bluuebunny/crossref_metadata_2025 huggingface dataset:
Concussion History and Time Since Concussion Do not Influence Static and Dynamic Balance in Collegiate Athletes
Authors: Merritt Eric D. , Brown Cathleen N. , Queen Robin M. , Simpson Kathy J. , Schmidt Julianne D.
Published: November 2016

Context:

Dynamic balance deficits exist following a concussion, sometimes years after injury. However, clinicians lack practical tools for assessing dynamic balance.

Objectives:

To determine if there are significant differences in static and dynamic balance performance between individuals with and without a history of concussion.

Design:

Cross sectional.

Setting:

Clinical research laboratory.

Patients or Other Participants:

45 collegiate student-athletes with a history of concussion (23 males, 22 females; age = 20.0 ± 1.4 y; height = 175.8 ± 11.6 cm; mass = 76.4 ± 19.2 kg) and 45 matched controls with no history of concussion (23 males, 22 females; age = 20.0 ± 1.3 y; height = 178.8 ± 13.2 cm; mass = 75.7 ± 18.2 kg).

Interventions:

Participants completed a static (Balance Error Scoring System) and dynamic (Y Balance Test-Lower Quarter) balance assessment.

Main Outcome Measures:

A composite score was calculated from the mean normalized Y Balance Test-Lower Quarter reach distances. Firm, foam, and overall errors were counted during the Balance Error Scoring System by a single reliable rater. One-way ANOVAs were used to compare balance performance between groups. Pearson’s correlations were performed to determine the relationship between the time since the most recent concussion and balance performance. A Bonferonni adjusted a priori α < 0.025 was used for all analyses.

Results:

Static and dynamic balance performance did not significantly differ between groups. No significant correlation was found between the time since the most recent concussion and balance performance.

Conclusions:

Collegiate athletes with a history of concussion do not present with static or dynamic balance deficits when measured using clinical assessments. More research is needed to determine whether the Y Balance Test-Lower Quarter is sensitive to acute balance deficits following concussion.
Serum Adiponectin Levels and Cardiorespiratory Fitness in Nonoverweight and Overweight Portuguese Adolescents: The LabMed Physical Activity Study
Authors: Agostinis-Sobrinho César , Moreira Carla , Abreu Sandra , Lopes Luís , Oliveira-Santos José , Steene-Johannessen Jostein , Mota Jorge , Santos Rute
Published: November 2016

Purpose:

This study examined the independent associations between cardiorespiratory fitness and circulating adiponectin concentration in adolescents, controlling for several potential covariates.

Methods:

This is a cross-sectional study in Portuguese adolescents. A sample of 529 (267 girls) aged 12–18 years were included and categorized as overweight and nonoverweight. Cardiorespiratory fitness was assessed by 20 meters shuttle run test. We measured serum adiponectin, high-sensitivity C-reactive protein, fasting glucose, insulin and HDL-cholesterol.

Results:

After adjustment for age, sex, pubertal stage, adherence to the Mediterranean diet, socioeconomic status, body fat percentage, insulin resistance, HDL-cholesterol and C-reactive protein, regression analysis showed a significant inverse association between adiponectin and cardiorespiratory fitness in nonoverweight participants (B=-0.359; p < .042). Analysis of covariance showed a significant difference between the highest cardiorespiratory fitness Healthy zone (above healthy zone) and the Under and the Healthy cardiorespiratory fitness zones in nonoverweight adolescents (p = .03) (F (2, 339) = 3.156, p < .001).

Conclusion:

Paradoxically, serum adiponectin levels are inversely associated with cardiorespiratory fitness in nonoverweight, but not in overweight adolescents. In nonoverweight adolescents, those with highest levels of cardiorespiratory fitness (above healthy zone) presented lower levels of adiponectin compared with those in Under and Healthy cardiorespiratory fitness zones.
Factors Associated With Moderate to Vigorous Physical Activity in Adolescents Born Preterm
Authors: Proulx Ketsia , Majnemer Annette , Dahan-Oliel Noémi , Mazer Barbara , Nadeau Line , Vanier Kathleen , Maltais Désirée B.
Published: November 2016

Purpose:

Little is known about the physical activity of adolescents born prematurely. This study aimed to: 1) describe relationships between moderate to vigorous physical activity (MVPA) in adolescents born prematurely and various factors and, 2) compare their MVPA level to guidelines.

Method:

A secondary analysis was performed using data from 64 adolescents (16.1 ± 2.5 years old, born £29 weeks gestation; 57.8% girls). Time spent in MVPA was based on accelerometry data. Sociodemographic, prematurity and comorbidity variables were based on questionnaire data or, for movement difficulty, from the results of the Movement Assessment Battery for Children—Second Edition.

Results:

Multiple regression analysis showed that participants who were older (b = -4.52, p < .001), female (b = 14.18, p = .014), with movement difficulty (b = 18.64, p = .014), with health problems (b = 11.78, p = .036) and without hyperactive behavior (trend, b = 2.04, p = .099) spent less time in MVPA. Together these variables explained 44.4% of the variance in MVPA. Most participants (79.7%) did not meet Canadian MVPA guidelines.

