Miracle-dz/UniFAR-FTUs huggingface dataset:
Author's Personal Copy Theoretical Computer Science on Selecting a Maximum Volume Sub-matrix of a Matrix and Related Problems

In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: a b s t r a c t Given a matrix A ∈ R m×n (n vectors in m dimensions), we consider the problem of selecting a subset of its columns such that its elements are as linearly independent as possible. This notion turned out to be important in low-rank approximations to matrices and rank revealing QR factorizations which have been investigated in the linear algebra community and can be quantified in a few different ways. In this paper, from a complexity theoretic point of view, we propose four related problems in which we try to find a sub-matrix C ∈ R m×k of a given matrix A ∈ R m×n such that (i) σ max (C) (the largest singular value of C) is minimum, (ii) σ min (C) (the smallest singular value of C) is maximum, (iii) κ(C) = σ max (C)/σ min (C) (the condition number of C) is minimum, and (iv) the volume of the parallelepiped defined by the column vectors of C is maximum. We establish the NP-hardness of these problems and further show that they do not admit PTAS. We then study a natural Greedy heuristic for the maximum volume problem and show that it has approximation ratio 2 −O(k log k). Our analysis of the Greedy heuristic is tight to within a logarithmic factor in the exponent, which we show by explicitly constructing an instance for which the Greedy heuristic is 2 −Ω(k) from optimal. When A has unit norm columns, a related problem is to select the maximum number of vectors with a given volume. We show that if the optimal solution selects k columns, then Greedy will select Ω(k/ log k) columns, providing a log k approximation.
Hierarchical cluster-based link state routing protocol for large self-organizing networks

Scalability is one of critical challenges for link-state routing protocols in mobile wireless networks. In this context, this paper proposes a proactive link-state protocol based on hierarchical clustering named L-HCLSR. The proposed protocol makes use of clustering algorithm to partition the network and to create a L-levels hierarchical structure of clusters. It uses the structure of clusters to create a virtual backbone useful to broadcast control messages in the entire network. Clustering and virtual structure are used to reduce the routing overhead. Besides, fish eye technique is used to more reduce the routing overhead. We study through simulations the performances of our protocol L-HCLSR with number of level L=1 and L=2, and we compare it to SA-OLSR and F-OLSR protocols. Simulations show that our protocol provides comparable or better performances.
Improved algorithms for fully dynamic geometric spanners and geometric routing

For a set <i>S</i> of points in ℝ<sup>d</sup>, a t-spanner is a sparse graph on the points of <i>S</i> such that between any pair of points there is a path in the spanner whose total length is at most <i>t</i> times the Euclidean distance between the points. In this paper, we show how to construct a (1 + ε)-spanner with <i>O</i>(<i>n/ε<sup>d</sup></i>) edges and maximum degree <i>O</i>(1/ε<i><sup>d</sup></i>) in time <i>O</i>(<i>n</i> log <i>n</i>). A spanner with similar properties was previously presented in [6, 8]. However, using our new construction (coupled with several other innovations) we obtain new results for two fundamental problems for constant doubling dimension metrics: The first result is an essentially optimal compact routing scheme. In particular, we show how to perform routing with a stretch of 1 + ∈, where the label size is [log <i>n</i>] and the size of the table stored at each point is only <i>O</i>(log <i>n</i>/ε<i><sup>d</sup></i>). This routing problem was first considered by Peleg and Hassin [11], who presented a routing scheme in the plane. Later, Chan <i>et al.</i> [6] and Abraham <i>et al.</i> [1] considered this problem for doubling dimension metric spaces. Abraham <i>et al.</i> [1] were the first to present a (1 + ∈) routing scheme where the label size depends solely on the number of points. In their scheme labels are of size of [log <i>n</i>], and each point stores a table of size <i>O</i>(log<sup>2</sup> <i>n</i>/ε<i><sup>d</sup></i>). In our routing scheme, we achieve routing tables of size <i>O</i>(log <i>n</i>/ε<i><sup>d</sup></i>), which is essentially the same size as a label (up to the factor of 1/ε<i><sup>d</sup></i>). The second and main result of this paper is the first <b>fully</b> dynamic geometric spanner with poly-logarithmic update time for both insertions and deletions. We present an algorithm that allows points to be inserted into and deleted from <i>S</i> with an amortized update time of <i>O</i>(log<sup>3</sup> <i>n</i>).
Cellular Functions and X-ray Structure of Anthrolysin O, a Cholesterol-dependent Cytolysin Secreted by Bacillus anthracis*

