bluuebunny/crossref_metadata_2025 huggingface dataset:
Multicenter Clinical Validation of a Cartridge-Based Real-Time PCR System for Detection of Coccidioides spp. in Lower Respiratory Specimens
Authors: Saubolle Michael A. , Wojack Bette R. , Wertheimer Anne M. , Fuayagem Atehkeng Z. , Young Stephen , Koeneman Brian A.
Published: December 2017

Available methods for the diagnosis of coccidioidomycosis have significant shortcomings relative to accuracy and timeliness. We retrospectively and prospectively evaluated the diagnostic performance and reproducibility of a new cartridge-based real-time PCR assay for
Coccidioides
spp. directly in lower respiratory secretions and compared them to today's “gold standard,” fungal culture. The GeneSTAT
Coccidioides
assay uses a 106-bp target sequence repeated multiple times (∼60×) per genome, thus lowering the limit of detection (LOD) for extracted DNA to 10 genome equivalents/ml. A total of 332 prospective and retrospective individual patient specimens were tested. The retrospective samples consisted of 100 bronchoalveolar lavage or bronchial wash (BAL/BW) (51 positive and 49 negative by culture) specimens that had been collected previously and stored at −70°C. These samples were tested by the GeneSTAT
Coccidioides
assay across three clinical test sites. The sensitivity was 100%, and the specificity ranged between 93.8% and 100%. There was minimal variance in the percent agreement across the three sites, 95.6% to 100%. Additionally, a total of 232 fresh (prospective) deidentified BAL/BW specimens were tested across the three clinical sites, which included a number of specimens from Southern California to provide a diversity of isolates. Specimens were tested by fungal culture, with any isolates of
Coccidioides
, except for one, being confirmed by molecular means (AccuProbe). The sensitivity of the GeneSTAT
Coccidioides
assay across the three sites was 100% (4/4) for positive fresh specimens, and the overall specificity of the assay was 99.6% (227/228), ranging from 98.1% to 100%. In testing for cross-reactivity, the assay was 100% specific when screened against 47 different bacterial, viral, and fungal species.
Performance of Ceftolozane-Tazobactam Etest, MIC Test Strips, and Disk Diffusion Compared to Reference Broth Microdilution for β-Lactam-Resistant Pseudomonas aeruginosa Isolates
Authors: Humphries Romney M. , Hindler Janet A. , Magnano Paul , Wong-Beringer Annie , Tibbetts Robert , Miller Shelley A.
Published: December 2017

The performance characteristics of the ceftolozane-tazobactam (C-T) Etest (bioMérieux, Marcy l'Etoile, France), MIC test strips (MTS; Liofilchem, Italy), and disk diffusion (Hardy, Santa Ana, CA) were evaluated for a collection of 308 beta-lactam-resistant isolates of
Pseudomonas aeruginosa
recovered from three institutions in Los Angeles, CA. Reference testing was performed by the reference broth microdilution (rBMD) method. MIC and disk results were interpreted using Clinical and Laboratory Standards Institute breakpoints. Overall, 72.5% of the isolates were susceptible to C-T by rBMD. Etest and disk diffusion demonstrated acceptable performance, whereas MTS yielded a greater than acceptable percentage of minor errors. Categorical agreement was 96.8% for Etest, 87.0% for MTS, and 92.9% for disk diffusion. No very major errors were observed by any test, and no major errors (ME) were observed by Etest or disk diffusion. Two ME (0.9% of susceptible isolates) were observed by MTS. The incidence of minor errors was 3.2%, 12.3%, and 7.1% for Etest, MTS, and disk diffusion, respectively. Essential agreement (EA) for Etest was excellent, at 97.7%, whereas the MICs obtained by MTS tended to be 1 to 2 dilutions higher than those obtained by rBMD, with an EA of 87.0%.
Factors Leading to the Loss of Natural Elite Control of HIV-1 Infection
Authors: Pernas María , Tarancón-Diez Laura , Rodríguez-Gallego Esther , Gómez Josep , Prado Julia G. , Casado Concepción , Dominguez-Molina Beatriz , Olivares Isabel , Coiras Maite , León Agathe , Rodriguez Carmen , Benito Jose Miguel , Rallón Norma , Plana Montserrat , Martinez-Madrid Onofre , Dapena Marta , Iribarren Jose Antonio , del Romero Jorge , García Felipe , Alcamí José , Muñoz-Fernández MaÁngeles , Vidal Francisco , Leal Manuel , Lopez-Galindez Cecilio , Ruiz-Mateos Ezequiel
Published: December 2017

HIV-1 elite controllers (EC) maintain undetectable viral loads (VL) in the absence of antiretroviral treatment. However, these subjects have heterogeneous clinical outcomes, including a proportion that loses HIV-1 control over time. In this work, we compared, in a longitudinal design, transient EC, analyzed before and after the loss of virological control, with persistent EC. The aim was to identify factors leading to the loss of natural virological control of HIV-1 infection with a longitudinal retrospective study design. Gag-specific T-cell responses were assessed by
in vitro
intracellular polycytokine production quantified by flow cytometry. Viral diversity determinations and sequence dating were performed in proviral DNA by PCR amplification at limiting dilution of
env
and
gag
genes. The expression profile of 70 serum cytokines and chemokines was assessed by multiplex immunoassays. We identified transient EC as subjects with low Gag-specific T-cell polyfunctionality, high viral diversity, and high proinflammatory cytokine levels before the loss of control. Gag-specific T-cell polyfunctionality was inversely associated with viral diversity in transient controllers before the loss of control (
r
= −0.8;
P
= 0.02). RANTES was a potential biomarker of transient control. This study identified virological and immunological factors, including inflammatory biomarkers associated with two different phenotypes within EC. These results may allow a more accurate definition of EC, which could help in better clinical management of these individuals and in the development of future curative approaches.

