Modeling and exact solution approaches for the distance-based critical node and edge detection problems

The performance of many networked systems including energy, telecommunication and transport networks is dependent on the functionality of a few components of these systems whose malfunction compromises optimal performance of the system. With respect to network connectivity as a performance metric, such components are termed critical nodes and edges. The optimisation problem associated with identifying critical nodes of a network is termed the critical node detection problem (CNDP). The CNDP has gained significant amount of research owing to its applicability in diverse real life problems including disaster management, social network analysis, and disease epidemiology, as well as its computational complexity. However, traditional models, whose underlying objective is to maximize network fragmentation fail to capture cohesiveness and extent of connectivity within the resultant network. Therefore, a new variant of the problem termed the distance-based critical node detection problem (DCNDP) was proposed to address this gap. The DCNDP takes into account pairwise distances between nodes as part of its network connectivity objective, which are modelled by pre-defined distance-based connectivity measure. Distance-based connectivity plays an important part in everyday life. For instance, our choice of route of travel and the cost of a flight ticket are influenced by the duration of travel and number of stopovers involved. Therefore, while a source-destination route might exist, if the duration of a trip via the route precludes attainment of a time-bound activity, then such is a practical disconnection. Similarly, in communication and telecommunication networks, speed and coverage are key operational issues for assessing connectivity which are both related to pairwise distances in the network. In this chapter, we study a generalization of the DCNDP on weighted networks, where distance between any source-destination (s-t) pair is not limited to hop distance (number of edges along an s-t path). We present a new model with fewer entities than the models in previous studies. Moreover, we show that the proposed model admits different distance-based connectivity measures, hence is valid for all existing classes of the distance-based critical node detection problem. We introduce a new version of the problem, in which edges rather than nodes are to be deleted. This version is useful for application contexts where it is impractical or too expensive to delete nodes. Furthermore, we study social and transportation networks, where we also demonstrate practical aspects of the problem. Some computational experiments on instances of different real-world networks are presented for the different application context studied using the proposed models and algorithm. The Chapter concludes with directions for future research

Mitochondria regulate inositol triphosphate‐mediated Ca 2+ release triggered by voltage‐dependent Ca 2+ entry in resistance arteries : Ca2+ entry activates IP3 receptors in smooth muscle

An increase in cytoplasmic Ca2+ concentration activates multiple cellular activities, including cell division, metabolism, growth, contraction and death. In smooth muscle Ca2+ entry via voltage-dependent Ca2+ channels leads to a relatively uniform increase in cytoplasmic Ca2+ levels that facilitates co-ordinated contraction throughout the cell. However certain functions triggered by voltage-dependent Ca2+ channels require periodic, pulsatile Ca2+ changes. The mechanism by which Ca2+ entry through voltage-dependent channels supports both co-ordinated contraction and distinct cellular responses driven by pulsatile Ca2+ changes is unclear. Here in intact resistance arteries we show that Ca2+ entry via voltage-dependent Ca2+ channels evokes Ca2+ release via inositol triphosphate receptors (IP3Rs), generating repetitive Ca2+ oscillations and waves. We also show that mitochondria play a vital role in regulating Ca2+ signals evoked by voltage-dependent Ca2+ entry by selectively modulating Ca2+ release via IP3Rs. Depolarizing the mitochondrial membrane inhibits Ca2+ release from internal stores, reducing the overall signal-generated Ca2+ influx without altering the signal resulting from voltage-dependent Ca2+ entry. Notably neither Ca2+ entry via voltage-dependent Ca2+ channels nor Ca2+ release via IP3Rs alters mitochondrial location or mitochondrial membrane potential in intact smooth muscle cells. Collectively these results demonstrate that activation of voltage-dependent Ca2+ channels drives Ca2+ entry, which subsequently triggers Ca2+ release from the internal store in smooth muscle cells. Mitochondria selectively regulate this process by modulating IP3R-mediated amplification of Ca2+ signals, ensuring that different cellular responses are precisely controlled

How do creative firms strategize creativity? : An exploratory study of haute cuisine

This empirical paper explores the process of strategizing creativity in haute cuisine, using the Hungarian Michelin-starred restaurants as a target population. Based on interviews with chefs as well as managers (owners, co-owners, whoever is “in charge” of the business side of the restaurant) from nearly all of the Hungarian Michelin-starred restaurants, we try to understand the dynamic unfolding through the interplay of potentially conflicting drives of creating and strategizing. Our work builds on a line of studies of creativity of chefs in haute cuisine, and we see this empirical paper as the logical next step. We realize through this study that creating and strategizing are even more intertwined and complex in this setting than we expected, and we identify several different archetypes of interactions, that we label based on the manager’s role as: investor, partner, and monarch

WP208: Whom do African election campaigns contact? : And does it matter?

