Soil nitrogen dynamics during stand development after clear-cutting of Japanese cedar (Cryptomeria japonica) plantations

We examined soil N dynamics, including inorganic N concentration, net N transformation rates, and estimated plant N uptake (EPNU) from soil N budgets, and litterfall inputs, in five Japanese cedar plantation stands of different ages (5, 16, 31, 42, and 89 years) in the Mt Gomadan Experimental Forest (GEF). Net soil N mineralization and nitrification rates did not differ significantly between the youngest and oldest stands; soil moisture and inorganic N concentration were higher in the youngest stand. The EPNU was highest in the 16-year-old stand and lowest in the 31-year-old stand, and had a significant negative correlation with litter C:N ratio. The oldest (89-year-old) stand had a higher soil C:N ratio, lower proportion of nitrification rate to mineralization rate (%NIT), and higher estimated plant NH4 + uptake than did the other stands, indicating that changes of soil organic matter quality can alter soil N dynamics. These results suggest that as a Japanese cedar plantation develops, soil N dynamics can be altered by the quantity and quality of input litter and soil organic matter, and can generate the imbalance between N supply from soil and N demand by plant

Deer grazing drove an assemblage‐level evolution of plant dwarfism in an insular system

屋久島のミニチュア植物群の進化はシカの採食圧が原因だった！80種にわたる植物の大規模な収れん進化の解明. 京都大学プレスリリース. 2024-05-10.1. Plant dwarfism, a syndrome characterised by a significant reduction in plantheight and organ size, is a widely observed pattern of stress-tolerant life-formevolution that results from local adaptation to harsh environmental conditions.The drivers of assemblage-level dwarfism have primarily been attributed to abi-otic factors, such as low temperature, aridity, poor soil fertility or frequent fires.While biotic factors such as grazing pressure from herbivores can contribute tothe establishment of plant dwarfism, these factors have rarely been tested at as-semblage levels. 2. Focusing on a dwarf plant assemblage comprising over 80 taxa on a small conti-nental island in Japan with a high deer density, we hypothesised that historicaldeer grazing could also be a factor contributing to the large-scale convergentevolution of dwarfism. 3. To test this hypothesis, we measured the size of 1908 individual plants of 40 taxapairs, comprising both palatable and unpalatable pairs from the island and theircounterpart taxa from neighbouring regions, and sought to assess which factors(i.e. low solar radiation, estimated divergence time, low nutrient conditions andgrazing pressure from deer) may have contributed to the formation of the dwarfplant assemblage on the island. We also performed genetic analysis to infer thetime frames for the establishment of dwarf taxa. 4. Statistical analyses revealed that plant size was significantly reduced mainlyamong the palatable taxa growing on the island, with preferential grazing by deerbeing identified as the most significant factor influencing plant size. Furthermore, genetic analyses revealed that dwarf ecotypes may have evolved over tens ofthousands of years. 5. Synthesis: To the best of our knowledge, this study is the first to demonstratethat interactions with herbivores can shape the assemblage-level convergence ofplant dwarfism. These findings enhance our current understanding of the forma-tion of plant functional diversity

Role of protein kinase C-δ in isoproterenol-induced amylase release in rat parotid acinar cells

In parotid acinar cells, β-adrenergic receptor activation results in accumulation of intracellular cAMP. Subsequently, cAMP-dependent protein kinase (PKA) is activated and consequently amylase release is provoked. In this paper, we investigated involvement of protein kinase C-δ(PKCδ), a novel isoform of PKC, in amylase release induced by β-adrenergic receptor stimulation. Amylase release stimulated with the β-agonsit isoproterenol (IPR) was inhibited by rottlerin, an inhibitor of PKCδ. IPR activated PKCδ and the effect of IPR were inhibited by a PKA inhibitor, H89. Myristoylated alanine-rich C kinase substrate (MARCKS), a major cellular substrate for PKC, was detected in rat parotid acinar cells, and a MARCKS inhibitor, MARCKS-related peptide, inhibited the IPR-induced amylase release. IPR stimulated MARCKS phosphorylation, which was found to be inhibited by H89 and rottlerin. These observations suggest that PKCδ activation is a downstream pathway of PKA activation and is involved in amylase release via MARCKS phosphorylation in rat parotid acinar cells stimulated with β-adrenergic agonist

ショウニ シッカン (<トクシュウ>キュウキュウ シッカン ノ シンリョウ ノ ジッサイ)

