The Communication Complexity of the Hamming Distance Problem

We investigate the randomized and quantum communication complexity of the Hamming Distance problem, which is to determine if the Hamming distance between two n-bit strings is no less than a threshold d. We prove a quantum lower bound of \Omega(d) qubits in the general interactive model with shared prior entanglement. We also construct a classical protocol of O(d \log d) bits in the restricted Simultaneous Message Passing model, improving previous protocols of O(d^2) bits (A. C.-C. Yao, Proceedings of the Thirty-Fifth Annual ACM Symposium on Theory of Computing, pp. 77-81, 2003), and O(d\log n) bits (D. Gavinsky, J. Kempe, and R. de Wolf, quant-ph/0411051, 2004).Comment: 8 pages, v3, updated reference. to appear in Information Processing Letters, 200

Severe major vessel injury during peadicle screw removal: a case report

IntroductionPedicle screw fixation (PSF) has been the standard therapy for the treatment of various spinal diseases. Although complications are identified regularly, iatrogenic vascular injury is one of the rare but life-threatening complications. In this literature, we describe the first case of inferior vena cava (IVC) injury during pedicle screw removal.Case descriptionA 31-year-old man was treated by percutaneous pedicle screw fixation for an L1 compression fracture. After a year, the fracture healed well and hardware removal surgery was performed. During the procedure, the hardware on the right was removed unremarkably except for the L2 pedicle screw which slipped into the retroperitoneum because of the improper technique. The CT angiogram revealed the screw had breached the anterior cortex of the L2 vertebral body and penetrated the IVC. After multidisciplinary cooperation, the defect of IVC was reconstructed and the L2 screw was removed from the posterior approach in the end.ResultThe patient recovered well and was discharged after 3 weeks without further events. The removal of the contralateral implants was unremarkable at 7 months postoperatively. At the 3-year follow-up, the patient returned to his normal daily activity without any complaints.ConclusionAlthough pedicle screw removal is a rather simple procedure, severe complications may have occurred from this procedure. Surgeons should keep vigilant to avoid the complication noted in this case

Neural LiDAR Fields for Novel View Synthesis

We present Neural Fields for LiDAR (NFL), a method to optimise a neural field scene representation from LiDAR measurements, with the goal of synthesizing realistic LiDAR scans from novel viewpoints. NFL combines the rendering power of neural fields with a detailed, physically motivated model of the LiDAR sensing process, thus enabling it to accurately reproduce key sensor behaviors like beam divergence, secondary returns, and ray dropping. We evaluate NFL on synthetic and real LiDAR scans and show that it outperforms explicit reconstruct-then-simulate methods as well as other NeRF-style methods on LiDAR novel view synthesis task. Moreover, we show that the improved realism of the synthesized views narrows the domain gap to real scans and translates to better registration and semantic segmentation performance.Comment: ICCV 2023 - camera ready. Project page: https://research.nvidia.com/labs/toronto-ai/nfl

HDAC 1 and 6 modulate cell invasion and migration in clear cell renal cell carcinoma

Indexación: Web of ScienceBackground: Class I histone deacetylases (HDACs) have been reported to be overexpressed in clear cell renal cell carcinoma (ccRCC), whereas the expression of class II HDACs is unknown. Methods: Four isogenic cell lines C2/C2VHL and 786-O/786-OVHL with differential VHL expression are used in our studies. Cobalt chloride is used to mimic hypoxia in vitro. HIF-2 alpha knockdowns in C2 and 786-O cells is used to evaluate the effect on HDAC 1 expression and activity. Invasion and migration assays are used to investigate the role of HDAC 1 and HDAC 6 expression in ccRCC cells. Comparisons are made between experimental groups using the paired T-test, the two-sample Student's T-test or one-way ANOVA, as appropriate. ccRCC and the TCGA dataset are used to observe the clinical correlation between HDAC 1 and HDAC 6 overexpression and overall and progression free survival. Results: Our analysis of tumor and matched non-tumor tissues from radical nephrectomies showed overexpression of class I and II HDACs (HDAC6 only in a subset of patients). In vitro, both HDAC1 and HDAC6 over-expression increased cell invasion and motility, respectively, in ccRCC cells. HDAC1 regulated invasiveness by increasing matrix metalloproteinase (MMP) expression. Furthermore, hypoxia stimulation in VHL-reconstituted cell lines increased HIF isoforms and HDAC1 expression. Presence of hypoxia response elements in the HDAC1 promoter along with chromatin immunoprecipitation data suggests that HIF-2 alpha is a transcriptional regulator of HDAC1 gene. Conversely, HDAC6 and estrogen receptor alpha (ER alpha) were co-localized in cytoplasm of ccRCC cells and HDAC6 enhanced cell motility by decreasing acetylated alpha-tubulin expression, and this biological effect was attenuated by either biochemical or pharmacological inhibition. Finally, analysis of human ccRCC specimens revealed positive correlation between HIF isoforms and HDAC. HDAC1 mRNA upregulation was associated with worse overall survival in the TCGA dataset. Conclusions: Taking together, these results suggest that HDAC1 and HDAC6 may play a role in ccRCC biology and could represent rational therapeutic targets.http://bmccancer.biomedcentral.com/articles/10.1186/s12885-016-2604-