Neutral Strategy Research Articles

Simple three-level neutral point voltage balance control strategy based on SVPWM

Abstract The unbalance of the neutral point voltage is an inherent problem of three-level neutral-point-clamped (NPC) inverter, the effect of neutral point voltage balancing which is caused by voltage vector is analyzed, and the relationship of the voltage offset and neutral point voltage is studied in this paper. This paper proposes a novel neutral point balance strategy for three-level NPC inverter based on space vector pulse width modulation (SVPWM). A voltage offset is added to the modulation wave, and a closed-loop neutral point voltage balance control system is designed. In the control system, the dwelling time of synthesis voltage vectors for SVPWM is varied to solve the problem of the unbalance of the neutral point voltage, the sequence of the voltage vectors maintains unchanging. Simulation and experimental results show the neutral point voltage balancing control strategy based on SVPWM is effective.

Using Maximum Drawdowns to Capture Tail Risk

We propose the use of maximum drawdown, the maximum peak to trough loss across a time series of compounded returns, as a simple method to capture an element of risk unnoticed by linear factor models: tail risk. Unlike other tail-risk metrics, maximum drawdown is intuitive and easy-to-calculate. We look at maximum drawdowns to assess tail risks associated with market neutral strategies identified in the academic literature. Our evidence suggests that academic anomalies are not anomalous: all strategies endure large drawdowns at some point in the time series. Many of these losses would trigger margin calls and investor withdrawals, forcing an investor to liquidate.

Hidden substance: mental disorder as a challenge to normatively neutral accounts of autonomy

AbstractMental capacity and autonomy are often understood to be normatively neutral – the only values or other norms they may presuppose are those the assessed person does or would accept. We show how mental disorder threatens normatively neutral accounts of autonomy. These accounts produce false positives, particularly in the case of disorders (such as depression, anorexia nervosa and schizophrenia) that affect evaluative abilities. Two normatively neutral strategies for handling autonomy-undermining disorder are explored and rejected: a blanket exclusion of mental disorder, and functional tests requiring consistency, expression of identity, reflective non-alienation or lack of compulsion. Finally, we suggest ways in which substantivist alternatives to neutrality can be made more promising through increased transparency, democratic contestability of conditions for capacity and autonomy, and a historically sensitive caution concerning restrictions of liberty.

Multipotent stromal cells skew monocytes towards an anti-inflammatory interleukin-10-producing phenotype by production of interleukin-6

Multipotent stromal cells have immunomodulatory capacities and have been used in transplantation and autoimmune diseases. One of the effects of multipotent stromal cells involves the inhibition of dendritic cell differentiation. Since interleukin-6 and interleukin-10 are known to play a role in inhibiting immature dendritic cell differentiation, we hypothesized that these cytokines may also mediate the inhibitory effect of human multipotent stromal cells in immature dendritic cell differentiation. In order to test this hypothesis monocytes were cultured with interleukin-4 and granulocyte-monocyte colony-stimulating factor in the presence or absence of culture-expanded bone marrow-derived multipotent stromal cells. Neutralization and cytokine-depletion strategies were applied to reveal the cellular source and effect of interleukin-6 and interleukin-10. Addition of multipotent stromal cells to monocyte cultures significantly reduced the generation of immature dendritic cells (CD14(-)CD1a(+)) and resulted in the generation of CD14(+)CD1a(-) cells that displayed a significantly reduced immunostimulatory effect. We found that culture supernatants of co-cultures of multipotent stromal cells and monocytes contained higher concentrations of interleukin-6 and interleukin-10. Multipotent stromal cells produced interleukin-6 and neutralizing this interleukin-6 reversed the inhibitory effect of the multipotent cells. Interleukin-10 was not produced by multipotent stromal cells, but exclusively by monocytes after exposure to multipotent stromal cell-produced interleukin-6. In conclusion, through constitutive production of interleukin-6, multipotent stromal cells prevent the differentiation of monocytes towards antigen-presenting immunogenic cells and skew differentiation towards an anti-inflammatory interleukin-10-producing cell type.

Optimal Convergence Trade Strategies

Convergence trades exploit temporary mispricing by simultaneously buying relatively underpriced assets and selling short relatively overpriced assets. This paper studies optimal convergence trades under both recurring and nonrecurring arbitrage opportunities represented by continuing and stopped cointegrated price processes and considers both fixed and stochastic (Poisson) horizons. Conventional long-short delta neutral strategies are generally suboptimal and it can be optimal to simultaneously go long (or short) in two mispriced assets. Optimal portfolio holdings critically depend on whether the risky asset position is liquidated when prices converge. Our theoretical results are illustrated on pairs of Chinese bank shares traded on both the Hong Kong and China stock exchanges. The Author 2013. Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com., Oxford University Press.

