bluuebunny/crossref_metadata_2025 huggingface dataset:
A Comparative Study of Visualizations with Different Granularities of Behavior for Communicating about Autism
Authors: Kong Ha Kyung , Lee John , Karahalios Karrie
Published: December 2017

This paper presents a comparative study of two webtools developed to capture engagement via visualization of coordinated communication behavior in children with autism. A clear preference arose for different tasks based on behavior granularity emphasis in the two visualizations. The survey and interview results further revealed the importance of showing behavior patterns, rather than displaying a single behavior without context, in behavior visualization. Based on the results, we propose three granularity-related features to incorporate into behavioral visualizations for communication in clinical settings: separating modalities, coordinating dyadic interactions, and displaying micro-behaviors.
Conspiracy Talk on Social Media
Authors: Kou Yubo , Gui Xinning , Chen Yunan , Pine Kathleen
Published: December 2017

Conspiracy theories have gained much academic and media attention recently, due to their large impact on public events. Crisis informatics researchers have examined conspiracy theories as a type of rumor. However, little is known about how conspiracy theories are produced and developed on social media. We present a qualitative study of conspiracy theorizing on Reddit during a public health crisis--the Zika virus outbreak. Using a mixed-methods approach including content analysis and discourse analysis, we identified types of conspiracy theories that appeared on Reddit in response to the Zika crisis, the conditions under which Zika conspiracy theories emerge, and the particular discursive strategies through which Zika conspiracy theories developed in online forums. Our analysis shows that conspiracy talk emerged as people attempted to make sense of a public health crisis, reflecting their emergent information needs and their pervasive distrust in formal sources of Zika information. Practical implications for social computing researchers, health practitioners, and policymakers are discussed.
Managing Disruptive Behavior through Non-Hierarchical Governance
Authors: Kou Yubo , Gui Xinning , Zhang Shaozeng , Nardi Bonnie
Published: December 2017

Disruptive behaviors such as flaming and vandalism have been part of the Internet since its beginning. Various models of hierarchical governance have been established and managed in different online venues, with both successes and failures. Recently, a new model of non-hierarchical governance has emerged using crowdsourcing technology to allow an online community to manage itself. How do people view and work with non-hierarchical governance? In this paper, we present an interview study with people from two sites: the video game League of Legends and Weibo, a microblogging site in China. We found that people were passionate about participation in crowdsourcing, but at the same time, struggled with the system, and acted beyond their designated role within the system. We derive implications for designing online non-hierarchical governance from our research.
'No Telling Passcodes Out Because They're Private'
Authors: Kumar Priya , Naik Shalmali Milind , Devkar Utkarsha Ramesh , Chetty Marshini , Clegg Tamara L. , Vitak Jessica
Published: December 2017

Children under age 12 increasingly use Internet-connected devices to go online. And while Internet use exposes people to privacy and security risks, few studies examine how these children perceive and address such concerns. To fill this gap, we conducted a qualitative study of 18 U.S. families with children ages 5-11. We found that children recognized certain privacy and security components from the contextual integrity framework, but children ages 5-7 had gaps in their knowledge. Children developed some strategies to manage concerns but largely relied on parents for support. Parents primarily used passive strategies to mediate children's device use and largely deferred teaching children about these concerns to the future. We argue that helping children develop strong privacy and security practices at a young age will prepare them to manage their privacy and security as adolescents and adults. We offer recommendations to scaffold children's learning on privacy and security.
Effectiveness and Users' Experience of Obfuscation as a Privacy-Enhancing Technology for Sharing Photos
Authors: Li Yifang , Vishwamitra Nishant , Knijnenburg Bart P. , Hu Hongxin , Caine Kelly
Published: December 2017

Current collaborative photo privacy protection solutions can be categorized into two approaches: controlling the recipient, which restricts certain viewers' access to the photo, and controlling the content, which protects all or part of the photo from being viewed. Focusing on the latter approach, we introduce privacy-enhancing obfuscations for photos and conduct an online experiment with 271 participants to evaluate their effectiveness against human recognition and how they affect the viewing experience. Results indicate the two most common obfuscations, blurring and pixelating, are ineffective. On the other hand, inpainting, which removes an object or person entirely, and avatar, which replaces content with a graphical representation are effective. From a viewer experience perspective, blurring, pixelating, inpainting, and avatar are preferable. Based on these results, we suggest inpainting and avatar may be useful as privacy-enhancing technologies for photos, because they are both effective at increasing privacy for elements of a photo and provide a good viewer experience.
Tinkering with Governance
Authors: Lindtner Silvia , Avle Seyram
Published: December 2017

