Natural Tension Research Articles

Ecological-based adaptation of agriculture to the soil and climatic conditions in Russian steppe

The article substantiates the urgency of environmental optimization of steppe land use, aimed at overcoming the acute challenges of our time, associated with the depletion of natural resources, climate change and food tension. The article analyzes the main problems of nature use, typical for steppe regions of Russia at a modern geoecological state of landscapes. The transboundary character of the territory under consideration is noted and the evolution of its landscapes under the influence of natural and anthropogenic factors, which make the study of the issues of rational use of natural resources and sustainable development of steppe regions actual, is described. The attention is focused on the significant participation of the mesoregion under consideration, which has the main share of the area of spread of black earths, in the production of agricultural products and strategic importance for the sustainable functioning of the Russian economy. Correlation-regression relations of the main ecological factors with productivity of grain agrocenoses are analyzed and ecologically oriented methods of increasing the efficiency of bioclimatic resources use of the mentioned territory are substantiated. Promising technological solutions, the introduction of which guarantees the maintenance of social and food security, will ensure the inexhaustible use of soil and land resources and reduce the anthropogenic impact on natural ecosystems, the preservation of biological diversity in the steppe regions in their agricultural use. The conclusion is made about the possibility of increasing the economic feasibility of crop production and noticeable soil-restoring and medium improving effects, new reserves to meet the needs of the modern generation and ensure social justice, while reducing the risks of impoverishment of the environment and limiting the life opportunities of future generations.

Knee joint laxity is restored in a bi-cruciate retaining TKA-design.

The goal is to evaluate the passive stability of a bicruciate retaining, cruciate retaining and bicruciate substituting TKA design in relation to the native knee stability in terms of the laxity envelope. A bicruciate retaining knee prosthesis was hypothesized to offer a closer to normal knee stability in vitro. Fourteen cadaveric knee specimens have been tested under passive conditions with and without external loads, involving a varus/valgus and an external/internal rotational torque, distraction/compression force and an anteroposterior shear force. Subsequently, the native knee, bicruciate retaining, cruciate retaining and finally a bicruciate substituting total knee arthroplasty were tested. Through the range of motion, the width of the varus/valgus and internal/external laxity envelope for the native knee and the bicruciate retaining knee were almost equivalent, whereas the cruciate retaining and the bicruciate substituting knee displayed less laxity and more joint distraction. In all prosthetic knees, an equal anteroposterior laxity was seen for the lateral and medial side whereas in the native knee, a difference in laxity was seen between the stable medial side and the more mobile lateral side. Bicruciate retaining knee prostheses can restore normal laxity and thus have the potential to offer more normal knee function. Restoration of natural peri-articular soft-tissue tension is clinically important because of its obvious effects on joint stability and range of motion. Furthermore, the results of this study could help to establish the ideal ligament tension and laxity in more conventional implants by approaching the normal values for passive knee evaluation as presented here.

No Place to Hide: Inadvertent Location Privacy Leaks on Twitter

AbstractThere is a natural tension between the desire to share information and keep sensitive information private on online social media. Privacy seeking social media users may seek to keep their location private by avoiding the mentions of location revealing words such as points of interest (POIs), believing this to be enough. In this paper, we show that it is possible to uncover the location of a social media user’s post even when it is not geotagged and does not contain any POI information. Our proposed approach Jasoosachieves this by exploiting the shared vocabulary between users who reveal their location and those who do not. To this end, Jasoosuses a variant of the Naive Bayes algorithm to identify location revealing words or hashtags based on both temporal and atemporal perspectives. Our evaluation using tweets collected from four different states in the United States shows that Jasooscan accurately infer the locations of close to half a million tweets corresponding to more than 20,000 distinct users (i.e., more than 50% of the test users) from the four states. Our work demonstrates that location privacy leaks do occur despite due precautions by a privacy conscious user. We design and evaluate countermeasures based Jasoosto mitigate location privacy leaks.

A Preliminary Study of U.S. Air Force Pilot Perceptions of the Pilot-Flight Surgeon Relationship.