IMPORTANCE
There is a rare group of HIV-infected patients who have the extraordinary capacity to maintain undetectable viral load levels in the absence of antiretroviral treatment, the so-called HIV-1 elite controllers (EC). However, there is a proportion within these subjects that eventually loses this capability. In this work, we found differences in virological and immune factors, including soluble inflammatory biomarkers, between subjects with persistent control of viral replication and EC that will lose virological control. The identification of these factors could be a key point for a right medical care of those EC who are going to lose natural control of viral replication and for the design of future immunotherapeutic strategies using as a model the natural persistent control of HIV infection.
Experimental Adaptive Evolution of Simian Immunodeficiency Virus SIVcpz to Pandemic Human Immunodeficiency Virus Type 1 by Using a Humanized Mouse Model
Authors: Sato Kei , Misawa Naoko , Takeuchi Junko S. , Kobayashi Tomoko , Izumi Taisuke , Aso Hirofumi , Nagaoka Shumpei , Yamamoto Keisuke , Kimura Izumi , Konno Yoriyuki , Nakano Yusuke , Koyanagi Yoshio
Published: December 2017

Human immunodeficiency virus type 1 (HIV-1), the causative agent of AIDS, originated from simian immunodeficiency virus from chimpanzees (SIVcpz), the precursor of the human virus, approximately 100 years ago. This indicates that HIV-1 has emerged through the cross-species transmission of SIVcpz from chimpanzees to humans. However, it remains unclear how SIVcpz has evolved into pandemic HIV-1 in humans. To address this question, we inoculated three SIVcpz strains (MB897, EK505, and MT145), four pandemic HIV-1 strains (NL4-3, NLCSFV3, JRCSF, and AD8), and two nonpandemic HIV-1 strains (YBF30 and DJO0131). Humanized mice infected with SIVcpz strain MB897, a virus phylogenetically similar to pandemic HIV-1, exhibited a peak viral load comparable to that of mice infected with pandemic HIV-1, while peak viral loads of mice infected with SIVcpz strain EK505 or MT145 as well as nonpandemic HIV-1 strains were significantly lower. These results suggest that SIVcpz strain MB897 is preadapted to humans, unlike the other SIVcpz strains. Moreover, viral RNA sequencing of MB897-infected humanized mice identified a nonsynonymous mutation in
env
, a G413R substitution in gp120. The infectivity of the gp120 G413R mutant of MB897 was significantly higher than that of parental MB897. Furthermore, we demonstrated that the gp120 G413R mutant of MB897 augments the capacity for viral replication in both
in vitro
cell cultures and humanized mice. Taken together, this is the first experimental investigation to use an animal model to demonstrate a gain-of-function evolution of SIVcpz into pandemic HIV-1.

IMPORTANCE
From the mid-20th century, humans have been exposed to the menace of infectious viral diseases, such as severe acute respiratory syndrome coronavirus, Ebola virus, and Zika virus. These outbreaks of emerging/reemerging viruses can be triggered by cross-species viral transmission from wild animals to humans, or zoonoses. HIV-1, the causative agent of AIDS, emerged by the cross-species transmission of SIVcpz, the HIV-1 precursor in chimpanzees, around 100 years ago. However, the process by which SIVcpz evolved to become HIV-1 in humans remains unclear. Here, by using a hematopoietic stem cell-transplanted humanized-mouse model, we experimentally recapitulate the evolutionary process of SIVcpz to become HIV-1. We provide evidence suggesting that a strain of SIVcpz, MB897, preadapted to infect humans over other SIVcpz strains. We further demonstrate a gain-of-function evolution of SIVcpz in infected humanized mice. Our study reveals that pandemic HIV-1 has emerged through at least two steps: preadaptation and subsequent gain-of-function mutations.
Influenza A Virus Reassortment Is Limited by Anatomical Compartmentalization following Coinfection via Distinct Routes
Authors: Richard Mathilde , Herfst Sander , Tao Hui , Jacobs Nathan T. , Lowen Anice C.
Published: December 2017

