bluuebunny/crossref_metadata_2025 huggingface dataset:
Examination of Strategies Fine Arts High School Students Use during the Practice and Learning of Instrumental Music
Authors: Uygun Mehtap Aydıner , Kılınçer Özlem
Published: March 2017

Like every field of learning, it is important to use various strategies in instrumental music to learn it easily and permanently and to attain the skills to learn independently. This requires determining the strategies used by students studying instrument education. The purpose of this study was to examine the strategies fine arts high school students use during the practice and learning of instrumental music. These strategies are the attention, rehearsal, elaboration, articulation-organization and comprehension monitoring strategies. Students’ levels of using practice and learning strategies were examined according to seven variables. The study group consisted of 139 students who were studying at Aksaray, Kayseri, Mersin and Niğde Fine Arts High Schools during the 2015-2016 academic year. The study data was collected using Personal Information Form and Scale for Strategies Used during the Practice and Learning of Instrumental Music. The results showed that students’ levels of elaboration strategies were higher than their levels of articulation-organization strategies. It was also determined that students’ levels of rehearsal and comprehension monitoring strategies were significantly higher than their levels of other strategies. Furthermore, it was found that students’ levels of using practice and learning strategies showed significant differences according to students’ experience, instrument practice duration, how they plan their instrument practice duration, from where they learned the strategy, their academic achievement level on the instrument and the factor motivating them to play instrument variables.
Maternal chronic hypoxia increases expression of genes regulating lung liquid movement and surfactant maturation in male fetuses in late gestation
Authors: McGillick Erin V. , Orgeig Sandra , Allison Beth J. , Brain Kirsty L. , Niu Youguo , Itani Nozomi , Skeffington Katie L. , Kane Andrew D. , Herrera Emilio A. , Giussani Dino A. , Morrison Janna L.
Published: March 2017

Key points

Chronic fetal hypoxaemia is a common pregnancy complication associated with intrauterine growth restriction that may influence respiratory outcome at birth.

We investigated the effect of maternal chronic hypoxia for a month in late gestation on signalling pathways regulating fetal lung maturation and the transition to air‐breathing at birth using isobaric hypoxic chambers without alterations to maternal food intake.

Maternal chronic hypoxia in late gestation increases fetal lung expression of genes regulating hypoxia signalling, lung liquid reabsorption and surfactant maturation, which may be an adaptive response in preparation for the successful transition to air‐breathing at birth.

In contrast to other models of chronic fetal hypoxaemia, late gestation onset fetal hypoxaemia promotes molecular regulation of fetal lung maturation. This suggests a differential effect of timing and duration of fetal chronic hypoxaemia on fetal lung maturation, which supports the heterogeneity observed in respiratory outcomes in newborns following exposure to chronic hypoxaemia in utero.

Chronic fetal hypoxaemia is a common pregnancy complication that may arise from maternal, placental and/or fetal factors. Respiratory outcome of the infant at birth likely depends on the duration, timing and severity of the hypoxaemic insult. We have isolated the effect of maternal chronic hypoxia (MCH) for a month in late gestation on fetal lung development. Pregnant ewes were exposed to normoxia (21% O2) or hypoxia (10% O2) from 105 to 138 days of gestation (term ∼145 days). At 138 days, gene expression in fetal lung tissue was determined by quantitative RT‐PCR. Cortisol concentrations were determined in fetal plasma and lung tissue. Numerical density of surfactant protein positive cells was determined by immunohistochemistry. MCH reduced maternal (106 ± 2.9 vs. 47 ± 2.8 mmHg) and fetal body weight (4.0 ± 0.4 vs. 3.2 ± 0.9 kg). MCH increased fetal lung expression of the anti‐oxidant marker CAT and decreased expression of the pro‐oxidant marker NOX‐4. MCH increased expression of genes regulating hypoxia signalling and feedback (HIF‐3α, KDM3A, SLC2A1, EGLN‐3). There was no effect of MCH on fetal plasma/lung tissue cortisol concentrations, nor genes regulating glucocorticoid signalling (HSD11B‐1, HSD11B‐2, NR3C1, NR3C2). MCH increased expression of genes regulating sodium (SCNN1‐B, ATP1‐A1, ATP1‐B1) and water (AQP‐4) movement in the fetal lung. MCH promoted surfactant maturation (SFTP‐B, SFTP‐D, ABCA3) at the molecular level, but did not alter the numerical density of surfactant positive cells in lung tissue. MCH in late gestation promotes molecular maturation of the fetal lung, which may be an adaptive response in preparation for the successful transition to air‐breathing at birth.
Simulation of Combustion Recession After End-of-Injection at Diesel Engine Conditions
Authors: Jarrahbashi Dorrin , Kim Sayop , Genzale Caroline L.
Published: March 2017

