bluuebunny/crossref_metadata_2025 huggingface dataset:
Quorum Sensing Is Accompanied by Global Metabolic Changes in the Opportunistic Human Pathogen Pseudomonas aeruginosa
Authors: Davenport Peter W. , Griffin Julian L. , Welch Martin
Published: April 2015

Pseudomonas aeruginosausesN-acyl-homoserine lactone (AHL)-dependent quorum sensing (QS) systems to control the expression of secreted effectors. These effectors can be crucial to the ecological fitness of the bacterium, playing roles in nutrient acquisition, microbial competition, and virulence. In this study, we investigated the metabolic consequences of AHL-dependent QS by monitoring the metabolic profile(s) of alasI rhlIdouble mutant (unable to make QS signaling molecules) and its wild-type progenitor as they progressed through the growth curve. Analysis of culture supernatants by1H-nuclear magnetic resonance (1H-NMR) spectroscopy revealed that at the point where AHL concentrations peaked in the wild type, the metabolic footprints (i.e., extracellular metabolites) of the wild-type andlasI rhlImutant diverged. Subsequent gas chromatography-mass spectrometry (GC-MS)-based analysis of the intracellular metabolome revealed QS-dependent perturbations in around one-third of all identified metabolites, including altered concentrations of tricarboxylic acid (TCA) cycle intermediates, amino acids, and fatty acids. Further targeted fatty acid methyl ester (FAME) GC-MS-based profiling of the cellular total fatty acid pools revealed that QS leads to changes associated with decreased membrane fluidity and higher chemical stability. However, not all of the changes we observed were necessarily a direct consequence of QS; liquid chromatography (LC)-MS analyses revealed that polyamine levels were elevated in thelasI rhlImutant, perhaps a response to the absence of QS-dependent adaptations. Our data suggest that QS leads to a global readjustment in central metabolism and provide new insight into the metabolic changes associated with QS during stationary-phase adaptation.

IMPORTANCEQuorum sensing (QS) is a transcriptional regulatory mechanism that allows bacteria to coordinate their gene expression profile with the population cell density. The opportunistic human pathogenPseudomonas aeruginosauses QS to control the production of secreted virulence factors. In this study, we show that QS elicits a global “metabolic rewiring” inP. aeruginosa. This metabolic rerouting of fluxes is consistent with a variety of drivers, ranging from altered QS-dependent transcription of “metabolic genes” through to the effect(s) of global “metabolic readjustment” as a consequence of QS-dependent exoproduct synthesis, as well as a general stress response, among others. To our knowledge, this is the first study of its kind to assess the global impact of QS on the metabolome.
Grouted gravel column-supported highway embankment over soft clay: case study
Authors: Liu Hanlong , Kong Gangqiang , Chu Jian , Ding Xuanming
Published: April 2015

In this paper, a simplified column construction method — the so-called grouted gravel column — and its application to construction of embankments over soft ground are introduced. The construction method, quality assurance (QA), and quality control (QC) of the grouted gravel columns are described. A case study on the application of this method to a highway embankment in China is also presented. The case study shows that about 50% of surface settlement and 60% of the differential settlement between the column head and soil occurred during the construction of the embankment. The column to soil stress ratio was 8.0 for columns with caps and 4.2 for columns without caps. Static load tests were also conducted to assess the bearing capacity of the columns.
Plant identity and density can influence arbuscular mycorrhizal fungi colonization, plant growth, and reproduction investment in coculture
Authors: Derelle Damien , Courty Pierre-Emmanuel , Dajoz Isabelle , Declerck Stéphane , van Aarle Ingrid M. , Carmignac David , Genet Patricia
Published: April 2015

Reciprocal effects between arbuscular mycorrhizal fungi (AMF) and plant communities are essential to study the complexity of interactions in a grassland ecosystem. Here, we investigated the effects of plant community density and composition on AMF colonization, plant growth, and reproduction investment. We developed an experimental system with three compartments, each containing either three or six Medicago truncatula Gaertn. plants, or three M. truncatula plants associated with three Silene vulgaris (Moench) Garcke plants. All three compartments shared the same common mycorrhizal network built either by Rhizophagus irregularis MUCL 43194, by Rhizophagus clarus MUCL 46238, or by both AMF in association grown in a central compartment on Plantago lanceolata L. Our results demonstrate an absence of effect of plant density but a positive influence of mixed cultures on AMF root colonization compared with monocultures. This higher AMF development resulted in a positive feedback on shoot biomass and number of flowers and fruits produced by M. truncatula. Although both fungal strains were present in root systems, co-inoculation did not generate a synergistic effect on plant development. These results highlight the importance of plant associations on AMF dynamics, which requires further investigation at the community scale to improve our understanding of the intricate AMF – host plant relationships.
Gene regulation by dietary microRNAs
Authors: Zempleni Janos , Baier Scott R. , Howard Katherine M. , Cui Juan
Published: April 2015

