bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Fatigue Failure Risk Based on On-Track Tests
Authors: Erviti Calvo Lara , Agirre Castellanos Gorka
Published: June 2016

When a mechanical component of a railway vehicle experiences failure due to fatigue, it is necessary to determine whether it has been an isolated failure or it is a systematic failure that may affect the whole fleet. The present work presents the methodology to be followed for the application of on-track tests to determine the probability of fatigue failure. By simulating a normal commercial service in one or multiple conditions, the stress levels experienced by the component are recorded. These stress levels are combined and extrapolated in order to determine the typical global stress history that the component will experience during its operational life. From this stress history, the risk of fatigue failure can be estimated by means of the cumulative damage method also known as Miner’s rule. For this calculation the measured stress levels have to be compared with an S-N curve. The problem arises because the S-N curves presented in the standards correspond to stresses in the direction perpendicular or longitudinal to the weld. The peculiarities of on-track tests imply that the direction of principal stress may vary continuously and the maximum stress value may be present in specific points of the record with directions that do not represent the normal behaviour of the piece. Different forms of dealing with the projection of the rosettes have been analyzed, and the influence of these considerations on the damage calculation has been studied.
Aging effect on microcirculation: A multiscale entropy approach on laser speckle contrast images
Authors: Khalil A. , Humeau‐Heurtier A. , Gascoin L. , Abraham P. , Mahé G.
Published: June 2016

Purpose:

It has long been known that age plays a crucial role in the deterioration of microvessels. The assessment of such deteriorations can be achieved by monitoring microvascular blood flow. Laser speckle contrast imaging (LSCI) is a powerful optical imaging tool that provides two‐dimensional information on microvascular blood flow. The technique has recently been commercialized, and hence, few works discuss the postacquisition processing of laser speckle contrast images recorded in vivo. By applying entropy‐based complexity measures to LSCI time series, we present herein the first attempt to study the effect of aging on microcirculation by measuring the complexity of microvascular signals over multiple time scales.

Methods:

Forearm skin microvascular blood flow was studied with LSCI in 18 healthy subjects. The subjects were subdivided into two age groups: younger (20–30 years old, n = 9) and older (50–68 years old, n = 9). To estimate age‐dependent changes in microvascular blood flow, we applied three entropy‐based complexity algorithms to LSCI time series.

Results:

The application of entropy‐based complexity algorithms to LSCI time series can differentiate younger from older groups: the data fluctuations in the younger group have a significantly higher complexity than those obtained from the older group.

Conclusions:

The effect of aging on microcirculation can be estimated by using entropy‐based complexity algorithms to LSCI time series.
The Effect of Higher Than Recommended Protein Feedings Post-Exercise on Recovery Following Downhill Running in Masters Triathletes
Authors: Doering Thomas M. , Reaburn Peter R. , Borges Nattai R. , Cox Gregory R. , Jenkins David G.
Published: June 2016

Following exercise-induced muscle damage (EIMD), masters athletes take longer to recover than younger athletes. The purpose of this study was to determine the effect of higher than recommended postexercise protein feedings on the recovery of knee extensor peak isometric torque (PIT), perceptions of recovery, and cycling time trial (TT) performance following EIMD in masters triathletes. Eight masters triathletes (52 ± 2 y, V̇O2max, 51.8 ± 4.2 ml•kg-1•min-1) completed two trials separated by seven days in a randomized, doubleblind, crossover study. Trials consisted of morning PIT testing and a 30-min downhill run followed by an eight-hour recovery. During recovery, a moderate (MPI; 0.3 g•kg-1•bolus-1) or high (0.6 g•kg-1•bolus-1) protein intake (HPI) was consumed in three bolus feedings at two hour intervals commencing immediately postexercise. PIT testing and a 7 kJ•kg-1 cycling TT were completed postintervention. Perceptions of recovery were assessed pre- and postexercise. The HPI did not significantly improve recovery compared with MPI (p > .05). However, comparison of within-treatment change shows the HPI provided a moderate beneficial effect (d = 0.66), attenuating the loss of afternoon PIT (-3.6%, d = 0.09) compared with the MPI (-8.6%, d = 0.24). The HPI provided a large beneficial effect (d = 0.83), reducing perceived fatigue over the eight-hour recovery (d = 1.25) compared with the MPI (d = 0.22). Despite these effects, cycling performance was unchanged (HPI = 2395 ± 297 s vs. MPI = 2369 ± 278 s; d = 0.09). In conclusion, doubling the recommended postexercise protein intake did not significantly improve recovery in masters athletes; however, HPI provided moderate to large beneficial effects on recovery that may be meaningful following EIMD.
Draft Genome Sequence of
Tokyovirus
, a Member of the Family
Marseilleviridae
Isolated from the Arakawa River of Tokyo, Japan
Authors: Takemura Masaharu
Published: June 2016

Members of the
Marseilleviridae
family are large DNA viruses with icosahedral particles that infect
Acanthamoeba
cells. This report presents a new
Marseilleviridae
family member discovered in a water/soil sample from a river in Tokyo, named
Tokyovirus
, with genome size of 370 to 380 kb.
Genome Sequence of the Autotrophic Acetogen Clostridium magnum DSM 2767
Authors: Uhlig Ronny , Poehlein Anja , Fischer Ralf-Jörg , Daniel Rolf , Bahl Hubert
Published: June 2016