Recent experimental observations show that lifted diesel flames tend to propagate back toward the injector after the end-of-injection (EOI) under conventional high-temperature conditions. The term “combustion recession” has been adopted to reflect this process dominated by “auto-ignition” reactions. This phenomenon is closely linked to the EOI entrainment wave and its impact on the transient mixture–chemistry evolution upstream of the lift-off length. A few studies have explored the physics of combustion recession with experiments and simplified modeling, but the details of the chemical kinetics and convective–diffusive transport of reactive scalars and the capability of engine computational fluid dynamics (CFD) simulations to accurately capture them are mainly unexplored. In this study, highly resolved numerical simulations have been employed to explore the mixing and combustion of a diesel spray after the EOI and the influence of modeling choices on the prediction of these phenomena. The simulations are centered on a temperature sweep around the engine combustion network (ECN) spray-A conditions, from 800 to 1000 K, where different combustion recession behaviors are observed experimentally. Reacting spray simulations are performed via openfoam, using a Reynolds-averaged Navier–Stokes (RANS) approach with a traditional Lagrangian–Eulerian coupled formulation. Two reduced chemical kinetics models for n-dodecane are used to evaluate the impact of low-temperature chemistry and mechanism formulation on predictions of combustion recession behavior. Observations from the numerical simulations are consistent with recent findings that a two-stage auto-ignition sequence drives the combustion recession process. Simulations with two different chemical mechanisms indicate that low-temperature chemistry reactions drive the likelihood of combustion recession.
Rapidly Pulsed Reductants for Diesel NOx Reduction With Lean NOx Traps: Comparison of Alkanes and Alkenes as the Reducing Agent
Authors: Reihani Amin , Patterson Brent , Hoard John , Fisher Galen B. , Theis Joseph R. , Lambert Christine K.
Published: March 2017

Lean NOx traps (LNTs) are often used to reduce NOx on smaller diesel passenger cars where urea-based selective catalytic reduction (SCR) systems may be difficult to package. However, the performance of LNTs at temperatures above 400 °C needs to be improved. Rapidly pulsed reductants (RPR) is a process in which hydrocarbons are injected in rapid pulses ahead of the LNT in order to improve its performance at higher temperatures and space velocities. This approach was developed by Toyota and was originally called Di-Air (diesel NOx aftertreatment by adsorbed intermediate reductants) (Bisaiji et al., 2011, “Development of Di-Air—A New Diesel deNOx System by Adsorbed Intermediate Reductants,” SAE Int. J. Fuels Lubr., 5(1), pp. 380–388). Four important parameters were identified to maximize NOx conversion while minimizing fuel penalty associated with hydrocarbon injections in RPR operation: (1) flow field and reductant mixing uniformity, (2) pulsing parameters including the pulse frequency, duty cycle, and magnitude, (3) reductant type, and (4) catalyst composition, including the type and loading of precious metal and NOx storage material, and the amount of oxygen storage capacity (OSC). In this study, RPR performance was assessed between 150 °C and 650 °C with several reductants including dodecane, propane, ethylene, propylene, H2, and CO. Under RPR conditions, H2, CO, C12H26, and C2H4 provided approximately 80% NOx conversion at 500 °C; however, at 600 °C the conversions were significantly lower. The NOx conversion with C3H8 was low across the entire temperature range. In contrast, C3H6 provided greater than 90% NOx conversion over a broad range of 280–630 °C. This suggested that the high-temperature NOx conversion with RPR improves as the reactivity of the hydrocarbon increases.
Filtering Mixing Planes for Low Reduced Frequency Analysis of Turbomachines
Authors: Pullan G. , Adamczyk J. J.
Published: March 2017

A class of problems in turbomachinery is characterized by unsteady interactions at low reduced frequencies. These interactions are often the result of perturbations with length-scale on the order of the machine circumference and examples include axial compressors operating with inlet distortion, fans with downstream pylons, and turbine rotors downstream of midframe struts. Typically, this unsteadiness is accompanied by higher frequency fluctuations caused by perturbations with a length-scale on the order of a blade pitch. Conventional numerical analysis of this class of problem requires computations with a time step governed by the high-frequency content but a greatly reduced run time could be achieved if the time step was dictated solely by the low reduced frequency, long length-scale, interaction of interest. In this paper, a filtering mixing plane technique is proposed that removes unwanted short length-scale perturbations at the interfaces between blade rows. This approach gives the user control over the amount of mixing that occurs at these interfaces with the limits being fully mixed-out to pitchwise uniformity (conventional mixing plane) or no mixing (conventional sliding plane). By choosing to retain only enough harmonics to resolve the low reduced frequency interaction of interest, an order of magnitude reduction in run time can be achieved.
Effect of Reynolds Number, Hole Patterns, and Target Plate Thickness on the Cooling Performance of an Impinging Jet Array—Part II: Conjugate Heat Transfer Results and Optimization
Authors: Li Weihong , Yang Li , Li Xueying , Ren Jing , Jiang Hongde
Published: March 2017

This study comprehensively illustrates the effect of Reynolds number, hole spacing, nozzle-to-target distance, and target plate thickness on the conjugate heat transfer (CHT) performance of an impinging jet array. Test models are composed of a specific thermal-conductivity material which exerts a matched model Biot number to that of engine condition. High-resolution temperature measurements are conducted on the impinging-target plate utilizing steady liquid crystal (SLC) with Reynolds numbers ranging from 5000 to 27,500. Different streamwise and spanwise jet-to-jet spacing (i.e., X/D and Y/D: 4–8), nozzle-to-target plate distance (Z/D: 0.75–3), and target plate thickness (t/D: 0.75–2.75) are employed to compose a total of 108 different geometries. Experimental measured temperature is utilized as boundary conditions to conduct finite element simulation. Local and averaged nondimensional temperature and averaged temperature uniformity of target plate “hot side” are obtained. Optimum hole spacing arrangements, impingement distance, and target plate thickness are pointed out to minimize hot side temperature, amount of cooling air and to maximize temperature uniformity. Also included are 2D predictions with different convective boundary conditions, i.e., local 2D distribution and row-averaged heat transfer coefficients (HTCs), to estimate the accuracy of temperature prediction in comparison with the conjugate results.
Butterfly Change in Electric Field-Dependent Young's Modulus: Bulge Test and Phase Field Model
Authors: Zhang Honglong , Yu Zejun , Pei Yongmao , Fang Daining
Published: March 2017

