ultra small 1 amp; 8764; 3 nm in size copper nanoparticles CuNPs and employed as electrocatalysts for CO2 electroreduction. The composite electrocatalysts exhibit a 2.5 fold enhancement in selectivity towards C1 products e.g., CH4 , compared to the pristine CuNPs. This enhancement is attributed to the strong electronic interactions between the CuNPs and the surface functionalities of PIL NVs. This study casts new aspects on using nanostructured PILs as new electrocatalyst supports in CO2 conversion to C1 product
Characteristic Evolution and Matching
I review the development of numerical evolution codes for general relativity
based upon the characteristic initial value problem. Progress in characteristic
evolution is traced from the early stage of 1D feasibility studies to 2D
axisymmetric codes that accurately simulate the oscillations and gravitational
collapse of relativistic stars and to current 3D codes that provide pieces of a
binary black hole spacetime. Cauchy codes have now been successful at
simulating all aspects of the binary black hole problem inside an artificially
constructed outer boundary. A prime application of characteristic evolution is
to extend such simulations to null infinity where the waveform from the binary
inspiral and merger can be unambiguously computed. This has now been
accomplished by Cauchy-characteristic extraction, where data for the
characteristic evolution is supplied by Cauchy data on an extraction worldtube
inside the artificial outer boundary. The ultimate application of
characteristic evolution is to eliminate the role of this outer boundary by
constructing a global solution via Cauchy-characteristic matching. Progress in
this direction is discussed.Comment: New version to appear in Living Reviews 2012. arXiv admin note:
updated version of arXiv:gr-qc/050809
Influence of socioeconomic factors on pregnancy outcome in women with structural heart disease
OBJECTIVE: Cardiac disease is the leading cause of indirect maternal mortality. The aim of this study was to analyse to what extent socioeconomic factors influence the outcome of pregnancy in women with heart disease. METHODS: The Registry of Pregnancy and Cardiac disease is a global prospective registry. For this analysis, countries that enrolled â„10 patients were included. A combined cardiac endpoint included maternal cardiac death, arrhythmia requiring treatment, heart failure, thromboembolic event, aortic dissection, endocarditis, acute coronary syndrome, hospitalisation for cardiac reason or intervention. Associations between patient characteristics, country characteristics (income inequality expressed as Gini coefficient, health expenditure, schooling, gross domestic product, birth rate and hospital beds) and cardiac endpoints were checked in a three-level model (patient-centre-country). RESULTS: A total of 30 countries enrolled 2924 patients from 89 centres. At least one endpoint occurred in 645 women (22.1%). Maternal age, New York Heart Association classification and modified WHO risk classification were associated with the combined endpoint and explained 37% of variance in outcome. Gini coefficient and country-specific birth rate explained an additional 4%. There were large differences between the individual countries, but the need for multilevel modelling to account for these differences disappeared after adjustment for patient characteristics, Gini and country-specific birth rate. CONCLUSION: While there are definite interregional differences in pregnancy outcome in women with cardiac disease, these differences seem to be mainly driven by individual patient characteristics. Adjustment for country characteristics refined the results to a limited extent, but maternal condition seems to be the main determinant of outcome
The Role of Information and Financial Reporting in Corporate Governance and Debt Contracting
We review recent literature on the role of financial reporting transparency in reducing governance-related agency conflicts among managers, directors, and shareholders, as well as in reducing agency conflicts between shareholders and creditors, and offer researchers some suggested avenues for future research. Key themes include the endogenous nature of debt contracts and governance mechanisms with respect to information asymmetry between contracting parties, the heterogeneous nature of the informational demands of contracting parties, and the heterogeneous nature of the resulting governance and debt contracts. We also emphasize the role of a commitment to financial reporting transparency in facilitating informal multiperiod contracts among managers, directors, shareholders, and creditors
Adição de inulina em géis de amido e leite utilizando planejamento experimental de misturas
Response of a CMS HGCAL silicon-pad electromagnetic calorimeter prototype to 20-300 GeV positrons
The Compact Muon Solenoid Collaboration is designing a new high-granularity
endcap calorimeter, HGCAL, to be installed later this decade. As part of this
development work, a prototype system was built, with an electromagnetic section
consisting of 14 double-sided structures, providing 28 sampling layers. Each
sampling layer has an hexagonal module, where a multipad large-area silicon
sensor is glued between an electronics circuit board and a metal baseplate. The
sensor pads of approximately 1 cm are wire-bonded to the circuit board and
are readout by custom integrated circuits. The prototype was extensively tested
with beams at CERN's Super Proton Synchrotron in 2018. Based on the data
collected with beams of positrons, with energies ranging from 20 to 300 GeV,
measurements of the energy resolution and linearity, the position and angular
resolutions, and the shower shapes are presented and compared to a detailed
Geant4 simulation
DrugGenEx-Net: a novel computational platform for systems pharmacology and gene expression-based drug repurposing
Characteristic Evolution and Matching
I review the development of numerical evolution codes for general relativity
based upon the characteristic initial value problem. Progress is traced from
the early stage of 1D feasibility studies to 2D axisymmetric codes that
accurately simulate the oscillations and gravitational collapse of relativistic
stars and to current 3D codes that provide pieces of a binary black spacetime.
A prime application of characteristic evolution is to compute waveforms via
Cauchy-characteristic matching, which is also reviewed.Comment: Published version http://www.livingreviews.org/lrr-2005-1
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