On consistency factors and efficiency of robust S-estimators

We tackle the problem of obtaining the consistency factors of robust S-estimators of location and scale both in regression and multivariate analysis. We provide theoretical results, proving new formulae for their calculation and shedding light on the relationship between these factors and important statistical properties of S-estimators. We also give computational advances, suggesting efficient procedures so that hardly any time is lost for their calculation when computing S-estimates. In addition, when the purpose is to fix the efficiency of the scale estimator, we are able to quantify to what extent the approximate algorithms which are currently available provide an acceptable solution, and when it is necessary to resort to the exact formulae. Finally, even if this paper concentrates on S-estimates and Tukey’s Biweight and optimal loss functions, the main results can be easily extended to calculate the tuning consistency factors for other popular loss function and other robust estimators.     

Structure and mechanical properties of Octopus vulgaris suckers

In this study, we investigate the morphology and mechanical features of Octopus vulgaris suckers, which may serve as a model for the creation of a new generation of attachment devices. Octopus suckers attach to a wide range of substrates in wet conditions, including rough surfaces. This amazing feature is made possible by the sucker''s tissues, which are pliable to the substrate profile. Previous studies have described a peculiar internal structure that plays a fundamental role in the attachment and detachment processes of the sucker. In this work, we present a mechanical characterization of the tissues involved in the attachment process, which was performed using microindentation tests. We evaluated the elasticity modulus and viscoelastic parameters of the natural tissues (E ∼ 10 kPa) and measured the mechanical properties of some artificial materials that have previously been used in soft robotics. Such a comparison of biological prototypes and artificial material that mimics octopus-sucker tissue is crucial for the design of innovative artificial suction cups for use in wet environments. We conclude that the properties of the common elastomers that are generally used in soft robotics are quite dissimilar to the properties of biological suckers.     

SMEs' Preference for Innovation Networks: A Choice Experimental Approach

The objective of this paper is to evaluate the importance of selected characteristics of innovation networks in affecting the decision of food SMEs when joining such networks. The paper develops and tests a series of hypotheses through a choice experiment exercise ran on a sample of 231 firms in six EU countries. The results showed that SMEs prefer networks that are composed of manufacturers and supply chain members, where information is shared confidentially among network partners, and when the network provides support to help the firm build its own networks of partners for innovation. In addition, SMEs' choice of the network is also affected by the interaction between specific network attributes and two firm characteristics, i.e. the firm's collaborative experience and innovation objectives. Based on the results, we conclude that the success of inter‐organizational networks depends on the fit between the network's design and the innovation and networking behaviour of the firms.     

Global Evaluation of Energy in Hybrid M-HTFC/MGT Systems in Cogenerative Arrangement

This work concerns the study of HSs （Hybrid Systems） that are made up of the integration of M-HTFC （Medium and High Temperature Fuel Cell） and MGT （Micro-Gas-Turbine）. Different typologies of hybrid systems are taken into account, which differ from each other in their plant layouts. The plants are considered in cogenerative arrangement. The aim of this study is to carry out an energetic analysis of the HS considered to obtain an analytical expression to depict the system operating in cogenerative arrangement. An energetic comparison among the systems analyzed based on some indexes is effected, which allows an evaluation of the plants performances in cogenerative arrangement. An energetic analysis is carried out, which is based on a ＂black box＂ depiction of the plant in which the components and the mutual interactions are highlighted. The fuel cell component of the plant is not analyzed as a black box, but each element that constitutes it, is elaborated as a subsystem.     

Furan and 5-hydroxymethylfurfural removal from high- and low-moisture foods

Foods with different moisture and fat contents (i.e. meat sauce and biscuits) were subjected to treatments at 4, 12 and 19 kPa for increasing lengths of time to remove furan and 5-hydroxymethylfurfural (HMF). The vacuum treatments were ineffective in removing HMF from both food types, as well as furan from the biscuits, unless this food was preliminary hydrated at high water activity. However, the vacuum treatments allowed furan to be removed from the high moisture food. In particular, 67% furan removal from the meat sauce was achieved by applying 12 kPa for 10 min. Sensory analysis results showed that meat sauce subjected to such a treatment presented the same odor intensity of the untreated sample. The post-process vacuum treatment could represent a reliable strategy to mitigate the furan levels in high moisture foods.     