From statistics and mapping to engineering and medicine, technology has long been a tool of governance, shaping how nation states control their own and other regions' populations and natural resources. More recently, a nation's capacity to cultivate citizens as tech innovators and entrepreneurs is considered an indicator of its economic prosperity and global power. We show how this turn towards innovation and entrepreneurship is central to how technological and political elites tinker with new modes of governance and define the relationship between the future of the nation and its citizenry in economic terms. Drawing from long-term multi-sited ethnographic research in the United States, China, and Africa, we present a subset of findings to show how these shifts in governance are being enacted through interconnections between politicians and technologists, and the products, spaces, and educational ideals they fund and create. We argue that making sense of these shifts in governance is essential for current and future CSCW scholarship as they intersect with issues of power within social computing.
Selfies as Social Movements
Authors: Liu Fannie , Ford Denae , Parnin Chris , Dabbish Laura
Published: December 2017

A new kind of online movement has emerged on social media: identity hashtag movements, through which individuals share "selfies" and personal stories to elucidate the experiences of marginalized social groups. These movements have the potential to counteract bias and enable social justice, but are enacted in a forum rife with identity and boundary management concerns. To understand this type of movement, we present a qualitative study of #ILookLikeAnEngineer, a hashtag created to challenge engineering stereotypes. We interviewed 32 people, including participants and non-participants of the movement, about their experiences with the hashtag. We found that personally identifiable participation promoted feelings of empowerment and strengthened connections within the marginalized community. At the same time, the personal and professional identity focus raised ambiguity about the boundaries of the collective and the movement's ability to change stereotypes. We discuss implications for online collective action and the use of social media for addressing stereotypes.
Write for Life
Authors: Ma Haiwei , Smith C. Estelle , He Lu , Narayanan Saumik , Giaquinto Robert A. , Evans Roni , Hanson Linda , Yarosh Svetlana
Published: December 2017

Expressive writing has been shown to improve physical, mental, and social health outcomes for patients struggling with difficult diagnoses. In many online health communities, writing comprises a substantial portion of the user experience, yet little work has explored how writing itself affects user engagement. This paper explores user engagement on CaringBridge, a prominent online community for writing about personal health journeys. We build a survival analysis model, defining a new set of variables that operationalize expressive writing, and comparing these effects to those of social support, which are well-known to benefit user engagement. Furthermore, we use machine learning methods to estimate that approximately one third of community members who self-identify with a cancer condition cease engagement due to literal death. Finally, we provide quantitative evidence that: (1) receiving support, expressive writing, and giving support, in decreasing magnitude of relative impact, are associated with user engagement on CaringBridge, and (2) that considering deceased sites separately in our analysis significantly shifts our interpretations of user behavior.
A Nine-Item Questionnaire for Measuring the Social Disfordance of Mediated Social Touch Technologies
Authors: Mejia Kenya , Yarosh Svetlana
Published: December 2017

Mediated Social Touch (MST) technologies focus on enhancing a communication experience by sensing, transmitting, and simulating social touch between remote partners. With interest in developing MST technologies continuing to grow, it is important to create standardized methods for measuring the effect of these novel systems. We designed and validated a 9-item questionnaire to measure the "Social Disfordance" of Mediated Social Touch, with three scales that focus on Social Discomfort, Communicational Expressiveness, and Need for Additional Consideration. A high degree of "social disfordance" of an MST system signifies that it may not provide the appropriate social affordances for mediating touch in a particular context. The development of the Social Disfordance of Mediated Social Touch (SDMST) instrument included a systematic literature review, expert feedback, and think-out-loud piloting. Its refinement included an exploratory factor analysis with a subsequent reduction of questions and scales. We report its psychometric properties, including metrics of inter-item reliability, convergent validity, test-retest reliability, and concurrent validity, confirming that these properties are sufficient for future use. We conclude with examples of scoring, appropriate use, and a discussion of the limitations.
Design Recommendations for Self-Monitoring in the Workplace
Authors: Meyer Andre N. , Murphy Gail C. , Zimmermann Thomas , Fritz Thomas
Published: December 2017

One way to improve the productivity of knowledge workers is to increase their self-awareness about productivity at work through self-monitoring. Yet, little is known about expectations of, the experience with, and the impact of self-monitoring in the workplace. To address this gap, we studied software developers, as one community of knowledge workers. We used an iterative, user-feedback-driven development approach (N=20) and a survey (N=413) to infer design elements for workplace self-monitoring, which we then implemented as a technology probe called WorkAnalytics. We field-tested these design elements during a three-week study with software development professionals (N=43). Based on the results of the field study, we present design recommendations for self-monitoring in the workplace, such as using experience sampling to increase the awareness about work and to create richer insights, the need for a large variety of different metrics to retrospect about work, and that actionable insights, enriched with benchmarking data from co-workers, are likely needed to foster productive behavior change and improve collaboration at work. Our work can serve as a starting point for researchers and practitioners to build self-monitoring tools for the workplace.
Spread of Employee Engagement in a Large Organizational Network
Authors: Mitra Tanushree , Muller Michael , Shami N. Sadat , Golestani Abbas , Masli Mikhil
Published: December 2017

