3,473 research outputs found

    Evaluating Security and Quality of Service Considerations in Critical Infrastructure Communication Networks

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    This thesis demonstrates the benefits of utility communication based on Internet technology, some dangers in using Internet technology in establishing a utility intranet connecting protection and control systems, and compares three different approaches to making reservations for routing traffic in the utility intranet based on different levels of background traffic. A model of expected background traffic on a national utility intranet is presented. The Utility Communication Architecture 2.0 and the International Electrotechnical Commission (IEC) 61850 began laying the groundwork in 2002 in establishing an infrastructure allowing power substations, program logic controllers, remote terminal units, intelligent electronic devices, and other devices to effectively and efficiently communicate over a utility intranet that is based on Internet standards using commercial of the shelf (COTS) components. This intranet will almost certainly be based on Internet standards due to their widespread use, low cost, and easy migration path over time. Even though itā€™s based on Internet technology the utility intranet will allow utilities to connect to one another without exposing them to threats from the Internet. This will provide utilities with the needed insight into other areas of the power grid enabling them to better manage its operation. The Electrical Power Communication Synchronization Simulator (EPOCHS) is used in this thesis to run simulations that models network traffic over a power infrastructure in order to show the effects of using different protocols, bandwidth reservations, and varying levels of background traffic will have on the quality of service of intranet traffic, with the end result of improving the insight the different regions of the utility intranet will have with each other. EPOCHS provides the required simulation environment needed to integrate a network simulator with an electromechanical power simulator to run the simulations. This research discusses the benefits of utility communication, the likely pitfalls in the use of Internet technology for protection and control systems, and technologies that can help mitigate those pitfalls. A total of 48 different simulation configurations are performed based on background traffic, reservation type, IP transport protocols, and routing scheme used to determine which configuration is best suited for use on a utility intranet

    PMCA2 silencing potentiates MDA-MB-231 breast cancer cell death initiated with the Bcl-2 inhibitor ABT-263

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    PMCA2 overexpression in some breast cancers suggests that this calcium pump isoform may play a role in breast pathophysiology. To investigate PMCA2 as a potential drug target for breast cancer therapy, we assessed the functional consequence of PMCA2 silencing on cell death pathways and calcium signals in the basal-like MDA-MB-231 breast cancer cell line. Silencing PMCA2 expression alone has no effect on MDA-MB-231 cell viability, however, PMCA2 silencing promotes calcium-induced cell death initiated with the calcium ionophore ionomycin. Assessment of cytoplasmic calcium responses generated with various agents including ionomycin demonstrates that in MDA-MB-231 cells, PMCA2 does not play a major role in shaping global calcium signals. We also examined the ability of PMCA2 silencing to modulate caspase-dependent cell death triggered by a Bcl-2 inhibitor that is in clinical development for the treatment of various cancers, ABT-263 (Navitoclax). Despite the lack of effect on global calcium responses, PMCA2 silencing augmented Bcl-2 inhibitor (ABT-263)-mediated MDA-MB-231 breast cancer cell death. These studies provide evidence that PMCA2 inhibitors could sensitize PMCA2-positive breast cancers to cell death initiators that work through mechanisms involving the Bcl-2 survival pathway

    Self-critical thinking and overgeneralisation in depression and eating disorders:An experimental study

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    Background: Self-critical thinking is common across psychological disorders. This study hypothesized that it may play an important role in ā€˜overgeneralizationā€™, the process of drawing general implications from an isolated negative experience. Aims: To explore the impact of two experimental tasks designed to elicit self-critical thoughts on the endorsement of general negative self-views of clinical and non-clinical populations. Method: Three groups (depression, eating disorders and non-clinical controls), completed standardized questionnaires and the two tasks. Participants rated their self-critical thinking and general negative self-beliefs before and after each task. Results: Following a failure experience, both clinical groups showed a greater increase in general negative self-views compared with controls, indicating greater overgeneralization. Both habitual and increases in state self-critical thinking were associated with overgeneralization while negative perfectionism was not. Overgeneralization was more strongly associated with post-task reduced mood than self-criticism. Conclusions: Self-critical thinking may be an important factor in the process of overgeneralization, and the increase in general negative self-views may be particularly crucial for lowering of mood

    Development of a Case Study Problem in Engineering Economics Based on a Telephone Replacement Undertaking at UW-Platteville

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    General Engineering 2820 (GE 2820) is a course offered to all undergraduate students at the College of Engineering, Mathematics, and Science (EMS), University of Wisconsin ā€“Platteville. A constant exercise for the instructors in this course is to update the course material with interesting case study problems which are then solved by students as an assignment. In recent days, the University of Wisconsin ā€“Platteville, is contemplating replacement of its current Voice over IP (VoIP) phone service (catered by the local utility company ā€œCentury Linkā€) with a ā€œUnified Communicationsā€ service. Current services cost the university 18,900permonth.Withthenewsystembeingcontemplatedandthesincetheuniversityhasnecessaryinfrastructureinplace,thecostfortheuniversityisestimatedtobeapproximately18,900 per month. With the new system being contemplated and the since the university has necessary infrastructure in place, the cost for the university is estimated to be approximately 7000 per month. Therefore, a breakeven analysis was undertaken for studying the economic feasibility of this undertaking by the students in this course. Part of this case study involved ā€“ defining the problem correctly, processing the interest rate data so as to calculate an appropriate effective annual rate, processing the financial data related to the phone services, and finally performing a breakeven study using the annual worth computation. Based on student performances, such case study problems have benefited the students in understanding the concepts of time value of money and various method of analysis in engineering economy

    Alcohol consumption and leukocyte telomere length.

