Novel design algorithm for low complexity programmable FIR filters based on extended double base number system

Coefficient multipliers are the stumbling blocks in programmable finite impulse response (FIR) digital filters. As the filter coefficients change either dynamically or periodically, the search for common subexpressions for multiplierless implementation needs to be performed over the entire gamut of integers of the desired precision, and the amount of shifts associated with each identified common subexpression needs to be memorized. The complexity of a quality search is thus beyond the existing design algorithms based on conventional binary and signed digit representations. This paper presents a new design paradigm for the programmable FIR filters by exploiting the extended double base number system (EDBNS). Due to its sparsity and innate abstraction of the sum of binary shifted partial products, the sharing of adders in the time-multiplexed multiple constant multiplication block of the programmable FIR filters can be maximized by a direct mapping from the quasi-minimum EDBNS. The multiplexing cost can be further reduced by merging double base terms. Logic synthesis results on more than one hundred programmable filters with filter taps ranging from 10 to 100 and coefficient word lengths of 8, 12, and 16 bits show that the average logic complexity and critical path delay of the programmable FIR filters designed by our proposed algorithm have been reduced by up to 47.81% and 14.32%, respectively over the existing design methods.Accepted versio

Tap delay-and-accumulate cost aware coefficient synthesis algorithm for the design of area-power efficient fir filters

Finite impulse response filters are widely used in digital signal processing applications. Prodigious research in the past two decades has substantially reduced the implementation cost of the multiple constant multiplication block. Further area and power consumption savings are stagnated by the structural adders and registers in the tap delay-and-accumulate line, which unfortunately dominate the overall hardware cost of FIR filter and are difficult to minimize by existing resource sharing approaches. Retiming or relocating the structural adders and registers can improve merely the throughput. To close the area-power efficiency gap, we reformulate the filter coefficient synthesis problem to explore the design space for the tap delay-and accumulate line by bisecting at some tap position. An efficient Genetic Algorithm is proposed to solve this integer programming problem at quadratic computational complexity by refining the search space for finding an optimized solution to fulfill the frequency response specifications. FPGA and ASIC logic synthesis results from twelve benchmark filter specifications showed that the average area and power consumptions of the solutions generated by our proposed algorithm have been reduced by up to 26.8% and 27.5% respectively, in comparison with the solutions obtained by existing design methods.Accepted versio

Early Transcriptional Response to DNA Virus Infection in Sclerotinia sclerotiorum

We previously determined that virions of Sclerotinia sclerotiorum hypovirulence associated DNA virus 1 (SsHADV-1) could directly infect hyphae of Sclerotinia sclerotiorum, resulting in hypovirulence of the fungal host. However, the molecular mechanisms of SsHADV-1 virions disruption of the fungal cell wall barrier and entrance into the host cell are still unclear. To investigate the early response of S. sclerotiorum to SsHADV-1 infection, S. sclerotiorum hyphae were inoculated with purified SsHADV-1 virions. The pre- and post-infection hyphae were collected at one–three hours post-inoculation for transcriptome analysis. Further, bioinformatic analysis showed that differentially expressed genes (DEGs) regulated by SsHADV-1 infection were identified in S. sclerotiorum. In total, 187 genes were differentially expressed, consisting of more up-regulated (114) than down-regulated (73) genes. The identified DEGs were involved in several important pathways. Metabolic processes, biosynthesis of antibiotics, and secondary metabolites were the most affected categories in S. sclerotiorum upon SsHADV-1 infection. Cell structure analysis suggested that 26% of the total DEGs were related to membrane tissues. Furthermore, 10 and 27 DEGs were predicted to be located in the cell membrane and mitochondria, respectively. Gene ontology enrichment analyses of the DEGs were performed, followed by functional annotation of the genes. Interestingly, one third of the annotated functional DEGs could be involved in the Ras-small G protein signal transduction pathway. These results revealed that SsHADV-1 virions may be able to bind host membrane proteins and influence signal transduction through Ras-small G protein-coupled receptors during early infection, providing new insight towards the molecular mechanisms of virions infection in S. sclerotiorum

Value of folate receptor-positive circulating tumour cells in the clinical management of indeterminate lung nodules: A non-invasive biomarker for predicting malignancy and tumour invasivenessResearch in context

Background: Non-invasive lung adenocarcinoma could benefit from limited resection, nonetheless, there is a lack of method to determine preoperative tumour invasiveness. We aimed to investigate whether folate receptor-positive circulating tumour cells (FR+-CTCs) in combination with maximum tumour diameter (MTD) determines, before surgery, the invasiveness of small-sized, indeterminate solitary pulmonary nodules (SPNs). Methods: A total of 382 patients with suspicious lung adenocarcinoma on computed tomography who were expected to undergo lung resection were enrolled in this study at three participating institutes and randomly assigned into training and validation cohorts. Before surgery, 3 mL peripheral blood was collected from all participants. FR+-CTCs were analyzed using immunomagnetic leukocyte depletion and quantitated by ligand-targeted PCR method. After surgery, the resected tissues were diagnosed by pathologists according to IASLC/ATS/ERS classification. Findings: FR+-CTC levels in the peripheral blood can differentiate benign from malignant nodules with a sensitivity of 78·6%–82·7% and a specificity of 68·8%–78·4%. Both FR+-CTC and MTD are independent predictive indices of invasive tumours for lung adenocarcinoma ≤2 cm based on multivariate analyses. Further, FR+-CTC count in combination with MTD can differentiate non-invasive cancers from invasive cancers with a sensitivity of 63·6%–81·8% and a specificity of 71·4%–89·7%. Interpretation: Detection of FR+-CTC is a reliable method to differentiate malignancy of indeterminate SPNs. Combining of FR+-CTC count and MTD could possibly enhance preoperative determination of the invasiveness of lung nodules and guide surgeons to select limited lung resection and avoid overtreatment for patients with non-invasive lesions. Fund: None. Keywords: Circulating tumour cells, Folate receptor, Non-small cell lung cancer, Tumour invasiveness, Limited lung resectio