224 research outputs found
Network-dependent modulation of brain activity during sleep
AbstractBrain activity dynamically changes even during sleep. A line of neuroimaging studies has reported changes in functional connectivity and regional activity across different sleep stages such as slow-wave sleep (SWS) and rapid-eye-movement (REM) sleep. However, it remains unclear whether and how the large-scale network activity of human brains changes within a given sleep stage. Here, we investigated modulation of network activity within sleep stages by applying the pairwise maximum entropy model to brain activity obtained by functional magnetic resonance imaging from sleeping healthy subjects. We found that the brain activity of individual brain regions and functional interactions between pairs of regions significantly increased in the default-mode network during SWS and decreased during REM sleep. In contrast, the network activity of the fronto-parietal and sensory-motor networks showed the opposite pattern. Furthermore, in the three networks, the amount of the activity changes throughout REM sleep was negatively correlated with that throughout SWS. The present findings suggest that the brain activity is dynamically modulated even in a sleep stage and that the pattern of modulation depends on the type of the large-scale brain networks
Distribution of local 137Cs anomalies on the seafloor near the Fukushima Dai-ichi Nuclear Power Plant
An estimated 3.5 ± 0.7 × 1015 Bq of 137Cs is thought to have been discharged into the ocean following the melt down at Fukushima Dai-ichi Nuclear Power Plant (F1NPP). While efforts have been made to monitor seafloor radiation levels, the sampling techniques used cannot capture the continuous distribution of radionuclides. In this work, we apply in situ measurement techniques using a towed gamma ray spectrometer to map the continuous distribution of 137Cs on the seafloor within 20 km of the F1NPP. The results reveal the existence of local 137Cs anomalies, with levels of 137Cs an order of magnitude higher than the surrounding seafloors. The sizes of the anomalies mapped in this work range from a few meters to a few hundreds of meters in length, and it is demonstrated that the distribution of these anomalies is strongly influenced by meter scale features of the terrain
Membrane-Type 1 Matrix Metalloproteinase Regulates Collagen-dependent Mitogen-Activated Protein/Extracellular Signal-Related Kinase Activation and Cell Migration
Membrane-type 1 matrix metalloproteinase modulates focal adhension stability and cell migration
Division of Molecular Viology and Oncolog
Circulating inhibin and testosterone during sexual maturation and reproductive seasonality of captive male killer whales (Orcinus orca)
The present study aimed to investigate the reproductive biology of male killer whales. Changes in the concentrations of two circulating testicular hormones, inhibin and testosterone, were monitored during sexual maturation of two male Type 1 Eastern Northern Atlantic killer whales over a period of 20 years. The two killer whales grew rapidly at the pubertal stage and reached a plateau at the age of 23 and 20 years, respectively, after which growth slowed down. In the younger male, circulating inhibin was higher in the juvenile than in the pubertal and mature stages; whereas circulating testosterone exhibited the opposite trend. The pubertal period was estimated to last approximately 5 years, from 12 to 17 years of age. In the elder male, circulating testosterone was high from the onset of this study (12 years of age), when the animal also sired successfully for the first time. This finding shows that the male killer whale is possible to sire even if it is not socially matured, if there is opportunity for copulation. During the mature stage, both animals exhibited significantly higher circulating testosterone concentrations in spring compared to autumn and winter; whereas no seasonal change was observed for circulating inhibin. These results clearly demonstrate that the male killer whale is a seasonal breeder, even though it is fertile throughout the year. This is the first study to elucidate the inhibin concentration and secretory source in the male killer whale
Gravity sensing in plant and animal cells
