316 research outputs found
The small GTPase Rab29 is a common regulator of immune synapse assembly and ciliogenesis
Acknowledgements We wish to thank Jorge Galán, Gregory Pazour, Derek Toomre, Giuliano Callaini, Joel Rosenbaum, Alessandra Boletta and Francesco Blasi for generously providing reagents and for productive discussions, and Sonia Grassini for technical assistance. The work was carried out with the financial support of Telethon (GGP11021) and AIRC.Peer reviewedPostprin
Nel positively regulates the genesis of retinal ganglion cells by promoting their differentiation and survival during development
Peer reviewedPublisher PD
H5N1 Whole-Virus Vaccine Induces Neutralizing Antibodies in Humans Which Are Protective in a Mouse Passive Transfer Model
BACKGROUND: Vero cell culture-derived whole-virus H5N1 vaccines have been extensively tested in clinical trials and consistently demonstrated to be safe and immunogenic; however, clinical efficacy is difficult to evaluate in the absence of wide-spread human disease. A lethal mouse model has been utilized which allows investigation of the protective efficacy of active vaccination or passive transfer of vaccine induced sera following lethal H5N1 challenge. METHODS: We used passive transfer of immune sera to investigate antibody-mediated protection elicited by a Vero cell-derived, non-adjuvanted inactivated whole-virus H5N1 vaccine. Mice were injected intravenously with H5N1 vaccine-induced rodent or human immune sera and subsequently challenged with a lethal dose of wild-type H5N1 virus. RESULTS: Passive transfer of H5N1 vaccine-induced mouse, guinea pig and human immune sera provided dose-dependent protection of recipient mice against lethal challenge with wild-type H5N1 virus. Protective dose fifty values for serum H5N1 neutralizing antibody titers were calculated to be ≤1∶11 for all immune sera, independently of source species. CONCLUSIONS: These data underpin the confidence that the Vero cell culture-derived, whole-virus H5N1 vaccine will be effective in a pandemic situation and support the use of neutralizing serum antibody titers as a correlate of protection for H5N1 vaccines
Cooperation, Norms, and Revolutions: A Unified Game-Theoretical Approach
Cooperation is of utmost importance to society as a whole, but is often
challenged by individual self-interests. While game theory has studied this
problem extensively, there is little work on interactions within and across
groups with different preferences or beliefs. Yet, people from different social
or cultural backgrounds often meet and interact. This can yield conflict, since
behavior that is considered cooperative by one population might be perceived as
non-cooperative from the viewpoint of another.
To understand the dynamics and outcome of the competitive interactions within
and between groups, we study game-dynamical replicator equations for multiple
populations with incompatible interests and different power (be this due to
different population sizes, material resources, social capital, or other
factors). These equations allow us to address various important questions: For
example, can cooperation in the prisoner's dilemma be promoted, when two
interacting groups have different preferences? Under what conditions can costly
punishment, or other mechanisms, foster the evolution of norms? When does
cooperation fail, leading to antagonistic behavior, conflict, or even
revolutions? And what incentives are needed to reach peaceful agreements
between groups with conflicting interests?
