Damping scales of neutralino cold dark matter

The lightest supersymmetric particle, most likely the neutralino, might account for a large fraction of dark matter in the Universe. We show that the primordial spectrum of density fluctuations in neutralino cold dark matter (CDM) has a sharp cut-off due to two damping mechanisms: collisional damping during the kinetic decoupling of the neutralinos at about 30 MeV (for typical neutralino and sfermion masses) and free streaming after last scattering of neutralinos. The last scattering temperature is lower than the kinetic decoupling temperature by one order of magnitude. The cut-off in the primordial spectrum defines a minimal mass for CDM objects in hierarchical structure formation. For typical neutralino and sfermion masses the first gravitationally bound neutralino clouds have to have masses above 10^(-7) solar masses.Comment: 13 pages, 5 figures; typos corrected; accepted by Physical Review

Dark matter and Colliders searches in the MSSM

We study the complementarity between dark matter experiments (direct detection and indirect detections) and accelerator facilities (the CERN LHC and a $\sqrt{s}= 1$ TeV $e^+e^-$ Linear Collider) in the framework of the constrained Minimal Supersymmetric Standard Model (MSSM). We show how non--universality in the scalar and gaugino sectors can affect the experimental prospects to discover the supersymmetric particles. The future experiments will cover a large part of the parameter space of the MSSM favored by WMAP constraint on the relic density, but there still exist some regions beyond reach for some extreme (fine tuned) values of the supersymmetric parameters. Whereas the Focus Point region characterized by heavy scalars will be easily probed by experiments searching for dark matter, the regions with heavy gauginos and light sfermions will be accessible more easily by collider experiments. More informations on both supersymmetry and astrophysics parameters can be thus obtained by correlating the different signals.Comment: 25 pages, 10 figures, corrected typos and reference adde

Materiality, health informatics and the limits of knowledge production

© IFIP International Federation for Information Processing 2014 Contemporary societies increasingly rely on complex and sophisticated information systems for a wide variety of tasks and, ultimately, knowledge about the world in which we live. Those systems are central to the kinds of problems our systems and sub-systems face such as health and medical diagnosis, treatment and care. While health information systems represent a continuously expanding field of knowledge production, we suggest that they carry forward significant limitations, particularly in their claims to represent human beings as living creatures and in their capacity to critically reflect on the social, cultural and political origins of many forms of data ‘representation’. In this paper we take these ideas and explore them in relation to the way we see healthcare information systems currently functioning. We offer some examples from our own experience in healthcare settings to illustrate how unexamined ideas about individuals, groups and social categories of people continue to influence health information systems and practices as well as their resulting knowledge production. We suggest some ideas for better understanding how and why this still happens and look to a future where the reflexivity of healthcare administration, the healthcare professions and the information sciences might better engage with these issues. There is no denying the role of health informatics in contemporary healthcare systems but their capacity to represent people in those datascapes has a long way to go if the categories they use to describe and analyse human beings are to produce meaningful knowledge about the social world and not simply to replicate past ideologies of those same categories

Establishment and characterization of a new human pancreatic adenocarcinoma cell line with high metastatic potential to the lung

<p>Abstract</p> <p>Background</p> <p>Pancreatic cancer is still associated with devastating prognosis. Real progress in treatment options has still not been achieved. Therefore new models are urgently needed to investigate this deadly disease. As a part of this process we have established and characterized a new human pancreatic cancer cell line.</p> <p>Methods</p> <p>The newly established pancreatic cancer cell line PaCa 5061 was characterized for its morphology, growth rate, chromosomal analysis and mutational analysis of the K-<it>ras</it>, EGFR and p53 genes. Gene-amplification and RNA expression profiles were obtained using an Affymetrix microarray, and overexpression was validated by IHC analysis. Tumorigenicity and spontaneous metastasis formation of PaCa 5061 cells were analyzed in pfp^-/-/rag2^-/-mice. Sensitivity towards chemotherapy was analysed by MTT assay.</p> <p>Results</p> <p>PaCa 5061 cells grew as an adhering monolayer with a doubling time ranging from 30 to 48 hours. M-FISH analyses showed a hypertriploid complex karyotype with multiple numerical and unbalanced structural aberrations. Numerous genes were overexpressed, some of which have previously been implicated in pancreatic adenocarcinoma (GATA6, IGFBP3, IGFBP6), while others were detected for the first time (MEMO1, RIOK3). Specifically highly overexpressed genes (fold change > 10) were identified as EGFR, MUC4, CEACAM1, CEACAM5 and CEACAM6. Subcutaneous transplantation of PaCa 5061 into pfp^-/-/rag2^-/-mice resulted in formation of primary tumors and spontaneous lung metastasis.</p> <p>Conclusion</p> <p>The established PaCa 5061 cell line and its injection into pfp^-/-/rag2^-/-mice can be used as a new model for studying various aspects of the biology of human pancreatic cancer and potential treatment approaches for the disease.</p

