4,799 research outputs found
Digital Ethnography as a Way to Explore Information Grounds on Twitter
Information grounds are social settings where information, people, and place come together to create information flow within a physical environment (Karen E. Pettigrew, 1998). Information grounds also facilitate the opportunistic discovery of information within social settings created temporarily by people gathered for some purpose other than seeking information, but the social environment stimulates spontaneous information sharing (K. E. Pettigrew, 1999), such as in hair salons, doctor's waiting rooms and other public places. Professional and scholarly use of social media is a rapidly emerging area of research. In this regard, qualitative analysis of data gathered from Twitter is a relatively unexplored area of Library and Information Science (LIS) research. This paper details the results of a qualitative study of Twitter using digital ethnography, in order to investigate the use of Twitter by IT professionals in forming communities of practice. This study is relevant to Library and Information Science (LIS) research as LIS professionals are part of the IT community of practice. This study used information grounds theory (K. E. Fisher, 2005) to explore Twitter as an online information ground. The research used online observation - conceptualised here as online ethnography or digital ethnography - and interviews to collect data. The online observations helped the researcher to understand the norms and culture of the participants along with patterns of behaviour. Interviews were used to understand the information grounds of the virtual environment through the participants' individual perspectives and their information experiences. A total of eleven participants were interviewed after a total of 734 tweets from these same participants were downloaded and analysed. Both interview and Twitter data were analysed using constructivist grounded theory (Charmaz, 2006). The findings highlight a variety of information sharing types, the role of information sharing in professional contexts, and the influences of Twitter on communication and social engagement, including a counterintuitive finding that professionals use Twitter not so much to seek or share information as much as to seek out a network of like-minded people. The significance of this study is in providing a fundamental understanding of the ways in which social media is used for professional reasons. It also proposes a systematic, qualitative data collection and data analysis approach to future research around Twitter and social media in general. This contribution not only helps LIS researchers, but can also help information professionals in the use of social media for professional purposes
Observation of second-harmonic generation induced by pure spin currents
Extensive efforts are currently being devoted to developing a new electronic
technology, called spintronics, where the spin of electrons is explored to
carry information. [1,2] Several techniques have been developed to generate
pure spin currents in many materials and structures. [3-10] However, there is
still no method available that can be used to directly detect pure spin
currents, which carry no net charge current and no net magnetization.
Currently, studies of pure spin currents rely on measuring the induced spin
accumulation with optical techniques [5, 11-13] or spin-valve configurations.
[14-17] However, the spin accumulation does not directly reflect the spatial
distribution or temporal dynamics of the pure spin current, and therefore
cannot monitor the pure spin current in a real-time and real-space fashion.
This imposes severe constraints on research in this field. Here we demonstrate
a second-order nonlinear optical effect of the pure spin current. We show that
such a nonlinear optical effect, which has never been explored before, can be
used for the non-invasive, non-destructive, and real-time imaging of pure spin
currents. Since this detection scheme does not rely on optical resonances, it
can be generally applied in a wide range of materials with different electronic
bandstructures. Furthermore, the control of nonlinear optical properties of
materials with pure spin currents may have potential applications in photonics
integrated with spintronics.Comment: 19 pages, 3 figures, supplementary discussion adde
Self-Affirmation Improves Problem-Solving under Stress
High levels of acute and chronic stress are known to impair problem-solving and creativity on a broad range of tasks. Despite this evidence, we know little about protective factors for mitigating the deleterious effects of stress on problem-solving. Building on previous research showing that self-affirmation can buffer stress, we tested whether an experimental manipulation of self-affirmation improves problem-solving performance in chronically stressed participants. Eighty undergraduates indicated their perceived chronic stress over the previous month and were randomly assigned to either a self-affirmation or control condition. They then completed 30 difficult remote associate problem-solving items under time pressure in front of an evaluator. Results showed that self-affirmation improved problem-solving performance in underperforming chronically stressed individuals. This research suggests a novel means for boosting problem-solving under stress and may have important implications for understanding how self-affirmation boosts academic achievement in school settings. © 2013 Creswell et al
A Terminal Velocity on the Landscape: Particle Production near Extra Species Loci in Higher Dimensions
We investigate particle production near extra species loci (ESL) in a higher
dimensional field space and derive a speed limit in moduli space at weak
coupling. This terminal velocity is set by the characteristic ESL-separation
and the coupling of the extra degrees of freedom to the moduli, but it is
independent of the moduli's potential if the dimensionality of the field space
is considerably larger than the dimensionality of the loci, D >> d. Once the
terminal velocity is approached, particles are produced at a plethora of nearby
ESLs, preventing a further increase in speed via their backreaction. It is
possible to drive inflation at the terminal velocity, providing a
generalization of trapped inflation with attractive features: we find that more
than sixty e-folds of inflation for sub-Planckian excursions in field space are
possible if ESLs are ubiquitous, without fine tuning of initial conditions and
less tuned potentials. We construct a simple, observationally viable model with
a slightly red scalar power-spectrum and suppressed gravitational waves; we
comment on the presence of additional observational signatures originating from
IR-cascading and individual massive particles. We also show that
moduli-trapping at an ESL is suppressed for D >> d, hindering dynamical
selection of high-symmetry vacua on the landscape based on this mechanism.Comment: 46 pages, 6 figures. V3: typos corrected compared to JHEP version,
conclusions unchange
Can We Really Prevent Suicide?