Behavioral statescan be transferred to others, leading people to behave in ways similar to those around them. Can this phenomenon of behavioral contagion be seen in the workplace? Using employees' organizational social media data and their workplace hierarchical network structure, we studied contagion across a large multinational corporation, focusing on an important workplace behavior - employee engagement. We measured employees' engagement based on their word choice in organizational social media, and we applied a longitudinal statistical technique which controls for homophily, employees' traits and prior expressions of engagement. We found that engagement and disengagement spread from one employee to another with direct peers exerting the strongest influence. While engagement-spread was more powerful laterally among people at the same organizational level, disengagement-spread followed the vertical managerial chain. Further, we found that disengaged co-workers exerted a stronger influence on employee's future engagement compared to the engaged co-workers. Our results suggest the need for organizations to sense and address workplace disengagement promptly. Moreover, our findings offer opportunities for using workplace interventions to promote engagement and mitigate disengagement.
Synchronous Text Messaging
Authors: Podlubny Martin , Rooksby John , Rost Mattias , Chalmers Matthew
Published: December 2017

We have created and evaluated a novel mobile messaging app named Curtains Messenger. The app has been designed to support synchrony in messaging. It does this by requiring users to be in the app at the same time as each other in order to send, receive and read messages. This design is contrary to typical apps where messages can be sent and read asynchronously at an individual's convenience. We have conducted a field trial in which 15 users installed the app on their own devices and used it in the wild. We present a qualitative analysis of interviews with the participants following the trial. The findings address how the app was used, how synchrony affected conversational flows, how synchrony raised issues of attention and intimacy, and what issues users faced in the practical work of conducting synchronous messaging. This work demonstrates how core concepts in the study of cooperative work such as a/synchrony can be drawn upon to reconsider taken-for-granted design features of mobile applications and the lived experience of communication.
Interpretations of Online Anonymity in Alcoholics Anonymous and Narcotics Anonymous
Authors: Rubya Sabirat , Yarosh Svetlana
Published: December 2017

How do individuals in twelve-step fellowships like Alcoholics Anonymous (AA) and Narcotics Anonymous (NA) interpret and enact "anonymity?" In this paper, we answer this question through a mixed-methods investigation. Through secondary analysis of interview data from 26 participants and an online questionnaire (N=285) we found three major interpretations of anonymity among AA and NA members: "unidentifiability," "social contract," and "program over individual." While unidentifiability has been the focus of computing investigations, the other interpretations provide a significant and novel lens on anonymity. To understand how and when the unidentifiability interpretation was most likely to be enacted, we conducted a quantitative analysis of traces of activity in a large online recovery community. We observed that members were less likely to enact "unidentifiability" if they were more connected to the particular community and had more time in recovery. We provide implications for future research on context-specific anonymity and implications for design in online recovery spaces and similar sensitive contexts.
Modeling Stress with Social Media Around Incidents of Gun Violence on College Campuses
Authors: Saha Koustuv , De Choudhury Munmun
Published: December 2017

Stress constitutes a persistent wellbeing challenge to college students, impacting their personal, social, and academic life. However, violent events on campuses may aggravate student stress, due to the induced fear and trauma. In this paper, leveraging social media as a passive sensor of stress, we propose novel computational techniques to quantify and examine stress responses after gun violence on college campuses. We first present a machine learning classifier for inferring stress expression in Reddit posts, which achieves an accuracy of 82%. Next, focusing on 12 incidents of campus gun violence in the past five years, and social media data gathered from college Reddit communities, our methods reveal amplified stress levels following the violent incidents, which deviate from usual stress patterns on the campuses. Further, distinctive temporal and linguistic changes characterize the campus populations, such as reduced cognition, higher self pre-occupation and death-related conversations. We discuss the implications of our work in improving mental wellbeing and rehabilitation efforts around crisis events in college student populations.
Simulation Experiments on (the Absence of) Ratings Bias in Reputation Systems
Authors: Thebault-Spieker Jacob , Kluver Daniel , Klein Maximilian A. , Halfaker Aaron , Hecht Brent , Terveen Loren , Konstan Joseph A.
Published: December 2017

As the gig economy continues to grow and freelance work moves online, five-star reputation systems are becoming more and more common. At the same time, there are increasing accounts of race and gender bias in evaluations of gig workers, with negative impacts for those workers. We report on a series of four Mechanical Turk-based studies in which participants who rated simulated gig work did not show race- or gender bias, while manipulation checks showed they reliably distinguished between low- and high-quality work. Given prior research, this was a striking result. To explore further, we used a Bayesian approach to verify absence of ratings bias (as opposed to merely not detecting bias). This Bayesian test let us identify an upper- bound: if any bias did exist in our studies, it was below an average of 0.2 stars on a five-star scale. We discuss possible interpretations of our results and outline future work to better understand the results.
Dyslexia in SNS
Authors: Vezzoli Yvonne , Vasalou Asimina , Porayska-Pomsta Kaska
Published: December 2017

