Effect of graffiti as placemaker: Istanbul Karakoy underpass example

Bu yazıda, sokak sanatı örneklerinden grafiti, yer oluşturma kavramı üzerinden ele alınmaktadır. Grafitinin, 1980’li yılların başında kentsel mekânlarda yayılan görselliği, sosyal ve mekânsal sorunları da beraberinde getirmiştir. Nedenselliği sürekli yenilenen, tür ve tarzlara ayrılarak gelişen grafitinin, mekânsal bağlamı da buna bağlı olarak değişkenlik göstermektedir. Bu nedenle; grafiti ve mekân etkileşimini, farklı disiplinlerin bakış açıları ile buluşturabilecek, grafitinin sosyal ve mekânsal boyutunun içinde barındırdığı insan ve mekân etkileşimini merkezine alan araştırmalara gereksinim artmaktadır. Yapılan bu çalışmanın amacı; kentsel mekân ve grafiti arasındaki çok yönlü etkileşimin, mekân ve kullanıcılarına yansıyan duygusal boyutlarını belirleyerek, grafitinin yer oluşturucu etkisini tartışmaktır. Çalışmada, yer oluşturma pratiği Etkileşim Üçgeni yönteminden (Triangulation Process) yararlanılarak; mekânsal uyarıcı etken (external stimulus)olarak, izinsiz grafiti örneklerinin (illegal graffiti) kentsel mekân ile olan etkileşimine odaklanılmaktadır. İstanbul’da grafitinin yoğun olarak bulunduğu Karaköy’ün merkezindeki Karaköy Alt Geçidi ve Çarşısında alan çalışması yapılmıştır. Araştırmanın gözlem süreci 36 aya (2015-2018 yılları arası) yayılmakta olup, alanda yazılma-silinme ve tekrar yazılma döngüsü içinde, 54 farklı grafiti konfigürasyonu belirlenmiştir. Bu döngüsel durumdan mekân kullanıcılarına geçen yer duygusunun boyutları ile grafitinin mekânsal nitelikleri arasındaki etkileşimin yer oluşturucu etkisi, hazırlanan çalışma modelinden yararlanılarak ortaya konulmaktadır. Yapılan bu çalışmanın grafiti ve yer oluşturma kavramını tartışan yeni araştırmalara farklı bir bakış sunması ve yol gösterici olması hedeflenmektedir.This research paper aims to discuss the spatial interaction of graffiti as unauthorized marking activity in public spaces. It proposes to clarify why interactions between graffiti and people in public spaces are important, and how graffiti evokes an external stimulus on people who see these marks on the surfaces of public spaces. In this article, the spatial effect of graffiti on the street is discussed through the concept of place-making. The importance of graffiti in public spaces began to be discussed in the early 1980s, and was considered t a kind of unauthorized street activity often associated with vandalism. However, in the 2000s this changed slightly and graffiti also began to be considered as a profound actor in bringing vitality and increased sociability to the streets according to the qualities of place-making. This drastic change in seeing graffiti has intensified the discussions about the new relationships between the concept of place-making and the motivations for graffiti writing in public spaces. Therefore, a multidisciplinary approach is needed to examine the various interactions between people and public spaces over the social and spatial effects of graffiti. Through a Qualitative Research approach based on a deeper understanding of social life, this paper focuses on the interactions between graffiti and people in public spaces. The conceptual framework of the paper is based on Whyte's Triangulation Process and the qualities of the sense of place that are related to place-making practice derived from the seminal literature of this work. Accordingly, a case study was completed via field work covering thirty-six months between 2015-2018. This fieldwork was conducted in the Karakoy Underpass, where Istanbul's graffiti-covered surfaces are frequently noticed. During the observation period, fifty-four different graffiti configurations were observed in situ and collected as visual documentation using photo and video recordings. Additionally, during the interview period of the fieldwork, conversations using semi-structured questions were carried out with the pedestrians passing through, graffiti writers, and the shopkeepers in the Karakoy Underpass. In order to decompose the data collected from the fieldwork, a prototype "Cross Matrix Table" was designed to show the multiple relationships between the spatial effect of graffiti and the triangulated interaction of public spaces. This Table also highlights the triangulated position of graffiti as an external stimulus that connects with the people as actors of everyday urban flux in public spaces. This paper provides empirical insights on how the Triangulation Process reflects the social interactions in public spaces. Accordingly, this research paper includes Qualitative Research steps of data collection and decomposes the findings with a suggested model "Cross Matrix Table" at the end of the study. The suggested "Cross Matrix Table" model with the decomposed data and case study demonstrates that there is an architectural need to investigate how everyday street art activities can reflect the qualities of the sense of place. This study not only enables graffiti to be seen as an activity performed on the street, but also to arouse interest in the concept of triangulation itself

Splenectomy in patients with idiopathic thrombocytopenic purpura: Analysis of 109 cases

