Pleistocene–Holocene marine ostracods from Mersin offshore sediments,Turkey, Eastern Mediterranean

Ostracod faunas from 18 gravity offshore cores taken from S-SW of Mersin–Ta?ucu harbour in Turkey (Eastern Mediterranean) at water depths comprised between 285 and 665 m were studied. Thirty-two (32) species have been identified. Argilloecia acuminata s.l. and Polycope cf. tholiformis are the dominant species in the studied area. The fauna corresponds very well to the “Argilloecia acuminata community, C11” from the Pleistocene to Holocene established by Sissingh (Sissingh, W., 1982. Ecostratigraphical outline history of the Late Cenozoic ostracode fauna of the Central and Eastern Mediterranean Basin. Proceedings of the Koninklijke Nederlandse Akademie van Wettenschappen B 85, 299–322), and indicates circalittoral to upper bathyal environment in the Mediterranean. The ostracod fauna of the Mersin offshore sediments also shows great similarities to those from the Adriatic Sea (Bonaduce, G., Ciampo, G., Masoli, M., 1975. Distribution of ostracoda in the Adriatic Sea. Pubblicazioni della Stazione Zoologica di Napoli 40 Suppl., 1–304), Sicily (Aiello, G., Barra, D., Bonaduce, G., 2000. Systematics and biostratigraphy of the Plio-Pleistocene Monte S. Nicola section (Gela, Sicily). Bollettino della Società Paleontologica Italiana 39, 83–112) and Bay of Naples (Müller, G.W., 1894. Die Ostracoden des Golfes von Neapel und der angrenzenden Meeresabschnitte. Zoologische Station zu Neapel. Fauna und Flora des Golfes von Neapel, Monographie 31, 1–404). Only a few species are common with the Aegean Sea and Sea of Marmara.     

Effect of light on the NADPH-protochlorophyllide oxidoreductase of Arabidopsis thaliana

A cDNA encoding the NADPH-protochlorophyllide oxidoreductase (Pchlide reductase) of Arabidopsis thaliana has been isolated and sequenced. The cDNA contains the complete reading frame for the precursor of the Pchlide reductase. The deduced amino acid sequence of the Arabidopsis enzyme closely resembles the corresponding sequences of barley and oat. The cDNA has been used as a template for the synthesis of the enzyme protein in Escherichia coli. An antiserum was raised against this enzyme protein and both the antiserum and the cDNA were used as experimental tools to study the effects of light on the Pchlide reductase in A. thaliana.When etiolated seedlings of Arabidopsis were exposed to light the enzyme activity and the concentration of the enzyme protein rapidly declined. Similar light effects have been described previously for other angiosperms. In contrast to most of these species, however, in Arabidopsis only minor changes in Pchlide reductase mRNA content could be observed when etiolated seedlings were exposed to light.     

Effects of Melatonin on Carbonic Anhydrase from Human Erythrocytes In Vitro and from Rat Erythrocytes In Vivo

The in vitro effects of melatonin (N-acetyl-5-methoxytryptamine) on human carbonic anhydrase isozymes (HCA-I and HCA-II) from human erythrocytes and in vivo effects on rat erythrocytes carbonic anhydrase (CA) were determined. Human erythrocyte carbonic anhydrase isozymes were purified by haemolysate preparation and Sepharose-4B-L tyrosine-sulfanilamide affinity gel chromatography. The HCA-I enzyme, having a specific activity of 7337.5?EU/mg protein, was purified 843-fold with a yield of 60% and the HCA-II enzyme, having a specific activity of 17067?EU/mg protein, was purified 1962-fold with a yield of 22.7%. For in vitro experiments, the enzyme activity was minimal at 2×10-4?M melatonin concentration and increased above this concentration. Ten mg?kg-1 melatonin was administered intraperitoneally and showed a stimulatory effect on the enzyme. Time-dependent in vivo studies were conducted for melatonin in Sprague–Dawley type rats. It was found that CA activity in the rat erythrocytes was decreased by the melatonin after 1 and 3 hours to 2500±500.0 and 1875±239.4 respectively which were statistically significant (p<0.05) differences to the control (2660±235.8). However, CA activity was restored to its normal level after 6?h (2666±235.7) (p>0.05) probably due to metabolism of the melatonin. The findings indicate that melatonin may be pharmacologically useful in some diseases.     

