Higher-order Laguerre-Gauss mode generation and interferometry for gravitational wave detectors

We report on the first experimental demonstration of higher-order Laguerre-Gauss (LGpl) mode generation and interferometry using a method scalable to the requirements of gravitational wave (GW) detection. GW detectors which use higher-order LGpl modes will be less susceptible to mirror thermal noise, which is expected to limit the sensitivity of all currently planned terrestrial detectors. We used a diffractive optic and a mode-cleaner cavity to convert a fundamental LG00 Gaussian beam into an LG33 mode with a purity of 98%. The ratio between the power of the LG00 mode of our laser and the power of the LG33 transmitted by the cavity was 36%. By measuring the transmission of our setup using the LG00, we inferred that the conversion efficiency specific to the LG33 mode was 49%. We illuminated a Michelson interferometer with the LG33 beam and achieved a visibility of 97%.Comment: 4 pages, 5 figure

Aging and Lexical Inhibition: The Effect of Orthographic Neighborhood Frequency in Young and Older Adults

The aim of this study was to examine whether the lexical inhibition underlying orthographic neighborhood effects in visual word recognition is changed with aging. To do so, orthographic neighborhood frequency was manipulated for French words that had either no higher frequency neighbor (e.g., taupe), or at least one higher frequency neighbor (e.g., the word loupe has two higher frequency neighbors, coupe and soupe). Young adults (mean age = 20.9 years) and older adults (mean age = 67.8 years) performed a standard lexical decision task. An interaction was found between age group and orthographic neighborhood frequency on word latencies. More precisely, an inhibitory effect of neighborhood frequency was observed for the young adults but not for the older ones. These data are consistent with the assumption of an age-related decline in lexical inhibition and activation. The findings are discussed in the framework of visual word recognition and agin

The Effect of the Balance of Orthographic Neighborhood Distribution in Visual Word Recognition

The present study investigated whether the balance of neighborhood distribution (i.e., the way orthographic neighbors are spread across letter positions) influences visual word recognition. Three word conditions were compared. Word neighbors were either concentrated on one letter position (e.g.,nasse/basse-lasse-tasse-masse) or were unequally spread across two letter positions (e.g.,pelle/celle-selle-telle-perle), or were equally spread across two letter positions (e.g.,litre/titre-vitre-libre-livre). Predictions based on the interactive activation model [McClelland & Rumelhart (1981). Psychological Review, 88, 375-401] were generated by running simulations and were confirmed in the lexical decision task. Data showed that words were more rapidly identified when they had spread neighbors rather than concentrated neighbors. Furthermore, within the set of spread neighbors, words were more rapidly recognized when they had equally rather than unequally spread neighbors. The findings are explained in terms of activation and inhibition processes in the interactive activation framewor

The Chemical Ecology of Benzoxazinoids

Benzoxazinoids are specialized metabolites that modulate plant physiology and plant interactions with their environment. In this review, we synthesize their multiple functions and ecological relevance. We first provide an overview of benzoxazinoid biosynthesis and highlight known regulatory elements involved in modulating their production. We then outline the role of benzoxazinoids in plant nutrition, vegetative and reproductive growth, and defense. We further summarize benzoxazinoid response to environmental factors such as temperature, drought, CO2, light, or nutrient levels and emphasize their potential role in tolerating abiotic stresses. Finally, we argue that benzoxazinoids act as a strong selective force on different trophic levels by shaping the plant interactions with microbes, insect herbivores, and competitor plants. Understanding the pivotal role of benzoxazinoids in plant biology is crucial to apprehend their impact on (agro)ecosystem functioning and diversity

