Reproducing the Higgs boson data with vector-like quarks

Vector-Like (VL) quarks arise in the main alternatives to the supersymmetric extensions of the Standard Model (SM). Given the experimental possibility of a 125 GeV Higgs boson with rates significantly different from the SM expectations, it is motivating to study the effects of VL quarks on the Higgs boson cross sections and branching ratios. We perform a systematic search for the minimal field contents and gauge group representations of VL quarks able to significantly improve the fit of the measured Higgs rates, and simultaneously, to satisfy the direct constraints on VL quark masses as well as the electro-weak precision tests. In particular, large enhancements can be achieved in certain diphoton channels - as pointed out by both the ATLAS and CMS Collaborations - optimizing then the Higgs rate fit. This is a consequence of the introduction of VL quarks, with high electric charges of 8/3 or -7/3, which are exchanged in the Higgs-to-diphoton loop. Interestingly, the field contents and formal Higgs couplings obtained here are similar to those of scenarios in warped/composite frameworks arising from different motivations. The various exotic-charge quarks predicted, possibly below the TeV scale, might lead to a rich phenomenology soon at the LHC.Comment: 11 pages, 4 figure

Salivary biomarker development using genomic, proteomic and metabolomic approaches.

The use of saliva as a diagnostic sample provides a non-invasive, cost-efficient method of sample collection for disease screening without the need for highly trained professionals. Saliva collection is far more practical and safe compared with invasive methods of sample collection, because of the infection risk from contaminated needles during, for example, blood sampling. Furthermore, the use of saliva could increase the availability of accurate diagnostics for remote and impoverished regions. However, the development of salivary diagnostics has required technical innovation to allow stabilization and detection of analytes in the complex molecular mixture that is saliva. The recent development of cost-effective room temperature analyte stabilization methods, nucleic acid pre-amplification techniques and direct saliva transcriptomic analysis have allowed accurate detection and quantification of transcripts found in saliva. Novel protein stabilization methods have also facilitated improved proteomic analyses. Although candidate biomarkers have been discovered using epigenetic, transcriptomic, proteomic and metabolomic approaches, transcriptomic analyses have so far achieved the most progress in terms of sensitivity and specificity, and progress towards clinical implementation. Here, we review recent developments in salivary diagnostics that have been accomplished using genomic, transcriptomic, proteomic and metabolomic approaches

European Marine Sand and Gravel Resources: Evaluation and environmental impacts of extraction - an introduction

Marine aggregates (sand and gravel) have emerged as a strategic mineral resource; this is due to an increasing general demand and to stricter regulations on the exploitation of landwon aggregates, in EU Member States. Annually, approx. 40 million m3 of marine sand and gravel are extracted, alone, from the North European inner (<60m water depth) continental shelf (www.sandandgravel.com/extraction). In the near future, the extraction will increase significantly, to provide vast quantities of material needed for the realisation of large-scale infrastructure projects, planned for Europe’s coastal areas; this is combined with the burgeoning general urbanisation of the coastal zone. At the same time, European coastal zones are under increasing pressure from coastal erosion. Thus, beach replenishment and other coastal defence schemes, requiring large quantities of suitable aggregate material, are necessary to manage such coastal retreat and accommodate the development (SELBY and OOMS, 1996; HUMPHREYS et al., 1996).Such increasing demand, together with the conservation of coastal ecosystems and diverse stakeholders’ interests, require that resource sustainability, environmental prudence and careful management are crucial components of the practice and regulation of marine aggregate operations. There is an urgent need for integrated and coherent approaches to the effective prospecting of commercially-viable marine sand and gravel deposits, the development of a science-based approach to their sustainable management, together with an environmental impact assessment of their exploitation. Such objectives require an interdisciplinary approach, to develop a thorough understanding of the sedimentary, hydrodynamic and ecological conditions of the inner continental shelf and adjacent coasts. Likewise, the use of ‘state-of-the-art’ approaches and instrumentation is needed.The main objectives of the RTN project EUMARSAND were: (a) to train young European researchers in individual research approaches; and (b) to provide them with an integrated and balanced view of the diverse and complex issues involved, through the application of a wide range of scientific approaches. As such, close co-operation between marine geologists, biologists, hydrodynamic and morphodynamic modellers and coastal engineers was established. The task of such a grouping was to integrate the research approaches involved in marine aggregate prospecting. Likewise, the undertaking of the assessment of the environmental impacts of offshore mining activities, using ‘state-of-the-art’ approaches and instrumentation.Nine Partners, from 8 countries, have been involved in the project, as listed in Table 1

