e-Philanthropy v2.001: From Entrepreneurial Adventure to an Online Community

Looks at interactive online services for philanthropy and volunteerism. Identifies, describes and anticipates the changing and maturing structure of Internet-facilitated information and services that support the various dimensions of the social sector

Unleashing New Resources and Entrepreneurship for the Common Good: A Scan, Synthesis, and Scenario for Action

Presents an overview of changes and corresponding opportunities related to how philanthropy and social change organizations and leaders are integrating market concepts into their work, value sets, and organizational structures

Molecular mechanism of influenza A NS1-mediated TRIM25 recognition and inhibition

RIG-I is a viral RNA sensor that induces the production of type I interferon (IFN) in response to infection with a variety of viruses. Modification of RIG-I with K63-linked poly-ubiquitin chains, synthesised by TRIM25, is crucial for activation of the RIG-I/MAVS signalling pathway. TRIM25 activity is targeted by influenza A virus non-structural protein 1 (NS1) to suppress IFN production and prevent an efficient host immune response. Here we present structures of the human TRIM25 coiled-coil-PRYSPRY module and of complexes between the TRIM25 coiled-coil domain and NS1. These structures show that binding of NS1 interferes with the correct positioning of the PRYSPRY domain of TRIM25 required for substrate ubiquitination and provide a mechanistic explanation for how NS1 suppresses RIG-I ubiquitination and hence downstream signalling. In contrast, the formation of unanchored K63-linked poly-ubiquitin chains is unchanged by NS1 binding, indicating that RING dimerisation of TRIM25 is not affected by NS1

Universality in two-dimensional Kardar-Parisi-Zhang growth

We analyze simulations results of a model proposed for etching of a crystalline solid and results of other discrete models in the 2+1-dimensional Kardar-Parisi-Zhang (KPZ) class. In the steady states, the moments W_n of orders n=2,3,4 of the heights distribution are estimated. Results for the etching model, the ballistic deposition (BD) model and the temperature-dependent body-centered restricted solid-on-solid model (BCSOS) suggest the universality of the absolute value of the skewness S = W_3 / (W_2)^(3/2) and of the value of the kurtosis Q = W_4 / (W_2)^2 - 3. The sign of the skewness is the same of the parameter \lambda of the KPZ equation which represents the process in the continuum limit. The best numerical estimates, obtained from the etching model, are |S| = 0.26 +- 0.01 and Q = 0.134 +- 0.015. For this model, the roughness exponent \alpha = 0.383 +- 0.008 is obtained, accounting for a constant correction term (intrinsic width) in the scaling of the squared interface width. This value is slightly below previous estimates of extensive simulations and rules out the proposal of the exact value \alpha=2/5. The conclusion is supported by results for the ballistic deposition model. Independent estimates of the dynamical exponent and of the growth exponent are 1.605 <= z <= 1.64 and \beta = 0.229 +- 0.005, respectively, which are consistent with the relations \alpha + z = 2 and z = \alpha / \beta.Comment: 8 pages, 9 figures, to be published in Phys. Rev.

Production and characterization of chitosan fibers and 3-D fiber mesh scaffolds for tissue engineering applicattions

This study reports on the production of chitosan fibers and 3-D fiber meshes for the use as tissue engineering scaffolds. Both structures were produced by means of a wet spinning technique. Maximum strain at break and tensile strength of the developed fibers were found to be 8.5% and 204.9 MPa, respectively. After 14 d of immersion in simulated body fluid (SBF), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and inductively coupled plasma emission (ICP) spectroscopy analyses showed that a bioactive Ca-P layer was formed on the surface of the fibers, meaning that they exhibit a bioactive behavior. The samples showed around 120% max. swelling in physiological conditions. The pore sizes of 3-D chitosan fiber mesh scaffolds were observed to be in the range of 100-500 m by SEM. The equilibrium-swelling ratio of the developed scaffolds was found to be around 170% (w/w) in NaCl solution at 37 °C. Besides that, the limit swelling strain was less than 30%, as obtained by mechanical spectroscopy measurements in the same conditions. The viscoelastic properties of the scaffolds were also evaluated by both creep and dynamic mechanical tests. By means of using short-term MEM extraction test, both types of structures (fibers and scaffolds) were found to be non-cytotoxic to fibroblasts. Furthermore, osteoblasts directly cultured over chitosan fiber mesh scaffolds presented good morphology and no inhibition of cell proliferation could be observed.FCT Foundation for Science and Technology, through funds from the POCTI and/or FEDER programmes

On the determination of the spin of the black hole in Cyg X-1 from X-ray reflection spectra

The spin of Cygnus X-1 is measured by fitting reflection models to Suzaku data covering the energy band 0.9-400 keV. The inner radius of the accretion disc is found to lie within 2 gravitational radii (r_g=GM/c^2) and a value for the dimensionless black hole spin is obtained of 0.97^{+0.014}_{-0.02}. This agrees with recent measurements using the continuum fitting method by Gou et al. and of the broad iron line by Duro et al. The disc inclination is measured at 23.7^{+6.7}_{-5.4} deg, which is consistent with the recent optical measurement of the binary system inclination by Orosz et al of 27+/-0.8 deg. We pay special attention to the emissivity profile caused by irradiation of the inner disc by the hard power-law source. The X-ray observations and simulations show that the index q of that profile deviates from the commonly used, Newtonian, value of 3 within 3r_g, steepening considerably within 2r_g, as expected in the strong gravity regime.Comment: 7 pages, 10 figures, MNRAS in pres

Conjugation of fibroin and starch to chitosan for increasing cell proliferation capacity

[Excerpt] In this study, chitosan conjugates with starch and fibroin were produced for increasing degradability in the presence of physiological enzymes and cell proliferation capacities of biomaterials. The degradation profile was monitored over prolonged time periods and characterization of chemical changes during degradation periods were investigated by spectroscopic methods. Various ratios of starch, fibroin and chitosan (%, (weight/weight)) were prepared. The in vitro cell culture studies were conducted to evaluate biocompatibility and proliferation capacities of conjugate materials. [...]info:eu-repo/semantics/publishedVersio

Enzymatic degradation behavior and cytocompatibility of silk fibroin–starch–chitosan conjugate membranes

The objective of this study was to investigate the influence of silk fibroin and oxidized starch conjugation on the enzymatic degradation behavior and the cytocompatability of chitosan based biomaterials. The tensile stress of conjugate membranes, which was at 50 Megapascal (MPa) for the lowest fibroin and starch composition (10 weight percent (wt.%)), was decreased significantly with the increased content of fibroin and starch. The weight loss of conjugates in α-amylase was more notable when the starch concentration was the highest at 30 wt.%. The conjugates were resistant to the degradation by protease and lysozyme except for the conjugates with the lowest starch concentration. After 10 days of cell culture, the proliferation of osteoblast-like cells (SaOS-2) was stimulated significantly by higher fibroin compositions and the DNA synthesis on the conjugate with the highest fibroin (30 wt.%) was about two times more compared to the native chitosan. The light microscopy and the image analysis results showed that the cell area and the lengths were decreased significantly with higher fibroin/chitosan ratio. The study proved that the conjugation of fibroin and starch with the chitosan based biomaterials by the use of non-toxic reductive alkylation crosslinking significantly improved the cytocompatibility and modulated the biodegradation, respectively.E.T. Baran thanks the Portuguese Foundation for Science and Technology for providing him a PostDoc scholarship (SFRH/BPD/30768/2006). This work was partially supported by the European Union funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758)