bluuebunny/crossref_metadata_2025 huggingface dataset:
Catabolism of 2-Hydroxypyridine by Burkholderia sp. Strain MAK1: a 2-Hydroxypyridine 5-Monooxygenase Encoded by
hpdABCDE
Catalyzes the First Step of Biodegradation
Authors: Petkevičius Vytautas , Vaitekūnas Justas , Stankevičiūtė Jonita , Gasparavičiūtė Renata , Meškys Rolandas
Published: March 2018

Microbial degradation of 2-hydroxypyridine usually results in the formation of a blue pigment (nicotine blue). In contrast, the
Burkholderia
sp. strain MAK1 bacterium utilizes 2-hydroxypyridine without the accumulation of nicotine blue. This scarcely investigated degradation pathway presumably employs 2-hydroxypyridine 5-monooxygenase, an elusive enzyme that has been hypothesized but has yet to be identified or characterized. The isolation of the mutant strain
Burkholderia
sp. MAK1 ΔP5 that is unable to utilize 2-hydroxypyridine has led to the identification of a gene cluster (designated
hpd
) which is responsible for the degradation of 2-hydroxypyridine. The activity of 2-hydroxypyridine 5-monooxygenase has been assigned to a soluble diiron monooxygenase (SDIMO) encoded by a five-gene cluster (
hpdA
,
hpdB
,
hpdC
,
hpdD
, and
hpdE
). A 4.5-kb DNA fragment containing all five genes has been successfully expressed in
Burkholderia
sp. MAK1 ΔP5 cells. We have proved that the recombinant HpdABCDE protein catalyzes the enzymatic turnover of 2-hydroxypyridine to 2,5-dihydroxypyridine. Moreover, we have confirmed that emerging 2,5-dihydroxypyridine is a substrate for HpdF, an enzyme similar to 2,5-dihydroxypyridine 5,6-dioxygenases that are involved in the catabolic pathways of nicotine and nicotinic acid. The proteins and genes identified in this study have allowed the identification of a novel degradation pathway of 2-hydroxypyridine. Our results provide a better understanding of the biodegradation of pyridine derivatives in nature. Also, the discovered 2-hydroxypyridine 5-monooxygenase may be an attractive catalyst for the regioselective synthesis of various
N
-heterocyclic compounds.

IMPORTANCE
The degradation pathway of 2-hydroxypyridine without the accumulation of a blue pigment is relatively unexplored, as, to our knowledge, no genetic data related to this process have ever been presented. In this paper, we describe genes and enzymes involved in this little-studied catabolic pathway. This work provides new insights into the metabolism of 2-hydroxypyridine in nature. A broad-range substrate specificity of 2-hydroxypyridine 5-monooxygenase, a key enzyme in the degradation, makes this biocatalyst attractive for the regioselective hydroxylation of pyridine derivatives.
The Opp (AmiACDEF) Oligopeptide Transporter Mediates Resistance of Serotype 2 Streptococcus pneumoniae D39 to Killing by Chemokine CXCL10 and Other Antimicrobial Peptides
Authors: Bruce Kevin E. , Rued Britta E. , Tsui Ho-Ching Tiffany , Winkler Malcolm E.
Published: March 2018

Antimicrobial peptides (AMPs), including chemokines, are produced during infections to kill pathogenic bacteria. To fill in gaps in knowledge about the sensitivities of
Streptococcus pneumoniae
and related
Streptococcus
species to chemokines and AMPs, we performed a systematic, quantitative study of inhibition by chemokine CXCL10 and the AMPs LL-37 and nisin. In a standard Tris-glucose buffer (TGS), all strains assayed lacked metabolic activity, as determined by resazurin (alamarBlue) reduction, and were extremely sensitive to CXCL10 and AMPs (50% inhibitory concentration [IC
50
], ∼0.04 μM). In TGS, changes in sensitivities caused by mutations were undetectable. In contrast, strains that retained reductive metabolic activity in a different assay buffer (NPB [10 mM sodium phosphate {pH 7.4}, 1% {vol/vol} brain heart infusion {BHI} broth]) were less sensitive to CXCL10 and AMPs than in TGS. In NPB, mutants known to respond to AMPs, such as Δ
dlt
mutants lacking
d
-alanylation of teichoic acids, exhibited the expected increased sensitivity.
S. pneumoniae
serotype 2 strain D39 was much (∼10-fold) less sensitive to CXCL10 killing in NPB than serotype 4 strain TIGR4, and the sensitivity of TIGR4 was unaffected by the absence of capsule. Candidate screening of strain D39 revealed that mutants lacking Opp (Δ
amiACDEF
) oligopeptide permease were significantly more resistant to CXCL10 than the wild-type strain. This increased resistance could indicate that Opp is a target for CXCL10 binding or that it transports CXCL10 into cells. Finally, Δ
ftsX
or Δ
ftsE
mutants of
Bacillus subtilis
or amino acid changes that interfere with FtsX function in
S. pneumoniae
did not impart resistance to CXCL10, in contrast to previous results for
Bacillus anthracis
, indicating that FtsX is not a general target for CXCL10 binding.

