436 research outputs found
Yatırımcı duyarlılığı temsilcilerive sermaye getirilerinin tahmini
Yatırımcı duyarlılığı davranışsal modellerin dayandığı temellerden biridir. Bu modeller, klasik teorilerin aksine duyarlılığa konu olan irrasyonel yatırımcıların piyasada aşırı ya da düşük değerlemelere
yol açtığı, dolayısıyla fiyatların dengeye gelemediğine ilişkin ampirik bulgular sunmaktadır. Yatırımcı
duyarlılığı, piyasadaki yatırımcıların ya da işlemcilerin eldeki bilgiler ile açıklanamayan inanışları olarak bilinmektedir. Duyarlılığın etkileri bu nedenle ilgi çekmektedir. Sermaye getirilerini tahmin eden
modellere uygulanan testler bu etkileri ölçmek için uygundur. Bu çalışmada yatırımcı duyarlılığı olarak
kullanılabilecek ölçütler ortaya konmuş ve bu ölçütleri temsil eden göstergelerin duyarlılığı ifade etmedeki başarısı tartışılmıştır. Temsilciler hakkında geniş bir literatür taraması sunan çalışmada, ayrıca
yoğun olarak kullanılan kapalı uçlu yatırım fonu iskontosu, Baker ve Wurgler bileşik duyarlılık endeksi
ile tüketici güveni ve duyarlılığını gösteren anketlere detaylı yer verilmiş ve getiriyi tahmin etme güçleri tartışılmıştır. Bu çalışma ile yatırımcı duyarlılığı ölçütü seçiminde araştırmacılara yol gösterilmesi
amaçlanmaktadır
Frequent demonstration of human herpesvirus 8 (HHV-8) in bone marrow biopsy samples from Turkish patients with multiple myeloma (MM)
In order to investigate the frequency of HHV-8 in MM patients from another geographic location, we obtained fresh bone marrow (BM) biopsies from Turkish patients with MM (n = 21), monoclonal gammopathy of undetermined significance (MGUS) (n = 2), plasmacytoma (n = 1) with BM plasma cell infiltration, various hematological disorders (n = 6), and five healthy Turkish controls. The frequency of HHV-8 was analyzed by polymerase chain reaction (PCR) in two independent laboratories in the USA and in Turkey. Using fresh BM biopsies, 17/21 MM patients were positive for HHV-8 whereas all five healthy controls, and six patients with other hematological disorders were negative. Two patients with MGUS, and one patient with a solitary plasmacytoma were also negative. The data from the two laboratories were completely concordant. Also using primer pairs for v IRF and v IL-8R confirmed the results observed with the KS330233 primers. Furthermore, sequence analysis demonstrated a C3 strain pattern in the ORF26 region which was also found in MM patients from the US. Thus, HHV-8 is present in the majority of Turkish MM patients, and the absence of the virus in healthy controls further supports its role in the pathogenesis of MM
Nonlinear behaviour of epoxy and epoxy-based nanocomposites: an integrated experimental and computational analysis
The focus of this study is on the nonlinear mechanical properties of epoxy and epoxy-based nanocomposites, exploring frequency and strain amplitude dependency. Nanocomposite samples of epoxy are reinforced with fumed silica (FS), halloysite nanotubes (HNT) and Albipox 1000 rubber (Evonik) nanoparticles. Considering these particles have different geometries and stiffnesses, they are expected to have significantly different influences on the mechanics of the resulting composite. To enhance the reliability of the results and to reveal the impact of nanofillers on the mechanics of the material more distinctly, the manufacturing process is designed to be the same for all the specimens within the same material groups to eliminate the effects of the manufacturing process. The comprehensive characterization process consists of Fourier-Transform InfraRed Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Dynamic Mechanical Analysis (DMA). The DMA tests are designed so that the material properties are measured depending on the vibration frequency and strain amplitude. Finally, the characterized nonlinear dynamic properties of these nanocomposites are used as the input material properties into a numerical model. In this simulation, a cantilever beam with representative nonlinear material properties, for these nanocomposites, is created, as example and its forced response is plotted under the same levels of excitation in the frequency domain. Key effects of the different nanofillers are identified using the resonance behavior, primarily focusing on the stiffness and damping of the epoxy-based nanocomposites. These experimental and numerical procedures followed show the significant impact of the nanoparticle reinforcements on the nonlinear nature of these epoxy-based composites
Genetic characterization of native donkey (Equus asinus) populations of Turkey using microsatellite markers
