Images out of water : aspects of the interpretation of Ancient maritime grafitti

Pictorial graffiti representing ships from prehistory, protohistory and the early medieval period are frequently examined by nautical historians and archaeologists seeking information about ancient ship technology. Examples of the academic discussion and interpretation of these images may be found from the nineteenth century to the present day, in a wide range of studies. Many of these works reflect their writers' casual, even disdainful attitudes to ancient graffiti. This may be seen in their approach to the information which these images appear to contain, which may concentrate, for example, on the certain aspects of particular subjects without reference to details in their immediate or wider contexts, which may have a bearing on the images' form and meaning. In a similar vein, other writers have interpreted ancient ship graffiti using concepts of art, such as the assumption of realism of depiction, which may be inappropriate to some early visual imagery. This thesis argues that ancient ship graffiti need a more detailed and systematic interpretation as both art and artefact before their contribution to nautical history may be more reliably evaluated. In order to explore the many challenges which these graffiti offer, a multi-disciplinary approach is used, to consider aspects of the relationship between formal art and graffiti, the psychology of image making, symbolism, the philosophy of interpretation, archaeology, and the social meaning of physical context. Following these theoretical discussions, five case studies from a number of different regional and chronological groups have been chosen to provide some examples of many of the issues which were considered. It is hoped that this study demonstrates that an approach to the interpretation of ancient ship graffiti which avoids a narrow concentration on nautical technology may reveal more of their potential as evidence, not only for the form and use of early ships, but also for other aspects of life in the past

Contribution of sleep research to the development of new antidepressants

Several sleep anomalies are known to accompany depression and other psychiatric disorders, and to be partially modified by drugs efficient on clinical symptoms. Many puzzling theoretical questions remain, even after 30 years of research, because these drugs do not act in a uniform way: some reduce slow-wave sleep while others increase it; some prolong rapid-eye movement sleep latency while others do not. The relationship between insomnia and depression is likely to be a close one, since a large majority of patients with depression suffer insomnia, and that insomnia can predate depression by a few years. However, questions remain here, too, since sleep deprivation is also an effective means to combat depression, and some patients present with hypersomnia rather than insomnia. This review details the action of all current classes of antidepressants on sleep. It examines the predictive value of baseline electronencephalographic sleep symptoms or early modifications due to treatment for eventual clinical efficiency. We will also discuss the two main theories on the relationship between sleep and depression. The action on sleep of all new drugs- and antidepressants in particular - is carefully examined during development, for insomnia is currently considered to be a major health concern in industrialized countries

Jet Lag

This chapter describes the phenomenon of Jet Lag and the symptoms associated with it, which vary not only from person to person, but also according to how many times zones are crossed, and in which direction. Homeostatic and circadian influences on sleep and vigilance are explained on the basis of Borbély’s two-process model. Jet Lag is reasonably well explained scientifically today: rapid changes of time zones disturb the functioning of the body clock, which remains stubbornly set on departure times for a while. This can make sleep shallow or non-existent for substantial parts of the night while vigilance is less than optimal during parts of the day. Two main lines of research are described: one endeavors to accelerate the adaptation process; the other helps to fight insomnia and sleepiness between arrival and adjustment to the new time zone. Besides practical things that can be done to reduce the burden of Jet Lag, the adjustment process can be speeded up using bright light and melatonin. Sleeping pills and neurostimulants may be added to compensate for insomnia and sleepiness

The Role of Consumer-based Fashion Equity in Developing Loyalty to Luxury Fashion Products in France

