Single Housing Research Articles

Positive reinforcement-based magnet training permits social housing in catheterized squirrel monkeys

BackgroundNon-human primates play a critical role in neuroscience research. Though they are social animals, laboratory study requirements can sometimes require single housing and thereby prevent social housing. New MethodTo eliminate single housing and promote well-being within our squirrel monkey colony, we used positive reinforcement training in combination with magnetic/mechanical clasps and custom jackets to permit pair housing of catheterized squirrel monkeys used in behavioral studies. ResultsAdult Saimiri boliviensis boliviensis monkeys (n = 7) readily progressed through a six-stage training procedure for cooperative handling and transport from the home cage to the experimental testing rooms.Comparison with existing methods and conclusions: Given the evidence of isolation induced stress and neurobiological consequences in multiple species, and consistent with an increased regulatory emphasis on social housing of non-human primates, the methods presented herein provide a method for handling squirrel monkeys in behavioral studies that is compatible with social housing.

Effects of single housing on behavior, corticosterone level and body weight in male and female mice

BackgroundExperimental mice are often single-housed either for an individual analysis (feeding behavior, imaging, calorimetry) or as a stress paradigm (social isolation) in translational biomedical research. Reports of the influence of single housing in rodents are conflicting and may depend on age and duration of isolation. Sex is often not included as a factor. In this study we investigated the effects of 4-week single housing in male and female mice on behavior, body weight, and serum corticosterone levels.ResultsBehavioral tests showed no effect on anhedonia and stress coping, anxiety and motor exploration. Social avoidance occurred in both males and females. Regarding physiological effects, single housing did not induce changes in serum corticosterone levels, but reduced body weight gain.ConclusionsWhile some mouse studies of chronic social isolation reported depression-related disturbances, our data suggest that single housing might be not necessarily be too stressful. This is important for animal welfare regulations and experiments in life science research.

A Novel Mouse Home Cage Lickometer System Reveals Sex- and Housing-Based Influences on Alcohol Drinking.

Alcohol use disorder (AUD) is a significant global health issue. Despite historically higher rates among men, AUD prevalence and negative alcohol-related outcomes in women are rising. Loneliness in humans has been associated with increased alcohol use, and traditional rodent drinking models involve single housing, presenting challenges for studying social enrichment. We developed LIQ PARTI (Lick Instance Quantifier with Poly-Animal RFID Tracking Integration), an open-source tool to examine home cage continuous access two-bottle choice drinking behavior in a group-housed setting, investigating the influence of sex and social isolation on ethanol consumption and bout microstructure in C57Bl/6J mice. LIQ PARTI, based on our previously developed single-housed LIQ HD system, accurately tracks drinking behavior using capacitive-based sensors and RFID technology. Group-housed female mice exhibited higher ethanol preference than males, while males displayed a unique undulating pattern of ethanol preference linked to cage changes, suggesting a potential stress or novelty-related response. Chronic ethanol intake distinctly altered bout microstructure between male and female mice, highlighting sex and social environmental influences on drinking behavior. Social isolation with the LIQ HD system amplified fluid intake and ethanol preference in both sexes, accompanied by sex- and fluid-dependent changes in bout microstructure. However, these effects largely reversed upon resocialization, indicating the plasticity of these behaviors in response to social context. Utilizing a novel group-housed home cage lickometer device, our findings illustrate the critical interplay of sex and housing conditions in voluntary alcohol drinking behaviors in C57Bl/6J mice, facilitating nuanced insights into the potential contributions to AUD etiology.

Single housing of juveniles accelerates early-stage growth but extends adult lifespan in African turquoise killifish.

Within the same species, individuals exhibiting faster growth tend to have shorter lifespans, even if their fast growth arises from early-life pharmacological interventions. However, in vertebrates, the impact of the early-life environment on the growth rate and lifespan has not been fully elucidated. In this study, by utilizing the short-lived African turquoise killifish, which is suitable for a comprehensive life-stage analysis in a brief timeframe, we explored the effects of housing density during the juvenile stage on holistic life traits. As a result, we found that lower housing densities resulted in faster growth, but led to longer adult lifespan, which was contrary to the common notion. Furthermore, the single-housed adult fish displayed a longer egg-laying period than did their group-housed counterparts. Our transcriptome analysis also demonstrated that, in terms of internal transcriptional programs, the life stage progression and aging process of single-housed fish were slower than those of group-housed fish. Collectively, our results suggest that sharing housing with others in early life might influence whole-life attributes, potentially leading to specific life history traits beyond the typical relationship between the growth rate and lifespan.

