Distant Destinations Research Articles

Dynamical Analysis of a Quadratic Megastable Chaotic Oscillator and Its Application in Biometric Fingerprint Image Encryption

This investigation centers on megastable systems, distinguished by their countable infinite attractors, with a particular emphasis on the Quadratic Megastable Oscillator (QMO). Unlike traditional megastable oscillators reliant on external excitation, our proposed QMO operates autonomously, contributing to its distinctiveness. Through a comprehensive exploration of the QMO, we elucidate various dynamical behaviors, enriching the understanding of its complex system dynamics. In contrast to conventional megastable oscillators, the QMO yields nested types of multiple attractors for diverse initial conditions, elegantly depicted in phase portraits. To gauge the sustainability of chaotic oscillation, we employ influential parameter bifurcation plots, providing a nuanced insight into the system’s dynamical evolution. The complexity of the proposed system is further underscored by its intricate basins of attraction, accommodating an infinite number of coexisting attractors. Exploring trajectory dynamics, we observe that certain initial conditions lead trajectories to distant destinations, evading the influence of local attractors. This behavior underscores the uniqueness of the QMO and highlights its potential applications in scenarios requiring nonlocalized attractor behaviors. Taking a practical turn, the QMO is applied to biometric fingerprint image encryption, demonstrating its efficacy in real-world applications. Rigorous statistical analyses and vulnerability assessments confirm the success of the QMO in providing secure encryption within chaotic system-based frameworks. This research contributes not only to the theoretical understanding of megastable systems but also establishes the QMO as a valuable tool in encryption applications, emphasizing its robustness and versatility in complex dynamical scenarios.

Malignant tumor cells engender second membrane-lined organelles for self-protection and tumor progression

Cancer is a leading cause of mortality in humans, but the efficacy of current treatments for many cancers is limited, as they lack unique mechanistically defined targets. Here, we show that, upon malignant transformation, aggressive oncocells generate a second membrane exterior to their plasma membrane to form cytocapsulas (CCs) and cytocapsular tubes (CCTs), which all together constitute cytocapsular oncocells with pleotropic biological functions in cancer patient tissues in vivo. Proteomic and biochemical analyses revealed that the PMCA2 calcium pump is highly up-regulated in CCs and CCTs in malignant tumors but not in normal tissues, thus identifying a unique cancer biomarker and target for cancer therapy. Cytocapsular oncocells are universally present in solid cancers and appear in hematologic cancers in immune organs. Multi-cell malignant tumors are also enveloped by protective CC membranes. These cytocapsular tumors (CTs) generate numerous CCTs that form freeways for cancer cell metastasis to both neighboring and distant destinations. Entire cytocapsular tumor networks (CTNs) dominate physical cancer metastasis pathways in cancer patients in vivo. Later, CCTs invade micro blood vessels and release cytocapsular oncocells into the blood, providing a source of circulating tumor cells. CTNs interconnect cytocapsular tumors in primary and secondary cancer niches, creating larger cytocapsular tumor network systems (CTNSs). Primary and secondary CTNSs are in turn interconnected, forming dynamic and integrated CTNSs. Thus, interconnected cytocapsular oncocells, CTNs, and CTNSs coordinate cancer progression via the integrated cytocapsular membrane systems.

The role of travelling distances: different planning, different motives

The impact of travel distance on travel planning and motives of travelling represents a notable research gap. This study aims to demonstrate that impacts of intention predictors are different, since longer distance increases complexities of planning; also – that a long-haul travelling is driven by different motives than short-haul travelling. The study is based on analysis of survey data from Lithuania. The findings showed differences in how beliefs impact intentions to travel to distant and nearby cities. Behavioural and normative beliefs had stronger impacts on intentions for nearby destinations, whereas control beliefs had strong impacts for distant destinations. Also, the sets of travel motives for long-haul destinations and for short-haul destinations had different structure of motives. The findings deepen understanding of travel distance as an aspect of travelling that differentiates impacts of travel intention antecedents and generates different sets of travel motives for long-haul and short-haul travelling.

