19 research outputs found

    Effectiveness of crack repairing measures in Tabuk City, Saudi Arabia

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    Concrete cracking and defect patterns can often indicate its causes. In this research paper, detailed description of cracks types, causes, and proper solutions is identified. The main objective of the paper is to measure the response of specialists about the probability of certain cracks causes and solutions, and to evaluate the effect of using epoxy materials in repairing concrete cracks. The present study shows that about 50% of responders indicated that cracks due to steel corrosion represent between 10-20% of building cracks. And about 80% of the responders indicated that crack due to load increasing is rarely occurred in the site. The interviewed specialists ensured that using epoxy materials are effective in solving most cracks’ problems. The experimental work results show that the flexural strength of epoxy repaired samples exceeded that of original samples. And the increase in flexural strength is inversely proportioned with sample depth

    The Effect Of Hot Spots On The Performance Of Mesh--Based Networks

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    Direct network performance is affected by different design parameters which include number of virtual channels, number of ports, routing algorithm, switching technique, deadlock handling technique, packet size, and buffer size. Another factor that affects network performance is the traffic pattern. In this thesis, we study the effect of hotspot traffic on system performance. Specifically, we study the effect of hotspot factor, hotspot number, and hot spot location on the performance of mesh-based networks. Simulations are run on two network topologies, both the mesh and torus. We pay more attention to meshes because they are widely used in commercial machines. Comparisons between oblivious wormhole switching and chaotic packet switching are reported. Overall packet switching proved to be more efficient in terms of throughput when compared to wormhole switching. In the case of uniform random traffic, it is shown that the differences between chaotic and oblivious routing are indistinguishable. Networks with low number of hotspots show better performance. As the number of hotspots increases network latency tends to increase. It is shown that when the hotspot factor increases, performance of packet switching is better than that of wormhole switching. It is also shown that the location of hotspots affects network performance particularly with the oblivious routers since their achieved latencies proved to be more vulnerable to changes in the hotspot location. It is also shown that the smaller the size of the network the earlier network saturation occurs. Further, it is shown that the chaos router’s adaptivity is useful in this case. Finally, for tori, performance is not greatly affected by hotspot presence. This is mostly due to the symmetric nature of tori

    Effectiveness of Newly Introduced Variable Message Signs in Al-Khobar, Saudi Arabia

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    Recently, Variable Message Signs (VMS) were introduced in Saudi Arabia and their reliability under local environment is being tested. This paper aims to evaluate the possible response of the drivers to VMS when used for messages related to traffic conditions. A major arterial in Al-Khobar city in Saudi Arabia with a massive VMS board was selected for this paper. The evaluation process started by interviewing drivers selected randomly from the study area. About 77% of the interviewed drivers indicated positive attitude toward messages requesting change of route. The drivers’ interviews demonstrated statistical relationship between the degree of response to messages requesting change of route and the reason for such request. The maximum response was for messages related to accidents, roadwork activities, and traffic congestion. A field experiment was also conducted along the studied arterial. It was found that VMS statistically increased the percentage of diverted traffic during specific peak periods.</p

    α-Synuclein interacts directly but reversibly with psychosine: implications for α-synucleinopathies

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    Aggregation of α-synuclein, the hallmark of α-synucleinopathies such as Parkinson´s disease, occurs in various glycosphingolipidoses. Although α-synuclein aggregation correlates with deficiencies in the lysosomal degradation of glycosphingolipids (GSL), the mechanism(s) involved in this aggregation remains unclear. We previously described the aggregation of α-synuclein in Krabbe´s disease (KD), a neurodegenerative glycosphingolipidosis caused by lysosomal deficiency of galactosyl-ceramidase (GALC) and the accumulation of the GSL psychosine. Here, we used a multi-pronged approach including genetic, biophysical and biochemical techniques to determine the pathogenic contribution, reversibility, and molecular mechanism of aggregation of α-synuclein in KD. While genetic knock-out of α-synuclein reduces, but does not completely prevent, neurological signs in a mouse model of KD, genetic correction of GALC deficiency completely prevents α-synuclein aggregation. We show that psychosine forms hydrophilic clusters and binds the C-terminus of α-synuclein through its amino group and sugar moiety, suggesting that psychosine promotes an open/aggregation-prone conformation of α-synuclein. Dopamine and carbidopa reverse the structural changes of psychosine by mediating a closed/aggregation-resistant conformation of α-synuclein. Our results underscore the therapeutic potential of lysosomal correction and small molecules to reduce neuronal burden in α-synucleinopathies, and provide a mechanistic understanding of α-synuclein aggregation in glycosphingolipidoses.Fil: Abdelkarim, Hazem. University of Illinois; Estados UnidosFil: Marshall, Michael S.. University of Illinois; Estados UnidosFil: Scesa, Giuseppe. University of Illinois; Estados UnidosFil: Smith, Rachael A.. University of Illinois; Estados UnidosFil: Rue, Emily. University of Illinois; Estados UnidosFil: Marshall, Jeffrey. University of Illinois; Estados UnidosFil: Elackattu, Vince. University Of Illinois Chicago; Estados UnidosFil: Stoskute, Monika. University Of Illinois Chicago; Estados UnidosFil: Issa, Yazan. University Of Illinois Chicago; Estados UnidosFil: Santos, Marta. University Of Illinois Chicago; Estados UnidosFil: Nguyen, Duc. University Of Illinois Chicago; Estados UnidosFil: Hauck, Zane. University Of Illinois Chicago; Estados UnidosFil: Van Breemen, Richard B.. University Of Illinois Chicago; Estados UnidosFil: Celej, Maria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Gaponenko, Vadim. University Of Illinois Chicago; Estados UnidosFil: Bongarzone, Ernesto R.. University Of Illinois Chicago; Estados Unido