Conclusion:

Study results suggest that physical activity interventions should especially target adolescents born prematurely who are older, female, with health problems, and with marked movement difficulties.
Facilitating Positive Youth Development by Fostering Collaboration Among Community-Based Sport and Physical Activity Programs
Authors: Petitpas Al , Van Raalte Judy , France Ted
Published: November 2016

Positive youth development (PYD) programs assist youth in acquiring the skills, attitudes, and values that are critical in coping with various risk factors in their communities. The purpose of this paper is to highlight strategies that sport psychology consultants can use to support PYD programs and develop collaboration and consistency of delivery among community youth serving agencies that use sport and physical activity-based experiences to promote positive youth development. In particular, the role of sport psychology consultants within sport and physical activity programs that serve as a catalyst for community youth development (CYD) is examined. Barriers to collaboration among community-based organizations are identified and strategies to overcome these obstacles are proposed. Sport psychology consultants are in a unique position to support PYD and CYD in the athletes and communities they serve.
Fusion reactor fuels up with bomb ingredient
Authors: Gibbs W. Wayt
Published: November 2016

Radioactive tritium promises a bigger bang for Sandia's Z machine but poses safety issues.
NSF says: Out with the old telescopes, in with the new
Authors: Clery Daniel
Published: November 2016

Agency wants to shed ownership of iconic radio dishes.
How the body learns to hurt
Authors: Underwood Emily
Published: November 2016

Glial cells turn up the volume on pain.
Growing Greenland's archaeologists
Authors: Kintisch Eli
Published: November 2016

In a land rich in artifacts, a paucity of archaeologists.
Webinar | Deciphering cancer: Genomic instability in cancer
Authors: O'Connor Mark J. , Whetstine Johnathan R.
Published: November 2016

While it is well established that DNA damage can increase the risk of cancer, changes to the epigenome or the chromatin architecture are equally important. DNA damage triggers a redistribution of DNA-binding proteins around the site of damage, resulting in localized and temporary alteration of chromatin structure. However, repeated cycles of DNA damage and repair may lead to permanent changes in the epigenome, thereby promoting the onset of pathological diseases such as cancer. This webinar will examine how we may be able to develop effective new therapeutic options for cancer treatment by targeting proteins responsible for chromatin modifications.

View the Webinar
The broad footprint of climate change from genes to biomes to people
Authors: Scheffers Brett R. , De Meester Luc , Bridge Tom C. L. , Hoffmann Ary A. , Pandolfi John M. , Corlett Richard T. , Butchart Stuart H. M. , Pearce-Kelly Paul , Kovacs Kit M. , Dudgeon David , Pacifici Michela , Rondinini Carlo , Foden Wendy B. , Martin Tara G. , Mora Camilo , Bickford David , Watson James E. M.
Published: November 2016

Accumulating impacts

Anthropogenic climate change is now in full swing, our global average temperature already having increased by 1°C from preindustrial levels. Many studies have documented individual impacts of the changing climate that are particular to species or regions, but individual impacts are accumulating and being amplified more broadly. Scheffers
et al.
review the set of impacts that have been observed across genes, species, and ecosystems to reveal a world already undergoing substantial change. Understanding the causes, consequences, and potential mitigation of these changes will be essential as we move forward into a warming world.

Science
, this issue p.
10.1126/science.aaf7671
Coordination-induced weakening of ammonia, water, and hydrazine X–H bonds in a molybdenum complex
Authors: Bezdek Máté J. , Guo Sheng , Chirik Paul J.
Published: November 2016

Coordinated scission of N–H or O–H bonds

Ammonia and water both have well-explored acid-base chemistry at room temperature, revolving around proton exchange. In contrast, radical chemistry involving H-atom exchange is comparatively rare in these molecules in the absence of a high-energy stimulus. Bezdek
et al.
now show that coordination of ammonia or water to a molybdenum complex substantially weakens the N–H or O–H bonds, so much so that heating to 60°C liberates hydrogen (see the Perspective by Hoover). Theoretical and electrochemical analyses reveal the underpinnings of the bond-weakening phenomenon.

Science
, this issue p.
730
; see also p.
707
Attosecond dynamics through a Fano resonance: Monitoring the birth of a photoelectron
Authors: Gruson V. , Barreau L. , Jiménez-Galan Á. , Risoud F. , Caillat J. , Maquet A. , Carré B. , Lepetit F. , Hergott J.-F. , Ruchon T. , Argenti L. , Taïeb R. , Martín F. , Salières P.
Published: November 2016

Watching as helium goes topsy-turvy

Theorists have long pondered the underpinnings of the Fano resonance, a spectral feature that resembles adjacent rightside-up and upside-down peaks. An especially well-studied instance of this feature appears in the electronic spectrum of helium as a transient state undergoes delayed ionization. Two studies have now traced the dynamics of this state in real time. Gruson
et al.
used photoelectron spectroscopy to extract the amplitude and phase of the electron wave packet after inducing its interference with reference wave packets tuned into resonance at variable delays. Kaldun
et al.
used extreme ultraviolet absorption spectroscopy to probe the transient state while variably forcing ionization with a strong near-infrared field.

