442 research outputs found
A psychology-driven computational analysis of political interviews
Can an interviewer influence the cooperativeness of an interviewee? The role of an interviewer in actualising a successful interview is an active field of social psychological research. A large-scale analysis of interviews, however, typically involves time-exorbitant manual tasks and considerable human effort. Despite recent advances in computational fields, many automated methods continue to rely on manually labelled training data to establish ground-truth. This reliance obscures explainability and hinders the mobility of analysis between applications. In this work, we introduce a cross-disciplinary approach to analysing interviewer efficacy. We suggest computational success measures as a transparent, automated, and reproducible alternative for pre-labelled data. We validate these measures with a small-scale study with human-responders. To study the interviewer’s influence on the interviewee we utilise features informed by social psychological theory to predict interview quality based on the interviewer’s linguistic behaviour. Our psychologically informed model significantly outperforms a bag-of-words model, demonstrating the strength of a cross-disciplinary approach toward the analysis of conversational data at scale
Propagation of Tau Pathology: Integrating Insights From Postmortem and In Vivo Studies
Cellular accumulation of aggregated forms of the protein tau is a defining feature of so-called tauopathies such as Alzheimer's disease, progressive supranuclear palsy, and chronic traumatic encephalopathy. A growing body of literature suggests that conformational characteristics of tau filaments, along with regional vulnerability to tau pathology, account for the distinct histopathological morphologies, biochemical composition, and affected cell types seen across these disorders. In this review, we describe and discuss recent evidence from human postmortem and clinical biomarker studies addressing the differential vulnerability of brain areas to tau pathology, its cell-to-cell transmission, and characteristics of the different strains that tau aggregates can adopt. Cellular biosensor assays are increasingly used in human tissue to detect the earliest forms of tau pathology, before overt histopathological lesions (i.e., neurofibrillary tangles) are apparent. Animal models with localized tau expression are used to uncover the mechanisms that influence spreading of tau aggregates. Further, studies of human postmortem-derived tau filaments from different tauopathies injected in rodents have led to striking findings that recapitulate neuropathology-based staging of tau. Furthermore, the recent advent of tau positron emission tomography and novel fluid-based biomarkers render it possible to study the temporal progression of tau pathology in vivo. Ultimately, evidence from these approaches must be integrated to better understand the onset and progression of tau pathology across tauopathies. This will lead to improved methods for the detection and monitoring of disease progression and, hopefully, to the development and refinement of tau-based therapeutics
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Optimising Human-Machine Collaboration for Efficient High-Precision Information Extraction from Text Documents
From science to law enforcement, many research questions are answerable only by poring over a large amount of unstructured text documents. While people can extract information from such documents with high accuracy, this is often too time-consuming to be practical. On the other hand, automated approaches produce nearly-immediate results, but are not reliable enough for applications where near-perfect precision is essential. Motivated by two use cases from criminal justice, we consider the benefits and drawbacks of various human-only, human–machine, and machine-only approaches. Finding no tool well suited for our use cases, we develop a human-in-the-loop method for fast but accurate extraction of structured data from unstructured text. The tool is based on automated extraction followed by human validation, and is particularly useful in cases where purely manual extraction is not practical. Testing on three criminal justice datasets, we find that the combination of the computer speed and human understanding yields precision comparable to manual annotation while requiring only a fraction of time, and significantly outperforms the precision of all fully automated baselines
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Protecting Children from Online Exploitation: Can a Trained Model Detect Harmful Communication Strategies?
