Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Opt Soc Am A Opt Image Sci Vis ; 41(4): 581-587, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38568658

RESUMO

This study investigates the just-noticeable difference (JND) in luminance below the 0.050c d/m 2 threshold not covered by the DICOM standard in medical imaging displays. A total of 21 healthy young adults were tested using an ultralow-luminance liquid crystal display at a viewing distance of 46 cm. The optotype featured a 4 cycle/deg rectangular wave-like stripe. The average percentage of correct responses for JND indices between -18 and 0 was 70.8%. Using the extended JND based on the Barten model that matches the current JND definition, we confirmed the JND at a very low luminance of 0.0500c d/m 2 or less. These findings suggest the feasibility of further refining the gradation differences in medical imaging displays.


Assuntos
Diagnóstico por Imagem , Adulto Jovem , Humanos , Limiar Diferencial
2.
Artigo em Inglês | MEDLINE | ID: mdl-37578835

RESUMO

A Gram-stain-negative, rod-shaped, non-motile and strictly aerobic bacterium, which showed biofilm-forming ability on polystyrene, designated as strain B-399T, was isolated from the estuarine sediment of the Arakawa River near Tokyo Bay. It grew at pH 6.0-8.5, at 15-35 °C and in the presence of 0-7.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain B-399T was clustered in the genus Sinisalibacter and has 96.94 % sequence similarity to Sinisalibacter lacisalsi X12M-4T, which was the only validly described species in this genus. On the basis of our genome sequencing analyses, the average nucleotide identity and digital DNA-DNA hybridization values between strains B-399T and S. lacisalsi X12M-4T were 79.54 and 22.30 %, respectively, which confirms that strain B-399T represents a novel species of the genus Sinisalibacter. The draft genome size and the DNA G+C content of strain B-399T were 4.12 Mb and 65.2 mol%, respectively. The major fatty acids (>10 %) of strain B-399T were C16 : 0, summed feature 8 (C18 : 1 ω6c and/or C18 : 1 ω7c) and C19 : 0 cyclo ω8c. The polar lipids were phosphatidylcholine, phosphatidylglycerol, an unidentified phospholipid, an unidentified aminolipid and unidentified lipids. The respiratory quinone was Q-10. These chemotaxonomic features were almost coincident with those of the genus Sinisalibacter. Therefore, strain B-399T should be classified as representing a new species of the genus Sinisalibacter, for which the name Sinisalibacter aestuarii sp. nov. is proposed. The type strain is B-399T (=NBRC 115629T=DSM 114148T).


Assuntos
Ácidos Graxos , Rios , Ácidos Graxos/química , Filogenia , RNA Ribossômico 16S/genética , Rios/microbiologia , Técnicas de Tipagem Bacteriana , Ubiquinona/química , DNA Bacteriano/genética , Composição de Bases , Análise de Sequência de DNA , Fosfolipídeos/química
3.
Radiol Phys Technol ; 16(2): 325-337, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37097551

RESUMO

The Japan Association of Radiological Technologists (JART) and the Japan Medical Imaging and Radiological Systems Industries Association jointly conducted a nationwide survey to reveal the current situation of diagnostic displays in Japan using a questionnaire on the performance and quality control (QC) of diagnostic displays for mammography and common use. The questionnaire for radiological technologists (RTs) was distributed via email to 4519 medical facilities throughout Japan, where RTs affiliated with JART were employed; 613 (13.6%) facilities responded. Diagnostic displays with suitable maximal luminance (500 cd/m2 or higher for mammography and 350 cd/m2 or higher for common use) and resolution (5 megapixels for mammography) have been widely used. However, while 99% of the facilities recognized the necessity of QC, only approximately 60% implemented it. This situation arose due to several barriers to QC implementation, such as insufficient devices, time, staff, knowledge, and the recognition of QC as a duty. The implementation of QC can lead to the avoidance of incidents or accidents caused by a decrease in luminance, variation in luminance response, and the influence of ambient light. Moreover, the barriers discouraging the implementation of QC are mainly related to a lack of human resources and budgets. Therefore, to popularize the QC of diagnostic displays in all facilities, it is crucial to identify countermeasures to eliminate these barriers and to continue positive actions for popularization.


