bluuebunny/crossref_metadata_2025 huggingface dataset:
Elucidation of the Photorhabdus temperata Genome and Generation of a Transposon Mutant Library To Identify Motility Mutants Altered in Pathogenesis
Authors: Hurst Sheldon , Rowedder Holli , Michaels Brandye , Bullock Hannah , Jackobeck Ryan , Abebe-Akele Feseha , Durakovic Umjia , Gately Jon , Janicki Erik , Tisa Louis S.
Published: April 2015

The entomopathogenic nematodeHeterorhabditis bacteriophoraforms a specific mutualistic association with its bacterial partnerPhotorhabdus temperata. The microbial symbiont is required for nematode growth and development, and symbiont recognition is strain specific. The aim of this study was to sequence the genome ofP. temperataand identify genes that plays a role in the pathogenesis of thePhotorhabdus-Heterorhabditissymbiosis. A draft genome sequence ofP. temperatastrain NC19 was generated. The 5.2-Mb genome was organized into 17 scaffolds and contained 4,808 coding sequences (CDS). A genetic approach was also pursued to identify mutants with altered motility. A bank of 10,000P. temperatatransposon mutants was generated and screened for altered motility patterns. Five classes of motility mutants were identified: (i) nonmotile mutants, (ii) mutants with defective or aberrant swimming motility, (iii) mutant swimmers that do not require NaCl or KCl, (iv) hyperswimmer mutants that swim at an accelerated rate, and (v) hyperswarmer mutants that are able to swarm on the surface of 1.25% agar. The transposon insertion sites for these mutants were identified and used to investigate other physiological properties, including insect pathogenesis. The motility-defective mutant P13-7 had an insertion in the RNase II gene and showed reduced virulence and production of extracellular factors. Genetic complementation of this mutant restored wild-type activity. These results demonstrate a role for RNA turnover in insect pathogenesis and other physiological functions.

IMPORTANCEThe relationship betweenPhotorhabdusand entomopathogenic nematodeHeterorhabditisrepresents a well-known mutualistic system that has potential as a biological control agent. The elucidation of the genome of the bacterial partner and role that RNase II plays in its life cycle has provided a greater understanding ofPhotorhabdusas both an insect pathogen and a nematode symbiont.
Novel Role for PilNO in Type IV Pilus Retraction Revealed by Alignment Subcomplex Mutations
Authors: Leighton Tiffany L. , Dayalani Neha , Sampaleanu Liliana M. , Howell P. Lynne , Burrows Lori L.
Published: April 2015

Type IV pili (T4P) are dynamic protein filaments that mediate bacterial adhesion, biofilm formation, and twitching motility. The highly conserved PilMNOP proteins form an inner membrane alignment subcomplex required for function of the T4P system, though their exact roles are unclear. Three potential interaction interfaces for PilNO were identified: core-core, coiled coils (CC), and the transmembrane segments (TMSs). A high-confidence PilNO heterodimer model was used to select key residues for mutation, and the resulting effects on protein-protein interactions were examined both in a bacterial two-hybrid (BTH) system and in their nativePseudomonas aeruginosacontext. Mutations in the oppositely charged CC regions or the TMS disrupted PilNO heterodimer formation in the BTH assay, while up to six combined mutations in the core failed to disrupt the interaction. When the mutations were introduced into theP. aeruginosachromosome at thepilNorpilOlocus, specific changes at each of the three interfaces—including core mutations that failed to disrupt interactions in the BTH system—abrogated surface piliation and/or impaired twitching motility. Unexpectedly, specific CC mutants were hyperpiliated but nonmotile, a hallmark of pilus retraction defects. These data suggest that PilNO participate in both the extension and retraction of T4P. Our findings support a model of multiple, precise interaction interfaces between PilNO; emphasize the importance of studying protein function in a minimally perturbed context and stoichiometry; and highlight potential target sites for development of small-molecule inhibitors of the T4P system.

IMPORTANCEPseudomonas aeruginosais an opportunistic pathogen that uses type IV pili (T4P) for host attachment. The T4P machinery is composed of four cell envelope-spanning subcomplexes. PilN and PilO heterodimers are part of the alignment subcomplex and essential for T4P function. Three potential PilNO interaction interfaces (the core-core, coiled-coil, and transmembrane segment interfaces) were probed using site-directed mutagenesis followed by functional assays in anEscherichia colitwo-hybrid system and inP. aeruginosa. Several mutations blocked T4P assembly and/or motility, including two that revealed a novel role for PilNO in pilus retraction, while other mutations affected extension dynamics. These critical PilNO interaction interfaces represent novel targets for small-molecule inhibitors with the potential to disrupt T4P function.
The Pseudomonas aeruginosa PA14 ABC Transporter NppA1A2BCD Is Required for Uptake of Peptidyl Nucleoside Antibiotics
Authors: Pletzer Daniel , Braun Yvonne , Dubiley Svetlana , Lafon Corinne , Köhler Thilo , Page Malcolm G. P. , Mourez Michael , Severinov Konstantin , Weingart Helge
Published: April 2015

