Using circuity as a network efficiency measure: the example of Paris

Cubukcu K. Mert 대한공간정보학회 2021 Spatial Information Research Vol.29 No.2

Circuity, also called as the detour index or the route factor, is the ratio of the network distance between two points to the Euclidean or ‘as-the-crow-flies’ distance. This study aims to present a simple yet effective procedure to assess the transport network efficiency in and between different parts of an urban area using circuity and concentering partitioning. As an example, the road network of the city of Paris and its vicinity is examined using planar network data from OpenStreetMap. The variation in circuity levels is analyzed by quantifying the physical structure of the street network through the use of graph theorybased topological indices. The findings reveal that the beta index, or the average number of edges per node, and the order of a node, or the number of edges connecting to a node, plan a more important role in having more direct routes with less circuity in a road network. It is concluded that that the priorities in city planning affect the efficiency of transportation and the efficiency of the network can be assessed by a simple yet effective procedure based on circuity to guide policymaking.

Ferromagnetism in Ga<SUB>0.90</SUB>Mn<SUB>0.10</SUB>As<SUB>1-y</SUB>P<SUB>y</SUB>: From The Metallic to the Impurity Band Conduction Regime

M. Cubukcu,H.J. von Bardeleben,J.L. Cantin,I. Vickridge,A. Lemaitre 한국자기학회 2010 한국자기학회 학술연구발표회 논문개요집 Vol.2010 No.12

Prognostic Significance of Human Epidermal Receptor (HER)-3 Immunohistochemical Expression in Patients with Metastatic Breast Cancer

Olmez, Omer Fatih,Evrensel, Turkkan,Cubukcu, Erdem,Ugras, Nesrin,Avci, Nilufer,Canhoroz, Mustafa,Deligonul, Adem,Hartavi, Mustafa,Olmez, Fatma,Cubukcu, Sinem,Tolunay, Sahsine,Kurt, Ender,Kanat, Ozkan Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.7

Background: Previous reports have shown that human epidermal receptor (HER)-3 overexpression may be associated with poor prognosis in patients with breast cancer, but results have been conflicting. In this study, we sought to investigate the prognostic significance of HER-3 immunohistochemical expression in patients with metastatic breast cancer. Methods: We retrospectively analyzed HER-3 immunohistochemical expression profiles in 45 paraffin-embedded specimens from patients who had been treated between 1996 and 2006 in the Department of Oncology of the Uludag University School of Medicine, Bursa, Turkey. Membranous or cytoplasmic dominant expression patterns of HER-3 were analyzed using the Rajkumar score and a cytoplasmic 4-point scoring system, respectively. Progression-free survival (PFS) and overall survival (OS) served as the main outcome measures. Results: The median PFS in the study participants was 9 months (interquartile range: 4.5-13 months), whereas the median OS was 20 months (interquartile range: 7.5-28 months). Categorization of the patient population according to HER-3 positive immunohistochemical expression did not reveal any statistically significant difference in terms of both PFS (p=0.70) and OS (p=0.81). The results of multivariable Cox regression analysis indicated that tumor size was the only independent predictor of PFS, whereas estrogen and progesterone receptor status was independently associated with OS. Conclusions: HER-3 immunohistochemical expression did not correlate with outcomes in Turkish patients with metastatic breast cancer. Although our results suggest that HER-3 expression in cancer specimens is not of prognostic significance, further prospective studies are warranted to confirm these results.

Spatial effects of transport infrastructure on regional growth: the case of Turkey

Elburz Zeynep,Cubukcu K. Mert 대한공간정보학회 2021 Spatial Information Research Vol.29 No.1

The provision of infrastructure is an important policy tool for promoting regional growth and reducing regional disparities. The main reason underlying this approach is the view that transportation promotes mobility, mobility promotes trade, and trade promotes economic growth. Based on this view, Turkey has invested in transportation infrastructure to reduce the regional economic inequalities since the 1960s. Between 2004 and 2014, governments have expended approximately 65 billion dollars for road infrastructure only. We believe that investigating the recent improvements in road infrastructure with a spatial perspective in an emerging economy as Turkey is necessary to generate more effective and practical regional policies. This study attempts to measure the latest developments of transportation infrastructure by analyzing the spatial effects of road transport infrastructure on regional economy in Turkish NUTS 2 regions between 2004 and 2014. We employ an augmented Cobb–Douglas production function model and use spatial Durbin model to estimate spatial effects. Apart from previous studies that employ spatial econometric models, we create a different spatial weight matrix for each year based on inverse distance to capture the change between the years 2004 and 2014. The results reveal that road infrastructure investment has significant and positive spatial spillover effects on regional growth. Any improvement in road transport infrastructure in a region causes a GDP increase in neighboring regions. Essentially the findings expose the importance of indirect effects of road transport infrastructure and contradict with previous non-spatial and overestimated effect results in the literature.

