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61.
Yasuhiko Murata Takako Yasuda Tomomi Watanabe-Asaka Shoji Oda Akiko Mantoku Kazuhiro Takeyama Masahiro Chatani Akira Kudo Satoko Uchida Hiromi Suzuki Fumiaki Tanigaki Masaki Shirakawa Koichi Fujisawa Yoshihiko Hamamoto Shuji Terai Hiroshi Mitani 《PloS one》2015,10(10)
To understand how humans adapt to the space environment, many experiments can be conducted on astronauts as they work aboard the Space Shuttle or the International Space Station (ISS). We also need animal experiments that can apply to human models and help prevent or solve the health issues we face in space travel. The Japanese medaka (Oryzias latipes) is a suitable model fish for studying space adaptation as evidenced by adults of the species having mated successfully in space during 15 days of flight during the second International Microgravity Laboratory mission in 1994. The eggs laid by the fish developed normally and hatched as juveniles in space. In 2012, another space experiment (“Medaka Osteoclast”) was conducted. Six-week-old male and female Japanese medaka (Cab strain osteoblast transgenic fish) were maintained in the Aquatic Habitat system for two months in the ISS. Fish of the same strain and age were used as the ground controls. Six fish were fixed with paraformaldehyde or kept in RNA stabilization reagent (n = 4) and dissected for tissue sampling after being returned to the ground, so that several principal investigators working on the project could share samples. Histology indicated no significant changes except in the ovary. However, the RNA-seq analysis of 5345 genes from six tissues revealed highly tissue-specific space responsiveness after a two-month stay in the ISS. Similar responsiveness was observed among the brain and eye, ovary and testis, and the liver and intestine. Among these six tissues, the intestine showed the highest space response with 10 genes categorized as oxidation–reduction processes (gene ontogeny term GO:0055114), and the expression levels of choriogenin precursor genes were suppressed in the ovary. Eleven genes including klf9, klf13, odc1, hsp70 and hif3a were upregulated in more than four of the tissues examined, thus suggesting common immunoregulatory and stress responses during space adaptation. 相似文献
62.
We studied a two-person game regarding deforestation in human-environment relationships. Each landowner manages a single land parcel where the state of land-use is forested, agricultural, or abandoned. The landowner has two strategies available: forest conservation and deforestation. The choice of deforestation provides a high return to the landowner, but it degrades the forest ecosystem services produced on a neighboring land parcel managed by a different landowner. Given spatial interactions between the two landowners, each landowner decides which strategy to choose by comparing the expected discounted utility of each strategy. Expected discounted utility is determined by taking into account the current and future utilities to be received, according to the state transition on the two land parcels. The state transition is described by a Markov chain that incorporates a landowner's choice about whether to deforest and the dynamics of agricultural abandonment and forest regeneration. By considering a stationary distribution of the Markov chain for land-use transitions, we derive explicit conditions for Nash equilibrium. We found that a slow regeneration of forests favors mutual cooperation (forest conservation). As the forest regenerates faster, mutual cooperation transforms to double Nash equilibria (mutual cooperation and mutual defection), and finally mutual defection (deforestation) leads to a unique Nash equilibrium. Two different types of social dilemma emerge in our deforestation game. The stag-hunt dilemma is most likely to occur under an unsustainable resource supply, where forest regenerates extremely slowly but agricultural abandonment happens quite rapidly. In contrast, the prisoner's dilemma is likely under a persistent or circulating supply of resources, where forest regenerates rapidly and agricultural abandonment occurs slowly or rapidly. These results show how humans and the environment mutually shape the dilemma structure in forest management, implying that solutions to dilemmas depend on environmental properties. 相似文献
63.
Intraspecific variation in seed production schedule and its effects on seed characteristics were examined in the deciduous
oak species Quercus serrata in Iwate Prefecture, northern Japan. Seed production schedule differed markedly among 31 individual trees. The median dates
of seed production differed by over 1 month between the earliest and latest individuals. Relationships between seed production
schedule and seed characteristics were investigated at two different scales: the among-tree scale and the within-tree scale.
At the within-tree scale, analyses revealed that the seeds dispersed by a tree later in the season tended to be larger in
size and lower in tannin concentration. Similarly, at the among-tree scale, analysis revealed that trees with a later seed
production schedule produced on average larger acorns. However, no clear tendency was observed between seed production schedule
and mean tannin concentration. The observed variation in seed production schedule is likely to affect seed fate per se, and
also via changes in seed characteristics. 相似文献
64.