The field-dependent Young's modulus shows a promising application in the design and miniaturization of phononic crystals, tunable mechanical resonators, interdigital transducers, etc. With the multifield bulge-test instrument developed by our group, the electric field-tunable elastic modulus of ferroelectric films has been studied experimentally. A butterfly change in the Young's modulus of lead titanate zirconate (PZT) film under biaxial tensile stress state with electric field has been discovered for the first time. Based on the phase field model, an electromechanical coupling model is constructed, and a case of PZT ferroelectric film subjected to a vertical electric field and horizontal tensile strains is simulated. The numerical results show that the change in the Young's modulus is proportional to the variation of volume fraction of 90-deg domain switching under a pure tensile strain. It is the constraint of 90-deg domain switching by the electric field that contributes to the butterfly change in the elastic modulus.
First record of the family Liacaridae (Acari, Oribatida) from Vietnam, with description of two new species
Authors: Ermilov Sergey G. , STARÝ JOSEF
Published: March 2017

The oribatid mite family Liacaridae (Acari, Oribatida) is recorded in Vietnam for the first time. Two new species of liacarids of the genera Liacarus and Xenillus are described from Tam Dao National Park, northern Vietnam. Liacarus vietnamensis sp. nov. is similar to L. laterostris Mihelčič, 1954 in the morphology of lamellar cusps (inner teeth well-developed; interlamellar tubercle absent) and in having long interlamellar setae and short notogastral setae, but differs by the directions of lamellar cusps and morphology of bothridial setae. Xenillus tamdaoensis sp. nov. is similar to X. longipilus Pérez-Íñigo & Peña, 1995 in having long notogastral setae, insertion of notogastral setae lm posterior to la, and the presence of an interlamellar tubercle, but differs by the morphology and position of lamellar cusps, size of the interlamellar tubercle and length of interlamellar setae.
Characteristics of spectro-temporal modulation frequency selectivity in humans
Authors: Oetjen Arne , Verhey Jesko L.
Published: March 2017

There is increasing evidence that the auditory system shows frequency selectivity for spectro-temporal modulations. A recent study of the authors has shown spectro-temporal modulation masking patterns that were in agreement with the hypothesis of spectro-temporal modulation filters in the human auditory system [Oetjen and Verhey (2015). J. Acoust. Soc. Am. 137(2), 714–723]. In the present study, that experimental data and additional data were used to model this spectro-temporal frequency selectivity. The additional data were collected to investigate to what extent the spectro-temporal modulation-frequency selectivity results from a combination of a purely temporal amplitude-modulation filter and a purely spectral amplitude-modulation filter. In contrast to the previous study, thresholds were measured for masker and target modulations with opposite directions, i.e., an upward pointing target modulation and a downward pointing masker modulation. The comparison of this data set with previous corresponding data with the same direction from target and masker modulations indicate that a specific spectro-temporal modulation filter is required to simulate all aspects of spectro-temporal modulation frequency selectivity. A model using a modified Gabor filter with a purely temporal and a purely spectral filter predicts the spectro-temporal modulation masking data.
Characterizing spontaneous otoacoustic emissions across the human lifespan
Authors: Abdala Carolina , Luo Ping , Shera Christopher A.
Published: March 2017

This study characterizes 1571 archival and newly acquired spontaneous otoacoustic emissions (SOAEs) from 632 human subjects with ages ranging from premature birth through the seventh decade of life. Automated detection and Lorentzian modeling were applied to identify SOAEs and characterize SOAE features throughout the human lifespan. Results confirm higher-level, higher-frequency, and more numerous SOAEs from neonates compared to young adults. Approximately 85% of newborns have measurable SOAEs as compared to 51%–68% for young adults. Newborn SOAEs are also an average of 5 to 6 dB higher in level than those from young-adult ears. These age differences may reflect immature ear-canal acoustics and/or the pristine condition of the neonatal cochlea. In addition, newborns as a group showed broader SOAE bandwidth and increased frequency jitter, possibly due to higher intracochlear noise; additionally, 22% of newborn SOAEs had a different, non-Lorentzian spectral shape. Aging effects were also observed: 40% of elderly ears had SOAEs, and these were greatly reduced in level, likely due to lower power gain in the aging cochlea. For all ages, SOAE bandwidths decreased with frequency in a way that mirrors the frequency dependence of stimulus-frequency otoacoustic emission delays as predicted by the standing-wave model of SOAE generation.
Generalized sidelobe canceller beamforming method for ultrasound imaging
Authors: Wang Ping , Li Na , Luo Han-wu , Zhu Yong-kun , Cui Shi-gang
Published: March 2017

