bluuebunny/crossref_metadata_2025 huggingface dataset:
HIV-1 Envelope Glycoprotein Trafficking through the Endosomal Recycling Compartment Is Required for Particle Incorporation
Authors: Kirschman Junghwa , Qi Mingli , Ding Lingmei , Hammonds Jason , Dienger-Stambaugh Krista , Wang Jaang-Jiun , Lapierre Lynne A. , Goldenring James R. , Spearman Paul
Published: December 2017

The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) encodes specific trafficking signals within its long cytoplasmic tail (CT) that regulate incorporation into HIV-1 particles. Rab11-family interacting protein 1C (FIP1C) and Rab14 are host trafficking factors required for Env particle incorporation, suggesting that Env undergoes sorting from the endosomal recycling compartment (ERC) to the site of particle assembly on the plasma membrane. We disrupted outward sorting from the ERC by expressing a C-terminal fragment of FIP1C (FIP1C560–649) and examined the consequences on Env trafficking and incorporation into particles. FIP1C560–649reduced cell surface levels of Env and prevented its incorporation into HIV-1 particles. Remarkably, Env was trapped in an exaggerated perinuclear ERC in a CT-dependent manner. Mutation of either the Yxxϕ endocytic motif or the YW795motif in the CT prevented Env trapping in the ERC and restored incorporation into particles. In contrast, simian immunodeficiency virus SIVmac239 Env was not retained in the ERC, while substitution of the HIV-1 CT for the SIV CT resulted in SIV Env retention in this compartment. These results provide the first direct evidence that Env traffics through the ERC and support a model whereby HIV-1 Env is specifically targeted to the ERC prior to FIP1C- and CT-dependent outward sorting to the particle assembly site on the plasma membrane.

IMPORTANCEThe HIV envelope protein is an essential component of the viral particle. While many aspects of envelope protein structure and function have been established, the pathway it follows in the cell prior to reaching the site of particle assembly is not well understood. The envelope protein has a very long cytoplasmic tail that interacts with the host cell trafficking machinery. Here, we utilized a truncated form of the trafficking adaptor FIP1C protein to arrest the intracellular transport of the envelope protein, demonstrating that it becomes trapped inside the cell within the endosomal recycling compartment. Intracellular trapping resulted in a loss of envelope protein on released particles and a corresponding loss of infectivity. Mutations of specific trafficking motifs in the envelope protein tail prevented its trapping in the recycling compartment. These results establish that trafficking to the endosomal recycling compartment is an essential step in HIV envelope protein particle incorporation.
Genome Sequences Reveal Cryptic Speciation in the Human Pathogen
Histoplasma capsulatum
Authors: Sepúlveda Victoria E. , Márquez Roberto , Turissini David A. , Goldman William E. , Matute Daniel R.
Published: December 2017

Histoplasma capsulatum
is a pathogenic fungus that causes life-threatening lung infections. About 500,000 people are exposed to
H. capsulatum
each year in the United States, and over 60% of the U.S. population has been exposed to the fungus at some point in their life. We performed genome-wide population genetics and phylogenetic analyses with 30
Histoplasma
isolates representing four recognized areas where histoplasmosis is endemic and show that the
Histoplasma
genus is composed of at least four species that are genetically isolated and rarely interbreed. Therefore, we propose a taxonomic rearrangement of the genus.

IMPORTANCE
The evolutionary processes that give rise to new pathogen lineages are critical to our understanding of how they adapt to new environments and how frequently they exchange genes with each other. The fungal pathogen
Histoplasma capsulatum
provides opportunities to precisely test hypotheses about the origin of new genetic variation. We find that
H. capsulatum
is composed of at least four different cryptic species that differ genetically and also in virulence. These results have implications for the epidemiology of histoplasmosis because not all
Histoplasma
species are equivalent in their geographic range and ability to cause disease.
Latency-Associated Expression of Human Cytomegalovirus US28 Attenuates Cell Signaling Pathways To Maintain Latent Infection
Authors: Krishna Benjamin A. , Poole Emma L. , Jackson Sarah E. , Smit Martine J. , Wills Mark R. , Sinclair John H.
Published: December 2017

Reactivation of human cytomegalovirus (HCMV) latent infection from early myeloid lineage cells constitutes a threat to immunocompromised or immune-suppressed individuals. Consequently, understanding the control of latency and reactivation to allow targeting and killing of latently infected cells could have far-reaching clinical benefits.
US28
is one of the few viral genes that is expressed during latency and encodes a cell surface G protein-coupled receptor (GPCR), which, during lytic infection, is a constitutive cell-signaling activator. Here we now show that in monocytes, which are recognized sites of HCMV latency
in vivo
, US28 attenuates multiple cell signaling pathways, including mitogen-activated protein (MAP) kinase and NF-κB, and that this is required to establish a latent infection; viruses deleted for US28 initiate a lytic infection in infected monocytes. We also show that these monocytes then become potent targets for the HCMV-specific host immune response and that latently infected cells treated with an inverse agonist of US28 also reactivate lytic infection and similarly become immune targets. Consequently, we suggest that the use of inhibitors of US28 could be a novel immunotherapeutic strategy to reactivate the latent viral reservoir, allowing it to be targeted by preexisting HCMV-specific T cells.