65.
Nakayama T Watanabe Y Oiso N Higuchi T Shigeta A Mizuguchi N Katou F Hashimoto K Kawada A Yoshie O 《Journal of immunology (Baltimore, Md. : 1950)》2010,185(11):6472-6479
Eotaxin-3/CCL26 is a functional ligand for CCR3 and abundantly produced by IL-4-/IL-13-stimulated vascular endothelial cells. CCL26 also functions as a natural antagonist for CCR1, CCR2, and CCR5. In this study, we report that CCL26 is yet a functional ligand for CX3CR1, the receptor for fractalkine/CX3CL1, which is expressed by CD16(+) NK cells, cytotoxic effector CD8(+) T cells, and CD14(low)CD16(high) monocytes. Albeit at relatively high concentrations, CCL26 induced calcium flux and chemotaxis in mouse L1.2 cells expressing human CX3CR1 but not mouse CX3CR1 and competed with CX3CL1 for binding to CX3CR1. In chemotaxis assays using human PBMCs, CCL26 attracted not only eosinophils but also CD16(+) NK cells, CD45RA(+)CD27(-)CD8(+) T cells, and CD14(low)CD16(high) monocytes. Intraperitoneal injection of CCL26 into mice rapidly recruited mouse eosinophils and intravenously transferred human CD16(+) NK cells into the peritoneal cavity. IL-4-stimulated HUVECs produced CCL26 and efficiently induced adhesion of cells expressing CX3CR1. Real-time PCR showed that skin lesions of psoriasis consistently contained CX3CL1 mRNA but not CCL26 mRNA, whereas those of atopic dermatitis contained CCL26 mRNA in all samples but CX3CL1 mRNA in only about half of the samples. Nevertheless, the skin lesions from both diseases consistently contained CX3CR1 mRNA at high levels. Thus, CCL26 may be partly responsible for the recruitment of cells expressing CX3CR1 in atopic dermatitis particularly when the expression of CX3CL1 is low. Collectively, CCL26 is another agonist for CX3CR1 and may play a dual role in allergic diseases by attracting eosinophils via CCR3 and killer lymphocytes and resident monocytes via CX3CR1. 相似文献
66.
Foraging sites, diet, and diving behavior of chick-rearing Adélie penguins, Pygoscelis adeliae , in fast sea-ice areas were investigated during two consecutive seasons with contrasting sea-ice conditions. During 1995/1996, fast sea ice covered the foraging range of penguins during the whole breeding season. In contrast, during 1996/1997, sea ice covered the area in December 1996, but gradually thinned and finally broke up, so that open sea appeared along the coast during February 1997. Foraging sites were concentrated in a small area in 1995/1996 and spread over a wider area in 1996/1997 as more small open-water areas were available. In both seasons, parents traveled to more distant foraging sites as the season progressed and, consequently, the foraging-trip duration increased. In both years, Euphausia superba and Pagothenia borchgrevinki dominated the diet in the early part of the season, while later in the season penguins fed mainly on E. superba in 1995/1996 and Pagothenia borchgrevinki and E. crystallorophias in 1996/1997. In 1995/1996, penguins tended to dive deeper—albeit for a relatively shorter duration—when feeding mainly on krill compared to when feeding on fish. In 1996/1997, there was no difference in the dive depth and duration between krill- and fish-eating trips. Our results suggest that prey distribution changes annually and seasonally, probably according to sea-ice conditions, and that consequently penguins modify their foraging sites, diving patterns, and diet according to these changes. 相似文献
67.