Analysis of the genome sequence ofPseudomonas aeruginosaPA14 revealed the presence of an operon encoding an ABC-type transporter (NppA1A2BCD) showing homology to the Yej transporter ofEscherichia coli. The Yej transporter is involved in the uptake of the peptide-nucleotide antibiotic microcin C, a translation inhibitor that targets the enzyme aspartyl-tRNA synthetase. Furthermore, it was recently shown that the Opp transporter fromP. aeruginosaPAO1, which is identical to Npp, is required for uptake of the uridyl peptide antibiotic pacidamycin, which targets the enzyme translocase I (MraY), which is involved in peptidoglycan synthesis. We used several approaches to further explore the substrate specificity of the Npp transporter. Assays of growth in defined minimal medium containing peptides of various lengths and amino acid compositions as sole nitrogen sources, as well as Biolog Phenotype MicroArrays, showed that the Npp transporter is not required for di-, tri-, and oligopeptide uptake. Overexpression of thenppoperon increased susceptibility not just to pacidamycin but also to nickel chloride and the peptidyl nucleoside antibiotic blasticidin S. Furthermore, heterologous expression of thenppoperon in ayej-deficient mutant ofE. coliresulted in increased susceptibility to albomycin, a naturally occurring sideromycin with a peptidyl nucleoside antibiotic. Additionally, heterologous expression showed that microcin C is recognized by theP. aeruginosaNpp system. Overall, these results suggest that the NppA1A2BCD transporter is involved in the uptake of peptidyl nucleoside antibiotics byP. aeruginosaPA14.

IMPORTANCEOne of the world's most serious health problems is the rise of antibiotic-resistant bacteria. There is a desperate need to find novel antibiotic therapeutics that either act on new biological targets or are able to bypass known resistance mechanisms. Bacterial ABC transporters play an important role in nutrient uptake from the environment. These uptake systems could also be exploited by a Trojan horse strategy to facilitate the transport of antibiotics into bacterial cells. Several natural antibiotics mimic substrates of peptide uptake routes. In this study, we analyzed an ABC transporter involved in the uptake of nucleoside peptidyl antibiotics. Our data might help to design drug conjugates that may hijack this uptake system to gain access to cells.
Chest wall abscesses due to continuous application of silicone gel sheets for keloid management
Authors: Tang Hon-Lok , Lau Keith K , Sam Ramin , Ing Todd S
Published: April 2015

A patient with three episodes of chest wall abscesses as a result of 6 years of round-the-clock, uninterrupted (except during bathing) application of silicone gel sheets to a chest wall keloid is described. Two of the episodes occurred during hot weather. It is suggested that, in the space beneath the silicone sheet, the higher humidity and temperature, both generated as a result of prolonged sheeting, especially during hot weather, might have caused the keloid and its neighbouring skin to become soggy. This sogginess might have facilitated bacterial invasion. It is suggested that some sheeting-free time during a 24 h period might be indicated so that a keloid and its adjacent skin have the time to recover from their sheeting-induced sogginess. A sheeting-free period might especially be needed in the face of sweat accumulation beneath the silicone sheet.
The Tanzanian trauma patients' prehospital experience: a qualitative interview-based study
Authors: Kuzma Kristin , Lim Andrew George , Kepha Bernard , Nalitolela Neema Evelyne , Reynolds Teri A
Published: April 2015

Objectives

We sought to characterise the prehospital experience of Tanzanian trauma patients, and identify barriers and facilitators to implement community-based emergency medical systems (EMS).

Settings

Our study was conducted in the emergency department of an urban national referral hospital in Tanzania.

Participants

A convenience sample of 34 adult trauma patients, or surrogate family members, presenting or referred to an urban referral emergency department in Tanzania for treatment of injury, participated in the study.

Interventions

Participation in semistructured, iteratively developed interviews until saturation of responses was reached.

Outcomes

A grounded theory-based approach to qualitative analysis was used to identify recurrent themes.

Results

We characterised numerous deficiencies within the existing clinic-to-hospital referral network, including missed/delayed diagnoses, limited management capabilities at pre-referral facilities and interfacility transfer delays. Potential barriers to EMS implementation include patient financial limitations and lack of insurance, limited public infrastructure and resources, and the credibility of potential first aid responders. Potential facilitators of EMS include communities’ tendency to pool resources, individuals’ trust of other community members to be first aid responders, and faith in community leaders to organise EMS response. Participants expressed a strong desire to learn first aid.

Conclusions

The composite themes generated by the data suggest that there are myriad structural, financial, institutional and cultural barriers to the implementation of a formal prehospital system. However, our analysis also revealed potential facilitators to a first-responder system that takes advantage of close-knit local communities and the trust of recognised leaders in society. The results suggest favourable acceptability for community-based response by trained lay people. There is significant opportunity for care improvements with short trainings and low-cost supply planning. Further research looking at the effects of delay on outcomes in this population is needed.
Quantification of mechanical and hydric components of soil reinforcement by plant roots
Authors: Veylon G. , Ghestem M. , Stokes A. , Bernard A.
Published: April 2015