IMPORTANCE
S. pneumoniae
(pneumococcus) is a human commensal bacterium and major opportunistic respiratory pathogen that causes serious invasive diseases, killing millions of people worldwide annually. Because of its increasing antibiotic resistance,
S. pneumoniae
is now listed as a “superbug” for which new antibiotics are urgently needed. This report fills in knowledge gaps and resolves inconsistencies in the scientific literature about the sensitivity of
S. pneumoniae
and related
Streptococcus
pathogens to chemokines and AMPs. It also reveals a new mechanism by which
S. pneumoniae
can acquire resistance to chemokine CXCL10. This mechanism involves the Opp (AmiACDEF) oligopeptide transporter, which plays additional pleiotropic roles in pneumococcal physiology, quorum sensing, and virulence. Taking the results together, this work provides new information about the way chemokines kill pneumococcal cells.
Environmental Role of Pathogenic Traits in Vibrio cholerae
Authors: Sakib S. Nazmus , Reddi Geethika , Almagro-Moreno Salvador
Published: March 2018

Vibrio cholerae
is a natural inhabitant of aquatic ecosystems. Some strains of
V. cholerae
can colonize human hosts and cause cholera, a profuse watery diarrhea.
Dynamics of paediatric urogenital schistosome infection, morbidity and treatment: a longitudinal study among preschool children in Zimbabwe
Authors: Osakunor Derick Nii Mensah , Mduluza Takafira , Midzi Nicholas , Chase-Topping Margo , Mutsaka-Makuvaza Masceline Jenipher , Chimponda Theresa , Eyoh Enwono , Mduluza Tariro , Pfavayi Lorraine Tsitsi , Wami Welcome Mkululi , Amanfo Seth Appiah , Murray Janice , Tshuma Clement , Woolhouse Mark Edward John , Mutapi Francisca
Published: March 2018

Background

Recent research has shown that in schistosome-endemic areas preschool-aged children (PSAC), that is, ≤5 years, are at risk of infection. However, there exists a knowledge gap on the dynamics of infection and morbidity in this age group. In this study, we determined the incidence and dynamics of the first urogenital schistosome infections, morbidity and treatment in PSAC.

Methods

Children (6 months to 5 years) were recruited and followed up for 12 months. Baseline demographics, anthropometric and parasitology data were collected from 1502 children. Urinary morbidity was assessed by haematuria and growth-related morbidity was assessed using standard WHO anthropometric indices. Children negative forSchistosoma haematobiuminfection were followed up quarterly to determine infection and morbidity incidence.

Results

At baseline, the prevalence ofS haematobiuminfection and microhaematuria was 8.5% and 8.6%, respectively. Based on different anthropometric indices, 2.2%–8.2% of children were malnourished, 10.1% underweight and 18.0% stunted. The fraction of morbidity attributable to schistosome infection was 92% for microhaematuria, 38% for stunting and malnutrition at 9%–34%, depending on indices used.S haematobium-positive children were at greater odds of presenting with microhaematuria (adjusted OR (AOR)=25.6; 95% CI 14.5 to 45.1) and stunting (AOR=1.7; 95% CI 1.1 to 2.7). Annual incidence ofS haematobiuminfection and microhaematuria was 17.4% and 20.4%, respectively. Microhaematuria occurred within 3 months of first infection and resolved in a significant number of children, 12 weeks post-praziquantel treatment, from 42.3% to 10.3%; P<0.001.

Conclusion

We demonstrated for the first time the incidence of schistosome infection in PSAC, along with microhaematuria, which appears within 3 months of first infection and resolves after praziquantel treatment. A proportion of stunting and malnutrition is attributable toS haematobiuminfection. The study adds scientific evidence to the calls for inclusion of PSAC in schistosome control programmes.
Interagency collaboration models for people with mental ill health in contact with the police: a systematic scoping review
Authors: Parker Adwoa , Scantlebury Arabella , Booth Alison , MacBryde Jillian Catherine , Scott William J , Wright Kath , McDaid Catriona
Published: March 2018

Objective

To identify existing evidence on interagency collaboration between law enforcement, emergency services, statutory services and third sector agencies regarding people with mental ill health.

Design

Systematic scoping review. Scoping reviews map particular research areas to identify research gaps.

Data sources and eligibility

ASSIA, CENTRAL, the Cochrane Library databases, Criminal Justice Abstracts, ERIC, Embase, MEDLINE, PsycINFO, PROSPERO and Social Care Online and Social Sciences Citation Index were searched up to 2017, as were grey literature and hand searches. Eligible articles were empirical evaluations or descriptions of models of interagency collaboration between the police and other agencies.

Study appraisal and synthesis

Screening and data extraction were undertaken independently by two researchers. Arksey’s framework was used to collate and map included studies.

Results

One hundred and twenty-five studies were included. The majority of articles were of descriptions of models (28%), mixed methods evaluations of models (18%) and single service evaluations (14%). The most frequently reported outcomes (52%) were ‘organisational or service level outcomes’ (eg, arrest rates). Most articles (53%) focused on adults with mental ill health, whereas others focused on adult offenders with mental ill health (17.4%). Thirteen models of interagency collaboration were described, each involving between 2 and 13 agencies. Frequently reported models were ‘prearrest diversion’ of people with mental ill health (34%), ‘coresponse’ involving joint response by police officers paired with mental health professionals (28.6%) and ‘jail diversion’ following arrest (23.8%).

