In order to prolong the network lifetime, energy-efficient protocols adapted to the features of wireless sensor networks should be used. This paper explores in depth the nature of heterogeneous wireless sensor networks, and finally proposes an algorithm to address the problem of finding an effective pathway for heterogeneous clustering energy. The proposed algorithm implements cluster head selection according to the degree of energy attenuation during the network’s running and the degree of candidate nodes’ effective coverage on the whole network, so as to obtain an even energy consumption over the whole network for the situation with high degree of coverage. Simulation results show that the proposed clustering protocol has better adaptability to heterogeneous environments than existing clustering algorithms in prolonging the network lifetime. In previous research, the sensor embedded system used to be in charge of dealing with the information, and sending the sensed information to the user terminal by multi-hop relay through a self-organized wireless communication network, so as to realize the “ubiquitous computing” concept. WSNs have created a new era for information acquisition and processing technology, and have promising application prospects in many fields, such as national defense, industry, smart city, Internet of things (IoT), cyber-physical system (CPS), radio frequency identification(RFID), etc. [Wireless sensor networks (WSNs) are deployed in monitoring regions equipped with a large number of sensor nodes with neither partition nor infrastructure support, through the wireless self-organized network in multi-hop communication mode . As a kiD), etc. . In the Present studies on WSNs are mainly confined to isomorphic network fields. Isomorphism in WSNs is used to simplify all of the node sensors to be of the same structure, while ignoring the effect the heterogeneity of any node brings to the design of network and protocols . At the At present the research on heterogeneous networks is still in the initial stages of exploration, and there are still a series of unsolved problems to be solved. For example, exploring the scientific meaning of heterogeneous wireless sensor networks, and the specific content of networks in heterogeneous forms. The heterogeneous network model is at present so simple that it cannot adequately describe the actual application scenarios, thus the problem of how to construct the heterogeneous network, that involves how to design energy efficient strategies in heterogeneous networks, and thereafter improve the energy efficiency of the heterogeneous network remains unresolved. Therefore, the utilization of a large number of isomorphic WSN theories in heterogeneous networks has a profound theoretical and practical significance.Sensor nodes organized in the form of clusters can effectively achieve energy savings in the network. Many energy-efficient routing protocols are designed based on the cluster structure . In the At present, many domestic and foreign experts have proposed numerous different distributed clustering algorithms. The widely adopted algorithms refer to isomorphic or heterogeneous networks, which can be divided into two categories, namely those with the same composition and different composition clustering algorithms. Because of the complexity and energy configuration of network evolution, it is very difficult to design a suitable heterogeneous network energy efficient clustering algorithm. Many algorithms under the isomorphism network environment find it difficult to make full use of the heterogeneous characteristics of energy, thus low energy nodes will die earlier than high energy nodes. The proposed protocol is designed for a heterogeneous network ,6, whichIn this paper, we focus on and explore in depth the nature of heterogeneous wireless sensor networks, and finally propose a novel energy-aware distributed clustering algorithm for heterogeneous wireless sensor networks (EDCA-H), which addresses the problem of finding an effective pathway for heterogeneous clustering energy. The proposed algorithm implements cluster head selection according to the degree of energy attenuation while the network is running and the degree of candidate nodes’ effective coverage on the whole network, so as to obtain an even energy consumption over the whole network for the situation with high degree of coverage.The rest of this paper is organized as follows: a brief introduction of works related to the topic of energy saving in heterogeneous wireless sensor networks is presented in Recently, most of the energy efficient protocols designed for heterogeneous networks are based on the clustering technique , which iIn those protocols, the nodes are equipped with the same energy at the beginning, but the networks cannot evolve equally for each node in expending energy, due to the radio communication characteristics, random events such as short-term link failures or the morphological characteristics of the field . Howeveret al. proposed a SEP scheme [et al. considered an event detection heterogeneous network with two types of nodes that included type-1 and type-0 node. Type-1 nodes had more battery energy than type-0 nodes. The key design features were that the energy supply was built into the nodes and the network lifetime was analyzed.According to the initial energy, Smaragdakis P scheme  for a twP scheme , Lee et et al. proposed a distributed energy efficient clustering algorithm (DEEC) [Zhu m (DEEC)  for multi.e., decreasing the network lifetime. In wireless sensor networks, due to the widespread presence of heterogeneous resource nodes, many researchers have done profound work probing into HWSNs.There are three common types of resource heterogeneity in sensor nodes: computational heterogeneity, link heterogeneity, and energy heterogeneity . Computaet al. proposed an energy efficient heterogeneous clustered (EEHC) scheme for heterogeneous wireless sensor networks, which particularly presented the setting, the energy model, and how the optimal number of clusters could be computed. In order to make more rational use of network energy and prolong the lifetime of multilevel heterogeneous wireless sensor networks, Peng et al. proposed a new heterogeneous sensor network model with heterogeneity of monitored objects and energy heterogeneity of all nodes, called energy-efficient prediction clustering algorithm (EEPCA) [In , Kumar e (EEPCA) .The low-energy nodes will die more quickly than the high-energy ones, because these clustering algorithms are unable to treat each node discriminatorily in terms of the energy discrepancy. Therefore, a heterogeneous network model in term of different initial energies was discussed in . From thet al. proposed a novel stable selection and reliable transmission protocol for clustering in heterogeneous wireless sensor networks, which can be applied to networks with three different kinds of heterogeneous nodes. Nodes in this protocol were divided into two common types: one performing the function of managing information and the others collecting different data . Type 1 had more complex hardware and software architectures, so they had more initial energy and greater data transfer capability, but the application of this protocol had been limited to networks with only two types of ordinary nodes. In [In , Zhou etodes. In , Attea aWe consider a probabilistic WSN consisting of In a multi-level heterogeneous network, the initial energy of nodes may be randomly distributed within a closed interval, such as p) rounds, the threshold T (n), then the node will become the cluster head in the next round and send a broadcast message. r denotes the number of current round, and r mod(1/optp) rounds, so each node has the opportunity to become the CH. The threshold function in Equation (1) is improved actually based on LEACH, and demonstrates the bootstrap if the node has not yet been elected as cluster head node in the current 1/p rounds. Meanwhile, the probability value assignment for CH selection is conducted randomly to ensure that the is a suitable number of cluster heads in the network, thus to improve the coverage ratio of the whole network. However, the threshold function is focused on the application of heterogeneous wireless sensor networks [If the node had not been cluster head (CH) for the last  into (4), we can obtain an approximation of the total energy consumed by a single node within a cluster. According to , we can Thus, the estimated value of the entire network lifetime is:In the later experiments, we consider the effect of random factors in which all nodes will not die at the same time. Then, Suppose that each node’s energy is consumed uniformly in every round, then the average energy in the round In order to prolong the lifetime of the whole network, we should ensure that all nodes die at the same time. Obviously, the nodes with higher residual energy should possess a much higher average probability In order to avoid data routing through areas sparely covered by the sensor nodes, the concept of coverage cost was originally introduced into DAPR as a routing metric by Perillo . Since tIn the Coverage Preserving Protocol, Nghiem proposed a cluster-head selection algorithm based on the coverage cost or normalized sensing coverage area of each sensor node . The senFor the simplest example, To calculate the coverage cost, every node m. The specific node Then, the equivalent distant With According to Equation (14), The cluster head nodes need not only collect and process data detected by cluster member nodes, but also are responsible for forwarding data, thus the reasonable selection of cluster heads is very important. In addition, the influence of the number of cluster head nodes on the network lifetime is crucial . If the The SEP protocol  is a hetIn general, the average probability We can extend this model to the case of a multi-level heterogeneous network. Through the use of the weighted probability of Equation (5) instead of the In which, The network lifetime is divided into different time periods, and each time section is divided into a node self-organizing scheduling stage and a working stage. Node selection is responsible for monitoring the target object in the scheduling phase, and the cluster head nodes target data acquisition at the cluster for forwarding to the sink node, while other nodes enter a sleep state. First, they perform as a neighbor node and broadcast a Protocol Independent Multicast (PIM) message. In order to avoid multiple nodes and sending the PIM message leading to channel conflict and message loss, in sending the PIM message we wait for a random time. The PIM message contains a node ID, node residual energy, location and other members in the cluster node ID and other information. A redundant coverage judgment needs to consider the coverage of all neighbor nodes. In order for this stage to have a minimum energy overhead, it just makes sure of the transmission distance to its one-hop neighbor nodes when sending a PIM message. In this way, each node can only receive data from one-hop neighbor nodes which send the PIM message. After collecting all the infor timeafter mation of neighbors, if we judge there is redundant coverage nodes, each node before dormancy waits for a period of time in order to avoid also being judged themselves as redundant nodes and the emergence of coverage blind spots. This waiting rule is implemented by setting the timer for a certain period of time after the end of the transition to a dormant state.(1)if (2)if Therefore, this paper introduces a node residual energy balance priority scheduling mechanism. For the cover-relevant nodes s and V, if the initial energies are In order to realize the activation of residual energy balance between nodes, reduce the activation of the nodes in a cycle exhausted energy probability, the value of Step 1. Send a PIM message, and collect information from neighbor nodes;Step 2. To determine whether redundant nodes are possible. If there is a redundant node, then there is a delay for a period Step 3. The possible redundant nodes monitor the communication channel in the delay period Step 4. At the end of the delay Step 5. At the end of the sleep preparation period, the transfer to a dormant state will be immediately started.2, 4, In this section, we perform simulations in MATLAB to evaluate the performance of both EDCA-H and other protocols. There are 100 sensor nodes randomly distributed in the 100 m × 100 m area. The base station is located at the top of the sensing area with the distance of 75 m. The base station and all the sensor nodes are assumed to be fixed. None of the sensor nodes are equipped with devices for detecting their own locations and their own location may be estimated with some localization algorithms. All the sensor nodes are homogeneous with limited energy. In the simulations of this section, let  LEACH-C , SEP [15 LEACH-C  and otheAs the parameter For two-level heterogeneity, we evaluate the performance of the different protocols by varying the parameters Furthermore, we also examine the number of rounds until 10% of the nodes run out of energy. Before these nodes die, the data transmission to the base station can be of high quality and reliability. Meanwhile, it can be noted that EDCA-H can obtaina stabler period than LEACH-C and SEP with the increase of As the LEACH algorithm does not consider the difference of nodes’ initial energy in heterogeneous wireless sensor networks, it makes good use of additional energy from the advanced nodes. The stabilization period is very short in DCHS and the nodes died according to a fixed rate. We find that our algorithm achieves the highest lifetime compared with the other approaches. Specifically, our algorithm improves the lifetime by 17.83% compared with DCHS and 8.79% compared with SEP. The improvement is less significant compared with SEP because SEP divides the area into several sectors in order to minimize the transmission distance from sensors to CHs as well as to balance the cluster size. However, EDCA-H can outperform LEACH-C in terms of effective amount of data as shown in In addition, we investigate the number of active nodes under the condition of different network size as shown in As can be seen from As a heterogeneous wireless sensor network energy consumption is not uniform, and the energy utilization rate is low. This paper studied the energy consumption of a heterogeneous clustered sensor network, and proposed a new energy efficient routing algorithm for clustering in such networks. The proposed method selects the cluster head node according to the energy of the nodes during the running of the network, so as to achieve high coverage. In the future, with the adoption of mobile sensor nodes, we will study whether the balance of energy consumption among nodes can be achieved through density regulation, which aims at maximizing network lifetime.


