Slow Rate Research Articles

Phenotypic memory in quorum sensing.

Quorum sensing (QS) is a regulatory mechanism used by bacteria to coordinate group behavior in response to high cell densities. During QS, cells monitor the concentration of external signals, known as autoinducers, as a proxy for cell density. QS often involves positive feedback loops, leading to the upregulation of genes associated with QS signal production and detection. This results in distinct steady-state concentrations of QS-related molecules in QS-ON and QS-OFF states. Due to the slow decay rates of biomolecules such as proteins, even after removal of the initial stimuli, cells can retain elevated levels of QS-associated biomolecules for extended periods of time. This persistence of biomolecules after the removal of the initial stimuli has the potential to impact the response to future stimuli, indicating a memory of past exposure. This phenomenon, which is a consequence of the carry-over of biomolecules rather than genetic inheritance, is known as "phenotypic" memory. This theoretical study aims to investigate the presence of phenotypic memory in QS and the conditions that influence this memory. Numerical simulations based on ordinary differential equations and analytical modeling were used to study gene expression in response to sudden changes in cell density and extracellular signal concentrations. The model examined the effect of various cellular parameters on the strength of QS memory and the impact on gene regulatory dynamics. The findings revealed that QS memory has a transient effect on the expression of QS-responsive genes. These consequences of QS memory depend strongly on how cell density was perturbed, as well as various cellular parameters, including the Fold Change in the expression of QS-regulated genes, the autoinducer synthesis rate, the autoinducer threshold required for activation, and the cell growth rate.

A General Approach to Activate Second-Scale Room Temperature Photoluminescence in Organic Small Molecules.

Organic small molecules that exhibit second-scale phosphorescence at room temperature are of interest for potential applications in sensing, anticounterfeiting, and bioimaging. However, such materials systems are uncommon-requiring millisecond to second-scale triplet lifetimes, efficient intersystem crossing, and slow rates of nonradiative recombination. Here, a simple and scalable approach is demonstrated to activate long-lived phosphorescence in a wide variety of molecules by suspending them in rigid polymer hosts and annealing them above the polymer's glass transition temperature. This process produces submicron aggregates of the chromophore, which suppresses intramolecular motion that leads to nonradiative recombination and minimizes triplet-triplet annihilation that quenches phosphorescence in larger aggregates. In some cases, evidence of excimer-mediated intersystem crossing that enhances triplet generation in aggregated chromophores is found. In short, this approach circumvents the current design rules for long-lived phosphors, which will streamline their discovery and development.

Concentrations of potentially endocrine disrupting chemicals in car cabin air and dust – Effect of temperature and ventilation

Materials in car cabins contain performance-enhancing semi-volatile organic compounds (SVOCs). As these SVOCs are not chemically bound to the materials, they can emit from the materials at slow rates to the surrounding, causing human exposure. This study aimed at increasing the understanding on abundance of SVOCs in car cabins by studying 18 potential endocrine disrupting chemicals in car cabin air (gas phase and airborne particles) and dust. We also studied how levels of these chemicals varied by temperature inside the car cabin along with ventilation settings, relevant to human exposure. A positive correlation was observed between temperature and SVOC concentration in both the gas and the particle phase, where average gas phase levels at 80 °C were a factor of 18–16,000 higher than average levels at 25 °C, while average particle phase levels were a factor of 4.6–40,000 higher for the studied substances. This study also showed that levels were below the limit of detection for several SVOCs during realistic driving conditions, i.e., with the ventilation activated. To limit human exposure to SVOCs in car cabins, it is recommended to ventilate a warm car before entering and have the ventilation on during driving, as both temperature and ventilation have a significant impact on SVOC levels.

Pragmatics via prosody in interaction optimization

The article represents a case study of Joaquin Phoenix’s acceptance speech, aimed at examining the interface of pragmatics and prosody. Relying on research into prosodic-pragmatic relationships and employing auditory prosody analysis combined with methods of pragmatic and discourse analysis, the article explores the interaction of prosody with speech acts, as well as with their related politeness and discursive strategies. Direct expressives are associated with three positive politeness strategies and are prosodically characterized by a normal or slow speech rate, normal or reduced volume, short intonation groups, very short pauses, a narrow pitch range, clear timbre, and a regular rhythm. The illocutionary force of indirect expressives relies on stylistic devices and markers of positive politeness, connoting emotional closeness and “sincerity” as components of felicity conditions for such acts. Indirect expressives are signaled by very short, short, or medium filled pauses, resonant timbre, low fall and stressed syllable, a descending stepping scale followed by a falling nucleus, high fall intonation groups, a rising intonation before key concepts, accelerated speech tempo, increased loudness, and emphasis on key words. The prosodic signals of expressive syntax and positive politeness coincide, except for markers emphasizing commonality. The “ecocentric” part of speech is constructed by representatives-reasoning that stimulates reflection without imposing views. This aligns with the negative politeness of non-imposition, marked by mitigators like hedges, bushes, and shields. The intonational accent on words with denotative or connotative meanings related to “discrimination” contributes to the discursive strategy of group polarization.