A modified generalized sidelobe canceller (IGSC) algorithm is proposed to enhance the resolution and robustness against the noise of the traditional generalized sidelobe canceller (GSC) and coherence factor combined method (GSC-CF). In the GSC algorithm, weighting vector is divided into adaptive and non-adaptive parts, while the non-adaptive part does not block all the desired signal. A modified steer vector of the IGSC algorithm is generated by the projection of the non-adaptive vector on the signal space constructed by the covariance matrix of received data. The blocking matrix is generated based on the orthogonal complementary space of the modified steer vector and the weighting vector is updated subsequently. The performance of IGSC was investigated by simulations and experiments. Through simulations, IGSC outperformed GSC-CF in terms of spatial resolution by 0.1 mm regardless there is noise or not, as well as the contrast ratio respect. The proposed IGSC can be further improved by combining with CF. The experimental results also validated the effectiveness of the proposed algorithm with dataset provided by the University of Michigan.
Basic occupational health services (BOHS) in community primary care: the MSF (Dhaka) model
Authors: Muralidhar Venkiteswaran , Ahasan Md Faizul , Khan Ahad Mahmud , Alam Mohammad Shariful
Published: March 2017

The Médecins Sans Frontiérs (MSF) established basic occupational health services to diagnose and treat work-related diseases among tannery, metal, plastics and garment workers and families in one of the more polluted areas of the world populated by 600 000 people. In spite of project limitations, an analysis of the 6-month data showed that of the original cohort of 5000, 3200 (64%) came for at least 1 consultation. Among them, 468 (14.6%) were diagnosed with suspected work-related diseases as per defined protocols. Follow-up consultation was performed for 1447 cases of occupational diseases and work-related injuries. The MSF experience begs the need for replication of such services in densely populated urban areas in developing nations like Bangladesh and India, where no specialty occupational health clinics exist in primary care but are desperately needed and where occupational health clinics on factory premises are exclusive to industry workers and are not accessible to communities.
Actinic cheilosis: early intervention prevents malignant transformation
Authors: Muthukrishnan Arvind , Bijai Kumar Laliytha
Published: March 2017

Potentially malignant disorders (PMD) have a high risk of malignant transformation. Habits such as tobacco and alcohol use predispose to PMD and subsequently to an oral carcinoma. Oral squamous cell carcinoma (OSCC) can occur even without the usage of tobacco. Occupational exposure to actinic rays may predispose to the development of OSCC in the lip. People who are involved in farming or those exposed to an environmental background radiation, such as ultraviolet rays, develop a PMD called actinic cheilosis. A high proportion of patients with actinic cheilosis develop an oral carcinoma when not diagnosed and treated in early stages. This case depicts the clinical and histological changes in a 61-year-old Indian man with actinic cheilosis.
Lithocholic acid: a new emergent protector of intestinal calcium absorption under oxidant conditions
Authors: Marchionatti Ana M. , Pérez Adriana , Rivoira María A. , Rodríguez Valeria A. , Tolosa de Talamoni Nori G.
Published: March 2017

LCA and 1,25(OH)2D3 are vitamin D receptor ligands with different binding affinity. The secosteroid stimulates intestinal Ca2+ absorption. Whether LCA alters this process remains unknown. The aim of our work was to determine the effect of LCA on intestinal Ca2+ absorption in the absence or presence of NaDOC, bile acid that inhibits the cation transport. The data show that LCA by itself did not alter intestinal Ca2+ absorption, but prevented the inhibitory effect of NaDOC. The concomitant administration of LCA avoided the reduction of intestinal alkaline phosphatase activity caused by NaDOC. In addition, LCA blocked a decrease caused by NaDOC on gene and protein expression of molecules involved in the transcellular pathway of intestinal Ca2+ absorption. The oxidative stress and apoptosis triggered by NaDOC were abrogated by LCA co-treatment. In conclusion, LCA placed in the intestinal lumen protects intestinal Ca2+ absorption against the inhibitory effects caused by NaDOC. LCA avoids the reduction of the transcellular Ca2+ movement, apparently by blocking the oxidative stress and apoptosis triggered by NaDOC, normalizing the gene and protein expression of molecules involved in Ca2+ movement. Therefore, LCA might become a possible treatment to improve intestinal calcium absorption under oxidant conditions.
Identification of candidate genes for the seed coat colour change in a Brachypodium distachyon mutant induced by gamma radiation using whole-genome re-sequencing
Authors: Lee Man Bo , Kim Dae Yeon , Seo Yong Weon
Published: March 2017

Brachypodium distachyon has been proposed as a model plant for agriculturally important cereal crops such as wheat and barley. Seed coat colour change from brown–red to yellow was observed in a mutant line (142-3) of B. distachyon, which was induced by chronic gamma radiation. In addition, dwarf phenotypes were observed in each of the lines 142-3, 421-2, and 1376-1. To identify causal mutations for the seed coat colour change, the three mutant lines and the wild type were subjected to whole-genome re-sequencing. After removing natural variations, 906, 1057, and 978 DNA polymorphisms were detected in 142-3, 421-2, and 1376-1, respectively. A total of 13 high-risk DNA polymorphisms were identified in mutant 142-3. Based on a comparison with DNA polymorphisms in 421-2 and 1376-1, candidate causal mutations for the seed coat colour change in 142-3 were selected. In the two independent Arabidopsis thaliana lines carrying T-DNA insertions in the AtCHI, seed colour change was observed. We propose a frameshift mutation in BdCHI1 as a causal mutation responsible for seed colour change in 142-3. The DNA polymorphism information for these mutant lines can be utilized for functional genomics in B. distachyon and cereal crops.
On the equivalence of separability and extendability of quantum states
Authors: Rajarama Bhat B. V. , Parthasarathy K. R. , Sengupta Ritabrata
Published: March 2017