Trafficking of soluble cargo to the vacuole is far from being a closed issue as it can occur by different routes and involve different intermediates. The textbook view of proteins being sorted at the post-Golgi level to the lytic vacuole via the pre-vacuole or to the protein storage vacuole mediated by dense vesicles is now challenged as novel routes are being disclosed and vacuoles with intermediate characteristics described. The identification of Vacuolar Sorting Determinants is a key signature to understand protein trafficking to the vacuole. Despite the long established vacuolar signals, some others have been described in the last few years, with different properties that can be specific for some cells or some types of vacuoles. There are also reports of proteins having two different vacuolar signals and their significance is questionable: a way to increase the efficiency of the sorting or different sorting depending on the protein roles in a specific context? Along came the idea of differential vacuolar sorting, suggesting a possible specialization of the trafficking pathways according to the type of cell and specific needs. In this review, we show the recent advances in the field and focus on different aspects of protein trafficking to the vacuoles. In the past decades, plants have also been exploited for the production of recombinant pharmaceutical products, such as edible vaccines, antibiotics and vitamins. Plant biologists are currently joining efforts for plant science to progress toward of a definition of integrated circuits of metabolic pathways and sub-cellular structures to accompanying the challenges imposed by animal and yeast sciences.Besides understanding plants as a whole organism, it is fundamental to track the subcellular mechanisms beneath. Identifying the molecules (proteins and enzymes), their biogenesis and their functions is fundamental to understand their role in plant cell homeostasis and ultimately to develop rational crop improvement strategies. The plant cell is effectively an integrated community of membrane-delimited compartments, each of which has evolved to optimize and separate specific biochemical functions. Functional organization of the endomembranes is a key cellular infrastructure allowing the cell the continuous adaptation needed for the metabolic and structural changes occurring in vegetative and reproductive tissues. The major production line of the cell biosynthetic factory is made by distinct organelles constitutive of the cell secretory pathway: Endoplasmic Reticulum, Golgi Apparatus, Endosomes, Pre-vacuolar and Vacuolar compartments. The specificities of plant endomembrane biology, notably the Endoplasmic Reticulum-Golgi complex or the endosomal and vacuolar organization, outline the amazing ability of plant cells to re-organize its membrane system according to the cell needs.Presently, studies on plant endomembrane focus on several lines of research: the functional characterization of compartments designing the endomembrane system, the identification of pathways and vesicle carriers to transport cargo molecules from one compartment to the other and the identification of molecular machineries associated with these transport specificities. Any protein trafficking within the endomembrane system is orchestrated by all the events, permitting to reach the right compartment, by the right route, at the right time.2.In most of the plant cells, the vacuole is the largest structure present and plays several roles in maintaining organization and cellular function and is involved in intracellular digestion of various materials, maintaining of turgor and accumulation of nutrients, ions and secondary metabolites. In seeds, protein storage vacuoles (PSVs) are the most abundant whereas in vegetative tissues the vacuolar functions are accomplished by large central vacuoles denominated lytic vacuoles (LV) ,2. The p+-ATPase, V-PPase and γ-TIP [Arabidopsis thaliana vacuome upon germination, illustrating the complexity of this system. Their results demonstrate a rapid and extreme reorganization of PSVs and LVs during early stages of seed germination, with the coexistence of two distinct compartments with very distinguishable roles.Vacuolar development and remodeling, particularly during seed germination, has gained a notorious importance given the immense changes occurring in a short time. It has been proposed that vacuolar membranes of PSV are transformed into those of central vacuoles upon germination . Findingnd γ-TIP ,9. Howevnd γ-TIP  observednd γ-TIP  describeThe vacuolar metabolome has gained interest recently as the preliminary results obtained provide the basis for future studies to compare the storage and lytic metabolomes that would allow a more comprehensive understanding of the vacuolar systems of transport and metabolism .3.cis-face as there is a protein sorting triangle between TGN, vacuole and endosome/plasma membrane. The number of SNARE proteins existing in the trans-GA illustrates the high differentiation degree and the large number of specific membrane-recognition events possible [Vacuolar sorting is nowadays and since the last decade one of the most advanced and attractive research field in what concerns secretory protein trafficking. Proteins inserted in the Endoplasmic Reticulum (ER) have different ways to reach the vacuole, and may use different halt-stations to do so. For instance they may go through the Golgi Apparatus (GA), or bypass the GA, they may reach the plasma membrane and come back to the vacuole or they may be stored in intermediate compartments before to be delivered. From the trans-Golgi network (TGN), transit routes to the cytoplasmic membrane and transport to the vacuole diverge. Proteins lacking a signal enter the so-called default pathway, being transported in vesicles that eventually fuse with the plasma membrane, releasing their contents to the outside . Vesiclepossible . Secretopossible ,14. Multpossible , but morConversely to the other routes described, vacuolar sorting of secretory proteins requires positive sorting at the TGN. The cargo proteins targeted to the vacuole are recognized at the GA level by vacuolar sorting receptors (VSRs) and are released into PVC/MVB after fusion of the transport carriers with their membrane. The VSR is then recycled back to the TGN and the cargo molecules are transported to the vacuole, where the fusion of the PVC/MVB with the tonoplast occurs . As the N- or C-terminal signal) [In a simplified version of protein transport to the vacuolar system two post-Golgi routes can be considered, ending in different vacuolar compartments—lytic or protein storage—being closely related to the type of signal present in the protein  ,16. Howe signal) . In the  signal) ,17. Cont signal) ,19.C-terminal signal or a signal in the middle of the protein sequence, are transported to the vacuole in dense vesicles derived from the Golgi complex. In a less studied route, observed in storage organs, proteins do not pass through the Golgi apparatus and are transported to the vacuole in vesicles derived from the endoplasmic reticulum (precursor-accumulating vesicles) [Transport to the lytic vacuole occurs after recognition of the sorting signal by the receptor BP-80 (binding protein of 80 kD), a membrane protein responsible for packaging the cargo-protein in clathrin-coated vesicles for transport to the pre-vacuolar compartment and, finally, to the lytic vacuole. Other proteins, with a esicles) ,19 Recenesicles) . At the esicles) . Despiteet al. [C-terminal Vacuolar Sorting Determinant (VSD) of tobacco chitinase and an N-terminal fusion with the sequence-specific VSD of the barley aleurain demonstrating a differential Endoglycosidase H (Endo-H) sensitivity and therefore differential glycan modifications of the glycosylated GFPs. Their finding suggests two different and independent routes to the vacuole for the two reporters and confirmed that GFPChi transport from the ER to the vacuole is not fully dependent on the Golgi apparatus even if the identity of the compartments through which GFPChi transit on their way to the vacuole could not be established. The characterization of intermediate compartments may be further complicated by evidences that new types of compartments may be specifically induced in some circumstances as described for Arabidopsis plants exposed to carbon starvation [Recently, Stigliano et al.  used twoarvation .The issue of multiple vacuolar transport routes has been already addressed for tonoplast proteins. Information on tonoplast proteins being delivered via three different transport routes was compiled by Robinson and Pimpl . Recent 4.N-terminal of the protein directed to the lytic vacuole. The second main group comprises the signals present at the C-terminal region of the protein (ctVSD) and normally designates proteins destined to the protein storage vacuole. These signals do not have any homologous sequence or size set, having in common that they are rich in hydrophobic amino acids and need to be exposed at the C-terminus to operate. Finally, the third group corresponds to signals dependent on the tertiary  structure of proteins (psVSD) and is most common in storage proteins. These sorting signals are present in the protein sequence, and may correspond to more than one polypeptide that function as whole when the protein acquires the native conformation [For all eukaryotic cells, the transport from the Golgi apparatus to the vacuole or lysosomes requires positive information from the protein. In mammals, the signal to transport proteins to the lysosome is the addition of a mannose 6-phosphate residue during the passage through the Golgi complex, while in plant cells, the vacuolar sorting is part of the peptide sequence ,27. Seveormation ,27,28.C-terminal region of alpha-subunit of soybean beta-conglycinin has two sorting signals, one of the ctVSD type and other of the sequence-specific type [et al. demonstrated that cardosin A is still able to reach the vacuole without one of the VSDs  and that each of them alone is able to redirect a normally secreted mCherry protein