Control Mechanisms Research Articles

Wirelessly Actuated Microfluidic Pump and Valve for Controlled Liquid Delivery in Dental Implants.

Enabling minimally invasive and precise control of liquid release in dental implants is crucial for therapeutic functions such as delivering antibiotics to prevent biofilm formation, infusing stem cells to promote osseointegration, and administering other biomedicines. However, achieving controllable liquid cargo release in dental implants remains challenging due to the lack of wireless and miniaturized fluidic control mechanisms. Here wireless miniature pumps and valves that allow remote activation of liquid cargo delivery in dental implants, actuated and controlled by external magnetic fields (<65 mT), are reported. A magnet-screw mechanism in a fluidic channel to function as a piston pump, alongside a flexible magnetic valve designed to open and close the fluidic channel, is proposed. The mechanisms are showcased by storing and releasing of liquid up to 52µL in a dental implant. The liquid cargos are delivered directly to the implant-bone interface, a region traditionally difficult to access. On-demand liquid delivery is further showed by a metal implant inside both dental phantoms and porcine jawbones. The mechanisms are promising for controllable liquid release after implant placement with minimal invasion, paving the way for implantable devices that enable long-term and targeted delivery of therapeutic agents in various bioengineering applications.

DNA stable isotope probing reveals the impact of trophic interactions on bioaugmentation of soils with different pollution histories

BackgroundBioaugmentation is considered a sustainable and cost-effective methodology to recover contaminated environments, but its outcome is highly variable. Predation is a key top-down control mechanism affecting inoculum establishment, however, its effects on this process have received little attention. This study focused on the impact of trophic interactions on bioaugmentation success in two soils with different pollution exposure histories. We inoculated a 13C-labelled pollutant-degrading consortium in these soils and tracked the fate of the labelled biomass through stable isotope probing (SIP) of DNA. We identified active bacterial and eukaryotic inoculum-biomass consumers through amplicon sequencing of 16S rRNA and 18S rRNA genes coupled to a novel enrichment factor calculation.ResultsInoculation effectively increased PAH removal in the short-term, but not in the long-term polluted soil. A decrease in the relative abundance of the inoculated genera was observed already on day 15 in the long-term polluted soil, while growth of these genera was observed in the short-term polluted soil, indicating establishment of the inoculum. In both soils, eukaryotic genera dominated as early incorporators of 13C-labelled biomass, while bacteria incorporated the labelled biomass at the end of the incubation period, probably through cross-feeding. We also found different successional patterns between the two soils. In the short-term polluted soil, Cercozoa and Fungi genera predominated as early incorporators, whereas Ciliophora, Ochrophyta and Amoebozoa were the predominant genera in the long-term polluted soil.ConclusionOur results showed differences in the inoculum establishment and predator community responses, affecting bioaugmentation efficiency. This highlights the need to further study predation effects on inoculum survival to increase the applicability of inoculation-based technologies.9HmCi-USiFQRck8tFgyMqrVideo

Real-Time Monitoring of mtDNA Aggregation and Mitophagy Induced by a Fluorescent Platinum Complex in Living Cells.

Mitochondrial DNA (mtDNA) is pivotal for mitochondrial morphology and function. Upon mtDNA damage, mitochondria undergo quality control mechanisms, including fusion, fission, and mitophagy. Real-time monitoring of mtDNA enables a deeper understanding of its effect on mitochondrial function and morphology. Controllable induction and real-time tracking of mtDNA dynamics and behavior are of paramount significance for studying mitochondrial function and morphology, facilitating a deeper understanding of mitochondria-related diseases. In this work, a fluorescent platinum complex was designed and developed that not only induces mitochondrial DNA (mtDNA) aggregation but also triggers mitochondrial autophagy (mitophagy) through the MDV pathway for damaged mtDNA clearance in living cells. Additionally, this complex allows for the real-time monitoring of these processes. This complex may serve as a valuable tool for studying mitochondrial microautophagy and holds promise for broader applications in cellular imaging and disease research.