Thermoneutral Housing has Limited Effects on Social Isolation-Induced Bone Loss in Male C57BL/6J Mice.

Social isolation is a major public health concern and is known to increase the risk for many diseases, including heart disease and dementia. The impact of social isolation on bone health, however, has not been well-studied. We previously found that four weeks of social isolation reduces bone in male mice. Isolated mice may experience more cold stress than mice housed in groups, as we commonly keep laboratory mice at temperatures below their ideal range, which could lead to bone loss. The aim of our study was therefore to test if housing mice at warmer temperatures, within their ideal temperature range, prevents isolation-induced bone loss in male mice. We found that housing mice at warmer temperatures did not fully prevent isolation-induced bone loss. We also found social isolation increased the expression of genes related to glucocorticoid signaling in bone across temperatures, as well as genes associated with mitochondrial metabolism within fat tissue. Overall, our results show that social isolation-induced bone loss is likely not a result of cold stress from single housing and provide insight into the mechanisms by which isolation causes bone loss.

Increasing the Efficiency of Wastewater Treatment by Using a Mixing Chamber in a Combined Filter

A combined scheme for wastewater treatment is proposed using a combined filter, which includes a reagent treatment section, a mixing chamber, a contact flocculation chamber and a sand-loaded filter. The main features of the operation of the mixing chamber located inside the filter housing are considered, which ensures the intensification of the coagulation process, due to the continuity of the coagulating and filtering process in a single housing without interrupting the process, due to which the flakes are not destroyed when moving from stage to stage. To confirm the efficiency of the mixing chamber, a number of laboratory experiments were carried out on model and river water. It has been confirmed that the use of the developed mixing chamber improves the filtration process by 15 to 30%. It was concluded that intensification of the filtration process would improve the efficiency of treatment facilities as a whole and ensure the quality of water for discharge into water bodies.

Pairing laboratory-housed adult male rhesus macaques (Macaca mulatta): Success rates in relation to behavioral response and duration of visual contact

While the benefits of pair housing have been well documented, less is known about increasing success in adult male macaque pair introductions. In this retrospective study, 95 unfamiliar adult male macaque (Macaca mulatta) pairs were examined to determine whether duration of visual contact, behavior, age, and weight were associated with success rate, with “success” defined as two weeks in full tactile contact without excessive behavioral indicators of incompatibility or injury requiring clinical treatment or care. Overall, the unfamiliar adult male pairs achieved a success rate of 72 % and wounding requiring medical attention was rare (2 %). A significant negative relationship between pair success and time in visual contact for pairs was found. Pairs who moved into tactile contact within 48-hours showed more positive social behaviors in protected and full contact and had a high rate of success (91 %), while those who exhibited negative social behaviors were maintained in visual contact for longer. Nevertheless, rapid signs of compatibility were not necessary for the formation of successful pairs. While social introduction success rates steadily declined with increased periods of maintained visual contact, longer durations of 3 days to 1 week (70 %), and 8+ days (58 %), were still accompanied by high to moderate success, respectively. These results indicate that when negative social behavior is present early in visual contact success may be expected to decrease, but it is not necessarily indicative of incompatibility. Providing extra time in visual contact can reduce overall incidences of single housing.