Assuntos
Mamografia , Radiologia , Humanos , Japão , Controle de Qualidade , Radiologia/métodos , Inquéritos e Questionários
4.
J Child Lang ; 50(2): 296-310, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-35220986

RESUMO

The empirical study of word learning is driven by a theoretical debate between lexical constraint and social-pragmatic accounts; it has still not been determined which of these two best explains the evidence. We investigated whether the markedness of a pointing accompanying a verbal reference could help to learn a part name. Participants were 35 two-and-a-half-year-olds, 42 four-and-a-half-year-olds, and 38 undergraduate university students in Japan. The experimenter pointed to a novel part (embedded in a novel whole object) with either "marked" pointing, which was touching the part with a small circular motion, or with usual pointing. Touch accompanied by circular motion reliably elicited learning of part names in all age groups. Usual distal pointing without motion reliably elicited learning of whole object names. The pattern of findings rejects a whole-object constraint in early word learning and demonstrates that marked pointing can promote learning novel part names, supporting a social-pragmatic account.


Assuntos
Desenvolvimento da Linguagem , Aprendizagem , Humanos , Aprendizagem Verbal , Vocabulário
5.
J Exp Psychol Learn Mem Cogn ; 48(2): 272-283, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35084926

RESUMO

Learning part names, such as hands of a clock, can be a challenge for children because of the whole object assumption; that is, a child will assume that a given label refers to the whole object (e.g., a clock) rather than the object part (e.g., hands of a clock). We examined the effect of gaze shifting and deliberate pointing on learning part names. The experiment consisted of 2 conditions: (a) no-shifting and (b) shifting-to-object. No-shifting was when the experimenter continuously looked at the participant's face after establishing mutual gaze even while pointing at an object part to teach the part name. The shifting-to-object condition was the same as the no-shifting condition, except for the experimenter's gaze shifting to the object when teaching part names. The results showed that 4-and-a-half-year-olds and adults correctly inferred a part name only during gaze shifting. Two-and-a-half-year-olds were not yet sensitive to this ostensive flow. Especially while learning part names, a continuous gaze at the face may violate the quantity maxim-that is, the criterion that the speaker must provide the appropriate amount of information-in Grice's cooperative principle. To utilize ostensive signals in learning part names, children need to notice the combination of gaze direction and ostensive signals, such as a pointing gesture. In 4-and-a-half-year-olds, the use of social-pragmatic information is more advanced, allowing them to understand an adult's pointing gesture when gaze shifting occurs. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Intenção , Aprendizagem , Criança , Gestos , Humanos
6.
Nat Mater ; 19(5): 508-511, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31988514

RESUMO

The diffusion of defects in crystalline materials1 controls macroscopic behaviour of a wide range of processes, including alloying, precipitation, phase transformation and creep2. In real materials, intrinsic defects are unavoidably bound to static trapping centres such as impurity atoms, meaning that their diffusion is dominated by de-trapping processes. It is generally believed that de-trapping occurs only by thermal activation. Here, we report the direct observation of the quantum de-trapping of defects below around one-third of the Debye temperature. We successfully monitored the de-trapping and migration of self-interstitial atom clusters, strongly trapped by impurity atoms in tungsten, by triggering de-trapping out of equilibrium at cryogenic temperatures, using high-energy electron irradiation and in situ transmission electron microscopy. The quantum-assisted de-trapping leads to low-temperature diffusion rates orders of magnitude higher than a naive classical estimate suggests. Our analysis shows that this phenomenon is generic to any crystalline material.