Disturbances, elevation, topography and spatial proximity drive vegetation patterns along an altitudinal gradient of a top biodiversity hotspot 总被引:1,自引:0,他引:1
Pedro V. Eisenlohr Luciana F. Alves Luís Carlos Bernacci Maíra C. G. Padgurschi Roseli B. Torres Eduardo M. B. Prata Flavio Antonio M. dos Santos Marco Antônio Assis Eliana Ramos André Luís C. Rochelle Fernando R. Martins Mariana C. R. Campos Fernando Pedroni Maryland Sanchez Larissa S. Pereira Simone A. Vieira José Ataliba M. A. Gomes Jorge Y. Tamashiro Marcos A. S. Scaranello Cora J. Caron Carlos Alfredo Joly 《Biodiversity and Conservation》2013,22(12):2767-2783
The correlation between vegetation patterns (species distribution and richness) and altitudinal variation has been widely reported for tropical forests, thereby providing theoretical basis for biodiversity conservation. However, this relationship may have been oversimplified, as many other factors may influence vegetation patterns, such as disturbances, topography and geographic distance. Considering these other factors, our primary question was: is there a vegetation pattern associated with substantial altitudinal variation (10–1,093 m a.s.l.) in the Atlantic Rainforest—a top hotspot for biodiversity conservation—and, if so, what are the main factors driving this pattern? We addressed this question by sampling 11 1-ha plots, applying multivariate methods, correlations and variance partitioning. The Restinga (forest on sandbanks along the coastal plains of Brazil) and a lowland area that was selectively logged 40 years ago were floristically isolated from the other plots. The maximum species richness (>200 spp. per hectare) occurred at approximately 350 m a.s.l. (submontane forest). Gaps, multiple stemmed trees, average elevation and the standard deviation of the slope significantly affected the vegetation pattern. Spatial proximity also influenced the vegetation pattern as a structuring environmental variable or via dispersal constraints. Our results clarify, for the first time, the key variables that drive species distribution and richness across a large altitudinal range within the Atlantic Rainforest. 相似文献
68.
Kubota Yasuhiko Iso Hiroyasu Ikehara Satoyo Tamakoshi Akiko 《Sleep and biological rhythms》2015,13(1):85-93
Sleep and Biological Rhythms - Sleep duration could affect glucose tolerance and mortality. However, the impact that sleep duration has on prognosis of people with diabetes is unclear. A cohort of... 相似文献
69.
Akiko Tomaru Ryota Sasaki Hidekazu Miyahara Akitoshi Okino Nobuhiro Ogawa Koji Hamasaki 《PloS one》2014,9(1)
It has been reported that planula larvae of some jellyfish prefer artificial substrates for settlement. This research focused on the relationship between the settlement of planulae and the wettability of artificial substrate surfaces. We used atmospheric plasmas to change the wettability of the surfaces of polycarbonate (PC) plates because plasma treatment has no chemical side effects. The treatment made the surfaces hydrophilic, as evidenced by the decrease of contact angle from 85° to 35°. X-ray photoelectron spectroscopy revealed that the change of wettability of the PC plates could be attributed to N2, which was probably ionized in the air above the plates. Scanning electron microscopy revealed no difference in the surface morphology of the plates before and after plasma treatment. Results of bioassays using treated PC plates showed that planulae tended to preferentially settle on hydrophobic surfaces. 相似文献
70.
Ryuichi Miura Takanori Kooriyama Misako Yoneda Akiko Takenaka Miho Doki Yasuyuki Goto Chizu Sanjoba Yasuyuki Endo Tomoko Fujiyuki Akihiro Sugai Kyoko Tsukiyama-Kohara Yoshitsugu Matsumoto Hiroki Sato Chieko Kai 《PLoS neglected tropical diseases》2015,9(7)
Canine distemper virus (CDV) vaccination confers long-term protection against CDV reinfection. To investigate the utility of CDV as a polyvalent vaccine vector for Leishmania, we generated recombinant CDVs, based on an avirulent Yanaka strain, that expressed Leishmania antigens: LACK, TSA, or LmSTI1 (rCDV–LACK, rCDV–TSA, and rCDV–LmSTI1, respectively). Dogs immunized with rCDV-LACK were protected against challenge with lethal doses of virulent CDV, in the same way as the parental Yanaka strain. To evaluate the protective effects of the recombinant CDVs against cutaneous leishmaniasis in dogs, dogs were immunized with one recombinant CDV or a cocktail of three recombinant CDVs, before intradermal challenge (in the ears) with infective-stage promastigotes of Leishmania major. Unvaccinated dogs showed increased nodules with ulcer formation after 3 weeks, whereas dogs immunized with rCDV–LACK showed markedly smaller nodules without ulceration. Although the rCDV–TSA- and rCDV–LmSTI1-immunized dogs showed little protection against L. major, the cocktail of three recombinant CDVs more effectively suppressed the progression of nodule formation than immunization with rCDV–LACK alone. These results indicate that recombinant CDV is suitable for use as a polyvalent live attenuated vaccine for protection against both CDV and L. major infections in dogs. 相似文献