Robust artificial neural networks and outlier detection. Technical report

Large outliers break down linear and nonlinear regression models. Robust regression methods allow one to filter out the outliers when building a model. By replacing the traditional least squares criterion with the least trimmed squares criterion, in which half of data is treated as potential outliers, one can fit accurate regression models to strongly contaminated data. High-breakdown methods have become very well established in linear regression, but have started being applied for non-linear regression only recently. In this work, we examine the problem of fitting artificial neural networks to contaminated data using least trimmed squares criterion. We introduce a penalized least trimmed squares criterion which prevents unnecessary removal of valid data. Training of ANNs leads to a challenging non-smooth global optimization problem. We compare the efficiency of several derivative-free optimization methods in solving it, and show that our approach identifies the outliers correctly when ANNs are used for nonlinear regression

The Early Stages of the Integration of the Internet in EU Newsrooms

The current study explores the perceived integration of the internet inside European newsrooms. The authors carried out a survey with 239 journalists working for 40 of the most-read outlets in 11 European countries.The study shows that journalists consider the internet a useful tool mainly for practical functions, rather than to enhance the core values and functions of their profession. However, news production continues to be based on direct interaction, and journalists’ professional identity is still anchored to print newspapers. Moreover, a lack of communication between publishers and newsrooms emerges. Professional and personal profiles and nationality play a relevant role in the development of attitudes towards the implementation of the internet in newsrooms

Growth and dislocation studies of β-HMX

Background: The defect structure of organic materials is important as it plays a major role in their crystal growth properties. It also can play a subcritical role in “hot-spot” detonation processes of energetics and one such energetic is cyclotetramethylene-tetranitramine, in the commonly used beta form (β-HMX). Results: The as-grown crystals grown by evaporation from acetone show prismatic, tabular and columnar habits, all with {011}, {110}, (010) and (101) faces. Etching on (010) surfaces revealed three different types of etch pits, two of which could be identified with either pure screw or pure edge dislocations, the third is shown to be an artifact of the twinning process that this material undergoes. Examination of the {011} and {110} surfaces show only one type of etch pit on each surface; however their natural asymmetry precludes the easy identification of their Burgers vector or dislocation type. Etching of cleaved {011} surfaces demonstrates that the etch pits can be associated with line dislocations. All dislocations appear randomly on the crystal surfaces and do not form alignments characteristic of mechanical deformation by dislocation slip. Conclusions: Crystals of β-HMX grown from acetone show good morphological agreement with that predicted by modelling, with three distinct crystal habits observed depending upon the supersaturation of the growth solution. Prismatic habit was favoured at low supersaturation, while tabular and columnar crystals were predominant at higher super saturations. The twin plane in β-HMX was identified as a (101) reflection plane. The low plasticity of β-HMX is shown by the lack of etch pit alignments corresponding to mechanically induced dislocation arrays. On untwinned {010} faces, two types of dislocations exist, pure edge dislocations with b = [010] and pure screw dislocations with b = [010]. On twinned (010) faces, a third dislocation type exists and it is proposed that these pits are associated with pure screw dislocations with b = [010]

INDIVIDUAL INFUSION OF M-HEALTH TECHNOLOGIES: DETERMINANTS AND OUTCOMES

Despite substantial research on IT implementation in the IS field, the healthcare industry has historically been considered a technological laggard and lacks direction for how to successfully infuse new technological innovations within individuals work practices. Theoretically, mobile-health (m-health) technologies, if infused in work practices can potentially enhance the quality of healthcare delivery. The question remains as to whether practitioners\u27 performance significantly improves and individual knowledge is enhanced through the infusion of these technologies. While a significant amount of extant literature focuses on initial technology adoption and acceptance, there remains a dearth of literature in the IS field focusing on the long term utilisation and associated benefits. This paper addresses this gap in extant literature through the development and testing of a conceptual model, exploring determinants of individual infusion of m-health technologies and their subsequent outcomes. This study reveals (a) key enablers of successful mobile infusion in a healthcare context and that successful infusion is determined by the characteristics of the: 1. technology 2. user and 3. task, (b) Infusion of mobile technologies leads to improvements in preventative care, greater decision making and reduced medical errors and, (c) Individuals perceive that knowledge is presented rather than created through mobile technologies

SODIUM FLUORIDE-INDUCED OXIDATIVE STRESS AND HISTOLOGICAL CHANGES IN LIVER OF SWISS ALBINO MICE AND AMELIORATION BY OCIMUM SANCTUM LINN.

