Secondary Operators Research Articles

RAdiation Dose Attenuation using RADPAD in CATH lab for primary and secondary operators - RADAR-CATH STUDY.

Radiation injury is an important concern for interventional cardiologists and needs to be addressed. RADPAD is a radiation protection drape that has been shown to reduce the radiation exposure of the primary operator (PO). While Indian data on radiation exposure of the PO in the cath lab are scarce, the exposure of the secondary operator (SO) is even less well studied. The aim of this study was to evaluate the efficacy of RADPAD drapes in reducing radiation doses in the cath lab for the primary as well as the secondary operator. A total of 160 patients (40 patients each with single vessel disease [SVD], double vessel disease [DVD] and triple vessel disease [TVD] undergoing coronary angioplasty, and 40 patients undergoing balloon mitral valvuloplasty [BMV]) were randomised in a 1:1 pattern to undergo a procedure with or without the use of RADPAD. For patients with SVD, DVD and TVD undergoing percutaneous coronary intervention (PCI) and those undergoing BMV, the % reduction with the use of RADPAD reduced the PO's received dose (in mrem) by 65%, 54%, 28% and 67%, respectively, as compared to without RADPAD. The % reduction in relative operator exposure for the PO for the 4 groups was 55%, 34%, 18% and 75%, respectively, with the use of RADPAD. The corresponding % reduction for the SO's received dose (in mrem) was 80%, 63%, 33% and 69% and for relative operator exposure was 74%, 46%, 23% and 76% in the 4 groups, respectively. RADPAD significantly reduces the radiation exposure of the primary and secondary operator during prolonged complex PCI and BMV procedures.

Investigation of scatter radiation intensities in the cardiac catheter laboratory: novel versus traditional shielding solutions.

A manufacturer has released a novel shielding solution (NSS): Rampart M1128 and claimed that the personal protective equipment (PPE) can be removed. This study investigates the scatter intensities with the NSS or the traditional shielding solutions (TSS) including the ceiling-suspended screen and the tableside lead drape. Isodose maps were generated by two series of measurements with an anthropomorphic phantom using NSS and TSS. Three survey meters were positioned at different heights to measure the scatter intensities at the eye, chest, and pelvic levels. Additional measurements were made at the primary and secondary operators? locations to evaluate the scatter intensities with different clinical projections. For the main operator positions, the isodose maps showed that NSS could result in a scatter dose that reduced by 80% to 95% compared to the same positions with TSS at the eye and chest levels. The corresponding result at the pelvic level was a reduction of 50%. These reductions should be compared to the additional protection by PPE: up to 80% reduction from lead eyeglasses and up to 95% from protective garments. Considering both operators at clinically relevant LAO projections, NSS resulted in scatter dose that was 80% to 96%, 76% to 96% and 25% to 60% lower than those of the TSS at eye, chest and pelvis levels. The protection of NSS is comparable with that of TSS alongside PPE at the eye but not at the chest and the pelvic levels under the setup of coronary angiography.

Coalition Formation for Outsourced Spectrum Sensing in Cognitive Radio Network

We inspect an opportunistic Cognitive Radio Network formed between a Primary Network Provider (PNP) and secondary IoT operators. In our system, spectrum-sensing duty is offloaded to a Sensing Agent (SA), which allows the IoT operators to improve data rate and reduce energy consumption otherwise needed for spectrum-sensing. IoT operators pay PNP for accessing licensed spectrum and SA for providing sensing as a service. We use Nash bargaining to finalize negotiations among PNP, IoT operators, and SA. Our investigation shows that incorporating SA improves the throughput and utility of PNP and IoT operators. Coalition formation among IoT operators helps them avoid intra-coalitional interference by accessing the spectrum in time-shared fashion. As the valuation of a coalition depends on other coalitions, we analyze coalition formation as a Partition Function Game. We emphasize economic fairness among the coalitions to prevent monopolization. We define a proportional fairness-based metric based on which the final coalition structure is determined. In general, finding an optimal coalition structure is an NP-hard problem. The fairness criterion, along with the unique properties of the Nash bargaining solution allows us to transform the coalition formation problem into a more tractable Number Partitioning Problem and develop an efficiently computable coalition formation technique.

Nursing and human-computer interaction in healthcare robots for older people: An integrative review.

