Capabilities of Earth-based radar facilities for near-Earth asteroid observations

We evaluated the planetary radar capabilities at Arecibo, the Goldstone 70-m DSS-14 and 34-m DSS-13 antennas, the 70-m DSS-43 antenna at Canberra, the Green Bank Telescope, and the Parkes Radio Telescope in terms of their relative sensitivities and the number of known near-Earth asteroids (NEAs) detectable per year in monostatic and bistatic configurations. In the 2015 calendar year, monostatic observations with Arecibo and DSS-14 were capable of detecting 253 and 131 NEAs respectively, with signal-to-noise ratios (SNRs) greater than 30/track. Combined, the two observatories were capable of detecting 276 NEAs. Of these, Arecibo detected 77 and Goldstone detected 32, or 30% and 24% the numbers that were possible. The two observatories detected an additional 18 and 7 NEAs respectively, with SNRs of less than 30/track. This indicates that a substantial number of potential targets are not being observed. The bistatic configuration with DSS-14 transmitting and the Green Bank Telescope receiving was capable of detecting about 195 NEAs, or ~50% more than with monostatic observations at DSS-14. Most of the detectable asteroids were targets of opportunity that were discovered less than 15 days before the end of their observing windows. About 50% of the detectable asteroids have absolute magnitudes > 25, which corresponds diameters < ~30 m.Comment: 12 pages, 7 figures, Accepted to A

Seroprevalence of Infection with Feline Morbilliviruses Is Associated with FLUTD and Increased Blood Creatinine Concentrations in Domestic Cats

Feline morbilliviruses (FeMV) are fairly newly discovered paramyxoviruses found in cats. The first description indicated an association with widely distributed chronic kidney disease (CKD) in the host species. In various studies, a global prevalence and a further genotype, designated FeMV-2, and the involvement of other organ systems in infected individuals were shown. Using an immunofluorescence assay, we detected an overall seroprevalence of FeMV in almost half of the cats investigated (n = 380), with a significantly increased proportion in younger animals. In comparison to European Shorthair cats, the rate of seropositivity is higher in pedigree cats. Regardless of the breed, FeMV infection was associated with increased blood creatinine concentrations, suggesting an association with CKD. Further analysis indicated that this association was the strongest in animals having high IFA titers against FeMV-2. In addition, a significant association between FeMV-positive status and the prevalence of feline lower urinary tract disease (FLUTD, or idiopathic cystitis) was detected. This association was dominated by cats having antibodies against FeMV-1 only. To further evaluate the positive correlation between FeMV seroprevalence and CKD as well as FLUTD, consideration of additional clinical characteristics and laboratory parameters is warranted, and controlled infection studies with both FeMV genotypes are necessary. Clinicians should, however, be aware of a possible link between renal and lower urinary tract disease and FeMV infections

Mutated Measles Virus Matrix and Fusion Protein Influence Viral Titer In Vitro and Neuro-Invasion in Lewis Rat Brain Slice Cultures

Measles virus (MV) can cause severe acute diseases as well as long-lasting clinical deteriorations due to viral-induced immunosuppression and neuronal manifestation. How the virus enters the brain and manages to persist in neuronal tissue is not fully understood. Various mutations in the viral genes were found in MV strains isolated from patient brains. In this study, reverse genetics was used to introduce mutations in the fusion, matrix and polymerase genes of MV. The generated virus clones were characterized in cell culture and used to infect rat brain slice cultures. A mutation in the carboxy-terminal domain of the matrix protein (R293Q) promoted the production of progeny virions. This effect was observed in Vero cells irrespective of the expression of the signaling lymphocyte activation molecule (SLAM). Furthermore, a mutation in the fusion protein (I225M) induced syncytia formation on Vero cells in the absence of SLAM and promoted viral spread throughout the rat brain slices. In this study, a solid ex vivo model was established to elucidate the MV mutations contributing to neural manifestation

