Identification of a 100 kDa Microtubule-Associated Protein from Xenopus Eggs

A 100 kDa protein was identified by a combination of microtubule affinity chromatography and microtubule co-sedimentation from Xenopus egg extracts. The 100 kDa protein was expressed in Stage VI oocytes and early embryos, and then decreased at tailbud stage. The 100 kDa protein was found in adult organs such as brain and liver. Immunofluorescent microscopy revealed that the 100 kDa protein was mainly detected in spinal cord, notochordal sheath, optic cup, lens and cement gland in tailbud embryos. In Xenopus A6 cells, the 100 kDa protein showed filamentous networks in the peripheral cytoplasm and uniform distribution around the nucleus. During cell division, the 100 kDa protein was localized to the mitotic apparatus. The 100 kDa protein may have some roles in microtubule dynamics, organization of the mitotic apparatus and maintenance of cell shape

KAJIAN STRUKTUR KOMUNITAS MOLUSKA DI PANTAI REKLAMASI TELUK MANADO

This study aims to determine the increase or decrease in mollusk species on the reclamation coast and also to determine the development of the mollusk community structure and its activities in the intertidal zone of the reclamation coast of Manado Bay. Based on the results of sampling obtained 15 species from 7 families. The mollusk density value is 58.30 Ind/m2. The diversity index obtained from the results of the analysis is classified as low, namely H' = 1.684. The dominance value obtained from the results of data analysis is low, namely C = 0.37. The highest species frequency value was found in the Cellana radiata species with a value of 0.60 and the lowest in the Menathais tuberosa species, Drupa rubusidaeus, Drupa ricinus, Nerita polita, with a 0.03 value. The relatively high significance index was found in the species Saccostrea cuccullata with a value of 106.28%, while the lowest value was found in the species Menathais tuberosa and Drupa ricinus with a value of 1.24%. The response and adaptation ability of mollusks in the intertidal zone varies based on the size of the species and their adaptability. The reclamation beach of Manado Bay has a temperature of 29.5 °C, salinity of 30 0 /00, and the obtained pH is 8. Based on these results, the reclamation coastal waters of Manado Bay are classified as good for mollusk life.Keywords: Community Structure, Mollusk, Reclamation

Origin for the enhanced copper spin echo decay rate in the pseudogap regime of the multilayer high-T_c cuprates

We report measurements of the anisotropy of the spin echo decay for the inner layer Cu site of the triple layer cuprate, Hg_0.8Re_0.2Ba_2Ca_2Cu_3O_8 (T_c=126 K) in the pseudogap T regime below T_pg ~ 170 K and the corresponding analysis for their interpretation. As the field alignment is varied, the shape of the decay curve changes from Gaussian (H_0 \parallel c) to single exponential (H_0 \perp c). The latter characterizes the decay caused by the fluctuations of adjacent Cu nuclear spins caused by their interactions with electron spins. The angular dependence of the second moment (T_{2M}^{-2} \equiv ) deduced from the decay curves indicates that T_{2M}^{-2} for H_0 \parallel c, which is identical to T_{2G}^{-2} (T_{2G} is the Gaussian component), is substantially enhanced, as seen in the pseudogap regime of the bilayer systems. Comparison of T_{2M}^{-2} between H_0 \parallel c and H_0 \perp c indicates that this enhancement is caused by electron spin correlations between the inner and the outer CuO_2 layers. These results provide the answer to the long-standing controversy regarding the opposite T dependences of (T_1T)^{-1} and T_{2G}^{-2} in the pseudogap regime of bi- and trilayer systems.Comment: 4 pages, 4 figure

Host investment into symbiosis varies among genotypes of the legume Acmispon strigosus, but host sanctions are uniform.

Efficient host control predicts the extirpation of ineffective symbionts, but they are nonetheless widespread in nature. We tested three hypotheses for the maintenance of symbiotic variation in rhizobia that associate with a native legume: partner mismatch between host and symbiont, such that symbiont effectiveness varies with host genotype; resource satiation, whereby extrinsic sources of nutrients relax host control; and variation in host control among host genotypes. We inoculated Acmispon strigosus from six populations with three Bradyrhizobium strains that vary in symbiotic effectiveness on sympatric hosts. We measured proxies of host and symbiont fitness in single- and co-inoculations under fertilization treatments of zero added nitrogen (N) and near-growth-saturating N. We examined two components of host control: 'host investment' into nodule size during single- and co-inoculations, and 'host sanctions' against less effective strains during co-inoculations. The Bradyrhizobium strains displayed conserved growth effects on hosts, and host control did not decline under experimental fertilization. Host sanctions were robust in all hosts, but host lines from different populations varied significantly in measures of host investment in both single- and co-inoculation experiments. Variation in host investment could promote variation in symbiotic effectiveness and prevent the extinction of ineffective Bradyrhizobium from natural populations

Can We Make Money with Fifth-order Autocorrelation in Japanese Stock Prices?

