Thermomechanical relaxation and different water states in cottonseed protein derived bioplastics

Thermomechanical relaxation events and different water states in cottonseed protein bioplastics are presented whilst investigating the effects of aldehyde cross-linking agents. Thermomechanical relaxation of cottonseed protein bioplastics associated with protein denaturation, moisture absorption and broad glass transitions (Tg) were observed from DSC and DMA measurements. It was shown that variation of the aldehyde influences the storage modulus at very low temperature (below Tg). From measurements of the water fusion point, enthalpy, vaporisation, and weight loss, three water states in the water-absorbed bioplastics are suggested; namely strongly-bound-to-polymer, weakly-bound-to-polymer and bulk-like water. The water content and unreacted cross-linking agents are influential factors in controlling formation of the different water states, whilst the selection of different aldehydes was found to be negligible. These results could be valuable for adjusting the thermomechanical relaxations of protein based bioplastics, and tailoring their properties in wet environments

The flux and provenance of dust delivered to the SW Pacific during the last glacial maximum

The funding for the TAN1106 voyage was from the Coasts and Oceans Physical Resources program awarded to the National Institute of Water and Atmospheric Research, New Zealand. This work was funded by NERC studentship NE/L002531/1 to R.S. and NERC grant NE/J021075/1 to G.L.F. R.G. and A.B. were supported by NERC grant NE/M004619/1 awarded to A.B.Atmospheric dust is a primary source of iron (Fe) to the open ocean, and its flux is particularly important in the high nutrient, low chlorophyll (HNLC) Southern Ocean where Fe currently limits productivity. Alleviation of this Fe limitation in the Subantarctic Zone of the Atlantic by increased dust-borne Fe supply during glacial periods has been shown to increase primary productivity. However, previous work has found no such increase in productivity in the Pacific sector. In order to constrain the relative importance of Southern Ocean Fe fertilization on glacial-interglacial carbon cycles, records of dust fluxes outside of the Atlantic sector of the Southern Ocean at the Last Glacial Maximum (LGM) are required. Here we use grain size and U-series analyses to reconstruct lithogenic and CaCO3 fluxes, and Nd, Sr and Pb isotopes to ascertain the provenance of terrigenous material delivered to four deep-water cores in the SW Pacific Ocean over the last ~30kyr. We find evidence for an increase in the relative proportion of fine-grained (0.5-12 ?m) terrigenous sediment and higher detrital fluxes during the LGM compared to the Holocene. The provenance of the LGM dust varied spatially, with an older, more "continental" signature (low εNd, high 87Sr/86Sr) sourced from Australia in the northern cores, and a younger, more volcanogenic source in the southern cores (high εNd, low 87Sr/86Sr), likely sourced locally from New Zealand. Given this increase in lithogenic flux to the HNLC subantarctic Pacific Southern Ocean during the LGM, factors besides Fe-supply must have regulated the biological productivity here.Publisher PDFPeer reviewe

The tight skin mouse: demonstration of mutant fibrillin-1 production and assembly into abnormal microfibrils

Mice carrying the Tight skin (Tsk) mutation harbor a genomic duplication within the fibrillin-1 (Fbn 1) gene that results in a larger than normal in-frame Fbn 1 transcript. In this study, the consequences of the Tsk mutation for fibrillin-containing microfibrils have been examined. Dermal fibroblasts from Tsk/+ mice synthesized and secreted both normal fibrillin (approximately 330 kD) and the mutant oversized Tsk fibrillin-1 (approximately 450 kD) in comparable amounts, and Tsk fibrillin-1 was stably incorporated into cell layers. Immunohistochemical and ultrastructural analyses of normal and Tsk/+ mouse skin highlighted differences in the gross organization and distribution of microfibrillar arrays. Rotary shadowing of high Mr preparations from Tsk/+ skin demonstrated the presence of abundant beaded microfibrils. Some of these had normal morphology and periodicity, but others were distinguished by diffuse interbeads, longer periodicity, and tendency to aggregate. The presence of a structurally abnormal population of microfibrils in Tsk/+ skin was unequivocally demonstrated after calcium chelation and in denaturating conditions. Scanning transmission electron microscopy highlighted the presence of more mass in Tsk/+ skin microfibrils than in normal mice skin microfibrils. These data indicate that Tsk fibrillin-1 polymerizes and becomes incorporated into a discrete population of beaded microfibrils with altered molecular organization

COSMOS: the COsmic-ray Soil Moisture Observing System

The newly-developed cosmic-ray method for measuring area-average soil moisture at the hectometer horizontal scale is being implemented in the COsmic-ray Soil Moisture Observing System (or the COSMOS). The stationary cosmic-ray soil moisture probe measures the neutrons that are generated by cosmic rays within air and soil and other materials, moderated by mainly hydrogen atoms located primarily in soil water, and emitted to the atmosphere where they mix instantaneously at a scale of hundreds of meters and whose density is inversely correlated with soil moisture. The COSMOS has already deployed more than 50 of the eventual 500 cosmic-ray probes, distributed mainly in the USA, each generating a time series of average soil moisture over its horizontal footprint, with similar networks coming into existence around the world. This paper is written to serve a community need to better understand this novel method and the COSMOS project. We describe the cosmic-ray soil moisture measurement method, the instrument and its calibration, the design, data processing and dissemination used in the COSMOS project, and give example time series of soil moisture obtained from COSMOS probes

Results of the First Coincident Observations by Two Laser-Interferometric Gravitational Wave Detectors

We report an upper bound on the strain amplitude of gravitational wave bursts in a waveband from around 800Hz to 1.25kHz. In an effective coincident observing period of 62 hours, the prototype laser interferometric gravitational wave detectors of the University of Glasgow and Max Planck Institute for Quantum Optics, have set a limit of 4.9E-16, averaging over wave polarizations and incident directions. This is roughly a factor of 2 worse than the theoretical best limit that the detectors could have set, the excess being due to unmodelled non-Gaussian noise. The experiment has demonstrated the viability of the kind of observations planned for the large-scale interferometers that should be on-line in a few years time.Comment: 11 pages, 2 postscript figure