A novel neutral current control scheme for three-phase four-wire distribution transformers

The neutral current can significantly harm the operation of a system, increase the losses of distribution transformers, and reduce the energy efficiency of a system. These negative effects of the neutral current highlight the importance and necessity of investigating neutral current control strategies. In this paper, we propose a novel scheme for controlling the neutral current caused by a linear unbalanced load in three-phase four-wire distribution transformers. The scheme, which is based on the static var compensator (SVC) technology, aims to: (i) control the neutral current, and (ii) reduce distribution transformer losses. It takes into account the effects of unbalanced fundamental currents and the SVC's compensating capability. Combining optimisation theory with a sequential quadratic programming method, we derive the optimal solution for the current control scenario we studied in this work. Simulation results show that our neutral current control scheme can significantly reduce the neutral current and distribution transformer losses. We also present some interesting observations on the SVC's capability and its significant impact on the neutral current and energy efficiency of a system. We hope that our work will encourage future research on SVC-based neutral current control approaches. © Institution of Engineers Australia, 2013.

A Novel Neutral Current Control Scheme for Three-Phase Four-Wire Distribution Transformers

The neutral current can significantly harm the operation of a system, increase the losses of distribution transformers, and reduce the energy efficiency of a system. These negative effects of the neutral current highlight the importance and necessity of investigating neutral current control strategies. In this paper, we propose a novel scheme for controlling the neutral current caused by a linear unbalanced load in three-phase four-wire distribution transformers. The scheme, which is based on the static var compensator (SVC) technology, aims to: (i) control the neutral current, and (ii) reduce distribution transformer losses. It takes into account the effects of unbalanced fundamental currents and the SVC’s compensating capability. Combining optimisation theory with a sequential quadratic programming method, we derive the optimal solution for the current control scenario we studied in this work. Simulation results show that our neutral current control scheme can significantly reduce the neutral current and distribution transformer losses. We also present some interesting observations on the SVC’s capability and its significant impact on the neutral current and energy efficiency of a system. We hope that our work will encourage future research on SVC-based neutral current control approaches.

Exploiting Market Integration for Pure Alpha Investments via Probabilistic Principal Factors Analysis

In this paper, a long-short beta neutral portfolio strategy is proposed based on earnings yields forecasts, where positions are modified by accounting for time-varying risk budgeting by employing an appropriate integration measure. In contrast to previous works, which primarily rely on a standard principal component analysis (PCA), here we exploit the advantages of a probabilistic PCA (PPCA) framework to extract the factors to be used for designing an efficient integration measure, as well as relating these factors to an asset-pricing model. Our experimental evaluation with a dataset of 12 developed equity market indexes reveals certain improvements of our proposed approach, in terms of an increased representation capability of the underlying principal factors, along with an increased robustness to noisy and/or missing data in the original dataset.

Neutral Fragment Filtering for Rapid Identification of New Diester-Diterpenoid Alkaloids in Roots of Aconitum carmichaeli by Ultra-High-Pressure Liquid Chromatography Coupled with Linear Ion Trap-Orbitrap Mass Spectrometry

A rapid and effective method was developed for separation and identification of diester-diterpenoid alkaloids (DDA) in the roots of Aconitum carmichaeli by ultra-high-pressure liquid chromatography coupled with high resolution LTQ-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MSn). According to accurate mass measurement and the characteristic neutral loss filtering strategy, a total of 42 diester-diterpenoid alkaloids (DDA) were rapidly detected and characterized or tentatively identified. Meanwhile, the proposed fragmentation pathways and the major diagnostic fragment ions of aconitine, mesaconitine and hypaconitine were investigated to trace DDA derivatives in crude plant extracts. 23 potential new compounds were successfully screened and characterized in Aconitum carmichaeli, including 16 short chain fatty acyls DDA, 4 N-dealkyl DDA and several isomers of aconitine, mesaconitine and hypaconitine.

The Immune “Combination Therapy” of Leukemia Using Adoptive Transfer and TGF-β Blockade.