MicroRNAs (miRNAs) silence genes through destabilizing mRNA or preventing translation of mRNA, thereby playing an essential role in gene silencing. Traditionally, miRNAs have been considered endogenous regulators of genes, i.e., miRNAs synthesized by an organism regulate the genes in that organism. Recently, that dogma has been challenged in studies suggesting that food-borne miRNAs are bioavailable and affect gene expression in mice and humans. While the evidence in support of this theory may be considered weak for miRNAs that originate in plants, there is compelling evidence to suggest that humans use bovine miRNAs in cow’s milk and avian miRNAs in chicken eggs for gene regulation. Importantly, evidence also suggests that mice fed a miRNA-depleted diet cannot compensate for dietary depletion by increased endogenous synthesis. Bioinformatics predictions implicate bovine miRNAs in the regulation of genes that play roles in human health and development. Current challenges in this area of research include that some miRNAs are unable to establish a cause-and-effect between miRNA depletion and disease in miRNA knockout mice, and sequence similarities and identities for bovine and human miRNAs render it difficult to distinguish between exogenous and endogenous miRNAs. Based on what is currently known about dietary miRNAs, the body of evidence appears to be sufficient to consider milk miRNA bioactive compounds in foods, and to increase research activities in this field.
Nonsingular black hole with a nonlinear electric source
Authors: Culetu Hristu
Published: April 2015

A modified version of the Reissner–Nordstrom (RN) metric is proposed on the grounds of the nonlinear electrodynamics model. The source of curvature is an anisotropic fluid with pr = -ρ which resembles the Maxwell stress tensor at r ≫ q2/2m, where q and m are the mass and charge of the particle, respectively. We found the black hole (BH) horizon entropy obeys the relation S = ∣W∣/2T = AH/4, with W the Komar energy and AH the horizon area. The electric field around the source depends not only on its charge but also on its mass. The corresponding electrostatic potential Φ(r) is finite everywhere, being -m/2q at the origin and nonzero asymptotically, with Φ∞ = m/q.
Systematic study of the elliptic flow parameter using a transport approach
Authors: Nasim Md. , Mohanty Bedangadas
Published: April 2015

Elliptic flow parameter, v2 is considered as a sensitive probe for early dynamics of the heavy-ion collision. In this work, we have discussed the effect of detector efficiency, procedure of centrality determination, effect of resonance decay and the procedure to correct event plane resolution on the measured v2 by standard event plane method within the framework of a transport model. The measured value of v2 depends on the efficiency in particle number counting by the detector. The effect of centrality determination is found to be negligible. The new method of event plane resolution correction for wide centrality bin yields results in v2 values closer to the true value of the v2. The contributions from the resonance decay seems to decrease the value of v2 of π and K within the Ultra relativistic Quantum Molecular Dynamics (UrQMD) model based calculation. We also propose a procedure to correct for an event bias effect on v2 arising while comparing the minimum bias collision centrality v2 values for different multi-strange hadrons. Finally, we have presented a model based confirmation of the recently proposed relation between v2 obtained using event plane method and scalar product method to the true value of v2.
INFLUENCE OF FRICTION IN TRANSPARENT TOOTH CORRECTION TREATMENT: FINITE ELEMENT METHOD
Authors: CAI YONGQING , YANG XIAOXIANG , HE BINGWEI
Published: April 2015

Objective: The objective was to evaluate the effect of frictional forces on the canine's translation and rotation in transparent tooth correction treatment. Materials and Methods: Based on computed tomography (CT) images of the teeth and their supporting tissues, solid models were used to build finite-element models. One canine was simulated translation and rotation in the buccolingual direction by aligners with different friction coefficients. Results: The change of the canine's rotation centers and periodontal ligament (PDL) stress with an increase of the friction coefficient in the two movement types were obtained. Conclusions: Friction coefficient has little effect on the canine's translation movement. While in rotation cases, the small friction coefficient seems to be helpful to gain the body movement type.
NANOINDENTATION AND ASH CONTENT STUDY OF AGE DEPENDENT CHANGES IN PORCINE CORTICAL BONE
Authors: CHITTENDEN MICHAEL , NAJAFI AHMAD RAEISI , LI JUN , JASIUK IWONA
Published: April 2015

Composition-structure-property relations of bone provide fundamental understanding of bone quality. The objective of this paper was to investigate age dependent changes in the composition, structure and mechanical properties of porcine femoral cortical bone at mid-diaphysis region from six age groups (1, 3.5, 6, 12, 30, 48 months). This study was motivated by the fact that limited data is available in the literature on young porcine cortical bone. Nanoindentation technique with Berkovich fluid cell tip was employed to measure the elastic modulus and hardness. Individual lamellae were indented in the longitudinal direction of bone in different microstructural components (osteonal, interstitial and plexiform bone). A grid of indentations was also made on one bone sample to obtain spatial variations in the elastic modulus and hardness. Ash and water content tests were performed to measure water, organic and mineral contents of bone as a function of age. Finally, high resolution micro-computed tomography was used to measure porosity and visualize three-dimensional void structures. We found that the elastic modulus and hardness of bone increased with age but at different rates in each microstructural component. The mineral content increased correspondingly with age while the porosity decreased. The obtained structure, composition, and mechanical properties data give new insights on the age related changes in young cortical bone and can serve as inputs for and validation of multiscale models of bone.
Hyperbolicity of high-order systems of evolution equations
Authors: Hilditch David , Richter Ronny
Published: April 2015

