High spectral resolution of GaAs/AlAs phononic cavities by subharmonic resonant pump-probe excitation

We present here precise measurement of the resonance frequency, lifetime and shape of confined acoustic modes in the tens of GHz regime in GaAs/AlAs superlattice planar and micropillar cavities at low temperature ($\sim 20\,\textrm{K}$). The subharmonic resonant pump-probe technique, where the repetition rate of the pump laser is tuned to a subharmonic of the cavity resonance to maximize the amplitude of the acoustic resonance, in combination with a Sagnac interferometer technique for high sensitivity ($\sim 10 \,\textrm{fm}$) to the surface displacement, has been used. The cavity fundamental mode at $\sim 20\,\textrm{GHz}$ and the higher order cavity harmonics up to $\sim 180\,\textrm{GHz}$ have been clearly resolved. Mechanical Q-values up to $2.7 \times 10^4$ have been measured in a planar superlattice, and direct spatial mapping of confined acoustic modes in a superlattice cavity micropillar has been demonstrated. The Q-frequency product obtained is $\sim 5 \times 10^{14}$ demonstrating the suitability of these superlattice cavities for optomechanical applications.Comment: 5 pages, 4 figure

Managers, Learning And The Multinational Firm: Theory And Evidence

This thesis examines the question of managerial/organizational advantages as a cause of foreign direct investment (FDI) and thus as the basis of multinational enterprises (MNE\u27s). Three approaches to this question are taken: historical, analytical, and empirical. Historically, managerial/organizational advantages as a cause of MNE\u27s is traced back to the early work of Southard and Phelps in the 1930\u27s. Analytically, three models of embodied-in-managers, intangible assets are advanced, of which two are non-strategic. In the strategic model, foreign direct investment is shown to be a dominant strategy when entry by former managers (defectors) is threatened. These models make use of Penrose\u27s notion of managerial constraint. Also, two models of the R & D/advertising MNE are provided.;These models yield a number of predictions which are tested against data on four hundred and fifty U.S. firms, obtained from Standard and Poors\u27, Moody\u27s, and U.S. Department of Commerce. Various measures of managerial/organizational efficiency, R & D, advertising, plant costs and tariffs are constructed, and regressed against measures of firm multinationality. The tests are performed using a general sample and a Canadian and European subsample. The results are encouraging. Measures of managerial/organizational ability are found to have the predicted effect on U.S. foreign direct investment

Cover Crops to Secure Low Herbicide Weed Control Strategies in Maize Grown with Reduced Tillage

As a key-element of conservation agriculture, the occasional or systematic suppression of full-inversion ploughing implies an adaptation of the cropping system. To assess the ability of cover crops to control weeds in a subsequent maize crop grown with reduced tillage, three annual experiments were implemented at the research station of Agroscope Changins, Nyon, Switzerland. Ten non-wintering cover crop (CC) species were sown in mid-summer and compared to a bare soil treatment in strip-plot experiments including different weeding strategies according to integrated weed management rules. In case of a predictable impasse for weed control, an alternative management option was chosen 1) at the end of winter: total herbicide application instead of no herbicide application, 2) at the beginning of May before maize sowing: minimum soil tillage instead of no tillage. The ability of cover crop species to control weed was evaluated at the stage 2-4 leaves of maize. The shoot dry matter yield of maize was measured at harvest at the end of August. At the beginning of November, mean CC dry shoot biomass varied between 1.2 and 11.1 t DM ha-1 depending on experimental year and CC species. On average over the three years, Asteraceae (Helianthusannuus and Guizotiaabyssinica) showed the highest shoot dry matter among the tested species (> 6.0 t DM ha-1). Legume species (Pisumsativum arvense, Trifolium alexandrinum and Vicia sativa) and Brassicaceae species (Brassicacampestrisoleifera and Raphanussativuslongipinnatus) presented the lowest 3-year mean shoot biomass (≤4.0 t DM ha-1) At the end of winter, the three legume species and Avenastrigosa showed the highest plant residue soil cover and Brassicaceae species the lowest one. CC residue soil cover at the end of winter was only slightly positively correlated with CC autumn shoot biomass. In three out of eight cases, the chosen weeding strategy was very efficient in terms of weed control at the stage 2-4 leaves of maize. In the remaining five cases, the weeding strategy did not succeed in preventing weed infestation at the beginning of maize development. A mean weed cover higher than 15% was observed when no total herbicide and/or no tillage was applied before maize sowing. In three out of these five cases, a significant CC effect on weed cover could be observed. CC species able to produce high amounts of biomass in autumn appeared to be useful in terms of weed control. The most efficient CC species varied from year to year: G. abyssinica in 2011, H. annuus in 2012 and A. strigosa in 2014. CC effect on maize yield was significant in a single case, but the effect of CC species tended to be positive compared to the control treatment without CC. Despite only partial efficacy, the use of cover crops is recommended for limiting weed incidence in cropping systems aimed at reducing soil tillage and herbicide use