Slow recovery rates and spatial aggregation of Triatoma infestans populations in an area with high pyrethroid resistance in the Argentine Chaco

BackgroundThe emergence of pyrethroid resistance has threatened the elimination of Triatoma infestans from the Gran Chaco ecoregion. We investigated the status and spatial distribution of house infestation with T. infestans and its main determinants in Castelli, a municipality of the Argentine Chaco with record levels of triatomine pyrethroid resistance, persistent infestation over 2005–2014, and limited or no control actions over 2015–2020.MethodsWe conducted a 2-year longitudinal survey to assess triatomine infestation by timed manual searches in a well-defined rural section of Castelli including 14 villages and 234 inhabited houses in 2018 (baseline) and 2020, collected housing and sociodemographic data by on-site inspection and a tailored questionnaire, and synthetized these data into three indices generated by multiple correspondence analysis.ResultsThe overall prevalence of house infestation in 2018 (33.8%) and 2020 (31.6%) virtually matched the historical estimates for the period 2005–2014 (33.7%) under recurrent pyrethroid sprays. While mean peridomestic infestation remained the same (26.4–26.7%) between 2018 and 2020, domestic infestation slightly decreased from 12.2 to 8.3%. Key triatomine habitats were storerooms, domiciles, kitchens, and structures occupied by chickens. Local spatial analysis showed significant aggregation of infestation and bug abundance in five villages, four of which had very high pyrethroid resistance approximately over 2010–2013, suggesting persistent infestations over space-time. House bug abundance within the hotspots consistently exceeded the estimates recorded in other villages. Multiple regression analysis revealed that the presence and relative abundance of T. infestans in domiciles were strongly and negatively associated with indices for household preventive practices (pesticide use) and housing quality. Questionnaire-derived information showed extensive use of pyrethroids associated with livestock raising and concomitant spillover treatment of dogs and (peri) domestic premises.ConclusionsTriatoma infestans populations in an area with high pyrethroid resistance showed slow recovery and propagation rates despite limited or marginal control actions over a 5-year period. Consistent with these patterns, independent experiments confirmed the lower fitness of pyrethroid-resistant triatomines in Castelli compared with susceptible conspecifics. Targeting hotspots and pyrethroid-resistant foci with appropriate house modification measures and judicious application of alternative insecticides with adequate toxicity profiles are needed to suppress resistant triatomine populations and prevent their eventual regional spread.Graphical

Significantly enhanced crystallization of poly(L‐lactide) by incorporation of poly(D‐lactide) grafted cellulose nanocrystals

AbstractPoly(L‐lactic acid) (PLLA), as a green, biodegradable polymer material, has garnered considerable attention due to its ease of processing and exceptional properties. However, the inherent slow crystallization rate and brittleness of PLLA substantially restrict its extensive applications across various domains. In present work, PLLA and poly(D‐lactide) (PDLA)‐modified cellulose nanocrystals (CNCs), referred as CNC‐g‐L and CNC‐g‐D, are serving as nano‐fillers to enhance the crystallization rate of PLLA. Our findings demonstrate that both nano‐fillers could enhance the crystallization rate of PLLA, but the CNC‐g‐D shows a more efficient nucleation agent compared with its counterpart, CNC‐g‐L. Isothermal crystallization analysis indicates that CNC‐g‐D substantially increases nucleation density of PLLA, with pronounced crystallization at an elevated temperature of 155°C as confirmed by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Wide‐angle x‐ray diffraction (WAXD) analysis shows the preformation of stereocomplex crystals on the CNC‐g‐D surface may result in a fast crystallization rate. Meanwhile, after incorporation of different nano‐fillers, the toughness property of PLLA has also been significantly enhanced. Our result has shown the CNC‐g‐D could serve as an efficient nucleation agent toward PLLA and also facilitate to aiding in establishing comprehensive structure–property relationships of polymer materials.