Advanced Propulsion for Fast Lunar Missions

Half a century ago the Apollo missions carried 12 people to spend a short time on the Moon. After all this time, the space agencies of some countries and a number of private companies committed themselves to restart human lunar exploration, this time with the aim to establish a long-term human presence on our satellite and to start a lunar economy. Most of the planned lunar missions are based on the use of chemical propulsion, which allows to perform the one-way Earth-Moon travel in 3 or 4 days. Recently NASA and DARPA joined forces to develop a nuclear thermal rocket for planetary and lunar missions. In spite of the relatively small distance of the Moon from the Earth, carrying the required payload to the Moon is costly and there is some interest in using more advanced propulsion systems, with the purposes of reducing both the travel time and the cost. In particular, advanced propulsion devices will be developed for travelling to more distant destinations and, when they will be available, they could be used with advantages also for the Moon. The aim of the present paper is to discuss the perspectives which will be opened in the future by the possibility of using nuclear (both thermal and electric) or solar electric propulsion and, in a more distant future, nuclear fusion propulsion to travel to the Moon. A number of examples of lunar missions performed with different types of advanced propulsion show what are the conditions at which these advances can be achieved and which are the constraints that will limit these efforts. Keywords: Lunar Missions, Human Lunar Exploration, Advanced Propulsion, Trajectory Optimization, Specific Impulse Optimization

Foreign workers, product quality, and trade: Evidence from a natural experiment

This paper shows that international labor mobility leads to higher-quality products, more trade, and more effective global value chains. Exploiting variation in the time and intensity at which Swiss localities (identified by their postal codes) were treated by the increasing availability of foreign workers caused by the implementation of the Swiss-EU Agreement on the Free Movement of Persons, I find that the inflow of high-skilled European workers led to an upgrade in the quality of inputs imported from their origin countries. Better intermediates show to be associated with a higher quality of output, making Swiss products more appealing for international markets and boosting exports. Therefore, the efficacy of Swiss global value chains improved both upstream—thanks to higher-quality intermediate inputs brought by the intensification of the existing buyer-seller relations—and downstream—because higher-quality products eased increasing exports to existing buyers and helped finding new customers, especially in distant destinations.

A combined review of vibration control strategies for high-speed trains and railway infrastructures: Challenges and solutions

People use trains as a means of transportation to travel to various nearby and distant destinations, resulting in an increasing amount of time spent inside such vehicles. Consequently, railway transportation sectors are focusing significantly more on enhancing passengers’ demand and level of satisfaction, including but not limited to high-speed travel, safety, and riding comfort. This paper provides a state-of-the-art review of available solutions for reducing undesired vibrations that have a substantial impact on improving the critical velocity limits of trains, maintaining the quality of riding comfort, and resolving safety concerns. In this regard, the solutions proposed for train vibration control are divided into two main categories: direct and indirect solutions. The direct solutions are those methods that are applied directly to trains’ bodies or bogies to attenuate the undesired vibrations, for example, improving the suspension/damper system, implementing active/semi-active control strategies, or applying various carriage optimization design modifications. Indirect solutions, on the other hand, are those that could indirectly affect trains’ vibrations, for example, controlling vibrations in railway bridge structures during train passages. Since the identification of vibration characteristics is assumed to be the first step in choosing proper solutions, particularly for active or semi-active control implementations, this review has examined the literature pertinent to modal identification of trains and railway infrastructures. Additionally, despite the installation of dampers between the bogie and suspension, the train’s equation of motion, and consequently, the vibration control of the bogie, has relied on the sky-hook model for decades. The fundamental problem for systems whose control strategies are based on the sky-hook concept is that the ‘sky’ does not actually exist. A solution to solve the sky-hook logic issue is using tuned rotatory inertia dampers and active rotatory inertia drivers which is addressed in this paper as well. Finally, it is concluded that these three solutions – employing a suspension/damper system in the bogie, an elastic connection for the train’s under-chassis-suspended equipment, and a ballastless railway – can practically mitigate vibration and noise in a train.

Enhancing the Communication of IoT Using African Buffalo Delay Tolerant and Risk Packet Jump Approach

The Internet of Things is used in many sectors for different applications in an efficient way. However, sharing huge data to distant destinations is a difficult task such as sending large data from remote area for healthcare application. So that the Delay Tolerant Network is used but, in some cases, the presence of selfish nodes in Delay Tolerant Network may drop all the packets. To overcome this problem the current research affords a novel African Buffalo Delay Tolerant Network with Risk Packet Jump (ABDTN –RPJ) mechanism to improve the communication channel by predicting the selfish and misbehavior node in an earlier stage. Besides, RPJ is introduced to split the huge data to the other neighboring nodes to reduce packet load on the node if the load is greater than the capacity of the node. Finally, the ABDTN –RPJ is implemented and evaluated using the NS2 simulator. The comparison results proved the efficiency of the proposed model by reducing the delay and drop rate.

