bluuebunny/crossref_metadata_2025 huggingface dataset:
Walking at non‐constant speeds: mechanical work, pendular transduction, and energy congruity
Authors: Balbinot G.
Published: February 2016

Although almost half of all walking bouts in urban environments consist of less than 12 consecutive steps and several day‐to‐day gait activities contain transient gait responses, in most studies gait analysis is performed at steady‐state. This study aimed to analyze external (Wext) and internal mechanical work (Wint), pendulum‐like mechanics, and elastic energy usage during constant and non‐constant speeds. The mechanical work, pendular transduction, and energy congruity (an estimate of storage and release of elastic energy) during walking were computed using two force platforms. We found that during accelerating gait (+NCS) energy recovery is maintained, besides extra W+ext, for decelerating gait (−NCS) poor energy recovery was counterbalanced by W−ext and C% predominance. We report an increase in elastic energy usage with speed (4–11%). Both W−ext and %C suggests that elastic energy usage is higher at faster speeds and related to −NCS (≈20% of elastic energy usage). This study was the first to show evidences of elastic energy usage during constant and non‐constant speeds.
An Ever Closer Union? The Nationalisation of Political Parties in Switzerland, 1991–2015
Authors: Bochsler Daniel , Mueller Sean , Bernauer Julian
Published: February 2016

The contribution of this research note is a systematic description of levels of party nationalisation in Switzerland, using results from the elections to the Swiss National Council between 1991 and 2015. Party nationalisation is understood as the territorial homogeneity of a party's electoral performance and measured using the inverted and standardised Gini index. Our results indicate a trend towards more nationalisation in the Swiss party system over the time period covered, and distinct patterns for single parties. The SVP and the GLP have made big leaps towards stronger nationalisation, with the former closing in on the levels of the SP and the FDP, while the CVP remains a weakly nationalised party, considering its size.
Campaign Strategies in the 2015 Swiss National Elections: Nationalization, Coordination, and Personalization
Authors: Bühlmann Marc , Zumbach David , Gerber Marlène
Published: February 2016

This research note examines parties' campaign strategies in the 2015 Swiss elections. We base our analyses on a collection of more than 5000 party advertisements, which were published in the forefront of the national elections in more than 50 daily and weekly national and cantonal print media. By comparing the amount of party and candidate ads, as well as the content and nature of the political advertisements, we explore the degree of professionalization of electoral campaigns in the most recent federal elections in terms of nationalization, coordination and personalization. First results show that although national campaign coordination exists, Swiss elections are to a considerable extent still cantonal and personal affairs.
Identification of a novel HLA‐C allele, HLA‐C*03:313, in a Japanese individual
Authors: Suzuki S. , Sato T. , Akatsuka H. , Kimura M. , Shiina T.
Published: February 2016

HLA‐C*03:313 differs from HLA‐C*03:04:01:01 by one non‐synonymous amino acid exchange E161G.
A novel HLA‐B*15 allele, HLA‐B*15:326, was identified in a Chinese bone marrow donor
Authors: Chen N.‐Y. , Zhang W. , He J.‐J. , He J. , Zhu F.‐M.
Published: February 2016

HLA‐B*15:326 has one base substitution at position 176G>A in exon 2 compared with HLA‐B*15:01:01:01.
Two novel HLA‐A alleles: A*24:258 and A*24:305 were identified in Chinese individuals
Authors: He J.‐J. , Chen N.‐Y. , Dong L.‐N. , He J. , Zhu F.‐M.
Published: February 2016

Both HLA‐A*24:258 and HLA‐A*24:305 differ from HLA‐A*24:01:01:01 by single nucleotide substitutions.
Identification of a novel HLA‐B*54:34 allele by polymerase chain reaction sequence‐based typing in a Chinese leukemia patient
Authors: Han Z.‐D. , Dong L‐N. , Wang W. , He J. , Zhu F.‐M.
Published: February 2016

HLA‐B*54:34 is different from HLA‐A*54:01:01 by a single nucleotide substitution at position 343 G>A.
Blood management after total joint arthroplasty in the United States: 19‐year trend analysis
Authors: Rasouli Mohammad R. , Maltenfort Mitchell G. , Erkocak Omer F. , Austin Mathew S. , Waters Jonathan H. , Parvizi Javad
Published: February 2016

BACKGROUND

Recent studies have failed to show reductions in rates of red blood cell (RBC) transfusion after total joint arthroplasty (TJA) in the United States. This study aims to report the 19‐year trend analysis of blood use in TJA, to determine predictors of RBC transfusion and association between RBC transfusion and in‐hospital mortality after TJA using a nationally representative database.

STUDY DESIGN AND METHODS

Nationwide inpatient sample (NIS) data from 1993 to 2011 were used. ICD‐9‐CM codes were used to identify TJA cases, RBC transfusion, autologous blood transfusion, and/or transfusion from cell salvage. Logistic regression analysis was performed to determine predictors of RBC transfusion and if transfusion increases risk of in‐hospital mortality.

