Capacity of different cell types to stimulate cytotoxic T lymphocyte precursor cells in the presence of interleukin 2

Plastic-adherent cells enriched for dendritic cells (AC) were found to be among the most potent stimulator cells for the activation of cytotoxic T lymphocytes (CTL) in vitro in the presence of interleukin 2 (IL 2) and a constant second set of allogeneic stimulator cells. Concanavalin A-activated nylon wool-nonadherent spleen cells ( CNWT ), concanavalin A-activated unfractionated spleen cells ( Cspl ), and some variants of the ESb T lymphoma line were equally effective as stimulator cells, however, and provoked a substantial cytotoxic response at concentrations of 10(4) cells per culture or less. In contrast, nonactivated nylon wool-nonadherent spleen cells ( NWT ) or unfractionated spleen cells (Spl) and cells of the P815 mastocytoma, the Meth A fibrosarcoma, and the T cell lymphomas Ly 5178 Eb and ESb did not stimulate cytotoxic responses at these cell concentrations. The strong stimulatory potential of the Cspl preparation was reduced by treatment with anti-Thy-1 antibody plus complement, whereas the stimulatory activity of the AC preparation was resistant to this treatment. All cell types tested expressed class I major histocompatibility antigens. Nonactivated NWT cells, in contrast to the CNWT preparation, showed no detectable staining with anti-I-E or anti-I-A antibodies and also a slightly weaker staining with class I antisera. Experiments with the tumor cell lines revealed, however, that there was no strict correlation between stimulatory potential and density of class I alloantigens or the expression of I-E determinants. Experiments on primary cytotoxic responses in vivo gave similar results. Experiments in cultures with a single set of stimulator cells and I region-compatible responder cells indicated that AC and Cspl or CNWT also have a markedly stronger capacity than NWT to induce IL 2-dependent DNA synthesis

Confounds in the Measurement of Predictive Expectations

Given the importance of predictive expectations in consumer satisfaction models, confounds in the measurement of expectations could result in misspecified models. Results of two empirical studies indicate that consumers interpret the word expect in numerous ways. A large minority of consumers interpret expect to mean desire. The magnitude of the resulting confounding effect is illustrated by comparing results using a measure of expectations alone with results obtained when using a measure of expectations together with a measure of desires in a side-by-side format

A probabilistic model to recover individual genomes from metagenomes

Shotgun metagenomics of microbial communities reveal information about strains of relevance for applications in medicine, biotechnology and ecology. Recovering their genomes is a crucial but very challenging step due to the complexity of the underlying biological system and technical factors. Microbial communities are heterogeneous, with oftentimes hundreds of present genomes deriving from different speci

Von der Finanzkrise zur Weltwirtschaftskrise (III): Die Rolle der Ungleichheit

Eine zentrale Ursache der aktuellen Krise, die von international renommierten Ökonomen betont wird aber in der öffentlichen Debatte in Deutschland noch wenig Beachtung findet, ist die rasante Zunahme der Einkommensungleichheit in vielen Industrieländern, aber auch in einigen Schwellenländern. In den USA haben viele Privathaushalte - unterstützt durch ein dereguliertes Finanzsystem - auf stagnierende Realeinkommen mit einer immer ausgedehnteren Kreditaufnahme reagiert. Nur so konnte der private Konsum über Jahre hinweg zur tragenden Stütze des Wirtschaftswachstums in den USA werden. Anders in Deutschland: Hier haben die schwache Lohnentwicklung und sozialpolitische Einschnitte nicht zu erhöhter Verschuldung, sondern zu Konsumverzicht geführt, dessen Ergebnis eine anhaltende binnenwirtschaftliche Wachstumsschwäche war. Spiegelbild der extremen, durch schwache Lohnzuwächse unterstützten Exportsteigerungen der deutschen Wirtschaft waren hohe Kapitalexporte sowie eine starke (und riskante) Auslandsorientierung des Bankensektors. Mit der aktuellen Krise sind beide Wachstumsmodelle an offensichtliche Grenzen gelangt. Ein Richtungswechsel in der Verteilungspolitik ist eine notwendige Bedingung für die künftige gesamtwirtschaftliche Stabilität der deutschen und auch der globalen Wirtschaft