Toward just and equitable mobility: Socioeconomic and perceptual barriers for electric vehicles and charging infrastructure in the United States

Based on a large-scale public survey, we identify and quantify the significance of key factors associated with the deployment of electric vehicles and charging infrastructure. Our results indicate that individual characteristics, such as income, age, region, and single vs. multi-family housing type can significantly affect electric vehicle purchase preferences, especially those concerning overnight charging and perceptions of benefits and barriers. Moreover, our results challenge earlier findings in the literature by showing how certain elements, such as expected electric driving range, certain travel behaviors (e.g., driving distance, destination types), the most common perceived benefits (e.g., cleaner air) or barriers (e.g., reliability concerns), and preferred location for public charging seem to not vary much or at all with the socioeconomic, demographic, and geographical variables examined in this study. We conclude with the implications for policies to advance equitable vehicle electrification. Our findings underscore the importance of lower-cost models of electric vehicles, home and public charging access, charging infrastructure planning, more integrated analysis of interlinked housing and transportation needs and solutions, the availability of alternative transportation modes, and the potential role of gas stations for electric vehicles. We encourage others to build on these results and have shared our complete survey instrument as an added contribution.

Justification of the Locations of Differential Pressure Sensors for Coarse and Fine Filter Elements Installed one Inside the Other in a Single Gas Filter Housing

Statement of the problem. The relevant task of ensuring the uninterrupted operation of modern gas pressure reduction systems is to develop and comprehensively substantiate the possibility of using two-stage filters for natural gas purification in gas reduction points and theoretically substantiate the method for calculating the pressure drop in cylindrical filter elements (CFE). Results. It is proved that when gas flows in the upper cross section of the filter, the pressure drop will be less than in lower cross sections, including the pressure drop in the lowest cross section. This leads to a larger amount of leaking gas, to a larger mass of impurities settling in the lower part of the filter elements of cylindrical coarse and fine cleaning and to a greater degree of their clogging. Therefore, it is recommended to place gas pressure sensors in the lower part of the internal volume of the coarse and fine-cleaned CFE, so that the flow direction of the coarse and finely purified gas washing the sensors at the location of the hole for measuring statistical pressure is tangential to the side surface of the sensor tube. Then the flow direction of the roughly and finely purified gas entering the holes of the sensors is carried out at an angle of 90° and the pressure gauges measure the static pressure. Conclusions. The locations of pressure drop sensors on coarse and fine filter elements installed one inside the other in a single gas filter housing are substantiated. The proposed arrangement of differential pressure sensors will significantly increase the possibility of receiving an earlier signal about the degree of clogging of the gas filter at the control room, as well as have a significant amount of time for timely removal of blockages formed in the coarse cleaning CFE and replacement of fine cleaning CFE.

Post occupancy evaluation of private open spaces in dwelling units in single family investment housing projects in Erbil city

Due to urbanization, it has been found that in many cases public open spaces in the city are not maintained, as new investments are trying to make use of the land to construct more buildings The shortage of public open spaces can be treated by providing a sufficient amount of private open spaces in housing estates. Furthermore, the designers need to consider the dwelling layout to provide the best environment for the residents; this will maintain a high level of household satisfaction. One main element of household satisfaction is open spaces. In this research paper, private open space assessments in 4 investment projects with 98 samples in Erbil were considered. To investigate and examine how the exterior environment of the dwellings affects the residents’ satisfaction, based on plot size and number of bedrooms, surveys were performed on selected projects through documentation surveys and questionnaires. Then the evaluation was performed through two stages, firstly the technical assessment stage according to Iraqi standards, and secondly the residents’ response stage regarding satisfaction levels. The research objectives were obtained using SPSS software, through the use of descriptive statistics, correlation, and regression analysis. The results of the research discovered that all the projects except Minara B were slightly above the minimum level, thus in the range of Iraqi standards. Moreover, the level of overall satisfaction with these projects ranged from neutral to slightly satisfied, with the residents’ responses stating that they needed more private open spaces.

