6,214 research outputs found
\u3cb\u3e\u3cem\u3eThe Drunkard\u27s Walk: How Randomness Rules Our Lives\u3c/em\u3e\u3c/b\u3e by Leonard Mlodinow, Pantheon Books 2008
Tribute: In Memoriam, Jeheskel Hezy Shoshani
The elephant community has lost one of its great ambassadors, Dr. Jeheskel Hezy Shoshani, at the age of 65. A wave of condolences and testimonials from colleagues and friends around the world followed his death on May 21, 2008
Birth Statistics for African (\u3cem\u3eLoxodonta africana\u3c/em\u3e) and Asian (\u3cem\u3eElephas maximus\u3c/em\u3e) Elephants in Human Care: History and Implications for Elephant Welfare
African (Loxodonta africana) and Asian elephants (Elephas maximus) have lived in the care of humans for many years, yet there is no consensus concerning some basic parameters describing their newborn calves. This study provides a broad empirical basis for generalizations about the birth heights, birth weights, birth times and gestation periods of elephant calves born in captivity. I obtained data concerning at least one of these four characteristics for 218 newborn calves from 74 institutions. Over the past 30 years, newborn Asian elephants have been taller and heavier than newborn African elephants. Neonatal African elephants exhibited sex differences in both weight and height, whereas neonatal Asian elephants have exhibited sex differences only in height. Primiparous dams ex situ are at least as old as their in situ counterparts, whereas ex situ sires appear to be younger than sires in range countries. Confirming earlier anecdotal evidence, both African [N= 47] and Asian [N = 91] dams gave birth most often at night
History: The Birth of America in 1882
This article concerns a New York Times story about the birth of the female Asian elephant calf, named America, at the winter headquarters of the Greatest Show on Earth in Bridgeport, Connecticut on February 2, 1882. Phineas T. Barnum, one of the owners of the show, and one prone to self-aggrandizing bluster, claimed that America was the second elephant ever born in captivity. America was born only to months before the arrival in New York of the most famous circus elephant of all time, Jumbo, on Easter Sunday, 1882, and only two years before the origin of a small wagon circus run by the five Ringling (originally, RΓΌngeling) brothers from Baraboo Wisconsin
Some Children\u27s Books About Elephants (1987-1997)
Literature review of children\u27s books about elephants from the Indianapolis Public Library
The Spatial Memory of African Elephants (\u3cem\u3eLoxodonta africana\u3c/em\u3e): Durability, Interference, and Response Biases
Women and elephants never forget an injury.
-Saki (H. H. Munro), Reginald on besetting sins, in Reginald (1904)
I am not sure whether the satirist H. H. Munro believed Saki\u27s claim, although it may well be true (at least with regard to elephants). This chapter will examine some characteristics of elephant memory more systematically than did Saki.
In general, it is to an animal\u27s advantage to remember some aspects (usually the stable features) of a situation for long periods and to remember other aspects (usually the unstable features) only temporarily. Consistent with recent arguments questioning the value of cognitive constructs for studying animal behavior (Grau 2002; Staddon 2001a,b; Wright and Watkins 1987), I will use reference memory and working memory (Baddeley and Hitch 1974; Honig 1978) only as descriptive terms indicating formal task requirements. (See Olton, Becker, and Handelmann 1979.) The stable characteristics of the test situation (such as the shape of the spatial array of food sources) are said to involve reference memory; those features that vary across trials (such as the sequence of food sites visited on a trial) are said to involve working memory. My main goal is to demonstrate that elephants can remember which locations they have visited during a spatial memory test similar to the radial maze (Olton and Samuelson 1976). The data will show that elephants rely on memory to solve several spatial problems, rather than relying on their response biases (Dale and Innis 1986) or their excellent olfactory abilities (Rasmussen and Krishnamurthy 2000). In addition, I will describe research showing that performance on the memory task is susceptible to proactive interference and that the retention of reference memory components of the test procedures is durable
Selectional Restrictions in HPSG
Selectional restrictions are semantic sortal constraints imposed on the
participants of linguistic constructions to capture contextually-dependent
constraints on interpretation. Despite their limitations, selectional
restrictions have proven very useful in natural language applications, where
they have been used frequently in word sense disambiguation, syntactic
disambiguation, and anaphora resolution. Given their practical value, we
explore two methods to incorporate selectional restrictions in the HPSG theory,
assuming that the reader is familiar with HPSG. The first method employs HPSG's
Background feature and a constraint-satisfaction component pipe-lined after the
parser. The second method uses subsorts of referential indices, and blocks
readings that violate selectional restrictions during parsing. While
theoretically less satisfactory, we have found the second method particularly
useful in the development of practical systems
Activity-dependent adenosine release may be linked to activation of Na+-K+ ATPase : an in vitro rat study
In the brain, extracellular adenosine increases as a result of neuronal activity. The mechanisms by which this occurs are only incompletely understood. Here we investigate the hypothesis that the Na+ influxes associated with neuronal signalling activate the Na+-K+ ATPase which, by consuming ATP, generates intracellular adenosine that is then released via transporters. By measuring adenosine release directly with microelectrode biosensors, we have demonstrated that AMPA-receptor evoked adenosine release in basal forebrain and cortex depends on extracellular Na+. We have simultaneously imaged intracellular Na+ and measured adenosine release. The accumulation of intracellular Na+ during AMPA receptor activation preceded adenosine release by some 90 s. By removing extracellular Ca2+, and thus preventing indiscriminate neuronal activation, we used ouabain to test the role of the Na+-K+ ATPase in the release of adenosine. Under conditions which caused a Na+ influx, brief applications of ouabain increased the accumulation of intracellular Na+ but conversely rapidly reduced extracellular adenosine levels. In addition, ouabain greatly reduced the amount of adenosine released during application of AMPA. Our data therefore suggest that activity of the Na+-K+ ATPase is directly linked to the efflux of adenosine and could provide a universal mechanism that couples adenosine release to neuronal activity. The Na+-K+ ATPase-dependent adenosine efflux is likely to provide adenosine-mediated activity-dependent negative feedback that will be important in many diverse functional contexts including the regulation of sleep
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