A Decision Making Model Proposal for Firewall Selection

( Cemal Aktürk ),( Ceren Cubukcu ) 한국인터넷정보학회 2021 KSII Transactions on Internet and Information Syst Vol.15 No.10

Covid-19 pandemic required all the world to use internet more actively. As a result, individuals and businesses are more open to digital threats. In order to provide security within the network, firewalls should be used. Firewalls act as a gateway between the corporate and the external networks. Therefore, it is more important than ever to choose the right firewall for each network. In this study, a new linear decision making model is proposed in order to find out the most suitable firewall and the estimates are completed according to this new model. Also, this model is compared with multi-objective optimization on the basis of ratio analysis (MOORA) method. This study distinguishes from other studies by proposing a new solution which ranks the firewall alternatives using linear and MOORA approaches. These approaches are used in many fields before but not in information technologies. Thus, this study can be considered quite innovative in terms of the problem it handles and the approaches used. It offers up-to-date and practical suggestions related to a decision making problem that has not been previously studied in the literature.

Patients with HER2-positive Early Breast Cancer Receiving Adjuvant Trastuzumab: Clinicopathological Features, Efficacy, and Factors Affecting Survival

Ulas, Arife,Kos, Tugba,Avci, Nilufer,Cubukcu, Erdem,Olmez, Omer Fatih,Bulut, Nilufer,Degirmenci, Mustafa Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.4

Background: The aim of the present study was to evaluate clinicopathological characteristics of our early stage breast cancer patients who are epidermal growth factor receptor 2 (HER2) overexpressed/amplified (HER2+), the efficacy of trastuzumab treatment and survival results. Materials and Methods: Patients with HER2-positive early stage breast cancer receiving adjuvant trastuzumab were investigated retrospectively. Clinicopathological features of 210 patients and treatment outcome were analysed. To evaluate survival rates, the Kaplan-Meier method was used. Univariate and multivariate analyses were conducted with the Cox regression model. Results: Mean age of the patients was 51.8, 71.9% being postmenopausal. Some 37.6% of patients were node negative, and 31% had T1 tumor size and 52.4% were positive for estrogen receptor. Of 210 patients, 89.5% completed planned 52 weeks adjuvant trastuzumab treatment. The median follow up was 27.5 months (6.0-86.0). Relapse free survival (RFS) was 68.0 months (95% CI: 62.1-74.0) and overall survival (OS) was 74.8 months (95% CI: 69.5-80.1). The 3 year OS for all patients was 92.0% and RFS was 79.6%. During follow up, relapse was detected at the rate of 14.3%. Trastuzumab associated cardiotoxicity was found at the rate of 3.3%. In univariate analyses, larger tumor size and grade III were significantly associated (p<0.05) with RFS. Multivariate analyses of covariates displaying p<0.05 identified grade III as an independent prognostic factor. Conclusions: In the present study, it was established that trastuzumab had a satisfactory safety profile and treatment efficacy as in other clinical studies and that among clinicopathological factors evaluated, only being grade 3 had a significant effect on RFS. The occurrence of relapse with adjuvant trastuzumab makes it necessary to identify molecular predictors, which will define this group better and help explain resistance to anti HER2 based therapies.

Somatostatin Receptor 2 and 5 Expressions in Gastroenteropancreatic Neuroendocrine Tumors in Turkey

Yerci, Omer,Sehitoglu, Ibrahim,Ugras, Nesrin,Cubukcu, Erdem,Yuce, Suleyman,Bedir, Recep,Cure, Erkan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.10

Background: Gastroenteropancreatic neuroendocrine tumors (GNs) are slow growing and although their incidence has increased in recent years, they are relatively rarely seen. Somatostatin analogues are used in the treatment of GNs that express somatostatin receptor (SR). We aimed to investigate the expression of SR2 and SR5 in GNs. Materials and Methods: In this study the expression of SR2 and SR5 was investigated immunohistochemically in 49 cases (26 males, 23 females) diagnosed and graded with GN according to the World Health Organization classification 2010. Results: The percentage of SR2 staining was 91.0% in grade 1, 82.8% in grade 2 and 100% in grade 3. On the other hand, the percentage of SR5 staining was 81.8% % in grade 1, 60.0% in grade 2 and 0% in grade 3. According to the tumor localization, the percentages of SR2 expression were as follows: pancreas 85.7%, stomach 100%, small bowel 70%, appendix 85.7% and rectum 100%. The percentages of SR5 expression were: pancreas 61,9%, stomach 37.5%, small bowel 70%, appendix 71.5% and rectum 66.6%. There was a significant negative correlation between ki67 percentage and SR5 expression (r=-0.341, p=0.016). Conclusions: In this study, GNs were found to highly express SR2 and SR5. Although the expression of SR2 and SR5 changed according to tumor localization, the expression of SR2 was higher than the expression of SR5 in GN. There was a significant negative correlation between ki67 and SR5. Accordingly, SR5 may be a prognostic indicator of GN.