Exchange of gene segments through reassortment is a major feature of influenza A virus evolution and frequently contributes to the emergence of novel epidemic, pandemic, and zoonotic strains. It has long been evident that viral diversification through reassortment is constrained by genetic incompatibility between divergent parental viruses. In contrast, the role of virus-extrinsic factors in determining the likelihood of reassortment has remained unclear. To evaluate the impact of such factors in the absence of confounding effects of segment mismatch, we previously reported an approach in which reassortment between wild-type (wt) and genetically tagged variant (var) viruses of the same strain is measured. Here, using wt/var systems in the A/Netherlands/602/2009 (pH1N1) and A/Panama/2007/99 (H3N2) strain backgrounds, we tested whether inoculation of parental viruses into distinct sites within the respiratory tract limits their reassortment. Using a ferret (
Mustella putorius furo
) model, either matched parental viruses were coinoculated intranasally or one virus was instilled intranasally whereas the second was instilled intratracheally. Dual intranasal inoculation resulted in robust reassortment for wt/var viruses of both strain backgrounds. In contrast, when infections were initiated simultaneously at distinct sites, strong compartmentalization of viral replication was observed and minimal reassortment was detected. The observed lack of viral spread between upper and lower respiratory tract tissues may be attributable to localized exclusion of superinfection within the host, mediated by innate immune responses. Our findings indicate that dual infections in nature are more likely to result in reassortment if viruses are seeded into similar anatomical locations and have matched tissue tropisms.

IMPORTANCE
Genetic exchange between influenza A viruses (IAVs) through reassortment can facilitate the emergence of antigenically drifted seasonal strains and plays a prominent role in the development of pandemics. Typical human influenza infections are concentrated in the upper respiratory tract; however, lower respiratory tract (LRT) infection is an important feature of severe cases, which are more common in the very young, the elderly, and individuals with underlying conditions. In addition to host factors, viral characteristics and mode of transmission can also increase the likelihood of LRT infection: certain zoonotic IAVs are thought to favor the LRT, and transmission via small droplets allows direct seeding into lower respiratory tract tissues. To gauge the likelihood of reassortment in coinfected hosts, we assessed the extent to which initiation of infection at distinct respiratory tract sites impacts reassortment frequency. Our results reveal that spatially distinct inoculations result in anatomical compartmentalization of infection, which in turn strongly limits reassortment.
The Neutralizing Linear Epitope of Human Herpesvirus 6A Glycoprotein B Does Not Affect Virus Infectivity
Authors: Wakata Aika , Kanemoto Satoshi , Tang Huamin , Kawabata Akiko , Nishimura Mitsuhiro , Jasirwan Chyntia , Mahmoud Nora Fahmy , Mori Yasuko
Published: December 2017

Human herpesvirus 6A (HHV-6A) glycoprotein B (gB) is a glycoprotein consisting of 830 amino acids and is essential for the growth of the virus. Previously, we reported that a neutralizing monoclonal antibody (MAb) called 87-y-13 specifically reacts with HHV-6A gB, and we identified its epitope residue at asparagine (Asn) 347 on gB. In this study, we examined whether the epitope recognized by the neutralizing MAb is essential for HHV-6A infection. We constructed HHV-6A bacterial artificial chromosome (BAC) genomes harboring substitutions at Asn347, namely, HHV-6A BACgB(N347K) and HHV-6A BACgB(N347A). These mutant viruses could be reconstituted and propagated in the same manner as the wild type and their revertants, and MAb 87-y-13 could not inhibit infection by either mutant. In a cell-cell fusion assay, Asn at position 347 on gB was found to be nonessential for cell-cell fusion. In addition, in building an HHV-6A gB homology model, we found that the epitope of the neutralizing MAb is located on domain II of gB and is accessible to solvents. These results indicate that Asn at position 347, the linear epitope of the neutralizing MAb, does not affect HHV-6A infectivity.

IMPORTANCE
Glycoprotein B (gB) is one of the most conserved glycoproteins among all herpesviruses and is a key factor for virus entry. Therefore, antibodies targeted to gB may neutralize virus entry. Human herpesvirus 6A (HHV-6A) encodes gB, which is translated to a protein of about 830 amino acids (aa). Using a monoclonal antibody (MAb) for HHV-6A gB, which has a neutralizing linear epitope, we analyzed the role of its epitope residue, N347, in HHV-6A infectivity. Interestingly, this gB linear epitope residue, N347, was not essential for HHV-6A growth. By constructing a homology model of HHV-6A gB, we found that N347 was located in the region corresponding to domain II. Therefore, with regard to its neutralizing activity against HHV-6A infection, the epitope on gB might be exposed to solvents, suggesting that it might be a target of the immune system.
Painful testicular metastasis from prostate adenocarcinoma
Authors: Lee Karla A , Mayer Erik , Khoo Vincent
Published: December 2017

A 60-year-old man presented with unilateral testicular pain and urinary frequency. His presenting prostate-specific antigen (PSA) was 100 ng/mL, and a biopsy revealed Gleason 4+4 prostate adenocarcinoma. The significance of his initial PSA was somewhat complicated by possible prostatitis and early initiation of bicalutamide. PSA rose on two occasions prior to radiotherapy but coincided with a flare of testicular pain on one of these. Whole-body staging diffusion-weighted MRI scan was negative. He was treated with 3 years of androgen deprivation therapy (ADT) and radical radiotherapy. PSA fell to undetectable levels on ADT. Twelve months following completion of ADT, PSA rose to 3.6 ng/mL. No disease recurrence was noted on restaging MRI pelvis. The patient was well, except for persistent testicular symptoms, which failed to resolve following multiple antibiotics. Testicular tumour markers were negative. Ultrasound findings were consistent with chronic epididymitis. A right orchidectomy was performed for symptomatic relief, confirming metastatic prostate adenocarcinoma.
Nerve abscess in pure neural leprosy mistaken for peripheral nerve sheath tumour with disastrous consequence: what can we learn?
Authors: Gupta Vishal , Dev Tanvi , Das Chandan J , Khanna Neena
Published: December 2017