7.
J Chem Ecol ; 45(5-6): 440-446, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30941560

RESUMO

The elytra of females of the white-spotted longhorn beetle, Anoplophora malasiaca (Coleoptera: Cerambycidae), are coated with a contact sex pheromone, which was previously shown to be composed of at least three chemical groups. Individually, the chemical groups had little pheromonal activity, but a blend of all three exhibited activity equal to that of the crude female extract. Two groups are female-specific aliphatic hydrocarbons and ketones, which were previously synthesized and confirmed to elicit mating behavior. The third group consists of three lactones, gomadalactones A, B, and C, whose chemical structures were previously identified. These have now been synthesized, and the contact sex pheromone activities of synthetic gomadalactones A, B, and C, and the diastereomer of gomadalactone C, were tested in bioassays in this study. When tested in combination with synthetic hydrocarbons and ketones at the same doses as found in female elytra extract, the individual gomadalactones and a blend showed potent pheromonal activity equivalent to that of the crude extract of the elytra of female beetles. This completes the identification of the essential components of the contact sex pheromone of A. malasiaca. Redundancy of components in the hydrocarbon and ketone groups required to elicit mating behavior was observed previously, and this was also true for the gomadalactones.


Assuntos
Besouros/fisiologia , Lactonas/síntese química , Atrativos Sexuais/química , Animais , Cromatografia Líquida de Alta Pressão , Feminino , Lactonas/isolamento & purificação , Lactonas/farmacologia , Masculino , Atrativos Sexuais/isolamento & purificação , Atrativos Sexuais/farmacologia , Comportamento Sexual Animal/efeitos dos fármacos
8.
Naturwissenschaften ; 101(2): 153-6, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24419707

RESUMO

Although mating status affects future mating opportunities, the biochemical changes that occur in response to mating are not well understood. This study investigated the effects of mating status on the quantities of sex pheromone components found in whole-body extracts and volatile emissions of females of the rice leaf bug, Trigonotylus caelestialium. When sampled at one of four time points within a 4-day postmating period, females that had copulated with a male had greater whole-body quantities of sex pheromone components than those of virgin females sampled at the same times. The quantities of sex pheromone components emitted by virgin females over a 24-h period were initially high but then steadily decreased, whereas 24-h emissions were persistently low among mated females when measured at three time points within the 4 days after mating. As a result, soon after mating, the mated females emitted less sex pheromones than virgin females, but there were no significant differences between mated and virgin females at the end of the experiment. Thus, postmating reduction in the rate of emission of sex pheromones could explain previously observed changes in female attractiveness to male T. caelestialium.


Assuntos
Heterópteros/fisiologia , Atrativos Sexuais/metabolismo , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Masculino , Fatores de Tempo
10.
J Chem Ecol ; 36(5): 548-52, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20425138

RESUMO

Previous work has shown that male sorghum plant bugs, Stenotus rubrovittatus (Matsumura) (Heteroptera: Miridae), are more attracted to young virgin females than to old virgin females and are not attracted to mated females. Therefore, we examined the effects of age and mating status on female sex pheromone levels. The pheromone components, hexyl butyrate, (E)-hex-2-en-1-yl butyrate, and (E)-4-oxohex-2-enal, were collected from females in two different ways. First, the compounds were extracted from whole bodies of each female and quantified by gas chromatography-mass spectrometry (GC-MS). Pheromone levels extracted from virgin female bodies decreased with age. In females that had just mated, pheromone levels did not differ from those of virgin females, and pheromone levels in mated females remained relatively constant up to 15 d after mating. This absence of change in pheromone levels extracted from whole bodies of mated females is not congruent with previous reports of lack of male attraction to these females. In a second method for pheromone recovery (adsorption on a PDMS-coated stir bar), GC-MS analysis showed that mated females released lower amounts of pheromone components compared to those emitted by virgin females of the same age (4 d). As was the case with whole body extracts, young virgin females (3 d) released higher amounts of pheromone components than did old virgin females (8 d). The results suggest that male response in S. rubrovittatus is dictated more by the quantities of pheromone components released into the volatile headspace by females than by the quantities present in the body.