IMPORTANCE
Human cytomegalovirus (HCMV) is a betaherpesvirus and a leading cause of morbidity and mortality among immunosuppressed individuals. HCMV can establish latent infection, where the viral genome is maintained in an infected cell, without production of infectious virus. A number of genes, including
US28
, are expressed by HCMV during latent infection. US28 has been shown to activate many cellular signaling pathways during lytic infection, promoting lytic gene expression and virus production. As such, the role of US28 remains unclear and seems at odds with latency. Here, we show that US28 has the opposite phenotype in cells that support latent infection—it attenuates cellular signaling, thereby maintaining latency. Inhibition of US28 with a small-molecule inhibitor causes HCMV latent infection to reactivate, allowing latently infected cells to be detected and killed by the immune system. This approach could be used to treat latent HCMV to clear it from human transplants.
Proposed Role for KaiC-Like ATPases as Major Signal Transduction Hubs in Archaea
Authors: Makarova Kira S. , Galperin Michael Y. , Koonin Eugene V.
Published: December 2017

All organisms must adapt to ever-changing environmental conditions and accordingly have evolved diverse signal transduction systems. In bacteria, the most abundant networks are built around the two-component signal transduction systems that include histidine kinases and receiver domains. In contrast, eukaryotic signal transduction is dominated by serine/threonine/tyrosine protein kinases. Both of these systems are also found in archaea, but they are not as common and diversified as their bacterial and eukaryotic counterparts, suggesting the possibility that archaea have evolved other, still uncharacterized signal transduction networks. Here we propose a role for KaiC family ATPases, known to be key components of the circadian clock in cyanobacteria, in archaeal signal transduction. The KaiC family is notably expanded in most archaeal genomes, and although most of these ATPases remain poorly characterized, members of the KaiC family have been shown to control archaellum assembly and have been found to be a stable component of the gas vesicle system in
Halobacteria
. Computational analyses described here suggest that KaiC-like ATPases and their homologues with inactivated ATPase domains are involved in many other archaeal signal transduction pathways and comprise major hubs of complex regulatory networks. We predict numerous input and output domains that are linked to KaiC-like proteins, including putative homologues of eukaryotic DEATH domains that could function as adapters in archaeal signaling networks. We further address the relationships of the archaeal family of KaiC homologues to the bona fide KaiC of cyanobacteria and implications for the existence of a KaiC-based circadian clock apparatus in archaea.

IMPORTANCE
Little is currently known about signal transduction pathways in
Archaea
. Recent studies indicate that KaiC-like ATPases, known as key components of the circadian clock apparatus in cyanobacteria, are involved in the regulation of archaellum assembly and, likely, type IV pili and the gas vesicle system in
Archaea
. We performed comprehensive comparative genomic analyses of the KaiC family. A vast protein interaction network was revealed, with KaiC family proteins as hubs for numerous input and output components, many of which are shared with two-component signal transduction systems. Putative KaiC-based signal transduction systems are predicted to regulate the activities of membrane-associated complexes and individual proteins, such as signal recognition particle and membrane transporters, and also could be important for oxidative stress response regulation. KaiC-centered signal transduction networks are predicted to play major roles in archaeal physiology, and this work is expected to stimulate their experimental characterization.
From Cell Death to Metabolism: Holin-Antiholin Homologues with New Functions
Authors: van den Esker Marielle H. , Kovács Ákos T. , Kuipers Oscar P.
Published: December 2017

Programmed cell death in bacteria is generally triggered by membrane proteins with functions analogous to those of bacteriophage holins: they disrupt the membrane potential, whereas antiholins antagonize this process. The holin-like class of proteins is present in all three domains of life, but their functions can be different, depending on the species. Using a series of biochemical and genetic approaches, in a recent article in
mBio
, Charbonnier et al. (mBio 8:e00976-17, 2017,
https://doi.org/10.1128/mBio.00976-17
) demonstrate that the antiholin homologue in
Bacillus subtilis
transports pyruvate and is regulated in an unconventional way by its substrate molecule. Here, we discuss the connection between cell death and metabolism in various bacteria carrying genes encoding these holin-antiholin analogues and place the recent study by Charbonnier et al. in an evolutionary context.
Tree Leaf Bacterial Community Structure and Diversity Differ along a Gradient of Urban Intensity
Authors: Laforest-Lapointe Isabelle , Messier Christian , Kembel Steven W.
Published: December 2017