Motivated by the notions of [Formula: see text]-extendability and complete extendability of the state of a finite level quantum system as described by Doherty et al. [Complete family of separability criteria, Phys. Rev. A 69 (2004) 022308], we introduce parallel definitions in the context of Gaussian states and using only properties of their covariance matrices, derive necessary and sufficient conditions for their complete extendability. It turns out that the complete extendability property is equivalent to the separability property of a bipartite Gaussian state.

Following the proof of quantum de Finetti theorem as outlined in Hudson and Moody [Locally normal symmetric states and an analogue of de Finetti’s theorem, Z. Wahrscheinlichkeitstheorie und Verw. Gebiete, 33(4) (1975/76) 343–351], we show that separability is equivalent to complete extendability for a state in a bipartite Hilbert space where at least one of which is of dimension greater than 2. This, in particular, extends the result of Fannes, Lewis, and Verbeure [Symmetric states of composite systems, Lett. Math. Phys. 15(3) (1988) 255–260] to the case of an infinite dimensional Hilbert space whose C* algebra of all bounded operators is not separable.
Maxwell–Boltzmann type Hawking radiation
Authors: Yoon Youngsub
Published: March 2017

Twenty years ago, Rovelli proposed that the degeneracy of black hole (i.e. the exponential of the Bekenstein–Hawking entropy) is given by the number of ways the black hole horizon area can be expressed as a sum of unit areas. However, when counting the sum, one should treat the area quanta on the black hole horizon as distinguishable. This distinguishability of area quanta is noted in Rovelli’s paper. Building on this idea, we derive that the Hawking radiation spectrum is not given by Planck radiation spectrum (i.e. Bose–Einstein distribution) but given by Maxwell–Boltzmann distribution.
A Wideband Digital Back-End for the Upgraded GMRT
Authors: Reddy Suda Harshavardhan , Kudale Sanjay , Gokhale Upendra , Halagalli Irappa , Raskar Nilesh , De Kishalay , Gnanaraj Shelton , Ajith Kumar B , Gupta Yashwant
Published: March 2017

Traditionally, back-ends for radio telescopes have been built using a hardware-based approach with ASICs, FPGAs, etc. With advancements in processing power of CPUs, software-based systems have emerged as an alternative option, which has received additional impetus with the advent of GPU-based computing. We present here the design of a hybrid system combining the best of FPGAs, CPUs and GPUs, to implement a next generation back-end for the upgraded GMRT. This back-end can process 400 MHz bandwidth signals from 32 dual-polarized antennas, for both interferometry and beamformer applications, including narrowband spectral line modes for the interferometer, incoherent array and phased array mode of operations for the beamfomer, and also a voltage mode attached to a real-time coherent dedispersion system for the beamformer. We describe in detail the design and architecture of this system, including the novel features and capabilities. We also present sample results from the system that validate its performance in conjunction with the entire receiver chain of the upgraded GMRT.
High-Performance Computing with Quantum Processing Units
Authors: Britt Keith A. , Humble Travis S.
Published: March 2017

The prospects of quantum computing have driven efforts to realize fully functional quantum processing units (QPUs). Recent success in developing proof-of-principle QPUs has prompted the question of how to integrate these emerging processors into modern high-performance computing (HPC) systems. We examine how QPUs can be integrated into current and future HPC system architectures by accounting for functional and physical design requirements. We identify two integration pathways that are differentiated by infrastructure constraints on the QPU and the use cases expected for the HPC system. This includes a tight integration that assumes infrastructure bottlenecks can be overcome as well as a loose integration that assumes they cannot. We find that the performance of both approaches is likely to depend on the quantum interconnect that serves to entangle multiple QPUs. We also identify several challenges in assessing QPU performance for HPC, and we consider new metrics that capture the interplay between system architecture and the quantum parallelism underlying computational performance.
Amplifiers for the Moran Process
Authors: Galanis Andreas , Göbel Andreas , Goldberg Leslie Ann , Lapinskas John , Richerby David
Published: March 2017

