368 research outputs found

    Intellectual property rights protection in the presence of exhaustible resources

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    We construct a research and development (R&D) based endogenous growth model with exhaustible resources and investigate whether protection of intellectual property rights (IPR) can sustain perpetual growth. We show that relatively weak IPR protection is sufficient to sustain perpetual growth when goods production is more resource-intensive, whereas relatively strong IPR protection is needed for perpetual growth if production is less resource-intensive. If the resource intensity in goods production is medium, even the strictest IPR protection cannot sustain perpetual growth when the quality improvements brought about by innovations are small enough. In this case, we find that R&D subsidies can complement IPR protection in sustaining perpetual growth. We derive the socially optimal level of IPR protection, which is increasing in the resource intensity of goods production. Furthermore, we also consider a case where resource is essential for R&D activities and show a knife-edge condition for perpetual growth

    Synergistic and Offset Effects of Fungal Species Combinations on Plant Performance

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    「1+1=2」じゃない共生の世界 --2種の菌が植物にもたらす相乗効果と相殺効果--. 京都大学プレスリリース. 2021-09-17.In natural and agricultural ecosystems, survival and growth of plants depend substantially on residing microbes in the endosphere and rhizosphere. Although numerous studies have reported the presence of plant-growth promoting bacteria and fungi in below-ground biomes, it remains a major challenge to understand how sets of microbial species positively or negatively affect plants’ performance. By conducting a series of single- and dual-inoculation experiments of 13 plant-associated fungi targeting a Brassicaceae plant species (Brassica rapa var. perviridis), we here systematically evaluated how microbial effects on plants depend on presence/absence of co-occurring microbes. The comparison of single- and dual-inoculation experiments showed that combinations of the fungal isolates with the highest plant-growth promoting effects in single inoculations did not have highly positive impacts on plant performance traits (e.g., shoot dry weight). In contrast, pairs of fungi with small/moderate contributions to plant growth in single-inoculation contexts showed the greatest effects on plants among the 78 fungal pairs examined. These results on the offset and synergistic effects of pairs of microbes suggest that inoculation experiments of single microbial species/isolates can result in the overestimation or underestimation of microbial functions in multi-species contexts. Because keeping single-microbe systems under outdoor conditions is impractical, designing sets of microbes that can maximize performance of crop plants is an important step for the use of microbial functions in sustainable agriculture

    Increased release of nitric oxide in ischemic hearts after exercise in patients with effort angina

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    AbstractObjectives. The aim of this study was to determine whether the release of nitric oxide (NO) from the ischemic heart increases during exercise in patients with effort angina.Background. Myocardial ischemia increases NO production in the canine heart, but no such increase has been demonstrated in the ischemic human heart.Methods. Fifteen patients with effort angina underwent supine ergometer exercise tests. All patients had severe proximal stenosis (>90%) in the left anterior descending coronary artery. The control group consisted of 17 subjects without coronary artery disease or systemic hemodynamic abnormalities.Results. Neither the lactate extraction ratio (LER) nor the difference in NO concentration between coronary venous and arterial blood (ΔVA[NO]) was affected by exercise in the control subjects. In patients with effort angina, neither variable differed from that in the control group at rest; however, exercise markedly decreased LER and significantly increased ΔVA(NO) (from 4.7 ± 0.3 to 16.5 ± 1.6 μmol/liter, p < 0.001) in the patient group. The extent of decrease in LER was significantly correlated with the extent of increase in ΔVA(NO) in the patients with effort angina (r2= −0.837, p < 0.001).Conclusions. Provocation of myocardial ischemia by exercise stress increases NO production in the hearts of patients with effort angina

    Factors Influencing Breast Density in Japanese Women Aged 40-49 in Breast Cancer Screening Mammography

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    A relatively large number of women in their 40s with high-density breasts, in which it can be difficult to detect lesions, are encountered in mammography cancer screenings in Japan. Here, we retrospectively investigated factors related to breast density. Two hundred women (40-49 years old) were examined at the screening center in our hospital. Multivariate analysis showed that factors such as small abdominal circumference, high HDL cholesterol, and no history of childbirth were related to high breast density in women in their 40s undergoing mammography. Other non-mammographic screening methods should be considered in women with abdominal circumferences <76cm, HDL-C >53mg/dl, and no history of childbirth, as there is a strong possibility of these women having high-density breasts that can make lesion detection difficult

    Association study of the vesicular monoamine transporter 1 (VMAT1) gene with schizophrenia in a Japanese population

