16 research outputs found
The dynamics of dissolved organic carbon concentration at the mountainous river in Japan
No full textSocial system, reproduction of helpers and sperm competition in the cooperatively breeding fishes (Julidochromis spp.) in Lake Tanganyika
No full textSeasonal occurrence and sexual maturation of Japanese pygmy squid (Idiosepius paradoxus) at the northern limits of their distribution
Get PDFThe distribution of aquatic animals is severely limited by water temperature. However, little is known about migration pattern, over-wintering and reproduction at the northern limits of their distribution. To investigate the sexual maturation of the Japanese pygmy squid (Idiosepius paradoxus) and its ability to survive during winter at the northern limits of its distribution, we conducted monthly collections at Usujiri in northern Japan and carried out low temperature tolerance experiments. Squids were collected only during four months in autumn and early winter. In autumn, all squids were large and sexually mature, and many egg masses were found on the surface of seagrass, whereas in early winter, only small immature squids were collected. A warm northward-flowing current reached near Usujiri in autumn. These results suggest that squids were transported by the current and some small squids were recruits that hatched at Usujiri. Field data and low temperature tolerance experiments showed that I. paradoxus can not survive in the low seawater temperature that occurs at Usujiri in winter. The migration pattern in I. paradoxus may differ from the major pattern where young fish are passively transported and never reproduce at the northern limits
Effects of organic matter in livestock manure digester liquid on microbial community structure and in situ activity of anammox granules
Get PDFAnaerobic ammonium oxidation (anammox) is a promising process for NH4+-rich wastewaters such as anaerobic digester liquids. In the present study, we investigated various properties of an up-flow column reactor containing anammox granules and fed with a real digester liquid at four different concentrations (Phases 1 to 4). The efficiencies of NH4+ and NO2- removal decreased by up to 32% and 42%, respectively, in the digester-liquid-fed reactor (reactor-DL). When the performance of reactor-DL deteriorated, the community structure, spatial distribution, and in situ anammox activity in the two reactors were further investigated using 16S rRNA gene-based phylogenetic analysis, fluorescence in situ hybridization (FISH), and microelectrode measurements. The phylogenetic analysis and FISH results showed that non-anammox bacteria were predominant in the granule outer layers in reactor-DL, whereas anammox bacteria still dominated the granule interiors. Microelectrode measurements showed clear evidence of NH4+ oxidation activity in the interiors of granules from reactor-DL. Batch experiments using anammox granules at different acetate concentrations indicated that concentrations up to 50 mM had no effects on the anammox activity, whereas inorganic carbon uptake decreased in the presence of acetate. The present study clearly shows that the anammox activity and anammox bacterial density in the granules were maintained after feeding the digester liquid to the reactor for 140 days
Host selection and ovipositor length in eight sympatric species of sculpins that deposit their eggs into tunicates or sponges
Get PDFInterspecific interactions between parasites and hosts can influence the evolution of behavioural and morphological adaptations of both parasites and their hosts. There is, however, little empirical evidence available regarding the evolution of reproductive traits driven by these interactions. In this paper, we investigated host selection and ovipositor length in nine sympatric marine sculpins that oviposit into tunicates or sponges. Field and genetic studies have revealed host use for eight out of nine species of sculpins investigated here: five species of Pseudoblennius, two species of Furcina and one species of Vellitor. For one species studied (V. minutus), no egg masses could be found. Ovipositor length reflects morphology of host species utilised: six sculpin species had extremely long ovipositors allowing females to attach eggs to the deep atrium of solitary tunicates, whereas the two species that attached their eggs to the small space of atrial siphon of colonial tunicates and the spongocoel of sponges had short ovipositors. Ovipositor length varied between solitary-tunicate spawners and species with longer ovipositors selected larger tunicates. Since the ancestral form is non-parasitic, the ovipositor evolved as an adaptation to utilise sponges and tunicates as hosts. Sculpins found sympatrically may show host specificity to avoid interspecific competition for spawning niches and ovipositors may have evolved depending on the species and size of host invertebrates