Mathematical analysis of a non‐convex optimal control problem for age‐structured mosquito populations

We present a rigorous mathematical analysis of a non‐convex optimal control problem for mosquito populations. The nonlinear model for the dynamics of the mosquito population takes in consideration the iterations among the immature (aquatic) subpopulation, the adult winged subpopulation, and the environment resources; the immature subpopulation is assumed to be age‐structured. Moreover, the action of certain control mechanisms on these subpopulations is also taken in account. The cost functional to be minimized is non‐convex. The proof of the existence of an optimal control is done by using fixed point arguments and a special minimizing sequence obtained with the help of Ekeland's variational principle.

In Palantir we trust? Regulation of data analysis platforms in public security

Organizations increasingly rely on digital technologies to perform tasks. To do so, they have to integrate data banks to make the data usable. We argue that there is a growing, academically underexplored market consisting of data integration and analysis platforms. We explain that, especially in the public sector, the regulatory implications of data integration and analysis must be studied because they affect vulnerable citizens and because it is not just a matter of state agencies overseeing technology companies but also of the state overseeing itself. We propose a platform-theory-based conceptual approach that directs our attention towards the specific characteristics of platforms—such as datafication, modularity, and multilaterality and the associated regulatory challenges. Due to a scarcity of empirical analyses about how public sector platforms are regulated, we undertake an in-depth case study of a data integration and analysis platform operated by Palantir Technologies in the German federal state of Hesse. Our analysis of the regulatory activities and conflicts uncovers many obstacles to effective platform regulation. Drawing on recent initiatives to improve intermediary liability, we ultimately point to additional paths for regulating public sector platforms. Our findings also highlight the importance of political factors in platform regulation-as-a-practice. We conclude that platform regulation in the public sector is not only about technology-specific regulation but also about general mechanisms of democratic control, such as the separation of power, public transparency, and civil rights.

Smart hydrogel composite for microenvironmental humidity regulation in cigar storage.

Environmental humidity profoundly influences various life activities, especially for plants that depend heavily on optimal humidity for growth. The humidity index is particularly crucial for preserving the functionality of plant leaves, notably in economically valuable plants such as cigar tobacco. This paper introduces a novel dual-layer moisturizing material, a PAS-PDMS composite, based on polyacrylamide/solketal (PAS) hydrogel and polydimethylsiloxane (PDMS). This material features a unique hierarchical water release mechanism. Comprehensive analyses, including thermogravimetric analysis, Fourier-transform infrared spectroscopy, low-field nuclear magnetic resonance, and dynamic water adsorption studies, confirm the water migration and humidity control mechanisms of the PAS-PDMS composite. This smart hydrogel composite regulates microenvironmental humidity bidirectionally. When applied to cigar boxes for storage, it stabilizes internal humidity at approximately 65%, maintaining this level for over 20 days. Furthermore, the PAS-PDMS composite exhibits superior mechanical properties and light transmittance, achieving an exceptional transmittance of 84%. In conclusion, the PAS-PDMS composite offers intelligent humidity control, providing a novel approach to the storage and preservation of cigars.

Change in Endogenous Pain Modulation Depending on Emotional States in Healthy Subjects: A Randomized Controlled Trial.

