Metal-Insulator-Like Behavior in Semimetallic Bismuth and Graphite

When high quality bismuth or graphite crystals are placed in a magnetic field directed along the c-axis (trigonal axis for bismuth) and the temperature is lowered, the resistance increases as it does in an insulator but then saturates. We show that the combination of unusual features specific to semimetals, i.e., low carrier density, small effective mass, high purity, and an equal number of electrons and holes (compensation), gives rise to a unique ordering and spacing of three characteristic energy scales, which not only is specific to semimetals but which concomitantly provides a wide window for the observation of apparent field induced metal-insulator behavior. Using magnetotransport and Hall measurements, the details of this unusual behavior are captured with a conventional multi-band model, thus confirming the occupation by semimetals of a unique niche between conventional metals and semiconductors.Comment: 4 pages, 4 figs, data and discussion on bismuth added, final published versio

A Curriculum Development Project for IBM Linux in Academia Program

This paper introduces the IBM Linux in Academia program and a curriculum development project initiated by the authors for the program. The service of IBM Linux in Academia program is based on the Linux virtual service concept in which a mainframe computer is partitioned into many Linux images supported by IBM’s Virtual Machine Operating System. On the IBM S/390 system, each image acts as an independent Linux server. This free service saves the acquisition and management cost of running multiple physically separated servers for participating universities. The curriculum development project intends to create and share curriculum materials for e-Business related courses among participants. The main IBM software used in this project includes DB2 Universal Database and WebSphere. The main objective in the first stage of this project is to develop a data warehouse generator to manipulate a large read-only database obtained from a real world health care application supplied by IBM. Through a web based user interface, an instructor could flexibly create a data warehouse using the Account Data Model developed by some of the authors from the read-only database with the desirable size and attributes to support pedagogical needs. Other aspects of the project are also addressed

Adapting to Latent Subgroup Shifts via Concepts and Proxies

We address the problem of unsupervised domain adaptation when the source domain differs from the target domain because of a shift in the distribution of a latent subgroup. When this subgroup confounds all observed data, neither covariate shift nor label shift assumptions apply. We show that the optimal target predictor can be non-parametrically identified with the help of concept and proxy variables available only in the source domain, and unlabeled data from the target. The identification results are constructive, immediately suggesting an algorithm for estimating the optimal predictor in the target. For continuous observations, when this algorithm becomes impractical, we propose a latent variable model specific to the data generation process at hand. We show how the approach degrades as the size of the shift changes, and verify that it outperforms both covariate and label shift adjustment

Reconstitution of an epithelial chloride channel. Conservation of the channel from mudpuppy to man

We have previously shown that monoclonal antibody E12 (MAb E12), one of several such antibodies raised against theophylline-treated Necturus gallbladder (NGB) epithelial cells, inhibits the chloride conductance in the apical membrane of that tissue. Since chloride channels are critical to the secretory function of epithelia in many different animals, we have used this antibody to determine whether the channels are conserved, and in an immunoaffinity column to isolate the channel protein. We now demonstrate that MAb E12 cross-reacts with detergent- solubilized extracts of different tissues from various species by enzyme-linked immunosorbent assay (ELISA). Western blot analysis shows that this monoclonal antibody recognizes proteins of Mr 219,000 in NGB, toad gallbladder, urinary bladder, and small intestine, A6 cells, rat colon, rabbit gastric mucosa, human lymphocytes, and human nasal epithelial cells, and inhibits the chloride conductance in toad gallbladder, rat colon, and human nasal epithelium. Detergent- solubilized protein eluted from an immunoaffinity column and then further purified via FPLC yields a fraction (Mr 200,000-220,000) which has been reconstituted into a planar lipid bilayer. There it behaves as a chloride-selective channel (PCl/PNa = 20.2 in a 150/50 mM trans- bilayer NaCl gradient) whose unit conductance is 62.4 +/- 4.6 pS, and which is blocked in the bilayer by the antibody. The gating characteristics of this channel indicate that it can exist as aggregates or as independent single channels, and that the antibody interferes with gating of the aggregates, leaving the unit channels unchanged. From these data we conclude that the protein of Mr 219,000 recognized by this monoclonal antibody is an important component of an epithelial chloride channel, and that this channel is conserved across a wide range of animal species