Conclusions

We identified 13 different interagency collaboration models catering for a range of mental health-related interactions. All but one of these models involved the police and mental health services or professionals. Several models have sufficient literature to warrant full systematic reviews of their effectiveness, whereas others need robust evaluation, by randomised controlled trial where appropriate. Future evaluations should focus on health-related outcomes and the impact on key stakeholders.
Prognostic value of Ki67 analysed by cytology or histology in primary breast cancer
Authors: Robertson Stephanie , Stålhammar Gustav , Darai-Ramqvist Eva , Rantalainen Mattias , Tobin Nicholas P , Bergh Jonas , Hartman Johan
Published: March 2018

Aims

The accuracy of biomarker assessment in breast pathology is vital for therapy decisions. The therapy predictive and prognostic biomarkers oestrogen receptor (ER), progesterone receptor, HER2 and Ki67 may act as surrogates to gene expression profiling of breast cancer. The aims of this study were to investigate the concordance of consecutive biomarker assessment by immunocytochemistry on preoperative fine-needle aspiration cytology versus immunohistochemistry (IHC) on the corresponding resected breast tumours. Further, to investigate the concordance with molecular subtype and correlation to stage and outcome.

Methods

Two retrospective cohorts comprising 385 breast tumours with clinicopathological data including gene expression-based subtype and up to 10-year overall survival data were evaluated.

Results

In both cohorts, we identified a substantial variation in Ki67 index between cytology and histology and a switch between low and high proliferation within the same tumour in 121/360 cases. ER evaluations were discordant in only 1.5% of the tumours. From cohort 2, gene expression data with PAM50 subtype were used to correlate surrogate subtypes. IHC-based surrogate classification could identify the correct molecular subtype in 60% and 64% of patients by cytology (n=63) and surgical resections (n=73), respectively. Furthermore, high Ki67 in surgical resections but not in cytology was associated with poor overall survival and higher probability for axillary lymph node metastasis.

Conclusions

This study shows considerable differences in the prognostic value of Ki67 but not ER in breast cancer depending on the diagnostic method. Furthermore, our findings show that both methods are insufficient in predicting true molecular subtypes.
Educational attainment of children born to mothers with epilepsy
Authors: Lacey Arron S , Pickrell William Owen , Thomas Rhys H , Kerr Mike P , White Cathy P , Rees Mark I
Published: March 2018

Objective

Small prospective studies have identified that children exposed to valproate in utero have poorer scores on cognitive testing. We wanted to identify whether children exposed to antiepileptic drugs (AEDs) in utero have poorer school performance.

Methods

We used anonymised, linked, routinely collected healthcare records to identify children born to mothers with epilepsy. We linked these children to their national attainment Key Stage 1 (KS1) tests in mathematics, language and science at the age of 7 and compared them with matched children born to mothers without epilepsy, and with the national KS1 results. We used the core subject indicator (CSI) as an outcome measure (the proportion of children achieving a minimum standard in all subjects) and the results in individual subjects.

Results

We identified 440 children born to mothers with epilepsy with available KS1 results. Compared with a matched control group, fewer children with mothers being prescribed sodium valproate during pregnancy achieved the national minimum standard in CSI (−12.7% less than the control group), mathematics (−12.1%), language (−10.4%) and in science (−12.2%). Even fewer children with mothers being prescribed multiple AEDs during pregnancy achieved a national minimum standard: CSI (by −20.7% less than the control group), mathematics (−21.9%), language (−19.3%) and science (−19.4%). We did not observe any significant difference in children whose mothers were prescribed carbamazepine or were not taking an AED when compared with the control group.

Conclusions

In utero exposure to AEDs in combination, or sodium valproate alone, is associated with a significant decrease in attainment in national educational tests for 7-year-old children compared with both a matched control group and the all-Wales national average. These results give further support to the cognitive and developmental effects of in utero exposure to sodium valproate as well as multiple AEDs, which should be balanced against the need for effective seizure control for women during pregnancy.
The frequency of leg autotomy and its influence on survival in natural populations of the wolf spider Pardosa valens
Authors: Brown Christopher A. , Amaya Carlos C. , Formanowicz Daniel R.
Published: March 2018

Autotomy occurs when an animal intentionally sacrifices an appendage to escape predation or free a limb. While immediately beneficial, loss of an appendage can lead to a variety of future costs. In many spiders, leg autotomy is common; previous work has sometimes demonstrated autotomy costs in some behaviors, while other times, no costs of autotomy occur. We examined frequency of autotomy in two riparian zone populations of the wolf spider Pardosa valens Barnes, 1959 and then used both mark–recapture work at these sites and laboratory predation trials to determine whether autotomy affected survival. Autotomy occurred in 31% of spiders; males were more likely than females to have a missing leg, but female reproductive status (carrying an egg sac or not) was unrelated to leg loss status. At both sites, survival over 1 week in the field was significantly higher for intact spiders than for spiders missing a leg, for both sexes and both female reproductive states. Additionally, when we paired intact and autotomized spiders with a predator (the larger wolf spider Rabidosa santrita (Chamberlin & Ivie, 1942)), autotomized spiders were more likely to be attacked and eaten. Our results suggest that leg autotomy in P. valens leads to a significant future survival cost, and we discuss how this cost may affect males and females differently.
MUTUAL FUND PERFORMANCE IN DEVELOPING AND ADVANCED WORLD NETWORKS
Authors: ZHANG KEYI , GENÇAY RAMAZAN
Published: March 2018