Chronic pain is a public health issue, leading to substantial healthcare costs and diminished quality of life for sufferers. While the role of anxiety in pain modulation has been extensively studied, the effects of other emotional states on the body's pain control mechanisms remain less understood. This study sought to explore how different emotions (happiness, anger, sadness, and interest) affect conditioned pain modulation (CPM) and the wind-up phenomenon in healthy adults. This randomized controlled, cross-over trial involved 28healthy participants aged 18-60. Participants watched video clips designed to induce specific emotions: happiness, anger, sadness, and interest. Emotional states were assessed using a 7-point Likert scale. Pain modulation was measured using CPM and the wind-up phenomenon. CPM was assessed with a hot water bath as the conditioning stimulus and pressure pain tolerance as the test stimulus. Wind-up was measured using pinprick needle stimulators and a visual analog scale. Data were analyzed using paired ttests to compare pre- and post-emotion induction values. Significant changes in emotional self-assessment values were observed for all emotions. Happiness increased CPM (4.6 ± 11.4, p = 0.04277), while sadness - 9.9 ± 23.1, p = 0.03211) and anger - 9.1 ±23.3, p = 0.04804) decreased it. Interest did not significantly alter CPM (- 5.1 ± 25.8, p = 0.31042). No significant effects were found for the wind-up phenomenon across any emotional states. This study shows that emotional states significantly affect the body's ability to modulate pain. Positive emotions like happiness enhance pain inhibition, while negative emotions such as sadness and anger impair it. These findings suggest that emotional modulation techniques could be integrated into pain management strategies to improve patient outcomes. Further research should explore a broader range of emotions and include objective measures to validate these results.

Strategies for communicating and mitigating algorithmic control on delivery platforms

Delivery platforms use algorithmic control mechanisms to control couriers’ work. Despite studies looking at how algorithmic control manifests on different delivery platforms, there is a dearth of research exploring how delivery platforms communicate their approaches to algorithmic control, what kinds of strategies delivery workers adopt to mitigate algorithmic control, and to what extent information regarding such ‘algoactivistic approaches’ is shared among communities of delivery couriers who in many cases are in direct competition with one another. To that end, two studies are conducted. Study 1 analyses five publicly listed delivery companies’ annual reports ( n = 14), highlighting a lack of transparency on how the platforms’ algorithms function. In Study 2, a netnographic approach is used to conduct interviews ( n = 12) and a qualitative analysis of delivery workers’ online discussion forum posts ( n = 830) on the discussion forum Reddit. Four approaches to mitigating algorithmic control are found, and the way these are shared among couriers is considered.

Public art’s counter-temporalities, the case of the Garden Library, south Tel Aviv

In research on public art, there is a tendency to link art’s transformative potentialities to its temporal dimensions, namely duration, rhythm and the type of social relations they produce. However, beyond acknowledgement of what it might do, temporality received little conceptual attention. Using The Garden Library as a case study, this article foregrounds temporality as a theoretical and methodological framework to examine public art’s performative and structural patterns. The Garden Library is a multi-lingual and cultural space for refugees and migrant workers founded by the art group Arteam in the southern neighbourhood Neve Sha’anan, Tel Aviv in 2009. This article traces the project’s changing temporalities and considers how they create an inclusive time-space that is largely unavailable for the migrant communities living in Israel. It largely draws from art history and human geography scholarship to conceptualise time and temporality in relation to space, practice, and displacement and to further deepen our understating of the unique modes of knowledge and socio-political critique public art enables. The article also brings forth the entanglement of multiple oppressed temporalities, including native Palestinians and non-Jewish refugees, and reads the Garden Library against the background of Israel’s settler-colonial and ethnocratic state. Centring temporality, therefore, has two goals. The first is to examine the usage of time, alongside space, as a control mechanism and to draw links between shared experiences of dislocation and dispossession that are often studied separately. The second is to amplify the occasional collisions and intersections of marginalised temporal landscapes, including that of the Mizrahi (Arab-Jews) working class residents of Neve Sha’anan, and the possibility of such moments to produce counter-temporalities that adjust and resist forms of spatio-temporal power.

NMDtxDB: Data-driven identification and annotation of human NMD target transcripts.

