Evaluation and Analysis of Array Antennas for Passive Coherent Location (PCL) Systems

Passive Coherent Location (PCL) systems use a special form of a radar receiver that exploits the ambient radiation in the environment to detect and track targets. Typical transmissions of opportunity that might be exploited include television and FM radiobroadcasts. PCL implies the use of a non-radar electromagnetic sources of illumination, such as commercial radio or television broadcasts also referred as transmitters of opportunity. The use of such illumination sources means that the receiver needs to process waveforms that are not designed for radar purposes. As a consequence, the receivers for PCL systems must be much more customized than traditional receivers, in order to obtain the most appropriate and best signal. Since antennas are the eyes of the receivers, processing of an incoming signal starts with the antennas. Yet, because PCL system is non-traditional, there has not been much work done in the evaluation of the antennas, even though PCL systems have some demanding constraints on the antenna system. During this research various array antenna designs will be studied by their radiation patterns, gain factors, input impedances, power efficiencies and other features by simulating these arrays in the computer environment. The goal is to show the better performance of the array antennas compared to traditional Yagi-Uda antennas that are currently used for PCL systems

The Teaching and Research Nexus in Turkish Academia: Lessons from an international survey

With the Humboldtian idea of university, the research-informed teaching has largely influenced university models all around the world since 19th century. Recent models, however, seem to more emphasize the role of research through entrepreneurial mindset and bring questions about the connections as well as controversies between teaching and research activities of academics. Utilizing related questions of an international survey, this study aims at shedding light on the teaching and research nexus in Turkish academia by focusing academics’ main activities and orientations. Our findings indicate that while Turkish academics have positive perceptions on the teaching and research nexus, rapid expansion in higher education and competitive global trends may have an influence on the academic profession, bringing contradictions regarding the interplay between teaching and research activities. We discuss our findings through the national changes and global trends in higher education and conclude with recommendations on enhancing the nexus between teaching and research.This research was supported by The Scientific and Technological Research Council of Turkey (TÜBİTAK - Project No: 117K917) and The Unit of Scientific Research Projects at Canakkale Onsekiz Mart University, Turkey (COMU-BAP - Project No: SBA-2017-1093)

The transformation of women artists representation: a feminist analysis of the historical narrative and Istanbul Modern's new works new horizons exhibition

This thesis is about the representation of women artists in the Istanbul Museum of Modern Art, exploring how these artists unsettle the male gaze of the State historically founded in the Turkish Art Scene. The Constitution of 1908 brought about a rapid ''westernization/modernization'' process, and the foundation of the Republic in 1923 assigned this move as a state policy. The art field was encouraged in this regard as a space reflecting the level of modernization of a country by this State led movement. The first Art Museum of Turkey founded in 1937 by the State as ''the Istanbul State Museum of Painting and Sculpture'' could be considered as part of the Kemalist republican project of modernity. The artists in the collection consisted of the military painters and of some upper class families' children educated in Europe or at home by some tutors, as well as of some artists graduated from the Academy of Fine Arts founded in 1883. There are a limited number of women artists' works in the same collection. Many of those women artists graduated from the Istanbul Academy of Fine Arts for Girls founded in 1914 -after 31 years of the first Academy-. After exploring the historical foundation of the male gaze in the sphere of art, this research in comparison with the State led art tradition, will seek to analyze the current representation of women artists in the private art museums founded in the last five years in Turkey through the example of Istanbul Modern. The frame of analysis will be Istanbul Modern's most comprehensive exhibition until now –New Works New Horizons- which claims to cover with an updated fresh look the history of Turkish Modern and Contemporary Art. The choice of artists and works will be explored with a feminist perspective to unveil what kind of a new historical narrative is offered and how the women artists and their works are positioned in it as well as how they challenge the female artist representation

Alternative Strategies for the Treatment of Classical Congenital Adrenal Hyperplasia: Pitfalls and Promises

Despite decades of different treatment algorithms, the management of congenital adrenal hyperplasia (CAH) remains clinically challenging. This is due to the inherent difficulty of suppressing adrenal androgen production using near physiological dosing of glucocorticoids (GC). As a result, alternating cycles of androgen versus GC excess can occur and may lead to short stature, obesity, virilization, and alterations in puberty. Novel therapeutic alternatives, including new and more physiological means of GC delivery, inhibitors at the level of CRH or ACTH secretion and/or action, as well as “rescue strategies”, such as GnRH analogs, anti-androgens, aromatase inhibitors, and estrogen receptor blockers, are available; many of these agents, however, still require active investigation in CAH. Bilateral adrenalectomy is effective but it is also still an experimental approach. Gene therapy and stem cells, to provide functional adrenal cortical tissue, are at preclinical stage but provide exciting avenues for a potential cure for CAH

Cushing Syndrome in a 6-Month-Old Infant due to Adrenocortical Tumor

Cushing syndrome is rare in infancy and usually due to an adrenocortical tumor (ACT). We report an infant with Cushing syndrome due to adrenocortical carcinoma. The patient presented at six months of age with a three-month history of growth failure, rapid weight gain, acne, and irritability. Physical examination showed obesity, hypertension, and Cushingoid features. Biochemical evaluation showed very high serum cortisol, mildly elevated testosterone, and suppressed ACTH. Abdominal MRI revealed a heterogeneous right adrenal mass extending into the inferior vena cava. Evaluation for metastases was negative. The tumor was removed surgically en bloc. Pathologic examination demonstrated low mitotic rate, but capsular and vascular invasion. She received no adjuvant therapy. Her linear growth has improved and Cushingoid features resolved. Hormonal markers and quarterly PET scans have been negative for recurrence 24 months postoperatively. In conclusion, adrenocortical neoplasms in children are rare, but should be considered in the differential diagnosis of Cushing syndrome

