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The accessibility of target gene, a factor critical for gene regulation, is controlled by epigenetic fine-tuning of chromatin organization. While there are multiple experimental techniques to study change of chromatin architecture with its epigenetic state, measurements from them are not always complementary. A qualitative discrepancy is noted between recent super-resolution imaging studies, particularly on Polycomb-group protein repressed domains in Drosophila cell. One of the studies shows that Polycomb-repressed domains are more compact than inactive domains and are segregated from neighboring active domains, whereas Hi-C and chromatin accessibility assay as well as the other super-resolution imaging studies paint a different picture. To examine this issue in detail, we analyzed Hi-C libraries of Drosophila chromosomes as well as distance constraints from one of the imaging studies, and modeled different epigenetic domains by employing a polymer-based approach. According to our chromosome models, both Polycomb-repressed and inactive domains are featured with a similar degree of intra-domain packaging and significant intermixing with adjacent active domains. The epigenetic domains explicitly visualized by our polymer model call for extra attention to the discrepancy of the super-resolution imaging with other measurements, although its precise physicochemical origin still remains to be elucidated.

Teknologi informasi dan komunikasi saat ini banyak menyentuh aspek-aspek kehidupan manusia sehari-hari. Dengan semakin berkembangnya teknologi maka banyak kegiatan yang semakin dipermudah penggunaan, pencatatan, dan pelaporannya. Universitas Advent Indonesia (UNAI) adalah sebuah institusi pendidikan yang menggunakan sistem informasi untuk pencatatan dan pelaporan dalam banyak hal, salah satunya adalah pencatatan dan pelaporan absensi kegiatan-kegiatan di asrama. Sistem informasi ini dapat diakses oleh mahasiswa dan juga orangtua/wali. Akan tetapi para orangtua/wali mahasiswa ingin mendapatkan informasi tersebut dengan cepat tanpa harus masuk ke dalam sistem informasi tersebut. Maka dari itu tujuan dari penelitian ini adalah: (1) mempermudah penyampaian informasi absensi kepada orang tua /wali yang anak-anaknya tinggal di asrama selama perkuliahan di Uiversitas Advent Indonesia, (2) melakukan efisiensi penggunaan kertas untuk pembuatan surat laporan dan pencatatan absensi, dan (3) menghilangkan kendala jarak dalam penyampaian informasi. Adapun kesimpulan dari penelitian ini adalah: (1) Sistem peringatan absensi asrama menggunakan WhatsApp memberikan kemudahan kepada Kepala Asrama dalam menyampaikan informasi kehadiran mahasiswa kepada orang tua mahasiswa, (2) Sistem ini memberikan kemudahan dalam menyampaikan informasi dalam jumlah yang banyak dengan waktu bersamaan.

We consider a geometric optimization problem of distributed multi-input multi-output (MIMO) radar systems with widely separated radar nodes in this article. The aim is to maximize the radar surveillance performance in a given area of interest by adjusting the node positions, while satisfying practical spatial distance constraints among radar nodes. Typical constraints can be, for example, the maximum distance constraints between nodes and fusion centers (FCs) due to limited communication and the minimum distance constraints to ensure a better system spatial diversity. To achieve this goal, we first derive an analytical expression for a weighted coverage ratio (WCR) metric to evaluate the system surveillance performance. Then, using the WCR metric as the objective function, we formulate a spatial constrained geometric optimization problem for three typical MIMO radar system architectures, each of which has a unique expression of distance constraints. However, the formulated optimization problem is computationally intractable for practical scenarios due to its high dimensionality, non-convexity and especially the complex spatial constraints. To solve this problem, we propose an enhanced particle swarm optimization (PSO) algorithm, and different from the standard PSO, the particles of the proposed enhanced PSO can properly consider the distance constraints within themselves during swarm optimization process. Finally, various numerical studies show that the proposed method can effectively maximize the surveillance performance while satisfying the complex distance constraints.

