The life of Gotthold Ferdinand Eisenstein

Gotthold Ferdinand Eisenstein (1823-1852) was one of the brilliant mathematicians of the nineteenth century. The main goal of this article is to give a translation – from German into English – of a Curriculum Vita that he wrote at age twenty, as part of his application for the Examination of General Maturity for University Entrance (Abitur). This has often been referred to as his autobiography. Some additional biographical information is also given, with the aim of providing some further insights into his life and character in general

Far infrared supplement: Catalog of infrared observations

The development of a new generation of orbital, airborne and ground-based infrared astronomical observatory facilities, including the infrared astronomical satellite (IRAS), the cosmic background explorer (COBE), the NASA Kuiper airborne observatory, and the NASA infrared telescope facility, intensified the need for a comprehensive, machine-readable data base and catalog of current infrared astronomical observations. The Infrared Astronomical Data Base and its principal data product, this catalog, comprise a machine-readable library of infrared (1 micrometer to 1000 micrometers) astronomical observations published in the scientific literature since 1965

FOOD NUTRITIONAL QUALITY: A PILOT STUDY ON CONSUMER AWARENESS

Retail food demand studies are becoming increasingly concerned with the role of nutrition and health, yet consumer perceptions and attitudes are often ignored. The purpose of this pilot study is to determine consumer perceptions involving nutrition levels for selected foods. The influence of demographics and information about nutrition and health on perceptions toward meat items are determined. Results generally indicate that consumer perceptions toward fat and cholesterol levels in meats are based on the comparison of animal sources, not the comparison of individual cuts or preparation techniques. Recent efforts in the study of retail food demand have moved toward the role of nutrition and health. Several attempts have been made to measure the role that nutrition plays in food value or purchase habits (LaFrance (1983), Huffman (1988), Brown and Shrader (1990)). These studies use actual nutritional content of foods consumed to estimate demand impacts. However, it is possible that consumers perceive the nutritional elements of certain foods to be significantly different than actual levels. Differences between actual and perceived levels represent measurement error in these variables. Such errors may adversely affect the results of our demand studies. Consumer misperceptions may be an especially important issue when a utility maximization model such as Lancaster's Consumer Goods Characteristics Model (CGCM) is used. In such a model, the utility function arguments are the characteristics of the goods not the goods themselves. If consumers misperceive the nutritional value of food products, such models should include the perceived levels of nutrition, not the actual levels. The CGCM has been used extensively in recent years. In particular, CGCM was used by Ladd and Suvannant (1976) to test if food prices were a sum of the values of certain nutrients; by Adrian and Daniels (1976) to estimate nutrient demand based in part on demographic variables; by Morgan, Metzen, and Johnson (1979) to estimate hedonic prices for breakfast cereal characteristics; and by Terry, Brooker, and Eastwood (1986) to estimate the demand for nutrients. Each of these studies used actual nutrition levels. If, however, perceived nutrition levels are different than the actual levels, the results and conclusions may be affected. Results from these models vary widely. In the case of some nutrients, the implicit values can switch from significantly positive to significantly negative across models. Some of the variability may be associated with specification and differences in time periods. However, some variation may result from differences in perceptions which also change over time. Models which do not directly specify nutrient levels may fall prey to another problem. Work by Brown and Schrader (1990) and later by Capps and Schmitz (1990) utilize an index of nutritional awareness. Models of this nature allow for consumer perceptions to be included. However, when results of these models are reviewed, the results are compared to actual data, not perceptions. These results may be compared to the wrong benchmarks. Thus perceptions need to be considered, regardless of the approach used.Food Consumption/Nutrition/Food Safety,

Cosmic-ray exposure ages of fossil micrometeorites from mid-Ordovician sediments at Lynna River, Russia

We measured the He and Ne concentrations of 50 individual extraterrestrial chromite grains recovered from mid-Ordovician (lower Darriwilian) sediments from the Lynna River section near St. Petersburg, Russia. High concentrations of solar wind-like He and Ne found in most grains indicate that they were delivered to Earth as micrometeoritic dust, while their abundance, stratigraphic position and major element composition indicate an origin related to the L chondrite parent body (LCPB) break-up event, 470 Ma ago. Compared to sediment-dispersed extraterrestrial chromite (SEC) grains extracted from coeval sediments at other localities, the grains from Lynna River are both highly concentrated and well preserved. As in previous work, in most grains from Lynna River, high concentrations of solar wind-derived He and Ne impede a clear quantification of cosmic-ray produced He and Ne. However, we have found several SEC grains poor in solar wind Ne, showing a resolvable contribution of cosmogenic 21Ne. This makes it possible, for the first time, to determine robust cosmic-ray exposure (CRE) ages in these fossil micrometeorites, on the order of a few hundred-thousand years. These ages are similar to the CRE ages measured in chromite grains from cm-sized fossil meteorites recovered from coeval sediments in Sweden. As the CRE ages are shorter than the orbital decay time of grains of this size by Poynting-Robertson drag, this suggests that the grains were delivered to Earth through direct injection into an orbital resonance. We demonstrate how CRE ages of fossil micrometeorites can be used, in principle, to determine sedimentation rates, and to correlate the sediments at Lynna River with the fossil meteorite-bearing sediment layers in Sweden.Comment: 25 pages, 4 figures, 2 table

The role of use cases in development of a reference framework for interoperability of data exchange in agriculture

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A Structural Comparison of Ordered and Non-Ordered Ion Doped Silicate Bioactive Glasses

One of the key benefits of sol-gel-derived glasses is the presence of a mesoporous structure and the resulting increase in surface area. This enhancement in textural properties has a significant e ect on the physicochemical properties of the materials. In this context the aim of this study was to investigate how sol-gel synthesis parameters can influence the textural and structural properties of mesoporous silicate glasses. We report the synthesis and characterization of metal ion doped sol-gel derived glasses with di erent dopants in the presence or absence of a surfactant (Pluronic P123) used as structure-directing templating agent. Characterization was done by several methods. Using a structure directing agent led to larger surface areas and highly ordered mesoporous structures. The chemical structure of the non-ordered glasses was modified to a larger extent than the one of the ordered glasses due to increased incorporation of dopant ions into the glass network. The results will help to further understand how the properties of sol-gel glasses can be controlled by incorporation of metal dopants, in conjunction with control over the textural properties, and will be important to optimize the properties of sol-gel glasses for specific applications, e.g., drug delivery, bone regeneration, wound healing, and antibacterial materials.European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 643050, project “HyMedPoly

On the sound of snapping shrimp

Snapping shrimp produce a snapping sound by an extremely rapid closure of their snapper claw. Source levels reported for Alpheus heterochaelis are as high as 220 dB (peak-to-peak) re. 1 µPa at 1 m distance. The loud snap has been attributed to the mechanical contact made when the snapper claw contracts. The recent ultra-high-speed imaging of the snapper claw closure at 40500 frames per second has revealed that the sound is, in fact, generated by the collapse of a cavitation bubble formed in a fast flowing water jet forced out from between the claws during claw closure. A temporal analysis of the sound recordings and the high-speed images shows that no sound is associated with the claw closure, while a very prominent signal is observed during the collapse of the cavitation bubble. Gallery of Fluid Motion\ud Award-winning entry 200