乳幼児は自分の症状を言葉で訴えることができない.したがって,親がみて病状を判断している.普段みている親が感じる子どもの変化に対する判断は重要である一方,親からみて子どもの疾病を初期か高次救急か区別することはできない.親にとってはすべてが高次救急なのである.少子化時代となり,数少ない子どもたちを大事に育てたいという親の意識が高まり, "いつでも安心できる質の高い小児医療"を求めるようになってきている.これに対し, "不要な受診を減らすべき"との医療者側の論理で対応するのではなく, "疾病で因っている子どもとその家族の不安を取り除くことが小児救急である"との原点に戻った立場で対応することが望ましい.小児救急の現場では,多くの軽症者のなかから重篤な疾患を見逃さない選別能力が必要とされる.また,結果として軽症に終わることがほとんどだが,早期に対応しないとその後病状の悪化を引き起し,軽症で治まらなくなることもあり得ることが小児の特徴と思われる.小児の救急疾患は数多くあるが,紙面の都合もあるので,今回は救急の現場でよく遭遇する代表的なものを症候別に5つ取り上げて解説する

The thiol-oxidizing agent diamide reduces isoproterenolstimulated amylase release in rat parotid acinar cells

In parotid acinar cells, activation of β-adrenergic receptors provokes exocytotic amylase release via the accumulation of intracellular cAMP. Cellular redox status plays a pivotal role in the regulation of various cellular functions. Cellular redox imbalance caused by the oxidation of cellular antioxidants, as a result of oxidative stress, induces significant biological damages. In this study, we examined effect of diamide, a thioloxidizing reagent, on amylase release in rat parotid acinar cells. In the presence of diamide, isoproterenol (IPR)-induced cAMP formation and amylase release were partially reduced. Diamide had no effect on amylase release induced by forskolin and mastoparan, an adenylate cyclase activator and heterotrimeric GTP binding protein activator, respectively. In the cells pretreated with diamide, the binding affinity of [3H]dihydroalprenolol to β-receptors was reduced. These results suggest that oxidative stress results in reduction of binding affinity of ligand on β-receptor and consequently reduces protein secretory function in rat parotid acinar cells

Evaluating the Need for and Effect of Percutaneous Transluminal Angioplasty on Arteriovenous Fistulas by Using Total Recirculation Rate per Dialysis Session (“Clearance Gap”)

The functioning of an arteriovenous fistula (AVF) used for vascular access during hemodialysis has been assessed mainly by dilution methods. Although these techniques indicate the immediate recirculation rate, the results obtained may not correlate with Kt/V. In contrast, the clearance gap (CL-Gap) method provides the total recirculation rate per dialysis session and correlates well with Kt/V. We assessed the correlation between Kt/V and CL-Gap as well as the change in radial artery (RA) blood flow speed in the fistula before percutaneous transluminal angioplasty (PTA) in 45 patients undergoing continuous hemodialysis. The dialysis dose during the determination of CL-Gap was 1.2 to 1.4 Kt/V. Patients with a 10% elevation or more than a 10% relative increase in CL-Gap underwent PTA (n＝45), and the values obtained for Kt/V and CL-Gap before PTA were compared with those obtained immediately afterward. The mean RA blood flow speed improved significantly (from 52.9 to 97.5cm/sec) after PTA, as did Kt/V (1.07 to 1.30) and CL-Gap (14.1% to －0.2%). A significant correlation between these differences was apparent (r＝－0.436 and p＝0.003). These findings suggest that calculating CL-Gap may be useful for determining when PTA is required and for assessing the effectiveness of PTA, toward obtaining better dialysis

Sources of uncertainty in estimating stream solute export from headwater catchments at three sites

Uncertainty in the estimation of hydrologic export of solutes has never been fully evaluated at the scale of a small-watershed ecosystem. We used data from the Gomadansan Experimental Forest, Japan, Hubbard Brook Experimental Forest, USA, and Coweeta Hydrologic Laboratory, USA, to evaluate many sources of uncertainty, including the precision and accuracy of measurements, selection of models, and spatial and temporal variation. Uncertainty in the analysis of stream chemistry samples was generally small but could be large in relative terms for solutes near detection limits, as is common for ammonium and phosphate in forested catchments. Instantaneous flow deviated from the theoretical curve relating height to discharge by up to 10% at Hubbard Brook, but the resulting corrections to the theoretical curve generally amounted to \u3c0.5% of annual flows. Calibrations were limited to low flows; uncertainties at high flows were not evaluated because of the difficulties in performing calibrations during events. However, high flows likely contribute more uncertainty to annual flows because of the greater volume of water that is exported during these events. Uncertainty in catchment area was as much as 5%, based on a comparison of digital elevation maps with ground surveys. Three different interpolation methods are used at the three sites to combine periodic chemistry samples with streamflow to calculate fluxes. The three methods differed by \u3c5% in annual export calculations for calcium, but up to 12% for nitrate exports, when applied to a stream at Hubbard Brook for 1997–2008; nitrate has higher weekly variation at this site. Natural variation was larger than most other sources of uncertainty. Specifically, coefficients of variation across streams or across years, within site, for runoff and weighted annual concentrations of calcium, magnesium, potassium, sodium, sulphate, chloride, and silicate ranged from 5 to 50% and were even higher for nitrate. Uncertainty analysis can be used to guide efforts to improve confidence in estimated stream fluxes and also to optimize design of monitoring programmes