Science
, this issue pp.
734
and
738
Single-molecule optomechanics in “picocavities”
Authors: Benz Felix , Schmidt Mikolaj K. , Dreismann Alexander , Chikkaraddy Rohit , Zhang Yao , Demetriadou Angela , Carnegie Cloudy , Ohadi Hamid , de Nijs Bart , Esteban Ruben , Aizpurua Javier , Baumberg Jeremy J.
Published: November 2016

A cool route to nanospectroscopy

Confining light to a cavity is often used to enhance the interaction between the light and a particle stored within the cavity. Benz
et al.
worked with a self-assembled monolayer of biphenyl-4-thiol molecules sandwiched between a gold film and a gold nanoparticle. They used laser irradiation to move atoms in the nanoparticle and produced a “picocavity” that was stable at cryogenic temperatures. The authors were then able to obtain time-dependent Raman spectra from individual molecules. Such subwavelength cavities that can localize light to volumes well below 1 nm
3
will enable optical experiments on the atomic scale.

Science
, this issue p.
726
A bioinspired iron catalyst for nitrate and perchlorate reduction
Authors: Ford Courtney L. , Park Yun Ji , Matson Ellen M. , Gordon Zachary , Fout Alison R.
Published: November 2016

Biological inspiration for reduction

Microorganisms have evolved sophisticated enzymatic machinery to reduce perchlorate and nitrate ions. Although the energetics of the pathways are different, the heme-containing active sites of the corresponding reductase enzymes are remarkably similar. Ford
et al.
constructed an inorganic catalyst to mediate these reactions based on these active sites, using a nonheme iron complex. A secondary coordination sphere near the iron center aligned the nitrate or perchlorate oxyanions and formed an iron-oxo complex. Regenerating the catalyst in the presence of protons and electrons released water—a potentially much more sustainable process than reduction strategies that require the use of harsh reagents.

Science
, this issue p.
741
Observing the ultrafast buildup of a Fano resonance in the time domain
Authors: Kaldun A. , Blättermann A. , Stooß V. , Donsa S. , Wei H. , Pazourek R. , Nagele S. , Ott C. , Lin C. D. , Burgdörfer J. , Pfeifer T.
Published: November 2016

Watching as helium goes topsy-turvy

Theorists have long pondered the underpinnings of the Fano resonance, a spectral feature that resembles adjacent rightside-up and upside-down peaks. An especially well-studied instance of this feature appears in the electronic spectrum of helium as a transient state undergoes delayed ionization. Two studies have now traced the dynamics of this state in real time. Gruson
et al.
used photoelectron spectroscopy to extract the amplitude and phase of the electron wave packet after inducing its interference with reference wave packets tuned into resonance at variable delays. Kaldun
et al.
used extreme ultraviolet absorption spectroscopy to probe the transient state while variably forcing ionization with a strong near-infrared field.

Science
, this issue pp.
734
and
738
Making the cut in the dark genome
Authors: Einstein Jaclyn M. , Yeo Gene W.
Published: November 2016

CRISPR screens will reveal important regulatory elements in the noncoding genome
Leprosy in red squirrels
Authors: Stinear Timothy P. , Brosch Roland
Published: November 2016

Red squirrels are an unexpected reservoir of otherwise human-restricted leprosy bacilli
Deborah S. Jin (1968–2016)
Authors: Regal Cindy , Ye Jun
Published: November 2016

A pioneer of ultracold quantum physics also promoted women in science
Who should direct WHO?
Authors: Heymann David L.
Published: November 2016

Last week, member states of the World Health Organization (WHO) advanced another step in the nearly 1-year rigorous process of selecting its next director-general. Candidates for the position presented their vision of international health work and the role of this global health body. Having worked at WHO in a number of capacities in the area of infectious diseases, I know well that international health covers a wide breadth of issues. Add to that noncommunicable diseases and matters such as intellectual property and universal health coverage, and it becomes clear that the next director-general must be a jack of all trades, but also a master of one—leadership in public health. Leadership in this role is about conceiving and articulating a vision, staying faithful to that vision in the face of undue influence, and effectively engaging with not only governments, but with all stakeholders to gain their support and enable the vision to be realized.
Reunifying America
Authors: Berg Jeremy
Published: November 2016

I was in Berlin on the night of the United States presidential election, waiting for the Falling Walls conference to begin on 9 November. The bruising 2016 presidential campaign revealed societal fragmentation across the nation. Being in Berlin to absorb the election news had some unique resonances. Here, history has shown that there can be grave dangers in division and benefits of unification. Yet countries everywhere are showing signs of deep polarization. We must understand more fully these divisions. Communities at all levels and across sectors must work hard on drawing citizenry, and the world, together. The scientific community must recognize its important role in helping to break down barriers and find solutions that will build better lives for everyone.
Upper Respiratory Tract Tuberculosis
Authors: Jindal Surinder K. , Jindal Aditya , Agarwal Ritesh
Published: November 2016