Indoor objects’ accessible area generation considering distance constraints is of important realistic significance for spatial analysis. To the best of our knowledge, few studies have been conducte...

We present three dimensional (3D) dust mapping of 12 supernova remnants (SNRs) in the Galactic anti-center (Galactic longitude $l$ between 150\degr\ and 210\degr) based on a recent 3D interstellar extinction map. The dust distribution of the regions which cover the full extents in the radio continuum for the individual SNRs are discussed. Four SNRs show significant spatial coincidences between molecular clouds (MCs) revealed from the 3D extinction mapping and the corresponding radio features. The results confirm the interactions between these SNRs and their surrounding MCs. Based on these correlations, we provide new distance estimates of the four SNRs, G189.1+3.0 (IC443, $d=1729^{+116}_{-94} \rm \,pc$), G190.9-2.2 ($d=1036^{+17}_{-81} \rm \,pc$), G205.5+0.5 ($d=941^{+96}_{-94}$ or $1257^{+92}_{-101} \rm \,pc$) and G213.0-0.6 ($d=1146^{+79}_{-80} \rm \,pc$). In addition, we find indirect evidences of potential interactions between SNRs and MCs for three other SNRs. New distance constraints are also given for these three SNRs., Comment: 14 pages, 13 figures, accepted for publication in MNRAS

Chemical cross-linking and mass spectrometry is of growing use for establishment of distance constraints on protein conformations and interactions. Whereas intra-protein cross-links can arise from proteins in isolation, inter-protein cross-links reflect proximity of two interacting proteins in the sample. Prediction of expected ratios of the number of inter-protein to intra-protein cross-links is hindered by lacking comprehensive knowledge on the interactome network and global occupancy levels for all interacting complex subunits. Here we determine the theoretical number of possible inter- and intra-protein cross-links in available PDB structures of proteins bound in complexes to predict a maximum expected fraction of inter-protein cross-links in large scale in vivo cross-linking studies. We show how the maximum fraction can guide interpretation of reported inter-protein fractions with respect to the extent of sample protein binding, comparing whole cell and lysate cross-linked samples as an example. We also demonstrate how an observation of inter-protein cross-link fractions greater than the maximum value can result from the presence of false positive cross-links which are predominantly inter-protein, their number estimable from the observed surplus fraction of inter-protein cross-links.

This paper presents a biased random-key genetic algorithm designed to solve the open vehicle routing problem with capacity and distance constraints. Consider a depot from which vehicles depart to deliver goods demanded by clients. Every client is served by one vehicle that is part of a homogeneous fleet. The vehicles initiate their routes at the depot and finish them after servicing the last client without returning to the depot. The problem’s objective function is to minimize the total distance traveled by the vehicles while respecting the capacity and maximum distance constraints. The potential applications in real life scenarios make this problem relevant among other vehicle routing problems. Three sets of benchmark problems from the literature are used to test the proposed algorithm. The obtained results show the algorithm’s good performance since the best-known solutions for 16 of the 30 instances were improved.

Although it is generally agreed that public primary education should be equally available to all, a spatial disparity of educational opportunity exists worldwide, for wealthy families can acquire residential locations with better access to the best schools. Random allocation of school places is considered to be an effective approach for breaking such spatial linkages. This study addresses the problem of achieving the optimal spatial equality of educational opportunity by re-assigning school places to demand nodes using a combined mechanism that introduces a random allocation into a proximity-based system. This study proposes the use of a probability distribution for a full description of educational opportunity. A new spatial allocation optimization model towards equal educational opportunity with the maximum school travel distance constraints and capacities constraints was developed to maximize the resemblance between the probability distributions across demand nodes (RES-based model). This model was applied to a case study of primary school allocation in the Shijingshan District of Beijing, China, and was resolved in a heuristic way. The solution was compared with those provided by a capacitated proximity-based model and a model also using the random mechanism but measuring educational opportunity by expectation values (VAR-based model). It was found that the introducing of random mechanism could significantly improve the spatial equality of educational opportunity with a significant loss of spatial efficiency. In addition, the solution provided by the RES-based model was quite different to that provided by the VAR-based model. An improvement in the resemblance of demand node probability distributions might lead to an increase in the variance of expectations. The resemblance approach proposed in this study may also be applied to the optimization of other random objectives.