We propose a new determinant of mutual fund performance persistence. We argue that different funds have different abilities to generate persistent performance and that such heterogeneity across funds can be explained by fund manager access to market information. To justify this hypothesis, we construct a network of mutual funds based on the commonality of their stock holdings and use network features to characterize how well a fund acquires and utilizes market information. Based on a sample of U.S. equity funds from 2001 to 2014, we find that a mutual fund with more complete information is more likely to possess momentum in performance.
Single top partner production at lepton colliders in the left–right twin Higgs model
Authors: Jiang Xingyu , Han Jinzhong , Hou Biaofeng , Yu Chunxu
Published: March 2018

In the framework of the left–right twin Higgs (LRTH) model, we investigate the single top partner production at lepton colliders. We calculate the production cross-sections of the processes [Formula: see text], [Formula: see text] [Formula: see text] and [Formula: see text] [Formula: see text] at [Formula: see text] TeV, and display some typical differential distributions of the final state particles.
Efficient priority queueing routing strategy on networks of mobile agents
Authors: Wu Gan-Hua , Yang Hui-Jie , Pan Jia-Hui
Published: March 2018

As a consequence of their practical implications for communications networks, traffic dynamics on complex networks have recently captivated researchers. Previous routing strategies for improving transport efficiency have paid little attention to the orders in which the packets should be forwarded, just simply used first-in–first-out queue discipline. Here, we apply a priority queuing discipline and propose a shortest-distance-first routing strategy on networks of mobile agents. Numerical experiments reveal that the proposed scheme remarkably improves both the network throughput and the packet arrival rate and reduces both the average traveling time and the rate of waiting time to traveling time. Moreover, we find that the network capacity increases with an increase in both the communication radius and the number of agents. Our work may be helpful for the design of routing strategies on networks of mobile agents.
Towards Dynamic Evolution of Runtime Variability Based on Computational Reflection
Authors: Ji-Wei Liu , Xin-Jun Mao
Published: March 2018

Given the frequently changing nature of the user requirements and environments in software systems, runtime variability in today’s software systems should be capable of evolving during execution. Computational reflection is required to facilitate accessing and customizing runtime variability during this evolution process. However, realizing this computational reflection includes various practical complexities since the runtime variability is typically neither explicitly represented in software systems nor changeable during runtime. To address this problem, this paper proposes a software architecture to support computational reflection of runtime variability, along with a corresponding causal-connection mechanism to realize the introspection and intercession (i.e. representing runtime variability model, and adding, removing, replacing variability elements and their relations). The proposed software architecture consists of a meta level that represents runtime variability model using objectification, and a base level that organizes and manipulates the implementation of variability elements via reconfiguration. The causal-connection mechanism integrated in our proposed model is designed to synchronize the representation and the implementation. Further, we developed a Reflective Runtime Variability Framework (R2VF) to support the development and operation of the systems with the reflection of runtime variability. The effectiveness and applicability of our approach has been evaluated by applying R2VF to Personal Data Resource Network.
Predicting Code Hotspots in Open-Source Software from Object-Oriented Metrics Using Machine Learning
Authors: Hilton Rod , Gethner Ellen
Published: March 2018

Software engineers are able to measure the quality of their code using a variety of metrics that can be derived directly from analyzing the source code. These internal quality metrics are valuable to engineers, but the organizations funding the software development effort find external quality metrics such as defect rates and time to develop features more valuable. Unfortunately, external quality metrics can only be calculated after costly software has been developed and deployed for end-users to utilize. Here, we present a method for mining data from freely available open source codebases written in Java to train a Random Forest classifier to predict which files are likely to be external quality hotspots based on their internal quality metrics with over 75% accuracy. We also used the trained model to predict hotspots for a Java project whose data was not used to train the classifier and achieved over 75% accuracy again, demonstrating the method’s general applicability to different projects.
EMSA: Extensibility Metric for Software Architecture
Authors: Kim Jungho , Kang Sungwon , Ahn Jongsun , Lee Seonah
Published: March 2018

Software extensibility, the capability of adding new functions to a software system, is established based on software architecture. Therefore, developers need to evaluate the capability when designing software architecture. To support the evaluation, researchers have proposed metrics based on quality models or scenarios. However, those metrics are vague or subjective, depending on specific systems and evaluators. We propose the extensibility metric for software architecture (EMSA), which represents the degree of extensibility of a software system based on its architecture. To reduce the subjectivity of the metric, we first identify a typical task of adding new functions to a software system. Second, we define the metrics based on the characteristics of software architecture and its changes and finally combine them into a single metric. The originality of EMSA comes from defining metrics based on software architecture and extensibility tasks and integrating them into one. Furthermore, we made an effort to translate the degree into effort estimation expressed as person-hours. To evaluate EMSA, we conducted two types of user studies, obtaining measurements in both a laboratory and a real-world project. The results show that the EMSA estimation is reasonably accurate [6.6% MMRE and 100% PRED(25%)], even in a real-world project (93.2% accuracy and 8.5% standard deviation).
Experimental Study on Pedestrians' Perception of Human-Induced Vibrations of Footbridges
Authors: Ma Rujin , Ke Lu , Wang Dalei , Chen Airong , Pan Zichao
Published: March 2018