The growing popularity of social media raises concerns about children's online safety. Of particular concern are interactions between minors and adults with predatory intentions. Unfortunately, previous research on online sexual grooming has relied on time-intensive manual annotation by domain experts, limiting both the scale and scope of possible interventions. This work explores the possibility of detecting predatory behaviours with accuracy comparable to expert annotators using machine learning (ML). Using a dataset of 6771 chat messages sent by child sex offenders, labelled by two of the authors who are forensic psychology experts, we study how well can deep learning algorithms identify eleven known predatory behaviours. We find that the best-performing ML models are consistent but not on par with expert annotation. We therefore consider a system where an expert annotator validates the ML algorithms outputs. The combination of human decision-making and computer efficiency yields precision - but not recall - comparable to manual annotation, while taking only a fraction of the time needed by a human annotator. Our findings underscore the promise of ML as a tool for assisting researchers in this area, but also highlight the current limitations in reliably detecting online sexual exploitation using ML
The Milky Way Nuclear Star Cluster
In the center of the Milky Way, as well as in many other galaxies, a compact
star cluster around a very massive black hole is observed. One of the possible
explanations for the formation of such Nuclear Star Clusters is based on the
'merging' of globular clusters in the inner galactic potential well. By mean of
sophisticated N-body simulations, we checked the validity of this hypothesis
and found that it may actually has been the one leading to the formation of the
Milky Way Nuclear Star Cluster.Comment: 4 pages, 2 figures, proceedings of "Stellar Clusters and Associations
- A RIA workshop on GAIA", 23-27 May 2011, Granada, Spai
Evaluation of a novel immunoassay to detect p-Tau Thr127 in the CSF to distinguish Alzheimer disease from other dementias
OBJECTIVE: To investigate whether p-tau T217 assay in cerebrospinal fluid (CSF) can distinguish Alzheimer's disease from other dementias and healthy controls. METHODS: We developed and validated a novel Simoa immunoassay to detect p-tau T217 in CSF. There was a total of 190 participants from three cohorts with AD (n = 77) and other neurodegenerative diseases (n = 69) as well as healthy subjects (n = 44). RESULTS: The p-tau T217 assay (cut-off 242 pg/ml) identified AD subjects with accuracy of 90%, with 78% positive predictive value (PPV), 97% negative predictive value (NPV), 93% sensitivity, 88% specificity compared favorably with p-tau T181 ELISA (52 pg/ml) showing 78% accuracy, 58% PPV, 98% NPV, 71% specificity, 97% sensitivity. The assay distinguished AD patients from age-matched healthy subjects (cut-off 163 pg/ml, sensitivity 98%, specificity 93%) similarly to p-tau T181 ELISA (cut-off 60 pg/ml, 96% sensitivity and 86% specificity). In AD patients, we found a strong correlation between p-tau T217-tau and p-tau T181, t-tau and Aβ40 but not with Aβ42. CONCLUSIONS: This study demonstrates that p-tau T217 displayed better diagnostic accuracy than p-tau T181. The data suggests that the new p-tau T217 assay has a potential as an AD diagnostic test in the clinical evaluation. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that a CSF immunoassay for p-tau T217 distinguishes AD from other dementias and healthy controls
An extremely top-heavy initial mass function in the galactic center stellar disks
Composite armors, having two or more different materials, contain a ceramic layer in the front face and a metallic or polymer matrix composite as support on the back side backing. The function of the ceramic layer is to erode and break up the projectile and to increase the contact surface of the metallic plate by forming a hard cone. The role of the metallic backing layer is to absorb the kinetic energy of the projectile and support the fragmented ceramic. The most impportant advantage of these materials over monolithic metallic armors is to reduce the thickness by using the ceramic layer in front of the metallic layer. This provides reducing the weight of armor. In this study, experiments have been conducted to describe ballistic performance of polymer matrix composites having different geometrical shapes. To do these experiments, aramid and polyethilen composite specimens were first fabricated as laminates in different geometrical shapes. Then, these composite plates at charpy harms were investigeted in varios speed bullet to cover the impact damageKompozit zırhlar iki veya daha fazla farklı malzemeden oluşan, yüzeyde seramik katman ile arkada metal veya polimer matrisli kompozit destek içeren malzemelerdir. Seramik katmanın işlevi mermiyi aşındırma ve parçalamanın yanısıra sert koni oluşturarak metal katmanın temas yüzeyini artırmaktır. Metal destek katmanının görevi ise merminin kinetik enerjisini emmek ve darbe sonrası oluşacak seramik parçaları tutmaktır. Bu malzemelerin, tamamen metalik olan zırhlara göre en önemli avantajı, metalik katmandan önce seramik katmanın kullanılması yoluyla zırh kalınlığının, dolayısı ile zırhın ağırlığının azalmasını sağlamaktadır. Bu çalışmada değişik geometriye sahip, polimer matrisli kompozitlerin, balistik performansını ölçmek için deneyler yapılmıştır. Bunun için önce Aramid ve polietilen numuneler düz, iki değişik çapta silindirik ve küre plakalar halinde üretilmiştir. Bu kompozit plakalara atış poligonunda atışlar yapılmış ve oluşan darbe hasarları incelenmiştir
Study of CP violation in Dalitz-plot analyses of B0 --> K+K-KS, B+ --> K+K-K+, and B+ --> KSKSK+
We perform amplitude analyses of the decays , , and , and measure CP-violating
parameters and partial branching fractions. The results are based on a data
sample of approximately decays, collected with the
BABAR detector at the PEP-II asymmetric-energy factory at the SLAC National
Accelerator Laboratory. For , we find a direct CP asymmetry
in of , which differs
from zero by . For , we measure the
CP-violating phase .
For , we measure an overall direct CP asymmetry of
. We also perform an angular-moment analysis of
the three channels, and determine that the state can be described
well by the sum of the resonances , , and
.Comment: 35 pages, 68 postscript figures. v3 - minor modifications to agree
with published versio
Standalone vertex finding in the ATLAS muon spectrometer
A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011
Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC
Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson
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