The fastest evolutionary trajectory.

Given two mutants, A and B, separated by n mutational steps, what is the evolutionary trajectory which allows a homogeneous population of A to reach B in the shortest time? We show that the optimum evolutionary trajectory (fitness landscape) has the property that the relative fitness increase between any two consecutive steps is constant. Hence, the optimum fitness landscape between A and B is given by an exponential function. Our result is precise for small mutation rates and excluding back mutations.

Wegener's granulomatosis complicated by intestinal ulcer due to cytomegalovirus infection and by thrombotic thrombocytopenic purpura.

A 61-year-old woman was admitted to our hospital because of acute kidney injury. She complained of general fatigue, appetite loss, and a high fever. Nodular lesions were observed on chest X-rays and there were >100 erythrocytes per high power field in her urinary sediment.

In-crystal and surface charge transport of electric-field-induced carriers in organic single-crystal semiconductors.

Gate-voltage dependence of carrier mobility is measured in high-performance field-effect transistors of rubrene single crystals by simultaneous detection of the longitudinal conductivity sigma(square) and Hall coefficient R(H). The Hall mobility mu(H) (identical with sigma(square)R(H)) reaches nearly 10 cm(2)/V s when relatively low-density carriers (<10(11) cm(-2)) distribute into the crystal. mu(H) rapidly decreases with higher-density carriers as they are essentially confined to the surface and are subjected to randomness of the amorphous gate insulators.

Characteristics of patients on hemodialysis therapy for more than 30 years.

Since its experimental introduction in 1960, hemodialysis has become a widely performed and relatively safe procedure. Therapeutic strategies have been developed, and the numbers of long-term survivors of hemodialysis therapy have been increasing. Hemodialysis therapy was introduced at Sangenjaya Hospital in October 1970, and the 16 patients who have survived for more than 30 years on hemodialysis therapy since its introduction at the hospital were enrolled in this study to investigate the characteristics of long-term hemodialysis patients.

Single-class orbits in nonlinear Leslie matrix models for semelparous populations.

The dynamics of a general nonlinear Leslie matrix model for a semelparous population is investigated. We are especially concerned with the attractivity of the single-class state, in which all but one cohort (or year-class) are missing. Our result shows that the single-class state is attractive if inter-class competition is severe.

Turing pattern formation with two kinds of cells and a diffusive chemical.

We study a three-variable Turing system with two kinds of cells and a diffusive chemical, considering the formation and maintenance of fish skin patterns with multiple pigment cells. The two types of cells are produced from undifferentiated cells. They inhibit the supply rate of the other cell type, forming local clusters of the same cell type.

Successfully-treated mesenteric non-Hodgkin's lymphoma involving hepatic mass--a case report.

A mesenteric diffuse large B-cell lymphoma which also involves the liver is very rare. We describe herein a mesenteric diffuse large B-cell lymphoma with hepatic involvement successfully treated by the combination of surgical resection and multiagent chemotherapy. A 77-year-old man was referred to our hospital because of a right lower abdominal tumor.

Establishment and characterization of androgen-independent human prostate cancer cell lines, LN-REC4 and LNCaP-SF, from LNCaP.

Aim: To investigate the mechanisms of androgen-independent growth in prostate cancer (PCa), we established two PCa cell lines, LN-REC4 and LNCaP-SF, from the androgen-dependent PCa cell line, LNCaP.

Materials And Methods: LN-Pre and LN-REC4 cells were generated from LNCaP tumors grown on intact and castrated severe combined immunodeficient (SCID) mouse, respectively. After we cultured LNCaP cells under a steroid-free conditions for 6 months in vitro, LNCaP-SF cells were established.

Coupled ecological-social dynamics in a forested landscape: spatial interactions and information flow.

We develop an agent-based model for forest harvesting to study how interactions between neighboring land parcels and the degree of information flow among landowners influence harvesting patterns. We assume a forest is composed of a number of land parcels that are individually managed. Each parcel is either mature forested, just-harvested, or immature forested.

Probability of resistance evolution for exponentially growing virus in the host.

Chemotherapy for tumor and pathogenic virus often faces an emergence of resistant mutants, which may lead to medication failure. Here we study the risk of resistance to evolve in a virus population which grows exponentially. We assume that infected cells experience a "proliferation event" of virus at a random time and that the number of newly infected cells from an infected cell follows a Poisson distribution.

Spatial extent of wave functions of gate-induced hole carriers in pentacene field-effect devices as investigated by electron spin resonance.

An electron spin resonance (ESR) method is applied to a pentacene field-effect device to investigate gate-induced hole carriers in such devices. Clear field-induced ESR signals are observed, demonstrating that all of the field-injected carriers have S = 1/2 spins. Anisotropic ESR signals due to unpaired pi electrons show the molecular orientation at the interface in the devices.

Bonding nature and structural phase transition in fullerene based nanomaterials.

Rare-earth-metal-doped fullerides with a nominal composition of R3C70 (R = Sm, Eu, Yb) adopt a pseudomonoclinic structure in which C70 dimers glued with rare-earth ions are involved. High-temperature powder X-ray diffraction experiments revealed that the dimers undergo reversible first-order structural phase transitions, associated with reduction of the unit cell volume, similar to the results observed in previous high-pressure experiments. Structural analyses showed that C70 molecules are realigned to form closely packed structures, causing a reduction of volume at high temperature.

Robustness of the signal transduction system of the mammalian JAK/STAT pathway and dimerization steps.

