1,013 research outputs found

    The Role of Physical, Human and Social Capital in Regional Financial Development Differences: An Analysis of Turkish Provinces

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    The Role of Physical, Human and Social Capital in Regional Financial Development Differences: An Analysis of Turkish Provinces Ercan Dulgeroglu , Sibel Bali Eryigit , Kadir Y. Eryigit and Filiz Gaygusuz Abstract With the undeniable importance of the financial markets in the economy, the factors stimulating financial development have started to be researched, particularly in recent times in a more intensive way. Starting from this point, the driving force of this study is both to contribute to international literature in this field and to fill a gap in the literature related to Turkey. The main purpose of this study is to explain the causes of regional financial development differences on the basis of capital accumulation. In order to answer the question ‘What is the effect and degree of importance of physical, human and social capital on the differences in regional financial development?’, in this study some indexes for financial development and each type of capital accumulation will be calculated using kernel principle components analysis and depending on the annual data of 81 provinces covering the period 2005 – 2009. As an index, the capital measurements can be seen in a comprehensive form allowing for more accurate measurement and evaluation of both the capital accumulation and financial development. By using the calculated indexes, then, financial development differences are evaluated with spatial panel data methods developed by Elhorst (2003). In this context, to our knowledge, this study is the first to take into account the effects of each type of capital on financial development in a model simultaneously. Keywords: Financial development, physical capital, human capital, social capital, spatial panel data analysis,

    Impact of lattice dynamics on the phase stability of metamagnetic FeRh: Bulk and thin films

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    We present phonon dispersions, element-resolved vibrational density of states (VDOS) and corresponding thermodynamic properties obtained by a combination of density functional theory (DFT) and nuclear resonant inelastic X-ray scattering (NRIXS) across the metamagnetic transition of B2 FeRh in the bulk material and thin epitaxial films. We see distinct differences in the VDOS of the antiferromagnetic (AF) and ferromagnetic (FM) phase which provide a microscopic proof of strong spin-phonon coupling in FeRh. The FM VDOS exhibits a particular sensitivity to the slight tetragonal distortions present in epitaxial films, which is not encountered in the AF phase. This results in a notable change in lattice entropy, which is important for the comparison between thin film and bulk results. Our calculations confirm the recently reported lattice instability in the AF phase. The imaginary frequencies at the XX-point depend critically on the Fe magnetic moment and atomic volume. Analyzing these non vibrational modes leads to the discovery of a stable monoclinic ground state structure which is robustly predicted from DFT but not verified in our thin film experiments. Specific heat, entropy and free energy calculated within the quasiharmonic approximation suggest that the new phase is possibly suppressed because of its relatively smaller lattice entropy. In the bulk phase, lattice degrees of freedom contribute with the same sign and in similar magnitude to the isostructural AF-FM phase transition as the electronic and magnetic subsystems and therefore needs to be included in thermodynamic modeling.Comment: 15 pages, 12 figure

    Nuclear Inelastic X-Ray Scattering of FeO to 48 GPa

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    The partial density of vibrational states has been measured for Fe in compressed FeO (w\"ustite) using nuclear resonant inelastic x-ray scattering. Substantial changes have been observed in the overall shape of the density of states close to the magnetic transiton around 20 GPa from the paramagnetic (low pressure) to the antiferromagnetic (high pressure) state. Our data indicate a substantial softening of the aggregate sound velocities far below the transition, starting between 5 and 10 GPa. This is consistent with recent radial x-ray diffraction measurements of the elastic constants in FeO. The results indicate that strong magnetoelastic coupling in FeO is the driving force behind the changes in the phonon spectrum of FeO.Comment: 4 pages, 4 figure

    Hidden carbon in Earth’s inner core revealed by shear softening in dense Fe₇C₃

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    Earth’s inner core is known to consist of crystalline iron alloyed with a small amount of nickel and lighter elements, but the shear wave (S wave) travels through the inner core at about half the speed expected for most iron-rich alloys under relevant pressures. The anomalously low S-wave velocity (v_S) has been attributed to the presence of liquid, hence questioning the solidity of the inner core. Here we report new experimental data up to core pressures on iron carbide Fe_7C_3, a candidate component of the inner core, showing that its sound velocities dropped significantly near the end of a pressure-induced spin-pairing transition, which took place gradually between 10 GPa and 53 GPa. Following the transition, the sound velocities increased with density at an exceptionally low rate. Extrapolating the data to the inner core pressure and accounting for the temperature effect, we found that low-spin Fe_7C_3 can reproduce the observed v_S of the inner core, thus eliminating the need to invoke partial melting or a postulated large temperature effect. The model of a carbon-rich inner core may be consistent with existing constraints on the Earth's carbon budget and would imply that as much as two thirds of the planet's carbon is hidden in its center sphere

    Nitrosylation of nitric-oxide-sensing regulatory proteins containing [4Fe-4S] clusters gives rise to multiple iron-nitrosyl complexes

