They Saw a Debate: Political Polarization Is Associated with Greater Multivariate Neural Synchrony When Viewing the Opposing Candidate Speak.

With rampant polarization in current U.S. politics, it seems as though political partisans with opposing viewpoints are living in parallel realities. Indeed, prior research shows that people's impressions/attitudes toward political candidates are intertwined with their political affiliation. The current study investigated the relationship between political affiliation and intersubject neural synchrony of multivariate patterns of activity during naturalistic viewing of a presidential debate. Before the 2016 U.S. presidential election, 20 individuals varying in political affiliation underwent functional neuroimaging while watching the first debate between candidates Hillary Clinton and Donald Trump. Pairs of participants with more polarized political affiliations were higher in neural synchrony in a system of brain regions involved in self-referential processing when viewing the opposing candidate speak compared with that candidate's supporters regardless of which extreme of the political spectrum they occupied. Moreover, pairs of political partisans matching in the candidate they supported were higher in neural synchrony when watching the candidate they opposed compared with the one they both supported. These findings suggest that political groups' shared understanding may be driven more by perceptions of outgroups than of their own party/candidates.

Accessory subunits are integral for assembly and function of human mitochondrial complex I.

Complex I (NADH:ubiquinone oxidoreductase) is the first enzyme of the mitochondrial respiratory chain and is composed of 45 subunits in humans, making it one of the largest known multi-subunit membrane protein complexes. Complex I exists in supercomplex forms with respiratory chain complexes III and IV, which are together required for the generation of a transmembrane proton gradient used for the synthesis of ATP. Complex I is also a major source of damaging reactive oxygen species and its dysfunction is associated with mitochondrial disease, Parkinson's disease and ageing. Bacterial and human complex I share 14 core subunits that are essential for enzymatic function; however, the role and necessity of the remaining 31 human accessory subunits is unclear. The incorporation of accessory subunits into the complex increases the cellular energetic cost and has necessitated the involvement of numerous assembly factors for complex I biogenesis. Here we use gene editing to generate human knockout cell lines for each accessory subunit. We show that 25 subunits are strictly required for assembly of a functional complex and 1 subunit is essential for cell viability. Quantitative proteomic analysis of cell lines revealed that loss of each subunit affects the stability of other subunits residing in the same structural module. Analysis of proteomic changes after the loss of specific modules revealed that ATP5SL and DMAC1 are required for assembly of the distal portion of the complex I membrane arm. Our results demonstrate the broad importance of accessory subunits in the structure and function of human complex I. Coupling gene-editing technology with proteomics represents a powerful tool for dissecting large multi-subunit complexes and enables the study of complex dysfunction at a cellular level.

Hypoxic Pulmonary Vasoconstriction Does Not Explain All Regional Perfusion Redistribution in Asthma.

RATIONALE: Regional hypoventilation in bronchoconstricted patients with asthma is spatially associated with reduced perfusion, which is proposed to result from hypoxic pulmonary vasoconstriction (HPV). OBJECTIVES: To determine the role of HPV in the regional perfusion redistribution in bronchoconstricted patients with asthma. METHODS: Eight patients with asthma completed positron emission tomographic/computed tomographic lung imaging at baseline and after bronchoconstriction, breathing either room air or 80% oxygen (80% O2) on separate days. Relative perfusion, specific ventilation (sV), and gas fraction (Fgas) in the 25% of the lung with the lowest specific ventilation (sVlow) and the remaining lung (sVhigh) were quantified and compared. MEASUREMENTS AND MAIN RESULTS: In the sVlow region, bronchoconstriction caused a significant decrease in sV under both room air and 80% O2 conditions (baseline vs. bronchoconstriction, mean ± SD, 1.02 ± 0.20 vs. 0.35 ± 0.19 and 1.03 ± 0.20 vs. 0.32 ± 0.16, respectively; P < 0.05). In the sVlow region, relative perfusion decreased after bronchoconstriction under room air conditions and also, to a lesser degree, under 80% O2 conditions (1.02 ± 0.19 vs. 0.72 ± 0.08 [P < 0.001] and 1.08 ± 0.19 vs. 0.91 ± 0.12 [P < 0.05], respectively). The Fgas increased after bronchoconstriction under room air conditions only (0.99 ± 0.04 vs. 1.00 ± 0.02; P < 0.05). The sVlow subregion analysis indicated that some of the reduction in relative perfusion after bronchoconstriction under 80% O2 conditions occurred as a result of the presence of regional hypoxia. However, relative perfusion was also significantly reduced in sVlow subregions that were hyperoxic under 80% O2 conditions. CONCLUSIONS: HPV is not the only mechanism that contributes to perfusion redistribution in bronchoconstricted patients with asthma, suggesting that another nonhypoxia mechanism also contributes. We propose that this nonhypoxia mechanism may be either direct mechanical interactions and/or unidentified intercellular signaling between constricted airways, the parenchyma, and the surrounding vasculature.

