Multiple Arrangements Research Articles

A multiscale sliding filament model of lymphatic muscle pumping

The lymphatics maintain fluid balance by returning interstitial fluid to veins via contraction/compression of vessel segments with check valves. Disruption of lymphatic pumping can result in a condition called lymphedema with interstitial fluid accumulation. Lymphedema treatments are often ineffective, which is partially attributable to insufficient understanding of specialized lymphatic muscle lining the vessels. This muscle exhibits cardiac-like phasic contractions and smooth muscle-like tonic contractions to generate and regulate flow. To understand the relationship between this sub-cellular contractile machinery and organ-level pumping, we have developed a multiscale computational model of phasic and tonic contractions in lymphatic muscle and coupled it to a lymphangion pumping model. Our model uses the sliding filament model (Huxley in Prog Biophys Biophys Chem 7:255–318, 1957) and its adaptation for smooth muscle (Mijailovich in Biophys J 79(5):2667–2681, 2000). Multiple structural arrangements of contractile components and viscoelastic elements were trialed but only one provided physiologic results. We then coupled this model with our previous lumped parameter model of the lymphangion to relate results to experiments. We show that the model produces similar pressure, diameter, and flow tracings to experiments on rat mesenteric lymphatics. This model provides the first estimates of lymphatic muscle contraction energetics and the ability to assess the potential effects of sub-cellular level phenomena such as calcium oscillations on lymphangion outflow. The maximum efficiency value predicted (40%) is at the upper end of estimates for other muscle types. Spontaneous calcium oscillations during diastole were found to increase outflow up to approximately 50% in the range of frequencies and amplitudes tested.

Zooming‐in – Visualization of active site heterogeneity in high entropy alloy electrocatalysts using scanning electrochemical cell microscopy

AbstractComplex solid solutions (“high entropy alloys” with a single solid‐solution phase) hold great promise in electrocatalysis because of their nearly unlimited number of different active sites exposed at the surface. It has been shown by theoretical studies that multiple arrangements of different elements directly neighboring a binding site create millions of differently active catalytic sites. We report a zooming‐in approach using scanning electrochemical cell microscopy (SECCM) to distinguish between the averaged electrochemical response of multiple active sites and active site‐specific electrochemical response. Using a thin film complex solid solution electrocatalyst and a range of SECCM single barrel capillaries with diameters from 1.2 µm to 50 nm, we observed an averaged electrochemical response for the oxygen reduction reaction with minor statistical variations for the larger capillary diameters. In contrast, significant statistical heterogeneity among the measured spots is observed for small capillary diameters. This statistical heterogeneity is attributed to the ability of the smaller probe size to address a comparatively smaller number of active sites with high or low activity dominating the measured electrocatalytic currents.

Compressive behavior of RC members with rectangular continuous transverse reinforcement

AbstractRectangular Continuous Transverse Reinforcement (RCTR), as a replacement for conventional ties, is a relatively new form of reinforcement that can accelerate and facilitate the construction of reinforcement for RC members. In this study, the compressive behavior of concrete members with this kind of reinforcement is experimentally and theoretically investigated. Twenty‐eight RC short column specimens with multiple arrangements for bar size and spacing of transverse reinforcement; including RCTR and conventional ties are examined under monotonic and half‐cyclic loadings. The results imply that RCTR is a valid substitute for traditional ties and to a certain extent can improve the compressive strength of RC members. Based on Elasto‐Plastic and Fracture (EPF) concrete model, a theoretical method is proposed in order to predict the behavior of such members, which conforms well with the experimental results. Furthermore, the validity of existing design provisions in the compressive design of these members is investigated.

An image-computable model of human visual shape similarity.

Shape is a defining feature of objects, and human observers can effortlessly compare shapes to determine how similar they are. Yet, to date, no image-computable model can predict how visually similar or different shapes appear. Such a model would be an invaluable tool for neuroscientists and could provide insights into computations underlying human shape perception. To address this need, we developed a model ('ShapeComp'), based on over 100 shape features (e.g., area, compactness, Fourier descriptors). When trained to capture the variance in a database of >25,000 animal silhouettes, ShapeComp accurately predicts human shape similarity judgments between pairs of shapes without fitting any parameters to human data. To test the model, we created carefully selected arrays of complex novel shapes using a Generative Adversarial Network trained on the animal silhouettes, which we presented to observers in a wide range of tasks. Our findings show that incorporating multiple ShapeComp dimensions facilitates the prediction of human shape similarity across a small number of shapes, and also captures much of the variance in the multiple arrangements of many shapes. ShapeComp outperforms both conventional pixel-based metrics and state-of-the-art convolutional neural networks, and can also be used to generate perceptually uniform stimulus sets, making it a powerful tool for investigating shape and object representations in the human brain.