Every year, suicide is among the top 20 leading causes of death globally for all ages. Unfortunately, suicide is difficult to prevent, in large part because the prevalence of risk factors is high among the general population. In this review, clinical and psychological risk factors are examined and methods for suicide prevention are discussed. Prevention strategies found to be effective in suicide prevention
include means restriction, responsible media coverage, and general public education, as well identification methods such as screening, gatekeeper training, and primary care physician education. Although the treatment for preventing suicide is difficult, follow-up that includes pharmacotherapy, psychotherapy, or both may be useful. However, prevention methods cannot be restricted to the individual. Community, social, and policy interventions will also be essentia
The impact of point mutations in the human androgen receptor : classification of mutations on the basis of transcriptional activity
Peer reviewedPublisher PD
Design of Experiments for Screening
The aim of this paper is to review methods of designing screening
experiments, ranging from designs originally developed for physical experiments
to those especially tailored to experiments on numerical models. The strengths
and weaknesses of the various designs for screening variables in numerical
models are discussed. First, classes of factorial designs for experiments to
estimate main effects and interactions through a linear statistical model are
described, specifically regular and nonregular fractional factorial designs,
supersaturated designs and systematic fractional replicate designs. Generic
issues of aliasing, bias and cancellation of factorial effects are discussed.
Second, group screening experiments are considered including factorial group
screening and sequential bifurcation. Third, random sampling plans are
discussed including Latin hypercube sampling and sampling plans to estimate
elementary effects. Fourth, a variety of modelling methods commonly employed
with screening designs are briefly described. Finally, a novel study
demonstrates six screening methods on two frequently-used exemplars, and their
performances are compared
The Role of Information Experience on IT Professionals' Twitter Use
© 2020 Walter de Gruyter GmbH, Berlin/Boston 2020. Twitter acts as an information gateway as it provides a place where professionals network and share their knowledge. Twitter has increasingly influenced the way people use and share information. However, limited research demonstrates IT professionals' information experience on Twitter impacts the way they use it for professional purposes. The study aimed to understand how such information experiences impact on the way IT professionals use Twitter for professional purposes. Eleven IT professionals were recruited for this study to understand the participants' information experience through their own individual perspective, with the data analysed using constructive grounded theory. This study revealed that IT professionals' information experience plays a vital role in creating professional networking and knowledge sharing in online spaces. These lived experiences influence the way IT professionals use Twitter for professional purposes. Thus, the findings of this study contribute to theoretical perspectives in the understanding of information experience perspectives within Twitter, along with a foundational understanding of the ways in which microblogging is used for professional purposes. The findings can help organisations understand and provide for this emerging channel of professional information sharing for its staff and stakeholders
Group-based memory rehabilitation for people with multiple sclerosis: subgroup analysis of the ReMiND trial
Background/Aim: Memory problems are frequently reported in people with multiple sclerosis (MS). These can be debilitating and affect individuals and their families. This sub-group analysis focused on the effectiveness of memory rehabilitation in patients with MS.
Methods: Data were extracted from a single blind randomised controlled trial, the ReMiND trial, which also included participants with traumatic brain injury and stroke. Participants were randomly allocated to compensation or restitution treatment programmes, or a self-help control. The programmes were manual-based and comprised two individual and ten group sessions. Outcome measures included assessments of memory, mood and activities of daily living. A total of 39 patients with MS participated in this study (ten males (26%), 29 females (74%); mean±SD age: 48.3±10.8 years). Results: Comparison of groups showed no significant effect of treatment on memory, but there were significant differences between compensation and restitution on self-report symptoms of emotional distress at both 5- (p=0.04) and 7-month (p=0.05) follow-up sessions. The compensation group showed less distress than the restitution group.
Conclusions: Individuals with MS who received compensation memory rehabilitation reported significantly less emotional distress than those who received restitution. Further research is needed to explore why self-reported memory problems did not differ between groups
Genome diversity of Epstein-Barr virus from multiple tumor types and normal infection
pstein-Barr virus (EBV) infects most of the world's population and is causally associated with several human cancers, but little is known about how EBV genetic variation might influence infection or EBV-associated disease. There are currently no published wild-type EBV genome sequences from a healthy individual and very few genomes from EBV-associated diseases. We have sequenced 71 geographically distinct EBV strains from cell lines, multiple types of primary tumor, and blood samples and the first EBV genome from the saliva of a healthy carrier. We show that the established genome map of EBV accurately represents all strains sequenced, but novel deletions are present in a few isolates. We have increased the number of type 2 EBV genomes sequenced from one to 12 and establish that the type 1/type 2 classification is a major feature of EBV genome variation, defined almost exclusively by variation of EBNA2 and EBNA3 genes, but geographic variation is also present. Single nucleotide polymorphism (SNP) density varies substantially across all known open reading frames and is highest in latency-associated genes. Some T-cell epitope sequences in EBNA3 genes show extensive variation across strains, and we identify codons under positive selection, both important considerations for the development of vaccines and T-cell therapy. We also provide new evidence for recombination between strains, which provides a further mechanism for the generation of diversity. Our results provide the first global view of EBV sequence variation and demonstrate an effective method for sequencing large numbers of genomes to further understand the genetics of EBV infection.
IMPORTANCE:
Most people in the world are infected by Epstein-Barr virus (EBV), and it causes several human diseases, which occur at very different rates in different parts of the world and are linked to host immune system variation. Natural variation in EBV DNA sequence may be important for normal infection and for causing disease. Here we used rapid, cost-effective sequencing to determine 71 new EBV sequences from different sample types and locations worldwide. We showed geographic variation in EBV genomes and identified the most variable parts of the genome. We identified protein sequences that seem to have been selected by the host immune system and detected variability in known immune epitopes. This gives the first overview of EBV genome variation, important for designing vaccines and immune therapy for EBV, and provides techniques to investigate relationships between viral sequence variation and EBV-associated diseases
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