ALBERT

Description: 〈p〉Increasing demand for higher energy efficiency calls for waste heat recovery technology. Thus, facilitating practical thermoelectric generation systems is strongly desired. One option is enhancing the thermoelectric power factor, 〈i〉S〈/i〉〈sup〉2〈/sup〉/〈i〉r〈/i〉, where 〈i〉S〈/i〉 is the Seebeck coefficient and 〈i〉r〈/i〉 is the electrical resistivity, although it is still challenging because of the trade-off between 〈i〉S〈/i〉 and 〈i〉r〈/i〉. We demonstrate that enhanced 〈i〉S〈/i〉〈sup〉2〈/sup〉/〈i〉r〈/i〉 can be achieved by incorporating magnetic interaction in ferromagnetic metals via the spin fluctuation arising from itinerant electrons. We show that electron-doped Heusler alloys exhibit weak ferromagnetism at 〈i〉T〈/i〉〈sub〉C〈/sub〉 near room temperature with a small magnetic moment. A pronounced enhancement around 〈i〉T〈/i〉〈sub〉C〈/sub〉 was observed, with a 20% improvement in the power factor from the case where spin fluctuation is suppressed by applying magnetic field. This result supports the merit of using spin fluctuation to further enhance thermoelectric properties and the potential to further probe correlations and synergy between magnetic and thermoelectric fields.〈/p〉

Description: Sex-determining regions (SDRs) or mating-type ( MT ) loci in two sequenced volvocine algal species, Chlamydomonas reinhardtii and Volvox carteri , exhibit major differences in size, structure, gene content, and gametolog differentiation. Understanding the origin of these differences requires investigation of MT loci from related species. Here, we determined the sequences of the minus and plus MT haplotypes of the isogamous 16-celled volvocine alga, Gonium pectorale , which is more closely related to the multicellular V. carteri than to C. reinhardtii . Compared to C. reinhardtii MT , G. pectorale MT is moderately larger in size, and has a less complex structure, with only two major syntenic blocs of collinear gametologs. However, the gametolog content of G. pectorale MT has more overlap with that of V. carteri MT than with C. reinhardtii MT , while the allelic divergence between gametologs in G. pectorale is even lower than that in C. reinhardtii . Three key sex-related genes are conserved in G. pectorale MT : GpMID and GpMTD1 in MT –, and GpFUS1 in MT +. GpFUS1 protein exhibited specific localization at the plus -gametic mating structure, indicating a conserved function in fertilization. Our results suggest that the G. pectorale–V. carteri common ancestral MT experienced at least one major reformation after the split from C. reinhardtii , and that the V. carteri ancestral MT underwent a subsequent expansion and loss of recombination after the divergence from G. pectorale . These data begin to polarize important changes that occurred in volvocine MT loci, and highlight the potential for discontinuous and dynamic evolution in SDRs.

Description: 〈p〉The Himalaya orogenic belt produces frequent large earthquakes that affect population centers along a length of over 2500 km. The 2015 Gorkha, Nepal earthquake (〈i〉M〈/i〉〈sub〉w〈/sub〉 7.8) ruptured the Main Himalayan Thrust (MHT) and allows direct measurements of the behavior of the continental collision zone. We study the MHT using seismic waveforms recorded by local stations that completely cover the aftershock zone. The MHT exhibits clear lateral variation along geologic strike, with the Lesser Himalayan ramp having moderate dip on the MHT beneath the mainshock area and a flatter and deeper MHT beneath the eastern end of the aftershock zone. East of the aftershock zone, seismic wave speed increases at MHT depths, perhaps due to subduction of an Indian basement ridge. A similar magnitude wave speed change occurs at the western end of the aftershock zone. These gross morphological structures of the MHT controlled the rupture length of the Gorkha earthquake.〈/p〉