The Moran process, as studied by Lieberman, Hauert, and Nowak, is a randomised algorithm modelling the spread of genetic mutations in populations. The algorithm runs on an underlying graph where individuals correspond to vertices. Initially, one vertex (chosen uniformly at random) possesses a mutation, with fitness
r
> 1. All other individuals have fitness 1. During each step of the algorithm, an individual is chosen with probability proportional to its fitness, and its state (mutant or nonmutant) is passed on to an out-neighbour which is chosen uniformly at random. If the underlying graph is strongly connected, then the algorithm will eventually reach
fixation
, in which all individuals are mutants, or
extinction
, in which no individuals are mutants. An infinite family of directed graphs is said to be
strongly amplifying
if, for every
r
> 1, the extinction probability tends to 0 as the number of vertices increases. A formal definition is provided in the article. Strong amplification is a rather surprising property—it means that in such graphs, the fixation probability of a uniformly placed initial mutant tends to 1 even though the initial mutant only has a fixed selective advantage of
r
> 1 (independently of
n
). The name “strongly amplifying” comes from the fact that this selective advantage is “amplified.” Strong amplifiers have received quite a bit of attention, and Lieberman et al. proposed two potentially strongly amplifying families—superstars and metafunnels. Heuristic arguments have been published, arguing that there are infinite families of superstars that are strongly amplifying. The same has been claimed for metafunnels. In this article, we give the first rigorous proof that there is an infinite family of directed graphs that is strongly amplifying. We call the graphs in the family “megastars.” When the algorithm is run on an
n
-vertex graph in this family, starting with a uniformly chosen mutant, the extinction probability is roughly
n
− 1/2
(up to logarithmic factors). We prove that all infinite families of superstars and metafunnels have larger extinction probabilities (as a function of
n
). Finally, we prove that our analysis of megastars is fairly tight—there is no infinite family of megastars such that the Moran algorithm gives a smaller extinction probability (up to logarithmic factors). Also, we provide a counterexample which clarifies the literature concerning the isothermal theorem of Lieberman et al.
Writes Wrought Right, and Other Adventures in File System Optimization
Authors: Yuan Jun , Zhan Yang , Jannen William , Pandey Prashant , Akshintala Amogh , Chandnani Kanchan , Deo Pooja , Kasheff Zardosht , Walsh Leif , Bender Michael A. , Farach-Colton Martin , Johnson Rob , Kuszmaul Bradley C. , Porter Donald E.
Published: March 2017

File systems that employ write-optimized dictionaries (WODs) can perform random-writes, metadata updates, and recursive directory traversals orders of magnitude faster than conventional file systems. However, previous WOD-based file systems have not obtained all of these performance gains without sacrificing performance on other operations, such as file deletion, file or directory renaming, or sequential writes.

Using three techniques,
late-binding journaling
,
zoning
, and
range deletion
, we show that there is no fundamental trade-off in write-optimization. These dramatic improvements can be retained while matching conventional file systems on
all
other operations.

BetrFS 0.2 delivers order-of-magnitude better performance than conventional file systems on directory scans and small random writes and matches the performance of conventional file systems on rename, delete, and sequential I/O. For example, BetrFS 0.2 performs directory scans 2.2 × faster, and small random writes over two orders of magnitude faster, than the fastest conventional file system. But unlike BetrFS 0.1, it renames and deletes files commensurate with conventional file systems and performs large sequential I/O at nearly disk bandwidth. The performance benefits of these techniques extend to applications as well. BetrFS 0.2 continues to outperform conventional file systems on many applications, such as as rsync, git-diff, and tar, but improves git-clone performance by 35% over BetrFS 0.1, yielding performance comparable to other file systems.
Corpus-Based Translation Induction in Indian Languages Using Auxiliary Language Corpora from Wikipedia
Authors: Tholpadi Goutham , Bhattacharyya Chiranjib , Shevade Shirish
Published: March 2017

Identifying translations from comparable corpora is a well-known problem with several applications. Existing methods rely on linguistic tools or high-quality corpora. Absence of such resources, especially in Indian languages, makes this problem hard; for example, state-of-the-art techniques achieve a mean reciprocal rank of 0.66 for English-Italian, and a mere 0.187 for Telugu-Kannada. In this work, we address the problem of comparable corpora-based translation correspondence induction (CC-TCI) when the only resources available are small noisy comparable corpora extracted from Wikipedia. We observe that translations in the source and target languages have many topically related words in common in other “auxiliary” languages. To model this, we define the notion of a
translingual theme
, a set of topically related words from auxiliary language corpora, and present a probabilistic framework for CC-TCI. Extensive experiments on 35 comparable corpora showed dramatic improvements in performance. We extend these ideas to propose a method for measuring cross-lingual semantic relatedness (CLSR) between words. To stimulate further research in this area, we make publicly available two new high-quality human-annotated datasets for CLSR. Experiments on the CLSR datasets show more than 200% improvement in correlation on the CLSR task. We apply the method to the real-world problem of cross-lingual Wikipedia title suggestion and build the
WikiTSu
system. A user study on
WikiTSu
shows a 20% improvement in the quality of titles suggested.
Merging in the Horn Fragment
Authors: Haret Adrian , Rümmele Stefan , Woltran Stefan
Published: March 2017

Belief merging is a central operation within the field of belief change and addresses the problem of combining multiple, possibly mutually inconsistent knowledge bases into a single, consistent one. A current research trend in belief change is concerned with representation theorems tailored to fragments of logic, in particular Horn logic. Hereby, the goal is to guarantee that the result of the change operations stays within the fragment under consideration. While several such results have been obtained for Horn revision and Horn contraction, merging of Horn theories has been neglected so far. In this article, we provide a novel representation theorem for Horn merging by strengthening the standard merging postulates. Moreover, we present concrete Horn merging operators satisfying all postulates.
Instance-Optimal Geometric Algorithms
Authors: Afshani Peyman , Barbay Jérémy , Chan Timothy M.
Published: March 2017