This study examined the published works related to healthcare robotics for older people using the attributes of health, nursing, and the human-computer interaction framework. An integrative literature review. A search strategy captured 55 eligible articles from databases (CINAHL, Embase, IEEE Xplore, and PubMed) and hand-searching approaches. Bibliometric and content analyses grounded on the health and nursing attributes and human-computer interaction framework were performed using MAXQDA. Finally, results were verified using critical friend feedback by a second reviewer. Most articles were from multiple authorship, published in non-nursing journals, and originating from developed economies. They primarily focused on applying healthcare robots in practice settings, physical health, and communication tasks. Using the human-computer interaction framework, it was found that older adults frequently served as the primary users while nurses, healthcare providers, and researchers functioned as secondary users and operators. Research articles focused on the usability, functionality, and acceptability of robotic systems. At the same time, theoretical papers explored the frameworks and the value of empathy and emotion in robots, human-computer interaction and nursing models and theories supporting healthcare practice, and gerontechnology. Current robotic systems are less anthropomorphic, operated through real-time direct and supervisory inputs, and mainly equipped with visual and auditory sensors and actuators with limited capability in performing health assessments. Results communicate the need for technological competency among nurses, advancements in increasing healthcare robot humanness, and the importance of conscientious efforts from an interdisciplinary research team in improving robotic system usability and utility for the care of older adults.

Dynamic Spectrum Sharing Optimization and Post-Optimization Analysis With Multiple Operators in Cellular Networks

Dynamic spectrum sharing aims to provide flexible spectrum usage and improve spectrum efficiency for cellular and noncellular networks. We propose two optimization models using stochastic optimization algorithms in which the secondary operator: 1) spends the minimal cost to achieve the target grade of service (GoS) assuming unrestricted budget or 2) gains the maximal profit to achieve the target GoS assuming restricted budget. We assume that there are spectrum resources available for secondary operators to borrow under a merchant mode . Results obtained from each model are then compared with results derived from algorithms in which spectrum borrowings are random. Comparisons showed that the gain in the results obtained from our proposed stochastic-optimization framework is significantly higher than heuristic counterparts. Second, post-optimization performance analysis of the operators in the form of blocking probability in various scenarios is investigated to determine the probable performance gain and degradation of the secondary and primary operators, respectively. We mathematically model the sharing agreement scenario and derive the closed-form solution of blocking probabilities for each operator. Results show how the secondary operator performs in terms of blocking probability under various offered loads and sharing capacity.

Detection and Leasing of Joint Space and Spectrum Opportunities by Multiple Secondary Network Operators in Cognitive Radio Systems

The fifth generation (5G) wireless networks are expected to achieve 1000 times higher capacity compared to the fourth generation (4G) wireless networks. This implies that maximizing the spectrum efficiency will be one of the key issues to 5G systems. In this paper we consider the problem of detecting and leasing the joint space and spectrum opportunities by a number of secondary network operators (SNOs) in a cognitive network. With the exploitation of an antenna array equipped at each SNO, the whole space in the view of the array can be sliced by multiple partially overlapped beams for each narrowband channel. We derive the energy detection probability of the primary users (PUs) at a given beam for each narrowband channel and the probabilities of that the PUs are located respectively at each neighboring beam under the condition of the PUs located at the given beam and the given narrowband channel. To maximize the spectrum utility, we propose to model the spectrum leasing market of the cognitive network for the obtained opportunities in the framework of the differential games, such that the spectrum price and demand are controlled by a dynamic system. We then derive the open-loop equilibria of the game. Simulation results confirm the efficacy of the proposed methods.

Regulatable and Modulable Background Expression Control in Prokaryotic Synthetic Circuits by Auxiliary Repressor Binding Sites.

Expression control in synthetic genetic circuitry, for example, for construction of sensitive biosensors, is hampered by the lack of DNA parts that maintain ultralow background yet achieve high output upon signal integration by the cells. Here, we demonstrate how placement of auxiliary transcription factor binding sites within a regulatable promoter context can yield an important gain in signal-to-noise output ratios from prokaryotic biosensor circuits. As a proof of principle, we use the arsenite-responsive ArsR repressor protein from Escherichia coli and its cognate operator. Additional ArsR operators placed downstream of its target promoter can act as a transcription roadblock in a distance-dependent manner and reduce background expression of downstream-placed reporter genes. We show that the transcription roadblock functions both in cognate and heterologous promoter contexts. Secondary ArsR operators placed upstream of their promoter can also improve signal-to-noise output while maintaining effector dependency. Importantly, background control can be released through the addition of micromolar concentrations of arsenite. The ArsR-operator system thus provides a flexible system for additional gene expression control, which, given the extreme sensitivity to micrograms per liter effector concentrations, could be applicable in more general contexts.