A 34-year-old Indian man presented to an orthopaedician with gradually progressive hypoesthesia affecting his right lower limb and an ipsilateral common peroneal nerve swelling around the knee. The nerve swelling was diagnosed as a peripheral nerve sheath tumour based on MRI findings and was excised, only to be revealed as leprous nerve abscess on histopathology later. The patient developed right foot drop as a result of common peroneal nerve biopsy. This case presents several learning points in the diagnosis of pure neural leprosy.
Vision in former very low birthweight young adults with and without retinopathy of prematurity compared with term born controls: the NZ 1986 VLBW follow-up study
Authors: Darlow Brian A , Elder Mark J , Kimber Bridget , Martin Julia , Horwood L John
Published: December 2017

Objective

There are few data on visual outcomes in adulthood of former very low birthweight (VLBW; <1500 g) infants. We aimed to assess vision at 27–29 years in a national cohort of VLBW infants born in 1986 and assessed for retinopathy of prematurity (ROP) when no treatment was available, compared with term born controls.

Methods

The cohort and controls attended a 2-day assessment in Christchurch as part of a larger study. Visual assessment included glasses prescription measured by focimeter, logarithm of the minimum angle of resolution (logMAR) distance visual acuity (VA), contrast sensitivity, autorefraction, retinal photographs and a questionnaire on vision-related everyday activities. Rates of reduced VA and myopia in the VLBW cohort at 27–29 were compared with the results of vision testing at 7–8 years.

Results

250 VLBW adults (77% those alive) gave study consent and 229 (45 with a history of ROP) were assessed in Christchurch, plus 100 term born controls. VLBW adults with ROP had reduced VA compared with no ROP and controls (mean logMAR score (SD); 0.003 (0.19), –0.021 (0.16), –0.078 (0.09), P=0.001). There were no differences in myopia (>2 D) between the groups but high myopia (>5 D) was confined to those with ROP. VLBW adults with ROP drove a car less often and had higher difficulties with everyday activities scores due to eyesight. Between 7–8 and 27–29 years rates of reduced VA were stable but myopia increased.

Conclusion

Former VLBW young adults with ROP have ongoing problems with vision affecting daily living and should continue in regular ophthalmological review.

Trial registration number

ACTRN12612000995875, Pre-results .
Nasal unsedated seated percutaneous endoscopic gastrostomy (nuPEG): a safe and effective technique for percutaneous endoscopic gastrostomy placement in high-risk candidates
Authors: McCulloch Adam , Roy Ovishek , Massey Dunecan , Hedges Rachel , Skerratt Serena , Wilson Nicola , Woodward Jeremy
Published: December 2017

Objective

Percutaneous endoscopic gastrostomy (PEG) tube placement is associated with a high risk of cardiorespiratory complications in patients with significant respiratory compromise. This study reports a case series of high-risk patients undergoing PEG placement using a modified technique—nasal unsedated seated PEG (nuPEG) placement.

Design

Retrospective review of 67 patients at high risk of complications undergoing PEG placement between September 2012 and December 2016.

Setting

UK specialist tertiary centre for clinical nutrition support.

Interventions

Patients underwent ‘push’ PEG placement using nasal endoscopy without sedation in a seated position.

Main outcome measures

Procedural success and tolerability, short term (within 24 hours), medium term (24 hours to 30 days) complications and survival were recorded.

Results

67 patients underwent 68 nuPEG placements. The majority had motor neuron disease (46/67). One patient developed a lower respiratory tract infection the following day. Two patients experienced accidental displacement of their PEG within 2 weeks. One patient died within 30 days of nuPEG insertion due to reasons unrelated to the procedure. Endoscopic comfort scores of 1 or 2 (98.0%) indicated good tolerance. A failure rate of 10.5% was attributed to intrathoracic displacement of the stomach, almost certainly due to the advanced stage of the neurological disease and associated diaphragmatic weakness.

Conclusions

Our experience with the nuPEG technique suggests that it is safe and well tolerated in high-risk patients. As a result, it has now entirely supplanted radiologically inserted gastrostomy insertion in our institution and we recommend it as the method of choice for gastrostomy tube insertion in such patients.
Imaging in low-grade glioma: a guide for neurologists
Authors: Larsen Jennifer , Hoggard Nigel , McKevitt Fiona M
Published: December 2017

The management of low-grade glioma (LGG) is shifting as evidence has emergedthat refutes the previously commonplace imaging-based ‘watch and wait’ approach, in favour of early aggressive surgical resection. This coupled with the recent 2016 update to the World Health Organisation Classification of Tumours of the Central Nervous System is changing LGG imaging and management. Recently in Practical Neurology the contemporary management of low-grade glioma and the changes to this grading system were discussed in detail.
1
In this complementary article, we discuss the role of imaging in the diagnosis, surgical planning and post-treatment follow-up of LGG. We describe the principles of imaging these tumours and use several cases to highlight some difficult scenarios.
Rituximab for corticosteroid-resistant relapsing IgG4-related intracranial pachymeningitis: report of two cases
Authors: Mageau Arthur , Shor Natalia , Fisselier Matthieu , Aboab Jennifer , Lecler Augustin , Rebours Celeste , Adle-Biassette Homa , Gout Olivier , Deschamps Romain
Published: December 2017