to the vacuole [For a peptide to be considered a true vacuolar sorting signal it must be both necessary and sufficient for this function ,29. Therfic type . Both offic type . The plafic type ). Pereir vacuole . The exi vacuole ,34.et al. [C-terminus is required for proper vacuolar sorting. The authors provided evidence that the C-terminal segment of a phaseolin polypeptide undergoes homotypic interactions that allow the formation of a disulfide bond when a Cys residue is introduced proximal to the AFVY C-terminal vacuolar sorting signal. Furthermore, the authors claimed that the vacuolar sorting signal of phaseolin is not necessary for those homotypic interactions and its sorting function can be partially replaced by a C-terminal Cys residue. Based on this data, the importance of multiple copies of vacuolar determinants in assembled homo-oligomeric storage proteins was discussed and is far from being clear. The ratio between number of vacuolar sorting determinants and the size of the passenger protein was also proposed to play a role in the sorting efficiency [Additionally, other study carried out by Pompa et al.  with theficiency . In ligh5.N-glycans confer important in vivo functions to glycoproteins, namely in cell signaling. Presently, little is known about the glycosylation pattern of plant vacuolar proteins. Stigliano and co-workers [In plants, the Golgi apparatus (GA) is a central key in relation to the synthesis of cell wall polysaccharides, and of glycolipids and glycoproteins for the cellular membranes. It has thus an important role in the modification and targeting of the protein and is involved in folding, processing and storage of proteins. It has been long discussed the role of the glycosylation in the vacuolar routes taken by proteins in the secretory pathway, in particular involving a GA bypass ,36. Stud-workers  developeN-glycans are useful “pharming” systems to produce biopharmaceuticals with reduced allergenicity. Therefore, the targeting of therapeutic proteins to the vacuole bypassing the GA would be an exciting approach to overcome the plant-specific glycosylation problem.The existence in plants of a new type of vacuolar traffic that can be used by leaf cells to transport vacuolar proteins offers a great potential, in particular for recombinant protein production in the near future. The available studies in this subject point to a stunning increase in protein production when it is targeted to the vacuole. The problem of targeting foreign proteins to the vacuole is that once entering the secretory pathway, proteins undergo post-translation modifications such as glycosylation. Despite plants produce the same glycosylation patterns as mammals in the ER, when entering the GA the trimming of the glycans is sufficiently different to cause immunogenicity risks. Plant systems with modified glycosylation pathways lacking potentially immunogenic 6.A new topic of discussion is arising in what concerns the vacuolar routes some proteins take in specific organs and how those routes changes in organs with a different metabolic activity. It was observed that the same protein can be either secreted to the apoplast or directed to the vacuole, or accumulate in PSVs or LVs traveling though different routes, depending on the cell type and developmental stage suggesting a tight mechanism of regulation of trafficking.C. cardunculus, cardosin A is mainly found in the protein storage vacuoles of the stigmatic papillae while cardosin B is found in the extracellular matrix of both stigma and style transmitting tissue [Arabidopsis thaliana seedlings. It has also been shown that preprocardosin A is processed along the vacuolar pathway and the last processing step to its mature form, including the removal of the internal PSI domain, occurs in the vacuole probably due to its acid environment [et al. [C-terminal VSD but also an unconventional PSI signal of cardosin A are sorting determinants and mediate two different trafficking pathways. In the experimental model used, the C-terminal signal is dominant over the PSI signal, as it dictates the route the protein takes to the vacuole. It is likely that the two signals act independently and provide the APs with a functional plasticity, controlling vacuolar traffic according to cell constraints or needs. Particularly relevant is the new insight into the regulatory function of the PSI domain in aspartic proteinase trafficking through a specific PSI signaling pathway, which may operate in parallel with another vacuolar pathway.Cardosins, an Aspartic Proteinase family identified in cardoons, illustrate such plurality and complexity in sorting mechanisms ,39. In tg tissue –42. In hironment . Howeverironment . Processironment , could b [et al. . The aut [et al.  demonstrIt was described a Golgi-independent route in which proteins can be transported directly from the ER to the LV by means of entities such as plant-specific endoplasmic reticulum bodies and authors argue that it could provide plants a means for rapid adaptation to environmental changes . Indeed,Arabidopsis seedlings. However, the authors also observed the presence of endoglycosidase-H-sensitive intermediate forms of cardosin A and the failure of the dominant-inhibitory Rab GTPases to completely inhibit processing of procardosin A. This was an early evidence of the existence of two vacuolar routes for cardosin A, one of them bypassing the GA as was subsequently demonstrated by Pereira and collaborators [et al. observed that an intermediate form of cardosin A is secreted from tobacco protoplasts and raised the hypothesis that cardosin A is first secreted as an intermediate processing form and targeted to the vacuole only after subsequent endocytosis from the apoplast. If there is indeed a PSI-mediated route of procardosina A to the cell wall and subsequent endocytosis to the vacuole remains to be proved.Duarte and collaborators  demonstrborators . Moreoveet al. studying the secretion patterns of cell-wall proteins in tobacco protoplasts and leaf epidermal cells, had observed that a protein fusion of polygalacturonase inhibitor protein, PGIP2–GFP reached the cell wall by passing through ER and Golgi stacks but was not stably retained in the cell wall due to internalization to an endosomal compartment and later to the vacuole. However, stable localization of PGIP2 in the cell wall was observed in the presence of a specific fungal endopolygalacturonase ligand in the cell wall. The authors describe cell wall-directed secretion routes distinguishable from the bulk-flow default secretion pathway labeled by secGFP and suggest that rigorous and more complex pathway controls than the simple mechanism of bulk flow are the basis of cell-wall growth and differentiation [De Caroli ntiation .The observed presence of the unprocessed precursor form of cardosin A in the cell walls of specific cell types ,41,45 alEvents that occur at the cell wall level in response to cell transition states (such as seed germination or pollen pistil interactions) or pathogen attack may involve sensing and signaling molecules that could somehow trigger cardosin A (and most probably many other proteins with similar characteristics), an otherwise vacuolar protein, to the apoplast.Proteins or peptides with predicted intracellular function or experimentally established intracellular localization are also secreted to the apoplast under certain conditions, or in specific tissues . Some maMechanisms of unconventional secretion have been identified for proteins that initially enter the secretory pathway through ER translocation and are secreted in a Golgi-independent manner, and also for “leaderless” cytoplasmic proteins lacking the presence of a signal peptide ,48. PossThe contribution of the different pathways postulated for cardosin A depends on cell type and cell requirements. Some pathways may be found in most, if not all, cell types, while others are associated with the specialized functions of particular cell types, and cell identity transitions and general changing developmental and environmental conditions.A model for the proposed trafficking pathways to and from the different compartments, not all necessarily operating in the same cell, is illustrated in the 7.Because of the variety in plant models, cell types and experimental approaches used to decipher vacuolar targeting processes, protein trafficking to the vacuole is far from being a closed issue. Novel routes are being disclosed and vacuoles with intermediate characteristics described. Also, the identity of the compartments through which protein are sorted to the vacuole remains elusive. Despite the long established vacuolar signals, some others have been described in the last few years, with different properties that can be specific for some cells or some types of vacuoles. Proteins having two different vacuolar signals have also been described and its significance is not clear although it may point to different sorting depending on the protein roles in a specific context.The same protein can be either secreted to the apoplast or directed to the vacuole, or accumulate in PSVs or LVs traveling though different routes, depending on the cell type and developmental stage suggesting a tight mechanism of regulation of trafficking. The glycosylation status of the proteins could also interfere with the route taken by the protein to the vacuole.Such plurality and complexity in sorting mechanisms strengthen the idea of differential vacuolar sorting, suggesting a possible specialization of the trafficking pathways according to the type of cell and its specialization in response to developmental programs, cell identity transitions and stress pathways.The identification of all required components of vacuolar sorting and its integration in cellular signaling and regulatory networks that regulate membrane traffic in changing developmental and environmental conditions will be the focus of future studies. Systems-level analysis and cell-type specific genomics will likely contribute to the ever-continuing unraveling of the complex issue of vacuolar targeting processes.