Anthrolysin O (ALO) is a pore-forming, cholesterol-dependent cytolysin (CDC) secreted by Bacillus anthracis, the etiologic agent for anthrax. Growing evidence suggests the involvement of ALO in anthrax pathogenesis. Here, we show that the apical application of ALO decreases the barrier function of human polarized epithelial cells as well as increases intracellular calcium and the internalization of the tight junction protein occludin. Using pharmacological agents, we also found that barrier function disruption requires increased intracellular calcium and protein degradation. We also report a crystal structure of the soluble state of ALO. Based on our analytical ultracentrifugation and light scattering studies, ALO exists as a monomer. Our ALO structure provides the molecular basis as to how ALO is locked in a monomeric state, in contrast to other CDCs that undergo antiparallel dimerization or higher order oligomerization in solution. ALO has four domains and is globally similar to perfringolysin O (PFO) and intermedilysin (ILY), yet the highly conserved undecapeptide region in domain 4 (D4) adopts a completely different conformation in all three CDCs. Consistent with the differences within D4 and at the D2-D4 interface, we found that ALO D4 plays a key role in affecting the barrier function of C2BBE cells, whereas PFO domain 4 cannot substitute for this role. Novel structural elements and unique cellular functions of ALO revealed by our studies provide new insight into the molecular basis for the diverse nature of the CDC family.
Assessing the president's vision: The Fletcher, Miller, and Hoffman panels

IT was A very appealing vision that President Reagan invited the public to share in his March 23 speech? "a vision of the future which offers hope," a world free of nuclear dread, where nuclear weapons will be rendered "impotent and obsolete. " The president chose a surprising way to present his vision. In the closing moments of a televised speech arguing for a larger military budget, Reagan abruptly changed topics and announced what was no less than a revolution in American strategic doctrine. At the heart of his vision was a repudiation of deterrence? the bedrock of American strategic nuclear policy for three decades. "I've become more and more deeply convinced," the president remarked,
Quantification and characterization of fluctuating cognition in dementia with Lewy bodies and Alzheimer's disease.

Fluctuating cognition (FC) is a common and important symptom in dementia, particularly dementia with Lewy bodies (DLB), although it has not been empirically quantified or characterised. Forty subjects (15 DLB, 15 AD, 10 elderly controls) were evaluated using a clinical FC severity scale, as well as receiving measures of variability in attentional performance and slow EEG rhythms across 90 s, 1 h and 1 week. DLB patients had significantly more severe FC and more severe variability in attentional and slow electrocortical measures than either AD patients or normal controls in all time frames. Attentional and EEG variability also correlated significantly with independent clinical ratings of FC. Clinical quantification and measures of attention and EEG variability can therefore make an important and standardised contribution to the assessment of FC in dementia, facilitating future treatment studies with important implications for the potential causative mechanisms and differential diagnosis.
Network-level cooperation with enhancements based on the physical layer

Recently, cognitive cooperation has received a great deal of attention, where the cognitive relay utilizes the periods of source silence to enable cooperation without consuming extra network resources. In this paper, we investigate more enhanced cooperative techniques on top of the existing network-layer conventional cognitive cooperation by exploiting more degrees of freedom at the physical layer. In a wireless multiple-access relay channel with two primary users and a cognitive relay, we first study a dynamic decode-and-forward scheme in which the relay can also be activated during the primary user's transmission, to provide more assistance for successful reception at the destination. Then, an adaptive superposition scheme is proposed by allowing the relay node to simultaneously serve packets relayed from the two users, according to the instantaneous channel feedback. The enhanced cooperation schemes are evaluated in the performance measure of the stable throughput region.
Finding Web-Based Anxiety Interventions on the World Wide Web: A Scoping Review