The use of vegetation to stabilize slopes with regard to shallow landslides is an ecological and economic alternative to traditional solutions of civil engineering. This study aims at quantifying the effect of soil water content on the reinforcement of soil by plant roots and determines how soil water content influences the failure modes of roots during shear. Direct shear box tests were performed on three species used in hillslope reforestation programs in Yunnan, China. Reinforcement was quantified and divided into a hydric component corresponding to the effect of water removal and a mechanical component reflecting the influence of roots on apparent cohesion and friction angle. It was shown that the hydric component of reinforcement can be of the same order as the mechanical component and that root system architectural traits influence the type of mechanical reinforcement (cohesive or frictional). We also demonstrate the potential development of matric suction effects on the shear strength of soil.
Niacin as antidyslipidemic drug
Authors: Julius Ulrich
Published: April 2015

Niacin is an important vitamin (B3) that can be used in gram doses to positively modify pathogenetically relevant lipid disorders: elevated LDL cholesterol, elevated non-HDL cholesterol, elevated triglycerides, elevated lipoprotein(a), and reduced HDL cholesterol. This review reports the latest published findings with respect to niacin’s mechanisms of action on these lipids and its anti-inflammatory and anti-atherosclerotic effects. In the pre-statin era, niacin was shown to have beneficial effects on cardiovascular end-points; but in recent years, two major studies performed in patients whose LDL cholesterol levels had been optimized by a statin therapy did not demonstrate an additional significant effect on these end-points in the groups where niacin was administered. Both studies have several drawbacks that suggest that they are not representative for other patients. Thus, niacin still plays a role either as an additive to a statin or as a substitute for a statin in statin-intolerant patients. Moreover, patients with elevated triglyceride and low HDL cholesterol levels and patients with elevated lipoprotein(a) concentrations will possibly benefit from niacin, although currently the study evidence for these indications is rather poor. Niacin may be useful for compliant patients, however possible side effects (flushing, liver damage) and contraindications should be taken into consideration.
The effect of kisspeptin on the regulation of vascular tone
Authors: Mezei Zsófia , Zamani-Forooshani Omid , Csabafi Krisztina , Szikszai Bence , Papp Eszter , Ónodi Ádám , Török Dóra , Leprán Ádám , Telegdy Gyula , Szabó Gyula
Published: April 2015

Kisspeptin has been implicated in cardiovascular control. Eicosanoids play a crucial role in the activation of platelets and the regulation of vascular tone. In the present study, we investigated the effect of kisspeptins on eicosanoid synthesis in platelets and aorta in vitro. Platelets and aorta were isolated from Wistar–Kyoto rats. After preincubation with different doses of kisspeptin, samples were incubated with [1-14C]arachidonic acid (0.172 pmol/mL) in tissue culture Medium 199. The amount of labeled eicosanoids was measured with liquid scintillation, after separation with overpressure thin-layer chromatography. Kisspeptin-13 stimulated the thromboxane synthesis. The dose–response curve was bell-shaped and the most effective concentration was 2.5 × 10−8mol/L, inducing a 27% increase. Lipoxygenase products of platelets displayed a dose-dependent elevation up to the dose of 5 × 10−8mol/L. In the aorta, kisspeptin-13 induced a marked elevation in the production of 6-keto-prostaglandin F1α, the stable metabolite of prostacyclin, and lipoxygenase products. Different effects of kisspeptin on cyclooxygenase and lipoxygenase products indicate that beyond intracellular Ca2+mobilization, other signaling pathways might also contribute to its actions. Our data suggest that kisspeptin, through the alteration of eicosanoid synthesis in platelets and aorta, may play a physiologic and (or) pathologic role in the regulation of vascular tone.
Endothelin ETAreceptor antagonist reverses naloxone-precipitated opioid withdrawal in mice
Authors: Bhalla Shaifali , Pais Gwendolyn , Tapia Melissa , Gulati Anil
Published: April 2015

Long-term use of opioids for pain management results in rapid development of tolerance and dependence leading to severe withdrawal symptoms. We have previously demonstrated that endothelin-A (ETA) receptor antagonists potentiate opioid analgesia and eliminate analgesic tolerance. This study was designed to investigate the involvement of central ET mechanisms in opioid withdrawal. The effect of intracerebroventricular administration of ETAreceptor antagonist BQ123 on morphine and oxycodone withdrawal was determined in male Swiss Webster mice. Opioid tolerance was induced and withdrawal was precipitated by the opioid antagonist naloxone. Expression of ETAand ETBreceptors, nerve growth factor (NGF), and vascular endothelial growth factor was determined in the brain using Western blotting. BQ123 pretreatment reversed hypothermia and weight loss during withdrawal. BQ123 also reduced wet shakes, rearing behavior, and jumping behavior. No changes in expression of vascular endothelial growth factor, ETAreceptors, and ETBreceptors were observed during withdrawal. NGF expression was unaffected in morphine withdrawal but significantly decreased during oxycodone withdrawal. A decrease in NGF expression in oxycodone- but not in morphine-treated mice could be due to mechanistic differences in oxycodone and morphine. It is concluded that ETAreceptor antagonists attenuate opioid-induced withdrawal symptoms.
First-principles investigations on the phase stability, elastic and thermodynamic properties of Zr–Al alloys
Authors: Wang Leini , Hou Songjun , Liang Dewei
Published: April 2015