Examining the relationship between socioeconomic structure and urban transport network efficiency: a circuity and spatial statistics based approach

Elif Su Karaaslan,K. Mert Cubukcu 대한공간정보학회 2023 Spatial Information Research Vol.31 No.5

Access to urban public transportation services is crucial for all city residents. Undoubtedly, more efficient public transportation services should be provided for the needy ones. The study aims to develop a simple yet efficient analytical approach to spatially determine the urban areas that receive inefficient public transportation services. In this study, the spatial distribution of the efficiency of public transportation and its relation to socioeconomic variables (per capita income level and population density) are examined at the neighborhood in Izmir, Turkey, level using circuity. The results from univariate and bivariate Global and Local Moran’s I analyses reveal that the high-efficiency levels are spatially clustered, Higher-income neighborhoods have better public transportation systems compared to lower-income ones. According to Bivariate Local Moran’s I analyses, among the 348 neighborhoods at least 31 and at most 81 neighborhoods are either in a High-High or Low-Low cluster for the four time periods considered. As for the relationship between circuity and density, at least 21 and at most 75 neighborhoods are a part of a cluster. The fact that there is a significant relationship between the efficiency of public transportation and socioeconomic variables calls for alteration in the planning policies regarding urban public transportation supply. Although the variation in public transport efficiency levels across the neighborhoods can partly be attributed to physical conditions, the city should provide equal accessibility and efficiency regardless of the socio-economic status of the neighborhoods. The findings can well be generalized for cities of similar sizes in developing countries.

The SOCS-1 -1478CA/del Polymorphism is not Associated with Colorectal Cancer or Age at Onset in Turkish Subjects

Hartavi, Mustafa,Kurt, Ender,Oral, Barbaros,Olmez, Omer Fatih,Cubukcu, Erdem,Deligonul, Adem,Avci, Nilufer,Manavoglu, Osman Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Background: Suppressor of cytokine signaling (SOCS)-1 acts as a key regulator of many cytokine signaling pathways and its abnormal expression has been identified in several human malignancies, suggesting potential roles in carcinogenesis. The aim of this study was to investigate any association between the functional SOCS-1 -1478CA>del polymorphism and colorectal cancer (CC) as well as age at onset in a Turkish clinical sample. Materials and Methods: A total of 122 subjects were enrolled in this case-control study (70 CC cases and 52 controls). The SOCS-1 -1478CA>del polymorphism was genotyped using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: The odds ratio of the del allele for CC relative to the CA allele was not significantly different between the groups (OR=0.71, 95% CI=0.41-1.22, p=0.27). This result did not change after adjustment for age and sex on multivariable regression analysis (OR=0.84, 95% CI=0.59-1.34, p=0.53). When the SOCS-1 -1478CA>del polymorphism was analyzed among CC patients in relation to the age at disease onset, we found no significant differences between subjects with the del/del, CA/del, and CA/CA genotypes. Conclusions: The results of our study did not point towards a major role of the SOCS-1 -1478CA>del polymorphism in the pathogenesis of CC in Turkish subjects.

Medication Errors in Chemotherapy Preparation and Administration: a Survey Conducted among Oncology Nurses in Turkey

Ulas, Arife,Silay, Kamile,Akinci, Sema,Dede, Didem Sener,Akinci, Muhammed Bulent,Sendur, Mehmet Ali Nahit,Cubukcu, Erdem,Coskun, Hasan Senol,Degirmenci, Mustafa,Utkan, Gungor,Ozdemir, Nuriye,Isikdogan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.5

Background: Medication errors in oncology may cause severe clinical problems due to low therapeutic indices and high toxicity of chemotherapeutic agents. We aimed to investigate unintentional medication errors and underlying factors during chemotherapy preparation and administration based on a systematic survey conducted to reflect oncology nurses experience. Materials and Methods: This study was conducted in 18 adult chemotherapy units with volunteer participation of 206 nurses. A survey developed by primary investigators and medication errors (MAEs) defined preventable errors during prescription of medication, ordering, preparation or administration. The survey consisted of 4 parts: demographic features of nurses; workload of chemotherapy units; errors and their estimated monthly number during chemotherapy preparation and administration; and evaluation of the possible factors responsible from ME. The survey was conducted by face to face interview and data analyses were performed with descriptive statistics. Chi-square or Fisher exact tests were used for a comparative analysis of categorical data. Results: Some 83.4% of the 210 nurses reported one or more than one error during chemotherapy preparation and administration. Prescribing or ordering wrong doses by physicians (65.7%) and noncompliance with administration sequences during chemotherapy administration (50.5%) were the most common errors. The most common estimated average monthly error was not following the administration sequence of the chemotherapeutic agents (4.1 times/month, range 1-20). The most important underlying reasons for medication errors were heavy workload (49.7%) and insufficient number of staff (36.5%). Conclusions: Our findings suggest that the probability of medication error is very high during chemotherapy preparation and administration, the most common involving prescribing and ordering errors. Further studies must address the strategies to minimize medication error in chemotherapy receiving patients, determine sufficient protective measures and establishing multistep control mechanisms.