Here we report the draft genome sequence (6.6 Mbp) of the type strain
Clostridium magnum
, an acetogen with two operons coding for two separate Rnf complexes.
C. magnum
grows on a broad range of organic substrates and converts CO
2
and H
2
to acetate using the Wood-Ljungdahl pathway.
Draft Genome Assembly of the Bloom-Forming Cyanobacterium
Nodularia spumigena
Strain CENA596 in Shrimp Production Ponds
Authors: Popin Rafael Vicentini , Rigonato Janaina , Abreu Vinicius Augusto Carvalho , Andreote Ana Paula Dini , Silveira Savênia Bonoto , Odebrecht Clarisse , Fiore Marli Fatima
Published: June 2016

We report here the draft genome assembly of the brackish cyanobacterium
Nodularia spumigena
strain CENA596 isolated from a shrimp production pond in Rio Grande do Sul, Brazil. The draft genome consists of 291 contigs with a total size of 5,189,679 bp. Secondary metabolite annotations resulted in several predicted gene clusters, including those responsible for encoding the hepatotoxin nodularin.
Complete Genome Sequence of Seoul Virus Strain Tchoupitoulas
Authors: Miles Rory W. , Lewandowski Kuiama , Atkinson Barry , Pullan Steven T. , Lloyd Graham , Bailey Daniel
Published: June 2016

Seoul virus (genus
Hantavirus
; family
Bunyaviridae
) is an emerging pathogen associated with cases of acute kidney injury in several countries across the globe. We report here the whole-genome sequence of the Tchoupitoulas strain of Seoul virus isolated in New Orleans, LA.
First Complete Genome Sequence of
Cherry virus A
Authors: Koinuma Hiroaki , Nijo Takamichi , Iwabuchi Nozomu , Yoshida Tetsuya , Keima Takuya , Okano Yukari , Maejima Kensaku , Yamaji Yasuyuki , Namba Shigetou
Published: June 2016

The 5′-terminal genomic sequence of
Cherry virus A
(CVA) has long been unknown. We determined the first complete genome sequence of an apricot isolate of CVA (7,434 nucleotides [nt]). The 5′-untranslated region was 107 nt in length, which was 53 nt longer than those of known CVA sequences.
Complete Genome Sequence of Mesorhizobium ciceri Strain CC1192, an Efficient Nitrogen-Fixing Microsymbiont of
Cicer arietinum
Authors: Haskett Timothy , Wang Penghao , Ramsay Joshua , O'Hara Graham , Reeve Wayne , Howieson John , Terpolilli Jason
Published: June 2016

We report the complete genome sequence of
Mesorhizobium ciceri
strain CC1192, an efficient nitrogen-fixing microsymbiont of
Cicer arietinum
(chickpea). The genome consists of 6.94 Mb distributed between a single chromosome (6.29 Mb) and a plasmid (0.65 Mb).
Complete Genome Sequence of Sphingopyxis terrae Strain 203-1 (NBRC 111660), a Polyethylene Glycol Degrader
Authors: Ohtsubo Yoshiyuki , Nonoyama Shouta , Nagata Yuji , Numata Mitsuru , Tsuchikane Keiko , Hosoyama Akira , Yamazoe Atsushi , Tsuda Masataka , Fujita Nobuyuki , Kawai Fusako
Published: June 2016

The complete genome sequence of
Sphingopyxis terrae
strain 203-1, which is capable of growing on polyethylene glycol, was determined. The genome consisted of a chromosome with a size of 3.98 Mb and a plasmid with a size of 4,328 bp. The strain was deposited to the National Institute of Technology and Evaluation (Tokyo, Japan) under the number NBRC 111660.
Complete Genome Sequence of Lysinibacillus sphaericus WHO Reference Strain 2362
Authors: Hernández-Santana Alejandra , Gómez-Garzón Camilo , Dussán Jenny
Published: June 2016

Lysinibacillus sphaericus
is a species that contains strains widely used in the biological control of mosquitoes. Here, we present the complete 4.67-Mb genome of the WHO entomopathogenic reference strain
L. sphaericus
2362, which is probably one of the most commercialized and studied strains. Genes coding for mosquitocidal toxin proteins were detected.
Complete Genome Sequence of Mycobacterium chelonae Type Strain CCUG 47445, a Rapidly Growing Species of Nontuberculous Mycobacteria
Authors: Jaén-Luchoro Daniel , Salvà-Serra Francisco , Aliaga-Lozano Francisco , Seguí Carolina , Busquets Antonio , Ramírez Antonio , Ruíz Mikel , Gomila Margarita , Lalucat Jorge , Bennasar-Figueras Antoni
Published: June 2016

Mycobacterium chelonae
strains are ubiquitous rapidly growing mycobacteria associated with skin and soft tissue infections, cellulitis, abscesses, osteomyelitis, catheter infections, disseminated diseases, and postsurgical infections after implants with prostheses, transplants, and even hemodialysis procedures. Here, we report the complete genome sequence of
M. chelonae
type strain CCUG 47445.
Richter's transformation presenting as splenic rupture after 6 years of complete remission of chronic lymphocytic leukaemia
Authors: Thyagarajan Braghadheeswar , Alagusundaramoorthy Sayee Sundar , Shah Lopa , Agrawal Abhinav
Published: June 2016