In natural forests, tree leaf surfaces host diverse bacterial communities whose structure and composition are primarily driven by host species identity. Tree leaf bacterial diversity has also been shown to influence tree community productivity, a key function of terrestrial ecosystems. However, most urban microbiome studies have focused on the built environment, improving our understanding of indoor microbial communities but leaving much to be understood, especially in the nonbuilt microbiome. Here, we provide the first multiple-species comparison of tree phyllosphere bacterial structures and diversity along a gradient of urban intensity. We demonstrate that urban trees possess characteristic bacterial communities that differ from those seen with trees in nonurban environments, with microbial community structure on trees influenced by host species identity but also by the gradient of urban intensity and by the degree of isolation from other trees. Our results suggest that feedback between human activity and plant microbiomes could shape urban microbiomes.
National survey of Ebola-related knowledge, attitudes and practices before the outbreak peak in Sierra Leone: August 2014
Authors: Jalloh Mohamed F , Sengeh Paul , Monasch Roeland , Jalloh Mohammad B , DeLuca Nickolas , Dyson Meredith , Golfa Sheku , Sakurai Yukiko , Conteh Lansana , Sesay Samuel , Brown Vance , Li Wenshu , Mermin Jonathan , Bunnell Rebecca
Published: December 2017

Background

The 2014–2015 Ebola epidemic in West Africa was the largest ever to occur. In the early phases, little was known about public knowledge, attitudes and practices (KAP) relating to Ebola virus disease (Ebola). Data were needed to develop evidence-driven strategies to address gaps in knowledge and practice.

Methods

In August 2014, we conducted interviews with 1413 randomly selected respondents from 9 out of 14 districts in Sierra Leone using multistage cluster sampling. Where suitable, Ebola-related KAP questions were adapted from other internationally validated questionnaires related to infectious diseases.

Results

All respondents were aware of Ebola. When asked unprompted, 60% of respondents could correctly cite fever, diarrhoea and vomiting as signs/symptoms of Ebola. A majority of respondents knew that avoiding infected blood and bodily fluids (87%) and contact with an infected corpse (85%) could prevent Ebola. However, there were also widespread misconceptions such as the belief that Ebola can be prevented by washing with salt and hot water (41%). Almost everyone interviewed (95%) expressed at least one discriminatory attitude towards Ebola survivors. Unprompted, self-reported actions taken to avoid Ebola infection included handwashing with soap (66%) and avoiding physical contact with patients with suspected Ebola (40%).

Conclusion

Three months into the 2014 Ebola outbreak in Sierra Leone, our findings suggest there was high awareness of the disease but misconceptions and discriminatory attitudes toward survivors remained common. These findings directly informed the development of a national social mobilisation strategy and demonstrated the importance of KAP assessment early in an epidemic.
Efficacy of a bovine colostrum and egg-based intervention in acute childhood diarrhoea in Guatemala: a randomised, double-blind, placebo-controlled trial
Authors: Gaensbauer James T , Melgar Mario A , Calvimontes Diva M , Lamb Molly M , Asturias Edwin J , Contreras-Roldan Ingrid L , Dominguez Samuel R , Robinson Christine C , Berman Stephen
Published: December 2017

Background

Treatments for paediatric diarrhoeal disease are limited. We assessed the impact of a bovine colostrum and egg-based treatment designed to reduce diarrhoea duration through non-specific and pathogen-directed mechanisms in children.

Methods

Randomised, double-blind, placebo-controlled trial of PTM202, derived from bovine colostrum and hyperimmune hen’s egg on the duration of acute diarrhoeal disease in Guatemalan children. PTM202 contains specific immunoglobulins that target rotavirus, enterotoxigenicEscherichia coli, Shiga toxin-producingE. coliand Salmonella. Children aged 6–35 months presenting to three sites (one rural and two urban) with acute non-bloody diarrhoea were computer randomised to receive three daily doses of PTM202 or placebo. The primary outcome was the post-treatment duration of diarrhoea assessed in the per protocol population. Diarrhoeal pathogens were identified in stool by multiplex PCR (FilmArray Gastrointestinal-Panel, BioFire, Salt Lake City, Utah, USA). Key secondary outcomes included postdiarrhoeal weight gain and impact on diarrhoeal duration stratified by study site and presence of PTM202-targeted organisms in stool at enrolment. Safety was assessed in all participants.

Results

From 9 March 2015 to 25 January 2016, 325 children were enrolled, and 301 (154 intervention and 147 placebo) were analysed for the primary outcome. No difference in diarrhoea duration was observed between intervention and placebo in the total population, but a significant reduction was observed in the treatment group among children with at least one targeted pathogen in stool (HR=1.46, P=0.02), an effect most pronounced in urban subjects (HR 2.20, P=0.007) who had fewer stool pathogens and better nutritional status. No impact on 2-week or 4-week weight gain was noted. No adverse events attributed to PTM202 occurred.

Conclusion

Results demonstrate the potential to target specific pathogens occurring in children with acute non-bloody diarrhoea and shorten illness duration using a novel, safe, nutrition-based intervention. PTM202 may represent a new tool to ameliorate the effects of acute diarrhoeal disease in low/middle-income populations.

Trial registration number

NCT02385773; Results.
The relevance and implications of signet-ring cell adenocarcinoma of the oesophagus
Authors: Bleaney Christopher William , Barrow Mickhaiel , Hayes Stephen , Ang Yeng
Published: December 2017

Aim

To review the current understanding of signet-ring type oesophageal adenocarcinoma including evidence for prognosis.

