Kyoto University

About: Kyoto University is a education organization based out in Kyoto, Japan. It is known for research contribution in the topics: Catalysis & Population. The organization has 85837 authors who have published 217215 publications receiving 6526826 citations. The organization is also known as: Kyōto University & Kyōto daigaku.

The stoichiometry of consumer-driven nutrient recycling: theory, observations, and consequences

Abstract: Ecologists are increasingly recognizing the importance of consumers in reg- ulating ecosystem processes such as nutrient cycling. Ecologists have recently made con- siderable progress in understanding nutrient cycling and trophic interactions in pelagic systems by application of a new concept, ecological stoichiometry, to consumer-driven processes. In this paper we synthesize these conceptual advances within pelagic ecology and attempt to illustrate how they may be usefully applied in other ecosystems. Stoichi- ometric theory shows that both grazer and algal elemental composition are critical param- eters influencing rates and ratios of nutrient release. Thus, the stoichiometry of nutrient recycling is a feedback mechanism linking grazer dynamics and algal nutritional status. Incorporation of such effects into a fully dynamic stoichiometric model generates profound changes in the predicted dynamics of algae and grazers, suggesting that adoption of a stoichiometric view may substantively alter our view of the interaction between trophic dynamics and nutrient cycling. The basic predictions of stoichiometric models of nutrient release are generally supported by experimental data showing that N:P release ratios are primarily a function of algal N:P ratio and secondarily a function of grazer N:P ratio, and that rates of P release by grazers are also related to food P:C. Furthermore, evidence for effects of nutrient release stoichiometry on phytoplankton communities and pelagic eco- system function is accumulating, including data showing consistent alterations in algal physiological status and ecosystem-scale changes in N fixation in response to altered grazer community structure and elemental composition. As the general features of the stoichi- ometry of algae-zooplankton interactions reflect fundamental biological processes linked to plant and animal mineral nutrition, the stoichiometric view of consumer-driven nutrient recycling can easily be applied to other ecosystems, including terrestrial and benthic food webs. A suite of potential applications of stoichiometric thinking to benthic and terrestrial habitats is suggested.

Hydrate-melt electrolytes for high-energy-density aqueous batteries

Abstract: Aqueous Li-ion batteries are attracting increasing attention because they are potentially low in cost, safe and environmentally friendly. However, their low energy density ( 130 Wh kg−1) and high voltage (∼2.3–3.1 V) represent significant progress towards performance comparable to that of commercial non-aqueous batteries (with energy densities of ∼150–400 Wh kg−1 and voltages of ∼2.4–3.8 V). Aqueous Li-ion batteries have considerably lower energy density than their non-aqueous counterparts. Here the authors report a room-temperature hydrate metal salt electrolyte that, when coupled with a spinel Li4Ti5O12 electrode, displays an energy density of 130 Wh kg−1.

Thyroid gland tumor diagnosis at US elastography

Abstract: PURPOSE: To prospectively evaluate the elastographic appearance of thyroid gland tumors and explore the potential sensitivity and specificity of ultrasonographic (US) elastography for differentiating benign and malignant tumors, with histopathologic analysis as the reference standard. MATERIALS AND METHODS: The study was institutional review board approved, and each patient gave written informed consent. Fifty-two thyroid gland lesions (22 malignant, 30 benign) in 31 consecutive patients (six men, 25 women; mean age, 49.7 years ± 14.7 [standard deviation]) were examined with real-time elastography in the elasticity imaging mode implemented on a clinical US scanner modified for research. In addition, the radiofrequency echo data stored during US were exported from the scanner and used for off-line strain image reconstruction. All elastograms were evaluated for the lesion visibility, relative brightness, and margin regularity and definition by using a four-point scale. In addition, normal thyroid gland tiss...

PEBP2/PEA2 represents a family of transcription factors homologous to the products of the Drosophila runt gene and the human AML1 gene.

Abstract: cDNAs representing the alpha subunit of polyomavirus enhancer binding protein 2 (PEBP2; also called PEA2) were isolated. The products of the cDNAs are highly homologous to that of Drosophila segmentation gene runt (run) for an N-proximal 128-amino acid region showing 66% identity. The run homology region encompasses the domain capable of binding to a specific nucleotide sequence motif and of dimerizing with the companion beta subunit. The human AML1 gene related to t(8;21) acute myeloid leukemia also had a run homology region. Together with the beta subunit, which increases the affinity of the alpha subunit to DNA without binding to DNA by itself, PEBP2 represents a newly discovered family of transcription factor. The major species of PEBP2 alpha mRNA was expressed in T-cell lines but not in B-cell lines tested. Evidence indicated that PEBP2 functions as a transcriptional activator and is involved in regulation of T-cell-specific gene expression.