Flight surgeons play a vital role in U.S. Air Force aviation operations by ensuring that pilots are medically prepared to meet the demands of military aviation. However, there is natural tension between pilots and flight surgeons. A pilot may be reluctant to share medical information with a flight surgeon who could negatively impact the pilot's career or flight status. In this preliminary study, we sought to identify pilot-perceived strengths and weaknesses in the relationship between U.S. Air Force aviators and their flight surgeons. An online survey regarding pilot-flight surgeon confidence and perceived values was distributed electronically to a convenience sample of U.S. Air Force aviators. Participants included U.S. Air Force active duty and Air Reserve Component (Air Force Reserve and Air National Guard) military aviators in addition to U.S. Air Force Academy aviation cadets. One hundred and seventy-three aviators participated in the survey. Respondents reported variable comfort in approaching flight surgeons with medical concerns and suggested that they believed other pilots might be withholding medical information from flight surgeons or seeking care from civilian physicians for career protection. We sought to examine the pilot-flight surgeon relationship and its impact on daily flying operations. While limited, results suggest that there may be gaps in trust between pilots and their flight surgeons. These findings could present an opportunity to improve the pilot-flight surgeon relationship by identifying factors that contribute to closer pilot-flight surgeon relationships.

Estilo gráfico no jornalismo em quadrinhos

Este artigo busca compreender as diferentes maneiras pelas quais o estilo gráfico pode se manifestar nas narrativas jornalísticas apresentadas em quadrinhos, e mais precisamente no modo como os traços autorais afetam o registro documental específico. Conceitos valorizados no campo jornalístico, como o imediatismo, a autenticidade e a objetividade são confrontados com o conceito de autoria gráfica. Para entender como se manifesta este contrato específico de leitura e para tratar destas naturais tensões que permeiam os quadrinhos, partimos do conceito de estilo visual, e mais especificamente o conceito de grafiação, encontrado na obra de Philippe Marion e que demostra como as marcas pictóricas do autor, sobretudo aquele inserido na narrativa, podem ativar campos de sensibilidade no receptor.

Natural Tensions in Aristotle’s Polis and Their Contemporary Manifestations

In this paper, I perform an analysis of Aristotle’s organic analogy when discussing the different “organs” of the Greek polis. I argue that this analysis demonstrates that the proper functioning of the polis depends upon the generation of different forms of life that will incline towards tension with one another, due to the fact that some members will be prevented by their form of life from enjoying the chief virtue of political life, namely, the accomplishment of human virtue and the good life. I argue that, at least within the context of the polis, there remains the possibility that those disenfranchised people experience sensuous recognition that they are contributing to human thriving. I contrast this with the modern city, in which what existed as a natural and visible tension in the polis becomes a concealed tension, with the result that no such recognition is possible, leaving modern city-dwellers alienated from the conditions that generate their forms of life.

Some Recent Cases in the Bottom of the Pyramid Concept: Lessons from India

Ethical concerns, challenges and problems are an integral part of every business endeavour because at the core of all business activity, there is the fundamental and natural tension between buyer and seller. Regardless of country, culture, income level, market served, product or service category, high or low tech, this tension is there, raising ethical questions that must be addressed. As has been emphasized above, engaging in business with the world’s poorest consumers towards the goal of eradicating global poverty creates its own unique set of ethical problems. Engagement with the base of the pyramid (BOP) markets can be successful only if the core elements of CSR are understood and incorporated into the BOP strategy. Satisfactory profits are essential, and the financial interest of shareholders can never be forgotten or neglected, but there are other stakeholders who must be considered as well. Indeed, engaging with the BOP creates an especially sensitive and complex stakeholder map. The ‘inclusive growth’ as a strategy of economic development received attention owing to growing concern that the benefits of economic growth have not been equitably shared. Growth is inclusive when it creates economic opportunities along with ensuring equal access to them.

Inventory Policies and Information Sharing: An Efficient Frontier Approach

We consider a two-tier inventory management system with one retailer and one supplier. The retailer serves a demand driven by a stationary moving average process (of possibly in nite order) and places periodic inventory replenishment orders to the supplier. In this setting, we study the interplay between information sharing and order smoothing under the assumption that rms' inventory cost parameters (e.g., per unit holding and backordering costs) are functions of two forms of supply chain variability: (i) on-hand inventory variability and (ii) replenishment order variability. We show that there is a natural tension between these two sources of variability and characterize a \Pareto frontier between them by identifying optimal inventory replenishment strategies that trade-o one type of variability for the other in a cost efficient way. For the case in which the retailer is able to share her complete demand history, we provide a full characterization of the efficient frontier, as well as of an optimal replenishment policy. On the other hand, when the retailer is not able (or willing) to share any demand information we provide a partial characterization of an optimal solution and show that information sharing does not always add value.We also show that the question of identifying conditions under which information sharing does o er value reduces to a delicate analysis of the invertibility (in a time series sense) of a specific stationary process.