Methods

We conducted a literature search of nine healthcare literature databases for articles detailing the biology and clinical outcomes of signet-ring cell adenocarcinoma of the oesophagus. The impact of signet-ring cell morphology was analysed and detailed in written text and tabular format. Current understanding of the biology of signet-ring cell adenocarcinoma of the oesophagus was summarised.

Results

Signet-ring cell carcinoma was represented in 7.61% of the 18 989 cases of oesophageal carcinoma reviewed in multiple studies. The presence of signet-ring cells conferred a worse prognosis and these tumours responded differently to conventional treatments as compared with typical adenocarcinoma. Little is known about the biological features of signet-ring cell adenocarcinoma of the oesophagus. Work in gastric lesions has identified potential targets for future treatments such asCDH1andRHOAgenes. Categorisation of signet-ring cell carcinomas by the proportion of signet-ring cells within tumours differs among clinicians despite WHO criteria for classification. The current UK guidelines for histopathological reporting of oesophageal tumours do not emphasise the importance of identifying signet-ring cells.

Conclusion

The presence of signet-ring cells in oesophageal adenocarcinomas leads to poorer clinical outcomes. Current understanding of signet-ring cell biology in oesophageal cancer is limited.
Persistent postural-perceptual dizziness (PPPD): a common, characteristic and treatable cause of chronic dizziness
Authors: Popkirov Stoyan , Staab Jeffrey P , Stone Jon
Published: December 2017

Persistent postural-perceptual dizziness (PPPD) is a newly defined diagnostic syndrome that unifies key features of chronic subjective dizziness, phobic postural vertigo and related disorders. It describes a common chronic dysfunction of the vestibular system and brain that produces persistent dizziness, non-spinning vertigo and/or unsteadiness. The disorder constitutes a long-term maladaptation to a neuro-otological, medical or psychological event that triggered vestibular symptoms, and is usefully considered within the spectrum of other functional neurological disorders. While diagnostic tests and conventional imaging usually remain negative, patients with PPPD present in a characteristic way that maps on to positive diagnostic criteria. Patients often develop secondary functional gait disorder, anxiety, avoidance behaviour and severe disability. Once recognised, PPPD can be managed with effective communication and tailored treatment strategies, including specialised physical therapy (vestibular rehabilitation), serotonergic medications and cognitive-behavioural therapy.
Lung tissue gene-expression signature for the ageing lung in COPD
Authors: de Vries Maaike , Faiz Alen , Woldhuis Roy R , Postma Dirkje S , de Jong Tristan V , Sin Don D , Bossé Yohan , Nickle David C , Guryev Victor , Timens Wim , van den Berge Maarten , Brandsma Corry-Anke
Published: December 2017

Introduction

COPD is a chronic, progressive, inflammatory disease of the lungs and the third leading cause of death worldwide. The current knowledge of the pathophysiology of COPD is limited and novel insights in underlying disease mechanisms are urgently needed. Since there are clear parallels between ageing and COPD, we investigated genes underlying lung ageing in general and abnormal lung ageing in COPD.

Methods

Whole genome mRNA profiling was performed on lung tissue samples (n=1197) and differential gene expression with increasing age was analysed using an adjusted linear regression model. Subsequent pathway analysis was performed using GeneNetwork and the gene-expression signature was compared with lung ageing in the Genotype-Tissue Expression (GTEx) project. In a subset of patients with COPD (n=311) and non-COPD controls (n=270), we performed an interaction analysis between age and COPD to identify genes differentially expressed with age in COPD compared with controls, followed by gene set enrichment pathway analysis.

Results

We identified a strong gene-expression signature for lung ageing with 3509 differentially expressed genes, of which 33.5% were found nominal significant in the GTEx project. Interestingly, we foundEDA2Ras a strong candidate gene for lung ageing. The age*COPD interaction analysis revealed 69 genes significantly differentially expressed with age between COPD and controls.

Conclusions

Our study indicates that processes related to lung development, cell-cell contacts, calcium signalling and immune responses are involved in lung ageing in general. Pathways related to extracellular matrix, mammalian target of rapamycin signalling, splicing of introns and exons and the ribosome complex are proposed to be involved in abnormal lung ageing in COPD.
Transcriptome patterns and blood physiology associated with homing success of sockeye salmon during their final stage of marine migration
Authors: Drenner S. Matthew , Hinch Scott G. , Furey Nathan B. , Clark Timothy D. , Li Shaorong , Ming Tobi , Jeffries Ken M. , Patterson David A. , Cooke Steven J. , Robichaud David , Welch David W. , Farrell Anthony P. , Miller Kristina M.
Published: December 2017

To better understand the mechanisms that lead to marine mortality of homing adult sockeye salmon (Oncorhynchus nerka), gill and blood biopsies were used in combination with biotelemetry to demonstrate how survival to freshwater entry is related to gene expression and physiological indices of stress. Microarray analysis of gene expression indicated multiple biological processes, including immune and stress responses, protein biosynthesis, and metabolism. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) analysis indicated fish with upregulation of genes related to stress and infection had higher marine survival compared with fish without this genomic signature. We proposed that higher marine survival of potentially stressed and immune compromised fish can be explained by stressed and infected fish being highly motivated to enter fresh water, leading to enhanced marine survival. However, once in a river, stressed and immune compromised fish could suffer higher mortality because of premature river entry. Overall, this study supports the idea that infection and stress are important biological processes influencing behaviour and fate of sockeye salmon during homing migrations.
On the theory of Lorentz gases with long range interactions
Authors: Nota Alessia , Simonella Sergio , Velázquez Juan J. L.
Published: December 2017