Background One relatively new and increasingly popular approach of increasing access to treatment is Web-based intervention programs. The advantage of Web-based approaches is the accessibility, affordability, and anonymity of potentially evidence-based treatment. Despite much research evidence on the effectiveness of Web-based interventions for anxiety found in the literature, little is known about what is publically available for potential consumers on the Web. Objective Our aim was to explore what a consumer searching the Web for Web-based intervention options for anxiety-related issues might find. The objectives were to identify currently publically available Web-based intervention programs for anxiety and to synthesize and review these in terms of (1) website characteristics such as credibility and accessibility; (2) intervention program characteristics such as intervention focus, design, and presentation modes; (3) therapeutic elements employed; and (4) published evidence of efficacy. Methods Web keyword searches were carried out on three major search engines (Google, Bing, and Yahoo—UK platforms). For each search, the first 25 hyperlinks were screened for eligible programs. Included were programs that were designed for anxiety symptoms, currently publically accessible on the Web, had an online component, a structured treatment plan, and were available in English. Data were extracted for website characteristics, program characteristics, therapeutic characteristics, as well as empirical evidence. Programs were also evaluated using a 16-point rating tool. Results The search resulted in 34 programs that were eligible for review. A wide variety of programs for anxiety, including specific anxiety disorders, and anxiety in combination with stress, depression, or anger were identified and based predominantly on cognitive behavioral therapy techniques. The majority of websites were rated as credible, secure, and free of advertisement. The majority required users to register and/or to pay a program access fee. Half of the programs offered some form of paid therapist or professional support. Programs varied in treatment length and number of modules and employed a variety of presentation modes. Relatively few programs had published research evidence of the intervention’s efficacy. Conclusions This review represents a snapshot of available Web-based intervention programs for anxiety that could be found by consumers in March 2015. The consumer is confronted with a diversity of programs, which makes it difficult to identify an appropriate program. Limited reports and existence of empirical evidence for efficacy make it even more challenging to identify credible and reliable programs. This highlights the need for consistent guidelines and standards on developing, providing, and evaluating Web-based interventions and platforms with reliable up-to-date information for professionals and consumers about the characteristics, quality, and accessibility of Web-based interventions.
An improved Koch snowflake fractal broadband antenna for wireless applications

This study proposes a compact improved Koch snowflake fractal broadband planar antenna for the second generation (2G) to the fourth generation (4G), WLAN and navigation wireless applications. The device is based on the principles and structural features of conventional Koch fractal monopole antenna elements, combined with the advantages of trapezoid CPW-fed structure. The proposed antenna adapted two iterations Koch snowflake fractal structure radiator with one iteration Koch snowflake fractal slot inside, which covers more than ten mobile applications with a bandwidth of 106.25% (1.5–4.9GHz) for GPS, BDS, GLONSS, GALILEO, DCS1800, TD-SCDMA, WCDMA, CDMA2000, LTE33-41/42/43, Bluetooth, WLAN and WiMAX frequency bands. The proposed antenna was fabricated on a G10/FR4 substrate with a dielectric constant of 4.4 and a size of 72𢈗42𢈗1. 6mm3. The measurement results reveal that the omni-directional radiation patterns achieve a gain of −1.7–2.35dBi and an efficiency of 31–64%. The good agreement between the measurement results and simulation validates the proposed design approach and satisfies the requirements for various wireless applications.
0.374 Pflop/s trillion-particle kinetic modeling of laser plasma interaction on roadrunner

