bluuebunny/crossref_metadata_2025 huggingface dataset:
An Efficient Reconciliation in Removing Errors Using Bose, Chaudhuri, Hocquenghem Code for Quantum Key Distribution
Authors: Qamar Riaz Ahmad , Maarof Mohd Aizaini , Ibrahim Subariah
Published: January 2013

A quantum key distribution protocol(QKD), known as BB84, was developed in 1984 by Charles Bennett and Gilles Brassard. The protocol works in two phases which are quantum state transmission and conventional post processing. In the first phase of BB84, raw key elements are distributed between two legitimate users by sending encoded photons through quantum channel whilst in the second phase, a common secret-key is obtained from correlated raw key elements by exchanging messages through a public channel e.g.; network or internet. The secret-key so obtained is used for cryptography purpose. Reconciliation is a compulsory part of post processing and hence of quantum key distribution protocol. The performance of a reconciliation protocol depends on the generation rate of common secret-key, number of bits disclosed and the error probability in common secrete-key. These characteristics of a protocol can be achieved by using a less interactive reconciliation protocol which can handle a higher initial quantum bit error rate (QBER). In this paper, we use a simple Bose, Chaudhuri, Hocquenghem (BCH) error correction algorithm with simplified syndrome table to achieve an efficient reconciliation protocol which can handle a higher quantum bit error rate and outputs a common key with zero error probability. The proposed protocol efficient in removing errors such that it can remove all errors even if QBER is 60%. Assuming the post processing channel is an authenticated binary symmetric channel (BSC).
The Investigation of Wind Energy Potential in Order to Estimate Power Plants in Baladeh Mazandaran, Iran
Authors: Gholamian S. Asghar , Soltani S. Bagher , Ilka R.
Published: January 2013

First step for achieving wind energy is to locate points with appropriate wind power density in a country. Wind data which are recorded in a synoptic weather station, are the best way to study the wind potential of an area. In this paper wind speed period of Baladeh synoptic weather station is studied, since it has the maximum average of wind speed among 15 stations of the MAZANDARAN Province. Weibull factors k and c are calculated for 40 months from September 2006 to December 2009 and wind power density is determined based on these data. The total average of factors k and c for a height for 50 m are 1.442 m/s and 5.1256 respectively. By using the average of factors, wind power density in 50 m height will be 147.40 watt/m2 which is categorized as weak potential in wind class. However by monthly investigation it is shown that with a 50 m wind, this station can be put in medium class in hot months of the year.
Biodegration of Dye Using Free Laccase and Sol-gel Laccase
Authors: Ahmad Shamsuri Nur Afiqah , Mohidem Nur Atikah , Mansor Azmi Fadziyana , Mat Hanapi
Published: January 2013

Malachite green oxalate dyes are of synthetic origin and their environmental existence is not well understood. They are resistant to direct aerobic bacterial degradation and form potentially carcinogenic aromatic amines. This study shows that applying the oxidative processes of enzymatic treatment with free laccase and sol-gel laccase could lead to dye degradation. The degradation of dye malachite green oxalate using free laccase and sol-gel laccase, respectively were 37% and 13% at 1 hour reaction. The optimum pH for the free laccase and sol-gel laccase respectively were at pH 5 and pH 6. The optimal temperature for degradation of dye by sol-gel laccase was at 40°C. These results showed that free laccase and sol-gel laccase have good performance in the degradation of malachite green oxalate dyes.

Pewarna oxalate hijau Malachite adalah sintetik asli dan kewujudan semulajadinya tidak begitu diketahui. Ia bersifat kalis degradasi bakteria aerobik dan membentuk amina aromatik yang berpotensi karsinogen. Kajian ini menunjukkan bahawa penggunaan proses oksidatif untuk rawatan enzim dengan lakase bebas dan lakase sol-gel boleh membawa kepada degradasi pewarna. Degradasi pewarna malachite hijau oxalate yang menggunakan lakase bebas dan lakase sol-gel, masing-masing adalah sebanyak 37% dan 13% pada 1 jam reaksi. pH optimum untuk lakase bebas and lakase sol gel, masing-masing adalah pada pH 5 dan pH 6. Suhu optimum bagi degradasi pewarna oleh lakase sol-gel adalah pada 40°C.
Textile Wastewater Treatment using Hybrid Chitosan-polyarcylamide Flocculant
Authors: Ngadi Norzita , Abdul Aziz Nurhayati Izad , Mohamed Razak Siti Fatimah
Published: January 2013

In this study, a ntural polymer, chitosan was modified with polyacrylamide (PAM) to prepare an efficient flocculant using redox grafting method. The effectiveness of the modified chitosan (chitosan grafted polyacrylamide) was tested on treatment of industrial textile wastewater. The effect of dosage, pH and settling time on the performance of flocculation process was also investigated. The treated textile wastewater was analyzed by its color removal, COD and turbidity reductions. The results obtained showed that the modified chitosan performed better than unmodified chitosan in the reduction of COD and turbidity of textile wastewater.