Foraminiferal biostratigraphy and sequence stratigraphy across the mid-Carboniferous boundary in the Central Taurides,Turkey

The Aladağ Unit is one of the main tectonic units in the Tauride Belt, located in southern Turkey. It includes a continuous Paleozoic carbonate sequence encompassing the mid-Carboniferous boundary, with outcrops being especially well exposed in the Hadim region. The boundary succession lithology is mainly composed of carbonates with intercalated quartz arenitic sandstone layers. Based on foraminifers, four biostratigraphic zones have been defined in the interval from the Upper Serpukhovian to the Lower Bashkirian. These zones are, in ascending order: the Eostaffella ex gr. ikensis—E. postmosquensis Zone (Zapaltyubinsky Horizon, Upper Serpukhovian); the Plectostaffella jakhensis—P. bogdanovkensis Zone, and the Millerella marblensis Zone (Bogdanovsky Horizon, lower Bashkirian); and the Semistaffella sp. Zone (Syuransky Horizon, lower Bashkirian). The mid-Carboniferous boundary occurs between the Eostaffella ex gr. ikensis—E. postmosquensis Zone and the Plectostaffella jakhensis—P. bogdanovkensis Zone. Boundary beds are characterized by eight, repeatedly occurring microfacies types, namely: (1) coated crinoidal packstone; (2) coated bioclastic grainstone; (3) oolitic grainstone; (4) oolitic packstone-grainstone; (5) intraclastic grainstone; (6) mudstone-wackestone; (7) quartz-peloidal packstone; and 8) quartz arenitic sandstone. Based on microfacies stacking patterns, various types of shallowing-upward cycles have been recognized. Depositional sequences and sequence boundaries are correlatable with those described from North America and Russia and Carboniferous global sea-level curves. The duration of cycles has been estimated as 100 ky, suggesting that cycle periodicities correspond to the Milankovitch eccentricity band.     

The effect of OSAS risk,excessive daytime sleepiness,insomnia severity and sleep quality on dry eye syndrome

Sleep and Biological Rhythms - The purpose of this study was to investigate the association between sleep disturbances and dry eye syndrome (DES). 201 patients with DES were included in this study....     

Coherent Control of Two-Dimensional Optical Absorption in a Quantum Dot Nanostructure

We investigate the two-dimensional (2D) optical absorption spectrum in a semiconductor quantum dot nanostructure driven by two orthogonal standing-wave lasers. It is found that, due to the position-dependent quantum interference effect, the 2D optical absorption spectrum can be easily controlled via adjusting the system parameters. Thus, our scheme may provide some technological applications in solid-state optoelectronics.     

Plasmonic Control of Refractive Index Without Absorption in Metallic Photonic Crystals Doped with Quantum Dots

Plasmonics - We investigate the refractive index without absorption in metallic photonic crystals doped with quantum dots. It is found that the absorption and dispersion of probe field can be...     

Characterization of a glucansucrase from Lactobacillus reuteri E81 and production of malto-oligosaccharides

Abstract

Glucansucrases, which can be produced by different Lactic Acid Bacteria (LAB), catalyze the synthesis of α-glucans with different structures and properties using sucrose as substrate. In this study, a novel glucansucrase (GTFA) from Lactobacillus reuteri E81 was identified and heterologously expressed. Alignments of GTFA with other glucansucrases revealed its novelty and a putative 3D model structure was obtained. The biochemical properties of the truncated enzyme without the N-terminal variable region, GTFA-ΔN, was characterized. The K_m and V_max were found to be 7.5?mM and 1.49?IU/mg, respectively, and it showed optimum activities at pH 7 and at 50?°C. The GTFA-ΔN produced in vitro an α-glucan with (α1 → 3) and (α1 → 6) glycosidic linkages using sucrose as the substrate. Importantly, GTFA-ΔN synthesized DP = 9 oligosaccharides using sucrose and maltose as the donor and acceptor sugars, respectively, as detected by TLC, HPLC, LC-MS and NMR analysis.