Lattice Boltzmann Equations-Based Model of the Convection Melt Flow Driven by the Combined Effects of Buoyancy, Surface Tension and Magnetic Body Forces with Heat Generation

The main topic of this paper is the development of a mathematical model, based on the Lattice Boltzmann equations (LBE), which is proposed for the simulation of the complex convective flow, held in an electrically conducting melt, driven by the combined action of buoyancy, surface-tension, and electromagnetic forces. The lattice Boltzmann method (LBM) is relatively novel and contrasts with the usual well-known methods to physical modeling in the domain of computational fluid dynamics (CFD). Indeed, the LBM describes the fluid (i.e. lattice fluid) at a microscopic level (molecular) and proposes models for the collision between molecules. The full continuum-level physics (i.e. the macroscopic hydrodynamic fields) is implicitly contained in the LB model. Indeed those macroscopic quantities are defined as moments of the so-called particle distribution functions. In the present work, a two-dimensions (2D) LBE-based model is developed to the simulation of convection melt flow driven by the combination of natural buoyancy, surface tension, and electromagnetic forces. The model is applied to numerical modeling of the problems of buoyancy, surface-tension, and electromagnetic driven convection melt flow in an enclosure. The melt system used has a low Prandtl number, which is appropriate to crystal growth melts.

Modeling of influence of stresses on indicators of resistance of mining rocks to mechanical destruction

The article deals with the problem of determining the expression for the components of the stress tensor of a rock mass that is exposed to rock-breaking tools. In solving this problem, the natural tension of the rocks and the stresses arising ahead, in the plane and on the boundary of the face of the cylindrical excavation were taken into account. Formulation presented in the form of a semi-infinite cylinder whose axis coincides with the axis ̅Z of the coordinate system. The solution is obtained in a cylindrical coordinate system in the form of analytical expressions, which is carried out by numerical integration of improper integrals.

Cost innovation – a value-creation strategy to transform over-priced industries

PurposeThis masterclass examines how two important new books propose to achieve cost innovation, a value creation strategy that can transform an over-priced industry.Design/methodology/approachIn their book, marketing gurus Stephen Wunker and Jennifer Luo Law highlight the potential of cost innovation in helping to create new market demand and transform the competitive dynamics in any industry sector, and they offer guidance on how to develop such a strategy. In their study of transformation by value creation, Professors Vijay Govindarajan and Ravi Ramamurti highlight the potential for cost innovations in emerging markets to help transform health care delivery in the West.FindingsThe authors showcased in this masterclass demonstrate how the value-based principles highlighted by Porter and Christensen and Kim and Mauborge are key to transforming any industry to make it more reliable, accessible and affordable.Practical implicationsCost innovation involves taking a fresh approach to the conventional way of delivering value in any given industry and looking for ways to reimagine it.Originality/valueThe notion of cost as a potential target for breakthrough innovation in its own right is still not widely recognized. As marketing consultants Wunker and Luo Law point out in Costovation: innovation and cost are still most often seen as “magnetic opposites,” the one in natural tension with the other. They set out to challenge this assumption and show how “innovation and cost-cutting” can become “a powerful duo, capable of reshaping markets and creating long-term competitive advantages.”

Molecular dynamics simulations of natural gas-water interfacial tensions over wide range of pressures

Natural gas-water interfacial tension (IFT) plays an important role in gas production and transportation as well as hydrate formation. While experiments can measure IFT from macroscopic perspective, the interfacial phenomena remain less clear at molecular level. In this work, we use molecular dynamics (MD) simulations to study hydrocarbon-water IFT up to 5000 bar at various temperature conditions. At each temperature, we study the IFT of C1-H2O system, C1 + C2 mixture-H2O system, C1 + C3 mixture-H2O system, and C1 + C2 + C3 mixture-H2O system. We find that IFTs decrease with increasing temperature at low pressure conditions, while the differences become insignificant at high pressures. Addition of C2 and C3 can lower IFT in line with the previous experimental findings, while C3 has a more pronounced effect than C2. However, after a certain pressure, IFT becomes similar for various hydrocarbon mixture-H2O systems. As pressure further increases, IFT gradually increases. At low and intermediate pressures, hydrocarbons can form adsorption layers on gas-water interfaces but become less significant at high pressures. We find that IFT decreases when the relative adsorption obtained from density distributions is positive but increases for negative relative adsorption at high pressures. This finding agrees well with previous molecular simulation work on C1-water interfacial tension. At low and intermediate pressures, relative adsorption becomes more significant when the heavier components (C2/C3) are added, resulting in a more pronounced IFT reduction effect. Our study provides fundamental understandings about the interfacial phenomena between hydrocarbon and water, and important insights into the energy prospection and flow assurance problems.