Dalam kajian ini, polimer semulajadi, kitosan telah di modifikasikan dengan poliacrylamid (PAM) untuk menghasilkan flokulan yang efektif dengan menggunakan kaedah tergabung redox. Keberkesanan kitosan termodifikasi (kitosan tergabung polyacrylamid) telah di uji ke atas rawatan air sisa industri tekstil. Kesan dos, pH dan masa pemendapan ke atas keberkesanan proses flokulasi juga telah di kaji. Air sisa yang terawat di analisa untuk penyingkiran warna, pengurangan COD dan pengurangan kekeruhan. Keputusan yang diperolehi menunjukkan bahawa kitosan termodifikasi adalah lebih baik daripada kitosan tidak termodifikasi dalam pengurangan COD dan pengurangan kekeruhan sisa air tekstil.
Pazopanib Enhances Paclitaxel-Induced Mitotic Catastrophe in Anaplastic Thyroid Cancer
Authors: Isham Crescent R. , Bossou Ayoko R. , Negron Vivian , Fisher Kelly E. , Kumar Rakesh , Marlow Laura , Lingle Wilma L. , Smallridge Robert C. , Sherman Eric J. , Suman Vera J. , Copland John A. , Bible Keith C.
Published: January 2013

Pazopanib and paclitaxel produce cytotoxic synergy in thyroid cancer models through inhibition of aurora kinase A.
Familial Hypercholesterolemia and Atherosclerosis in Cloned Minipigs Created by DNA Transposition of a Human
PCSK9
Gain-of-Function Mutant
Authors: Al-Mashhadi Rozh H. , Sørensen Charlotte B. , Kragh Peter M. , Christoffersen Christina , Mortensen Martin B. , Tolbod Lars P. , Thim Troels , Du Yutao , Li Juan , Liu Ying , Moldt Brian , Schmidt Mette , Vajta Gabor , Larsen Torben , Purup Stig , Bolund Lars , Nielsen Lars B. , Callesen Henrik , Falk Erling , Mikkelsen Jacob Giehm , Bentzon Jacob F.
Published: January 2013

A transgenic pig model of familial hypercholesterolemia can be used for translational atherosclerosis research.
Mighty Minipig in Fight Against Cardiovascular Disease
Authors: Agarwala Anandita , Billheimer Jeffrey , Rader Daniel J.
Published: January 2013

A cloned transgenic minipig model of hypercholesterolemia and accelerated atherosclerosis could accelerate discovery of new therapies for atherosclerotic cardiovascular disease.
Solving Pathogen Sudoku
Authors: Shrout Joshua D.
Published: January 2013

A new screen dissects complex interactions between pathogen and host to pinpoint factors responsible for virulence.
Optimizing dimodular nonribosomal peptide synthetases and natural dipeptides in an Escherichia coli heterologous host
Authors: Wyatt Morgan A. , Magarvey Nathan A.
Published: January 2013

Nonribosomal peptides are an important class of natural products that have a broad range of biological activities. Their structural complexity often prevents simple chemical synthesis, and production from the natural producer is often low, which deters pharmaceutical development. Expression of biosynthetic machinery in heterologous host organisms like Escherichia coli is one way to access these structures, and subsequent optimization of these systems is critical for future development. We utilized the aureusimine biosynthetic gene cluster as a model system to identify the optimal conditions to produce nonribosomal peptides in the isopropyl β-d-1-thiogalactopyranoside (IPTG)-inducible T7 promoter system of pET28. Single reaction monitoring of nonribosomal products was used to find the optimal concentration of IPTG, postinduction temperature, and the effect of amino acid precursor supplementation. In addition, principle component analysis of these extracts identified 3 previously undiscovered pyrazine products of the aureusimine biosynthetic locus, highlighting the utility of heterologously expressing nonribosomal peptide synthetases to find new products.
Impact of hypoxia on the metabolism of Greenland halibut (Reinhardtius hippoglossoides)
Authors: Dupont-Prinet Aurélie , Vagner Marie , Chabot Denis , Audet Céline
Published: January 2013

Greenland halibut (Reinhardtius hippoglossoides), especially juveniles, are frequently found in severely hypoxic areas (18%–25% saturation) of the St. Lawrence Estuary. We investigated the tolerance of this species to hypoxia and evaluated the consequences of low oxygen levels on metabolic capacity. At 5 °C, juveniles had a higher critical oxygen threshold than adults (15% versus 11% saturation), indicating that they were less tolerant to hypoxia. Severe hypoxia (19% saturation) did not affect the juveniles' standard metabolic rate but significantly reduced (by 55%) their maximum metabolic rate compared with normoxia. Consequently, the aerobic scope was reduced by 72% in hypoxia compared with normoxia. In juveniles, severe hypoxia increased the duration of digestive processes. The decrease in aerobic scope in hypoxia and the determination of critical oxygen threshold at a saturation level close to actual field dissolved oxygen values strongly suggest that juveniles from the St. Lawrence Estuary are living at the edge of their metabolic capacity. Consequently, the growth and distribution of Greenland halibut could be affected if there are further declines in dissolved oxygen availability.
Mepivacaine-induced contraction involves phosphorylation of extracellular signal-regulated kinase through activation of the lipoxygenase pathway in isolated rat aortic smooth muscle
Authors: Lee Hyo Min , Ok Seong-Ho , Sung Hui-Jin , Eun So Young , Kim Hye Jung , Lee Soo Hee , Kang Sebin , Shin Il-Woo , Lee Heon Keun , Chung Young-Kyun , Choi Mun-Jeoung , Bae Sung Il , Sohn Ju-Tae
Published: January 2013