Gravity determines shape of body tissue and affects the functions of life, both in plants and animals. The cellular response to gravity is an active process of mechanotransduction. Although plants and animals share some common mechanisms of gravity sensing in spite of their distant phylogenetic origin, each species has its own mechanism to sense and respond to gravity. In this review, we discuss current understanding regarding the mechanisms of cellular gravity sensing in plants and animals. Understanding gravisensing also contributes to life on Earth, e.g., understanding osteoporosis and muscle atrophy. Furthermore, in the current age of Mars exploration, understanding cellular responses to gravity will form the foundation of living in space
Development of fully automated and ultrasensitive assays for urinary adiponectin and their application as novel biomarkers for diabetic kidney disease
Glomerular filtration rate (GFR) and urinary albumin excretion rate (UAER) are used to diagnose and classify the severity of chronic kidney disease. Total adiponectin (T-AN) and high molecular weight adiponectin (H-AN) assays were developed using the fully automated immunoassay system, HI-1000 and their significance over conventional biomarkers were investigated. The T-AN and H-AN assays had high reproducibility, good linearity, and sufficient sensitivity to detect trace amounts of adiponectin in the urine. Urine samples after gel filtration were analyzed for the presence of different molecular isoforms. Low molecular weight (LMW) forms and monomers were the major components (93%) of adiponectin in the urine from a diabetic patient with normoalbuminuria. Urine from a microalbuminuria patient contained both high molecular weight (HMW) (11%) and middle molecular weight (MMW) (28%) adiponectin, although the LMW level was still high (52%). The amount of HMW (32%) and MMW (42%) were more abundant than that of LMW (24%) in a diabetic patient with macroalbuminuria. T-AN (r = − 0.43) and H-AN (r = − 0.38) levels showed higher correlation with estimated GFR (eGFR) than UAER (r = − 0.23). Urinary levels of both T-AN and H-AN negatively correlated with renal function in diabetic patients and they may serve as new biomarkers for diabetic kidney disease
c-Axis Transport and Resistivity Anisotropy of Lightly- to Moderately-Doped La_{2-x}Sr_{x}CuO_{4} Single Crystals: Implications on the Charge Transport Mechanism
Both the in-plane and the out-of-plane resistivities (\rho_{ab} and \rho_{c})
are measured in high-quality La_{2-x}Sr_{x}CuO_{4} (LSCO) single crystals in
the lightly- to moderately-doped region, x = 0.01 to 0.10, and the resistivity
anisotropy is determined. In all the samples studied, the anisotropy ratio \rho
_{c}/\rho_{ab} quickly increases with decreasing temperature, although in
non-superconducting samples the strong localization effect causes \rho
_{c}/\rho_{ab} to decrease at low temperatures. Most notably, it is found that
\rho_{c}/\rho_{ab} at moderate temperatures (100 - 300 K) is almost completely
independent of doping in the non-superconducting regime (x = 0.01 to 0.05);
this indicates that the same charge confinement mechanism that renormalizes the
c-axis hopping rate is at work down to x = 0.01. It is discussed that this
striking x-independence of \rho_{c}/\rho_{ab} is consistent with the idea that
holes form a self-organized network of hole-rich regions, which also explains
the unusually metallic in-plane transport of the holes in the lightly-doped
region. Furthermore, the data for x > 0.05 suggest that the emergence of the
superconductivity is related to an increase in the c-axis coupling.Comment: 7 pages, 5 figures, submitted to Phys. Rev.
ブンベン ゼンゴ ノ クロゲワシュ ト ホルスタインシュ ボシウシ ニ オケル ニュウ ナラビニ ケッセイチュウ レチノイドリョウ ト カロテノイドリョウ ノ ヘンドウ
