bluuebunny/crossref_metadata_2025 huggingface dataset:
A Validation Study of the Repeatability and Accuracy of Atomic Force Microscopy Indentation Using Polyacrylamide Gels and Colloidal Probes
Authors: Lee Donghee , Ryu Sangjin
Published: December 2016

The elasticity of soft biological materials is a critical property to understand their biomechanical behaviors. Atomic force microscopy (AFM) indentation method has been widely employed to measure the Young's modulus (E) of such materials. Although the accuracy of the method has been recently evaluated based on comparisons with macroscale E measurements, the repeatability of the method has yet to be validated for rigorous biomechanical studies of soft elastic materials. We tested the AFM indentation method using colloidal probes and polyacrylamide (PAAM) gels of E < 20 kPa as a model soft elastic material after having identified optimal trigger force and probe speed. AFM indentations repeated with time intervals show that the method is well repeatable when performed carefully. Compared with the rheometric method and the confocal microscopy indentation method, the AFM indentation method is evaluated to have comparable accuracy and better precision, although these elasticity measurements appear to rely on the compositions of PAAM gels and the length scale of measurement. Therefore, we have confirmed that the AFM indentation method can reliably measure the elasticity of soft elastic materials.
Inspiration and Fixation: The Influences of Example Designs and System Properties in Idea Generation
Authors: Vasconcelos Luis A. , Cardoso Carlos C. , Sääksjärvi Maria , Chen Chih-Chun , Crilly Nathan
Published: December 2016

When tackling problems, designers might be inspired by different sources, whether concrete or abstract. The more concrete sources often comprise representations of potential solutions or examples of existing designs. The more abstract sources often represent the desirable properties of engineered systems, such as modular system architectures. We performed an experiment with 60 novice designers to compare the inspiration effects from these two types of stimuli. Participants were asked to solve a design problem, having been exposed to a concrete example design, an abstract system property, both, or no stimulus at all. Their design work was assessed according to four metrics: fluency, diversity, commonness, and conformity. Exposure to either the example design or the system property reduced the fluency and diversity of ideas, and exposure to both stimuli reduced these measures even further. While there was no difference in the inspiration effects from the example and the property in terms of fluency, diversity, and commonness; results for conformity showed that each stimulus constrained participants differently: encouraging ideas similar to one type of stimulus, while discouraging ideas similar to the other type. In combination with other work on inspiration and fixation, these findings can help shape how design is taught and how inspiration tools are developed.
Research on Rolling Parallel Robot With Hydraulic Driven Antiparallelogram Chain
Authors: Shen Haikuo , Zhang Kaihua , Nejati Afsoon
Published: December 2016

Aiming at acquiring large deformation capability, powerful strength output, rapid response, and flexible locomotion, a novel three degrees-of-freedoms (DOFs) rolling parallel robot is proposed. This robot adopts the parallel mechanism, and its structure can guarantee the stiffness of the robot. The large capability of deformation can be obtained by taking advantage of the antiparallelogram mechanism with an enlarging mechanism of extension ratio. Hydraulic actuation is used for the telescopic input, which can increase the locomotion flexibility and the strength output of the robot. Rolling motion of the robot can be reached through planning and controlling the relations between the center of mass (CM) of the robot and the supporting region. The mechanical construction and configuration of the robot are described, the rolling gaits are planned, and the optimal locomotion law is given. Based on the law, the kinematic model of the robot is created. The kinematic model is validated by the given numerical example. The locomotion feasibility of two locomotion periods is analyzed. A set of experimental tests on the hydraulic system and the robotic system are performed. Results of four rolling experiments verify the reliability of the experimental system and the rapid response capability and also verify the validity and feasibility of the theoretical analysis and the rolling locomotion.
Development of Kinetic Models for the Long-Term Corrosion Behavior of Candidate Alloys for the Canadian SCWR
Authors: Steeves G. , Cook W.
Published: December 2016

Corrosion behavior of Inconel 625 and Incoloy 800H, two of the candidate fuel cladding materials for Canadian supercritical water-cooled reactor (SCWR) designs, was evaluated by exposing the metals to supercritical water (SCW) in the University of New Brunswick’s flow loop. A series of experiments were conducted over a range of temperatures between 370 °C and 600 °C, and the corrosion rates were evaluated as the weight change of the materials over the exposure time (typical experiments measured the weight change at intervals of 100, 250, and 500 h, with some longer-term exposures included). Scanning electron microscopy (SEM) was used to examine and quantify the oxide films formed during exposure and the corrosion mechanisms occurring on the candidate metals. Data from in-house experiments were used to create an empirical kinetic equation for each material that was then compared to literature values of weight change. Dissolved oxygen concentrations varied between experimental sets, but for simplicity were ignored since the effect of dissolved oxygen has been demonstrated to be a minor secondary effect. Activation energies for the alloys were determined with Inconel 625 and Incoloy 800 H showing a distinct difference between the low-temperature electrochemical corrosion (EC) mechanism and direct high-temperature chemical oxidation (CO). The results were modeled using these separate effects showing dependence on the bulk density and dielectric constant of the supercritical water through the hydrogen ion concentration.
Girls’ Sport in Northern Uganda: A Postcolonial Feminist Exploration of Definitions and Benefits
Authors: Johnson Alicia J. , Whitley Meredith A.
Published: December 2016