RESULTS

A total of 2,225,054 TJA cases were identified. Using multivariate analysis, there was an increase in the rate of RBC transfusion over the study period (odds ratio [OR], 1.049; 95% confidence interval [CI], 1.048‐1.050; p < 0.001). One‐stage bilateral TJA (OR, 3.30; 95% CI, 3.24‐3.37; p < 0.001), anemia due to chronic blood loss (OR, 2.69; 95% CI, 2.59‐2.74, p < 0.001), deficiency anemia (OR, 2.59; 95% CI, 2.56‐2.62; p < 0.001), and Charlson comorbidity index (OR, 1.24; 95% CI, 1.23‐1.24; p < 0.001) were independent predictors of allogeneic blood transfusion. Transfusion of autologous blood reduced need for RBC transfusion (OR, 0.84; 95% CI, 0.82‐0.85; p < 0.001). RBC transfusion was an independent predictor of in‐hospital mortality (OR, 1.537; 95% CI, 1.395‐1.694; p < 0.001).

CONCLUSION

An increase in the rate of RBC use after TJA and the association between allogeneic blood transfusion and mortality are worrisome. Implementing more effective blood conservation strategies is recommended.
Comparison of Strain Rosettes and Digital Image Correlation for Measuring Vertebral Body Strain
Authors: Gustafson Hannah , Siegmund Gunter , Cripton Peter
Published: February 2016

Strain gages are commonly used to measure bone strain, but only provide strain at a single location. Digital image correlation (DIC) is an optical technique that provides the displacement, and therefore strain, over an entire region of interest on the bone surface. This study compares vertebral body strains measured using strain gages and DIC. The anterior surfaces of 15 cadaveric porcine vertebrae were prepared with a strain rosette and a speckled paint pattern for DIC. The vertebrae were loaded in compression with a materials testing machine, and two high-resolution cameras were used to image the anterior surface of the bones. The mean noise levels for the strain rosette and DIC were 1 με and 24 με, respectively. Bland–Altman analysis was used to compare strain from the DIC and rosette (excluding 44% of trials with some evidence of strain rosette failure or debonding); the mean difference ± 2 standard deviations (SDs) was −108 με ± 702 με for the minimum (compressive) principal strain and −53 με ± 332 με for the maximum (tensile) principal strain. Although the DIC has higher noise, it avoids the relatively high risk we observed of strain gage debonding. These results can be used to develop guidelines for selecting a method to measure strain on bone.
Classroom Journal Club: Collaborative Study of Contemporary Primary Literature in the Biomechanics Classroom
Authors: Kuxhaus Laurel , Corbiere Nicole C.
Published: February 2016

Current engineering pedagogy primarily focuses on developing technical proficiency and problem solving skills; the peer-review process for sharing new research results is often overlooked. The use of a collaborative classroom journal club can engage students with the excitement of scientific discovery and the process of dissemination of research results, which are also important lifelong learning skills. In this work, a classroom journal club was implemented and a survey of student perceptions spanning three student cohorts was collected. In this collaborative learning activity, students regularly chose and discussed a recent biomechanics journal article, and were assessed based on specific, individual preparation tasks. Most student-chosen journal articles were relevant to topics discussed in the regular class lecture. Surveys assessed student perceptions of the activity. The survey responses show that, across all cohorts, students both enjoyed the classroom journal club and recognized it as an important learning experience. Many reported discussing their journal articles with others outside of the classroom, indicating good engagement. The results demonstrate that student engagement with primary literature can foster both technical knowledge and lifelong learning skills.
Unusually Effective Nanofiller a Contradiction of Microfiller-Specific Mechanisms of PTFE Composite Wear Resistance?
Authors: Bhargava Suvrat , Blanchet Thierry A.
Published: February 2016

Wear rates of polytetrafluoroethylene (PTFE) filled with micrometer- and nanometer-sized particles of copper, silicon nitride, and γ-phase alumina were measured under dry sliding conditions using a pin-on-plate tribometer. In their ability to limit the wear rate, micrometer-sized copper particles were found to be better than their nanometer-sized counterparts, though by only small margins, with a 20 wt.% loading of the micrometer-sized copper particles resulting in a tenfold reduction in the wear rate over that of unfilled PTFE. With 10 wt.% loading of micrometer-sized particles of silicon nitride and γ-phase alumina, very low wear rates of ∼5 × 10−7 mm3/N·m and ∼2.5 × 10−7 mm3/N·m, respectively, were measured. Wear rate of unfilled PTFE under the same testing conditions, also measured here, was found to be about 3.6 × 10−4 mm3/N·m. In all the three cases (copper, silicon nitride, and γ-phase alumina), wear resistance was either lost fractionally or completely when the size of the filler particles was reduced from the microscale to a few tens of nanometers, with nanoscale silicon nitride filler resulting in even slightly higher wear rates and larger platelike wear debris than unfilled PTFE. Micrographs of the wear tracks and the generated wear debris seem to indicate that all three filler materials in the form of more effective larger microparticles reduce wear by a common mechanism of interrupting wear debris production and limiting wear debris size, further supporting Tanaka and Kawakami's 1982 proposal of a broad general mechanism of PTFE wear reduction by filler particles having at least a requisite microscale size. Recent reports of extreme PTFE wear resistance imparted by few limited nanofiller particles appear to be reflective of an additional wear reduction mechanism they may specifically possess, rather than a contradiction of previously proposed microparticle wear reduction mechanisms.
On Constitutive Relations for Friction From Thermodynamics and Dynamics
Authors: Bryant Michael D.
Published: February 2016