We study properties of evolution equations which are first order in time and arbitrary order in space (FTNS). Following Gundlach and Martín-García (2006) we define strong and symmetric hyperbolicity for FTNS systems and examine the relationship between these definitions, and the analogous concepts for first-order systems. We demonstrate equivalence of the FTNS definition of strong hyperbolicity with the existence of a strongly hyperbolic first-order reduction. We also demonstrate equivalence of the FTNS definition, up to N = 4, of symmetric hyperbolicity with the existence of a symmetric-hyperbolic first-order reduction.
IMPACT ASSESSMENT RESEARCH: ACHIEVEMENTS, GAPS AND FUTURE DIRECTIONS
Authors: FISCHER THOMAS B. , NOBLE BRAM
Published: April 2015

Welcome to this special JEAPM issue on impact assessment (IA) research, which — besides this introductory paper — includes 16 short papers contributed by a wide range of leading IA researchers from around the world. These papers provide for an overview of achievements, gaps and future directions for IA research. The collection of papers is the outcome of a targeted call to researchers representing a wide range of IA areas and regions. This has resulted in what we believe is an impressive compilation of contributions on environmental impact assessment (EIA), strategic environmental assessment (SEA), health impact assessment (HIA) and social impact assessment (SIA) as well as theoretical, applied and normative aspects of IA, with a particular focus on sustainable development from European, North and South American, Asian, African and Australian authors.
Micromechanical Analysis of SiC/Al Metal Matrix Composites: Finite Element Modeling and Damage Simulation
Authors: Qing Hai , Liu Tianliang
Published: April 2015

The influence of interface strengths and microstructures on the strength and damage of SiC particle reinforced aluminum Metal Matrix Composite (MMC) is investigated under uniaxial tensile, simple shear, biaxial tensile and combined tensile and shear loadings. An algorithm to generate automatically the microstructural models of MMCs with random distribution of particle shapes, dimensions, orientations and locations is proposed and implemented within Matlab. A damage model based on the stress triaxial indicator is developed to simulate the ductile failure of metal matrix, the other damage model based on the maximum principal stress criterion is developed to simulate the brittle failure of SiC particles, and 2D cohesive element is utilized to describe interface decohesion between matrix and particles. A series of numerical experiments are performed to study the macroscopic stress–strain relationships and microscale damage evolution in MMCs under different loading conditions.
A Nonlinear Mathematical Model of Thermoelastic Thin Plates with Voids and Its Applications
Authors: Zhu Yuan-Yuan , Zhong Zheng , Cheng Chang-Jun
Published: April 2015

Following the linear theory of thermoelastic materials with voids, a generalized Hamilton variational principle is extended to the thermoelastic plates with voids under the case of large deflection, and a 3D nonlinear mathematical model is presented. In this process, the balance equation of the entropy is converted to an equivalent form without the first-order time-derivative by integral, and the concept of the moments for the volume fraction of voids and temperature field is introduced. As application, the nonlinear dynamic and aerodynamic characteristics of simply-supported rectangular thermoelastic plates with voids for four different materials are studied and compared by using a Galerkin approach. The effects of the initial deflections and material parameters are considered in detail. In addition to providing a generalized Hamilton variational principle and a 3D nonlinear mathematical model, it is also provided a valuable numerical method to solve the dynamic problem directly in the paper. The theory and the method can be applied to solving various problems of the thermoelastic plates with voids easily.
Testing Planarity of Partially Embedded Graphs
Authors: Angelini Patrizio , Di Battista Giuseppe , Frati Fabrizio , Jelínek Vít , Kratochvíl Jan , Patrignani Maurizio , Rutter Ignaz
Published: April 2015

We study the following problem: given a planar graph
G
and a planar drawing (embedding) of a subgraph of
G
, can such a drawing be extended to a planar drawing of the entire graph
G
? This problem fits the paradigm of extending a partial solution for a problem to a complete one, which has been studied before in many different settings. Unlike many cases, in which the presence of a partial solution in the input makes an otherwise easy problem hard, we show that the planarity question remains polynomial-time solvable. Our algorithm is based on several combinatorial lemmas, which show that the planarity of partially embedded graphs exhibits the ‘TONCAS’ behavior “the obvious necessary conditions for planarity are also sufficient.” These conditions are expressed in terms of the interplay between (1) the rotation system and containment relationships between cycles and (2) the decomposition of a graph into its connected, biconnected, and triconnected components. This implies that no dynamic programming is needed for a decision algorithm and that the elements of the decomposition can be processed independently.

Further, by equipping the components of the decomposition with suitable data structures and by carefully splitting the problem into simpler subproblems, we make our algorithm run in linear time.