Continuum robot, as known as snake-like robot, usually does not include rigid links and has the ability to reach into a confined space by shaping itself into smooth curves. This paper presents the design of a three-segment continuum robot for minimally invasive surgery. The continuum robot employs a single super-elastic nitinol rod as the backbone and concentric disks assembled on the backbone for tendons attachment. Each segment is driven by four tendons and controlled by two linear actuators. The length of each segment is optimized based on the surgical workspace. A visual servo system is designed to assist the surgeon in operating the robot. Simulation experiment is conducted to demonstrate the proposed design. A continuum robot is a flexible robot inspired by caterpillars, elephant trunks, octopus arms, and mammalian tongues. The robot can vary its nature shape because of the materials flexibility and is capable of reaching into a complex environment. Therefore, the continuum robot has the potential in single-port access surgery and natural orifice transluminal.The basic elements of a continuum robot are backbone, actuators, and disks, as shown in Fig. It is generally assumed that the segment of continuum robot bends with constant curvature . The kinControl of continuum robot possesses a great challenge because of the compliance of continuum robot. The dynamic model of a planar continuum robot has been introduced . The dynA three-segment continuum robot for minimally invasive surgery has been developed in this study. The robot employs a single super-elastic nitinol rod as the backbone. Twelve tendons passing through the concentric disks are used to operate the robot. These tendons are divided into three groups. Each group has two pairs of tendons and is controlled by two linear actuators. The segment length is determined by the cable nodes in the group, which can be adjusted by varying the position of the nodes. Moreover, the approximate boundary of reachable workspace is formulated. A unique method is proposed to minimize the length of continuum robot. Finally, a visual servo system is designed.z-axis (y-axis (The mechanical structure of the proposed continuum robot is shown in Fig. One of the differences between the continuum robot developed in this paper and the continuum robots driven by three tendons is arrangement of actuators. Two common arrangements of actuators are shown in Fig. n is the number of disks. Equation (The configuration of each segment robot is defined by three parameters: the curvature (entclass1pt{minimaThe three-segment continuum robot developed in this paper has six DOFs. The workspace of each segment is determined by three parameters: In this paper, the range of θ. Therefore, the length should be minimized to improve the dexterity of the continuum robot. The dimensional synthesis can be described as the following optimization problem:Now the dimensional synthesis of continuum robot can be analyzed based on the requirement of surgical workspace. Suppose that the surgical workspace is a cuboid, i.e., After the mechanical structure of continuum robot is developed, the next step is to design an interactive system for assisting surgeon in controlling the robot in a user-friendly way.It is assumed that camera can capture all the feature points on each segment of the continuum robot. Then, the configuration of segment can be determined by the feature point (The numerical solution of configuration (d on Eq. . The cond on Eq.  can be aTo verify the design of the continuum robot, the continuum robot prototype was developed. The system consists of linear actuators, cables, pulleys, drivers, camera, digital pen, and digitizer tablet, as shown in Fig. To control the continuum robot, a PD controller was designed with visual feedback. The desired configuration was set as This paper presents the design of a three-segment continuum robot. The approximate boundary of workspace is formulated. The configuration of each segment is determined. In the future, the visual servo control system will be developed, and the controller will be improved.


The pathogenesis of Monteggia injuries remains controversial. The current study biomechanically explored the pathological changes during Monteggia fractures using finite element analysis.Two cadaveric forearm specimens underwent computed tomography in both the prone and supine positions. The images were imported to Mimics to construct three-dimensional images. The obtained models of the annular ligaments were assembled onto the bones. Two thin gaps were produced at the proximal third of the ulna to simulate a Monteggia fracture. The models were analyzed mechanically. The initial fracture process was simulated by constraining the distal portions of the radius and ulna and the dorsal fracture sites of the ulna. The mechanical changes of the annular ligament in the two positions were observed and compared.Z-axial displacement of the annular ligament was close to that along the Y-axis, although with a significant difference (P < 0.01). In the supine position, the X-axial displacement dramatically increased (P < 0.01), while it was noticeably decreased along the Z-axis (P < 0.01).In the prone position, the maximum Biomechanical changes may partially explain the pathological changes in the annular ligament during Monteggia fractures; longitudinal displacement of the radial head causes it to slip out of the annular ligament while the ligament remains intact. The Monteggia fracture was originally described as a fracture of the proximal third of the ulna with an anterior dislocation of the radial head. However, due to the common characteristics of several types of upper extremity injuries, the definition of the Monteggia fracture has now been expanded to include all ulna fractures accompanied by radial head dislocation regardless of the location of the fracture or the direction of the dislocation. This type of fracture is usually observed in pediatric patients between 7 and 10 years of age. Pediatric surgeons have sought to understand the mechanism of this fracture because a missed diagnosis or chronic dislocation of the radial head poses treatment challenges.The pathogenesis of the Monteggia injury remains controversial. Evens described it as a fracture of the ulna with continued pronation that causes leveling out of the radial head . He prodIn our previous clinical study, we reported that the annular ligaments were intact in pediatric patients with type I and type III Monteggia fractures, with transverse ruptures of the joint capsule at the lower margin of the ligament . Most ofTo prove this hypothesis and to explore the mechanical explanation for the pathology, we designed this biomechanical study using finite element analysis (FEA), which is widely accepted as the most practical and reliable method of analyzing mechanical structures in the field of engineering. Recent developments in computer technology, in both hardware and software, have promoted its medical use. Many studies that apply FEA to the analysis of bones, such as the tibia , femur , and pelTwo forearm specimens were obtained from the cadaver of a patient who died in his 40s. The specimens were put in prone and supine positions for computed tomography  scanning . The obtained images were stored in the Digital Imaging and Communications in Medicine (DICOM) format, adjusted according to the bone window in the CT workstation, and then transferred to Mimics , where three-dimensional images were constructed, smoothed, and meshed superficially. The current study was approved by the Ethical Committee of Yantaishan Hospital.Using the contours of the ulna and radius, a model of the annular ligament was generated. A hollow cylinder and two cuboids with a thickness of 1.5 mm were produced first and then were merged together as a combination. The cylinder contains the radial head and the cuboids touch the sides of the ulna. Boolean subtraction was used to form the ultimate ligament model Figures . This moTo accurately capture the three-dimensional (3D) geometry of the bones and the ligament, mesh refinement was performed for the areas with high stress gradients to systematically increase the mesh density until a desired level of accuracy was achieved, whereas preliminary model processing was performed to identify the areas with high discretization errors.The cortical and cancellous bones were assumed to be linearly isotropic and homogeneous in elements, whereas the ligament was nonlinear because it only undergoes traction forces . The resTwo models were ultimately constructed: the forearm in the prone position and the forearm in the supine position. The element and node data are summarized in Table Y-axis in both models . Paired X-, Y-, and Z-axes were all significantly different  was close to that along the Y-axis (anteroposterior), although they were significantly different (P < 0.01). The displacement of the ligament along the X-axis  was comparatively small (P < 0.01). In the supine position, the displacement along the X-axis dramatically increased (P < 0.01), whereas it was noticeably decreased along the Z-axis (P < 0.01). The overall displacement of the ligament was primarily along the Y- and Z-axes. Between the two models, the X- and Z-axis displacements were significantly different (P < 0.01), while the Y-axis displacements were not significantly different (P > 0.01)  Table .Figure 4The stress concentration after loading is shown in Figure Although it has been frequently discussed in the literature, the mechanism underlying a Monteggia fracture remains controversial. In our previous clinical study, we hypothesized on the basis of surgical observations that the radial head was forced out of the annular ligament by traction rather than by a transverse force . Since tFEA has two advantages. First, it can avoid the interference caused by individual differences in bone density, and second, it more clearly shows the changes in the annular ligament when compared with entity model analysis. However, a disadvantage of FEA is the difficulty in simulating the material property of an entity accurately. To overcome this shortcoming, we presented our results in terms of ratios.The most difficult part of FEA model generation lies in the construction of the annular ligament. Because the annular ligament is too delicate to be extracted and because obtaining an intact ligament model from CT scans is impractical, we artificially constructed it according to the contour of the radial head. We then assembled it onto the bones to form a bone-ligament combination model. Because the normal friction property of the annular ligament was changed into a gluey property, we successfully simplified the analytical complexity. Accordingly, the stress on the ligament was indirectly expressed by its displacement.In this study, we simulated the entire fracture process by constraining the distal radius and ulna in the model. Although muscles definitely play a role during the process of loading, we omitted their effect because this study focused on the mechanical pathological changes in the annular ligament, which were separate from the fracture site. More specifically, we studied what would happen after ulnar yielding but before the yielding of the bone.Y- and Z-axes with the maximum Z-axial displacement close to the Y-axial displacement even though they were significantly different (P < 0.01), whereas the displacement along the X-plane was comparatively minor (P < 0.01). In the supine position, the displacement on the X-plane dramatically increased (P < 0.01), whereas displacement on the Z-plane noticeably decreased (P < 0.01). These findings suggest that the radial head is less likely to dislocate from the lower edge of the ligament while in a supine position than in a prone position. This is consistent with the report by Evens that excessive pronation plays an important role in the production of type I fractures [The results showed that, in the prone position, the overall displacement of the annular ligament was primarily along the t P < 0.0, whereasractures . AlthougIn surgery, we found that as the angulation of the ulna fracture increases, the radial head begins to move distally apart from the annular ligament and finally detaches from the ligament; a prone position of the forearm will facilitate the process of this detachment . Based oThis study has some limitations. First, FEA cannot perfectly simulate the real situation that occurs during injury due to the complexity of human anatomic structures and the imperfections of the FEA software. With the development of computer-aided engineering software, this shortcoming of FEA may be overcome. Second, it is difficult to obtain sufficient fresh specimens (without preservative). The properties of the intersection of the annular ligament and capsule could be greatly affected by preservatives. Although the mechanical property values were assigned to the bone and the ligament according to the literature, the final property values could be affected by the thickness of the cortical and cancellous bones in different specimens. Therefore, it would be theoretically better to increase the number of specimens to obtain mean values for the structural indices.Z-axial displacement of the annular ligament in the prone position than in the supine position explained the longitudinal stretch of the radial head out of an intact annular ligament that was observed during surgery. This clear explanation of annular ligament pathology may guide surgeons when they are treating a Monteggia fracture-dislocation.In this study, we constructed a FEA model of the ulna and radius in combination with the annular ligament. A Monteggia fracture was simulated by constraining both the distal portions of the radius and ulna and the dorsal fracture sites of the ulna. The greater