We prove the existence of an algorithm
A
for computing 2D or 3D convex hulls that is optimal for
every point set
in the following sense: for every sequence σ of
n
points and for every algorithm
A
′ in a certain class
A
, the running time of
A
on input σ is at most a constant factor times the running time of
A
′ on the worst possible permutation of σ for
A
′. In fact, we can establish a stronger property: for every sequence σ of points and every algorithm
A
′, the running time of
A
on σ is at most a constant factor times the average running time of
A
′ over all permutations of σ. We call algorithms satisfying these properties
instance optimal
in the
order-oblivious
and
random-order
setting. Such instance-optimal algorithms simultaneously subsume output-sensitive algorithms and distribution-dependent average-case algorithms, and all algorithms that do not take advantage of the order of the input or that assume the input are given in a random order.

The class
A
under consideration consists of all algorithms in a decision tree model where the tests involve only
multilinear
functions with a constant number of arguments. To establish an instance-specific lower bound, we deviate from traditional Ben-Or-style proofs and adopt a new adversary argument. For 2D convex hulls, we prove that a version of the well-known algorithm by Kirkpatrick and Seidel [1986] or Chan, Snoeyink, and Yap [1995] already attains this lower bound. For 3D convex hulls, we propose a new algorithm.

We further obtain instance-optimal results for a few other standard problems in computational geometry, such as maxima in 2D and 3D, orthogonal line segment intersection in 2D, finding bichromatic
L
∞
-close pairs in 2D, offline orthogonal range searching in 2D, offline dominance reporting in 2D and 3D, offline half-space range reporting in 2D and 3D, and offline point location in 2D. Our framework also reveals a connection to distribution-sensitive data structures and yields new results as a byproduct, for example, on online orthogonal range searching in 2D and online half-space range reporting in 2D and 3D.
Machine Learning--Based Parametric Audiovisual Quality Prediction Models for Real-Time Communications
Authors: Demirbilek Edip , Grégoire Jean-Charles
Published: March 2017

In order to mechanically predict audiovisual quality in interactive multimedia services, we have developed machine learning--based no-reference parametric models. We have compared Decision Trees--based ensemble methods, Genetic Programming and Deep Learning models that have one and more hidden layers. We have used the Institut national de la recherche scientifique (INRS) audiovisual quality dataset specifically designed to include ranges of parameters and degradations typically seen in real-time communications. Decision Trees--based ensemble methods have outperformed both Deep Learning-- and Genetic Programming--based models in terms of Root-Mean-Square Error (RMSE) and Pearson correlation values. We have also trained and developed models on various publicly available datasets and have compared our results with those of these original models. Our studies show that Random Forests--based prediction models achieve high accuracy for both the INRS audiovisual quality dataset and other publicly available comparable datasets.
A report on the genetic improvement workshop@GECCO 2016
Authors: Bruce Bobby
Published: March 2017

In July I was fortunate enough to attend the 2nd Genetic Improvement workshop in Denver, hosted under the Genetic and Evolutionary Computing Conference (GECCO) umbrella. For those unaware, Genetic Improvement (or simply 'GI') is an emerging area of software engineering that attempts to use search-based techniques to improve code. I myself have spent much of the last two years emerging myself in GI literature and carrying out investigations relevant to the field. Even in this short time I have been privileged to witness it grow from the solving of toy problems to frameworks capable of outperforming human-driven manual alternatives (readers need look no further than the winners of this year's Humie awards). Events such as the GI workshop serve as a platform for ideas, research proposals, and new experimental results to be discussed. They fill a niche for those who wish to discuss research with others in a structured manner while avoiding the restrictive formalities of submitting to a conference or journal. Building on the success of the 1st workshop (hosted in Madrid last year) the event was extended to cover three consecutive sessions at the GECCO conference. Pleasingly attendance was high with an audience full of both familiar faces and curious newcomers.
ACM-W scholarships
Authors: Auger Anne , Yang Jing , O'Reilly Una-May , Moscovici Eva , Ochoa Gabriela , Mariani Thainá , Vostinar Anya , Heck Samantha , Pappa Gisele , Volz Vanessa , Tusar Tea , Dali Narjess
Published: March 2017

ACM-W provides support for women undergraduate and graduate students in Computer Science and related programs to attend research conferences. This exposure to the CS research world can encourage a student to continue on to the next level (Undergraduate to Graduate, Masters to Ph.D, Ph.D. to an industry or academic position). The student does not have to present a paper at the conference she attends.
Navigation with a tiny brain
Authors: Philippides Andrew
Published: March 2017

