Lacunarity of Fractal Superlattices: a Remote Estimation using Wavelets

The lacunarity provides a useful parameter for describing the distribution of gap sizes in discrete self-similar (fractal) superlattices and is used in addition to the similarity dimension to describe fractals. We show here that lacunarity, as well as the similarity dimension, can be remotely estimated from the wavelet analysis of superlattices impulse response. As a matter of fact, the skeleton—the set of wavelet-transform modulus-maxima—of the reflected signal overlaps two hierarchical structures in the time-scale domain: such that one allows the direct remote extraction of the similarity dimension, while the other may provide an accurate estimation of the lacunarity of the interrogated superlattice. Criteria for the choice of the mother wavelet are established for impulse response corrupted by additive Gaussian white noise

A simple and rapid device for measuring planktonic primary production by in situ sampling, and 14C injection and incubation

A system (LET GO) is described that enables measurements of primary production at sea after #in situ incubation, with 14C being injected at depth immediately after enclosure of the sample. Each incubation cell, about 200 ml, is made of two transparent plexiglass cups facing each other. Mechanical energy to operate the system is provided by the tension of the nylon line between the drifting buoy, which holds the experimental equipment, and a weight at the bottom : when the line is strained, the two cups enclose the water sample, and the 14C is delivered by a syringe. Absence of metallic or rubber parts ensures that toxicity effects are minimized and that reliable results can be expected. Furthermore, #in situ incubations can start 1 or 2 min after arrival on station, leaving the research vessel and winches available for other tasks. These points make it possible to make #in situ$ 14C incubations during most oceanographic cruises and to increase greatly the acquisition rate of primary production data. The LET GO device has been tested in parallel with the conventional technique. Both techniques showed similar vertical patterns. Carbon fixation measured with the LET GO, however, was greater by a factor 1.3. (Résumé d'auteur

Sex, aggression and pair-bond : a study on the serotonergic regulation of female sexual function in the marmoset monkey

Women diagnosed with a sexual dysfunction often suffer from marked distress and interpersonal difficulty that arise from unwanted, persistent or recurrent low sexual desire (hypoactive sexual desire disorder, HSDD). An imbalance of excitatory and inhibitory neurotransmitters has been proposed to underlie certain forms of HSDD. Serotonin (5-HT) is a key neurotransmitter involved in female sexual inhibition. Animal studies that apply 5-HT receptor subtype specific ligands permit mechanistic examination of 5-HT mediated effects on sexual behavior. The aim of this thesis was to investigate the serotonergic regulation of female sexual behavior in the common marmoset (Callithrix jacchus), a nonhuman primate that is characterized by a pairmate social setting comparable to humans. The experimental agents employed in the study were (1) flibanserin, a 5-HT1A agonist, 5-HT2A antagonist and putative pharmacotherapeutic treatment for HSDD in women, and (2) 8-OH-DPAT, a prototype 5-HT1A agonist. Neuroendocrine, PET imaging and genetic experiments were conducted to explore hormonal, brain activity and gene expression patterns that underlie female sexual behavior. While flibanserin, administered daily to the female for several weeks, enhanced the male pairmate’s sexual interest and increased pro-social interactions between pairmates, 8-OH-DPAT reduced female sexual receptivity and increased aggressive interactions between pairmates. HPA responses to restraint stress were enhanced after both flibanserin and 8-OH-DPAT. Furthermore, 8-OH-DPAT treated females showed reduced glucose uptake to the medial occipital cortex that correlated with sexual rejection behavior, while gene transcription of the serotonin transporter in the dorsal raphé nucleus, and of oxytocin in the medial preoptic area of the hypothalamus, was increased. Gene cluster analysis of microarray data indicated brain region-specific alterations in neural development, neurotransmission and energy production after 8-OH-DPAT. The results presented in this thesis demonstrate that pair-bond quality between partners and sexual behavior are closely linked and suggest that oxytocin may be the pivot of serotonergic regulation of female sexual behavior, pair-bond and pharmacotherapy of HSDD.Boehringer Ingelheim; Reseach Facilities Improvement Program, National Institutes of Health, U.S.A.; Netherlands Organization for Scientific Research (NWO); Royal Netherlands Academy of Arts and Sciences (KNAW

Sublogarithmic uniform Boolean proof nets

Using a proofs-as-programs correspondence, Terui was able to compare two models of parallel computation: Boolean circuits and proof nets for multiplicative linear logic. Mogbil et. al. gave a logspace translation allowing us to compare their computational power as uniform complexity classes. This paper presents a novel translation in AC0 and focuses on a simpler restricted notion of uniform Boolean proof nets. We can then encode constant-depth circuits and compare complexity classes below logspace, which were out of reach with the previous translations.Comment: In Proceedings DICE 2011, arXiv:1201.034