Histone H1x in mouse ventral hippocampus associates with, but does not cause behavioral adaptations to stress

Prior research has identified differential protein expression levels of linker histone H1x within the ventral hippocampus (vHipp) of stress-susceptible versus stress-resilient mice. These mice are behaviorally classified based on their divergent responses to chronic social stress. Here, we sought to determine whether elevated vHipp H1x protein levels directly contribute to these diverging behavioral adaptations to stress. First, we demonstrated that stress-susceptible mice uniquely express elevated vHipp H1x protein levels following chronic stress. Given that linker histones coordinate heterochromatin compaction, we hypothesize that elevated levels of H1x in the vHipp may impede pro-resilience transcriptional adaptations and prevent development of the resilient phenotype following social stress. To test this, 8–10-week-old male C57BL/6 J mice were randomly assigned to groups undergoing 10 days of chronic social defeat stress (CSDS) or single housing, respectively. Following CSDS, mice were classified as susceptible versus resilient based on their social interaction behaviors. We synthesized a viral overexpression (OE) vector for H1x and transduced all stressed and single housed mice with either H1x or control GFP within vHipp. Following viral delivery, we conducted social, anxiety-like, and memory-reliant behavior tests on distinct cohorts of mice. We found no behavioral adaptations following H1x OE compared to GFP controls in susceptible, resilient, or single housed mice. In sum, although we confirm elevated vHipp protein levels of H1x associate with susceptibility to social stress, we observe no significant behavioral consequence of H1x OE. Thus, we conclude elevated levels of H1x are associated with, but are not singularly sufficient to drive development of behavioral adaptations to stress.

A novel mouse home cage lickometer system reveals sex- and housing-based influences on alcohol drinking.

Alcohol use disorder (AUD) is a significant global health issue. Despite historically higher rates among men, AUD prevalence and negative alcohol-related outcomes in women are rising. Loneliness in humans has been associated with increased alcohol use, and traditional rodent drinking models involve single housing, presenting challenges for studying social enrichment. We developed LIQ PARTI (Lick Instance Quantifier with Poly-Animal RFID Tracking Integration), an open-source tool to examine home cage continuous access two-bottle choice drinking behavior in a group-housed setting, investigating the influence of sex and social isolation on ethanol consumption and bout microstructure in C57Bl/6J mice. LIQ PARTI, based on our previously developed single-housed LIQ HD system, accurately tracks drinking behavior using capacitive-based sensors and RFID technology. Group-housed female mice exhibited higher ethanol preference than males, while males displayed a unique undulating pattern of ethanol preference linked to cage changes, suggesting a potential stress-related response. Chronic ethanol intake distinctly altered bout microstructure between male and female mice, highlighting sex and social environmental influences on drinking behavior. Social isolation with the LIQ HD system amplified fluid intake and ethanol preference in both sexes, accompanied by sex- and fluid-dependent changes in bout microstructure. However, these effects largely reversed upon resocialization, indicating the plasticity of these behaviors in response to social context. Utilizing a novel group-housed home cage lickometer device, our findings illustrate the critical interplay of sex and housing conditions in voluntary alcohol drinking behaviors in C57Bl/6J mice, facilitating nuanced insights into the potential contributions to AUD etiology.

Effects of social housing on alcohol intake in mice depend on the non-social environment.

Excessive alcohol consumption leads to serious health problems. Mechanisms regulating the consumption of alcohol are insufficiently understood. Previous preclinical studies suggested that non-social environmental and social environmental complexities can regulate alcohol consumption in opposite directions. However, previous studies did not include all conditions and/or did not include female rodents. Therefore, in this study, we examined the effects of social versus single housing in standard versus non-standard housing conditions in male and female mice. Adult C57BL/6 J mice were housed in either standard shoebox cages or in automated Herdsman 2 (HM2) cages and exposed to a two-bottle choice procedure with 3% or 6% ethanol versus water for 5 days. The HM2 cages use radiotracking devices to measure the fluid consumption of individual mice in an undisturbed and automated manner. In both housing conditions, mice were housed either at one or at four per cage. In standard cages, group housing of animals decreased alcohol consumption and water consumption. In HM2 cages, group housing significantly increased ethanol preference and decreased water intake. There were no significant differences in these effects between male and female animals. These observations were similar for 3 and 6% ethanol solutions but were more pronounced for the latter. The effects of social environment on ethanol preference in HM2 cages were accompanied by an increase in the number of approaches to the ethanol solution and a decrease in the number of approaches to water. The differences in ethanol intake could not be explained by differences in locomotor or exploratory activity as socially housed mice showed fewer non-consummatory visits to the ethanol solutions than single-housed animals. In addition, we observed that significant changes in behaviors measuring the approach to the fluid were not always accompanied by significant changes in fluid consumption, and vice versa, suggesting that it is important to assess both measures of motivation to consume alcohol. Our results indicate that the direction of the effects of social environment on alcohol intake in mice depends on the non-social housing environment. Understanding mechanisms by which social and non-social housing conditions modulate alcohol intake could suggest approaches to counteract environmental factors enhancing hazardous alcohol consumption.