Genetic and morphological relationships of fieldwrens (Calamanthus): implications for conservation status and management

ABSTRACT Sound taxonomy is important for providing a scientific basis for the listing of threatened taxa and allowing informed decisions for conservation management. The Australian fieldwrens (Acanthizidae: Calamanthus spp.), small passerines of shrublands across mesic to arid southern Australia, have been challenging in this respect. Difficulties in interpreting the variation in morphology and colouration across their geographic range have resulted in taxonomic controversy for a century; multiple arrangements of species and subspecies have been proposed, including a prevailing view that there are two species and seven subspecies in the Rufous Fieldwren, Calamanthus campestris complex. Two island subspecies (C. campestris hartogi and C. c. dorrie) are currently listed as Vulnerable. We hypothesised that C. campestris is monotypic (including C. montanellus) and that variation is clinal across mainland populations. Results of our genetic, morphological and colour pattern analyses are largely consistent with this hypothesis. However, we did find evidence of genetic divergence between eastern and western populations and some genetic support for recognition of C. c. hartogi (Dirk Hartog Island) based on divergence in nuclear allele frequencies. Together, our results provide a strong case for the hypotheses that C. montanellus is a synonym of C. campestris, and that rather than consisting of seven subspecies, C. campestris comprises two mainland subspecies C. c. campestris and C. c. rubiginosus east and west, respectively, of 133 degrees longitude, and only one island subspecies, C. c. hartogi. In this regard, the currently recognised C. c. dorrie is nominated for removal from threatened species lists.

THE US POLICY SHIFT FROM ‘PIVOT TO ASIA’ TO ‘FREE INDO PACIFIC’: IMPLICATIONS FOR PAKISTAN

Asia Pacific, which is extended Eastward to the states of Oceania, Westward to Pakistan, Southward to New Zealand, and Northward to Mongolia, is currently a pivot of the globe due to its economic growth. Since last two decades, it has got status of ‘growth center’ owing to its high economic growth rate. The United States (US) had been very active in Asia Pacific throughout the Cold War period, but in post-Cold War era, it was disengaged due to its pre-occupation in Middle East. However, the rise of China attracted US again with multiple arrangements at political, economic and social fronts. There are two world views about the US presence in Asia Pacific. The first one asserts that the Asia Pacific is more secure without the presence of US, while others takes the US presence as a patron for stability and solidarity within the region. The US policy of ‘Pivot to Asia’, ‘Asia Pacific’ commonly known as ‘Rebalancing’ ensured its new commitment of deep engagement in Southeast Asia. Policy shift under Trump administration from ‘Pivot to Asia’ to ‘Free Indo-Pacific’ has direct as well indirect implications for Pakistan. The study analyses the US strategies and polices under the theory of ‘Offensive Realism,’ where ‘rational powers uncertain of intentions and capable of military offensive strive to survive’. Analytical, descriptive approaches are adopted in order to analyse US ongoing strategies.

Pakistan’s Policy Postures towards Shanghai Cooperation Organization (SCO): An Analysis

