The Keio Twin Research Center has conducted two longitudinal twin cohort projects and has collected three independent and anonymous twin data sets for studies of phenotypes related to psychological, socio-economic, and mental health factors. The Keio Twin Study has examined adolescent and adult cohorts, with a total of over 2,400 pairs of twins and their parents. DNA samples are available for approximately 600 of these twin pairs. The Tokyo Twin Cohort Project has followed a total of 1,600 twin pairs from infancy to early childhood. The large-scale cross-sectional twin study (CROSS) has collected data from over 4,000 twin pairs, from 3 to 26 years of age, and from two high school twin cohorts containing a total of 1,000 pairs of twins. These data sets of anonymous twin studies have mainly targeted academic performance, attitude, and social environment. The present article introduces the research designs and major findings of our center, such as genetic structures of cognitive abilities, personality traits, and academic performances, developmental effects of genes and environment on attitude, socio-cognitive ability and parenting, genes x environment interaction on attitude and conduct problem, and statistical methodological challenges and so on. We discuss the challenges in conducting twin research in Japan.

Plasmodium falciparum has for some time been developing resistance against known anti-malarial drugs, and therefore a new drug is urgently needed. Selenium (Se), an essential trace element, in the form of inorganic Se, selenite (SeO32−), has been reported to have an anti-plasmodial effect, but its mechanism is still unclear. In the present study, we evaluated the anti-plasmodial effect of several Se compounds against P. falciparum in vitro. The anti-plasmodial effect of several Se compounds was analysed and their apoptosis-inducing activity was evaluated by morphological observation, DNA fragmentation assay and mitochondrial function analysis. SeO32−, methylseleninic acid, selenomethionine and selenocystine have anti-plasmodial effects with 50% inhibition concentration at 9, 10, 45, and 65 μm, respectively, while selenate and methylselenocysteine up to 100 μm have no effect on parasite growth. The effective Se compounds caused the parasites to become shrunken and pyknotic and significantly increased mitochondrial damage against P. falciparum compared to the untreated control. In conclusion, SeO32−, methylseleninic acid, selenomethionine and selenocystine have anti-plasmodial activities that induce apoptosis-like cell death in P. falciparum, and the anti-plasmodial effects of Se seem to be based on its chemical forms. The apoptosis-like cell-death mechanism in P. falciparum can be beneficial to respond to the growing problem of drug resistance.

Impact resistance of a hot-forged TiAl alloy with a composition of Ti-42∼44Al-5∼10M: M=V, Mn(at%), consisting of lamellar, γ and β grain of which the hot-workability was improved by introducing β phase, has been investigated using an instrumented Charpy impact test, tensile test at high strain rate and foreign object attack test. In instrumented Charpy impact test the absorbed energies for crack initiation and propagation were measured, and the effect of microstructure on the absorbed energies has been analyzed, by paying attention to the grain size, interlamellar spacing and lamellar area fraction. In tensile test at high strain rate, the dependence of strain rate of hot-extruded TiAl alloy is obtained and compared with that of Nickel based superalloy, Inconel 713C. In foreign object attack test with taper plate specimen modified turbine blade and brass ball as foreign object, the relation between impact damage and thickness of specimen at attack point is investigated. A limit of impact energy, at which there isn't a crack on buck of attack point, is obtained with each thickness about hot-forged TiAl alloy, Ti-42Al-5Mn. Therefore, the method of improvement of toughness and assessment of impact resistance of TiAl alloy is shown in this study.

Only eight cases of bilateral middle-ear squamous cell carcinoma (SCC) have been reported to date. We present the case of a 75-year-old male with bilateral middle-ear SCC and review the previously reported cases. The patient was diagnosed as having moderately-differentiated SCC in the left middle ear in February 1995 and well-differentiated SCC in the right middle ear in September 1997. He initially received radiation therapy with 60Co pendulum (64 Gy) in the left ear and was subsequently treated by Liniac irradiation (50 Gy) in the right ear. He has now been followed up at our ENT clinic for 29 months without vertigo or facial nerve palsy since the second radiation therapy. Although he has a residual tumour in the right middle ear invading the middle cranial fossa dura, no sign of recurrence has been detected in the left ear.

Several lipomas of the nasal cavity and paranasal sinus have previously been reported to date. We present a 21-year-old case with nasal lipoma situated on the left posterior of part of the nasal septum, operated on endoscopically. The present case is, to our knowledge, the first report on nasal lipoma in the adult.

The effects of a sheared poloidal flow on the m = 1 (poloidal mode number) and n = 1 (toroidal mode number) kinetic internal kink mode are simulated by the linearized version of the gyro-reduced MHD code, GRM3D-2F, based on a two-field and two-fluid gyro-reduced MHD model, including the kinetic effects of electron inertia and the perturbed electron pressure gradients along the magnetic field. A parameter study for different values of de (collisionless electron skin depth) with a fixed value of ρs = 0 (ion Larmor radius estimated by the electron temperature) shows that the smaller-de case, which has the smaller growth rate, is stabilized by the smaller sheared poloidal flow. When ρs is raised to ρs > de for a fixed value of de, the instability is stabilized by the smaller shear flow compared with the case of ρs < de, although the growth rate without the flow is larger for ρs > de. Since de is very much less than the minor radius, and ρs > de for the existing and future experiments, it is possible that even a quite small sheared poloidal flow may have a crucial influence on the kinetic internal kink mode.