Automated Colour Identification and Quantification in Children's Drawings of God

Colour is still a relatively neglected aspect in the study both of religious art and of children’s artistic expression of the divine. Our research addresses this important gap and adds to psychological research on religious representations and conceptualization of the divine. From drawings collected in four different cultural and religious environments: Japanese (Buddhism and Shinto), Russian-Buryat (Buddhism, Shamanism), Russian-Slavic (Christian Orthodoxy) and French-speaking Swiss (Catholic and reformed Christianity) we show that children often imagine and depict god using the same colours: primarily yellow and blue. Apparently, god is often imagined by children as light or in light (yellow) and dwelling in the sky (blue). These results parallel historical and religious studies showing that the light enjoys prominent and most powerful symbolism and association with the divine. Complementary analysis of possible effect of child’s age, gender, and schooling (religious or regular) did not affect the main result. This research also introduced a novel approach to data analysis by using computer vision in psychological studies of children’s drawings. The automated colour identification method was developed to extract colours from scans of drawings. Despite some difficulties, this new methodology opens an interesting avenue for future research in children’s drawings and visual art

Nouvelle méthode statistique pour l'analyse de données de ChIP-chip

International audienceLa méthode de Chromatin ImmunoPrecipitation on chip (ChIP on chip ou ChIP-chip) a pour but de détecter les sites de fixation des protéines (généralement des facteurs de transcription) sur la molécule d'ADN. L'analyse statistique des données consiste a rechercher des régions de pics significatifs synonymes de sites de fixation. La méthode que nous avons élaborée est issue de la théorie des valeurs extrêmes et particulièrement de la méthode POT (Peaks Over Threshold). Cette méthode consiste à modéliser les données de queues de distribution, en ne retenant que les valeurs dépassant un certain seuil, elle a la particularité de modéliser d'une part les intensités de dépassement de seuil, mais aussi les positions d'occurrences de ces dépassements de seuil. Cette méthode va nous permettre de déterminer un seuil au delà duquel les pics pourront être considérés comme significatifs

Cervical porcupine quill foreign body involving the spinal cord of a dog: a description of various imaging modality findings

Although porcupine quill injuries are common in dogs, the detailed appearance of the quill on diagnostic ultrasound, computed tomography, and magnetic resonance imaging has not been sufficiently described. A 4-year-old, intact, female Jack Russel terrier presented with severe neck pain and ataxia after an altercation with a porcupine 2 weeks earlier. Radiology, diagnostic ultrasound, computed tomography and magnetic resonance imaging were all utilised to identify a quill imbedded in the cervical vertebral canal and cervical musculature and were compared to each other. Surgical removal of the quill, guided by imaging findings, led to the resolution of the clinical signs in the patient. Previous ultrasound imaging reports have just stated that the quill consists of parallel hyperechoic lines, and do not mention the finer hyperechoic lines in between and do not try to provide a reason for the appearance. Previous computed tomography (CT) reports just mention identifying the quill on CT images (whether or not CT could identify the fragments), but do not go into detail about the attenuating appearance of the quill nor try to relate this to the composition of the quill. This is to the authors’ knowledge the first report with detailed imaging descriptions of a case of cranial cervical vertebral canal porcupine quill foreign body in a dog. This is also the first report to allude to a possible difference in imaging findings related to quill structure because of keratin orientation and melanin content. The ideal imaging modality to use remains elusive, but ultrasound, computed tomography and magnetic resonance imaging could all identify the quill

Testing predictions on body mass and gut contents: dissection of an African elephant Loxodonta africana Blumenbach 1797

The values reported in the literature for the total gastrointestinal tract (GIT) content mass of elephants are lower than expected from interspecific mammalian regression. This finding agrees with theoretical considerations that elephants should have less capacious GITs than other herbivorous mammals, resulting in short ingesta retention times. However, the data on elephants was so far derived from either diseased zoo specimens or free-ranging animals subjected to an unknown hunting stress. In this study, we weighed the wet contents of the GIT segments of a captive African elephant that was euthanased because of a positive serological tuberculosis test, but that was clinically healthy, did not show a reduced appetite, and ingested food up to the time of euthanasia. The animal weighed 3,140kg and its total gut contents were 542kg or 17% of body mass. This is in close accord with the published mammalian herbivore regression equation of Parra (Comparison of foregut and hindgut fermentation in herbivores. In: Montgomery GG (ed) The ecology of arboreal folivores. Smithsonian Institution Press, Washington DC, pp205-230, 1978) and contradicts the notion that elephants have comparatively less capacious gastrointestinal tracts. Data on the individual gut segments, however, do support earlier suspicions that elephants have a comparatively less capacious caecum and a disproportionally capacious colo