This study proposes an architecture for an interactive motion-based traffic simulation environment. In order to enhance modeling realism involving actual human beings, the proposed architecture integrates multiple types of simulation, including: (i) motion-based driving simulation, (ii) pedestrian simulation, (iii) motorcycling and bicycling simulation, and (iv) traffic flow simulation. The architecture has been designed to enable the simulation of the entire network; as a result, the actual driver, pedestrian, and bike rider can navigate anywhere in the system. In addition, the background traffic interacts with the actual human beings. This is accomplished by using a hybrid mesomicroscopic traffic flow simulation modeling approach. The mesoscopic traffic flow simulation model loads the results of a user equilibrium traffic assignment solution and propagates the corresponding traffic through the entire system. The microscopic traffic flow simulation model provides background traffic around the vicinities where actual human beings are navigating the system. The two traffic flow simulation models interact continuously to update system conditions based on the interactions between actual humans and the fully simulated entities. Implementation efforts are currently in progress and some preliminary tests of individual components have been conducted. The implementation of the proposed architecture faces significant challenges ranging from multiplatform and multilanguage integration to multievent communication and coordination. A vast number of studies have illustrated the potential of driving simulators to analyze actual driver behavior for multiple purposes, such as traffic safety and information provision –5. The hThe National Advanced Driving Simulator (NADS) Laboratory  at the UThe Human Factors Interdisciplinary Research in Simulation and Transportation Program (HumanFIRST) at the University of Minnesota has the Driving Environment Simulator (DES) . DES is UC-win/Road  is a VirThis study proposes an architecture for an interactive motion-based traffic simulation environment. Although the existing driving simulation models provide tremendous capabilities to study driving behavior in a safe and controlled environment, there are multiple aspects of the real-world that can be addressed to significantly enhance modeling realism. The proposed architecture integrates multiple types of simulation, including (i) a motion-based driving simulation; (ii) a pedestrian simulation; (iii) a motorcycling and bicycling simulation; and (iv) a traffic flow simulation. This integration enables the simultaneous and interactive interaction between actual and simulated drivers, pedestrians, and bike riders. In addition, the architecture provides capabilities to simulate the entire network at a reasonable price; in this way, the drivers, pedestrians, and bike riders can navigate anywhere in the system.To increase modeling realism, the proposed architecture enables actual humans to experience background traffic and the background traffic to be affected by the decisions and behavior of the actual humans navigating the system. To achieve this interaction, the background traffic is modeled using a hybrid mesomicroscopic modeling approach for traffic flow simulation. The mesoscopic traffic flow simulation module of the hybrid model loads the results of a user equilibrium traffic assignment solution and propagates the corresponding traffic throughout the entire system. The microscopic traffic flow simulation model provides background traffic around the vicinities where actual human beings are navigating the system. The two traffic flow simulation models interact continuously to update system conditions, based on the interactions between actual humans and the fully simulated entities. The interaction between actual and background traffic has tremendous implications. For example, in the real-world, an accident, as consequence of a human error, can affect a large portion of the traffic system. These types of scenarios of significant interest for a number of applications cannot be modeled realistically without using the proposed architecture that integrates the driving simulator and the microscopic traffic flow simulator. Such scenario requires capabilities to propagate traffic and represent congestion related phenomena including queue formation and dissipation as well as spillback and spillover. Existing driving simulation models do not provide such capabilities because they do not model background traffic using realistic traffic flow models.The evaluation of driver and pedestrian behavior for traffic safety projects including distracted driving and/or walking and driving and/or walking under the influence of alcohol or drugs –5.The evaluation of multiple mechanisms or technologies designed to assist the driving task and to improve traffic safety. Some of these mechanisms and technologies include crosswalks, flashing lights, infrared sensors to detect pedestrians, distance warning systems, dynamic cruise control, automatic braking systems, and dynamic navigation.The simultaneous study of the interactions among drivers, pedestrians, and bikers as well as the interactions of them with the infrastructure and the control and information mechanisms and the different technologies used influencing behavior and/or assisting the navigation tasks. The existing literature –17 relieThe training of first responders and emergency personnel. Multiple potential emergency scenarios can be designed and used to provide adequate training in safe and controlled environment. Burke et al.  documentDepending upon the nature of the experiment, a scenario can be designed using a single simulator or any instances of simulators. Some examples for which the proposed system can be used include the following:In this study, implementation efforts are currently in progress, and some preliminary tests of individual components have been conducted. The implementation of the proposed architecture faces significant challenges, ranging from multiplatform and multilanguage integration to multievent communication and coordination. To address some of those challenges and achieve the greatest benefits at the lowest cost, state-of-the-art technologies currently are being used to implement the proposed architecture. Some of these technologies include (i) Open Street Maps (OSM) ; (ii) BlA Car Simulator. This simulator generates motion and the corresponding forces based on the roadway conditions and the driver's behavior and actions. Hence, the human being driving in the driving simulator experiences a realistic journey and reveals a behavior that is not artificially affected by unrealistic modeling. This driver is termed in this study the virtual driver. In the experimental framework, a SimCraft motion-based driving simulator with 3 Degrees of Freedom (3DoFs) is used.A Pedestrian Simulator. This simulator comprises Microsoft Kinect to capture and display the movements of walking human.A Bicycle and Motorcycle Simulator. This is a motion-based simulator with capabilities to simulate a self-powered or fuel-powered bike. It consists of a computer CPU with a graphics card, a Head-Up-Display setup or LCD screen, a motion base, and a joystick.A Central Simulation Server. This server runs simultaneously on parallel CPUs the mesoscopic and microscopic simulations and provides the background traffic to the driving, pedestrian, and bike simulators. It also takes care of the communication and data transfer between the different simulators. The implementation involves a high end supercomputer running Microsoft Windows 7 64-bit edition and networking hardware including a 1000BaseT Gigabit Ethernet as well as the necessary routers and switches to complete the network.The proposed architecture uses a multiplayer framework where each player is connected to the traffic system through a communication network (LAN or internet). The corresponding system architecture diagram and data flow diagram are shown in Figures Hybrid Simulation Module. This hybrid simulation module is required to provide realistic and consistent traffic around the vicinity of the virtual driver and to capture the consequences of the driver actions on the entire system. It combines a microscopic and a mesoscopic traffic flow simulators. In this module, the actions and location of the virtual driver are directly and continuously incorporated into the microscopic model. The microscopic simulator continuously receives traffic from and sends traffic to the mesoscopic simulator considering the boundary established by the location of the virtual driver.Virtual Reality (VR) Module. This module creates a simulated world around the vicinity of the virtual driver and provides the associated audio and 3D graphics. It receives information from the hybrid simulation module and provides information to the virtual driver.Vehicle Dynamics Module. This module generates the motion related information for each of the simulators based on the traffic conditions and the users' actions.Communication Module. This module enables communication between the server and the client module. It is responsible for synchronizing the transfer of information between the client and the server. For various reasons, the modules proposed in this architecture are being developed using different environments. Hence, the Common Object Request Broker Architecture (CORBA) is to enable interoperability across different language and platforms [latforms .Data Collection Module. This module collects a vast array of data including drivers' and pedestrians' behavior as well as the associated traffic characteristics.The data flow diagram illustrated in The server module integrates all the information and it is responsible for tracking the entire system performance using a communication and data collection module and a simulation engine. The simulation engine receives information from all the clients via the communication. That information is stored via the data collection module. Information about system states is also sent to each of the clients using the communication module.Some simulators such as STISIM Drive  only supThe proposed architecture can be used for any network with the required information. In this study and for demonstration purposes, the Las Vegas road network was created using OSM data. Lane data, traffic control, and signal settings were obtained from an existing traffic simulation model. To obtain the correct mapping, the coordinates from OSM were matched with those in the existing model. A portion of the roadway network created using this approach is shown in Most driving simulators provide background traffic around the virtual driver using survey data and hourly volumes/distributions  or the dIn order to adequately represent both the microlevel vehicle dynamics around the virtual driver and the traffic dynamics in the rest of the network, a hybrid simulation model that integrates a microscopic and a mesoscopic traffic flow simulation model is proposed. Félez et al.  have envCritical aspects in the development of hybrid simulation models are the compatibility of two different traffic flow streams and the propagation of traffic conditions at the interfaces . TrafficμSim zone, is defined by the position of the virtual driver. The following methods can be used to define this region:Method 1 (Moving μSimlink). Use the microscopic simulation model only on the roadway link where the virtual driver is present. Show the Virtual Reality