Mind the (synthesis) gap: examining where academic FPGA tools lag behind industry

Firstly, we present VTR-to-Bitstream v2.0, the latest version of our open-source toolchain that takes Verilog input and produces a packed, placed— and now routed—solution that can be programmed onto the Xilinx commercial FPGA architecture. Secondly, we apply this updated tool to measure the gap between academic and industrial FPGA tools by examining the quality of results at each of the three main compilation stages: synthesis, packing & placement, routing. Our findings indicate that the delay gap (according to Xilinx static timing analysis) for academic tools breaks down into a 31% degradation with synthesis, 10% with packing & placement, and 15% with routing. This leads us to believe that opportunities for improvement exist not only within VPR, but also in the front-end tools that lie upstream

Dysregulation of of phospholipid-specific phagocytosis by B1 B cells in diet-induced obese mice

B1 B cells have received increasing attention recently due to their newly discovered phagocytic and microbicidal capabilities. Several studies have demonstrated that B1 cells can phagocytize polystyrene fluorescent particles, bacteria (Staphylococcus aureus, Escherichia coli), and even apoptotic cells. Nevertheless, little is known about the biological significance of this seemingly redundant function of B1 B cells as compared to that of conventional phagocytes. Here we investigate the unique phosphotidylcholine (PtC)-specific B1 B cell phagocytosis. PtC is a major phospholipid in the biological membrane and a classical antigen recognized by B1 B cell-derived natural antibodies. These antibodies play important roles in immune defense as well as tissue homeostasis. Here we report that B1 cells preferentially phagocytose PtC-coated beads, differing from that of conventional macrophages. We further attest that these beads were truly internalized and subsequently fused with hydrolytic lysosomes indicated by increasing fluorescent intensity of a pH-sensitive dye. Despite the differences in antigen specificity, phagocytosis of both B1 cells and macrophages can be inhibited by the microtubule-inhibitor, Colchicine, in a dose-dependent manner. Most intriguingly, upon chronic high-fat diet (HFD) consumption by the host, B1 cell phagocytosis starts to lose antigen-specificity for PtC. Morphologically, some of these B1 B cells in DIO mice show enlarged cytosol and engulfed more beads, indicating a transition to macrophage-like cells. Our study suggests for the first time that B1 B cells have unique phospholipid-specific phagocytosis capacity, which is affected by diet-induced obesity