Sport is increasingly used as a tool for development and peacebuilding to reach an array of populations (Hayhurst, 2009), including girls and women in the Two-Thirds World (Brady, 2005; Hayhurst, 2014; Saavedra, 2009). However, scholars have cautioned against a universal definition of sport considering its historical link to colonization (Darnell & Hayhurst, 2011; Saavedra, 2009) as well as the promotion of universal benefits of sport for girls (Brady, 2005; Larkin, Razack, & Moola, 2007). Therefore, a postcolonial feminist framework was employed to qualitatively explore how 12 secondary school girls in northern Uganda define sport. In addition, participants in this study identified the benefits that they and other girls and women receive from participating in sport. Semistructured interviews were conducted face-to-face and were transcribed, coded, and thematized by the researchers. Trustworthiness was established by engaging a peer debriefer from Uganda and critical awareness of researcher positionality through reflexivity. Results include how the participants defined sport and physical activity, some as a singular and others as a binary concept, and how girls benefit from participating in sport in northern Uganda. The identified benefits include aspects of health, social life, engagement, opportunities, socioemotional development, and competition. Many of these benefits are congruent with literature from within and outside of Uganda; however, the results also indicate a need for a deeper understanding of how communities define and benefit from sport where sport for development programs are delivered. Connections between the results and the postcolonial feminist framework, study limitations and future research directions are also discussed.
The “Squat-n-Swap”: A Pilot Exercise Intervention to Promote Increased Physical Activity among Mothers of Young Children
Authors: Skidmore Brook L. , Keeler Linda , Chalmers Gordon , Russell Keith
Published: December 2016

A large majority of mothers of young children are not sufficiently physically active to obtain health benefits, and motherhood itself has been associated with irregular physical activity. Ironically, however, a mother’s demanding and busy life presents a situation for which exercise may be extremely advantageous. Therefore, the purpose of the current study was to determine the effectiveness of an exercise intervention for increasing physical activity levels and perceived social support for exercise among mothers of young children who serve as primary caregivers. Thirty one mothers with at least one child under the age of five participated in the study. A treatment group (n = 16) participated in an instructor-led “Squat-n-Swap” exercise program once per week for four weeks, followed by four weeks without instructor supervision. A control group (n = 15) did not participate in the exercise program. Participants completed a questionnaire before and after the study. Mixed between-within groups ANOVAs with a significance of p < .05 were used to analyze the data, in addition to post hoc t tests. A chi square analysis was also used. Cross tabs revealed positive changes in women’s perceptions of changes in their physical activity levels. Results also revealed significant interactions for support in the forms of childcare, information, companionship, and validation. The “Squat-N-Swap” model might be a useful option for mothers of young children who would benefit from social support to exercise; however, more research is needed to ascertain this program’s effectiveness in increasing physical activity levels among this population.
AAAS reaches out to theology students
Authors: Jarvis Michaela
Published: December 2016

Program fosters dialogue between scientific and religious communities
Distribution and clinical impact of functional variants in 50,726 whole-exome sequences from the DiscovEHR study
Authors: Dewey Frederick E. , Murray Michael F. , Overton John D. , Habegger Lukas , Leader Joseph B. , Fetterolf Samantha N. , O’Dushlaine Colm , Van Hout Cristopher V. , Staples Jeffrey , Gonzaga-Jauregui Claudia , Metpally Raghu , Pendergrass Sarah A. , Giovanni Monica A. , Kirchner H. Lester , Balasubramanian Suganthi , Abul-Husn Noura S. , Hartzel Dustin N. , Lavage Daniel R. , Kost Korey A. , Packer Jonathan S. , Lopez Alexander E. , Penn John , Mukherjee Semanti , Gosalia Nehal , Kanagaraj Manoj , Li Alexander H. , Mitnaul Lyndon J. , Adams Lance J. , Person Thomas N. , Praveen Kavita , Marcketta Anthony , Lebo Matthew S. , Austin-Tse Christina A. , Mason-Suares Heather M. , Bruse Shannon , Mellis Scott , Phillips Robert , Stahl Neil , Murphy Andrew , Economides Aris , Skelding Kimberly A. , Still Christopher D. , Elmore James R. , Borecki Ingrid B. , Yancopoulos George D. , Davis F. Daniel , Faucett William A. , Gottesman Omri , Ritchie Marylyn D. , Shuldiner Alan R. , Reid Jeffrey G. , Ledbetter David H. , Baras Aris , Carey David J.
Published: December 2016

Unleashing the power of precision medicine

Precision medicine promises the ability to identify risks and treat patients on the basis of pathogenic genetic variation. Two studies combined exome sequencing results for over 50,000 people with their electronic health records. Dewey
et al.
found that ∼3.5% of individuals in their cohort had clinically actionable genetic variants. Many of these variants affected blood lipid levels that could influence cardiovascular health. Abul-Husn
et al.
extended these findings to investigate the genetics and treatment of familial hypercholesterolemia, a risk factor for cardiovascular disease, within their patient pool. Genetic screening helped identify at-risk patients who could benefit from increased treatment.