We demonstrate the outstanding performance and scalability of the VPIC kinetic plasma modeling code on the heterogeneous IBM Roadrunner supercomputer at Los Alamos National Laboratory. VPIC is a three-dimensional, relativistic, electromagnetic, particle-in-cell (PIC) code that self-consistently evolves a kinetic plasma. VPIC simulations of laser plasma interaction were conducted at unprecedented fidelity and scale-up to 1.0 times 1012 particles on as many as 136 times 106 voxels-to model accurately the particle trapping physics occurring within a laser-driven hohlraum in an inertial confinement fusion experiment. During a parameter study of laser reflectivity as a function of laser intensity under experimentally realizable hohlraum conditions, we measured sustained performance exceeding 0.374 Pflop/s (s.p.) with the inner loop itself achieving 0.488 Pflop/s (s.p.). Given the increasing importance of data motion limitations, it is notable that this was measured in a PIC calculation-a technique that typically requires more data motion per computation than other techniques (such as dense matrix calculations, molecular dynamics N-body calculations and Monte-Carlo calculations) often used to demonstrate supercomputer performance. This capability opens up the exciting possibility of using VPIC to model, from first-principles, an issue critical to the success of the multi-billion dollar DOE/NNSA National Ignition Facility.
A New Scenario Decomposition Method for Large-Scale Stochastic Optimization

A novel parallel decomposition algorithm is developed for large, multistage stochastic optimization problems. The method decomposes the problem into subproblems that correspond to scenarios. The subproblems are modified by separable quadratic terms to coordinate the scenario solutions. Convergence of the coordination procedure is proven for linear programs. Subproblems are solved using a nonlinear interior point algorithm. The approach adjusts the degree of decomposition to fit the available hardware environment. Initial testing on a distributed network of workstations shows that an optimal number of computers depends upon the work per subproblem and its relation to the communication capacities. The algorithm has promise for solving stochastic programs that lie outside current capabilities.
The impact of smoke on respiratory hospital outcomes during the 2002–2003 bushfire season, Victoria, Australia

Background and objective: Uncontrolled bushfires produce copious amounts of smoke that can result in adverse effects on human health and so are important considerations for emergency, public health and environmental protection agencies. During January to March 2003, the north‐east and Alpine regions of the state of Victoria experienced major bushfires that created a blanket of smoke over the entire state for extended periods of time. This study aimed to explore the daily trends in air pollutants and temporal correlations with changes in respiratory outcomes and to determine whether variation in particulate matter < 10 µm (PM10), visibility‐reducing particles and ozone produced by bushfires could explain variation in respiratory outcomes.
A Limited Broadcast Algorithm (LBA)

In wireless Ad hoc networks, broadcast plays an important role in the process of route finding and maintenance. The efficiency of broadcast affects the performance of the whole network largely. The paper proposes a limited broadcast algorithm (LBA), which defines a neighbor information table and chooses some neighbor nodes as transmission nodes in order to reduce the redundant radio broadcasts and improve the broadcast efficiency. We can also modify the broken route through neighbor information table. The simulation result shows that LBA controls the broadcast storm problem and improves the network performance.
Factors Controlling Storage, Sources, and Diagenetic State of Organic Carbon in a Prograding Subaerial Delta: Wax Lake Delta, Louisiana

Wax Lake Delta, southern Louisiana, is a coastal delta that formed following the dredging of a river channel in 1941 and is a field model for investigating the geomorphology, ecology, carbon dynamics, and carbon storage capacity in young prograding deltas. However, it is unknown how the transition from subaqueous to subaerial sediments affects the sources and quality of the sequestered carbon. We investigated these variations within the sediments of Wax Lake Delta using amino acid, lignin, and stable carbon isotope compositions of the organic matter (OM). A principal component analysis of these proxies highlighted variability in organic carbon (OC) composition with changes in elevation. The transition from subaqueous to subaerial sediments at 0‐cm mean lower low water is an important component of the OM composition. In addition to the changes observed for OM source and quality, the OC loadings (OC/SA; mg C/m2) also increase as the delta aggrades and accumulates sediments with loadings typical of delta topsets and mobile mud banks (OC/SA < 0.4) to riverine sediments (0.5 < OC/SA < 1) and eventually to highly productive regions (OC/SA > 1). Linking this multiproxy approach with environmental variables such as elevation provides a path for incorporating OM dynamics into geomorphic models.
Distributed STDMA in Ad Hoc Networks