Price and Inventory Competition in Oligopoly TV White Space Markets

In this paper, we investigate an oligopoly-competitive TV white space (TVWS) market, where multiple secondary network operators compete to serve a common pool of secondary end users by using TVWS purchased from a white space database. We first study the competitive interactions among secondary operators. Specifically, we formulate the interactions as a noncooperative price-inventory competition game, where operators determine the spectrum inventory (purchased from the database) and the service price (charged to end users) simultaneously. We prove the existence and uniqueness of the Nash equilibrium using the supermodular game theory. Then, we study the impact of the database manager's wholesale pricing strategy on the market equilibrium. Specifically, we analytically show how the wholesale prices affect the operators' equilibrium inventory and pricing decisions. Based on this analysis, we further propose two different spectrum wholesale pricing strategies that maximize the database manager's profit and the total network profit, respectively. Our simulations evaluate the performance difference between these two wholesale pricing strategies.

An analytical model for optimal spectrum leasing under constraints of quality of service in CRNs

Cognitive radio improves spectrum efficiency and mitigates spectrum scarcity by allowing cognitive users to opportunistically access idle chunks of the spectrum owned by licensed users. In long-term spectrum leasing markets, secondary network operators make a decision about how much spectrum is optimal to fulfill their users’ data transmission requirements. We study this optimization problem in multiple channel scenarios. Under the constrains of expected user admission rate and quality of service, we model the secondary network into a dynamic data transportation system. In this system, the spectrum accesses of both primary users and secondary users are in accordance with stochastic processes, respectively. The main metrics of quality of service we are concerned with include user admission rate, average transmission delay and stability of the delay. To quantify the relationship between spectrum provisioning and quality of service, we propose an approximate analytical model. We use the model to estimate the lower and upper bounds of the optimal amount of the spectrum. The distance between the bounds is relatively narrow. In addition, we design a simple algorithm to compute the optimum by using the bounds. We conduct numerical simulations on a slotted multiple channel dynamic spectrum access network model. Simulation results demonstrate the preciseness of the proposed model. Our work sheds light on the design of game and auction based dynamic spectrum sharing mechanisms in cognitive radio networks.

The Civiiiability For Damage's Caused To The Goods From Loading to Discharge BY Sea Carriage

Maritime transport, maritime law is an important issue, and a turning point in the study of the subjects of this type of transport, civil liability to compensate damages to the goods during transit is. Dispute about responsibility for maritime transport operators, technical developments in the various aspects that, in recent decades, formed in marine transport, and has led a variety of contracts, in addition to the transport operators, who spoke of the responsibility as a secondary transport operators, ship owner, tenant, ship, forwarder and drainage contractors, and the arise, so that the works of jurisprudence is visible, the various stages of transportation, and the responsibility of identifying persons involved in each of these steps, based on domestic and international jurisprudence, the objectives of this article.

Joint Operator Pricing and Network Selection Game in Cognitive Radio Networks: Equilibrium, System Dynamics and Price of Anarchy

This paper addresses the joint pricing and network selection problem in cognitive radio networks (CRNs). The problem is formulated as a Stackelberg game, where the primary and secondary operators (POs and SOs) first set the network subscription price to maximize their revenue. Then, users perform the network selection process, deciding whether to pay more for a guaranteed service or to use a cheaper best-effort secondary network, where congestion and low throughput may be experienced. We derive optimal stable price and network selection settings. More specifically, we use the Nash equilibrium concept to characterize the equilibria for the price setting game. On the other hand, a Wardrop equilibrium is reached by users in the network selection game since, in our model, a large number of users must individually determine the network to which they should connect. Furthermore, we study network users' dynamics using a population game model, and we determine its convergence properties under replicator dynamics, which is a simple yet effective selection strategy. Numerical results demonstrate that our game model captures the main factors behind cognitive network pricing and network selection, thus representing a promising framework for the design and understanding of CR systems.

Decentralized Bargain: A Two-Tier Market for Efficient and Flexible Dynamic Spectrum Access

Market mechanisms have been exploited as important means for spectrum acquisition and access in cognitive radio networks. In this paper, we propose a two-tier market for decentralized dynamic spectrum access. In the proposed Tier-1 market, spectrum is traded from a primary user (PU) to secondary users (SUs) in a relatively large time scale to reduce signaling overhead. Then, driven by dynamic traffic demands, SUs set up the Tier-2 market to redistribute channels among themselves in a small time scale. More specifically, we use a Nash bargain game to model the spectrum acquisition of SUs in the Tier-1 market and derive the equilibrium prices. We then employ a strategic bargain game to study the spectrum redistribution in the Tier-2 market, where SUs can exchange channels with low overhead through random matching, bilateral bargain, and the predetermined market equilibrium price. We investigate how various factors, such as the availability of channels and bargain partners, matching strategies, and traffic dynamics, affect the market relationships. This work provides new understanding on the spectrum market and valuable guidelines to primary and secondary network operators.