This paper focuses on the better performance between the garment simulation result and the simulation speed. For simplicity and clarity, a notation “PART” is defined to indicate the areas between the garment and the human body satisfying some constraints. The discrete mechanical model can be achieved by the two-stage process. In the first stage, the garment can be divided into several PARTs constrained by the distance. In the second stage, the mechanical model of each PART is formulated with a mathematical expression. Thus, the mechanical model of the garment can be obtained. Through changing the constrained distance, the simulation result and the simulation speed can be observed. From the variable distance, a desired value can be chosen for an optimal value. The results of simulations and experiments demonstrate that the better performance can be achieved at a higher speed by saving runtime with the acceptable simulation results and the efficiency of the proposed scheme can be verified as well.

The high-precision geolocation of Internet hosts plays an important role in many applications, such as online advertising and deception detection. The existing typical high-precision geolocation algorithms usually utilize single-hop or relative delay to geolocate an Internet host at street-level granularity. However, it is difficult to accurately measure the single-hop or relative delay within a city. This challenge sometimes results in large geolocation errors. To solve this problem, a street-level geolocation algorithm based on router multilevel partitioning is proposed. Unlike existing typical algorithms, the proposed algorithm makes a credible hypothesis that each router has a relatively stable service object for a period of time. By analyzing the connection between routers and landmarks, the possible geographic service ranges of routers are inferred from the geographic distribution of landmarks. Then, distance constraints arising from routers' service ranges are formed to estimate the geographic location of the target IP. Theoretical analysis of the geolocation error shows that the maximum and average errors of the proposed algorithm are less than those of existing typical algorithms. The proposed algorithm is evaluated by geolocating a total of 12,152 target IP addresses located in four cities in different regions. The experimental results show that, compared with the existing typical street-level geolocation algorithms SLG and NC-Geo, the average median error of the proposed algorithm decreases from 4.735 km and 3.776 km to 3.25 km, representing error reductions of approximately 31.36% and 13.96%, respectively.

Multiple Traveling Repairman Problem with Distance Constraints (MTRPD) is an extension of the NP-hard Multiple Traveling Repairman Problem. In MTRPD, a fleet of identical vehicles is dispatched to serve a set of customers with the following constraints. First, each vehicle's travel distance is limited by a threshold. Second, each customer must be visited exactly once. Our goal is to find the visiting order that minimizes the sum of waiting times. To solve MTRPD we propose to combine the Insertion Heuristic (IH), Variable Neighborhood Search (VNS), and Tabu Search (TS) algorithms into an effective two-phase metaheuristic that includes a construction phase and an improvement phase. In the former phase, IH is used to create an initial solution. In the latter phase, we use VNS to generate various neighborhoods, while TS is employed to mainly prohibit from getting trapped into cycles. By doing so, our algorithm can support the search to escape local optima. In addition, we introduce a novel neighborhoods’ structure and a constant time operation which are efficient for calculating the cost of each neighboring solution. To show the efficiency of our proposed metaheuristic algorithm, we extensively experiment on benchmark instances. The results show that our algorithm can find the optimal solutions for all instances with up to 50 vertices in a fraction of seconds. Moreover, for instances from 60 to 80 vertices, almost all found solutions fall into the range of 0.9 %-1.1 % of the optimal solutions' lower bounds in a reasonable duration. For instances with a larger number of vertices, the algorithm reaches good-quality solutions fast. Moreover, in a comparison to the state-of-the-art metaheuristics, our proposed algorithm can find better solutions.