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    The relationship between alcohol consumption and mortality generally exhibits a U-shaped curve. The longevity observed with moderate alcohol consumption may be explained by other confounding factors, and, if such a relationship is present, the mechanism is not well understood. Indeed, the optimal amount of alcohol consumption for health has yet to be determined. Leukocyte telomere length is an emerging quantifiable marker of biological age and health, and a shorter telomere length is a predictor of increased mortality. Because leukocyte telomere length is a quantifiable and objectively measurable biomarker of aging, we sought to identify the amount of alcohol consumption associated with the longest telomere length and least telomere length attrition. Among over 2,000 participants from two distinct cohort studies, we found no pattern of alcohol consumption that was associated with longer telomere length or less telomere length attrition over time. Binge drinking may reduce telomere length. Using telomere length as a marker of age and health, these data fail to demonstrate any benefits of alcohol consumption, even when consumed in moderation

    The Ī¼ opioid agonist morphine modulates potentiation of capsaicin-evoked TRPV1 responses through a cyclic AMP-dependent protein kinase A pathway

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    BACKGROUND: The vanilloid receptor 1 (TRPV1) is critical in the development of inflammatory hyperalgesia. Several receptors including G-protein coupled prostaglandin receptors have been reported to functionally interact with the TRPV1 through a cAMP-dependent protein kinase A (PKA) pathway to potentiate TRPV1-mediated capsaicin responses. Such regulation may have significance in inflammatory pain. However, few functional receptor interactions that inhibit PKA-mediated potentiation of TRPV1 responses have been described. RESULTS: In the present studies we investigated the hypothesis that the Ī¼ opioid receptor (MOP) agonist morphine can modulate forskolin-potentiated capsaicin responses through a cAMP-dependent PKA pathway. HEK293 cells were stably transfected with TRPV1 and MOP, and calcium (Ca(2+)) responses to injection of the TRPV1 agonist capsaicin were monitored in Fluo-3-loaded cells. Pre-treatment with morphine did not inhibit unpotentiated capsaicin-induced Ca(2+ )responses but significantly altered capsaicin responses potentiated by forskolin. TRPV1-mediated Ca(2+ )responses potentiated by the direct PKA activator 8-Br-cAMP and the PKC activator Phorbol-12-myristate-13-acetatewere not modulated by morphine. Immunohistochemical studies confirmed that the TRPV1 and MOP are co-expressed on cultured Dorsal Root Ganglion neurones, pointing towards the existence of a functional relationship between the G-protein coupled MOP and nociceptive TRPV1. CONCLUSION: The results presented here indicate that the opioid receptor agonist morphine acts via inhibition of adenylate cyclase to inhibit PKA-potentiated TRPV1 responses. Targeting of peripheral opioid receptors may therefore have therapeutic potential as an intervention to prevent potentiation of TRPV1 responses through the PKA pathway in inflammation

    Differential effects of two-pore channel protein 1 and 2 silencing in MDA-MB-468 breast cancer cells

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    Two-pore channel proteins, TPC1 and TPC2, are calcium permeable ion channels found localized to the membranes of endolysosomal calcium stores. There is increasing interest in the role of TPC-mediated intracellular signaling in various pathologies; however their role in breast cancer has not been extensively evaluated. TPC1 and TPC2 mRNA was present in all non-tumorigenic and tumorigenic breast cell lines assessed. Silencing of TPC2 but not TPC1 attenuated epidermal growth factor-induced vimentin expression in MDA-MB-468 breast cancer cells. This effect was not due to a general inhibition of epithelial to mesenchymal transition (EMT) as TPC2 silencing had no effect on epidermal growth factor (EGF)-induced changes on E-cadherin expression. TPC1 and TPC2 were also shown to differentially regulate cyclopiazonic acid (CPA)-mediated changes in cytosolic free Ca. These findings indicate potential differential regulation of signaling processes by TPC1 and TPC2 in breast cancer cells

    p-Wave holographic superconductors with Weyl corrections

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    We study the (3+1) dimensional p-wave holographic superconductors with Weyl corrections both numerically and analytically. We describe numerically the behavior of critical temperature TcT_{c} with respect to charge density Ļ\rho in a limited range of Weyl coupling parameter Ī³\gamma and we find in general the condensation becomes harder with the increase of parameter Ī³\gamma. In strong coupling limit of Yang-Mills theory, we show that the minimum value of TcT_{c} obtained from analytical approach is in good agreement with the numerical results, and finally show how we got remarkably a similar result in the critical exponent 1/2 of the chemical potential Ī¼\mu and the order parameter with the numerical curves of superconductors.Comment: 7 pages, 1 figure, 1 table. One refrence added, presentations improve

    Consequences of activating the calcium-permeable ion channel TRPV1 in breast cancer cells with regulated TRPV1 expression

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    Increased expression of specific calcium channels in some cancers and the role of calcium signaling in proliferation and invasion have led to studies assessing calcium channel inhibitors as potential therapies for some cancers. The use of channel activators to promote death of cancer cells has been suggested, but the risk of activators promoting cancer cell proliferation and the importance of the degree of channel over-expression is unclear. We developed an MCF-7 breast cancer cell line with inducible TRPV1 overexpression and assessed the role of TRPV1 levels on cell death mediated by the TRPV1 activator capsaicin and the potential for submaximal activation to promote proliferation. The TRPV1 level was a determinant of cell death induced by capsaicin. A concentration response curve with varying TRPV1 expression levels identified the minimum level of TRPV1 required for capsaicin induced cell death. At no level of TRPV1 over-expression or capsaicin concentration did TRPV1 activation enhance proliferation. Cell death induced by capsaicin was necrotic and associated with up-regulation of c-Fos and RIP3. These studies suggest that activators of specific calcium channels may be an effective way to induce necrosis and that this approach may not always be associated with enhancement of cancer cell proliferation
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