Richter's transformation is a rare clinical condition occurring in about 5–10% of patients with chronic lymphocytic leukaemia (CLL). Patients usually present with lymphadenopathy, hepatosplenomegaly and elevated serum lactate dehydrogenase levels. These patients have a very poor prognosis with a median survival of about 10 months. We present a patient, with a history of CLL in complete remission, who presented with splenic rupture requiring splenectomy. She was eventually diagnosed with diffuse large B-cell lymphoma with Richter's transformation.
Virus-associated haemophagocytic lymphohistiocytosis in a young Filipino man
Authors: Yu Marc Gregory , Chua Jamie
Published: June 2016

Haemophagocytic lymphohistiocytosis (HLH) is a rare syndrome of pathological immune activation characterised by extreme inflammation. We present a case of a young Filipino man consulting for non-specific symptoms of fever, body malaise and weight loss. Prominent physical examination findings included gross pallor, cachexia and hepatosplenomegaly. Laboratory results revealed pancytopaenia, while bone marrow examination revealed haemophagocytosis. Further workup for HLH showed hypertriglyceridaemia, hypofibrinogenaemia and hyperferritinaemia (fulfilling 6 of 8 diagnostic criteria). Exhaustive serological and haematological examinations showed chronic hepatitis B virus infection and past evidence of Epstein-Barr virus infection as possible triggers. The patient was started on antiviral therapy, high-dose steroids and chemotherapy. He initially improved, but eventually succumbed to severe fungal sepsis and pulmonary haemorrhage. An autopsy confirmed the diagnosis of HLH.
Second‐year student diary
Authors: Perrett Rosie
Published: June 2016

After five weeks' revising, Rosie Perrett has left behind her world of flashcards, mind‐maps and sticky notes. She has finished her exams and her second year at Liverpool.
Effects of stream-adjacent logging in fishless headwaters on downstream coastal cutthroat trout
Authors: Bateman Douglas S. , Sloat Matthew R. , Gresswell Robert E. , Berger Aaron M. , Hockman-Wert David P. , Leer David W. , Skaugset Arne E.
Published: June 2016

To investigate effects of headwater logging on downstream coastal cutthroat trout (Oncorhynchus clarkii clarkii) populations, we monitored stream habitat and biotic indicators including biomass, abundance, growth, movement, and survival over 8 years using a paired-watershed approach. Reference and logged catchments were located on private industrial forestland on ∼60-year harvest rotation. Five clearcuts (14% of the logged catchment area) were adjacent to fishless portions of the headwater streams, and contemporary regulations did not require riparian forest buffers in the treatment catchment. Logging did not have significant negative effects on downstream coastal cutthroat trout populations for the duration of the sample period. Indeed, the only statistically significant response of fish populations following logging in fishless headwaters was an increase in late-summer biomass (g·m−2) of age-1+ coastal cutthroat trout in tributaries. Ultimately, the ability to make broad generalizations concerning effects of timber harvest is difficult because response to disturbance (anthropogenically influenced or not) in aquatic systems is complex and context-dependent, but our findings provide one example of environmentally compatible commercial logging in a regenerated forest setting.
Behavioural reactions of three-spined sticklebacks to simulated risk of predation—Effects of predator distance and movement
Authors: Näslund Joacim , Pettersson Leo , Johnsson Jörgen I
Published: June 2016

The behavioural response of animals to predation risk commonly depends on the behaviour of potential predators. Here, we report an experiment investigating effects of predator model (a life-like wooden trout model) distance and movement on the behaviour of three-spined sticklebacks Gasterosteus aculeatus L. in a standardized experimental setting. When the predator model was immobile, the behaviour of the sticklebacks could, in general, not be clearly distinguished from a no-predator control treatment. When moving the predator 41 cm towards the stickleback, clear anti-predator behaviours were observed. However, behavioural expression depended on the distance to the predator. At the two farthest distances (approaching from 129 to 88 cm and from 170 to 129 cm), the sticklebacks approached the predator and spent little time freezing. At the two closest distances (approaching from 88 to 47 cm and from 47 to 6 cm), the sticklebacks increased the distance to the predator model and froze their movements. These results suggest that the closest-distance groups showed avoidance behaviour, whereas the farthest-distance groups instead appeared to start inspecting the potential predator. This provides evidence for conditional anti-predator behaviour and highlights the importance of considering distance to, and movement of predator models when interpreting data from standardized behavioural trials.
Some results on equivariant contact geometry for partial flag varieties
Authors: Crooks Peter , Rayan Steven
Published: June 2016

We study equivariant contact structures on complex projective varieties arising as partial flag varieties [Formula: see text], where [Formula: see text] is a connected, simply-connected complex simple group of type ADE and [Formula: see text] is a parabolic subgroup. We prove a special case of the LeBrun-Salamon conjecture for partial flag varieties of these types. The result can be deduced from Boothby’s classification of compact simply-connected complex contact manifolds with transitive action by contact automorphisms, but our proof is completely independent and relies on properties of [Formula: see text]-equivariant vector bundles on [Formula: see text]. A byproduct of our argument is a canonical, global description of the unique [Formula: see text]-invariant contact structure on the isotropic Grassmannian of 2-planes in [Formula: see text].
COST-BENEFIT ANALYSIS OF UNION MEMBERSHIP WITHOUT COLLECTIVE BARGAINING BENEFITS
Authors: CHEW SOON BENG , TANG YANG
Published: June 2016