In 2018 Pakistan as well as India participated for the first time as a full scale member of Shanghai Cooperation Organization (SCO) that held at Qingdao city of China on June 9-10. Obviously, that provided a brilliant opportunity to show willingness and readiness to contribute to the effectiveness of the SCO. Pakistan’s inclusion into the organization has opened a timely opportunity to bid for regional peace and economic prosperity for its nation. There are multiple arrangements which help Pakistan to come in the streamline as well as allow the Muslim state to support ongoing priority interests of the organization. Due to Pakistan’s membership many changes are expected in the domestic legislation and international commitments generated out of organizational common interest. Moreover, it will have great impact (but positive) on Islamabad’s traditional behavior towards regional and international politics particularly on the front of its foreign policy. This article makes the point that among many opportunities that Pakistan’s inclusion into SCO brings, there are few challenges for the country as well. For example, inclusion of Pakistan in the SCO is not an isolated decision; India was also given the full membership to join the organization as a permanent member. Traditionally, both Pakistan and India have zero tolerance for each other when it comes to their national security dynamics. Other than United Nations and SAARC, SCO is the third organization where both countries will be sitting together, though UN is quite a different one. Likewise, SAARC, if both the countries maintain the same status-quo of bashing each other, the very purpose of SCO will go in vain. Also, this article proposes that Pakistan shall not be allowed to label itself as a negative factor in the SCO. Therefore, this research paper has shed light on Pakistan’s previous inability to benefit from regional organizations while suggesting a way forward for her engagement with the SCO. Believing on the great potential of Pakistan and SCO, this paper has adopted deductive methodology with that of ‘economics defines politics’ as a conceptual framework.

Characterization and stabilization of nano-metakaolin colloidal suspensions

Nanometric powders bear significant problems in the efficiency of dispersion. The ideal situation would be to ensure full nanoparticle separation in suspensions or composites matrix, which is hard to achieve due to the high reactivity and aggregation. This study evaluates the conditions to stabilize nano-metakaolin (NMK) in water suspension by analyzing the influence of solute concentration, pH, type and content of dispersants. Potentiometric titration curves, zeta potential and average particle size measurements were performed, along with rheological measurements, at different times: 0 h, 3 h, 6 h and 24 h. NMK particles showed the same tendency of surface charge distribution, regardless of solute concentration. The dispersed NMK particles presented two isoelectric points, attributed to the multiple arrangements they form when in suspension. Polycarboxylate (PC) was the dispersant that provided greater dispersion stability. Regarding the rheological and zeta potential measurements, the suspensions presented stability up to 24 h.

Why are the institutional injustice and the lack of fairness omnipresent in Serbia? A pragmatic assessment of plural orders of worth

Recent results from Round 9 of the European Social Survey (ESS) indicate that Serbia differs from other European countries in terms of justice and fairness. Whereas the Serbian people?s dissatisfaction relating to unjust income distribution, unfair employment chances and political institutions may not be surprising, these findings still raise a dozen questions. Situated within contemporary discussions on normativity in sociology and survey methodology, this paper aims to reassess the moral grammar of these judgments. By endorsing tenets of pragmatic sociology and its principal aim to recognize the plural modes of valuation and criticism and reflective capacities of social actors to judge and evaluate, this paper develops around few major points. First, we underline how most major approaches to axiology remain stuck in a co-determinist framework, thereby renewing a number of dualisms. Instead, we opt for a relational approach and further present how the theoretical model of Boltanski and Thev?not enables the locating of different assessments of worth. After setting our methodological framework against the ?externalist? epistemology, we explore our key assumption that the above-mentioned high rates come as a problem of a feasible ?truce? between the domestic regime and the civic polity, ruled by proclaimed legality, representativeness and impersonal character. We trace the problem of incorporating multiple arrangements as a problem of generality, by relating these to two layers of information acquired through the ESS. One involves the analysis of the domestic polity covering the household situation in terms of organization and unveiling the specific worth given to care and protection. Another layer is derived from regression analysis which affirms that the absence of fairness in civic polity correlates with a higher degree of worth given to the domestic one, but also that the latter situation depicts a deeper ontological puzzle about making a mild transition to the assumed ?horizontality? of civic matters.

High gear ratio mechanical transmissions for actuators: Simplified models for efficiency under opposing and aiding loads

Planetary gear drives are widely employed in electrical and hydraulic actuation systems, to adapt a high speed, low torque motor to a low speed, high torque user, within strict weight and volume constraints. During the early design phases of these devices, accurate yet simple simulation models are required to evaluate the performance of a given configuration of the device. Similar models are also useful within diagnostic and health monitoring analyses of existing machines, as a discrepancy between the actual behaviour of the physical system and that predicted by its digital twin may be the effect of a damage. This work compares different models available in literature for the efficiency of high gear ratio mechanical transmissions; the models are applied to multiple arrangements common for planetary drives, and the results in form of an efficiency map for the transmissions are compared and discussed. The simulations provide different levels of detail, and require different levels of knowledge about the specific architecture of the system. All of them are able to deal with dry friction; additionally, the different behaviour of the transmission under the effect loads aligned in the same direction of speed or in the opposite one is accounted for.