Finally, we consider several generalizations of the problem, such as minimizing the number of edges of the partial embedding that need to be rerouted to extend it, and argue that they are NP-hard. We also apply our algorithm to the simultaneous graph drawing problem
Simultaneous Embedding with Fixed Edges (Sefe)
. There we obtain a linear-time algorithm for the case that one of the input graphs or the common graph has a fixed planar embedding.
Hierarchical Bayesian Inference and Recursive Regularization for Large-Scale Classification
Authors: Gopal Siddharth , Yang Yiming
Published: April 2015

In this article, we address open challenges in large-scale classification, focusing on how to effectively leverage the dependency structures (hierarchical or graphical) among class labels, and how to make the inference scalable in jointly optimizing all model parameters. We propose two main approaches, namely the hierarchical Bayesian inference framework and the recursive regularization scheme. The key idea in both approaches is to reinforce the similarity among parameter across the nodes in a hierarchy or network based on the proximity and connectivity of the nodes. For scalability, we develop hierarchical variational inference algorithms and fast dual coordinate descent training procedures with parallelization. In our experiments for classification problems with hundreds of thousands of classes and millions of training instances with terabytes of parameters, the proposed methods show consistent and statistically significant improvements over other competing approaches, and the best results on multiple benchmark datasets for large-scale classification.
On the Performance of Smith’s Rule in Single-Machine Scheduling with Nonlinear Cost
Authors: Höhn Wiebke , Jacobs Tobias
Published: April 2015

We consider a single-machine scheduling problem. Given some continuous, nondecreasing cost function, we aim to compute a schedule minimizing the weighted total cost, where the cost of each job is determined by the cost function value at its completion time. This problem is closely related to scheduling a single machine with nonuniform processing speed. We show that for piecewise linear cost functions it is strongly NP-hard. The main contribution of this article is a tight analysis of the approximation guarantee of Smith’s rule under any convex or concave cost function. More specifically, for these wide classes of cost functions we reduce the task of determining a worst-case problem instance to a continuous optimization problem, which can be solved by standard algebraic or numerical methods. For polynomial cost functions with positive coefficients, it turns out that the tight approximation ratio can be calculated as the root of a univariate polynomial. We show that this approximation ratio is asymptotically equal to
k

(
k
− 1)/(
k
+ 1)

, denoting by
k
the degree of the cost function. To overcome unrealistic worst-case instances, we also give tight bounds for the case of integral processing times that are parameterized by the maximum and total processing time.
Directed Subset Feedback Vertex Set Is Fixed-Parameter Tractable
Authors: Chitnis Rajesh , Cygan Marek , Hajiaghayi Mohammataghi , Marx Dániel
Published: April 2015

Given a graph
G
and an integer
k
, the
Feedback Vertex Set
(FVS) problem asks if there is a vertex set
T
of size at most
k
that hits all cycles in the graph. The first fixed-parameter algorithm for FVS in undirected graphs appeared in a monograph of Mehlhorn in 1984. The fixed-parameter tractability (FPT) status of FVS in directed graphs was a long-standing open problem until Chen et al. (STOC ’08, JACM ’08) showed that it is fixed-parameter tractable by giving a 4

k

k
! ·
n

O
(1)

time algorithm. There are two subset versions of this problems: We are given an additional subset
S
of vertices (resp., edges), and we want to hit all cycles passing through a vertex of
S
(resp., an edge of
S
); the two variants are known to be equivalent in the parameterized sense. Recently, the
Subset
FVS problem in undirected graphs was shown to be FPT by Cygan et al. (ICALP’11, SIDMA’13) and independently by Kakimura et al. (SODA ’12). We generalize the result of Chen et al. (STOC ’08, JACM ’08) by showing that a
Subset
FVS in directed graphs can be solved in time 2

O
(
k
3
)

ċ
n

O
(1)

(i.e., FPT parameterized by size
k
of the solution). By our result, we complete the picture for FVS problems and their subset versions in undirected and directed graphs. The technique of random sampling of important separators was used by Marx and Razgon (STOC ’11, SICOMP ’14) to show that
Undirected Multicut
is FPT, and it was generalized by Chitnis et al. (SODA ’12, SICOMP ’13) to directed graphs to show that
Directed Multiway Cut
is FPT. In addition to proving the FPT of a
Directed Subset
FVS, we reformulate the random sampling of important separators technique in an abstract way that can be used with a general family of transversal problems. We believe this general approach will be useful for showing the FPT of other problems in directed graphs. Moreover, we modify the probability distribution used in the technique to achieve better running time; in particular, this gives an improvement from 2

2
O
(
k
)

to 2

O
(
k
2
)

in the parameter dependence of the
Directed Multiway Cut
algorithm of Chitnis et al. (SODA ’12, SICOMP ’13).
The Discrete and Semicontinuous Fréchet Distance with Shortcuts via Approximate Distance Counting and Selection
Authors: Avraham Rinat Ben , Filtser Omrit , Kaplan Haim , Katz Matthew J. , Sharir Micha
Published: April 2015

The
Fréchet distance
is a well-studied similarity measure between curves. The
discrete Fréchet distance
is an analogous similarity measure, defined for two sequences of
m
and
n
points, where the points are usually sampled from input curves. We consider a variant, called the
discrete Fréchet distance with shortcuts
, which captures the similarity between (sampled) curves in the presence of outliers. When shortcuts are allowed only in one noise-containing curve, we give a randomized algorithm that runs in
O
((
m
+
n
)
6/5 + ε
) expected time, for any ε > 0. When shortcuts are allowed in both curves, we give an
O
((
m
2/3
n
2/3
+
m
+
n
)log 
3
(
m
+
n
))-time deterministic algorithm.