Spatial reuse TDMA is a collision-free access scheme for ad hoc networks. The idea is to let spatially separated radio terminals reuse the same time slot when the resulting interferences are not too severe. In this paper we describe the properties a distributed STDMA algorithm must have in order to be efficient, and describe the first step towards such an algorithm. Furthermore, we evaluate this first step and show that it can give the same capacity as a a centralized reference algorithm.
Comparison of Survey, Federal, and Commercial Address Data Quality

This report summarizes matching of survey, commercial, and administrative records housing units to the Census Bureau Master Address File (MAF). We document overall MAF match rates in each data set and evaluate differences in match rates across a variety of housing characteristics. Results show that over 90 percent of records in survey data from the American Housing Survey (AHS) match to the MAF. Commercial data from CoreLogic matches at much lower rates, in part due to missing address information and poor match rates for multi-unit buildings. MAF match rates for administrative records from the Department of Housing and Urban Development are also high, and open the possibility of using this information in surveys such as the AHS.
SEPARATE: a machine learning method based on semi-global partitions

This article presents a machine learning method for solving classification and approximation problems. This method uses the divide-and-conquer algorithm design technique (taken from machine learning models based on a tree), with the aim of achieving design ease and good results on the training examples and allows semi-global actions on its computational elements (a feature taken from neural networks), with the aim of attaining good generalization and good behavior in the presence of noise in training examples. Finally, some results obtained after solving several problems with a particular implementation of SEPARATE are presented together with their analysis.
Stereo based ROIs generation for detecting pedestrians in close proximity

Region of Interests (ROIs) generation plays a critical role in pedestrian detection systems. The challenge lies in generating as few ROIs as possible at low computational complexity, while ensuring none of the pedestrians in the scene are omitted. However, existing ROIs generation methods either result in a large number of irrelevant ROIs or are compute-intensive. In addition, distinguishing pedestrians who are in close proximity is still a big challenge. In this paper, we propose an efficient stereo based ROIs generation method that is based on a two-level incremental segmentation strategy. An adaptive strategy is first employed to identify a minimal set of clusters from the u-disparity image. The initial clusters are then further refined to distinguish pedestrians in close proximity. Experimental results based on a challenging benchmark show that the proposed algorithm outperforms two state-of-art baseline algorithms by being able to distinguish pedestrians in close proximity with a small number of ROIs.
Immunocytochemical Localization of Lipocalin-Type Prostaglandin D Synthase in the Bull Testis and Epididymis and on Ejaculated Sperm1

Abstract Previously, we identified a 26-kDa fertility-associated protein in bull seminal plasma as lipocalin-type prostaglandin D synthase. The objective of the present study was to immunohistochemically localize this enzyme to the various cell types within the bull testis and seven subsegments of the epididymis, and on ejaculated sperm in order to gain further insight into its potential function in male reproduction. In the testis, immunoperoxidase staining was localized within the elongating spermatids and Sertoli cells of the seminiferous tubules, varying with the stage of the spermatogenic cycle. The highest level of staining occurred during stages III–VII. The cuboidal epithelial cells of the rete testis and efferent ducts were also immunoreactive. Expression of lipocalin-type prostaglandin D synthase was not uniform in the seven epididymal subsegments, suggesting a possible role in sperm maturation. In all epididymal regions, expression was limited to the epithelial principal cells; no immunoreactivity was apparent in other cell types. Lipocalin-type prostaglandin D synthase was strikingly localized in the caput epididymidis, while moderate to weak staining was observed in the remainder of the epididymis. Droplets of reaction product observed within the lumen increased progressively from the caput to cauda. Using fluorescence microscopy, we also localized lipocalin-type prostaglandin D synthase to the apical ridge of the acrosome on ejaculated sperm.