No se fían

It is a standard practice to test for the signature of homologous recombination in studies examining the genetic diversity of bacterial populations. Although it has emerged that homologous recombination rates can vary widely between species, comparing the results from different studies is made difficult by the diversity of estimation methods used. Here, Multi Locus Sequence Typing (MLST) datasets from a wide variety of bacteria and archaea are analyzed using the ClonalFrame method. This enables a direct comparison between species and allows for a first exploration of the question whether phylogeny or ecology is the primary determinant of homologous recombination rate

Scheduling Maintenance and Determining Crew Size for Stochastically Failing Equipment

Past treatment of the single machine maintenance problem has shown that preventive maintenance may be desirable for equipment for which failures are caused at least partially by wear-out factors. In all previous treatment, however, the size of the maintenance-repair crew has been held constant and the optimal maintenance period has then been determined. This paper develops a simultaneous solution for the maintenance-repair crew size and the optimal maintenance period. The optimal maintenance period is seen to shift as the size of the maintenance-repair crew varies. For the multi-machine maintenance problem, the sharing of the maintenance-repair crew creates a queuing system. Because of its complexity, an analytical solution of this multi-machine maintenance queuing system is not feasible. A simulation model was used to develop a set of general rules for scheduling maintenance for the multi-machine case.

Prognostic role of natural killer cells in pediatric mixed cellularity and nodular sclerosing Hodgkin's disease

OBJECTIVE: To study natural killer cells' spontaneous cytotoxic capacity against tumor cells and their prognostic significance in classical Hodgkin's disease

Alternative prognostic factors in pediatric embryonal rhabdomyosarcoma: Nm23 expression, proliferative activity and angiogenesis

Possible clinical relevance of Nm23 expression, angiogenesis and proliferative activity were evaluated as prognostic parameters in childhood embryonal rhabdomyosarcoma (RMS)

Can axillary reverse mapping avoid lymphedema in node positive breast cancer patients?

BACKGROUND: Tracing lymphatic drainage of the ipsilateral arm of node positive breast cancer patients, termed "axillary reverse mapping" (ARM), has recently been described in several reports. We analyzed our experience with this new technique in patients scheduled for axillary lymph node dissection (ALND) and evaluated its usefulness for reducing the incidence of lymphedema. METHODS: Blue dye was injected subcutaneously along the intermuscular groove of the upper inner arm; radioisotope was injected subcutaneously in the interdigital webspace of the hand. All blue and radioactive lymph vessels and lymph nodes were recorded. Only unsuspicious "ARM lymph nodes" located in the lateral part of the axillary basin were preserved. All other level I and II axillary lymph nodes were removed. Resected ARM nodes were immediately separated from all other lymph nodes. RESULTS: ARM was performed in 143 patients subsequently undergoing ALND. ARM lymph nodes were successfully identified in 112 cases (78%). In 55 patients at least one ARM lymph node had to be removed. In 14 of these, tumor involvement was confirmed. In 71 patients one or more ARM nodes were preserved. During a median follow-up time of 19 months no axillary recurrence was noted. 35 of 114 evaluated patients developed lymphedema. Preservation of ARM lymph nodes did not significantly decrease the incidence of lymphedema. CONCLUSION: ARM is feasible for patients with node positive breast cancer. However, we found no evidence that it reduces the incidence of lymphedema