Mepivacaine is an aminoamide local anesthetic with an intermediate duration that intrinsically produces vasoconstriction both in vivo and in vitro. This study investigated the arachidonic acid metabolic pathways involved in mepivacaine-induced contraction, and elucidated the associated cellular mechanism with a particular focus on extracellular signal-regulated kinase (ERK) in endothelium-denuded rat aorta. Isolated rat thoracic aortic rings were suspended for isometric tension recording. Cumulative mepivacaine concentration–response curves were generated in the presence or absence of the following inhibitors: quinacrine dihydrochloride, nordihydroguaiaretic acid, phenidone, AA-861, indomethacin, NS-398, SC-560, fluconazole, PD 98059, and verapamil. Mepivacaine-induced ERK phosphorylation, 5-lipoxygenase (5-LOX) expression, and cyclooxygenase (COX)-2 expression in rat aortic smooth muscle cells were detected by Western blot analysis in the presence or absence of inhibitors. Mepivacaine produced tonic contraction in isolated endothelium-denuded rat aorta. Quinacrine dihydrochloride, nordihydroguaiaretic acid, phenidone, AA-861, NS-398, PD 98059, and verapamil attenuated mepivacaine-induced contraction in a concentration-dependent manner. However, fluconazole had no effect on mepivacaine-induced contraction. PD 98059, quinacrine dihydrochloride, nordihydroguaiaretic acid, AA-861, phenidone, and indomethacin attenuated mepivacaine-induced ERK phosphorylation. Mepivacaine upregulated 5-LOX and COX-2 expression. These results suggest that mepivacaine-induced contraction involves ERK activation, which is primarily mediated by the 5-LOX pathway and in part by the COX-2 pathway.
NCS 613 exhibits anti-inflammatory effects on PBMCs from lupus patients by inhibiting p38 MAPK and NF-κB signalling pathways while reducing proinflammatory cytokine production
Authors: Yougbaré Issaka , Boire Gilles , Roy Michelle , Lugnier Claire , Rouseau Éric
Published: January 2013

Systemic lupus erythematosus (SLE) is a polymorphic and multigenic autoimmune disease that evolves into progressive and chronic inflammation of multiple joints and organs. Phosphorylation and activation of p38 MAPK, along with the resulting overproduction of interleukin (IL)-1β, IL-6, and tumour necrosis factor (TNF)-α is a hallmark of inflammatory disorders. Here, we investigated the anti-inflammatory pathway modulated by NCS 613, a specific PDE4 inhibitor, on human peripheral blood mononuclear cells (PBMCs) from 5 healthy donors and 12 SLE patients. PDE4 subtypes, p38 MAPK, and IκBα protein levels were analyzed by Western blot, while NF-κB and PDE4B immunostaining was assessed in control and lipopolysaccharide (LPS) -pretreated PBMCs. Proinflammatory cytokines were quantified by ELISA, while IL-1β mRNA was resolved by RT–qPCR. NCS 613 treatment decreased PDE4B and upregulated PDE4C in human PBMCs from healthy donors and SLE patients. LPS stimulation increased p38 MAPK phosphorylation and NF-κB translocation to the nucleus, which was abolished by NCS 613 treatment. Concomitantly, NCS 613 restored IκBα detection levels in human PBMCs from both healthy donors and SLE patients. This compound also abolished LPS-induced inflammation in PBMCs by reducing IL-6, IL-8, and TNF-α cytokines. NCS 613 is a small molecule displaying anti-inflammatory properties that may provide an alternative or complementary strategy for SLE management.
Between Networks and Communities: Challenges for an Optimal Innovation Structure
Authors: Koen Lourens , Maasdorp Christiaan
Published: January 2013

Inter-organisational networks and communities of practice are two areas of inquiry of interest to knowledge management, especially when innovation is an important organisational goal. These two areas are separated by different foci, assumptions and approaches. For this reason they are often seen as opposing approaches to enabling innovation. The paper argues that whilst networks and communities are different structures, they have complementary roles to play in innovation and when combined could bring organisations closer to an optimal innovative structure. It is proposed that innovation networks are conducive to the exploration aspects and communities of practice support exploitation aspects of the innovation process. What is to be considered optimum will be dependent on the specific context determined by several network concepts, namely strength and density of ties, cognitive distance, and absorptive capacity.
Leakage in data mining
Authors: Kaufman Shachar , Rosset Saharon , Perlich Claudia , Stitelman Ori
Published: January 2013

