8,080 research outputs found

    Two-stage bimodal volcanism in a Late Cretaceous arc/back-arc setting, NE Turkey: Constraints from volcano-stratigraphy, zircon U–Pb and 40Ar/39Ar geochronology and whole-rock elemental and Sr-Nd-Pb isotope geochemistry

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    © 2023 Elsevier B.V.The eastern Blacksea magmatic arc (EBMA) in the eastern Sakarya Zone (ESZ) provides an excellent opportunity to investigate birth of an extensional intra-arc and back-arc settings in the Late Cretaceous over the Early Cretaceous northern passive margin of the Neotethys Ocean. Volcano-stratigraphy clearly shows that the Late Cretaceous volcanic activity of the EBMA occurred in two major phases. Bimodality, characterized by mafic/basaltic rocks at the base and felsic/silicic types on top of it, is a typical feature of the lower (LVS) and upper (UVS) volcanic successions in the Giresun region of the ESZ. U–Pb and Ar–Ar ages support the volcanic succession as two-stage (LVS: ca. 92–85 and UVS: ca. 83–67 Ma) bimodal volcanism. Both the volcanic successions are represented by similar rock types consisting of tholeiitic to calc-alkaline basalt-basaltic andesites and calc-alkaline to shoshonitic dacite-rhyolites. Basaltic (M1- and M2-series) and felsic/silicic (F1- and F2-series) samples of the LVS and UVS have an arc-like signature with enriched large ion lithophile elements (LILEs) and light rare earth elements (LREEs) and depleted high field strength elements (HFSEs). Also, the felsic/silicic samples of the F1- and F2-series show prominent negative Sr and Eu anomalies (Eu/Eu* = 0.4 to 0.9), suggesting that plagioclase fractionation played a key role on the evolution of both felsic series. Bimodal rock series in two phases have a wide range of 87Sr/86Sr(i) (0.7048–0.7075) and 143Nd/144Nd(i) (0.5123–0.5127) ratios with variable ɛNd(i) values of −3.8 to +3.0. 206Pb/204Pb(i), 207Pb/204Pb(i) and 208Pb/204Pb(i) isotope ratios of the Giresun volcanic rocks vary in the range of 17.97–18.52, 15.55–15.65 and 37.53–38.56, respectively. Geochemical and isotopic data suggest that the parental magma of the M1-basaltic rocks were probably derived from a shallow (spinel-bearing) mantle metasomatized by slab/sediment-derived fluids. In contrast, the M2-basalts seem to have been originated from a deeper mantle source (spinel-garnet transition zone) enriched by slab/sediment-derived fluids and hydrous melts (bulk sediment) metasomatism with some contributions of lower/upper crustal materials. The least evolved basaltic samples in two phases are consistent with moderate (∼10–15%) to high degree (∼20–30%) partial melting of the metasomatized mantle. The silicic melts of the F1- and F2-rocks series, on the other hand, were likely derived from melting of lower crustal materials consisting of meta-basalts/andesites and lesser amount of meta-sediments. Subsequently, these melts experienced FC ± AFC and mixing processes during their ascent and emplacement to generate high-silica (rhyolitic) melts. Our data, combined with previous studies, suggest that two-stage bimodal volcanic rocks of the Late Cretaceous in the ESZ were formed in the transition from an extensional continental intra-arc to a back-arc setting during the northward subduction of the northern branch of Neotethys Ocean

    Beyond expectations: disease duration and psychological burden in psoriatic arthritis

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    This study aims to investigate the relationship between disease duration and psychological burden in PsA and to identify the risk factors associated with psychological distress. Patients with PsA who met CASPAR classification criteria enrolled by Turkish League Against Rheumatism (TLAR)-Network. Patients were categorized into three groups based on disease duration: early stage (< 5 years), middle stage (& GE; 5, < 10 years), and late stage (& GE; 10 years). All patients underwent clinical and laboratory assessment using standardized protocol and case report forms. The associations between psychological variables and clinical parameters were assessed by a multivariate analysis. Of the 1113 patients with PsA (63.9% female), 564 (%50.7) had high risk for depression and 263 (%23.6) for anxiety. The risk of psychological burden was similar across all PsA groups, and patients with a higher risk of depression and anxiety also experienced greater disease activity, poorer quality of life, and physical disability. Multivariate logistic regression revealed that female gender (OR = 1.52), PsAQoL (OR = 1.13), HAQ (OR = 1.99), FiRST score (OR = 1.14), unemployment/retired (OR = 1.48) and PASI head score (OR = 1.41) were factors that influenced the risk of depression, whereas the current or past enthesitis (OR = 1.45), PsAQoL (OR = 1.19), and FiRST score (OR = 1.26) were factors that influenced the risk of anxiety. PsA patients can experience a comparable level of psychological burden throughout the course of their disease. Several socio-demographic and disease-related factors may contribute to mental disorders in PsA. In the present era of personalized treatment for PsA, evaluating psychiatric distress can guide tailored interventions that improve overall well-being and reduce disease burden