IgG4-related disease is now recognised as an important cause of intracranial and spinal hypertrophic pachymeningitis. Treatment with corticosteroids generally leads to significant clinical improvement. We present two cases of IgG4 pachymeningitis unresponsive to corticosteroids who improved with rituximab.
Invariance principle via orthomartingale approximation
Authors: Giraudo Davide
Published: December 2017

We obtain a necessary and sufficient condition for the orthomartingale-coboundary decomposition. We establish a sufficient condition for the approximation of the partial sums of a strictly stationary random fields by those of stationary orthomartingale differences. This condition can be checked under multidimensional analogues of the Hannan condition and the Maxwell–Woodroofe condition.
FLEXIBILITY BEHAVIOR OF CORONARY STENTS: THE ROLE OF LINKER INVESTIGATED WITH NUMERICAL SIMULATION
Authors: SHEN XIANG , DENG YONG-QUAN , JI SONG , XIE ZHONG-MIN , ZHU HONG-FEI
Published: December 2017

Flexibility is a vital property of stents and different stent structures lead to different flexibility behaviors. In this study, the finite element analysis was adopted and a virtual bending deformation was imposed to quantify the effects of linker pattern, linker number, bending direction and linker location on flexibility. Stent performance indicators, including stress distribution, deformation patterns and bending stiffness, were examined. Results indicate that higher levels of stresses are found on the linker struts, associated with much larger deformation. The linker number plays the most significant role in flexibility, and simply decreasing linker number could result in a sharp increase in flexibility and a decrease in stress. The linker pattern has great impact on stent flexibility, especially on the behavior of self-contact. Stents with different linker patterns could respond differently in the course of bending, and the stent with an offset peak-to-peak linker pattern is the best choice. It is also found that stent flexibility can be improved when fewer linkers lie in the compression area and the linker directions between two adjacent rows are consistent. The results obtained could provide useful information for the improvement of stent design and clinical choice.
On the index-r-free sequences over finite cyclic groups
Authors: Liu Chao
Published: December 2017

Let [Formula: see text] be a finite cyclic group of order [Formula: see text]. Every sequence [Formula: see text] over [Formula: see text] can be written in the form [Formula: see text] where [Formula: see text] and [Formula: see text], and the index [Formula: see text] of [Formula: see text] is defined as the minimum of [Formula: see text] over all [Formula: see text] with [Formula: see text]. Let [Formula: see text] and [Formula: see text] be any fixed integers. We prove that, for every sufficiently large integer [Formula: see text] divisible by [Formula: see text], there exists a sequence [Formula: see text] over [Formula: see text] of length [Formula: see text] having no subsequence [Formula: see text] of index [Formula: see text], which has substantially improved the previous results in this direction.
A note on Diophantine approximation by unlike powers of primes
Authors: Mu Quanwu , Qu Yunyun
Published: December 2017

It is proved that if [Formula: see text] are nonzero real numbers, not all of the same sign and [Formula: see text] is irrational, then for given real numbers [Formula: see text] and [Formula: see text], [Formula: see text], the inequality [Formula: see text] has infinitely many solutions in prime variables [Formula: see text]. This result constitutes an improvement upon that of Liu for the range [Formula: see text].
New optimal covering arrays using an orderly algorithm
Authors: Izquierdo-Marquez Idelfonso , Torres-Jimenez Jose
Published: December 2017

A covering array [Formula: see text] is an [Formula: see text] array such that every [Formula: see text] subarray covers at least once each [Formula: see text]-tuple from [Formula: see text] symbols. For given [Formula: see text], [Formula: see text], and [Formula: see text], the minimum number of rows for which exists a CA is denoted by [Formula: see text] (CAN stands for Covering Array Number) and the corresponding CA is optimal. Optimal covering arrays have been determined algebraically for a small subset of cases; but another alternative to find CANs is the use of computational search. The present work introduces a new orderly algorithm to construct non-isomorphic covering arrays; this algorithm is an improvement of a previously reported algorithm for the same purpose. The construction of non-isomorphic covering arrays is used to prove the nonexistence of certain covering arrays whose nonexistence implies the optimality of other covering arrays. From the computational results obtained, the following CANs were established: [Formula: see text] for [Formula: see text], [Formula: see text], and [Formula: see text]. In addition, the new result [Formula: see text], and the already known existence of [Formula: see text], imply [Formula: see text].
A Survey on Fully Homomorphic Encryption
Authors: Martins Paulo , Sousa Leonel , Mariano Artur
Published: December 2017

It is unlikely that a hacker is able to compromise sensitive data that is stored in an encrypted form. However, when data is to be processed, it has to be decrypted, becoming vulnerable to attacks. Homomorphic encryption fixes this vulnerability by allowing one to compute directly on encrypted data. In this survey, both previous and current Somewhat Homomorphic Encryption (SHE) schemes are reviewed, and the more powerful and recent Fully Homomorphic Encryption (FHE) schemes are comprehensively studied. The concepts that support these schemes are presented, and their performance and security are analyzed from an engineering standpoint.
Systematic Literature Review on Usability of Firewall Configuration
Authors: Voronkov Artem , Iwaya Leonardo Horn , Martucci Leonardo A. , Lindskog Stefan
Published: December 2017

