Understanding the retinal basis of vision across species

The vertebrate retina first evolved some 500 million years ago in ancestral marine chordates. Since then, the eyes of different species have been tuned to best support their unique visuoecological lifestyles. Visual specializations in eye designs, large-scale inhomogeneities across the retinal surface and local circuit motifs mean that all species' retinas are unique. Computational theories, such as the efficient coding hypothesis, have come a long way towards an explanation of the basic features of retinal organization and function; however, they cannot explain the full extent of retinal diversity within and across species. To build a truly general understanding of vertebrate vision and the retina's computational purpose, it is therefore important to more quantitatively relate different species' retinal functions to their specific natural environments and behavioural requirements. Ultimately, the goal of such efforts should be to build up to a more general theory of vision

Ertüchtigung der Flachschleifmaschine ELB SF 30

Aufbauend auf dem Praktikumsbericht wird in der vorliegenden Bachelorarbeit, das Thema „Ertüchtigung der Flachschleifmaschine ELB“ weiter behandelt. Es wird dabei speziell die Einführung eines neuen Bedienpanels an der Maschine konkretisiert. Zu Beginn erfolgt die Auswahl eines geeigneten Panels, welches zu der vorhandenen Steuerung kompatibel ist. Daraufhin folgt die Vorstellung der Visualisierungssoftware, sowie der Software zum Testen der projektierten Oberfläche des Bediengerätes. Im weiteren Verlauf finden sich Erläuterungen zur Programmierung des Panels, bezogen auf das ELB-Projekt wieder. Das letzte Kapitel bezieht sich auf die konkrete SPS-Lösung zwei ausgewählter Steuerungsfunktionen, zum einen die Magnetsteuerung und zum anderen die Querantriebsteuerung

Treatment of viral hepatitis in pregnancy

Viral hepatitis can be caused by the hepatitis A, B, C, D and E viruses. In the Western world, hepatitis A, B or C do not seem to influence the course of pregnancy, whereas hepatitis E infection, when contracted during the second or third trimester, seems to have a higher risk of developing into a fulminant hepatitis. Mother-to-infant transmission of hepatitis A seems to be very uncommon. The majority of HBsAg-positive and HBeAg-positive mothers can transmit the disease vertically. The timing of transmission is predominantly peripartum, and newborns of HBsAg-positive mothers should receive hepatitis B immunoglobulins within 12 h of birth, with HBV vaccine at birth and 1 and 6 months later. Hepatitis C is more often a chronic disease. Vertical transmission of hepatitis C is considered to be relatively rare but high viraemia or coinfection with HIV can increase this risk. There is currently no treatment to prevent this vertical transmission and pregnancies among HCV-positive mothers should not be discouraged. Infants should be tested for anti-HCV at 1 year and followed for the development of hepatitis. Breast feeding does not seem to play an important role in the transmission of hepatitis B and