969 research outputs found
Spontaneous Magnetisation in a Quantum Wire
An existence of predominant symmetrical spin configuration (spin polarised
phase) and "diluted" density of states (pseudo-gap) in a layer under the Fermi
level in a quantum wire is predicted. The condition of cross-over from
non-polarised phase to polarised one was derived. The transition occurs for
sufficiently low electron density in a wire and is accompanied by an acute
decrease of electron density of states near the Fermi level.It may result in a
corresponding decrease of conductance. A similar effect may exist in a
two-dimensional electron gas.Comment: 8 pages, 1 figur
Quantitative real-time RT-PCR of CD24 mRNA in the detection of prostate cancer
BACKGROUND: Gene expression profiling has recently shown that the mRNA for CD24 is overexpressed in prostate carcinomas (Pca) compared to benign or normal prostate epithelial tissues. Immunohistochemical studies have reported the usefulness of anti-CD24 for detecting prostate cancer over the full range of prostate specimens encountered in surgical pathology, e.g. needle biopsies, transurethral resection of prostate chips, or prostatectomies. It is a small mucin-like cell surface protein and thus promises to become at least a standard adjunctive stain for atypical prostate biopsies. We tested the usefulness of real-time RT-PCR for specific and sensitive detection of CD24 transcripts as a supplementary measure for discriminating between malignant and benign lesions in prostatic tissues. METHODS: Total RNA was isolated from snap-frozen chips in 55 cases of benign prostatic hyperplasia (BPH) and from frozen sections in 59 prostatectomy cases. The latter contain at least 50% malignant epithelia. Relative quantification of CD24 transcripts was performed on the LightCycler instrument using hybridization probes for detection and porphobilinogen deaminase transcripts (PBGD) for normalization. RESULTS: Normalized CD24 transcript levels showed an average 2.69-fold increase in 59 Pca-cases (mean 0.21) when compared to 55 cases of BPH (mean 0.08). This difference was highly significant (p < 0.0001). The method has a moderate specificity (47.3%) but a high sensitivity (86.4%) if the cutoff is set at 0.0498. CD24 expression levels among Pca cases were not statistically associated with the tumor and lymph-node stage, the grading (WHO), the surgical margins, or the Gleason score. CONCLUSION: The present study demonstrates the feasibility of quantitative CD24 RNA transcript detection in prostatic tissues even without previous laser microdissection
Pflanzen für die Gesundheit-Vorstellung eines neuen interdisziplinären Forschungsprojektes zum ökologischen Anbau von Arzneipflanzen
Ecologically grown medicinal plants containing bioactive compounds hold great poten-tial as high-value niche crops for farmers. However, the way to grow these plants differs from traditional crops. Growing techniques, harvest methods and postharvest handling of the raw material plays a crucial role regarding the quality of the raw material that the farmers can offer. The purpose of a new research project financed by EU-Interreg IIIA programme is among other things to carry out production, harvest and processing experiments with plants containing bioactive plant compounds that hold a preventive effect toward diabetes II.
One of the project´s goals is to draw up cultivation instructions for the primary producers to use when cultivating the plants in question. Examples of the plants that are being examined in the project are Goat´s Rue (Galega officinalis) and Fenugreek (Trigonella foenum-graecum)
Standard survey methods for estimating colony losses and explanatory risk factors in Apis mellifera
This chapter addresses survey methodology and questionnaire design for the collection of data pertaining to estimation of honey bee colony loss rates and identification of risk factors for colony loss. Sources of error in surveys are described. Advantages and disadvantages of different random and non-random sampling strategies and different modes of data collection are presented to enable the researcher to make an informed choice. We discuss survey and questionnaire methodology in some detail, for the purpose of raising awareness of issues to be considered during the survey design stage in order to minimise error and bias in the results. Aspects of survey design are illustrated using surveys in Scotland. Part of a standardized questionnaire is given as a further example, developed by the COLOSS working group for Monitoring and Diagnosis. Approaches to data analysis are described, focussing on estimation of loss rates. Dutch monitoring data from 2012 were used for an example of a statistical analysis with the public domain R software. We demonstrate the estimation of the overall proportion of losses and corresponding confidence interval using a quasi-binomial model to account for extra-binomial variation. We also illustrate generalized linear model fitting when incorporating a single risk factor, and derivation of relevant confidence intervals
Sterile neutrinos with eV masses in cosmology -- how disfavoured exactly?
We study cosmological models that contain sterile neutrinos with eV-range
masses as suggested by reactor and short-baseline oscillation data. We confront
these models with both precision cosmological data (probing the CMB decoupling
epoch) and light-element abundances (probing the BBN epoch). In the minimal
LambdaCDM model, such sterile neutrinos are strongly disfavoured by current
data because they contribute too much hot dark matter. However, if the
cosmological framework is extended to include also additional relativistic
degrees of freedom -- beyond the three standard neutrinos and the putative
sterile neutrinos, then the hot dark matter constraint on the sterile states is
considerably relaxed. A further improvement is achieved by allowing a dark
energy equation of state parameter w<-1. While BBN strongly disfavours extra
radiation beyond the assumed eV-mass sterile neutrino, this constraint can be
circumvented by a small nu_e degeneracy. Any model containing eV-mass sterile
neutrinos implies also strong modifications of other cosmological parameters.