Using drugs alone in single room occupancy housing: Understanding environmental drivers of overdose risk

BackgroundAcross North America most overdose deaths occur in housing, largely due to individuals using drugs alone. In cities, fatalities are disproportionately concentrated in low-income housing, including single room occupancy (SRO) housing. While research has highlighted how SROs operate as risk environments for various poor outcomes, there has been little attention to specific drug use practices (i.e., using alone) associated with overdose vulnerability in these spaces. This study explores how environmental contexts of SROs shape overdose risks, with specific attention to practices of using drugs alone. MethodsIn-depth semi-structured interviews were conducted with 30 people who use drugs (PWUD) living in Vancouver SROs. Interviews covered topics such as social-structural environments of housing, drug use practices, and housing-based harm reduction. Thematic analysis drew on the intersectional risk environment framework. ResultsNarratives positioned SROs as extensions of public space, with similar expectations of risks and behaviours as in public spaces. For some participants, using alone in their room was characterized as a practice in claiming privacy within the context of a public existence. Participants highlighted how certain features of SRO's social-structural environments were routinely leveraged against them (e.g., security cameras, staff surveillance), suggesting using alone as a tactic to minimize risks of hyper-surveillance and punitive policies. Further, participants discussed using alone as “safer,” describing how this practice mitigated place-based risks of social-structural harms (e.g., violence, criminalization) in ways that eclipsed overdose risk. ConclusionUsing drugs alone may be understood as a spatial negotiation of vulnerability to diverse harms produced by environmental contexts of SROs. Interventions accounting for broader contextual factors (e.g., improvements housing quality/quantity, providing a safer supply of drugs) that render using alone as instrumental to survival, and that reduce the implicit threat of punishment from intensive surveillance and control practices are critical to reduce vulnerability to overdose and other harms.

Pebble to the Metal: A Boulder Approach to Enrichment for Danio rerio.

Zebrafish are an established and widely used animal model, yet there is limited understanding of their welfare needs. Despite an increasing number of studies on zebrafish enrichment, in-tank environmental enrichment remains unpopular among researchers. This is due to perceived concerns over health/hygiene when it comes to introducing enrichment into the tank, although actual evidence for this is sparse. To accommodate this belief, regardless of veracity, we tested the potential benefits of enrichments presented outside the tank. Thus, we investigated the preferences and physiological stress of zebrafish with pictures of pebbles placed underneath the tank. We hypothesized that zebrafish would show a preference for enriched environments and have lower stress levels than barren housed zebrafish. In our first experiment, we housed zebrafish in a standard rack system and recorded their preference for visual access to a pebble picture, with two positive controls: visual access to conspecifics, and group housing. Using a crossover repeated-measures factorial design, we tested if the preference for visual access to pebbles was as strong as the preference for social contact. Zebrafish showed a strong preference for visual access to pebbles, equivalent to that for conspecifics. Then, in a second experiment, tank water cortisol was measured to assess chronic stress levels of zebrafish housed with or without a pebble picture under their tank, with group housing as a positive control. Cortisol levels were significantly reduced in zebrafish housed with pebble pictures, as were cortisol levels in group housed zebrafish. In fact, single housed zebrafish with pebble pictures showed the same cortisol levels as group housed zebrafish without pebble pictures. Thus, the use of an under-tank pebble picture was as beneficial as being group housed, effectively compensating for the stress of single housing. Pebble picture enrichment had an additive effect with group housing, where group housed zebrafish with pebble pictures had the lowest cortisol levels of any treatment group.