The understanding of complex biological systems is still hampered by limited knowledge of biologically relevant quaternary protein structures. Here, we demonstrate quaternary structure determination in biological samples using a combination of chemical cross-linking, high-resolution mass spectrometry and high-accuracy protein structure modeling. This approach, termed targeted cross-linking mass spectrometry (TX-MS), relies on computational structural models to score sets of targeted cross-linked peptide signals acquired using a combination of mass spectrometry acquisition techniques. We demonstrate the utility of TX-MS by creating a high-resolution quaternary model of a 1.8 MDa protein complex composed of a pathogen surface protein and ten human plasma proteins. The model is based on a dense network of cross-link distance constraints obtained directly in a mixture of human plasma and live bacteria. These results demonstrate that TX-MS can increase the applicability of flexible backbone docking algorithms to large protein complexes by providing rich cross-link distance information from complex biological samples., Protein structure determination in complex biological samples is still challenging. Here, the authors develop a computational modeling-guided cross-linking mass spectrometry method, obtaining a high-resolution model of a 1.8 MDa protein assembly from cross-links detected in a mixture of human plasma and bacteria.

[EN] Arc routing problems consist basically of finding one or several routes traversing a given set of arcs and/or edges that must be serviced. The Close-Enough Arc Routing Problem, or Generalized Directed Rural Postman Problem, does not assume that customers are located at specific arcs, but can be serviced by traversing any arc of a given subset. Real-life applications include routing for meter reading, in which a vehicle equipped with a receiver travels a street network. If the vehicle gets within a certain distance of a meter, the receiver collects its data. Therefore, only a few streets which are close enough to the meters need to be traversed. In this paper we study the generalization of this problem to the case in which a fleet of vehicles is available. This problem, the Distance-Constrained Close Enough Arc Routing Problem, consists of finding a set of routes with minimum total cost such that their length does not exceed a maximum distance. In this article, we propose a new formulation for the Distance-Constrained Close Enough Arc Routing Problem and present some families of valid inequalities that we use in a branch-and-cut algorithm for its solution. Extensive computational experiments have been performed on a set of benchmark instances and the results are compared with those obtained with other heuristic and exact methods., This work was supported by the Spanish Ministerio de Ciencia, Innovacion y Universidades (MICIU) and Fondo Social Europeo (FSE) through project PGC2018-099428-B-I00. The authors want to thank the comments and suggestions done by two anonymous referees that have contributed to improve the content and readability of the article.

We study the problem of satisfying the maximum number of distance geometry constraints with minimum experimental error. This models the determination of the shape of proteins from atomic distance data which are obtained from nuclear magnetic resonance experiments and exhibit experimental and systematic errors. Experimental errors are represented by interval constraints on Euclidean distances. Systematic errors occur from a misassignment of distances to wrong atomic pairs: we represent such errors by maximizing the number of satisfiable distance constraints. We present many mathematical programming formulations, as well as a “matheuristic” algorithm based on reformulations, relaxations, restrictions and refinement. We show that this algorithm works on protein graphs with hundreds of atoms and thousands of distances.