Constitutive and dynamic relations for friction coefficient are presented. A first thrust combines the laws of thermodynamics to relate heat, energy, matter, entropy, and work of forces. The equation sums multiple terms—each with a differential of a variable multiplied by a coefficient—to zero. Thermodynamic considerations suggest that two variables, internal energy and entropy production, must depend on the others. Linear independence of differentials renders equations that yield thermodynamic quantities, properties, and forces as functions of internal energy and entropy production. When applied to a tribocontrol volume, constitutive laws for normal and friction forces, and coefficient of friction are derived and specialized for static and kinetic coefficients of friction. A second thrust formulates dynamics of sliding, with friction coefficient and slip velocity as state variables. Differential equations derived via Newton's laws for velocity and the degradation entropy generation (DEG) theorem for friction coefficient model changes to the sliding interface induced by friction dissipation. The solution suggests that the transition from static to kinetic coefficient of friction with respect to slip velocity for lubricant starved sliding is a property of the motion dynamics of sliding interacting with the dynamics of change of the surface morphology. Finally, sliding with stick-slip was simulated to compare this model to others.
Optimized Design of a Large Reversible Thrust Bearing
Authors: Ettles Chris M. , López Guillermo D. , Borgna Hugo
Published: February 2016

The thrust bearing duty in a pump-turbine generator can be quite arduous, since the pad support system must be symmetrical about the center of the pad, yet the oil-film must converge adequately for either direction of rotation. Special care must be taken with large machines since the thermal and elastic deformation of the pads will increase nonlinearly with size B of the pad, for example, as B2 when thermal deformation is considered. However from first principles, the thickness of the oil film will increase with only the square root of size B½. Poorly shaped films can develop when a design standard is scaled-up to larger sizes. Three options for the thrust bearing design of a particular pump-turbine were considered: (a) “semihard” supports for the pads such as a spring-disk insert, (b) “piston-type” supports in the back of the pads, which are machined to form shallow pistons that fit into recesses, allowing the pads to be supported hydrostatically, and (c) a symmetric arrangement of coil springs. In this instance, an upper limit of thrust bearing temperature was specified. Penalties would incur if this were exceeded. It is shown using a design code (GENMAT) that the best performance is achieved with a spring support (option c), arranged to give a convex film shape in the direction of sliding, and a slightly concave film in the radial direction. This is achieved by limiting the extent of the spring pack in the circumferential direction so that there are unsupported “overhangs” at the lead and trail edges. The radial concavity is arranged by having the spring pack extend edge-to-edge in the radial direction. The bearing has performed very well since commissioning. The original machining patterns are untouched after thousands of reversals under load. The pads appear as new.
Why isn't Contrast Enhanced Ultrasound for Focal Liver Lesions used more in daily practice?
Authors: Sporea Ioan
Published: February 2016

.
Usefulness of ultrasound for the diagnosis of dermatofibroma
Authors: Zarchi Kian , Kromann Charles B. , Wortsman Ximena , Jemec Gregor B.E.
Published: February 2016

.
Diagnostic imaging findings of pelvic retroperitoneal ganglioneuroma in a child: a case report with the emphasis on initial ultrasound findings
Authors: Mut Deniz Turkyılmaz , Soylemez Umut Percem Orhan , Demir Mesut , Tanık Canan , Ozel Alper
Published: February 2016

Ganglioneuromas are rare benign tumors of neural crest origin developed along the sympathetic chain. The pelvic retroperitoneum is the rarest location of these tumors. Clinically these tumors are commonly asypmtomatic even if they reach large sizes. Here we report the radiological features of a 16 year old boy with pathologically proven retroperitoneal ganglioneuroma that was detected initially by ultrasound. Relevant literature is also discussed.
Feasibility of Transient Elastography with M and XL probes in real life
Authors: Sporea Ioan , Șirli Roxana , Mare Ruxandra , Popescu Alina , Ivașcu Siegfried Cristian
Published: February 2016

Aim: Reliable liver stiffness measurement (RLSM) using Transient Elastography (TE) with the standard M probe are difficult to obtain in overweight (BMI≥25kg/m2) and obese (BMI>30kg/m2) patients. The aim of our paper was to assess the feasibility of TE in daily practice using both M and XL probes. Material and method: We studied retrospectively 3235 patients with chronic liver disease assessed by TE first by the M probe (standard probe – transducer frequency 3.5 MHz), and if the measurements were unreliable, with the XL probe (transducer frequency 2.5 MHz). Reliable measurements were defined as the median of 10 valid measurements with a success rate ≥ 60% and an interquartile range < 30%. Results of liver elasticity were expressed in kiloPascals (kPa). Results: RLSM by M probe were obtained in 62.2% (2015/3235) patients, and by XL probe in 1011/1220 (80%) of patients with unreliable measurements by M probe; thus we obtained RLSM in 93.5% of 3235 cases.In overweight patients we obtained RLSM in 89.9% (1039/1156) cases: in 63.1% (729) by M probe and in 26.8% (310) by XL probe. In obese patients we obtained RLSM in 83.8% (746/890):  in 18.4% (164) by M probe and in 65.4% (582) by XL probe. Thus, by using both probes, RLSM were obtained in 1785 (87.2%) of overweight and obese patients. Conclusion: The feasibility of the M probe was 62.2% in our Department. Reliable measurements using M or XL probe allowed the evaluation of liver stiffness in 93.5% of cases. By using both M and XL probes, reliable LSM by TE can be obtained in the majority of obese and overweight patients (87.2%).
Photonic biosensor based on photocorrosion of GaAs/AlGaAs quantum heterostructures for detection of Legionella pneumophila
Authors: Aziziyan Mohammad R. , Hassen Walid M. , Morris Denis , Frost Eric H. , Dubowski Jan J.
Published: February 2016