Conservation-oriented management benefits the Black-faced Spoonbill, an endangered migratory waterbird

Active conservation management is crucial for maintaining and recovering populations of threatened species. Yet, there are remarkably few studies quantifying the benefits of conservation management and comparing ecological and anthropogenic influences on populations. We investigate these issues using the Black-faced Spoonbill Platalea minor as a case study. This species is an endangered migratory waterbird that garnered significant conservation attention along the East Asian-Australasian Flyway. Its global population has shown an upward trend recently, yet the speed of recovery has varied spatially. Understanding the species’ occurrence across wintering sites and the factors driving the geographical variation in recovery is vital for examining the benefits of management. In winter 2021–2022, we surveyed the occurrence and abundance of Black-faced Spoonbills and gathered data on environmental conditions across six important wintering sites in Taiwan and the Chinese mainland. Our results indicated a preference for larger wetlands with water depths of 10–20cm. Birds were more likely to be present in wetlands receiving conservation management interventions. Wetlands with vegetated bunds and fewer artificial materials tended to attract larger flocks. The contribution of wetland size and conservation management aimed at increasing spoonbill abundance varied across regions, with a more significant positive effect of conservation management observed in Taiwan. Our results serve as a valuable reference for regional conservation planning and wetland management in wintering areas, aiding their long-term conservation. In line with this, we recommend increased conservation management efforts informed by our findings, particularly in regions with relatively slow recovery rates.

Crystallization and performance evolution of PHBV nanocomposites through annealing: The role of surface modification of CNCs

To address the brittleness challenge of polyhydroxybutyrate-co-valerate (PHBV) rooting from its slow nucleation rate, cellulose nanocrystals (CNCs) were employed as bio-based nano nucleation and reinforcement agents. CNCs were further functionalized through succinylation using aliphatic dodecyl succinic anhydride (DDSA), for improved compatibility and dispersion within PHBV. Nanocomposites of PHBV incorporating pristine or DDSA-modified CNC (mCNC) were prepared through solution mixing followed by melt injection molding. The study focused on investigating how CNCs and mCNCs affect the crystallization behavior, thermal, rheological, and mechanical properties of PHBV nanocomposites over time, in the course of annealing or conditioning. Thermal results revealed that the incorporation of neat CNCs generally improving stability due to restricted polymer chain mobility and hydrogen bonding, while DDSA-modified CNCs show varied effects depending on the concentration, sometimes diminishing stability due to increased chain mobility. Polarized optical microscopy revealed the superior nucleation efficiency of mCNC, especially at low contents, leading to smaller and numerous spherulites over conditioning. Rheological analysis indicated a dilution effect of the hairy mCNCs, decreasing both dynamic modulus and complex viscosity. Mechanical properties, assessed through tensile testing and dynamic mechanical analysis after 15 days of conditioning, demonstrated the evolving effect of CNCs on aging-induced embrittlement and thermo-mechanical performance of PHBV during storage. The results revealed that incorporating 1 wt% mCNCs effectively toughened PHBV, increasing Young's modulus, and decreasing Tg without scarifying elongation at break compared to neat PHBV. The findings position mCNCs as a promising nucleation agent which retains PHBV nanocomposites toughness after aging.

Heterologous glucose-6-phosphate dehydrogenase empowers the biofuel potential of Tetradesmus obliquus via generating lipogenic NADPH

Large-scale production of biofuels from oleaginous microalgal feedstocks in a commercially feasible manner is hampered by their relatively slow growth rates and overall lipid yield than the rapidly proliferating algal species. Therefore, it is pivotal to obviate this bottleneck by augmenting lipid overproduction in fast-growing microalgal species by heterologous overexpression lipogenic genes from model oleaginous species. In this regard, the pentose phosphate pathway of Tetradesmus obliquus was perturbed by heterologous overexpression of glucose-6-phosphate dehydrogenase (PtG6PD) from the model pennate diatom Phaeodactylum tricornutum, known for its oleaginicity. The role of PtG6PD in increasing lipid production was reported in the heterologous T. obliquus. Total lipid content was increased by 2.09- and 2.31-fold in transgenic lines than WT by elevating the lipogenic NADPH, without any negative impact on their growth rates. Interestingly, lipid yields in the transgenic strains reached up to 93 mg/L and 103 mg/L which showed a further 2-fold enhancement under nitrogen-deficient conditions. Furthermore, it was demonstrated that PtG6PD overexpression also altered fatty acid composition, with a specific increment in total monounsaturated fatty acids. Our results uncovered the pivotal role of the pentose phosphate pathway in supplying lipogenic NADPH in T. obliquus and identified key genetic targets for lipid biosynthesis enhancement in alternative hosts. Altogether, these findings open avenues for metabolic engineering in non-model and fast-growing non-oleaginous microalgal species, thereby presenting a promising strategy for empowering commercially viable photosynthetic cell factories for biofuel production.

