74,834 research outputs found
Faster K-Means Cluster Estimation
There has been considerable work on improving popular clustering algorithm
`K-means' in terms of mean squared error (MSE) and speed, both. However, most
of the k-means variants tend to compute distance of each data point to each
cluster centroid for every iteration. We propose a fast heuristic to overcome
this bottleneck with only marginal increase in MSE. We observe that across all
iterations of K-means, a data point changes its membership only among a small
subset of clusters. Our heuristic predicts such clusters for each data point by
looking at nearby clusters after the first iteration of k-means. We augment
well known variants of k-means with our heuristic to demonstrate effectiveness
of our heuristic. For various synthetic and real-world datasets, our heuristic
achieves speed-up of up-to 3 times when compared to efficient variants of
k-means.Comment: 6 pages, Accepted at ECIR 201
Neuroscientistsā everyday experiences of ethics: The interplay of regulatory, professional, personal and tangible ethical spheres
Copyright @ 2013 The Authors. This article has been published using OnlineOpen. Re-use of this article is permitted in accordance with the Terms and Conditions set out at http://wileyonline
library.com/onlineopen#OnlineOpen_Terms.The ethical issues neuroscience raises are subject to increasing attention, exemplified in the emergence of the discipline neuroethics. While the moral implications of neurotechnological developments are often discussed, less is known about how ethics intersects with everyday work in neuroscience and how scientists themselves perceive the ethics of their research. Drawing on observation and interviews with members of one UK group conducting neuroscience research at both the laboratory bench and in the clinic, this article examines what ethics meant to these researchers and delineates four specific types of ethics that shaped their day-to-day work: regulatory, professional, personal and tangible. While the first three categories are similar to those identified elsewhere in sociological work on scientific and clinical ethics, the notion of ātangible ethicsā emerged by attending to everyday practice, in which these scientistsā discursive distinctions between right and wrong were sometimes challenged. The findings shed light on how ethical positions produce and are, in turn, produced by scientific practice. Informing sociological understandings of neuroscience, they also throw the category of neuroscience and its ethical specificity into question, given that members of this group did not experience their work as raising issues that were distinctly neuro-ethical.Wellcome Trus
Linear and Nonlinear Optical Properties of Mn doped Benzimidazole Thin Films
In the present work, the Mn doped benzimidazole (BMZ) thin films were
prepared by simple chemical bath deposition technique. The material was
directly deposited as thin film on glass substrates and the metal concentration
in the solution was varied in weight percentage in order to investigate the
dopant effect on the properties of thin films. Similarly, the Mn doped BMZ
films were deposited in different solution temperature to study the effect of
deposition temperature on the properties of thin films. The PXRD and FT-IR
spectroscopy are used to study the structural and the presence of functional
groups in the BMZ medium. Depending upon the solution temperature, thickness of
the films varying from 0.6 to 1.2 {\mu}m and the optical transparency of the
samples increases with the increasing temperature up to 50 {\deg}C. Second
Harmonic Generation (SHG) efficiency of the films is measured for all the
films. Third order nonlinear optical properties of the films were analyzed
using Z-scan technique. The experimental results show that Mn doped BMZ films
exhibits saturation absorption and negative nonlinearity.Comment: This has been presented in DAE 58th Solid State Symposium held at
Thapar University, Patiala, Punjab, India. Will be published in AIP
conference proceedings soo
Pion Mass Modification in presence of external magnetic field
In this work, the self energies of and up to one loop
order have been calculated in the limit of weak external magnetic field. The
effective masses are explicitly dependent on the magnetic field which are
modified significantly for the pseudoscalar coupling due to weak field
approximation of the external field. On the other hand, for the pseudovector
coupling, there is a modest increment in the effective masses of the pions.
These theoretical developments are relevant for the study of the
phenomenological aspect of mesons in the context of neutron stars as well as
heavy ion collisions.Comment: Published in conference proceedings of DAE-HEP-2016 (XXII DAE High
Energy Physics Symposium, New Delhi, India
The differential contribution of tumour necrosis factor to thermal and mechanical hyperalgesia during chronic inflammation
Therapies directed against tumour necrosis factor (TNF) are effective for the treatment of rheumatoid arthritis and reduce pain scores in this condition. In this study, we sought to explore mechanisms by which TNF contributes to inflammatory pain in an experimental model of arthritis. The effects of an anti-TNF agent, etanercept, on behavioural pain responses arising from rat monoarthritis induced by complete Freund's adjuvant were assessed and compared with expression of TNF receptors (TNFRs) by dorsal root ganglion (DRG) cells at corresponding time points. Etanercept had no effect on evoked pain responses in normal animals but exerted a differential effect on the thermal and mechanical hyperalgesia associated with rat arthritis induced by complete Freund's adjuvant (CFA). Joint inflammation was associated with increased TNFR1 and TNFR2 expression on DRG cells, which was maintained throughout the time course of the model. TNFR1 expression was increased in neuronal cells of the DRG bilaterally after arthritis induction. In contrast, TNFR2 expression occurred exclusively on nonneuronal cells of the macrophage-monocyte lineage, with cell numbers increasing in a TNF-dependent fashion during CFA-induced arthritis. A strong correlation was observed between numbers of macrophages and the development of mechanical hyperalgesia in CFA-induced arthritis. These results highlight the potential for TNF to play a vital role in inflammatory hyperalgesia, both by a direct action on neurons via TNFR1 and by facilitating the accumulation of macrophages in the DRG via a TNFR2-mediated pathway
Table S5. Recombination hotspots in Azospirillum genomes Strains a Direct b repeats Palindromic c repeats IS
d element
Biomolecular imaging and electronic damage using X-ray free-electron lasers
Proposals to determine biomolecular structures from diffraction experiments
using femtosecond X-ray free-electron laser (XFEL) pulses involve a conflict
between the incident brightness required to achieve diffraction-limited atomic
resolution and the electronic and structural damage induced by the
illumination. Here we show that previous estimates of the conditions under
which biomolecular structures may be obtained in this manner are unduly
restrictive, because they are based on a coherent diffraction model that is not
appropriate to the proposed interaction conditions. A more detailed imaging
model derived from optical coherence theory and quantum electrodynamics is
shown to be far more tolerant of electronic damage. The nuclear density is
employed as the principal descriptor of molecular structure. The foundations of
the approach may also be used to characterize electrodynamical processes by
performing scattering experiments on complex molecules of known structure.Comment: 16 pages, 2 figure
Using BIM to achieve Architectural Engineering undergraduate learning outcomes
Building Information Modelling is a process integrating 3D graphics and data. It is being adopted into the AECOO industries and by default into the delivery of undergraduate Architectural Programs. This object approach offers a range of benefits over the more traditional CAD approach that uses lines and arcs and manual techniques, by adding the third dimension and creating a database model. It redefines the ways of thinking and working for students and future architects and architectural engineers. The requirements of architectural programs are defined through their learning objectives to meet professional requirements such as those set by the ARB and the RIBA. This paper aims to investigate how the capabilities of BIM can be utilized to deliver the requirements of undergraduate architectural engineering programs in a more effective manner. .
