Vertical fatty acid composition in the blubber of leopard seals and the implications for dietary analysis

AbstractThe analysis of blubber fatty acids (FAs) is a useful tool to infer diet of mammals that live in remote regions where year-round studies are difficult. The FA may not be distributed uniformly within the blubber, which can have implications for dietary predictive studies. The aim of this study was to determine the FA composition in the blubber core of the Antarctic leopard seal, Hydrurga leptonyx, and evaluate the potential implications of FA stratification for dietary analysis. The blubber cores of 24 seals were sub-sectioned into outer, middle and inner layers and their FA were compared to those of their potential prey species. A vertical variation in FA composition was found across the whole blubber core of the leopard seal. 17 FAs were found at greater than trace amounts (>0.5%) across all samples and the most abundant were: C18:1ω9, C16:1, C22:6ω3, C16:0 and C18:1ω7, which accounted for approximately 70% of the total FA. Almost all FAs had a continuous gradient through the blubber. Principal Component Analysis confirmed separation between inner and outer layers while the middle layer was a transition. The stratification of the leopard seal blubber was similar to the general pattern observed in a variety of marine species: monounsaturated FA (MUFA) dominated the three layers being more abundant in the outer layer, polyunsaturated (PUFA) and saturated FA (SFA) were more abundant in the inner layer. Polyunsaturated FAs are of dietary origin and SFAs are chemically inert so they can be used as a long-term reserve, which suggest that the inner layer is the site of deposition of the FA obtained from diet. The influence of prey on the composition of the leopard seals' blubber was clearer in the inner layer, although neither outer nor inner layers exactly matched the FA of the potential prey. This suggests that there are other components influencing the FA composition of this predator; therefore, in order to carry out dietary analysis it is important to consider the stratification of blubber and to use the inner layer, where the influence of diet is more evident. This has significant implications for sampling methods in the field

Interpreting Helioseismic Structure Inversion Results of Solar Active Regions

Helioseismic techniques such as ring-diagram analysis have often been used to determine the subsurface structural differences between solar active and quiet regions. Results obtained by inverting the frequency differences between the regions are usually interpreted as the sound-speed differences between them. These in turn are used as a measure of temperature and magnetic-field strength differences between the two regions. In this paper we first show that the "sound-speed" difference obtained from inversions is actually a combination of sound-speed difference and a magnetic component. Hence, the inversion result is not directly related to the thermal structure. Next, using solar models that include magnetic fields, we develop a formulation to use the inversion results to infer the differences in the magnetic and thermal structures between active and quiet regions. We then apply our technique to existing structure inversion results for different pairs of active and quiet regions. We find that the effect of magnetic fields is strongest in a shallow region above 0.985R_sun and that the strengths of magnetic-field effects at the surface and in the deeper (r < 0.98R_sun) layers are inversely related, i.e., the stronger the surface magnetic field the smaller the magnetic effects in the deeper layers, and vice versa. We also find that the magnetic effects in the deeper layers are the strongest in the quiet regions, consistent with the fact that these are basically regions with weakest magnetic fields at the surface. Because the quiet regions were selected to precede or follow their companion active regions, the results could have implications about the evolution of magnetic fields under active regions.Comment: Accepted for publication in Solar Physic

The design, construction and performance of the MICE scintillating fibre trackers

This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2011 ElsevierCharged-particle tracking in the international Muon Ionisation Cooling Experiment (MICE) will be performed using two solenoidal spectrometers, each instrumented with a tracking detector based on diameter scintillating fibres. The design and construction of the trackers is described along with the quality-assurance procedures, photon-detection system, readout electronics, reconstruction and simulation software and the data-acquisition system. Finally, the performance of the MICE tracker, determined using cosmic rays, is presented.This work was supported by the Science and Technology Facilities Council under grant numbers PP/E003214/1, PP/E000479/1, PP/E000509/1, PP/E000444/1, and through SLAs with STFC-supported laboratories. This work was also supportedby the Fermi National Accelerator Laboratory, which is operated by the Fermi Research Alliance, under contract No. DE-AC02-76CH03000 with the U.S. Department of Energy, and by the U.S. National Science Foundation under grants PHY-0301737,PHY-0521313, PHY-0758173 and PHY-0630052. The authors also acknowledge the support of the World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan

Mobile inquiry-based learning with sensor-data in the school: Effects on student motivation