Upper respiratory tract involvement in cases of tuberculosis (TB) of the head and neck continues to be described in the most recent reports from several different regions, including some from developed countries. Laryngeal TB is the most common of all forms of upper respiratory tract TB (URT-TB). Pulmonary lesions in URT-TB are present in about 20% of adults and about 50 to 60% of children. Systemic manifestations are uncommon. URT-TB is especially seen in patients with a variety of risk factors, such as the presence of human immunodeficiency virus (HIV) infection, diabetes, smoking, alcoholism, drug abuse, malignancies, and use of immunosuppressive drugs. Nodules or ulcerative lesions are seen on morphological examination. Endoscopic examination is required for mucosal lesions. Diagnosis of TB is suspected on an epidemiological basis in high-prevalence countries or from the failure of a patient to respond to routine treatment. Smear and/or histopathological examinations help in establishing the final etiological diagnosis. Treatment includes standard anti-TB chemotherapy for at least 6 months with four primary drugs during the initial intensive phase of 2 months and two or three primary drugs during the remaining maintenance phase of 4 months. Treatment is modified on the basis of culture and sensitivity reports in cases of suspected drug resistance. Surgical intervention may be required for some patients with abscess formation and progressive disease unresponsive to medical therapy. Airway obstruction, although rare, even in fulminant cases may require tracheostomy for relief.
Genetic characterization of physical activity behaviours in university students enrolled in kinesiology degree programs
Authors: Many Gina M. , Kendrick Zachary , Deschamps Chelsea L. , Sprouse Courtney , Tosi Laura L. , Devaney Joseph M. , Gordish-Dressman Heather , Barfield Whitney , Hoffman Eric P. , Houmard Joseph A. , Pescatello Linda S. , Vogel Hans J. , Shearer Jane , Hittel Dustin S.
Published: November 2016

Studies of physical activity behaviours have increasingly shown the importance of heritable factors such as genetic variation. Nonsynonymous polymorphisms of alpha-actinin 3 (ACTN3) and the β-adrenergic receptors 1 and 3 (ADRB1 and ADRB3) have been previously associated with exercise capacity and cardiometabolic health. We thus hypothesized that these polymorphisms are also related to physical activity behaviours in young adults. To test this hypothesis we examined relationships between ACTN3 (R577X), ARDB1 (Arg389Gly), ADRB3 (Trp64Arg), and physical activity behaviours in university students. We stratified for student enrollment in kinesiology degree programs compared with nonmajors as we previously found this to be a predictor of physical activity. We did not identify novel associations between physical activity and ACTN3. However, the minor alleles of ADRB1 and ADRB3 were significantly underrepresented in kinesiology students compared with nonmajors. Furthermore, carriers of the ADRB1 minor allele reported reduced participation in moderate physical activity and increased afternoon fatigue compared with ancestral allele homozygotes. Together, these findings suggest that the heritability of physical activity behaviours in young adults may be linked to nonsynonymous polymorphisms within β-adrenergic receptors.
One-pot synthesis of propynoates and propynenitriles
Authors: Shu Fan , Zheng Qingjuan , Dong Wanrong , Peng Zhihong , An Delie
Published: November 2016

An efficient transformation towards propynoates and propynenitriles is herein described. The practical methodology was conducted at low temperature (–78 or –60 °C) in a one-pot manner with the assistance of base rather than any transition metal catalysts. The base-induced protocol exhibits good functional group tolerance (up to 28 examples) and high efficiency (up to 92% yields) towards substituted acetylenes of great synthetic significance, which was also well demonstrated by the gram-scale reactions.
On the irregularity of some molecular structures
Authors: Abdo Hosam , Dimitrov Darko , Gao Wei
Published: November 2016

Measures of the irregularity of chemical graphs could be helpful for QSAR/QSPR studies and for the descriptive purposes of biological and chemical properties such as melting and boiling points, toxicity, and resistance. Here, we consider the following four established irregularity measures: the irregularity index by Albertson, the total irregularity, the variance of vertex degrees, and the Collatz–Sinogowitz index. Through the means of graph structural analysis and derivation, we study the above-mentioned irregularity measures of several chemical molecular graphs that frequently appear in chemical, medical, and material engineering, as well as the nanotubes: TUC4C8(S), TUC4C8(R), zigzag TUHC6, TUC4, Armchair TUVC6, then dendrimers Tk,d, and the circumcoronene series of benzenoid Hk. In addition, the irregularities of Mycielski’s constructions of cycle and path graphs are analyzed.
The presence of parasitic mites on small mammals in Algonquin Provincial Park, Ontario, Canada
Authors: Bobbie Colleen B. , Schmidt Elliott , Foley Janet , Schulte-Hostedde Albrecht I.
Published: November 2016

Here we identify, for the first time, a generalist orange parasitic mite found on multiple small-mammal species in Algonquin Provincial Park, Ontario, Canada. Results from 18S rRNA sequencing suggest that these mites may belong to the family Trombiculidae (Acari: Trombidiformes), although morphological and additional genetic analyses are needed to confirm this identification. The presence of these mites was associated with lower body condition in North American red squirrels (Tamiasciurus hudsonicus (Erxleben, 1777)), suggesting that these mites may be a detriment to fitness in small mammals or are more successful when targeting individuals in poorer condition. A lack of sex-biased host infection, emergence dates outside of the host reproductive season, and stability of mite prevalence across study years indicate mite population dynamics may be driven predominantly by factors external from host status, such as climatic conditions or habitat preference. Future research should focus on providing additional reliable identification of these mites, as well as broadening our knowledge on their range, pathogenicity, and impact on small-mammal community dynamics.
Perturbation to TBM mixing and its phenomenological implications
Authors: Sruthilaya M. , Gollu Srinu
Published: November 2016

