Quantum speed limit for physical processes

The evaluation of the minimal evolution time between two distinguishable states of a system is important for assessing the maximal speed of quantum computers and communication channels. Lower bounds for this minimal time have been proposed for unitary dynamics. Here we show that it is possible to extend this concept to nonunitary processes, using an attainable lower bound that is connected to the quantum Fisher information for time estimation. This result is used to delimit the minimal evolution time for typical noisy channels.Comment: results unchanged; new in this version: greater focus on geometrical interpretation of results, added references, improvements in style, comments on exclusion window left mainly for the supplemental material; main article: 7 pages (including references), 2 figures; supplemental material: 5 pages, 4 figure

Absorption-Fluctuation Theorem for Nuclear Reactions: Brink-Axel, Incomplete Fusion and All That

We discuss the connection between absorption, averages and fluctuations in nuclear reactions. The fluctuations in the entrance channel result in the compound nucleus, Hauser-Feshbach, cross section, the fluctuations in the intermediate channels, result in modifications of multistep reaction cross sections, while the fluctuations in the final channel result in hybrid cross sections that can be used to describe incomplete fusion reactions. We discuss the latter in details and comment on the validity of the assumptions used in the develpoment of the Surrogate method. We also discuss the theory of multistep reactions with regards to intermediate state fluctuations and the energy dependence and non-locality of the intermediate channels optical potentials.Comment: 9 pages. Contribution to the International Workshop on Compound-Nuclear Reactions and Related Topics (CNR*2007), October 22-26, 2007, Fish Camp, California. To be published in AIP Proceedings (Editor Jutta Escher

Immunopathological properties of the Campylobacter jejuni flagellins and the adhesin CadF as assessed in a clinical murine infection model

Background: Campylobacter jejuni infections constitute serious threats to human health with increasing prevalences worldwide. Our knowledge regarding the molecular mechanisms underlying host-pathogen interactions is still limited. Our group has established a clinical C. jejuni infection model based on abiotic IL-10-/- mice mimicking key features of human campylobacteriosis. In order to further validate this model for unraveling pathogen-host interactions mounting in acute disease, we here surveyed the immunopathological features of the important C. jejuni virulence factors FlaA and FlaB and the major adhesin CadF (Campylobacter adhesin to fibronectin), which play a role in bacterial motility, protein secretion and adhesion, respectively. Methods and results: Therefore, abiotic IL-10-/- mice were perorally infected with C. jejuni strain 81-176 (WT) or with its isogenic flaA/B (ΔflaA/B) or cadF (ΔcadF) deletion mutants. Cultural analyses revealed that WT and ΔcadF but not ΔflaA/B bacteria stably colonized the stomach, duodenum and ileum, whereas all three strains were present in the colon at comparably high loads on day 6 post-infection. Remarkably, despite high colonic colonization densities, murine infection with the ΔflaA/B strain did not result in overt campylobacteriosis, whereas mice infected with ΔcadF or WT were suffering from acute enterocolitis at day 6 post-infection. These symptoms coincided with pronounced pro-inflammatory immune responses, not only in the intestinal tract, but also in other organs such as the liver and kidneys and were accompanied with systemic inflammatory responses as indicated by increased serum MCP-1 concentrations following C. jejuni ΔcadF or WT, but not ΔflaA/B strain infection. Conclusion: For the first time, our observations revealed that the C. jejuni flagellins A/B, but not adhesion mediated by CadF, are essential for inducing murine campylobacteriosis. Furthermore, the secondary abiotic IL-10-/- infection model has been proven suitable not only for detailed investigations of immunological aspects of campylobacteriosis, but also for differential analyses of the roles of distinct C. jejuni virulence factors in induction and progression of disease

Primary care physicians' knowledge and attitudes towards genetic testing for breast-ovarian cancer predisposition

Background: Primary health care providers are expected to be directly involved in the genetic testing for cancer susceptibility. This study assessed physicians' knowledge, attitude and perception of their role towards testing for hereditary breast-ovarian cancer. Design: A mail-in survey was sent to all general practitioners, internists, obstetrician-gynecologists and oncologists in private practice in Geneva county, Switzerland. Questions included socio-demographic variables, knowledge about hereditary breast-ovarian cancer, attitude towards testing and assessment of their role in the pre- and post-test procedure. Results: Two hundred fifty-nine (65%) of four hundred questionnaires were returned of which two hundred forty-three (61%) were analysed. Response rates were similar between specialties; women answered more frequently. The majority of the respondents (87%) approved of genetic susceptibility testing. The most common objection to testing was the absence of approved strategies for the prevention and detection of early breast cancer. Most physicians felt they had an active part to play in the pre-test procedure, the disclosure of results, and especially the consultants' long-term care and support (99%). Physicians correctly answered a third (32%) of the knowledge questions. The abstention rate for individual items ranged from 13% to 60%. Scores varied by specialty. Oncologists were more knowledgeable than gynecologists, internists and general practitioners. Conclusions: The majority of the primary care physicians in this study have a favourable attitude and are ready to play a prominent role in genetic counseling and testing for breast-ovarian cancer predisposition. Defective knowledge scores, however, underline the need for targeted educational program