A photometric redshift sample of luminous red galaxies (LRGs) obtained from the DECam Legacy Survey (DECaLS) is analyzed to probe cosmic distances by exploiting the wedge approach of the two-point correlation function. Although the cosmological information is highly contaminated by the uncertainties existing in the photometric redshifts from the galaxy map, an angular diameter distance can be probed at the perpendicular configuration in which the measured correlation function is minimally contaminated. An ensemble of wedged correlation functions selected up to a given threshold based on having the least contamination was studied in previous work (Sridhar & Song 2019) using simulations, and the extracted cosmological information was unbiased within this threshold. We apply the same methodology for analyzing the LRG sample from DECaLS, which will provide the optical imaging for targeting two-thirds of the Dark Energy Spectroscopic Instrument footprint and measure the angular diameter distances at z = 0.69 and z = 0.87 to be and with a fractional error of 4.77% and 6.09%, respectively. We obtain a value of H 0 = 66.58 ± 5.31 km s-1 Mpc-1, which supports the H 0 measured by all other baryon acoustic oscillation results and is consistent with the ΛCDM model. © 2020. The American Astronomical Society. All rights reserved.., The Photometric Redshifts for the Legacy Surveys (PRLS) catalog used in this paper was produced thanks to funding from the U.S. Department of Energy Office of Science, Office of High Energy Physics, via grant DE-SC0007914. The Legacy Surveys consist of three individual and complementary projects: the Dark Energy Camera Legacy Survey (AST-0950945 Michigan, the National Optical Astronomy Observatory, the University of Nottingham, the Ohio State UniversityDECaLS; NOAO Proposal ID 2014B-0404; PIs: David Schlegel and Arjun Dey), the Beijing-Arizona Sky Survey (BASS; NOAO Proposal ID 2015A-0801; PIs: Zhou Xu and Xiaohui Fan), and the Mayall z-band Legacy Survey (MzLS; NOAO Proposal ID 2016A-0453; PI: Arjun Dey). DECaLS, BASS, and MzLS together include data obtained, respectively, at the Blanco telescope, Cerro Tololo InterAmerican Observatory, the National Optical Astronomy Observatory (NOAO); the Bok telescope, Steward Observatory, University of Arizona; and the Mayall telescope, Kitt Peak National Observatory, NOAO. The Legacy Surveys project is honored to be permitted to conduct astronomical research on Iolkam Du'ag (Kitt Peak), a mountain with particular significance to the Tohono O'odham Nation. This project used data obtained with the Dark Energy Camera (DECam), which was constructed by the Dark Energy Survey (DES) collaboration. Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and AstroParticle Physics at the Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundacao Carlos Chagas Filho de Amparo, Financiadora de Estudos e Projetos, Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico and the Ministerio da Ciencia, Tecnologia e Inovacao, the Deutsche Forschungsgemeinschaft and the Collaborating Institutions in the Dark Energy Survey. The Collaborating Institutions are Argonne National Laboratory, the University of California at Santa Cruz, the University of Cambridge, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid, the University of Chicago, University College London, the DES-Brazil Consortium, the University of Edinburgh, the Eidgenossische Technische Hochschule (ETH) Zurich, Fermi National Accelerator Laboratory, the University of Illinois at UrbanaChampaign, the Institut de Ciencies de l'Espai (IEEC/CSIC), the Institut de Fisica d'Altes Energies, Lawrence Berkeley National Laboratory, the Ludwig-Maximilians Universitat Munchen and the associated Excellence Cluster Universe, the University of Michigan, the National Optical Astronomy Observatory, the University of Nottingham, the Ohio State University, the University of Pennsylvania, the University of Portsmouth, SLAC National Accelerator Laboratory, Stanford University, the University of Sussex, and Texas A&M University. The Legacy Survey team makes use of data products from the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE), which is a project of the Jet Propulsion Laboratory/California Institute of Technology. NEOWISE is funded by the National Aeronautics and Space Administration. The Legacy Surveys imaging of the DESI footprint is supported by the Director, Office of Science, Office of High Energy Physics of the U.S. Department of Energy under Contract No. DE-AC02-05CH1123; by the National Energy Research Scientific Computing Center, a DOE Office of Science User Facility under the same contract; and by the U.S. National Science Foundation, Division of Astronomical Sciences under Contract No. AST-0950945 to NOAO.

A bar-joint framework is a realisation of a graph consisting of stiff bars linked by universal joints. The framework is rigid if the only bar-length preserving continuous motions of the joints arise from isometries. A rigid framework is isostatic if deleting any single edge results in a flexible framework. Generically, rigidity depends only on the graph and we say an Assur graph is a pinned isostatic graph with no proper pinned isostatic subgraphs. Any pinned isostatic graph can be decomposed into Assur components which may be of use for mechanical engineers in decomposing mechanisms for simpler analysis and synthesis. A direction-length framework is a generalisation of bar-joint framework where some distance constraints are replaced by direction constraints. We initiate a theory of Assur graphs and Assur decompositions for direction-length frameworks using graph orientations and spanning trees and then analyse choices of pinning set.