Defining the effective temperature of a quantum driven system from current-current correlation functions

We calculate current-current correlation functions and find an expression for the zero-frequency noise of multiterminal systems driven by harmonically time-dependent voltages within the Keldysh non-equilibrium Green's functions formalism. We also propose a fluctuation-dissipation relation for current-current correlation functions to define an effective temperature. We discuss the behavior of this temperature and compare it with the local temperature determined by a thermometer and with the effective temperature defined from a single-particle fluctuation-dissipation relation. We show that for low frequencies all the definitions of the temperature coincide.Comment: 11 pages, 5 figure

Isolation of chromosome clusters from metaphase-arrested HeLa cells

We have developed a simplified approach for the isolation of metaphase chromosomes from HeLa cells. In this method, all the chromosomes from a cell remain together in a bundle which we call a “metaphase chromosome cluster”. Cells are arrested to 90–95% in metaphase, collected by centrifugation, extracted with non-ionic detergent in a low ionic strength buffer at neutral pH, and homogenised to strip away the cytoskeleton. The chromosome clusters which are released can then be isolated in a crude state by pelleting or they can be purified away from nearly all the interphase nuclei and cytoplasmic debris by banding in a Percoll TM density gradient. — This procedure has the advantages that it is quick and easy, metaphase chromatin is recovered in high yield, and Ca ++ is not needed to stabilise the chromosomes. Although the method does not yield individual chromosomes, it is nevertheless very useful for both structural and biochemical studies of mitotic chromatin. The chromosome clusters also make possible biochemical and structural studies of what holds the different chromosomes together. Such information could be useful in improving chromosome isolation procedures and for understanding suprachromosomal organisation of the nucleus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47359/1/412_2004_Article_BF00327351.pd

TRY plant trait database – enhanced coverage and open access

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Search for the Zγ decay mode of new high-mass resonances in pp collisions at √s = 13 TeV with the ATLAS detector

This letter presents a search for narrow, high-mass resonances in the Zγ final state with the Z boson decaying into a pair of electrons or muons. The √s = 13 TeV pp collision data were recorded by the ATLAS detector at the CERN Large Hadron Collider and have an integrated luminosity of 140 fb−1. The data are found to be in agreement with the Standard Model background expectation. Upper limits are set on the resonance production cross section times the decay branching ratio into Zγ. For spin-0 resonances produced via gluon–gluon fusion, the observed limits at 95% confidence level vary between 65.5 fb and 0.6 fb, while for spin-2 resonances produced via gluon–gluon fusion (or quark–antiquark initial states) limits vary between 77.4 (76.1) fb and 0.6 (0.5) fb, for the mass range from 220 GeV to 3400 GeV

Search for a new heavy scalar particle decaying into a Higgs boson and a new scalar singlet in final states with one or two light leptons and a pair of τ-leptons with the ATLAS detector

A search for a new heavy scalar particle X decaying into a Standard Model (SM) Higgs boson and a new singlet scalar particle S is presented. The search uses a proton-proton (pp) collision data sample with an integrated luminosity of 140 fb−1 recorded at a centre-of-mass energy of s√ = 13 TeV with the ATLAS detector at the Large Hadron Collider. The most sensitive mass parameter space is explored in X mass ranging from 500 to 1500 GeV, with the corresponding S mass in the range 200–500 GeV. The search selects events with two hadronically decaying τ-lepton candidates from H → τ+τ− decays and one or two light leptons (ℓ = e, μ) from S → VV (V = W, Z) decays while the remaining V boson decays hadronically or to neutrinos. A multivariate discriminant based on event kinematics is used to separate the signal from the background. No excess is observed beyond the expected SM background and 95% confidence level upper limits between 72 fb and 542 fb are derived on the cross-section σ(pp → X → SH) assuming the same SM-Higgs boson-like decay branching ratios for the S → VV decay. Upper limits on the visible cross-sections σ(pp → X → SH → WWττ) and σ(pp → X → SH → ZZττ) are also set in the ranges 3–26 fb and 6–33 fb, respectively