Cascade Control of the Ground Station Module of an Airborne Wind Energy System

An airborne wind energy system (AWES) can harvest stronger wind streams at higher altitudes which are not accessible to conventional wind turbines. The operation of AWES requires a controller for the tethered aircraft/kite module (KM), as well as a controller for the ground station module (GSM). The literature regarding the control of AWES mostly focuses on the trajectory tracking of the KM. However, an advanced control of the GSM is also key to the successful operation of an AWES. In this paper we propose a cascaded control strategy for the GSM of an AWES during the traction or power generation phase. The GSM comprises a winch and a three-phase induction machine (IM), which acts as a generator. In the outer control-loop, an integral sliding mode control (SMC) algorithm is designed to keep the winch velocity at the prescribed level. A detailed stability analysis is also presented for the existence of the SMC for the perturbed winch system. The rotor flux-based field oriented control (RFOC) of the IM constitutes the inner control-loop. Due to the sophisticated RFOC, the decoupled and instantaneous control of torque and rotor flux is made possible using decentralized proportional integral (PI) controllers. The unknown states required to design RFOC are estimated using a discrete time Kalman filter (DKF), which is based on the quasi-linear model of the IM. The designed GSM controller is integrated with an already developed KM, and the AWES is simulated using MATLAB and Simulink. The simulation study shows that the GSM control system exhibits appropriate performance even in the presence of the wind gusts, which account for the external disturbance

Lymphocyte and monocyte flow cytometry immunophenotyping as a diagnostic tool in uncharacteristic inflammatory disorders

<p>Abstract</p> <p>Background</p> <p>Patients with uncharacteristic inflammatory symptoms such as long-standing fatigue or pain, or a prolonged fever, constitute a diagnostic and therapeutic challenge. The aim of the present study was to determine if an extended immunophenotyping of lymphocytes and monocytes including activation markers can define disease-specific patterns, and thus provide valuable diagnostic information for these patients.</p> <p>Methods</p> <p>Whole blood from patients with gram-negative bacteraemia, neuroborreliosis, tuberculosis, acute mononucleosis, influenza or a mixed connective tissue disorders, as diagnosed by routine culture and serology techniques was analysed for lymphocyte and monocyte cell surface markers using a no-wash, no-lyse protocol for multi-colour flow cytometry method. The immunophenotyping included the activation markers HLA-DR and CD40. Plasma levels of soluble TNF alpha receptors were analysed by ELISA.</p> <p>Results</p> <p>An informative pattern was obtained by combining two of the analysed parameters: (i), the fractions of HLA-DR-expressing CD4+ T cells and CD8+ T cells, respectively, and (ii), the level of CD40 on CD14+ CD16- monocytes. Patients infected with gram-negative bacteria or EBV showed a marked increase in monocyte CD40, while this effect was less pronounced for tuberculosis, borrelia and influenza. The bacterial agents could be distinguished from the viral agents by the T cell result; CD4+ T cells reacting in bacterial infection, and the CD8+ T cells dominating for the viruses. Patients with mixed connective tissue disorders also showed increased activation, but with similar engagement of CD4+ and CD8+ T cells. Analysis of soluble TNF alpha receptors was less informative due to a large inter-individual variation.</p> <p>Conclusion</p> <p>Immunophenotyping including the combination of the fractions of HLA-DR expressing T cell subpopulations with the level of CD40 on monocytes produces an informative pattern, differentiating between infections of bacterial and viral origin. Furthermore, a quantitative analysis of these parameters revealed the novel finding of characteristic patterns indicating a subacute bacterial infection, such as borreliosis or tuberculosis, or a mixed connective tissue disorder. The employed flow cytometric method is suitable for clinical diagnostic laboratories, and may help in the assessment of patients with uncharacteristic inflammatory symptoms.</p

Adverse Drug Reactions in Children—A Systematic Review

Adverse drug reactions in children are an important public health problem. We have undertaken a systematic review of observational studies in children in three settings: causing admission to hospital, occurring during hospital stay and occurring in the community. We were particularly interested in understanding how ADRs might be better detected, assessed and avoided

