Miracle-dz/UniFAR-FTUs huggingface dataset:
CDPU: Co-designing Compression and Decompression Processing Units for Hyperscale Systems

General-purpose lossless data compression and decompression ("(de)compression") are used widely in hyperscale systems and are key "datacenter taxes". However, designing optimal hardware compression and decompression processing units ("CDPUs") is challenging due to the variety of algorithms deployed, input data characteristics, and evolving costs of CPU cycles, network bandwidth, and memory/storage capacities. To navigate this vast design space, we present the first large-scale data-driven analysis of (de)compression usage at a major cloud provider by profiling Google's datacenter fleet. We find that (de)compression consumes 2.9% of fleet CPU cycles and 10--50% of cycles in key services. Demand is also artificially limited; 95% of bytes compressed in the fleet use less capable algorithms to reduce compute, motivating a CDPU that changes cost vs. size tradeoffs. Prior work has improved the microarchitectural state-of-the-art for CDPUs supporting various algorithms in fixed contexts. However, we find that higher-level design parameters like CDPU placement, hash table sizing, history window sizes, and more have as significant of an impact on the viability of CDPU integration, but are not well-studied. Thus, we present the first end-to-end design/evaluation framework for CDPUs, including: 1. An open-source RTL-based CDPU generator that supports many run-time and compile-time parameters. 2. Integration into an open-source RISC-V SoC for rapid performance and silicon area evaluation across CDPU placements and parameters. 3. An open-source (de)compression benchmark, HyperCompressBench, that is representative of (de)compression usage in Google's fleet. Using our framework, we perform an extensive design space exploration running HyperCompressBench. Our exploration spans a 46× range in CDPU speedup, 3× range in silicon area (for a single pipeline), and evaluates a variety of CDPU integration techniques to optimize CDPU designs for hyperscale contexts. Our final hyperscale-optimized CDPU instances are up to 10× to 16× faster than a single Xeon core, while consuming a small fraction (as little as 2.4% to 4.7%) of the area.
A Survey on Thwarting Memory Corruption in RISC-V

With embedded devices becoming more pervasive and entrenched in society, it is paramount to keep these systems secure. A threat plaguing these systems consists of software vulnerabilities that cause memory corruption, potentially allowing an attacker to breach the device. Software-based countermeasures exist, but suffer from high overhead. In this survey, we investigate whether this could be mitigated using dedicated hardware. Driven by the advancements of open hardware, we focus on implementations for RISC-V, a novel and open architecture tailored for customization. We distinguish between methods validating memory accesses beforehand, obfuscating information necessary for an attack, and detecting memory values corrupted earlier. We compare on qualitative metrics, such as the security coverage and level of transparency, and performance in both software and hardware. Although current implementations do not easily allow for a fair comparison as their evaluation methodologies vary widely, we show that current implementations are suitable to minimize the runtime overhead with a relatively small area overhead. Nevertheless, we identified that further research is still required to mitigate more fine-grained attacks such as intra-object overflows, to integrate into more sophisticated protected execution environments towards resilient systems that are automatically recoverable, and to move towards more harmonized evaluation.
Brief Announcement: Discrete Incremental Voting

We consider a type of pull voting suitable for discrete numeric opinions which can be compared on a linear scale, for example, 1 ('disagree strongly'), 2 ('disagree'), . , 5 ('agree strongly'). On observing the opinion of a random neighbour, a vertex changes its opinion incrementally towards the value of the neighbour's opinion, if different. For opinions drawn from a set {1, 2, . , k}, the opinion of the vertex would change by +1 if the opinion of the neighbour is larger, or by −1, if it is smaller. It is not clear how to predict the outcome of this process, but we observe that the total weight of the system, that is, the sum of the individual opinions of all vertices, is a martingale. This allow us analyse the outcome of the process on some classes of dense expanders such as clique graphs Kn and random graphs Gn,p for suitably large p. If the average of the original opinions satisfies i ≤ c ≤ i + 1 for some integer i, then the asymptotic probability that opinion i wins is i + 1 − c, and the probability that opinion i + 1 wins is c − i. With high probability, the winning opinion cannot be other than i or i + 1. To contrast this, we show that for a path and opinions 0, 1, 2 arranged initially in non-decreasing order along the path, the outcome is very different. Any of the opinions can win with constant probability, provided that each of the two extreme opinions 0 and 2 is initially supported by a constant fraction of vertices.
Towards Latency-First Wireless Embedded Networks

