Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Influence of match congestion on performances in the National Basketball Association

The ability to recover from official match-play across a single and multiple matches is often considered a key factor in subsequent performance for modern professional basketball. The aims of this study were to: (i) explore the differences in match performances between different match congestion cycles (i.e., matches separated by zero, one, or two or greater days of rest); and (ii) identify the key performance indicators (KPIs) discriminating between winning and losing during different match congestion cycles. The current study indicated that scoring close to (i.e., within the paint) (ES = 0.08) or very far away (i.e., Three-point, ES = 0.05) was significantly greater for winning matches separated by 1- and 2-days of rest compared to consecutive matches (i.e., 0 rest days between matches). Additionally, shooting efficiency (P < 0.001), and attaining Defensive Rebounds (P < 0.001) and Steals (P < 0.001), were significant offensive and defensive KPIs that differentiated winning and losing teams. Similarly, opponent quality and match pace were important situational variables that affected match outcome during different match congestion cycles. While match location had an impact on winning following 1- and 2-days of rest, it had no impact for back-to-back matches (i.e., 0 days between matches). The current results will support coaches' offensive, defensive and recovery strategies during various match congestion cycles for a greater probability of winning NBA matches

PowerSAS.m&#x2014;An Open-Source Power System Simulation Toolbox Based on Semi-Analytical Solution Technologies

In handling complex power system simulation tasks, semi-analytical solution (SAS) methods have proven to be numerically robust and computationally efficient. They provide a competitive alternative to traditional numerical approaches. Still, there is inadequate power system simulation software, especially the open-source tools, that implements this technology. This paper introduces PowerSAS.m, an open-source toolbox that closes this gap by providing SAS baseline simulation options for power system steady-state and dynamic simulations. At its core, it implements a novel SAS method and encloses various heuristics and simulation techniques to ensure enhanced computational performance. In case studies, we verify PowerSAS.m in benchmarking comparisons and demonstrate its functionalities in grid analysis scenarios

GReM: Dynamic SSD Resource Allocation in Virtualized Storage Systems with Heterogeneous IO Workloads

In a shared virtualized storage system that runs VMs with heterogeneous IO demands, it becomes a problem for the hypervisor to cost-effectively partition and allocate SSD resources among multiple VMs. There are two straightforward approaches to solving this problem: equally assigning SSDs to each VM or managing SSD resources in a fair competition mode. Unfortunately, neither of these approaches can fully utilize the benefits of SSD resources, particularly when the workloads frequently change and bursty IOs occur from time to time. In this paper, we design a Global SSD Resource Management solution - GReM, which aims to fully utilize SSD resources as a second-level cache under the consideration of performance isolation. In particular, GReM takes dynamic IO demands of all VMs into consideration to split the entire SSD space into a long-term zone and a short-term zone, and cost-effectively updates the content of SSDs in these two zones. GReM is able to adaptively adjust the reservation for each VM inside the long-term zone based on their IO changes. GReM can further dynamically partition SSDs between the long- and short-term zones during runtime by leveraging the feedbacks from both cache performance and bursty workloads. Experimental results show that GReM can capture the cross-VM IO changes to make correct decisions on resource allocation, and thus obtain high IO hit ratio and low IO management costs, compared with both traditional and state-of-the-art caching algorithms

Privacy-Enhanced Federated Learning: A Restrictively Self-Sampled and Data-Perturbed Local Differential Privacy Method

As a popular distributed learning framework, federated learning (FL) enables clients to conduct cooperative training without sharing data, thus having higher security and enjoying benefits in processing large-scale, high-dimensional data. However, by sharing parameters in the federated learning process, the attacker can still obtain private information from the sensitive data of participants by reverse parsing. Local differential privacy (LDP) has recently worked well in preserving privacy for federated learning. However, it faces the inherent problem of balancing privacy, model performance, and algorithm efficiency. In this paper, we propose a novel privacy-enhanced federated learning framework (Optimal LDP-FL) which achieves local differential privacy protection by the client self-sampling and data perturbation mechanisms. We theoretically analyze the relationship between the model accuracy and client self-sampling probability. Restrictive client self-sampling technology is proposed which eliminates the randomness of the self-sampling probability settings in existing studies and improves the utilization of the federated system. A novel, efficiency-optimized LDP data perturbation mechanism (Adaptive-Harmony) is also proposed, which allows an adaptive parameter range to reduce variance and improve model accuracy. Comprehensive experiments on the MNIST and Fashion MNIST datasets show that the proposed method can significantly reduce computational and communication costs with the same level of privacy and model utility

The protective effects of dietary Clostridium butyricum supplementation on hepatic ischemia reperfusion injury in rats