Environment to the extent of the driver's visibility limit. Use mesoscopic simulation on all the other links. Thus, the μSim zone is the link where the virtual driver is located and it changes according to the position of the virtual driver.Method 2 (Moving μSimzone). Use the microscopic simulation model in a zone around the position of the virtual driver. Show the Virtual Reality Environment to the extent of the driver's visibility limit. Use mesoscopic simulation on links other than those modeled using micro simulation. Thus, the μSim zone is the fixed zone with respect to position of the virtual driver.The proposed hybrid simulation model integrates the DynusT© , a mesosIn both methods, the problem of conserving vehicles should be solved at the boundary of mesoscopic and microscopic integration. In each simulation interval of the mesoscopic model, the entire network is updated based on the mesoscopic logic and the states at the boundary between the meso and micro models. However, the network states covered by the micro simulation model govern that zone.The objective here is to generate actual vehicle motion dynamics so as to enhance modeling realism. This motion produces physiological and psychological reactions similar to those present in a real-world driving experience. Motion-axis simulators can be used to generate vehicular motion dynamics using DOFs ranging from two to fourteen –14, 25. Vehicle motion dynamics are generated using SimCraft 3DOFs motion-based simulator. Although 6DOFs are desired to reproduce most vehicle dynamics, the 3DOFs can realistically reproduce the most important motions such as the effects of acceleration/deceleration as well as changes on roadway geometry. The motion dynamics are generated based on the actions of the virtual driver, the geometric characteristics of the roadway, and the interactions with other vehicles. Hence, motion dynamics must be seamlessly synchronized with the Virtual Reality module.Existing pedestrian models , 32 requSensors can be used to capture the movements of various entities as well as human behavior including, for example, a pedestrian observing traffic while crossing a street and the walking speed relative to the traffic conditions. Traffic safety is highly influenced by users' behavior and their interactions. According to a report by the National Highway Traffic Safety Administration (NHTSA) , every yThe pedestrian simulator consists of a state-of-the-art Natural Interaction Sensor (Microsoft Kinect) and a head-mounted display. The movements of human walking are captured using the Microsoft Kinect. The Kinect consists of sensors that identify joints, body structure, facial features, and voice. The head-mounted display is to project the traffic conditions for the pedestrian. These traffic conditions are obtained using the communication module in the pedestrian simulation client.The Virtual Reality Environment is used to provide all the background as well as the traffic conditions representing the real-world to the various human beings navigating the system using the proposed simulators. The Virtual Reality Environment includes seven different components: simulation, interaction, artificiality, immersion, telepresence, full-body immersion, and network communication . These cIn this study, the Virtual Reality Environment is created using 3D models . To acceThe Virtual Reality Environment is generated only to include the visibility limits for the virtual driver(s) and virtual pedestrian(s). The generated Virtual Reality Environment includes pedestrians as well as different classes of vehicles, such as cars and trucks. Different levels of visibility are available according to weather and time of day conditions. These conditions are recreated using various rendering techniques such as shading and reflecting.One of the primary objectives of the proposed architecture is the collection of data about the vehicles, the users, and the system performance. Vehicle data includes variables such as lateral position, vehicle trajectories, vehicle heading angle, acceleration/deceleration, and braking times. Users' data includes variables such as perception-reaction times, physiological data obtained from electrocardiograms, galvanic skin response, and body temperature. The hybrid simulation model will collect system performance data. The data collection module is included in every single client so as to collect the corresponding information.The initial implementation of the proposed architecture began with control of the driving simulator using the Software Development Kit (SDK) provided by the manufacturer, SimCraft. A control module was created using a Dynamic Link Library (.dll) file provided in SDK. Blender  was chosMicrosoft Kinect is currently being used for the development of the pedestrian simulator. A walk identification module has been created with a text output. This will later be developed and integrated into the pedestrian simulator. Blender  is used Future work includes (i) the implementation of hybrid simulation model for the driving and pedestrian simulators; (ii) the graphics module for Virtual Reality Environment; (iii) the development of hardware for bicycle and motorcycle simulator; and (iv) the integration, coordination, and synchronization of all the components of the proposed architecture.This study has proposed an architecture for an interactive and motion-based simulation of a vehicular and pedestrian traffic system. The proposed architecture increases the realism of existing alternative modeling approaches by explicitly and simultaneously including actual drivers, pedestrians, and bikers. In addition, the architecture enables the modeling of the entire network with reasonable investment of resources. To the best of our knowledge, there is no alternative architecture that simultaneously considers all the elements of reality considered here. Existing modeling frameworks focus on a particular component of the real-world system; the reaming components are ignored or modeled using artificial entities. State-of-the-art modeling and analysis tools such as simulation-based Dynamic Traffic Assignment, CORBA, and Open Street Maps enable the implementation of the proposed architecture. Implementation of the architecture will provide the unique capability to study countless traffic problems using actual human beings.


Plant decomposition is dependant on the activity of the soil biota and its interactions with climate, soil properties, and plant residue inputs. This work assessed the roles of different groups of the soil biota on litter decomposition, and the way they are modulated by soil use. Litterbags of different mesh sizes for the selective exclusion of soil fauna by size  were filled with standardized dried leaves and placed on the same soil under different use intensities: naturalized grasslands, recent agriculture, and intensive agriculture fields. During five months, litterbags of each mesh size were collected once a month per system with five replicates. The remaining mass was measured and decomposition rates calculated. Differences were found for the different biota groups, and they were dependant on soil use. Within systems, the results show that in the naturalized grasslands, the macrofauna had the highest contribution to decomposition. In the recent agricultural system it was the combined activity of the macro- and mesofauna, and in the intensive agricultural use it was the mesofauna activity. These results underscore the relative importance and activity of the different groups of the edaphic biota and the effects of different soil uses on soil biota activity. The edaphic biota is the main factor directly responsible for soil organic matter turnover and nutrient cycling due to the diversity of processes in which it takes part . Among tSoil fauna largely control the decomposition process through breakdown of litter. digestion, and stimulation of microorganism activities . Their sThe edaphic biota is classified according to the size of the adults into three groups: the microfauna, the mesofauna, and the macrofauna . Each coAgroecosystems are continuously under the anthropic impact of different agricultural practices, which causes changes in their biotic and abiotic components both in time and in space. These changes in turn, affect the structure and function of the soil biota , thus meIn order to understand in greater detail the role of the different soil fauna groups in the decomposition process, the hierarchical model proposed by Three litterbag mesh sizes were used to hierarchically exclude each group of the edaphic biota according to size. Therefore, the contribution of each group to organic matter decomposition was evaluated.The working hypothesis was that plant litter decomposition rates would differ between the different soil fauna groups, and that those differences would be modulated by the different soil use intensities.The study was carried out in the rolling pampas of central Argentina. With over fifty million hectares of agricultural land, it is one of the biggest and most productive plains in the world . Three aFestuca sp., 2-Cattle-grazing fields turned into agriculture 2 years before the start of the study (RA). Litter in this place was dominated by agricultural species, such as soybean and corn in summer and wheat in winter, and 3-Intensive Agriculture fields with almost 40 years of continuous and intensive agriculture (IA). Litter in this place was dominated by soybean. All the fields were left fallow during the duration of this experiment. The experimental sites ranged in size from 0.5 to 45 hectares.The soil for all treatments was a mollisol from the typical arguidoll group . In incrFive different sites per treatment (soil use intensity) were selected as replicates. At each site, decomposition bags (20 × 20 cm) were placed with three different mesh sizes for the selective exclusion of the epigeic soil organisms according to size: 4 mm mesh size ; 2 mm mesh size for the selective exclusion of the Macrofauna (Microfauna + Mesofauna); and 0.25 mm mesh size to further exclude the Macrofauna and Mesofauna (hereafter Microfauna). These different size-excluded groups represent three different complexity groups of the soil biota.Glycine max L.) were placed. Soybean leaves were used to standardize the litter material offered, because it was the last crop in the agricultural systems, and it has been the most common crop in the region during the last ten years. The senescent leaves were collected in the same field on autumn before harvest and dried at 30 °C. The bags were placed on the surface of the soil and covered lightly with plant residues after harvest to improve the natural decomposition of this crop in the pampas on end-autumn, winter and spring. A total of 270 litterbags were distributed among treatments and replicates, with no more than 10 bags per square meter at any site. The experiment was set to run for six sampling dates, but it was terminated after five months when one of the replicates approached zero RM. Bags were retrieved at 17, 53, 94, 126, and 171 days after the bags were placed. Every sampling date, one bag of each mesh size (3) was retrieved per replicate (5) and agroecosystem (3), thus processing 45 litterbags each sampling date, for a total of 225 litterbags over the 5 sampling dates. The material was then dried at 30 °C to constant weight. The remaining material was weighted and the percentage of remaining mass (%RM) calculated.In each bag 5 g of dry, senescent soybean leaves  found for each edaphic biota group within agricultural systems analyzed by two-way ANOVA can be seen on p < 0.05).These results allow for the analysis of the slopes of the decomposition rates between different mesh sizes within agricultural uses –4. A covk) calculated for the Total Biota was significantly higher and different (p < 0.05) from the other two groups, with no differences between them. In the Recent Agriculture system (k) of the Total Biota was significantly higher than that of the Microfauna alone, while the Microfauna + Mesofauna group did not differ with the other two groups. In the Intensive Agriculture system, the decomposition rate of the Microfauna was significantly lower than the other two groups that did not differ from each other  when compared to the two agricultural systems .Overall, a total of five collembola families, twenty-one acari superfamilies and nine earthworm species were identified in all the sampling sites altogether (data not shown).In this work, two of the selected agroecosystems had been each under the same use for several decades, while the third system was of intermediate disturbance. It was assumed