Science
, this issue p.
10.1126/science.aaf6814
, p.
10.1126/science.aaf7000
Large benefits to marine fisheries of meeting the 1.5°C global warming target
Authors: Cheung William W. L. , Reygondeau Gabriel , Frölicher Thomas L.
Published: December 2016

Marine benefits of the Paris Agreement

Keeping recent global agreements to limit temperature increases to 1.5° to 2°C above preindustrial levels will have benefits across terrestrial ecosystems. But what about marine ecosystems? Cheung
et al.
modeled the influence of temperature increases on two key measures of fishery sustainability, catch and species turnover (see the Perspective by Fulton). Limiting temperature increases to 1.5°C substantially improved catch potential and decreased turnover of harvested species. These results provide further support for meeting this important goal.

Science
, this issue p.
1591
; see also p.
1530
Mass seasonal bioflows of high-flying insect migrants
Authors: Hu Gao , Lim Ka S. , Horvitz Nir , Clark Suzanne J. , Reynolds Don R. , Sapir Nir , Chapman Jason W.
Published: December 2016

Mass movement of “invisibles”

We know a lot about vertebrate migrations globally. However, the majority of animals that live on this planet are invertebrates, and we know very little about their movements. Hu
et al.
monitored the migration of large and small insects over the southern United Kingdom for a decade. They found that more than a trillion insects move across this region annually. The movement of such a large biomass has considerable impacts on the ecosystems between which the insects migrate.

Science
, this issue p.
1584
Active cortical dendrites modulate perception
Authors: Takahashi Naoya , Oertner Thomas G. , Hegemann Peter , Larkum Matthew E.
Published: December 2016

Now you feel it, now you don't

What determines the detection of a sensory stimulus? To address this question, Takahashi
et al.
combined in vivo two-photon imaging, electrophysiology, optogenetics, and behavioral analysis in a study of mice. Calcium signals in apical dendrites of pyramidal neurons in the somatosensory cortex controlled the perceptual threshold of the mice's whiskers. Strong reduction of dendritic calcium signaling impaired the perceptual detection threshold so that an identical stimulus could no longer be noticed.

Science
, this issue p.
1587
Response to Comment on “Structural basis of histone H3K27 trimethylation by an active polycomb repressive complex 2”
Authors: Jiao Lianying , Liu Xin
Published: December 2016

Zhang
et al
. suggested that in the crystal structure of a polycomb repressive complex 2 from
Chaetomium thermophilum
(
ct
PRC2), a flexible linker region, but not the H3K27M cancer mutant peptide, better fits the electron density. Based on our new data, we agree with this alternative interpretation and provide the crystal structure of
ct
PRC2 bound to a bona fide H3K27M sequence.
Emergence of hierarchical structural complexities in nanoparticles and their assembly
Authors: Zeng Chenjie , Chen Yuxiang , Kirschbaum Kristin , Lambright Kelly J. , Jin Rongchao
Published: December 2016

Probing packing rules

The crystals of a well-defined ligand-covered gold nanoparticle can reveal how packing into a lattice happens. Zeng
et al.
synthesized nanoparticles with a 246-atom gold core surrounded by 80 4-methylbenzenethiol ligands. These nearly spherical nanoparticles did not pack into a cubic arrangement but instead formed a lower-symmetry monoclinic structure. A hierarchy of interparticle ligand interactions controlled the packing, including sets of chiral packing arrangements that reversed between layers.

Science
, this issue p.
1580
More than a day in the life of a comet
Authors: Russo N. Dello
Published: December 2016

Learning how a comet evolves can reveal the nature of the early solar system
Awesome universal chirp
Authors: Berg Jeremy
Published: December 2016

In 1978, while I was an undergraduate student, Kip Thorne came to Stanford University to give a seminar on a proposed search for gravitational waves. The auditorium quickly filled with experts and inquisitive students like me. As Thorne described a quest for these ripples in space-time, the audience grew palpably skeptical. Albert Einstein had predicted the existence of gravitational waves based on his theory of general relativity, but even he was doubtful that they would ever be detected because they were anticipated to be so weak. Listening to Thorne propose an approach for measuring such waves, I had no idea that he and his colleagues were about to begin a 40-year journey to discover what
Science
now recognizes as the 2016 Breakthrough of the Year. The announcement that gravitational waves had indeed been detected opens up a new window into the universe (see the News story on p.
1516
).
Committing CAR T cells to memory
Authors: Thomas Susan Napier
Published: December 2016

T memory stem cell phenotype induced by tethered IL-15 augments anticancer effects of CAR T cell therapy.
An Expanded Transposon Mutant Library Reveals that Vibrio fischeri δ-Aminolevulinate Auxotrophs Can Colonize Euprymna scolopes
Authors: Lyell Noreen L. , Septer Alecia N. , Dunn Anne K. , Duckett Drew , Stoudenmire Julie L. , Stabb Eric V.
Published: December 2016