Traditional unions rely on collective bargaining benefits to attract workers to the union. A key ingredient of collective bargaining benefits is union wage premium which will force employers to retrench some workers. A macro-focused union differs from traditional union or micro-focused union in two ways. First, a macro-focused union will work together with the government and management to raise productivity and therefore shift the demand for labor curve upward. Second, the macro-focused union will want to maximize employment and therefore aim at competitive wage level for not only its members but non-union members too. Consequently, this may create a huge free ridership problem as workers may refuse to pay the member fee but still enjoy the club benefits. This paper focuses on a situation where a macro-focused labor union offers non-collective bargaining benefits through offering discount to a subset of consumption goods. However, individual workers’ preference is not publicly observed. The union leader may pay a certain survey fee to find out. Therefore, in the equilibrium, the union leader needs to weigh the benefits of larger union size against the costs of survey fee. Similarly, on the workers’ side, the tradeoff is the union member fee together with some psychology cost of being a union member against a discount on his favorable consumption goods. We develop a mathematical framework that incorporates all these elements above. We show both theoretically and quantitatively what determines the equilibrium union size and union leader’s survey decisions. Moreover, we also examine at the aggregate level, how the union workers’ and union leader’s welfare levels may respond to certain changes in economic fundamentals, such as preference shift and changes in survey fee, etc.
The magnetic susceptibility on the transverse antiferromagnetic Ising model: Analysis of the reentrant behavior
Authors: Neto Minos A. , de Sousa J. Ricardo , Padilha Igor T. , Rodriguez Salmon Octavio D. , Roberto Viana J. , Dinóla Neto F.
Published: June 2016

We study the three-dimensional antiferromagnetic Ising model in both uniform longitudinal [Formula: see text] and transverse [Formula: see text] magnetic fields by using the effective-field theory (EFT) with finite cluster [Formula: see text] spin (EFT-1). We analyzed the behavior of the magnetic susceptibility to investigate the reentrant phenomena that we have seen in the same phase diagram previously obtained in other papers. Our results shows the presence of two divergences in the susceptibility that indicates the existence of a reentrant behavior.
A note on weak and strong probabilistic solutions for a stochastic quasilinear parabolic equation of generalized polytropic filtration
Authors: Ali Zakaria Idriss , Sango Mamadou
Published: June 2016

In this paper, we investigate a class of stochastic quasilinear parabolic problems with nonstandard growth in the functional setting of generalized Sobolev spaces. The deterministic version of the equation was first introduced and studied by Samokhin, as a generalized model for polytropic filtration. We establish an existence result of weak probabilistic solutions when the forcing terms do not satisfy Lipschitz conditions. Under Lipschitzity of the nonlinear external forces, [Formula: see text] and [Formula: see text], we obtain the uniqueness of the weak probabilistic solutions. Combining the uniqueness and the famous Yamada–Watanabe result we prove the existence of the unique strong probabilistic solution.
Eigen function and corresponding eigen values of charge carriers in V-grooves quantum wires with variable width
Authors: Zaheri Ali Hossein Mohammad
Published: June 2016

In this work, we have calculated analytically the energy spectra of electrons and holes in V-grooves quantum wires. To modify wire structure, we have used the equations which suggested in the work of Inoshita et al. We introduce a new effective potential scheme which is applicable and matchable with actual interface geometry of this groove of ridge quantum wires. By applying this effective potential and considering a suitable transformed coordinate that allows the decoupling of the two-dimensional wave functions, we have calculated eigen values of the charge carriers in three states as well as the wave functions. We found that by increasing the curvature at the top of quantum wire [Formula: see text] the energy eigen value decreases. Our results are in good agreement with the earlier investigations.
2015 Update of the discoveries of nuclides
Authors: Thoennessen M.
Published: June 2016

The 2015 update of the discovery of nuclide project is presented. Twenty new nuclides were observed for the first time in 2015. An overall review of all previous assignments was made in order to apply the discovery criteria consistently to all elements. In addition, a list of isotopes published so far only in conference proceedings or internal reports is included.
Structural, spectroscopic (FT-IR, FT-Raman, NMR) and computational analysis (DOS, NBO, Fukui) of 3,5-dimethylisoxazole and 4-(chloromethyl)-3,5-dimethylisoxazole: A DFT study
Authors: Kavitha T. , Velraj G.
Published: June 2016

The theoretical and computational analysis of two isoxazole derivatives 3,5-dimethylisoxazole and 4-chloromethyl-3,5-dimethylisoxazole were carried out along with some of the experimental evidences. The density functional theory calculations of these compounds were done with DFT/B3LYP/6-31+G(d,p) basis set using Gaussian 09 software. From the DFT calculations, the optimization geometry, vibrational analysis, electronic properties, local reactivity descriptors, natural bond orbitals, and other structural properties of the title compounds were elucidated. The chemical shifts of every C and H atom of the title compounds were calculated using Gauge Independent Atomic orbitals (GIAO) method for both proton and carbon NMR spectra. The molecular electrostatic potential of DMI has been found out and the difference in MEP on addition of chloromethyl group is also discussed. The hyperpolarizability calculations of the investigated molecules shows that the nonlinear optical activity of CDMI is greater when compared to DMI.
Study of Various Nanostructures Titania with Graphene Composites: The Preparation and Photocatalytic Activities
Authors: Dai Bolin , Tao Hong , Lin Yu-Jung , Chang Chang-Tang
Published: June 2016