State estimation and sensor location for Entrained-Flow Gasification Systems using Kalman Filter

This study presents the estimation of key unknown states for a pilot-scale gasifier using Kalman Filter (KF). The transient behaviour of a pilot-scale gasification unit is represented using a dynamic reduced order model. This model consists of 479 state variables including molar fractions for the species, temperature, and slag thickness across the gasifier. The quality of the state estimation provided by KF has been evaluated under multiple arrangements of the number and the location of the sensors available for the top section of the gasifier. Also, plant-model mismatch, additive uncertainty in the prior estimation, and load-following scenarios have been considered. The results show that KF is capable of estimating the unknown states for a large variety of changes in the gasifier’s inputs, even though online temperature sensors are only available in limited locations across the gasifier.

Polydisperse molecular architecture of connexin 26/30 heteromeric hemichannels revealed by atomic force microscopy imaging

Connexin (Cx) protein forms hemichannels and gap junctional channels, which play diverse and profound roles in human physiology and diseases. Gap junctions are arrays of intercellular channels formed by the docking of two hemichannels from adjacent cells. Each hexameric hemichannel contains the same or different Cx isoform. Although homomeric Cxs forms have been largely described functionally and structurally, the stoichiometry and arrangement of heteromeric Cx channels remain unknown. The latter, however, are widely expressed in human tissues and variation might have important implications on channel function. Investigating properties of heteromeric Cx channels is challenging considering the high number of potential subunit arrangements and stoichiometries, even when only combining two Cx isoforms. To tackle this problem, we engineered an HA tag onto Cx26 or Cx30 subunits and imaged hemichannels that were liganded by Fab-epitope antibody fragments via atomic force microscopy. For Cx26-HA/Cx30 or Cx30-HA/Cx26 heteromeric channels, the Fab-HA binding distribution was binomial with a maximum of three Fab-HA bound. Furthermore, imaged Cx26/Cx30-HA triple liganded by Fab-HA showed multiple arrangements that can be derived from the law of total probabilities. Atomic force microscopy imaging of ringlike structures of Cx26/Cx30-HA hemichannels confirmed these findings and also detected a polydisperse distribution of stoichiometries. Our results indicate a dominant subunit stoichiometry of 3Cx26:3Cx30 with the most abundant subunit arrangement of Cx26-Cx26-Cx30-Cx26-Cx30-Cx30. To our knowledge, this is the first time that the molecular architecture of heteromeric Cx channels has been revealed, thus providing the basis to explore the functional effect of these channels in biology.

Melting of multiple PCMs with different arrangements inside a heat exchanger for energy storage

Latent heat storage using Phase Change Materials (PCMs) is an important promising solution for addressing the renewable energy fluctuation problem. The low thermal conductivity of PCMs that substantially contributes to very slow storage and recovery of energy is a major obstacle. This study investigated the performance of multiple PCMs for different arrangements in a horizontally positioned heat exchanger during melting of the PCMs. The results identified the effects of conduction and natural convection heat transfer for different PCM arrangements in the heat exchanger. Numerical simulations were conducted for the defined geometries. The model developed for the study was validated against a published related study. Results in the form of liquid fraction contour and Nusselt number ratio plots are presented and discussed. It was found that the application of multiple arrangement of the PCMs has different effects on the heat transfer mechanisms. Natural convection has a significant positive effect on the heat transfer characteristics of these systems in all the arrangements studied. The parallel arrangement enhances conduction, leading to 40% reduced melting time, when only conduction heat transfer is considered, but it suppresses natural convection, while the series arrangement enhances natural convection heat transfer significantly. Compared to all the arrangements studied, the series arrangement was found to be superior for energy storage. With it, 15.5% reduction in complete melting time was achieved compared to the single PCM arrangement. Natural convection enhancement in this arrangement led to 50% complete melting time reduction, compared to the case of only conduction heat transfer. It was also found that the application of multiple PCMs increases the storage capacity by about 25%.