Objectives: Splenectomy is performed in order to provide the treatment in the patients with severe idiopathic thrombocytopenic purpura, refractory to medical treatment. In this study, we aimed to investigate the postoperatif and longterm outcomes in the patients who underwent splenectomy with the diagnosis of idiopathic thrombocytopenic purpura.Materials and Methods: Between 2001-2010 at Dicle University Medical Faculty, General Surgery Department, a retrospective review of the 109 patients who had undergone splenectomy for ITP was reviewed. Age, gender, presence of accessory spleens and location, duration of the operation, number of preoperative platelet tranfusion, number of preoperative and postoperative blood transfusion, length of hospital stay, long-term outcomes, morbidity and mortality were recorded.Results: The mean age was 37.10 ± 16.62 (16-72), and there were 88 (80.7%) female and 21 (19.3%) male patients. The mean operation time was 44.87 ± 10:32 (30-120) minutes. The average postoperative blood and preoperative platelet transfusion were 1.63 ± 0.85 (0-3) and 2.01 ± 0.71 (1-3) units, respectively. The accessory spleens were encountered in 20 (18.3%) patients at the ultrasonographic examination. And also the accessory spleens were encountered in 23 (21.1%) patients during operation and confirmed with histopathologic examination. The most common localization of accessory spleens were splenic hilus. The postoperative complications were occurred in 16 patients (14.7%) and the most complication was atelectasia. The mean length of hospital stay was 4:56 ± 2:45 (2-12) days. Patients were followed for an average of 28 (9-48) months. At the follow-up period, 1 (0.9 %) patient had died.Conclusion: Splenectomy can be performed safely in the treatment of the patients with idiopathic thrombocytopenic purpura unresponsive to medical treatment. Long-term good results can be obtained with splenectomy in these patients. The accessory spleens should not be overlooked to prevent recurrences

Conductance Quantization at zero magnetic field in InSb nanowires

Ballistic electron transport is a key requirement for existence of a topological phase transition in proximitized InSb nanowires. However, measurements of quantized conductance as direct evidence of ballistic transport have so far been obscured due to the increased chance of backscattering in one dimensional nanowires. We show that by improving the nanowire-metal interface as well as the dielectric environment we can consistently achieve conductance quantization at zero magnetic field. Additionally, studying the sub-band evolution in a rotating magnetic field reveals an orbital degeneracy between the second and third sub-bands for perpendicular fields above 1T

Towards high mobility InSb nanowire devices

We study the low-temperature electron mobility of InSb nanowires. We extract the mobility at 4.2 Kelvin by means of field effect transport measurements using a model consisting of a nanowire-transistor with contact resistances. This model enables an accurate extraction of device parameters, thereby allowing for a systematic study of the nanowire mobility. We identify factors affecting the mobility, and after optimization obtain a field effect mobility of $\sim2.5\mathbin{\times}10^4$ cm$^2$/Vs. We further demonstrate the reproducibility of these mobility values which are among the highest reported for nanowires. Our investigations indicate that the mobility is currently limited by adsorption of molecules to the nanowire surface and/or the substrate.Comment: 13 pages, 5 figures (main text); 7 pages, 2 figures, 2 tables (supplementary text

Andreev reflection in the fractional quantum Hall state

We construct high-quality graphene-based van der Waals devices with narrow superconducting niobium nitride (NbN) electrodes, in which superconductivity and robust fqH coexist. We find crossed Andreev reflection (CAR) across the superconductor separating two fqH edges. Our observed CAR probabilities in the particle-like fractional fillings are markedly higher than those in the integer and hole-conjugate fractional fillings and depend strongly on temperature and magnetic field unlike the other fillings. Further, we find a filling-independent CAR probability in integer fillings, which we attribute to spin-orbit coupling in NbN allowing for Andreev reflection between spin-polarized edges. These results provide a route to realize novel topological superconducting phases in fqH-superconductor hybrid devices based on graphene and NbN.Comment: Revised text, additional main and appendix figure

COVID-19 in pediatric patients undergoing chronic dialysis and kidney transplantation

The study aims to present the incidence of COVID-19 in pediatric patients undergoing renal replacement therapy (RRT) and to compare the severity and outcomes of the disease between the dialysis and kidney transplant (KTx) groups. This multicenter observational study was conducted between 1 April and 31 December 2020 in Istanbul. Members of the Istanbul branch of the Turkish Pediatric Nephrology Association were asked to report all confirmed cases of COVID-19 who were on RRT, as well as the number of prevalent RRT patients under the age of 20. A total of 46 confirmed cases of COVID-19 were reported from 12 centers, of which 17 were dialysis patients, and 29 were KTx recipients. Thus, the incidence rate of COVID-19 was 9.3% among dialysis patients and 9.2% among KTx recipients over a 9-month period in Istanbul. Twelve KTx recipients and three dialysis patients were asymptomatic (p = 0.12). Most of the symptomatic patients in both the dialysis and KTx groups had a mild respiratory illness. Only two patients, one in each group, experienced a severe disease course, and only one hemodialysis patient had a critical illness that required mechanical ventilation. In the entire cohort, one hemodialysis patient with multiple comorbidities died. Conclusion: While most cases are asymptomatic or have a mild disease course, pediatric patients undergoing dialysis and a kidney transplant are at increased risk for COVID-19. What is Known: In adult population, both dialysis patients and kidney transplant recipients are at increased risk for severe illness of COVID-19 and have higher mortality rate. Children with kidney transplantation are not at increased risk for COVID-19 and most have mild disease course. Data on children on dialysis are scarce. What is New: Pediatric patients undergoing dialysis and kidney transplantation have an increased risk for COVID-19. Most patients undergoing renal replacement therapy either on dialysis or transplanted develop asymptomatic or mild COVID-19 disease with a favorable outcome

