University of Tsukuba

About: University of Tsukuba is a education organization based out in Tsukuba, Ibaraki, Japan. It is known for research contribution in the topics: Population & Gene. The organization has 36352 authors who have published 79483 publications receiving 1934752 citations. The organization is also known as: Tsukuba daigaku & Tsukuba University.

Ghrelin-induced food intake is mediated via the orexin pathway

Abstract: The hypothalamus regulates energy intake by integrating the degree of starvation or satiation with the status of the environment through a variety of neuronal and blood-derived signals. Ghrelin, a peptide produced in the stomach and hypothalamus, stimulates feeding and GH secretion. Centrally administered ghrelin exerts an orexigenic activity through the neuropeptide Y (NPY) and agouti-related protein systems. The interaction between ghrelin and other hypothalamic orexigenic peptides, however, has not been clarified. Here, we investigated the anatomical interactions and functional relationship between ghrelin and two orexigenic peptides, orexin and melanin-concentrating hormone (MCH), present in the lateral hypothalamus. Ghrelin-immunoreactive axonal terminals made direct synaptic contacts with orexin-producing neurons. Intracerebroventricular administration of ghrelin induced Fos expression, a marker of neuronal activation, in orexin-producing neurons but not in MCH-producing neurons. Ghrelin remained competent to induce Fos expression in orexin-producing neurons following pretreatment with anti-NPY IgG. Pretreatment with anti-orexin-A IgG and anti-orexin-B IgG, but not anti-MCH IgG, attenuated ghrelin-induced feeding. Administration of NPY receptor antagonist further attenuated ghrelin-induced feeding in rats treated with anti-orexin-IgGs. Ghrelin-induced feeding was also suppressed in orexin knockout mice. This study identifies a novel hypothalamic pathway that links ghrelin and orexin in the regulation of feeding behavior and energy homeostasis.

A consensus linkage map of the chicken genome

Abstract: A consensus linkage map has been developed in the chicken that combines all of the genotyping data from the three available chicken mapping populations. Genotyping data were contributed by the laboratories that have been using the East Lansing and Compton reference populations and from the Animal Breeding and Genetics Group of the Wageningen University using the Wageningen/Euribrid population. The resulting linkage map of the chicken genome contains 1889 loci. A framework map is presented that contains 480 loci ordered on 50 linkage groups. Framework loci are defined as loci whose order relative to one another is supported by odds greater then 3. The possible positions of the remaining 1409 loci are indicated relative to these framework loci. The total map spans 3800 cM, which is considerably larger than previous estimates for the chicken genome. Furthermore, although the physical size of the chicken genome is threefold smaller then that of mammals, its genetic map is comparable in size to that of most mammals. The map contains 350 markers within expressed sequences, 235 of which represent identified genes or sequences that have significant sequence identity to known genes. This improves the contribution of the chicken linkage map to comparative gene mapping considerably and clearly shows the conservation of large syntenic regions between the human and chicken genomes. The compact physical size of the chicken genome, combined with the large size of its genetic map and the observed degree of conserved synteny, makes the chicken a valuable model organism in the genomics as well as the postgenomics era. The linkage maps, the two-point lod scores, and additional information about the loci are available at web sites in Wageningen (http://www.zod.wau.nl/vf/research/chicken/frame_chicken.html) and East Lansing (http://poultry.mph.msu.edu/).

Mission Design of LiteBIRD

Abstract: LiteBIRD is a next-generation satellite mission to measure the polarization of the cosmic microwave background (CMB) radiation. On large angular scales the B-mode polarization of the CMB carries the imprint of primordial gravitational waves, and its precise measurement would provide a powerful probe of the epoch of inflation. The goal of LiteBIRD is to achieve a measurement of the characterizing tensor to scalar ratio $$r$$ to an uncertainty of $$\delta r=0.001$$ . In order to achieve this goal we will employ a kilo-pixel superconducting detector array on a cryogenically cooled sub-Kelvin focal plane with an optical system at a temperature of 4 K. We are currently considering two detector array options; transition edge sensor (TES) bolometers and microwave kinetic inductance detectors. In this paper we give an overview of LiteBIRD and describe a TES-based polarimeter designed to achieve the target sensitivity of 2 $$\upmu $$ K arcmin over the frequency range 50–320 GHz.