Recreational drug use and chemsex among HIV-infected in-patients: a unique screening opportunity.

OBJECTIVES: While a high rate of recreational drug use (RDU) has been documented among HIV-infected out-patients, particularly in men who have sex with men (MSM), there is a distinct lack of data for HIV-infected in-patients. Hospital admission offers a unique opportunity to engage drug users. We aimed to establish and characterize RDU among new admissions to a large dedicated London HIV in-patient unit and compare it to RDU among general medical admissions to inform clinical pathways. METHODS: A prospective opt-out survey was administered to all new HIV-positive admissions over a 10-week period (cases) and all medical Acute Assessment Unit admissions over two 24-h periods (controls). All provided consent for urine toxicology upon admission. RESULTS: Data were collected in 59 of 65 (91%) newly admitted HIV-positive individuals and in 48 of 54 (89%) non-HIV-positive medical admissions. HIV-infected in-patients were more likely than non-HIV-positive medical admissions to be male (P < 0.0001) (71% MSM), to be younger (P < 0.0001), to report current RDU (41 vs. 10%, respectively; P = 0.0001), to have a positive urine toxicology screen (19 vs. 2%, respectively; P = 0.0091) and to be a drug-related admission (15% vs. none; P = 0.004). Thirteen of 26 HIV-infected current recreational drug users admitted to sexualized drug taking and nine to injecting drugs. Twenty-seven per cent (seven of 26) were known to drug services. Crystal methamphetamine, mephedrone, gamma butyrolactone/gamma hydroxybutyrate and ketamine were exclusively taken by MSM. In total, 13 of 59 HIV-infected in-patients had current or past infection with hepatitis C virus, of whom 92% reported lifetime drug use. CONCLUSIONS: These data strongly support the use of formal screening and drug service referral pathways at the time of admission to hospital to engage HIV-positive drug users.

Sequential Revision of Belief, Trust Type, and the Order Effect.

Objective To investigate how people's sequential adjustments to their position are impacted by the source of the information. Background There is an extensive body of research on how the order in which new information is received affects people's final views and decisions as well as research on how they adjust their views in light of new information. Method Seventy college-aged students, 60% of whom were women, completed one of eight different randomly distributed booklets prepared to create the eight different between-subjects treatment conditions created by crossing the two levels of information source with the four level of order conditions. Based on the information provided, participants estimated the probability of an attack, the dependent measure. Results Confirming information from an expert intelligence officer significantly increased the attack probability from the initial position more than confirming information from a longtime friend. Conversely, disconfirming information from a longtime friend decreased the attack probability significantly more than the same information from an intelligence officer. Conclusion It was confirmed that confirming and disconfirming evidence were differentially affected depending on information source, either an expert or a close friend. The difference appears to be due to the existence of two kinds of trust: cognitive-based imbued to an expert and affective-based imbued to a close friend. Application Purveyors of information need to understand that it is not only the content of a message that counts but that other forces are at work such as the order in which information is received and characteristics of the information source.

