195 research outputs found

    The effect of university campuses on the spatial cultures of two mid-sized towns: A comparative study of Nottingham, UK and Eskisehir, Turkey

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    This study focuses on the effects that university campuses and the presence of students has had on the growth and economy of two mid-sized cities. It examines the extent to which the existence of university campuses affects their local economies, and attempts to define the contribution of students to urban sustainability. Students are discussed in the context of university cities as examples of 'creative cities', so attractive to urban decision-makers. The university itself is presented as a 'creative industry', an indicator for socio-economically sustainable cities. The research then describes how universities manifest their roles in the public realm in a spatial way. To do so, two case studies are presented, Nottingham (UK) and Eskisehir (Turkey), which are similar in terms of demography and the location of their campuses. The study investigates both the relationship of campus locations with their surrounding areas, and the relationships that students have with their cities and local populations, using historical and contemporary maps, land use surveys, on site observations and questionnaire results about user activities. The research examines the historical development of the university areas in the case-study cities in terms of their spatial structure and social morphology. The campus areas are divided into three categories according to their location in the city: the 'city centre', 'edge of the city' and 'outside of the city'. The locations of student accommodation are also mapped. The main analysis explores the emergent relationships of campuses and student areas to urban centres, using space syntax measures of network accessibility and area users routes. The aim of the study is to better grasp the relationship between campus and city by considering the presence and the distribution of university buildings and students in urban space in historical perspective. It highlights a better understanding of how student populations affect the socio-economic development of cities, can contribute to a better comprehension of the 'creative city' and the 'sustainable city'

    Determination of shallow S-wave attenuation by down-hole waveform deconvolution: a case study in Istanbul (Turkey)

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    The estimation of shear-wave velocity and attenuation in near-surface geology is of primary importance in engineering seismology. In fact, their knowledge is essential for site response studies when preparing improved seismic hazard scenarios. In this study, we propose two approaches for estimating the average shear-wave quality factor Qs by using recordings of a vertical array of accelerometers. The methods are mainly based on the deconvolution of the wavefield recorded in a borehole with that recorded at the surface. The first method requires the Fourier transform of the deconvolved wavefield to be fitted with a theoretical transfer function valid for the vertical or nearly vertical (in the case at hand up to 30° incidence angle) propagation of S-waves. The second method is based on the spectral fitting of the Fourier transform of only the acausal part of the deconvolved wavefield with a theoretical transfer function. Both methods can be applied without any prior knowledge of the subsoil structure (since they are based on empirical data analysis) and do not require a precise knowledge of the azimuthal orientation of the sensors in the boreholes (which is seldom available). First, we describe the theoretical framework of the proposed methodologies for Qs estimation, which are based on the assumption that the structure in the borehole is weakly heterogeneous in the vertical direction (that is, no large impedance contrast exists between the borehole sensor and the surface). Second, by using synthetic accelerograms, we verify that in a realistic subsoil structure, the assumption of vertical homogeneity can hold and we investigate the robustness and the suitability of the proposed methods. Finally, only the method that was shown to provide the more stable results, based on fitting the borehole-to-surface spectral ratio with a theoretical function, is applied to earthquakes signals recorded by a vertical array of accelerometers installed in Ataköy (western Istanbul). Results show that using borehole data provides a fair and robust estimate of an average Qs (of about 30, 46 and 99 for the 0-50, 0-70, 0-140 m depth ranges, respectively), that can be used for numerical simulations of ground motion

    Is photobleaching necessary for Raman imaging of bone tissue using a green laser?

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    AbstractRaman microspectroscopy is widely used for musculoskeletal tissues studies. But the fluorescence background obscures prominent Raman bands of mineral and matrix components of bone tissue. A 532-nm laser irradiation has been used efficiently to remove the fluorescence background from Raman spectra of cortical bone. Photochemical bleaching reduces over 80% of the fluorescence background after 2 h and is found to be nondestructive within 40 min. The use of electron multiplying couple charge detector (EMCCD) enables to acquire Raman spectra of bone tissues within 1–5 s range and to obtain Raman images less than in 10 min

    Electronic Structure and Magnetic Exchange Coupling in Ferromagnetic Full Heusler Alloys

