A comparison of human and pig decomposition rates and odour profiles in an Australian environment

© 2018, © 2018 Australian Academy of Forensic Sciences. Cadaver-detection dogs are trained to locate victim remains; however, their training is challenging owing to limited access to human remains. Animal analogues, such as pigs, are typically used as alternative training aids. This project aimed to compare the visual decomposition and volatile organic compound (VOC) profile of human and pig remains in an Australian environment, to determine the suitability of pig remains as human odour analogues for cadaver-detection dog training. Four human cadavers and four pig carcasses were placed in an outdoor environment at the Australian Facility for Taphonomic Experimental Research (AFTER) across two seasons. Decomposition was monitored progressively in summer and winter. VOCs were collected onto sorbent tubes and analysed using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry. Visual observations highlighted the differences in decomposition rates, with pig remains progressing through all stages of decomposition, and human remains undergoing differential decomposition and mummification. Chemical and statistical analysis highlighted variations in the composition and abundance of VOCs over time between the odour profiles. This study concluded that the visual decomposition and VOC profile of pig and human remains was dissimilar. However, in cooler conditions the results from each species became more comparable, especially during the early stages of decomposition

Dynamical electron transport through a nanoelectromechanical wire in a magnetic field

We investigate dynamical transport properties of interacting electrons moving in a vibrating nanoelectromechanical wire in a magnetic field. We have built an exactly solvable model in which electric current and mechanical oscillation are treated fully quantum mechanically on an equal footing. Quantum mechanically fluctuating Aharonov-Bohm phases obtained by the electrons cause nontrivial contribution to mechanical vibration and electrical conduction of the wire. We demonstrate our theory by calculating the admittance of the wire which are influenced by the multiple interplay between the mechanical and the electrical energy scales, magnetic field strength, and the electron-electron interaction

Galaxy clusters at high redshift and evolution of brightest cluster galaxies

Identification of high redshift clusters is important for studies of cosmology and cluster evolution. Using photometric redshifts of galaxies, we identify 631 clusters from the Canada-France-Hawaii Telescope (CFHT) Wide field, 202 clusters from the CHFT Deep field, 187 clusters from the Cosmic Evolution Survey (COSMOS) and 737 clusters from the Spitzer Wide-area InfraRed Extragalactic survey (SWIRE) field. The redshifts of these clusters are in the range of 0.1<z<1.6. Merging these cluster samples gives 1644 clusters in the four survey fields, of which 1088 are newly identified and more than half are from the large SWIRE field. Among 228 clusters of z>1, 191 clusters are newly identified, and most of them from the SWIRE field. With this large sample of high redshift clusters, we study the color evolution of the brightest cluster galaxies (BCGs). The colors r'-z' and r^+-m_{3.6\mu m} of the BCGs are consistent with a stellar population synthesis model in which the BCGs are formed at redshift z_f>2 and evolved passively. The colors g'-z' and B-m_{3.6\mu m} of the BCGs at redshifts z>0.8 are systematically bluer than the passive evolution model for galaxy formed at z_f~2, indicating star formation in high redshift BCGs.Comment: 10 pages, 14 figures, 2 tables; added reference, corrected typos; Table 2 is available at http://zmtt.bao.ac.cn/wzl/CV_wen.ht

On thermalization of magnetic nano-arrays at fabrication

We propose a model to predict and control the statistical ensemble of magnetic degrees of freedom in Artificial Spin Ice (ASI) during thermalized adiabatic growth. We predict that as-grown arrays are controlled by the temperature at fabrication and by their lattice constant, and that they can be described by an effective temperature. If the geometry is conducive to a phase transition, then the lowest temperature phase is accessed in arrays of lattice constant smaller than a critical value, which depends on the temperature at deposition. Alternatively, for arrays of equal lattice constant, there is a temperature threshold at deposition and the lowest temperature phase is accessed for fabrication temperatures {\it larger rather than smaller} than this temperature threshold. Finally we show how to define and control the effective temperature of the as-grown array and how to measure critical exponents directly. We discuss the role of kinetics at the critical point, and applications to experiments, in particular to as-grown thermalized square ASI, and to magnetic monopole crystallization in as-grown honeycomb ASI.Comment: 14 pages, 2 figures. A theoretical approach to experimental results reported in: Morgan J P, Stein A, Langridge S and Marrows C (2010) Nature Physics 7 7