Owing to the slenderness and lightness of most modern footbridges, vibration serviceability assessment becomes a crucial issue in the design process. As one of the key factors, the vibration comfort criterion has an important influence on the assessment of the final result. However, there is an obvious lack of experimental studies in this field, especially regarding the pedestrians' perception of the induced vibrations. In this study, an experiment was conducted to investigate the pedestrians' perception of human-induced vibrations of footbridges. During the experiment, the subjects walked on a pathway that was mounted on top of a shaking table. By imposing sinusoidal excitations with different amplitudes and frequencies, the experiment aimed to determine the influence of the two factors on the walking people's perception. Based on the data collected, perception scales were proposed for both the vertical and lateral vibrations of the footbridge. The established scales comprise five levels that depend on the acceleration amplitude and the frequency. Finally, a comparison between the proposed scales, existing comfort criteria in the literature and international codes was carried out.
MONETARY POLICY TRANSMISSION IN A MACROECONOMIC AGENT-BASED MODEL
Authors: SCHASFOORT JOERI , GODIN ANTOINE , BEZEMER DIRK , CAIANI ALESSANDRO , KINSELLA STEPHEN
Published: March 2018

In this paper we explore the variety of monetary policy transmission channels in an agent-based macroeconomic model. We identify eight transmission channels and present a model based on [Caiani et al., J. Econ. Dyn. Contr. 69 (2016) 375–480], extended with an interbank market. We then analyze model simulation results of interest rate shocks in terms of GDP and inflation for four of the transmission channels. We find these effects to be small, in line with the view that monetary policy is a weak tool to control inflation.
Effectiveness of falls prevention intervention programme in community-dwelling older people in Thailand: Randomized controlled trial
Authors: Suttanon Plaiwan , Piriyaprasarth Pagamas , Krootnark Kitsana , Aranyavalai Thanyaporn
Published: March 2018

Background: Although there is extensive research on falls prevention, most of this knowledge is from western countries, and this may limit its usefulness when implementing in countries with different culture and healthcare systems.

Objective: This study evaluated the feasibility and effectiveness of a falls prevention intervention programme for older people in Thailand.

Methods: Two hundred and seventy-seven community-dwelling older people were randomized to either an intervention programme which included an education about falls risk management plus a home-based balance exercise delivered by a physiotherapist for four-month duration or control group. Falls, balance, physical activity, and other falls risk factors were measured at baseline and after programme completion.

Results: About 90% of the participants in the intervention group completed the programme, with very high adherence to the exercise programme, though poor compliance with the suggestions of other falls risks management. There were no falls or injuries related to the exercise programme reported. There was no significant difference in falls rate between the two groups.

Conclusion: This falls prevention program was not effective in reducing falls in community-dwelling older people in Thailand. However, the study provided encouraging evidence that home-based balance exercise could be practically implemented in older people living in communities in Thailand.
Revisiting the Riemann Zeta function at positive even integers
Authors: Alladi Krishnaswami , Defant Colin
Published: March 2018

Using Parseval’s identity for the Fourier coefficients of [Formula: see text], we provide a new proof that [Formula: see text].
On the value-distribution of the difference between logarithms of two symmetric power L-functions
Authors: Matsumoto Kohji , Umegaki Yumiko
Published: March 2018

We consider the value distribution of the difference between logarithms of two symmetric power [Formula: see text]-functions at [Formula: see text]. We prove that certain averages of those values can be written as integrals involving a density function which is constructed explicitly.
On certain biquadratic equations, II
Authors: Schinzel A. , Skałba M.
Published: March 2018

We prove among other things that the equation [Formula: see text] has no integral solutions [Formula: see text] with [Formula: see text] for [Formula: see text]. Moreover, we deal with related equations with [Formula: see text] on the right-hand side. In the second section, we give some numerical examples of solutions.
Social Control in China: Towards a “Smart” and Sophisticated System
Authors: SHAN Wei
Published: March 2018

To guarantee a “successful” 19th Congress of the Communist Party, the Chinese regime had mobilised all its resources to maintain stability in 2017. With sophisticated internet censorship, artificial intelligence and big data technology, social control mechanism in the country has become “smarter”, more effective and more successful in reducing social unrest. In the long term, however, it may face challenges due to value changes in society.
Chips for artificial intelligence
Authors: Monroe Don
Published: March 2018

Companies are racing to develop hardware that more directly empowers deep learning.
Deep ROI-Based Modeling for Urban Human Mobility Prediction
Authors: Jiang Renhe , Song Xuan , Fan Zipei , Xia Tianqi , Chen Quanjun , Chen Qi , Shibasaki Ryosuke
Published: March 2018