Libraries of defined mutants are valuable research tools but necessarily lack gene knockouts that are lethal under the conditions used in library construction. In this study, we augmented a
Vibrio fischeri
mutant library generated on a rich medium (LBS, which contains [per liter] 10 g of tryptone, 5 g of yeast extract, 20 g of NaCl, and 50 mM Tris [pH 7.5]) by selecting transposon insertion mutants on supplemented LBS and screening for those unable to grow on LBS. We isolated strains with insertions in
alr
,
glr
(
murI
),
glmS
, several heme biosynthesis genes, and
ftsA
, as well as a mutant disrupted 14 bp upstream of
ftsQ
. Mutants with insertions in
ftsA
or upstream of
ftsQ
were recovered by addition of Mg
2+
to LBS, but their cell morphology and motility were affected. The
ftsA
mutant was more strongly affected and formed cells or chains of cells that appeared to wind back on themselves helically. Growth of mutants with insertions in
glmS
,
alr
, or
glr
was recovered with
N
-acetylglucosamine (NAG),
d
-alanine, or
d
-glutamate, respectively. We hypothesized that NAG,
d
-alanine, or
d
-glutamate might be available to
V. fischeri
in the
Euprymna scolopes
light organ; however, none of these mutants colonized the host effectively. In contrast,
hemA
and
hemL
mutants, which are auxotrophic for δ-aminolevulinate (ALA), colonized at wild-type levels, although mutants later in the heme biosynthetic pathway were severely impaired or unable to colonize. Our findings parallel observations that legume hosts provide
Bradyrhizobium
symbionts with ALA, but they contrast with virulence phenotypes of
hemA
mutants in some pathogens. The results further inform our understanding of the symbiotic light organ environment.

IMPORTANCE
By supplementing a rich yeast-based medium, we were able to recover
V. fischeri
mutants with insertions in conditionally essential genes, and further characterization of these mutants provided new insights into this bacterium's symbiotic environment. Most notably, we show evidence that the squid host can provide
V. fischeri
with enough ALA to support its growth in the light organ, paralleling the finding that legumes provide
Bradyrhizobium
ALA in symbiotic nodules. Taken together, our results show how a simple method of augmenting already rich media can expand the reach and utility of defined mutant libraries.
Residues in the gp41 Ectodomain Regulate HIV-1 Envelope Glycoprotein Conformational Transitions Induced by gp120-Directed Inhibitors
Authors: Pacheco Beatriz , Alsahafi Nirmin , Debbeche Olfa , Prévost Jérémie , Ding Shilei , Chapleau Jean-Philippe , Herschhorn Alon , Madani Navid , Princiotto Amy , Melillo Bruno , Gu Christopher , Zeng Xin , Mao Youdong , Smith Amos B. , Sodroski Joseph , Finzi Andrés
Published: December 2016

Interactions between the gp120 and gp41 subunits of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) trimer maintain the metastable unliganded form of the viral spike. Binding of gp120 to the receptor, CD4, changes the Env conformation to promote gp120 interaction with the second receptor, CCR5 or CXCR4. CD4 binding also induces the transformation of Env into the prehairpin intermediate, in which the gp41 heptad repeat 1 (HR1) coiled coil is assembled at the trimer axis. In nature, HIV-1 Envs must balance the requirements to maintain the noncovalent association of gp120 with gp41 and to evade the host antibody response with the need to respond to CD4 binding. Here we show that the gp41 HR1 region contributes to gp120 association with the unliganded Env trimer. Changes in particular amino acid residues in the gp41 HR1 region decreased the efficiency with which Env moved from the unliganded state. Thus, these gp41 changes decreased the sensitivity of HIV-1 to cold inactivation and ligands that require Env conformational changes to bind efficiently. Conversely, these gp41 changes increased HIV-1 sensitivity to small-molecule entry inhibitors that block Env conformational changes induced by CD4. Changes in particular gp41 HR1 amino acid residues can apparently affect the relative stability of the unliganded state and CD4-induced conformations. Thus, the gp41 HR1 region contributes to the association with gp120 and regulates Env transitions from the unliganded state to downstream conformations.

IMPORTANCEThe development of an efficient vaccine able to prevent HIV infection is a worldwide priority. Knowledge of the envelope glycoprotein structure and the conformational changes that occur after receptor engagement will help researchers to develop an immunogen able to elicit antibodies that block HIV-1 transmission. Here we identify residues in the HIV-1 transmembrane envelope glycoprotein that stabilize the unliganded state by modulating the transitions from the unliganded state to the CD4-bound state.
Toll-Like Receptor Signaling and Its Inducible Proteins
Authors: Satoh Takashi , Akira Shizuo
Published: December 2016

Studies that bridge innate immunity and various diseases are making rapid advances. Macrophages and dendritic cells play a leading role in innate immunity, using pattern recognition receptors (PRRs) to sense both pathogen invasion and danger signals. Among these PRRs, the Toll-like receptors (TLRs) play a central role in the immune response by recognizing not only pathogen-associated molecular patterns from bacteria and viruses but also damage-associated molecular patterns from dying or injured cells. These TLR family molecules facilitate not only the elimination of pathogens but also the development of various disorders, including arteriosclerosis, cancer, and metabolic syndrome. TLRs activate signaling pathways that result in the production of cytokines, chemokines, and various inducible molecules associated with the immune response. Although most components of the innate immune signaling pathways, such as the TLR family and its downstream signaling, have been identified, the physiological roles of many TLR signal-inducible proteins remain unclear. Recent studies have shown that some TLR-inducible proteins are critical in the immune response and the development of various disorders. In this review, we focus on the TLR signaling pathways and the roles of some TLR-inducible proteins.
Eatwell Guide: modelling the dietary and cost implications of incorporating new sugar and fibre guidelines
Authors: Scarborough Peter , Kaur Asha , Cobiac Linda , Owens Paul , Parlesak Alexandr , Sweeney Kate , Rayner Mike
Published: December 2016