Current physical-layer networking technology primarily optimises for reliability rather than latency, thus unnecessarily impairing latency-sensitive applications such as real-time control in embedded, wireless, and dense networks. This extended abstract introduces a set of novel low-level networking primitives that optimise such networks for latency, pushing latency-inducing failures up the stack. The development of and experiments on a 25-node prototype network show that the resulting symbol-synchronous architecture unlocks application scenarios formerly reserved for wired networks, offering sub-millisecond network latency across multiple hops for real-time control, in-the-loop classification based on distributed data from 10s of nodes in milliseconds, and a 25--75% traffic reduction when data is subject to large measurement noise.
Accelerating Personalized Recommendation with Cross-level Near-Memory Processing

The memory-intensive embedding layers of the personalized recommendation systems are the performance bottleneck as they demand large memory bandwidth and exhibit irregular and sparse memory access patterns. Recent studies propose near memory processing (NMP) to accelerate memory-bound embedding operations. However, due to the load imbalance caused by the skewed access frequency of the embedding data, existing NMP solutions that exploit fine-grained memory parallelism fail to translate the increasingly massive internal bandwidth to performance improvements, leading to resource underutilization and hardware overhead. We propose an efficient yet practical fine-grained NMP accelerator for embedding operations. We architect ReCross, a cross-level NMP architecture that exploits rank, bank-group, and subarray-level memory parallelism in a unified DIMM-based memory system by supporting rank, bank-group, and bank-level NMP to accommodate various bandwidth requirements of embedding data. In addition, we present a novel embedding partitioning technique to quantify the bandwidth requirements of embedding tables and allocate them to appropriate NMP levels. ReCross innovatively collaborates the data and architecture characteristics for the NMP embedding layer acceleration, achieving high resource utilization and performance. Our evaluation shows that ReCross outperforms a state-of-the-art bank-group level NMP solution, TRiM-G, by 2.5× with nearly the same area overhead and bank-level NMP solution, TRiM-B, by 1.8× with an area overhead reduction of 4×.
SpotifyExplained: User-centric Mobile Application for Music Exploration

Many music streaming services, such as Spotify, contain a large volume of heavy users, whose user profiles may contain tens to hundreds artists or hundreds to thousands favorite tracks. For those users, it may be difficult to understand, what data the service collected about them, what is the base for its automated decisions (e.g., recommendations) and why are particular items suggested to them. This may decrease user’s willingness to explore the suggested content and may eventually lead to the decrease of user satisfaction and trust. In this demo, we present SpotifyExplained Android application, which is built on top of Spotify API and aims to bridge the aforementioned understandability gap. Specifically, the application contains several tunable views on users’ music profiles and visually explain the connections between both the already known content as well as newly suggested items.
Natural monobacterial environments modulate viral infection in Caenorhabditis elegans