The paradigm of neurodiversity provides a theoretical scaffold to challenge the idea of dyslexia as a deficit, by considering how difficulties related to literacy may reflect possible cognitive strengths and opportunities for learning. In this paper we adopt this perspective which associates dyslexia with strengths in visual, oral and three-dimensional thinking. Our goal is to understand if and how the multimodal affordances of SNS mediate participation and new literacies for dyslexic youth, and how these affordances interact with identity work. Seven young people struggling with literacy were interviewed about their use of SNS. Our results show that the visual affordances of SNS enable new forms of participation and expression, furthering our understanding of visual literacies. Nonetheless, despite the pervasive use of visual affordances to perform identity work, we also find that young people's learning differences are not always obviated but re-constructed, or even confronted in SNS.
Quantified Baby
Authors: Wang Junqing , O'Kane Aisling Ann , Newhouse Nikki , Sethu-Jones Geraint Rhys , de Barbaro Kaya
Published: December 2017

Baby wearable technologies are becoming increasingly popular, particularly in early infancy. However, little research has been conducted to investigate how baby wearable technologies are adopted and used in parenting. This paper presents a two-week in-depth situated study with six mothers in their homes consisting of contextual entry and exit interviews, video recordings of "out-of-box" experiences, and a diary study. Using interpretative phenomenological analysis, participants' use and expectations of the baby wearable technology were examined. Use of the device directly impacted upon parents' knowledge production and anxiety, and influenced the perceived physicality and social factors of parenting. We frame these findings around sociological norms of the vulnerable child and responsible mother, as well as the notion of "lived informatics", where individuals' interaction with the technology influenced the perception, use and impact of the baby wearable on everyday parenting practices and familial relationships.
Understanding Collaborative Decision Making Around a Large-Scale Interactive Tabletop
Authors: Westendorf Lauren , Shaer Orit , Varsanyi Petra , van der Meulen Hidde , Kun Andrew L.
Published: December 2017

We present findings from an empirical study of how groups of eight users collaborate on a decision-making task around an interactive tabletop. To our knowledge, this is the first study to examine co-located collaboration in larger groups (of 8-12 users) seated around a large-scale high-resolution multi-touch horizontal display. Our findings shed light on: 1) the effect of collaboration patterns of larger groups on equity of participation; 2) the role of participants' position around the tabletop in forming collaborations; and 3) the mechanisms, which facilitate coordination and collaboration in larger group interacting around large-scale tabletops; We also contribute computational methods that leverage image processing to analyze interaction around large-scale tabletops. Finally, we discuss implications for the design of large-scale tabletop systems for supporting co-located collaboration in larger groups.
Cross-Strait Frenemies
Authors: Yang Shengnan , Chen Pei-Ying , Shih Patrick C. , Bardzell Jeffrey , Bardzell Shaowen
Published: December 2017

Contributing to research on social activism as a form of collective action, we report on Diba, a sizable group of Chinese nationalists, who overcame the Great Firewall in order to troll Taiwan's political leadership. Diba's political activism can be characterized as negotiating a tension between two seemingly opposed goals. On the one hand is their construction of a pro-PRC message using the tactics of Internet subcultures (memes, trolling, etc.), but toned down to meet standards of civility. On the other hand, by collectively breaching the Great Firewall and establishing Facebook accounts, the group transgressed PRC technical and legal norms, which were designed to prevent unsanctioned collective action. We argue that the Diba Expedition exemplifies the coordinated use of a complex, transnational social media ecology to support and produce a mass-scale event and newsworthy spectacle, loosened if not severed from state control, and a discursively innovative polysemous message targeted at diverse international audiences: civilized trolling.
SqueezeBands
Authors: Yarosh Svetlana , Mejia Kenya , Unver Baris , Wang Xizi , Yao Yuan , Campbell Akin , Holschuh Brad
Published: December 2017

Mediated social touch technologies aim to transmit the sense of touch between two or more physically distributed partners. Previous work in CSCW has focused mostly on vibrotactile actuation, though there is also significant recent interest in exploring a wider variety of haptic actuation modalities. In this paper, we explore Shape Memory Alloys as a novel means for constriction and heat activation. We demonstrate the feasibility of this approach by implementing the SqueezeBands system, which augments social gestures over videochat with haptic actuation. We describe an evaluation of the system with 57 pairs of participants, collaborating on tasks either high or low emotional salience. Our results demonstrate that SqueezeBands encourage greater and more diverse demonstrations of touch and that they may be particularly appropriate for easing mental and physical demand in high emotion tasks. We end with a discussion of the opportunities and challenges in leveraging Shape Memory Alloy actuation for mediated social touch.
Out With The Old, In With The New?
Authors: Yu Bowen , Wang Xinyi , Lin Allen Yilun , Ren Yuqing , Terveen Loren , Zhu Haiyi
Published: December 2017