We also consider the semicontinuous Fréchet distance with one-sided shortcuts, where we have a sequence of
m
points and a polygonal curve of
n
edges, and shortcuts are allowed only in the sequence. We show that this problem can be solved in randomized expected time
O
((
m
+
n
)
2/3
m
2/3
n
1/3
log (
m
+
n
)).

Our techniques are novel and may find further applications. One of the main new technical results is: Given two sets of points
A
and
B
in the plane and an interval
I
, we develop an algorithm that decides whether the number of pairs (
x
,
y
) ∈
A
×
B
whose distance dist(
x
,
y
) is in
I
is less than some given threshold
L
. The running time of this algorithm decreases as
L
increases. In case there are more than
L
pairs of points whose distance is in
I
, we can get a small sample of pairs that contain a pair at approximate median distance (i.e., we can approximately “bisect”
I
). We combine this procedure with additional ideas to search, with a small overhead, for the optimal one-sided Fréchet distance with shortcuts, using a very fast decision procedure. We also show how to apply this technique for approximating distance selection (with respect to rank), and a somewhat more involved variant of this technique is used in the solution of the semicontinuous Fréchet distance with one-sided shortcuts. In general, the new technique can be applied to optimization problems for which the decision procedure is very fast but standard techniques like parametric search makes the optimization algorithm substantially slower.
Mapping Simple Polygons
Authors: Chalopin Jérémie , Das Shantanu , Disser Yann , Mihalák Matúš , Widmayer Peter
Published: April 2015

We consider the exploration of a simple polygon
P
by a robot that moves from vertex to vertex along edges of the visibility graph of
P
. The visibility graph has a vertex for every vertex of
P
and an edge between two vertices if they see each other—that is, if the line segment connecting them lies inside
P
entirely. While located at a vertex, the robot is capable of ordering the vertices it sees in counterclockwise order as they appear on the boundary, and for every two such vertices, it can distinguish whether the angle between them is convex (⩽ π) or reflex ( > π). Other than that, distant vertices are indistinguishable to the robot. We assume that an upper bound on the number of vertices is known.

We obtain the general result that a robot exploring any locally oriented, arc-labeled graph
G
can always determine the
base graph
of
G
. Roughly speaking, this is the smallest graph that cannot be distinguished by a robot from
G
by its observations alone, no matter how it moves. Combining this result with various other techniques allows the ability to show that a robot exploring a polygon
P
with the preceding capabilities is always capable of reconstructing the visibility graph of
P
. We also show that multiple identical, indistinguishable, and deterministic robots of this kind can always solve the weak rendezvous problem in which they need to position themselves such that they mutually see each other—for instance, such that they form a clique in the visibility graph.
Attacking the Internet Using Broadcast Digital Television
Authors: Oren Yossef , Keromytis Angelos D.
Published: April 2015

In the attempt to bring modern broadband Internet features to traditional broadcast television, the Digital Video Broadcasting (DVB) consortium introduced a specification called Hybrid Broadcast-Broadband Television (HbbTV), which allows broadcast streams to include embedded HTML content that is rendered by the television. This system is already in very wide deployment in Europe and has recently been adopted as part of the American digital television standard. Our analyses of the specifications, and of real systems implementing them, show that the broadband and broadcast systems are combined insecurely. This enables a large-scale exploitation technique with a localized geographical footprint based on Radio Frequency (RF) injection, which requires a minimal budget and infrastructure and is remarkably difficult to detect. In this article, we present the attack methodology and a number of follow-on exploitation techniques that provide significant flexibility to attackers. Furthermore, we demonstrate that the technical complexity and required budget are low, making this attack practical and realistic, especially in areas with high population density: In a dense urban area, an attacker with a budget of about 450 can target more than 20,000 devices in a single attack. A unique aspect of this attack is that, in contrast to most Internet of Things/Cyber-Physical System threat scenarios, where the attack comes from the data network side and affects the physical world, our attack uses the physical broadcast network to attack the data network.
Near-Optimal Scheduling Mechanisms for Deadline-Sensitive Jobs in Large Computing Clusters
Authors: Jain Navendu , Menache Ishai , Naor Joseph (Seffi) , Yaniv Jonathan
Published: April 2015

We consider a market-based resource allocation model for batch jobs in cloud computing clusters. In our model, we incorporate the importance of the due date of a job rather than the number of servers allocated to it at any given time. Each batch job is characterized by the work volume of total computing units (e.g., CPU hours) along with a bound on maximum degree of parallelism. Users specify, along with these job characteristics, their desired due date and a value for finishing the job by its deadline. Given this specification, the primary goal is to determine the
scheduling
of cloud computing instances under capacity constraints in order to maximize the social welfare (i.e., sum of values gained by allocated users). Our main result is a new (CC-kċss-1)-approximation algorithm for this objective, where
C
denotes cloud capacity,
k
is the maximal bound on parallelized execution (in practical settings,
k
<
C
) and
s
is the slackness on the job completion time, that is, the minimal ratio between a specified deadline and the earliest finish time of a job. Our algorithm is based on utilizing dual fitting arguments over a strengthened linear program to the problem.

