Dynamical effects in multifragmentation at intermediate energies

The fragmentation of the quasi-projectile is studied with the INDRA multidetector for different colliding systems and incident energies in the Fermi energy range. Different experimental observations show that a large part of the fragmentation is not compatible with the statistical fragmentation of a fully equilibrated nucleus. The study of internal correlations is a powerful tool, especially to evidence entrance channel effects. These effects have to be included in the theoretical descriptions of nuclear multifragmentation.Comment: 13 pages, 26 figures, submitted to Physical Review

A New Computational Tool for the Phenomenological Analysis of Multipassage Tumor Growth Curves

Multipassage experiments are performed by subcutaneous implantation in lab animals (usually mice) of a small number of cells from selected human lines. Tumor cells are then passaged from one mouse to another by harvesting them from a growing tumor and implanting them into other healthy animals. This procedure may be extremely useful to investigate the various mechanisms involved in the long term evolution of tumoral growth. It has been observed by several researchers that, contrary to what happens in in vitro experiments, there is a significant growth acceleration at each new passage. This result is explained by a new method of analysis, based on the Phenomenological Universalities approach. It is found that, by means of a simple rescaling of time, it is possible to collapse all the growth curves, corresponding to the successive passages, into a single curve, belonging to the Universality Class U2. Possible applications are proposed and the need of further experimental evidence is discussed

Tracking tumor evolution via prostate-specific antigen: an individual post-operative study

<p>Abstract</p> <p>Background</p> <p>The progress of the prostate-specific antigen (PSA) level after radical prostatectomy is observed for a patient in order to extract information about the mode of tumor cell growth. Although PSA values are determined routinely to find the doubling time of the prostate marker, to our knowledge, this analysis is the first in the literature.</p> <p>Results</p> <p>The prostate tumor marker values were determined regularly after the surgery and plotted on a logarithmic scale against time. An initial rapid-growth mode changed to a slower power-law regime within two years of surgery. Our analysis associates this observation with a transition in the growth mode from unrestricted growth of dispersed cells to their clumping into macroscopic structures.</p> <p>Conclusions</p> <p>Such studies may help determine the appropriate time window for postoperative therapies in order to increase the life expectancy of the patient.</p

Efficient and Robust NK-Cell Transduction With Baboon Envelope Pseudotyped Lentivector

NK-cell resistance to transduction is a major technical hurdle for developing NK-cell immunotherapy. By using Baboon envelope pseudotyped lentiviral vectors (BaEV-LVs) encoding eGFP, we obtained a transduction rate of 23.0 ± 6.6% (mean ± SD) in freshly-isolated human NK-cells (FI-NK) and 83.4 ± 10.1% (mean ± SD) in NK-cells obtained from the NK-cell Activation and Expansion System (NKAES), with a sustained transgene expression for at least 21 days. BaEV-LVs outperformed Vesicular Stomatitis Virus type-G (VSV-G)-, RD114- and Measles Virus (MV)- pseudotyped LVs (p &lt; 0.0001). mRNA expression of both BaEV receptors, ASCT1 and ASCT2, was detected in FI-NK and NKAES, with higher expression in NKAES. Transduction with BaEV-LVs encoding for CAR-CD22 resulted in robust CAR-expression on 38.3 ± 23.8% (mean ± SD) of NKAES cells, leading to specific killing of NK-resistant pre-B-ALL-RS4;11 cell line. Using a larger vector encoding a dual CD19/CD22-CAR, we were able to transduce and re-expand dual-CAR-expressing NKAES, even with lower viral titer. These dual-CAR-NK efficiently killed both CD19KO- and CD22KO-RS4;11 cells. Our results suggest that BaEV-LVs may efficiently enable NK-cell biological studies and translation of NK-cell-based immunotherapy to the clinic

Multidisciplinary approach to reconstructing local pastoral activities: an example from the Pyrenean Mountains (Pays Basque)

International audienceIn this study archaeology, history and palaeoecology (modern and fossil data sets of pollen and nonpollen palynomorphs) were used to reconstruct small-scale pastoral activities in the Pyrenees Mountains during the last two millennia. Modern pollen assemblages from the major vegetation units (both natural andanthropogenic) are studied on one restricted watershed area. A correlative model (RDA) of 61 modern pollen spectra and 35 external variables distinguishes two groups of taxa, providing information on the nature and spatial extent of human impact on the landscape. The first pool indicates local pastoral activities, and the second one implies regional input from outside the studied watershed, and is not characteristic of a specific land use. These pools are described as 'Local Pastoral Pollen Indicators' (LPPI) for this particular mountain region on crystalline bedrock and 'Regional Human Activities Pollen Indicators' (RHAPI). The modern data set is used to aid interpretation of the local pollen sequence of Sourzay that covers the last 2000 calendar years BP, using RDA reconstructions, and best modern analogues as a means of comparing modern and fossil spectra. The study also demonstrates agreement between the independent interpretations of two fossil proxies, LPPI and coprophilous fungi