Combination Service for Time-variable Gravity Fields (COST-G): operations and new developments

Since its start of operations in July 2019, IAGâ?Ts Combination Service for Time-variable Gravity fields (COST-G) is providing a complete time-series of combined monthly GRACE gravity fields and a regularly updated time-series of monthly gravity fields derived from kinematic Swarm orbits. Starting from October 2020, the COST-G product line is complemented by a time-series of operationally combined and monthly updated GRACE-FO gravity fields. All these combinations are performed by variance component estimation on the solution level. We report on new developments, i.e., a planned extension of COST-G to include Chinese analysis centers of GRACE and GRACE-FO data, a re-consideration of the combination strategy to better focus on the range of spherical harmonic coefficients most relevant for the users, and the potential application of COST-G products for orbit determination of altimeter satellites

Constraints on Energy Intake in Fish: The Link between Diet Composition, Energy Metabolism, and Energy Intake in Rainbow Trout

The hypothesis was tested that fish fed to satiation with iso-energetic diets differing in macronutrient composition will have different digestible energy intakes (DEI) but similar total heat production. Four iso-energetic diets (2×2 factorial design) were formulated having a contrast in i) the ratio of protein to energy (P/E): high (HP/E) vs. low (LP/E) and ii) the type of non-protein energy (NPE) source: fat vs. carbohydrate which were iso-energetically exchanged. Triplicate groups (35 fish/tank) of rainbow trout were hand-fed each diet twice daily to satiation for 6 weeks under non-limiting water oxygen conditions. Feed intake (FI), DEI (kJ kg−0.8 d−1) and growth (g kg−0.8 d−1) of trout were affected by the interaction between P/E ratio and NPE source of the diet (P<0.05). Regardless of dietary P/E ratio, the inclusion of carbohydrate compared to fat as main NPE source reduced DEI and growth of trout by ∼20%. The diet-induced differences in FI and DEI show that trout did not compensate for the dietary differences in digestible energy or digestible protein contents. Further, changes in body fat store and plasma glucose did not seem to exert a homeostatic feedback control on DEI. Independent of the diet composition, heat production of trout did not differ (P>0.05). Our data suggest that the control of DEI in trout might be a function of heat production, which in turn might reflect a physiological limit related with oxidative metabolism

Benefits of protected areas for nonbreeding waterbirds adjusting their distributions under climate warming

Climate warming is driving changes in species distributions and community composition. Many species have a so-called climatic debt, that is, shifts in range lag behind shifts in temperature isoclines. Inside protected areas (PAs), community changes in response to climate warming can be facilitated by greater colonization rates by warm-dwelling species, but also mitigated by lowering extirpation rates of cold-dwelling species. An evaluation of the relative importance of colonization-extirpation processes is important to inform conservation strategies that aim for both climate debt reduction and species conservation. We assessed the colonization-extirpation dynamics involved in community changes in response to climate inside and outside PAs. To do so, we used 25 years of occurrence data of nonbreeding waterbirds in the western Palearctic (97 species, 7071 sites, 39 countries, 1993-2017). We used a community temperature index (CTI) framework based on species thermal affinities to investigate species turnover induced by temperature increase. We determined whether thermal community adjustment was associated with colonization by warm-dwelling species or extirpation of cold-dwelling species by modeling change in standard deviation of the CTI (CTISD). Using linear mixed-effects models, we investigated whether communities in PAs had lower climatic debt and different patterns of community change than communities outside PAs. For CTI and CTISD combined, communities inside PAs had more species, higher colonization, lower extirpation, and lower climatic debt (16%) than communities outside PAs. Thus, our results suggest that PAs facilitate 2 independent processes that shape community dynamics and maintain biodiversity. The community adjustment was, however, not sufficiently fast to keep pace with the large temperature increases in the central and northeastern western Palearctic. Our results underline the potential of combining CTI and CTISD metrics to improve understanding of the colonization-extirpation patterns driven by climate warming

Graphics and visualization - the essential features for the classification of systems

Advances in computer graphics in the recent twenty years have stimulated different schemes to classify research directions and systems. In the early days, graphics systems were identified to be vector or raster graphics in terms of technology. Sutherland's Sketchpad system was the first example that allowed to distinguish between passive and interactive computer graphics. Dimensions of the geometric data model classified systems to be a 2D or 3D system. This scheme was used by standardization activities in computer graphics during the last decade. However, the approaches of standard committees to develop a reference model for computer graphics have shown very clearly that the variety of systems and the complexity within one graphics system prevents from the establishment of an easy-to-understand model. Taxonomies in scientific visualization (MzCo-87) focussed on the integration of different disciplines like computer graphics and computer vision, and the use of available, mostly heterog eneous system components and peripherals. At least, scientific visualization has shown very clearly that computer graphics today is very different from drawing and image processing. Our understanding (Felg-90) of scientific visualization comprises outstanding system requirements like: massive amounts of complex and multidimensional data to be processed, peripheral and algorithmic means for interactive data exploration, manifold alternative (physical and logical) visual (but also non-visual) data presentation techniques, and computational models for physical phenomena. Consequently, scientific visualization requires a correspondence between the human perception and the abstract computer-internal representation of the physical world. Visualization in scientific computing needs this correspondence, virtual reality even requires more! Virtual reality presumes integrated presentation, feedback and simulation techniques and demands realtime! Realtime in this context is defined as the evalu

User-tailored interaction development in 2D, 3D, and VR with UC-AID med

The discussion on the advantages and disadvantages of 2D, 3D, and VR interfaces and their applicability to different types of systems, users, and information, led to a series of stand-alone implementations that lack the possibility of realizing an integrated approach. The acceptance of the different interaction techniques will depend on their success in practical applications, i.e. with systems that are used by different users for different purposes. Since this acceptance is especially hard to achieve in computer-critical environments, such as medicine, we developed a software environment that allows for the development, integration, and user-centered evaluation of existing and new interaction techniques for their use in medical applications. This environment is equipped with an innovative message-passing functionality that provides the communication to and among application objects in 2D, 3D, and VR. Furthermore, the environment contains a component for user-adapted interaction and system support at runtime. (orig.)SIGLEAvailable from TIB Hannover: RR 4367(96-5) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Virtual design II: an advanced VR development environment

This paper presents an overview of virtual reality system technology and its application within the Fraunhofer Demonstration Centre for VR. The Virtual Design II development environment including various pre-processing and editing tools is introduced and its benefit for the realization of efficient and high-quality virtual worlds is highlighted. A broad range of applications realized wwith Virtual Desing II demonstrate the usability of virtual reality technology, which enables new dimensions in computer-supported applications

Burrows H., Campos H., DELATTRE Cédric, Dupre C., Encarnacao T., Fauchon M., GAIGNARD Clément, Hellio C., Ito J., LAROCHE Céline, MICHAUD Philippe, Pais A., PIERRE Guillaume, Serive B., Watanabe M.

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