Origin and hydrodynamics of xylem sap in tree stems, and relationship to root uptake of soil water

Although 10 years have passed since Japan's Fukushima nuclear accident, the future radiation risk from ¹³⁷Cs contamination of wood via root uptake is a serious concern. We estimated the depth at which the roots of evergreen coniferous sugi (Cryptomeria japonica) and broadleaf deciduous konara (Quercus serrata) trees actively take up soil water by using positive δD values from the artificial D₂O tracer and seasonal changes in the δ¹⁸O values of soil water as a natural environmental tracer. We compared the tracer concentration changes in xylem sap with those in the soil water and ascertained that both tree species primarily took up water from a depth of 20 cm, though with mixing of water from other depths. Using sap hydrodynamics in tree stems, we found that water circulation was significantly slower in heartwood than in sapwood. Heartwood water was not supplied by direct root uptake of soil water. The measured diffusion coefficients for D₂O, K⁺, Cs⁺, and I⁻ in xylem stems were greater in sapwood than in heartwood, and their magnitude was inversely correlated with their molecular weights. The distribution of D₂O and ¹³⁷Cs concentrations along the radial stem could be explained by simulations using the simple advective diffusion model

Optimization of the moment of inertia and the release conditions of a discus

AbstractThis paper describes the concurrent optimization of the design of a discus and the skill with which it is thrown. The objective function for optimization is the flight distance, where longer is better. Thirteen control variables are considered, twelve of which are concerned with the skill of the thrower. These determine the launch conditions, which are controlled by the thrower when he or she throws the discus. The final variable is concerned with the discus itself. This is the moment of inertia on its transverse axis. The optimization was carried out with the aid of a genetic algorithm, and the entire trend for each generation between the objective function and the control variables could be visualized with the aid of self organizing maps. It was found that the flight distance achieved with concurrent optimization was longer than that optimized for skill alone. In the case of the optimal flight, the angle of attack should always be less than the stalling angle

テンイセイ サイガン Sister Mary Joseph’s nodule ノ 2レイ

The nodular umbilical metastasis of the visceral carcinoma has been termed the “SisterMary Joseph’s nodule” (SMJN), and is one of signs of a terminal condition. There are variousroutes of metastasis according to anatomical and embryological specificity. We reporttwo cases of metastatic adenocarcinoma of the umbilicus, and also reviewed the 108 cases ofSNJN that have been reported in Japan.The patients were 49 year-old man and 84 year-old woman who were referred to ourhospital with umbilical nodules. Examination by computed tomographies, a biopsy and anextirpation of umbilical nodules showed that the primary malignancies were the pancreascancer and the gallbladder cancer.Of 110 SMJN cases in Japan, thirty-one were men and seventy-six were women, and theprimary focus was found in the stomach (45/103 : 39%), ovarium (18/103 : 13%), pancreas (14/103 : 15%) or colon (11/103 : 12%). In fifty-two cases (52/94 : 55%), initial presentation of theinternal organ carcinoma was an umbilical nodule.It is generally reported that the prognosis of the patient with SMJN is extremely poor,but a few cases get the long survival after extirpation of SMJN. In order to decide propertreatment and prognosis, it is necessary us to further examine the primary malignancy andthe route of metastasis for the SMJN patient

Bacterial nucleoid dynamics: oxidative stress response in Staphylococcus aureus

A single-molecule-imaging technique, atomic force microscopy (AFM) was applied to the analyses of the genome architecture of Staphylococcus aureus. The staphylococcal cells on a cover glass were subjected to a mild lysis procedure that had maintained the fundamental structural units in Escherichia coli. The nucleoids were found to consist of fibrous structures with diameters of 80 and 40 nm. This feature was shared with the E. coli nucleoid. However, whereas the E. coli nucleoid dynamically changed its structure to a highly compacted one towards the stationary phase, the S. aureus nucleoid never underwent such a tight compaction under a normal growth condition. Bioinformatic analysis suggested that this was attributable to the lack of IHF that regulate the expression of a nucleoid protein, Dps, required for nucleoid compaction in E. coli. On the other hand, under oxidative conditions, MrgA (a staphylococcal Dps homolog) was over-expressed and a drastic compaction of the nucleoid was detected. A knock-out mutant of the gene encoding the transcription factor (perR) constitutively expressed mrgA, and its nucleoid was compacted without the oxidative stresses. The regulatory mechanisms of Dps/MrgA expression and their biological significance were postulated in relation to the nucleoid compaction