Photocorrosion of semiconductors is strongly sensitive to the presence of surface states, and it could be influenced by electrically charged molecules immobilized near the semiconductor/electrolyte interface. The underlying mechanism is related to band bending of the semiconductor structure near the surface and the associated distribution of excited electrons and holes. The authors have employed photoluminescence of GaAs/AlGaAs quantum heterostructures for monitoring in situ the photocorrosion effect, and demonstrating detection of nongrowing Legionella pneumophila suspended in phosphate buffered saline solution. Antibody functionalized samples allowed direct detection of these bacteria at 104 bacteria/ml. The authors discuss the sensitivity of the process related to the ability of creating conditions suitable for photocorrosion proceeding at extremely slow rates and the interaction of an electric charge of bacteria with the surface of a biofunctionalized semiconductor.
Slippery when sticky: Lubricating properties of thin films of Taxus baccata aril mucilage
Authors: Røn Troels , Rishikesan Sankaranarayanan , Chronakis Ioannis S. , Lee Seunghwan
Published: February 2016

Mucilage is hydrogel produced from succulent plants and microorganisms displaying unique adhesiveness and slipperiness simultaneously. The objective of this study is to establish an understanding on the lubricating mechanisms of the mucilage from Taxus baccata aril as thin, viscous lubricant films. Oscillation and flow rheological studies revealed that T. baccata mucilage is shear-thinning, thixotropic, and weak hydrogel that is highly stretchable under shear stress due to its high density physical crosslinking characteristics. In addition, T. baccata mucilage showed a distinct Weissenberg effect, i.e., increasing normal force with increasing shear rate, and thus it contributes to deplete the lubricant from tribological interfaces. Lubrication studies with a number of tribopairs with varying mechanical properties and surface wettability have shown that the lubricity of T. baccata mucilage is most effectively manifested at soft, hydrophilic, and rolling tribological contacts. Based on tenacious spreading on highly wetting surfaces, slip plane can be formed within mucilage hydrogel network even when the lubricating films cannot completely separate the opposing surfaces. Moreover, highly stretchable characteristics of mucilage under high shear enhance smooth shearing of two opposing surfaces as lubricating film.
Previously undiagnosed fatal familial haemophagocytic lymphohistiocytosis in a 24-year-old woman
Authors: Barmettler Sara , Nowak Richard J , Parker Terri , Price Christina
Published: February 2016

We present a case of a 24-year-old woman with previously undiagnosed familial haemophagocytic lymphohistiocytosis (HLH). The patient presented with fevers and cough and was found to have pancytopaenia. She underwent an extensive work up and initially met only 3 of 8 criteria for HLH. Owing to high clinical suspicion, soluble CD25 level was sent and HLH2004 protocol initiated. The soluble CD25 level returned elevated with other laboratory work and the patient met criteria for diagnosis of HLH. Genetic studies revealed a homozygous mutation in PRF1 with absent perforin in cytotoxic cells, consistent with familial HLH. The patient expired before intrathecal chemotherapy could be initiated. This case illustrates the potential for familial HLH to present at an older age, and highlights the importance of early recognition and initiation of treatment of HLH, as patients may not initially fulfil the diagnostic criteria for HLH, and mortality is high if left untreated.
Unsteady flow over an expanding cylinder in a nanofluid containing gyrotactic microorganisms
Authors: Chen Hui , Liang Hongxing , Xiao Tianli , Du Heng , Shen Ming
Published: February 2016

In this paper, an analysis is made for the unsteady flow due to an expanding cylinder in a nanofluid that contains both nanoparticles and gyrotactic microoganisms with suction. The nonlinear system of partial differential equations is transformed into high-order nonlinear ordinary differential equations using similarity transformations, and then solved numerically using a shooting method with fourth-fifth-order Runge–Kutta integration technique. The influences of significant physical parameters on the distributions of the velocity, temperature, nanoparticle volume fraction, as well as the density of motile microorganisms are graphically presented and discussed in detail. It is found that dual solutions exist for both stretching and shrinking cases and the range of dual solutions increases with the strength of the expansion. The results also indicate that larger bioconvection Peclet number and smaller Schmidt number lead to an increased concentration of microorganisms and thicker boundary layer thickness.
Thermodynamic descriptions of polytropic gas and its viscous type as dark energy candidates
Authors: Moradpour Hooman , Sabet Mohammad-Taghi Mohammadi
Published: February 2016