Objectives

To model food group consumption and price of diet associated with achieving UK dietary recommendations while deviating as little as possible from the current UK diet, in order to support the redevelopment of the UK food-based dietary guidelines (now called the Eatwell Guide).

Design

Optimisation modelling, minimising an objective function of the difference between population mean modelled and current consumption of 125 food groups, and constraints of nutrient and food-based recommendations.

Setting

The UK.

Population

Adults aged 19 years and above from the National Diet and Nutrition Survey 2008–2011.

Main outcome measures

Proportion of diet consisting of major foods groups and price of the optimised diet.

Results

The optimised diet has an increase in consumption of ‘potatoes, bread, rice, pasta and other starchy carbohydrates’ (+69%) and ‘fruit and vegetables’ (+54%) and reductions in consumption of ‘beans, pulses, fish, eggs, meat and other proteins’ (−24%), ‘dairy and alternatives’ (−21%) and ‘foods high in fat and sugar’ (−53%). Results within food groups show considerable variety (eg, +90% for beans and pulses, −78% for red meat). The modelled diet would cost £5.99 (£5.93 to £6.05) per adult per day, very similar to the cost of the current diet: £6.02 (£5.96 to £6.08). The optimised diet would result in increased consumption of n-3 fatty acids and most micronutrients (including iron and folate), but decreased consumption of zinc and small decreases in consumption of calcium and riboflavin.

Conclusions

To achieve the UK dietary recommendations would require large changes in the average diet of UK adults, including in food groups where current average consumption is well within the recommended range (eg, processed meat) or where there are no current recommendations (eg, dairy). These large changes in the diet will not lead to significant changes in the price of the diet.
Bucket foundation model testing under tensile axial loading
Authors: Vaitkune Evelina , Ibsen Lars Bo , Nielsen Benjaminn Nordahl
Published: December 2016

The present study focusses on bucket foundation behaviour under long-term cyclic loading. The paper analyses testing results of a bucket foundation model exposed to cyclic tensile loading. The model, with dimensions of 1 m in diameter and 0.5 m in skirt length, was, installed in dense water-saturated sand. Slow monotonic loading tests and cyclic tensile loading tests were performed (up to 40 000 load cycles) including tests with mean cyclic loading in tension, which is a unique testing condition. High-quality data were documented for load, displacement, and pore pressure response. Conclusions have been drawn regarding static and cyclic loading stiffness and displacement development during long-term cyclic loading. Four cyclic loading tests induced partially drained soil conditions and showed that pore pressure can accumulate during the long-term loading. Post-cyclic monotonic tensile loading tests showed up to 25% reduction in load capacity of the foundation. The research results provide valuable information for the design of an upwind bucket foundation under a jacket structure.
Prevailing scenario of women in physics in Pakistan: A case study of Southern Punjab
Authors: Khan Sobia Ali , Mahboob Memona , Yaqoob Tahira , Zeerak Nosheena , Rani Malika
Published: December 2016

The present study reveals the current status of women physicists of Southern Punjab, which is an undeveloped area of Pakistan. To flourish as a growing nation, Pakistani setup needs a change in society, where women are given equal rights in the field of education. This study will also give a brief description of factors due to which female students face hurdles for higher education in physics.
How to communicate effectively in graduate advising
Authors: Wagner H.H. , Temple S. , Dankert I. , Napper R.
Published: December 2016

This paper completes a two-part series on graduate advising that integrates concepts from adult learning, leadership, and psychology into a conceptual framework for graduate advising. The companion paper discussed how to establish a learning-centered working relationship where advisor and graduate student collaborate in different roles to develop the student’s competence and confidence in all aspects of becoming a scientist. To put these ideas into practice, an advisor and a student need to communicate effectively. Here, we focus on the dynamics of day-to-day interactions and discuss (1) how to provide feedback that builds students’ competence and confidence, (2) how to choose the way we communicate and avoid a mismatch between verbal and nonverbal communication, and (3) how to prevent and resolve conflict. Miscommunication may happen out of a lack of understanding of the psychological aspects of human interactions. Therefore, we draw on concepts from Educational Transactional Analysis to provide advisors and students with an understanding of the psychological aspects of graduate advising as a basis for effective communication. Case studies illustrate the relevance of the concepts presented, and four worksheets ( Supplementary Material ) support their practical implementation.
A New Self-Certified Convertible Authenticated Encryption Scheme Based on Discrete Logarithm Problem
Authors: Chande Manoj Kumar , Lee Cheng-Chi , Li Chun-Ta
Published: December 2016