The microbes associated with an organism play a pivotal role in modulating their host susceptibility to viral infections. However, the influence of individual microbes on viral infections is not well understood. Here, we examined the impact of 67 naturally bacterial associates on Caenorhabditis elegans susceptibility to Orsay virus. Our findings reveal that viral infection of C. elegans is significantly influenced by monobacterial environments. The majority of tested natural bacterial environments reduced C. elegans viral infection while some increased susceptibility compared to an Escherichia coli environmental reference. The reduction in viral infection is not caused by degradation of the virions or poor nutrition of C. elegans by the bacteria. The reduction in viral infection does not require known antiviral responses, including RNA interference and transcriptional regulation downstream of the RIG-I homolog DRH-1. However, one bacterium, Lelliottia JUb276, reduced susceptibility but does not induce resistance to viral infection in drh-1 mutants. Our research underscores the importance of considering the natural biotic environment in studies of viral infections and provides insights for future research on host-microbes-virus interactions and viral immunity. AUTHOR CONTRIBUTIONS Conceptualization: RG, MAF; Formal analysis: RG; Investigation: RG; Resources: MAF; Data Curation: RG; Writing - Original Draft: RG, MAF; Writing - Review & Editing: RG, MAF; Visualization: RG; Supervision: MAF; Project administration: RG, MAF; Funding acquisition: RG, MAF.
Phylogenetic and population structure of the nod-free but nodulating Bradyrhizobium phylogroup

Bradyrhizobium is a main rhizobial lineage of which the majority of its members nodulate legume plants using Nod factors (NFs) encoded by the nod genes. However, the “photosynthetic” phylogroup within Bradyrhizobium (PB) does not contain nod genes but are still capable of establishing a nitrogen-fixing symbiosis with some tropical legumes of the Aeschynomene genus. Furthermore, members of this phylogroup colonize rice roots and promote plant growth. Despite this unique combination of ecological features, genomes of only 13 PB members are sequenced, and almost all are isolated from Aeschynomene spp. nodules. Here, we sequenced 208 new PB members predominantly associated with rice. The extended PB phylogroup comprises three main clades: a basal clade with significant expansion of its diversity, followed by the diversification of a singleton clade from a new clade exclusively represented by our strains. Although the PB strains universally lack the canonical nod genes, all 27 assayed strains representing the broad diversity of these clades induced nodules on Aeschynomene indica. Interestingly, significant differences in the efficiency of symbiosis between the main clades were observed and the singleton clade showed an intermediate symbiotic phenotype aligning well with its intermediate phylogenetic position. Our strain collection expands the phylogenetic and ecological diversity of the nod-free but nodulating Bradyrhizobium and shows that the NF-independent nodulation of Aeschynomene is a common trait of this phylogroup, in contrast to the photosynthetic trait originally thought as its unifying feature.
Time and Space Dependent Backgrounds from Nonsupersymmetric Strings

We investigate maximally symmetric backgrounds in nonsupersymmetric string vacua with D-branes and O-planes localized in the compact space. We find a class of solutions with a perturbative string coupling constant in all regions of spacetime. Depending on the particular model, we find either a time evolution with a big-bang type singularity or a space dependent background with generically orbifold singularities. We show that the result can be interpreted as a supersymmetric bulk with some symmetries broken by the boundaries. We also discuss an interesting connection to Lorentzian and Euclidian orbifolds. Unité Mixte de Recherche du CNRS (UMR 8627).
A Triangular Plate Element with Drilling Degrees of Freedom, for Large Rotation Analyses of Built-up Plate/Shell Structures, Based on the Reissner Variational Principle and the von Karman Nonlinear Theory in the Co-rotational Reference Frame

