205 research outputs found
Grundlagen und Qualifikationen soziologischer Beratung
Der Beitrag greift die auf der IX. Tagung für Angewandte Soziologie 'Soziologische Beratung' geführten intensiven Diskussionen um Profil, Aufgabengebiete und Qualifikationen von Beratern und Beraterinnen auf. Geklärt werden sollen die Begriffe 'soziologische Beratung' und 'soziologische Beratungskompetenz'. Ziel ist dabei, über Chancen und Risiken der Präzisierung und Standardisierung eines Berufsfeldes für Soziologen nachzudenken und zu eruieren, welche Möglichkeiten soziologische Beratung eröffnen kann bzw. wo und wie sich soziologische Beratung gegen andere Beratung abgrenzt. Damit wird letztendlich ein Orientierungsrahmen für eine systematische Qualifizierung in soziologischer Beratung geschaffen und gegenüber der Öffentlichkeit das Leistungsspektrum soziologischer Beratung transparenter und attraktiver gemacht.(ICH
Mycobacterium tuberculosis Affects Protein and Lipid Content of Circulating Exosomes in Infected Patients Depending on Tuberculosis Disease State
Tuberculosis (TB), which is caused by the bacterium Mycobacterium tuberculosis (Mtb), is
still one of the deadliest infectious diseases. Understanding how the host and pathogen interact
in active TB will have a significant impact on global TB control efforts. Exosomes are increasingly
recognized as a means of cell-to-cell contact and exchange of soluble mediators. In the case of TB,
exosomes are released from the bacillus and infected cells. In the present study, a comprehensive
lipidomics and proteomics analysis of size exclusion chromatography-isolated plasma-derived exosomes from patients with TB lymphadenitis (TBL) and treated as well as untreated pulmonary TB
(PTB) was performed to elucidate the possibility to utilize exosomes in diagnostics and knowledge
building. According to our findings, exosome-derived lipids and proteins originate from both the
host and Mtb in the plasma of active TB patients. Exosomes from all patients are mostly composed of
sphingomyelins (SM), phosphatidylcholines, phosphatidylinositols, free fatty acids, triacylglycerols
(TAG), and cholesterylesters. Relative proportions of, e.g., SMs and TAGs, vary depending on the
disease or treatment state and could be linked to Mtb pathogenesis and dormancy. We identified
three proteins of Mtb origin: DNA-directed RNA polymerase subunit beta (RpoC), Diacyglycerol
O-acyltransferase (Rv2285), and Formate hydrogenase (HycE), the latter of which was discovered to
be differently expressed in TBL patients. Furthermore, we discovered that Mtb infection alters the
host protein composition of circulating exosomes, significantly affecting a total of 37 proteins. All TB
patients had low levels of apolipoproteins, as well as the antibacterial proteins cathelicidin, Scavenger
Receptor Cysteine Rich Family Member (SSC5D), and Ficolin 3 (FCN3). When compared to healthy
controls, the protein profiles of PTB and TBL were substantially linked, with 14 proteins being coregulated. However, adhesion proteins (integrins, Intercellular adhesion molecule 2 (ICAM2), CD151,
Proteoglycan 4 (PRG4)) were shown to be more prevalent in PTB patients, while immunoglobulins,
Complement component 1r (C1R), and Glutamate receptor-interacting protein 1 (GRIP1) were found
to be more abundant in TBL patients, respectively. This study could confirm findings from previous
reports and uncover novel molecular profiles not previously in focus of TB research. However, we
applied a minimally invasive sampling and analysis of circulating exosomes in TB patients. Based on the findings given here, future studies into host–pathogen interactions could pave the way for the
development of new vaccines and therapies
Almost-Hermitian Random Matrices: Crossover from Wigner-Dyson to Ginibre eigenvalue statistics
By using the method of orthogonal polynomials we analyze the statistical
properties of complex eigenvalues of random matrices describing a crossover
from Hermitian matrices characterized by the Wigner- Dyson statistics of real
eigenvalues to strongly non-Hermitian ones whose complex eigenvalues were
studied by Ginibre.