The convertible authentication encryption (CAE) scheme, enables the signatory to send a secret message and its associated signature to a designated receiver. If some dispute happens, then the receiver has the ability to get ordinary signature by converting the ciphertext signature. The receiver can solely perform this signature conversion without any extra computational costs. The recipient of the signature can prove himself that he/she is the actual designated recipient. We incorporate self - certified public key (SCPK) systems into a CAE scheme to propose our CAE scheme with authentication and computationally indistinguishable. Our CAE scheme provide robust security and apply it to different online financial applications. The security analysis reflects that, our CAE scheme satisfies all the security requirements. Moreover, it does not require additional certificate verification because the public key authentication and signature verification can be done in single logical step. Finally, from the result of performance analysis shows, that the presented CAE scheme is cost efficient than the existing Wu et al.’s scheme.
Optimizing Weather Model Radiative Transfer Physics for Intel’s Many Integrated Core (MIC) Architecture
Authors: Michalakes John , Iacono Michael J. , Jessup Elizabeth R.
Published: December 2016

Large numerical weather prediction (NWP) codes such as the Weather Research and Forecast (WRF) model and the NOAA Nonhydrostatic Multiscale Model (NMM-B) port easily to Intel's Many Integrated Core (MIC) architecture. But for NWP to significantly realize MIC’s one- to two-TFLOP/s peak computational power, we must expose and exploit thread and fine-grained (vector) parallelism while overcoming memory system bottlenecks that starve oating-point performance. We report on our work to improve the Rapid Radiative Transfer Model (RRTMG), responsible for 10-20 percent of total NMM-B run time. We isolated a standalone RRTMG benchmark code and workload from NMM-B and then analyzed performance using hardware performance counters and scaling studies. We restructured the code to improve vectorization, thread parallelism, locality, and thread contention. The restructured code ran three times faster than the original on MIC and, also importantly, 1.3x faster than the original on the host Xeon Sandybridge.
Rank Factor Granules with Fuzzy Collaborative Clustering and Factor Space Theory
Authors: Liu Shihu , Yu Fusheng , Wang Patrick S. P.
Published: December 2016

This paper makes a discussion on the ranking problem of factor granules where each granule is composed by three parts: the patterns, the factors and the factor-induced information. Hereinto, the factor-induced information refers to the pattern’s attributes and the relationship between any two patterns. The overall ranking process is based on the ideology of fuzzy collaborative clustering, by considering a referential factor granule. The collaborative information, i.e. the partition matrices of factor granules, are used to collaborate the clustering for the referential factor granule. These collaborative information are obtained from different sources by different methods. Specially, one kind is obtained from the qualitative data by factor theory-based method. By comparing the difference of the referential factor granule before and after collaboration in aspect of clustering results, we can sort these factor granules: the little the difference, the closer to the top of the sequence.
OPTIMAL CONTROL APPLIED IN AN ANTHRAX EPIZOOTIC MODEL
Authors: PANTHA BUDDHI , DAY JUDY , LENHART SUZANNE
Published: December 2016

Anthrax is a rapidly fatal, infectious disease which occurs in many animal species, particularly herbivore mammals, and is one of the main causes of population decline in several national parks worldwide. As the infected animals face inevitable death and each infected carcass contributes spores to the surrounding environment, infected carcasses and the infected animals are the main sources of new infections. Thus any control measure should focus on vaccinating susceptible animals and the proper disposal of infected carcasses. In this paper, a system of ordinary differential equations modeling an anthrax epizootic in a wildlife reserve is formulated. Two controls representing vaccination of the susceptible animals and disposal of the infected carcasses are investigated in order to minimize the number of infected animals, the number of infected carcasses and the cost of vaccination and carcass disposal. Model parameters are estimated by using outbreak data from Malilangwe Wildlife Reserve, Zimbabwe, and some numerical results for the optimal control problem are presented.
Long-Term Life Test Data Modeling and Field Correlation — An HDD Experience
Authors: Sun Feng-Bin , Zhang Yao
Published: December 2016

Not every company can afford or is willing to invest in long-term life testing due to time and cost constraints. But such a test can provide very valuable insight about product field behavior during its lifetime. Authors of this paper present a case study on hard disk drive long-term life test data analysis. In order to deal with the non-monotonic hazard rate behavior, the bi-modal mixed life distribution and bi-modal competing failure modeling are applied to fit the time to failure data. The model parameters’ estimation, their physical implications, and field long-term reliability predictions using these two approaches are discussed and compared. The recommendations are given regarding the applicability of each model from an engineering application perspective.
Viscous generalized Chaplygin gas interacting with f(R,T) gravity
Authors: Baffou E. H. , Houndjo M. J. S. , Salako I. G.
Published: December 2016

In this paper, we study in Friedmann–Robertson–Walker universe the interaction between the viscous generalized Chaplygin gas with [Formula: see text] gravity, which is an arbitrary function of the Ricci scalar [Formula: see text] and the trace [Formula: see text] of the energy–momentum tensor. Assuming that the contents of universe are dominated by a generalized Chaplygin gas and dark energy, we obtained the modified Friedmann equations and also the time-dependent energy density and pressure of dark energy due to the shear and bulk viscosities for three interacting models depending on an input parameter [Formula: see text]. Within the simple form of scale factor (power-law), we discuss the graphical representation of dark energy density parameter and investigate the shear and bulk viscosities effects on the accelerating expansion of the universe for each interacting model.
A Micromechanical Method to Predict Macroscopic Behavior of Brittle Creep Failure in Rock
Authors: Li Xiaozhao , Shao Zhushan
Published: December 2016