In the interferon-gamma (IFNgamma)-activated Janus Kinase (JAK)/signal transducer and activator of transcription 1 (STAT1) pathway, multiple steps of STAT1 dimerization are required prior to gene expression that produce antiviral molecules. By interpreting experimental results, an existing mathematical model suggested that only phosphorylated STAT1 dimers could translocate to the nucleus and activate gene transcription. In this paper, we examine the role of STAT1 dimerization steps by studying the dynamic behaviors of four alternative models.

Potassium Phthalocyanine, KPc: one-dimensional molecular stacks bridged by K+ ions.

We report the synthesis of potassium phthalocyanine (KPc) and its structural characterization by synchrotron X-ray powder diffraction. We find that while KPc adopts the beta-polymorphic structural type (monoclinic space group P21/a) common for many MPc solids, its structure is characterized by unique features. The K+ ions, which are statistically disordered over two symmetry-equivalent positions, reside in the intrastack spacing of the rodlike molecular assemblies and strongly bond equidistantly to selected N atoms of the two neighboring Pc rings along the chain direction with an unusual 5-fold coordination.

Ring of C60 polymers formed by electron or hole injection from a scanning tunneling microscope tip.

Carrier (electron or hole) injection from a scanning tunneling microscope tip causes various surface modifications on the molecular scale. We report that injection into C60 close-packed layers forms a ring-shaped distribution of C60 polymers. This can be explained on the basis of the radial propagation and energy dissipation of carriers.

Electrical conducting bis(oxalato)platinate complex with direct connection of CuII ions.

Reactions of K1.62[Pt(ox)2].2H2O and [Cu(bpy)(H2O)3](NO3)2 yielded partially oxidized one-dimensional (1D) bis(oxalato)platinates of [Cu(bpy)(H2O)n]6[Pt(ox)2]7.

Utilization of hydrophobic bacterium Rhodococcus opacus B-4 as whole-cell catalyst in anhydrous organic solvents.

Rhodococcus opacus strain B-4, which has recently been isolated as an organic solvent-tolerant bacterium, has a high hydrophobicity and exhibits a high affinity for hydrocarbons. This bacterium was able to survive for at least 5 days in organic solvents, including n-tetradecane, oleyl alcohol, and bis(2-ethylhexyl) phthalate (BEHP), which contained water less than 1% (w/v). The biocatalytic ability of R.

Global analyses of evolutionary dynamics and exhaustive search for social norms that maintain cooperation by reputation.

Reputation formation is a key to understanding indirect reciprocity. In particular, the way to assign reputation to each individual, namely a norm that describes who is good and who is bad, greatly affects the possibility of sustained cooperation in the population. Previously, we have exhaustively studied reputation dynamics that are able to maintain a high level of cooperation at the ESS.

Ferroelectric polarization flop in a frustrated magnet MnWO4 induced by a magnetic field.

The relationship between magnetic order and ferroelectric properties has been investigated for MnWO4 with a long-wavelength magnetic structure. Spontaneous electric polarization is observed in an elliptical spiral spin phase. The magnetic-field dependence of electric polarization indicates that the noncollinear spin configuration plays a key role for the appearance of the ferroelectric phase.

Increase in Tc upon reduction of doping in LixZrNCl superconductors.

We revealed a detailed phase diagram of the very lightly doped regime in Li-intercalated superconductors, LixZrNCl, to which previous studies have never gained access owing to the difficulty in synthesizing single-phase samples. A continuous and uniform Li intercalation without any indication of phase separation was carefully confirmed by means of synchrotron x-ray diffraction and Raman scattering experiments. Upon reducing the carrier density below x=0.

The age incidence of chronic myeloid leukemia can be explained by a one-mutation model.

Chronic myeloid leukemia (CML) is associated with the Philadelphia chromosome, which arises by a reciprocal translocation between chromosomes 9 and 22 and harbors the BCR-ABL fusion oncogene. It is unknown whether any other mutations are needed for the chronic phase of the disease. The CML incidence increases as a function of age with an exponent of approximately 3.

Optimal conservation strategy in fluctuating environments with species interactions: resource-enhancement of the native species versus extermination of the alien species.

Alien species are often a major threat to native species. We consider optimal conservation strategies for a population whose viability is affected both by an alien species (such as a competitor, a predator, or a pathogen) and by random fluctuations of the environment (e.g.

A symmetry of fixation times in evoultionary dynamics.

In this paper, we show that for evolutionary dynamics between two types that can be described by a Moran process, the conditional fixation time of either type is the same irrespective of the selective scenario. With frequency dependent selection between two strategies A and B of an evolutionary game, regardless of whether A dominates B, A and B are best replies to themselves, or A and B are best replies to each other, the conditional fixation times of a single A and a single B mutant are identical. This does not hold for Wright-Fisher models, nor when the mutants start from multiple copies.

How canalization can make loops: a new model of reticulated leaf vascular pattern formation.

Formation of the vascular system in plant leaves can be explained by the canalization hypothesis which states that veins are formed in an initially homogeneous field by a self-organizing process between the plant hormone auxin and auxin carrier proteins. Previous models of canalization can generate vein patterns with branching but fail to generate vein patterns with closed loops. However, closed vein loops are commonly observed in plant leaves and are important in making them robust to herbivore attacks and physical damage.

A model for the circadian rhythm of cyanobacteria that maintains oscillation without gene expression.

An intriguing property of the cyanobacterial circadian clock is that endogenous rhythm persists when protein abundances are kept constant either in the presence of translation and transcription inhibitors or in the constant dark condition. Here we propose a regulatory mechanism of KaiC phosphorylation for the generation of circadian oscillations in cyanobacteria. In the model, clock proteins KaiA and KaiB are assumed to have multiple states, regulating the KaiC phosphorylation process.