Explant Culture of Ovarian Tissue

INTRODUCTION: In this study, it was aimed to isolate, reproduce and characterize stromal cells migrating from tissues by creating ovarian tissue explant culture. It is also aimed to create a mixed cell culture (ovarian stromal stem cells and ovarian surface epithelium) with the tissues obtained from different parts of the ovary and to examine the interactions of the cells with each other. METHODS: Explant cultures were formed from ovarian tissues of 4 week old (prepubertal) two female Wistar Albino type rats. Then, the expression of CD29, CD54, CD90 (mesenchymal stem cell surface antigen) and CD45 (hematopoietic stem cell surface antigen) was investigated by performing flow cytometry analysis on proliferating ovarian stromal cells in the 2nd passage (P2). RESULTS: The proliferation abilities and morphological characteristics of the cells in the culture medium were examined by serial passaging. In flow cytometry analysis of isolated ovarian stromal cells, it was determined that they expressed CD54, CD90 and CD45 surface antigens, but did not express CD29 surface antigens. DISCUSSION AND CONCLUSION: In the analysis, we determined that the ovarian stromal cells we isolated and produced in the culture medium expressed hematopoietic and some mesenchymal stem cell markers

Low disorder and high valley splitting in silicon

The electrical characterisation of classical and quantum devices is a critical step in the development cycle of heterogeneous material stacks for semiconductor spin qubits. In the case of silicon, properties such as disorder and energy separation of conduction band valleys are commonly investigated individually upon modifications in selected parameters of the material stack. However, this reductionist approach fails to consider the interdependence between different structural and electronic properties at the danger of optimising one metric at the expense of the others. Here, we achieve a significant improvement in both disorder and valley splitting by taking a co-design approach to the material stack. We demonstrate isotopically-purified, strained quantum wells with high mobility of 3.14(8)$\times$10$^5$ cm$^2$/Vs and low percolation density of 6.9(1)$\times$10$^{10}$ cm$^{-2}$. These low disorder quantum wells support quantum dots with low charge noise of 0.9(3) $\mu$eV/Hz$^{1/2}$ and large mean valley splitting energy of 0.24(7) meV, measured in qubit devices. By striking the delicate balance between disorder, charge noise, and valley splitting, these findings provide a benchmark for silicon as a host semiconductor for quantum dot qubits. We foresee the application of these heterostructures in larger, high-performance quantum processors

COVID-19 in pediatric nephrology centers in Turkey

Background/aim: There is limited data on COVID-19 disease in children with kidney disease. We aimed to investigate the characteristics and prognosis of COVID-19 in pediatric nephrology patients in Turkey. Materials and methods: This was a national, multicenter, retrospective cohort study based on an online survey evaluating the data between 11th March 2020 and 11th March 2021 as an initial step of a detailed pediatric nephrology COVID-19 registry. Results: Two hundred and three patients (89 girls and 114 boys) were diagnosed with COVID-19. One-third of these patients (36.9%) were between 10–15 years old. Half of the patients were on kidney replacement therapy: kidney transplant (KTx) recipients (n = 56, 27.5%), patients receiving chronic hemodialysis (n = 33, 16.3%) and those on peritoneal dialysis (PD) (n = 18, 8.9%). Fifty-four (26.6%) children were asymptomatic. Eighty-two (40.3%) patients were hospitalized and 23 (28%) needed intensive care unit admission. Fifty-five percent of the patients were not treated, while the remaining was given favipiravir (20.7%), steroid (16.3%), and hydroxychloroquine (11.3%). Acute kidney injury developed in 19.5% of hospitalized patients. Five (2.4%) had MIS-C. Eighty-three percent of the patients were discharged without any apparent sequelae, while 7 (3.4%) died. One hundred and eight health care staff were infected during the study period. Conclusion: COVID-19 was most commonly seen in patients who underwent KTx and received HD. The combined immunosuppressive therapy and frequent exposure to the hospital setting may increase these patients’ susceptibility. Staff infections before vaccination era were alarming, various precautions should be taken for infection control, particularly optimal vaccination coverage