This paper presents an elementary finite element method for geometrically nonlinear large rotation analyses of built-up plate/shell structures comprising of thin members. The tangent stiffness matrix of the element in the updated Lagrangian co-rotational reference frame is developed, based on the von Karman nonlinear theory of plates, and the Reissner variational principle, allowing for unsymmetric stresses and drilling rotations, useful in the analysis of built-up plate and shell structure. The finite rotation of the co-rotational reference frame relative to a globally fixed Cartesian frame, is simply determined from the finite displacement vectors of the nodes of the element in the global reference frame, thus allowing for an elementary transformation of the tangent stiffness matrix from the updated co-rotational reference frame to the globally fixed Cartesian frame. The element employed here is a 3-node plate element with 6 degrees of freedom per node, including 1 drilling degree of freedom and 5 degrees of freedom [3 displacements, and the derivatives of the transverse displacement around two independent axes in the plane of the plate in the co-rotational reference frame]. The (18×18) tangent stiffness matrices of the plate element in the updated Lagrangian co-rotational reference frame are derived, based on the assumptins that: (1) the inplane stress resultants Nαβ (unsymmetric) are constant in each element; (2) the bending moments Mαβ (symmetric) are linear and C0 within each element; and (3) the transverse rotations θi (including the drilling degrees of θ3) are linear and C0 within each element. When compared to the primal approach wherein C1 continuous trial functions for transverse displacements over each element are necessary, the trial functions for 1 Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Department of Geotechnical Engineering, Tongji University, Shanghai 200092, P.R. China 2 Center for Aerospace Research & Education, University of California, Irvine 3 Lloyd’s Register Educational Trust (LRET) Center of Excellence, Pusan National University, Korea 274 Copyright © 2010 Tech Science Press CMES, vol.61, no.3, pp.273-312, 2010 the transverse bending moments and the rotations are very simple in the current approach, and can be assumed to be linear within each element. The present (18×18) tangent stiffness matrices of the plate, based on the Reissner variational principle and the von Karman type simplified nolinear plate theory in the co-rotational reference frame, lead to analyses, which are much simpler and more physically-based, than many others in the literature for large rotation/deformation analysis of builtup plate/shell structures [such as component plates joined at an angle]. Numerical examples demonstrate the accuracy and robustness of the present method.
Neural Mechanisms of Creative Problem Solving: From Representational Change to Memory Formation

Despite the need for innovative solutions to contemporary challenges, the neural mechanisms driving creative problem-solving still remain largely unknown. We focused on the powerful creative process of insight, wherein rapid knowledge reorganization and integration—termed representational change—yield solutions that evoke suddenness, positive emotion, and enduring memory. We posit that this process manifests as abrupt shifts in activation patterns within brain regions housing solution-relevant information, including the visual cortex for visual problems, alongside regions linked to feelings of emotion, suddenness and subsequent memory. Our findings substantiate these hypotheses, revealing sudden representational changes in visual cortex, conjoined with activations in the amygdala and hippocampus—forming an interconnected network. Importantly, the representational change and hippocampal effects serve as predictive markers of subsequent memory. This study provides the foremost clear evidence of an integrated insight mechanism and its lasting memory influence. Implications extend to education, emphasising the significance of discovery-based learning approaches for boosting knowledge retention.
Top-down modulation in canonical cortical circuits with short-term plasticity

Cortical dynamics and computations are strongly influenced by diverse GABAergic interneurons, including those expressing parvalbumin (PV), somatostatin (SST), and vasoactive intestinal peptide (VIP). Together with excitatory (E) neurons, they form a canonical microcircuit and exhibit counterintuitive nonlinear phenomena. One instance of such phenomena is response reversal, whereby SST neurons show opposite responses to top-down modulation via VIP depending on the presence of bottom-up sensory input, indicating that the network may function in different regimes under different stimulation conditions. Combining analytical and computational approaches, we demonstrate that model networks with multiple interneuron subtypes and experimentally identified short-term plasticity mechanisms can implement response reversal. Surprisingly, despite not directly affecting SST and VIP activity, PV-to-E short-term depression has a decisive impact on SST response reversal. We show how response reversal relates to inhibition stabilization and the paradoxical effect in the presence of several short-term plasticity mechanisms demonstrating that response reversal coincides with a change in the indispensability of SST for network stabilization. In summary, our work suggests a role of short-term plasticity mechanisms in generating nonlinear phenomena in networks with multiple interneuron subtypes and makes several experimentally testable predictions.
Involvement of a serotonin/GLP-1 circuit in adolescent isolation-induced diabetes