Identifying undiagnosed HIV in men who have sex with men (MSM) by offering HIV home sampling via online gay social media: a service evaluation.

BACKGROUND: An estimated one in eight men who have sex with men (MSM) in London lives with HIV, of which 16% are undiagnosed. It is a public health priority to minimise time spent undiagnosed and reduce morbidity, mortality and onward HIV transmission. 'Dean Street at Home' provided an online HIV risk self-assessment and postal home HIV sampling service aimed at hard-to-reach, high-risk MSM. OBJECTIVES: This 2-year service evaluation aims to determine the HIV risk behaviour of users, the uptake of offer of home sampling and the acceptability of the service. METHODS: Users were invited to assess their HIV risk anonymously through messages or promotional banners on several gay social networking websites. Regardless of risk, they were offered a free postal HIV oral fluid or blood self-sampling kit. Reactive results were confirmed in clinic. A user survey was sent to first year respondents. RESULTS: 17 361 respondents completed the risk self-assessment. Of these, half had an 'identifiable risk' for HIV and a third was previously untested. 5696 test kits were returned. 121 individuals had a reactive sample; 82 (1.4% of returned samples) confirmed as new HIV diagnoses linked to care; 14 (0.25%) already knew their diagnosis; and 14 (0.25%) were false reactives. The median age at diagnosis was 38; median CD4 505 cells/µL and 20% were recent infections. 61/82 (78%) were confirmed on treatment at the time of writing. The post-test email survey revealed a high service acceptability rate. CONCLUSIONS: The service was the first of its kind in the UK. This evaluation provides evidence to inform the potential roll-out of further online strategies to enhance community HIV testing.

Vacuum pressure generation via microfabricated converging-diverging nozzles for operation of automated pneumatic logic.

Microfluidic devices with integrated pneumatic logic enable automated fluid handling without requiring external control instruments. These chips offer the additional advantage that they may be powered by vacuum and do not require an electricity source. This work describes a microfluidic converging-diverging (CD) nozzle optimized to generate vacuum at low input pressures, making it suitable for microfluidic applications including powering integrated pneumatic logic. It was found that efficient vacuum pressure was generated for high aspect ratios of the CD nozzle constriction (or throat) width to height and diverging angle of 3.6(o). In specific, for an inlet pressure of 42.2 psia (290.8 kPa) and a volumetric flow rate of approximately 1700 sccm, a vacuum pressure of 8.03 psia (55.3 kPa) was generated. To demonstrate the capabilities of our converging - diverging nozzle device, we connected it to a vacuum powered peristaltic pump driven by integrated pneumatic logic and obtained tunable flow rates from 0 to 130 µL/min. Finally, we demonstrate a proof of concept system for use where electricity and vacuum pressure are not readily available by powering a CD nozzle with a bicycle tire pump and pressure regulator. This system is able to produce a stable vacuum sufficient to drive pneumatic logic, and could be applied to power automated microfluidics in limited resource settings.

Pneumatic oscillator circuits for timing and control of integrated microfluidics.

Frequency references are fundamental to most digital systems, providing the basis for process synchronization, timing of outputs, and waveform synthesis. Recently, there has been growing interest in digital logic systems that are constructed out of microfluidics rather than electronics, as a possible means toward fully integrated laboratory-on-a-chip systems that do not require any external control apparatus. However, the full realization of this goal has not been possible due to the lack of on-chip frequency references, thus requiring timing signals to be provided from off-chip. Although microfluidic oscillators have been demonstrated, there have been no reported efforts to characterize, model, or optimize timing accuracy, which is the fundamental metric of a clock. Here, we report pneumatic ring oscillator circuits built from microfluidic valves and channels. Further, we present a compressible-flow analysis that differs fundamentally from conventional circuit theory, and we show the utility of this physically based model for the optimization of oscillator stability. Finally, we leverage microfluidic clocks to demonstrate circuits for the generation of phase-shifted waveforms, self-driving peristaltic pumps, and frequency division. Thus, pneumatic oscillators can serve as on-chip frequency references for microfluidic digital logic circuits. On-chip clocks and pumps both constitute critical building blocks on the path toward achieving autonomous laboratory-on-a-chip devices.

