571 research outputs found
Locally constrained diffusion process on locally densified distance spaces with applications to shape retrieval
Optimizing Handover of As-Built Data Using BIM for Highways
An efficient maintenance of the UK’s transportation network is of critical importance to the
country’s economy and among the top priorities of the government and public agencies (e.g.
Network Rail, Highways England). The public transportation agencies have huge data sets
related to asset management and maintenance. However, those data sets are usually held in
disparate platforms and have been historically developed using multiple standards and
formats. As a result, full value of such data is often not fully realized. Effective management
of asset data and availability of reliable information as and when needed, could bring in key
benefits for effective management of the transportation network. This paper aims to present
the initial findings of a research effort understanding the potential of Building Information
Modelling (BIM) in handover processes for a more efficient maintenance of highways
assets, and discuss the way forward. The research methodology applied is systematic
literature review and two recent best practice cases in the Highways Sector. The research
findings suggest that efficient data management through BIM could provide a structured
framework to improve asset handover and maintenance. However, it is important to capture
the current handover practices between the construction and maintenance phase, and
maintenance processes in the UK’s highways sector, both of which seem to be absent in the
literature at the moment
Deep Over-sampling Framework for Classifying Imbalanced Data
Class imbalance is a challenging issue in practical classification problems
for deep learning models as well as traditional models. Traditionally
successful countermeasures such as synthetic over-sampling have had limited
success with complex, structured data handled by deep learning models. In this
paper, we propose Deep Over-sampling (DOS), a framework for extending the
synthetic over-sampling method to exploit the deep feature space acquired by a
convolutional neural network (CNN). Its key feature is an explicit, supervised
representation learning, for which the training data presents each raw input
sample with a synthetic embedding target in the deep feature space, which is
sampled from the linear subspace of in-class neighbors. We implement an
iterative process of training the CNN and updating the targets, which induces
smaller in-class variance among the embeddings, to increase the discriminative
power of the deep representation. We present an empirical study using public
benchmarks, which shows that the DOS framework not only counteracts class
imbalance better than the existing method, but also improves the performance of
the CNN in the standard, balanced settings
Hydrostatic pressure does not cause detectable changes to survival of human retinal ganglion
Purpose: Elevated intraocular pressure (IOP) is a major risk factor for glaucoma. One consequence of raised IOP is that ocular tissues are subjected to increased hydrostatic pressure (HP). The effect of raised HP on stress pathway signaling and retinal ganglion cell (RGC) survival in the human retina was investigated. Methods: A chamber was designed to expose cells to increased HP (constant and fluctuating). Accurate pressure control (10-100mmHg) was achieved using mass flow controllers. Human organotypic retinal cultures (HORCs) from donor eyes (<24h post mortem) were cultured in serum-free DMEM/HamF12. Increased HP was compared to simulated ischemia (oxygen glucose deprivation, OGD). Cell death and apoptosis were measured by LDH and TUNEL assays, RGC marker expression by qRT-PCR (THY-1) and RGC number by immunohistochemistry (NeuN). Activated p38 and JNK were detected by Western blot. Results: Exposure of HORCs to constant (60mmHg) or fluctuating (10-100mmHg; 1 cycle/min) pressure for 24 or 48h caused no loss of structural integrity, LDH release, decrease in RGC marker expression (THY-1) or loss of RGCs compared with controls. In addition, there was no increase in TUNEL-positive NeuN-labelled cells at either time-point indicating no increase in apoptosis of RGCs. OGD increased apoptosis, reduced RGC marker expression and RGC number and caused elevated LDH release at 24h. p38 and JNK phosphorylation remained unchanged in HORCs exposed to fluctuating pressure (10-100mmHg; 1 cycle/min) for 15, 30, 60 and 90min durations, whereas OGD (3h) increased activation of p38 and JNK, remaining elevated for 90min post-OGD. Conclusions: Directly applied HP had no detectable impact on RGC survival and stress-signalling in HORCs. Simulated ischemia, however, activated stress pathways and caused RGC death. These results show that direct HP does not cause degeneration of RGCs in the ex vivo human retina
The genetic profile of childhood neuromuscular disorders: A single center experience