Two-point statistical measures (as e.g. spectral form factor, number variance
and small distance behavior of the nearest neighbor distance distribution
) are studied in more detail. In particular, we found that the latter
function may exhibit unusual behavior for some parameter
values.Comment: 4 pages, RevTE
Reducing nonideal to ideal coupling in random matrix description of chaotic scattering: Application to the time-delay problem
We write explicitly a transformation of the scattering phases reducing the
problem of quantum chaotic scattering for systems with M statistically
equivalent channels at nonideal coupling to that for ideal coupling. Unfolding
the phases by their local density leads to universality of their local
fluctuations for large M. A relation between the partial time delays and
diagonal matrix elements of the Wigner-Smith matrix is revealed for ideal
coupling. This helped us in deriving the joint probability distribution of
partial time delays and the distribution of the Wigner time delay.Comment: 4 pages, revtex, no figures; published versio
Statistics of S-matrix poles for chaotic systems with broken time reversal invariance: a conjecture
In the framework of a random matrix description of chaotic quantum scattering
the positions of matrix poles are given by complex eigenvalues of an
effective non-Hermitian random-matrix Hamiltonian. We put forward a conjecture
on statistics of for systems with broken time-reversal invariance and
verify that it allows to reproduce statistical characteristics of Wigner time
delays known from independent calculations. We analyze the ensuing two-point
statistical measures as e.g. spectral form factor and the number variance. In
addition we find the density of complex eigenvalues of real asymmetric matrices
generalizing the recent result by Efetov\cite{Efnh}.Comment: 4 page
Delay times and reflection in chaotic cavities with absorption
Absorption yields an additional exponential decay in open quantum systems
which can be described by shifting the (scattering) energy E along the
imaginary axis, E+i\hbar/2\tau_{a}. Using the random matrix approach, we
calculate analytically the distribution of proper delay times (eigenvalues of
the time-delay matrix) in chaotic systems with broken time-reversal symmetry
that is valid for an arbitrary number of generally nonequivalent channels and
an arbitrary absorption rate 1/\tau_{a}. The relation between the average delay
time and the ``norm-leakage'' decay function is found. Fluctuations above the
average at large values of delay times are strongly suppressed by absorption.
The relation of the time-delay matrix to the reflection matrix S^{\dagger}S is
established at arbitrary absorption that gives us the distribution of
reflection eigenvalues. The particular case of single-channel scattering is
explicitly considered in detail.Comment: 5 pages, 3 figures; final version to appear in PRE (relation to
reflection extended, new material with Fig.3 added, experiment
cond-mat/0305090 discussed
Molecular Dynamics for Fermions
The time-dependent variational principle for many-body trial states is used
to discuss the relation between the approaches of different molecular dynamics
models to describe indistinguishable fermions. Early attempts to include
effects of the Pauli principle by means of nonlocal potentials as well as more
recent models which work with antisymmetrized many-body states are reviewed
under these premises.
Keywords: Many-body theory; Fermion system; Molecular dynamics; Wave-packet
dynamics; Time-dependent variational principle; Statistical properties;
Canonical ensemble; Ergodicity; Time averagingComment: 97 pages, 13 postscript figures. To be published in July 2000 issue
of Reviews of Modern Physics. More information at http://www-aix.gsi.de/~fmd
Antimicrobial peptides of the Cecropin-family show potent antitumor activity against bladder cancer cells
<p>Abstract</p> <p>Background</p> <p>This study evaluated the cytotoxic and antiproliferative efficacy of two well-characterized members of the Cecropin-family of antimicrobial peptides against bladder tumor cells and benign fibroblasts.</p> <p>Methods</p> <p>The antiproliferative and cytotoxic potential of the Cecropins A and B was quantified by colorimetric WST-1-, BrdU- and LDH-assays in four bladder cancer cell lines as well as in murine and human fibroblast cell lines. IC<sub>50 </sub>values were assessed by logarithmic extrapolation, representing the concentration at which cell viability was reduced by 50%. Scanning electron microscopy (SEM) was performed to visualize the morphological changes induced by Cecropin A and B in bladder tumor cells and fibroblasts.