Rhamphocottus nagaakii (Cottoidea : Rhamphocottidae), a new species of grunt sculpin from the northwestern Pacific, with notes on the phylogeography of the genus Rhamphocottus
Get PDFA new species of grunt sculpin, Rhamphocottus nagaakii inhabiting the northwestern Pacific, previously identified as Rhamphocottus richardsonii Gunther 1874, is described based on genetic evidence and morphological differences. The new species can be distinguished based on morphometric characters related to the head, including head length [45.3-54.6% of standard length (SL)], postorbital head length (18.8-25.5% SL) and the length of pectoral-fin base (15.8-20.7% SL), which are smaller than in R. richardsonii (53.6-60.5% SL, 26.2-31.7% SL, and 19.5-25.2% SL, respectively). Genetic differences between two species markedly exceed levels for intra-specific differences. Rhamphocottus nagaakii is considered to have arisen from a common ancestor of the two species, which probably inhabited somewhere the North Pacific Rim around the Aleutian Archipelago. During a period of cooling in the Pliocene or the Miocene, R. nagaakii and R. richardsonii became separated to the southern regions of the northwestern and northeastern Pacific, and subsequently underwent speciation
Melatonin suppression during a simulated night shift in medium intensity light is increased by 10-minute breaks in dim light and decreased by 10-minute breaks in bright light
Get PDFExposure to light at night results in disruption of endogenous circadian rhythmicity and/or suppression of pineal melatonin, which can consequently lead to acute or chronic adverse health problems. In the present study, we investigated whether exposure to very dim light or very bright light for a short duration influences melatonin suppression, subjective sleepiness, and performance during exposure to constant moderately bright light. Twenty-four healthy male university students were divided into two experimental groups: Half of them (mean age: 20.0 +/- 0.9 years) participated in an experiment for short-duration (10 min) light conditions of medium intensity light (430 lx, medium breaks) vs. very dim light (< 1 lx, dim breaks) and the other half (mean age: 21.3 +/- 2.5 years) participated in an experiment for short-duration light conditions of medium intensity light (430 lx, medium breaks) vs. very bright light (4700 lx, bright breaks). Each simulated night shift consisting of 5 sets (each including 50-minute night work and 10-minute break) was performed from 01:00 to 06:00 h. The subjects were exposed to medium intensity light (550 lx) during the night work. Each 10-minute break was conducted every hour from 02:00 to 06:00 h. Salivary melatonin concentrations were measured, subjective sleepiness was assessed, the psychomotor vigilance task was performed at hourly intervals from 21:00 h until the end of the experiment. Compared to melatonin suppression between 04:00 and 06:00 h in the condition of medium breaks, the condition of dim breaks significantly promoted melatonin suppression and the condition of bright breaks significantly diminished melatonin suppression. However, there was no remarkable effect of either dim breaks or bright breaks on subjective sleepiness and performance of the psychomotor vigilance task. Our findings suggest that periodic exposure to light for short durations during exposure to a constant light environment affects the sensitivity of pineal melatonin to constant light depending on the difference between light intensities in the two light conditions (i.e., short light exposure vs. constant light exposure). Also, our findings indicate that exposure to light of various intensities at night could be a factor influencing the light-induced melatonin suppression in real night work settings
Association between decrease in frequency of going out and oral function in older adults living in major urban areas