eDNA metabarcoding analysis reveals the consequence of creating ecosystem‐scale refugia from deer grazing for the soil microbial communities

シカの森林被害は土壌微生物にも波及する --大規模生態系操作実験と環境DNA分析の融合--. 京都大学プレスリリース. 2023-12-22.Ungulate overbrowsing is a growing problem in forests worldwide due to its prolonged and pervasive impact on plant biodiversity and ecosystem functioning. It has been shown that overbrowsing not only reduces plant species diversity and biomass (i.e., direct effects) but also causes a loss of associated trophic levels that could potentially feedback to influence plant community structure (i.e., indirect effects). One of the primary pathways of such indirect effects that have not been fully examined is the impact of overbrowsing on soil microorganisms. Recent studies have shown that soil microorganisms maintain vegetation diversity and drive succession, so it is of critical importance to understand how soil microbial communities might be affected by or protected from the deer impact. To assess the consequence of creating artificial grazing refugia on the structure and composition of soil microbial communities, we compared the distribution and abundance of soil microbial taxa (bacteria, archaea, fungi) at the fenced versus unfenced control sites in the context of a catchment-scale field experiment in Japan. The eDNA metabarcoding analysis of soil microbial communities showed that the numbers of archaea and basidiomycetes fungal species were greater in the fenced site than in the control, while no such pattern was found for bacteria and ascomycetes fungi. Despite the lack of significant influence of the fence treatment on taxonomic composition in the soil fungal communities, their functional guild composition was influenced by the fenced treatment, with significant changes in the abundance of animal pathogens. Thus, although the effect of fencing on soil microbial communities is characterized by complex responses that vary from taxon to taxon, our work suggests that creating ecosystem-scale refugia from deer overgrazing might help sustain certain, if not all, taxa of soil microbial communities

Clinical features and subdural lesions in childhood onset Haemophilus influenzae meningitis

It becomes difficult to treat the onset of childhood Haemophilus influenza type b( Hib) meningitis due tothe appearance of b-lactamase negative ampicilin resistance( BLNAR). We investigated the clinical featuresof Hib meningitis with subdural lesions. From January 2000 to December 2006, we experienced 8 patientswith Hib meningitis. All patients were not inoculated with Hib vaccine. Five of them were onset under 1year old. Rapid latex diagnoses were made in 5 patients, among whom 4 patients showed Hib positive. Thegenotypes were determined in 4 patients with BLNAR. Combined with cefotaxime sodium (CTX) and ampicillin(ABPC) were used in 3 patients for the initial antibiotics, panipenem/betamipron( PAPM/BP) in 2,meropenem hydrate( MEPM) in 1, MEPM + ceftriaxone sodium( CTRX) in 1, and concomitant use of dexamethasonein 7 paitents. MRI showed subdural hygroma in 4 patients and subdural abscess in 4 patients.Subdural lesions appeared on Day 1 to Day 18 from the onset. Three patients with subdural abscess haveperformed subdural taps, and 2of them with difficulties after subdural taps were necessary to do oral administrationof chloramphenicol( CP).In our report, all of the patients developed subdural lesions. The development of subdural lesions cannotbe avoided with only the conventional antibiotics and dexamethasone therapy. Our cases suggested earliersubdural taps with oral administration of CP might be to improve both the general condition and control thesubdural lesions with Hib meningitis. Moreover, we should pay attention to the preventive vaccination ofHib

The Japanese space gravitational wave antenna; DECIGO

DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. DECIGO is expected to open a new window of observation for gravitational wave astronomy especially between 0.1 Hz and 10 Hz, revealing various mysteries of the universe such as dark energy, formation mechanism of supermassive black holes, and inflation of the universe. The pre-conceptual design of DECIGO consists of three drag-free spacecraft, whose relative displacements are measured by a differential Fabry– Perot Michelson interferometer. We plan to launch two missions, DECIGO pathfinder and pre- DECIGO first and finally DECIGO in 2024