We construct and study the stochastic force field generated by a Poisson distribution of sources at finite density, [Formula: see text] in [Formula: see text] each of them yielding a long range potential [Formula: see text] with possibly different charges [Formula: see text]. The potential [Formula: see text] is assumed to behave typically as [Formula: see text] for large [Formula: see text], with [Formula: see text]. We will denote the resulting random field as “generalized Holtsmark field”. We then consider the dynamics of one tagged particle in such random force fields, in several scaling limits where the mean free path is much larger than the average distance between the scatterers. We estimate the diffusive time scale and identify conditions for the vanishing of correlations. These results are used to obtain appropriate kinetic descriptions in terms of a linear Boltzmann or Landau evolution equation depending on the specific choices of the interaction potential.
Elementary proof of congruences involving sum of binomial coefficients
Authors: Apagodu Moa
Published: December 2017

We provide elementary proof of several congruences involving single sum and multisums of binomial coefficients.
Low Overhead CS-Based Heterogeneous Framework for Big Data Acceleration
Authors: Kulkarni Amey , Shea Colin , Abtahi Tahmid , Homayoun Houman , Mohsenin Tinoosh
Published: December 2017

Big data processing on hardware gained immense interest among the hardware research community to take advantage of fast processing and reconfigurability. Though the computation latency can be reduced using hardware, big data processing cost is dominated by data transfers. In this article, we propose a low overhead framework based on compressive sensing (CS) to reduce data transfers up to 67% without affecting signal quality. CS has two important kernels: “sensing” and “reconstruction.” In this article, we focus on CS reconstruction is using orthogonal matching pursuit (OMP) algorithm. We implement the OMP CS reconstruction algorithm on a domain-specific PENC many-core platform and a low-power Jetson TK1 platform consisting of an ARM CPU and a K1 GPU. Detailed performance analysis of OMP algorithm on each platform suggests that the PENC many-core platform has 15× and 18× less energy consumption and 16× and 8× faster reconstruction time as compared to the low-power ARM CPU and K1 GPU, respectively. Furthermore, we implement the proposed CS-based framework on heterogeneous architecture, in which the PENC many-core architecture is used as an “accelerator” and processing is performed on the ARM CPU platform. For demonstration, we integrate the proposed CS-based framework with a hadoop MapReduce platform for a face detection application. The results show that the proposed CS-based framework with the PENC many-core as an accelerator achieves a 26.15% data storage/transfer reduction, with an execution time and energy consumption overhead of 3.7% and 0.002%, respectively, for 5,000 image transfers. Compared to the CS-based framework implementation on the low-power Jetson TK1 ARM CPU+GPU platform, the PENC many-core implementation is 2.3× faster for the image reconstruction part, while achieving 29% higher performance and 34% better energy efficiency for the complete face detection application on the Hadoop MapReduce platform.
Predictable Shared Cache Management for Multi-Core Real-Time Virtualization
Authors: Kim Hyoseung , Rajkumar Ragunathan (Raj)
Published: December 2017

Real-time virtualization has gained much attention for the consolidation of multiple real-time systems onto a single hardware platform while ensuring timing predictability. However, a shared last-level cache (LLC) on modern multi-core platforms can easily hamper the timing predictability of real-time virtualization due to the resulting temporal interference among consolidated workloads. Since such interference caused by the LLC is highly variable and may have not even existed in legacy systems to be consolidated, it poses a significant challenge for real-time virtualization. In this article, we propose a predictable shared cache management framework for multi-core real-time virtualization. Our framework introduces two hypervisor-level techniques, vLLC and vColoring, that enable the cache allocation of individual tasks running in a virtual machine (VM), which is not achievable by the current state of the art. Our framework also provides a cache management scheme that determines cache allocation to tasks, designs VMs in a cache-aware manner, and minimizes the aggregated utilization of VMs to be consolidated. As a proof of concept, we implemented vLLC and vColoring in the KVM hypervisor running on x86 and ARM multi-core platforms. Experimental results with three different guest OSs (i.e., Linux/RK, vanilla Linux, and MS Windows Embedded) show that our techniques can effectively control the cache allocation of tasks in VMs. Our cache management scheme yields a significant utilization benefit compared to other approaches while satisfying timing constraints.
The Experience Sampling Method on Mobile Devices
Authors: van Berkel Niels , Ferreira Denzil , Kostakos Vassilis
Published: December 2017