The use of visual information for navigation is a universal strategy for sighted animals, amongst whom social insects are particular experts. The general interest in studies of insect navigation is in part due to their small brains; biomimetic engineers can take inspiration from elegant and parsimonious control solutions, while biologists look for a description of the minimal cognitive requirements for complex spatial behaviours. We take an interdisciplinary approach to studying visual guided navigation by combining behavioural experiments with modelling and robotics to understand how complex behaviour can emerge from the combination of a simple sensory system and brain, interacting with innate behaviours all tuned to the natural habitat. In so doing, we show that an agent can robustly navigate without ever knowing where it is, without specifying when or what it should learn, nor requiring it to recognise specific objects, places routes or maps. This leads to an algorithm in which navigation is driven by familiarity detection rather than explicit recall, with sensory data specifying actions not locations. Route navigation is thus recast as a search for familiar views, allowing an agent to encode routes through visually complex worlds in a single layer neural network after a single training run. We suggest that this work is a specific example of a more general idea which has implications for engineers seeking nature-inspired solutions: By considering how animals directly acquire and use task-specific information through specialised sensors, brains and behaviours, we can solve complex problems without complex processing.
Cadmium Toxicity Affects Phytochemicals and Nutrient Elements Composition of Lettuce (Lactuca sativa L.)
Authors: Jibril Sani Ahmad , Hassan Siti Aishah , Ishak Che Fauziah , Megat Wahab Puteri Edaroyati
Published: March 2017

Lettuce varieties Bombilasta BBL and Italian 167 were treated with different concentrations of cadmium (0, 3, 6, 9, and 12 mg/L) in a nutrient film technique (NFT) system to study its toxicity on phytochemicals and nutrient elements. Antioxidants analysis which employed DPPH and FRAP, flavonoids, phenolic, vitamin C, malondialdehyde (MDA), and proline indicated significant effects of Cd treatment on the varieties tested. Different concentration levels of Cd lead to positive interactions in FRAP, phenolic, and MDA but no significant effect in flavonoids, vitamin C, and proline. Contents of macro- and microelements in the varieties were significantly affected with increase in the toxicity levels of Cd in all nutrient elements tested with interactions exhibited for iron, manganese, and zinc.
Effect of Red Orange Juice Consumption on Body Composition and Nutritional Status in Overweight/Obese Female: A Pilot Study
Authors: Azzini E. , Venneria E. , Ciarapica D. , Foddai M. S. , Intorre F. , Zaccaria M. , Maiani F. , Palomba L. , Barnaba L. , Tubili C. , Maiani G. , Polito A.
Published: March 2017

The main objective of this research was to determine whether a commercial orange juice rich in anthocyanins could have an effect on body weight and on clinical parameters related to obesity including antioxidant status, lipid profile, and metabolic and inflammatory biomarkers. 11 women with an average BMI of 34.4 ± 4.8 kg/m2 were enrolled in a pilot study. Over a period of 12 weeks they received 500 mL daily dose into two doses (250 mL) of commercial red orange juice (COJ). The biochemical parameters were measured at baseline and at the end of the study (12 weeks). One month later upon free diet, a follow‐up was performed measuring the same variables. The daily consumption of 500 mL of COJ had no significant effects on body weight, while there was a decrease in total cholesterol and LDL cholesterol. The grade of obesity implies different changes in inflammation biomarkers. In obese women, our data do not seem to support evidence that commercial red orange juice consumption acts as functional food preventing obesity and metabolic disorders such as insulin resistance and/or inflammatory status.
Student Academic Performance: The Role of Motivation, Strategies, and Perceived Factors Hindering Liberian Junior and Senior High School Students Learning
Authors: Gbollie Charles , Keamu Harriett Pearl
Published: March 2017

The nature of motivation and learning strategy use is vital to improving student learning outcomes. This study was intended to explore the motivational beliefs and learning strategy use by Liberian junior and senior high school students in connection with their academic performance. It also solicited students’ self‐reports about presumed factors hindering their learning. Utilizing a cross‐sectional quantitative research design, 323 participants took part in the study from 2 counties. Motivated Strategies for Learning Questionnaire (MSLQ) was adapted and 12 potential learning hindrances were identified and used as instruments. Data analyses were conducted using SPSS 17.0. The results showed the motivational belief component of extrinsic goal orientation as the most preferred belief and test anxiety was the least possessed belief. Rehearsal strategies were found to be the most frequently used, while help seeking was reported to be the least strategy considered. The result also showed significant relationships between the two constructs. In addition, the study found some learning hindrances. A number of conclusions as well as some practical recommendations for action relative to the improvement of student performance have been advanced.
The Association between Imaging Parameters of the Paraspinal Muscles, Spinal Degeneration, and Low Back Pain
Authors: Kalichman Leonid , Carmeli Eli , Been Ella
Published: March 2017

This narrative review investigated imaging parameters of the paraspinal muscles and their association with spinal degenerative features and low back pain (LBP) found in the literature. Three principal signs of muscle degeneration were detected on imaging: decreased muscle size, decreased radiographic density, and increased fat deposits. Men have a higher density of paraspinal muscles than women, younger individuals have a higher density than older ones, and lean individuals have a higher density than those with an increased body mass index. Fatty infiltration appears to be a late stage of muscular degeneration and can be measured noninvasively by an MRI scan. Fatty infiltration in the lumbar multifidus is common in adults and is strongly associated with LBP, especially in women, independent of body composition. Fatty infiltration develops in areas where most degenerative changes are found. MR spectroscopy studies have corroborated that the lumbar multifidus in LBP subjects has a significantly higher fat content than asymptomatic controls. There is a strong need for establishing uniform methods of evaluating normal parameters and degenerative changes of the paraspinal muscles. Additional imaging studies are needed to improve the understanding of the association and causal relationships between LBP, spinal degeneration, and changes in the paraspinal muscles.