Deemed “one of the top ten data mining mistakes”, leakage is the introduction of information about the data mining target that should not be legitimately available to mine from. In addition to our own industry experience with real-life projects, controversies around several major public data mining competitions held recently such as the INFORMS 2010 Data Mining Challenge and the IJCNN 2011 Social Network Challenge are evidence that this issue is as relevant today as it has ever been. While acknowledging the importance and prevalence of leakage in both synthetic competitions and real-life data mining projects, existing literature has largely left this idea unexplored. What little has been said turns out not to be broad enough to cover more complex cases of leakage, such as those where the classical independently and identically distributed (i.i.d.) assumption is violated, that have been recently documented. In our new approach, these cases and others are explained by explicitly defining modeling goals and analyzing the broader framework of the data mining problem. The resulting definition enables us to derive general methodology for dealing with the issue. We show that it is possible to avoid leakage with a simple specific approach to data management followed by what we call a learn-predict separation, and present several ways of detecting leakage when the modeler has no control over how the data have been collected. We also offer an alternative point of view on leakage that is based on causal graph modeling concepts.
Triangle listing in massive networks
Authors: Chu Shumo , Cheng James
Published: January 2013

Triangle listing
is one of the fundamental algorithmic problems whose solution has numerous applications especially in the analysis of complex networks, such as the computation of clustering coefficients, transitivity, triangular connectivity, trusses, etc. Existing algorithms for triangle listing are mainly in-memory algorithms, whose performance cannot scale with the massive volume of today's fast growing networks. When the input graph cannot fit in main memory, triangle listing requires random disk accesses that can incur prohibitively huge I/O cost. Some streaming, semistreaming, and sampling algorithms have been proposed but these are approximation algorithms. We propose an I/O-efficient algorithm for triangle listing. Our algorithm is exact and avoids random disk access. Our results show that our algorithm is scalable and outperforms the state-of-the-art in-memory and local triangle estimation algorithms.
Determining the Currency of Data
Authors: Fan Wenfei , Geerts Floris , Wijsen Jef
Published: January 2013

Data in real-life databases become obsolete rapidly. One often finds that multiple values of the same entity reside in a database. While all of these values were once correct, most of them may have become stale and inaccurate. Worse still, the values often do not carry reliable timestamps. With this comes the need for studying data currency, to identify the current value of an entity in a database and to answer queries with the current values, in the absence of reliable timestamps.

This article investigates the currency of data. (1) We propose a model that specifies partial currency orders in terms of simple constraints. The model also allows us to express what values are copied from other data sources, bearing currency orders in those sources, in terms of copy functions defined on correlated attributes. (2) We study fundamental problems for data currency, to determine whether a specification is consistent, whether a value is more current than another, and whether a query answer is certain no matter how partial currency orders are completed. (3) Moreover, we identify several problems associated with copy functions, to decide whether a copy function imports sufficient current data to answer a query, whether a copy function can be extended to import necessary current data for a query while respecting the constraints, and whether it suffices to copy data of a bounded size. (4) We establish upper and lower bounds of these problems, all matching, for combined complexity and data complexity, and for a variety of query languages. We also identify special cases that warrant lower complexity.
SCALLA
Authors: Li Boduo , Mazur Edward , Diao Yanlei , McGregor Andrew , Shenoy Prashant
Published: January 2013

Today’s one-pass analytics applications tend to be data-intensive in nature and require the ability to process high volumes of data efficiently. MapReduce is a popular programming model for processing large datasets using a cluster of machines. However, the traditional MapReduce model is not well-suited for one-pass analytics, since it is geared towards batch processing and requires the dataset to be fully loaded into the cluster before running analytical queries. This article examines, from a systems standpoint, what architectural design changes are necessary to bring the benefits of the MapReduce model to incremental one-pass analytics. Our empirical and theoretical analyses of Hadoop-based MapReduce systems show that the widely used sort-merge implementation for partitioning and parallel processing poses a fundamental barrier to incremental one-pass analytics, despite various optimizations. To address these limitations, we propose a new data analysis platform that employs hash techniques to enable fast in-memory processing, and a new frequent key based technique to extend such processing to workloads that require a large key-state space. Evaluation of our Hadoop-based prototype using real-world workloads shows that our new platform significantly improves the progress of map tasks, allows the reduce progress to keep up with the map progress, with up to 3 orders of magnitude reduction of internal data spills, and enables results to be returned continuously during the job.
Ubiquity symposium: Evolutionary computation and the processes of life
Authors: Mo Hongwei
Published: January 2013

In this article evolutionary computation (EC) is considered as a kind of nature-inspired computing (NIC) paradigm. EC not only has great effect on the development of computing methods from structure to process, but also has great effect on many aspects of our society as a ubiquitous or general computational thinking. EC is still one of the best choices for problem solving among all methods when people face more and more complex problems.
Ubiquity symposium: Evolutionary computation and the processes of life
Authors: Michalewicz Zbigniew
Published: January 2013

During the past 35 years the evolutionary computation research community has been studying properties of evolutionary algorithms. Many claims have been made---these varied from a promise of developing an automatic programming methodology to solving virtually any optimization problem (as some evolutionary algorithms are problem independent). However, the most important claim was related to applicability of evolutionary algorithms to solving very complex business problems, i.e. problems, where other techniques failed. So it might be worthwhile to revisit this claim and to search for evolutionary algorithm-based software applications, which were accepted by businesses and industries. In this article Zbigniew Michalewicz attempts to identify reasons for the mismatch between the efforts of hundreds of researchers who make substantial contribution to the field of evolutionary computation and the number of real-world applications, which are based on concepts of evolutionary algorithms.
Prize-collecting steiner network problems
Authors: Hajiaghayi Mohammadtaghi , Khandekar Rohit , Kortsarz Guy , Nutov Zeev
Published: January 2013

In the Steiner Network problem, we are given a graph
G
with edge-costs and connectivity requirements

r
uv

between node pairs
u,v
. The goal is to find a minimum-cost subgraph
H
of
G
that contains

r
uv

edge-disjoint paths for all
u,v
∈
V
. In Prize-Collecting Steiner Network problems, we do not need to satisfy all requirements, but are given a
penalty function
for violating the connectivity requirements, and the goal is to find a subgraph
H
that minimizes the cost plus the penalty. The case when

r
uv

∈ {0,1} is the classic Prize-Collecting Steiner Forest problem.