Reduction in operator radiation exposure during transradial catheterization and intervention using a simple lead drape

Transradial access for cardiac catheterization and intervention is a recognized method for reducing complications and improving patient comfort. However, there are concerns over possible increased operator radiation exposure. We tested the hypothesis that a simple lead drape would reduce operator exposure in transradial procedures. Patients undergoing either diagnostic or interventional procedures using transradial access were assigned in an alternating manner to the use of a 0.5-mm lead apron across the patient's abdomen in addition to standard operator protection. Patients were divided into 4 groups: (left enhanced shielding vs left standard shielding; right enhanced shielding vs right standard shielding). Dosimeters were taped to the primary and secondary operators' left wrist and outside the thyroid guard. The operator exposure was measured for each site on every case in centigray. In standard shielded patients, there was no increase in operator exposure between the left and right approach patients at any measurement site. Measured exposure was reduced with enhanced shielding at all dosimeter sites except the secondary operator's collar (both left and right) and the primary operator's collar from the right. There was no significant difference in fluoroscopy, air kerma, or dose area product between standard and enhanced shielded patients. The use of a lead drape reduces the rate of operator radiation exposure at multiple measurement sites. Use of the left radial approach was not associated with an increase in operator exposure compared with the right radial approach.

Duopoly Competition in Dynamic Spectrum Leasing and Pricing

This paper presents a comprehensive analytical study of two competitive secondary operators' investment (i.e., spectrum leasing) and pricing strategies, taking into account operators' heterogeneity in leasing costs and users' heterogeneity in transmission power and channel conditions. We model the interactions between operators and users as a three-stage dynamic game, where operators simultaneously make spectrum leasing decisions in Stage I, and pricing decisions in Stage II, and then users make purchase decisions in Stage III. Using backward induction, we are able to completely characterize the dynamic game's equilibria. We show that both operators' investment and pricing equilibrium decisions process interesting threshold properties. For example, when the two operators' leasing costs are close, both operators will lease positive spectrum. Otherwise, one operator will choose not to lease and the other operator becomes the monopolist. For pricing, a positive pure strategy equilibrium exists only when the total spectrum investment of both operators is less than a threshold. Moreover, two operators always choose the same equilibrium price despite their heterogeneity in leasing costs. Each user fairly achieves the same service quality in terms of signal-to-noise ratio (SNR) at the equilibrium, and the obtained predictable payoff is linear in its transmission power and channel gain. We also compare the duopoly equilibrium with the coordinated case where two operators cooperate to maximize their total profit. We show that the maximum loss of total profit due to operators' competition is no larger than 25 percent. The users, however, always benefit from operators' competition in terms of their payoffs. We show that most of these insights are robust in the general SNR regime.

2012 American college of cardiology foundation/society for cardiovascular angiography and interventions expert consensus document on cardiac catheterization laboratory standards update: American college of cardiology foundation task force on expert consensus documents society of thoracic surgeons society for vascular medicine

2012 American college of cardiology foundation/society for cardiovascular angiography and interventions expert consensus document on cardiac catheterization laboratory standards update: American college of cardiology foundation task force on expert consensus documents society of thoracic surgeons society for vascular medicine

Entry, Competition, and Regulation in Cognitive Radio Scenarios: A Simple Game Theory Model

Spectrum management based on private commons is argued to be a realistic scenario for cognitive radio deployment within the current mobile market structure. A scenario is proposed where a secondary entrant operator leases spectrum from a primary incumbent operator. The secondary operator innovates incorporating cognitive radio technology, and it competes in quality of service and price against the primary operator in order to provide service to users. We aim to assess which benefit users get from the entry of secondary operators in the market. A game theory‐based model for analyzing both the competition between operators and the subscription decision by users is proposed. We conclude that an entrant operator adopting an innovative technology is better off entering the market, and that a regulatory authority should intervene first allowing the entrant operator to enter the market and then setting a maximum amount of spectrum leased. This regulatory intervention is justified in terms of users utility and social welfare.

