Improved control strategy of DFIG-based wind turbines using direct torque and direct power control techniques

This paper presents different control strategies for a variable-speed wind energy conversion system (WECS), based on a doubly fed induction generator. Direct Torque Control (DTC) with Space-Vector Modulation is used on the rotor side converter. This control method is known to reduce the fluctuations of the torque and flux at low speeds in contrast to the classical DTC, where the frequency of switching is uncontrollable. The reference for torque is obtained from the maximum power point tracking technique of the wind turbine. For the grid-side converter, a fuzzy direct power control is proposed for the control of the instantaneous active and reactive power. Simulation results of the WECS are presented to compare the performance of the proposed and classical control approaches.Peer reviewedFinal Accepted Versio

Allergic sensitization: screening methods

Experimental in silico, in vitro, and rodent models for screening and predicting protein sensitizing potential are discussed, including whether there is evidence of new sensitizations and allergies since the introduction of genetically modified crops in 1996, the importance of linear versus conformational epitopes, and protein families that become allergens. Some common challenges for predicting protein sensitization are addressed: (a) exposure routes; (b) frequency and dose of exposure; (c) dose-response relationships; (d) role of digestion, food processing, and the food matrix; (e) role of infection; (f) role of the gut microbiota; (g) influence of the structure and physicochemical properties of the protein; and (h) the genetic background and physiology of consumers. The consensus view is that sensitization screening models are not yet validated to definitively predict the de novo sensitizing potential of a novel protein. However, they would be extremely useful in the discovery and research phases of understanding the mechanisms of food allergy development, and may prove fruitful to provide information regarding potential allergenicity risk assessment of future products on a case by case basis. These data and findings were presented at a 2012 international symposium in Prague organized by the Protein Allergenicity Technical Committee of the International Life Sciences Institute’s Health and Environmental Sciences Institute

Inputs to quality: supervision, management, and community involvement in health facilities in Egypt in 2004

<p>Abstract</p> <p>Background</p> <p>As low- and middle-income countries experience economic development, ensuring quality of health care delivery is a central component of health reform. Nevertheless, health reforms in low- and middle-income countries have focused more on access to services rather than the quality of these services, and reporting on quality has been limited. In the present study, we sought to examine the prevalence and regional variation in key management practices in Egyptian health facilities within three domains: supervision of the facility from the Ministry of Health and Population (MOHP), managerial processes, and patient and community involvement in care.</p> <p>Methods</p> <p>We conducted a cross-sectional analysis of data from 559 facilities surveyed with the Egyptian Service Provision Assessment (ESPA) survey in 2004, the most recent such survey in Egypt. We registered on the Measure Demographic and Health Survey (DHS) website <url>http://legacy.measuredhs.com/login.cfm</url> to gain access to the survey data. From the ESPA sampled 559 MOHP facilities, we excluded a total of 79 facilities because they did not offer facility-based 24-hour care or have at least one physician working in the facility, resulting in a final sample of 480 facilities. The final sample included 76 general service hospitals, 307 rural health units, and 97 maternal and child health and urban health units (MCH/urban units). We used standard frequency analyses to describe facility characteristics and tested the statistical significance of regional differences using chi-square statistics.</p> <p>Results</p> <p>Nearly all facilities reported having external supervision within the 6 months preceding the interview. In contrast, key facility-level managerial processes, such as having routine and documented management meetings and applying quality assurance approaches, were uncommon. Involvement of communities and patients was also reported in a minority of facilities. Hospitals and health units located in Urban Egypt compared with more rural parts of Egypt were significantly more likely to have management committees that met at least monthly, to keep official records of the meetings, and to have an approach for reviewing quality assurance activities.</p> <p>Conclusions</p> <p>Although the data precede the recent reform efforts of the MOHP, they provide a baseline against which future progress can be measured. Targeted efforts to improve facility-level management are critical to supporting quality improvement initiatives directed at improving the quality of health care throughout the country.</p

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Theory and phenomenology of two-Higgs-doublet models

We discuss theoretical and phenomenological aspects of two-Higgs-doublet extensions of the Standard Model. In general, these extensions have scalar mediated flavour changing neutral currents which are strongly constrained by experiment. Various strategies are discussed to control these flavour changing scalar currents and their phenomenological consequences are analysed. In particular, scenarios with natural flavour conservation are investigated, including the so-called type I and type II models as well as lepton-specific and inert models. Type III models are then discussed, where scalar flavour changing neutral currents are present at tree level, but are suppressed by either specific ansatze for the Yukawa couplings or by the introduction of family symmetries. We also consider the phenomenology of charged scalars in these models. Next we turn to the role of symmetries in the scalar sector. We discuss the six symmetry-constrained scalar potentials and their extension into the fermion sector. The vacuum structure of the scalar potential is analysed, including a study of the vacuum stability conditions on the potential and its renormalization-group improvement. The stability of the tree level minimum of the scalar potential in connection with electric charge conservation and its behaviour under CP is analysed. The question of CP violation is addressed in detail, including the cases of explicit CP violation and spontaneous CP violation. We present a detailed study of weak basis invariants which are odd under CP. A careful study of spontaneous CP violation is presented, including an analysis of the conditions which have to be satisfied in order for a vacuum to violate CP. We present minimal models of CP violation where the vacuum phase is sufficient to generate a complex CKM matrix, which is at present a requirement for any realistic model of spontaneous CP violation.Comment: v3: 180 pages, 506 references, new chapter 7 with recent LHC results; referee comments taken into account; submitted to Physics Report

