61 research outputs found
Parachuting Behavior and Predation by Ants in the Nettle Caterpillar, Scopelodes contracta
This paper documents the bizarre descending behavior from the tree crown to the ground of the larvae of the moth, Scopelodes contracta Walker (Lepidoptera: Limacodidae) and the interaction of the larva with predatory ants. S. contracta larvae infest leaves of many tree species in urban areas and orchards in Japan. Mature larvae and leaves without basal leaf parts were found under trees of four species infested with S. contracta larvae in Osaka, Japan. Individual larvae riding on leaves were observed falling from tree crowns to the ground. Many S. contracta cocoons were found in the soil below the trees two weeks after the observed parachuting. These observations indicate that S. contracta larvae parachuted to the ground where they spin their cocoons in the soil. When a larva that had just parachuted down was returned to an arboreal twig, the larva repeated the parachuting behavior. This parachuting behavior appears to be adaptive, because larvae can descend to the ground safely and with low energy cost. Worker ants of Tetramorium tsushimae Emery (Hymenoptera: Formicidae) and Pristomyrmex punctatus Mayr (Hymenoptera: Formicidae) occasionally attacked larvae on the ground before they had a chance to burrow in the soil
Basal ganglia correlates of fatigue in young adults
Although the prevalence of chronic fatigue is approximately 20% in healthy individuals, there are no studies of brain structure that elucidate the neural correlates of fatigue outside of clinical subjects. We hypothesized that fatigue without evidence of disease might be related to changes in the basal ganglia and prefrontal cortex and be implicated in fatigue with disease. We aimed to identify the white matter structures of fatigue in young subjects without disease using magnetic resonance imaging (MRI). Healthy young adults (n = 883; 489 males and 394 females) were recruited. As expected, the degrees of fatigue and motivation were associated with larger mean diffusivity (MD) in the right putamen, pallidus and caudate. Furthermore, the degree of physical activity was associated with a larger MD only in the right putamen. Accordingly, motivation was the best candidate for widespread basal ganglia, whereas physical activity might be the best candidate for the putamen. A plausible mechanism of fatigue may involve abnormal function of the motor system, as well as areas of the dopaminergic system in the basal ganglia that are associated with motivation and reward
Effectiveness and cost-effectiveness of an exposure-based return-to-work programme for patients on sick leave due to common mental disorders: design of a cluster-randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>To reduce the duration of sick leave and loss of productivity due to common mental disorders (CMDs), we developed a return-to-work programme to be provided by occupational physicians (OPs) based on the principles of exposure in vivo (RTW-E programme). This study evaluates this programme's effectiveness and cost-effectiveness by comparing it with care as usual (CAU). The three research questions we have are: 1) Is an RTW-E programme more effective in reducing the sick leave of employees with common mental disorders, compared with care as usual? 2) Is an RTW-E programme more effective in reducing sick leave for employees with anxiety disorders compared with employees with other common mental disorders? 3) From a societal perspective, is an RTW-E programme cost-effective compared with care as usual?</p> <p>Methods/design</p> <p>This study was designed as a pragmatic cluster-randomized controlled trial with a one-year follow-up and randomization on the level of OPs. We aimed for 60 OPs in order to include 200 patients. Patients in the intervention group received the RTW-E programme. Patients in the control group received care as usual. Eligible patients had been on sick leave due to common mental disorders for at least two weeks and no longer than eight weeks. As primary outcome measures, we calculated the time until full return to work and the duration of sick leave. Secondary outcome measures were time until partial return to work, prevalence rate of sick leave at 3, 6, 9, and 12 months' follow-up, and scores of symptoms of distress, anxiety, depression, somatization, and fatigue; work capacity; perceived working conditions; self-efficacy for return to work; coping behaviour; avoidance behaviour; patient satisfaction; and work adaptations. As process measures, we used indices of compliance with the intervention in the intervention group and employee-supervisor communication in both groups. Economic costs were calculated from a societal perspective. The total costs consisted of the costs of consuming health care, costs of production loss due to sick leave and reduced productivity, and out-of-pocket costs of patients for travelling to their OP.</p> <p>Discussion</p> <p>The results will be published in 2009. The strengths and weaknesses of the study protocol are discussed.</p> <p>Trial registration</p> <p>ISRCTN72643128</p
Soft Coral Sarcophyton (Cnidaria: Anthozoa: Octocorallia) Species Diversity and Chemotypes