This study presents the first insights to the genetic diversity and structure of the Turkish donkey populations. The primary objectives were to detect the main structural features of Turkish donkeys by microsatellite markers. A panel of 17 microsatellite markers was applied for genotyping 314 donkeys from 16 locations of Turkey. One hundred and forty‐two alleles were identified and the number of alleles per locus ranged from 4 to 12. The highest number of alleles was observed in AHT05 (12) and the lowest in ASB02 and HTG06 (4), while ASB17 was monomorphic. The mean HO in the Turkish donkey was estimated to be 0.677, while mean HE was 0.675. The polymorphic information content (PIC) was calculated for each locus and ranged from 0.36 (locus ASB02) to 0.98 (locus AHT05), which has the highest number of alleles per locus in the present study. The average PIC in our populations was 0.696. The average coefficient of gene differentiation (GST) over the 17 loci was 0.020 ± 0.037 (p < 0.01). The GST values for single loci ranged from −0.004 for LEX54 to 0.162 for COR082. Nei’s gene diversity index (Ht) for loci ranged from 0.445 (ASB02) to 0.890 (AHT05), with an average of 0.696. A Bayesian clustering method, the Structure software, was used for clustering algorithms of multi‐locus genotypes to identify the population structure and the pattern of admixture within the populations. When the number of ancestral populations varied from K = 1 to 20, the largest change in the log of the likelihood function (ΔK) was when K = 2. The results for K = 2 indicate a clear separation between Clade I (KIR, CAT, KAR, MAR, SAN) and Clade II (MAL, MER, TOK, KAS, KUT, KON, ISP, ANT, MUG, AYD and KAH) populations. © 2020 by the authors. Licensee MDPI, Basel, Switzerland
Polymyalgia Rheumatica (PMR) Special Interest Group at OMERACT 11: outcomes of importance for patients with PMR
We worked toward developing a core outcome set for clinical research studies in polymyalgia rheumatica (PMR) by conducting (1) patient consultations using modified nominal group technique; (2) a systematic literature review of outcome measures in PMR; (3) a pilot observational study of patients presenting with untreated PMR, and further discussion with patient research partners; and (4) a qualitative focus group study of patients with PMR on the meaning of stiffness, using thematic analysis. (1) Consultations included 104 patients at 4 centers. Symptoms of PMR included pain, stiffness, fatigue, and sleep disturbance. Function, anxiety, and depression were also often mentioned. Participants expressed concerns about diagnostic delay, adverse effects of glucocorticoids, and fear of relapse. (2) In the systematic review, outcome measures previously used for PMR include pain visual analog scores (VAS), morning stiffness, blood markers, function, and quality of life; standardized effect sizes posttreatment were large. (3) Findings from the observational study indicated that asking about symptom severity at 7 AM, or "on waking," appeared more relevant to disease activity than asking about symptom severity "now" (which depended on the time of assessment). (4) Preliminary results were presented from the focus group qualitative study, encompassing broad themes of stiffness, pain, and the effect of PMR on patients' lives. It was concluded that further validation work is required before a core outcome set in PMR can be recommended. Nevertheless, the large standardized effect sizes suggest that pain VAS is likely to be satisfactory as a primary outcome measure for assessing response to initial therapy of PMR. Dissection of between-patient heterogeneity in the subsequent treatment course may require attention to comorbidity as a potential confounding factor
Sinusoidal obstruction syndrome/veno-occlusive disease: current situation and perspectives—a position statement from the European Society for Blood and Marrow Transplantation (EBMT)
Sinusoidal obstruction syndrome or veno-occlusive disease (SOS/VOD) is a potentially life-threatening complication of hematopoietic SCT (HSCT). This review aims to highlight, on behalf of the European Society for Blood and Marrow Transplantation, the current knowledge on SOS/VOD pathophysiology, risk factors, diagnosis and treatments. Our perspectives on SOS/VOD are (i) to
accurately identify its risk factors; (ii) to define new criteria for its diagnosis; (iii) to search for SOS/VOD biomarkers and (iv) to propose prospective studies evaluating SOS/VOD prevention and treatment in adults and children
Aneurysm Ostium Angle: A Predictor of the Need for Stent as Assistance for Endovascular Aneurysm Coiling in Internal Carotid Artery Sidewall Aneurysms
BACKGROUND AND PURPOSE: There is no satisfactory parameter that can predict the need for assistant devices for endovascular aneurysm coiling. Our aim was to evaluate the utility of MOA as a predictor of the need for stent-assisted coiling in ICA sidewall aneurysms
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