Methodology to incorporate stuck condition of the circuit breaker in reliability evaluation of electrical distribution networks

The random failure of a circuit breaker (CB) in a power distribution network adversely impacts its ability to maintain supply continuity to its electricity customers. Among different CB failure modes, the failure to open, or the stuck condition, of a normally closed CB causes the operation of its backup breaker(s) leading to outages of multiple healthy feeders. Stuck condition is a low-probability failure event, but has wide-spread consequences when it occurs. This study proposes a generalised analytical methodology to identify the failure events due to the stuck breaker condition. The complexity of the reliability evaluation of a modern distribution system involving multiple switching arrangements is achieved through a search algorithm and repeated matrix operations that can readily be implemented in a computer program. The methodology is illustrated using a test distribution network. The usefulness of the methodology is demonstrated by quantifying the impact of the stuck breaker condition on load point and system reliability indices. The developed methodology can be a useful tool for industrial/commercial customers and utilities to incorporate the impact of breaker failures, including stuck breaker conditions, and make wise investment decisions in the upgrade and maintenance of the distribution network components and the protection system.

To Label or Not? Governing the Costs and Benefits of Geographic Indication of an African Forest Honey Value Chain

Geographical Indication (GI) has been proposed as a development tool, benefitting producers, consumers and local communities by creating value, improving market access, protecting local knowledge and natural resources and contributing to social cohesion as producers work together to solve common problems. However, scientific evidence on the socio-economic and environmental effects of governing value chains and origin landscapes through this voluntary, market-based arrangement is scarce. Honey appears ideal for GI labelling: having unique, physically identifiable and geographically localisable properties dependent upon the local ecosystem and beekeeping practices. White honey from the Kilum-Ijim forest in the Cameroon Highlands was GI registered in 2013 aiming to guarantee product quality, increase beekeeper selling prices and protect the forest. Panel data from stakeholder interviews, market surveys and participatory action research, shows the extent to which the GI benefited beekeepers, and how the honey value chain and landscape developed since registration. Although honey production and productivity remained steady, profits augmented as prices increased and sales became more nationwide, improving beekeeper’s living standards, appearing attributable to the GI. Deforestation however continued, and imposter brands abound, signalling potential supply shortages, increased input costs and competition which could affect future profits and the GI reputation; changing the distribution of benefits to suppliers rather than beekeepers. This suggests that whilst the Oku white honey GI has had a short-term positive livelihood effects, longer-term positive impacts conserving the landscape have been ineffective, and the durability of economic impacts is questionable. Although multiple arrangements govern the value chain and landscape, even together they are insufficient to balance the many demands on this productive landscape, suggesting the limits of weak institutions and non-state governance to protect vulnerable landscapes and ecosystems, and producer’s livelihoods. This reality check of the benefits from the Oku white honey GI highlights the importance of coherent, effective governance of both landscapes and the markets for its products.

Buckling analysis of porous FGM sandwich plates under various types nonuniform edge compression based on higher order shear deformation theory

This study intends to model the effect of porosity type defect and analyze the consequences of porosity on the buckling characteristic of various types of FGM sandwich combinations. Here, we consider four types of FGM sandwich combinations considering the multiple arrangements of the constituent layers (i.e., two face sheets and a core). Further, the combinations of all kinds of sandwiches are considered in such a way that there is no material discontinuity or jump. The porosity defects are modeled in this work as the criteria of stiffness reduction and incorporated in the rule of mixture. Finally, results are calculated by considering two types of porosity distribution, evenly and unevenly, while modeling the FGM plate. The buckling response of FGM sandwich plates has been analyzed under a nonuniform in-plane edge load. The application of nonuniform in-plane loads causes in-plane stresses to be nonlinear. Hence, in-plane stresses need to be calculated apriori for the buckling study of the FGM plate under nonuniform load. Further, the effects of various parameters like porosity contents, sandwich combinations, aspect ratio, thickness ratio, boundary conditions on buckling load of FGM plate have been studied in this paper.