Firewalls are network security components that handle incoming and outgoing network traffic based on a set of rules. The process of correctly configuring a firewall is complicated and prone to error, and it worsens as the network complexity grows. A poorly configured firewall may result in major security threats; in the case of a network firewall, an organization’s security could be endangered, and in the case of a personal firewall, an individual computer’s security is threatened. A major reason for poorly configured firewalls, as pointed out in the literature, is usability issues. Our aim is to identify existing solutions that help professional and non-professional users to create and manage firewall configuration files, and to analyze the proposals in respect of usability. A systematic literature review with a focus on the usability of firewall configuration is presented in the article. Its main goal is to explore what has already been done in this field. In the primary selection procedure, 1,202 articles were retrieved and then screened. The secondary selection led us to 35 articles carefully chosen for further investigation, of which 14 articles were selected and summarized. As main contributions, we propose a taxonomy of existing solutions as well as a synthesis and in-depth discussion about the state of the art in firewall usability. Among the main findings, we perceived that there is a lack (or even an absence) of usability evaluation or user studies to validate the proposed models. Although all articles are related to the topic of usability, none of them clearly defines it, and only a few actually employ usability design principles and/or guidelines.
Project Management Practices as a Subject of Research for CSCW
Authors: Bossen Claus , Leimbach Timo
Published: December 2017

The 'project' is a prevalent form for organising endeavours of construction, innovation, IT development and organisational change. 'Projects' involve coordination and cooperation between colocated and distributed actors, and are relevant for CSCW (computer supported cooperative work) research as a particular kind of cooperative work. A survey of CSCW publications only identified 26 papers that explicitly address project management (PM), of which most primarily focus on IT development. We argue that CSCW's conceptual and methodological tools can make significant contributions to PM research, practice and its computational support. We point to four issues of relevance for future CSCW research on projects: continue to sophisticate the empirical and conceptual understanding of projects, broaden research beyond IT projects into other domains, develop agile approaches beyond IT development and focus on computational support for project work and management. In all, we argue that CSCW can advance our understanding of project work and management and the design of adequate computational support.
Seeing Sound
Authors: Cartwright Mark , Seals Ayanna , Salamon Justin , Williams Alex , Mikloska Stefanie , MacConnell Duncan , Law Edith , Bello Juan P. , Nov Oded
Published: December 2017

Audio annotation is key to developing machine-listening systems; yet, effective ways to accurately and rapidly obtain crowdsourced audio annotations is understudied. In this work, we seek to quantify the reliability/redundancy trade-off in crowdsourced soundscape annotation, investigate how visualizations affect accuracy and efficiency, and characterize how performance varies as a function of audio characteristics. Using a controlled experiment, we varied sound visualizations and the complexity of soundscapes presented to human annotators. Results show that more complex audio scenes result in lower annotator agreement, and spectrogram visualizations are superior in producing higher quality annotations at lower cost of time and human labor. We also found recall is more affected than precision by soundscape complexity, and mistakes can be often attributed to certain sound event characteristics. These findings have implications not only for how we should design annotation tasks and interfaces for audio data, but also how we train and evaluate machine-listening systems.
Suppressing the Search Engine Manipulation Effect (SEME)
Authors: Epstein Robert , Robertson Ronald E. , Lazer David , Wilson Christo
Published: December 2017

A recent series of experiments demonstrated that introducing ranking bias to election-related search engine results can have a strong and undetectable influence on the preferences of undecided voters. This phenomenon, called the Search Engine Manipulation Effect (SEME), exerts influence largely through order effects that are enhanced in a digital context. We present data from three new experiments involving 3,600 subjects in 39 countries in which we replicate SEME and test design interventions for suppressing the effect. In the replication, voting preferences shifted by 39.0%, a number almost identical to the shift found in a previously published experiment (37.1%). Alerting users to the ranking bias reduced the shift to 22.1%, and more detailed alerts reduced it to 13.8%. Users' browsing behaviors were also significantly altered by the alerts, with more clicks and time going to lower-ranked search results. Although bias alerts were effective in suppressing SEME, we found that SEME could be completely eliminated only by alternating search results -- in effect, with an equal-time rule. We propose a browser extension capable of deploying bias alerts in real-time and speculate that SEME might be impacting a wide range of decision-making, not just voting, in which case search engines might need to be strictly regulated.
Linguistic Markers Indicating Therapeutic Outcomes of Social Media Disclosures of Schizophrenia
Authors: Ernala Sindhu Kiranmai , Rizvi Asra F. , Birnbaum Michael L. , Kane John M. , De Choudhury Munmun
Published: December 2017