Get PDFAim To examine the association between a decrease in the frequency of going out and oral function in independent older adults living in the urban area of Tokyo. Methods The participants analyzed were 785 older adults from the "Takashimadaira Study" (344 men and 441 women, age 77.0 +/- 4.6 years). This study investigated the following items: decrease in frequency of going out; basic characteristics (sex, age); physical factors, such as oral function (difficulty chewing, difficulty swallowing, dry mouth); body pain; the Japan Science and Technology Agency Index of Competence; physical activities; psychological factors, such as the Geriatric Depression Scale-15 score; and social and environmental factors, such as the presence or absence of participation in organization activities. Results To investigate the factors associated with a decrease in frequency of going out, logistic regression analysis showed an association with age (OR 1.08, 95% CI 1.03-1.13), difficulty chewing (OR 2.41, 95% CI 1.52-3.83), dry mouth (OR 1.68, 95% CI 1.07-2.64), body pain (OR 1.78, 95% CI 1.14-2.78), Japan Science and Technology Agency Index of Competence scores (OR 0.91, 95% CI 0.84-0.99), physical activities (OR 0.99, 95% CI 0.98-1.00), Geriatric Depression Scale-15 scores (OR 1.13, 95% CI 1.05-1.21) and organization activities (OR 1.94, 95% CI 1.22-3.07). Covariance structural analyses showed that both "difficulty chewing" and "dry mouth" significantly affected "decrease in frequency of going out." In addition, decrease in frequency of going out was significantly affected by " Geriatric Depression Scale-15 scores" through oral function. Conclusions The relationship between oral function and decrease in frequency of going out was clarified, after the multifaceted factors were adjusted. Geriatr Gerontol Int 2019; center dot center dot: center dot center dot-center dot center dot
Role of ferritin in the cytodifferentiation of periodontal ligament cells
No full textThis study investigated the expression and functions of ferritin, which is involved in osteoblastogenesis, in the periodontal ligament (PDL). The PDL is one of the most important tissues for maintaining the homeostasis of teeth and tooth-supporting tissues. Real-time PCR analyses of the human PDL revealed abundant expression of Puffin light polypeptide (FTL) and ferritin heavy polypeptide (FTH), which encode the highly-conserved iron storage protein, ferritin. Immunohistochemical staining demonstrated predominant expression of FTL and FTH in mouse PDL tissues in vivo. In in vitro-maintained mouse PDL cells, FTL and FTH expressions were upregulated at both the mRNA and protein levels during the course of cytodifferentiation and mineralization. Interestingly, stimulation of PDL cells with exogenous apoferritin (iron-free ferritin) increased calcified nodule formation and alkaline phosphatase activity as well as the mRNA expressions of mineralization-related genes during the course of cytodifferentiation. On the other hand, RNA interference of FTH inhibited the mineralized nodule formation of PDL cells. This is the first report to demonstrate that ferritin is predominantly expressed in PDL tissues and positively regulates the cytodifferentiation and mineralization of PDL cells. (C) 2012 Elsevier Inc. All rights reserved.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000310101000034&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Biochemistry & Molecular BiologyBiophysicsSCI(E)PubMed7ARTICLE4643-64842
Ethanol and cyclophosphamide induce similar nephrotoxic effects: possible role for Nox4 and superoxide
Get PDFWe tested the hypothesis that ethanol consumption would aggravate the renal damage induced by cyclophosphamide (CYP). Male C57BL/6J mice from control (n=8) and CYP (n=12) groups had free access to filtered water and standard rodent chow for 12 weeks. Then, 24 h before euthanasia mice received an intraperitoneal injection of saline or CYP (300 mg/kg). Mice from ethanol (n=8) and CYP + ethanol (n=12) groups had free access to increasing doses of ethanol for 12 weeks. Twenty four hours before euthanasia, mice from ethanol and CYP + ethanol groups received an intraperitoneal injection of saline or CYP, respectively. Ethanol, CYP or the association of both drugs augmented serum levels of creatinine and increased the levels of superoxide (O2•-) generation and thiobarbituric acid reactive substances (TBARS) in the renal cortex. Up-regulation of Nox4 and increased activity of superoxide dismutase (SOD) were detected in the renal cortex of mice treated with ethanol, CYP or the combination of these drugs. However, these molecular alterations induced by CYP were not potentiated by ethanol consumption. Our findings revealed that chronic ethanol consumption had no potentiating effect on the nephrotoxic effects displayed by CYP. It is possible that the combination of these drugs showed no synergistic effect because they share the same molecular mechanisms of renal toxicity.The presentation of the authors' names and (or) special characters in the title of the pdf file of the accepted manuscript may differ slightly from what is displayed on the item page. The information in the pdf file of the accepted manuscript reflects the original submission by the author