We first report that one-minute returns on TOPIX have exhibited significant autocorrelation at five-minute intervals since 1997/98, which implies there is an arbitrage opportunity. Special quotes that are issued whenever there is a price jump in excess of a predetermined band seem to be the source of this autocorrelation, since these have been updated at five-minute intervals since August 1998. Individual stock returns also exhibit fifth-order autocorrelation, but this disappears when the data with special quotes are excluded from the sample. The arbitrage opportunities, however, turn out to be spurious since trading is suspended whenever a special quote is issued

A switchable controlled-NOT gate in a spin-chain NMR quantum computer

A method of switching a controlled-NOT gate in a solid-stae NMR quantum computer is presented. Qubits of I=1/2 nuclear spins are placed periodically along a quantum spin chain (1-D antiferromagnet) having a singlet ground state with a finite spin gap to the lowest excited state caused by some quantum effect. Irradiation of a microwave tuned to the spin gap energy excites a packet of triplet magnons at a specific part of the chain where control and target qubits are involved. The packet switches on the Suhl-Nakamura interaction between the qubits, which serves as a controlled NOT gate. The qubit initialization is achieved by a qubit initializer consisting of semiconducting sheets attached to the spin chain, where spin polarizations created by the optical pumping method in the semiconductors are transferred to the spin chain. The scheme allows us to separate the initialization process from the computation, so that one can optimize the computation part without being restricted by the initialization scheme, which provides us with a wide selection of materials for a quantum computer.Comment: 8 pages, 5 figure

The impact of crystal phase transition on the hardness and structure of kidney stones

The version of record of this article, first published in Urolithiasis, is available online at Publisher’s website: https://doi.org/10.1007/s00240-024-01556-5.Calcium oxalate kidney stones, the most prevalent type of kidney stones, undergo a multi-step process of crystal nucleation, growth, aggregation, and secondary transition. The secondary transition has been rather overlooked, and thus, the effects on the disease and the underlying mechanism remain unclear. Here, we show, by periodic micro-CT images of human kidney stones in an ex vivo incubation experiment, that the growth of porous aggregates of calcium oxalate dihydrate (COD) crystals triggers the hardening of the kidney stones that causes difficulty in lithotripsy of kidney stone disease in the secondary transition. This hardening was caused by the internal nucleation and growth of precise calcium oxalate monohydrate (COM) crystals from isolated urine in which the calcium oxalate concentrations decreased by the growth of COD in closed grain boundaries of COD aggregate kidney stones. Reducing the calcium oxalate concentrations in urine is regarded as a typical approach for avoiding the recurrence. However, our results revealed that the decrease of the concentrations in closed microenvironments conversely promotes the transition of the COD aggregates into hard COM aggregates. We anticipate that the suppression of the secondary transition has the potential to manage the deterioration of kidney stone disease

Evidence for Solution-Mediated Phase Transitions in Kidney Stones: Phase Transition Exacerbates Kidney Stone Disease

Maruyama M., Tanaka Y., Momma K., et al. Evidence for Solution-Mediated Phase Transitions in Kidney Stones: Phase Transition Exacerbates Kidney Stone Disease. Crystal Growth and Design 23, 4285 (2023); https://doi.org/10.1021/acs.cgd.3c00108.In this study, we investigated calcium oxalate (CaOx) kidney stones and showed direct evidence of the solution-mediated phase transition of calcium oxalate dihydrate (COD; the metastable phase) to calcium oxalate monohydrate (COM; the stable phase). We examined the crystal phases, crystal textures, and protein distributions within thin sections of calcium oxalate kidney stones. Observation with a polarized-light microscope showed that the outline of the mosaic texture, in which COM crystals are assembled in a mosaic pattern, roughly coincides with COD’s crystallographically stable face angles. Microfocus X-ray CT measurement captured the intermediate process of the phase transition, starting inside the COD single crystal and gradually transforming to COM crystals. In addition, the distribution of osteopontin and prothrombin fragment-1, common proteins contained in urine and visualized by multicolor fluorescence immunostaining, showed no apparent striations inside the COM single crystals with the mosaic texture, although the striation is apparent inside the COD single crystals. This is probably because the phase transition of mosaic-like COM occurred in a semiclosed system inside the COD single crystal, so the effect of periodic (day-night, seasonal, etc.) urinary protein concentration changes was small. On the other hand, striations were visible in concentrically laminated COM. This indicated that concentrically laminated COM formed in response to the changes in urinary protein concentrations. From the above, we conclude that the COD single crystals and the concentrically laminated COM seen in CaOx stones are primary structures, and the mosaic COM is a secondary structure that is a pseudomorph formed by the solution-mediated phase transition from COD single crystals