Access to Justice and the Evolution of Class Action Litigation in Australia

The federal and Victorian class action regimes are intended to facilitate aggregation of multiple claims. Aggregation can improve efficiency by combining similar claims and can enhance access to justice by providing a mechanism to litigate small claims. This article considers whether these efficiency and access aims are being achieved. The authors argue that whilst some developments in class action jurisprudence have been consistent with these legislative aims, other have not. Several features of Australian class action jurisprudence and practice have hampered the healthy development of the legislative regimes, including adverse costs orders, unclear threshold requirements, evasive posturing and unresolved class communication issues. Finally, having identified these difficulties, the authors propose reform possibilities and priorities

Specific interactions leading to transgressive overyielding in cover crop mixtures

Growing mixtures of species instead of sole crops is expected to increase the ecosystem services provided by cover crops. This study aimed at understanding the interactions between species and investigating how they affect the performance of the mixture. Four species were combined in six bispecific mixtures in a field experiment. The performance of each species when grown in a mixture was compared to its performance as a sole crop at different sowing densities, to characterise the influence of intra- and interspecific competition for each species. Intra- and interspecific competition coefficients were quantified using a response surface design and the hyperbolic yield-density equation. Interactions between the four species ranged from facilitation to competition. Most of the mixtures exhibited transgressive overyielding. Without nitrogen (N) fertilisation, high complementarity between species allowed to achieve the highest biomass. With N fertilisation, high dominance of one mixture component should be avoided to achieve good performance. A revised approach in the use of the land equivalent ratio for the evaluation of cover crop mixtures is also proposed in this study. It allows to better identify transgressive overyielding in mixtures and to better characterise the effect of one species on the other within the mixture

Prediction of cancer survival for cohorts of patients most recently diagnosed using multi-model inference.

Despite a large choice of models, functional forms and types of effects, the selection of excess hazard models for prediction of population cancer survival is not widespread in the literature. We propose multi-model inference based on excess hazard model(s) selected using Akaike information criteria or Bayesian information criteria for prediction and projection of cancer survival. We evaluate the properties of this approach using empirical data of patients diagnosed with breast, colon or lung cancer in 1990-2011. We artificially censor the data on 31 December 2010 and predict five-year survival for the 2010 and 2011 cohorts. We compare these predictions to the observed five-year cohort estimates of cancer survival and contrast them to predictions from an a priori selected simple model, and from the period approach. We illustrate the approach by replicating it for cohorts of patients for which stage at diagnosis and other important prognosis factors are available. We find that model-averaged predictions and projections of survival have close to minimal differences with the Pohar-Perme estimation of survival in many instances, particularly in subgroups of the population. Advantages of information-criterion based model selection include (i) transparent model-building strategy, (ii) accounting for model selection uncertainty, (iii) no a priori assumption for effects, and (iv) projections for patients outside of the sample

Integration of environmental data in BIM tool & linked building data

Environmental assessment is a critical need to ensure building sustainability. In order to enhance the sustainability of building, involved actors should be able to access and share not only information about the building but also data about products and especially their environmental assessment. Among several approaches that have been proposed to achieve that, semantic web technologies stand out from the crowd by their capabilities to share data and enhance interoperability in between the most heterogeneous systems. This paper presents the implementation of a method in which semantic web technologies and particularly Linked Data have been combined with Building Information Modelling (BIM) tools to foster building sustainability by introducing products with their environmental assessment in building data during the modelling phase. Based on Linked Building Data (LBD) vocabularies and environmental data, several ontologies have been generated in order to make both of them available as Resource Description Framework (RDF) graphs. A database access plugin has been developed and installed in a BIM tool. In that way, the LBD generated from the BIM tool contains, for each product a reference to its environmental assessment which is contained in a triplestore

Implantation of esterified hyaluronic acid in microdissected Reinke's space after vocal fold microsurgery

laryngeal and vocal results obtained after microflap excision of benign vocal fold lesions and immediate implantation of esterified hyaluronic acid(EHA) in the surgical wound are described in this study. Prospective and comparative study on 83 patients ( 33 implanted with EHA and 50 not implanted). Longest follow up is 4 years. The objectives are to confirm the innocuity of the technique, to demonstrate the laryngeal and vocal evolution at short and long term, and to evaluate the eventual positive impact of EHA implantation on the pliability of the superficial layer of the lamina propria (SLLP) and on voice. The use of EHA implant in microdissected SLLP is safe and leads to good laryngeal and vocal outcomes in the treated patients