Probiotics into outer space: feasibility assessments of encapsulated freeze-dried probiotics during 1 month’s storage on the International Space Station

Suppression of immune function during long spaceflights is an issue that needs to be overcome. The well-established probiotic Lactobacillus casei strain Shirota (LcS) could be a promising countermeasure, and we have launched a project to investigate the efficacy of its use on the International Space Station (ISS). As a first step, we developed a specialist probiotic product for space experiments, containing freeze-dried LcS in capsule form (Probiotics Package), and tested its stability through 1 month of storage on the ISS. The temperature inside the ISS ranged from 20.0 to 24.5 °C. The absorbed dose rate of the flight sample was 0.26 mGy/day and the dose equivalent rate was 0.52 mSv/day. The number of live LcS was 1.05 × 1011 colony-forming units/g powder (49.5% of the initial value) 6 months after the start of the study; this value was comparable to those in the two ground controls. Profiles of randomly amplified polymorphic DNA, sequence variant frequency, carbohydrate fermentation, reactivity to LcS-specific antibody, and the cytokine-inducing ability of LcS in the flight sample did not differ from those of the ground controls. We can therefore maintain the viability and basic probiotic properties of LcS stored as a Probiotics Package on the ISS

Staphylococcus aureus requires cardiolipin for survival under conditions of high salinity

BackgroundThe ability of staphylococci to grow in a wide range of salt concentrations is well documented. In this study, we aimed to clarify the role of cardiolipin (CL) in the adaptation of Staphylococcus aureus to high salinity.ResultsUsing an improved extraction method, the analysis of phospholipid composition suggested that CL levels increased slightly toward stationary phase, but that this was not induced by high salinity. Deletion of the two CL synthase genes, SA1155 (cls1) and SA1891 (cls2), abolished CL synthesis. The cls2 gene encoded the dominant CL synthase. In a cls2 deletion mutant, Cls1 functioned under stress conditions, including high salinity. Using these mutants, CL was shown to be unnecessary for growth in either basal or high-salt conditions, but it was critical for prolonged survival in high-salt conditions and for generation of the L-form.ConclusionsCL is not essential for S. aureus growth under conditions of high salinity, but is necessary for survival under prolonged high-salt stress and for the generation of L-form variants

Subaru Hyper Suprime-Cam Survey for An Optical Counterpart of GW170817

We perform a $z$-band survey for an optical counterpart of a binary neutron star coalescence GW170817 with Subaru/Hyper Suprime-Cam. Our untargeted transient search covers $23.6$ deg$^2$ corresponding to the $56.6\%$ credible region of GW170817 and reaches the $50\%$ completeness magnitude of $20.6$ mag on average. As a result, we find 60 candidates of extragalactic transients, including J-GEM17btc (a.k.a. SSS17a/DLT17ck). While J-GEM17btc is associated with NGC 4993 that is firmly located inside the 3D skymap of GW170817, the other 59 candidates do not have distance information in the GLADE v2 catalog or NASA/IPAC Extragalactic Database (NED). Among 59 candidates, 58 are located at the center of extended objects in the Pan-STARRS1 catalog, while one candidate has an offset. We present location, $z$-band apparent magnitude, and time variability of the candidates and evaluate the probabilities that they are located inside of the 3D skymap of GW170817. The probability for J-GEM17btc is $64\%$ being much higher than those for the other 59 candidates ($9.3\times10^{-3}-2.1\times10^{-1}\%$). Furthermore, the possibility, that at least one of the other 59 candidates is located within the 3D skymap, is only $3.2\%$. Therefore, we conclude that J-GEM17btc is the most-likely and distinguished candidate as the optical counterpart of GW170817.Comment: 14 pages, 9 figures. Accepted for publication in PASJ (Publications of the Astronomical Society of Japan