In this paper, at first, we focus on a Friedmann–Robertson–Walker (FRW) universe in which the dark energy candidate satisfies the polytropic equation of state and study thermodynamics of dark energy. Bearing the thermal fluctuation theorem in mind, we establish a relation between the thermal fluctuation of the system and mutual interaction between the dark energy and dark matter. Generalization to a viscous polytropic gas is also investigated. We point to a condition for decaying the dark energy candidate into the dark matter needed for alleviating the coincidence problem. The effects of dark energy candidates and their interactions with other parts of the cosmos on the horizon entropy as well as the second law of thermodynamics are also addressed. Our study suggests a correction term besides the Bekenstein entropy, which carries the information of the dark energy candidate, its interaction with other parts of the cosmos, and its viscosity.
Extrapolating from Limited Uncertain Information in Large-Scale Combinatorial Optimization Problems to Obtain Robust Solutions
Authors: Climent Laura , Wallace Richard J. , O'Sullivan Barry , Freuder Eugene C.
Published: February 2016

Data uncertainty in real-life problems is a current challenge in many areas, including Operations Research (OR) and Constraint Programming (CP). This is especially true given the continual and accelerating increase in the amount of data associated with real-life problems, to which Large Scale Combinatorial Optimization (LSCO) techniques may be applied. Although data uncertainty has been studied extensively in the literature, many approaches do not take into account the partial or complete lack of information about uncertainty in real-life settings. To meet this challenge, in this paper we present a strategy for extrapolating data from limited uncertain information to ensure a certain level of robustness in the solutions obtained. Our approach is motivated and evaluated with real-world applications of harvesting and supplying timber from forests to mills and the well known knapsack problem with uncertainty.
Automorphisms of braid groups on orientable surfaces
Authors: An Byung Hee
Published: February 2016

In this paper, we compute the automorphism groups [Formula: see text] and [Formula: see text] of braid groups [Formula: see text] and [Formula: see text] on every orientable surface [Formula: see text], which are isomorphic to group extensions of the extended mapping class group [Formula: see text] by the transvection subgroup except for a few cases. We also prove that [Formula: see text] is always a characteristic subgroup of [Formula: see text], unless [Formula: see text] is a twice-punctured sphere and [Formula: see text].
Computational characterization of the all-atom structure and the calcium binding sites of the LH1–RC core complex fromThermochromatium tepidum
Authors: Khrenova M. G. , Grigorenko B. L. , Zhang J.-P. , Wang P. , Nemukhin A. V.
Published: February 2016

The all-atom model of the photosynthetic core complex composed of the light-harvesting system (LH1) and the reaction center (RC) from a thermophilic purple bacterium Thermochromatium tepidum is constructed. We compare the structural parameters of this complex embedded into the lipid bilayer to those reported for the recently resolved crystal structure of the LH1–RC. We focus on the local structure of the binding sites of the calcium ions regulating stability and optical spectra of the core complex. We show the differences between the computationally derived model and the crystal structure at the extramembrane region of the LH1 polypeptides where the calcium binding sites are located.
Stability assessment of QKD procedures in commercial quantum cryptography systems versus quality of dark channel
Authors: Jacak Monika , Melniczuk Damian , Jacak Janusz , Jóźwiak Ireneusz , Gruber Jacek , Jóźwiak Piotr
Published: February 2016

In order to assess the susceptibility of the quantum key distribution (QKD) systems to the hacking attack including simultaneous and frequent system self-decalibrations, we analyze the stability of the QKD transmission organized in two commercially available systems. The first one employs non-entangled photons as flying qubits in the dark quantum channel for communication whereas the second one utilizes the entangled photon pairs to secretly share the cryptographic key. Applying standard methods of the statistical data analysis to the characteristic indicators of the quality of the QKD communication (the raw key exchange rate [RKER] and the quantum bit error rate [QBER]), we have estimated the pace of the self-decalibration of both systems and the repeatability rate in the case of controlled worsening of the dark channel quality.
Study on a noninvasive method for rapid screening Human Serum albumin injectables by Raman spectroscopy
Authors: Zhao Yu , Ji Nan , Li Xiuji , Hou Jifeng , Li Min , Yang Yongjian , Tian Ping , Sun Xinmei , Xiao Xinyue , Yin Lihui
Published: February 2016

Human serum albumin (HSA) injectable product is a severely afflicted area on drug safety due to its high price and restricted supply. Raman spectroscopy performances high specificity on HSA detection and it is even possible to determine HSA injectable products noninvasively. In this study, we developed a noninvasive rapid screening method for of HSA injectable products by using portable Raman spectrometer. Qualitative models were established by using principal component analysis combined with classical least squares (PCA-CLS) algorithm, while quantitative model was established by using partial least squares (PLS) algorithm. Model transfer in different instruments of both the same and different apparatus modules was further discussed in this paper. A total of 34 HSA injectable samples collected from markets were used for verification. The identification results showed 100% accuracy and the predicted concentrations of those identified as true HSA were consistent with their labeled concentrations. The quantitative results also indicated that model transfer was excellent in the same apparatus modules of Raman spectrometer at all concentration levels, and still good enough in the different apparatus modules although the relative standard deviation (RSD) value showed a little increasing trend at low HSA concentration level. In conclusion, the method was proved to be feasible and efficient for screening HSA injections, especially on its screening speed and the consideration of glass containers. Moreover, with inspiring results on the model transfer, the method could be used as a universal screening mean to different Raman instruments.
PPAR Agonists and 3D Alginate Encapsulation Accelerate Oligodendrocyte Differentiation of Mouse Embryonic Stem Cells
Authors: Dollé Jean-Pierre , Schloss Rene S. , Yarmush Martin L.
Published: February 2016