Brittle creep in rock has great significance for the prediction of important geohazards and stability of deep underground excavations. A major challenge in this area is to link the time-dependent cracking with macroscopic mechanical behavior. In this paper, Ashby and Sammis’ microcrack model and Charles’ crack growth law are employed to investigate the time-dependent cracking during brittle creep in rock. Based on the macroscopic and micromechanical definition of damage in rock, a new theoretical model is suggested to establish the linkage between microcrack length and macroscopic strain. In order to verify the rationality of the suggested model, comparison between theoretical and experimental results is presented. Using this new model, brittle creep of Sanxia granite is investigated and discussed in detail. It is found that evolutions of wing crack length, strain, and damage perform a similar process during brittle creep and could be divided into three phases. Effects of model parameters on creep failure behaviors also are studied.
Fluid–Structure Interaction of High Aspect-Ratio Hair-Like Micro-Structures Through Dimensional Transformation Using Lattice Boltzmann Method
Authors: Devaraj H. , Aw Kean C. , Haemmerle E. , Sharma R.
Published: December 2016

3D printed hair-like micro-structures have been previously demonstrated in a novel micro-fluidic flow sensor aimed at sensing air flows down to rates of a few milliliters per second. However, there is a lack of in-depth understanding of the structural response of these ‘micro-hairs' under a fluid flow field. This paper demonstrates the use of lattice Boltzmann methods (LBM) to understand this structural response towards a better optimization of the micro-hair flow sensors designed to suit the end applications' needs. The LBM approach was chosen as an efficient alternative to simulate Navier–Stokes equations for modeling fluid flow around complex geometries primarily for improved accuracy and simplicity with lesser computational costs. As the spatial dimensions of the sensor's flow channel are much larger in comparison to the actual micro-hairs (the sensing element), a multidimensional approach of combining two-dimensional (D2Q9) and three-dimensional (D3Q19) lattice configurations were implemented for improved computational speeds and efficiency. The drag force on the micro-hairs was estimated using the momentum-exchange method in the D3Q19 configuration and this drag force is transferred to the structural analysis model which determines the micro-hair deformation using Euler–Bernoulli beam theory. The entirety of the LBM Fluid–Structure Interaction (FSI) model was implemented within MATLAB and the obtained results are compared against the numerical model implemented on a commercially available software package.
Modeling and analyzing the impact of temperature and rainfall on mosquito population dynamics over Kwazulu-Natal, South Africa
Authors: Abiodun Gbenga J. , Witbooi Peter , Okosun Kazeem O.
Published: December 2016

Malaria parasites are strongly dependent on Anopheles mosquitoes for transmission; for this reason, mosquito population dynamics are a crucial determinant of malaria risk. However, temperature and rainfall play a significant role in both aquatic and adult stages of the Anopheles. Consequently, it is important to understand the biology of malaria vector mosquitoes in the study of malaria transmission. In this study, we develop a climate-based, ordinary-differential-equation model to analyze how rainfall and temperature determine mosquito population size. In the model, we consider in detail the influence of ambient temperature on gonotrophic and sporogonic cycles over Amajuba District, Kwazulu-Natal Province, South Africa. In particular, we further use the model to simulate the spatial distribution of the mosquito biting rate over the study region. Our results reflect high seasonality of the population of An. gambiae over the region and also demonstrate the influence of climatic factors on the mosquito population dynamics.
Symplectic diffeomorphisms with limit shadowing
Authors: Lee Manseob
Published: December 2016

Let [Formula: see text] be a symplectic diffeomorphism on a closed [Formula: see text][Formula: see text]-dimensional Riemannian manifold [Formula: see text]. In this paper, we show that [Formula: see text] is Anosov if any of the following statements holds: [Formula: see text] belongs to the [Formula: see text]-interior of the set of symplectic diffeomorphisms satisfying the limit shadowing property or [Formula: see text] belongs to the [Formula: see text]-interior of the set of symplectic diffeomorphisms satisfying the limit weak shadowing property or [Formula: see text] belongs to the [Formula: see text]-interior of the set of symplectic diffeomorphisms satisfying the s-limit shadowing property.
Banach algebra with generalized derivations
Authors: Tiwari S. K. , Prajapati B. , Sharma R. K.
Published: December 2016

Let [Formula: see text] be a unital prime Banach algebra over complex field [Formula: see text] with unity and [Formula: see text] be a nonzero continuous linear generalized derivation associated with a nonzero continuous linear derivation [Formula: see text]. In this paper, we investigate the commutativity of [Formula: see text]. In particular, we prove that a unital prime Banach algebra [Formula: see text] is commutative if one of the following holds; (i) either [Formula: see text] or [Formula: see text], (ii) either [Formula: see text] or [Formula: see text], for sufficiently many [Formula: see text], for any complex numbers [Formula: see text] and an integer [Formula: see text].
Identifying the Peri-Urbanized Rural Areas in China: Estimation Based on Firm-level Data of the First and Second National Economic Censuses
Authors: LI Yuhong
Published: December 2016