An experimental and computational approach for identification of protein-protein interactions by ex vivo chemical crosslinking and mass spectrometry (CLMS) has been developed that takes advantage of the specific characteristics of cyanurbiotindipropionylsuccinimide (CBDPS), an affinity-tagged isotopically coded mass spectrometry (MS)-cleavable crosslinking reagent. Utilizing this reagent in combination with a crosslinker-specific data-dependent acquisition strategy based on MS2 scans, and a software pipeline designed for integrating crosslinker-specific mass spectral information led to demonstrated improvements in the application of the CLMS technique, in terms of the detection, acquisition, and identification of crosslinker-modified peptides. This approach was evaluated on intact yeast mitochondria, and the results showed that hundreds of unique protein- protein interactions could be identified on an organelle proteome-wide scale. Both known and previously unknown protein-protein interactions were identified. These interactions were assessed based on their known sub-compartmental localizations. Additionally, the identified crosslinking distance constraints are in good agreement with existing structural models of protein complexes involved in the mitochondrial electron transport chain.

This paper presents a hybrid grasshopper optimization algorithm using a novel decoder and local search to solve instances of the open vehicle routing problem with capacity and distance constraints. The algorithm&rsquo, s decoder first defines the number of vehicles to be used and then it partitions the clients, assigning them to the available routes. The algorithm performs a local search in three neighborhoods after decoding. When a new best solution is found, every route is locally optimized by solving a traveling salesman problem, considering the depot and clients in the route. Three sets containing a total of 30 benchmark problems from the literature were used to test the algorithm. The experiments considered two cases of the problem. In the first, the primary objective is to minimize the total number of vehicles and then the total distance to be traveled. In the second case, the total distance traveled by the vehicles is minimized. The obtained results showed the algorithm&rsquo, s proficient performance. For the first case, the algorithm was able to improve or match the best-known solutions for 21 of the 30 benchmark problems. For the second case, the best-known solutions for 18 of the 30 benchmark problems were found or improved by the algorithm. Finally, a case study from a real-life problem is included.

Significance Fibrinogen hexamers are major components of blood clots. After release of fibrinopeptides resulting in fibrin monomers, clot formation occurs through fibrin oligomerization followed by lateral aggregation, packing into fibrin fibers, and consequent branching. Shedding light on fibrin clots by in situ cross-linking mass spectrometry and structural modeling extends our current knowledge of the structure of fibrin with regard to receptor-binding hotspots. Further restraint-driven molecular docking reveals how fibrin oligomers laterally aggregate into clots and uncovers the molecular architecture of the clot to albumin interaction. We hypothesize this interaction is involved in the prevention of clot degradation. Mapping known mutations validates the generated structural model and, for a subset, brings their molecular mechanisms into view., Upon activation, fibrinogen forms large fibrin biopolymers that coalesce into clots which assist in wound healing. Limited insights into their molecular architecture, due to the sheer size and the insoluble character of fibrin clots, have restricted our ability to develop novel treatments for clotting diseases. The, so far resolved, disparate structural details have provided insights into linear elongation; however, molecular details like the C-terminal domain of the α-chain, the heparin-binding domain on the β-chain, and other functional domains remain elusive. To illuminate these dark areas, we applied cross-linking mass spectrometry (XL-MS) to obtain biochemical evidence in the form of over 300 distance constraints and combined this with structural modeling. These restraints additionally define the interaction network of the clots and provide molecular details for the interaction with human serum albumin (HSA). We were able to construct the structural models of the fibrinogen α-chain (excluding two highly flexible regions) and the N termini of the β-chain, confirm these models with known structural arrangements, and map how the structure laterally aggregates to form intricate lattices together with the γ-chain. We validate the final model by mapping mutations leading to impaired clot formation. From a list of 22 mutations, we uncovered structural features for all, including a crucial role for βArg’169 (UniProt: 196) in lateral aggregation. The resulting model can potentially serve for research on dysfibrinogenemia and amyloidosis as it provides insights into the molecular mechanisms of thrombosis and bleeding disorders related to fibrinogen variants. The structure is provided in the PDB-DEV repository (PDBDEV_00000030).

