Samples were collected seasonally from three stations in the Dardanelles between April 2016 and October 2017 to determine the effects of biological and physicochemical properties of the coastal system on the isotopic compositions of the most abundant copepod species, Acartia clausi and Calanus helgolandicus, and a cladoceran, Penilia avirostris. Plankton samples were collected horizontally with a 200-µm-mesh plankton net and isotopic analyses were performed by mass spectrometry after identification to species level. Total zooplankton abundance reached its maximum in spring and summer. The δ 13 C values of copepods showed statistically significant differences both between stations and seasons. As a selective feeder, C. helgolandicus had the highest values in both δ 13 C and δ 15 N. Being a filter feeder, P. avirostris distinctly differed from C. helgolandicus and A. clausi. Enrichment was observed in δ 15 N values of copepods in winter, when the highest values of total suspended solids and chlorophyll-a were determined. The results showed that δ 13 C values of the copepods were under the influence of environmental and biological factors. Additionally, dietary differences between herbivorous groups and other groups were clearly demonstrated, as well as differences in the diets of filter-feeding and selectively-feeding zooplanktonic species.
Previous studies suggest FGF10, which is expressed in the ventral hypothalamus, plays important roles in axon guidance and in vasculature guidance of the developing hypothalamus. Here, using ex vivo analyses in chick, we show that FGF10 exerts concentration dependent functions in angiogenesis and hypothalamic axon guidance. At lower concentration of 100ng/ml, FGF10 promotes angiogenesis in chorioallantoic membrane endothelial capillaries (CAMs), but FGF10 does not alter the endothelial growth significantly at higher concentration (500ng/ml, P>0.05). Simultaneously, FGF10 exerts a graded action, at lower concentration FGF10 attracts both magnocellular and parvocellular axons; but at higher concentration, FGF10 repels parvocellular TH+ (tyrosine hydroxylase) axons, and attracts magnocelluar vasopressin+ axons in the hypothalamus.
In this study, seasonal stable isotope compositions of zooplankton and particulate organic matter were analyzed from the coastal zone in Kepez Harbor, the discharge point of a waste treatment plant. The results were compared with the results of a control station located 10 km away from the harbor. Zooplankton samples were collected horizontally with a 200 µm mesh plankton net from the surface waters. POM samples were collected with a 5L Nansen bottle and filtered through precombusted GF/F filters. Variables such as temperature, salinity, chlorophyll-a as well as oil-grease and chemical oxygen demand were also determined in the study sites. The salinity values in the control station were significantly higher than the harbor station through the whole year. The δ 13 C values of POM in the control station were significantly higher than the values observed in the harbor station. The δ 15 N values of zooplankton in the harbor were higher than the values obtained in the control station; however, the differences were not significant. The values of oil-grease obtained in two stations were lower than the values pronounced in EPA, EU, and Turkish Regulations. The study showed that the stable isotope compositions were affected by terrestrial inputs and high currents rather than the facilities comprised in the harbor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.