A Comparison of Antlions, Bees, Darkling Beetles and Velvet Ants Across Sand Dune and Non-Sand Dune Habitats at Ash Meadows National Wildlife Refuge

Insects fulfill important roles within all ecosystems, including deserts, and interact directly and indirectly with the endemic and endangered species at the Ash Meadows National Wildlife Refuge (AMNWR). Here I investigate the variability of species richness, diversity, abundance and community composition of four insect groups between stabilized sand dune habitats, unstabilized sand dune habitats and non-sand dune habitats. The insects examined in this thesis include antlions (Myrmeleontidae), bees (Apiformes), darkling beetles (Tenebrionidae) and velvet ants (Mutillidae). As the impact and interactions of two of the insect groups, antlions and velvet ants, are largely unknown within any ecosystem, this thesis also includes a faunal study of velvet ants at AMNWR and their spatial and temporal variation at the refuge. Generalized linear mixed models were used to identify significant differences in richness, diversity and abundance for each insect group between the stabilized sand dune, unstabilized sand dune and non-sand dune habitats. Species richness differed between habitats for antlions, beetles and velvet ants over the study period. Diversity differed between habitats for antlions and beetles, and abundance differed between habitats for all groups over the study period. Nearly every habitat supported some unique species. The faunal survey of velvet ants revealed minor variation in flight times between species and a unique pattern of temporal niche partitioning in one species. Habitat preferences were observed for seven of 42 velvet ant species at AMNWR. In a comparison of the diversity of velvet ants between AMNWR and the Nevada Test Site (NTS), six velvet ant species that occurred at the NTS were not found at AMNWR. Diagnoses and a key are provided for the velvet ants of AMNWR. This thesis increases the number of known terrestrial invertebrates at the refuge and provides a comparison of terrestrial insect distribution and habitat use at AMNWR. These investigations contribute to the goals and objectives of the U. S. Fish and Wildlife Service to obtain basic inventories and understand the terrestrial habitat use of invertebrates at AMNWR

Characterization of Iridium Coated Rhenium Used in High-Temperature, Radiation-Cooled Rocket Thrusters

Materials used for radiation-cooled rocket thrusters must be capable of surviving under extreme conditions of high-temperatures and oxidizing environments. While combustion efficiency is optimized at high temperatures, many refractory metals are unsuitable for thruster applications due to rapid material loss from the formation of volatile oxides. This process occurs during thruster operation by reaction of the combustion products with the material surface. Aerojet Technical Systems has developed a thruster cone chamber constructed of Re coated with Ir on the inside surface where exposure to the rocket exhaust occurs. Re maintains its structural integrity at high temperature and the Ir coating is applied as an oxidation barrier. Ir also forms volatile oxide species (IrO2 and IrO3) but at a considerably slower rate than Re. In order to understand the performance limits of Ir-coated Re thrusters, we are investigating the interdiffusion and oxidation kinetics of Ir/Re. The formation of iridium and rhenium oxides has been monitored in situ by Raman spectroscopy during high temperature exposure to oxygen. For pure Ir, the growth of oxide films as thin as approximately 200 A could be easily detected and the formation of IrO2 was observed at temperatures as low as 600 C. Ir/Re diffusion test specimens were prepared by magnetron sputtering of Ir on Re substrates. Concentration profiles were determined by sputter Auger depth profiles of the heat treated specimens. Significant interdiffusion was observed at temperatures as low as 1000 C. Measurements of the activation energy suggest that below 1350 C, the dominant diffusion path is along defects, most likely grain boundaries, rather than bulk diffusion through the grains. The phases that form during interdiffusion have been examined by x ray diffraction. Analysis of heated test specimens indicates that the Ir-Re reaction produces a solid solution phase of Ir dissolved in the HCP structure of Re

Electrical detection of 31P spin quantum states

In recent years, a variety of solid-state qubits has been realized, including quantum dots, superconducting tunnel junctions and point defects. Due to its potential compatibility with existing microelectronics, the proposal by Kane based on phosphorus donors in Si has also been pursued intensively. A key issue of this concept is the readout of the P quantum state. While electrical measurements of magnetic resonance have been performed on single spins, the statistical nature of these experiments based on random telegraph noise measurements has impeded the readout of single spin states. In this letter, we demonstrate the measurement of the spin state of P donor electrons in silicon and the observation of Rabi flops by purely electric means, accomplished by coherent manipulation of spin-dependent charge carrier recombination between the P donor and paramagnetic localized states at the Si/SiO2 interface via pulsed electrically detected magnetic resonance. The electron spin information is shown to be coupled through the hyperfine interaction with the P nucleus, which demonstrates the feasibility of a recombination-based readout of nuclear spins