Rapidly developing location acquisition technologies have provided us with big GPS trajectory data, which offers a new means of understanding people's daily behaviors as well as urban dynamics. With such data, predicting human mobility at the city level will be of great significance for transportation scheduling, urban regulation, and emergency management. In particular, most urban human behaviors are related to a small number of important regions, referred to as Regions-of-Interest (ROIs). Therefore, in this study, a deep ROI-based modeling approach is proposed for effectively predicting urban human mobility. Urban ROIs are first discovered from historical trajectory data, and urban human mobility is designated using two types of ROI labels (ISROI and WHICHROI). Then, urban mobility prediction is modeled as a sequence classification problem for each type of label. Finally, a deep-learning architecture built with recurrent neural networks is designed as an effective sequence classifier. Experimental results demonstrate that the superior performance of our proposed approach to the baseline models and several real-world practices show the applicability of our approach to real-world urban computing problems.
Robust Sensor-Orientation-Independent Feature Selection for Animal Activity Recognition on Collar Tags
Authors: Kamminga Jacob W. , Le Duc V. , Meijers Jan Pieter , Bisby Helena , Meratnia Nirvana , Havinga Paul J.M.
Published: March 2018

Fundamental challenges faced by real-time animal activity recognition include variation in motion data due to changing sensor orientations, numerous features, and energy and processing constraints of animal tags. This paper aims at finding small optimal feature sets that are lightweight and robust to the sensor's orientation. Our approach comprises four main steps. First, 3D feature vectors are selected since they are theoretically independent of orientation. Second, the least interesting features are suppressed to speed up computation and increase robustness against overfitting. Third, the features are further selected through an embedded method, which selects features through simultaneous feature selection and classification. Finally, feature sets are optimized through 10-fold cross-validation. We collected real-world data through multiple sensors around the neck of five goats. The results show that activities can be accurately recognized using only accelerometer data and a few lightweight features. Additionally, we show that the performance is robust to sensor orientation and position. A simple Naive Bayes classifier using only a single feature achieved an accuracy of 94 % with our empirical dataset. Moreover, our optimal feature set yielded an average of 94 % accuracy when applied with six other classifiers. This work supports embedded, real-time, energy-efficient, and robust activity recognition for animals.
An Energy-efficient and Lightweight Indoor Localization System for Internet-of-Things (IoT) Environments
Authors: Kwak Myeongcheol , Park Youngmong , Kim Junyoung , Han Jinyoung , Kwon Taekyoung
Published: March 2018

Each and every spatial point in an indoor space has its own distinct and stable fingerprint, which arises owing to the distortion of the magnetic field induced by the surrounding steel and iron structures. This phenomenon makes many indoor positioning techniques rely on the magnetic field as an important source of localization. Most of the existing studies, however, have leveraged smartphones that have a relatively high computational power and many sensors. Thus, their algorithmic complexity is usually high, especially for commercial location-based services. In this paper, we present an energy-efficient and lightweight system that utilizes the magnetic field for indoor positioning in Internet of Things (IoT) environments. We propose a new hardware design of an IoT device that has a BLE interface and two sensors (magnetometer and accelerometer), with the lifetime of one year when using a coin-size battery. We further propose an augmented particle filter framework that features a robust motion model and a localization heuristic with small sensory data. The prototype-based evaluation shows that the proposed system achieves a median accuracy of 1.62 m for an office building, while exhibiting low computational complexity and high energy efficiency.
Calibrating Low-Cost Sensors by a Two-Phase Learning Approach for Urban Air Quality Measurement
Authors: Lin Yuxiang , Dong Wei , Chen Yuan
Published: March 2018

Urban air quality information, e.g., PM2.5 concentration, is of great importance to both the government and society. Recently, there is a growing interest in developing low-cost sensors, installed on moving vehicles, for fine-grained air quality measurement. However, low-cost mobile sensors typically suffer from low accuracy and thus need careful calibration to preserve a high measurement quality. In this paper, we propose a two-phase data calibration method consisting of a linear part and a nonlinear part. We use MLS (multiple least square) to train the linear part, and use RF (random forest) to train the nonlinear part. We propose an automatic feature selection algorithm based on AIC (Akaike information criterion) for the linear model, which helps avoid overfitting due to the inclusion of inappropriate features. We evaluate our method extensively. Results show that our method outperforms existing approaches, achieving an overall accuracy improvement of 16.4% in terms of PM2.5 levels compared with state-of-the-art approach.
Xnavi
Authors: Nomiyama Masato , Takeuchi Toshiki , Onimaru Hiroyuki , Tanikawa Tomohiro , Narumi Takuji , Hirose Michitaka
Published: March 2018

Though an increasing number of people is now involved in travel planning owing to the spread of the internet, it is still difficult for travelers to plan trips on their own. It is especially difficult for tourists using automobiles because they have several choices of accessible places. To make itineraries easily, travelers require a travel planning system that suggests two types of experiences: experiences characterizing the travel area and experiences stemming from a flow between the former experiences. Existing systems do not list specific spontaneous experiences of interest to travelers. In response, Xnavi, a travel planning system for drivers based on experience flows, is proposed, which provides these types of experiences. To recommend experience flows, Xnavi extracts experience keywords related to the travel area using natural language processing based on the TF-IDF method and also extracts flows of tourist attractions' attributes based on association analysis of driving histories. Trials of the proposed method and a user study were conducted. The results show that Xnavi is effective at suggesting experiences and satisfying tourists with their plans.
TOAST
Authors: Shi Weinan , Yu Chun , Yi Xin , Li Zhen , Shi Yuanchun
Published: March 2018