To accommodate the recently observed nonzero reactor mixing angle [Formula: see text], we consider the lepton mixing matrix as tri-bimaximal mixing (TBM) form in the leading order along with a perturbation in neutrino sector. The perturbation is taken to be a rotation in 23 plane followed by a rotation in 13 plane, i.e. [Formula: see text]. We obtain the allowed values of the parameters [Formula: see text], [Formula: see text] and [Formula: see text], which can accommodate all the observed mixing angles consistently and calculate the phenomenological observables such as the Dirac CP violating phase [Formula: see text], Jarlskog invariant [Formula: see text], effective Majorana mass [Formula: see text] and [Formula: see text], the electron neutrino mass. We find that [Formula: see text] can take any values between [Formula: see text] and [Formula: see text] and [Formula: see text] always comes below its experimental upper limit.
Microstructural features and mechanical properties of 18 MeV He+ ions irradiated pure Zr
Authors: Rafique Mohsin , Chae San , Kim Yong-Soo
Published: November 2016

Samples of pure zirconium (Zr) were irradiated by 18 MeV helium (He[Formula: see text]) ions in the dose range 0.00162–0.0324 dpa at 373 K by using Cyclotron accelerator. The atomic force microscopy (AFM) results indicated an increase in average surface roughness of Zr by increasing the irradiation dose. The AFM images revealed nucleation and growth of nano- and micro-size hillocks at lower doses (0.00162–0.00324 dpa), whereas formation of a volcano-like cavities and craters was observed within these hillocks by increasing the radiation dose from 0.00324 to 0.0324 dpa. The high-resolution X-ray diffraction (XRD) results showed a variation in the intensities and positions of the diffraction peaks after the irradiation. The transmission electron microscopy (TEM) results reported a significant decrease in the grain size after the He[Formula: see text] irradiation. The values of grain size, calculated using the TEM, were found to be in good agreement with the crystallite size calculated using the XRD analysis. The yield stress (YS) was increased by increasing the irradiation dose up to 0.0162 dpa, however, the YS exhibited a decreasing trend with a further increase of the dose. The changes in YS were elucidated by grain size reduction and localized heating at higher doses.
Narrow-dual-band perfect absorption plasmonic sensor in metamaterials based on the coupling of two resonators
Authors: Bai Ruiping , Jin Xing Ri , Zhang Ying Qiao , Zhang Shou , Lee Youngpak
Published: November 2016

We propose a narrow-dual-band metamaterial perfect absorber (MPA) made of metal-insulator-metal multilayer composite based on the coupling of two resonators. The absorptance of dual resonant peak all exceeding 95% at [Formula: see text][Formula: see text]nm and 98% at [Formula: see text][Formula: see text]nm ([Formula: see text] is the length of ‘left’–‘right’ pair), respectively, where the full absorption width at half-maximum is about 3% (low frequency) and 5% (high frequency). The narrow distance of dual resonant peak is 31.4[Formula: see text]THz together with 43.6[Formula: see text]THz when [Formula: see text][Formula: see text]nm and 290[Formula: see text]nm, respectively. In addition, we demonstrate that the MPA can work as a sensitive sensor for refractive index sensing. The figure of merit FOM* reaches 197.7 (low frequency) and 274.8 (high frequency) when [Formula: see text][Formula: see text]nm. The narrow-dual-band peak position can be controlled by changing [Formula: see text] as well.
Studies on growth and characterization of nonlinear optical L-tartaric acid–nicotinamide single crystal
Authors: Alexandar A. , Surendran P. , Sakthy Priya S. , Lakshmanan A. , Rameshkumar P.
Published: November 2016

Organic nonlinear optical (NLO) single crystal of L-tartaric acid–nicotinamide (LTN) has been grown by slow evaporation solution technique at a constant temperature of 40[Formula: see text]C. The grown crystals were subjected to various characterization techniques in order to examine their suitability for various applications. Powder X-ray diffraction (PXRD) analysis revealed that the compound is formed without any impurities. Functional groups and formation of the title compound were confirmed using FTIR analysis. Optical behavior of the material was examined using UV–Vis NIR spectrum analysis and the lower cut-off wavelength and optical band gap energy were calculated. Microhardness, dielectric and piezoelectric studies have been carried out at ambient conditions. Electronic properties such as valence electron plasma energy, Penn gap, Fermi energy and electronic polarizability were calculated by Clausius–Mossotti relation. Photoluminescence analysis was carried out to study the luminescence nature of the crystal and its defect states. In addition photoconductivity, etching studies and powder Kurtz and Perry second harmonic generation (SHG) test were carried out.
Vote Overreporting and a Survey Experiment: The Case of the Taiwan National Elections
Authors: WU CHUNG-LI , SU XIAOCHEN
Published: November 2016

The misreporting of voter turnout, prevalent in survey data across the world, has received comparatively little attention anywhere apart from in some western countries. This study evaluates the use of questions specifically designed to mitigate the level of vote overreporting for the 2012 national elections in Taiwan. After a theoretical examination of social desirability and memory failure, the two primary causes of misreporting, we present the results of a split-question experiment featuring two questions designed to mitigate overreporting. While the findings reveal that the experiment with changes to the questionnaire context was far from successful because of a low reported turnout for the control question, it is the case that, as hypothesized, reported voter turnout differs vastly among the different questions, with the question mitigating for social desirability resulting in higher figures than that for memory failure.
Numerical Simulations of Impacts of the 2004 Indian Ocean Tsunami on Coastal Morphological Changes Around the Ulee Lheue Bay of Aceh, Indonesia
Authors: Syamsidik  , Tursina  , Meutia Asrita , Al’ala Musa , Fahmi Mirza , Meilianda Ella
Published: November 2016