The paper discusses the design, implementation and evaluation of a pilot project that integrated inquiry-based learning with mobile game design and introduced mobile devices and sensors into classroom learningweSPOT Project - IST (FP7/2007-2013) under grant agreement N° 318499The project was supported by the SURFnet innovation grant for sustainable ICT solutions

Tomato: a crop species amenable to improvement by cellular and molecular methods

Tomato is a crop plant with a relatively small DNA content per haploid genome and a well developed genetics. Plant regeneration from explants and protoplasts is feasable which led to the development of efficient transformation procedures. In view of the current data, the isolation of useful mutants at the cellular level probably will be of limited value in the genetic improvement of tomato. Protoplast fusion may lead to novel combinations of organelle and nuclear DNA (cybrids), whereas this technique also provides a means of introducing genetic information from alien species into tomato. Important developments have come from molecular approaches. Following the construction of an RFLP map, these RFLP markers can be used in tomato to tag quantitative traits bred in from related species. Both RFLP's and transposons are in the process of being used to clone desired genes for which no gene products are known. Cloned genes can be introduced and potentially improve specific properties of tomato especially those controlled by single genes. Recent results suggest that, in principle, phenotypic mutants can be created for cloned and characterized genes and will prove their value in further improving the cultivated tomato.

Exploring the stability of super heavy elements: First measurement of the fission barrier of 254No

The gamma-ray multiplicity and total energy emitted by the heavy nucleus 254No have been measured at 2 different beam energies. From these measurements, the initial distributions of spin I and excitation energy E * of 254No were constructed. The distributions display a saturation in excitation energy, which allows a direct determination of the fission barrier. 254No is the heaviest shell-stabilized nucleus with a measured fission barrier. © Owned by the authors, published by EDP Sciences, 2014

Spectroscopy of neutron-deficient nuclei near the Z=82 closed shell via symmetric fusion reactions

In-beam and decay-spectroscopy studies of neutron-deficient nuclei near the Z=82 shell closure were carried out using the Fragment Mass Analyzer (FMA) and the Gammasphere array, in conjunction with symmetric fusion reactions and the Recoil Decay Tagging (RDT) technique. The primary motivation was to study properties of 179Tl and 180Tl, and their daughter, and grand-daughter isotopes. For the first time, in-beam structures associated with 179Tl and 180Tl were observed, as well as γ rays associated with the 180Tl α decay. No long-lived isomer was identified in 180Tl, in contrast with the known systematics for the heavier odd-odd Tl isotopes

Evolution of collective and noncollective structures in Xe 123

An experiment involving a heavy-ion-induced fusion-evaporation reaction was carried out where high-spin states of Xe123 were populated in the Se80(Ca48,5n)Xe123 reaction at 207 MeV beam energy. Gamma-ray coincidence events were recorded with the Gammasphere Ge detector array. The previously known level scheme was confirmed and enhanced with the addition of five new band structures and several interband transitions. Cranked Nilsson-Strutinsky (CNS) calculations were performed and compared with the experimental results in order to assign configurations to the bands

Core excitations beyond maximally aligned configurations in 123I

High-spin states in 123I have been populated in the 80Se(48Ca,p4n)123I reaction at 207 MeV and γ-ray coincidence events have been recorded with the Gammasphere spectrometer. The level scheme of 123I has been extended up to spin I=63/2. The nucleus undergoes a shape transition from moderately deformed states with collective rotation at low spins to noncollective oblate configurations at higher spins. Maximally aligned terminating states involving all nine particles outside the 114Sn core and states with one particle antialigned are identified. A large number of weak transitions feed the terminating states. Cranked Nilsson-Strutinsky calculations have been performed to determine possible configurations for the observed energy levels

Highly deformed band structures due to core excitations in Xe 123

High-spin states in Xe123 were populated in the Se80(Ca48, 5n)Xe123 reaction at a beam energy of 207 MeV. γ-ray coincidence events were recorded with the Gammasphere spectrometer. Four new high-spin bands have been discovered in this nucleus. The bands are compared with those calculated within the framework of cranked Nilsson-Strutinsky and cranked Nilsson-Strutinsky-Bogoliubov models. It is concluded that the configurations of the bands involve two-proton excitations across the Z=50 as well as excitation of neutrons across the N=82 shell gaps resulting in a large deformation, 2≈0.30 and γ≈5°C