A Macro-to-Micro Interface for the Control of Cellular Organization.

The spatial organization of cellular communities plays a fundamental role in determining intercellular communication and emergent behavior. However, few tools exist to modulate tissue organization at the scale of individual cells, particularly in the case of dynamic manipulation. Micromechanical reconfigurable culture achieves dynamic control of tissue organization by culturing adherent cells on microfabricated plates that can be shifted to reorganize the arrangement of the cells. While biological studies utilizing this approach have been previously reported, this paper focuses on the engineering of the device, including the mechanism for translating manual manipulation to precise microscale position control, fault-tolerant design for manufacture, and the synthetic-to-living interface.

Microfluidic serial dilution ladder.

Serial dilution is a fundamental procedure that is common to a large number of laboratory protocols. Automation of serial dilution is thus a valuable component for lab-on-a-chip systems. While a handful of different microfluidic strategies for serial dilution have been reported, approaches based on continuous flow mixing inherently consume larger amounts of sample volume and chip real estate. We employ valve-driven circulatory mixing to address these issues and also introduce a novel device structure to store each stage of the dilution process. The dilution strategy is based on sequentially mixing the rungs of a ladder structure. We demonstrate a 7-stage series of 1 : 1 dilutions with R(2) equal to 0.995 in an active device area of 1 cm(2).

Microfabrication of High-Resolution Porous Membranes for Cell Culture.

Microporous membranes are widely utilized in cell biology to study cell-cell signaling and cell migration. However, the thickness and low porosity of commercial track-etched membranes limit the quality of cell imaging and the degree of cell-cell contact that can be achieved on such devices. We employ photolithography-based microfabrication to achieve porous membranes with pore diameter as small as 0.9 µm, up to 40% porosity, and less than 5% variation in pore size. Through the use of a soap release layer, membranes as thin as 1 µm can be achieved. The thin membranes minimally disrupt contrast enhancement optics, thus allowing good quality imaging of unlabeled cells under white light, unlike commercial membranes. In addition, the polymer membrane materials display low autofluorescence even after patterning, facilitating high quality fluorescence microscopy. Finally, confocal imaging suggests that substantial cell-cell contact is possible through the pores of these thin membranes. This membrane technology can enhance existing uses of porous membranes in cell biology as well as enable new types of experiments.

Reducing Uncertainty Through Mutual Information in Structural and Systems Biology.

Systems biology models are useful models of complex biological systems that may require a large amount of experimental data to fit each model's parameters or to approximate a likelihood function. These models range from a few to thousands of parameters depending on the complexity of the biological system modeled, potentially making the task of fitting parameters to the model difficult - especially when new experimental data cannot be gathered. We demonstrate a method that uses structural biology predictions to augment systems biology models to improve systems biology models' predictions without having to gather more experimental data. Additionally, we show how systems biology models' predictions can help evaluate novel structural biology hypotheses, which may also be expensive or infeasible to validate.

Required Mental Health Evaluation Before Initiating Gender-Affirming Hormones: Trans and Nonbinary Perspectives.