Cellular replacement therapies for myelin disorders require large numbers of cells and relatively mature oligodendrocytes. Oligodendrocyte differentiation from a pluripotent state often involves long protracted protocols. In this study, we investigated the effect that activation of peroxisome proliferator activator receptors (PPAR) alpha, delta and gamma would have on oligodendrocyte differentiation of mouse embryonic stem (mES) cells. Using a two-dimensional (2D) differentiation platform, oligodendrocyte differentiation stalled at the immature oligodendrocyte stage, i.e., CNPase positive cells. When PPAR agonists for alpha, delta and gamma were added, oligodendrocyte differentiation was accelerated with higher numbers of O1 and CNPase positive cells being detected. PPAR agonist addition also resulted in phenotypic changes with alpha agonist addition resulting in an increase in process length compared to control with some increased secondary branching, delta agonist addition resulted in longer primary process length, and gamma agonist addition resulted in a larger cell soma and more tertiary branching patterns. Placing mES cells into a three-dimensional (3D) alginate nanoporous microcapsule environment, we were able to further mature cells to a myelin basic protein (MBP) expressing stage. The exposure of cells to PPAR agonists within the alginate microcapsules resulted in accelerated maturation with PPAR delta in particular showing a sustained high expression of MBP. The combined effect of PPAR activation in a 3D environment demonstrates a relatively simple and efficient method to differentiate mES cells into mature oligodendrocytes.
Impossibility Results for Truthful Combinatorial Auctions with Submodular Valuations
Authors: Dobzinski Shahar , Vondrák Jan
Published: February 2016

A long-standing open question in algorithmic mechanism design is whether there exist computationally efficient truthful mechanisms for combinatorial auctions, with performance guarantees close to those possible without considerations of truthfulness. In this article, we answer this question negatively: the requirement of truthfulness can impact dramatically the ability of a mechanism to achieve a good approximation ratio for combinatorial auctions.

More precisely, we show that every universally truthful randomized mechanism for combinatorial auctions with submodular valuations that approximates optimal social welfare within a factor of
m
1/2−ϵ
must use exponentially many value queries, where
m
is the number of items. Furthermore, we show that there exists a class of succinctly represented submodular valuation functions, for which the existence of a universally truthful polynomial-time mechanism that provides an
m
1/2−ϵ
-approximation would imply
NP
=
RP
. In contrast, ignoring truthfulness, there exist constant-factor approximation algorithms for this problem, and ignoring computational efficiency, the VCG mechanism is truthful and provides optimal social welfare. These are the first hardness results for truthful polynomial-time mechanisms for any type of combinatorial auctions, even for deterministic mechanisms.

Our approach is based on a novel
direct hardness
technique that completely skips the notoriously hard step of characterizing truthful mechanisms. The characterization step was the main obstacle for proving impossibility results in algorithmic mechanism design so far.
Feasibility of Fork-Join Real-Time Task Graph Models
Authors: Sun Jinghao , Guan Nan , Wang Yang , Deng Qingxu , Zeng Peng , Yi Wang
Published: February 2016

In the formal analysis of real-time systems, modeling of branching codes and modeling of intratask parallelism structures are two of the most important research topics. These two real-time properties are combined, resulting in the fork-join real-time task (FJRT) model, which extends the digraph-based task model with forking and joining semantics. We prove that the EDF schedulability problem on a preemptive uniprocessor for the FJRT model is coNP-hard in the strong sense, even if the utilization of the task system is bounded by a constant strictly less than 1. Then, we show that the problem becomes tractable with some slight structural restrictions on parallel sections, for which we propose an exact schedulability test with pseudo-polynomial time complexity. Our results thus establish a borderline between the tractable and intractable FJRT models.
Constructing Maintainable Semantic Relation Network from Ambiguous Concepts in Web Content
Authors: Leung Kenneth Wai-Ting , Jiang Di , Lee Dik Lun , Ng Wilfred
Published: February 2016

The semantic network is a form of knowledge that represents various relationships between concepts with ambiguity. The knowledge can be employed to identify semantically related objects. It helps, for example, a recommender system to generate effective recommendations to the users. We propose to study a new semantic network, namely, the
Concept Relation Network (CRN)
, which is efficiently constructed and maintained using existing web search engines. CRN tackles the uncertainty and dynamics of web content, and thus is optimized for many important web applications, such as social networks and search engines. It is a large semantic network for the collection, analysis, and interpretation of web content, and serves as a cornerstone for applications such as web search engines, recommendation systems, and social networks that can benefit from a large-scale knowledge base. In this article, we present two applications for CRN: (1) search engine and web analytic and (2) semantic information retrieval. Experimental results show that CRN effectively enhances these applications by considering the heterogenous and polysemous nature of web content.
Do Anesthesiologists Know What They Are Doing? Mining a Surgical Time-Series Database to Correlate Expert Assessment with Outcomes
Authors: Myers Risa B. , Frenzel MD John C. , Ruiz Md Joseph R. , Jermaine Christopher M.
Published: February 2016