</p> <p>Results</p> <p>Cecropin A and B inhibit bladder cancer cell proliferation and viability in a dose-dependent fashion. The average IC<sub>50 </sub>values of Cecropin A and B against all bladder cancer cell lines ranged between 73.29 μg/ml and 220.05 μg/ml. In contrast, benign fibroblasts were significantly less or not at all susceptible to Cecropin A and B. Both Cecropins induced an increase in LDH release from bladder tumor cells whereas benign fibroblasts were not affected. SEM demonstrated lethal membrane disruption in bladder cancer cells as opposed to fibroblasts.</p> <p>Conclusion</p> <p>Cecropin A and B exert selective cytotoxic and antiproliferative efficacy in bladder cancer cells while sparing targets of benign murine or human fibroblast origin. Both peptides may offer novel therapeutic strategies for the treatment of bladder cancer with limited cytotoxic effects on benign cells.</p
Tight correlation between expression of the Forkhead transcription factor FOXM1 and HER2 in human breast cancer
BACKGROUND: FOXM1 regulates expression of cell cycle related genes that are essential for progression into DNA replication and mitosis. Consistent with its role in proliferation, elevated expression of FOXM1 has been reported in a variety of human tumour entities. FOXM1 is a gene of interest because recently chemical inhibitors of FOXM1 were described to limit proliferation and induce apoptosis in cancer cells in vitro, indicating that FOXM1 inhibitors could represent useful anticancer therapeutics. METHODS: Using immunohistochemistry (IHC) we systematically analysed FOXM1 expression in human invasive breast carcinomas (n = 204) and normal breast tissues (n = 46) on a tissue microarray. Additionally, using semiquantitative realtime PCR, a collection of paraffin embedded normal (n = 12) and cancerous (n = 25) breast tissue specimens as well as benign (n = 3) and malignant mammary cell lines (n = 8) were investigated for FOXM1 expression. SPSS version 14.0 was used for statistical analysis. RESULTS: FOXM1 was found to be overexpressed in breast cancer in comparison to normal breast tissue both on the RNA and protein level (e.g. 8.7 fold as measured by realtime PCR). We found a significant correlation between FOXM1 expression and the HER2 status determined by HER2 immunohistochemistry (P < 0.05). Univariate survival analysis showed a tendency between FOXM1 protein expression and unfavourable prognosis (P = 0.110). CONCLUSION: FOXM1 may represent a novel breast tumour marker with prognostic significance that could be included into multi-marker panels for breast cancer. Interestingly, we found a positive correlation between FOXM1 expression and HER2 status, pointing to a potential role of FOXM1 as a new drug target in HER2 resistant breast tumour, as FOXM1 inhibitors for cancer treatment were described recently. Further studies are underway to analyse the potential interaction between FOXM1 and HER2, especially whether FOXM1 directly activates the HER2 promoter
A review of nitrogen isotopic alteration in marine sediments
Key Points: Use of sedimentary nitrogen isotopes is examined; On average, sediment 15N/14N increases approx. 2 per mil during early burial; Isotopic alteration scales with water depth
Abstract:
Nitrogen isotopes are an important tool for evaluating past biogeochemical cycling from the paleoceanographic record. However, bulk sedimentary nitrogen isotope ratios, which can be determined routinely and at minimal cost, may be altered during burial and early sedimentary diagenesis, particularly outside of continental margin settings. The causes and detailed mechanisms of isotopic alteration are still under investigation. Case studies of the Mediterranean and South China Seas underscore the complexities of investigating isotopic alteration. In an effort to evaluate the evidence for alteration of the sedimentary N isotopic signal and try to quantify the net effect, we have compiled and compared data demonstrating alteration from the published literature. A >100 point comparison of sediment trap and surface sedimentary nitrogen isotope values demonstrates that, at sites located off of the continental margins, an increase in sediment 15N/14N occurs during early burial, likely at the seafloor. The extent of isotopic alteration appears to be a function of water depth. Depth-related differences in oxygen exposure time at the seafloor are likely the dominant control on the extent of N isotopic alteration. Moreover, the compiled data suggest that the degree of alteration is likely to be uniform through time at most sites so that bulk sedimentary isotope records likely provide a good means for evaluating relative changes in the global N cycle
- …