分娩前後の黒毛和種およびホルスタイン種の母子牛間における乳並びに血清中レチノイド量とカロテノイド量の変動を明らかにするために,2つの試験を実施した.すなわち,試験1で分娩前後の黒毛和種6頭とそれらから生まれた子牛6頭の合計12頭を用いて,分娩直後から7ヵ月間の母子牛の血清中レチノールとβカロテン量を測定した。試験2では,黒毛母牛5頭とこれらから分娩された子牛5頭,並びにホルスタイン母牛5頭とこれらから分娩された子牛5頭の合計20頭を用いて,分娩前から分娩8~12週間の乳並びに血中のレチノイド量およびカロテノイド量の変動について精査した。その結果は以下のように要約される.(1) 出生直後の子牛血清中レチノール量は,母牛のそれに比較して少なく,1ヵ月後には,0.19μg/mlの低値を示し,母牛の0.31μg/mlに対して約1/2量であった。(2) 子牛の血清中レチノール量は,出生3ヵ月以降急激に増加し,6ヵ月後には母牛のレチノール量と同等の値を示し,それ以降は顕著な変動を認めなかった。(3) 母乳中レチニールパルミテート量は,分娩直後から1週後にかけて顕著な増加を示し,それ以降は急激に減少し,極微量が検出されるか,あるいは測定限界以下であった。(4) 乳中レチノール量は,分娩後急激に減少し,極微量か測定限界以下であった。(5) αカロテンは黒毛母牛とホルスタイン母牛の血清中のみに認められた。(6) βカロテンは,分娩直後の初乳中に多く含まれ,それ以降は急激に減少した。また,サイレージ給与量が多く,βカロテン含有の高い配合飼料を給与したホルスタイン母牛の血清中に高い値のレチノール量とβカロテン量が認められた。母牛の血中βカロテン量が分娩2週後から増加するのに対して,子牛血中のそれは極めて微量で推移する傾向が認められた。We curried out experiments to investigate the fluctuation of retinoid and carotenoid level in milk, sera and compound feed of Japanese Black and Holstein dams and calves of before and after the parturition. At the first experiment, we used Japanese Black dams (6 heads) and their calves (6 heads), and compared the change of retinol and β carotene level in their sera at parturition and up to 7 months after parturition. The results showed retinol level (0.21μg/ml) in sera of calves at birth were low than that (0.28μg/ml) of dam. Retinol level of one month old calves showed 0.19μg/ml. However, retinol level in sera of calves sharply increased 3 months after parturition, and that of calves showed similar level to dam\u27s retinol level in sera. At the second experiment, we used 5 dam and 5 calves of Japanese Black and the same number of Holstein to investigate the fluctuation of retinoid and carotenoid in sera and milk a before and after parturition. The level of retinyl palmitate in milk sharply increased from parturition to 1 month after parturition, but then rapidly decreased, and the vestigial level were detected in analysis by HPLC (Shimazu Co., Ltd, LC-6A). Retinol level in milk sharply decreased after parturition, and it was almost undetected or only in extremely small amounts in analysis by HPLC. α carotene level showed only in sera of dam. A lot of β carotene was contained in colostrums, but it rapidly decreased from that time. The a results suggested that a large volume of retinoid and carotenoid were transferred from the dam\u27s blood to the calves at the fetal stage and from the colostrums to the new born
ニホンウズラ COTURNIX JAPONICA マッショウケツリンパキュウカッセイカ ニ オケル 4シュ ノ マイトージェン ノ バイヨウシテキノウド
ニホンウズラの末梢血リンパ球活性化におけるConA, PHA-L, PHA-MとPWMのマイトージェンの至適培養濃度を検討した。末梢血よりリンパ球をPercoll密度勾配遠心法により分離し,2×106/ml浮遊液に調製し,各マイトージェンを0~1,000μg/ml添加したRPMI1640培地(血清不含)で0,24,48,72時間培養した。各培養時間後にMTTアッセイにより細胞活性を測定し,培養0時間の測定値を1として各培養条件での細胞活性率を算出した。その結果,ConAおよびPHA-M刺激では濃度依存的に細胞活性率は低下した。一方,PWM刺激時の細胞活性率はPWM濃度依存的に上昇した。また,PHA-L刺激時の細胞活性率は濃度によって異なる反応を呈した。すなわちPHA-L1.0μg/mlでは,培養48時間後に低下した細胞活性率が72時間培養後に高くなり,濃度2.5μg/ml以上,培養48時間後の細胞活性率は他の3つのマイトージェンに比べて常に高く,さらに濃度12.5および125μg/mlでは,48時間培養後に最も高くなり,500μg/mlでは72時間培養後に最も高くなった。マイトージェンとして最も利用されているConAはニホンウズラの末梢リンパ球に対しては生存阻害的に働くことが示唆された。PWMは4つのマイトージェンの中で24時間培養後に全濃度において最も細胞活性率が高くなり,その活性化された細胞の作用によって48時間培養後の1~25μg/mlの低濃度で低下し,強い抑制細胞間相互作用が働いたことが示唆された。以上のことから,ウズラリンパ球に対しConAは細胞死誘導に有効であり,PWMは一部の細胞に対してのみ高濃度の500μg/ml以上で培養時間とその濃度を変えることにより特定なリンパ球サブセットを効率的に活性化しうることが示唆された。ウズラリンパ球に対してPHA-Mは低濃度の1~2.5μg/ml濃度,48と72時間培養で活性化効果があり,最もマイトージェンとして適しているのは他のマイトージェンと顕著に異なり濃度による活性化抑制・阻害効果を示さないPHA-Lであり,48時間培養で1~1000μg/mlの広範囲な濃度で活性化効果が得られることが明確となった。The aim of this study was to identify and establish optimal concentrations of four different mitogens : ConcanavalinA (ConA), pokeweed mitogen (PWM), phytohemagglutinin-M (PHA-M), and phytohemagglutinin-L (PHA-L) in stimulating purified peripheral blood lymphocytes (PBL) from Japanese quails. PBL were analyzed on their ability to respond to each of the four mitogens. Our results suggest that the effective dose for PBL activation and proliferation in Japanese quails are 50~1,000μg/ml for 48h with PWM, 1.25~2.5μg/ml for 72 h with PHA-M, and 1~1,000μg/ml for 48h with PHA-L. ConA was least effective among 4 mitogens to activate quail PBL and higher concentrations was adversely affect PBL viability. PWM did not promote PBL response at low concentrations (1~12.5μg/ml), but concentrations greater than 500μg/ml PWM induced the activation of PBL. PHA-M stimulated PBL in a dose-dependent manner, and the most effective response was observed at the PHA-M concentrations of 50μg/ml or more and culture time of 72 hours. On the other hand, PHA-L was effective at a wide range of concentrations, making it the most suitable mitogen for Japanese quail PBL activation and proliferation. Further, these findings support the idea that a high dose of ConA can induce apoptosis in quail PBL. Although PWM had relatively little effect on overall quail PBL activation and proliferation, there is reason to believe that certain lymphocyte subsets within the Japanese quail PBL population might be activated with a high dose of PWM
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