Nearly any group is subject to
turnover
: some people leave, while others join. Turnover can be especially high in online groups, since participation typically is strictly voluntary. We investigated the effects of member turnover in online groups, specifically in Wikipedia's WikiProjects. We based our studies on theories from organizational science, which suggest that it is not just the amount of turnover, but the
characteristics
of those leaving and those joining that matter. We characterized leavers and newcomers by their prior productivity, tenure (in the group or community), and participation in other groups within the larger community. Furthermore, we considered the moderating effect of group size on turnover. We analyzed data from 88,427 editors who participated in 1,054 WikiProjects, finding that (1) the positive effects of newcomers to a group were larger than the negative effects of leavers, (2) prior productivity, tenure, and participation in other groups all played significant roles, and (3) the effects of leavers and newcomers were amplified in larger groups.
I Didn't Know that You Knew I Knew
Authors: Yuan Chien Wen , Hanrahan Benjamin V. , Lee Sooyeon , Rosson Mary Beth , Carroll John M.
Published: December 2017

It is important to support independent living for people with visual impairments (PVI). Part of this can be accomplished with individual assistive technologies. However, in this paper we emphasize the social and collaborative needs for PVI to fully integrate into society as equals. The study assesses how PVI collaborate with different types of sighted partners when shopping together. We chose to study grocery shopping because it is a critical and challenging task for PVI. We conducted field observations and in-depth interviews with five PVI and their sighted shopping partners, including spouses, caseworkers, and store-provided courtesy shoppers. We found several factors that modulated these collaborations with varying forms of common ground: 1) knowledge about how to assist PVI; 2) interpersonal knowledge resulting from common experience and interpersonal relationship history; and 3) knowledge of shopping as a practice. We discuss our findings with respect to the implications for designing collaborative interactions.
Feature Selection
Authors: Li Jundong , Cheng Kewei , Wang Suhang , Morstatter Fred , Trevino Robert P. , Tang Jiliang , Liu Huan
Published: December 2017

Feature selection, as a data preprocessing strategy, has been proven to be effective and efficient in preparing data (especially high-dimensional data) for various data-mining and machine-learning problems. The objectives of feature selection include building simpler and more comprehensible models, improving data-mining performance, and preparing clean, understandable data. The recent proliferation of big data has presented some substantial challenges and opportunities to feature selection. In this survey, we provide a comprehensive and structured overview of recent advances in feature selection research. Motivated by current challenges and opportunities in the era of big data, we revisit feature selection research from a data perspective and review representative feature selection algorithms for conventional data, structured data, heterogeneous data and streaming data. Methodologically, to emphasize the differences and similarities of most existing feature selection algorithms for conventional data, we categorize them into four main groups: similarity-based, information-theoretical-based, sparse-learning-based, and statistical-based methods. To facilitate and promote the research in this community, we also present an open source feature selection repository that consists of most of the popular feature selection algorithms (http://featureselection.asu.edu/). Also, we use it as an example to show how to evaluate feature selection algorithms. At the end of the survey, we present a discussion about some open problems and challenges that require more attention in future research.
Geomagnetism for Smartphone-Based Indoor Localization
Authors: He Suining , Shin Kang G.
Published: December 2017

Geomagnetism has recently attracted considerable attention for indoor localization due to its pervasiveness and independence from extra infrastructure. Its location signature has been observed to be temporally stable and spatially discernible for localization purposes. This survey examines and analyzes the recent challenges and advances in geomagnetism-based indoor localization using smartphones. We first study smartphone-based geomagnetism measurements. We then review recent efforts in database construction and computation reduction, followed by state-of-the-art schemes in localizing the target. For each category, we identify practical deployment challenges and compare related studies. Finally, we summarize future directions and provide a guideline for new researchers in this field.
Server Location Verification (SLV) and Server Location Pinning
Authors: Abdou Abdelrahman , Oorschot P. C. Van
Published: December 2017

We introduce the first known mechanism providing realtime server location verification. Its uses include enhancing server authentication by enabling browsers to automatically interpret server location information. We describe the design of this new measurement-based technique, Server Location Verification (SLV), and evaluate it using PlanetLab. We explain how SLV is compatible with the increasing trends of geographically distributed content dissemination over the Internet, without causing any new interoperability conflicts. Additionally, we introduce the notion of (verifiable)
server location pinning
(conceptually similar to certificate pinning) to support SLV, and evaluate their combined impact using a server-authentication evaluation framework. The results affirm the addition of new security benefits to the existing TLS-based authentication mechanisms. We implement SLV through a location verification service, the simplest version of which requires no server-side changes. We also implement a simple browser extension that interacts seamlessly with the verification infrastructure to obtain realtime server location-verification results.
Compiler-Assisted Loop Hardening Against Fault Attacks
Authors: Proy Julien , Heydemann Karine , Berzati Alexandre , Cohen Albert
Published: December 2017