Building Bridges: Bilateral Manager Connections and International Trade

We investigate whether top managers with personal ties to a foreign country facilitate trade with that country by overcoming bilateral trade barriers that obstruct international business relationships. Using individual managers' nationality, we construct a novel database of bilateral top manager connections. We analyze the trade effects of these bilateral manager connections both on the firm and on the country level. On the country level, we provide evidence for a positive effect on both bilateral exports and imports. On the firm level, we find positive effects on destination-specific foreign sales. We show that this firm-level effect is especially pronounced for institutionally distant destinations, which we interpret as bridging the gap between institutionally dissimilar countries. Furthermore, the effect is stronger for destinations with less developed institutions indicating that manager connections help overcoming trade barriers created by low institutional quality. Moreover, we show that the strength of this effect also depends on characteristics of the individual manager. Namely, the effect differs between connections of male and female managers.Gender discriminating institutions in the destination country severely downsize the pro-trade effect of female managers' connections, which could give rise to an unintended importing of gender inequality regarding management positions.

Sustainability Initiatives for Green Tourism Development: The Case of Wayanad, India

Mainstream sustainability discussions draw focus to the balance between commercial and environmental interests. Responsible tourism (RT) practices are an outcome of these discussions and RT is a significant contributor to the “greenification” of economies in many countries. Green tourism promotes travel that supports natural and cultural aspirations, while also supporting protection of the destination community’s limited resources. Kerala, India, is a pioneer in implementing RT. The present study exploratively analyzes the RT initiatives at different phases, especially within the lens of sustainable responsible tourism initiatives for green tourism development. The research is descriptive in nature and is guided by the bottom line approach (TBL) for green economic development. The findings highlight the dynamics of challenges experienced in the different phases of RT implementation. Based on our analysis of the secondary data, the first phase implementation of RT was not very successful; the second and the third phases seemed to be more promising. The study also throws light on the need for future studies in other culturally distant destinations; this will result in promising practices being adopted as alternative strategies for sustainable tourism development globally.

Foreign Workers, Product Quality, and Trade: Evidence from a Natural Experiment

This paper shows that international labor mobility attenuates information frictions, and leads to higher-quality products, more trade, and more effective global value chains. Exploiting the variation in the time and intensity at which Swiss postal codes were hit by the increasing availability of foreign workers due to the implementation of the Swiss-EU Agreement on the Free Movement of Persons, I find that the inflow of high-skilled European workers led to an upgrade in the quality of inputs imported from their origin countries. Better intermediates improved the quality of output, making Swiss products more appealing for international markets and boosting exports. Therefore, the efficacy of Swiss global value chains improved: upstream thanks to higher-quality intermediate inputs brought by the intensification of the existing buyer-seller relations; and downstream because higher-quality products eased increasing exports to existing buyers and helped finding new customers, especially in distant destinations.

Changes to human faecal microbiota after international travel

BackgroundThe aim was to investigate whether travelling to less-resourced destinations influences the composition of faecal microbiota in generally healthy adults. MethodIn this prospective observational study, 47 adults (median age, 24 years; 73% females) travelled from Sweden to distant destinations for 1–12 weeks. Five faecal samples, two before and three after travel, were analysed by 16S amplicon massive parallel sequencing. Subjects had taken no antibiotics within three months of each sampling. ResultsThe overall composition of faecal microbiota was not affected by travel. However, when looking at the relative abundance of individual bacterial taxa, Enterobacteriaceae demonstrated a 10-fold increase immediately after the trip as compared to the samples taken before travelling. Conversely, the relative abundance of Christensenellaceae had decreased equally much. Both these changes were reversible within nine weeks. ConclusionsInternational travel, even to less-resourced countries, did not appear to alter the overall diversity of human faecal microbiota as studied here after travelling. However, Enterobacteriaceae bacteria, often associated with infection, inflammation, and antibiotic resistance, showed dramatically elevated levels, and Christensenellaceae, frequently associated with healthy conditions, demonstrated remarkably declined levels in relative abundance as detected immediately after travel. Both these changes returned to original pre-travel levels within nine weeks.