An Analysis of Language in University Students' Text Messages

Concerns over effects of ‘textisms’ on literacy have been reinforced by research identifying processing costs associated with reading textisms. But to what extent do such studies reflect actual textism use? This study examined the textual characteristics of 936 text messages in English (13391 words). Message length, nonstandard spelling, sender and message characteristics and word frequency were analyzed. The data showed that 25% of word content used nonstandard spelling, the most frequently occurring category involving omission of capital letters. Types of nonstandard spelling varied only slightly depending on the purpose of the text message, while the overall proportion of nonstandard spelling did not differ significantly. Less than 0.2% of content was ‘semantically unrecoverable.’ Implications for experimental studies of textisms are discussed.     

Three-dimensional fuzzy graphene ultra-microelectrodes for subcellular electrical recordings

Microelectrode arrays (MEAs) have enabled investigation of cellular networks at sub-millisecond temporal resolution. However, current MEAs are limited by the large electrode footprint since reducing the electrode's geometric area to sub-cellular dimensions leads to a significant increase in impedance thus affecting its recording capabilities. We report a breakthrough ultra-microelectrodes platform by leveraging the outstanding surface-to-volume ratio of nanowire-templated out-of-plane synthesized three-dimensional fuzzy graphene (NT-3DFG). The enormous surface area of NT-3DFG leads to 140-fold reduction in electrode impedance compared to bare Au microelectrodes, thus enabling scaling down the geometric size by 625-fold to ca. 2 μm × 2 μm. The out-of-plane morphology of NT-3DFG leads to a tight seal with the cell membrane thus enabling recording of electrical signals with high signal-to-noise ratio (SNR) of > 6. This work highlights the possibility to push the limits of the conventional MEA technology to enable electrophysiological investigation at sub-cellular level without the need of any surface coatings. This presented approach would greatly impact our basic understanding of signal transduction within a single cell as well as complex cellular assemblies.

     

The importance of geographical distance to different types of R&D collaboration in the pharmaceutical industry

ABSTRACT

Innovation within companies is generated by a combination of different types of knowledge from external and geographically dispersed sources. Although the geographical dimension of collaboration has previously been investigated, studies have not distinguished between different types of knowledge involved in collaboration. This article analyses how the number of collaborations between pharmaceutical multinational companies (MNCs) and external organizations is affected by geographical distance, distinguishing between four knowledge types: basic science, clinical science, core knowledge, and exploration knowledge. We use co-publications as a proxy for collaborations. Our results show that collaborations in basic science and core knowledge areas are more negatively affected by geographical distance than collaborations within clinical science and exploration knowledge areas. This suggests that the importance of geographic proximity depends on the type of knowledge that is being transferred in R&D collaborations. Our results have implications for companies´ collaboration strategies and their choices for the R&D sites´ location.     

Biogenic amine production by Oenococcus oeni during malolactic fermentation of wines obtained using different strains of Saccharomyces cerevisiae

Twenty-six wild Oenococcus oeni strains were investigated for their ability to form biogenic amines during malolactic fermentation in synthetic medium and in wine. Eight strains produced histamine and tyramine in screening broth at concentrations of 2.6-5.6 mg/L and 1.2-5.3 mg/L, respectively. Based on their ability to form biogenic amines, five strains were selected to inoculate three wines obtained by the fermentation of three different Saccharomyces cerevisiae strains (A, B, and C). All bacterial strains could perform malolactic fermentation for short periods in wine C, whereas only one strain performed complete malolactic fermentation in wines A and B. Two O. oeni strains (261 and 351) produced histamine and tyramine in wine C. Time-course analysis of these compounds showed that for both strains, histamine and tyramine production began at day 10 and finished on day 25, after the end of malolactic fermentation. These results indicate that the ability of O. oeni to produce histamine and tyramine is dependent on the bacterial strain and on the wine composition, which in turn depends on the yeast strain used for fermentation, and on the length of bacteria-yeast contact time after the completion of malolactic fermentation.