Sustainability Attributes in Real Estate Development: Private Perspectives on Advancing Energy Regulation in a Liberalized Market

In real estate markets where energy efficiency certificates are not mandatory, such as Santiago in Chile, incorporating solutions that respond to the growing demand for sustainability entails a natural tension between their acceptance as necessary measures and the way they are addressed by the market. Under this mechanism, sustainability attributes have been introduced that are communicated individually through real estate promotion. A methodology consisting of two approaches was utilized to investigate the cross-validation of attributes, in terms of supply and demand, and the evolution of them in 8255 real estate advertisements for the period 2012–2017. Their positioning was more evident in higher-value homes, where they were identified as consolidated attributes, while they are considered innovations at the lower end of the market. However, as evidence suggests, sustainability attributes decline in relative importance over time, ceasing to be considered marks of distinction. This suggests that this model should be reviewed from a public policy perspective, with the understanding that the current voluntary standards must compete with other attributes. At the same time, it is necessary to make progress in the improvement of the obligatory minimum standards with the objective of establishing a more demanding baseline that incentivizes competitiveness in the market.

Computational Modeling of Wound Suture: A Review.

Suturing is an acquired skill which is based on a surgeon's experience. To date, no two sutures are the same with respect to the type of knot, tension, or suture material. With advancement in medical technologies, robotic suturing is becoming more and more important to operate on complex and difficult to reach internal surgical sites. While it is very difficult to translate a surgeon's suturing expertise to an automated environment, computational models could be employed to estimate baseline suture force requirements for a given wound shape, size, and suture material, which could be subsequently processed by a robot. In the literature, there have been few attempts to characterize wound closure and suture mechanics using simple two- and three-dimensional computational models. Single and multiple skin layers (epidermis, dermis, and hypodermis) and tissues with different wound geometries and sizes have been simulated under simple wound flap displacements to estimate suture force requirements. Also, recently, sutures were modeled to simulate a realistic wound closure via suture pulling, and skin prestress effect due to the natural tension of skin was incorporated in a few models to understand its effects on wound closure mechanics. An extensive review of this literature on computational modeling of wound suture would provide valuable insights into the areas in which further research work is required. Discussion of various computational challenges in modeling sutures in a numerical environment will help in better understanding the roadblocks and the required advancements in suture modeling.

Preprints and Cardiovascular Science: Prescient or Premature?

Medical journals currently find themselves in the throes of 2 powerful trends: (1) a growing concern for the irreproducibility of scientific reports, and (2) a rising imperative to accelerate dissemination of new knowledge in the digital era. Without question, the individual merit of tackling each issue is readily apparent. Irreproducibility of scientific reports is surprisingly common and contributes to an overall loss of confidence in research by the public and other stakeholders. And who could argue with efforts to leverage new online technologies to distribute information as rapidly and widely as possible? However, it also is evident that, at times, these 2 challenges of research reliability and timeliness may be at cross purposes. To tackle the former, editors have traditionally insisted on careful, detailed, and time-consuming vetting of a manuscript’s data, methods, and conclusions before publication. This largely occurs through the use of external peer review, and the American Heart Association portfolio of journals has prided itself on its ability to adhere to this high standard for its manuscripts. Efforts to address timeliness involve authors finding new ways to share raw data and preliminary conclusions, often before peer review, in the hopes of accelerating dissemination. Although natural tensions between these 2 challenges have always existed for journals and their authors, from a practical standpoint there really was no conflict. Until recently, it remained virtually impossible for authors to distribute their work without journals. The emergence of preprint servers in the digital era changes this equation while also raising new questions. For those unfamiliar with them, preprints are online postings of scientific reports in a public venue before their official publication in a journal.1 The types of manuscripts represented by preprints include research articles, editorials, perspectives, and reviews. They are typically formatted as if ready for submission to a journal …

"Crack": Beichuan in Ruins

This discussion interrogates the ruins of Beichuan, a county town in North Sichuan that was destroyed and rendered uninhabitable by the 2008 Wenchuan earthquake. Those ruins exist today in two principal forms. The remains of the original townsite have been evacuated and opened to the public as an open-air memorial; and earthquake museums have preserved artifacts recovered from the townsite and organized them alongside supporting texts, images, exhibits, dioramas, and amusement attractions. The ghost town, it is argued, ruptures the reform-era sense of national progress and development, forcing its observers and participants to acknowledge loss and absence. Connecting to a wider discourse, the National Earthquake Memorial Museum (NEMM) attempts to piece that sensibility back together by creating a particular memory of the massive state-led relief effort, by disciplining the catastrophe through inquiry and education, and by sublimating the earthquake through science, planning, and building. Although they remain emotionally separate, the ruins and NEMM have a natural tension with one another. Away from the epicenter, the privately managed Wenchuan Earthquake Museum (WEM) combines ruins and narrative to capture the strange objectivity that comes from any effort to make sense of what is ultimately insensible.