that by the time of the experiment, the structure and composition of the edaphic fauna in each system was already in equilibrium with the inputs and local use regime of each agroecosystem. Therefore, the results on decomposition rates are proper of the fauna already adapted to each agroecosystem.In this way, the original edaphic fauna of the region was assumed to be best represented by the edaphic fauna in the NG system. In the Intensive Agriculture system, the original fauna was subjected to decades of strong habitat changes brought about by tillage, fertilizers, pesticides, changes in temperature regime, water availability, and soil structure .The results show that the relative contribution of each fauna group to decomposition rate is different between systems, which is an indication that the structure and composition of the edaphic fauna is different from one system to another.k = 0.0074), since no difference was found when the Mesofauna was further excluded (k = 0.0032) (k = 0.0088) with Microfauna alone (k = 0.001) (k) from 0.0086 to 0.0025  . In the = 0.001) . This reo 0.0025 .When examined across systems, only the Microfauna presented significant differences between agroecosystems . This grInterestingly, and despite what other authors found for similar soils , there wIn interpreting the results presented, it is important to keep in mind that the litterbag system employed, and the way they were deployed on the soil surface, attracts mainly epigeic soil fauna. Therefore, most of the results are relevant mainly to this group.The results obtained in this work clearly support the working hypothesis. The data show that the different groups of the epigeic soil biota contribute differently to litter decomposition, and that this differential contribution is being mediated by the differences in soil use. Interestingly enough, these groups present complementary activities depending on soil use intensity, since no differences in decomposition rates were found between uses when the decomposition rates of the entire soil biota were compared. However, the contribution of each group of the soil fauna to the total litter decomposition changed across soil uses.Being the less disturbed system, the Naturalized Grassland is the closest to the original, pristine condition of the soil systems studied. In these conditions, the Macrofauna is the relevant group as reflected by the lowering of the decomposition rate brought about by its selective exclusion with no further effect when the Mesofauna was also excluded. Indeed, results from previous authors  indicateIn the Recent Agriculture system, which is of intermediate disturbance, the combined effects of both the Macrofauna and Mesofauna are relevant, since the only significant difference is the result of their exclusion together.The results from the most disturbed system, the Intensive Agriculture, show the Mesofauna as the relevant group, for the only significant decrease in decomposition rate takes place when this group is excluded. These results are thoroughly consistent with the hierarchical model proposed by When analyzed across systems the results for the Microfauna showed higher decomposition rates for the least anthropized Naturalized Grasslands when compared to both agricultural systems. No differences were found for the Total Fauna or the Macro + Mesofauna across systems. These results suggests a negative effect of the agricultural practices on the Microfauna in particular. This is consistent with previous research showing evidence that agricultural management affects the structure of the microbial community . ResultsDespite their recognized importance, the interactions between the different groups of the soil biota are still largely unknown and one of the most studied topics in soil ecology . CoûteauIt was also found that under organic agricultural management, the Mesofauna increases its abundance  possiblyIn terrestrial ecosystems, the empirical evidence is scarce but it is known that when a soil community has a high diversity of functional traits, it has effects that facilitate interactions promoting decomposition . More evThe continuous disturbances in the studied agricultural systems could be selectively pressing certain organisms or groups over others. In this way, disturbances would allow for the establishment and development of soil biota adapted to anthropized systems, in detriment of the original soil biota, most likely close to the one in the Naturalized Grassland system.From the results presented here, it can also be concluded that Microfauna is the most sensitive group to anthropic disturbances, and therefore, it should be the group to be taken particularly into account when devising sustainable agricultural practices.In conclusion, when looked at them separately the different soil uses studied in this work strongly modulate the decomposition activity of each group of the soil fauna, even though the total decomposition rate remains the same for all the studied systems when the whole soil biota is present. These differences are likely due to changes in the structure and functioning of each one of the faunal groups of the soil biota studied, brought about by the different soil use intensities.Finally, the results shown in this work point to a replacement of the relative contribution to decomposition of the different faunal groups as use intensity increases. In the less disturbed environments, it is the Macrofauna group which contributed the most to decomposition; this is consistent with the hierarchical model presented by 10.7717/peerj.826/supp-1Supplemental Information 1Remaining mass for all treatments and sampling datesClick here for additional data file.


This occurs via the concerted action of numerous proteins, including DnaA, which acts as an initiator. The origin sequences vary across species, but all bacterial oriCs contain the information necessary to guide assembly of the DnaA protein complex at oriC, triggering the unwinding of DNA and the beginning of replication. The requisite information is encoded in the unique arrangement of specific sequences called DnaA boxes, which form a framework for DnaA binding and assembly. Other crucial sequences of bacterial origin include DNA unwinding element  and binding sites for additional proteins that positively or negatively regulate the initiation process. In this review, we summarize our current knowledge and understanding of the information encoded in bacterial origins of chromosomal replication, particularly in the context of replication initiation and its regulation. We show that oriC encoded instructions allow not only for initiation but also for precise regulation of replication initiation and coordination of chromosomal replication with the cell cycle . We focus on Escherichia coli, and then expand our discussion to include several other microorganisms in which additional regulatory proteins have been recently shown to be involved in coordinating replication initiation to other cellular processes . We discuss diversity of bacterial oriC regions with the main focus on roles of individual DNA recognition sequences at oriC in binding the initiator and regulatory proteins as well as the overall impact of these proteins on the formation of initiation complex.Replication of the bacterial chromosome initiates at a single origin of replication that is called  For a long time, the presence of these genes was assumed to mark the chromosomal localization of oriC  of bacteria . This is thought to enable a robust response to unfavorable conditions by allowing bacteria to increase the gene dosage in response to stress-induced initiation events  of the entire oriC region might be high enough to enable the oriC region from one species to autonomously replicate in another species . The replication origin on the other chromosome is plasmid like, and it is activated by initiators that lack homology to DnaA   to ~950 bps (Streptomyces)  between the oriC subregions  and Mollicutes     formation in various bacterial species. However, it remains difficult to interpret the differences in bacterial oriCs in the context of their activities. As discussed above, the oriC regions characterized to date are quite diverse in terms of their chromosomal loci, genetic contexts, nucleotide sequences, lengths and continuities. However, they are all composed of three basic functional modules: a cluster (or multiple clusters) of DnaA boxes, the DUE region, and other sequences that are recognized by regulatory proteins. These modules constitute the central management system for orisome formation, but their numbers and relative localizations vary across organisms  adopts the structure of a right-handed helical filament to directly stimulate DNA unwinding , whose exact sequences, numbers and layouts reflect the diversity of the various organisms. DnaA boxes from different bacteria do, however, share a common core sequence (Table E. coli (TTATCCACA), with the exception of that of T. maritima. In closely related organisms, the high-affinity box sequence is conserved, as seen in E. coli, V. cholerae, Pseudomonas putida and P. aeruginosa, which all belong to a branch of the γ-proteobacteria , which are considered high-GC organisms, the “perfect” DnaA box contains G or C at the third position: TT(G/C)TCCACA   with respect to the “perfect” E. coli sequence   and the Orc1/Cdc6-binding sequences in Archaea   are similar to the corresponding part of the nine-nucleotide DnaA boxes. The importance of this six-nucleotide motif as an integral part of a bacterial DnaA box is further supported by the recent study of the C. crescentus oriC, where five six-nucleotide boxes (termed W-boxes) were identified in addition to the two known nine-nucleotide high-affinity G-boxes  represents an alternative type of DnaA-recognized sequence   is bound efficiently by the M. tuberculosis and E. coli DnaA proteins, but neither protein was able to bend the ScoriC structure in the manner of the native DnaA protein  but not the other   .The E. coli comprises three 13-mer repeats) separated by short, non-AT-rich insertions. DUE regions are thermodynamically unstable compared to their neighboring sequences, rendering them susceptible to superhelical stress arising from the formation of the DnaA oligomer  is tightly controlled. The relevant protein regulators are primarily involved in controlling the initial assembly of the DnaA oligomer along the origin of replication. The formation of an active orisome depends on the presence of proteins that: (i) regulate DnaA protein activity ; (ii) facilitate the interactions between DnaA monomers ; or (iii) bind oriC and modulate the interaction of the DnaA protein with the origin of replication  (other than DnaA) .Transmission of genetic material to nascent cells requires precise regulation of chromosome replication and its coordination with the cell cycle. Since chromosomal replication is mainly regulated at the initiation stage, the principal activity of the A) Table  regulatioriC  binding sites, and exert their indirect effects by changing the DNA structure of the origin to modulate the binding of additional oriBPs.The oriBP regulators can be divided into three classes depending on their target sequences: (i) those that interact with DnaA boxes or in their close vicinity; (ii) those that interact with AT-rich sequences within the DUE; and (iii) those that interact with other sequences within C Figure . The oriE. coli, in which ~11 oriC binding proteins have been identified . Here, the recognition sequence for IHF overlaps the C-binding site for CtrA, which negatively regulates chromosomal replication in C. crescentus . In this system, IHF binding leads to the displacement of CtrA from Cori, allowing the DNA to bend and promoting replication . It prevents the formation of the open complex without displacing IHF or DnaA from the DNA  and amino acid metabolism  , but their specific roles and contributions to the replication initiation process are not yet known , the regulation of replication initiation must also be adjusted to the developmental stage to ensure that each nascent cell receives a single copy of the chromosome , whereas increased levels of MtrA appear to be associated with deficient autonomous replication of the minichromosome  a limited number of other organisms . Future studies should examine how differences in origin structure are translated to the species-specific characteristics of DnaA oligomerization and its control by regulatory proteins. In addition, many important aspects of the replication initiation process remain to be discovered, particularly in pathogens, including the answers to questions, such as:How is