In this paper, we employ first-principles methods based on electronic density functional theory (DFT) to investigate the phase stability, elastic and thermodynamic properties of Zr – Al binary substitutional alloys which are Zr 3 Al , Zr 2 Al , ZrAl , ZrAl 2 and ZrAl 3. By analyzing the elastic constants and enthalpy of formation, those phases both satisfy the generalized stability criteria and the results show that ZrAl 2 is the most stable. Due to high bulk modulus B, shear modulus G and Youngs modulus Y, ZrAl 2 also possesses excellent mechanical properties. Moreover, it is expected that there will be covalent bonding between Zr and Al atom in ZrAl 2 compound, which is confirmed by the electronic structure and the differences of charge density discussions. In the end, based on the calculated elastic modulus, the elastic wave velocity, Debye temperature ΘD and specific heat CV are discussed. As a result, ZrAl 3 possesses the highest Debye temperature and sound velocity, meaning a larger associated thermal conductivity and higher melting temperature.
Celery Seed Extract Blocks Peroxide Injury in Macrophages via Notch1/NF-κB Pathway
Authors: Si Yanhong , Guo Shoudong , Fang Yongqi , Qin Shucun , Li Furong , Zhang Ying , Jiao Peng , Zhang Chunduo , Gao Linlin
Published: April 2015

Oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cell formation and injury is one of the major atherogenic factors. This study is aimed to investigate the protective effect of celery seed extract (CSE) on ox-LDL-induced injury of macrophages and the underlying signaling pathway. RAW264.7 macrophages were pre-incubated with CSE for 24 h, followed by stimulation with ox-LDL. Oil red O staining and enzymatic colorimetry indicated CSE significantly lessened lipid droplets and total cholesterol (TC) content in ox-LDL-injured macrophages. ELISA revealed that CSE decreased the secretion of inflammatory cytokine TNF-α and IL-6 by 12–27% and 5–15% respectively. MTT assay showed CSE promoted cell viability by 16–40%. Cell apoptosis was also analyzed by flow cytometry and laser scanning confocal microscope and the data indicated CSE inhibited ox-LDL-induced apoptosis of macrophages. Meanwhile, western blot analysis showed CSE suppressed NF-κBp65 and notch1 protein expressions stimulated by ox-LDL in macrophages. These results suggest that CSE inhibits ox-LDL-induced macrophages injury via notch1/NF-κB pathway.
An Integrating Model of Knowledge Management for Improved Pediatric Healthcare Practice
Authors: Maiga G. , Mutuwa P. L.
Published: April 2015

Pediatric care practitioners are faced with increasing amounts of data that is not matched by an equivalent ability to manage and apply it for improved healthcare. Contributing to this are lack of tools and systems to aid in knowledge management. This paper presents the results of a study on a model that focusses on integrating the Knowledge management processes that contribute to improved pediatric care delivery in the context of Uganda. A field survey was conducted to empirically test the model of knowledge management in Pediatric Healthcare (PHC). The requirements were used to extend existing Knowledge management models in order to describe one suitable for pediatrics knowledge management and practice. The study identified technology, People, Storage and pediatrics knowledge integration as important requirements for successful implementation of Knowledge management in PHC practice. Regression analysis was done to show the relationships in the proposed mode and the results indicate its suitability for knowledge management in pediatric practice.
Self-Censorship in Social Media: A Case Study of Hacettepe University
Authors: Yilmaz Bülent , Soylu Demet
Published: April 2015

In today's technological and information rich society, millions of people are using social media as part of online socialisation and virtual life. They create and share contents such as pictures, texts and videos. Social media takes on the role of being the platform in which individuals can freely express themselves. Individuals have the opportunity of networking in the form of creating and sharing content, brainstorming, chatting, and expressing opinions thanks to the reflective and refractive (Medeni and Medeni, 2012) characteristic of social media. But social media which is supposed to provide a space for free expression is subject to different forms of censorship. As a result, social media and censorship have become interwoven terms. According to the Universal Declaration of Human Rights, individuals have the right to express their ideas, opinions freely regardless of the types of media used. Even though social media might be controlled in the same way as traditional media, it can be stated that censorship is taking many forms due to the emergence of the intelligence methods with the capability of governments to monitor and counteract social media (Papic and Noonan, 2011). In this study, self-censorship as well as the underlying causes of censorship in social media will be discussed. Censorship and self-censorship which are embedded within each other will be studied from psychological, sociological and linguistic aspects. The study explores the extent of self-censorship in social media using a population comprising of 37 senior students of Department of Information Management, Hacettepe University.
An Exploratory Study of Knowledge Management for Enhanced Efficiency and Effectiveness: The Transformation of the Planning System in the UK Local Government
Authors: Khilji Nasrullah K. , Roberts Stephen A.
Published: April 2015

