NUI Maynooth Eprint Archive
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Evaluation of an Ag85B Immunosensor with Potential for Electrochemical Mycobacterium Tuberculosis Diagnostics
No full textTuberculosis remains a major global health concern, especially in the developing world, and monitoring/early detection of the disease relies on low cost technologies that provide rapid and accurate results. Mycobacterium tuberculosis is the responsible bacterial pathogen and it is currently estimated by the World Health Organisation (WHO), that one quarter of the world's population, mainly in the developing world, is infected with TB. The overall aim of this work was to advance a screening electrochemical sensor for label free detection of Ag85B, a member of the Antigen 85 complex—major secretary protein of M. tuberculosis and biomarker for disease. An indirect ELISA Ag85B assay was optimised with capture antibody and antigen levels determined via a checkerboard titration (0.625 μg ml−1 and 2.5 μg ml−1 respectively). Following assay development, crosslinking of the bioreceptor Anti-Ag85B onto electrochemically deposited gold nanoparticle (AuNP) modified carbon electrodes was achieved and Ag85B binding successfully evaluated electrochemically via cyclic voltammetry. Following each modification step, ΔEp of a redox probe was monitored and overall results show that GCE/AuNP/anti-Ag85B electrochemical transducers are a viable method for Ag85B detection, capable of measuring antigen levels <2.5 μg ml−1
On the analysis of hyper-parameter space for a genetic programming system with iterated F-Race
No full textEvolutionary algorithms (EAs) have been with us for several decades and are highly popular given that they have proved competitive in the face of challenging problems’ features such as deceptiveness, multiple local optima, among other characteristics. However, it is necessary to define multiple hyper-parameter values to have a working EA, which is a drawback for many practitioners. In the case of genetic programming (GP), an EA for the evolution of models and programs, hyper-parameter optimization has been extensively studied only recently. This work builds on recent findings and explores the hyper-parameter space of a specific GP system called neat-GP that controls model size. This is conducted using two large sets of symbolic regression benchmark problems to evaluate system performance, while hyper-parameter optimization is carried out using three variants of the iterated F-Race algorithm, for the first time applied to GP. From all the automatic parametrizations produced by optimization process, several findings are drawn. Automatic parametrizations do not outperform the manual configuration in many cases, and overall, the differences are not substantial in terms of testing error. Moreover, finding parametrizations that produce highly accurate models that are also compact is not trivially done, at least if the hyper-parameter optimization process (F-Race) is only guided by predictive error. This work is intended to foster more research and scrutiny of hyper-parameters in EAs, in general, and GP, in particular
Machine Learning Techniques for the Detection of Inappropriate Erotic Content in Text
No full textNowadays, children have access to Internet on a regular basis. Just like the real world, the Internet has many unsafe locations where kids may be exposed to inappropriate content in the form of obscene, aggressive, erotic or rude comments. In this work, we address the problem of detecting erotic/sexual content on text documents using Natural Language Processing (NLP) techniques. Following an approach based on Machine Learning techniques, we have assessed twelve models resulting from the combination of three text encoders (Bag of Words, Term Frequency-Inverse Document Frequency and Word2vec) together with four classifiers (Support Vector Machines (SVMs), Logistic Regression, k-Nearest Neighbours and Random Forests). We evaluated these alternatives on a new created dataset extracted from public data on the Reddit Website. The best performance result was achieved by the combination of the text encoder TF-IDF and the SVM classifier with linear kernel with an accuracy of 0.97 and F-score 0.96 (precision 0.96/recall 0.95). This study demonstrates that it is possible to detect erotic content on text documents and therefore, develop filters for minors or according to user's preferences
Investigating behavior inhibition in obsessive‐compulsive disorder: Evidence from eye movements
No full textWe investigated the role of inhibition failure in Obsessive Compulsive Disorder (OCD) through an eye tracking experiment. Twenty‐five subjects with OCD were recruited, as well as 25 with Generalized Anxiety Disorder (GAD) and 25 healthy controls. A 3 (group: OCD group, GAD group and control group) × 2 (target eccentricity: far and near) × 2 (saccade task: prosaccade and antisaccade) mixed design was used, with all participants completing two sets of tasks involving both prosaccade (eye movement towards a target) and antisaccade (eye movement away from a target). The main outcome was the eye movement index, including the saccade latency (the time interval from the onset of the target screen to the first saccade) and the error rate of saccade direction. The antisaccade latency and antisaccade error rates for OCDs were much higher than those for GADs and healthy controls. OCDs had longer latency and error rates for antisaccades than for prosaccades, and for far‐eccentricity rather than near‐eccentricity stimuli. These results suggest that OCDs experience difficulty with behavior inhibition, and that they have higher visual sensitivity to peripheral stimuli. In particular, they show greatest difficulty in inhibiting behavior directed towards peripheral stimuli
How do Spanish heritage speakers in the US assign gender to English nouns in Spanish-English code-switching? The effect of noun canonicity and code switcher type
No full textPrevious studies have observed different gender assignment strategies for English nouns in Spanish-English code-switching (CS). However, these studies have not investigated the role of noun gender canonicity of the Spanish equivalent, they have only examined participants in bilingual speaker mode, and most studies have not explored the role of bilingual language experience. The current study compares gender assignment by heritage speakers of Spanish in a monolingual speaker mode and a bilingual speaker mode, considering the role of noun gender canonicity and CS