Etiological and clinical characteristics of central diabetes insipidus in children: a single center experience

Abstract Background Central diabetes insipidus (CDI) results from a number of conditions affecting the hypothalamic-neurohypophyseal system to cause vasopressin deficiency. Diagnosis of CDI is challenging, and clinical data and guidelines for management are lacking. We aim to characterize clinical and radiological characteristics of a cohort of pediatric patients with CDI. Methods A chart review of 35 patients with CDI followed at North Carolina Children’s Hospital from 2000 to 2015 was undertaken. The frequencies of specific etiologies of CDI and characteristic magnetic resonance imaging (MRI) findings were determined. The presence of additional hormone deficiencies at diagnosis and later in the disease course was ascertained. Patient characteristics and management strategies were evaluated. Results The cohort included 14 female and 21 male patients with a median age of 4.7 years (range, less than 1 month to 16 years) at diagnosis. Median duration of follow-up was 5 years (range, 2 months to 16 years). The cause of CDI was intracranial mass in 13 patients (37.2 %), septo-optic dysplasia in 9 patients (25.7 %), holoprosencephaly in 5 patients (14.2 %), Langerhans cell histiocytosis in 3 patients (8.6 %), isolated pituitary hypoplasia in 2 patients (5.7 %), and encephalocele in 1 patient (2.9 %). Patients were symptomatic for a mean of 6.3 months (range, less than 1 month to 36 months) prior to diagnosis of CDI. Growth hormone (GH), thyrotropin (TSH), adrenocorticotropic hormone (ACTH), and gonadotropin deficiencies were present at diagnosis in 34, 23, 23, and 6 % of patients, respectively. GH, TSH, ACTH, and gonadotropin deficiencies were diagnosed during follow-up in 23, 40, 37, and 14 % of patients, respectively. In patients with structural CNS abnormalities, development of additional hormone deficiencies occurred anywhere from 2 months to 13 years after the time of initial presentation. Conclusions All patients in our cohort had an underlying organic etiology for CDI, with intracranial masses and CNS malformations being most common. Therefore, MRI of the brain is indicated in all pediatric patients with CDI. Other pituitary hormone deficiencies should be investigated at diagnosis as well as during follow-up

The Use of Infrapatellar Fat Pad-Derived Mesenchymal Stem Cells in Articular Cartilage Regeneration: A Review.

Cartilage is frequently damaged with a limited capacity for repair. Current treatment strategies are insufficient as they form fibrocartilage as opposed to hyaline cartilage, and do not prevent the progression of degenerative changes. There is increasing interest in the use of autologous mesenchymal stem cells (MSC) for tissue regeneration. MSCs that are used to treat articular cartilage defects must not only present a robust cartilaginous production capacity, but they also must not cause morbidity at the harvest site. In addition, they should be easy to isolate from the tissue and expand in culture without terminal differentiation. The source of MSCs is one of the most important factors that may affect treatment. The infrapatellar fat pad (IPFP) acts as an important reservoir for MSC and is located in the anterior compartment of the knee joint in the extra-synovial area. The IPFP is a rich source of MSCs, and in this review, we discuss studies that demonstrate that these cells have shown many advantages over other tissues in terms of ease of isolation, expansion, and chondrogenic differentiation. Future studies in articular cartilage repair strategies and suitable extraction as well as cell culture methods will extend the therapeutical application of IPFP-derived MSCs into additional orthopedic fields, such as osteoarthritis. This review provides the latest research concerning the use of IPFP-derived MSCs in the treatment of articular cartilage damage, providing critical information for the field to grow

The evaluation of Pat-Pat related injuries in the western black sea region of Turkey

BACKGROUND: Accidents caused by motorized vehicle in the agricultural sector are frequently observed. In Turkey; accidents arising from motorized vehicles, named Pat-Pat, which are used by farmers in the Western Black Sea region is not unusual. METHODS: One hundred five patients who were brought into the Emergency Department of Duzce University, Medical Faculty Hospital between September 2009 and August 2010 due to Pat-Pat related accidents were evaluated. RESULTS: The cases consisted of 73 (69.5%) males and 32 (30.5%) females, ranging from 2 to 73 years of age. In the 10-39 age group, a total of 63 (60.0%) cases were determined. The months when the greatest rate of cases applied to the hospital consisted of July, August, September and the season is summer. The cases were exposed to trauma in roads in 54 (51.4%), and 51 (48.6%) occurred in agricultural area without roads. Eighty seven (82.9%) cases were injured due to the overturning of vehicle. The patients were brought to the hospital using a private vehicle in 54 (51.4%) of the cases and in 51 (48.6%) cases, 112 ambulance system was used. The cases were determined to apply to the hospital most frequently between 6 pm-12 am. The injuries frequently consisted of head-neck and spine traumas, thorax traumas and upper extremity traumas. In 55 (52.4%) cases, open wound-laceration was determined. Seventy five (71.4%) cases were treated in the Emergency Department, and 28 (26.7%) were hospitalized. Three (2.9%) cases were deceased. CONCLUSIONS: Serious injuries can occur in Pat-Pat related accidents, and careful systematic physical examination should be conducted. In order to prevent these accidents, education of farm operators and engineering studies on the mechanics and safety of these vehicles should be taken and legal regulations should be created