    The ameliorative effect of Primula vulgaris on cisplatin-induced nephrotoxicity in rats and quantification of its phenolic components using LC-ESI-MS/MS

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    Cisplatin (CDDP) is an important chemotherapeutic agent, accumulation of which in kidney tissue causes nephrotoxicity and renal failure. The aim of this study was to evaluate, for the first time in the literature, the protective effect of dimethyl sulfoxide (DMSO) extract of Primula vulgaris leaf (PVE) against CDDP-induced nephrotoxicity in rats.The PVE content was characterized using liquid chromatography-mass spectrometry. Nephrotoxicity was induced with a single dose of CDDP (7.5 mg/kg). Thirty female Wistar-Albino rats were divided into five groups (control, DMSO, CDDP (7.5 mg/kg), CDDP + PVE (25 mg/kg), and CDDP + PVE (50 mg/kg)). Biochemical and histopathological analyses were then performed.Rutin, gallic acid, p-coumaric acid and protocatechuic acid were identified as major components of PVE. Total antioxidant status and glutathione (GSH) values increased significantly in the serum samples from the treatment group compared to the CDDP group, while blood urea nitrogen, creatinine, oxidative stress index, malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), total oxidant status, and 8-hydroxy-2′-deoxyguanosine (8-OHdG) values decreased significantly. GSH levels increased significantly in the treatment group compared to the CDDP group, while TNF-α, caspase-3, 8-OHdG, MDA levels and damage scores decreased significantly.In conclusion, PVE exhibited strong protective effects through its anti-apoptotic, antioxidant, and anti-inflammatory activities against nephrotoxicity and oxidative damage caused by CDDP in rats

    AN APPLICATION OF AGENT-BASED TRAFFIC FLOW MODEL FOR MARITIME SAFETY MANAGEMENT EVALUATION

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    This paper aims to analyze maritime traffic safety assessment via a traffic flow simulation model. The model was developed via the NetLogo platform, agent-based modeling, and simulation approach. And it is implemented on an open sea area, at the Aegean Sea to show its applicability. The model is verified through experiments conducted in the area. The simulation outputs give the risky locations and scores. Dangerous locations and risk scores in the area are determined as the outputs of the simulation runs. A traffic separation scheme is established to prove the model's suitability as adaptable and updatable. After the scheme is implemented, the potential collision locations and scores change considerably. The developed model is convenient to simulate various conditions by changing the input parameters on maritime traffic safety.</jats:p

    OECD Ülkelerinde Yolsuzluk ve Belirleyicilerinin Hiyerarşik Kümeleme ile Analizi

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    Yolsuzluk siyasi, iktisadi ve mali birçok göstergede bozulmalara yol açan temel bir sorundur. Söz konusu göstergelerin de yolsuzluğun düzeyi üzerinde etkili olabilmesi, yolsuzluğun uzun vadeli olarak ele alınmasını gerektirmektedir. Bu bağlamda, çalışmanın amacı yolsuzlukla birlikte sosyoekonomik faktörler kapsamında OECD ülkelerinin nasıl kümelendiklerini ortaya koymaktır. Çalışmada 2014-2020 yıllarına ait yolsuzluk ve yolsuzlukla ilişkili seçilmiş değişkenler kullanılarak hiyerarşik kümeleme esas alınmış ve Ward Minimum Varyans yöntemi ile analiz edilmiştir. Elde edilen sonuçlara göre, OECD ülkelerinin iki ana kümeye ayrıldığı ve bazı ülkelerde benzerlikler bakımından yakınsamalar olduğu tespit edilmiştir. Yakınsan ülkelerin ise benzer siyasi, iktisadi ve mali tecrübelere sahip oldukları görülmüştür.Corruption is a pervasive challenge that negatively impacts various political, economic, and financial indicators. Addressing corruption necessitates a comprehensive and sustained effort towards corruption control to enhance the effectiveness of such indicators. This study aims to investigate the clustering of OECD countries based on socioeconomic factors and corruption. Specifically, hierarchical clustering using the Ward Minimum Variance method was conducted on selected corruption-related variables for 2014-2020. The findings reveal the division of OECD countries into two primary clusters, with similarities identified among certain countries. Convergent countries share common political, economic, and financial experiences