Enzyme-free method for preparation of sturgeon extracts with antioxidant, hepatoprotective and immune-enhancing functions

Sturgeon has a long lifespan and slow evolutionary rate due to their powerful endogenous antioxidant system. This work aimed to assess the in vitro and in vivo antioxidant activity of sturgeon extracts from both muscle and roe. The extraction process without enzyme hydrolysis is not only simple, but also can produce extracts with better free radicals scavenging abilities than enzymatic hydrolysates in both cellular and in vivo experiments. Moreover, in mouse models with liver injury and immunosuppression treatment, the sturgeon extracts demonstrated strong hepatoprotective and immune-enhancing functions, comparable to vitamin C and ginseng extract supplements, which were attributed to abundant antioxidant peptides of the extracts. The 15 isolated peptides exhibited diverse free radical scavenging ability. Therefore, the sturgeon extracts showed high potential to be applied in food and biomedical industries.

Enhancing marine biodegradability of poly(butylene succinate) by blending with 16-hydroxyhexadecanoic acid and poly(ε-caprolactone)

One potential solution for reducing marine pollution from plastic waste is to replace conventional plastics with biodegradable alternatives. However, most chemosynthetically biodegradable aliphatic polyesters, such as poly(butylene succinate) (PBS), exhibit extremely slow biodegradation rates in marine environments. To address this problem, we present a novel method to enhance the marine biodegradability of PBS by blending it with 10 wt.% of 16-hydroxyhexadecanoic acid (16HHD) and poly(ε-caprolactone) (PCL). The weight loss rates of the PBS samples with 16HHD and PCL were 18.4- and 7.8-times faster than that of pristine PBS. Scanning electron micrographs of PBS blended with 16HHD and PCL after oceanic incubation for four months showed a rough surface, suggesting that enzymatic degradation occurred. Additionally, unlike pristine PBS, samples with 16HHD and PCL demonstrated biochemical oxygen demand (BOD) biodegradabilities of 90.4% and 83.2%, respectively, under marine conditions. Analysis of the microbial community of BOD testing using 16S ribosomal RNA gene sequencing indicated that the addition of 16HHD and PCL changed the microbial community compared to pristine PBS. These findings demonstrate how blending PBS with 16HHD and PCL enhances its marine biodegradability, thereby offering a promising avenue for addressing plastic pollution in marine ecosystems.

Advancements in Hybrid Additive Manufacturing: Integrating SLM and LMD for High-Performance Applications

Additive manufacturing (AM) technologies enable near-net-shape designs and demand-oriented material usage, which significantly minimizes waste. This points to a substantial opportunity for further optimization in material savings and process design. The current study delves into the advancement of sustainable manufacturing practices in the automotive industry, emphasizing the crucial role of lightweight construction concepts and AM technologies in enhancing resource efficiency and reducing greenhouse gas emissions. By exploring the integration of novel AM techniques such as selective laser melting (SLM) and laser metal deposition (LMD), the study aims to overcome existing limitations like slow build-up rates and limited component resolution. The study’s core objective revolves around the development and validation of a continuous process chain that synergizes different AM routes. In the current study, the continuous process chain for DMG MORI Lasertec 65 3D’s LMD system and the DMG MORI Lasertec 30 3D’s was demonstrated using 316L and 1.2709 steel materials. This integrated approach is designed to significantly curtail process times and minimize component costs, thus suggesting an industry-oriented process chain for future manufacturing paradigms. Additionally, the research investigates the production and material behavior of components under varying manufacturing processes, material combinations, and boundary layer materials. The culmination of this study is the validation of the proposed process route through a technology demonstrator, assessing its scalability and setting a benchmark for resource-efficient manufacturing in the automotive sector.