Wave forces during the 2004 Indian Ocean tsunami have caused morphological deformations of some coastal areas in Aceh, Indonesia. The sediment transport process during the tsunami wave propagation around near shore areas is a challenging numerical problem. To observe the coastal morphological changes after the Indian Ocean tsunami, this study numerically simulates the coastline changes, sedimentation and erosion areas, and seabed profiles changes around the Ulee Lheue Bay of Aceh, which was severely damaged by the tsunami. Two-dimensional horizontal areas were simulated by Cornell Multi-grid Coupled Tsunami (COMCOT) and Delft3D. Data of the nearshore area were collected from previous measurements acquired by the Indonesian Navy. According to the results, sediment in the sea area was deposited approximately 2.5[Formula: see text]km from the initial coastline, at the northern part of one small island occupying the Ulee Lheue Bay. This island reduced the energy of the tsunami waves during the backwash process, dumping a significant amount of eroded sediment near the coastline area.
A Compact Implementation of Salsa20 and Its Power Analysis Vulnerabilities
Authors: Mazumdar Bodhisatwa , Ali Sk. Subidh , Sinanoglu Ozgur
Published: November 2016

In this article, we present a compact implementation of the Salsa20 stream cipher that is targeted towards lightweight cryptographic devices such as radio-frequency identification (RFID) tags. The Salsa20 stream cipher, ann addition-rotation-XOR (ARX) cipher, is used for high-security cryptography in NEON instruction sets embedded in ARM Cortex A8 CPU core-based tablets and smartphones. The existing literature shows that although classical cryptanalysis has been effective on reduced rounds of Salsa20, the stream cipher is immune to software side-channel attacks such as branch timing and cache timing attacks. To the best of our knowledge, this work is the first to perform hardware power analysis attacks, where we evaluate the resistance of all eight keywords in the proposed compact implementation of Salsa20. Our technique targets the three subrounds of the first round of the implemented Salsa20. The correlation power analysis (CPA) attack has an attack complexity of 2
19
. Based on extensive experiments on a compact implementation of Salsa20, we demonstrate that all these keywords can be recovered within 20,000 queries on Salsa20. The attacks show a varying resilience of the key words against CPA that has not yet been observed in any stream or block cipher in the present literature. This makes the architecture of this stream cipher interesting from the side-channel analysis perspective. Also, we propose a lightweight countermeasure that mitigates the leakage in the power traces as shown in the results of Welch’s
t
-test statistics. The hardware area overhead of the proposed countermeasure is only 14% and is designed with compact implementation in mind.
Low-discrepancy blue noise sampling
Authors: Ahmed Abdalla G. M. , Perrier Hélène , Coeurjolly David , Ostromoukhov Victor , Guo Jianwei , Yan Dong-Ming , Huang Hui , Deussen Oliver
Published: November 2016

We present a novel technique that produces two-dimensional low-discrepancy (LD) blue noise point sets for sampling. Using one-dimensional binary van der Corput sequences, we construct two-dimensional LD point sets, and rearrange them to match a target spectral profile while preserving their low discrepancy. We store the rearrangement information in a compact lookup table that can be used to produce arbitrarily large point sets. We evaluate our technique and compare it to the state-of-the-art sampling approaches.
Parallel recursive filtering of infinite input extensions
Authors: Nehab Diego , Maximo André
Published: November 2016

Filters with slowly decaying impulse responses have many uses in computer graphics. Recursive filters are often the fastest option for such cases. In this paper, we derive closed-form formulas for computing the exact initial feedbacks needed for recursive filtering infinite input extensions. We provide formulas for the constant-padding (e.g. clamp-to-edge), periodic (repeat) and even-periodic (mirror or reflect) extensions. These formulas were designed for easy integration into modern block-parallel recursive filtering algorithms. Our new modified algorithms are state-of-the-art, filtering images faster even than previous methods that ignore boundary conditions.
3D attention-driven depth acquisition for object identification
Authors: Xu Kai , Shi Yifei , Zheng Lintao , Zhang Junyu , Liu Min , Huang Hui , Su Hao , Cohen-Or Daniel , Chen Baoquan
Published: November 2016

We address the problem of autonomously exploring unknown objects in a scene by consecutive depth acquisitions. The goal is to reconstruct the scene while online identifying the objects from among a large collection of 3D shapes. Fine-grained shape identification demands a meticulous series of observations attending to varying views and parts of the object of interest. Inspired by the recent success of attention-based models for 2D recognition, we develop a
3D Attention Model
that selects the best views to scan from, as well as the most informative regions in each view to focus on, to achieve efficient object recognition. The region-level attention leads to focus-driven features which are quite robust against object occlusion. The attention model, trained with the 3D shape collection, encodes the temporal dependencies among consecutive views with deep recurrent networks. This facilitates order-aware view planning accounting for robot movement cost. In achieving instance identification, the shape collection is organized into a hierarchy, associated with pre-trained hierarchical classifiers. The effectiveness of our method is demonstrated on an autonomous robot (PR) that explores a scene and identifies the objects to construct a 3D scene model.
Representing and scheduling procedural generation using operator graphs
Authors: Boechat Pedro , Dokter Mark , Kenzel Michael , Seidel Hans-Peter , Schmalstieg Dieter , Steinberger Markus
Published: November 2016