Canvassing is an important way in which political parties around the world raise awareness and connect with voters. Despite this, the literature on parties in new democracies, and Africa in particular, has tended to overlook this form of activity, focusing instead on vote buying, mass rallies, and meetings. In this paper, we use public opinion survey data from Afrobarometer and the Comparative National Elections Project to show that overall rates of canvassing in Africa are similar to other new, as well as many established, democracies. The data also challenge several dominant views of party campaigns in the Africanist literature. First, African parties do not concentrate primarily on turning out their base, rather than reaching across the partisan divide. Indeed, the opposite is the case. African parties expend more energy contacting nonpartisan independents and opposition supporters, and thus make a potentially meaningful contribution to the supply of multiparty competition. Second, the vast majority of contacts occur without any clientelist exchanges of material goods between parties and individual voters. And third, while incumbent parties enjoy canvassing advantages over opposition parties in around one-third of the surveyed countries, opposition parties (viewed collectively) match the party in power in terms of the ground game in another third, and enjoy higher rates of contact in yet another third. At the country level, we find that people are more likely to be contacted in societies with higher rates of grassroots party structures. While parties are more likely to canvass citizens who live in neighbourhoods with good roads, they also contact at higher rates in rural, less developed, and more violent and less secure neighbourhoods. Within these neighbourhoods, parties are likely to contact citizens who are more visible in terms of their participation in community-level politics. Finally, while parties contact people who are already more likely to vote, we show that contact increases the odds of voting even further, by around one-third

A technology enriched approach to increasing rehabilitation dose after stroke : clinical feasibility study

Objective: To assess the feasibility of a multi-technology, group-based, approach to increasing rehabilitation dose early after stroke. Methods: Mixed methods design reporting recruitment, dropout, safety, dose and acceptability. Setting: Acute Hospital Stroke Unit Participants: Sixty stroke patients, 9.0 median (IQR 12.8) days after stroke, referred for rehabilitation, without contraindications to light exercise. Intervention: Personalised rehabilitation delivered in supervised groups, using a multi-technology rehabilitation gym, in addition to usual care. Main measures: Feasibility was based on achieving recruitment rates over 3.2 per month, dropout rates below 6%, absence of suspected unexpected serious adverse reactions and shoulder pain prevalence below 60%. Acceptability was derived from interviews with the clinical team. Dose (rehabilitation time) was recorded manually. Function was measured with the modified Rivermead Mobility Index and Therapy Outcome Measure. Results: Feasibility was satisfactory with high recruitment rates (6 per month), low dropout (2%), no suspected unexpected serious adverse reactions and low prevalence (19%) of shoulder pain. Thematic analysis of interview data indicated the clinical team (n=9) found the intervention acceptable and identified organisational constraints to higher doses. Participants attended an average of 9.1 (1-32) sessions during their hospital stay (23.0 days, SD 19.7), with sessions lasting 52 minutes (SD 15.7), on average. The modified Rivermead Mobility Index and Therapy Outcome Measure increased by 17.9 (SD 8.6) and 5.7 points (SD 2.4), respectively. Conclusions: Strong feasibility findings support future trials of multi-technology, group-based rehabilitation. This novel approach is an encouraging step toward achieving recommended doses of rehabilitation after stroke but needs further investigation

Presumptive tests for xylazine-a computer vision approach

Abuse of xylazine is an immediate global public health concern. We report the distinct and measurable colour changes when xylazine is exposed to the Mandelin, Marquis and Mecke presumptive test reagents. The colour changes observed with xylazine are distinct from those of drugs that give colour changes from the same presumptive tests. To overcome the subjective limitations of determining spot test results by-eye, we applied image and video analyses to quantify the distinctive features of presumptive tests with xylazine and thus differentiate it from other illicit substances tested under the same conditions, including morphine, fentanyl, heroin and methamphetamine. Herein, experimental protocols utilising Kineticolor, a computer vision software, were developed to qualitatively and quantitatively study presumptive tests for xylazine detection. To the best of our knowledge, these findings represent the first presumptive test strategy towards specific, quantifiable and potentially field-ready detection of xylazine

An acoustic isolator-type metamaterial for ultrasound attenuation at MHz frequencies