The nonsense-mediated RNA decay (NMD) pathway is a crucial mechanism of mRNA quality control. Current annotations of NMD substrate RNAs are rarely data-driven, but use general established rules. We present a dataset with 4 cell lines and combinations for SMG5, SMG6 and SMG7 knockdowns or SMG7 knockout. Based on this dataset, we implemented a workflow that combines Nanopore and Illumina sequencing to assemble a transcriptome, which is enriched for NMD target transcripts. Moreover, we use coding sequence information from Ensembl, Gencode consensus RiboSeq ORFs and OpenProt to enhance the CDS annotation of novel transcript isoforms. In summary, 302,889 transcripts were obtained from the transcriptome assembly process, out of which, 24% are absent from Ensembl database annotations, 48,213 contain a premature stop codon and 6,433 are significantly upregulated in three or more comparisons of NMD active vs deficient cell lines. We present an in-depth view on these results through the NMDtxDB database, which is available at https://shiny.dieterichlab.org/app/NMDtxDB, and supports the study of NMD-sensitive transcripts. We open sourced our implementation of the respective web-application and analysis workflow at https://github.com/dieterich-lab/NMDtxDB and https://github.com/dieterich-lab/nmd-wf.

RNF149 Destabilizes IFNGR1 in Macrophages to Favor Postinfarction Cardiac Repair.

Macrophage-driven inflammation critically involves in cardiac injury and repair following myocardial infarction (MI). However, the intrinsic mechanisms that halt the immune response of macrophages, which is critical to preserve homeostasis and effective infarct repair, remain to be fully defined. Here, we aimed to determine the ubiquitination-mediated regulatory effects on averting exaggerated inflammatory responses in cardiac macrophages. We used transcriptome analysis of mouse cardiac macrophages and bone marrow-derived macrophages to identify the E3 ubiquitin ligase RNF149 (ring finger protein 149) as a modulator of macrophage response to MI. Employing loss-of-function methodologies, bone marrow transplantation approaches, and adenovirus-mediated RNF149 overexpression in macrophages, we elucidated the functional role of RNF149 in MI. We explored the underlying mechanisms through flow cytometry, transcriptome analysis, immunoprecipitation/mass spectrometry analysis, and functional experiments. RNF149 expression was measured in the cardiac tissues of patients with acute MI and healthy controls. RNF149 was highly expressed in murine and human cardiac macrophages at the early phase of MI. Knockout of RNF149, transplantation of Rnf149-/- bone marrow, and bone marrow macrophage-specific RNF149-knockdown markedly exacerbated cardiac dysfunction in murine MI models. Conversely, overexpression of RNF149 in macrophages attenuated the ischemia-induced decline in cardiac contractile function. RNF149 deletion increased infiltration of proinflammatory monocytes/macrophages, accompanied by a hastened decline in reparative subsets, leading to aggravation of myocardial apoptosis and impairment of infarct healing. Our data revealed that RNF149 in infiltrated macrophages restricted inflammation by promoting ubiquitylation-dependent proteasomal degradation of IFNGR1 (interferon gamma receptor 1). Loss of IFNGR1 rescued deleterious effects of RNF149 deficiency on MI. We further demonstrated that STAT1 (signal transducer and activator of transcription 1) activation induced Rnf149 transcription, which, in turn, destabilized the IFNGR1 protein to counteract type-II IFN (interferon) signaling, creating a feedback control mechanism to fine-tune macrophage-driven inflammation. These findings highlight the significance of RNF149 as a molecular brake on macrophage response to MI and uncover a macrophage-intrinsic posttranslational mechanism essential for maintaining immune homeostasis and facilitating cardiac repair following MI.

Host-imposed control mechanisms in legume-rhizobia symbiosis.