Secure elements widely used in smartphones, digital consumer electronics, and payment systems are subject to fault attacks. To thwart such attacks, software protections are manually inserted requiring experts and time. The explosion of the Internet of Things (IoT) in home, business, and public spaces motivates the hardening of a wider class of applications and the need to offer security solutions to non-experts. This article addresses the automated protection of loops at compilation time, covering the widest range of control- and data-flow patterns, in both shape and complexity. The security property we consider is that a sensitive loop must always perform the expected number of iterations; otherwise, an attack must be reported. We propose a generic compile-time loop hardening scheme based on the duplication of termination conditions and of the computations involved in the evaluation of such conditions. We also investigate how to preserve the security property along the compilation flow while enabling aggressive optimizations. We implemented this algorithm in LLVM 4.0 at the Intermediate Representation (IR) level in the backend. On average, the compiler automatically hardens 95% of the sensitive loops of typical security benchmarks, and 98% of these loops are shown to be robust to simulated faults. Performance and code size overhead remain quite affordable, at 12.5% and 14%, respectively.
SLOOP
Authors: Azhar M. Waqar , Stenström Per , Papaefstathiou Vassilis
Published: December 2017

Most systems allocate computational resources to each executing task without any actual knowledge of the application’s Quality-of-Service (QoS) requirements. Such best-effort policies lead to overprovisioning of the resources and increase energy loss. This work assumes applications with soft QoS requirements and exploits the inherent timing slack to minimize the allocated computational resources to reduce energy consumption.

We propose a lightweight progress-tracking methodology based on the outer loops of application kernels. It builds on online history and uses it to estimate the total execution time. The prediction of the execution time and the QoS requirements are then used to schedule the application on a heterogeneous architecture with big out-of-order cores and small (LITTLE) in-order cores and select the minimum operating frequency, using DVFS, that meets the deadline. Our scheme is effective in exploiting the timing slack of each application. We show that it can reduce the energy consumption by more than 20% without missing any computational deadlines.
MBZip
Authors: Kanakagiri Raghavendra , Panda Biswabandan , Mutyam Madhu
Published: December 2017

Compression techniques at the last-level cache and the DRAM play an important role in improving system performance by increasing their effective capacities. A compressed block in DRAM also reduces the transfer time over the memory bus to the caches, reducing the latency of a LLC cache miss. Usually, compression is achieved by exploiting data patterns present within a block. But applications can exhibit data locality that spread across multiple consecutive data blocks. We observe that there is significant opportunity available for compressing multiple consecutive data blocks into one single block, both at the LLC and DRAM. Our studies using 21 SPEC CPU applications show that, at the LLC, around 25% (on average) of the cache blocks can be compressed into one single cache block when grouped together in groups of 2 to 8 blocks. In DRAM, more than 30% of the columns residing in a single DRAM page can be compressed into one DRAM column, when grouped together in groups of 2 to 6. Motivated by these observations, we propose a mechanism, namely, MBZip, that compresses multiple data blocks into one single block (called a zipped block), both at the LLC and DRAM. At the cache, MBZip includes a simple tag structure to index into these zipped cache blocks and the indexing does not incur any redirectional delay. At the DRAM, MBZip does not need any changes to the address computation logic and works seamlessly with the conventional/existing logic. MBZip is a synergistic mechanism that coordinates these zipped blocks at the LLC and DRAM. Further, we also explore silent writes at the DRAM and show that certain writes need not access the memory when blocks are zipped. MBZip improves the system performance by 21.9%, with a maximum of 90.3% on a 4-core system.
Protean Careers at Work: Self-Direction and Values Orientation in Psychological Success
Authors: Hall Douglas T. (Tim) , Yip Jeffrey , Doiron Kathryn
Published: December 2017

How do self-direction and personal values influence career outcomes? Such questions have been central in research on the protean career—a career process characterized by the exercise of self-direction and an intrinsic values orientation in the pursuit of psychological success. This article provides an integrative review, with a focus on three empirically supported protean processes—identity awareness, adaptability, and agency. In addition, we discuss the role of protean careers in the contemporary work environment, clarify definitional and measurement issues, recommend research directions, and provide practical implications for organizations. Our underlying assumption throughout this discussion is that the elements of a protean career orientation (PCO) are basic elements of human needs for growth and meaning. In addition, we discuss how protean careers can be beneficial for organizations. In particular, we identify the “Protean Paradox” as a phenomenon that merits further investigation. More specifically, the protean paradox is a process by which greater levels of individual self-direction and values orientation, thus serving the purpose and interests of the individual, can also have a positive influence on the groups and organizations in which they work. Our recommendations for future research and practice promote these qualities in the contemporary world of work.
Transcription factor ΔFosB acts within the nucleus of the solitary tract to increase mean arterial pressure during exposures to intermittent hypoxia
Authors: Wu Qiong , Cunningham J. Thomas , Mifflin Steve
Published: December 2017