In this article, we present a novel linear programming relaxation for the Prize-Collecting Steiner Network problem, and by rounding it, obtain the first constant-factor approximation algorithm for submodular and monotone nondecreasing penalty functions. In particular, our setting includes all-or-nothing penalty functions, which charge the penalty even if the connectivity requirement is slightly violated; this resolves an open question posed by Nagarajan et al. [2008]. We further generalize our results for element-connectivity and node-connectivity.
Distributed algorithms for multicommodity flow problems via approximate steepest descent framework
Authors: Awerbuch Baruch , Khandekar Rohit , Rao Satish
Published: January 2013

We consider solutions for distributed multicommodity flow problems, which are solved by multiple agents operating in a cooperative but uncoordinated manner. We show first distributed solutions that allow (1 + ϵ) approximation and whose convergence time is essentially linear in the maximal path length, and is independent of the number of commodities and the size of the graph. Our algorithms use a very natural approximate steepest descent framework, combined with a blocking flow technique to speed up the convergence in distributed and parallel environment. Previously known solutions that achieved comparable convergence time and approximation ratio required
exponential
computational and space overhead per agent.
Online scheduling of packets with agreeable deadlines
Authors: Jeż Łukasz , Li Fei , Sethuraman Jay , Stein Clifford
Published: January 2013

This article concerns an online packet scheduling problem that arises as a natural model for buffer management at a network router. Packets arrive at a router at integer time steps, and are buffered upon arrival. Packets have non-negative weights and integer deadlines that are (weakly) increasing in their arrival times. In each integer time step, at most one packet can be sent. The objective is to maximize the sum of the weights of the packets that are sent by their deadlines. The main results include an optimal (ϕ := (1 + √ 5)/2 ≈ 1.618)-competitive deterministic online algorithm, a (4/3 ≈ 1.33)-competitive randomized online algorithm against an oblivious adversary, and a 2-speed 1-competitive deterministic online algorithm. The analysis does not use a potential function explicitly, but instead modifies the adversary's buffer and credits the adversary to account for these modifications.
Lost in translation
Authors: Reed Daniel
Published: January 2013

The
Communications
Web site, http://cacm.acm.org, features more than a dozen bloggers in the BLOG@CACM community. In each issue of
Communications
, we'll publish selected posts or excerpts.

twitter

Follow us on Twitter at http://twitter.com/blogCACM

http://cacm.acm.org/blogs/blog-cacm

Daniel Reed on straddling the intellectual divide between technology experts and policymakers.
Five lessons from really good history
Authors: Haigh Thomas
Published: January 2013

Lessons learned from four award-winning books on the history of information technology.
What college could be like
Authors: Khan Salman
Published: January 2013

Imagining an optimized education model.
Conference-journal hybrids
Authors: Grudin Jonathan , Mark Gloria , Riedl John
Published: January 2013

Considering how to combine the best elements of conferences and journals.
The web won't be safe or secure until we break it
Authors: Grossman Jeremiah
Published: January 2013

Unless you have taken very particular precautions, assume every website you visit knows exactly who you are.
Real-time human pose recognition in parts from single depth images
Authors: Shotton Jamie , Sharp Toby , Kipman Alex , Fitzgibbon Andrew , Finocchio Mark , Blake Andrew , Cook Mat , Moore Richard
Published: January 2013

We propose a new method to quickly and accurately predict human
pose
---the 3D positions of body joints---from a single depth image, without depending on information from preceding frames. Our approach is strongly rooted in current object recognition strategies. By designing an intermediate representation in terms of body parts, the difficult pose estimation problem is transformed into a simpler per-pixel classification problem, for which efficient machine learning techniques exist. By using computer graphics to synthesize a very large dataset of training image pairs, one can train a classifier that estimates body part labels from test images invariant to pose, body shape, clothing, and other irrelevances. Finally, we generate confidence-scored 3D proposals of several body joints by reprojecting the classification result and finding local modes.

The system runs in under 5ms on the Xbox 360. Our evaluation shows high accuracy on both synthetic and real test sets, and investigates the effect of several training parameters. We achieve state-of-the-art accuracy in our comparison with related work and demonstrate improved generalization over exact whole-skeleton nearest neighbor matching.
Proving expansion in three steps
Authors: Yehudayoff Amir
Published: January 2013

This text is meant to be an introduction to a recent strategy introduced by Bourgain and Gamburd (following a work of Helfgott) for proving graph-expansion. The strategy is designed for graphs H that are defined using some underlying group G.

