PRONOM-ROAR: Adding Format Profiles to a Repository Registry to Inform Preservation Services

To date many institutional repository (IR) software suppliers have pushed the IR as a digital preservation solution. We argue that the digital preservation of objects in IRs may better be achieved through the use of light-weight, add-on services. We present such a service – PRONOM-ROAR – that generates file format profiles for IRs. This demonstrates the potential of using third- party services to provide preservation expertise to IR managers by making use of existing machine interfaces to IRs

New rules in the workplace : applying object-relations theory to explain problem Internet and email behaviour in the workplace

While the Internet and email can be great assets to an organisation, especially in respect to creating new knowledge, nonetheless a number of problems have accompanied the introduction of the Internet into the workplace. Some of these problems include: _cyberslacking_, cyber- harassment and _Netiquette_. Employers have attempted to obviate these problems by developing Internet usage policies, implementing filtering software and monitoring their workers. It has also been suggested that psychological tests could assist employers in identifying potentially _problem_ employees. Although each of these methods have their uses, none of them have been successful in dealing with such problems. We argue that if we are better able to conceptualise cyberspace and the relationship workers have with this space, then we may be able to develop more effective solutions to deal with these new problems in the workplace. This paper attempts to do just that, by drawing upon object-relations theories, developed by Winnicott, Bollas and Klein. We also draw upon Serres_ work on quasi-objects. We believe that cyberspace is a unique and important tool for organisations to utilise, but if not understood well, the existing problems that have already emerged, and those yet to emerge, will continue to be ineffectively addressed

FEM modelling of the three stages of friction stir spot welding

A three-dimensional modelling of the Friction Stir Spot Welding process was carried out by means of a two-dimensional continuum with symmetry of revolution around the tool axis. The model included the plunging, dwelling and withdrawal stages of two (Formula presented.) mm thick AA6061 alloy plates joining process. A highly viscous flow model was adopted, as well as the hypothesis of full stick contact between tool and material. The model was solved by means of the Finite Element Method (FEM) and Arbitrary Lagrangian Eulerian (ALE) techniques in an axisymmetric domain with mesh tracking and algorithms to account for contact and free flow. Numerical results were compared to experimental data found in literature. The maximum temperature for the pin front face was found within less than (Formula presented.) % of the experimental value. The velocity field were found close to those reported in literature and the final shape of the weld flash was similar to its experimental counterpart.Fil: Carr, Gustavo Eduardo. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Biocca, Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lombera, Guillermo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Urquiza, Santiago Adrian. Universidad Nacional de Mar del Plata; Argentin

Reply to "Overstated Claims of Efficacy and Safety. Comment On:Optimal Nutritional Status for a Well-Functioning Immune System Is an Important Factor to Protect against Viral Infections. Nutrients 2020, 12, 1181"

We thank Vorland et al [...

Computational modelling of the FSSW joining for the analysis of the welding process

En el presente trabajo se estudia el proceso de friction stir spot welding de planchuelas de aleación de aluminio AA6082 utilizando dos métodos de cálculo sucesivos. En una primera etapa se modela la inserción del perno en el material a soldar como un problema unidimensional axisimétrico no estacionario.De este caso se extrae el campo de temperaturas que es utilizado como campo de condiciones térmicas iniciales al momento de modelar el proceso de permanencia en el paso siguiente. Esta segunda etapa del proceso se realiza mediante un modelo bidimensional axisimétrico considerando al material constitutivamenteviscoplástico y, consecuentemente, resolviendo un problema de flujo de Stokes con viscosidades no lineales. Como resultados de este caso se obtienen los campos de velocidades, temperaturas y tensiones para todo el continuo. Las estimaciones realizadas se comparan con resultados experimentales de soldaduras de punto por fricción agitación.In this work, the friction stir spot welding process of AA6082 aluminium allow slabs is studied by means of two different methods of calculation. Firstly, the pin insertion is modelled as an axisymmetric one dimensional non stationary problem. The resulting temperatures field is used in the second phase of calculus as initial thermal conditions at the moment of modelling the following tool dwelling process. This second phase the welding process is modelled using an axysimmetric continuum, assuming a viscoplastic material, therefore solving a Stokes’ flow problem with non linear viscosity. The velocity, temperatures and stress fields are obtained for the whole domain. The obtained results are compared to experimental results in friction stir spot weldments.Fil: Carr, Gustavo Eduardo. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Santiago, Diego A.. Universidad Nacional de Mar del Plata; ArgentinaFil: Urquiza, Santiago Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Lombera, Guillermo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; Argentin