Microfluidic synthesis of monodisperse and size-tunable CsPbBr3 supraparticles

The highly controlled, microfluidic template-assisted self-assembly of CsPbBr3 nanocrystals into spherical supraparticles is presented, achieving precise control over average supraparticle size through the variation of nanocrystal concentration and droplet size; thus facilitating the synthesis of highly monodisperse, sub-micron supraparticles (with diameters between 280 and 700 nm)

O CONHECIMENTO EM CONSTRUÇÃO: DAS FORMULAÇÕES DE JEAN PIAGET À TEORIA DE SISTEMAS COMPLEXOS

Resenha crítica sobre o livro "O conhecimento em construção: das formulações de Jean Piaget à teoria de sistemas complexos", de Rolando García

Strengthening Europe's Capability in Biological Ocean Observations

This publication is primarily aimed at stakeholders involved in ocean observing, spanning diverse roles from commissioning, managing, funding and coordinating, to developing, implementing, or advising on, ocean observation programmes. Such programmes will have strategic and policy drivers but their main purpose may vary from predominantly researchdriven scientific purposes to environmental monitoring for providing data and reporting to legally-binding regulations or directives. The main focus is on European capabilities but set in a global context with the various actors spanning a variety of geographical scales from national to regional and European. Key stakeholder organizations include environmental or other agencies; marine research institutions, their researchers and operators; international and regional ocean observing initiatives and programmes; national, regional and European policy makers and their advisors; national stations for observations; etc.). It will also be of interest to the wider marine and maritime research and policy community. The main aim of the publication is to increase the relevance of current (and future) European biological ocean observation capacity to strengthen global efforts towards our understanding of the ocean and enhance marine biodiversity conservation, for maintaining a healthy ocean for healthy societies. This document explains why biological ocean observations are needed to assess progress against national and international conservation targets, the Sustainable Development Goals (SDGs), the Blue Growth agenda and to contribute to key EU directives including the Marine Strategy Framework Directive (MSFD). To achieve this, the publication highlights the need of biological ocean observations to reflect clearly defined hypotheses about potential causes of change, including the combined impacts of local and global drivers, and to support the management of our impacts on the ocean. Additionally, it calls for flexible biological ocean observing programmes to capture the relevant drivers operating at multiple spatial scales, by networking and integration of ongoing monitoring programmes, methodological standardization and appropriate policies of data integration and dissemination. It then presents key variables, elements and information products to inform on the status and trends of marine biodiversity

The importance of Southern Ocean frontal systems for the improvement of body condition in southern elephant seals

Funding: Natural Environment Research Council, Grant/Award Numbers: NE/E018289/1, NE/L501852/1 NER/D/S/2002/00426; Scottish Funding Council, Grant/Award Number: HR09011.1. As top predators, it has been suggested that southern elephant seals serve as sentinels of ecosystem status to inform management and conservation.2. This is because southern elephant seals annually undertake two large‐scale foraging migrations for 2–3 and 7–8 months to replenish resources after fasting during breeding and moulting and often rely on dynamic macroscale latitudinal fronts to provide favourable foraging through aggregating prey.3. Yet it is largely unknown whether southern elephant seals respond to changes in frontal systems over the years, whether their foraging success is associated with specific frontal systems shifts, and how flexible southern elephant seals populations are in behaviourally adapting to changes in frontal systems.4. This study examines the relationship between frontal systems and the resource acquisition of 64 southern elephant seals during four post‐moult and three post‐breeding migrations between 2005 and 2010.5. Satellite‐relay‐data‐loggers provided in situ measurements concurrent with >27,500 dive profiles to define fronts and interfrontal zones between the Subtropical Frontal Zone and the Southern Boundary of the Antarctic Circumpolar Current. For >430,000 in situ measurements water mass properties could be identified.6. Generally, southern elephant seals associate more frequently with more southerly, higher‐latitude fronts/zones. Body condition improvements related to a given frontal system or water mass vary strongly according to year, season, month and sex.7. The variability in body condition improvements is higher in some frontal systems than in others, probably owing to shifts in the Subantarctic and Polar Front.8. During a migration, some individuals stay within ≤3 frontal systems, whilst others change between several frontal systems and primarily improve their body condition in upper ocean waters.9. Southern elephant seals do not trace particular water masses across frontal systems, and both surface and deep foraging strategies are used.10. This suggests that southern elephant seals do not target particular water masses but adjust foraging and movement strategies to exploit boundary areas at which mixing and prey aggregation is high.11. The large behavioural plasticity towards the spatio‐temporal variability in the different oceanographic regions they encounter could indicate resilience against environmental changes.PostprintPeer reviewe