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A read-only transaction or query is a transaction which does not modify any data. Read-only transactions could be processed with general transaction processing algorithms, but in many cases it is more efficient to process read-only transactions with special algorithms which take advantage of the knowledge that the transaction only reads. This paper defines the various consistency and currency requirements that read-only transactions may have. The processing of the different classes of read-only transactions in a distributed database is discussed. The concept of R insularity is introduced to characterize both the read-only and update algorithms. Several simple update and read-only transaction processing algorithms are presented to illustrate how the query requirements and the update algorithms affect the read-only transaction processing algorithms.
Whole-genome reconstruction of bacterial pathogens has become an important tool for tracking transmission and antimicrobial resistance gene spread, but highly accurate and complete assemblies have largely only historically been achievable using hybrid long- and short-read sequencing. We previously found the Oxford Nanopore Technologies (ONT) R10.4/kit12 flowcell/chemistry produced improved assemblies over the R9.4.1/kit10 combination, however long-read only assemblies contained more errors compared to Illumina-ONT hybrid assemblies. ONT have since released an R10.4.1/kit14 flowcell/chemistry upgrade and recommended the use of Bovine Serum Albumin (BSA) during library preparation, both of which reportedly increase accuracy and yield. They have also released updated basecallers trained using native bacterial DNA containing methylation sites intended to fix systematic basecalling errors, including common adenosine (A) to guanine (G) and cytosine (C) to thymine (T) substitutions. To evaluate these improvements, we successfully sequenced four bacterial reference strains, namely Escherichia coli , Klebsiella pneumoniae , Pseudomonas aeruginosa and Staphylococcus aureus , and nine genetically diverse E. coli bloodstream infection-associated isolates from different phylogroups and sequence types, both with and without BSA. These sequences were de novo assembled and compared against Illumina-corrected reference genomes. In this small evaluation of 13 isolates we found that nanopore long-read-only R10.4.1/kit 14 assemblies with updated basecallers trained using bacterial methylated DNA produce accurate assemblies with ≥40×depth, sufficient to be cost-effective compared with hybrid ONT/Illumina sequencing in our setting.
In recent years, prompt tuning has proven effective in adapting pre-trained vision-language models to downstream tasks. These methods aim to adapt the pre-trained models by introducing learnable prompts while keeping pretrained weights frozen. However, learnable prompts can affect the internal representation within the self-attention module, which may negatively impact performance variance and generalization, especially in data-deficient settings. To address these issues, we propose a novel approach, Read-only Prompt Optimization (RPO). RPO leverages masked attention to prevent the internal representation shift in the pre-trained model. Further, to facilitate the optimization of RPO, the read-only prompts are initialized based on special tokens of the pre-trained model. Our extensive experiments demonstrate that RPO outperforms CLIP and CoCoOp in base-to-new generalization and domain generalization while displaying better robustness. Also, the proposed method achieves better generalization on extremely data-deficient settings, while improving parameter efficiency and computational overhead. Code is available at https://github.com/mlvlab/RPO.
Internet users increasingly rely on publicly available data for everything from software installation to investment decisions. Unfortunately, the vast majority of public content on the Internet comes with no integrity or authenticity guarantees. This paper presents the self-certifying read-only file system, a content distribution system providing secure, scalable access to public, read-only data.The read-only file system makes the security of published content independent from that of the distribution infrastructure. In a secure area (perhaps off-line), a publisher creates a digitally signed database out of a file system's contents. The publisher then replicates the database on untrusted content-distribution servers, allowing for high availability.The read-only file system avoids performing any cryptographic operations on servers and keeps the overhead of cryptography low on clients, allowing servers to scale to a large number of clients. Measurements of an implementation show that an individual server running on a 550-Mhz Pentium III with FreeBSD can support 1,012 connections per second and 300 concurrent clients compiling a large software package.
A remarkable crystal called molybdenum oxychloride could help make futuristic technologies like smart contact lenses and ultrathin AR glasses a reality。 Scientists have created the first detailed experimental map of its optical properties, revealing the strongest light-bending effect ever measured in a natural material。 The crystal can act either l
Researchers have developed a compact quantum detector that makes terahertz radiation much easier to detect。 A specially designed metasurface funnels incoming energy into tiny active regions, greatly strengthening the electrical signal produced。 The approach boosted efficiency by roughly 20 times compared to earlier designs and could pave the way fo
A new AI-powered chip from UC Davis can analyze light and chemicals using a device tiny enough to fit almost anywhere。 By combining smart silicon sensors with machine learning, it achieves lab-style spectral analysis without the bulky equipment
New studies suggest consciousness can't be judged solely by behavior, whether it's a chatbot discussing philosophy or a bee searching for nectar。 Researchers are increasingly focusing on the internal mechanisms of brains and computers, concluding that today's AI is likely not conscious while leaving open the possibility for both conscious insects a
Researchers have discovered how microscopic imperfections and atomic vibrations can be used to control a powerful quantum effect in an advanced material。 The effect can turn alternating electrical signals from the environment directly into the kind of current electronic devices need, without traditional components。 As temperature changes, the signa
By stacking custom-designed silver nanoparticles like nanoscale LEGO bricks, scientists stabilized a mysterious crystal phase that had never been observed before。 The material not only solves a longstanding puzzle in materials science but also exhibits promising quantum properties at room temperature
"We look forward to working with Roscosmos on a collaborative approach to address the leaks
Scientists say moons around rogue planets wandering through the galaxy could remain warm enough for life thanks to tidal heating and hydrogen-rich atmospheres。 These dark, starless worlds may have had stable oceans for billions of years — long enough for complex life to potentially emerge
NASA’s PExT terminal has shown that spacecraft can seamlessly communicate through multiple government and commercial networks, a major step beyond traditional single-network systems。 The mission is now expanding to test new capabilities that could help create a more flexible, reliable communications infrastructure for future space missions
NASA’s Psyche spacecraft just used Mars as a giant gravitational slingshot to continue its journey toward a strange metal rich asteroid。 The close flyby boosted the spacecraft’s speed by about 1,000 mph while also producing rare crescent images of Mars glowing through its dusty atmosphere
Scientists have proposed a new method for finding tightly bound supermassive black hole pairs by searching for stars that flash repeatedly as their light is magnified by the black holes’ gravity。 The timing and brightness of these bursts could provide a unique fingerprint of black holes slowly spiraling toward a future collision