Gonadal development of striped catfish (Pangasianodon hypophthalmus) in climate-caused salinity intrusion

Salinity intrusion is one of the major climate-caused problems globally. The present work evaluated the impacts of salinity on the gonadal improvement in striped catfish (Pangasianodon hypophthalmus). The fingerlings of striped catfish (8.63 g) were cultured at three different salinity levels (0, 4, and 8 ppt) for two years. Gonadal development was assessed by gonadosomatic index (GSI) and histological analysis over six months at the end of two years of rearing from April to September. The gonad histological observations and the associated changes in GSI showed that the male and female striped catfish cultured in different salinity conditions could complete testicular and ovarian maturation at 4 and 8 ppt salinity by June and July, as they have grown at 0 ppt salinity. The current findings indicate that despite a slow rate of development, salinity up to 8 ppt showed a positive impact on the gonadal development of striped catfish. Asian J. Med. Biol. Res. 2024, 10(2), 89-98

Optimizing Mouse Primary Lens Epithelial Cell Culture: A Comprehensive Guide to Trypsinization.

Lens epithelial cells (LECs) play multiple important roles in maintaining the homeostasis and normal function of the lens. LECs determine lens growth, development, size, and transparency. Conversely, dysfunctional LECs can lead to cataract formation and posterior capsule opacification (PCO). Consequently, establishing a robust primary LEC culture system is important to researchers engaged in lens development, biochemistry, cataract therapeutics, and PCO prevention. However, cultivating primary LECs has long presented challenges due to their limited availability, slow proliferation rate, and delicate nature. This study addresses these hurdles by presenting a comprehensive protocol for primary LEC culture. The protocol encompasses essential steps such as the formulation of an optimized culture medium, precise isolation of lens capsules, trypsinization techniques, subculture procedures, harvest protocols, and guidelines for storage and shipment. Throughout the culture process, cell morphology was monitored using phase-contrast microscopy. To confirm the authenticity of the cultured LECs, immunofluorescence assays were conducted to detect the presence and subcellular distribution of critical lens proteins, namely αA- and γ-crystallins. This detailed protocol equips researchers with a valuable resource for cultivating and characterizing primary LECs, enabling advancements in our comprehension of lens biology and the development of therapeutic strategies for lens-related disorders.

Reliable identification based intelligent PID tuning for long-period process control under different working conditions

Background: Chemical process models change frequently with operating conditions. However, the industry mostly adopts an off-line calibration and online fixed value commissioning scheme, which can be difficult to maintain control quality. Therefore, a long-cycle online intelligent PID controller calibration scheme is necessary.Methods: Firstly, a high-order linear dynamic model is used as the identification model, and online recursive identification technology is utilized. Secondly, a comprehensive performance index is selected to ensure both stability and rapidity of dynamic transitions. Finally, the slow rate updated PID parameters are obtained during the process control, and the Levy Memory Particle Swarm Optimization (LMPSO) search is applied to harvest the optimal solution.Significant findings: This paper has presented an intelligent PID tuning method based on reliable identification technology. The main contributions include: (i) By using Lyapunov theory, the boundedness of identification error using the proposed algorithm is guaranteed; (ii) The LMPSO algorithm is proposed to enhance global search capability and search efficiency; (iii) A novel optimization scheme is proposed for a full-process online closed-loop intelligent PID controller. The scheme aims to improve the industrial controller's performance without altering its structure.

The ultrasound leaching kinetics of copper in the H2SO4 dissolution process

ABSTRACT The atmospheric immersion copper dissolution method, commonly employed in the current copper foil production process, is confronted with challenges such as low oxidation ability and the formation of passivation layers on the copper surface. These issues result in slow copper dissolution rates, significantly restricting copper foil production. To overcome this limitation, ultrasound is used to improve the copper dissolution process. The impact of ultrasound on the rate and kinetics of copper dissolution in a sulfuric acid solution was studied. Various factors, including ultrasound power, temperature, Cu2+ concentration, sulfuric acid concentration, and air flow rate, were analysed to assess their influence on the rate of copper dissolution. The optimised dissolution conditions were determined to be 30 g/L Cu2+, 120 g/L sulfuric acid, 300 mL/min air flow, 60°C, and 300 W ultrasonic power. The copper dissolution rate is 1.96 times higher when ultrasound is applied compared to conventional conditions. According to the kinetic study, ultrasound reduced the apparent activation energy from 61.12 kJ/mol to 46.44 kJ/mol, significantly lowering the potential barrier for copper dissolution. This study provides valuable insights for accelerating the dissolution process of copper using ultrasound-assisted technology.