Self-disclosure of stigmatized conditions is known to yield therapeutic benefits. Social media sites are emerging as promising platforms enabling disclosure around a variety of stigmatized concerns, including mental illness. What kind of behavioral changes precede and follow such disclosures? Do the therapeutic benefits of "opening up" manifest in these changes? In this paper, we address these questions by focusing on disclosures of schizophrenia diagnoses made on Twitter. We adopt a clinically grounded quantitative approach to first identify temporal phases around disclosure during which symptoms of schizophrenia are likely to be significant. Then, to quantify behaviors before and after disclosures, we define linguistic measures drawing from literature on psycholinguistics and the socio-cognitive model of schizophrenia. Along with significant linguistic differences before and after disclosures, we find indications of therapeutic outcomes following disclosures, including improved readability and coherence in language, future orientation, lower self preoccupation, and reduced discussion of symptoms and stigma perceptions. We discuss the implications of social media as a new therapeutic tool in supporting disclosures of stigmatized conditions.
Novice and Expert Sensemaking of Crowdsourced Design Feedback
Authors: Foong Eureka , Gergle Darren , Gerber Elizabeth M.
Published: December 2017

Online feedback exchange (OFE) systems are an increasingly popular way to test concepts with millions of target users before going to market. Yet, we know little about how designers make sense of this abundant feedback. This empirical study investigates how expert and novice designers make sense of feedback in OFE systems. We observed that when feedback conflicted with frames originating from the participant's design knowledge, experts were more likely than novices to question the inconsistency, seeking critical information to expand their understanding of the design goals. Our results suggest that in order for OFE systems to be truly effective, they must be able to support nuances in sensemaking activities of novice and expert users.
Operationalizing Conflict and Cooperation between Automated Software Agents in Wikipedia
Authors: Geiger R. Stuart , Halfaker Aaron
Published: December 2017

This paper replicates, extends, and refutes conclusions made in a study published in PLoS ONE ("Even Good Bots Fight"), which claimed to identify substantial levels of conflict between automated software agents (or bots) in Wikipedia using purely quantitative methods. By applying an integrative mixed-methods approach drawing on trace ethnography, we place these alleged cases of bot-bot conflict into context and arrive at a better understanding of these interactions. We found that overwhelmingly, the interactions previously characterized as problematic instances of conflict are typically better characterized as routine, productive, even collaborative work. These results challenge past work and show the importance of qualitative/quantitative collaboration. In our paper, we present quantitative metrics and qualitative heuristics for operationalizing bot-bot conflict. We give thick descriptions of kinds of events that present as bot-bot reverts, helping distinguish conflict from non-conflict. We computationally classify these kinds of events through patterns in edit summaries. By interpreting found/trace data in the socio-technical contexts in which people give that data meaning, we gain more from quantitative measurements, drawing deeper understandings about the governance of algorithmic systems in Wikipedia. We have also released our data collection, processing, and analysis pipeline, to facilitate computational reproducibility of our findings and to help other researchers interested in conducting similar mixed-method scholarship in other platforms and contexts.
Service Providers of the Sharing Economy
Authors: Ke Qing
Published: December 2017

Many "sharing economy" platforms, such as Uber and Airbnb, have become increasingly popular, providing consumers with more choices and suppliers a chance to make profit. They, however, have also brought about emerging issues regarding regulation, tax obligation, and impact on urban environment, and have generated heated debates from various interest groups. Empirical studies regarding these issues are limited, partly due to the unavailability of relevant data. Here we aim to understand service providers of the sharing economy, investigating who joins and who benefits, using the Airbnb market in the United States as a case study. We link more than 211 thousand Airbnb listings owned by 188 thousand hosts with demographic, socio-economic status (SES), housing, and tourism characteristics. We show that income and education are consistently the two most influential factors that are linked to the joining of Airbnb, regardless of the form of participation or year. Areas with lower median household income, or higher fraction of residents who have Bachelor's and higher degrees, tend to have more hosts. However, when considering the performance of listings, as measured by number of newly received reviews, we find that income has a positive effect for entire-home listings; listings located in areas with higher median household income tend to have more new reviews. Our findings demonstrate empirically that the disadvantage of SES-disadvantaged areas and the advantage of SES-advantaged areas may be present in the sharing economy.
Would You Slack That?
Authors: McGregor Susan E. , Watkins Elizabeth Anne , Caine Kelly
Published: December 2017

Journalistic work is increasingly conducted using cooperative technologies. But while journalists need security and privacy just like professionals in sectors like health and education, constrained finances and missing legal requirements cause journalists to rely mostly on third-party platforms for their professional communications. In this study, we analyze how journalists manage professional collaborations across myriad tasks and contexts, with a focus on how their security and privacy concerns may shape these behaviors. We find that journalists' relatively open information-sharing practices may reflect the strength of their informal intra-organizational networks, rather than their organizational commitment per se. Moreover, while journalists' like many workers' manage their security and privacy concerns by avoiding sensitive communications via certain channels, the physical shrinking newsrooms of is reducing opportunities for the face-to-face communications journalists rely on for secure, private, professional exchange. Journalists' self-censorship on collaborative platforms therefore warrants particular attention given journalism's essential role in the public sphere.
Inferring Individual Social Capital Automatically via Phone Logs
Authors: Singh Vivek K. , Ghosh Isha
Published: December 2017

