Lipid changes within the epidermis of living skin equivalents observed across a time-course by MALDI-MS imaging and profiling

© 2015 Mitchell et al. Abstract Background: Mass spectrometry imaging (MSI) is a powerful tool for the study of intact tissue sections. Here, its application to the study of the distribution of lipids in sections of reconstructed living skin equivalents during their development and maturation is described. Methods: Living skin equivalent (LSE) samples were obtained at 14 days development, re-suspended in maintenance medium and incubated for 24 h after delivery. The medium was then changed, the LSE re-incubated and samples taken at 4, 6 and 24 h time points. Mass spectra and mass spectral images were recorded from 12 μm sections of the LSE taken at each time point for comparison using matrix assisted laser desorption ionisation mass spectrometry. Results: A large number of lipid species were identified in the LSE via accurate mass-measurement MS and MSMS experiments carried out directly on the tissue sections. MS images acquired at a spatial resolution of 50 μm × 50 μm showed the distribution of identified lipids within the developing LSE and changes in their distribution with time. In particular development of an epidermal layer was observable as a compaction of the distribution of phosphatidylcholine species. Conclusions: MSI can be used to study changes in lipid composition in LSE. Determination of the changes in lipid distribution during the maturation of the LSE will assist in the identification of treatment responses in future investigations

Seagrass and marine resources in the Dugong protection areas of Upstart Bay, Newry Region, Sand Bay, Llewellyn Bay, Ince Bay and the Clairview Region, April/May 1999 and October 1999

The Marine Plant Ecology Group (Queensland Fisheries Service, Queensland Department of Primary Industries) was commissioned by the Great Barrier Reef Marine Park Authority to undertake two (one autumn and one spring) detailed seagrass surveys of the Dugong Protection Areas in Upstart Bay, Newry region, Sand Bay, Llewellyn Bay, Ince Bay, and a reconnaissance survey in the Clairview region. The information gathered from these surveys enhances the understanding and subsequent management of seagrass resources for fisheries and as dugong feeding habitats

Fibre architecture design of 3D woven composite with genetic algorithms: a unit cell based optimisation framework and performance assessment

There are vast possibilities in fibre architecture design of 3D woven reinforcement. This paper considers the application of Genetic Algorithm (GA) in 3D woven composites optimisation. A set of real and integral variables, representing 3D fibre architecture, are formulated into a mixed integer Genetic Algorithm. The objective function is evaluated through automation of the unit cell based finite element analysis, by using the open source pre-processor TexGen and the commercial solver ABAQUS. The mixed integer Genetic Algorithm is adapted to a micro-population, aiming to improve computational efficiency. The study uses statistical tests to quantify the performance of the Genetic Algorithm schemes and the choice of parameters. The proposed approach was applied to the optimisation of 3D woven composites for maximum buckling resistance for the case of a landing gear brace. This study demonstrated that the optimisation converged to the optimum design within 20 iterations, considering 300 out of 7000 permissible solutions. In terms of buckling performance, the optimum design performed twice as well as cross-ply laminated composites and at least 50% better than known orthogonal 3D woven composites

Fibre architecture design of 3D woven composite with genetic algorithms: a unit cell based optimisation framework and performance assessment

There are vast possibilities in fibre architecture design of 3D woven reinforcement. This paper considers the application of Genetic Algorithm (GA) in 3D woven composites optimisation. A set of real and integral variables, representing 3D fibre architecture, are formulated into a mixed integer Genetic Algorithm. The objective function is evaluated through automation of the unit cell based finite element analysis, by using the open source pre-processor TexGen and the commercial solver ABAQUS. The mixed integer Genetic Algorithm is adapted to a micro-population, aiming to improve computational efficiency. The study uses statistical tests to quantify the performance of the Genetic Algorithm schemes and the choice of parameters. The proposed approach was applied to the optimisation of 3D woven composites for maximum buckling resistance for the case of a landing gear brace. This study demonstrated that the optimisation converged to the optimum design within 20 iterations, considering 300 out of 7000 permissible solutions. In terms of buckling performance, the optimum design performed twice as well as cross-ply laminated composites and at least 50% better than known orthogonal 3D woven composites

