2,046 research outputs found
Recommended from our members
Dynamic Pricing, Advanced Metering, and Demand Response in Electricity Markets
Presents an overview and analysis of the possible approaches to bringing an active demand side into electricity markets. Part of a series of research reports that examines energy issues facing California
Urban Growth in Germany – The Impact of Localization and Urbanization Economies
This study examines the impact of localization and urbanization economies as well as the impact of city size on urban growth in German cities from 2003 to 2007. Although, from a theoretical perspective, agglomeration economies are supposed to have positive impacts on regional growth, prior empirical studies do not show consistent results. Especially little is known about agglomeration economies in Germany, where interregional support policy and the characteristics of the federal system are further determinants of urban growth. The results of the econometric analysis show a U-shaped relationship between specialization and urban growth, which particularly holds for manufacturing industries. We do not find evidence for the impact of Jacobs-externalities; however, city size shows a positive (but decreasing) effect on urban growth.agglomeration, localization economies, urbanization economies, urban growth, specialization, diversification
Highly-efficient state-selective sub-microsecond photoionization detection of single atoms
We experimentally demonstrate a detection scheme suitable for state analysis
of single optically trapped atoms in less than 1 {\mu}s with an overall
detection efficiency {\eta} exceeding 98%. The method is based on
hyperfine-state-selective photoionization and subsequent registration of the
correlated photoion-electron pairs by coincidence counting via two opposing
channel electron multipliers. The scheme enables the calibration of absolute
detection efficiencies and might be a key ingredient for future quantum
information applications or precision spectroscopy of ultracold atoms.Comment: 4 pages, 4 figure
Tyrosine dephosphorylation of H2AX modulates apoptosis and survival decisions.
Life and death fate decisions allow cells to avoid massive apoptotic death in response to genotoxic stress. Although the regulatory mechanisms and signalling pathways controlling DNA repair and apoptosis are well characterized, the precise molecular strategies that determine the ultimate choice of DNA repair and survival or apoptotic cell death remain incompletely understood. Here we report that a protein tyrosine phosphatase, EYA, is involved in promoting efficient DNA repair rather than apoptosis in response to genotoxic stress in mammalian embryonic kidney cells by executing a damage-signal-dependent dephosphorylation of an H2AX carboxy-terminal tyrosine phosphate (Y142). This post-translational modification determines the relative recruitment of either DNA repair or pro-apoptotic factors to the tail of serine phosphorylated histone H2AX (gamma-H2AX) and allows it to function as an active determinant of repair/survival versus apoptotic responses to DNA damage, revealing an additional phosphorylation-dependent mechanism that modulates survival/apoptotic decisions during mammalian organogenesis
Towards a loophole-free test of Bell's inequality with entangled pairs of neutral atoms
Experimental tests of Bell's inequality allow to distinguish quantum
mechanics from local hidden variable theories. Such tests are performed by
measuring correlations of two entangled particles (e.g. polarization of photons
or spins of atoms). In order to constitute conclusive evidence, two conditions
have to be satisfied. First, strict separation of the measurement events in the
sense of special relativity is required ("locality loophole"). Second, almost
all entangled pairs have to be detected (for particles in a maximally entangled
state the required detector efficiency is 82.8%), which is hard to achieve
experimentally ("detection loophole"). By using the recently demonstrated
entanglement between single trapped atoms and single photons it becomes
possible to entangle two atoms at a large distance via entanglement swapping.
Combining the high detection efficiency achieved with atoms with the space-like
separation of the atomic state detection events, both loopholes can be closed
within the same experiment. In this paper we present estimations based on
current experimental achievements which show that such an experiment is
feasible in future.Comment: 6 pages, 3 figures, to be published in Advanced Science Letter
Epigenomic Regulation of Androgen Receptor Signaling: Potential Role in Prostate Cancer Therapy.
Androgen receptor (AR) signaling remains the major oncogenic pathway in prostate cancer (PCa). Androgen-deprivation therapy (ADT) is the principle treatment for locally advanced and metastatic disease. However, a significant number of patients acquire treatment resistance leading to castration resistant prostate cancer (CRPC). Epigenetics, the study of heritable and reversible changes in gene expression without alterations in DNA sequences, is a crucial regulatory step in AR signaling. We and others, recently described the technological advance Chem-seq, a method to identify the interaction between a drug and the genome. This has permitted better understanding of the underlying regulatory mechanisms of AR during carcinogenesis and revealed the importance of epigenetic modifiers. In screening for new epigenomic modifiying drugs, we identified SD-70, and found that this demethylase inhibitor is effective in CRPC cells in combination with current therapies. The aim of this review is to explore the role of epigenetic modifications as biomarkers for detection, prognosis, and risk evaluation of PCa. Furthermore, we also provide an update of the recent findings on the epigenetic key processes (DNA methylation, chromatin modifications and alterations in noncoding RNA profiles) involved in AR expression and their possible role as therapeutic targets
Accurate prediction of gene feedback circuit behavior from component properties
A basic assumption underlying synthetic biology is that analysis of genetic circuit elements, such as regulatory proteins and promoters, can be used to understand and predict the behavior of circuits containing those elements. To test this assumption, we used time‐lapse fluorescence microscopy to quantitatively analyze two autoregulatory negative feedback circuits. By measuring the gene regulation functions of the corresponding repressor–promoter interactions, we accurately predicted the expression level of the autoregulatory feedback loops, in molecular units. This demonstration that quantitative characterization of regulatory elements can predict the behavior of genetic circuits supports a fundamental requirement of synthetic biology
- …