Neuromuscular Diseases are a heterogeneous group of childhood disorders, and differential diagnosis can be challenging. Although there is no definitive treatment for the most of this group of diseases, early diagnosis is important with the development of new treatment methods. In this study, we aimed to draw attention to the importance of new generation genetic tests in diagnosing neuromuscular diseases. In this retrospective study, we reviewed the records of 800 patients with suspected neuromuscular diseases followed in the Neuromuscular Clinic of Marmara University Pendik Training and Research Hospital between December 2011 and January 2023 according to their demographic, clinical and genetic characteristics. Patients who were diagnosed with Duchenne muscular dystrophy and spinal muscular atrophy with targeted gene testing were excluded from the study. The results of targeted gene testing, clinical exome sequencing (CES), whole exome sequencing (WES) and mitochondrial genome analysis were analysed
Evaluation of continuous improvement programmes
The study began with the problem posed by an organisation for a group of researchers in the UK. There was a need to carry out an in-depth study to evaluate the continuous improvement programmes in the context of Lean Construction, and the following question emerged: How to evaluate the continuous improvement programme? This paper aims to understand how the literature on continuous improvement, including quality circles (QCs), small group activities (SGAs), and continuous improvement cells (CICs), can help to conduct the evaluation of continuous improvement programmes. The paper includes a literature review to gain an understanding of the problem from a theoretical perspective. Continuous improvement techniques are assessed in the framework of the TFV theory, with the main focus on the flow and the waste concepts. A logic model framework is used to synthesize the literature review findings and to establish an initial proposal for the evaluation of continuous improvement programmes in the Lean Construction context. This paper does not include any empirical study or actual measure and cannot ascertain the definitive benefits of continuous improvement techniques. Also, the paper does not propose any definitive procedure on how to evaluate continuous improvement techniques
Visual Management (VM) supporting collaborative practices in infrastructure engineering design
Managing the design of complex engineering systems requires an organisational structure and an information system to support collaboration among all stakeholders. Technological developments in information management have the potential to facilitate interactions across physical boundaries, even more during the Covid-19 pandemic. Visual Management (VM) is an information management strategy, as well as a means for communication between individuals, supporting collaborative work. However, there is a lack of effective understanding of how digital VM can support infrastructure engineering design. The adoption of digital collaborative VM in the context addressed is new, under rapid evolution, and there is limited understanding of how the users embrace VM while interacting with it. The aim of the paper is to explore the adoption of VM, focusing on digital whiteboards, to support collaborative practices in design processes. The ongoing investigation is carried out in collaboration with an infrastructure design and consultancy company, and follows the action research approach. The VM effectiveness was investigated by analysing the whiteboards applicability to diverse functions and comparing digital and manual implementations. Initial findings include understanding digital whiteboards as a means for collaboration among individuals with different perceptions to establish a common point of view, as it allows the information to be transferred across time and space, identifies abnormalities, and supports problem-solving. By creating a common ground, it has the potential to support complex and emergent interactions in the collaborative space
TGF-beta(2)- and H2O2-Induced Biological Changes in Optic Nerve Head Astrocytes Are Reduced by the Antioxidant Alpha-Lipoic Acid
Background/Aims: The goal of the present study was to determine whether transforming growth factor-beta(2) (TGF-beta(2))- and oxidative stress-induced cellular changes in cultured human optic nerve head (ONH) astrocytes could be reduced by pretreatment with the antioxidant alpha-lipoic acid (LA). Methods: Cultured ONH astrocytes were treated with 1.0 ng/ml TGF-beta(2) for 24 h or 200 mu M hydrogen peroxide (H2O2) for 1 h. Lipid peroxidation was measured by a decrease in cis-pari-naric acid fluorescence. Additionally, cells were pretreated with different concentrations of LA before TGF-beta 2 or H2O2 exposure. Expressions of the heat shock protein (Hsp) alpha B-crystallin and Hsp27, the extracellular matrix (ECM) component fibronectin and the ECM-modulating protein connective tissue growth factor (CTGF) were examined with immunohistochemistry and real-time PCR analysis. Results: Both TGF-beta(2) and H2O2 increased lipid peroxidation. Treatment of astrocytes with TGF-beta(2) and H2O2 upregulated the expression of alpha B-crystallin, Hsp27, fibronectin and CTGF. Pretreatment with different concentrations of LA reduced the TGF-beta(2)- and H2O2-stimulated gene expressions. Conclusion: We showed that TGF-beta(2)- and H2O2-stimulated gene expressions could be prevented by pretreatment with the antioxidant LA in cultured human ONH astrocytes. Therefore, it is tempting to speculate that the use of antioxidants could have protective effects in glaucomatous optic neuropathy. Copyright (C) 2012 S. Karger AG, Base
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