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    BACKGROUND: Vesicular monoamine transporters (VMATs) mediate accumulation of monoamines such as serotonin, dopamine, adrenaline, and noradrenaline from the cytoplasm into storage organelles. The VMAT1 (alternatively solute carrier family 18: SLC18A1) regulates such biogenic amines in neuroendocrine systems. The VMAT1 gene maps to chromosome 8p21.3, a locus with strong evidence of linkage with schizophrenia. A recent study reported that a non-synonymous single nucleotide polymorphism (SNP) of the gene (Pro4Thr) was associated with schizophrenia. METHODS: We attempted to replicate this finding in a Japanese sample of 354 schizophrenics and 365 controls. In addition, we examined 3 other non-synonymous SNPs (Thr98Ser, Thr136Ile, and Val392Leu). Genotyping was performed by the TaqMan allelic discrimination assay. RESULTS: There was no significant difference in genotype or allele distribution of the three SNPs of Pro4Thr, Thr136Ile, or Val392Leu between patients and controls. There was, however, a significant difference in genotype and allele distributions for the Thr98Ser polymorphism between the two groups (P = 0.01 for genotype and allele). When sexes were examined separately, significant differences were observed in females (P = 0.006 for genotype, P = 0.003 for allele), but not in males. The Thr98 allele was more common in female patients than in female controls (odds ratio 1.69, 95% CI 1.19–2.40, P = 0.003). Haplotype-based analyses also provided evidence for a significant association in females. CONCLUSION: We failed to replicate the previously reported association of Pro4Thr of the VMAT1 gene with schizophrenia. However, we obtained evidence for a possible role of the Thr98Ser in giving susceptibility to schizophrenia in women

    Possible impact of ADRB3 Trp64Arg polymorphism on BMI in patients with schizophrenia

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    Background: The beta 3-adrenoceptor (ADRB3) gene Trp64Arg polymorphism has been shown to be associated with obesity as well as type 2 diabetes and cardiovascular disease. The incidence of overweight and the risks of type 2 diabetes and cardiovascular disease are also increased in major depression and schizophrenia. We hypothesized that the Trp64Arg polymorphism may be associated with increased risk of schizophrenia and depression. Methods: The Trp64Arg was genotyped in 504 patients with schizophrenia, 650 with major depressive disorder (MOD), and 1170 healthy controls. Of these participants, body mass index (BMI) data were available for 125 patients with schizophrenia, 219 with MDD, and 261 controls. Results: No significant difference in genotype or allele distribution was found across the diagnostic groups. No significant difference in BMI was observed between the Arg allele carriers and the non-carriers in the MDD and the control groups. However, patients with schizophrenia carrying the Arg allele had significantly higher BMI (Mean (SD): Arg carriers: 26.5 (6.9), Arg non-carriers: 23.8 (4.3); P=0.019) and a higher rate of being overweight (BMI of 25 or more) compared to their counterparts (Trp/Trp group) (% overweight (SE): Arg carriers: 52.3 (7.5), Arg non-carriers: 32.1 (5.2); P=0.027). Conclusions: We obtained no evidence for the association of ADRB3 Trp64Arg with the development of MDD or schizophrenia. However, the Arg allele was found to be associated with higher BMI and being overweight in patients with schizophrenia. This may imply that genotyping ADRB3 is of clinical use to detect schizophrenic individuals at risk for developing obesity.ArticlePROGRESS IN NEURO-PSYCHOPHARMACOLOGY & BIOLOGICAL PSYCHIATRY. 38(2):341-344 (2012)journal articl

    Possible association between Interleukin-1beta gene and schizophrenia in a Japanese population

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    Background: Several lines of evidence have implicated the pro-inflammatory cytokine interleukin-1beta (IL-1 beta) in the etiology of schizophrenia. Although a number of genetic association studies have been reported, very few have systematically examined gene-wide tagging polymorphisms. Methods: A total of 533 patients with schizophrenia (302 males: mean age +/- standard deviation 43.4 +/- 13.0 years; 233 females; mean age 44.8 +/- 15.3 years) and 1136 healthy controls (388 males: mean age 44.6 +/- 17.3 years; 748 females; 46.3 +/- 15.6 years) were recruited for this study. All subjects were biologically unrelated Japanese individuals. Five tagging polymorphisms of IL-1 beta gene (rs2853550, rs1143634, rs1143633, rs1143630, rs16944) were examined for association with schizophrenia. Results: Significant difference in allele distribution was found between patients with schizophrenia and controls for rs1143633 (P = 0.0089). When the analysis was performed separately in each gender, significant difference between patients and controls in allele distribution of rs1143633 was observed in females (P = 0.0073). A trend towards association was also found between rs16944 and female patients with schizophrenia (P = 0.032). Conclusions: The present study shows the first evidence that the IL-1 beta gene polymorphism rs1143633 is associated with schizophrenia susceptibility in a Japanese population. The results suggest the possibility that the influence of IL-1 beta gene variations on susceptibility to schizophrenia may be greater in females than in males. Findings of the present study provide further support for the role of IL-1 beta in the etiology of schizophrenia

