1,115 research outputs found
Classification of cryptocurrency coins and tokens by the dynamics of their market capitalisations
We empirically verify that the market capitalisations of coins and tokens in
the cryptocurrency universe follow power-law distributions with significantly
different values, with the tail exponent falling between 0.5 and 0.7 for coins,
and between 1.0 and 1.3 for tokens. We provide a rationale for this, based on a
simple proportional growth with birth & death model previously employed to
describe the size distribution of firms, cities, webpages, etc. We empirically
validate the model and its main predictions, in terms of proportional growth
(Gibrat's law) of the coins and tokens. Estimating the main parameters of the
model, the theoretical predictions for the power-law exponents of coin and
token distributions are in remarkable agreement with the empirical estimations,
given the simplicity of the model. Our results clearly characterize coins as
being "entrenched incumbents" and tokens as an "explosive immature ecosystem",
largely due to massive and exuberant Initial Coin Offering activity in the
token space. The theory predicts that the exponent for tokens should converge
to 1 in the future, reflecting a more reasonable rate of new entrants
associated with genuine technological innovations
Search of molecular markers linked to apomixis in species of the genus Paspalum (Plicatula Group).
Laser thermal ablation to treat a recurrent soft-tissue sarcoma of the leg : A case report
We present the case of a 52-year-old male patient with recurrence of a soft-tissue sarcoma of the left leg treated with percutaneous laser ablation. The patient received the diagnosis of sarcoma for the first time in 2011; further local recurrences and a pulmonary metastatic spread occurred during follow-up, so the patient has been treated several times with chemotherapy, limb-sparing surgery and radiotherapy. In September 2017, a new local recurrence of sarcoma occurred, for which limb amputation was proposed but refused by the patient. Laser ablation with ultrasound guidance was performed, with complete ablation at 6 months and limb salvage
Accuracy of inference on the physics of binary evolution from gravitational-wave observations
The properties of the population of merging binary black holes encode some of
the uncertain physics of the evolution of massive stars in binaries. The binary
black hole merger rate and chirp mass distribution are being measured by
ground-based gravitational-wave detectors. We consider isolated binary
evolution and explore how accurately the physical model can be constrained with
such observations by applying the Fisher information matrix to the merging
black hole population simulated with the rapid binary population synthesis code
COMPAS. We investigate variations in four COMPAS parameters: common envelope
efficiency, kick velocity dispersion, and mass loss rates during the luminous
blue variable and Wolf--Rayet stellar evolutionary phases. We find that 1000
observations would constrain these model parameters to a fractional accuracy of
a few percent. Given the empirically determined binary black hole merger rate,
we can expect gravitational-wave observations alone to place strong constraints
on the physics of stellar and binary evolution within a few years.Comment: 12 pages, 9 figures; version accepted by Monthly Notices of the Royal
Astronomical Societ
Estimativas da diversidade genética de acessos de Paspalum spp. com ouso de marcadores microssatélites.
Editores técnicos: João de Mendonça Naime, Caue Ribeiro, Maria Alice Martins, Elaine Cristina Paris, Paulino Ribeiro Villas Boas, Ladislau Marcelino Rabello
Targeting the MET oncogene by concomitant inhibition of receptor and ligand via an antibody-“decoy” strategy
MET, a master gene sustaining "invasive growth," is a relevant target for cancer precision therapy. In the vast majority of tumors, wild-type MET behaves as a "stress-response" gene and relies on the ligand (HGF) to sustain cell "scattering," invasive growth and apoptosis protection (oncogene "expedience"). In this context, concomitant targeting of MET and HGF could be crucial to reach effective inhibition. To test this hypothesis, we combined an anti-MET antibody (MvDN30) inducing "shedding" (i.e., removal of MET from the cell surface), with a "decoy" (i.e., the soluble extracellular domain of the MET receptor) endowed with HGF-sequestering ability. To avoid antibody/decoy interaction-and subsequent neutralization-we identified a single aminoacid in the extracellular domain of MET-lysine 842-that is critical for MvDN30 binding and engineered the corresponding recombinant decoyMET (K842E). DecoyMET(K842E) retains the ability to bind HGF with high affinity and inhibits HGF-induced MET phosphorylation. In HGF-dependent cellular models, MvDN30 antibody and decoyMET(K842E) used in combination cooperate in restraining invasive growth, and synergize in blocking cancer cell "scattering." The antibody and the decoy unbridle apoptosis of colon cancer stem cells grown in vitro as spheroids. In a preclinical model, built by orthotopic transplantation of a human pancreatic carcinoma in SCID mice engineered to express human HGF, concomitant treatment with antibody and decoy significantly reduces metastatic spread. The data reported indicate that vertical targeting of the MET/HGF axis results in powerful inhibition of ligand-dependent MET activation, providing proof of concept in favor of combined target therapy of MET "expedience.
Ăvolutions rĂ©centes de la productivitĂ© : accĂ©lĂ©ration structurelle dans la zone euro et ralentissement structurel aux Ătats-Unis ?
La croissance de la productivitĂ© dans la zone euro et aux Ătats-Unis a connu sur la pĂ©riode rĂ©cente des inflexions significatives, respectivement Ă la hausse et Ă la baisse, qui sembleraient relever en partie dâĂ©volutions structurelles.ProductivitĂ©, technologies de lâinformation et de la communication (TIC), dynamique sectorielle, Ă©volutions structurelles.
La situation financiĂšre des sociĂ©tĂ©s non financiĂšres en France 1995-2006. Baisse du taux dâĂ©pargne et recours accru Ă lâendettement.
Comme le montrent les statistiques de comptabilitĂ© nationale et les comptes dâentreprise, le taux de marge et la rentabilitĂ© Ă©conomique des entreprises ayant stagnĂ©, la hausse des dividendes et des impĂŽts pĂšse sur le taux dâĂ©pargne. Lâinvestissement, spĂ©cialement dynamique dans le secteur immobilier, est donc financĂ© par un surcroĂźt dâendettement.ComptabilitĂ© nationale, comptabilitĂ© dâentreprise, endettement, Ă©pargne, rentabilitĂ©.
Massive Stellar Mergers as Precursors of Hydrogen-rich Pulsational Pair Instability Supernovae
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