Determinants of export pricing at the firm-level: evidence from Egypt

The study explains the export pricing behaviors of Egyptian firms using detailed customs data and high-dimensional fixed effects. Firstly, it finds that more productive firms (as proxied by firms’ importation of intermediate inputs and capital goods) charge higher export prices which are correlated with higher revenues, providing an evidence for competition in quality, rather than price, amongst firms. Secondly, firms with more destinations charge a higher price for their exported products and a wider price range across markets. Thirdly, firms charge higher prices for more distant and richer destinations, whereas they charge lower prices for larger-sized and less central ones. This could be explained by variable mark-ups across destinations, where higher mark-ups are set in more distant, richer, smaller (less competitive), and more central destinations. It could also indicate that higher quality product versions are sent to more distant destinations (Alchian-Allen or selection effects) and richer ones (demand effect). Lastly, firms charge higher prices for destinations with a larger prevalence of technical measures or those imposing specifically restrictive ones, potentially reflecting an adverse effect of these measures on the number of exporting firms, allowing survivors to charge higher mark-ups. Alternatively, this could reflect firms’ quality upgrading in compliance with such measures.

Regional destination attributes that attract domestic tourists: the role of man-made venues for leisure and recreation

This paper examines the influence of man-made attractions for leisure and recreation on domestic tourists' preferences amongst regional destinations, and the moderating role of these attractions on the negative effect of distance on tourists' choices. A mixed multinomial logit model is employed for 368 cities in Colombia grouped into 28 provinces. Factor analysis is utilised to identify the latent variable that groups several man-made attractions for leisure and recreation. Results show that domestic tourists' choices of a regional destination increase as the number of man-made attractions for leisure and recreation rises, although there is taste heterogeneity between tourists explained by their city of origin. Findings also show that the decline in domestic tourists' preferences for a regional destination due to increases in travel distance can be lessened through the construction and/or enhancement of man-made venues for leisure and recreation in the destination; a strategy that can serve to reduce monetary poverty in distant destinations that have attributes to attract tourists.

Management of Soil Fertility and Agricultural Intensification in NW Iberia, 1750–1900

Abstract This article describes agricultural practices of fertilization in the NW of the Iberian Peninsula between 1750 and 1900, where a leguminous plant called gorse (Ulex Europaeus) was used as bedding for livestock in order to produce manure. During the period examined, this whole region experienced a process of agricultural intensification which resulted in a net loss of nutrients in the soil. Peasants dealt with the increasing nutrient requirements by adapting land and livestock management in order to produce more manure during the second half of the 20th century. However, this was done at the expense of nutrient reserves in extensively managed areas, all of which resulted in an unsustainable agricultural pattern. Our data also suggest that the context of nutrient scarcity could be related to changes in the migration pattern, which started to be more intense after 1850 and preferred distant destinations (America), thus switching from seasonal to permanent stays.

How will self-driving vehicles affect U.S. megaregion traffic? The case of the Texas Triangle

This paper anticipates the impacts of self-driving or “autonomous” vehicles (AVs), shared AVs, and Atrucks on travel across the Texas Triangle megaregion using year 2040 land use (and network) forecasts. A statewide travel demand model forecasts changes in trip generation, mode and destination choices, and thus vehicle-miles traveled (VMT), congestion, and travel patterns across the megaregion. Results suggest travelers' shifting to more distant destinations, with average person-trip distance rising from 14 to 16 miles. Within-region airline passenger travel is predicted to fall by 82%, as travelers shift to self-driving ground transport options. Without travel demand management (like credit-based congestion pricing and mandated tight headways between AVs), congestion issues will grow, due to an average 47% VMT increase, especially in the region's major cities (Houston, Dallas, San Antonio, and Austin). Automobile travel is anticipated to rise across all distance categories, with increases most evident between suburban and urban zones. Almost 9.6% of link flows will exceed capacity, relative to 4.6% of segments in the no-AV case (for year 2040). Four of the 15 freight industries are predicted to experience an increase of more than 100 million ton-miles per day, due to the introduction of Atrucks, with rising truck trades largely between Houston and other major cities.

Reaching Up, Down, In, and Around: Couple and Family Coping During the Coronavirus Pandemic.

The worldwide coronavirus (COVID‐19) has had profound effects on all aspects of life: physical health, the ability to travel locally or to more distant destinations, material and financial resources, and psychosocial wellbeing. Couples, families, and communities and individual persons in those relationships have struggled to cope with emerging depression, anxiety, and trauma, and the rise of relational conflict. In this article, we suggest that the existential nature of the pandemic’s challenges requires more than just the usual psychosocial interventions. We propose a taxonomy of responses to foster coping and resilience—“Reaching Up, Down, In, and Around.” “Reaching Up” includes accessing spiritual, religious, and ethical values. “Reaching Down” includes ideas and practices that foster a revised relationship with the Earth and its resources, and that engage families to participate in activities that aid the Earth’s recovery from decades of human‐caused damage. “Reaching In” represents a turn towards experiences available in the mind and in shared minds in relationships that provide pleasure, excitement, joy, and peace, given that external sources of these emotions are of limited availability due to quarantine. “Reaching Around” involves reframing the mandate for “social distancing” as fostering social connection and support while maintaining physical distancing. The challenges for family therapists, whose practices are confined largely to online therapy, and who are struggling with the same fears and constraints as those persons they are attempting to help, are also discussed.