The strategy consists of three steps, which, in Sarnak's terminology, correspond to the three steps of a chess game: opening, middle-game and endgame. In the opening, the objective is to prove that the girth of H is logarithmic. In the middle-game, the goal is to prove a productgrowth theorem for subsets of G. The endgame consists of establishing a "mixing property" for G. There are two methods for proving a mixing property: using pairwise independence and using basic representation theory.
Computability in distributed computing
Authors: Herlihy Maurice , Rajsbaum Sergio , Raynal Michel
Published: January 2013

What can and cannot be computed in a distributed system is a complex function of the system's communication model, timing model, and failure model. This tutorial surveys some important results about computability in the canonical distributed system model, where processes execute asynchronously, they communicate by reading and writing shared memory, and they fail by crashing. It explains the fundamental role that topology plays in the distributed computability theory.
WTTM 2012, the fourth workshop on the theory of transactional memory
Authors: Gramoli Vincent , Milani Alessia
Published: January 2013

In conjunction with PODC 2012, the TransForm project (Marie Curie Initial Training Network) and EuroTM (COST Action IC1001) supported the 4th edition of the Workshop on the Theory of Transactional Memory (WTTM 2012). The objective of WTTM was to discuss new theoretical challenges and recent achievements in the area of transactional computing. The workshop took place on July 19, 2012, in Madeira, Portugal.

This year's WTTM was a milestone event for two reasons. First, because the same year, the two seminal articles on hardware and software transactional memories [15, 21] were recognized as outstanding papers on principles of distributed computing, whose significance and impact on the theory and practice of distributed computing have been evident for at least a decade. Second, the winners of this prestigious ACM/EATCS Edsger W. Dijkstra Prize, Maurice Herlihy, Eliot Moss, Nir Shavit and Dan Touitou, were present at the workshop and three of them discussed their current progress with other outstanding researchers from the field. This report is intended to give highlights of the problems discussed during the workshop.
Hybrid aggregates
Authors: Strunk John D.
Published: January 2013

Relative to traditional hard disk drives (HDDs), solid state drives (SSDs) provide a very large number of I/Os per second, but they have limited capacity. From a cost-effectiveness perspective, SSDs provide significantly better random I/O throughput per dollar than a typical disk, but the capacity provided per dollar spent on SSDs limits them to the most demanding of datasets. Traditionally, Data ONTAP® storage aggregates have been provisioned using a single type of disk. This restriction limits the costeffectiveness of the storage pool to that of the underlying disks.

The Hybrid Aggregates project within the Advanced Technology Group (ATG) explored the potential to combine multiple disk types within a single aggregate. One of the primary goals of the project was to determine whether a hybrid aggregate, composed of SSDs (for their cost-effective performance) and Serial-ATA (SATA) disks (for their cost-effective capacity), could simultaneously provide better cost/performance and cost/throughput ratios than an all Fibre-Channel (FC) solution.

The project has taken a two-pronged approach to building a prototype system capable of supporting hybrid aggregates. The first part of the project investigated the changes necessary for Data ONTAP RAID and WAFL® layers to support a hybrid aggregate. This included propagating disk-type information to WAFL, modifying WAFL to support the allocation of blocks from a particular storage class (i.e., disk type), and repurposing the existing writeafter- read and segment-cleaning infrastructure to support the movement of data between storage classes. The second part of the project examined potential policies for allocating and moving data between storage classes within a hybrid aggregate. Through proper policies, it is possible to automatically segregate the data within the aggregate such that the SSD-backed portion of the aggregate absorbs a large fraction of the I/O requests, leaving the SATA disks to contribute capacity for colder data.

This paper describes the implementation of the Hybrid Aggregates prototype and the policies for automatic data placement and movement that have been evaluated. It also presents some performance results from the prototype system.
The first joint international workshop on entity-oriented and semantic search (JIWES)
Authors: Balog Krisztian , Carmel David , de Vries Arjen P. , Herzig Daniel M. , Mika Peter , Roitman Haggai , Schenkel Ralf , Serdyukov Pavel , Duc Thanh Tran
Published: January 2013

The First Joint International Workshop on Entity-oriented and Semantic Search (JIWES) workshop was held on Aug 16, 2012 in Portland, Oregon, USA, in conjunction with the 35th Annual International ACM SIGIR Conference (SIGIR 2012). The objective for the workshop was to bring together academic researchers and industry practitioners working on entity-oriented search to discuss tasks and challenges, and to uncover the next frontiers for academic research on the topic. The workshop program accommodated two invited talks, eight refereed papers divided into two technical paper sessions, and a group discussion.
The Lattice Compatibility Theory: Arguments for Recorded I-III-O2 Ternary Oxide Ceramics Instability at Low Temperatures beside Ternary Telluride and Sulphide Ceramics
Authors: Boubaker K.
Published: January 2013

Some recorded behaviours differences between chalcopyrite ternary oxide ceramics and telluride and sulphides are investigated in the framework of the recently proposed Lattice Compatibility Theory (LCT). Alterations have been evaluated in terms of Urbach tailing and atomic valence shell electrons orbital eigenvalues, which were calculated through several approximations. The aim of the study was mainly an attempt to explain the intriguing problem of difficulties of elaborating chalcopyrite ternary oxide ceramics (I-III-O2) at relatively low temperatures under conditions which allowed crystallization of ternary telluride and sulphides.
Designing a Durable Energy Policy
Authors: Carlson Ann E. , Fri Robert W.
Published: January 2013