Detecting transcriptomic structural variants in heterogeneous contexts via the Multiple Compatible Arrangements Problem

BackgroundTranscriptomic structural variants (TSVs)—large-scale transcriptome sequence change due to structural variation - are common in cancer. TSV detection from high-throughput sequencing data is a computationally challenging problem. Among all the confounding factors, sample heterogeneity, where each sample contains multiple distinct alleles, poses a critical obstacle to accurate TSV prediction.ResultsTo improve TSV detection in heterogeneous RNA-seq samples, we introduce the Multiple Compatible Arrangements Problem (MCAP), which seeks k genome arrangements that maximize the number of reads that are concordant with at least one arrangement. This models a heterogeneous or diploid sample. We prove that MCAP is NP-complete and provide a frac{1}{4}-approximation algorithm for k=1 and a frac{3}{4}-approximation algorithm for the diploid case (k=2) assuming an oracle for k=1. Combining these, we obtain a frac{3}{16}-approximation algorithm for MCAP when k=2 (without an oracle). We also present an integer linear programming formulation for general k. We characterize the conflict structures in the graph that require k>1 alleles to satisfy read concordancy and show that such structures are prevalent.ConclusionsWe show that the solution to MCAP accurately addresses sample heterogeneity during TSV detection. Our algorithms have improved performance on TCGA cancer samples and cancer cell line samples compared to a TSV calling tool, SQUID. The software is available at https://github.com/Kingsford-Group/diploidsquid.

Estructuras de los arreglos residenciales y desigualdades en México

El objetivo de este trabajo es indagar si el tipo de arreglo residencial familiar influye en la calidad de vida de sus integrantes, aspecto que se ve reflejado en desigualdades en el bienestar socioeco-nómico, desigualdades de género en el ejercicio del poder y desigualdades según el grado de ur-banización del lugar de residencia. La fuente de datos empleada es la Encuesta Intercensal 2015. La clasificación de los arreglos está basada en Laslett y Wall (1972) que permite distinguir entre arreglos simples y múltiples. Para el análisis, se construyó un índice de bienestar y se aplicaron modelos de regresión logística binarios. Los principales resultados son los siguientes. El tipo de arreglo residencial más ventajoso en términos del bienestar socioeconómico de sus miembros es el nuclear, mientras que, en el caso del arreglo monoparental, depende de su composición. En ge-neral, la figura de “jefe” del arreglo residencial asignada por sus integrantes, atribuye con mucha frecuencia a los hombres esta característica; esta situación varía según el tipo de arreglo. En la Ciudad de México, contexto altamente urbanizado, los arreglos nucleares son menos frecuentes, el clima educativo es más alto y la jefatura femenina más usual.

Global Pandemics and the Economics of Global Value Chains: COVID-19 and the Production of Medical Devices

Pandemics change the dynamics of GVCs in fundamental ways, notably in those producing the medical devices needed to fight them. I outline a modified rationale for globally-integrated production in this sector and show how considerations of costs, skills and resources that drive GVC structure in other industries are transformed in medical-device GVCs. I present the trade-off between the benefits of global integration and the imperative of speed of response and secured supply as giving rise to multiple arrangements of the production and supply of medical devices that combine local, regional and global production. I outline implications for theory and policy.

Numerical study on the heat transfer performance and efficiency in a rectangular duct with new winglet shapes in turbulent flow

The present study numerically investigates the three-dimensional flow and heat transfer characteristics in a rectangular duct equipped with four different winglet shapes. Besides the conventional delta winglet, the new delta-cut, arrow and X winglet are studied. To evaluate the winglet’s performance, Nusselt number, friction factor, and thermal efficiency enhancement are compared to that of a smooth duct. All simulations are carried out for Reynolds numbers ranging from Re=4000 to Re=12000. The winglets are arranged as single and 2×2 configuration. In the multiple arrangement, the longitudinal pitch between the winglet rows is varied as 5, 7 and 9 times the channel height. The results show the highest Nusselt number enhancement of 12.4% for the case of single winglet and 35.5% for the 2×2 arrangement for the delta winglet, accompanied by the maximum pressure drop. The arrow winglet achieves the maximum efficiency augmentation of 7.2% for single and 9.5% for 2×2 arrangement. The analysis of flow structure shows a contribution of secondary vortices occurring besides the primary longitudinal vortices behind the winglets to heat transfer enhancement. The longitudinal pitch variation in multiple winglets arrangement has been found to have a negligible influence on the heat transfer rate, pressure loss, and efficiency.