108 research outputs found

    Tensile behavior of newly developed undercut anchor in cracked and uncracked concrete

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    The authors have been designing a post-installed anchor that fixes itself into concrete material by expanding the anchor tip in an upward direction, and conducted tensile loading tests to confirm its fundamental dynamic characteristics. The test results on three types of test specimens, with anchor morphology as a parameter, indicate that the final failure modes were all anchor bar fractures, and a stable yield strength was confirmed. Additionally, the yield strength characteristics of the proposed anchor in cases where cracks are present on the concrete surface, wherein the anchors are fixed, were experimentally confirmed

    Fish assemblages associated with three types of artificial reefs: density of assemblages and possible impacts on adjacent fish abundance

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    We evaluated the effectiveness of wooden artificial reefs (ARs) as fish habitat. Three types of ARs, made of cedar logs, broadleaf tree logs, and PVC pipes, respectively, were deployed in triplicate at 8-m depth off Maizuru, Kyoto Prefecture, Sea of Japan, in May 2004. Fish assemblages associated with each of the nine ARs were observed by using SCUBA twice a month for four years. Fish assemblages in the adjacent habitat were also monitored for two years before and four years after reef deployment. In the surveyed areas (ca. 10 m2) associated with each of the cedar, broadleaf, and PVC ARs, the average number of fish species was 4.14, 3.49, and 3.00, and the average number of individuals was 40.7, 27.9, and 20.3, respectively. The estimated biomass was also more greater when associated with the cedar ARs than with other ARs. Visual censuses of the habitat adjacent to the ARs revealed that the number of fish species and the density of individuals were not affected by the deployment of the ARs. Our results support the superiority of cedar as an AR material and indicate that deployment of wooden ARs causes no reduction of fish abundance in adjacent natural reefs

    Changes in leaf water use after removal of leaf lower surface hairs on Mallotus macrostachyus (Euphorbiaceae) in a tropical secondary forest in Malaysia.

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    Leaf hairs may assist in maintaining high leaf water use efficiency in tropical secondary forest tree species. We compared leaf temperature, transpiration, photosynthesis and water use efficiency between hairy and depilated leaves in Mallotus macrostachyus (Euphorbiaceae), to determine the role of leaf hair in leaf water use efficiency (WUE) in tropical degraded secondary forest in Malaysia. Measurements were made on five mature individuals growing in sun-exposed conditions and five in shaded conditions. The hair dry weight per unit leaf area was significantly greater in sun leaves than in shade leaves. The transpiration rate (Trmax) of depilated leaves in sun-exposed conditions was slightly higher than in hairy leaves in both morning and afternoon measurements. In contrast, Trmax in the shade leaves was almost identical in hairy and depilated leaves. Leaf stomatal conductance (g s) in the morning showed almost the same value among leaf types and light conditions. In the afternoon, g s slightly decreased from the morning values in both sun and shade conditions. In the morning, the leaf water use efficiency (A max/Trmax) in both conditions did not differ significantly between hairy and depilated leaves. However, in the afternoon, WUE in the depilated leaves was significantly lower than in hairy leaves in sun-exposed conditions. These observations suggest that leaf hairs in M. macrostachyus contribute to the high leaf water use efficiency in drought conditions, such as high vapor pressure deficit experienced at midday in degraded tropical secondary forests

    Growth and photosynthetic response of four Malaysian indigenous tree species under different light conditions.

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    Growth and photosynthetic response of four indigenous tree seedlings, i.e. Dyera costulata, Dipterocarpus baudii, Neobalanocarpus heimii and Gonystylus affinis were studied under different light conditions in a degraded secondary forest. Maximum photosynthesis (Amax) was measured at 2 and 12 months after planting. The ratio of variable to maximum fluorescence (Fv/Fm) was determined. Leaves measured at 2 and 12 months after planting were old leaves present on the seedlings and new leaves that had expanded after planting respectively. Seedling growth was measured over four years. Changes in the growth rate and Amax with canopy openness were categorised into two groups. The growth and Amax of the first group (D. costulata and D. baudii) were maximum at 30-40% canopy openness. This group may be suitable for planting under large canopy gaps. The second group (G. affinis and N. heimii) showed maximum growth and Amax at relatively low canopy openness (less than 20%). Leaves in the second group suffered chronic photoinhibition under large gap. These species were suitable to be planted under low light conditions

    Leaf photosynthetic and growth responses on four tropical tree species to different light conditions in degraded tropical secondary forest, Peninsular Malaysia.

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    Leaf ecophysiological responses and height growth were studied in four indigenous tree seedlings planted under different size gaps in degraded tropical secondary forest. Dyera costulata, Dipterocarpus baudii, Neobalanocarpus heimii, and Pouteria sp. were selected for study species. The leaf photosynthetic rate at light saturation (Amax), light compensation point (Ic), leaf nitrogen content, and SPAD value were measured at two months after planting. The ratio of variable to the maximum fluorescence (Fv/Fm), which represents the maximal photochemical efficiency of photosystem II was also determined at two months after planting. All measurement leaves were old leaves, which had acclimated before the planting light condition. Canopy openness above the seedlings was estimated from a hemispherical photograph, ranged from 6 to 53%. The relationships between canopy openness and Amax among species were categorized into two groups. The first group (N. heimii and Pouteria), which had relatively high wood density and late successional status, showed that the maximum Amax appeared under relatively low canopy openness such as approximately 10%. Amax of the second group (D. costulata and Dip. baudii), which had relatively low wood density and high light demand, maximized from 20 to 40% of canopy openness. Seedling height growth of the first group was lower than the second group. The first group also showed lower Fv/Fm at high canopy openness than the second group. These responses indicated that the first group may be categorized to less tolerant species for strong light conditions during the early transplanted stage. Ic of D. costulata, N. heimii and Pouteria decreased with decreasing canopy openness. These species have high acclimation ability to shade conditions from the early transplanted stage, since these responses contribute to raise the photosynthetic efficiency under shade conditions