    Negative correlation between cerebrospinal fluid oxytocin levels and negative symptoms of male patients with schizophrenia

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    Background: Accumulating evidence indicates that oxytocin plays an important role in social interactions. Previous studies also suggest altered oxytocin function in patients with schizophrenia and depression. However, few studies have examined the central oxytocin levels in these disorders. Methods: Cerebrospinal fluid (CSF) oxytocin levels were measured by ELISA in male participants consisting of 27 patients with schizophrenia, 17 with major depressive disorder (MDD), and 21 healthy controls. Results: CSF oxytocin levels of patients with schizophrenia or MDD did not differ significantly with healthy controls. The antidepressant dose or the Hamilton depression rating scale score did not significantly correlate with the oxytocin levels in MDD patients. CSF oxytocin levels in schizophrenic patients significantly negatively correlated with second generation antipsychotic dose (r=-0.49, P=0.010) but not with first generation antipsychotic dose (r=-0.13, P=0.50). A significant correlation was observed between oxytocin levels and negative subscale of PANSS (r=-0.38, P=0.050). This correlation remained significant even after controlling for second generation antipsychotic dose (r=-0.47, P=0.016). Conclusions: We obtained no evidence of altered CSF oxytocin levels in patients with schizophrenia or those with MDD. However, lower oxytocin levels may be related to higher second generation antipsychotic dose and more severe negative symptoms in schizophrenia.ArticleSCHIZOPHRENIA RESEARCH. 139(1-3):201-206 (2012)journal articl

    Modulation of cortisol responses to the DEX/CRH test by polymorphisms of the interleukin-1beta gene in healthy adults

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    <p>Abstract</p> <p>Background</p> <p>Recently, hypothalamus-pituitary-adrenal (HPA) axis function assessed with the combined dexamethasone (DEX)/corticotropin releasing hormone (CRH) test has been shown to be associated with response to antidepressant treatment. A polymorphism (rs16944) in the interleukin-1beta (<it>IL-1β</it>) gene has also been reported to be associated with the medication response in depression. These findings prompted us to examine the possible association between <it>IL-1β </it>gene polymorphisms and HPA axis function assessed with the DEX/CRH test.</p> <p>Methods</p> <p>DEX/CRH test was performed in 179 healthy volunteers (45 males: mean age 40.5 ± 15.8 years; 134 females: mean age 47.1 ± 13.2 years). Five tagging single nucleotide polymorphisms (SNPs) of <it>IL-1β </it>gene (rs2853550, rs1143634, rs1143633, rs1143630, rs16944) were selected at an r<sup>2 </sup>threshold of 0.80 with a minor allele frequency > 0.1. Genotyping was performed by the TaqMan allelic discrimination assay. A two-way factorial analysis of variance (ANOVA) was performed with the DEX/CRH test results as the dependent variable and genotype and gender as independent variables. To account for multiple testing, <it>P </it>values < 0.01 were considered statistically significant for associations between the genotypes and the cortisol levels.</p> <p>Results</p> <p>The cortisol levels after DEX administration (DST-Cortisol) showed significant associations with the genotypes of rs16944 (<it>P </it>= 0.00049) and rs1143633 (<it>P </it>= 0.0060), with no significant gender effect or genotype × gender interaction. On the other hand, cortisol levels after CRH administration (DEX/CRH-Cortisol) were affected by gender but were not significantly influenced by the genotype of the examined SNPs, with no significant genotype × gender interaction.</p> <p>Conclusions</p> <p>Our results suggest that genetic variations in the <it>IL-1β </it>gene contribute to the HPA axis alteration assessed by DST-Cortisol in healthy subjects. On the other hand, no significant associations of the <it>IL-1β </it>gene polymorphisms with the DEX/CRH-Cortisol were observed. Confirmation of our findings in futures studies may add new insight into the communication between the immune system and the HPA axis.</p
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