Legumes are ecologically and economically important plants that contribute to nutrient cycling and agricultural sustainability, features tied to their intimate symbiosis with nitrogen-fixing rhizobia. Rhizobia vary dramatically in quality, ranging from highly growth-promoting to non-beneficial; therefore, legumes must optimize their symbiosis with rhizobia through host mechanisms that select for beneficial rhizobia and limit losses to non-beneficial strains. In this Perspective, we examine the considerable scientific progress made in decoding host control over rhizobia, empirically examining both molecular and cellular mechanisms and their effects on rhizobia symbiosis and its benefits. We consider pre-infection controls, which require the production and detection of precise molecular signals by the legume to attract and select for compatible rhizobia strains. We also discuss post-infection mechanisms that leverage the nodule-level and cell-level compartmentalization of symbionts to enable host control over rhizobia development and proliferation in planta. These layers of host control each contribute to legume fitness by directing host resources towards a narrowing subset of more-beneficial rhizobia.

A novel adaptive event‐triggered security consensus control mechanism for leader‐following multi‐agent systems under hybrid random cyber attacks

A novel adaptive event‐triggered security consensus control mechanism for leader‐following multi‐agent systems under hybrid random cyber attacks

Neuroscience: A bottom-up mechanism for cognitive control?

Cognitive control is often conceived of as occurring top-down, with prefrontal cortical areas exerting control over other parts of the brain. A new study demonstrates what might be considered a 'bottom-up' mechanism for cognitive control, involving the disinhibition of orbitofrontal cortex by subcortical regions.

Trust-Building Behaviors and Control Mechanisms in Hierarchical Dyads: A Grounded Model

Trust-Building Behaviors and Control Mechanisms in Hierarchical Dyads: A Grounded Model

State of Exception or the New Normal? An Evaluation of Pandemic Tracking Technologies and Their Implications for Citizenship

This article forms a critical examination of how the increased digitalization of daily life, exemplified by pandemic digital technologies of tracking apps and digital Covid-19 passports, affects ethical principles of privacy, subjectivity and autonomy, fundamental in a traditional notion of citizenship. The pandemic crisis has been an example of the increasing use of automated technologies across various domains, where society has become deeply reliant on these technologies. I argue that in ethical terms, the pandemic crisis has moved the borders of what is accepted by governments and citizens and have normalised far-reaching tools of registration, calculation, and surveillance. The pandemic state of exception has necessitated and legalised a temporary suspension of normal civil rights and replaced them with spatial ordering, automated surveillance, and the application of advanced and intrusive digital monitoring tools. Based on an empirical account of tracking apps I discuss the consequences for citizenship based on two theoretical figures: Michel Foucault´s concept of “bio-politics” and the concept of “a state of exception” as theorized by German political philosopher Carl Schmidt. Where traditional concepts of citizenships have focused on individual rights, responsibilities and articipation in civic life, bio-politics emphasizes a management and regulation of populations with less focus on individual agency and more on statistical analysis and control mechanisms. Technologies and discourses of automation are inter-related; digital innovation legitimize and strengthen an adherent automation of political logics, framed as a politics of necessity, where calculative predictions and technological facts leave little room for political subjectivity and values. In the concluding section it is discussed whether the rapid automation catalyzed by the pandemic was a state of emergency, necessitated by a pandemic threat, or rather represents a more profound change, a new normal for citizenship.

Active fault-tolerant control for asynchronous machines using EKF-based fault estimation and 3-H-bridge inverter mitigation of ITSCs

This paper introduces an active fault-tolerant control system designed to effectively detect and mitigate inter-turn short-circuit (ITSC) faults in asynchronous machines. Utilizing the extended Kalman filter, the system precisely estimates electrical parameters, including resistances and inductances, crucial for identifying such faults. By integrating these estimations into the control mechanism, the system dynamically detects, isolates, and adjusts control laws based on fault severity assessments. The proposed controller, built upon an accurate three-phase faulty model, not only addresses torque ripple issues but also incorporates a 3-H-bridge inverter to manage current imbalances, particularly in degraded operating conditions. To evaluate its efficacy and robustness, comprehensive numerical simulations were conducted using MATLAB/SIMULINK. Results validate the effectiveness of the proposed control approach in ensuring the uninterrupted safe operation of asynchronous motors, even in the presence of ITSC faults, presenting a promising solution for enhancing fault tolerance in industrial settings. Further exploration is warranted to assess its real-world applicability and potential limitations across diverse operational scenarios. This system’s implementation promises practical benefits by bolstering operational reliability and safety in industrial machinery, contributing to improved workforce safety and reduced downtime, thus offering significant social advantages.

