Modulated model predictive control with optimized overmodulation

Finite Set Model Predictive Control (FS-MPC) has many advantages, such as a fast dynamic response and an intuitive implementation. For these reasons, it has been thoroughly researched during the last decade. However, the wave form produced by FS-MPC has a switching component whose spread spectrum remains a major disadvantage of the strategy. This paper discusses a modulated model predictive control that guarantees a spectrum switching frequency in the linear modulation range and extends its optimized response to the overmodulation region. Due to the equivalent high gain of the predictive control, and to the limit on the voltage actuation of the power converter, it is expected that the actuation voltage will enter the overmodulation region during large reference changes or in response to load impacts. An optimized overmodulation strategy that converges towards FS-MPC’s response for large tracking errors is proposed for this situation. This technique seamlessly combines PWM’s good steadystate switching performance with FS-MPC’s high dynamic response during large transients. The constant switching frequency is achieved by incorporating modulation of the predicted current vectors in the model predictive control of the currents in a similar fashion as conventional Space-Vector Pulse Width Modulation (SV-PWM) is used to synthesize an arbitrary voltage reference. Experimental results showing the proposed strategy’s good steady-state switching performance, its FS-MPC-like transient response and the seamless transition between modes of operation are presented for a permanent magnet synchronous machine drive

Investigation of Changing Pore Topology and Porosity during Matrix Acidizing using Different Chelating Agents

Core flooding acidizing experiments on sandstone/carbonate formation are usually performed in the laboratory to observe different physical phenomena and to design acidizing stimulation jobs for the field. During the tests, some key parameters are analyzed such as pore volume required for breakthrough as well as pressure. Hydrochloric acid (HCl) is commonly used in the carbonate matrix acidizing while Mud acid (HF: HCl) is usually applied during the sandstone acidizing to remove damage around the well bore. However, many problems are associated with the application of these acids, such as fast reaction, corrosion and incompatibility of HCl with some minerals (illite). To overcome these problems, chelating agents (HEDTA, EDTA and GLDA) were used in this research. Colton tight sandstone and Guelph Dolomite core samples were used in this study. The experiments usually are defined in terms of porosity, permeability, dissolution and pore topology. Effluent samples were analyzed to determine dissolved iron, sodium, potassium, calcium and other positive ions using Inductively Coupled Plasma (ICP). Meanwhile Nuclear Magnetic Resonance (NMR) was employed to determine porosity and pore structure of the core sample. Core flood experiments on Berea sandstone cores and dolomite samples with dimensions of 1.5 in × 3 in were conducted at a flow rate of 1 cc/min under 150oF temperature. NMR and porosity analysis concluded that applied chemicals are effective in creating fresh pore spaces. ICP analysis concluded that HEDTA showed good ability to chelate calcium, sodium, magnesium, potassium and iron. It can be established from the analysis that HEDTA can increase more amount of permeability as compared to other chelates

Goal Orientations among Yarmouk University Students and their Relationship with Self- Regulated Learning

This study aimed at exploring the relationship of goal orientations with self-regulated learning among Yarmouk University students in light of faculty and gender. The sample of the study consisted of 684 students. Two scales were used: a goal orientations scale, and aself-regulated learning scale. The results showed statisticallysignificant differences in the means of participants' scores on the goal orientation scales due to the student gender in mastery goals, and performance-avoidance goals; females scored higher on these subscales than males. No significant gender difference was found in performance-approach goals. The results also showed significant differences in the means scores on the self-regulated learning scale due to gender; females once again scored higher than males on all skills, except for the planning and goal specification skill. No significant difference, however, was found in self-regulated learning due tostudent faculty or the interaction between faculty and gender

The Global Alliance for Infections in Surgery: Defining a Model for Antimicrobial Stewardship-Results From an International Cross-Sectional Survey