In this paper, we present the concept of operator graph scheduling for high performance procedural generation on the graphics processing unit (GPU). The operator graph forms an intermediate representation that describes all possible operations and objects that can arise during a specific procedural generation. While previous methods have focused on parallelizing a specific procedural approach, the operator graph is applicable to all procedural generation methods that can be described by a graph, such as L-systems, shape grammars, or stack based generation methods. Using the operator graph, we show that all partitions of the graph correspond to possible ways of scheduling a procedural generation on the GPU, including the scheduling strategies of previous work. As the space of possible partitions is very large, we describe three search heuristics, aiding an optimizer in finding the fastest valid schedule for any given operator graph. The best partitions found by our optimizer increase performance of 8 to 30x over the previous state of the art in GPU shape grammar and L-system generation.
Descent methods for elastic body simulation on the GPU
Authors: Wang Huamin , Yang Yin
Published: November 2016

We show that many existing elastic body simulation approaches can be interpreted as descent methods, under a nonlinear optimization framework derived from implicit time integration. The key question is how to find an effective descent direction with a low computational cost. Based on this concept, we propose a new gradient descent method using Jacobi preconditioning and Chebyshev acceleration. The convergence rate of this method is comparable to that of L-BFGS or nonlinear conjugate gradient. But unlike other methods, it requires no dot product operation, making it suitable for GPU implementation. To further improve its convergence and performance, we develop a series of step length adjustment, initialization, and invertible model conversion techniques, all of which are compatible with GPU acceleration. Our experiment shows that the resulting simulator is simple, fast, scalable, memory-efficient, and robust against very large time steps and deformations. It can correctly simulate the deformation behaviors of many elastic materials, as long as their energy functions are second-order differentiable and their Hessian matrices can be quickly evaluated. For additional speedups, the method can also serve as a complement to other techniques, such as multi-grid.
Gesture3D
Authors: Bessmeltsev Mikhail , Vining Nicholas , Sheffer Alla
Published: November 2016

Artists routinely use
gesture drawings
to communicate ideated character poses for storyboarding and other digital media. During subsequent posing of the 3D character models, they use these drawing as a reference, and perform the posing itself using 3D interfaces which require time and expert 3D knowledge to operate. We propose the first method for automatically posing 3D characters directly using gesture drawings as an input, sidestepping the manual 3D posing step. We observe that artists are skilled at quickly and effectively conveying poses using such drawings, and design them to facilitate a single perceptually consistent pose interpretation by viewers. Our algorithm leverages perceptual cues to parse the drawings and recover the artist-intended poses. It takes as input a vector-format rough gesture drawing and a rigged 3D character model, and plausibly poses the character to conform to the depicted pose. No other input is required. Our contribution is two-fold: we first analyze and formulate the pose cues encoded in gesture drawings; we then employ these cues to compute a plausible image space projection of the conveyed pose and to imbue it with depth. Our framework is designed to robustly overcome errors and inaccuracies frequent in typical gesture drawings. We exhibit a wide variety of character models posed by our method created from gesture drawings of complex poses, including poses with occlusions and foreshortening. We validate our approach via result comparisons to artist-posed models generated from the same reference drawings, via studies that confirm that our results agree with viewer perception, and via comparison to algorithmic alternatives.
Robust background identification for dynamic video editing
Authors: Zhang Fang-Lue , Wu Xian , Zhang Hao-Tian , Wang Jue , Hu Shi-Min
Published: November 2016

Extracting background features for estimating the camera path is a key step in many video editing and enhancement applications. Existing approaches often fail on highly dynamic videos that are shot by moving cameras and contain severe foreground occlusion. Based on existing theories, we present a new, practical method that can reliably identify background features in complex video, leading to accurate camera path estimation and background layering. Our approach contains a local motion analysis step and a global optimization step. We first divide the input video into overlapping temporal windows, and extract local motion clusters in each window. We form a directed graph from these local clusters, and identify background ones by finding a minimal path through the graph using optimization. We show that our method significantly outperforms other alternatives, and can be directly used to improve common video editing applications such as stabilization, compositing and background reconstruction.
Adaptive matrix column sampling and completion for rendering participating media
Authors: Huo Yuchi , Wang Rui , Hu Tianlei , Hua Wei , Bao Hujun
Published: November 2016

Several scalable many-light rendering methods have been proposed recently for the efficient computation of global illumination. However, gathering contributions of virtual lights in participating media remains an inefficient and time-consuming task. In this paper, we present a novel sparse sampling and reconstruction method to accelerate the gathering step of the many-light rendering for participating media. Our technique explores the observation that the scattered lightings are usually locally coherent and of low rank even in heterogeneous media. In particular, we first introduce a matrix formation with light segments as columns and eye ray segments as rows, and formulate the gathering step into a matrix sampling and reconstruction problem. We then propose an adaptive matrix column sampling and completion algorithm to efficiently reconstruct the matrix by only sampling a small number of elements. Experimental results show that our approach greatly improves the performance, and obtains up to one order of magnitude speedup compared with other state-of-the-art methods of many-light rendering for participating media.
Optimal voronoi tessellations with hessian-based anisotropy
Authors: Budninskiy Max , Liu Beibei , de Goes Fernando , Tong Yiying , Alliez Pierre , Desbrun Mathieu
Published: November 2016

