13,174 research outputs found

    On presuppositions in requirements

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    Fish Foods in Relation to Fish Culture

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    The necessity for a solution to the fish culture problem was long ago felt in the crowded districts of Europe. The economic demand that food be produced for the ever increasing population of these districts resulted in directing attention to the comparatively waste small inland ponds and lakes, once plentifully inhabited by food fish but now almost completely exhausted. It was to meet this situation, then, that the pioneer fish culturists began working at methods to raise the waste waters to their former degree of productive usefulness in yielding food

    Vascular Structure of the Kidney in the Snapping and Painted Turtles

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    This paper deals with the vascularization of the kidney in Chrysemys marginata belli (Gray) and Chelydra serpentina. The arrangement of the vessels in the kidney of the painted turtle produces a true renal portal system while that in the kidney of the snapping turtle permits a considerable amount of blood to shunt around the capillaries of the kidney

    Galileo In-Situ Dust Measurements in Jupiter's Gossamer Rings

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    During its late orbital mission at Jupiter the Galileo spacecraft made two passages through the giant planet's gossamer ring system. The impact-ionization dust detector on board successfully recorded dust impacts during both ring passages and provided the first in-situ measurements from a dusty planetary ring. In all, a few thousand dust impacts were counted with the instrument accumulators during both ring passages, but only a total of 110 complete data sets of dust impacts were transmitted to Earth. Detected particle sizes range from about 0.2 to 5 micron, extending the known size distribution by an order of magnitude towards smaller particles than previously derived from optical imaging (Showalter et al. 2008). The grain size distribution increases towards smaller particles and shows an excess of these tiny motes in the Amalthea gossamer ring compared to the Thebe ring. The size distribution for the Amalthea ring derived from our in-situ measurements for the small grains agrees very well with the one obtained from images for large grains. Our analysis shows that particles contributing most to the optical cross-section are about 5 micron in radius, in agreement with imaging results. The measurements indicate a large drop in particle flux immediately interior to Thebe's orbit and some detected particles seem to be on highly-tilted orbits with inclinations up to 20 deg.Comment: 13 figures, 4 tables, submitted to Icaru

    Possible Indication of Narrow Baryonic Resonances Produced in the 1720-1790 MeV Mass Region

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    Signals of two narrow structures at M=1747 MeV and 1772 MeV were observed in the invariant masses M_{pX} and M_{\pi^{+}X} of the pp->ppX and pp->p\pi^{+}X reactions respectively. Many tests were made to see if these structures could have been produced by experimental artefacts. Their small widths and the stability of the extracted masses lead us to conclude that these structures are genuine and may correspond to new exotic baryons. Several attempts to identify them, including the possible "missing baryons" approach, are discussed.Comment: 17 pages including 8 figures and 3 tables. ReVte

    Frequency of occurrence of numbers in the World Wide Web

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    The distribution of numbers in human documents is determined by a variety of diverse natural and human factors, whose relative significance can be evaluated by studying the numbers' frequency of occurrence. Although it has been studied since the 1880's, this subject remains poorly understood. Here, we obtain the detailed statistics of numbers in the World Wide Web, finding that their distribution is a heavy-tailed dependence which splits in a set of power-law ones. In particular, we find that the frequency of numbers associated to western calendar years shows an uneven behavior: 2004 represents a `singular critical' point, appearing with a strikingly high frequency; as we move away from it, the decreasing frequency allows us to compare the amounts of existing information on the past and on the future. Moreover, while powers of ten occur extremely often, allowing us to obtain statistics up to the huge 10^127, `non-round' numbers occur in a much more limited range, the variations of their frequencies being dramatically different from standard statistical fluctuations. These findings provide a view of the array of numbers used by humans as a highly non-equilibrium and inhomogeneous system, and shed a new light on an issue that, once fully investigated, could lead to a better understanding of many sociological and psychological phenomena.Comment: 5 pages, 4 figure

    Literature-driven Curation for Taxonomic Name Databases

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    Digitized biodiversity literature provides a wealth of content for using biodiversity knowledge by machines. However, identifying taxonomic names and the associated semantic metadata is a difficult and labour intensive process. We present a system to support human assisted creation of semantic metadata. Information extraction techniques auto-matically identify taxonomic names from scanned documents. They are then presented to users for manual correction or verification. The tools that support the curation process include taxonomic name identification and mapping, and community-driven taxonomic name verification. Our research shows the potential for these information extrac-tion techniques to support research and curation in disciplines dependent upon scanned document

    An Experimental Circulatory Arrest Model in the Rat to Evaluate Calcium Antagonists in Cerebral Resuscitation

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    A circulatory arrest model in the rat was developed for use in cerebral and cardiac resuscitation studies. Whole-body ischemia was produced for 8 to 18 minutes by arresting the heart with a cold potassium chloride cardioplegic solution. Following cardiopulmonary resuscitation, minimal, standardized intensive care was provided. As the duration of ischemia was increased from 8 to 18 minutes, survival immediately following resuscitation decreased from 100% to 25%, and survival at 48 hours after ischemia decreased from 80% to 0%. Thirty per cent of the rats recovering from 11 minutes of ischemia suffered motor seizures. Survival and the incidence of motor seizures appear to be good measures of outcome following ischemic circulatory arrest. These measures can be used to test the possible anti-ischemic actions of calcium antagonists or other drugs
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