BACKGROUND: Antimicrobial Stewardship Programs (ASPs) have been promoted to optimize antimicrobial usage and patient outcomes, and to reduce the emergence of antimicrobial-resistant organisms. However, the best strategies for an ASP are not definitively established and are likely to vary based on local culture, policy, and routine clinical practice, and probably limited resources in middle-income countries. The aim of this study is to evaluate structures and resources of antimicrobial stewardship teams (ASTs) in surgical departments from different regions of the world. METHODS: A cross-sectional web-based survey was conducted in 2016 on 173 physicians who participated in the AGORA (Antimicrobials: A Global Alliance for Optimizing their Rational Use in Intra-Abdominal Infections) project and on 658 international experts in the fields of ASPs, infection control, and infections in surgery. RESULTS: The response rate was 19.4%. One hundred fifty-six (98.7%) participants stated their hospital had a multidisciplinary AST. The median number of physicians working inside the team was five [interquartile range 4-6]. An infectious disease specialist, a microbiologist and an infection control specialist were, respectively, present in 80.1, 76.3, and 67.9% of the ASTs. A surgeon was a component in 59.0% of cases and was significantly more likely to be present in university hospitals (89.5%, p \u3c 0.05) compared to community teaching (83.3%) and community hospitals (66.7%). Protocols for pre-operative prophylaxis and for antimicrobial treatment of surgical infections were respectively implemented in 96.2 and 82.3% of the hospitals. The majority of the surgical departments implemented both persuasive and restrictive interventions (72.8%). The most common types of interventions in surgical departments were dissemination of educational materials (62.5%), expert approval (61.0%), audit and feedback (55.1%), educational outreach (53.7%), and compulsory order forms (51.5%). CONCLUSION: The survey showed a heterogeneous organization of ASPs worldwide, demonstrating the necessity of a multidisciplinary and collaborative approach in the battle against antimicrobial resistance in surgical infections, and the importance of educational efforts towards this goal

Biofilm Formation by Borrelia Burgdorferi Sensu Lato

Bacterial biofilms are microbial communities held together by an extracellular polymeric substance matrix predominantly composed of polysaccharides, proteins and nucleic acids. We had previously shown that Borrelia burgdorferi sensu stricto, the causative organism of Lyme disease in the United States is capable of forming biofilms in vitro. Here, we investigated biofilm formation by B. afzelii and B. garinii, which cause Lyme disease in Europe. Using various histochemistry and microscopy techniques, we show that B. afzelii and B. garinii form biofilms, which resemble biofilms formed by B. burgdorferisensu stricto. High-resolution atomic force microscopy revealed similarities in the ultrastructural organization of the biofilms form by three Borrelia species. Histochemical experiments revealed a heterogeneous organization of exopolysaccharides among the three Borrelia species. These results suggest that biofilm formation might be a common trait of Borrelia genera physiology

Dynamic Wireless Information and Power Transfer Scheme for Nano-Empowered Vehicular Networks

In this paper, we investigate the wireless power transfer and energy-efficiency (EE) optimization problem for nano-centric vehicular networks operating over the terahertz band. The inbody nano-sensors harvest energy from a power station via radio-frequency signal and then use the harvested energy to transmit data to the sink node. By considering the properties of terahertz band (i.e., sensitivity to distance and frequency over the communication path), we adopt the Brownian motion model to develop a time-variant terahertz channel model and to describe the mobility of the nano-sensors. Thus, based on the channel model and energy resources, we further develop a long-term EE optimization problem. The EE optimization is further converted into a series of energy-efficient resource allocation problems over the time slots via equivalent transformation method. The resource allocation problem for each timeslot, which is formulated as a mixed integer nonlinear programming (MINLP), is solved based on the particle swarm optimization (PSO) method. In addition, a dynamic PSO-based EE optimization (DPEEO) algorithm is developed to obtain the sub-optimal solution for the EE optimization problem. By exploiting the special structure of the reformulated problem, an improved DPEEO algorithm, is presented which can handle the problem’s constraints quite well, decreases the research space, and greatly reduces the length of the convergence time. Simulation results validate the theoretical analysis of our system

Thermodynamic mapping of effector protein interfaces with RalA and RalB.

RalA and RalB are members of the Ras family of small G proteins and are activated downstream of Ras via RalGEFs. The RalGEF-Ral axis represents one of the major effector pathways controlled by Ras and as such is an important pharmacological target. RalA and RalB are approximately 80% identical at the amino acid level; despite this, they have distinct roles both in normal cells and in the disease state. We have used our structure of RalB-RLIP76 to guide an analysis of Ral-effector interaction interfaces, creating panels of mutant proteins to probe the energetics of these interactions. The data provide a physical mechanism that underpins the effector selective mutations commonly employed to dissect Ral G protein function. Comparing the energetic landscape of the RalB-RLIP76 and RalB-Sec5 complexes reveals mutations in RalB that lead to differential binding of the two effector proteins. A panel of RLIP76 mutants was used to probe the interaction between RLIP76 and RalA and -B. Despite 100% sequence identity in the RalA and -B contact residues with RLIP76, differences still exist in the energetic profiles of the two complexes. Therefore, we have revealed properties that may account for some of the functional separation observed with RalA and RalB at the cellular level. Our mutations, in both the Ral isoforms and RLIP76, provide new tools that can be employed to parse the complex biology of Ral G protein signaling networks. The combination of these thermodynamic and structural data can also guide efforts to ablate RalA and -B activity with small molecules and peptides.Captain Stephanos FoundationThis is the author accepted manuscript. The final version is available from the American Chemical Society via http://dx.doi.org/10.1021/bi501530