Collective Approach to Complex Food System Issues, the Case of The Ohio State University

Urban universities are uniquely positioned to make powerful and lasting contributions to the grand challenge of food security. To better understand the various dimensions related to the university’s role in food systems, this case study explores intentional linkages, significant developments, natural tensions, and emerging impacts at the Ohio State University. Discoveries from this analysis can guide urban university decision makers as they confront complex food system challenges.

Energy security, moratoria and domestic gas: Australia, LNG and its gas policy catch-22

In a region undergoing rapid and profound geopolitical change, energy security will be more important than ever. As a key regional energy producer, Australia will play a fundamental role in the energy security of its major trading partners. However, ironically, it also faces energy security challenges of its own. Over the next 12months, as Australia becomes the world’s largest producer of liquefied natural gas (LNG), its own domestic gas demand will also continue to grow. At the same time, one or more of our LNG facilities is expected to start to face significant upstream gas supply constraints. All of them will experience greater global competition. Yet, ever increasing pressure continues to be exerted on Australia’s governments to restrict, curb or even completely stop further exploration and development of hydrocarbons around the country. In New South Wales, Victoria and the Northern Territory that pressure has effectively ended new gas exploration and development for the foreseeable future. Elsewhere, it has resulted in increased regulation and uncertainty. There is a natural tension between Australia’s domestic energy security, its economic and national security interests in remaining at the heart of regional energy security, and important environmental objectives. However, these concepts and priorities do not need to be mutually exclusive, but can be achieved in balance with the right policy settings. This paper will discuss the political impasse we have reached, and the main policy options available to thread the needle between securing an economic domestic supply of gas and allowing our gas explorers, producers and exporters to continue to grow. It will seek to provide a practical analysis against the backdrop of the rapidly changing regional economic and political environment, as well as seeking to inform and stimulate the broader debate.

Experimental study on tissue phantoms to understand the effect of injury and suturing on human skin mechanical properties.

Skin injuries are the most common type of injuries occurring in day-to-day life. A skin injury usually manifests itself in the form of a wound or a cut. While a shallow wound may heal by itself within a short time, deep wounds require surgical interventions such as suturing for timely healing. To date, suturing practices are based on a surgeon's experience and may vary widely from one situation to another. Understanding the mechanics of wound closure and suturing of the skin is crucial to improve clinical suturing practices and also to plan automated robotic surgeries. In the literature, phenomenological two-dimensional computational skin models have been developed to study the mechanics of wound closure. Additionally, the effect of skin pre-stress (due to the natural tension of the skin) on wound closure mechanics has been studied. However, in most of these analyses, idealistic two-dimensional skin geometries, materials and loads have been assumed, which are far from reality, and would clearly generate inaccurate quantitative results. In this work, for the first time, a biofidelic human skin tissue phantom was developed using a two-part silicone material. A wound was created on the phantom material and sutures were placed to close the wound. Uniaxial mechanical tests were carried out on the phantom specimens to study the effect of varying wound size, quantity, suture and pre-stress on the mechanical behavior of human skin. Also, the average mechanical behavior of the human skin surrogate was characterized using hyperelastic material models, in the presence of a wound and sutures. To date, such a robust experimental study on the effect of injury and sutures on human skin mechanics has not been attempted. The results of this novel investigation will provide important guidelines for surgical planning and validation of results from computational models in the future.

Systems thinking and the leadership conundrum in health care

The ability to think in terms of a system is critical to achieving common direction, alignment, and commitment in highly distributed health systems. In Canada, provincial and territorial ministries of health provide leadership on the direction of health reform while leadership to align system levels is determined by a far more distributed group of actors. There is a natural tension between organisational (or ‘tribal’) identity and loyalty and a system-wide loyalty and identity. A major research project in Canada reveals that the challenge for health system leaders is to find the most constructive balance within this tension.