Purpose: Gender-affirming hormones (hormones)-the use of sex hormones to induce desired secondary sex characteristics in transgender and nonbinary (TGNB) individuals-are vital health care for many TGNB people. Some hormone providers require a letter from a mental health provider before hormone initiation. We explore the perspectives of TGNB individuals regarding the impact of the letter requirement on their experience of care. Methods: We conducted semistructured interviews with 21 TGNB individuals who have sought or are receiving hormones. We purposively sampled respondents who were (n=12) and were not (n=8) required to provide a letter. An Advisory Board of transgender individuals guided the methodology. Interviews were transcribed verbatim and coded both inductively and deductively. Results: We identified three themes related to the letter requirement: (1) Mental health: While participants appreciated the importance of therapy, the letter requirement did not serve this purpose; (2) Trans identity: The process of obtaining a letter created doubt in participants' own transness, along with a resistance to the pathologization and conflation of mental illness with transness; and (3) Care relationships: The letter requirement negatively impacted the patient-provider relationship. Participants felt the need to self-censor or to perform a version of transness they thought the provider expected; this process decreased their trust in care professionals. Conclusion: A letter requirement did not improve mental health and had several negative consequences. Removal of this requirement will improve access to hormones and may paradoxically improve mental health.

Fibroblasts influence muscle progenitor differentiation and alignment in contact independent and dependent manners in organized co-culture devices.

Myoblasts are precursor muscle cells that lie nascent to mature skeletal muscle. Once muscle is damaged, these cells migrate, fuse, and regenerate the muscle tissue. It is known that skeletal muscle can partially regenerate in vivo after muscle tissue damage. However, this regeneration does not always occur, especially in more severe injuries. Cellular therapy using tissue-engineering approaches has been shown to improve organ repair and function. To exploit potential benefits of using cell therapy as an avenue for skeletal muscle repair, it is important to understand the cellular dynamics underlying skeletal myocyte formation and growth. Cardiac fibroblasts have been shown to have a major influence on cardiomyocyte function, repair, and overall spatial distribution. However, little is known regarding fibroblasts' role on skeletal myocyte function. In this study, we utilized a reconfigurable co-culture device to understand the contact and paracrine effects of fibroblasts on skeletal myocyte alignment and differentiation using murine myoblast and fibroblast cell lines. We demonstrate that myotube alignment is increased by direct contact with fibroblasts, while myotube differentiation is reduced both in the gap and contact configurations with fibroblasts after 6 days of co-culture. Furthermore, neutralizing antibodies to FGF-2 can block these effects of fibroblasts on myotube differentiation and alignment. Finally, bi-directional signaling is critical to the observed myoblast-fibroblast interactions, since conditioned media could not reproduce the same effects observed in the gap configuration. These findings could have direct implications on cell therapies for repairing skeletal muscle, which have only utilized skeletal myoblasts or stem cell populations alone.

Stochastic Gradient Bayesian Optimal Experimental Designs for Simulation-based Inference.

Simulation-based inference (SBI) methods tackle complex scientific models with challenging inverse problems. However, SBI models often face a significant hurdle due to their non-differentiable nature, which hampers the use of gradient-based optimization techniques. Bayesian Optimal Experimental Design (BOED) is a powerful approach that aims to make the most efficient use of experimental resources for improved inferences. While stochastic gradient BOED methods have shown promising results in high-dimensional design problems, they have mostly neglected the integration of BOED with SBI due to the difficult non-differentiable property of many SBI simulators. In this work, we establish a crucial connection between ratio-based SBI inference algorithms and stochastic gradient-based variational inference by leveraging mutual information bounds. This connection allows us to extend BOED to SBI applications, enabling the simultaneous optimization of experimental designs and amortized inference functions. We demonstrate our approach on a simple linear model and offer implementation details for practitioners.

Pneumatic computers for embedded control of microfluidics.

Alternative computing approaches that interface readily with physical systems are well suited for embedded control of those systems. We demonstrate finite state machines implemented as pneumatic circuits of microfluidic valves and use these controllers to direct microfluidic liquid handling procedures on the same chip. These monolithic integrated systems require only power to be supplied externally, in the form of a vacuum source. User input can be provided directly to the chip by covering pneumatic ports with a finger. State machines with up to four bits of state memory are demonstrated, and next-state combinational logic can be fully reprogrammed by changing the hole-punch pattern on a membrane in the chip. These pneumatic computers demonstrate a framework for the embedded control of physical systems and open a path to stand-alone lab-on-a-chip devices capable of highly complex functionality.