This paper explores the theoretical and conceptual frameworks, which are informing discussions about how the local government planning system in the UK can embrace the potential of knowledge management to deliver a smart and sustainable approach to physical and urban planning. The general environment of UK planning is contextualized. A number of frameworks are identified: Planning performance agreements (PPAs model); national planning policy framework (NPPF model); Killian pretty review (KPR model); planning portal (PP model); control shift framework (CSF model); framework for communities and local government (FCLG model); and the Nonaka and Takeuchi knowledge framework (SECI model). The authors propose a pragmatic framework (CMT model) and set this in the context of fieldwork being carried out over a period in five planning authorities in the South East Midlands of the UK. The implementation of such a framework will require a recognition of both social factors and technologies, including the key supportive and preventive factors. The growing availability of technology platforms, familiarity with the digital environment and factors pushing market and organisational change provide opportunities to realise necessary and important changes.
Variational principles for multisymplectic second-order classical field theories
Authors: Prieto-Martínez Pedro Daniel , Román-Roy Narciso
Published: April 2015

We state a unified geometrical version of the variational principles for second-order classical field theories. The standard Lagrangian and Hamiltonian variational principles and the corresponding field equations are recovered from this unified framework.
Self-Organizing Map for Fingerprinting-Based Cooperative Localization in Dynamic Indoor Environments
Authors: Xiao Wendong , Papapostolou Apostolia , Chaouchi Hakima , Wei Ming
Published: April 2015

Wireless Local Area Network (WLAN) fingerprinting methods based on 802.11 signal strength are becoming increasingly the dominating indoor positioning techniques, due to their independence from radio propagation models and cost-effectiveness in terms of hardware and deployment requirements. However, frequent environmental changes cause inconsistency between the fingerprints stored in the radio map and the current radio behavior, thus jeopardizing their accuracy. Re-calibration of the area for updating the radio map incurs considerable amount of time and manual effort. In this paper, we aim to overcome this limitation by adapting to the new radio characteristics through user cooperation and thus eliminating the need of re-calibration. To that end, we propose a cooperative learning algorithm, whereby users exchange their real-time signal measurements in order to refine their estimated locations. The refinement process relies on the neural network structure of self-organizing map (SOM) which is of special interest for localization due to the key property of its neurons in self-organizing in geographic structures based on their similarity to a high-dimensional input data. In our solution, each user is regarded as a neuron of its local SOM network and runs in distributed fashion a modified version of SOM learning algorithm by considering its signal relationship with its neighboring users. Performance evaluation results demonstrate accuracy improvement over both the baseline deterministic and probabilistic fingerprinting approaches, while keeping the communication and computational overheads low.
Teach foundational language principles
Authors: Ball Thomas , Zorn Benjamin
Published: April 2015

Industry is ready and waiting for more graduates educated in the principles of programming languages.
Dynamic Provable Data Possession
Authors: Erway C. Chris , Küpçü Alptekin , Papamanthou Charalampos , Tamassia Roberto
Published: April 2015

As storage-outsourcing services and resource-sharing networks have become popular, the problem of efficiently proving the integrity of data stored at untrusted servers has received increased attention. In the Provable Data Possession (PDP) model, the client preprocesses the data and then sends them to an untrusted server for storage while keeping a small amount of meta-data. The client later asks the server to prove that the stored data have not been tampered with or deleted (without downloading the actual data). However, existing PDP schemes apply only to static (or append-only) files. We present a definitional framework and efficient constructions for Dynamic Provable Data Possession (DPDP), which extends the PDP model to support provable updates to stored data. We use a new version of authenticated dictionaries based on rank information. The price of dynamic updates is a performance change from
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blocks while maintaining the same (or better, respectively) probability of misbehavior detection. Our experiments show that this slowdown is very low in practice (e.g., 415KB proof size and 30ms computational overhead for a 1GB file). We also show how to apply our DPDP scheme to outsourced file systems and version control systems (e.g., CVS).
Activity Sensor
Authors: Sang Jitao , Mei Tao , Xu Changsheng
Published: April 2015

While on the go, people are using their phones as a personal concierge discovering what is around and deciding what to do. Mobile phone has become a recommendation terminal customized for individuals—capable of recommending activities and simplifying the accomplishment of related tasks. In this article, we conduct usage mining on the check-in data, with summarized statistics identifying the local recommendation challenges of huge solution space, sparse available data, and complicated user intent, and discovered observations to motivate the hierarchical, contextual, and sequential solution. We present a point-of-interest (POI) category-transition--based approach, with a goal of estimating the visiting probability of a series of successive POIs conditioned on current user context and sensor context. A mobile local recommendation demo application is deployed. The objective and subjective evaluations validate the effectiveness in providing mobile users both accurate recommendation and favorable user experience.
Identifying Authorities in Online Communities
Authors: Bouguessa Mohamed , Romdhane Lotfi Ben
Published: April 2015

Several approaches have been proposed for the problem of identifying authoritative actors in online communities. However, the majority of existing methods suffer from one or more of the following limitations: (1) There is a lack of an automatic mechanism to formally discriminate between authoritative and nonauthoritative users. In fact, a common approach to authoritative user identification is to provide a ranked list of users expecting authorities to come first. A major problem of such an approach is the question of where to stop reading the ranked list of users. How many users should be chosen as authoritative? (2) Supervised learning approaches for authoritative user identification suffer from their dependency on the training data. The problem here is that labeled samples are more difficult, expensive, and time consuming to obtain than unlabeled ones. (3) Several approaches rely on some user parameters to estimate an authority score. Detection accuracy of authoritative users can be seriously affected if incorrect values are used. In this article, we propose a parameterless mixture model-based approach that is capable of addressing the three aforementioned issues in a single framework. In our approach, we first represent each user with a feature vector composed of information related to its social behavior and activity in an online community. Next, we propose a statistical framework, based on the multivariate beta mixtures, in order to model the estimated set of feature vectors. The probability density function is therefore estimated and the beta component that corresponds to the most authoritative users is identified. The suitability of the proposed approach is illustrated on real data extracted from the Stack Exchange question-answering network and Twitter.
Gatling
Authors: Lee Hyojeong , Seibert Jeff , Fistrovic Dylan , Killian Charles , Nita-Rotaru Cristina
Published: April 2015