    Waning efficacy in a long-term AAV-mediated gene therapy study in the murine model of Krabbe disease

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    Neonatal AAV9-gene therapy of the lysosomal enzyme galactosylceramidase (GALC) significantly ameliorates central and peripheral neuropathology, prolongs survival, and largely normalizes motor deficits in Twitcher mice. Despite these therapeutic milestones, new observations identified the presence of multiple small focal demyelinating areas in the brain after 6-8 months. These lesions are in stark contrast to the diffuse, global demyelination that affects the brain of naive Twitcher mice. Late-onset lesions exhibited lysosomal alterations with reduced expression of GALC and increased psychosine levels. Furthermore, we found that lesions were closely associated with the extravasation of plasma fibrinogen and activation of the fibrinogen-BMP-SMAD-GFAP gliotic response. Extravasation of fibrinogen correlated with tight junction disruptions of the vasculature within the lesioned areas. The lesions were surrounded by normal appearing white matter. Our study shows that the dysregulation of therapeutic GALC was likely driven by the exhaustion of therapeutic AAV episomal DNA within the lesions, paralleling the presence of proliferating oligodendrocyte progenitors and glia. We believe that this is the first demonstration of diminishing expression in vivo from an AAV gene therapy vector with detrimental effects in the brain of a lysosomal storage disease animal model. The development of this phenotype linking localized loss of GALC activity with relapsing neuropathology in the adult brain of neonatally AAV-gene therapy-treated Twitcher mice identifies and alerts to possible late-onset reductions of AAV efficacy, with implications to other genetic leukodystrophies

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Barriers of Occupational Safety Implementation in Infrastructure Projects: Gaza Strip Case

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    Infrastructure projects are the foundation for essential public services and have an influential position in societal development. Although the role of infrastructure projects is substantial, they can involve complexities and safety issues that lead to an unsafe environment, and which impacts the project key stakeholders. Therefore, this study aimed to evaluate the barriers to implementing occupational safety in infrastructure projects in the Gaza Strip, which cause serious threats and reduce project performance. To evaluate the barriers, 39 items were highlighted and modified as per the construction context and environment, and which later were distributed in the form of a questionnaire, to get feedback from consultants and contractors. The analysis shows that in the safety policy barriers group, consultants and contractors both ranked the item “a contractor committed to an occupational safety program is not rewarded” first. In the management barriers group, consultants and contractors both ranked the item “safety engineer does not have significant powers, such as stopping work when needed” in the first place. In the behavior and culture barriers group, consultants and contractors both ranked the item “workers who are not committed to occupational safety are not excluded” in the first place. Overall, both consultants and contractors shared the same viewpoint in classifying the barriers in the working environment. The outcome of this study is beneficial for Palestinian construction industry policymakers, so they can monitor the highlighted barriers in on-going infrastructure projects and can modify the safety guidelines accordingly

    Amperometric Bioelectronic Tongue for glucose determination

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    An amperometric Bioelectronic Tongue is reported for glucose determination that contains eight sensor electrodes constructed using different metal electrodes (Pt, Au), oxidoreductase enzymes (glucose oxidase, ascorbate oxidase, uricase), and membrane coatings (Nafion, chitosan). The response to varying concentrations of glucose, ascorbic acid, uric acid, and acetaminophen was tested for two models, concentration determination by current density measurements at individual electrodes and concentration determination by a linear regression model for the entire electrode array. The reduced chi-squared for the full array model was found to be about one order of magnitude lower than that for the individual-electrode model. Discrimination of glucose from chemical interference by the other three species is accomplished through a combination of enzyme catalysis, metal electrocatalysis, and membrane surface charge. The benefit of incorporating enzyme electrodes into the sensor array is illustrated by the lower correlation coefficients between different enzyme electrodes relative to non-enzyme coated electrodes. This approach can be more generally applied to detection of other substrates of oxidoreductase enzymes

    Synthesis and Structure–Activity Relationships of 1-Aryl-β-carbolines as Affinity Probes for the 5-Hydroxytryptamine Receptor

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    Simple β-carbolines have been shown to bind several protein receptors that are important for signaling in the central nervous system. Herein, we expand our previous efforts into the synthesis and biological activity of these heterocycles by studying their neuropharmacological activity. A diverse set of 1-aryl-β-carbolines has been synthesized via Suzuki cross-coupling from a common triflate precursor and several substituted aryl boronic acids. The resulting 26-member library was subjected to primary screening at 10 μM for activity against 40 protein receptors implicated in brain signaling. The Ki was subsequently determined for several lead structures. The most potent activity, as low as 100 nM, was found against the 5-hydroxytryptamine subtype-2 family of receptors. In-depth structure–activity relationships for these synthetic β-carbolines have been developed, which point to the importance of a 3-indolyl substituent attached to the 1-position of the β-carboline and a 6-methoxy substituent on the β-carboline core
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