Different kinds of graphene (GN)/titania nanocomposites using graphene and P25 or Titanium (IV) n-butoxide (TBOT) as precursors were prepared with hydrothermal method. To investigate the differences of the photocatalytic properties of composites with various shapes of titanium dioxide (TiO[Formula: see text], three types of TiO2, including titanium nanotubes (TNT), titanium nanosheets (TNS) and titanium nanoparticles (TNP) were successfully prepared and combined with GN to form the composites. The prepared composites were confirmed by Ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction (XRD), Fourier transform infrared (FTIR), X-ray Photoelectron Spectroscopy (XPS), and transmission electron microscopy (TEM), etc. Photocatalytic activities of composites were carried out by the degradation of Reactive Black 5 (RBk5) and Norfloxacin (NFXC) under the radiation of UV lamp. Results indicate that the differences in the TiO2 morphology of the composites greatly influence the catalytic properties. In addition, the heterojunction between graphene and TiO2 also play an important role in the photocatalytic abilities of composites. In this study, it can be seen that the prepared composites exhibit higher photocatalytic activity including excellent adsorption capacity and photo-degradation ability than P25. The photocatalytic activity of GN–TNS is higher than that of GN–TiO2 and GN–TNT.
Applications of Gold Nanoparticles in Biosensors
Authors: Yu Xinjun , Jiao Yang , Chai Qinyuan
Published: June 2016

Gold nanoparticles (AuNPs) as one of the most stable metal nanoparticles have demonstrated extensive applications in recent years. This paper will give a focus on the AuNPs as biosensors, due to their inertness, unique optical properties, high surface area, and various surface functionalization methods. Synthesis of AuNps and the surface functionalization will be discussed in the first part. The size, shape, and stability can be controlled by different synthetic methods, while reductant usually needed. By surface functionalization with different molecules such as polymers, nucleic acids, and proteins, AuNPs will aggregate when specified molecule linkages showing up enables selective detections. The application in biosensing to detect proteins, oligonucleotide, glucose, and heavy metals will be exemplified, followed by the summary and future perspective part in the conclusion.
The BLIS Framework
Authors: Van Zee Field G. , Smith Tyler M. , Marker Bryan , Low Tze Meng , Geijn Robert A. Van De , Igual Francisco D. , Smelyanskiy Mikhail , Zhang Xianyi , Kistler Michael , Austel Vernon , Gunnels John A. , Killough Lee
Published: June 2016

BLIS is a new software framework for instantiating high-performance BLAS-like dense linear algebra libraries. We demonstrate how BLIS acts as a productivity multiplier by using it to implement the level-3 BLAS on a variety of current architectures. The systems for which we demonstrate the framework include state-of-the-art general-purpose, low-power, and many-core architectures. We show, with very little effort, how the BLIS framework yields sequential and parallel implementations that are competitive with the performance of ATLAS, OpenBLAS (an effort to maintain and extend the GotoBLAS), and commercial vendor implementations such as AMD’s ACML, IBM’s ESSL, and Intel’s MKL libraries. Although most of this article focuses on single-core implementation, we also provide compelling results that suggest the framework’s leverage extends to the multithreaded domain.
RunStream
Authors: Khalid Ayesha , Paul Goutam , Chattopadhyay Anupam , Abediostad Faezeh , Din Syed Imad Ud , Hassan Muhammad , Biswas Baishik , Ravi Prasanna
Published: June 2016

We present RunStream, a rapid prototyping framework for realizing stream cipher implementations based on algorithmic specifications and architectural customizations desired by the users. In the dynamic world of cryptography where newer recommendations are frequently proposed, the need of such tools is imperative. It carries out design validation and generates an optimized software implementation and a synthesizable Register Transfer Level Verilog description. Our framework enables speedy benchmarking against critical resources like area, throughput, power, and latency and allows exploration of alternatives. Using RunStream, we successfully implemented various stream ciphers and benchmarked the quality of results to be at par with published hand-optimized implementations.
Ensuring Security and Privacy Preservation for Cloud Data Services
Authors: Tang Jun , Cui Yong , Li Qi , Ren Kui , Liu Jiangchuan , Buyya Rajkumar
Published: June 2016

With the rapid development of cloud computing, more and more enterprises/individuals are starting to outsource local data to the cloud servers. However, under open networks and not fully trusted cloud environments, they face enormous security and privacy risks (e.g., data leakage or disclosure, data corruption or loss, and user privacy breach) when outsourcing their data to a public cloud or using their outsourced data. Recently, several studies were conducted to address these risks, and a series of solutions were proposed to enable data and privacy protection in untrusted cloud environments. To fully understand the advances and discover the research trends of this area, this survey summarizes and analyzes the state-of-the-art protection technologies. We first present security threats and requirements of an outsourcing data service to a cloud, and follow that with a high-level overview of the corresponding security technologies. We then dwell on existing protection solutions to achieve secure, dependable, and privacy-assured cloud data services including data search, data computation, data sharing, data storage, and data access. Finally, we propose open challenges and potential research directions in each category of solutions.
Write Skew and Zipf Distribution
Authors: Yang Yue , Zhu Jianwen
Published: June 2016