Patients Infected with CRF07_BC Have Significantly Lower Viral Loads than Patients with HIV-1 Subtype B: Mechanism and Impact on Disease Progression

The circulating recombinant form (CRF) 07_BC is the most prevalent HIV-1 strain among injection drug users (IDUs) in Taiwan. It contains a 7 amino-acid deletion in its p6gag. We conducted a cohort study to compare viral loads and CD4 cell count changes between patients infected with subtype B and CRF07_BC and to elucidate its mechanism. Twenty-one patients infected with CRF07_BC and 59 patients with subtype B were selected from a cohort of 667 HIV-1/AIDS patients whom have been followed up for 3 years. Generalized estimated equation was used to analyze their clinical data and the results showed that patients infected with CRF07_BC had significantly lower viral loads (about 58,000 copies per ml less) than patients with subtype B infection (p = 0.002). The replicative capacity of nine CRF07_BC and four subtype B isolates were compared and the results showed that the former had significantly lower replicative capacity than the latter although all of them were CCR5- tropic and non-syncytium inducing viruses. An HIV-1-NL4-3 mutant virus which contains a 7 amino-acid deletion in p6gag (designated as 7d virus) was generated and its live cycle was investigated. The results showed that 7d virus had significantly lower replication capacity, poorer protease-mediated processing and viral proteins production. Electron microscopic examination of cells infected with wild-type or 7d virus demonstrated that the 7d virus had poorer and slower viral maturation processes: more viruses attached to the cell membrane and higher proportion of immature virions outside the cells. The interaction between p6gag and Alix protein was less efficient in cells infected with 7d virus. In conclusion, patients infected with CRF07_BC had significantly lower viral loads than patients infected with subtype B and it may due to the deletion of 7 amino acids which overlaps with Alix protein-binding domain of the p6gag

Exhaled volatile organic compounds in patients with non-small cell lung cancer: cross sectional and nested short-term follow-up study

BACKGROUND: Non-invasive diagnostic strategies aimed at identifying biomarkers of lung cancer are of great interest for early cancer detection. The aim of this study was to set up a new method for identifying and quantifying volatile organic compounds (VOCs) in exhaled air of patients with non-small cells lung cancer (NSCLC), by comparing the levels with those obtained from healthy smokers and non-smokers, and patients with chronic obstructive pulmonary disease. The VOC collection and analyses were repeated three weeks after the NSCLC patients underwent lung surgery. METHODS: The subjects' breath was collected in a Teflon(® )bulb that traps the last portion of single slow vital capacity. The 13 VOCs selected for this study were concentrated using a solid phase microextraction technique and subsequently analysed by means of gas cromatography/mass spectrometry. RESULTS: The levels of the selected VOCs ranged from 10(-12 )M for styrene to 10(-9 )M for isoprene. None of VOCs alone discriminated the study groups, and so it was not possible to identify one single chemical compound as a specific lung cancer biomarker. However, multinomial logistic regression analysis showed that VOC profile can correctly classify about 80 % of cases. Only isoprene and decane levels significantly decreased after surgery. CONCLUSION: As the combination of the 13 VOCs allowed the correct classification of the cases into groups, together with conventional diagnostic approaches, VOC analysis could be used as a complementary test for the early diagnosis of lung cancer. Its possible use in the follow-up of operated patients cannot be recommended on the basis of the results of our short-term nested study

Low carbon innovation in China: from overlooked opportunities and challenges to transitions in power relations and practices

This paper explores environmental innovation in the largest emerging economy – China - and its potential for contributing to global transitions to low-carbon, more sustainable patterns of development. It builds on earlier studies bringing alternative forms of low(er)-technology, ‘below-the-radar’, ‘disruptive’ and/or social innovation into its analysis. In addition, however, the paper develops our understanding of low-carbon innovation by paying particular attention to issues of changing power relations and social practices; theoretical issues that need attention in the literature generally but are notably absent when studying transitions in China. This shift in perspective allows four neglected questions to be introduced and, in each case, points to both opportunities and challenges to low-carbon system transition that are overlooked by an orthodox focus on technological innovations alone. These are briefly illustrated by drawing on examples from three key domains of low-carbon innovation: solar-generated energy; electric urban mobility; and food and agriculture