Touch typing on flat surfaces (e.g. interactive tabletop) is challenging due to lack of tactile feedback and hand drifting. In this paper, we present TOAST, an eyes-free keyboard technique for enabling efficient touch typing on touch-sensitive surfaces. We first formalized the problem of keyboard parameter (e.g. location and size) estimation based on users' typing data. Through a user study, we then examined users' eyes-free touch typing behavior on an interactive tabletop with only asterisk feedback. We fitted the keyboard model to the typing data, results suggested that the model parameters (keyboard location and size) changed not only between different users, but also within the same user along with time. Based on the results, we proposed a Markov-Bayesian algorithm for input prediction, which considers the relative location between successive touch points within each hand respectively. Simulation results showed that based on the pooled data from all users, this model improved the top-1 accuracy of the classical statistical decoding algorithm from 86.2% to 92.1%. In a second user study, we further improved TOAST with dynamical model parameter adaptation, and evaluated users' text entry performance with TOAST using realistic text entry tasks. Participants reached a pick-up speed of 41.4 WPM with a character-level error rate of 0.6%. And with less than 10 minutes of practice, they reached 44.6 WPM without sacrificing accuracy. Participants' subjective feedback also indicated that TOAST offered a natural and efficient typing experience.
SpiderWalk
Authors: Wang Liang , Cheng Wen , Pan Lijia , Gu Tao , Wu Tianheng , Tao Xianping , Lu Jian
Published: March 2018

This paper presents the design and implementation of the SpiderWalk system for circumstance-aware transportation activity detection using a novel contact vibration sensor. Different from existing systems that only report the type of activity, our system detects not only the activity but also its circumstances (e.g., road surface, vehicle, and shoe types) to provide better support for applications such as activity logging, location tracking, and smart persuasive applications. Inspired by but different from existing audio-based context detection approaches using microphones, the SpiderWalk system is designed and implemented using an ultra-sensitive, flexible contact vibration sensor which mimics the spiders' sensory slit organs. By sensing vibration patterns from the soles of shoes, the system can accurately detect transportation activities with rich circumstance information while resisting undesirable external signals from other sources or speech that may cause the data assignment and privacy preserving issues. Moreover, our system is implemented by reusing existing audio devices and can be used by an unmodified smartphone, making it ready for large-scale deployments. Finally, a novel temporal and spatial correlated classification approach is proposed to accurately detect the complex combinations of transportation activities and circumstances based on the output of each individual classifiers. Experiments conducted on a real-world data set suggest our system can accurately detect different transportation activities and their circumstances with an average detection accuracy of 93.8% with resource overheads comparable to existing audio- and GPS-based systems.
PrivateHunt
Authors: Xie Xiaoyang , Zhang Fan , Zhang Desheng
Published: March 2018

Recently, for-hire vehicle services (FHV, e.g., Uber and Lyft) have become essential to people's daily transportation. Similar to taxis, how to effectively dispatch these FHV based on demand and supply is important for both FHV passengers and drivers. Based on real-world multi-source data, we identify two new challenges for FHV dispatching: (i) diverse demand: FHV passengers are a mix of passengers previously using taxis, buses, subways, or private vehicles; (ii) uncertain supply: FHV drivers join and leave the FHV system with spatiotemporal dynamics. As a result, the state-of-the-art taxi dispatching techniques cannot be applied to FHV systems. In this paper, we design the first FHV dispatching system PrivateHunt based on extremely large-scale urban transportation data from New York City and Shenzhen in China. In particular, we present (i) a passenger demand model based on taxi, bus, subway, and private vehicle data; (ii) a driver supply model based on small-scale FHV data; (iii) a dispatching technique for FHV vehicles based on proposed demand/supply models to reduce idle driving time. We implement PrivateHunt based on 14 thousand taxis, 13 thousand buses, and 8-line subway system and 10 thousand private vehicles. The experimental results show that our data-driven dispatching strategy significantly outperforms the state-of-the-art dispatching strategies without data-driven FHV insights.
Detecting Popular Temporal Modes in Population-scale Unlabelled Trajectory Data
Authors: Xu Fengli , Xia Tong , Cao Hancheng , Li Yong , Sun Funing , Meng Fanchao
Published: March 2018

With the rapid process of urbanization, revealing the underlying mechanisms behind urban mobility has become a crucial research problem. The movements of urban dwellers are often constituted by their daily routines, and exhibit distinct and contextual temporal modes, i.e., the patterns of individuals allocating their time across different locations. In this paper, we investigate a novel problem of detecting popular temporal modes in population-scale unlabelled trajectory data. Our key finding is that the detected temporal modes capture the semantic feature of human's living style, and is able to unravel meaningful correlations between urban mobility and human behavior.