Although the U.S. energy system seems to resist the changes necessary to meet today's challenges related to energy security and climate change, the system has gone through massive change several times since 1850. A major driver in each of these earlier transitions was an economic value, such as mobility, that markets could capture. Because environmental and security values are public goods, changing today's energy system will require a policy that creates a market signal reflecting these values. However, it is also necessary to craft a policy framework that is both durable over a long time period and able to adapt to new information as it becomes available. This essay examines some of the possible attributes of a durable and adaptable policy. The discussion is necessarily preliminary because relatively little formal research exists on this topic. However, even a preliminary examination suggests that considerations of policy durability could affect the choice between a carbon tax and a cap-and-trade system.
Rethinking the Scale, Structure & Scope of U.S. Energy Institutions
Authors: Dworkin Michael H. , Sidortsov Roman V. , Sovacool Benjamin K.
Published: January 2013

This essay notes some of the key institutions created in the twentieth century for the purpose of delivering energy in North America. Those institutions are being challenged by a combination of stresses in three interconnected areas: reliability, economics, and environmental sustainability. The essay argues that these three stresses create an “energy trilemma” requiring institutional reform. We suggest that new and modified institutions can best be understood if we evaluate them along three dimensions: institutional scale, structure, and scope. We consider real-world examples of recent institutions in light of each of these dimensions and note both successes and concerns that those factors illuminate. We conclude by noting that some institutional changes will be organic and unplanned; but many others, including responses to climate change, will benefit from conscious attention to scale, structure, and scope by those engaged in designing and building the energy institutions needed in the twenty-first century.
Energy in the Context of Sustainability
Authors: Bierbaum Rosina M. , Matson Pamela A.
Published: January 2013

Today and in the coming decades, the world faces the challenge of meeting the needs of a still-growing human population, and of doing it sustainably – that is, without affecting the ability of future generations to meet their needs. Energy plays a pivotal role in this challenge, both because of its importance to economic development and because of the myriad interactions and influences it has on other critical sustainability issues. In this essay, we explore some of the direct interactions between energy and other things people need, such as food, water, fuel, and clean air, and also some of its indirect interactions with climate, ecosystems, and the habitability of the planet. We discuss some of the challenges and potential unintended consequences that are associated with a transition to clean, affordable energy as well as opportunities that make sense for energy and other sustainability goals. Pursuing such opportunities is critical not just to meeting the energy needs of nine billion people, but also to meeting their other critical needs and to maintaining a planet that supports human life in the near and long term.
The Transnational Politics of Energy
Authors: Keohane Robert O. , Victor David G.
Published: January 2013

Creating effective energy policy is hard, in part because it often requires effective international coordination. For most salient energy-related issues – such as control of the emissions that cause global climate change or the building of stockpiles to make oil supplies more secure – international coordination is inherently difficult. Solutions lie in making these problems more manageable by working in small groups of relevant countries; successful cooperation also hinges on finding incentive-compatible commitments that align, to the extent feasible, with national interests and are focused on areas where cooperation will yield tangible joint gains. The outcomes of such cooperation efforts are likely to be decentralized complexes of networked institutions rather than integrated, hierarchical treaties that govern a coherently defined issue-area.
Language Learning without Control: The Role of the PFC
Authors: Friederici Angela D. , Mueller Jutta L. , Sehm Bernhard , Ragert Patrick
Published: January 2013

Learning takes place throughout lifetime but differs in infants and adults because of the development of the PFC, a brain region responsible for cognitive control. To test this hypothesis, adults were investigated in a language learning paradigm under inhibitory, cathodal transcranial direct current stimulation over PFC. The experiment included a learning session interspersed with test phases and a test-only session. The stimulus material required the learning of grammatical dependencies between two elements in a novel language. In a parallel design, cathodal transcranial direct current stimulation over the left PFC, right PFC, or sham stimulation was applied during the learning session but not during the test-only session. Event-related brain potentials (ERPs) were recorded during both sessions. Whereas no ERP learning effects were observed during the learning session, different ERP learning effects as a function of prior stimulation type were found during the test-only session, although behavioral learning success was equal across conditions. With sham stimulation, the ERP learning effect was reflected in a centro-parietal N400-like negativity indicating lexical processes. Inhibitory stimulation over the left PFC, but not over the right PFC, led to a late positivity similar to that previously observed in prelinguistic infants indicating associative learning. The present data demonstrate that adults can learn with and without cognitive control using different learning mechanisms. In the presence of cognitive control, adult language learning is lexically guided, whereas it appears to be associative in nature when PFC control is downregulated.
Searching for Something Familiar or Novel: Top–Down Attentional Selection of Specific Items or Object Categories
Authors: Wu Rachel , Scerif Gaia , Aslin Richard N. , Smith Tim J. , Nako Rebecca , Eimer Martin
Published: January 2013