Gut microbiota promotes pain chronicity in Myosin1A deficient male mice

Chronic pain is a heavily debilitating condition and a huge socio-economic burden, with no efficient treatment. Over the past decade, the gut microbiota has emerged as an important regulator of nervous system’s health and disease states. Yet, its contribution to the pathogenesis of chronic somatic pain remains poorly documented. Here, we report that male but not female mice lacking Myosin1a (KO) raised under single genotype housing conditions (KO-SGH) are predisposed to develop chronic pain in response to a peripheral tissue injury. We further underscore the potential of MYO1A loss-of-function to alter the composition of the gut microbiota and uncover a functional connection between the vulnerability to chronic pain and the dysbiotic gut microbiota of KO-SGH males. As such, parental antibiotic treatment modifies gut microbiota composition and completely rescues the injury-induced pain chronicity in male KO-SGH offspring. Furthermore, in KO-SGH males, this dysbiosis is accompanied by a transcriptomic activation signature in the dorsal root ganglia (DRG) macrophage compartment, in response to tissue injury. We identify CD206+CD163- and CD206+CD163+ as the main subsets of DRG resident macrophages and show that both are long-lived and self-maintained and exhibit the capacity to monitor the vasculature. Consistently, in vivo depletion of DRG macrophages rescues KO-SGH males from injury-induced chronic pain underscoring a deleterious role for DRG macrophages in a Myo1a-loss-of function context. Together, our findings reveal gene-sex-microbiota interactions in determining the predisposition to injury-induced chronic pain and point-out DRG macrophages as potential effector cells.

Hartmann–Sprenger Energy Separation Effect for the Quasi-Isothermal Pressure Reduction of Natural Gas: Feasibility Analysis and Numerical Simulation

The present paper provides a brief overview of the existing methods for energy separation and an analysis of the possibility of the practical application of the Hartmann–Sprenger effect to provide quasi-isothermal pressure reduction of natural gas at the facilities within a gas transmission system. The recommendations of external authors are analyzed. A variant of a quasi-isothermal pressure regulator is proposed, which assumes the mixing of flows after energy separation. Using a numerical simulation of gas dynamics, it is demonstrated that the position of the resonators can be determined on the basis of calculations of the structure of the underexpanded jet without taking into account the resonator and, accordingly, without the need for time-consuming calculations of the dynamics of the processes. Based on the results of simulating the gas dynamics of two nozzle–resonator pairs installed in a single flow housing, it is shown that, in order to optimize the regulator length, the width of the passage between the two nearest resonators should be greater than or equal to the sum of diameters of the critical sections of the nozzles. Numerical vibroacoustic analysis demonstrated that the most dangerous part of the resonator is the frequency of its natural oscillations.

Daytime spatial relationships in a family group of black rhinoceros Diceros bicornis at the Hiroshima City Asa Zoological Park, Japan.

Although black rhinoceros Diceros bicornis are mostly solitary in the wild, the Hiroshima City Asa Zoological Park (Asa Zoo) has kept a family group together during the daytime, with good reproductive performance over five decades. Management procedures at the zoo include temporary single housing of the mother before and after giving birth, which facilitates maintenance of a compatible family group. We recorded intra-group spatial relationships for 4 years and 4 months, during which time an adult female reared two consecutive calves. During daytime she remained in an enclosure with her new calf, one or two older offspring, and an adult male, the sire of all her offspring. Proximity (within two adult body-lengths) scores between the mother and her two calves were especially high during the first year after birth, and only slightly lower for her older offspring. The adult male had the lowest proximity scores. The spatial relationships were visualized by applying multidimensional scaling (MDS) to the proximity scores. Mother and calves were plotted close to each other, with older offspring slightly farther apart on the two-dimensional MDS representation; the adult male was more distant from the other group members. These findings indicate clear follower-type characteristics in the mother-calf pair and also older immature offspring, albeit to a lesser degree. Although black rhinoceros are generally solitary in the wild, our results duplicate observations of some wild black rhinoceros groups containing an adult female, her calf, and an older immature, with adult males being largely solitary.

Upscaling Plasma-Based CO2 Conversion: Case Study of a Multi-Reactor Gliding Arc Plasmatron.