    Steroid psychosis in a polyarteritis nodosa patient successfully treated with risperidone: tracking serum brain-derived neurotrophic factor levels longitudinally

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    We previously reported a case in which steroid-induced psychosis was eliminated with risperidone treatment in a patient with polyarteritis nodosa (PN). In the present report, we longitudinally tracked the serum levels of brain-derived neurotrophic factor (BDNF). We found that corticosteroid lowered serum BDNF levels, and improvement of psychiatric symptoms was intact with the serum BDNF levels seen in the patients

    An easy-to-implement, non-invasive head restraint method for monkey fMRI

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    Tanaka R., Watanabe K., Suzuki T., et al. An easy-to-implement, non-invasive head restraint method for monkey fMRI. NeuroImage 285, 120479 (2024); https://doi.org/10.1016/j.neuroimage.2023.120479.Functional magnetic resonance imaging (fMRI) in behaving monkeys has a strong potential to bridge the gap between human neuroimaging and primate neurophysiology. In monkey fMRI, to restrain head movements, researchers usually surgically implant a plastic head-post on the skull. Although time-proven to be effective, this technique could create burdens for animals, including a risk of infection and discomfort. Furthermore, the presence of extraneous objects on the skull, such as bone screws and dental cement, adversely affects signals near the cortical surface. These side effects are undesirable in terms of both the practical aspect of efficient data collection and the spirit of “refinement” from the 3R's. Here, we demonstrate that a completely non-invasive fMRI scan in awake monkeys is possible by using a plastic head mask made to fit the skull of individual animals. In all of the three monkeys tested, longitudinal, quantitative assessment of head movements showed that the plastic mask has effectively suppressed head movements, and we were able to obtain reliable retinotopic BOLD signals in a standard retinotopic mapping task. The present, easy-to-make plastic mask has a strong potential to simplify fMRI experiments in awake monkeys, while giving data that is as good as or even better quality than that obtained with the conventional head-post method

    Ontogenetic changes in carbohydrate storage and sprouting ability in pioneer tree species in Peninsular Malaysia

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    Sprouting ability is highly variable among different tree species. In many cases, there are trade-offs in carbon allocations between growth and storage in seedlings. However, this trade-off is likely to change with growth stages from seedling to mature plant because carbon investments in reproductive activities and/or risk of disturbance also change by species and growth stage. To examine how sprouting ability and carbohydrate storage change with growth stage, we compared two tropical secondary-forest trees, Macaranga bancana and M. gigantea, which have different ecological traits. Maximum tree size and growth rate are higher in M. gigantea. We monitored sprout growth and stored resources, including total non-structural carbohydrate (TNC) and nitrogen in the root, among different tree sizes for 12 months following stem-cutting treatment. Sprouting ability (total sprout mass) and TNC concentrations were significantly higher in small individuals than in larger specimens in both species. TNC concentration decreased in all size classes after stem cutting. Macaranga bancana had greater sprout survivorship than M. gigantea, which had higher sprouting ability in larger tree-size classes. Thus, sprouting ability likely depends on root TNC concentration and tree-size class in both Macaranga species. Higher TNC concentration and sprout survival rates in M. bancana may be related to greater carbon allocation in survival than in growth. This hypothesis is consistent with the ecological traits of M. bancana, such as its growth rate, which was lower than that of M. gigantea

    A Multicenter, Open-label, Clinical Trial to Assess the Effectiveness and Safety of Allogeneic Hematopoietic Stem Cell Transplantation Using Reduced-intensity Conditioning in Relapsed/refractory Anaplastic Large-cell Lymphoma in Children

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    No standard treatment for relapsed or refractory anaplastic large-cell lymphoma (ALCL) has been established. This study is a multicenter, open-label trial to examine the effectiveness and safety of transplantation with reduced-intensity conditioning (RIC) for patients under 20 years old with relapsed or refractory ALCL. We defined RIC as the administration of fludarabine (30 mg/m2/day) for five days plus melphalan (70 mg/m2/day) for two days and total body irradiation at 4 Gy, followed by allogeneic hematopoietic stem cell transplantation

    Importance of Second-look Endoscopy on an Empty Stomach for Finding Gastric Bezoars in Patients with Gastric Ulcers

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     Most gastric bezoars can be treated with endoscopic fragmentation combined with or without cola dissolution, whereas laparotomy or laparoscopic surgery is generally inevitable for small intestinal bezoars because they cause small bowel obstruction. Therefore, early diagnosis and management of gastric bezoars are necessary to prevent bezoar-induced ileus. To investigate the incidence of overlooked gastric bezoars during the initial esophagogastroduodenoscopy, we retrospectively reviewed the cases of 27 patients diagnosed with gastrointestinal bezoars. The bezoars were diagnosed using esophagogastroduodenoscopy (n=25), abdominal ultrasonography (n=1), and barium follow-through examination (n=1). Bezoars were overlooked in 9/25 patients (36.0%) during the initial endoscopy examination because the bezoars were covered with debris in the stomach. Of the 9 patients, 8 had concomitant gastric ulcers, and the other patient had gastric lymphoma. Although a computed tomography (CT) scan was performed before the second-look endoscopy in 8 of the 9 patients, the bezoars were mistaken as food debris on CT findings and were overlooked in these patients. In conclusion, gastric bezoars may not be discovered during the initial esophagogastroduodenoscopy and CT scan. In cases with debris in the stomach, second-look endoscopy is essential to detect bezoars
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