Understanding workload characteristics is essential to storage systems design and performance optimization. With the emergence of flash memory as a new viable storage medium, the new design concern of flash endurance arises, necessitating a revisit of workload characteristics, in particular, of the write behavior. Inspired by Web caching studies where a Zipf-like access pattern is commonly found, we hypothesize that write count distribution at the block level may also follow Zipf’s Law. To validate this hypothesis, we study 48 block I/O traces collected from a wide variety of real and benchmark applications. Through extensive analysis, we demonstrate that the Zipf-like pattern indeed widely exists in write traffic provided its disguises are removed by statistical processing. This finding implies that write skew in a large class of applications could be analytically expressed and, thus, facilitates design tradeoff explorations adaptive to workload characteristics.
Diversifying Query Auto-Completion
Authors: Cai Fei , Reinanda Ridho , Rijke Maarten De
Published: June 2016

Query auto-completion assists web search users in formulating queries with a few keystrokes, helping them to avoid spelling mistakes and to produce clear query expressions, and so on. Previous work on query auto-completion mainly centers around returning a list of completions to users, aiming to push queries that are most likely intended by the user to the top positions but ignoring the redundancy among the query candidates in the list. Thus, semantically related queries matching the input prefix are often returned together. This may push valuable suggestions out of the list, given that only a limited number of candidates can be shown to the user, which may result in a less than optimal search experience.

In this article, we consider the task of diversifying query auto-completion, which aims to return the correct query completions early in a ranked list of candidate completions and at the same time reduce the redundancy among query auto-completion candidates. We develop a greedy query selection approach that predicts query completions based on the current search popularity of candidate completions and on the aspects of previous queries in the same search session. The popularity of completion candidates at query time can be directly aggregated from query logs. However, query aspects are implicitly expressed by previous clicked documents in the search context. To determine the query aspect, we categorize clicked documents of a query using a hierarchy based on the open directory project. Bayesian probabilistic matrix factorization is applied to derive the distribution of queries over all aspects. We quantify the improvement of our greedy query selection model against a state-of-the-art baseline using two large-scale, real-world query logs and show that it beats the baseline in terms of well-known metrics used in query auto-completion and diversification. In addition, we conduct a side-by-side experiment to verify the effectiveness of our proposal.
Byte-Addressable Update Scheme to Minimize the Energy Consumption of PCM-Based Storage Systems
Authors: Yang Ming-Chang , Chang Yuan-Hao , Tsao Che-Wei
Published: June 2016

In recent years, phase-change memory (PCM) has generated a great deal of interest because of its byte addressability and nonvolatility properties. It is regarded as a good alternative storage medium that can reduce the performance gap between the main memory and the secondary storage in computing systems. However, its high energy consumption on writes is a challenging issue in the design of battery-powered mobile computing systems. To reduce the energy consumption, we exploit the byte addressability and the asymmetric read-write energy/latency of PCM in an energy-efficient update scheme for journaling file systems. We also introduce a concept called the 50% rule to determine/recommend the best update strategy for block updates. The proposed scheme only writes modified data, instead of the whole updated block, to PCM-based storage devices without extra hardware support. Moreover, it guarantees the sanity/integrity of file systems even if the computing system crashes or there is a power failure during the data update process. We implemented the proposed scheme on the Linux system and conducted a series of experiments to evaluate the scheme. The results are very encouraging.
HCloud
Authors: Delimitrou Christina , Kozyrakis Christos
Published: June 2016

Cloud computing promises flexibility and high performance for users and cost efficiency for operators. To achieve this, cloud providers offer instances of different sizes, both as long-term reservations and short-term, on-demand allocations. Unfortunately, determining the best provisioning strategy is a complex, multi-dimensional problem that depends on the load fluctuation and duration of incoming jobs, and the performance unpredictability and cost of resources. We first compare the two main provisioning strategies (reserved and on-demand resources) on Google Compute Engine (GCE) using three representative workload scenarios with batch and latency-critical applications. We show that either approach is suboptimal for performance or cost. We then present HCloud, a hybrid provisioning system that uses both reserved and on-demand resources. HCloud determines which jobs should be mapped to reserved versus on-demand resources based on overall load, and resource unpredictability. It also determines the optimal instance size an application needs to satisfy its Quality of Service (QoS) constraints. We demonstrate that hybrid configurations improve performance by 2.1x compared to fully on-demand provisioning, and reduce cost by 46% compared to fully reserved systems. We also show that hybrid strategies are robust to variation in system and job parameters, such as cost and system load.
SpaceJMP
Authors: El Hajj Izzat , Merritt Alexander , Zellweger Gerd , Milojicic Dejan , Achermann Reto , Faraboschi Paolo , Hwu Wen-mei , Roscoe Timothy , Schwan Karsten
Published: June 2016

Memory-centric computing demands careful organization of the virtual address space, but traditional methods for doing so are inflexible and inefficient. If an application wishes to address larger physical memory than virtual address bits allow, if it wishes to maintain pointer-based data structures beyond process lifetimes, or if it wishes to share large amounts of memory across simultaneously executing processes, legacy interfaces for managing the address space are cumbersome and often incur excessive overheads. We propose a new operating system design that promotes virtual address spaces to first-class citizens, enabling process threads to attach to, detach from, and switch between multiple virtual address spaces. Our work enables data-centric applications to utilize vast physical memory beyond the virtual range, represent persistent pointer-rich data structures without special pointer representations, and share large amounts of memory between processes efficiently.