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    The reaction of protein-bound iron–sulfur (Fe-S) clusters with nitric oxide (NO) plays key roles in NO-mediated toxicity and signaling. Elucidation of the mechanism of the reaction of NO with DNA regulatory proteins that contain Fe-S clusters has been hampered by a lack of information about the nature of the iron-nitrosyl products formed. Herein, we report nuclear resonance vibrational spectroscopy (NRVS) and density functional theory (DFT) calculations that identify NO reaction products in WhiD and NsrR, regulatory proteins that use a [4Fe-4S] cluster to sense NO. This work reveals that nitrosylation yields multiple products structurally related to Roussin's Red Ester (RRE, [Fe2(NO)4(Cys)2]) and Roussin's Black Salt (RBS, [Fe4(NO)7S3]. In the latter case, the absence of 32S/34S shifts in the Fe−S region of the NRVS spectra suggest that a new species, Roussin's Black Ester (RBE), may be formed, in which one or more of the sulfide ligands is replaced by Cys thiolates

    Turner syndrome and associated problems in turkish children: A multicenter study

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    Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population. Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014. Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosi) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto’s thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%. Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan. © Journal of Clinical Research in Pediatric Endocrinology

    Measuring velocity of sound with nuclear resonant inelastic x-ray scattering

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    Nuclear resonant inelastic x-ray scattering is used to measure the projected partial phonon density of states of materials. A relationship is derived between the low-energy part of this frequency distribution function and the sound velocity of materials. Our derivation is valid for harmonic solids with Debye-like low-frequency dynamics. This method of sound velocity determination is applied to elemental, composite, and impurity samples which are representative of a wide variety of both crystalline and noncrystalline materials. Advantages and limitations of this method are elucidated

    Aurora kinase A drives the evolution of resistance to third-generation EGFR inhibitors in lung cancer.

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    Although targeted therapies often elicit profound initial patient responses, these effects are transient due to residual disease leading to acquired resistance. How tumors transition between drug responsiveness, tolerance and resistance, especially in the absence of preexisting subclones, remains unclear. In epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma cells, we demonstrate that residual disease and acquired resistance in response to EGFR inhibitors requires Aurora kinase A (AURKA) activity. Nongenetic resistance through the activation of AURKA by its coactivator TPX2 emerges in response to chronic EGFR inhibition where it mitigates drug-induced apoptosis. Aurora kinase inhibitors suppress this adaptive survival program, increasing the magnitude and duration of EGFR inhibitor response in preclinical models. Treatment-induced activation of AURKA is associated with resistance to EGFR inhibitors in vitro, in vivo and in most individuals with EGFR-mutant lung adenocarcinoma. These findings delineate a molecular path whereby drug resistance emerges from drug-tolerant cells and unveils a synthetic lethal strategy for enhancing responses to EGFR inhibitors by suppressing AURKA-driven residual disease and acquired resistance

    Mechanism of selective benzene hydroxylation catalyzed by iron-containing zeolites

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    A direct, catalytic conversion of benzene to phenol would have wide-reaching economic impacts. Fe zeolites exhibit a remarkable combination of high activity and selectivity in this conversion, leading to their past implementation at the pilot plant level. There were, however, issues related to catalyst deactivation for this process. Mechanistic insight could resolve these issues, and also provide a blueprint for achieving high performance in selective oxidation catalysis. Recently, we demonstrated that the active site of selective hydrocarbon oxidation in Fe zeolites, named α-O, is an unusually reactive Fe(IV)=O species. Here, we apply advanced spectroscopic techniques to determine that the reaction of this Fe(IV)=O intermediate with benzene in fact regenerates the reduced Fe(II) active site, enabling catalytic turnover. At the same time, a small fraction of Fe(III)-phenolate poisoned active sites form, defining a mechanism for catalyst deactivation. Density-functional theory calculations provide further insight into the experimentally defined mechanism. The extreme reactivity of α-O significantly tunes down (eliminates) the rate-limiting barrier for aromatic hydroxylation, leading to a diffusion-limited reaction coordinate. This favors hydroxylation of the rapidly diffusing benzene substrate over the slowly diffusing (but more reactive) oxygenated product, thereby enhancing selectivity. This defines a mechanism to simultaneously attain high activity (conversion) and selectivity, enabling the efficient oxidative upgrading of inert hydrocarbon substrates

    Antioxidant and antiproliferative effects of different Raphanus Sativus L. extracts

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    This study aimed to investigate the phenolic and flavonoid levels, antioxidant activities and antiproliferative effects of Japanese, Chinese, Black, and Kohlrabi radish species on HEK293 immortalized human embryonic kidney cells in cell culture medium. DPPH radical scavenging activity, total polyphenol, and flavonoid content of the extracts were measured spectrophotometrically. The highest total flavonoid content in sap of radish extraction and methanolic extraction was 0.12±0.02 mg/g RE and 0.10±0.00 mg/g RE in Chinese radish; the highest total polyphenol content was 0.32±0.03 mg/g GAE and 0.23±0.03 mg/g GAE in Black radish; the DPPH radical scavenging activity is approved 39.68±2.43 µg/g GAE in Japanese radish in sap of radish extraction and 84.59±3.50 µg/g GAE in Black radish in methanolic extraction respectively. DPPH radical scavenging activity was higher in the methanolic extraction of all radishes. The antiproliferative effects of different extracts in HEK293 cells were investigated by the MTT method. The IC50 concentration was found at lower doses in the methanolic extraction of whole radishes compared to the sap of radish extractions. The lowest dose of antiproliferative effect was observed in red radish (160 mg/ml) in methanolic extraction, and the antiproliferative effect increased dose-dependent. As a result, both antioxidant content and antiproliferative effect may vary depending on the type of radish, soil, and geographical conditions of the region where it is grown
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