Anesthesiologists are taught to carefully manage patient vital signs during surgery. Unfortunately, there is little empirical evidence that vital sign management, as currently practiced, is correlated with patient outcomes. We seek to validate or repudiate current clinical practice and determine whether or not clinician evaluation of surgical vital signs correlate with outcomes. Using a database of over 90,000 cases, we attempt to determine whether those cases that anesthesiologists would subjectively decide are “low quality” are more likely to result in negative outcomes. The problem reduces to one of multi-dimensional time-series classification. Our approach is to have a set of expert anesthesiologists independently label a small number of training cases, from which we build classifiers and label all 90,000 cases. We then use the labeling to search for correlation with outcomes and compare the prevalence of important 30-day outcomes between providers.

To mimic the providers’ quality labels, we consider several standard classification methods, such as dynamic time warping in conjunction with a kNN classifier, as well as complexity invariant distance, and a regression based upon the feature extraction methods outlined by Mao et al. 2012 (using features such as time-series mean, standard deviation, skew, etc.). We also propose a new feature selection mechanism that learns a hidden Markov model to segment the time series; the fraction of time that each series spends in each state is used to label the series using a regression-based classifier. In the end, we obtain strong, empirical evidence that current best practice is correlated with reduced negative patient outcomes. We also learn that all of the experts were able to significantly separate cases by outcome, with higher prevalence of negative 30-day outcomes in the cases labeled as “low quality” for almost all of the outcomes investigated.
In defense of programming
Authors: Ben-Ari Mordechai (Moti)
Published: February 2016

We all know that computing is exciting, yet students claim to find programming boring. We try to reassure them that
computing is not just programming
. While this is trivially true, I believe that it overlooks the fundamental place of programming in computing and can lead to adverse effects if pursued too zealously.
TAS-MAC
Authors: Liu Chin-Jung , Huang Pei , Xiao Li
Published: February 2016

Duty cycling improves energy efficiency but limits throughput and introduces significant end-to-end delay in wireless sensor networks. In this article, we present a traffic-adaptive synchronous MAC protocol (TAS-MAC), which is a high-throughput, low-delay MAC protocol tailored for low power consumption. It achieves high throughput by adapting time division multiple access (TDMA) to a novel traffic-adaptive allocation mechanism that assigns time slots only to nodes located on active routes. TAS-MAC reduces the end-to-end delay by notifying all nodes on active routes of incoming traffic in advance. These nodes will claim time slots for data transmission and forward a packet through multiple hops in a cycle. The desirable traffic-adaptive feature is achieved by decomposing traffic notification and data-transmission scheduling into two phases, specializing their duties and improving their efficiency, respectively. Simulation results and experiments on TelosB motes demonstrate that the two-phase design significantly improves the throughput of current synchronous MAC protocols and achieves the similar low delay of slot-stealing-assisted TDMA with much lower power consumption.
A Logic-Based Benders Decomposition Approach for Mapping Applications on Heterogeneous Multicore Platforms
Authors: Emeretlis Andreas , Theodoridis George , Alefragis Panayiotis , Voros Nikolaos
Published: February 2016

The development of efficient methods for mapping applications on heterogeneous multicore platforms is a key issue in the field of embedded systems. In this article, a novel approach based on the Logic-Based Benders decomposition principle is introduced for mapping complex applications on these platforms, aiming at optimizing their execution time. To provide optimal solutions for this problem in a short time, a new hybrid model that combines Integer Linear Programming (ILP) and Constraint Programming (CP) models is introduced. Also, to reduce the complexity of the model and its solution time, a set of novel techniques for generating additional constraints called Benders cuts is proposed. An extensive set of experiments has been performed in which synthetic applications described by Directed Acyclic Graphs (DAGs) were mapped to a number of heterogeneous multicore platforms. Moreover, experiments with DAGs that correspond to two real-life applications have also been performed. Based on the experimental results, it is proven that the proposed approach outperforms the pure ILP model in terms of the solution time and quality of the solution. Specifically, the proposed approach is able to find an optimal solution within a time limit of 2 hours in the vast majority of performed experiments, while the pure ILP model fails. Also, for the cases where both methods fail to find an optimal solution within the time limit, the solution of the proposed approach is systematically better than the solution of the ILP model.
Parameterized Verification of Asynchronous Shared-Memory Systems
Authors: Esparza Javier , Ganty Pierre , Majumdar Rupak
Published: February 2016

We characterize the complexity of the safety verification problem for parameterized systems consisting of a leader process and arbitrarily many anonymous and identical contributors. Processes communicate through a shared, bounded-value register. While each operation on the register is atomic, there is no synchronization primitive to execute a sequence of operations atomically.

