Revisiting Ulysses Observations of Interstellar Helium

We report the results of a comprehensive reanalysis of Ulysses observations of interstellar He atoms flowing through the solar system, the goal being to reassess the interstellar He flow vector and to search for evidence of variability in this vector. We find no evidence that the He beam seen by Ulysses changes at all from 1994-2007. The direction of flow changes by no more than ~0.3 deg and the speed by no more than ~0.3 km/s. A global fit to all acceptable He beam maps from 1994-2007 yields the following He flow parameters: V_ISM=26.08+/-0.21 km/s, lambda=75.54+/-0.19 deg, beta=-5.44+/-0.24 deg, and T=7260+/-270 K; where lambda and beta are the ecliptic longitude and latitude direction in J2000 coordinates. The flow vector is consistent with the original analysis of the Ulysses team, but our temperature is significantly higher. The higher temperature somewhat mitigates a discrepancy that exists in the He flow parameters measured by Ulysses and the Interstellar Boundary Explorer, but does not resolve it entirely. Using a novel technique to infer photoionization loss rates directly from Ulysses data, we estimate a density of n_He=0.0196+/-0.0033 cm^-3 in the interstellar medium.Comment: to appear in The Astrophysical Journa

A Ulysses Detection of Secondary Helium Neutrals

The Interstellar Boundary EXplorer (IBEX) mission has recently studied the flow of interstellar neutral He atoms through the solar system, and discovered the existence of a secondary He flow likely originating in the outer heliosheath. We find evidence for this secondary component in Ulysses data. By coadding hundreds of Ulysses He beam maps together to maximize signal-to-noise, we identify a weak signal that is credibly associated with the secondary component. Assuming a laminar flow from infinity, we infer the following He flow parameters: V=12.8+/-1.9 km/s, lambda=74.4+/-1.8 deg, beta=-10.5+/-4.1 deg, and T=3000+/-1100 K; where lambda and beta are the ecliptic longitude and latitude direction in J2000 coordinates. The secondary component has a density that is 4.9+/-0.9% that of the primary component. These measurements are reasonably consistent with measurements from IBEX, with the exception of temperature, where our temperature is much lower than IBEX's T=9500 K. Even the higher IBEX temperature is suspiciously low compared to expectactions for the outer heliosheath source region. The implausibly low temperatures are due to the incorrect assumption of a laminar flow instead of a diverging one, given that the flow in the outer heliosheath source region will be deflecting around the heliopause. As for why the IBEX and Ulysses T values are different, difficulties with background subtraction in the Ulysses data are a potential source of concern, but the discrepancy may also be another effect of the improper laminar flow assumption, which could affect the IBEX and Ulysses analyses differently.Comment: 9 pages, 4 figures, to appear in The Astrophysical Journa

Debugging Quadrocopter Trajectories in Mixed Reality

Debugging and monitoring robotic applications is a very intricate and error-prone task. To this end, we propose a mixed-reality approach to facilitate this process along a concrete scenario. We connected the Microsoft HoloLens smart glass to the Robot Operating System (ROS), which is used to control robots, and visualize arbitrary flight data of a quadrocopter. Hereby, we display holograms correctly in the real world based on a conversion of the internal tracking coordinates into coordinates provided by a motion capturing system. Moreover, we describe the synchronization process of the internal tracking with the motion capturing. Altogether, the combination of the HoloLens and the external tracking system shows promising preliminary results. Moreover, our approach can be extended to directly manipulate source code through its mixed-reality visualization and offers new interaction methods to debug and develop robotic applications

Religious revelation, secrecy and the limits of visual representation

This article seeks to contribute to a more adequate understanding of the adoption of modern audiovisual mass media by contemporary religious groups. It does so by examining Pentecostal-charismatic churches as well as the Christian mass culture instigated by its popularity, and so-called traditional religion in Ghana, which develop markedly different attitudes towards audiovisual mass media and assume different positions in the public sphere. Taking into account the complicated entanglement of traditional religion and Pentecostalism, approaching both religions from a perspective of mediation which regards media as intrinsic to religion, and seeking to avoid the pitfall of overestimating the power of modern mass media to determine the world, this article seeks to move beyond an unproductive recurrence to oppositions such as tradition and modernity, or religion and technology. It is argued that instead of taking as a point of departure more or less set ideas about the nexus of vision and modernity, the adoption of new mass media by religious groups needs to be analyzed by a detailed ethnographic investigation of how these new media transform existing practices of religious mediation. Special emphasis is placed on the tension between the possibilities of gaining public presence through new media, and the difficulty in authorizing these media, and the experiences they induce, as authentic. Copyright © 2006 SAGE Publications

The muscarinic receptor antagonist propiverine exhibits α1-adrenoceptor antagonism in human prostate and porcine trigonum