Social capital is one of the most fundamental concepts in social computing. Individual social capital is often connected with one's happiness levels, well-being, and propensity to cooperate with others. The dominant approach for quantifying individual social capital remains self-reported surveys and generator-methods, which are costly, attention-consuming, and fraught with biases. Given the important role played by mobile phones in mediating human social lives, this study explores the use of phone metadata (call and SMS logs) to automatically infer an individual's social capital. Based on Williams' Social Capital survey as ground truth and ten-week phone data collection for 55 participants, we report that (1) multiple phone-based social features are intrinsically associated with social capital; and (2) analytics algorithms utilizing phone data can achieve high accuracy at automatically inferring an individual's bridging, bonding, and overall social capital scores. Results pave way for studying social capital and its temporal dynamics at an unprecedented scale.
Gender Bias in the Job Market
Authors: Tang Shiliang , Zhang Xinyi , Cryan Jenna , Metzger Miriam J. , Zheng Haitao , Zhao Ben Y.
Published: December 2017

For millions of workers, online job listings provide the first point of contact to potential employers. As a result, job listings and their word choices can significantly affect the makeup of the responding applicant pool. Here, we study the effects of potentially gender-biased terminology in job listings, and their impact on job applicants, using a large historical corpus of 17 million listings on LinkedIn spanning 10 years. We develop algorithms to detect and quantify gender bias, validate them using external tools, and use them to quantify job listing bias over time. We then perform a user survey over two user populations (N
1=469
, N
2=273
) to validate our findings and to quantify the end-to-end impact of such bias on applicant decisions. Our findings show gender-bias has decreased significantly over the last 10 years. More surprisingly, we find that impact of gender bias in listings is dwarfed by our respondents' inherent bias towards specific job types.
To Share, or Not to Share?
Authors: Tausczik Yla , Wang Ping
Published: December 2017

Open innovation contests have been incredibly successful at producing creative designs and solutions. While participants compete for prizes in these contests, over half of contests conducted on online platforms allow participants to share ideas during contests, for benefits such as individual learning, community building, and cumulative innovation. Such sharing, however, is at tension with the competitive nature of crowd contests. To understand this tension, this study investigates community-level sharing of code on Kaggle, a contest platform for predictive modeling. Analyzing data on 25 contests in 2015 and 2016, we find that 10% of users shared code during contests, that participants doing medium well in the contest were the most likely to share code, and that sharing code improved individual, but not collective performance. These findings allow us to contribute insights about the participants, conditions, processes, and outcomes of community-level collaboration to both research on and design of open innovation contests.
Technologies, Methods, and Values
Authors: Wallace James R. , Oji Saba , Anslow Craig
Published: December 2017

The field of Computer Supported Cooperative Work has constantly evolved to meet the changing needs of individuals at home, at work, and online. To understand how these changes impacted CSCW research, we systematically reviewed 1209 papers and notes published at the ACM Conference on Computer Supported Cooperative Work between 1990 and 2015. When considered with results from two previous literature reviews, covering 1990 - 1998 and 1998 - 2004 respectively, our analysis provides perspective on 25 years of groupware research. We show that the field has responded to, not anticipated, changes in the computing landscape, long-term trends away from 'systems' and explanatory research, and a lack of bibliographic research that synthesizes findings. Finally, we discuss implications of these trends for CSCW research: how results are synthesized across the field, what kinds of research we value, and how multi-device ecologies are studied.
Supporting Virtual Team Formation through Community-Wide Deliberation
Authors: Wen Miaomiao , Maki Keith , Dow Steven , Herbsleb James D. , Rose Carolyn
Published: December 2017

Team-based learning is a structured, small-group learning method that has been associated with many positive outcomes in traditional classroom settings. However, relatively little research has focused on how to form and support teams within online learning platforms, such as Massive Open Online Courses (MOOCs). A number of challenges arise for team formation in voluntary online classes: students may drop out and leave their team, and even if they do persist with the course, the team may not work together effectively. In this paper, we introduce a team-formation strategy that incorporates a deliberation process, where participants hold discussions in preparation for the collaboration task. First, we present a crowdsourced experiment that compares teams that are formed before or after a community deliberation process. Results demonstrate that teams engaging in a larger community deliberative process prior to team formation exhibit better team performance--as measured by team collaboration product quality--than pre-discussion teams. In a second crowdsourced experiment, we further explore the benefits of community-wide processes by automatically assigning teams based on participants' transactive interaction during deliberation. The results demonstrate advantages in terms of team performance for teams formed based on observed interactions during the community-level deliberation, compared to randomly formed teams. Finally, in a case study, we demonstrate how we successfully adapted the team formation strategy for use in a small MOOC.
Persuading Teammates to Give
Authors: Yang Diyi , Kraut Robert E.
Published: December 2017

Dual processing theories in psychology suggest that people process persuasive requests by assessing the quality of arguments (systematic processing) or by relying on heuristic rules (heuristic processing). However, the factors that act as systematic and heuristic processing cues and affect the success of persuasion have not been adequately described in social lending contexts. This research examines the effectiveness of systematic and heuristic cues in persuasive requests in Kiva lending teams intended to convince members to donate. An analysis of 88,596 requests exchanged in 1,610 teams shows that certain heuristic processing cues (e.g., liking between requesters and potential lenders, advocates low authority in their teams and the importance of the team to the lender) strongly predicted whether lenders would contribute to a loan request. In contrast, cues that required systematic processing are less influential. We also found that behavioral cues are more important than verbal ones. We discuss the theoretical and practical implications of our work.