Nomenclature revision for encapsulated follicular variant of papillary thyroid carcinoma:a paradigm shift to reduce overtreatment of indolent tumors

Although growing evidence points to highly indolent behavior of encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC), most patients with EFVPTC are treated as having conventional thyroid cancer

Prognostic biomarkers in patients with human immunodeficiency virusâ positive disease with head and neck squamous cell carcinoma

BackgroundWe examined the prognostic value of a panel of biomarkers in patients with squamous cell carcinoma of the head and neck (SCCHN) who were human immunodeficiency virus (HIV) positive (HIVâ positive head and neck cancer) and HIV negative (HIVâ negative head and neck cancer).MethodsTissue microarrays (TMAs) were constructed using tumors from 41 disease siteâ matched and ageâ matched HIVâ positive head and neck cancer cases and 44 HIVâ negative head and neck cancer controls. Expression of tumor biomarkers was assessed by immunohistochemistry (IHC) and correlations examined with clinical variables.ResultsExpression levels of the studied oncogenic and inflammatory tumor biomarkers were not differentially regulated by HIV status. Among patients with HIVâ positive head and neck cancer, laryngeal disease site (P = .003) and Clavienâ Dindo classification IV (CD4) counts <200 cells/μL (P = .01) were associated with poor prognosis. Multivariate analysis showed that p16 positivity was associated with improved overall survival (OS; P < .001) whereas increased expression of transforming growth factorâ beta (TGFâ β) was associated with poor clinical outcome (P = .001).ConclusionDisease site has significant effect on the expression of biomarkers. Expression of tumor TGFâ β could be a valuable addition to the conventional risk stratification equation for improving head and neck cancer disease management strategies.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139994/1/hed24911.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139994/2/hed24911_am.pd

Factors associated with hospital service satisfaction in a sample of Arab subjects with schizophrenia

<p>Abstract</p> <p>Background</p> <p>Assessment of patients' satisfaction with health care services could help to identify the strengths and weaknesses of the system and provide guidance for further development. The study's objectives were to: (i) assess the pattern of satisfaction with hospital care for a sample of people with schizophrenia in Kuwait, using the Verona Service Satisfaction Scale (VSSS-EU); ii) compare the pattern of satisfaction with those of similar studies; and iii) assess the association of VSSS seven domains with a number of variables representing met and unmet needs for care, family caregiver burden, severity of psychopathology, level of psychosocial functioning, socio-demographic characteristics, psychological well-being and objective quality of life.</p> <p>Methods</p> <p>Consecutive outpatients in stable condition and their family caregivers were interviewed with the VSSS-EU and measures of needs for care, caregiver burden, quality of life and psychopathology.</p> <p>Results</p> <p>There were 130 patients (66.1%m, mean age 36.8). While over two-thirds expressed satisfaction with the domains of "overall satisfaction", "professionals' skills", "access", "efficacy", and "relatives' involvement", only about one-third were satisfied with the domains of "information" and "types of intervention". The later two domains were the areas in which European patients had better satisfaction than our patients, while our patients expressed better satisfaction than the Europeans in the domain of "relatives' involvement". In multiple regression analyses, self-esteem, positive and negative affect were the most important correlates of the domains of service satisfaction, while clinical severity, caregiver burden and health unmet needs for care played relatively minor roles.</p> <p>Conclusion</p> <p>The noted differences and similarities with the international data, as well as the predictive power of self-esteem and affective state, support the impression that patients' attitudes towards psychiatric care involve a complex relationship between clinical, personal and socio-cultural characteristics; and that many of the factors that impact on satisfaction with service relate to individual psychological characteristics. The weaknesses in the system, highlighted by the pattern of responses of the participants, indicate possible gaps in the provision of comprehensive psychiatric care in the country and obviate the need for public mental health education and development of services to enhance the quality of care.</p

RbR_b and RcR_c in the Two Higgs Doublet Model with Flavor Changing Neutral Currents

A study of $R_b$ and $R_c$ is presented in the context of a Two Higgs Doublet Model (2HDM) with flavor changing scalar currents (FCSC). Implications of the model for the $\rho$-parameter and for $b\to s\gamma$ are also considered. The experimental data on $R_b$ places stringent constraints on the model parameters. The configuration of the model needed to account for $R_b$ is found to be irreconcilable with constraints from $b\to s\gamma$ and $\rho$. In particular, if R^{\rm exp}_b>R^{\sss{\rm SM}}_b persists then this version of 2HDM will be ruled out or require significant modifications. Noting that aspects of the experimental analysis for $R_b$ and $R_c$ may be of some concern, we also disregard $R^{\rm exp}_b$ and $R^{\rm exp}_c$ and give predictions for these using constraints from $b\to s\gamma$ and $\rho$ parameter only. We emphasize the theoretical and experimental advantages of the observable R_{b+c}\equiv \Gamma(Z\to b\bar b\mbox{ or } c\bar c)/\Gamma(Z\to\mbox{hadrons}). We also stress the role of R_\ell\equiv \Gamma(Z\to\mbox{hadrons})/\Gamma(Z\to \ell^+\ell^-) in testing the Standard Model (SM) despite its dependence on QCD corrections. Noting that in models with FCNC the amplitude for $Z\to c\bar c$ receives a contribution which grows with $m^2_t$, the importance and uniqueness of precision $Z\to c\bar c$ measurements for constraining flavor changing $t\bar c$ currents is underscored.Comment: 35 pages, 5 Postscript figures, 10 Postscript files used in the tex file, uses epsf.st