Novel Real-Time PCR Method To Detect Escherichia coli O157:H7 in Raw Milk Cheese and Raw Ground Meat

Raw milk, raw milk cheeses, and raw ground meat have been implicated in Escherichia coli O157:H7 outbreaks. Developing methods to detect these bacteria in raw milk and meat products is a major challenge for food safety. The aim of our study was to develop a real-time PCR assay to detect E. coli O157:H7 in raw milk cheeses and raw ground meat. Well-known primers targeting a mutation at position +93 of the uidA gene in E. coli O157:H7 were chosen, and a specific TaqMan-minor groove binder probe was designed. This probe targets another mutation, at position +191 of the uidA gene in E. coli O157:H7. The first step in the study was to evaluate the specificity of this probe with 156 different O157:H7/NM strains and 48 non-O157:H7/NM strains of E. coli. The sensitivity of the method was evaluated by pre- and postinoculation of cheeses and meat enrichments with different E. coli O157:H7 strains. All the E. coli O157:H7 isolates tested were positive, and none of the other bacteria were detected. Our results indicate that this method is sensitive enough to detect 10(2) E. coli O157:H7 isolates per ml of cheese or meat enrichment broth (24 h at 41.5° C) and is more sensitive than the International Organization for Standardization reference method. We can conclude that this new real-time PCR protocol is a useful tool for rapid, specific, and sensitive detection of E. coli O157:H7 in raw milk and raw ground meat products.     

Sourdough fermentation of wheat fractions rich in fibres before their use in processed food

Fibre‐rich fractions of wheat are an important source of minerals but also contain considerable amounts of phytic acid, known to impair mineral absorption. This study explores the efficiency of wheat bran sourdough fermentation on phytate hydrolysis and mineral solubility, in comparison with whole‐wheat flour. In vitro trials were performed to assess the consequences of the addition of calcium carbonate (CaCO₃), an alkalinising salt, on phytic acid breakdown and mineral bioavailability during sourdough fermentation. Sourdough fermentation was found effective for solubilising minerals in whole‐wheat flours but was less effective with bran. In addition, sourdough acidity was blunted by the addition of CaCO₃, whereas degradation of phytic acid remained effective. Despite extensive breakdown of phytic acid (almost 70%), the addition of calcium exerted a very negative effect on zinc solubility. In conclusion, a pre‐fermentation process of whole cereals or bran, in suitable conditions of hydration, allows degradation of the major part of phytic acid and optimal mineral bioavailability. Copyright © 2007 Society of Chemical Industry     

uSafe: A privacy-aware and participative mobile application for citizen safety in urban environments

Recent mobile applications empower citizens to monitor noise pollution or report on features of their urban environment. One important aspect of urban life has, however, not been sufficiently addressed, namely the safety of citizens. We present a privacy-aware application called uSafe, in which users indicate how safe they feel in geographical locations. These feelings are then consolidated into summary maps accessible by other users and urban planners. We evaluate our concept with a questionnaire-based study involving 183 participants. The results confirm the utility of uSafe and show that privacy protection is a decisive factor in their decision to contribute to it.     

Curved focal plane detector array for wide field cameras

Miniaturization is the main goal for system design in future cameras. This paper offers a novel method to scale down the optical system and to improve the image quality. As with the human retina, the detector array is spherically bent to fit the curved image surface; so the field curvature aberration is directly suppressed, leading to a better resolution and a simplified optical design. By thinning the substrate, the device is monolithically curved without modifying the fabrication process of the active pixels. Optical characterizations have been performed on planar and curved focal plane based cameras to illustrate the optical advantages of detector array curvature.     

Synthesis, electron tomography and single-particle optical response of twisted gold nano-bipyramids

A great number of works focus their interest on the study of gold nanoparticle plasmonic properties. Among those, sharp nanostructures appear to exhibit the more interesting features for further developments. In this paper, a complete study on bipyramidal-like gold nanostructures is presented. The nano-objects are prepared in high yield using an original method. This chemical process enables a precise control of the shape and the size of the particles. The specific photophysical properties of gold bipyramids in suspension are ripened by recording the plasmonic response of single and isolated objects. Resulting extinction spectra are precisely correlated to their geometrical structure by mean of electron tomography at the single-particle level. The interplay between the geometrical structure and the optical properties of twisted gold bipyramids is further discussed on the basis of numerical calculations. The influence of several parameters is explored such as the structural aspect ratio or the tip truncation. In the case of an incident excitation polarized along the particle long axis, this study shows how the plasmon resonance position can be sensitive to these parameters and how it can then be efficiently tuned on a large wavelength range.     