The Experience Sampling Method (ESM) is used by scientists from various disciplines to gather insights into the intra-psychic elements of human life. Researchers have used the ESM in a wide variety of studies, with the method seeing increased popularity. Mobile technologies have enabled new possibilities for the use of the ESM, while simultaneously leading to new conceptual, methodological, and technological challenges. In this survey, we provide an overview of the history of the ESM, usage of this methodology in the computer science discipline, as well as its evolution over time. Next, we identify and discuss important considerations for ESM studies on mobile devices, and analyse the particular methodological parameters scientists should consider in their study design. We reflect on the existing tools that support the ESM methodology and discuss the future development of such tools. Finally, we discuss the effect of future technological developments on the use of the ESM and identify areas requiring further investigation.
Digital Privacy Challenges with Shared Mobile Phone Use in Bangladesh
Authors: Ahmed Syed Ishtiaque , Haque Md. Romael , Chen Jay , Dell Nicola
Published: December 2017

Prior research on technology use in the Global South suggests that people in marginalized communities frequently share a single device among multiple individuals. However, the data privacy challenges and tensions that arise when people share devices have not been studied in depth. This paper presents a qualitative study with 72 participants that analyzes how families in Bangladesh currently share mobile phones, their usage patterns, and the tensions and challenges that arise as individuals seek to protect the privacy of their personal data. We show how people share devices out of economic need, but also because sharing is a social and cultural practice that is deeply embedded in Bangladeshi society. We also discuss how prevalent power relationships affect sharing practices and reveal gender dynamics that impact the privacy of women's data. Finally, we highlight strategies that participants adopted to protect their private data from the people with whom they share devices. Taken together, our findings have broad implications that advance the CSCW community's understanding of digital privacy outside the Western world.
Motivating Participation in Crowdsourced Policymaking
Authors: Aitamurto Tanja , Saldivar Jorge
Published: December 2017

In this paper, we examine the changes in motivation factors in crowdsourced policymaking. By drawing on longitudinal data from a crowdsourced law reform, we show that people participated because they wanted to improve the law, learn, and solve problems. When crowdsourcing reached a saturation point, the motivation factors weakened and the crowd disengaged. Learning was the only factor that did not weaken. The participants learned while interacting with others, and the more actively the participants commented, the more likely they stayed engaged. Crowdsourced policymaking should thus be designed to support both epistemic and interactive aspects. While the crowd's motives were rooted in self-interest, their knowledge perspective showed common-good orientation, implying that rather than being dichotomous, motivation factors move on a continuum. The design of crowdsourced policymaking should support the dynamic nature of the process and the motivation factors driving it.
Collaborative Problem Solving in an Open-Ended Scientific Discovery Game
Authors: Bauer Aaron , Popović Zoran
Published: December 2017

Countless human pursuits depend upon collaborative problem solving, especially in complex, open-ended domains. As part of the growing technological support for such collaboration, an opportunity exists to design systems that actively guide and facilitate collaborative problem solving toward the most productive outcomes. A better understanding of the dynamics of open-ended collaboration on complex problems is needed to realize this opportunity. Motivated by this need for better understanding, we investigate the collaborative problem solving ecosystem of the scientific-discovery game Foldit. Our investigation is guided by two primary questions: how do the social aspects of Foldit impact an individual's behavior? and what factors have significant impact on group success? We find that collaboration and competition are associated with increased participation and that collaboration increases individual performance. We also find that measures of group skill, individual skill, and participation correlate with better group performance.
Threading is Sticky
Authors: Budak Ceren , Garrett R. Kelly , Resnick Paul , Kamin Julia
Published: December 2017

The Guardian
---the fifth most widely read online newspaper in the world as of 2014---changed conversations on its commenting platform by altering its design from non-threaded to single-level threaded in 2012. We studied this naturally occurring experiment to investigate the impact of conversation threading on user retention as mediated by several potential changes in conversation structure and style. Our analysis shows that the design change made new users significantly more likely to comment a second time, and that this increased stickiness is due in part to a higher fraction of comments receiving responses after the design change. In mediation analysis, other anticipated mechanisms such as reciprocal exchanges and comment civility did not help to explain users' decision to return to the commenting system; indeed, civility did not increase after the design change and reciprocity declined. These analyses show that even simple design choices can have a significant impact on news forums' stickiness. Further, they suggest that this influence is more powerfully shaped by affordances---the new system made responding easier---than by changes in users' attention to social norms of reciprocity or civility. This has an array of implications for designers.
Friends Don't Need Receipts
Authors: Caraway Monica , Epstein Daniel A. , Munson Sean A.
Published: December 2017

We study the inclusion of a social awareness stream (SAS) in the peer-to-peer payment app Venmo. While SASs are prominent in many social network sites, such as Facebook and Twitter, Venmo's use offers an illustrative example of how SASs can be used in task-oriented apps, particularly in a domain, finance, which people often view as sensitive. Through interviews with 14 Venmo users and surveys of 164 peer-to-peer payment app users and 80 Venmo users, we find uses consistent with other SASs and uncover novel uses that reflect the unusual inclusion of an SAS within a utilitarian app for personal finance. For many users, the SAS is a flexible feature that creates an experience that blends their task-driven use with social benefits. People write purely functional transaction descriptions with strangers, while in transactions with friends, they sometimes craft playful descriptions that enhance their experience or perform their social relationships. The SAS provides opportunities for learning about how to use the application and for keeping up with friends. The results of this study extend the CSCW community's knowledge of SASs and offer guidance to designers considering use of SAS in a variety of applications.
You Can't Stay Here
Authors: Chandrasekharan Eshwar , Pavalanathan Umashanthi , Srinivasan Anirudh , Glynn Adam , Eisenstein Jacob , Gilbert Eric
Published: December 2017