Oil slicks : food safety issues

This article reviews current knowledge on food hazards associated with hydrocarbons and maximum permissible levels. The French sea food safety administration is presented. Finally, the management of the oil slicks and their outcome in France at the end of 1999 and in 2002 are described.Les auteurs résument l'état actuel de nos connaissances sur les risques alimentaires liés aux hydrocarbures et les seuils réglementaires adoptés en conséquence. L'organisation administrative française pour le contrôle de la salubrité des denrées animales issues de la mer est ensuite présentée. Enfin, les modalités et les résultats de la gestion des épisodes de marée noire survenus en France fin 1999 et 2002 sont décrits

Ten Years of Valuation of the Local Impact of Atmospheric Pollution: from Scientific Assessments to Political Decisions

This paper focuses on the economic valuation of the impact of local air pollution. Two main issues are considered: 1. The scientific issue: what is estimated, how and why? The main studies from the nineties are presented here. Two strong issues are stressed, with the diversity of valuation methods, on the one hand, and the debates on how to take the long term into account and the discount technique, on the other. 2. The political issue: how the results from the economic field are analysed and used to establish official values for public policies? The methods used in the transport sector in three different European countries (France, Sweden and Switzerland) are studied here.To conclude, we highlight the discrepancy between these two processes and, wherever possible, offer solutions to reach better synergy.Local air pollution ; External costs ; Economic valuation ; Official values ; Public decision ; International comparison

Les exploitations agricoles en difficulté : un aspect de la pauvreté en agriculture ?

Diffusion du document : INRA Station d'Economie et Sociologie rurales 65 rue de Saint-Brieuc 35042 Rennes Cedex (FRA)Le concept. de "pauvreté" ne fait pas partie de ceux que nous avons utilisés couramment. dans les recherches menées jusqu’à présent Les travaux que nous réalisons depuis quelque temps sur l'analyse des mécanismes de financement des exploitations agricoles nous conduisent à mettre en évidence de fortes inégalités dans l'agriculture, inégalités qui sont au cœur du processus de modernisation du secteur.Des disparités constatées dans le domaine de financement, il est possible de passer à celles qui existent sur le plan des revenus et de la consommation. on peut même dire que nous sommes confrontés en permanence à la question : quelle incidence les disparités relevées dans l'accumulation du capital en agriculture, ont-elles sur la vie des familles d'agriculteurs

Effects of constant infusion with insulin-like growth factor-I (IGF-I) to immature female rats on body weight gain, tissue growth, and sexual function: Evidence that such treatment does not affect sexual maturation or fertility

Plasma levels for insulin-like growth factor-I (IGF-I) steadily increase in female rats between 20 and 40 d of life, and this increase is intimately related to the wellknown growth spurt occurring at this age. Since specific actions of IGF-I related to sexual function have been described at the ovarian and hypothalamic levels, an endocrine role of rising circulating IGF-I levels during sexual maturation cannot be excluded. Therefore, the impact of adult-type plasma IGF-I levels during the juvenile age, on body weight (BW) gain, growth of several organs, sexual development, and fertility has been evaluated. Female Sprague-Dawley rats were infused with rhIGF-I (2 and 4 μg/g BW/d, using Alzet minipumps), between 20 and 41 d of life. When infusing 2 μg/g BW/d, plasma levels for IGF-I were increased 1.5- to 2-fold over controls at all ages studied. They were further increased with the higher dosage, but only after 35 d of age. Plasma levels for insulin-like growth factor binding protein (IGFBP)-1 to-3 were clearly increased. BW gain was significantly increased, but only with the higher dosage. Tail length was never modified. In contrast, a growth acceleration for spleen, kidneys, adrenals, and ovaries was observed with both dosages. The ovarian weight of treated animals represented approx 140% of control animals with the 4 μg/g BW/d dosage. Histology of the enlarged ovaries did not reveal any abnormalities. No meaningful modification of the timing of vaginal opening was observed, and fertility was not compromised by previous rhIGF-I infusion during the 20-41 d age period. In summary, early exposure to increased (adult-like) plasma IGF-I levels did not modify BW gain or tail length, but affected the development of spleen, kidneys, adrenals, and ovaries. Exposure to supraphysiological plasma IGF-I levels (>1200 ng/mL), accelerated BW gain and increased the weight of all organs studied. No signs of precocious sexual maturation were seen and fertility was normal. In conclusion, prematurely increased plasma IGF-I levels affected somatotropic parameters, but not the onset of sexual functio