Atmospheric pressure plasmas have shifted in recent years from being a burgeoning research field in the academic setting to an actively investigated technology in the chemical, oil, and environmental industries. This is largely driven by the climate change mitigation efforts, as well as the evident pathways of value creation by converting greenhouse gases (such as CO2) into useful chemical feedstock. Currently, most high technology readiness level (TRL) plasma-based technologies are based on volumetric and power-based scaling of thermal plasma systems, which results in large capital investment and regular maintenance costs. This work investigates bringing a quasi-thermal (so-called "warm") plasma setup, namely, a gliding arc plasmatron, from a lab-scale to a pilot-scale capacity with an increase in throughput capacity by a factor of 10. The method of scaling is the parallelization of plasmatron reactors within a single housing, with the aim of maintaining a warm plasma regime while simultaneously improving build cost and efficiency (compared to separate reactors operating in parallel). Special attention is also given to the safety and control features implemented in the setup, a key component required for integration into industrial systems. The performance of the multi-reactor gliding arc plasmatron (MRGAP) reactor is investigated, focusing on the influence of flow rate and the number of active reactors. The location of active reactors was deemed to have a negligible effect on the monitored metrics of conversion, energy efficiency, and energy cost. The optimum operating conditions were found to be with the most active reactors (five) at the highest investigated flow rate (80 L/min). Analysis of results suggests that an optimum conversion (9%) and plug power-based energy efficiency (19%) can be maintained at a specific energy input (SEI) around 5.3 kJ/L (or 1 eV/molecule). The concept of parallelization of plasmatron reactors within a singular housing was demonstrated to be a viable method for scaling up from a lab-scale to a prototype-scale device, with performance analysis suggesting that increasing the power (through adding more reactor channels) and total flow rate, while maintaining an SEI around 5.3 or 4.2 kJ/L, i.e., 1.3 or 1 eV/molecule (based on plug power and plasma-deposited power, respectively), can result in increased conversion rate without sacrificing absolute conversion or energy efficiency.

Abstract WMP120: MicroRNAs as a Therapeutic Target to Reduce Microglial Activation After Post-Stroke Social Isolation

Introduction: Loneliness and social isolation (SI) are associated with increased risk of stroke and other vascular disorders, along with all-cause mortality. However, it is unknown what mechanisms mediate how social factors affect stroke recovery. Methods: To investigate the negative effects of post-stroke SI on brain miRNA profiles, aged (18-20 months) C57BL/6 male mice were utilized. Three days following a 60-minute transient right middle cerebral artery occlusion (MCAO), mice were randomly assigned to pair housing (PH) or single housing (SI). At post-stroke timepoints (specifically day 3 after the stroke), the infarct was equal between groups, reducing the possibility of differential effects resulting from different infarct sizes. At two-time intervals (post-stroke SI D4 and D27), temporal miRNA profiling of the ipsilateral hemisphere was performed. Results: Distinct miRNA candidates were significantly altered in post-stroke SI, within the brain across both acute and chronic time points (n=4/grp, FDR adjusted *p<0.05). MiR-10a-5p and miR-10b-5p were observed to have crucial nodes in the pool of miRNAs that interacted with the largest group of miRNAs for post-stroke at SI D4 and D27, respectively. KEGG pathway analysis showed 4 days of isolation resulted in the enrichment of pathways related to microglial activation and 27 days of isolation lead to the activation of neuronal-specific pathways that regulate cognition and motivation (FDR adjusted *p<0.05). At post-stroke SI D4, significant microglial activation was observed in independent validation cohorts as assessed by the median fluorescence intensity (MFI) of purinergic receptor P2Y12 (P2RY12), in CD45 int CD11b + P2RY12 + cells in the brain. MFI of P2RY12 was significantly downregulated in post-stroke SI mice at D4 (n=7-8/grp, *p<0.05) compared to PH mice. Conclusions: These findings validate our hypothesis that post-stroke SI exacerbates microglia activation and leads to differential expression of miRNAs involved in regulating microglial pathways. Taken together, utilizing miRNA-based therapies to restore miRNA-profiles in the brain may be able to alleviate the detrimental impact of post-stroke SI on chronic depressive-like phenotypes.