The 10k zCOSMOS: morphological transformation of galaxies in the group environment since z~1

We study the evolution of galaxies inside and outside of the group environment since z=1 using a large well defined set of groups and galaxies from the zCOSMOS-bright redshift survey in the COSMOS field. The fraction of galaxies with early-type morphologies increases monotonically with M_B luminosity and stellar mass and with cosmic epoch. It is higher in the groups than elsewhere, especially at later epochs. The emerging environmental effect is superposed on a strong global mass-driven evolution, and at z~0.5 and log(M*/Msol)~10.2, the "effect" of group environment is equivalent to (only) about 0.2 dex in stellar mass or 2 Gyr in time. The stellar mass function of galaxies in groups is enriched in massive galaxies. We directly determine the transformation rates from late to early morphologies, and for transformations involving colour and star formation indicators. The transformation rates are systematically about twice as high in the groups as outside, or up to 3-4 times higher correcting for infall and the appearance of new groups. The rates reach values, for masses around the crossing mass 10^10.5 Msol, as high as (0.3-0.7)/Gyr in the groups, implying transformation timescales of 1.4-3 Gyr, compared with less than 0.2/Gyr, i.e. timescales >5 Gyr, outside of groups. All three transformation rates decrease at higher stellar masses, and must decrease also at the lower masses below 10^10 Msol which we cannot well probe. The rates involving colour and star formation are consistently higher than those for morphology, by a factor of about 50%. Our conclusion is that the transformations which drive the evolution of the overall galaxy population since z~1 must occur at a rate 2-4 times higher in groups than outside of them.Comment: 21 pages, 13 figures, submitted to Ap

The XMM-Newton Wide-Field Survey in the COSMOS field (XMM-COSMOS): demography and multiwavelength properties of obscured and unobscured luminous AGN

We report the final optical identifications of the medium-depth (~60 ksec), contiguous (2 deg^2) XMM-Newton survey of the COSMOS field. XMM-Newton has detected ~800 X-ray sources down to limiting fluxes of ~5x10^{-16}, ~3x10^{-15}, and ~7x10^{-15} erg/cm2/s in the 0.5-2 keV, 2-10 keV and 5-10 keV bands, respectively. The work is complemented by an extensive collection of multi-wavelength data from 24 micron to UV, available from the COSMOS survey, for each of the X-ray sources, including spectroscopic redshifts for ~50% of the sample, and high-quality photometric redshifts for the rest. The XMM and multiwavelength flux limits are well matched: 1760 (98%) of the X-ray sources have optical counterparts, 1711 (~95%) have IRAC counterparts, and 1394 (~78%) have MIPS 24micron detections. Thanks to the redshift completeness (almost 100%) we were able to constrain the high-luminosity tail of the X-ray luminosity function confirming that the peak of the number density of logL_X>44.5 AGN is at z~2. Spectroscopically-identified obscured and unobscured AGN, as well as normal and starforming galaxies, present well-defined optical and infrared properties. We devised a robust method to identify a sample of ~150 high redshift (z>1), obscured AGN candidates for which optical spectroscopy is not available. We were able to determine that the fraction of the obscured AGN population at the highest (L_X>10^{44} erg s^{-1}) X-ray luminosity is ~15-30% when selection effects are taken into account, providing an important observational constraint for X-ray background synthesis. We studied in detail the optical spectrum and the overall spectral energy distribution of a prototypical Type 2 QSO, caught in a stage transitioning from being starburst dominated to AGN dominated, which was possible to isolate only thanks to the combination of X-ray and infrared observations.Comment: ApJ, in press. 59 pages, 14 figures, 2 Tables. A few typos corrected and a reference added. Table 2 is also available at http://www.mpe.mpg.de/XMMCosmos/xmm53_release ; a version of the paper in ApJ format (27 pages) is available at http://www.mpe.mpg.de/XMMCosmos/xmm53_release/brusa_xmmcosmos_optid.pd

Differential requirements for Tousled-like kinases 1 and 2 in mammalian development