Based on the new approximation algorithm, we construct truthful allocation and pricing mechanisms, in which reporting the true value and other properties of the job (deadline, work volume, and the parallelism bound) is a dominant strategy for all users. To that end, we extend known results for single-value settings to provide a general framework for transforming allocation algorithms into truthful mechanisms in domains of single-value and multi-properties. We then show that the basic mechanism can be extended under proper Bayesian assumptions to the objective of maximizing revenues, which is important for public clouds. We empirically evaluate the benefits of our approach through simulations on data-center job traces, and show that the revenues obtained under our mechanism are comparable with an
ideal
fixed-price mechanism, which sets an on-demand price using oracle knowledge of users’ valuations. Finally, we discuss how our model can be extended to accommodate uncertainties in job work volumes, which is a practical challenge in cloud settings.
Diet-induced obesity exacerbates metabolic and behavioral effects of polycystic ovary syndrome in a rodent model
Authors: Ressler Ilana B. , Grayson Bernadette E. , Ulrich-Lai Yvonne M. , Seeley Randy J.
Published: April 2015

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting women of reproductive age. Although a comorbidity of PCOS is obesity, many are lean. We hypothesized that increased saturated fat consumption and obesity would exacerbate metabolic and stress indices in a rodent model of PCOS. Female rats were implanted with the nonaromatizable androgen dihydrotestosterone (DHT) or placebo pellets prior to puberty. Half of each group was maintained ad libitum on either a high-fat diet (HFD; 40% butter fat calories) or nutrient-matched low-fat diet (LFD). Irrespective of diet, DHT-treated animals gained more body weight, had irregular cycles, and were glucose intolerant compared with controls on both diets. HFD/DHT animals had the highest levels of fat mass and insulin resistance. DHT animals demonstrated increased anxiety-related behavior in the elevated plus maze by decreased distance traveled and time in the open arms. HFD consumption increased immobility during the forced-swim test. DHT treatment suppressed diurnal corticosterone measurements in both diet groups. In parallel, DHT treatment significantly dampened stress responsivity to a mild stressor. Brains of DHT animals showed attenuated c-Fos activation in the ventromedial hypothalamus and arcuate nucleus; irrespective of DHT-treatment, however, all HFD animals had elevated hypothalamic paraventricular nucleus c-Fos activation. Whereas hyperandrogenism drives overall body weight gain, glucose intolerance, anxiety behaviors, and stress responsivity, HFD consumption exacerbates the effect of androgens on adiposity, insulin resistance, and depressive behaviors.
Temporal Patterns of Shrub Vegetation and Variation with Precipitation in Gurbantunggut Desert, Central Asia
Authors: Yang Yuguang , Zhao Chengyi , Han Ming , Li Yike , Yang Ruihong
Published: April 2015

The relationship between shrub vegetation and precipitation is one important component of desert vegetation responses to climate change, but it has not been understood completely because of its complexity and nonlinearity. In this study, we used MODIS NDVI data and precipitation data from 2004 to 2012 to evaluate the relationship between the shrub vegetation and precipitation within Gurbantunggut Desert, Central Asia. Correlation analysis was employed to explore the relationship between NDVI and precipitation within growing season, within cross growing season, and on interannual scale. The results showed that NDVI could be classified into three temporal changing patterns within growing season, and NDVI was significantly correlated with the precipitation integrated by time durations and time lags within growing season; NDVI was significantly correlated with precipitation in the early growing season, but this relationship was not so obvious in the middle or late growing season; and the NDVI variational patterns depended on mean annual precipitation and the distribution of precipitation throughout the year. Precipitation had significant influence on shrub vegetation within Gurbantunggut Desert. Our findings provide basic knowledge for the relationship between precipitation and shrub vegetation, and it is helpful to understand how the desert vegetation responds to climate change in the future.
Efficacy and Safety of Yokukansan in Treatment-Resistant Schizophrenia: A Randomized, Multicenter, Double-Blind, Placebo-Controlled Trial
Authors: Miyaoka Tsuyoshi , Furuya Motohide , Horiguchi Jun , Wake Rei , Hashioka Sadayuki , Thoyama Masaya , Murotani Kenta , Mori Norio , Minabe Yoshio , Iyo Masaomi , Ueno Shuichi , Ezoe Sachiko , Hoshino Syuzo , Seno Haruo
Published: April 2015

Objectives. We aimed at evaluating both the efficacy and safety of TJ-54 (Yokukansan) in patients with treatment-resistant schizophrenia. This randomized, multicenter, double-blind, placebo-controlled study was conducted.Methods. One hundred and twenty antipsychotic-treated inpatients were included. Patients were randomized to adjuvant treatment with TJ-54 or placebo. During a 4-week follow-up, psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS).Results. TJ-54 showed a tendency of being superior to placebo in reduction total, positive, and general PANSS scores in treatment-resistant schizophrenia, but the difference was not statistically significant in both per-protocol set (PPS) and intention-to-treat (ITT). However, in PPS analysis, compared to the placebo group, the TJ-54 group showed statistically significant improvements in the individual PANSS subscale scores for lack of spontaneity and flow of conversation (TJ-54:−0.23±0.08; placebo:−0.03±0.08,P<0.018), tension (TJ-54:−0.42±0.09; placebo:−0.18±0.09,P<0.045), and poor impulse control (TJ-54:−0.39±0.10; placebo:−0.07±0.10,P<0.037).Conclusions. The results of the present study indicate that TJ-54 showed a tendency of being superior to placebo in reduction PANSS scores in treatment-resistant schizophrenia, but the difference was not statistically significant. However, compared to the placebo group, TJ-54 group showed statistically significant improvements in the individual PANSS subscale scores.
Oscillation Criteria of Third-Order Nonlinear Damped Dynamic Equations on Time Scales
Authors: Qiu Yang-Cong
Published: April 2015