Objective: The present study was designed to evaluate hepatotoxicity induced by sodium fluoride (NaF) in Swiss albino mice and amelioration by Ocimum sanctum Linn.Methods: Mice were divided into six groups, Group I received tap water, Group II received low dose of NaF (8 mg/L), Group III high dose of NaF (80 mg/L) in drinking water, Group IV tap water along with 250 mg/kg body weight/day leaf extract of O. sanctum Linn., Group V 8 mg/L NaF in drinking water and 250 mg/kg body weight leaf extract of O. sanctum Linn., and Group VI 80 mg/L NaF in drinking water along with leaf extract of O. sanctum Linn. 250 mg/kg body weight/day for 90 days. On the 91st day, the animals were autopsied and liver tissue samples were taken to assess histopathological changes and oxidative stress by estimating glutathione peroxidase, superoxide dismutase, and catalase.Results: A highly significant decrease in the activity of antioxidant enzymes occurred with the high dose (Group III). Hepatic histopathological architecture exhibited deformities, namely, ballooning, hypertrophy, hepatocellular necrosis, infiltration of mononuclear cells, deformed central vein, sinusoidal dilation, and binucleated cells. Low-dose group (Group II) showed a significant decrease in antioxidant enzyme levels as compared to control group, and histological sections of liver showed dilated sinusoids, infiltration of mononuclear cells, ballooning, and hypertrophy of hepatocytes. Groups IV and V showed no pathological features. Group VI showed less damage to the liver as compared to Group III.Conclusion: The results revealed that the administration of leaf extract of O. sanctum Linn. elicited protection against NaF-induced hepatotoxicity and oxidative stress. It may, therefore, be inferred that fluoride caused hepatotoxicity in Swiss albino mice at the tested dose levels can be ameliorated by O. sanctum Linn

A survey to investigate the association of pain, foot disability and quality of life with corns

Background Corns are a common foot problem affecting a large proportion of the population. This study describes the characteristics of corns experienced by 201 participants taking part in a randomised controlled trial to investigate associations between demographic and corn parameters on pain, foot related disability and quality of life (QoL). Methods Pain from the main (index) corn was measured using a visual analogue scale (VAS); foot related disability was assessed with the Foot Disability Questionnaire (now known as the Manchester Foot Pain and Disability Index) and quality of life was recorded with the EQ-5D questionnaire. The effect of demographic and corn parameters on the pain and quality of life outcomes was assessed with analysis of variance (ANOVA) methods. The effect of the same factors on a linear combination of the foot-related disability outcome measures was assessed using multivariate ANOVA methods. Pain was also tested for its mediating properties on the causal pathway between the independent variables and quality of life. Results The mean pain score was 5.29 points on a 10 cm VAS, with females reporting substantively higher pain levels than males. Age affected foot-related disability, with lower levels on all domains of the MFPDI reported in older participants; each year of advancing age was associated with falls of: 0.009 points on the Concern about Appearance (CA) domain; 0.047 points on the Functional Limitation (FL) domain and 0.048 points on the Pain Intensity (PI) domain. Sex and corn type also affected disability, with higher scores reported by females and participants with plantar corns. Conclusions The effect of pain was shown to mediate the relationship between sex and foot-related disability. The presence of plantar corns has a more detrimental effect on QoL than dorsal/inter-digital corns

Identifying muon sites "by eye" in KPF6 and KBF4

Molecular magnets are one of the key research themes of µSR, but locating the muon stopping site in these compounds using density functional theory is often very challenging as their unit cells tend to contain a very large number of atoms. Nevertheless, many molecular magnets contain the [PF6]− and [BF4]− molecular ions, which, due to their fluorine nuclei, produce a distinctive µSR spectrum, which can give information about the muon stopping site. This paper details the calculation of the muon sites in the much simpler materials KPF6 and KBF4, providing insights which can be applied to situations where these molecular ions are found in complicated molecular magnets

Axin2 as regulatory and therapeutic target in newborn brain injury and remyelination.

Permanent damage to white matter tracts, comprising axons and myelinating oligodendrocytes, is an important component of brain injuries of the newborn that cause cerebral palsy and cognitive disabilities, as well as multiple sclerosis in adults. However, regulatory factors relevant in human developmental myelin disorders and in myelin regeneration are unclear. We found that AXIN2 was expressed in immature oligodendrocyte progenitor cells (OLPs) in white matter lesions of human newborns with neonatal hypoxic-ischemic and gliotic brain damage, as well as in active multiple sclerosis lesions in adults. Axin2 is a target of Wnt transcriptional activation that negatively feeds back on the pathway, promoting β-catenin degradation. We found that Axin2 function was essential for normal kinetics of remyelination. The small molecule inhibitor XAV939, which targets the enzymatic activity of tankyrase, acted to stabilize Axin2 levels in OLPs from brain and spinal cord and accelerated their differentiation and myelination after hypoxic and demyelinating injury. Together, these findings indicate that Axin2 is an essential regulator of remyelination and that it might serve as a pharmacological checkpoint in this process