A Real Options Perspective on Pattern, Process, and Outcomes of Entrepreneurial Internationalization

Especially in this era of de-globalization, uncertainty plays a major role in both entrepreneurial and internationalization processes. Yet, prior international entrepreneurship (IE) and international business (IB) literature has not fully accounted for the nature of high and changing levels of host country uncertainty when predicting firms’ entrepreneurial internationalization patterns and outcomes. By applying real options theory (ROT), we re-conceptualize firms’ entrepreneurial internationalization pattern, process, and outcomes as the results of active uncertainty leveraging in the face of high and changing levels of host country institutional and economic uncertainty. Utilizing a representative sample of 680 U.S. new international firms that exported to 115 different host countries between the year 2009 and 2019, we find that host country uncertainty positively relates to firms’ choice of “real option” entry (i.e., low initial investment combined with high collaboration). In contrast to the predictions of Transaction Cost Economic (TCE) approaches to internationalization, a ROT approach enables firms to achieve relatively faster entry, enter more distant destinations, and allows flexibility to exit markets over time. More importantly, we discovered firms using such “real options” entry strategies can mitigate the negative performance impact of host country uncertainty.

Chemokine receptor CXCR7 non-cell-autonomously controls pontine neuronal migration and nucleus formation

Long distance tangential migration transports neurons from their birth places to distant destinations to be incorporated into neuronal circuits. How neuronal migration is guided during these long journeys is still not fully understood. We address this issue by studying the migration of pontine nucleus (PN) neurons in the mouse hindbrain. PN neurons migrate from the lower rhombic lip first anteriorly and then turn ventrally near the trigeminal ganglion root towards the anterior ventral hindbrain. Previously we showed that in mouse depleted of chemokine receptor CXCR4 or its ligand CXCL12, PN neurons make their anterior-to-ventral turn at posteriorized positions. However, the mechanism that spatiotemporally controls the anterior-to-ventral turning is still unclear. Furthermore, the role of CXCR7, the atypical receptor of CXCL12, in pontine migration has yet to be examined. Here, we find that the PN is elongated in Cxcr7 knockout due to a broadened anterior-to-ventral turning positions. Cxcr7 is not expressed in migrating PN neurons en route to their destinations, but is strongly expressed in the pial meninges. Neuroepithelium-specific knockout of Cxcr7 does not recapitulate the PN phenotype in Cxcr7 knockout, suggesting that CXCR7 acts non-cell-autonomously possibly from the pial meninges. We show further that CXCR7 regulates pontine migration by modulating CXCL12 protein levels.

EXPORT AND INVENTORY: EVIDENCE FROM CHINESE FIRMS

This paper investigates the effect of export on firm inventory using Chinese firm data. We find that exporting increases firms’ inventory stocks. Also, exporting to more distant destinations is associated with less frequent and more concentrated export transactions.

Exercise Countermeasures to Neuromuscular Deconditioning in Spaceflight.

The mechanical unloading of spaceflight elicits a host of physiological adaptations including reductions in muscle mass, muscle strength, and muscle function and alterations in central interpretation of visual, vestibular, and proprioceptive information. Upon return to a terrestrial, gravitational environment, these result in reduced function and performance, the potential consequences of which will be exacerbated during exploration missions to austere and distant destinations such as the moon and Mars. Exercise is a potent countermeasure to unloading-induced physiological maladaptations and has been employed since the early days of spaceflight. In-flight exercise hardware has evolved from rudimentary and largely ineffective devices to the current suite onboard the International Space Station (ISS) comprised of a cycle ergometer, treadmill, and resistance exercise device; these contemporary devices have either fully protected or significantly attenuated neuromuscular degradation in spaceflight. However, unlike current microgravity operations on the ISS, future exploration missions will include surface operations in partial gravity environments, which will require greater physiological capacity and work output of their crews. For these flights, it is critical to identify physiological thresholds below which task performance will be impaired and to develop exercise countermeasures-both pre- and in-flight-to ensure that crewmembers are able to safely and effectively complete physically demanding mission objectives. © 2020 American Physiological Society. Compr Physiol 10:171-196, 2020.