Kompetenzsteuerung in Teams durch transaktives Wissen

Innerhalb der soziokognitiven Teamforschung ist das Konzept des transaktiven Wissens als zentraler Erfolgsfaktor erkannt worden, der für eine effiziente Steuerung der individuellen Kompetenzen von Teammitgliedern sorgt. Transaktives Wissen beinhaltet Wissen um das Wissen der anderen; es dient sowohl der Kompetenzsteuerung als auch der Erklärung von Kompetenzentstehung auf Teamebene. Nach der Einordnung dieses Konzepts in den übergeordneten Zusammenhang von Teamkompetenzen widmet sich der Beitrag schwerpunktmäßig der Frage seiner konkreten Gestaltung. Um den Entwicklungsbedarf an transaktivem Wissen abschätzen zu können, ist zunächst die Analyse der Teamaufgabe notwendig. Sodann werden zwei Gestaltungsphasen näher betrachtet: die vorbereitende und die begleitende Phase. In der vorbereitenden Phase ist Mitgliederwissen gezielt offenzulegen. Dies wird u.a. durch den Einsatz von Cross Training erreicht. In der begleitenden Phase ist die Grundlage dafür zu schaffen, dass Wissen fortlaufend aktualisiert werden kann. Hierzu dient zum einen der Aufbau von Team Situation Awareness, zum anderen die regelmäßige Durchführung von After Action Reviews. Abschließend werden offene Forschungsfragen skizziert und weitere mögliche Anwendungsfelder von transaktivem Wissen aufgezeigt.Abstract: Transactive knowledge, i.e. knowing who knows what within a team setting, has been identified as a key factor for explaining the combination of individual knowledge, skills, and abilities (KSA) in the socio-cognitive team research. To know what others know helps team members in better searching and retrieving relevant information. Transactive knowledge therefore may lead us to open the black box of the evolution of team-based competencies, too. It can be divided into task-related and biographical knowledge about our colleagues. It also includes a precise understanding of team members’ personalities and their status as well as the knowledge about their social ties outside the team. Finegrained knowledge about each other affects the efficiency and smoothness of cooperation among team members. We provide an explanation on how it actually can be managed, after showing the basic functions of transactive knowledge. Besides the technological infrastructure fostering communication processes, the analysis of the team task offers information on the requirements for the development of transactive knowledge: The task complexity decides about whether transactive knowledge is a means to substitute for one another (as it is the case for simple tasks on the shop floor), or whether it is used as a means to create a transspecialist understanding (as it is the case for highly-qualified workers, e.g. in new product development teams). Task interdependence on the contrary decides about how important the development of transactive knowledge generally is. Without intensive interaction the training of team members to build up transactive knowledge will be nothing but a waste of resources. We therefore focus on highly interdependent project teams consisting of members being not familiar with each other, i.e. members who work together for the first time. Two training sequences are discussed in detail: Knowledge disclosure and knowledge updating. In the first training sequence knowledge about one another needs to be disclosed, preparing the team to perform well. Cross-training is an appropriate training instrument in this context. Cross-training refers to a strategy in which each team member is trained on the tasks, duties, and responsibilities of his or her fellow team members. It consists of positional clarification, positional modeling, and positional rotation. The second sequence is used in teams while performing. For successful teams it is necessary to maintain team situation awareness, i.e. to create a shared understanding of what is going on. This is crucial for recognizing changes of members’ KSAs and changes in the environment. Without interpersonal feedback situation awareness can hardly be achieved. The after action review (AAR) which has its origin in the US Army is an instrument being able to effectively institutionalize such task-oriented feedback processes. Four basic questions are to be answered in regularly team meetings: What happened? What should have happened? Why did it happen? What can we do better? The AAR is not only essential for creating situation awareness but also for updating knowledge about one another. Finally, open questions are discussed

Determining asteroid spin states using radar speckles

Knowing the shapes and spin states of near-Earth asteroids is essential to understanding their dynamical evolution because of the Yarkovsky and YORP effects. Delay-Doppler radar imaging is the most powerful ground-based technique for imaging near-Earth asteroids and can obtain spatial resolution of <10 m, but frequently produces ambiguous pole direction solutions. A radar echo from an asteroid consists of a pattern of speckles caused by the interference of reflections from different parts of the surface. It is possible to determine an asteroid’s pole direction by tracking the motion of the radar speckle pattern. Speckle tracking can potentially measure the poles of at least several radar targets each year, rapidly increasing the available sample of NEA pole directions. We observed the near-Earth asteroid 2008 EV5 with the Arecibo planetary radar and the Very Long Baseline Array in December 2008. By tracking the speckles moving from the Pie Town to Los Alamos VLBA stations, we have shown that EV5 rotates retrograde. This is the first speckle detection of a near-Earth asteroid

MiRP1 forms IKr potassium channels with HERG and is associated with cardiac arrhythmia.

A novel potassium channel gene has been cloned, characterized, and associated with cardiac arrhythmia. The gene encodes MinK-related peptide 1 (MiRP1), a small integral membrane subunit that assembles with HERG, a pore-forming protein, to alter its function. Unlike channels formed only with HERG, mixed complexes resemble native cardiac IKr channels in their gating, unitary conductance, regulation by potassium, and distinctive biphasic inhibition by the class III antiarrhythmic E-4031. Three missense mutations associated with long QT syndrome and ventricular fibrillation are identified in the gene for MiRP1. Mutants form channels that open slowly and close rapidly, thereby diminishing potassium currents. One variant, associated with clarithromycin-induced arrhythmia, increases channel blockade by the antibiotic. A mechanism for acquired arrhythmia is revealed: genetically based reduction in potassium currents that remains clinically silent until combined with additional stressors