Stability and mobility of supported Nin (n = 1–10) clusters on ZrO2(111) and YSZ(111) surfaces: a density functional theory study

The performance of supported metal catalysts, such as nickel nanoparticles decorating yttria-stabilized zirconia (YSZ), depends on their microstructure and the metal–support interface. Here, we have used spin polarized density functional theory (DFT) to evaluate different Ni cluster geometries and determined the electronic structure of the most stable configurations. We have described the interaction of Nin (n = 1–10) clusters supported on the cubic ZrO2(111) and YSZ(111) surfaces, which show a preference for pyramidal shapes rather than flat structures wetting the surface. The interfacial interaction is characterized by charge transfer from the cluster to the surface. We also show how yttrium, present in YSZ, affects the Ni–Ni interaction. Through analysing the difference between the cohesive energy and the clustering energy, we show the preference of Ni–Ni bond formation over Ni-surface interaction; this energy difference decreases with the increase of the Nin cluster size. From the evaluation of the Ni atomic hopping rates on YSZ, we have demonstrated that under different temperature conditions, Ni atoms aggregate with other atoms and clusters, which affects the cluster size stability

Enhanced Characterization of the Smell of Death by Comprehensive Two-Dimensional Gas Chromatography-Time-of-Flight Mass Spectrometry (GCxGC-TOFMS)

Soon after death, the decay process of mammalian soft tissues begins and leads to the release of cadaveric volatile compounds in the surrounding environment. The study of postmortem decomposition products is an emerging field of study in forensic science. However, a better knowledge of the smell of death and its volatile constituents may have many applications in forensic sciences. Domestic pigs are the most widely used human body analogues in forensic experiments, mainly due to ethical restrictions. Indeed, decomposition trials on human corpses are restricted in many countries worldwide. This article reports on the use of comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC-TOFMS) for thanatochemistry applications. A total of 832 VOCs released by a decaying pig carcass in terrestrial ecosystem, i.e. a forest biotope, were identified by GCxGC-TOFMS. These postmortem compounds belong to many kinds of chemical class, mainly oxygen compounds (alcohols, acids, ketones, aldehydes, esters), sulfur and nitrogen compounds, aromatic compounds such as phenolic molecules and hydrocarbons. The use of GCxGC-TOFMS in study of postmortem volatile compounds instead of conventional GC-MS was successful

The community of Hymenoptera parasitizing necrophagous Diptera in an urban biotope

Most reports published in the field of forensic entomology are focused on Diptera and neglect the Hymenoptera community. However, Hymenoptera are part of the entomofaunal colonisation of a dead body. The use of Hymenoptera parasitoids in forensic entomology can be relevant to evaluate the time of death. Hymenoptera parasitoids of the larvae and pupae of flies may play an important role in the estimation of the post-mortem period, because their time of attack is often restricted to a small, well-defined windows of time in the development of the host insect. However, these parasitoids can interfere with the developmental times of colonising Diptera, and therefore a better understanding of their ecology is needed. The work reported here monitored the presence of adult Hymenoptera parasitoids on decaying pig carcasses in an urban biotope during the summer season (from May to September). Six families and six species were recorded in the field: Aspilota fuscicornis Haliday, Alysia manducator Panzer, Nasonia vitripennis Walker, Tachinaephagus zealandicus Ashmead, Trichopria sp., and Figites sp. In the laboratory, five species emerged from pupae collected in the field: Trichopria sp., Figites sp., A. manducator, N. vitripennis, and T. zealandicus. These five species colonise a broad spectrum of Diptera hosts, including those species associated with decomposing carcasses: Calliphoridae, Muscidae, Fanniidae, and Sarcophagida

Egg laying preferences and larval performance in Dermestes maculatus

Dermestes maculatus DeGeer (Coleoptera: Dermestidae) is both a pest of dried stored products and, through its colonization of carrion, a forensically important species. However, little is known about the consequences of female oviposition site preferences on larval growth and development. To examine this, non-virgin female beetles were offered a choice of food resources that had been aged to various extents to explore the adaptive nature of female oviposition preferences. Dermestes maculatus females consistently preferred to oviposit on muscle in contrast to either fat or bone marrow. Constraining larvae onto one of the three resource types confirmed that larvae grew faster and eclosed into larger adults when fed on muscle than when fed on either fat or bone marrow. In addition, the degree of sexual dimorphism was also related to food resource, with the greatest extent of size dimorphism (females larger than males) being evident on the preferred muscle resource. This conforms to the view that intraspecific variation in sexual size dimorphism is driven by intersexual differences in phenotypic plasticity, with females being able to reach greater size than males when conditions are good. The results indicate that D. maculatus female oviposition preferences are adaptive in that adult oviposition choice can enhance offspring fitness and so broadly conforms to the oviposition preference-larval performance hypothesis as noted in a number of phytophagous insects. © 2013 The Netherlands Entomological Society

Multinational corporations and industrial relations research: A road less travelled

While there is a large body of academic debate surrounding human resource management issues in MNCs, industrial relations issues often fail to receive the same degree of attention. This paper attempts to move the debate forward by critically reviewing some of the key debates surrounding industrial relations (IR) in an international context. Firstly, some key themes surrounding the comparison of industrial relations across borders and IR in multinational companies are delineated and defined. We then consider the reasons why an international IR (IIR) perspective has been under-represented in the literature to date. The paper then explores the contribution which an international IR perspective can bring to the study of management practices in MNCs. This is discussed in terms of IIR¿s potential contribution in terms of an alternative analytical approach and also differences in its substantive coverage. The impact of IR systems on MNC location and relocation decisions, key issues for employees, trade unions and managers of MNCs, is then discussed as an example of the former. We then consider the potential for, and evidence of, international collective bargaining as a potential counter-balance to the power the MNC in the global environment as an example of a differing area of substantive coverage of IIR. Finally some avenues for potential study are outlined.peer-reviewe