AbstractAbstract 3017The immunosuppressive cytokine Transforming Growth factor-beta (TGF-β), either tumor or T cell-derived, can significantly alter T-dependent immune responses to tumors in mouse models. However, the role of TGF-β neutralization on other cell types of the tumor microenvironment and the ensuing impact on immunotherapies is still unclear. Moreover, pre-clinical models aimed at harnessing the likely synergy between TGF- β signaling blockade and immunotherapy are lacking. Using the TGF- β producing, acute lymphoblastic leukemia/lymphoma cell line EL4, we undertook to characterize how TGF-β affects the leukemic microenvironment and the outcome of adoptive immunotherapy. After inoculation, EL4 cells form large tumor masses that attract a wide variety of leukocytes, including mono-myeloid cells and T lymphocytes (5–10% of tumor cellularity). In order to assess whether TGF-β contributed to shape the leukemic microenvironment, we administered the pan anti-TGF-β antibody 1D11 or isotype control to EL4 bearing mice. Antibodies were administered after leukemic cell inoculation for a period of three weeks (300 μg three times a week). The systemic administration of 1D11 altered the EL-4 leukemia microenvironment. Notably, the concentration of inflammatory cytokines IL-2, GM-CSF and MIP-1α increased along with a trend in the abundance of CD44 positive CD4 T cells and myeloid cells infiltrating the tumors. However, the administration of anti-TGF-β antibody failed to alter tumor growth kinetics or vasculogenesis. These results 1) imply that the mobilization of immune effectors cells following TGF-β neutralization is insufficient and 2) correlate with our in vitro data which showed that TGF-β blockade have no impact on EL4 cells growth and apoptosis. Although insufficient by itself, could the use of TGF-β neutralizing strategies nonetheless improve the outcome of cancer immunotherapies? In order to investigate how inhibition of TGF-β signaling in the microenvironment can alter the outcome of adoptive immunotherapy, we designed an autologous adoptive immunotherapy model of leukemia. We have generated specific anti-EL4 responses using a vaccination and an in vitro restimulation system. Following in vitro stimulation with EL4 cells vs. splenocyte lysate, T cell effectors induced 34.42 % and 4.3% specific lysis respectively against EL4 targets. The injection of these effectors in sub-lethally irradiated leukemia bearing syngeneic hosts led to 50% survival at 120 days post adoptive transfer (n=6) compared to 0% survival in unprimed host. In order to assess whether concomitant TGF-β blockade improves this response, we are currently testing the in vivo efficacy of our strategy in the context of TGF-β neutralization in terms of survival and leukemia infiltration by T cells. The possibility to harness the combined effects of TGF- β signaling blockade and current immunotherapeutic approaches has immediate translational relevance given the numerous anti-TGF modalities currently being developed. Disclosures:No relevant conflicts of interest to declare.

Neutrality of equity market neutral strategy to period and index

This study examines the performance of equity market neutral (EMN) hedge funds by estimating alpha and beta, using monthly excess returns of the Fidelity Investments Spartan® US Bond Index Fund, the S&P 500 index and two indices of EMN strategies. The study investigates how much exposure to systematic risk is experienced by EMN hedge funds and hence by the investors in such funds. In addition, the article ascertains the stability of the estimated betas of EMN hedge fund indices. Results show that EMN fund indices had no systematic (stock and bond market) risk before the subprime mortgage crises of 2008. During the crises, the DJ Credit Suisse EMN index showed a positive beta in excess of 0.4, yet the Greenwich Van Hedge EMN index showed a beta less than 0.1. Similarly, the DJ Credit Suisse EMN index had no bond market beta up until November 2008. The Greenwich Van Hedge EMN index had almost no exposure to the market. The results were sensitive to market conditions and the EMN index. DJCS and GVH both had positive stock market alphas, which turned insignificant around October 2008. Similarly, both indices had positive bond market alphas, which turned insignificant around August–November 2008.

European Equity Pairs Trading: The Effect of Data Frequency on Risk and Return

This article examines an equity pairs trading strategy using daily, weekly and monthly European share price data over the period 1998–2007. The authors shows that when stocks are matched into pairs with minimum distance between normalised historical prices, a simple trading rule based on volatility between these prices yields annualised raw returns of up to 15% for the weekly data frequency. Bootstrap results suggest returns from the strategy are attributable to skill rather than luck, while insignificant beta coefficients provide evidence that this is a market neutral strategy. Resistance of the strategy’s returns to reversal factors suggest pairs trading is fundamentally different to previously documented reversal strategies based on concepts such as mean reversion.