We analyze the complexity of the safety verification problem when processes are modeled by finite-state machines, pushdown machines, and Turing machines. The problem is coNP-complete when all processes are finite-state machines, and is PSPACE-complete when they are pushdown machines. The complexity remains coNP-complete when each Turing machine is allowed boundedly many interactions with the register. Our proofs use combinatorial characterizations of computations in the model, and in the case of pushdown systems, some language-theoretic constructions of independent interest. Our results are surprising, because parameterized verification problems on slight variations of our model are known to be undecidable. For example, the problem is undecidable for finite-state machines operating with synchronization primitives, and already for two communicating pushdown machines. Thus, our results show that a robust, decidable class can be obtained under the assumptions of anonymity and asynchrony.
Fairy Lights in Femtoseconds
Authors: Ochiai Yoichi , Kumagai Kota , Hoshi Takayuki , Rekimoto Jun , Hasegawa Satoshi , Hayasaki Yoshio
Published: February 2016

We present a method of rendering aerial and volumetric graphics using femtosecond lasers. A high-intensity laser excites physical matter to emit light at an arbitrary three-dimensional position. Popular applications can thus be explored, especially because plasma induced by a femtosecond laser is less harmful than that generated by a nanosecond laser. There are two methods of rendering graphics with a femtosecond laser in air: producing holograms using spatial light modulation technology and scanning of a laser beam by a galvano mirror. The holograms and workspace of the system proposed here occupy a volume of up to 1 cm
3
; however, this size is scalable depending on the optical devices and their setup. This article provides details of the principles, system setup, and experimental evaluation, and discusses the scalability, design space, and applications of this system. We tested two laser sources: an adjustable (30--100fs) laser that projects up to 1,000 pulses/s at an energy of up to 7mJ/pulse and a 269fs laser that projects up to 200,000 pulses/s at an energy of up to 50μJ/pulse. We confirmed that the spatiotemporal resolution of volumetric displays implemented using these laser sources is 4,000 and 200,000 dots/s, respectively. Although we focus on laser-induced plasma in air, the discussion presented here is also applicable to other rendering principles such as fluorescence and microbubbles in solid or liquid materials.
Supporting the Design of Machine Learning Workflows with a Recommendation System
Authors: Jannach Dietmar , Jugovac Michael , Lerche Lukas
Published: February 2016

Machine learning and data analytics tasks in practice require several consecutive processing steps. RapidMiner is a widely used software tool for the development and execution of such analytics workflows. Unlike many other algorithm toolkits, it comprises a visual editor that allows the user to design processes on a conceptual level. This conceptual and visual approach helps the user to abstract from the technical details during the development phase and to retain a focus on the core modeling task. The large set of preimplemented data analysis and machine learning operations available in the tool, as well as their logical dependencies, can, however, be overwhelming in particular for novice users.

In this work, we present an add-on to the RapidMiner framework that supports the user during the modeling phase by recommending additional operations to insert into the currently developed machine learning workflow. First, we propose different recommendation techniques and evaluate them in an offline setting using a pool of several thousand existing workflows. Second, we present the results of a laboratory study, which show that our tool helps users to significantly increase the efficiency of the modeling process. Finally, we report on analyses using data that were collected during the real-world deployment of the plug-in component and compare the results of the live deployment of the tool with the results obtained through an offline analysis and a replay simulation.
Power and Limits of Structural Display Rules
Authors: Ciabattoni Agata , Ramanayake Revantha
Published: February 2016

What can (and cannot) be expressed by structural display rules? Given a display calculus, we present a systematic procedure for transforming axioms into structural rules. The conditions for the procedure are given in terms of (purely syntactic) abstract properties of the base calculus; thus, the method applies to large classes of calculi and logics. If the calculus satisfies certain additional properties, we prove the converse direction, thus characterising the class of axioms that can be captured by structural display rules. Determining if an axiom belongs to this class or not is shown to be decidable. Applied to the display calculus for tense logic, we obtain a new proof of Kracht’s Display Theorem I.
Efficient Flattening Algorithm for Hierarchical and Dynamic Structure Discrete Event Models
Authors: Bae Jang Won , Bae Sang Won , Moon Il-Chul , Kim Tag Gon
Published: February 2016

Discrete event models are widely used to replicate, analyze, and understand complex systems. DEVS (Discrete Event System Specification) formalism enables hierarchical modeling, so it provides an efficiency in the model development of complex models. However, the hierarchical modeling incurs prolonged simulation executions due to indirect event exchanges through the model hierarchy. Although direct event paths are applied to mitigate this overhead, the situation becomes even worse when a model changes its structures during simulation execution, called a dynamic structure model. This article suggests Coupling Relation Graph (CRG) and Strongly Coupled Component (SCC) concepts to improve hierarchical and dynamic structure DEVS simulation execution. CRG is a directed graph representing DEVS model structure, and SCC is a group of connected components in a CRG. Using CRG and SCC, this article presents (1) how to develop CRG from a DEVS model and (2) how to construct and update direct event paths with respect to dynamic structural changes. In particular, compared to the previous works, the proposed method focuses on the reduction of the updating costs for the direct event paths. Through theoretical and empirical analyses, this article shows that the proposed method significantly reduces the simulation execution time, especially when a simulation model contains lots of components and changes its model structures frequently. We expect that the proposed method would support the faster simulation executions of complex hierarchical and dynamic structure models.