ΔFosB is a member of the activator protein-1 family of transcription factors. ΔFosB has low constitutive expression in the central nervous system and is induced after exposure of rodents to intermittent hypoxia (IH), a model of the arterial hypoxemia that accompanies sleep apnea. We hypothesized ΔFosB in the nucleus of the solitary tract (NTS) contributes to increased mean arterial pressure (MAP) during IH. The NTS of 11 male Sprague-Dawley rats was injected (3 sites, 100 nl/site) with a dominant negative construct against ΔFosB (ΔJunD) in an adeno-associated viral vector (AAV)-green fluorescent protein (GFP) reporter. The NTS of 10 rats was injected with AAV-GFP as sham controls. Two weeks after NTS injections, rats were exposed to IH for 8 h/day for 7 days, and MAP was recorded using telemetry. In the sham group, 7 days of IH increased MAP from 99.8 ± 1.1 to 107.3 ± 0.5 mmHg in the day and from 104.4 ± 1.1 to 109.8 ± 0.6 mmHg in the night. In the group that received ΔJunD, IH increased MAP during the day from 95.9 ± 1.7 to 101.3 ± 0.4 mmHg and from 100.9 ± 1.7 to 102.8 ± 0.5 mmHg during the night (both IH-induced changes in MAP were significantly lower than sham, P < 0.05). After injection of the dominant negative construct in the NTS, IH-induced ΔFosB immunoreactivity was decreased in the paraventricular nucleus ( P < 0.05); however, no change was observed in the rostral ventrolateral medulla. These data indicate that ΔFosB within the NTS contributes to the increase in MAP induced by IH exposure.

NEW & NOTEWORTHY The results of this study provides new insights into the molecular mechanisms that mediate neuronal adaptations during exposures to intermittent hypoxia, a model of the hypoxemias that occur during sleep apnea. These adaptations are noteworthy as they contribute to the persistent increase in blood pressure induced by exposures to intermittent hypoxia.
Cardiac performance is limited by oxygen delivery to the mitochondria in the crystalloid-perfused working heart
Authors: Kuzmiak-Glancy Sarah , Covian Raúl , Femnou Armel N. , Glancy Brian , Jaimes Rafael , Wengrowski Anastasia M. , Garrott Kara , French Stephanie A. , Balaban Robert S. , Kay Matthew W.
Published: December 2017

The left ventricular working, crystalloid-perfused heart is used extensively to evaluate basic cardiac function, pathophysiology, and pharmacology. Crystalloid-perfused hearts may be limited by oxygen delivery, as adding oxygen carriers increases myoglobin oxygenation and improves myocardial function. However, whether decreased myoglobin oxygen saturation impacts oxidative phosphorylation (OxPhos) is unresolved, since myoglobin has a much lower affinity for oxygen than cytochrome c oxidase (COX). In the present study, a laboratory-based synthesis of an affordable perfluorocarbon (PFC) emulsion was developed to increase perfusate oxygen carrying capacity without impeding optical absorbance assessments. In left ventricular working hearts, along with conventional measurements of cardiac function and metabolic rate, myoglobin oxygenation and cytochrome redox state were monitored using a novel transmural illumination approach. Hearts were perfused with Krebs-Henseleit (KH) or KH supplemented with PFC, increasing perfusate oxygen carrying capacity by 3.6-fold. In KH-perfused hearts, myoglobin was deoxygenated, consistent with cytoplasmic hypoxia, and the mitochondrial cytochromes, including COX, exhibited a high reduction state, consistent with OxPhos hypoxia. PFC perfusate increased aortic output from 76 ± 6 to 142 ± 4 ml/min and increased oxygen consumption while also increasing myoglobin oxygenation and oxidizing the mitochondrial cytochromes. These results are consistent with limited delivery of oxygen to OxPhos resulting in an adapted lower cardiac performance with KH. Consistent with this, PFCs increased myocardial oxygenation, and cardiac work was higher over a wider range of perfusate Po2. In summary, heart mitochondria are limited by oxygen delivery with KH; supplementation of KH with PFC reverses mitochondrial hypoxia and improves cardiac performance, creating a more physiological tissue oxygen delivery.

