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The purpose of this study was to assess the influence of anthropogenic modification of coastal habitats on fish assemblages in Taiwan, comparing the abundance, species richness and taxonomic composition of fishes on natural v. artificial habitats. While there was no significant variation in the abundance or richness of fishes between natural and artificial habitats, the species composition of fishes in artificial habitats was significantly different from that of natural habitats. Natural reefs were characterized by greater abundance of Stethojulis spp. (Labridae), Abudefduf spp. (Pomacentridae) and Thalassoma spp. (Labridae), whereas anthropogenic habitats were dominated by Parupeneus indicus (Mullidae), Pempheris oualensis (Pempheridae) and Parapriacanthus ransonneti (Pempheridae). In general, it appears that specialist reef-associated species are being replaced with fishes that are much more generalist in their habitat-use. The loss of natural coastal habitats may threaten some species that cannot live in anthropogenically altered habitats, though the overall abundance and diversity of coastal fishes was not significantly different between natural and artificial habitats in Taiwan. [ABSTRACT FROM AUTHOR]

The purpose of this study was to define a biomarker panel for detection of cancer cells in cytologically negative sputum and to evaluate the panel for assessment of lung cancer risk. We examined 19 genetic and epigenetic markers using a sensitive fluorescence-based method in cytologically negative sputum and in lung tumour tissues from 82 lung cancer patients. We also used these markers to test the sputum of 37 cancer-free individuals who were matched by age, sex, and smoking habit. Based on the concordance of biomarkers in lung tumours and corresponding sputum, and the low prevalence in cancer-free individuals, we selected seven markers for a nested case-control study: microsatellite instability of D9S942; loss of heterozygosity of D9S286, D9S942, GATA49D12, and D13S170; and methylation of p16INK4a and RARβ. Based on the assumption that a lung cancer cell has alterations in two or more of the seven biomarkers, we compared the pattern of biomarker alteration in lung tumours and corresponding sputum. Our comparison yielded a sensitivity of 82%, specificity of 75%, and concordance of 79%. Three cancer-free individuals were considered to have an elevated risk based on the criterion that their sputum showed alteration in two of the seven biomarkers. One individual was indeed diagnosed as having lung cancer 18 months after sputum collection. In the nested case-control study, six biomarkers showed significantly increased odds ratios ranging from 3.14 to 11.24. Our study defines a biomarker panel for detection of cancer cells in cytologically negative sputum and verifies its use for risk assessment of lung cancer. In combination with conventional diagnostic tools, this multiple genetic and epigenetic panel should improve the detection or risk assessment of lung cancer. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

An analog of the Datta-Das spin field-effect transistor (FET) is investigated, which is all graphene and based on the valley degree of freedom of electrons/holes. The "valley FET" envisioned consists of a quantum wire of gapped graphene (channel) sandwiched between two armchair graphene nanoribbons (source and drain), with the following correspondence to the spin FET: valley (K and K') -o- spin (up and down), armchair graphene nanoribbons <-» ferromagnetic leads, graphene quantum wire -e- semiconductor quantum wire, valley-orbit interaction <-> Rashba spin-orbit interaction. The device works as follows. The source (drain) injects (detects) carriers in a specific valley polarization. A side gate electric field is applied to the channel and modulates the valley polarization of carriers due to the valley-orbit interaction, thus controlling the amount of current collected at the drain. The valley FET is characterized by (i) smooth interfaces between leads and the channel, (ii) strong valley-orbit interaction for electrical control of drain current, and (iii) vanishing interband valley-flip scattering. By its analogy to the spin FET, the valley FET provides a potential framework to develop low-power FETs for graphene-based nanoelectronics. [ABSTRACT FROM AUTHOR]

Both spin-liquid and magnetically ordered phases of both half-integer and integer low-spin quantum magnets are of interest, since the magnetic structures found in the latter case usually have no classical counterparts. Such a magnetic structure was found in a combined experimental and theoretical study of the integer spin system Ni(NO3)2. Our thermodynamic measurements have revealed a magnetically ordered phase with small spontaneous magnetization at TC = 5.5K. The magnetization saturation of about 2μB at low temperatures corresponds to the high-spin state (S = 1) of Ni2+ ions evidenced in L2,3 edges in x-ray absorption spectroscopy spectra. We show that a consistent description of the available data is possible within a noncollinear umbrella-type ferrimagnetic ground state model for which both intra- and interlayer magnetic interactions should be antiferromagnetic. Such a scenario is suggested by the first-principles and model calculations. [ABSTRACT FROM AUTHOR]