6,988 research outputs found
Metastable Solid Solutions in the Gallium Antimonide-Germanium Pseudobinary System
Abstract unavailable
Knowledge in the dark: scientific challenges and ways forward
A key dimension of our current era is Big Data, the rapid rise in produced data and information; a key frustration is that we are nonetheless living in an age of ignorance, as the real knowledge and understanding of people does not seem to be substantially increasing. This development has critical consequences, for example it limits the ability to find and apply effective solutions to pressing environmental and socioeconomic challenges. Here, we propose the concept of “knowledge in the dark”—or short: dark knowledge—and outline how it can help clarify key reasons for this development: (i) production of biased, erroneous, or fabricated data and information; (ii) inaccessibility and (iii) incomprehensibility of data and information; and (iv) loss of previous knowledge. Even in the academic realm, where financial interests are less pronounced than in the private sector, several factors lead to dark knowledge, that is they inhibit a more substantial increase in knowledge and understanding. We highlight four of these factors—loss of academic freedom, research biases, lack of reproducibility, and the Scientific tower of Babel—and offer ways to tackle them, for example establishing an international court of arbitration for research and developing advanced tools for research synthesis
The visitor from an ancient galaxy: A planetary companion around an old, metal-poor red horizontal branch star
We report the detection of a planetary companion around HIP 13044, a
metal-poor red horizontal branch star belonging to a stellar halo stream that
results from the disruption of an ancient Milky Way satellite galaxy. The
detection is based on radial velocity observations with FEROS at the 2.2-m
MPG/ESO telescope. The periodic radial velocity variation of P=16.2 days can be
distinguished from the periods of the stellar activity indicators. We computed
a minimum planetary mass of 1.25 Jupiter masses and an orbital semimajor axis
of 0.116 AU for the planet. This discovery is unique in three aspects: First,
it is the first planet detection around a star with a metallicity much lower
than few percent of the solar value; second, the planet host star resides in a
stellar evolutionary stage that is still unexplored in the exoplanet surveys;
third, the planetary system HIP 13044 most likely has an extragalactic origin
in a disrupted former satellite of the Milky Way.Comment: 5 pages, 2 figures, 2 tables, submitted to the Proceedings of the
276th IAU Symposium "The Astrophysics of Planetary Systems
Is there a role for carbohydrate restriction in the treatment and prevention of cancer?
Over the last years, evidence has accumulated suggesting that by systematically reducing the amount of dietary carbohydrates (CHOs) one could suppress, or at least delay, the emergence of cancer, and that proliferation of already existing tumor cells could be slowed down. This hypothesis is supported by the association between modern chronic diseases like the metabolic syndrome and the risk of developing or dying from cancer. CHOs or glucose, to which more complex carbohydrates are ultimately digested, can have direct and indirect effects on tumor cell proliferation: first, contrary to normal cells, most malignant cells depend on steady glucose availability in the blood for their energy and biomass generating demands and are not able to metabolize significant amounts of fatty acids or ketone bodies due to mitochondrial dysfunction. Second, high insulin and insulin-like growth factor (IGF)-1 levels resulting from chronic ingestion of CHO-rich Western diet meals, can directly promote tumor cell proliferation via the insulin/IGF1 signaling pathway. Third, ketone bodies that are elevated when insulin and blood glucose levels are low, have been found to negatively affect proliferation of different malignant cells in vitro or not to be usable by tumor cells for metabolic demands, and a multitude of mouse models have shown anti-tumorigenic properties of very low CHO ketogenic diets. In addition, many cancer patients exhibit an altered glucose metabolism characterized by insulin resistance and may profit from an increased protein and fat intake
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