This paper presents a variational method to generate cell complexes with local anisotropy conforming to the Hessian of any given convex function and for any given local mesh density. Our formulation builds upon approximation theory to offer an anisotropic extension of Centroidal Voronoi Tessellations which can be seen as a dual form of Optimal Delaunay Triangulation. We thus refer to the resulting anisotropic polytopal meshes as
Optimal Voronoi Tessellations.
Our approach sharply contrasts with previous anisotropic versions of Voronoi diagrams as it employs first-type Bregman diagrams, a generalization of power diagrams where sites are augmented with not only a scalar-valued weight but also a vector-valued shift. As such, our OVT meshes contain only convex cells with straight edges, and admit an embedded dual triangulation that is combinatorially-regular. We show the effectiveness of our technique using off-the-shelf computational geometry libraries.
Printone
Authors: Umetani Nobuyuki , Panotopoulou Athina , Schmidt Ryan , Whiting Emily
Published: November 2016

This paper presents an interactive design interface for three-dimensional free-form musical wind instruments. The sound of a wind instrument is governed by the acoustic resonance as a result of complicated interactions of sound waves and internal geometries of the instrument. Thus, creating an original free-form wind instrument by manual methods is a challenging problem. Our interface provides interactive sound simulation feedback as the user edits, allowing exploration of original wind instrument designs. Sound simulation of a 3D wind musical instrument is known to be computationally expensive. To overcome this problem, we first model the wind instruments as a passive resonator, where we ignore coupled oscillation excitation from the mouthpiece. Then we present a novel efficient method to estimate the resonance frequency based on the boundary element method by formulating the resonance problem as a minimum eigenvalue problem. Furthermore, we can efficiently compute an approximate resonance frequency using a new technique based on a generalized eigenvalue problem. The designs can be fabricated using a 3D printer, thus we call the results "print-wind instruments" in association with woodwind instruments. We demonstrate our approach with examples of unconventional shapes performing familiar songs.
Learning-based view synthesis for light field cameras
Authors: Kalantari Nima Khademi , Wang Ting-Chun , Ramamoorthi Ravi
Published: November 2016

With the introduction of consumer light field cameras, light field imaging has recently become widespread. However, there is an inherent trade-off between the angular and spatial resolution, and thus, these cameras often sparsely sample in either spatial or angular domain. In this paper, we use machine learning to mitigate this trade-off. Specifically, we propose a novel learning-based approach to synthesize new views from a sparse set of input views. We build upon existing view synthesis techniques and break down the process into disparity and color estimation components. We use two sequential convolutional neural networks to model these two components and train both networks simultaneously by minimizing the error between the synthesized and ground truth images. We show the performance of our approach using only four corner sub-aperture views from the light fields captured by the Lytro Illum camera. Experimental results show that our approach synthesizes high-quality images that are superior to the state-of-the-art techniques on a variety of challenging real-world scenes. We believe our method could potentially decrease the required angular resolution of consumer light field cameras, which allows their spatial resolution to increase.
Simulating the structure and texture of solid wood
Authors: Liu Albert Julius , Dong Zhao , Hašan Miloš , Marschner Steve
Published: November 2016

Wood is an important decorative material prized for its unique appearance. It is commonly rendered using artistically authored 2D color and bump textures, which reproduces color patterns on flat surfaces well. But the dramatic anisotropic specular figure caused by wood fibers, common in curly maple and other species, is harder to achieve. While suitable BRDF models exist, the texture parameter maps for these wood BRDFs are difficult to author---good results have been shown with elaborate measurements for small flat samples, but these models are not much used in practice. Furthermore, mapping 2D image textures onto 3D objects leads to distortion and inconsistencies. Procedural volumetric textures solve these geometric problems, but existing methods produce much lower quality than image textures. This paper aims to bring the best of all these techniques together: we present a comprehensive volumetric simulation of wood appearance, including growth rings, color variation, pores, rays, and growth distortions. The fiber directions required for anisotropic specular figure follow naturally from the distortions. Our results rival the quality of textures based on photographs, but with the consistency and convenience of a volumetric model. Our model is modular, with components that are intuitive to control, fast to compute, and require minimal storage.
Temporally coherent completion of dynamic video
Authors: Huang Jia-Bin , Kang Sing Bing , Ahuja Narendra , Kopf Johannes
Published: November 2016

We present an automatic video completion algorithm that synthesizes missing regions in videos in a temporally coherent fashion. Our algorithm can handle dynamic scenes captured using a moving camera. State-of-the-art approaches have difficulties handling such videos because viewpoint changes cause image-space motion vectors in the missing and known regions to be inconsistent. We address this problem by jointly estimating optical flow and color in the missing regions. Using pixel-wise forward/backward flow fields enables us to synthesize temporally coherent colors. We formulate the problem as a non-parametric patch-based optimization. We demonstrate our technique on numerous challenging videos.