n essential component of opportunistic behavior is oppor?tunity recognition, the recognition of those conditions that facilitate the pursuit of some suspended goal. Opportunity recognition is a special case of situation assessment, the pro?cess of sizing up a novel situation. The ability to recognize opportunities for reinstating suspended problem contexts (one way in which goals manifest themselves in design) is crucial to creative design. In order to deal with real world oppor?tunity recognition, we attribute limited inferential power to relevant suspended goals. W e propose that goals suspended in the working memory monitor the internal (hidden) represen?tations of the currently recognized objects. A suspended goal is satisfied when the current internal representation and a sus?pended goal "match". W e propose a computational model for working memory and we compare it with other relevant theo?ries of opportunistic planning. This working memory model is implemented as part of our IMPROVISER system.

Interfaces between different fluids can be unstable with regard to hydrodynamic instabilities such as viscous fingering or buoyancy-driven convection. To study such instabilities experimentally for transparent fluids, dyes or chemical indicators are most often used to track the dynamics. While the interfacial deformation can easily be tracked by color changes, it is difficult to have access to the internal flow structure for comparison with theoretical predictions. To overcome this problem, a modification of a Schlieren technique is introduced to image 3D flows during viscously driven instabilities in a horizontal Hele-Shaw cell without using any dye or chemical indicator. The method is exquisitely sensitive, readily yielding information about 3D flows in gaps under a millimeter and allowing imaging of the flow structure internal to the fingers, rather than merely imaging the flow boundary. Following a description of the technique, visualization of dynamics for nonreactive water–glycerol and reactive displacements is presented revealing previously unobserved internal flows. These flows are tentatively interpreted in terms of known theoretical predictions.

Abstract: Fingering is a hydrodynamic instability that occurs when a more mobile fluid displaces a fluid of lower mobility. When the primary source of the mobility difference is viscosity, the instability is termed viscous fingering. Viscous fingering is often, though not always, undesirable in industrial processes, particularly secondary petroleum recovery. Linear stability analysis by Hejazi et al. has indicated that the production of a non-monotonic viscosity profile can stabilize the interface. Herein, we use step-growth polymerization at the interface between two miscible monomers as a model system. In particular, a dithiol monomer displaced a diacrylate that reacted to form a linear polymer that behaves as a Newtonian fluid. Viscous fingering was imaged in a horizontal Hele-Shaw cell via Schlieren, which is sensitive to changes in index of refraction, and therefore polymer conversion. By varying reaction rate via initiator concentration along with flow rate via a syringe pump, we were able to demonstrate increasing stabilization of the flow with increasing Damköhler number. Graphical abstract: [Figure not available: see fulltext.].

Nephropathy due to BK virus (BKV) infection is an evolving challenge in patients undergoing hematopoietic stem cell transplantation (HSCT). We hypothesized that BKV infection was a marker of kidney function decline and a poor prognostic factor in HSCT recipients who experience this complication. In this retrospective study, we analyzed all patients who underwent their first allogeneic HSCT at our institution between 2004 and 2012. We evaluated the incidence of persistent kidney function decline, which was defined as a confirmed reduction in estimated glomerular filtration rate of at least 25% from baseline using the Chronic Kidney Disease Epidemiology equation. Cox proportional hazard regression was used to model the cause-specific hazard of kidney function decline, and the Fine-Gray method was used to account for the competing risks of death. Among 2477 recipients of a first allogeneic HSCT, BK viruria was detected in 25% (n = 629) and kidney function decline in 944 (38.1%). On multivariate analysis, after adjusting for age, sex, acute graft-versus-host disease (GVHD), chronic GVHD, preparative conditioning regimen, and graft source, BK viruria remained a significant risk factor for kidney function decline (p < 0.001). In addition, patients with BKV infection and kidney function decline experienced worse overall survival. After allogeneic HSCT, BKV infection was strongly and independently associated with subsequent kidney function decline and worse patient survival after HSCT.

Bendamustine has shown a favorable safety profile when included in chemotherapy regimens for several types of lymphoma, including CLL. This study investigated the long-term effect of adding bendamustine to a conditioning regimen on survival, rate of engraftment, immune recovery and GvHD after allogeneic stem cell transplantation (alloSCT) in CLL patients. These outcomes were compared with the fludarabine, cyclophosphamide and rituximab (FCR) conditioning regimen. We reviewed the data for 89 CLL patients treated on three trials at our institution. Twenty-six (29%) patients received bendamustine, fludarabine and rituximab (BFR) and 63 (71%) received FCR. Patient characteristics were similar in both groups. Ten (38%) BFR-treated patients vs only two (3%) FCR-treated patients did not experience severe neutropenia (P=<0.001). The 3-year overall survival estimates for the BFR and FCR groups were 82 and 51% (P=0.03), and the 3-year PFS estimates were 63% and 27% (P=0.001), respectively. The 2-year treatment-related mortality was 8 and 23% and the incidence of grade 3 or 4 GvHD was 4% and 10%, respectively. This study is the first to report that addition of bendamustine to alloSCT conditioning for CLL patients is associated with improved survival and lower mortality, myelosuppression, and GvHD.