Nachrufe auf Hermann von Helmholtz und Helmholtz' Tischrede gehalten bei der Feier des 70. Geburtstages

Hermann Helmholtz lehrte von 1858 bis 1871 als Physiologieprofessor an der Heidelberger Universität. Der vielseitige Gelehrte befasste sich in Heidelberg intensiv mit den Grundlagen der Geometrie. Die Nachrufsammlung enthält: 1.) Theodor Wilhelm Engelmann (Universität Utrecht) 2.) Emil du Bois-Reymond (Physikalische Gesellschaft Berlin) 3.) Otto Bütschli (Naturhist.-med. Verein zu Heidelberg) 4.) Wilhelm von Bezold (Wissenschaftliche Vereine in Berlin) 5.) Albert Waag (Stadt Heidelberg) 6.) Emil du Bois-Reymond (Akademie der Wissenschaften zu Berlin) 7.) Briefe von Anna von Helmholtz Außerdem wurde die von Hermann von Helmholtz gehaltene Tischrede anl. seines 70. Geburtstages beigefügt

The Dogs of Ninkilim, part two: Babylonian rituals to counter field pests

This article presents editions of all the extant Babylonian incantations against field pests. The sources date to the first millennium BC and many have not been published before. They are mostly tablets of the Neo-Assyrian period, from Ashurbanipal's library at Nineveh, but the corpus also contains some Neo-Babylonian fragments from Nineveh, as well as a tablet from Sultantepe (ancient Huzirina) and two Late Babylonian tablets from southern Mesopotamia. Some of the pieces certainly belong to a series called in antiquity Zu-buru-dabbeda “To Seize the Locust-Tooth”, a compendium of incantations and rituals designed to combat by magic means the destruction of crops by locusts, insect larvae and other pests; other pieces are parts of related and similar texts. Some of the rituals require the observation of the Goat-star rising above the eastern horizon, which suggests they were performed at night as a precautionary measure during the winter months of the barley-growing season

Explicit Logic Circuits Discriminate Neural States

The magnitude and apparent complexity of the brain's connectivity have left explicit networks largely unexplored. As a result, the relationship between the organization of synaptic connections and how the brain processes information is poorly understood. A recently proposed retinal network that produces neural correlates of color vision is refined and extended here to a family of general logic circuits. For any combination of high and low activity in any set of neurons, one of the logic circuits can receive input from the neurons and activate a single output neuron whenever the input neurons have the given activity state. The strength of the output neuron's response is a measure of the difference between the smallest of the high inputs and the largest of the low inputs. The networks generate correlates of known psychophysical phenomena. These results follow directly from the most cost-effective architectures for specific logic circuits and the minimal cellular capabilities of excitation and inhibition. The networks function dynamically, making their operation consistent with the speed of most brain functions. The networks show that well-known psychophysical phenomena do not require extraordinarily complex brain structures, and that a single network architecture can produce apparently disparate phenomena in different sensory systems

On Babylonian lavatories and sewers

This study begins by examining the archaeological and documentary evidence for lavatories (toilets) and foul-water drains in ancient Mesopotamian dwelling houses. It goes on to investigate the use, etymology and history of the Akkadian word asurrû: in the Old Babylonian period it served mainly as a term for a kind of foul-water drain or “sewer” but later shed that meaning

Depth plane separation affects both Lightness Contrast and Assimilation

Lightness contrast and assimilation are two opposite phenomena: contrast occurs when a grey target perceptually acquires a complementary colour than the bordering, inducing, surfaces; assimilation is when a grey target perceptually acquires the same colour component as the inducers. Previous research has shown that both phenomena are affected by the manipulation of depth between the inducers and target. However, different results have been reported; it is not clear whether contrast persists when inducers are non-coplanar with the target. Previous studies differ for the spatial configuration of the stimuli and the technique adopted to manipulate depth. The aim of this research was to measure the effects of manipulating the depth between inducers and target in comparable conditions. Results show that contrast persists, but largely reduces, after depth manipulation whilst assimilation reverses to contrast. Furthermore, interesting asymmetries between white and black inducers emerged with white inducers favouring contrast and black inducers favouring assimilation. These results provide further evidence that high-level processes of visual processing are involved in both phenomena; with important consequences for lightness theories