Specifically, we represent the temporal mode of a trajectory as a partition of the time duration, where the time slices associated with same locations are partitioned into same subsets. Such abstraction decouples the temporal modes from actual physical locations, and allows individuals with similar temporal modes yet completely different physical locations to have similar representations. Based on this insight, we propose a pipeline system composed of three components: 1) noise handler that eliminates the noises in the raw mobility records, 2) representation extractor for temporal modes, and 3) popular temporal modes detector. By applying our system on three real-world mobility datasets, we demonstrate that our system effectively detects the popular temporal modes embedded in population-scale mobility datasets, which is easy to be interpreted and can be justified through the associated PoIs and mobile applications usage. More importantly, our further experiments reveal insightful correlations between the popular temporal modes and individuals' social economic status, i.e. occupation information, which sheds light on the mechanisms behind urban mobility.
SharedEdge
Authors: Yang Yu , Zhang Fan , Zhang Desheng
Published: March 2018

Estimating travel time on the highway in real time is of great importance for transportation services. Previous work has been mainly focusing on the city scale for a particular transportation system, e.g., taxi, bus, and metro. Little research has been conducted to estimate fine-grained real-time travel time in state-level highway systems. This is because the traditional solutions based on probe vehicles or loop sensors cannot scale to state-level highway systems due to their large spatial coverage. Recently, the adoption of Electric Toll Collection (ETC) systems (e.g. EZ-pass) brings a new opportunity to estimate the real-time travel time in the highway systems with little marginal cost. However, the key challenge is that ETC data only record the coarse-grained total travel time between a pair of toll stations rather than fine-grained travel time in each individual highway edge. To address this challenge, we design SharedEdge to estimate the fine-grained edge travel time with large-scale streaming ETC data. The key novelty is that we estimate real-time fine-grained travel time (i.e., edge travel time) without using fine-grained data (i.e. GPS trajectories or loop sensor data), by a few techniques based on Bayesian Graphical models and Expectation Maximization. More importantly, we implement our SharedEdge in the Guangdong Province, China with an ETC system covering 69 highways and 773 toll stations with a length of 7, 000 km. Based on this implementation, we evaluate SharedEdge in details by comparing it with some baselines and the state-of-the-art models. The evaluation results show that SharedEdge outperforms other methods in terms of travel time estimation accuracy when compared with the ground truth obtained by 114 thousand GPS-equipped vehicles.
From Fresnel Diffraction Model to Fine-grained Human Respiration Sensing with Commodity Wi-Fi Devices
Authors: Zhang Fusang , Zhang Daqing , Xiong Jie , Wang Hao , Niu Kai , Jin Beihong , Wang Yuxiang
Published: March 2018

Non-intrusive respiration sensing without any device attached to the target plays a particular important role in our everyday lives. However, existing solutions either require dedicated hardware or employ special-purpose signals which are not cost-effective, significantly limiting their real-life applications. Also very few work concerns about the theory behind and can explain the large performance variations in different scenarios. In this paper, we employ the cheap commodity Wi-Fi hardware already ubiquitously deployed around us for respiration sensing. For the first time, we utilize the Fresnel diffraction model to accurately quantify the relationship between the diffraction gain and human target's subtle chest displacement and thus successfully turn the previously considered "destructive" obstruction diffraction in the First Fresnel Zone (FFZ) into beneficial sensing capability. By not just considering the chest displacement at the frontside as the existing solutions, but also the subtle displacement at the backside, we achieve surprisingly matching results with respect to the theoretical plots and become the first to clearly explain the theory behind the performance distinction between lying and sitting for respiration sensing. With two cheap commodity Wi-Fi cards each equipped with just one antenna, we are able to achieve higher than 98% accuracy of respiration rate monitoring at more than 60% of the locations in the FFZ. Furthermore, we are able to present the detail heatmap of the sensing capability at each location inside the FFZ to guide the respiration sensing so users clearly know where are the good positions for respiration monitoring and if located at a bad position, how to move just slightly to reach a good position.
iDial
Authors: Zhang Maotian , Dai Qian , Yang Panlong , Xiong Jie , Tian Chang , Xiang Chaocan
Published: March 2018

Smart wearable devices have become pervasive and are playing a more important role in our everyday lives. However, the small screen size and very few buttons make the interaction and control cumbersome and inconvenient. Previous solutions to mitigate this problem either require extra dedicated hardware, or instrument the user's fingers with special purpose sensors, limiting their real-life applications. We present iDial, a novel real time approach that enables a virtual dial plate on the hand back, extending the interaction beyond the small screen of wearable devices. iDial only employs the already built-in microphone and motion sensors of the commercial-off-the-shelf (COTS) device to facilitate interactions between user and wearable, without any extra hardware involved. The key idea is to exploit the acoustic signatures extracted from passive subtle acoustic signals to accurately recognize the virtual keys input on the skin of the hand back. We innovatively locate the virtual keys on the 4 pieces of metacarpal bones to significantly reduce the possibility of casual inputs. iDial also takes advantages of the motion sensor fusion already available inside the wearable to achieve robustness against the ambient noise and human voices efficiently. We design and implement iDial on the Samsung Gear S2 smartwatch. Our extensive experiments show that iDial is able to achieve an average recognition accuracy of 96.7%, and maintain high accuracies across varying user behaviors and different environments. iDial achieves a below 0.5s end-to-end latency with all the computations and processes happening at the cheap commodity wearable.