ABSTRACT Purpose: This study investigated the effects of oral administration of Clostridium butyricum (C. butyricum) on inflammation, oxidative stress, and gut flora in rats with hepatic ischemia reperfusion injury (HIRI). Methods: The rats from C. butyricum group were given C. butyricum for 5 days. Then, hepatic ischemia for 30 min and reperfusion for 6 h were performed in all the rats. After the animals were sacrificed, alanine transaminase (ALT), aspartate aminotransferase (AST), lipopolysaccharide (LPS) in serum, short-chain fatty acids (SCFAs), and gut microbiota composition in feces, and malondialdehyde (MDA), glutathione (GSH), tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), Toll-like receptor 4 (TLR4), nuclear factor-kappa Bp65 (NF-κBp65) and histological analysis in the liver were performed. Results: The rats given C. butyricum showed decreased ALT, AST, LPS, and MDA; improved GSH and histological damage; changes in SCFAs; declined TNF-α, IL-6, TLR4, and pNF-κBp65/NF-κBp65; and changes in the gut microbial composition, which decreased the Firmicutes/Bacteroidetes ratio and increased the relative abundance (RA) of probiotics. Conclusions: C. butyricum supplementation protected against HIRI by regulating gut microbial composition, which contributed to the decreased LPS and attenuation of inflammation and oxidative stress. These indicate C. butyricum may be a potent clinical preoperative dietary supplement for HIRI

C–H Activation of Cp* Ligand Coordinated to Ruthenium Center: Synthesis and Reactivity of a Thiolate-Bridged Diruthenium Complex Featuring Fulvene-like Cp* Ligand

In the presence of weak base Et₃N, the interaction of [Cp*Ru­(μ-η²:​η⁴-bdt)­RuCp*] (<b>1</b>, Cp* = η⁵-C₅Me₅; bdt = benzene-1,2-dithio­late) with 2 equiv of Fc·PF₆ resulted in facile C–H activation of one methyl group in coordinated Cp* to give a diruthenium complex with a fulvene-like Cp* ligand, [(η⁵:​η¹-C₅Me₄­CH₂)­Ru­(μ-η²:​η⁴-bdt)­RuCp*]­[PF₆] (<b>2­[PF</b>_<b>6</b><b>]</b>), in which the fulvene-like Cp* moiety is best described as an η⁵:η¹-tetra­methyl­fulvene ligand based on ¹H NMR and ¹³C NMR spectroscopic data. When complex <b>2­[PF</b>_<b>6</b><b>]</b> was subjected to the electrophilic attack of HCl, an intact Cp* group was regenerated from the fulvene-like Cp* ligand along with the formation of the chloride bridged complex [Cp*Ru­(μ-η²:​η²-bdt)­(μ-Cl)­RuCp*]­[PF₆] (<b>3­[PF</b>_<b>6</b><b>]</b>). While complex <b>2­[PF</b>_<b>6</b><b>]</b> reacted with iodine, functionalization of a Cp* methyl group was realized to give a Cp* ring iodine-substituted complex [(η⁵-C₅Me₄­CH₂I)­Ru­(<i>t</i>-I)­(μ-η²:​η⁴-bdt)­RuCp*]­[PF₆] (<b>4­[PF</b>_<b>6</b><b>]</b>) in excellent yield. Importantly, reaction of <b>2­[PF</b>_<b>6</b><b>]</b> with elemental sulfur led to the S–S bond fission of S₈ following insertion of a disulfide fragment into the Ru–methylene bond to produce [(η⁵:​η¹-C₅Me₄­CH₂S₂)­Ru­(μ-η²:​η⁴-bdt)­RuCp*]­[PF₆] (<b>5­[PF</b>_<b>6</b><b>]</b>), which provides strong chemical evidence for structural description of the fulvene-like Cp* ligand in <b>2­[PF</b>_<b>6</b><b>]</b>. Most strikingly, treatment of <b>2­[PF</b>_<b>6</b><b>]</b> with CO and ^<i>t</i>BuNC resulted in the coordination mode switch of the fulvene-like Cp* ligand from η⁵:η¹ on one ruthenium center to μ-η⁵:η¹ between two ruthenium centers to afford [Ru­(μ-η⁵:​η¹-C₅Me₄­CH₂)­(<i>t</i>-CO)­(μ-η²:​η²-bdt)­RuCp*]­[PF₆] (<b>6­[PF</b>_<b>6</b><b>]</b>) and [Ru­(μ-η⁵:​η¹-C₅Me₄­CH₂)­(<i>t</i>-^<i>t</i>BuNC)­(μ-η²:​η²-bdt)­RuCp*]­[PF₆] (<b>7­[PF</b>_<b>6</b><b>]</b>), respectively