The relationships between N:Si:P molar ratio and coastal marine phytoplankton in Izmir Bay (Eastern Aegean Sea-Turkey)

N:P, Si:N and Si:P ratios are one of the most important factor having a control on the dominance of phytoplankton groups both in oceans and coastal waters. The changes of these ratios have a limiting effect on the growth of the phytoplankton groups. This study aimed that to determine effects of the N:P:Si ratios to coastal phytoplankton groups in Izmir Bay on a weekly basis after activated the Big Channel Waste Water Treatment project. For this purpose, nutrients and Chl-a levels were analyzed from sea water which were taken from 0, 5, 10 m and bottom depths of the Gulf of Izmir on a weekly basis between 2003-2004. At the end of the study, results of analysis from water samples which were taken from three stations on a weekly basis between 2003-2004 from the Gulf of Izmir the ratios of nutrient values (N:P, Si:P, Si:N and C:Chl a) were compared. In conclusion, the average N:P, Si:P, Si:N and Chl a:C values were 2.55±0.31, 4.19 ± 0.56, 2.78±0.41, 0.0080±0.0011 for the Meles station (Station 1), 2.31+0.29, 4:39 ± 0.67, 3.74±0.58, 0.0083±0.O011 for the Yacht harbor station (Station 2) and 1.99±0.32, 4.56 ± 0.59, 4.35±0.71, 0.0067±0.0009 for the Cigli station (Station 3), respectively. The emergence of processes acting on Reactive Phosphate and TIN in different times reveal a great difference onto the temporal distribution of these two nutrients in the Inner part of İzmir Bay. Thus, indirect evidences about these processes have been obtained from the nutrients and their rates of distribution. © by PSP

A stable trimeric influenza hemagglutinin stem as a broadly protective immunogen

The identification of human broadly neutralizing antibodies (bnAbs) targeting the hemagglutinin (HA) stem revitalized hopes of developing a universal influenza vaccine. Using a rational design and library approach, we engineered stable HA stem antigens ("mini-HAs") based on an H1 subtype sequence. Our most advanced candidate exhibits structural and bnAb binding properties comparable to those of full-length HA, completely protects mice in lethal heterologous and heterosubtypic challenge models, and reduces fever after sublethal challenge in cynomolgus monkeys. Antibodies elicited by this mini-HA in mice and nonhuman primates bound a wide range of HAs, competed with human bnAbs for HA stem binding, neutralized H5N1 viruses, and mediated antibody-dependent effector activity. These results represent a proof of concept for the design of HA stem mimics that elicit bnAbs against influenza A group 1 viruse