Fashion and luxury represent long-term forces for many French businesses. These forces rely on products changing very often, and on people renewing their wardrobe following the new trends. Hence, the adoption of fashion products raises questions about why and how products appeal to followers, despite their constantly varying attributes. Little is known about how fashion trends may induce people to purchase luxury fashion products even in France where many luxury brands are from. This study argues that fashion supersedes product specificities; therefore, the proposed concept of consumer-based fashion equity may explain the value added by fashion to luxury products. Based on Keller’s (1993) conceptual model of brand equity and its adaptation to the concept of fashion, this study proposes a new model to explain loyalty to luxury fashion products. Through our qualitative study, values are identified and point out a new explanation on why French followers choose luxury fashion products, above and beyond their product characteristics. The findings suggest that managers may use fashion equity as a competitive advantage for the development of their luxury products and even develop loyalty towards them. Keywords: Fashion Equity, Luxury, Followers, Loyalty DOI: 10.7176/JMCR/81-02 Publication date:August 31st 202

Efferent controls in crustacean mechanoreceptors

International audienceSince the 1960s it has been known that central neural networks can elaborate motor patterns in the absence of any sensory feedback. However, sensory and neuromodulatory inputs allow the animal to adapt the motor command to the actual mechanical configuration or changing needs. Many studies in invertebrates, particularly in crustacea, have described several mechanisms of sensory-motor integration and have shown that part of this integration was supported by the efferent control of the mechanosensory neurons themselves. In this article, we review the findings that support such an efferent control of mechanosensory neurons in crustacea. Various types of crustacean proprioceptors feeding information about joint movements and strains to central neural networks are considered, together with evidence of efferent controls exerted on their sensory neurons. These efferent controls comprise (1) the neurohormonal modulation of the coding properties of sensory neurons by bioamines and peptides; (2) the presynaptic inhibition of sensory neurons by GABA, glutamate and histamine; and (3) the long-term potentiation of sensory-motor synapses by glutamate. Several of these mechanisms can coexist on the same sensory neuron, and the functional significance of such multiple modulations is discussed

Triple transitivity and non-free actions in dimension one

We show that if $G$ is either: (1) a group of homeomorphisms of the circle such that the action of $G$ on $S^1$ is minimal, proximal, non-topologically free and satisfies some mild assumption; (2) a group of automorphisms of a tree $T$ such that the action of $G$ on the boundary $\partial T$ is minimal and non-topologically free; then the following holds: every 3-transitive faithful action of $G$ on a set is conjugate to the action on an orbit in $S^1$ or $\partial T$. As a corollary, we obtain sharp upper bounds for the transitivity degree of these groups. These results produce new classes of infinite groups whose transitivity degree is known. In the Appendix we show that if a group satisfies a non-trivial mixed identity, then either it contains a normal subgroup isomorphic to a finitary alternating group, or it has finite transitivity degree.Comment: 26 pages. v1-> v2: addition of an appendix and some minor correction

A commutator lemma for confined subgroups and applications to groups acting on rooted trees

A subgroup $H$ of a group $G$ is confined if the $G$-orbit of $H$ under conjugation is bounded away from the trivial subgroup in the space $\operatorname{Sub}(G)$ of subgroups of $G$. We prove a commutator lemma for confined subgroups. For groups of homeomorphisms, this provides the exact analogue for confined subgroups (hence in particular for URSs) of the classical commutator lemma for normal subgroups: if $G$ is a group of homeomorphisms of a Hausdorff space $X$ and $H$ is a confined subgroup of $G$, then $H$ contains the derived subgroup of the rigid stabilizer of some open subset of $X$. We apply this commutator lemma to the study of URSs and actions on compact spaces of groups acting on rooted trees. We prove a theorem describing the structure of URSs of weakly branch groups and of their non-topologically free minimal actions. Among the applications of these results, we show: 1) if $G$ is a finitely generated branch group, the $G$-action on $\partial T$ has the smallest possible orbital growth among all faithful $G$-actions; 2) if $G$ is a finitely generated branch group, then every embedding from $G$ into a group of homeomorphisms of strongly bounded type (e.g. a bounded automaton group) must be spatially realized; 3) if $G$ is a finitely generated weakly branch group, then $G$ does not embed into the group IET of interval exchange transformations.Comment: 48 pages. v1->v2: minor revisio