Assuntos
Heterópteros/metabolismo , Atrativos Sexuais/química , Fatores Etários , Animais , Butiratos/análise , Butiratos/isolamento & purificação , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Heterópteros/fisiologia , Masculino , Comportamento Sexual Animal , Maturidade Sexual
11.
Eur J Neurosci ; 28(5): 893-902, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18691330

RESUMO

Male moths discriminate conspecific female-emitted sex pheromones. Although the chemical components of sex pheromones have been identified in more than 500 moth species, only three components in Bombyx mori and Heliothis virescens have had their receptors identified. Here we report the identification of receptors for the main sex-pheromone components in three moth species, Plutella xylostella, Mythimna separata and Diaphania indica. We cloned putative sex-pheromone receptor genes PxOR1, MsOR1 and DiOR1 from P. xylostella, M. separata and D. indica, respectively. Each of the three genes was exclusively expressed with an Or83b orthologous gene in male olfactory receptor neurons (ORNs) that are surrounded by supporting cells expressing pheromone-binding-protein (PBP) genes. By two-electrode voltage-clamp recording, we tested the ligand specificity of Xenopus oocytes co-expressing PxOR1, MsOR1 or DiOR1 with an OR83b family protein. Among the seven sex-pheromone components of the three moth species, the oocytes dose-dependently responded only to the main sex-pheromone component of the corresponding moth species. In our study, PBPs were not essential for ligand specificity of the receptors. On the phylogenetic tree of insect olfactory receptors, the six sex-pheromone receptors identified in the present and previous studies are grouped in the same subfamily but have no relation with the taxonomy of moths. It is most likely that sex-pheromone receptors have randomly evolved from ancestral sex-pheromone receptors before the speciation of moths and that their ligand specificity was modified by mutations of local amino acid sequences after speciation.


Assuntos
Mariposas/metabolismo , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Atrativos Sexuais/fisiologia , Comportamento Sexual Animal/fisiologia , Olfato/genética , Animais , Células Cultivadas , Clonagem Molecular , Relação Dose-Resposta a Droga , Evolução Molecular , Feminino , Regulação da Expressão Gênica/fisiologia , Lepidópteros/citologia , Lepidópteros/genética , Lepidópteros/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Mariposas/citologia , Mariposas/genética , Neurônios Receptores Olfatórios/metabolismo , Oócitos/efeitos dos fármacos , Oócitos/fisiologia , Técnicas de Patch-Clamp , Filogenia , Receptores Odorantes/isolamento & purificação , Xenopus laevis
12.
Biosci Biotechnol Biochem ; 69(5): 957-65, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15914916

RESUMO

Two distinct electroantennographycally active (EAG-active) components, A and B, and a weakly active component C were found in a solvent extract from virgin females of the Ishigaki strain of the tussock moth, Orgyia postica (Walker). Components A, B, and C were found in the extract of the females at 4.0, 0.5, and 4.0 ng/female respectively. Components A, B, and C were identified as (6Z,9Z,11S,12S)-11,12-epoxyhenicosa-6,9-diene [(11S,12S)-1: posticlure], (6Z)-henicos-6-en-11-one (2), and (6Z,9Z)-henicosa-6,9-diene (3), respectively. Component B was absent in the extract from the Okinawa strain, in which components A and C were present at 2.0 and 1.5 ng/female respectively. (11S,12S)-1 and the racemic mixture showed attractiveness for both the Okinawa and Ishigaki strains, whereas (11R,12R)-1 did not. The addition of 2 significantly reduced the trap catches with (11S,12S)-1 on the Okinawa strain which lacked 2, while there was no significant inhibitory effect on the Ishigaki strain. The addition of 3 to (11S,12S)-1 did not significantly affect trap catches at Ishigaki or Okinawa. This confirmed that the attractant pheromone of O. postica of the Ishigaki strain is also (11S,12S)-1.


Assuntos
Mariposas/fisiologia , Atrativos Sexuais/química , Animais , Comportamento Animal/fisiologia , Feminino , Japão , Masculino , Mariposas/química , Mariposas/genética , Atrativos Sexuais/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...