We describe our prototype implementations in the DragonFly BSD and Barrelfish operating systems. We also present programming semantics and a compiler transformation to detect unsafe pointer usage. We demonstrate the benefits of our work on data-intensive applications such as the GUPS benchmark, the SAMTools genomics workflow, and the Redis key-value store.
Silent Shredder
Authors: Awad Amro , Manadhata Pratyusa , Haber Stuart , Solihin Yan , Horne William
Published: June 2016

As non-volatile memory (NVM) technologies are expected to replace DRAM in the near future, new challenges have emerged. For example, NVMs have slow and power-consuming writes, and limited write endurance. In addition, NVMs have a data remanence vulnerability, i.e., they retain data for a long time after being powered off. NVM encryption alleviates the vulnerability, but exacerbates the limited endurance by increasing the number of writes to memory. We observe that, in current systems, a large percentage of main memory writes result from data shredding in operating systems, a process of zeroing out physical pages before mapping them to new processes, in order to protect previous processes' data. In this paper, we propose Silent Shredder, which repurposes initialization vectors used in standard counter mode encryption to completely eliminate the data shredding writes. Silent Shredder also speeds up reading shredded cache lines, and hence reduces power consumption and improves overall performance. To evaluate our design, we run three PowerGraph applications and 26 multi-programmed workloads from the SPEC 2006 suite, on a gem5-based full system simulator. Silent Shredder eliminates an average of 48.6% of the writes in the initialization and graph construction phases. It speeds up main memory reads by 3.3 times, and improves the number of instructions per cycle (IPC) by 6.4% on average. Finally, we discuss several use cases, including virtual machines' data isolation and user-level large data initialization, where Silent Shredder can be used effectively at no extra cost.
Scalable Kernel TCP Design and Implementation for Short-Lived Connections
Authors: Lin Xiaofeng , Chen Yu , Li Xiaodong , Mao Junjie , He Jiaquan , Xu Wei , Shi Yuanchun
Published: June 2016

With the rapid growth of network bandwidth, increases in CPU cores on a single machine, and application API models demanding more short-lived connections, a scalable TCP stack is performance-critical. Although many clean-state designs have been proposed, production environments still call for a bottom-up parallel TCP stack design that is backward-compatible with existing applications.

We present Fastsocket, a BSD Socket-compatible and scalable kernel socket design, which achieves table-level connection partition in TCP stack and guarantees connection locality for both passive and active connections. Fastsocket architecture is a ground up partition design, from NIC interrupts all the way up to applications, which naturally eliminates various lock contentions in the entire stack. Moreover, Fastsocket maintains the full functionality of the kernel TCP stack and BSD-socket-compatible API, and thus applications need no modifications.

Our evaluations show that Fastsocket achieves a speedup of 20.4x on a 24-core machine under a workload of short-lived connections, outperforming the state-of-the-art Linux kernel TCP implementations. When scaling up to 24 CPU cores, Fastsocket increases the throughput of Nginx and HAProxy by 267% and 621% respectively compared with the base Linux kernel. We also demonstrate that Fastsocket can achieve scalability and preserve BSD socket API at the same time. Fastsocket is already deployed in the production environment of Sina WeiBo, serving 50 million daily active users and billions of requests per day.
memif
Authors: Lin Felix Xiaozhu , Liu Xu
Published: June 2016

To harness a heterogeneous memory hierarchy, it is advantageous to integrate application knowledge in guiding frequent memory move, i.e., replicating or migrating virtual memory regions. To this end, we present memif, a protected OS service for asynchronous, hardware-accelerated memory move. Compared to the state of the art -- page migration in Linux, memif incurs low overhead and low latency; in order to do so, it not only redefines the semantics of kernel interface but also overhauls the underlying mechanisms, including request/completion management, race handling, and DMA engine configuration. We implement memif in Linux for a server-class system-on-chip that features heterogeneous memories. Compared to the current Linux page migration, memif reduces CPU usage by up to 15% for small pages and by up to 38x for large pages; in continuously serving requests, memif has no need for request batching and reduces latency by up to 63%. By crafting a small runtime atop memif, we improve the throughputs for a set of streaming workloads by up to 33%. Overall, memif has opened the door to software management of heterogeneous memory.
An Energy-interference-free Hardware-Software Debugger for Intermittent Energy-harvesting Systems
Authors: Colin Alexei , Harvey Graham , Lucia Brandon , Sample Alanson P.
Published: June 2016

Energy-autonomous computing devices have the potential to extend the reach of computing to a scale beyond either wired or battery-powered systems. However, these devices pose a unique set of challenges to application developers who lack both hardware and software support tools. Energy harvesting devices experience power intermittence which causes the system to reset and power-cycle unpredictably, tens to hundreds of times per second. This can result in code execution errors that are not possible in continuously-powered systems and cannot be diagnosed with conventional debugging tools such as JTAG and/or oscilloscopes. We propose the Energy-interference-free Debugger, a hardware and software platform for monitoring and debugging intermittent systems without adversely effecting their energy state. The Energy-interference-free Debugger re-creates a familiar debugging environment for intermittent software and augments it with debugging primitives for effective diagnosis of intermittence bugs. Our evaluation of the Energy-interference-free Debugger quantifies its energy-interference-freedom and shows its value in a set of debugging tasks in complex test programs and several real applications, including RFID code and a machine-learning-based activity recognition system.
Norepinephrine Regulates Keratinocyte Proliferation to Promote the Growth of Hair Follicles
Authors: Kong Yanan , Liu Yishu , Pan Liangli , Cheng Biao , Liu Hongwei
Published: June 2016