We establish oscillation criteria of third-order nonlinear damped dynamic equations on time scales of the formr1tr2txΔtγΔΔ+ft, xt,xσt, xgt, xΔt=0by employing functions in some function classes and the generalized Riccati transformation. Two examples are given to show the significance of the conclusions.
Characterization of the Industrial Residues of Seven Fruits and Prospection of Their Potential Application as Food Supplements
Authors: Sancho Soraya de Oliveira , da Silva Ana Raquel Araújo , Dantas Allan Nilson de Sousa , Magalhães Ticiane Alencar , Lopes Gisele Simone , Rodrigues Sueli , da Costa José Maria Correia , Fernandes Fabiano André Narciso , Silva Maria Goretti de Vasconcelos
Published: April 2015

Seven residues from tropical fruit (acerola, cashew apple, guava, mango, papaya, pineapple, and sapota) processing were prospected for physicochemical parameters (pH, total soluble solids, water activity, reducing sugar, acidity, protein, moisture, ash, and lipids), functional compounds (total phenolic content, anthocyanins, ascorbic acid, and free radical scavenging activity—DPPH), fatty acid profile, and mineral content. Prospection of these industrial residues aimed its use as potential sources for food supplementation. Acerola residue was found to be a valuable source of anthocyanins, phenolics, and vitamin C; cashew apple residue could be a source of unsaturated fatty acids; pineapple and papaya residues could be used, respectively, as manganese and phosphorous source.
Amniotic Mesenchymal Stem Cells Can Enhance Angiogenic Capacity via MMPsIn VitroandIn Vivo
Authors: Jiang Fei , Ma Jie , Liang Yi , Niu Yuming , Chen Ning , Shen Ming
Published: April 2015

The aim of this study was to evaluate the angiogenic capacity and proteolytic mechanism of coculture using human amniotic mesenchymal stem cells (hAMSCs) with human umbilical vein endothelial cells (HUVECs)in vivoandin vitroby comparing to those of coculture using bone marrow mesenchymal stem cells with HUVEC. For thein vivoexperiment, cells (HUVEC-monoculture, HUVEC-hAMSC coculture, and HUVEC-BMMSC coculture) were seeded in fibrin gels and injected subcutaneously in nude mice. The samples were collected on days 7 and 14 and histologically analyzed by H&E and CD31 staining. CD31-positive staining percentage and vessel-like structure (VLS) density were evaluated as quantitative parameters for angiogenesis. The increases of CD31-positive staining area and VLS density in both HUVEC-hAMSC group and HUVEC-BMMSC group were found between two time points, while obvious decline of those was observed in HUVEC-only group. For thein vitroexperiment, we utilized the same 3D culture model to investigate the proteolytic mechanism related to capillary formation. Intensive vascular networks formed by HUVECs were associated with hAMSCs or BMMSCs and related to MMP2 and MMP9. In conclusion, hAMSCs shared similar capacity and proteolytic mechanism with BMMSCs on neovascularization.
Simulation of Droplet Impacting on Elastic Solid with the SPH Method
Authors: Ma Xiao-Jing , Geni Mamtimin
Published: April 2015

The phenomenon of droplet impacting on solid surfaces widely exists in both nature and engineering systems. However, one concern is that the microdeformation of solid surface is difficult to be observed and measured during the process of impacting. Since the microdeformation can directly affect the stability of the whole system, especially for the high-rate rotating components, it is necessary to study this phenomenon. Aiming at this problem, a new numerical simulation algorithm based on the Smoothed Particle Hydrodynamics (SPH) method is brought forward to solve fluid-solid coupling and complex free surface problems in the paper. In order to test and analyze the feasibility and effectiveness of the improved SPH method, the process of a droplet impacting on an elastic plate was simulated. The numerical results show that the improved SPH method is able to present more detailed information about the microdeformation of solid surface. The influence of the elastic modulus of solid on the impacting process was also discussed.
Peripheral Thrombosis and Necrosis after Minimally Invasive Redo Mitral Valve Replacement due to Unknown Etiology: Difficult Diagnosis of Heparin Induced Thrombocytopenia
Authors: Nakamura Yoshitsugu , Bainbridge Daniel T. , Kiaii Bob
Published: April 2015

We report on a 75-year-old male with acute onset of peripheral thrombosis causing necrosis of the fingers, elbow, and toes associated with thrombocytopenia after minimally invasive redo mitral valve replacement. Both warfarin and dalteparin were commenced on postoperative day 1 and his INR reached 2.1 on postoperative day 4. On postoperative day 5, the patient developed peripheral thrombosis which progressed to necrosis on postoperative day 6. Platelet counts decreased significantly on the same day. His clinical features were compatible with heparin induced thrombocytopenia (HIT). However, serology testing was negative and the diagnosis was never confirmed. The patient was treated for HIT and platelet count improved eventually. Although no clear consensus exists, we believe this case illustrates why therapy for HIT should be initiated when clinical features strongly suggest HIT despite a negative serology test, unless an alternate diagnosis can be found.
Preparation, Characterization, and Dissolution Rate In Vitro Evaluation of Total Panax Notoginsenoside Nanoparticles, Typical Multicomponent Extracts from Traditional Chinese Medicine, Using Supercritical Antisolvent Process
Authors: Zhang Ying , Zhao Xiuhua , Li Wengang , Zu Yuangang , Li Yong , Wang Kunlun
Published: April 2015