The regulation of chromatin structure is critical for a wide range of essential cellular processes. The Tousled-like kinases, TLK1 and TLK2, regulate ASF1, a histone H3/H4 chaperone, and likely other substrates, and their activity has been implicated in transcription, DNA replication, DNA repair, RNA interference, cell cycle progression, viral latency, chromosome segregation and mitosis. However, little is known about the functions of TLK activity in vivo or the relative functions of the highly similar TLK1 and TLK2 in any cell type. To begin to address this, we have generated Tlk1- and Tlk2-deficient mice. We found that while TLK1 was dispensable for murine viability, TLK2 loss led to late embryonic lethality because of placental failure. TLK2 was required for normal trophoblast differentiation and the phosphorylation of ASF1 was reduced in placentas lacking TLK2. Conditional bypass of the placental phenotype allowed the generation of apparently healthy Tlk2-deficient mice, while only the depletion of both TLK1 and TLK2 led to extensive genomic instability, indicating that both activities contribute to genome maintenance. Our data identifies a specific role for TLK2 in placental function during mammalian development and suggests that TLK1 and TLK2 have largely redundant roles in genome maintenance

TbUNC119 and Its Binding Protein Complex Are Essential for Propagation, Motility, and Morphogenesis of Trypanosoma brucei Procyclic Form Cells

Flagellum-mediated motility of Trypanosoma brucei is considered to be essential for the parasite to complete stage development in the tsetse fly vector, while the mechanism by which flagellum-mediated motility is controlled are not fully understood. We thus compared T. brucei whole gene products (amino acid sequence) with Caenorhabditis elegans UNC (uncoordinated) proteins, in order to find uncharacterized motility-related T. brucei genes. Through in silico analysis, we found 88 gene products which were highly similar to C. elegans UNC proteins and categorized them as TbCEUN (T. brucei gene products which have high similarity to C. elegans UNC proteins). Approximately two thirds of the 88 TbCEUN gene products were kinesin-related molecules. A gene product highly similar to C. elegans UNC119 protein was designated as TbUNC119. RNAi-mediated depletion of TbUNC119 showed no apparent phenotype. However, knock-down analysis of both TbUNC119 and its binding protein (TbUNC119BP) which was found by yeast two-hybrid analysis showed characteristic phenotypes, including reduced motility, morphological change (extended cell shape), and cellular apoptosis. Based on the observed phenotypes, possible function of the TbUNC119 and TbUNC119BP is discussed

Technique for Resolving Low-lying Isomers in the Experimental Storage Ring (ESR) and the Occurrence of an Isomeric State in 192Re

A recent experiment using projectile fragmentation of a 197Au beam on a 9Be target, combined with the fragment recoil separator and experimental storage ring at ring at GSI, has uncovered an isomeric state in 192Re at 267(10) keV with a half-life of ∼6

Bayesian Phylogeography Finds Its Roots

As a key factor in endemic and epidemic dynamics, the geographical distribution of viruses has been frequently interpreted in the light of their genetic histories. Unfortunately, inference of historical dispersal or migration patterns of viruses has mainly been restricted to model-free heuristic approaches that provide little insight into the temporal setting of the spatial dynamics. The introduction of probabilistic models of evolution, however, offers unique opportunities to engage in this statistical endeavor. Here we introduce a Bayesian framework for inference, visualization and hypothesis testing of phylogeographic history. By implementing character mapping in a Bayesian software that samples time-scaled phylogenies, we enable the reconstruction of timed viral dispersal patterns while accommodating phylogenetic uncertainty. Standard Markov model inference is extended with a stochastic search variable selection procedure that identifies the parsimonious descriptions of the diffusion process. In addition, we propose priors that can incorporate geographical sampling distributions or characterize alternative hypotheses about the spatial dynamics. To visualize the spatial and temporal information, we summarize inferences using virtual globe software. We describe how Bayesian phylogeography compares with previous parsimony analysis in the investigation of the influenza A H5N1 origin and H5N1 epidemiological linkage among sampling localities. Analysis of rabies in West African dog populations reveals how virus diffusion may enable endemic maintenance through continuous epidemic cycles. From these analyses, we conclude that our phylogeographic framework will make an important asset in molecular epidemiology that can be easily generalized to infer biogeogeography from genetic data for many organisms