In 2015, Reddit closed several subreddits-foremost among them r/fatpeoplehate and r/CoonTown-due to violations of Reddit's anti-harassment policy. However, the effectiveness of banning as a moderation approach remains unclear: banning might diminish hateful behavior, or it may relocate such behavior to different parts of the site. We study the ban of r/fatpeoplehate and r/CoonTown in terms of its effect on both participating users and affected subreddits. Working from over 100M Reddit posts and comments, we generate hate speech lexicons to examine variations in hate speech usage via causal inference methods. We find that the ban worked for Reddit. More accounts than expected discontinued using the site; those that stayed drastically decreased their hate speech usage-by at least 80%. Though many subreddits saw an influx of r/fatpeoplehate and r/CoonTown "migrants," those subreddits saw no significant changes in hate speech usage. In other words, other subreddits did not inherit the problem. We conclude by reflecting on the apparent success of the ban, discussing implications for online moderation, Reddit and internet communities more broadly.
Korero
Authors: Chua Soon Hau , Monserrat Toni-Jan Keith Palma , Yoon Dongwook , Kim Juho , Zhao Shengdong
Published: December 2017

In asynchronous online discussions, users actively reference visual materials (e.g., video, document) to provide supporting evidence and additional context. However, creating and comprehending complex references can be challenging, especially when there are multiple referents to refer, or when a referent is highly specific (e.g., specific sentences in a paper rather than the paper as a whole). To identify users' challenges in making references with multiple and specific referents while using existing discussion tools, we conducted an observational study and a preliminary interview. Based on the design lessons, we built Korero, a discussion interface that aims to facilitate complex referencing actions. For evaluation, we compared Korero against conventional interfaces in two user studies with referencing tasks of different referential difficulty. We found that Korero not only significantly reduces the time and effort in making references with multiple and specific referents, but also shows potential in increasing users' engagement with the discussion and referent materials.
Digital Technologies and Intimate Partner Violence
Authors: Freed Diana , Palmer Jackeline , Minchala Diana Elizabeth , Levy Karen , Ristenpart Thomas , Dell Nicola
Published: December 2017

Digital technologies, including mobile devices, cloud computing services, and social networks, play a nuanced role in intimate partner violence (IPV) settings, including domestic abuse, stalking, and surveillance of victims by abusive partners. However, the interactions among victims of IPV, abusers, law enforcement, counselors, and others --- and the roles that digital technologies play in these interactions --- are poorly understood. We present a qualitative study that analyzes the role of digital technologies in the IPV ecosystem in New York City. Findings from semi-structured interviews with 40 IPV professionals and nine focus groups with 32 survivors of IPV reveal a complex set of socio-technical challenges that stem from the intimate nature of the relationships involved and the complexities of managing shared social circles. Both IPV professionals and survivors feel that they do not possess adequate expertise to be able to identify or cope with technology-enabled IPV, and there are currently insufficient best practices to help them deal with abuse via technology. We also reveal a number of tensions and trade-offs in negotiating technology's role in social support and legal procedures. Taken together, our findings contribute a nuanced understanding of technology's role in the IPV ecosystem and yield recommendations for HCI and technology experts interested in aiding victims of abuse.
Beyond Information Content
Authors: Gao Ge , Hwang Sun Young , Culbertson Gabriel , Fussell Susan R. , Jung Malte F.
Published: December 2017

When people communicate, their messages convey affect alongside informational content. The affective dimension of messages is often unclear and open to multiple interpretations especially in an intercultural context. Thus, interlocutors may or may not achieve a state of affective grounding in which each person's affective behaviors are correctly interpreted by his/her partners. The current study examines the effects of culture on affective grounding. We conducted a laboratory experiment in which pairs of participants, half from America (A) and half from China (C), collaborated over instant messaging (IM). We found that affective grounding was harder to achieve for AA and AC pairs, but easier for CC pairs. We propose several design solutions to facilitate affective grounding in remote collaborations.
Investigating Support Seeking from Peers for Pregnancy in Online Health Communities
Authors: Gui Xinning , Chen Yu , Kou Yubo , Pine Katie , Chen Yunan
Published: December 2017