Combining regenerative medicine strategies to provide durable reconstructive options: auricular cartilage tissue engineering

Recent advances in regenerative medicine place us in a unique position to improve the quality of engineered tissue. We use auricular cartilage as an exemplar to illustrate how the use of tissue-specific adult stem cells, assembly through additive manufacturing and improved understanding of postnatal tissue maturation will allow us to more accurately replicate native tissue anisotropy. This review highlights the limitations of autologous auricular reconstruction, including donor site morbidity, technical considerations and long-term complications. Current tissue-engineered auricular constructs implanted into immune-competent animal models have been observed to undergo inflammation, fibrosis, foreign body reaction, calcification and degradation. Combining biomimetic regenerative medicine strategies will allow us to improve tissue-engineered auricular cartilage with respect to biochemical composition and functionality, as well as microstructural organization and overall shape. Creating functional and durable tissue has the potential to shift the paradigm in reconstructive surgery by obviating the need for donor sites

Eosinophilic Colitis

Abstract Eosinophilic gastrointestinal disorders (EGID) form a heterogeneous group of diseases, which are classified according to the site of involvement and to the depth of infiltration of the different layers of the gut. The prevalence of these diseases decreases toward the distal part of the gastrointestinal tract. Since it was first described on pathological specimens by Kaijser in 1937, approximately 300 cases of eosinophilic gastroenteritis have been published. The diagnosis of primary EGID is based on the presence of gastrointestinal symptoms; on histology showing eosinophilic infiltration, usually with eosinophils in an intraepithelial position; and on the exclusion of secondary causes of eosinophilia such as drugs, malignancy, or inflammatory bowel disease. Peripheral eosinophilia is not necessary for the diagnosis

Telephone consultations in place of face to face out-patient consultations for patients discharged from hospital following surgery: a systematic review

Background: Routine follow-up following uncomplicated surgery is being delivered by telephone in some settings. Telephone consultations may be preferable to patients and improve outpatient resource use. We aimed to compare the effectiveness of telephone consultations with face to face follow-up consultations, in patients discharged from hospital following surgery. Methods. Seven electronic databases (including Medline, Embase and PsycINFO) were searched from inception to July 2011. Comparative studies of any design in which routine follow-up via telephone was compared with face to face consultation in patients discharged from hospital after surgery were included. Study selection, data extraction and quality appraisal were performed independently by two reviewers with consensus reached by discussion and involvement of a third reviewer where necessary. Results: Five papers (four studies; 865 adults) met the inclusion criteria. The studies were of low methodological quality and reported dissimilar outcomes precluding any formal synthesis. Conclusions: There has been very little comparative evaluation of different methods of routine follow-up care in patients discharged from hospital following surgery. Further work is needed to establish a role for telephone consultation in this patient group

Traumatic tympanic membrane perforations: an overview in tertiary care hospital

Abstract This hospital-based prospective study was conducted in the Department of Ear Nose Throat, Head and Neck Surgery, Government Medical College Srinagar, Jammu and Kashmir, for a period of 1 year from June 2013 to June 2014 with the aim of studying the aetiological factors, clinical presentation and management options for traumatic tympanic membrane perforations. A total of 50 patients with traumatic perforations of the tympanic membrane were enrolled in the study, comprising of 34 males and 16 females patients. Age of the patients ranged from 12 to 56 years, with a mean age of 32 years. The results showed that the most common mode of trauma was slaps (56%); sudden hearing loss and tinnitus were the two most common presentations (92%). Audiometry shows that the larger the tympanic membrane perforation, the larger the air–bone gap. Hearing loss was highest at the lowest frequencies and generally decreased as the frequency increased. The differences in air–bone gaps between small and large perforations were significant at all frequencies (P<0.05, Student’s t-test). Overall, 72% of patients responded to conservative management, whereas 28% needed fat myringoplasty and/or chemical cauterization