Global child health in higher education in Germany : a mixed-methods study

Germany has an ambitious global health strategy, yet its universities provide few opportunities for global child health researchers. Improved understanding of the reasons and the academic role of global child health is needed

Hubble Space Telescope Observations of Comet 9P/Tempel 1 during the Deep Impact Encounter

We report on the Hubble Space Telescope program to observe periodic comet 9P/Tempel 1 in conjunction with NASA's Deep Impact mission. Our objectives were to study the generation and evolution of the coma resulting from the impact and to obtain wide-band images of the visual outburst generated by the impact. Two observing campaigns utilizing a total of 17 HST orbits were carried out: the first occurred on 2005 June 13-14 and fortuitously recorded the appearance of a new, short-lived fan in the sunward direction on June 14. The principal campaign began two days before impact and was followed by contiguous orbits through impact plus several hours and then snapshots one, seven, and twelve days later. All of the observations were made using the Advanced Camera for Surveys (ACS). For imaging, the ACS High Resolution Channel (HRC) provides a spatial resolution of 36 km (16 km/pixel) at the comet at the time of impact. Baseline images of the comet, made prior to impact, photometrically resolved the comet's nucleus. The derived diameter, 6.1 km, is in excellent agreement with the 6.0 +/- 0.2 km diameter derived from the spacecraft imagers. Following the impact, the HRC images illustrate the temporal and spatial evolution of the ejecta cloud and allow for a determination of its expansion velocity distribution. One day after impact the ejecta cloud had passed out of the field-of-view of the HRC.Comment: 15 pages, 14 postscript figures. Accepted for publication in Icarus special issue on Deep Impac

Dezentrales Koordinationskonzept zur multilateralen kollaborativen Produktions- und Distributionsplanung

Modelle, die integrativ Produktions- und Transportplanung simultan optimieren können, stoßen in der aktuellen Supply Chain Management-Forschung ebenso wie Konzepte zur dezentralen Planung auf großes Interesse. Im vorliegenden Beitrag wird ein VMI-Konzept vorgestellt, das eine koordinierte Planung der Lieferdaten und -mengen bzw. der Transporte zwischen den beteiligten Lieferanten anstrebt. Es wird gezeigt, welche Verbesserungen erzielt werden können und welches die daraus resultierenden Anforderungen an ein Framework zur Abbildung und Lösung dezentraler Planungskonzepte sind

catena-Poly[[diaqua­lithium]-μ-[rac-cis-(2-carb­oxy­cyclo­hexane-1-carboxyl­ato-κ2 O 1:O 2]]

In the structure of the title compound, [Li(C8H11O4)(H2O)2]n, the distorted tetra­hadral LiO4 coordination sphere comprises two water mol­ecules and two carboxyl O-atom donors from separate bridging cis-2-carb­oxy­cyclo­hexane-1-carboxyl­ate monoanions [Li—O = 1.887 (4)–1.946 (3) Å], giving chain substructures which extend along [010]. Water–water and water–carboxyl O—H⋯O hydrogen bonds stabilize these chain structures and provide inter­chain links, resulting in a two-dimensional layered structure extending parallel to (100)

Determination of the light curve of the Rosetta target asteroid (2867) Steins by the OSIRIS cameras onboard Rosetta

7 pp.-- Article published by EDP Sciences and available at http://www.aanda.org or http://dx.doi.org/10.1051/0004-6361:20066694.-- Table 2 is only available in electronic form at http://www.aanda.org.[Context] In 2004 asteroid (2867) Steins has been selected as a flyby target for the Rosetta mission. Determination of its spin period and the orientation of its rotation axis are essential for optimization of the flyby planning.[Aims] Measurement of the rotation period and light curve of asteroid (2867) Steins at a phase angle larger than achievable from ground based observations, providing a high quality data set to contribute to the determination of the orientation of the spin axis and of the pole direction.[Methods] On March 11, 2006, asteroid (2867) Steins was observed continuously for 24 h with the scientific camera system OSIRIS onboard Rosetta. The phase angle was 41.7 degrees, larger than the maximum phase angle of 30 degrees when Steins is observed from Earth. A total of 238 images, covering four rotation periods without interruption, were acquired.[Results] The light curve of (2867) Steins is double peaked with an amplitude of ≈0.23 mag. The rotation period is 6.052 ± 0.007 h. The continuous observations over four rotation periods exclude the possibility of period ambiguities. There is no indication of deviation from a principal axis rotation state. Assuming a slope parameter of G = 0.15, the absolute visual magnitude of Steins is 13.05 ± 0.03.The OSIRIS imaging system on board Rosetta is managed by the Max-Planck-Intitute for Solar System Research in Katlenburg-Lindau (Germany), thanks to an International collaboration between Germany, France, Italy, Spain, and Sweden. The support of the national funding agencies DLR, CNES, ASI, MEC, and SNSB is gratefully acknowledged. We acknowledge the work of the Rosetta Science Operations Centre at ESA/ESTEC and of the Rosetta Mission Operations Centre at ESA/ESOC who made these observations possible on short notation and operated the spacecraft. S.C.L. acknowledges support from the Leverhulme Trust. This research made use of JPL’s online ephemeris generator (HORIZONS).Peer reviewe