Mechanism of active flow control using a novel spike aerodome-channel concept in the hypersonic flow: A numerical study

Among the design requirements of hypersonic vehicles, reducing aerodynamic heating and drag force simultaneously is the main challenge. This paper proposes a novel spike aerodome-channel combination concept to realize the flow field reconstruction around the hypersonic blunt body. The novel configuration is investigated in the axisymmetric flow at a Mach number of 6 at zero angle of attack. The two-dimensional Reynold-averaged Navier–Stokes equations are numerically solved, and the shear-stress transport k–ω model is the turbulence model implemented in this study. Parameters such as spike length and lateral jet location are investigated to explore the drag and heat reduction performance and the flow control features. The obtained results show that the application of the novel spike aerodome-channel concept alters the flow field by eliminating or replacing the strong bow shock wave, and the design of hypersonic vehicles can benefit from the application of the proposed concept. The blunt body coupled with a frustum of cone-tipped spike-channel configuration provides a remarkable drag reduction effect of 20.71% with respect to the case without channel. Considering the effect of lateral jet location, the drag reduction performance of the case with LR = 0.75 is superior to that of the root jet case at the same spike length, and a considerable drag reduction of 28.93% is obtained with L/D = 2.4. In addition, longer spike length is beneficial for improving drag reduction performance, while excellent efficiency of heat protection is obtained in a certain spike length range. For the case of L/D = 1.6 with root jet, the peak Stanton number is significantly decreased by 33.51%.

Septins promote macrophage pyroptosis by regulating gasdermin D cleavage and ninjurin-1-mediated plasma membrane rupture.

The septin cytoskeleton is primarily known for roles in cell division and host defense against bacterial infection. Despite recent insights, the full breadth of roles for septins in host defense is poorly understood. In macrophages, Shigella induces pyroptosis, a pro-inflammatory form of cell death dependent upon gasdermin D (GSDMD) pores at the plasma membrane and cell surface protein ninjurin-1 (NINJ1) for membrane rupture. Here, we discover that septins promote macrophage pyroptosis induced by lipopolysaccharide (LPS)/nigericin and Shigella infection, but do not affect cytokine expression or release. We observe that septin filaments assemble at the plasma membrane, and cleavage of GSDMD is impaired in septin-depleted cells. We found that septins regulate mitochondrial dynamics and the expression of NINJ1. Using a Shigella-zebrafish infection model, we show that septin-mediated pyroptosis is an invivo mechanism of infection control. The discovery of septins as a mediator of pyroptosis may inspire innovative anti-bacterial and anti-inflammatory treatments.

Macroscale brain states support the control of semantic cognition

A crucial aim in neuroscience is to understand how the human brain adapts to varying cognitive demands. This study investigates network reconfiguration during controlled semantic retrieval in differing contexts. We analyze brain responses to two semantic tasks of varying difficulty – global association and feature matching judgments – which are contrasted with non-semantic tasks on the cortical surface and within a whole-brain state space. Demanding semantic association tasks elicit activation in anterior prefrontal and temporal regions, while challenging semantic feature matching and non-semantic tasks predominantly activate posterior regions. Task difficulty also modulates activation along different dimensions of functional organization, suggesting different mechanisms of cognitive control. More demanding semantic association judgments engage cognitive control and default mode networks together, while feature matching and non-semantic tasks are skewed towards cognitive control networks. These findings highlight the brain’s dynamic ability to tailor its networks to support diverse neurocognitive states, enriching our understanding of controlled cognition.