Investigation of steel corrosion in MX80 bentonite at 120°C

Corrosion experiments were performed on two metallic substrates, a ferritic–pearlitic steel (P285NH) and a ferritic one (Armco), in silicate environment during 30 days at 120°C. Corrosion products were characterized in terms of morphology (scanning electron microscope and transmission electron microscopy), composition (energydispersive X-ray spectroscopy) and structure (µ-Raman, selected area electron diffraction, X-ray absorption near edge structure). Results show a nanometric inner layer made of compact and adherent nanocrystallized magnetite with, locally a thickness up to several micrometers due to the metal microstructure. An outer layer of Fe-rich phyllosilicate, smectite and serpentine, more porous than the inner one and poorly adherent is observed around both the samples.     

Easy methods for the electropolymerization of porphyrins based on the oxidation of the macrocycles

Two different methods of electropolymerization of porphyrins have been investigated and compared. They consist in the nucleophilic attack of Lewis bases onto electrogenerated dications of octaethylporphyrins. In the first method, a nucleophilic group has been directly grafted onto the macrocycle (ZnOEP-meso-bpy⁺), while in the second one, free di-nucleophilic compounds (Nu–Nu) have been used in presence of a non-substituted porphyrin (ZnOEP). The advantage of the second method is to easily modify the nature of the bridging spacer between the macrocycles. Characterizations of the polymer obtained from the second method in the case of dipyridinium-tetrazine spacer are presented.     

Increasing emotional competence improves psychological and physical well-being, social relationships, and employability.

This study builds on earlier work showing that adult emotional competencies (EC) could be improved through a relatively brief training. In a set of 2 controlled experimental studies, the authors investigated whether developing EC could lead to improved emotional functioning; long-term personality changes; and important positive implications for physical, psychological, social, and work adjustment. Results of Study 1 showed that 18 hr of training with e-mail follow-up was sufficient to significantly improve emotion regulation, emotion understanding, and overall EC. These changes led in turn to long-term significant increases in extraversion and agreeableness as well as a decrease in neuroticism. Results of Study 2 showed that the development of EC brought about positive changes in psychological well-being, subjective health, quality of social relationships, and employability. The effect sizes were sufficiently large for the changes to be considered as meaningful in people's lives. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Key Resources and Internationalization Modes of Creative Knowledge‐Intensive Business Services: The Case of Design Consultancies

In the ‘knowledge economy’, knowledge‐intensive business services (KIBS) are a key driver for innovation and competitiveness. The internationalization of these businesses raises challenges given their specificities such as knowledge intensity, the importance of customer interaction and intimacy in service delivery. This paper focuses on design consultancies as a specific type of creative KIBS for which these characteristics are emphasized. The objective of this research is to analyse the resources leveraged by the firms to compete internationally. It is based on 11 case studies of design consultancies located in five different countries (France, Italy, Portugal, Spain and the UK) that were selected for their capacity to perform at the international level for several years. The paper advances three internationalization modes depending on contingent variables and focusing on specific resources that enable international competitiveness: star‐based, process‐based and glocality‐based. In star‐based creative KIBS, the individual designer has developed a reputation that attracts customers internationally, operating as a brand. In process‐based creative KIBS, the reputation of a collective creative process attracts clients from other countries. In glocality‐based creative KIBS, the geographical proximity obtained by opening international offices helps to develop a close understanding of the client through frequent interactions, and also to know the client's market well and to better understand local codes and signs. These modes complement those presented in the existing internationalization literature which takes the peculiarities of creative KIBS into consideration.     

Adaptive control scheme for uncertain time-delay systems

The paper exposes some of the potential of a recently introduced backstepping transformation for linear uncertain time-delay systems to address the classic problems of equilibrium regulation under partial measurements, disturbance rejection, parameter or delay adaptation. For each of these problems, an implementable control strategy is proposed. It is analyzed through a convergence analysis of infinite dimensional dynamics, based on a transport partial differential equation representation of the estimated input delay and the mentioned backstepping transformation. The considered controllers contain this representation of the system, under the form of a distributed parameter system, and use it to determine relevant adaptation strategies. An illustration example is proposed.