We report a study of peer support in online health communities for pregnancy care along three gestational stages (trimesters) to investigate how pregnant women seek and receive peer support during different stages of pregnancy. Using Babycenter.com as our research setting, we found that pregnant women sought peer support due to constrained access to healthcare providers, dissatisfaction with healthcare services/medical advice, limited offline social support, and unavailability of information in other venues. While the particular topics of concern typifying each trimester were distinct, pregnant women consistently sought advice, informal and formal knowledge, reassurance, and emotional support from peers during each stage of pregnancy. BabyCenter.com peers provided support by leveraging their own experiential knowledge and passing along clinical expertise acquired during the course of their own healthcare. We discuss design implications for health services and IT systems that meet pregnant women's temporal and multi-faceted needs during prenatal care.
Two Sides to Every Story
Authors: He Helen Ai , Yamashita Naomi , Wacharamanotham Chat , Horn Andrea B. , Schmid Jenny , Huang Elaine M.
Published: December 2017

Global virtual teams experience intercultural conflict. Yet, research on how Computer-Mediated Communication (CMC) tools can mitigate such conflict is minimal. We conducted an experiment with 30 Japanese-Canadian dyads who completed a negotiation task over email. Dyads were assigned to one of three conditions: C1) no feedback; C2) automated language feedback of participant emails based on national culture dimensions; and C3) automated language feedback (as in C2), and participants' shared self-reflections of that feedback. Results show Japanese and Canadian partners interpreted the negotiation task differently, resulting in perceptions of intercultural conflict and negative impressions of their partner. Compared to C1, automated language feedback (C2) and shared self-reflections (C3) made cultural differences more salient, motivating participants to empathize with their partner. Shared self-reflections (C3) served as a meta-channel to communication, providing insight into each partner's intentions and cultural values. We discuss implications for CMC tools to mitigate perceptions of intercultural conflict.
Evaluating a Computational Approach to Labeling Politeness
Authors: Hoffman Erin R. , McDonald David W. , Zachry Mark
Published: December 2017

Social computing researchers are beginning to apply machine learning tools to classify and analyze social media data. Our interest in understanding politeness in an online community focused our attention on tools that would help automate politeness analysis. This paper highlights one popular classification tool designed to score the politeness of text. Our application of this tool to Wikipedia data yielded some unexpected results. Those unexpected results led us to question how the tool worked and its effectiveness relative to human judgment and classification. We designed a user study to revalidate the tool with crowdworkers labeling samples of content from Wikipedia talk pages, imitating the original efforts to validate the tool. This revalidation points to challenges for automatic labeling. Based on our results, this paper reconsiders politeness in online communities as well as broader trends in the use of machine classifiers in social computing research.
High-resolution Temporal Representations of Alcohol and Tobacco Behaviors from Social Media Data
Authors: Huang Tom , Elghafari Anas , Relia Kunal , Chunara Rumi
Published: December 2017

Understanding tobacco- and alcohol-related behavioral patterns is critical for uncovering risk factors and potentially designing targeted social computing intervention systems. Given that we make choices multiple times per day, hourly and daily patterns are critical for better understanding behaviors. Here, we combine natural language processing, machine learning and time series analyses to assess Twitter activity specifically related to alcohol and tobacco consumption and their sub-daily, daily and weekly cycles. Twitter self-reports of alcohol and tobacco use are compared to other data streams available at similar temporal resolution. We assess if discussion of drinking by inferred underage versus legal age people or discussion of use of different types of tobacco products can be differentiated using these temporal patterns. We find that time and frequency domain representations of behaviors on social media can provide meaningful and unique insights, and we discuss the types of behaviors for which the approach may be most useful.
A Sociotechnical Study of a Community-based Rewards Program
Authors: Irannejad Bisafar Farnaz , Ponnada Aditya , Shamekhi Ameneh , Parker Andrea G.
Published: December 2017

Individual empowerment is defined as an increased sense of confidence and control over one's life. Empowerment is critical in low-income communities, and can be facilitated through the development of social, financial and human capital. We present a qualitative study of a community program that seeks to empower low-income neighborhood residents through a mobile application that connects them to local resources. Our findings highlight how the application and offline socio-organizational mechanisms worked in tandem to create gateways for capital building-sparking connections (to people and opportunities) that residents leveraged with varying motivations and outcomes. We also discuss how the interplay of newly-developed financial, social, and human capital contributed to residents' sense of empowerment and impacted their families. We contribute to CSCW by extending an existing community informatics framework, characterizing the value of sociotechnical systems that holistically build social, financial, and human capital amongst neighborhood residents.
Quality Standards, Service Orientation, and Power in Airbnb and Couchsurfing
Authors: Klein Maximilian , Zhao Jinhao , Ni Jiajun , Johnson Isaac , Hill Benjamin Mako , Zhu Haiyi
Published: December 2017

Although Couchsurfing and Airbnb are both online communities that help users host strangers in their homes, they differ in an important sense: Couchsurfing prohibits monetary payment while Airbnb is built around it.We conducted interviews with users experienced on both Couchsurfing and Airbnb ("dual-users") to better understand systemic differences between the platforms. Based on these interviews we propose that, compared to Couchsurfing, Airbnb: (1) appears to require higher quality services, (2) places more emphasis on places over people, and (3) shifts social power from hosts to guests. Using public profiles from both platforms, we present analyses exploring each theme. Finally, we present evidence showing that Airbnb's growth has coincided with a decline in Couchsurfing. Taken together, our findings paint a complex picture of the changing character of network hospitality.