O033 Ligand-independent blockade of TLR4 activation represents a promising strategy to protect from inflammatory disease pathogenesis in islet-transplantation

Introduction Dysregulation of Toll-like receptor 4 (TLR4) signaling via numerous exogenous and endogenous ligands appears to play an underlying role in the pathogenesis of multiple inflammatory diseases. Since multiple TLR4 ligands may be upregulated in a single disease condition, blockade of TLR4 activation via a ligand-independent mechanism is an attractive strategy for disease intervention. A ligand-independent anti-TLR4 neutralizing antibody evaluated as a novel strategy for TLR4 neutralization. Methods An anti-human TLR4 mAb, NI-0101, was generated and shown to bind to human TLR4 in a region involved in receptor dimerization. Using exogenous, endogenous or chemical ligands, the capacity to block TLR4 activation was evaluated. Subsequently, NI-0101 was tested in islet-induced immune cell activation. Furthermore, the corresponding mouse surrogate antibody was tested in a laboratory model of islet transplantation. Results Due to inhibition of TLR4 dimerization, NI-0101 efficiently blocked the activation of TLR4 by different ligands. Consistent with its ligand-independent mechanism of action, a similar inhibitory potency of NI-0101 was observed at different concentrations of the activating ligand. In addition, NI-0101 could block human islet-induced human immune cell activation, further confirming the ability of NI-0101 to block TLR4 activation independently of the ligand. To determine the effects of NI-0101 in vivo , we used the mouse surrogate antibody of NI-0101, 5E3. 5E3 effectively protected grafted islets in a mouse model of islet transplantation. Conclusion The therapeutic anti-human TLR4 mAb, NI-0101, has the capacity to interfere with not only LPS but also signaling of TLR4 through endogenous and chemical ligands. When used in an in vitro model of islet-induced immune cell activation, NI-0101 blocked immune cell activation. Furthermore, we demonstrated that anti-TLR4 mAb is efficient in protecting grafted islets in a mouse islet transplantation model. Taken together, these data promote ligand-independent blockade of TLR4 activation as a promising strategy in blocking disease pathogenesis.

ChemInform Abstract: Ruthenium‐Catalyzed Isoquinolone Synthesis Through C—H Activation Using an Oxidizing Directing Group.

AbstractThe redox neutral strategy circumvents the use of wasteful metal oxidants and leads to a clean process.

Consolidation of a WSN and Minimax Method to Rapidly Neutralise Intruders in Strategic Installations

Due to the sensitive international situation caused by still-recent terrorist attacks, there is a common need to protect the safety of large spaces such as government buildings, airports and power stations. To address this problem, developments in several research fields, such as video and cognitive audio, decision support systems, human interface, computer architecture, communications networks and communications security, should be integrated with the goal of achieving advanced security systems capable of checking all of the specified requirements and spanning the gap that presently exists in the current market. This paper describes the implementation of a decision system for crisis management in infrastructural building security. Specifically, it describes the implementation of a decision system in the management of building intrusions. The positions of the unidentified persons are reported with the help of a Wireless Sensor Network (WSN). The goal is to achieve an intelligent system capable of making the best decision in real time in order to quickly neutralise one or more intruders who threaten strategic installations. It is assumed that the intruders’ behaviour is inferred through sequences of sensors’ activations and their fusion. This article presents a general approach to selecting the optimum operation from the available neutralisation strategies based on a Minimax algorithm. The distances among different scenario elements will be used to measure the risk of the scene, so a path planning technique will be integrated in order to attain a good performance. Different actions to be executed over the elements of the scene such as moving a guard, blocking a door or turning on an alarm will be used to neutralise the crisis. This set of actions executed to stop the crisis is known as the neutralisation strategy. Finally, the system has been tested in simulations of real situations, and the results have been evaluated according to the final state of the intruders. In 86.5% of the cases, the system achieved the capture of the intruders, and in 59.25% of the cases, they were intercepted before they reached their objective.

Carbon Remediation for the Airline Industry via ATF Drop-in Substitution: Strategic and Operational Perspective

The need to address environmental challenges by aviation industry is apparently obvious. As evidenced within the industry, it takes a three pronged strategy - more efficient aircraft, improving operational efficiencies and development of sustainable biofuels. In terms of actual growth of airline business, the two major drivers are domestic air service expansion within BRIC economies and rapid spread of Low Cost Carrier (LLC) models. Focusing not only on environmental challenges, even sustainable business development and growth of LCC depends critically on ATF substitution by alternative fuels. The inherent need for carbon subsidy and airline-airport partnership towards sustainable substitution with bio-alternatives is discussed in first part of the paper. A framework for such an airline airport win-win partnership is delineated. In the second half of the paper, focus shifts to complexity of operationalisation of blended ATF strategy for airlines as well as manufacturer from a sophisticated operational safety and liability perspective. The need for aircraft manufacturer and airline cum airport partnerships for globally acceptable and operational safety for partial drop-in substitution on the lines of biofuel certification standardisation and usability is examined. The authors highlight that carbon neutral strategy by aviation industry is not just critical in terms of environmental dimension but as would be evidenced in the coming decades critical in terms of capitalistic interests as well. © 2012 SAE International.