The Copy & The Real Thing: Changing Perceptions Between the Rubens Centennials in 1877 and 1977

In this paper I examine the changing relationship between mechanical reproductions and the original artwork in the context of the Rubens centennials in 1877 and 1977. Drawing on theorists such as Walter Benjamin, Dean MacCannell, Hans Belting and Boris Groys, I argue that the mechanism of copying generates a double logic of image perception: a simultaneous centrifugal and centripetal circulation of images that affects how people perceive art in modern society. I explore this perception dynamic by looking at two photo-exhibitions during the Rubens centennials

Rubens in the age of mechanical reproduction : the oeuvre of Peter Paul Rubens in illustrated art books, film and television (1877-1977)

Photographic and cinematic reproductions mediate our understanding of art. Acting as a learning tool, a stand-in for the original or a souvenir, it is impossible to think of art history without them. Unfortunately, there is a lack of critical approach toward these images. It is often overlooked how mechanical reproductions are unique interpretations with specific dimensions, textures and colour tones, mediating the original material and creating another (hi)story of the authentic artwork. Besides, each reproduction is used within a narrative, depending on the function of the medium in which it occurs. These media should therefore be understood as curatorial spaces, with all the institutional consequences. The examination of the mechanical reproductions of the works by baroque painter Peter Paul Rubens between his 300th and 400th birthday celebrations (1877 – 1977) reveals a lot of the choices that were made in order to create a “good reproduction”. Drawing on the theoretical discourse initiated by leading scholars such as Erwin Panofsky, Walter Benjamin, André Malraux and John Berger, we can distinguish different strategies (succession, juxtaposition, isolation) in order to decompose the multiplicity of visualisations and narratives that are generated by a single artwork. Due to the monumentality of Rubens’ works, most reproductions are made in situ; therefore revealing technical challenges and subjective aesthetical choices. Close-ups, zooming and cut outs will be more commonly used than with easel paintings. Moreover, his triptychs question whether or not to reproduce the frame as part of the artwork. How do these choices and interventions alter the meaning of the original image? What remains of the ‘master of colour’ in a black and white reproduction? How are Rubens’ dynamic compositions transformed when put into motion by the camera? Can we distinguish an evolution in the Rubens reception by looking at the formal characteristics of reproduction media

Neuroplasticity induced by peripheral nerve stimulation

PhD ThesisNon-invasive methods have been developed to induce plastic changes in the sensorimotor cortex. These rely on stimulating pairs of afferent nerves. By associative stimulation (AS) of two afferent nerves, excitability changes in the motor cortex occur as indicated by studies reporting changes in motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS). Repetitive stimulation of those nerves has a potential in rehabilitation and treatment of neurological disorders like stroke or spinal cord injury. Despite promising results and applications in human subjects using these methods, little is understood about the underlying basis for the changes which are seen. In the present study, behavioural, electrophysiological and immunohistochemical assessments were performed before and after paired associative and non-associative (NAS) median and ulnar nerve stimulation. Two macaque monkeys were trained to perform a skilled finger abduction task using refined behavioural methods. Monkeys were not able to move their thumb and index finger as selectively after one hour of paired AS as indicated by an increased number of errors and decreased performance measures. NAS however decreased error numbers and led to increased performances. Additionally, I recorded from identified pyramidal tract neurons and unidentified cells in primary motor cortex (M1), in two macaque monkeys before and after one hour of AS (and NAS) of the median and ulnar nerve. Cell discharge was recorded in response to electrical stimulation of each nerve independently. Some cells in M1 showed changed firing rates in response to nerve stimulation after AS (and NAS). Subsequently, structural changes in response to one week of paired AS were investigated. The laminar-specific density of parvalbumin-positive interneurons, perineuronal nets and the colocalisation of these two entities changed on the stimulated (in comparison to the non-stimulated) sensorimotor cortex. These findings suggest that the sensorimotor cortex undergoes plastic changes in response to AS (and NAS).Wellcome Trus