Notably, the inferred cold dark matter density can shift up by 20 to 75%
relative to the standard LambdaCDM value.Comment: 14 pages, 6 figures, v2: minor changes, matches version accepted for
publication in JCA
E-government adoption: A cultural comparison
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ Springer Science + Business Media, LLC 2008.E-government diffusion is an international phenomenon. This study compares e-government adoption in the U.K. to adoption in the U.S. In particular, this study seeks to determine if the same factors are salient in both countries. Several studies have explored citizen acceptance of e-government services in the U.S. However, few studies have explored this phenomenon in the U.K. To identify the similarities and differences between the U.K. and the U.S. a survey is conducted in the U.K. and the findings are compared to the literature that investigates diffusion in the U.S. This study proposes a model of e-government adoption in the U.K. based on salient factors in the U.S. A survey is administered to 260 citizens in London to assess the importance of relative advantage, trust and the digital divide on intention to use e-government. The results of binary logistic regression indicate that there are cultural differences in e-government adoption in the U.K. and the U.S. The results indicate that of the prevailing adoption constructs, relative advantage and trust are pertinent in both the U.S. and the U.K., while ICT adoption barriers such as access and skill may vary by culture. Implications for research and practice are discussed
Planet Hunters X: Searching for Nearby Neighbors of 75 Planet and Eclipsing Binary Candidates from the K2 Kepler Extended Mission
We present high-resolution observations of a sample of 75 K2 targets from
Campaigns 1-3 using speckle interferometry on the Southern Astrophysical
Research (SOAR) telescope and adaptive optics (AO) imaging at the Keck II
telescope. The median SOAR -band and Keck -band detection limits at 1"
were ~mag and ~mag, respectively. This
sample includes 37 stars likely to host planets, 32 targets likely to be
eclipsing binaries (EBs), and 6 other targets previously labeled as likely
planetary false positives. We find nine likely physically bound companion stars
within 3" of three candidate transiting exoplanet host stars and six likely
EBs. Six of the nine detected companions are new discoveries; one of the six,
EPIC 206061524, is associated with a planet candidate. Among the EB candidates,
companions were only found near the shortest period ones ( days), which is
in line with previous results showing high multiplicity near short-period
binary stars. This high-resolution data, including both the detected companions
and the limits on potential unseen companions, will be useful in future planet
vetting and stellar multiplicity rate studies for planets and binaries.Comment: Accepted in A
Learning through exchange about organic agriculture - case of Europe and Australia
LEAFSE is the catch word for an innovative program of exchange study for young Australians and Europeans, with organic agriculture as the focal point of their Masters level studies. Two years ago, the European Commission and the Australian Department of Education, Science and Technology (DEST) came up with the call for applications for a pilot project to support international mobility of tertiary students between the two continents. The grand aims set for the exchange included providing students with an international outlook and a range of perspectives, preparing them for the global marketplace, enable their understanding and empathy for different cultures and traditions and foster exchange of information. A number of us with an interest and an already existing academic network in organic agriculture proposed LEAFSE - Learning through Exchange - Agriculture, Food Systems and Environment, a winning project, which was chosen as the single pilot project from a field of well over a dozen contenders. Within the broader theme of Agriculture, Food Systems and Environment, we named organic farming as the focal point of the exchange, and we were aware of the immense possibilities for learning through exchange inter-continentally in this field.
Under this project, Master's level students from EU study for a semester at a partner university in Australia, and students from Australia study for a semester at a partner university in EU. The partners in the programme are,
from Europe:
• The Royal Veterinary and Agricultural University, Denmark
• University of Wales, Aberystwyth, United Kingdom
• Wageningen University and Research Centre, The Netherlands
• University of Kassel, Witzenhausen, Germany, and
from Australia:
• University of Western Sydney, New South Wales
• University of New England, New South Wales
• University of Western Australia, Western Australia
• University of Queensland, Queensland
The project has an innovative but manageable framework for mobility of the students, a joint programme of study which incorporates many novel elements including holistic thinking, experiential and integrated learning and use of newer tools of communication technologies, and above all, a structure that fosters a high degree of inter-cultural understanding and network building. When completed, the pilot phase of the project would have enabled exchange of 36 students from each continent, nine from each participating institution. The respective government agencies provide the students with an adequate stipend to cover travel and living expenses for six months of study.
The project has been running on target and the results of the first year of exchange have been more than impressive. This presentation will be a joint effort by the faculty and a number of participating students to demonstrate the cultural, agricultural, pedagogic, and practical lessons that have been learnt from this exchange in the field of organic farming. It will also highlight some of the challenges which need to be overcome in our efforts towards shaping sustainable agricultural and food systems which are cognizant of our respective environments
Trim17, novel E3 ubiquitin-ligase, initiates neuronal apoptosis
Accumulating data indicate that the ubiquitin-proteasome system controls apoptosis by regulating the level and the function of key regulatory proteins. In this study, we identified Trim17, a member of the TRIM/RBCC protein family, as one of the critical E3 ubiquitin ligases involved in the control of neuronal apoptosis upstream of mitochondria. We show that expression of Trim17 is increased both at the mRNA and protein level in several in vitro models of transcription-dependent neuronal apoptosis. Expression of Trim17 is controlled by the PI3K/Akt/GSK3 pathway in cerebellar granule neurons (CGN). Moreover, the Trim17 protein is expressed in vivo, in apoptotic neurons that naturally die during post-natal cerebellar development. Overexpression of active Trim17 in primary CGN was sufficient to induce the intrinsic pathway of apoptosis in survival conditions. This pro-apoptotic effect was abolished in Bax(-/-) neurons and depended on the E3 activity of Trim17 conferred by its RING domain. Furthermore, knock-down of endogenous Trim17 and overexpression of dominant-negative mutants of Trim17 blocked trophic factor withdrawal-induced apoptosis both in CGN and in sympathetic neurons. Collectively, our data are the first to assign a cellular function to Trim17 by showing that its E3 activity is both necessary and sufficient for the initiation of neuronal apoptosis. Cell Death and Differentiation (2010) 17, 1928-1941; doi: 10.1038/cdd.2010.73; published online 18 June 201
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