Visual search is often guided by top–down attentional templates that specify target-defining features. But search can also occur at the level of object categories. We measured the N2pc component, a marker of attentional target selection, in two visual search experiments where targets were defined either categorically (e.g., any letter) or at the item level (e.g., the letter C) by a prime stimulus. In both experiments, an N2pc was elicited during category search, in both familiar and novel contexts (Experiment 1) and with symbolic primes (Experiment 2), indicating that, even when targets are only defined at the category level, they are selected at early sensory-perceptual stages. However, the N2pc emerged earlier and was larger during item-based search compared with category-based search, demonstrating the superiority of attentional guidance by item-specific templates. We discuss the implications of these findings for attentional control and category learning.
Jews, Gentiles, and the Kingdom of God: The Parable of the Wicked Tenants in Narrative Perspective (Mark 12:1-12)
Authors: Iverson Kelly R.
Published: January 2013

The identification of the “others” in Mark's Parable of the Wicked Tenants is widely disputed and has not been adequately addressed from a narrative perspective. Through a reconsideration of the vineyard and tenants, as well as the wider plot structure of the narrative, this article argues that the anonymous “others” to whom the vineyard is given are the Gentiles. Understood within the context of the Gentile mission, the parable describes Israel's obstinance and the expansion of the kingdom, while at the same time foreshadowing the proclamation of the gospel to the nations, which is to be carried out by the followers of Jesus.
The Peoples' Bible, Imbokodo and the King's Mother's Teaching of Proverbs 31
Authors: Stiebert Johanna
Published: January 2013

The aim of this article is, first, to look closely at a new NRSV Bible, The Peoples' Bible, putting to the test its own call for reading inclusively, with acknowledgement of and sensitivity to the diverse societies and cultures of the USA, particularly marginalized minority groups. Following general comments and praise for this exciting new publication, the editorial decision to juxtapose a short description of ubuntu theology with Prov. 31:8-9 will be examined. In the course of this article, several distinctly South African examples of biblical criticism will be described. Next, the postcolonial-critical method called Imbokodo, developed and practised by Old Testament scholar Makhosazana Nzimande, will be applied to Prov. 31:1-9 to foreground a new and illuminating perspective, which is ultimately skeptical of the (at least implicit) suggestion of the appropriateness of associating Prov. 31:8-9 and ubuntu. As will become clear, tackling this topic has been a challenge for the author in some profound and personal respects.
Images, Words and Stories: Exploring their Transformative Power in Reading Biblical Texts Ecologically
Authors: Wainwright Elaine M.
Published: January 2013

This essay is theoretical rather than interpretive in that I seek to develop a process or processes for reading biblical texts ecologically. I identify initially a significant epistemic shift that Lorraine Code calls ecological thinking as the context in which ecological reading takes place. I emphasize that reading ecologically is a process rather than a fixed approach, drawing imagery and language from Earth's processes that are characterized by reciprocity and multi-dimensionality. As a critical process, ecological reading will be characterized by suspicion and reconfiguration in their reciprocity. They will inform the range of reading procedures that uncover the inner texture and intertexture of the text. Having borrowed these two aspects of textual reading from Vernon Robbins” socio-rhetorical approach and nuanced them in relation to an ecological reading which recognizes the centrality of “habitat,” I propose a more significant development of Robbins' approach in that I replace his “social and cultural texture” with what I call “ecological texture,” suggesting that “inter-con/textuality” is a way of naming the various tools and procedures that will facilitate a reading of this ecological texture of the biblical text. I name my ecological reading process eco-rhetorical and conclude by noting that it cannot remain text-bound but must be integrated into the praxis of ecocitizenship.
Modelling Dependence in Latin American Markets Using Copula Functions
Authors: Miguel-Angel Canela , Eduardo Pedreira
Published: January 2013

Two important issues in the analysis of association among financial markets are the degree of dependence and the underlying shape commanding the cross-market dependencies, so that any model used to describe this association must cope with both the issues. In the study presented in this article, we approach the modelling of dependence in two stages. The first stage is based on modelling the dependence between the returns of two assets by means of a single Archimedean copula, whereas the second one takes advantage of the mixture between copulas to gain the necessary flexibility to capture different tail dependence patterns. Both stages have been followed in modelling the dependence among the daily returns of seven Latin American country indices, a regional index and a worldwide index. Our findings have important implications for portfolio risk management.

JEL Classification: G11, G15
Conditional Relation between Systematic Risk and Returns in the Conventional and Downside Frameworks: Evidence from the Indonesian Market
Authors: Nurjannah  , Galagedera Don U.A. , Brooks Robert
Published: January 2013

Unconditional pricing models fail to support a positive risk–return trade-off. When excess market return is negative an inverse relationship between the capital asset pricing model (CAPM) beta and equal-weighted and value-weighted portfolio return is observed. To accommodate market movement in the pricing model, two volatility regimes (high/low) is delineated by specifying a threshold on conditional market volatility estimated via a generalised autoregressive conditional heteroscedasticity (GARCH) process. In the low volatility regime, the CAPM beta risk premium and the downside beta risk premium are negative. This observation is robust to the level of the threshold used and is more pronounced in value-weighted portfolios. When the market condition and market movement is incorporated together as conditioning variables, a strong relationship between CAPM beta and return is uncovered.

JEL Classification: G12