Purpose: to further develop an implementation strategy for BIM in the undergraduate program of architectural engineering that helps in achieving the learning outcomes.
Design/Methodology/Approach: In order to ensure transparency and reliability in the formulated solutions, the adopted methodology for this research is the design science since it deals with explicit problems and provides solutions by creating an artifact. The design science method also provides validation for the proposed solution by peer assessment. At the educational level, the study explores the undergraduate curriculum by taking case studies of programs and their learning outcomes that are set under the criteria of ARB and RIBA. The research analyzes these case studies in an attempt to detect the problems and define the requirements to solve the gaps.
Findings: The findings of the literature review identify the gaps that exist in the curriculum of the undergraduate architecture programs in the UK. The methodology is designed to develop a framework that acts as a guideline in implementing BIM in education. This paper sets the parameters for tutors to integrate BIM effectively into architectural undergraduate programs which shall promote the development of undergraduate students.
Originality/Value: The adoption of BIM within the architectural curriculum has been partial or immature up till this time. This paper addresses the effective implementation of BIM within the undergraduate programs which shall act as an original guideline that can aid professional institutions
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Membrane-bound Ī²-catenin degradation is enhanced by ETS2-mediated Siah1 induction in Helicobacter pylori-infected gastric cancer cells.
Ī²-catenin has two different cellular functions: intercellular adhesion and transcriptional activity. The E3 ubiquitin ligase Siah1 causes ubiquitin-mediated degradation of the cytosolic Ī²-catenin and therefore, impairs nuclear translocation and oncogenic function of Ī²-catenin. However, the effect of Siah1 on the cell membrane bound Ī²-catenin has not been studied. In this study, we identified that the carcinogenic bacterium H. pylori increased ETS2 transcription factor-mediated Siah1 protein expression in gastric cancer cells (GCCs) MKN45, AGS and Kato III. Siah1 protein level was also noticeably higher in gastric adenocarcinoma biopsy samples as compared to non-cancerous gastric epithelia. Siah1 knockdown significantly decreased invasiveness and migration of H. pylori-infected GCCs. Although, Siah1 could not increase degradation of the cytosolic Ī²-catenin and its nuclear translocation, it enhanced degradation of the membrane-bound Ī²-catenin in the infected GCCs. This loss of membrane-bound pool of Ī²-catenin was not associated with the proteasomal degradation of E-cadherin. Thus, this work delineated the role of Siah1 in increasing invasiveness of H. pylori-infected GCCs
EFFECTS OF BODY WEIGHT AND COMPOSITION ON BONE MINERAL CONTENT
A. Wong1, S. P. Shultz1,2
1Seattle University, Seattle, WA; 2Monmouth University, West Long Branch, NJ
Increased bodyweight (BW) is considered a protective condition for bone mineral content (BMC) in individuals with obesity due to the absorption of larger forces. However, little research has considered the effects on BMC based on stratified weight class and by body composition variables including lean mass (LM) and fat mass (FM). PURPOSE: To determine the relationship between BMC and BW normalized by LM and FM when stratified by weight class. METHODS: A dataset was amalgamated using DXA-measured variables that included BMC, BW, LM, and FM. A total of 32,066 adults from 13 datasets were included in the study. BMI classes were stratified based on WHO classifications. BW was normalized to LM (BW/LM) and FM (BW/FM). Paired t-tests were conducted to determine the differences between body tissue (LM vs FM) as well as normalized BW (BW/LM vs BW/FM). Pearsonās correlations were conducted for each BMI class to examine relationships between BMC and BW, BW/LM, and BW/FM. RESULTS: The paired t-tests produced significant differences between FM with LM (p\u3c0.001) and BW/LM with BW/FM (p\u3c0.001). For each BMI class, BW (p\u3c0.01) and BW/FM (p\u3c0.01) were positively correlated to BMC, while BW/LM (p\u3c0.01) was negatively correlated to BMC (Table 1). CONCLUSION: Positive correlations indicate that increases in total BW and BW/FM can be protective for BMC. Mechanisms driving the negative correlation between BMC and BW/LM need to be explored
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