Hyperdimensional computing with holographic and adaptive encoder.

Introduction: Brain-inspired computing has become an emerging field, where a growing number of works focus on developing algorithms that bring machine learning closer to human brains at the functional level. As one of the promising directions, Hyperdimensional Computing (HDC) is centered around the idea of having holographic and high-dimensional representation as the neural activities in our brains. Such representation is the fundamental enabler for the efficiency and robustness of HDC. However, existing HDC-based algorithms suffer from limitations within the encoder. To some extent, they all rely on manually selected encoders, meaning that the resulting representation is never adapted to the tasks at hand. Methods: In this paper, we propose FLASH, a novel hyperdimensional learning method that incorporates an adaptive and learnable encoder design, aiming at better overall learning performance while maintaining good properties of HDC representation. Current HDC encoders leverage Random Fourier Features (RFF) for kernel correspondence and enable locality-preserving encoding. We propose to learn the encoder matrix distribution via gradient descent and effectively adapt the kernel for a more suitable HDC encoding. Results: Our experiments on various regression datasets show that tuning the HDC encoder can significantly boost the accuracy, surpassing the current HDC-based algorithm and providing faster inference than other baselines, including RFF-based kernel ridge regression. Discussion: The results indicate the importance of an adaptive encoder and customized high-dimensional representation in HDC.

Modifications in the piperazine ring of nucleozin affect anti-influenza activity.

The infection caused by the influenza virus is a latent tret. The limited access to vaccines and approved drugs highlights the need for additional antiviral agents. Nucleozin and its analogs have gain attention for their promising anti-influenza activity. To contribute to the advancement of the discovery and design of nucleozin analogs, we analyzed piperazine-modified nucleozin analogs to increase conformational freedom. Also, we describe a new synthetic strategy to obtain nucleozin and its analogues, three molecules were synthesized and two of them were biologically evaluated in vitro. Although the analogues were less active than nucleozin, the loss of activity highlights the need for the piperazine ring to maintain the activity of nucleozin analogs. Interestingly, this result agrees with the prediction of anti-influenza activity made with a QSAR model presented in this work. The proposed model and the synthetic route will be useful for the further development of nucleozin analogs with antiviral activity.

Laparoscopic management as the initial treatment of acute small bowel obstruction.

OBJECTIVES: We prospectively evaluated our experience with laparoscopic management of acute small bowel obstruction (SBO). METHODS: The study group included all patients requiring surgical intervention based on complete mechanical SBO by clinical assessment or who had failed conservative management. Patients with malignant causes were excluded. Experienced laparoscopic surgeons performed all operations. RESULTS: Between January 1998 to January 2003, 61 patients required operative intervention for acute SBO. Causes included adhesions, internal hernia, incarcerated incisional hernia, and inflammatory bowel disease. Laparoscopic techniques (LAP) alone were successfully used to complete 41 cases (67%). Twenty patients (33%) were converted (CONV) to either mini-laparotomy [7 patients (35%)] or standard midline laparotomy [13 patients (65%)]. A single band was identified in 25 patients (41%). Complications occurred in both groups. CONCLUSIONS: We believe all patients requiring surgery in the setting of acute small bowel obstruction should undergo a laparoscopic approach initially. By specifically identifying those patients with a single band as the cause of obstruction, a significant number of patients will be spared a large laparotomy incision. Conversion should not be viewed as failure, but rather, a sometimes necessary step in the optimal management of these patients.