Adenylyl Cyclase α and cAMP Signaling Mediate Plasmodium Sporozoite Apical Regulated Exocytosis and Hepatocyte Infection

Malaria starts with the infection of the liver of the host by Plasmodium sporozoites, the parasite form transmitted by infected mosquitoes. Sporozoites migrate through several hepatocytes by breaching their plasma membranes before finally infecting one with the formation of an internalization vacuole. Migration through host cells induces apical regulated exocytosis in sporozoites. Here we show that apical regulated exocytosis is induced by increases in cAMP in sporozoites of rodent (P. yoelii and P. berghei) and human (P. falciparum) Plasmodium species. We have generated P. berghei parasites deficient in adenylyl cyclase α (ACα), a gene containing regions with high homology to adenylyl cyclases. PbACα-deficient sporozoites do not exocytose in response to migration through host cells and present more than 50% impaired hepatocyte infectivity in vivo. These effects are specific to ACα, as re-introduction of ACα in deficient parasites resulted in complete recovery of exocytosis and infection. Our findings indicate that ACα and increases in cAMP levels are required for sporozoite apical regulated exocytosis, which is involved in sporozoite infection of hepatocytes

Investigation of four-wavelength regenerator using polarization- and direction-multiplexing

We demonstrate a four-channel extension to the Mamyshev regenerator and investigate its potential for the simultaneous processing of 4 times 10 Gb/s return-to-zero wavelength division-multiplexed channels. Mitigation of the interchannel nonlinearities is achieved through the rapid walkoff induced by both the large differential group delay of a specially developed polarization maintaining highly nonlinear fiber and a bidirectional architecture. Numerical and experimental results demonstrate the reduction of interchannel crosstalk as well as the potential of the scheme for 2R regeneration

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Not AvailableIn the water deficit regions of Asom, the transplantd rice is affected in it’s critical growth stages. To minimize risk of short season drought, rice-fish system of integrated farming is a measure followed by the farmers using harvested water. Formation of dykes in this system is also useful during floods to prevent instrusion of water.Not Availabl

2R regeneration of two 130 Gbit/s channels within a single fiber

We experimentally demonstrate the simultaneous all-optical regeneration of two 130Gbit/s signals in a single highly nonlinear fibre using self-phase modulation and offset filtering. No degradation was observed due to the presence of the second channel