From the financial crisis to the world economic crisis: The role of inequality

A central cause of the crisis, which the public debate has taken little notice of so far, is the rapid increase of income inequality in many industrialised countries, but also in some emerging economies. In the USA many private households have reacted to stagnating real incomes by increasingly extending their borrowing. This was facilitated by a deregulated financial system. Only thus could private consumption become the main pillar of economic growth in the USA for years. The opposite holds for Germany: here the weak wage dynamics and social spending cuts have induced consumption restraint rather than higher debt, thus causing an extended period of weak domestic growth. High capital exports and a strong (and risky) foreign market involvement of the banking sector were the flip side of the extreme export hikes of the German economy, which were enhanced by weak wage increases. In the current financial crisis the limits of these opposite growth models become evident: both are based on the necessity to compensate the sluggish trend resulting from an increasing income inequality with other sources of demand. These consisted either in increased household borrowing (USA, UK, Spain) or in export- led growth (Germany, Japan, China).English version of IMK Report No. 41, translated from German into English by Katja Rietzler. German version: http://hdl.handle.net/10419/106050Eine zentrale Ursache der aktuellen Krise, die von international renommierten Ökonomen betont wird aber in der öffentlichen Debatte in Deutschland noch wenig Beachtung findet, ist die rasante Zunahme der Einkommensungleichheit in vielen Industrieländern, aber auch in einigen Schwellenländern. In den USA haben viele Privathaushalte - unterstützt durch ein dereguliertes Finanzsystem - auf stagnierende Realeinkommen mit einer immer ausgedehnteren Kreditaufnahme reagiert. Nur so konnte der private Konsum über Jahre hinweg zur tragenden Stütze des Wirtschaftswachstums in den USA werden. Anders in Deutschland: Hier haben die schwache Lohnentwicklung und sozialpolitische Einschnitte nicht zu erhöhter Verschuldung, sondern zu Konsumverzicht geführt, dessen Ergebnis eine anhaltende binnenwirtschaftliche Wachstumsschwäche war. Spiegelbild der extremen, durch schwache Lohnzuwächse unterstützten Exportsteigerungen der deutschen Wirtschaft waren hohe Kapitalexporte sowie eine starke (und riskante) Auslandsorientierung des Bankensektors. Mit der aktuellen Krise sind beide Wachstumsmodelle an offensichtliche Grenzen gelangt. Ein Richtungswechsel in der Verteilungspolitik ist eine notwendige Bedingung für die künftige gesamtwirtschaftliche Stabilität der deutschen und auch der globalen Wirtschaft

The large longitudinal spread of solar energetic particles during the January 17, 2010 solar event

We investigate multi-spacecraft observations of the January 17, 2010 solar energetic particle event. Energetic electrons and protons have been observed over a remarkable large longitudinal range at the two STEREO spacecraft and SOHO suggesting a longitudinal spread of nearly 360 degrees at 1AU. The flaring active region, which was on the backside of the Sun as seen from Earth, was separated by more than 100 degrees in longitude from the magnetic footpoints of each of the three spacecraft. The event is characterized by strongly delayed energetic particle onsets with respect to the flare and only small or no anisotropies in the intensity measurements at all three locations. The presence of a coronal shock is evidenced by the observation of a type II radio burst from the Earth and STEREO B. In order to describe the observations in terms of particle transport in the interplanetary medium, including perpendicular diffusion, a 1D model describing the propagation along a magnetic field line (model 1) (Dr\"oge, 2003) and the 3D propagation model (model 2) by (Dr\"oge et al., 2010) including perpendicular diffusion in the interplanetary medium have been applied, respectively. While both models are capable of reproducing the observations, model 1 requires injection functions at the Sun of several hours. Model 2, which includes lateral transport in the solar wind, reveals high values for the ratio of perpendicular to parallel diffusion. Because we do not find evidence for unusual long injection functions at the Sun we favor a scenario with strong perpendicular transport in the interplanetary medium as explanation for the observations.Comment: The final publication is available at http://www.springerlink.co

Resistive Magnetic Field Generation at Cosmic Dawn

Relativistic charged particles (CR for cosmic-rays) produced by Supernova explosion of the first generation of massive stars that are responsible for the re-ionization of the universe escape into the intergalactic medium, carrying an electric current. Charge imbalance and induction give rise to a return current, $\vec j_t$, carried by the cold thermal plasma which tends to cancel the CR current. The electric field, $\vec E=\eta \vec j_t$, required to draw the collisional return current opposes the outflow of low energy cosmic rays and ohmically heats the cold plasma. Owing to inhomogeneities in the resistivity, $\eta(T)$, caused by structure in the temperature, $T$, of the intergalactic plasma, the electric field possesses a rotational component which sustains Faraday's induction. It is found that magnetic field is robustly generated throughout intergalactic space at rate of 10$^{-17}-10^{-16}$ Gauss/Gyr, until the temperature of the intergalactic medium is raised by cosmic reionization. The magnetic field may seed the subsequent growth of magnetic fields in the intergalactic environment.Comment: 8 pages, 4 figures, substantially expanded for the sake of a more detailed presentation of the model. Title slightly simplified. Results unchanged. Higher resolution version available at http://www.exp-astro.phys.ethz.ch/miniati/miniatiandbell.pd

Drift-induced deceleration of Solar Energetic Particles

We investigate the deceleration of Solar Energetic Particles (SEPs) during their propagation from the Sun through interplanetary space, in the presence of weak to strong scattering in a Parker spiral configuration, using relativistic full orbit test particle simulations. The calculations retain all three spatial variables describing particles’ trajectories, allowing to model any transport across the magnetic field. Large energy change is shown to occur for protons, due to the combined effect of standard adiabatic deceleration and a significant contribution from particle drift in the direction opposite to that of the solar wind electric field. The latter drift-induced deceleration is found to have a stronger effect for SEP energies than for galactic cosmic rays. The kinetic energy of protons injected at 1 MeV is found to be reduced by between 35 and 90% after four days, and for protons injected at 100 MeV by between 20 and 55%. The overall degree of deceleration is a weak function of the scattering mean free path, showing that, although adiabatic deceleration plays a role, a large contribution is due to particle drift. Current SEP transport models are found to account for drift-induced deceleration in an approximate way and their accuracy will need to be assessed in future work