The water regime of dwarf planet (1) Ceres

The traditional view of minor bodies in the (inner) Solar System is that they are split into icy comets and rocky asteroids. However this has been challenged by recent results, such as the discovery of comets on asteroidal orbits in the outer asteroid belt (between Mars and Jupiter) and the detection of water ice frost on the surface of asteroid (24) Themis. The discovery of water ice on the surface of asteroids has profound implications for how the Solar System formed, and challenges our ideas about the stability of ice in the inner Solar System. The study of volatiles in the asteroid belt places strong constraints on the temperature and composition distribution in the proto-planetary disk,and on possible sources of terrestrial water, and strongly constrains formation models of the early Solar System

HERA LIDAR INSTRUMENT DEVELOPEMENT

The AIDA (Asteroid Impact & Deflection Assessment) is a collaboration between NASA DART mission and ESA Hera mission. The aim is to study asteroid deflection through a kinetic collision. For this mission two spacecrafts will be developed DART provided by NASA and HERA provided by ESA. DART spacecraft will collide with Didymoon, while the orbit change is monitored by ground stations. HERA spacecraft will study the post impact scenario. The HERA spacecraft is composed by the main spacecraft and two small CubeSats. HERA will study the asteroid with imaging, Radar, Satellite-to-Satellite Doppler tracking, Lidar, Seismometry and Gravimetry. We report a first iteration on the LIDAR instrument that we called HELENA (HERA LIDAR ENGINEERING MODEL ALTIMETER). HELENA is a TOF altimeter that provides time tagged distances and velocity measurements. The instrument can be used to support near asteroid navigation and provides scientific information (e.g. asteroid 3D topography, fall dawn velocity).The development of this instrument is done in the frame of an ESA activity. The LIDAR design comprises a microchip laser and a low noise sensor. The synergies between these two technologies enable the development of a compact instrument for range measurements of up to 20 km. We report the LIDAR design, namely, optics, opto-mechanics and electronics

The 12,460-Year Hohenheim Oak and Pine Tree-Ring Chronology from Central Europe—A Unique Annual Record for Radiocarbon Calibration and Paleoenvironment Reconstructions

ABSTRACT. The combined oak and pine tree-ring chronologies of Hohenheim University are the backbone of the Holocene radiocarbon calibration for central Europe. Here, we present the revised Holocene oak chronology (HOC) and the Preboreal pine chronology (PPC) with respect to revisions, critical links, and extensions. Since 1998, the HOC has been strengthened by new trees starting at 10,429 BP (8480 BC). Oaks affected by cockchafer have been identified and discarded from the chro-nology. The formerly floating PPC has been cross-matched dendrochronologically to the absolutely dated oak chronology, which revealed a difference of only 8 yr to the published 14C wiggle-match position used for IntCal98. The 2 parts of the PPC, which were linked tentatively at 11,250 BP, have been revised and strengthened by new trees, which enabled us to link both parts of the PPC dendrochronologically. Including the 8-yr shift of the oak-pine link, the older part of the PPC (pre-11,250 BP) needs to be shifted 70 yr to older ages with respect to the published data (Spurk 1998). The southern German part of the PPC now covers 2103 yr from 11,993–9891 BP (10,044–7942 BC). In addition, the PPC was extended significantly by new pine chronologies from other regions. A pine chronology from Avenches and Zürich, Switzerland, and another from the Younger Dryas forest of Cottbus, eastern Germany, could be crossdated and dendrochronologically matched to the PPC. The abso-lutely dated tree-ring chronology now extends back to 12,410 cal BP (10,461 BC). Therefore, the tree-ring-based 14C calibra-tion now reaches back into the Central Younger Dryas. With respect to the Younger Dryas-Preboreal transition identified in the ring width of our pines at 11,590 BP, the absolute tree-ring chronology now covers the entire Holocene and 820 yr of th

The ESA Hera mission to the binary asteroid (65803) Didymos: Planetary defense and science

The Hera mission is in development for launch in 2024 within the ESA Space Safety Program. Hera will contribute to the first deflection test of an asteroid, in the framework of the international NASA and ESA-supported Asteroid Impact and Deflection Assessment (AIDA) collaboration. Hera will also offer a great science return