Peri-urbanized rural areas are villages in which the non-agricultural population and industries are concentrated to a certain extent but rural administration is still practiced. It is an important factor affecting the quality of China's urbanization. On the basis of clarifying the characteristics and formation mechanism of peri-urbanized areas, the paper develops a method of identifying the peri-urbanized rural areas in China that is, the number of industrial employees in the village is not less than 900 and the grass-roots organization is the village committee. It makes an estimation of the peri-urbanization rate with the firm-level data of the first and second National Economic Censuses, and finds that the distribution of industrial employment at village level in China is “scattered” and “fat tailed”. While most of the industrial enterprises in rural areas are scattered, peri-urbanized rural areas centralize more than half of the industrial employees; China's peri-urbanization level is relatively high with a growing and deepening tendency, and it is closely related to the economic development.
China’s Alternative Roles in Countering International Economic Cyber Espionage
Authors: Xiaofeng Wang
Published: December 2016

This article examines China’s respective roles as a suspect, victim, and stakeholder in countering international economic cyber espionage (ECE) activities. Refuting the widespread evidence and cases that have misguided those with interests or concerns in cyber security issues, the author underscores the cognitive defects and logical fallacies in the prevailing suspicion and accusations against China. Not only is China among the victims of ECE activities, it will face even more ECE threats in the future. With growing cyber capacity, however, China has been determined to develop into a strong cyber power while playing a more active role as a key stakeholder in containing ECE activities. To maintain a secure and favorable cyberspace, the international community must join hands in working out a common code of conduct in cyberspace, acknowledging China’s strenuous efforts and indispensable role in international cyberspace governance. The United States, in particular, needs to adopt a legal approach in seeking to settle ECE disputes with China while making more commitments to their bilateral cooperation against economic cybercrime.
Revisiting China’s Investment in Latin America
Authors: Shixue Jiang
Published: December 2016

It is easy to understand China’s increasing enthusiasm for overseas investment, given that its economy is continuing to grow at a relatively high speed and its foreign exchange reserves are expanding. Promoting overseas investment under the national “go global” strategy not only helps China tap into the external market and embrace a more important role in world economic affairs, but is beneficial to the economy and society of host countries as well. China’s investment in Latin America serves as a good example. Apart from helping to fill in the shortfall of capital, Chinese investment also enhances employment and infrastructure in many Latin American countries. In order to increase the stock of Chinese investment in Latin America to US$250 billion by 2025, as Chinese President Xi Jinping declared in January 2015, Latin American countries need to improve their domestic environment for investment, while Chinese enterprises must learn to take on more corporate social responsibility (CSR). Furthermore, Latin American countries and China should work together to develop broader and more efficient channels to exchange market information about investment opportunities.
Crowdsourced Mobile Data Transfer with Delay Bound
Authors: Do Ngoc , Zhao Ye , Hsu Cheng-Hsin , Venkatasubramanian Nalini
Published: December 2016

In this article, we design a crowdsourcing system, CrowdMAC, where mobile devices form a local community or marketplace to share network access and transfer data for each other. CrowdMAC enables (i) mobile clients to select and exploit multiple mobile hotspots in its vicinity for data transfer and (ii) mobile hotspots to open their cellular connectivity to admit/serve delay-bounded requests from mobile users for a fee. The evaluations of CrowdMAC indicate that (i) mobile clients can tune preferred trade-offs between cost and delay through a control knob, (ii) mobile hotspots comply with all delay bounds, and (iii) the system ensures stable and efficient transfer.
Artificial intelligence
Authors: Kaplan Jerry
Published: December 2016

Social and cultural conventions are an often-neglected aspect of intelligent-machine development.
Effects of international trafficking in arms regulations changes
Authors: Straub Jeremy
Published: December 2016

Considering the impact of recent ITAR changes to the U.S. software industry and software education.
Research for practice
Authors: Bailis Peter , Yang Jean , Reddi Vijay Janapa , Zhu Yuhao
Published: December 2016

Expert-curated guides to the best of CS research.
How we teach CS2All, and what to do about database decay
Authors: Barr Valerie , Stonebraker Michael , Fernandez Raul Castro , Deng Dong , Brodie Michael
Published: December 2016

The
Communications
Web site, http://cacm.acm.org, features more than a dozen bloggers in the BLOG@CACM community. In each issue of
Communications
, we'll publish selected posts or excerpts.

twitter

Follow us on Twitter at http://twitter.com/blogCACM

http://cacm.acm.org/blogs/blog-cacm

Valerie Barr considers how to make computer science education meaningful and relevant to all, while a team from the Massachusetts Institute of Technology Computer Science and Artificial Intelligence Laboratory offers strategies to counter database decay.
Bias in technology
Authors: Mone Gregory
Published: December 2016

As leading companies release troubling diversity statistics, experts search for solutions.
Mapping the internet of things
Authors: Wright Alex
Published: December 2016

Researchers are discovering surprising new risks across the fast-growing IoT.