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    Density-functional studies of the electronic structures and exchange interaction parameters have been performed for a series of ferromagnetic full Heusler alloys of general formula Co2_2MnZ (Z = Ga, Si, Ge, Sn), Rh2_2MnZ (Z = Ge, Sn, Pb), Ni2_2MnSn, Cu2_2MnSn and Pd2_2MnSn, and the connection between the electronic spectra and the magnetic interactions have been studied. Different mechanisms contributing to the exchange coupling are revealed. The band dependence of the exchange parameters, their dependence on volume and valence electron concentration have been thoroughly analyzed within the Green function technique.Comment: 9 figures, 6 table

    Resource dedication problem in a multi-project environment

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    There can be different approaches to the management of resources within the context of multi-project scheduling problems. In general, approaches to multiproject scheduling problems consider the resources as a pool shared by all projects. On the other hand, when projects are distributed geographically or sharing resources between projects is not preferred, then this resource sharing policy may not be feasible. In such cases, the resources must be dedicated to individual projects throughout the project durations. This multi-project problem environment is defined here as the resource dedication problem (RDP). RDP is defined as the optimal dedication of resource capacities to different projects within the overall limits of the resources and with the objective of minimizing a predetermined objective function. The projects involved are multi-mode resource constrained project scheduling problems with finish to start zero time lag and non-preemptive activities and limited renewable and nonrenewable resources. Here, the characterization of RDP, its mathematical formulation and two different solution methodologies are presented. The first solution approach is a genetic algorithm employing a new improvement move called combinatorial auction for RDP, which is based on preferences of projects for resources. Two different methods for calculating the projects’ preferences based on linear and Lagrangian relaxation are proposed. The second solution approach is a Lagrangian relaxation based heuristic employing subgradient optimization. Numerical studies demonstrate that the proposed approaches are powerful methods for solving this problem

    The evaluation of doxorubicin-induced cardiotoxicity: Comparison of Doppler and tissue Doppler-derived myocardial performance index

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    Background: Doxorubicin is a chemotherapeutic agent used in a wide spectrum of cancers. However, cardiotoxic effects have limited its clinical use. The early detection of doxorubicin-induced cardiotoxicity is crucial. The purpose of our study was to assess values of Doppler and tissue Doppler imaging (TDI)-derived myocardial performance index (MPI) in adult cancer patients receiving doxorubicin treatment. Methods: A total of 45 patients underwent echocardiographic examinations before any doxorubicin had been administered and then after doxorubicin. Doppler and TDI-derived MPI of left ventricular (LV) were determined in the evaluation of cardiotoxicity. Additionally, TDI-derived MPI of right ventricular (RV) was determined. Results: All patients underwent control echocardiographic examination after mean 5 ± 1.7 months. The LV MPI obtained by both Doppler and TDI were increased after doxorubicin treatment (0.56 ± 0.11, 0.61 ± 0.10, p = 0,005 vs 0.51 ± 0.09, 0.59 ± 0.09, p = 0.001, respectively). There was no correlation between Doppler-derived MPI and cumulative doxorubicin dose (coefficient of correlation 0.11, p = 0.6). TDI-derived MPI was correlated with cumulative doxorubicin dose (coefficient of correlation 0.35, p = 0.015), but this correlation is weak (r = 0.38). The study population was divided into two groups according to doxorubicin dose (below and above 300 mg level). There was a moderate correlation between TDI-derived MPI and less than 300 mg of doxorubicin dose (coefficient of correlation 0.51, p = 0.028). However, Doppler-derived MPI was not correlated with less than 300 mg of doxorubicin dose (coefficient of correlation 0.38, p = 0.123). Also, there was no significant change in the TDI-derived RV-MPI (0.49 ± 0.14, 0.50 ± 0.12, p = 0.56). Conclusions: TDI-derived MPI is a useful parameter and an early indicator compared with Doppler-derived MPI in the detection of cardiotoxicity during the early stages. Also, doxorubicin administration does not affect RV function

    A Distinct Gene Module for Dysfunction Uncoupled from Activation in Tumor-Infiltrating T Cells