A LacI-DNA Looping Landscape and Allosteric Effects on the Loop Shapes

The lac operon and its repressor (LacI) are the prototype model for gene regulation. LacI negatively regulates lacZYA by binding a primary DNA operator site overlapping the promoter, and repression is enhanced by secondary operators that deliver LacI via looping intervening DNA. LacI's ability to form stable loops with a variety of DNA lengths has been attributed to protein flexibility and/or to multiple loop topologies. Previously developed DNA constructs in which looping is hyperstabilized by an A-tract bend placed between two operators provide different loop shapes depending on the operator/bend helical phasing. Here, FRET is used to characterize the sequence/structure landscape of a set of related constructs with systematically varied operator/bend phasings. Donor and acceptor fluorophores positioned on either side of the operator provide multiple distance constraints on the orientations of the LacI-DNA loop. The results suggest that LacI can form many different looped states whose relative energetics can be measured. Also, IPTG addition demonstrates that inducer-bound LacI still forms stable loops, probably with different geometries relative to the repressed state. This comprehensive looping landscape should allow determination of whether protein flexibility is necessary to explain the results.

Inter-Operator Spectrum Sharing from a Game Theoretical Perspective

We address the problem of spectrum sharing where competitive operators coexist in the same frequency band. First, we model this problem as a strategic non-cooperative game where operators simultaneously share the spectrum according to the Nash Equilibrium (NE). Given a set of channel realizations, several Nash equilibria exist which renders the outcome of the game unpredictable. Then, in a cognitive context with the presence of primary and secondary operators, the inter-operator spectrum sharing problem is reformulated as a Stackelberg game using hierarchy where the primary operator is the leader. The Stackelberg Equilibrium (SE) is reached where the best response of the secondary operator is taken into account upon maximizing the primary operator's utility function. Moreover, an extension to the multiple operators spectrum sharing problem is given. It is shown that the Stackelberg approach yields better payoffs for operators compared to the classical water-filling approach. Finally, we assess the goodness of the proposed distributed approach by comparing its performance to the centralized approach.

Mentors Decrease Compliance with Best Sterile Practices during Central Venous Catheter Placement in the Trauma Resuscitation Unit

In the academic trauma unit during initial evaluation and resuscitation of trauma victims, central venous catheters are often placed by multiple operators. There are few data on compliance with accepted, standard sterile practices during such procedures. Prospective data were tabulated from video capture of 144 consecutive central venous catheterizations in a trauma resuscitation unit, during peak hours, by a team of trained video technicians. The physicians were surgical and emergency medicine residents. The number of primary operators (trainees) and secondary operators (mentors) for each line was recorded from the video analysis, as well as physician adherence to the use of maximum barrier precautions (MBP; sterile gown, gloves, full operative drape, cap, and mask). Procedures were stratified by level of urgency: Emergent (n = 7), semi-emergent (n = 20), and elective (n = 113). The subclavian vein was used for 73% of the elective catheter placements. For elective central venous catheters, 99 of 113 primary operators (88%) observed MBP, whereas only 31 of 45 secondary operators (69%) did so (p < or = 0.01). Among the 45 elective central venous catheters placed with a secondary operator, there were four instances of frank contamination (9%). Secondary operators, typically trauma surgery attendings, trauma/critical care fellows, or senior surgical residents, function as mentors in academic institutions and act as role models. Secondary operators participated in many of the studied cases, yet failed to demonstrate consistent use of MBP. In elective central venous catheter placement, those where there was the greatest opportunity to follow MBP, we observed a statistically significant difference in compliance rate between the primary and secondary operators. The study suggests the need to address the performance of the secondary operators and to educate them, as although they may be technically experienced in placing central venous catheters, they may comply less consistently with MBP.

Secondary differential operators

Let Ч be an arbitrary sustem of partial (non-linear differential equations. Higher infinitesimal sysmmetries of Ч may be interpreted as vector fields on the «manifoldå Sol Ч of all local solution of this system. The paper deals with construction of differential operators of arbitrary orders on Sol Ч. These approaches to construction of the theory of these operators, geometric and functional are presented, and their equivalence is proved when Ч is the trivial equation. Coincidence of «extrinsicå and «intrinsicå geometric secondary operator is proved for an arbitrary system Ч. It is shown that each geometric secondary operator may be approximated by a sum of compositions of evolution differentiations with any possible accuracy, a description of geometric secondary operators in local coordinates is algo given. These results are obtained by studying the geometry of finite jets and infinitely prolonged equations.