Fast phase retrieval without unwrapping for 3D measurement based on digital phase difference

Phase unwrapping is still a tough task for fringe projection profilometry (FPP), due to the heavy computation burden and slow rate of the existing phase unwrapping algorithms. To speed up the retrieval of the absolute phase, a fast phase retrieval algorithm without unwrapping for 3D measurement based on digital phase difference is presented in this paper. Firstly, 4-step phase-shifting profilometry is utilized to retrieve a complex-valued map, who contains the complete phase information of the measurement object in its phase part. Instead of extracting the phase map from the complex-valued map directly, a novel complex-valued map containing the differential phase is obtained by the division between the complex-valued map and its pixel-shifted version. Then, the differential phase can be extracted from the novel complex-valued map by regular phase extraction operation easily. Finally, the absolute phase can be retrieved by integrating the differential phase along the inverse pixel-shifted direction. This proposed algorithm can retrieve the absolute phase easily and fast, while the measurement object has continuous surface with the phase variation in the range of (−π, π]. Simulated and experimental results were demonstrated to present that this algorithm has faster phase retrieval rate than existing algorithms and has no obvious jump error, which allows fast and high-quality phase retrieval.

Drastically Accelerated Radical Recombination Kinetics of a Hexaarylbiimidazole Derivative.

More than 60 years have passed since the discovery of hexaarylbiimidazole (HABI), which exhibits a characteristic photochromism that produces colored lophyl radicals through a radical dissociation reaction induced by light irradiation and reverts to its original state through a radical recombination reaction in the dark. Lophyl radicals are relatively stable among organic radicals, have low reactivity with oxygen, and have a very slow radical recombination reaction rate. HABI has been used industrially as a photoinitiator to date. However, the guidelines for molecular design to accelerate the thermal reverse reaction of HABI are still unknown and remain a challenge. We found that suppressing the rotation of the phenyl groups attached to the 4- and 5-positions of the imidazole ring of HABI is effective in accelerating the radical recombination reaction. The simple molecular design strategy to accelerate the thermal reverse reaction of HABI is expected to improve the performance of photoinitiators and photoresponsive materials that utilize HABI as a photoresponsive unit.

Towards Open-Source Cloud Adoption : Exploring the Determinants

The trends in cloud computing development have become fundamental building blocks to many business information system models and innovations, the architects are designing cloud systems to be as effective and beneficial as possible. In this paradigm, open-source cloud platforms are part of the design philosophy that drives innovation in cloud services. The adoption of open-source cloud has become pervasive in the modern enterprise; this has been accelerated by perceived benefits of openness. The power in the community of developers and openness fosters development of hardened, secure and reliable solutions. These features enable a collaborative source code, modification and customization geared towards innovation with positive impact on the design, aligning perfectly with the dynamic nature of open-source cloud solutions. However, the slow adoption rate in the modern enterprises has been attributed to a lack of understanding of open-source cloud adoption. This study explores the determinants of open-source cloud adoption in the context of higher learning institutions. A deductive thematic analysis technique was utilized in the study.

The relationship of rate and pause features to the communicative participation of people living with ALS.

Many people living with amyotrophic lateral sclerosis (PALS) report restrictions in their day-to-day communication (communicative participation). However, little is known about which speech features contribute to these restrictions. This study evaluated the effects of common speech symptoms in PALS (reduced overall speaking rate, slowed articulation rate, and increased pausing) on communicative participation restrictions. Participants completed surveys (the Communicative Participation Item Bank-short form; the self-entry version of the ALS Functional Rating Scale-Revised) and recorded themselves reading the Bamboo Passage aloud using a smartphone app. Rate and pause measures were extracted from the recordings. The association of various demographic, clinical, self-reported, and acoustic speech features with communicative participation was evaluated with bivariate correlations. The contribution of salient rate and pause measures to communicative participation was assessed using multiple linear regression. Fifty seven people living with ALS participated in the study (mean age = 61.1 years). Acoustic and self-report measures of speech and bulbar function were moderately to highly associated with communicative participation (Spearman rho coefficients ranged from rs = 0.48 to rs = 0.77). A regression model including participant age, sex, articulation rate, and percent pause time accounted for 57% of the variance of communicative participation ratings. Even though PALS with slowed articulation rate and increased pausing may convey their message clearly, these speech features predict communicative participation restrictions. The identification of quantitative speech features, such as articulation rate and percent pause time, is critical to facilitating early and targeted intervention and for monitoring bulbar decline in ALS.