PIEZO1-HaloTag hiPSCs: Bridging Molecular, Cellular and Tissue Imaging.

PIEZO1 channels play a critical role in numerous physiological processes by transducing diverse mechanical stimuli into electrical and chemical signals. Recent studies underscore the importance of endogenous PIEZO1 activity and localization in regulating mechanotransduction. To enable physiologically and clinically relevant human-based studies, we genetically engineered human induced pluripotent stem cells (hiPSCs) to express a HaloTag fused to endogenous PIEZO1. Combined with super-resolution imaging, our chemogenetic approach allows precise visualization of PIEZO1 in various cell types. Further, the PIEZO1-HaloTag hiPSC technology allows non-invasive monitoring of channel activity via Ca2+-sensitive HaloTag ligands, with temporal resolution approaching that of patch clamp electrophysiology. Using lightsheet imaging of hiPSC-derived neural organoids, we also achieve molecular scale PIEZO1 imaging in three-dimensional tissue samples. Our advances offer a novel platform for studying PIEZO1 mechanotransduction in human cells and tissues, with potential for elucidating disease mechanisms and development of targeted therapeutics.

Pyoderma gangrenosum-like ulcer caused by Helicobacter cinaedi in a patient with x-linked agammaglobulinaemia.

Cutaneous lesions of the legs have been linked to Helicobacter species in a number of patients with X-linked agammaglobulinaemia (XLA), a primary immunodeficiency. We describe a 26-year-old patient with XLA, who was referred with an extensive skin ulcer that enlarged gradually over the course of 7 years. The ulcer resembled pyoderma gangrenosum (PG), and extended from below the knee to the ankle. The man (who has sex with men) was negative for human immunodeficiency virus. Helicobacter cinaedi was identified by 16S ribosomal (r)DNA PCR analysis from a biopsy of the lesion. This fastidious organism has been implicated previously in causing unexplained skin macules in one other patient with XLA. We suggest that early consideration of infection with Helicobacter species in immunocompromised patients who present with unexplained cutaneous lesions is important, as a prolonged antibiotic course can lead to clinical improvement.

Fabrication of Multilayer Molds by Dry Film Photoresist.

Dry film photoresists are widely employed to fabricate high-aspect-ratio microstructures, such as molds for microfluidic devices. Unlike liquid resists, such as SU-8, dry films do not require a cleanroom facility, and it is straightforward to prepare uniform and reproducible films as thick as 500 µm. Multilayer patterning, however, can be problematic with dry film resists even though it is critical for a number of microfluidic devices. Layer-to-layer mask alignment typically requires the first layer to be fully developed, making the pattern visible, before applying and patterning the second layer. While a liquid resist can flow over the topography of previous layers, this is not the case with dry film lamination. We found that post-exposure baking of dry film photoresists can preserve a flat topography while revealing an image of the patterned features that is suitable for alignment to the next layer. We demonstrate the use of this technique with two different types of dry film resist to fabricate master molds for a hydrophoresis size-sorting device and a cell chemotaxis device.

Phase-Optimized Peristaltic Pumping by Integrated Microfluidic Logic.

Microfluidic droplet generation typically entails an initial stabilization period on the order of minutes, exhibiting higher variation in droplet volume until the system reaches monodisperse production. The material lost during this period can be problematic when preparing droplets from limited samples such as patient biopsies. Active droplet generation strategies such as antiphase peristaltic pumping effectively reduce stabilization time but have required off-chip control hardware that reduces system accessibility. We present a fully integrated device that employs on-chip pneumatic logic to control phase-optimized peristaltic pumping. Droplet generation stabilizes in about a second, with only one or two non-uniform droplets produced initially.