In 2020, stay-at-home orders were implemented to stem the spread of SARS-CoV-2 worldwide. Social isolation can be particularly harmful to children and adolescents—during the pandemic, the prevalence of obesity increased by ∼37% in persons aged 2-19. Obesity is often comorbid with type 2 diabetes, which was not assessed in this human pandemic cohort. Here, we investigated whether male mice isolated throughout adolescence develop type 2 diabetes in a manner consistent with human obesity-induced diabetes, and explored neural changes that may underlie such an interaction. We find that isolating C57BL/6J mice throughout adolescence is sufficient to induce type 2 diabetes. We observed fasted hyperglycemia, diminished glucose clearance in response to an insulin tolerance test, decreased insulin signaling in skeletal muscle, decreased insulin staining of pancreatic islets, increased nociception, and diminished plasma cortisol levels compared to group-housed control mice. Using Promethion metabolic phenotyping chambers, we observed dysregulation of sleep and eating behaviors, as well as a time-dependent shift in respiratory exchange ratio of the adolescent-isolation mice. We profiled changes in neural gene transcription from several brain areas and found that a neural circuit between serotonin-producing and GLP-1-producing neurons is affected by this isolation paradigm. Overall, spatial transcription data suggest decreased serotonin neuron activity (via decreased GLP-1-mediated excitation) and increased GLP-1 neuron activity (via decreased serotonin-mediated inhibition). This circuit may represent an intersectional target to further investigate the relationship between social isolation and type 2 diabetes, as well as a pharmacologically-relevant circuit to explore the effects of serotonin and GLP-1 receptor agonists. Article Highlights Isolating C57BL/6J mice throughout adolescence is sufficient to induce type 2 diabetes, presenting with fasted hyperglycemia. Adolescent-isolation mice have deficits in insulin responsiveness, impaired peripheral insulin signaling, and decreased pancreatic insulin production. Transcriptional changes across the brain include the endocannabinoid, serotonin, and GLP-1 neurotransmitters and associated receptors. The neural serotonin/GLP-1 circuit may represent an intersectional target to further investigate the relationship between social isolation and type 2 diabetes. Serotonin-producing neurons of adolescent-isolation mice produce fewer transcripts for the GLP-1 receptor, and GLP-1 neurons produce fewer transcripts for the 5-HT1A serotonin receptor.
Discovery of Theta Ribozymes in Gut Phages–Implications for tRNA and Alternative Genetic Coding

Ribozymes, relics of the “RNA world”, are essential across all domains of life. Nonetheless, the functions and genomic contexts of recently discovered small ribozymes, such as minimal hepatitis delta virus (HDV)-like ribozymes, remain elusive. Using bioinformatic analyses, we identified a novel subfamily of minimal HDV-like ribozymes, coined theta ribozymes. Hundreds of unique examples were found adjacent to viral tRNAs within Caudoviricetes bacteriophages of the mammalian gut virome. In vitro experiments confirm site-specific self-scission activity, suggesting their involvement in processing tRNA 3’-trailers. Intriguingly, a significant fraction of theta ribozymes is associated with viral suppressor tRNAs, potentially regulating the late-stage assembly of recoded bacteriophages. These findings advance the understanding of RNA-based mechanisms underlying the intricate interplay between the bacterial and viral parts of the mammalian gut microbiome. One-Sentence Summary Newly unveiled theta ribozymes associate with suppressor tRNAs of alternatively coded gut phages: a potential lytic switch.
Non-existence of homotopical upper bounds for the chromatic number

Hom complex ${\rm Hom} (T,G)$ is a CW-complex which is a generalization of neighborhood complex introduced by Lov\'asz in his proof of Kneser's conjecture. If $T$ belongs to a certain class of graphs, including complete graphs $K_n$ and odd cycles $C_{2r+1}$, then it is known that the connectivity of the Hom complex ${\rm Hom}(T,G)$ gives a lower bound for the chromatic number of $G$. On the other hand, we show that for a finite family $\mathcal{F}$ of finite graphs, for a non-bipartite graph $G$, and for an integer $m$, there is an inclusion $G \hookrightarrow H$ which induces a homotopy equivalence ${\rm Hom}(T,G) \rightarrow {\rm Hom}(T,H)$ for all $T \in \mathcal{F}$, but $\chi(H) \geq \chi(G) + n$.