Passive Immune Neutralization Strategies for Prevention and Control of Influenza A Infections

Although vaccination significantly reduces influenza severity, seasonal human influenza epidemics still cause more than 250,000 deaths annually. Vaccine efficacy is limited in high-risk populations such as infants, the elderly and immunosuppressed individuals. In the event of an influenza pandemic (such as the 2009 H1N1 pandemic), a significant delay in vaccine availability represents a significant public health concern, particularly in high-risk groups. The increasing emergence of strains resistant to the two major anti-influenza drugs, adamantanes and neuraminidase inhibitors, and the continuous circulation of avian influenza viruses with pandemic potential in poultry, strongly calls for alternative prophylactic and treatment options. In this review, we focus on passive virus neutralization strategies for the prevention and control of influenza type A viruses.

TNF blockade requires 1,25(OH)2D3 to control human Th17-mediated synovial inflammation

ObjectivesT helper 17 (Th17) cells from patients with early rheumatoid arthritis (RA) induce a proinflammatory feedback loop upon RA synovial fibroblast (RASF) interaction, including autocrine interleukin (IL)-17A production. A major...

Supervision practices in specialty mental health probation: What happens in officer–probationer meetings?

As the correctional population continues to increase, probation agencies struggle to adequately supervise offenders with unique needs, including those with mental disorder. Although more than 100 U.S. probation agencies have implemented specialty mental health case-loads, little is known about their practices. Based on detailed observations of 83 audio-taped meetings, we examined interactions between probationers and officers in a prototypic specialty agency, focusing on the extent to which practices comport with evidence-based risk reduction principles. We found that specialty officers (a) more frequently discussed probationers' general mental health than any individual criminogenic need, (b) chiefly questioned, directed, affirmed, and supported (rather than confronted) probationers, and (c) relied more heavily on neutral strategies and positive pressures (e.g., inducements) rather than negative pressures (e.g., threats of incarceration) to monitor and enforce compliance. Implications for "what works" to promote community integration for probationers with mental disorder are discussed.

Annexin A1 N-Terminal Derived Peptide Ac2-26 Exerts Chemokinetic Effects on Human Neutrophils

It is postulated that peptides derived from the N-terminal region of Annexin A1, a glucocorticoid-regulated 37-kDa protein, could act as biomimetics of the parent protein. However, recent evidence, amongst which the ability to interact with distinct receptors other then that described for Annexin A1, suggest that these peptides might fulfill other functions at variance to those reported for the parent protein. Here we tested the ability of peptide Ac2-26 to induce chemotaxis of human neutrophils, showing that this peptide can elicit responses comparable to those produced by the canonical activator formyl-Met-Leu-Phe (or FMLP). However, whilst disruption of the chemical gradient abolished the FMLP response, addition of peptide Ac2-26 in the top well of the chemotaxis chamber did not affect (10 μM) or augmented (at 30 μM) the neutrophil locomotion to the bottom well, as elicited by 10 μM peptide Ac2-26. Intriguingly, the sole addition of peptide Ac2-26 in the top wells produced a marked migration of neutrophils. A similar behavior was observed when human primary monocytes were used. Thus, peptide Ac2-26 is a genuine chemokinetic agent toward human blood leukocytes. Neutralization strategies indicated that engagement of either the GPCR termed FPR1 or its cognate receptor FPR2/ALX was sufficient to sustain peptide Ac2-26 induced neutrophil migration. Similarly, application of pharmacological inhibitors showed that cell locomotion to peptide Ac2-26 was mediated primarily by the ERK, but not the JNK and p38 pathways. In conclusion, we report here novel in vitro properties for peptide Ac2-26, promoting neutrophil and monocyte chemokinesis; a process that may contribute to accelerate the resolution phase of inflammation. We postulate that the generation of Annexin A1 N-terminal peptides at the site of inflammation may expedite the egress of migrated leukocytes thus promoting the return to homeostasis.