Our detailed quantitative analysis reveals a large variety of interesting
results, which are relevant for society, law and economics, and have
implications for the evolution of language and culture as well
Measurement of the Relative Branching Fraction of to Charged and Neutral B-Meson Pairs
We analyze 9.7 x 10^6 B\bar{B}$ pairs recorded with the CLEO detector to
determine the production ratio of charged to neutral B-meson pairs produced at
the Y(4S) resonance. We measure the rates for B^0 -> J/psi K^{(*)0} and B^+ ->
J/psi K^{(*)+} decays and use the world-average B-meson lifetime ratio to
extract the relative widths f+-/f00 = Gamma(Y(4S) -> B+B-)/Gamma(Y(4S) ->
B0\bar{B0}) = = 1.04 +/- 0.07(stat) +/- 0.04(syst). With the assumption that
f+- + f00 = 1, we obtain f00 = 0.49 +/- 0.02(stat) +/- 0.01(syst) and f+- =
0.51 +/- 0.02(stat) +/- 0.01(syst). This production ratio and its uncertainty
apply to all exclusive B-meson branching fractions measured at the Y(4S)
resonance.Comment: 11 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
First Observation of the Decays and B^{0}\to D^{*-}p\bar{n}$
We report the first observation of exclusive decays of the type B to D^* N
anti-N X, where N is a nucleon. Using a sample of 9.7 times 10^{6} B-Bbar pairs
collected with the CLEO detector operating at the Cornell Electron Storage
Ring, we measure the branching fractions B(B^0 \to D^{*-} proton antiproton
\pi^+) = ({6.5}^{+1.3}_{-1.2} +- 1.0) \times 10^{-4} and B(B^0 \to D^{*-}
proton antineutron) = ({14.5}^{+3.4}_{-3.0} +- 2.7) times 10^{-4}. Antineutrons
are identified by their annihilation in the CsI electromagnetic calorimeter.Comment: 9 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Study of the Decays B0 --> D(*)+D(*)-
The decays B0 --> D*+D*-, B0 --> D*+D- and B0 --> D+D- are studied in 9.7
million Y(4S) --> BBbar decays accumulated with the CLEO detector. We determine
Br(B0 --> D*+D*-) = (9.9+4.2-3.3+-1.2)e-4 and limit Br(B0 --> D*+D-) < 6.3e-4
and Br(B0 --> D+D-) < 9.4e-4 at 90% confidence level (CL). We also perform the
first angular analysis of the B0 --> D*+D*- decay and determine that the
CP-even fraction of the final state is greater than 0.11 at 90% CL. Future
measurements of the time dependence of these decays may be useful for the
investigation of CP violation in neutral B meson decays.Comment: 21 pages, 5 figures, submitted to Phys. Rev.
A Search for
We report results of a search for in a sample of 9.7 million
charged meson decays. The search uses both and
decay modes of the , and demands exclusive reconstruction of the
companion decay to suppress background. We set an upper limit on the
branching fraction at 90%
confidence level. With slight modification to the analysis we also establish
at 90% confidence
level.Comment: 10 ages postscript, also available through
http://w4.lns.cornell.edu/public/CLN
Impacts of urbanisation on the native avifauna of Perth, Western Australia
Urban development either eliminates, or severely fragments, native vegetation, and therefore alters the distribution and abundance of species that depend on it for habitat. We assessed the impact of urban development on bird communities at 121 sites in and around Perth, Western Australia. Based on data from community surveys, at least 83 % of 65 landbirds were found to be dependent, in some way, on the presence of native vegetation. For three groups of species defined by specific patterns of habitat use (bushland birds), there were sufficient data to show that species occurrences declined as the landscape changed from variegated to fragmented to relictual, according to the percentage of vegetation cover remaining. For three other groups (urban birds) species occurrences were either unrelated to the amount of vegetation cover, or increased as vegetation cover declined. In order to maximise the chances of retaining avian diversity when planning for broad-scale changes in land-use (i.e. clearing native vegetation for housing or industrial development), land planners should aim for a mosaic of variegated urban landscapes (\u3e60 % vegetation retention) set amongst the fragmented and relictual urban landscapes (% vegetation retention) that are characteristic of most cities and their suburbs. Management actions for conserving remnant biota within fragmented urban landscapes should concentrate on maintaining the integrity and quality of remnant native vegetation, and aim at building awareness among the general public of the conservation value of remnant native vegetation
Measurements of B --> D_s^{(*)+} D^{*(*)} Branching Fractions
This article describes improved measurements by CLEO of the and branching fractions, and first evidence
for the decay , where
represents the sum of the , , and
L=1 charm meson states. Also reported is the first
measurement of the polarization in the decay . A partial reconstruction technique, employing only the fully
reconstructed and slow pion from the decay, enhances sensitivity. The observed branching fractions are
, , and , where the first error is statistical,
the second systematic, and the third is due to the uncertainty in the branching fraction. The measured longitudinal
polarization, , is consistent with
the factorization prediction of 54%.Comment: 26 pages (LaTeX), 15 figures. To be submitted to PR
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