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    Reversing the dysfunctional T cell state that arises in cancer and chronic viral infections is the focus of therapeutic interventions; however, current therapies are effective in only some patients and some tumor types. To gain a deeper molecular understanding of the dysfunctional T cell state, we analyzed population and single-cell RNA profiles of CD8+tumor-infiltrating lymphocytes (TILs) and used genetic perturbations to identify a distinct gene module for T cell dysfunction that can be uncoupled from T cell activation. This distinct dysfunction module is downstream of intracellular metallothioneins that regulate zinc metabolism and can be identified at single-cell resolution. We further identify Gata-3, a zinc-finger transcription factor in the dysfunctional module, as a regulator of dysfunction, and we use CRISPR-Cas9 genome editing to show that it drives a dysfunctional phenotype in CD8+TILs. Our results open novel avenues for targeting dysfunctional T cell states while leaving activation programs intact

    Relation between the frequency of CD34+ bone marrow derived circulating progenitor cells and the number of diseased coronary arteries in patients with myocardial ischemia and diabetes

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    <p>Abstract</p> <p>Background</p> <p>Bone marrow-derived circulating progenitor cells (BM-CPCs) in patients with coronary heart disease are impaired with respect to number and mobilization. However, it is unknown whether the mobilization of BM-CPCs depends on the number of diseased coronary arteries. Therefore, in our study, we analysed the correlation between the diseased coronary arteries and the frequency of CD34/45+ BM-CPCs in peripheral blood (PB) in patients with ischemic heart disease (IHD).</p> <p>Methods</p> <p>The frequency of CD34/45<sup>+ </sup>BM-CPCs was measured by flow cytometry in 120 patients with coronary 1 vessel (IHD1, n = 40), coronary 2 vessel (IHD2, n = 40), coronary 3 vessel disease (IHD3, n = 40) and in a control group of healthy subjects (n = 40). There was no significant difference of the total number of cardiovascular risk factors between IHD groups, beside diabetes mellitus (DM), which was significantly higher in IHD3 group compared to IHD2 and IHD1 groups.</p> <p>Results</p> <p>The frequency of CD34/45<sup>+ </sup>BM-CPCs was significantly reduced in patients with IHD compared to the control group (CD34/45<sup>+</sup>; p < 0.001). The frequency of BM-CPCs was impaired in patients with IHD3 compared to IHD1 (CD34/45<sup>+</sup>; p < 0.001) and to IHD2 (CD34/45<sup>+</sup>; p = 0.001). But there was no significant difference in frequency of BM-CPCs between the patients with IHD2 and IHD1 (CD34/45<sup>+</sup>; p = 0.28). In a subgroup we observed a significant negative correlation between levels of hemoglobin AIc (HbAIc) and the frequency of BM-CPCs (CD34/45<sup>+</sup>; p < 0.001, r = -0.8).</p> <p>Conclusions</p> <p>The frequency of CD34/45<sup>+ </sup>BM-CPCs in PB is impaired in patients with IHD. This impairment may augment with an increased number of diseased coronary arteries. Moreover, the frequency of CD34/45<sup>+ </sup>BM-CPCs in ischemic tissue is further impaired by diabetes in patients with IHD.</p

    Learning lessons from the 2011 Van Earthquake to enhance healthcare surge capacity in Turkey

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    Historically, Turkey has adopted a reactive approach to natural hazards which resulted in significant losses. However, following the 1999 Kocaeli Earthquake, a more proactive approach has been adopted. This study aims to explore the way this new approach operates on the ground. A multi-national and multi-disciplinary team conducted a field investigation following the 2011 Van Earthquake to identify lessons to inform healthcare emergency planning in Turkey and elsewhere. The team interviewed selected stakeholders including, healthcare emergency responders, search and rescue services, ambulance services, and health authority representatives, in addition to conducting a focus group. Data were analysed according to an open coding process and SWOT analysis. The findings suggest that the approach succeeded in developing a single vision by consolidating official efforts in a more structured way, mobilising many governmental and non-governmental organisations, securing significant amounts of resources including physical and human, and increasing the resilience and flexibility of infrastructure to expand its capacity. However, more attention is required to the development of stronger management procedures and acquisition of further resources
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