Research on the soft coral genus Sarcophyton extends over a wide range of fields, including marine natural products and the isolation of a number of cembranoid diterpenes. However, it is still unknown how soft corals produce this diverse array of metabolites, and the relationship between soft coral diversity and cembranoid diterpene production is not clear. In order to understand this relationship, we examined Sarcophyton specimens from Okinawa, Japan, by utilizing three methods: morphological examination of sclerites, chemotype identification, and phylogenetic examination of both Sarcophyton (utilizing mitochondrial protein-coding genes MutS homolog: msh1) and their endosymbiotic Symbiodinium spp. (utilizing nuclear internal transcribed spacer of ribosomal DNA: ITS- rDNA). Chemotypes, molecular phylogenetic clades, and sclerites of Sarcophyton trocheliophorum specimens formed a clear and distinct group, but the relationships between chemotypes, molecular phylogenetic clade types and sclerites of the most common species, Sarcophyton glaucum, was not clear. S. glaucum was divided into four clades. A characteristic chemotype was observed within one phylogenetic clade of S. glaucum. Identities of symbiotic algae Symbiodinium spp. had no apparent relation to chemotypes of Sarcophyton spp. This study demonstrates that the complex results observed for S. glaucum are due to the incomplete and complex taxonomy of this species group. Our novel method of identification should help contribute to classification and taxonomic reassessment of this diverse soft coral genus
Spectral, tensor, and ab initio theoretical analysis of optical second harmonic generation from the rutile TiO_2(110) and (001) faces
We overview of our recent experimental study on the optical second harmonic (SH) response of the rutile TiO_2(110) and (001) faces, and the analysis of these results by phenomenological electromagnetic theory using nonlinear susceptibility tensors and by ab initio theory using the self-consistent full potential linearized augmented plane-wave (FLAPW) method within the local-density approximation. Since bulk rutile TiO_2 has a uniaxial crystal structure of symmetry D^_, nonlinear optical response of its surface and bulk showed remarkable anisotropy. The TiO_2(110) face exhibited stronger reflected SH response when the incident electric field was directed parallel than perpendicular to the [001] axis, while the TiO_2(001) face exhibited relatively isotropic SH response. The anisotropy of the SH intensity patterns depended remarkably on the incident photon energy and the polarization combination. By using a phenomenological electromagnetic theory, we performed a simultaneous analysis of the SH intensity patterns from the (110) and (001) faces as a function of the sample rotation angle around its surface normal. As a result we could separate the contributions from the surface second-order and bulk higher order nonlinear susceptibilities. We also found that the SH intensity spectra as a function of the SH photon energy depended strongly on the sample rotation angle and the polarization combination of the fundamental and SH light. The onset of the SH resonance of the TiO_2(110) face was located at 2ηω~3.4 eV when the induced nonlinear polarization was perpendicular to the surface. It was located at 2ηω~3.2 eV when the induced nonlinear polarization is parallel to the [001] direction in the surface plane. These onset energies were higher than the onset energy of the bulk linear absorption at 3.0 eV. On the other hand, the onset energy of the SH resonance of the (001) face was found at 2ηω~3.0 eV. Discussion was given on the physical meaning of the observed SH intensity spectra. Furthermore, ab initio calculation of the nonlinear optical response from the TiO_2(110) surface using the FLAPW method was performed. The calculated results agreed very well with the experimental SH intensity patterns and spectra. We found both from the phenomenological and ab initio calculation that the main SH response from the TiO_2(110) surface originated from the Ti-O-Ti-O- zigzag chains on the TiO_2(110) surface
RS3PE syndrome presenting as vascular endothelial growth factor associated disorder
Methods: Vascular endothelial growth factor(165) (VEGF(165)), tumour necrosis factor α (TNFα), and interleukin 1ß (IL1ß) were measured by enzyme linked immunosorbent assay (ELISA) in serum samples from three patients with RS3PE syndrome. As controls, serum samples from 26 healthy volunteers, 12 patients with rheumatoid arthritis, 10 patients with systemic lupus erythematosus, 13 patients with polymyositis/dermatomyositis, 13 patients with vasculitis syndrome, and 6 patients with mixed connective tissue disease were also analysed. Synovial hypervascularity of patients with RS3PE syndrome was estimated by rate of enhancement (E-rate) in a dynamic MRI study. Results: Serum concentrations of VEGF(165) (mean (SD) 2223.3 (156.3) pg/ml) were significantly higher in patients with active RS3PE syndrome than in controls before corticosteroid treatment. TNFα and IL1ß levels were similar in patients and controls. Synovial hypervascularity in affected joints and subcutaneous oedema decreased during corticosteroid treatment, in parallel with the fall in serum VEGF(165). Conclusions: VEGF promotes synovial inflammation and vascular permeability in patients with RS3PE syndrome, suggesting that RS3PE can be classified as a VEGF associated disorder
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