Total Panax notoginsenosides nanoparticles, typical multicomponent extracts from traditional Chinese medicine, were prepared with a supercritical antisolvent (SAS) process using ethanol as solvent and carbon dioxide as antisolvent. The optimum conditions were determined to be as follows: TPNS solution concentration of 2.5 mg/mL, TPNS solution flow rate of 6.6 mL/min, precipitation temperature of 40°C, and precipitation pressure of 20 MPa. Under the optimum conditions, TPNS nanoparticles with a MPS of 141.5 ± 18.2 nm and total saponins amounts (TSA) of 78.9% were obtained. The TPNS nanoparticles obtained were characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), Fourier‐transform infrared spectroscopy (FTIR), differential scanning calorimeters (DSC), and high performance liquid chromatography (HPLC). The results showed that the chemical and crystal structure of the obtained TPNS nanoparticles has not changed. Dissolution in vitro studies showed that the solubility and dissolution rate of notoginsenosides R1 and ginsenoside Rb1 in TPNS nanoparticles are higher than these in raw TPNS, with no obvious difference in Rg1. These results suggest that TPNS nanoparticles can be helpful to the improvement of its bioavailability for the treatment of cardiovascular diseases.
Increased Clearance of Reactive Aldehydes and Damaged Proteins in Hypertension-Induced Compensated Cardiac Hypertrophy: Impact of Exercise Training
Authors: Campos Juliane Cruz , Fernandes Tiago , Bechara Luiz Roberto Grassmann , Paixão Nathalie Alves da , Brum Patricia Chakur , Oliveira Edilamar Menezes de , Ferreira Julio Cesar Batista
Published: April 2015

Background. We previously reported that exercise training (ET) facilitates the clearance of damaged proteins in heart failure. Here, we characterized the impact of ET on cardiac protein quality control during compensated ventricular hypertrophy in spontaneously hypertensive rats (SHR).Methods and Results. SHR were randomly assigned into sedentary and swimming-trained groups. Sedentary SHR displayed cardiac hypertrophy with preserved ventricular function compared to normotensive rats, characterizing a compensated cardiac hypertrophy. Hypertensive rats presented signs of cardiac oxidative stress, depicted by increased lipid peroxidation. However, these changes were not followed by accumulation of lipid peroxidation-generated reactive aldehydes and damaged proteins. This scenario was explained, at least in part, by the increased catalytic activity of both aldehyde dehydrogenase 2 (ALDH2) and proteasome. Of interest, ET exacerbated cardiac hypertrophy, improved ventricular function, induced resting bradycardia, and decreased blood pressure in SHR. These changes were accompanied by reduced cardiac oxidative stress and a consequent decrease in ALDH2 and proteasome activities, without affecting small chaperones levels and apoptosis in SHR.Conclusion. Increased cardiac ALDH2 and proteasomal activities counteract the deleterious effect of excessive oxidative stress in hypertension-induced compensated cardiac hypertrophy in rats. ET has a positive effect in reducing cardiac oxidative stress without affecting protein quality control.
Molecular Mechanoneurobiology: An Emerging Angle to Explore Neural Synaptic Functions
Authors: Hu Wei , An Chenyi , Chen Wei J.
Published: April 2015

Neural synapses are intercellular asymmetrical junctions that transmit biochemical and biophysical information between a neuron and a target cell. They are very tight, dynamic, and well organized by many synaptic adhesion molecules, signaling receptors, ion channels, and their associated cytoskeleton that bear forces. Mechanical forces have been an emerging factor in regulating axon guidance and growth, synapse formation and plasticity in physiological and pathological brain activity. Therefore, mechanical forces are undoubtedly exerted on those synaptic molecules and modulate their functions. Here we review current progress on how mechanical forces regulate receptor-ligand interactions, protein conformations, ion channels activation, and cytoskeleton dynamics and discuss how these regulations potentially affect synapse formation, stabilization, and plasticity.
Stochastic Phenomena in One-Dimensional Rulkov Model of Neuronal Dynamics
Authors: Bashkirtseva Irina
Published: April 2015

We study the nonlinear Rulkov map-based neuron model forced by random disturbances. For this model, an overview of the variety of stochastic regimes is given. For the parametric analysis of these regimes, the stochastic sensitivity functions technique is used. In a period-doubling zone, we analyze backward stochastic bifurcations modelling changes of modality of noisy neuron spiking. Noise-induced transitions in a zone of bistability are considered. It is shown how such random transitions can generate a new neuronal regime of the stochastic bursting and transfer the system from order to chaos. A transient zone of values of noise intensity corresponding to the onset of noise-induced bursting and chaotization is localized by the stochastic sensitivity functions technique.