In this article, we propose Gatling, a framework that automatically finds performance attacks caused by insider attackers in large-scale message-passing distributed systems. In performance attacks, malicious nodes deviate from the protocol when sending or creating messages, with the goal of degrading system performance. We identify a representative set of basic malicious message delivery and lying actions and design a greedy search algorithm that finds effective attacks consisting of a subset of these actions. Although lying malicious actions are protocol dependent, requiring the format and meaning of messages, Gatling captures them without needing to modify the target system by using a type-aware compiler. We have implemented and used Gatling on nine systems, a virtual coordinate system, a distributed hash table lookup service and application, two multicast systems and one file sharing application, and three secure systems designed specifically to tolerate insiders, two based on virtual coordinates and one using Outlier Detection, one invariant derived from physical laws, and the last one a Byzantine resilient replication system. We found a total of 48 attacks, with the time needed to find each attack ranging from a few minutes to a few hours.
Geospatial Estimation-Based Auto Drift Correction in Wireless Sensor Networks
Authors: Kumar Dheeraj , Rajasegarar Sutharshan , Palaniswami Marimuthu
Published: April 2015

Wireless sensor networks are often deployed in large numbers, over a large geographical region, in order to monitor the phenomena of interest. Sensors used in the sensor networks often suffer from random or systematic errors such as drift and bias. Even if they are calibrated at the time of deployment, they tend to drift as time progresses. Consequently, the progressive manual calibration of such a large-scale sensor network becomes impossible in practice. In this article, we address this challenge by proposing a collaborative framework to automatically detect and correct the drift in order to keep the data collected from these networks reliable. We propose a novel scheme that uses geospatial estimation-based interpolation techniques on measurements from neighboring sensors to collaboratively predict the value of phenomenon being observed. The predicted values are then used iteratively to correct the sensor drift by means of a Kalman filter. Our scheme can be implemented in a centralized as well as distributed manner to detect and correct the drift generated in the sensors. For centralized implementation of our scheme, we compare several kriging- and nonkriging-based geospatial estimation techniques in combination with the Kalman filter, and show the superiority of the kriging-based methods in detecting and correcting the drift. To demonstrate the applicability of our distributed approach on a real world application scenario, we implement our algorithm on a network consisting of Wireless Sensor Network (WSN) hardware. We further evaluate single as well as multiple drifting sensor scenarios to show the effectiveness of our algorithm for detecting and correcting drift. Further, we address the issue of high power usage for data transmission among neighboring nodes leading to low network lifetime for the distributed approach by proposing two power saving schemes. Moreover, we compare our algorithm with a blind calibration scheme in the literature and demonstrate its superiority in detecting both linear and nonlinear drifts.
Oracle v. Google
Authors: Sprigman Christopher Jon
Published: April 2015

Copyrighting APIs threatens significant harm to both consumers and the software industry.
Discouraging sedentary behaviors using interactive play
Authors: Mandryk Regan L. , Gerling Kathrin M.
Published: April 2015

This forum is dedicated to personal health in all its many facets: decision-making, goal setting, celebration, discovery, reflection, and coordination, among others. We look at innovations in interactive technologies and how they help address current critical healthcare challenges. ---
Gillian R. Hayes, Editor
Fingers, thumbs, and people
Authors: Hoober Steven
Published: April 2015

Designing for the way users really hold and touch their phones and tablets
Printed electronics for human-computer interaction
Authors: Steimle Jürgen
Published: April 2015

Envisioning, designing, and implementing the user interface require a comprehensive understanding of interaction technologies. In this forum we scout trends and discuss new technologies with the potential to influence interaction design. ---
Albrecht Schmidt, Editor
MaD
Authors: Françoise Jules , Schnell Norbert , Borghesi Riccardo , Bevilacqua Frédéric
Published: April 2015

Mapping by demonstration for continuous sonification.
Effect of feed restriction and subsequent re-alimentation on hormones and genes of the somatotropic axis in cattle
Authors: Keogh Kate , Waters Sinéad M. , Kelly Alan K. , Wylie Alastair R. G. , Kenny David A.
Published: April 2015