Preliminary evaluation of an acoustic technique for mapping tropical seagrass habitats

Seagrass meadows in Queensland are important nursery habitat for commercial species of penaeid prawns and fish. Seagrasses are essential food for dugong, Dugong dugon, and green sea turtles, Chelonia mydas (Linnaeus) and act as nutrient and sediment sinks. Seagrasses in coastal regions play important roles in maintaining sediment stability and water clarity. Coastal seagrass meadows are therefore an important resource economically and ecologically. Information on the species composition, abundance and distribution of seagrasses is used by management to zone for protection of seagrass habitats

Dynamically Induced Spontaneous Symmetry Breaking in 3-3-1 Models

We show that in SU(3)_C X SU(3)_L X U(1)_N (3-3-1) models embedded with a singlet scalar playing the role of the axion, after imposing scale invariance, dynamical symmetry breaking of Peccei-Quinn symmetry occurs through the one-loop effective potential for the singlet field. We, then, analyze the structure of spontaneous symmetry breaking by studying the new scalar potential for the model, and verify that electroweak symmetry breaking is tightly connected to the 3-3-1 breaking by the strong constraints among their vacuum expectation values. This offers a valuable guide to write down the correct pattern of symmetry breaking for multi-scalar theories. We also obtained that the accompanying massive pseudo-scalar, instead of acquiring mass of order of Peccei-Quinn scale as we would expect, develops a mass at a much lower scale, a consequence solely of the dynamical breaking.Comment: 12 pages, typos corrected, improved text, conclusions unchange

Baseline survey of Hinchinbrook region seagrasses - October (spring) 1996

Current coastal zone management issues in the Hinchinbrook region include protection of fisheries habitats, dugong habitat areas and increases in aquaculture, agriculture and tourist operations. A regional coastal management plan which is being developed, also requires detailed information on seagrass resources for the coastal zone from Dunk Island in the north, to Cleveland Bay in the south. Decreases in estimates of dugong abundance in the southern half of the Great Barrier Reef region since the 1980's have also prompted the need for detailed baseline and monitoring surveys of seagrasses in this and other regions

Novel sources of Flavor Changed Neutral Currents in the 331RHN331_{RHN} model

Sources of Flavor Changed Neutral Currents (FCNC) naturally emerge from a well motivated framework called 3-3-1 with right-handed neutrinos model, $331_{RHN}$ for short, mediated by an extra neutral gauge boson $Z^{\prime}$. Following previous works we calculate these sources and in addition we derive new ones coming from CP-even and -odd neutral scalars which appear due to their non-diagonal interactions with the physical standard quarks. Furthermore we show that bounds related to the neutral mesons systems $K_L-K_S$ and $D_1^0 - D_2^0$ may be significantly strengthened in the presence of these new interactions allowing us to infer stronger constraints on the parameter space of the model.Comment: Published version. 10 pages, 6 figure

The seesaw mechanism at TeV scale in the 3-3-1 model with right-handed neutrinos

We implement the seesaw mechanism in the 3-3-1 model with right-handed neutrinos. This is accomplished by the introduction of a scalar sextet into the model and the spontaneous violation of the lepton number. We identify the Majoron as a singlet under $SU_L(2)\otimes U_Y(1)$ symmetry, which makes it safe under the current bounds imposed by electroweak data. The main result of this work is that the seesaw mechanism works already at TeV scale with the outcome that the right-handed neutrino masses lie in the electroweak scale, in the range from MeV to tens of GeV. This window provides a great opportunity to test their appearance at current detectors, though when we contrast our results with some previous analysis concerning detection sensitivity at LHC, we conclude that further work is needed in order to validate this search.Comment: about 13 pages, no figure