This research uses the acoustic coda phase delay method to estimate relative changes in air temperature between explosions with varying event masses and heights of burst. It also places a bound on source-receiver distance for the method. Previous studies used events with different shapes, height of bursts, and masses and recorded the acoustic codas at source-receiver distances less than 1 km. This research further explores the method using explosions that differ in mass (by up to an order of magnitude) and are placed at varying heights. Source-receiver distances also cover an area out to 7 km. Relative air temperature change estimates are compared to complementary meteorological observations. Results show that two explosions that differ by an order of magnitude cannot be used with this method because their propagation times in the near field and their fundamental frequencies are different. These differences are expressed as inaccuracies in the relative air temperature change estimates. An order of magnitude difference in mass is also shown to bias estimates higher. Small differences in height of burst do not affect the accuracy of the method. An upper bound of 1 km on source-receiver distance is provided based on the standard deviation characteristics of the estimates.

Multiple Traveling Repairman Problem (MTRP) is a class of NP-hard combinatorial optimization problems. In this paper, an other variant of MTRP, also known as Multiple Traveling Repairman Problem with Distance Constraint (MTRPD) is introduced. In MTRPD problem, a fleet of vehicles serve a set of customers. Each vehicle that starts from the depot is not allowed to travel a distance longer than a limit and each customer must be visited exactly once. The goal is to find the order of customer visits that minimizes the sum of waiting time. To the best of our knowledge, the problem has not been studied much previously, even though it is a natural and practical extension of the Traveling Repairman Problem or Multiple Traveling Repairman Problem case. In our work, we propose a metaheuristic algorithm which is mainly based on the principles of Greedy Randomized Adaptive Search Procedure (GRASP) and Variable Neighborhood Descent (VND) to solve the problem. The GRASP is used to build an initial solution which is good enough in construction phase. In a cooperative way, the VND is employed to generate diverse neighborhoods in improvement phase, therefore, it can prevent the search to escape from local optimal. Extensive numerical experiments on benchmark instances show that our algorithm can find the optimal solutions with up to 50 vertices in several instances. For larger instances, our algorithm obtains provably near-optimal solutions, even for large instances.

Acoustic recording units (ARUs) have recently been used in place of field observers to survey birds. To test whether data obtained from ARUs and from point counts by a field observer are directly comparable, we surveyed Tasmanian forest birds using these two methods at exactly the same times and places. Data derived from ARUs were similar to those obtained by the field observer without distance constraints for (a) the total numbers of species detected at each of three points, and (b) both the number and composition of species within each of the 13 5-minute surveys at each point. However, data sets obtained by each method comprised more records of certain species, largely because of calls being detected by one method but not by the other. Additional differences between methods arose because ARUs could not detect birds seen by the field observer that were not calling, and ARUs sometimes led to false positive identifications when the person listening to recordings was unable to distinguish mimetic calls from those of the species being mimicked. Because ARUs appeared to detect many calls from beyond 100 m, their use to survey a particular patch of vegetation requires placement (within the vegetation patch) at distances greater than 100 m from the edge of the patch to prevent the inclusion of calls from non-target vegetation.

The use of minimally invasive procedures for diagnosis and treatment decisions means that very often cytological samples are the only material available for testing. Cytology has evolved from a strictly morphological approach to the routine use of immunohistochemistry. The advent of personalized medicine has increased the demand for molecular testing, making rapid on-site evaluation even more relevant. This article presents current rapid on-site evaluation practice patterns in different settings, with a special focus on the variety of professionals involved. Technological advances such as telepathology can help to alleviate distance constraints. This article also provides an overview of telecytopathology, describing challenges to its implementation and how to address them. Issues such as hardware, personnel training, communication, guidelines, validation, use, and future directions are highlighted. Cancer Cytopathol 2017;125(6 suppl):449-54. © 2017 American Cancer Society.