First-principles study of locally disordered structures of Mn-induced GaAs(001)-(2 × 2) surface

Various atomic arrangements of the Mn-induced GaAs(001) surface, consisting of one Ga–As dimer and one Mn atom in the (2 × 2) unit, have been investigated by first-principles calculations. The most stable arrangement is reasonable in view of the classical electrostatic theory. It has been revealed that the topmost Ga–As dimers tend to be aligned along the [11 ̅0] direction, while they are less ordered along the [110] direction. These anisotropic orderings, that is, anisotropic interactions, imply that the Mn atom, which is located between the Ga–As dimers, enhances the local electrostatic interaction between the dimers along the [11 ̅0] direction, as a result of the dielectric anisotropy at the surface

Older sisters and younger brothers: The impact of siblings on preference for competition

Studies in psychology have long argued the possibility that sibling structure, such as birth order and the gender of siblings, shapes one's feminine and masculine personality traits, such as a preference for competition. In light of recent developments in the economics literature on the gender gap, this implies that familial environment could explain why some women do opt for competition, while the vast majority of women do not and, thus, are underrepresented on the career ladder. By conducting a controlled experiment on Japanese high school students, this study quantifies the impact of sibling structure on one's preference for competition, and examines whether a long-debated sibling hypothesis in psychology is supported from the viewpoint of experimental economics. Consistent with the hypothesis, our results reveal that men with older sisters were significantly less likely to enter a competitive environment compared with only sons. This effect is comparable in size to the effect of being female on the decision to compete. Our study also found moderate evidence that women with younger brothers were more likely to compete than only daughters

Biochemical and molecular diagnosis of mitochondrial respiratory chain disorders

AbstractBiochemical diagnosis of mitochondrial respiratory chain disorders requires caution to avoid misdiagnosis of secondary enzyme defects, and can be improved by the use of conservative diagnostic criteria. Pathogenic mutations causing mitochondrial disorders have now been identified in more than 30 mitochondrial DNA (mtDNA) genes encoding respiratory chain subunits, ribosomal- and t-RNAs. mtDNA mutations appear to be responsible for most adult patients with mitochondrial disease and approximately a quarter of paediatric patients. A family history suggesting maternal inheritance is the exception rather than the norm for children with mtDNA mutations, many of whom have de novo mutations. Prenatal diagnosis and pre-implantation genetic diagnosis can be offered to some women at risk of transmitting a mtDNA mutation, particularly those at lower recurrence risk. Mutations in more than 30 nuclear genes, including those encoding for respiratory chain subunits and assembly factors, have now been shown to cause mitochondrial disorders, creating difficulties in prioritising which genes should be studied by mutation analysis in individual patients. A number of approaches offer promise to guide the choice of candidate genes, including Blue Native-PAGE immunoblotting and microarray expression analysis

Bio-mimetic Control of Mobile Robots Based on a Model of Bacterial Chemotaxis

This paper proposes a new control method of mobile robots based on a model of bacterial chemotaxis including not only intracellular information processing but also motor control on the basis of the molecular evidence. E. coli is chosen as a target bacterium, which has a simple molecular structure and is amenable to biochemical and genetic analysis. First, a computer model of the chmotaxis is developed to simulate its emergence. Parameters included in the model are regulated using the genetic algorithm in such a way that a fitness representing the chemotactic ability is maximized. Then, using a mobile robot incorporated this chemotactic model, experiments of trajectory generation are preformed, and it is confirmed that the mobile robot can be controlled based on the bacterial model

Molecular analysis of holocarboxylase synthetase deficiency: a missense mutation and a single base deletion are predominant in Japanese patients

AbstractHolocarboxylase synthetase (HCS) deficiency is an inherited disease of biotin metabolism characterized by a unique pattern of organic aciduria, metabolic acidosis, and skin lesions. By analysis of five patients in four unrelated families, two mutations were identified: a transition from T to C which causes an amino-acid substitution of proline for leucine at position 237 (L237P) and a single deletion of guanine (delG 1067) followed by premature termination. One patient was homozygous for the L237P mutation, three patients in two families were compound heterozygotes of the missense and deletion alleles, and the other patient was heterozygous for the L237P mutation. Inheritance was successfully demonstrated in all of the patients' families by a modified PCR followed by restriction enzyme digestion. The two mutations accounted for seven of eight mutant alleles, while neither mutation was detected in 108 normal healthy Japanese children (216 alleles). Transient expression in cultured fibroblasts from a patient showed that the L237P mutation was responsible for decreased HCS activity. These results suggest that the L237P and delG1067 mutations are frequent disease-causing mutations in Japanese patients with HCS deficiency. This PCR-based technique may therefore be useful for detecting mutations among Japanese patients

Prediction of Boron Concentrations in Blood from Patients on Boron Neutron Capture Therapy

Background: In boron neutron capture therapy, blood boron concentration is the key factor to calculate radiation dose, however, blood sampling is difficult during neutron irradiation. Materials and Methods: The prediction of blood boron concentrations for BNCT treatment planning has been prospectively investigated using patient data obtained at first craniotomy after the infusion of a low dose of sodium undecahydroclosododecaborate. Results: The boron biodistribution data showed a biexponential pharmacokinetic profile. If the final boron concentration at 6 or 9 hours after the end of the infusion is within the 95% confidence interval of the prediction, direct prediction from biexponential fit will reduce the error of blood boron concentrations during irradiation to around 6%. Conclusion: Actual boron concentrations during BNCT were reasonably and accurately predictable from the test data

Prenatal diagnosis of severe mitochondrial diseases caused by nuclear gene defects: a study in Japan

Prenatal diagnoses of mitochondrial diseases caused by defects in nuclear DNA (nDNA) or mitochondrial DNA have been reported in several countries except for Japan. The present study aimed to clarify the status of prenatal genetic diagnosis of mitochondrial diseases caused by nDNA defects in Japan. A comprehensive genomic analysis was performed to diagnose more than 400 patients, of which, 13 families (16 cases) had requested prenatal diagnoses. Eight cases diagnosed with wild type homozygous or heterozygous variants same as either of the heterozygous parents continued the pregnancy and delivered healthy babies. Another eight cases were diagnosed with homozygous, compound heterozygous, or hemizygous variants same as the proband. Of these, seven families chose to terminate the pregnancy, while one decided to continue the pregnancy. Neonatal- or infantile-onset mitochondrial diseases show severe phenotypes and lead to lethality. Therefore, such diseases could be candidates for prenatal diagnosis with careful genetic counseling, and prenatal testing could be a viable option for families

Identification of 45 New Neutron-Rich Isotopes Produced by In-Flight Fission of a 238U Beam at 345 MeV/nucleon

A search for new isotopes using in-flight fission of a 345 MeV/nucleon 238U beam has been carried out at the RI Beam Factory at the RIKEN Nishina Center. Fission fragments were analyzed and identified by using the superconducting in-flight separator BigRIPS. We observed 45 new neutron-rich isotopes: 71Mn, 73,74Fe, 76Co, 79Ni, 81,82Cu, 84,85Zn, 87Ga, 90Ge, 95Se, 98Br, 101Kr, 103Rb, 106,107Sr, 108,109Y, 111,112Zr, 114,115Nb, 115,116,117Mo, 119,120Tc, 121,122,123,124Ru, 123,124,125,126Rh, 127,128Pd, 133Cd, 138Sn, 140Sb, 143Te, 145I, 148Xe, and 152Ba