Rubens’ musée imaginaire : utopic endeavors in overcoming the dispersion of the artist’s oeuvre through the use of mechanical reproductions

When we look at the exhibition catalogues made for the occasion of the 400th birthday celebration of the Belgian Baroque painter Peter Paul Rubens in 1977, the amount of exhibitions dedicated to, or using (engraved) reproductions reveals a problem that goes back to the 17th century itself: Rubens’ oeuvre is – and has always been – dispersed over the European continent. The commissioned and often site-specific works became part of Royal, ecclesiastical and state collections. Therefore, it is impossible to get a full overview of the artist’s practice. André Malraux tackled this problem of art’s attachment to a specific place in Le Musée Imaginaire (1947). Through the use of mechanical reproductions, Malraux argued, all artworks, regardless of their location, material or size, could be brought together in one curatorial space, i.e. the art book. Rubens was the first to acknowledge the problem of the dispersion of his work. Through the foundation of a reproduction workshop, he was able to reach a larger audience and compare compositions that could never be seen together in real live. Ever since, there has been a desire to assemble Rubens’ oeuvre in one place. For the Rubens celebrations in 1877, the Belgian photographer Joseph Maes launched the idea to create an exhaustive photographical collection of the oeuvre. In 1938, the conservator of paintings at the Louvre, René Huyghe, used the possibilities of the art film as an alternative for traveling exhibitions in the context of Rubens et Son Temps (1936, Musée de l’Orangerie, Paris). These examples demonstrate how the Rubens reception has always depended on reproductions. As Barbara E. Savedoff argues, this dependence on the reproduced image – be it graphic, photographic or cinematic – inevitably alters the way we look at originals. Furthermore, reproductions appear in media, such as art books, film and television. Apart from text and sound, these media use different visual strategies (succession, juxtaposition, isolation), generating multiple visualizations and narratives of a single artwork. All these curatorial manifestations can be interpreted as musées imaginaires: utopic endeavors to assemble Rubens’ oeuvre in one “placeless place”. This contribution proposes an examination of the way Rubens’ oeuvre is represented, through the comparison of photographic and cinematic images in different media; drawing on theoretical discourses initiated by Erwin Panofsky, Walter Benjamin, André Malraux and John Berger, among others

Macrobenthos characteristics and distribution, following intensive sand extraction from a subtidal sandbank

Macrobenthic fauna are investigated, to establish the nature and vulnerability of benthic communities to aggregate mining on a subtidal sandbank, the Kwinte Bank, in the Southern Bight of the North Sea. Within the central part of this sandbank, a depression (5 m deep) has been created, as a result of 20 years of dredging over the same small area (1 km long and 700 m wide). Three stations were sampled within this central depression; two on the western border; and two to the east of the depression. Another station was sampled in a “non-exploited” area to the north of the depression. Four stations were sampled outside of the concession area, on the adjacent Middelkerke Bank. The hypothesis is tested as to whether or not the density, species richness, taxon and community composition do not differ, between the depression and the adjacent sites (with similar sediment composition) on top of the sandbank. In addition, it is examined whether these parameters differ between the depression and reference sites, at the adjacent undisturbed sandbank. Differences in density and species richness could not be detected, between the different locations. Compared to the reference stations at the Middelkerke Bank and locations next to the depression, crustaceans (amphipods and in particular Bathyporeia spp.) and echinoderms (Ophiura spp. and Echinocardium cordatum) were more abundant in the area of the depression, suggesting a higher similarity to the swale environment, than was the case previously. The observed trends were similar, for both of the sampling periods, February and November 2004. However, the species composition difference has been observed within the context of the wide range of species assemblages described earlier for the Kwinte Bank, together with other Belgian subtidal sandbanks. Sand extraction has created small-scale habitat differences on the Kwinte Bank, to which the benthic fauna have adjusted; however, this is not significant on a true larger scale of the sandbank system, one year after cessation of the intensive disturbance