Psychological factors and stress can cause hair loss. The sympathetic-adrenal-medullary (SAM) axis has been reported to regulate the growth of hair follicles (HF). The sympathetic nerve is a component of the SAM axis, but it has not been sufficiently or convincingly linked to hair growth. In this study, we demonstrate that chemical sympathectomy via administration of the neurotoxin 6-hydroxydopamine (6-OHDA) to mice inhibited HF growth, but treatment with the β-adrenoceptor antagonist propranolol (PR) had no effect. HF length and skin thickness were greater in PR-treated and control mice than in 6-OHDA-treated mice, as evidenced by hematoxylin and eosin staining. Furthermore, we found that the reduced HF growth in sympathectomized animals was accompanied by a decreased keratinocyte proliferation. Moreover, the neurotransmitter norepinephrine (NE) was found to efficiently promote HF growth in an organotypic skin culture model. Together, these findings suggest that sympathetic nerves regulate keratinocyte behaviors to promote hair growth, providing novel insights into stress-related, chemotherapy-, and radiotherapy-induced alopecia.
Surgery for Colorectal Cancer - Trends, Developments, and Future Perspectives
Authors: Rentsch Markus , Schiergens Tobias , Khandoga Andrej , Werner Jens
Published: June 2016

Background: Although colorectal surgery is long established as the mainstay treatment for colon cancer, certain topics regarding technical fine-tuning to increase postsurgical recurrence-free survival have remained a matter of debate throughout the past years. These include complete mesocolic excision (CME), treatment strategies for metastatic disease, significance of hyperthermic intraperitoneal chemotherapy (HIPEC), and surgical techniques for the treatment of colorectal cancer recurrence. In addition, new surgical techniques have been introduced in oncologic colorectal surgery, and their potential to provide sufficiently radical resection has yet to be proven. Methods: A structured review of the literature was performed to identify the current state of the art with regard to the mentioned key issues in colorectal surgery. Results: This article provides a comprehensive review of the current literature addressing the above-mentioned current challenges in colorectal surgery. The focus lies on the impact of CME and, in relation to this, on lymph node dissection, as well as on treatment of metastatic disease including peritoneal spread, and finally on the treatment of recurrent disease. Conclusion: Uniformly, the current literature reveals that surgery aiming at complete malignancy elimination within multimodal treatment approaches represents the fundamental quantum leap for the achievement of long-term tumor-free survival.
Prevalence of Vitreoretinal Interface Abnormalities as Detected by Spectral-Domain Optical Coherence Tomography
Authors: Jacob Julie , Stalmans Peter
Published: June 2016

Purpose: The primary objective of this study was to determine the prevalence of vitreomacular interface (VMI) changes on optical coherence tomography (OCT) in the general population. Second, other OCT changes were described. Methods: Abnormalities in the VMI were diagnosed by OCT scan and graded according to the International Vitreomacular Traction Study (IVTS) Group classification and subdivided into 3 grades according to John et al. [Retina 2014;34:442-446]. Results: The estimated prevalence of vitreomacular abnormalities within a Belgian population aged ≥50 years was 1.17% [confidence interval (CI 0.38-3.62)] for focal vitreomacular traction (VMT) grade 1; 0.39% (CI 0.05-2.76) for focal VMT grade 2; 8.17% (CI 5.33-12.53) for focal vitreomacular adhesion, and 17.9% (CI 13.41-23.9) for broad vitreomacular adhesion. Conclusion: The prevalence of vitreomacular abnormalities within a Belgian study cohort was reported. These results closely match previously reported data on the prevalence of VMT. Correct knowledge of the epidemiology of VMI disorders and early diagnosis will enable adequate intervention.
Renal Sympathetic Denervation: Hibernation or Resurrection?
Authors: Papademetriou Vasilios , Doumas Michael , Tsioufis Costas
Published: June 2016

The most current versions of renal sympathetic denervation have been invented as minimally invasive approaches for the management of drug-resistant hypertension. The anatomy, physiology and pathophysiology of renal sympathetic innervation provide a strong background supporting an important role of the renal nerves in the regulation of blood pressure (BP) and volume. In addition, historical data with surgical sympathectomy and experimental data with surgical renal denervation indicate a beneficial effect on BP levels. Early clinical studies with transcatheter radiofrequency ablation demonstrated impressive BP reduction, accompanied by beneficial effects in target organ damage and other disease conditions characterized by sympathetic overactivity. However, the failure of the SYMPLICITY 3 trial to meet its primary efficacy end point raised a lot of concerns and put the field of renal denervation into hibernation. This review aims to translate basic research into clinical practice by presenting the anatomical and physiological basis for renal sympathetic denervation, critically discussing the past and present knowledge in this field, where we stand now, and also speculating about the future of the intervention and potential directions for research.