Researching the delivery of health and nutrition interventions for women and children in the context of armed conflict: Lessons on research challenges and strategies from BRANCH Consortium case studies of Somalia, Mali, Pakistan and Afghanistan

Background: The BRANCH Consortium recently conducted 10 mixed-methods case studies to investigate the provision of health and nutrition interventions for women and children in conflict-affected countries, aiming to better understand the dominant influences on humanitarian health actors\u27 programmatic decision-making and how such actors surmount intervention delivery barriers. In this paper, the research challenges encountered and the mitigating strategies employed by the case study investigators in four of the BRANCH case study contexts are discussed: Somalia, Mali, Pakistan and Afghanistan.Discussion: Many of the encountered research challenges were anticipated, with investigators adopting mitigation strategies in advance or early on, but others were unexpected, with implications for how studies were ultimately conducted and how well the original study aims were met. Insecurity was a fundamental challenge in all study contexts, with restricted geographical access and concerns for personal safety affecting sampling and data collection plans, and requiring reliance on digital communications, remote study management, and off-site team meetings wherever possible. The need to navigate complex local sociopolitical contexts required maximum reliance on local partners\u27 knowledge, expertise and networks, and this was facilitated by early engagement with a wide range of local study stakeholders. Severe lack of reliable quantitative data on intervention coverage affected the extent to which information from different sources could be triangulated or integrated to inform an understanding of the influences on humanitarian actors\u27 decision-making.Conclusion: Strong local partners are essential to the success of any project, contributing not only technical and methodological capacity but also the insight needed to truly understand and interpret local dynamics for the wider study team and to navigate those dynamics to ensure study rigour and relevance. Maintaining realistic expectations of data that are typically available in conflict settings is also essential, while pushing for more resources and further methodological innovation to improve data collection in such settings. Finally, successful health research in the complex, dynamic and unpredictable contexts of conflict settings requires flexibility and adaptability of researchers, as well as sponsors and donors

PATHOGENIC EFFECTS ASSOCIATED WITH TRYPANOSOMA DANILEWSKYI STRAIN FCC 1 INFECTION IN JUVENILE COMMON CARP, CYPRINUS CARPIO L

ABSTRACT Mortality and pathological effects caused by Trypanosoma danilewskyi strain F Cc 1 in laboratory-infected single breed juvenile common carp were investigated in this study. The study was divided into two parts. In the first part, four groups (A-D) each containing 20 fish (4 months old) were inoculated intraperitoneally with various size of inocula; 1000, 25,000 and 50,000 live trypanosomes/fish in groups A-C respectively while group D was injected 0.2 ml of PSG (phosphate buffered saline with glucose, pH 7, filter sterilized)/fish as a control. Blood was examined at 10 days intervals to monitor the development of parasitemia. All dead fish were counted and their blood and body fluids were examined for the presence of trypanosomes. The second part of the study was conducted under the similar conditions as first part to measure the pathological effects induced by the infection of T. danilewskyi strain FCc 1. Two groups, (A & B) each containing 40 fish (5 months old) were inoculated with 50,000 live trypanosomes/fish in group A and 0.2 ml PSG/fish in group B (control). Blood was examined at 10 days intervals and used for the estimation of parasitemia, hematocrit, hemoglobin and thin blood smear preparations. In the first part of study no fish died in groups A & D, 12.5 % mortality was observed in group B and 50 % in group C. The second part revealed a significant decrease in hematocrit, hemoglobin, erythrocyte counts and significant increase in leukocytes counts was observed in infected fish (group A) when compared to the control (group B) at the same interval of time. Thus it is concluded that Trypanosoma danilewskyi strain F Cc 1 is a potential hemoflagellate pathogen of juvenile common carp as it causes mortality, anemia and altered blood parameters