The objective of this study was to characterize the effect of feed restriction and compensatory growth during re-alimentation on the functionality of the somatotropic axis. We blocked 60 bulls into one of two groups: 1) restricted feed allowance for 125 days ( period 1) (RES, n = 30) followed by ad libitum feeding for 55 days ( period 2) or 2) ad libitum access to feed throughout (ADLIB, n = 30). A growth hormone releasing hormone (GHRH) challenge was performed during each period. At the end of each period, 15 animals from each treatment were slaughtered and hepatic tissue collected. Hepatic expression of 13 genes of the somatotropic axis was measured by qRT-PCR. RES displayed a lower growth rate during period 1 (0.6 vs. 1.9 kg/day; P < 0.001), subsequently gaining more than ADLIB animals during period 2 (2.5 vs. 1.4 kg/day; P < 0.001). Growth hormone response to GHRH was not different between treatments at either time-point ( P > 0.05); however, resultant plasma IGF-1 was lower in period 1 and greater in period 2 in RES animals ( P < 0.05). Expression of IGFBP2 was higher ( P < 0.01) and IGF1 ( P < 0.001) and GHRIA ( P < 0.05) lower in RES compared with ADLIB during period 1, with no difference evident in period 2 ( P > 0.05). Collectively, the results of this study are consistent with uncoupling of the somatotropic axis following feed restriction. However, there is no evidence from this study that the somatotropic axis per se is a significant contributor to compensatory growth.
Novel Serum Biomarkers to Differentiate Cholangiocarcinoma from Benign Biliary Tract Diseases Using a Proteomic Approach
Authors: Janvilisri Tavan , Leelawat Kawin , Roytrakul Sittiruk , Paemanee Atchara , Tohtong Rutaiwan
Published: April 2015

Background and Aim. Cholangiocarcinoma (CCA) is the most frequent biliary malignancy, which poses high mortality rate due to lack of early detection. Hence, most CCA cases are present at the advanced to late stages with local or distant metastasis at the time of diagnosis. Currently available tumor markers including CA19-9 and CEA are inefficient and of limited usage due to low sensitivity and specificity. Here, we attempt to identify serum tumor markers for CCA that can effectively distinguish CCA from benign biliary tract diseases (BBTDs).Methods. Serum samples from 19 CCA patients and 17 BBTDs were separated by SDS-PAGE followed with LC-MS/MS and were subjected to statistical analysis and cross-validation to identify proteins whose abundance was significantly elevated or suppressed in CCA samples compared to BBTDs.Results. In addition to identifying several proteins previously known to be differentially expressed in CCA and BBTDs, we also discovered a number of molecules that were previously not associated with CCA. These included FAM19A5, MAGED4B, KIAA0321, RBAK, and UPF3B.Conclusions. Novel serum biomarkers to distinguish CCA from BBTDs were identified using a proteomic approach. Further validation of these proteins has the potential to provide a biomarker for differentiating CCA from BBTDs.
Timed Bromocriptine-QR Therapy Reduces Progression of Cardiovascular Disease and Dysglycemia in Subjects with Well-Controlled Type 2 Diabetes Mellitus
Authors: Chamarthi Bindu , Gaziano J. Michael , Blonde Lawrence , Vinik Aaron , Scranton Richard E. , Ezrokhi Michael , Rutty Dean , Cincotta Anthony H.
Published: April 2015

Background.Type 2 diabetes (T2DM) patients, including those in good glycemic control, have an increased risk of cardiovascular disease (CVD). Maintaining good glycemic control may reduce long-term CVD risk. However, other risk factors such as elevated vascular sympathetic tone and/or endothelial dysfunction may be stronger potentiators of CVD. This study evaluated the impact of bromocriptine-QR, a sympatholytic dopamine D2 receptor agonist, on progression of metabolic disease and CVD in T2DM subjects in good glycemic control (HbA1c ≤7.0%).Methods.1834 subjects (1219 bromocriptine-QR; 615 placebo) with baseline HbA1c ≤7.0% derived from the Cycloset Safety Trial (this trial is registered with ClinicalTrials.gov Identifier:NCT00377676), a 12-month, randomized, multicenter, placebo-controlled, double-blind study in T2DM, were evaluated. Treatment impact upon a prespecified composite CVD endpoint (first myocardial infarction, stroke, coronary revascularization, or hospitalization for angina/congestive heart failure) and the odds of losing glycemic control (HbA1c >7.0% after 52 weeks of therapy) were determined.Results.Bromocriptine-QR reduced the CVD endpoint by 48% (intention-to-treat; HR: 0.52 [0.28−0.98]) and 52% (on-treatment analysis; HR: 0.48 [0.24−0.95]). Bromocriptine-QR also reduced the odds of both losing glycemic control (OR: 0.63 (0.47−0.85),p=0.002) and requiring treatment intensification to maintain HbA1c ≤7.0% (OR: 0.46 (0.31−0.69),p=0.0002).Conclusions.Bromocriptine-QR therapy slowed the progression of CVD and metabolic disease in T2DM subjects in good glycemic control.
Automated Segmentation of Cerebellum Using Brain Mask and Partial Volume Estimation Map
Authors: Lee Dong-Kyun , Yoon Uicheul , Kwak Kichang , Lee Jong-Min
Published: April 2015