Spin Squeezing as a Probe of Emergent Quantum Orders

Nuclear magnetic resonance (NMR) experiments can reveal local properties in materials, but are often limited by the low signal-to-noise ratio. Spin squeezed states have an improved resolution below the Heisenberg limit in one of the spin components, and have been extensively used to improve the sensitivity of atomic clocks, for example. Interacting and entangled spin ensembles with non-linear coupling are a natural candidate for implementing squeezing. Here, we propose measurement of the spin-squeezing parameter that itself can act as a local probe of emergent orders in quantum materials. In particular, we demonstrate how to investigate an anisotropic electric field gradient via its coupling to the nuclear quadrupole moment. While squeezed spin states are pure, the squeezing parameter can be estimated for both pure and mixed states. We evaluate the range of fields and temperatures for which a thermal-equilibrium state is sufficient to improve the resolution in an NMR experiment and probe relevant parameters of the quadrupole Hamiltonian, including its anisotropy

Multi-modal spectroscopy of phase transitions

To understand a phase transition, independent measurement of the value and variation in each physical parameter of a material's Hamiltonian is vital. Conventional one-dimensional spectroscopy, which studies dynamical responses to fields, struggles to distinguish between different sources of noise. Multi-dimensional spectroscopy can avoid this issue and probe symmetry-specific Hamiltonian parameters by analyzing how the time delay between applied pulses ($\tau$) affects the response. In this work, we present a spectroscopic technique based on the multi-dimensional paradigm which can measure a quadrupolar interaction (inversion symmetric) even in the presence of large magnetic noise (inversion asymmetric). Inversion symmetric combinations of spin operators are found to give clear sinusoidal responses in $\tau$ due to periodic refocusing. The time-scale on which the magnetization partially decays in $\tau$ provides a direct measure of the distribution of interaction strengths, even when the average value of the interaction is zero. This method independently measures the distributions of different forms of disorder, helping elucidate which microscopic symmetry drives a phase transition.Comment: 14 pages, 8 figure

Corridor Volatility Risk and Expected Returns

This paper examines the pricing of volatility risk using SPX corridor implied volatility. We decompose model-free implied volatility into various components using different segments of the cross-section of out-of-the money put and call option prices. We find that only model-free volatility computed from the cross-section of out-of-the-money call option prices carries a significant negative risk premium in the cross-section of stock returns and subsumes all relevant information for forecasting future volatility. Our empirical results provide strong evidence that SPX out-of-the money put option prices do not contain useful information for pricing aggregate volatility risk in the cross-section of stock returns

Multiple functionally divergent and conserved copies of alpha tubulin in bdelloid rotifers.

BACKGROUND: Bdelloid rotifers are microscopic animals that have apparently survived without sex for millions of years and are able to survive desiccation at all life stages through a process called anhydrobiosis. Both of these characteristics are believed to have played a role in shaping several unusual features of bdelloid genomes discovered in recent years. Studies into the impact of asexuality and anhydrobiosis on bdelloid genomes have focused on understanding gene copy number. Here we investigate copy number and sequence divergence in alpha tubulin. Alpha tubulin is conserved and normally present in low copy numbers in animals, but multiplication of alpha tubulin copies has occurred in animals adapted to extreme environments, such as cold-adapted Antarctic fish. Using cloning and sequencing we compared alpha tubulin copy variation in four species of bdelloid rotifers and four species of monogonont rotifers, which are facultatively sexual and cannot survive desiccation as adults. Results were verified using transcriptome data from one bdelloid species, Adineta ricciae. RESULTS: In common with the typical pattern for animals, monogonont rotifers contain either one or two copies of alpha tubulin, but bdelloid species contain between 11 and 13 different copies, distributed across five classes. Approximately half of the copies form a highly conserved group that vary by only 1.1% amino acid pairwise divergence with each other and with the monogonont copies. The other copies have divergent amino acid sequences that evolved significantly faster between classes than within them, relative to synonymous changes, and vary in predicted biochemical properties. Copies of each class were expressed under the laboratory conditions used to construct the transcriptome. CONCLUSIONS: Our findings are consistent with recent evidence that bdelloids are degenerate tetraploids and that functional divergence of ancestral copies of genes has occurred, but show how further duplication events in the ancestor of bdelloids led to proliferation in both conserved and functionally divergent copies of this gene.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are