NEW & NOTEWORTHY Optical absorbance spectroscopy of intrinsic chromophores reveals that the commonly used crystalloid-perfused working heart is oxygen limited for oxidative phosphorylation and associated cardiac work. Oxygen-carrying perfluorocarbons increase myocardial oxygen delivery and improve cardiac function, providing a more physiological mitochondrial redox state and emphasizing cardiac work is modulated by myocardial oxygen delivery.
A novel mtDNA repair fusion protein attenuates maladaptive remodeling and preserves cardiac function in heart failure
Authors: Bradley Jessica M. , Li Zhen , Organ Chelsea L. , Polhemus David J. , Otsuka Hiroyuki , Islam Kazi N. , Bhushan Shashi , Gorodnya Olena M. , Ruchko Mykhaylo V. , Gillespie Mark N. , Wilson Glenn L. , Lefer David J.
Published: December 2017

Oxidative stress results in mtDNA damage and contributes to myocardial cell death. mtDNA repair enzymes are crucial for mtDNA repair and cell survival. We investigated a novel, mitochondria-targeted fusion protein (Exscien1-III) containing endonuclease III in myocardial ischemia-reperfusion injury and transverse aortic constriction (TAC)-induced heart failure. Male C57/BL6J mice (10–12 wk) were subjected to 45 min of myocardial ischemia and either 24 h or 4 wk of reperfusion. Exscien1-III (4 mg/kg ip) or vehicle was administered at the time of reperfusion. Male C57/BL6J mice were subjected to TAC, and Exscien1-III (4 mg/kg i.p) or vehicle was administered daily starting at 3 wk post-TAC and continued for 12 wk. Echocardiography was performed to assess left ventricular (LV) structure and function. Exscien1-III reduced myocardial infarct size ( P < 0.01) at 24 h of reperfusion and preserved LV ejection fraction at 4 wk postmyocardial ischemia. Exscien1-III attenuated TAC-induced LV dilation and dysfunction at 6–12 wk post-TAC ( P < 0.05). Exscien1-III reduced ( P < 0.05) cardiac hypertrophy and maladaptive remodeling after TAC. Assessment of cardiac mitochondria showed that Exscien1-III localized to mitochondria and increased mitochondrial antioxidant and reduced apoptotic markers. In conclusion, our results indicate that administration of Exscien1-III provides significant protection against myocardial ischemia and preserves myocardial structure and LV performance in the setting of heart failure.

NEW & NOTEWORTHY Oxidative stress-induced mitochondrial DNA damage is a prominent feature in the pathogenesis of cardiovascular diseases. In the present study, we demonstrate the efficacy of a novel, mitochondria-targeted fusion protein that traffics endonuclease III specifically for mitochondrial DNA repair in two well-characterized murine models of cardiac injury and failure.
Heart functional and structural compendium of cardiosplenic and cardiorenal networks in acute and chronic heart failure pathology
Authors: Halade Ganesh V. , Kain Vasundhara , Ingle Kevin. A.
Published: December 2017

Heart failure (HF) secondary to myocardial infarction (MI) is linked to kidney complications that comprise cellular, structural, functional, and survival indicators. However, HF research is focused on left ventricular (LV) pathology. Here, we determined comprehensive functional analysis of the LV using echocardiography in transition from acute heart failure (AHF) to progressive chronic heart failure (CHF) pathology and developed a histological compendium of the cardiosplenic and cardiorenal networks in pathological remodeling. In surgically induced MI using permanent coronary ligation, the LV dysfunction is pronounced, with myocardium necrosis, wall thinning, and 20–30% LV rupture events that indicated AHF and CHF pathological remodeling in C57BL/6 male mice (2–4 mo old, n = 50). Temporal LV function analysis indicated that fractional shortening and strain are reduced from day 1 to day 5 in AHF and sustained to advance to CHF from day 28 to day 56 compared with naïve control mice ( n = 6). During the transition of AHF ( day 1 to day 5) to advanced CHF ( day 28 to day 56), histological and cellular changes in the spleen were definite, with bimodal inflammatory responses in kidney inflammatory biomarkers. Likewise, there was a unidirectional, progressive, and irreversible deposition of compact collagen in the LV along with dynamic changes in the cardiosplenic and cardiorenal networks post-MI. The renal histology and injury markers suggested that cardiac injury triggers irreversible dysregulation that actively alters the cardiosplenic and cardiorenal networks. In summary, the novel strategies or pathways that modulate comprehensive cardiosplenic and cardiorenal networks in AHF and CHF would be effective approaches to study either cardiac repair or cardiac pathology.

NEW & NOTEWORTHY The present compendium shows irreversible ventricular dysfunction as assessed by temporal echocardiography while histological and structural measurements of the spleen and kidney added a novel direction to study cardiosplenic and cardiorenal networks in heart failure pathology. Therefore, the consideration of systems biology and integrative approach is essential to develop novel treatments.

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