replication initiation coordinated with the cell cycles of different pathogens upon host infection?How do host signals modulate or influence replication initiation in pathogenic bacteria?In sum, the bacterial origins differ across organisms in the organization of their DNA modules, but all origins encode comprehensive instructions for the assembly and disassembly of the orisome-forming proteins, enabling the timely regulation of this first and crucial step in chromosomal replication. The instructions direct the sequential binding of DnaA molecules to the available array of high- and low-affinity DnaA boxes to form a nucleoprotein complex that triggers the unwinding of DNA within the AT-rich region of the The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Lung cancer is one of the malignancies causing deaths worldwide. The yet to be developed non-invasive diagnostic techniques, are a challenge for early detection of cancer before it progresses to its later stages. The currently available diagnostic methods are expensive or invasive, and are not fit for general screening purposes. Early identification not only helps in detecting primary cancer, but also in treating its secondaries; which creates a need for easily applicable tests to screen individuals at risk. A detailed review of the various screening methods, including the latest trend of breath analysis using gold nanoparticles, to identify cancer at its early stage, are studied here. The VOC based breath biomarkers are used to analyze the exhaled breath of the patients. These biomarkers are utilized by Chemiresistors coated with gold nanoparticles, which are found to be the most suited technique for early detection of lung cancer. This technique is highly accurate and is relatively easy to operate and was tested on smokers and non-smokers. This review also gives as an outline of the fabrication and working of the device Na-Nose. The Chemiresistors coated with Gold nanoparticles, show a great potential in being an non-invasive and cost-effective diagnostic technique for early detection of lung cancer. Lung cancer accounts for around 28% of cancer-related deaths worldwide . More thSymptoms like persistent cough, blood filled sputum, pain in the chest, change in the voice pattern and recurrent pneumonia or bronchitis are mainly noticed in the last stage of lung cancer and the techniques used for its detection and diagnosis is expensive. The current techniques used are:Chest X-ray1) shows a chest X-Ray of normal lungs and another chest X-ray pointing to an abnormal mass present inside the lungs.Chest X-ray cannot be used in the detection of lung tumours in their earliest stages. Coincidentally around 10% of lung cancer cases are discovered only when people undergo a chest X-ray for other respiratory conditions. Fig.  PFT is used to measure the amount of air taken in and released out by the lungs. Since Lung cancer constricts the flow of air in and out of the lungs, it transfers poor amount of oxygen into the blood, thus aiding in lung cancer detection.Chest TomographyAfter the patient is diagnosed by chest X-ray, further examination of lung tissues is done using CT, which gives an indication whether the cancer is present in the lungs or has spread to the other parts of the body.Bronchoscopy with BiopsyExamination of the interior region of the lungs can be done using a bronchoscope and a biopsy of a lung nodule or mass taken. This technique can be uncomfortable for one to undergo and the assessment of the biopsied tissue is expensive -6.2), for lung cancer were first found by Gordon and colleagues in 1985, using Gas Chromatography-Mass Spectrometry (GC-MS) [Since ancient times, physicians have known that a person’s breath gives an indication of one’s health conditions. For example, people with diabetes have a ‘fruity’ smell and people with kidney disease have a fish-like smell to their breath , which h (GC-MS) .National Institute of Health states that a biomarker is an indicator of any normal biological, pathogenic or pharmacological responses that take place in the human body. These biomarkers are present in various regions of the human body such as, the cells of the tumor growth, fluids in the body which include blood, urine, cerebrospinal fluid, sputum, saliva, and breath. Their discovery, will lead to a non-invasive, early detection of a few types of cancer . This haThe surface of cancerous tissue emits chemicals in the form of Volatile organic compounds (VOCs) which can be detected by sensors (chemiresistors) on a Nano-sensor array. These sensors can differentiate between the breath of a healthy and cancerous individual. This forms the foundation for a fast, accurate method for detection of cancer , 14.1 [The exhaled breath is made up of oxygen, carbon dioxide, nitrogen, water, inert gases and volatile substances. These volatile substances can be produced endogenously or exogenously. The endogenous breath biomarkers for lung cancer are described in Table 1 .Around 42 VOCs represent lung cancer VOC biomarkers, out of which the important VOCs are:Acetaldehyde (below 2-10 ppb) Formaldehyde (below 2-10 ppb) Undecane (24±4 ppb) Isopropene (72.9- 81.5 ppb) Methanol (below 118.5 ppb)Ethylbenzene (145±35 ppb) Acetone (below 458.7 ppb) The Exhaled Breath VOC Analyzers can be further used in the early detection of breast cancer by the detection of VOC biomarkers that include the derivatives of alkanes such as tridecane, hexanal, heptanal, tetradecane and dodecane , 17. ForThe Exhaled breath VOC analyzers are devices used for the detection of the VOCs, whose abnormal levels point to the presence of cancer in the human body. These devices have to be fine-tuned by validating the biomarkers with respect to their pure compounds to achieve high sensitivity, specificity and accuracy for them to be used as a screening tool for the early detection of lung cancer . FollowiGC-MS system is versatile in determining a wide range of VOCs . Gas chr3), the VOCs adsorb onto a sensor where a change in conductivity, color or oscillation of a crystal is detected by the sensing system of the E-nose. The E-nose responds to only a mixture of compounds in the sample. The pattern recognition system interprets and detects the high levels of VOCs causing Lung cancer [In the Electronic nose (E-Nose) as portrayed in Fig. , that are highly effective for the mass screening of individuals for lung cancer.The screening techniques described above aren’t cost-effective and are slow. They require the use of complex instruments for the dehumidification of the breath biomarkers. Many of these techniques are difficult to use, thus creating a need for highly experienced analysts for the operation and the interpretation of the results . This crNano-Nose analyses the gases present in the breath and identifies those gases that stipulate the presence of lung cancer. It works by binding gases to specific chemiresistors coated with gold nanomaterials, thus aiding in the detection of volatile organic compounds (VOC) of the exhaled breath.Researchers throughout the world are working on a revolutionary device to detect lung cancer and other types of cancers, using exhaled breaths of the patients. A few scientists have developed a device containing a carbon-based sensor embedded with gold nanoparticles .Gold nanoparticles are highly sensitive in the detection of biomarkers at lower concentration levels . They arMono-layered capped gold nanoparticles are thermally air stable of reduced dispersity, have well controlled size and are well spaced , 44. As The electrodes present in the Chemiresistors, are coated with a conducting polymer film. The thin electrically- conductive polymer films swell due to the chemical reaction of the volatile organic chemicals with that of the films, thus causing a change in electrical resistance across the film. The chemiresistor can be used repeatedly as it regains its original condition by the release of the chemicals in the environment .Metallic nanoparticles are synthesized in a two-phase system which is composed of aqueous and non-aqueous solutions. These solutions are combined with techniques of extraction of ions. The metallic monolayered nanoparticles are then coated with a hydrophobic layer of alkanethiols. First the ions from an aqueous solution are transferred with the help of a phasetransfer reagent to a toluene solution. Then the reduction of gold is done with an aqueous borohydride solution which is later capped with thiols . Lastly 5), fourteen different chemiresistive MCNP films deposited on micrometric electrical transducers, are combined onto a sensor array. They are insensitive to the water molecules in the exhaled breath and are placed inside a test chamber [As shown in Fig. ( chamber . Deposit chamber .The sensor array is first tested by evacuating the chamber and exposing it to a mixture of artificially designed VOC biomarker breath patterns. The procedure is repeated and the signals obtained, are scrutinized using a standard PCA algorithm , 49.Analyzing the relationship between multiple variables within a multi-dimensional data, requires a statistical method such as PCA, which can reduce the dimension of the data using linear feature extraction technique. Each sensor data is retained and arranged into a matrix format where the sensor types are arranged in rows and the measurement numbers are arranged in columns. The percentage-resistance changes and slopes are used in the calculation of the covariance matrix and its values of the Eigenvector and Eigen value. The two principle components discriminate between non-overlapping healthy and lung cancer group. This is used in the interpretation of PCA results, in the score plot containing the projection of two cluster data onto the two dimensional planes . The datThe highly sensitive and accurate GC-MS, with 87% reproducibility, are rarely used because they are expensive, difficult to use and require highly experienced analysts to operate them and interpret the results , 17. Electronic nose cannot obtain quantitative data as the sensors are not selective. If more than one type of vapour is present, a quantitative output from one sensor is likely to be erroneous  and therQuartz microbalance gives an accuracy of 80%, sensitivity of 85% with 100% specificity. Their main drawback lies in the stability and precision due to the requirement for the pre-concentration of the breath samples collected , 52.The sensitivity of the Colorimeter is 73.3% and specificity 72.4%. They are generally less preferred due to their low sensitivity and the inability to work in the presence of humidity and the need for the pre-concentration of the collected breath .The accuracy of Cyranose 360 is 85% but is not used as it’s slow, costly, requires complex instruments and cannot detect VOCs in the presence of humidity .The electronic nose containing chemiresistors coated with gold nanoparticles have an accuracy of around 88%. The long chain thiols used in the synthesis of the monolayered gold particles differ in their polarity and vapor pressure. This provides good stability to the device for a period of three months . Change The advantages of this technique include a high accuracy in discriminating between malignant and benign disease. The breath analysis test can be repeated in short intervals, without the requirement for dehumidification. Large volume of sample can be collected and the test is easy to perform. It can be tested on smokers as well as non-smokers and has a great potential as a screening test. The limitations of exhaled breath analysis include the lack of recommended guidelines for sampling of exhaled breath. Also a need arises, to bring down the cost of the gold nanoparticles. Collection and analysis of the samples using techniques such as mass spectrometry and infrared spectroscopy also hinder in the faster analysis of the breath biomarkers.For the early detection of lung cancer, standard diagnostic techniques cannot be used as they detect abnormalities at the later stages. An innovative, portable technique is required for the early detection of lung cancer. VOC biomarker testing in the samples of exhaled breath is a non-invasive approach. Nanotechnology can be used in the development of a simple, portable and effective screening device for lung cancer, as the surface area of the nanoparticles is high, making them more suitable as breath biomarkers. A Chemiresistor uses monolayered gold nanoparticles for being biocompatible and their ability to detect VOCs at very low concentrations. A much greater potential exists if this technology can be used to diagnose other types of cancer, which could mean enhanced opportunities to save lives , 53 and