Biogeochemistry of photosymbiosis in host tissues and skeletons of the species Tridacna

Algal/invertebrate endosymbiose are common in the marine environment and appear to be nutritional in nature. The giant Tridacnid clams form a mutualistic extracellular endosymbiosis with dinoflagellate algae (zooxanthellae) of the species Symbiodiniunt microadriaticum. The large size of the Tridacnids is generally attributed to the nutritional role of their endosymbionts. This thesis examines the nature and mechanisms by which important biochemicals, such as lipids, are translocated from the symbionts to the host. Methodologies have been developed to enable the determination of the carbon isotope composition of individual saturated and polyunsaturated fatty acids to enable natural abundance isotopic variations in these compounds to be investigated in the Tridacnid-algal symbiosis. Compound specific isotope analysis of fatty acids in different species of Tridacnids, their zooxanthellae and non-symbiotic species reveal that several fatty acids are apparently directly translocated from algae to host. Evidence is presented for the synthesis of fatty acids from acetate by the clam. Carbon isotopic data also reveal that carbon limitation may play a role in lipid metabolsim in giant clams. Compound specific isotope analysis has also been used to investigate the contribution of translocated compounds during a diel cycle in clam haemolymph and reveals that concentrations of key metabolites vary over the diel cycle as a function of irradiance. The cyclic sugar alcohol scyllo-inositol was detected in clam haemolymph, which may be related to osmoregulation in the clam or to a signalling role in cell proliferation. Oxygen and carbon stable isotope compositions and strontium abundances of shell carbonate are examined in several clams subjected to varying degrees of phosphate and ammonium nutrient supplementation to investigate the relationship between growth rate and stable isotope compositions and strontium contents

A comparative study of the GC-MS response for qualitative analysis of FAMEs under direct thermal desorption in diffrent types of liners

The work discusses the influence that different types of liners may have on the transfer of analytes onto the GC column, and hence on the quality of the GC-MS response for their quantitative analysis, at low concentrations. An Optic_3 programmable temperature inlet was used for sample transfer. The analytes were separated on a BPX-5 capillary column, using an Agilent system of a gas chromatograph coupled to a quadrupole mass detector operating in the SIM mode. Selected ions peak areas were determined to assess the GC-MS response. The method linearity, reproducibility, LOQ and LOD are compared for three different liners, using dilutions of a mix of long chain FAMEs standards

SDN-enabled Smart Building Energy Management for Hybrid Solar-Geothermal Integrated System

To provide a reliable resilient cost effective and environment friendly energy solution the hybrid solar geothermal integrated energy system has shown promises in recent time By addressing the limitations of conventional nonrenewable energy systems the combination of solar and geothermal energy can offer a more sustainable efficient and secure source of energy for future However implementing a building energy management model for a hybrid solar geothermal integrated system poses several issues such as integration complexity control strategy complications optimal resource allocation data accessibility and reliability and energy storage challenges As a result a centralized controlled programmable and robust networking platform is required for hybrid solar geothermal integrated system In this regard software defined networking SDN based energy management system EMS can be employed that can offer programmable autonomous and intelligent decision making features Therefore to ensure intelligent harmonize renewable energy sources optimize energy distribution and enhance energy efficiency this paper provides an SDN enabled smart building EMS for hybrid solar geothermal integrated system Additionally a new robust energy management algorithm is also developed which can dynamically manage the hybrid EMS utilizing the real time date Moreover for evaluating the performance of the SDN empowered architecture an investigation based on simulation is executed which demonstrates that the proposed model is capable of generating 1000 W solar energy as well as the geothermal system provides a daily heat exchange rate of 45 12

High resolution climate isotopic record of the Last Interglacial from a stalagmite formed in a cave entrance from southwestern France

Geophysical Research Abstracts. EGU2007-A-1008

The early Danian hyperthermal event at Boltysh (Ukraine): relation to Cretaceous-Paleogene boundary events

The Boltysh meteorite impact crater formed in the Ukrainian Shield on the margin of the Tethys Ocean a few thousand years before the Cretaceous-Paleogene boundary and was rapidly filled by a freshwater lake. Sediments filling the lake vary from early lacustrine turbidites and silts to ~300 m of fine silts, organic carbon–rich muds, oil shales, and lamenites that record early Danian terrestrial climate signals at high temporal resolution. Combined carbon isotope and palynological data show that the fine-grained organic carbon–rich lacustrine sediments preserve a uniquely complete and detailed negative carbon isotope excursion in an expanded section of several hundred meters. The position of the carbon isotope excursion in the early Danian stage of the Paleogene period, around 200 k.y. above the Cretaceous-Paleogene boundary, leads us to correlate it to the Dan-C2 carbon isotope excursion recorded in marine sediments of the same age. The more complete Boltysh carbon isotope excursion record indicates a δ13C shift of around -3‰, but also a more extended recovery period, strikingly similar in pattern to the highest fidelity carbon isotope excursion records available for the Toarcian and Paleocene-Eocene hyperthermal events. Changes in floral communities through the carbon isotope excursion recorded at Boltysh reflect changing biomes caused by rapidly warming climate, followed by recovery, indicating that this early Danian hyperthermal event had a similar duration to the Toarcian and Paleocene-Eocene events

Sea–land oxygen isotopic relationships from planktonic foraminifera and speleothems in the Eastern Mediterranean region and their implication for paleorainfall during interglacial intervals

The oxygen and carbon stable isotope compositions of cave speleothems provide a powerful method for understanding continental climate change. Here, we examine the question of the regionality of this isotopic record and its linkage with the marine isotopic record in the Eastern Mediterranean (EM) region. The study presents a new, accurately dated 250-kyr δ18O and δ13C record determined from speleothems of the Peqiin Cave, Northern Israel. Its comparison with the continuous 185-kyr isotopic record of the Soreq Cave speleothems from Central Israel reveals striking similarities. Thus, a strong regional climatic signal, brought about by variations in temperature and rainfall amount, is reflected in both cave records. Low δ18O minima in the Peqiin profile for the last 250- to 185-kyr period (interglacial marine isotopic stage 7) match the timing of sapropels 9 to 7 and are indicative of high rainfall in the EM region at these times. The combined Soreq and Peqiin δ18O record for the last 250 kyr excellently matches the published Globigerinoides ruber (G. ruber) marine δ18O record for the EM Sea, with the isotopic compositional difference ΔG.ruber-speleothems remaining relatively constant at −5.6 ± 0.7‰, thus establishing for the first time a robust, exploitable link between the land and the marine isotopic records. The correspondence of low δ18O speleothem values and high cave water stands with low G. ruber δ18O values during interglacial sapropel events indicates that these periods were characterized by enhanced rainfall in the EM land and sea regions. By use of sea surface temperatures derived from alkenone data as a proxy for land temperatures at the Soreq Cave, we calculate the paleorainfall δ18O values and its amounts. Maximum rainfall and lowest temperature conditions occurred at the beginning of the sapropel events and were followed by decrease in rainfall and increase in temperatures, leading to arid conditions. The record for the last 7000 yr shows a trend toward increasing aridity and agrees well with climatic and archeological data from North Africa and the Middle East