Acoustic metamaterials (AMMs) offer significant promise for ultrasound probe backing layers due to their capacity to enhance acoustic energy dissipation through tailored sub-wavelength structures. However, practical implementation remains challenging due to difficulties in reliably reproducing the micron-scale features required for MHz-frequency operation, and the lack of quality assurance processes linking design intent to fabricated performance. This work presents the evaluation of a 3D-printed acoustic isolator-type metamaterial (AI-MM) backing designed for MHz operation using a custom aluminum oxide resin. Directional transmission intensity measurements revealed frequency-dependent asymmetry in forward and backward wave propagation (in both experiments and simulations), consistent with passive acoustic isolator behavior. X-ray micro-CT imaging of AI-MM samples revealed dimensional deviations, apex rounding, and local density variation. Attenuation spectra showed that AI-MM backings consistently outperformed homogeneous controls in both simulation and experiment, with frequency-dependent trends indicating enhanced scattering and viscous losses. A local attenuation peak near 2.6 MHz was within the operational range estimated from the measured geometry (2.22–2.94 MHz), underscoring the importance of linking performance to real-world fabrication. These findings support the potential of AI-MMs as tunable passive components in ultrasound systems and highlight the need for integrated design, fabrication, and validation workflows

Scaffolding of success : support, educational equity and the lifelong reality of care experience

Transitions from care into adulthood are often a shift from dependence to independence. Yet for care-experienced individuals, this process is neither linear nor complete at a predetermined age. Despite progressive Scottish policies—such as The Promise—many still face unequal access to support. This article explores how structural and relational scaffolding can transform outcomes. Drawing on the lived and professional knowledge of three care-experienced authors, it examines how language, relationship-based practice, and support influence definitions of success. Reframing care experience as lifelong challenges systems to provide enduring, person-centered support. While research affirms the importance of responsive scaffolding, few studies center the voices of care-experienced adults in defining what effective support looks like. This article addresses that gap by placing care-experienced authors not as subjects, but as analysts and advocates. The article is based on a collaborative, care-informed reflective process. The authors adapted the Gibbs Reflective Cycle to suit a trauma-aware and relational approach. Their reflections are not anecdotal—they are critically analyzed, thematically structured, and used as evidence to interrogate systems and propose alternatives. Key findings highlight the importance of sustained relational practice, responsive educational support, and recognizing care experience as lifelong

Nebular spectra of kilonovae with detailed recombination rates. I. light r -process composition

To investigate spectra of kilonovae in the nonlocal thermal equilibrium phase (t ≳ 1 week), we perform atomic calculations for dielectronic recombination (DR) rates for the light r-process elements Se (Z = 34), Rb (Z = 37), Sr (Z = 38), Y (Z = 39), and Zr (Z = 40) using the HULLAC code. For the different elements, our results for the DR rate coefficients for recombining from the ionization states of II to I, III to II, and IV to III vary between 2 × 10−12–5 × 10−11 cm3 s−1, 10−13–5 × 10−11 cm3 s−1, and 2 × 10−15–10−11 cm3 s−1, respectively, at a temperature of T = 10,000 K. Using this new atomic data (DR), we study the impact on kilonova model spectra at phases of t = 10 days and t = 25 days after the merger using the spectral synthesis code SUMO. Compared to models using the previous treatment of recombination as a constant rate, the new models show significant changes in ionization and temperature, and, correspondingly, in emergent spectra. With the new rates, we find that Zr (Z = 40) plays a yet more dominant role in kilonova spectra for light r-process compositions. Furthermore, we show that previously predicted mid-infrared (e.g., [Se III] 4.55 μm) and optical (e.g., Rb I 7802, 7949 Å) lines weaken in the new model. Instead, [Se I] 5.03 μm emerges as a signature. These results demonstrate the importance of considering the detailed microphysics for modelling and interpreting the late-time kilonova spectra

A British Common Law? : Public Law after the 1707 Union between England and Scotland

In the 1953 Scottish case of MacCormick v. Lord Advocate, John MacCormick and Ian Hamilton sought to challenge the publication of a proclamation pursuant to the Royal Titles Act 1953 designating the new Queen’s royal title as ‘Elizabeth the Second of the United Kingdom of Great Britain’. Although there had previously been a Queen Elizabeth, she had reigned only in England, never in Scotland, and crucially before the creation of the Kingdom of Great Britain in 1707 in accordance with the Treaty of Union. According to MacCormick and Hamilton, therefore, the adoption of the numerals ‘the Second’ was contrary to Article I of the Treaty of Union which, being a fundamental condition of the Treaty, was ultra vires of the powers of the Westminster Parliament. The case was dismissed by both the Outer House and Inner House of the Court of Session, albeit on different grounds, with the Lord President (Lord Cooper) in the latter doing so in part on the basis that the Court of Session lacked the competence necessary to determine whether or not any governmental acts conform with the terms of the Treaty of Union