Combination therapy of male lower urinary tract symptoms with α(1)-adrenoceptor and muscarinic receptor antagonists attracts increasing interest. Propiverine is a muscarinic receptor antagonist possessing additional properties, i.e., block of L-type Ca(2+) channels. Here, we have investigated whether propiverine and its metabolites can additionally antagonize α(1)-adrenoceptors. Human prostate and porcine trigone muscle strips were used to explore inhibition of α(1)-adrenoceptor-mediated contractile responses. Chinese hamster ovary (CHO) cells expressing cloned human α(1)-adrenoceptors were used to determine direct interactions with the receptor in radioligand binding and intracellular Ca(2+) elevation assays. Propiverine concentration-dependently reversed contraction of human prostate pre-contracted with 10 μM phenylephrine (-log IC(50) [M] 4.43 ± 0.08). Similar inhibition was observed in porcine trigone (-log IC(50) 5.01 ± 0.05), and in additional experiments consisted mainly of reduced maximum phenylephrine responses. At concentrations ≥1 μM, the propiverine metabolite M-14 also relaxed phenylephrine pre-contracted trigone strips, whereas metabolites M-5 and M-6 were ineffective. In radioligand binding experiments, propiverine and M-14 exhibited similar affinity for the three α(1)-adrenoceptor subtypes with -log K (i) [M] values ranging from 4.72 to 4.94, whereas the M-5 and M-6 did not affect [(3)H]-prazosin binding. In CHO cells, propiverine inhibited α(1)-adrenoceptor-mediated Ca(2+) elevations with similar potency as radioligand binding, again mainly by reducing maximum responses. In contrast to other muscarinic receptor antagonists, propiverine exerts additional L-type Ca(2+)-channel blocking and α(1)-adrenoceptor antagonist effects. It remains to be determined clinically, how these additional properties contribute to the clinical effects of propiverine, particularly in male voiding dysfunctio

Autophagy and ATP-induced anti-apoptosis in antigen presenting cells (APC) follows the cytokine storm in patients after major trauma

Severe trauma and the systemic inflammatory response syndrome (SIRS) occur as a result of a cytokine storm which is in part due to ATP released from damaged tissue. This pathology also leads to increased numbers of immature antigen presenting cells (APC) sharing properties of dendritic cells (DC) or macrophages (MΦ). The occurrence of immature APC appears to coincide with the reactivation of herpes virus infections such as Epstein Barr virus (EBV). The aim of this study was the comparative analysis of the ultrastructural and functional characteristics of such immature APC. In addition, we investigated EBV infection/ reactivation and whether immature APC might be targets for natural killers (NK). Significant macroautophagy, mitochondrial degradation and multivesicular body formation together with the identification of herpes virus particles were morphological findings associated with immature APC. Exogenous stressors such as ATP further increased morphological signs of autophagy, including LC3 expression. Functional tests using fluorescent bacteria proved impaired phagolysosome fusion. However, immature APC were susceptible to NK-92-mediated cytolysis. We found evidence for EBV latency state II infection by detecting EBV-specific LMP1 and EBNA2 in immature APC and in whole blood of these patients. In summary, trauma-induced cytokine storms may induce maturation arrest of APC, promote ATP-induced autophagy, support EBV persistence and impair the degradation of phagocytozed bacteria through inefficient phagolysosome fusion. The susceptibility to NK-mediated cytolysis supports the hypothesis that NK function is likely to contribute to immune reconstitution after major trauma by regulating immature APC, and ATP-induced autophagy and survival

Matched Filters, Mate Choice and the Evolution of Sexually Selected Traits

Background Fundamental for understanding the evolution of communication systems is both the variation in a signal and how this affects the behavior of receivers, as well as variation in preference functions of receivers, and how this affects the variability of the signal. However, individual differences in female preference functions and their proximate causation have rarely been studied. Methodology/Principal Findings Calling songs of male field crickets represent secondary sexual characters and are subject to sexual selection by female choice. Following predictions from the “matched filter hypothesis” we studied the tuning of an identified interneuron in a field cricket, known for its function in phonotaxis, and correlated this with the preference of the same females in two-choice trials. Females vary in their neuronal frequency tuning, which strongly predicts the preference in a choice situation between two songs differing in carrier frequency. A second “matched filter” exists in directional hearing, where reliable cues for sound localization occur only in a narrow frequency range. There is a strong correlation between the directional tuning and the behavioural preference in no-choice tests. This second “matched filter” also varies widely in females, and surprisingly, differs on average by 400 Hz from the neuronal frequency tuning. Conclusions/Significance Our findings on the mismatch of the two “matched filters” would suggest that the difference in these two filters appears to be caused by their evolutionary history, and the different trade-offs which exist between sound emission, transmission and detection, as well as directional hearing under specific ecological settings. The mismatched filter situation may ultimately explain the maintenance of considerable variation in the carrier frequency of the male signal despite stabilizing selection

SIRT1 Regulates HIV Transcription via Tat Deacetylation

The human immunodeficiency virus (HIV) Tat protein is acetylated by the transcriptional coactivator p300, a necessary step in Tat-mediated transactivation. We report here that Tat is deacetylated by human sirtuin 1 (SIRT1), a nicotinamide adenine dinucleotide-dependent class III protein deacetylase in vitro and in vivo. Tat and SIRT1 coimmunoprecipitate and synergistically activate the HIV promoter. Conversely, knockdown of SIRT1 via small interfering RNAs or treatment with a novel small molecule inhibitor of the SIRT1 deacetylase activity inhibit Tat-mediated transactivation of the HIV long terminal repeat. Tat transactivation is defective in SIRT1-null mouse embryonic fibroblasts and can be rescued by expression of SIRT1. These results support a model in which cycles of Tat acetylation and deacetylation regulate HIV transcription. SIRT1 recycles Tat to its unacetylated form and acts as a transcriptional coactivator during Tat transactivation

Single Molecule Imaging Reveals Differences in Microtubule Track Selection Between Kinesin Motors

Molecular motors differentially recognize and move cargo along discrete microtubule subpopulations in cells, resulting in preferential transport and targeting of subcellular cargoes