experience. Results revealed a language mode effect, where participants used significantly more masculine determiners with the same feminine nouns in the CS session than those in the Spanish monolingual session where they used a feminine determiner. Further evidence of a language mode effect was found in the effect of noun canonicity and bilingual
language experience. Noun canonicity was only significant in the Spanish monolingual session, where participants used significantly more masculine determiners with non-canonical nouns. Bilingual language experience was only significant in the CS session, where regular code switchers used more
masculine default determiners than infrequent code switchers and non-code switchers, while in Spanish-only, all these groups behaved similarl
Application of multiplatform, multispectral remote sensors for mapping intertidal macroalgae: A comparative approach
No full textPrecipitation trends in the island of Ireland using a dense, homogenized, observational dataset
No full textA dense monthly precipitation dataset of Ireland and Northern Ireland was homogenized with several modern homogenization methods. The efficiency of these homogenizations was tested by examining the similarity of homogenization results both in the real data homogenization and in the homogenization of a simulated dataset. The analysis of homogenization results shows that the real dataset is characterized by a large number of, but mostly small, non-climatic biases, and a moderate reduction of such biases can be achieved with homogenization. Finally, a combination of the ACMANT and Climatol homogenization results was applied to improve the data accuracy before the trend calculations. These two methods were selected for their proven high accuracy, missing data tolerance and ability to complete time series via the infilling of missing values before the trend calculations. Metadata were used within the Climatol method. To facilitate this analysis the study area was split into smaller climatic regions by using the Ward clustering method. Five climatic zones consistent with the known spatial patterns of precipitation in Ireland were established. Linear regression fitting and the Mann-Kendall test were applied. Low frequency fluctuations were also examined by applying a Gaussian filter. The results show that the precipitation amount generally increases in the study area, particularly in the northwestern region. The most significant increasing trends for the whole study period (1941–2010) are found for late winter and spring precipitation, as well as for the annual totals. In the period from the early 1970s the increase of precipitation is general in all seasons of the year except in winter, but the statistical significance of this increase is weak
Adaptive transmission rate for LQG control over Wi-Fi: A cross-layer approach
No full textThis work studies the problem of LQG control when the link between the sensor and the controller relies on a Wi-Fi network. Unfortunately, the communication on a wireless medium is sensitive to noise in the transmission band, which is characterized by the Signal-to-Noise Ratio (SNR). Wi-Fi allows to switch among different bit-rates in real-time thus permitting to trade-off lower loss probabilities for larger latency or vice-versa to achieve better closed-loop performance. To exploit this feature, under a constant SNR scenario, we propose a cross-layer approach where the bit-rate is optimally selected based on a control performance metric (i.e. minimum LQG cost) and a model-based controller is used to compensate for the packet losses. Under time-varying SNR, we additionally propose a (sub-optimal) on-line rate adaptation strategy and we guarantee the closed-loop stability under some mild conditions. Numerical comparisons with emulation-based approaches using TrueTime, a realistic Matlab-based Wi-Fi simulator, are included to show the benefits of the adaptive approach under time-varying SNR scenarios
Being green in a materialistic world: Consequences for subjective well-being
No full textThis paper explores the potential negative side‐effects of the sustainability movement
in societies with large segments of materialistic consumers. Across three studies,
there is evidence that a conflict between materialistic and green value profiles can
arise in consumers. When it arises, it seems to be related to diminished well‐being.
Study 1 shows that consumers with a higher value conflict (VC) experienced higher
levels of stress. Consumers with higher degrees of stress then reported lower
satisfaction with life. Study 2 reveals the underlying process by which this value
conflict affects well‐being. The results suggest that the value conflict is related to a
reduced clarity of consumers’ self‐concept (SCC), which in turn is related to increased
levels of stress and a lower satisfaction with life. Results of Study 3 show that
preference for consistency (PfC) serves as a boundary condition to this effect. The
negative effect of VC on SCC is most pronounced among consumers high in PfC,
while low PfC consumers seem to suffer less from the negative consequences of a
conflict between green and materialistic values. Conceptual and public‐policy
implications of these results are discussed
COVID-19 paranoia in a patient suffering from schizophrenic psychosis – a case report
No full textThe COVID-19 pandemic affects mental health, both in healthcare
settings and broader society. Fear responses in both the uninfected and
infected may reach psychopathological levels that require psychiatric
interventions (Duan and Zhu, 2020), and physicians and mental health
professionals may have particularly high need for psychological support
in the case of development of stress-related disorders (Chen et al.,
2020). An area of key concern is the potential of the psychological
context of the pandemic to exacerbate existing psychiatric conditions
and influence the manifestation of their symptomatology. Here we report the case of a patient with schizophrenia presenting with COVD-19-
related delusions and hallucinations, illustrating the potential of
COVID-19 to precipitate entry into a psychotic phase and impact
symptom manifestation