While segmentation of the cerebellum is an indispensable step in many studies, its contrast is not clear because of the adjacent cerebrospinal fluid, meninges, and cerebra peduncle. Thus, various cerebellar segmentation methods, such as a deformable model or a template-based algorithm might exhibit incorrect segmentation of the venous sinuses and the cerebellar peduncle. In this study, we propose a fully automated procedure combining cerebellar tissue classification, a template-based approach, and morphological operations sequentially. The cerebellar region was defined approximately by removing the cerebral region from the brain mask. Then, the noncerebellar region was trimmed using a morphological operator and the brain-stem atlas was aligned to the individual brain to define the brain-stem area. The proposed method was validated with the well-known FreeSurfer and ITK-SNAP packages using the dice similarity index and recall and precision scores. As a result, the proposed method was significantly better than the other methods for the dice similarity index (0.93, FreeSurfer: 0.92, ITK-SNAP: 0.87) and precision (0.95, FreeSurfer: 0.90, ITK-SNAP: 0.93). Therefore, it could be said that the proposed method yielded a robust and accurate segmentation result. Moreover, additional postprocessing with the brain-stem atlas could improve its result.
Energy Aware Simple Ant Routing Algorithm for Wireless Sensor Networks
Authors: Jabbar Sohail , Iram Rabia , Imran Muhammad , Ahmad Awais , Paul Anand , Minhas Abid Ali , Iftikhar Mohsin
Published: April 2015

Network lifetime is one of the most prominent barriers in deploying wireless sensor networks for large-scale applications because these networks employ sensors with nonrenewable scarce energy resources. Sensor nodes dissipate most of their energy in complex routing mechanisms. To cope with limited energy problem, we present EASARA, an energy aware simple ant routing algorithm based on ant colony optimization. Unlike most algorithms, EASARA strives to avoid low energy routes and optimizes the routing process through selection of least hop count path with more energy. It consists of three phases, that is, route discovery, forwarding node, and route selection. We have improved the route discovery procedure and mainly concentrate on energy efficient forwarding node and route selection, so that the network lifetime can be prolonged. The four possible cases of forwarding node and route selection are presented. The performance of EASARA is validated through simulation. Simulation results demonstrate the performance supremacy of EASARA over contemporary scheme in terms of various metrics.
Mature Cystic Teratoma in Douglas’ Pouch
Authors: Ohshima Kenji , Umeda Anna , Hosoi Ayako , Yamamoto Toshiya , Munakata Satoru
Published: April 2015

Mature cystic teratoma is one of the most common ovarian neoplasms, but extragonadal teratoma is rare. Teratoma in Douglas’ pouch is extremely rare, and only 12 cases have been reported since the first case was described in 1978. We report a 20-year-old woman with a multicystic mass in Douglas’ pouch that was treated via laparoscopic resection. The tumor consisted of cysts lined by stratified squamous epithelium with an accumulation of keratin debris and various mature tissues. No immature elements or malignancy was found in the tumor, confirming the pathologic diagnosis of a mature cystic teratoma. The teratoma contained no ovarian tissues and both of the ovaries were intact on laparoscopy. These findings suggest that the teratoma originated primarily in Douglas’ pouch rather than being caused by autoamputation of a previously existing ovarian teratoma. This is the first case that simultaneously showed normal ovaries and a teratoma in Douglas’ pouch on laparoscopy.
Numerical Modeling for Discrete Multibody Interaction and Multifeild Coupling Dynamics Using the SPH Method
Authors: Halik Azhar , Imin Rahmatjan , Geni Mamtimin , Jin Afang , Mou Yangyang
Published: April 2015

Discrete multibody interaction and contact problems and the multiphase interactions such as the sand particles airflow interactions by Aeolian sand transport in the desert are modeled by using the different kernel smoothing lengths in SPH method. Each particle defines a particular kernel smoothing length such as larger smoothing length which is used to calculate continuous homogenous body. Some special smoothing lengths are used to approximate interaction between the discrete particles or objects in contact problems and in different field coupling problem. By introducing the Single Particle Model (SPM) and the Multiparticle Model (MPM), the velocity exchanging phenomena are discussed by using different elastic modules. Some characteristics of the SPM and MPM are evaluated. The results show that the new SPH method can effectively solve different discrete multibody correct contact and multiphase mutual interference problems. Finally, the new SPH numerical computation and simulation process are verified.
Regulatory Role of Small Nucleolar RNAs in Human Diseases
Authors: Stepanov Grigory A. , Filippova Julia A. , Komissarov Andrey B. , Kuligina Elena V. , Richter Vladimir A. , Semenov Dmitry V.
Published: April 2015

Small nucleolar RNAs (snoRNAs) are appreciable players in gene expression regulation in human cells. The canonical function of box C/D and box H/ACA snoRNAs is posttranscriptional modification of ribosomal RNAs (rRNAs), namely, 2′-O-methylation and pseudouridylation, respectively. A series of independent studies demonstrated that snoRNAs, as well as other noncoding RNAs, serve as the source of various short regulatory RNAs. Some snoRNAs and their fragments can also participate in the regulation of alternative splicing and posttranscriptional modification of mRNA. Alterations in snoRNA expression in human cells can affect numerous vital cellular processes. SnoRNA level in human cells, blood serum, and plasma presents a promising target for diagnostics and treatment of human pathologies. Here we discuss the relation between snoRNAs and oncological, neurodegenerative, and viral diseases and also describe changes in snoRNA level in response to artificial stress and some drugs.