    The effect of the calcium channel blocker nimodipine on hippocampal BDNF/Ach levels in rats with experimental cognitive impairment

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    Objective: Alzheimer’s disease (AD) occurs in approximately 10% to 30% of individuals aged 65 or older worldwide. Novel therapeutic agents therefore need to be discovered in addition to traditional medications. Nimodipine appears to possess the potential to reverse cognitive impairment-induced dysfunction in learning and memory through its regulatory effect on the brain-derived neurotrophic factor (BDNF), acetylcholine (Ach), and acetylcholinesterase (AChE) pathway in the hippocampus and prefrontal cortex. Methods: Twenty-four male Sprague Dawley rats weighing 380 ± 10 g were used for behavioral and biochemical analyses. These were randomly and equally assigned into one of three groups. Group 1 received saline solution alone via the intraperitoneal (i.p) route, and Group 2 received 1 mg/kg/day i.p. scopolamine once a day for three weeks for induction of learning and memory impairments. In Group 3, 10 mg/kg/day nimodipine was prepared in tap water and administered orally every day for three weeks, followed after 30 min by 1 mg/kg/day scopolamine i.p. Behavior was evaluated using the Morris Water Maze test. BDNF, ACh, and AChE levels were determined using the ELISA test in line with the manufacturer’s instructions. Results: Nimodipine treatment significantly increased the time spent in the target quadrant and the number of entries into the target quadrant compared to the scopolamine group alone. Additionally, BDNF and ACh levels in the hippocampus and prefrontal cortex decreased following 20-day scopolamine administration, while AChE activation increased. Conclusion: Nimodipine exhibited potentially beneficial effects by ameliorating cognitive decline following scopolamine administration in the hippocampus and prefrontal cortex

    Agomelatine attenuates cisplatin-induced cognitive impairment via modulation of BDNF/TrkB signaling in rat hippocampus

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    Cisplatin is a drug used effectively in the treatment of malignant tumors. However, cisplatin has many side effects, including cognitive impairment. Agomelatine, a synthetic melatonin analogue, is an important antidepressant. Increasing evidence has shown that agomelatine may be a potential neuroprotective agent. The aim of this study was to investigate the effect of agomelatine on learning and memory functions in cisplatin-induced cognitive impairment in a rat model. Male rats were administered agomelatine and cisplatin for 4 weeks. Neurobehavioral tests were performed at the end of the 4th week. After behavioral tests, rats were euthanized and BDNF, TNF, IL-1β, MDA and GSH levels were measured in hippocampal homegenates by ELISA. In addition, nNOS and TrkB receptor activity were measured immunohistochemically. The results showed that agomelatine significantly improved cognitive functions in spatial memory tests in rats with cisplatin-induced cognitive impairment. In addition, agomelatine treatment positively affected the discrimination index (DI). On the other hand, agomelatine treatment elevated cisplatin-suppressed hippocampal BDNF levels. Agomelatine treatment reduced cisplatin-induced neuroinflammation by suppressing TNF and IL-1β levels. Similarly, agomelatine reduced oxidative stress in the hippocampus. Histological findings showed that agomelatine treatment reduced pyramidal neuron damage in hippocampal DG, CA1 and CA3. Cisplatin increased nNOS and TrkB positivity in DG, CA1 and CA3 neurons compared to control. In contrast, agomelatine treatment decreased both nNOS and TrkB positive scores. These findings indicate that agomelatine reduces cisplatin-related cognitive impairment by exerting anti-inflammatory action and possibly by the modulation of the BDNF/TrkB/nNOS pathways in the hippocampus

    Öğretmenlik Kariyer Basamakları ve Yazılı Sınavına İlişkin Türkçe Öğretmenlerinin Görüşleri: Neyi, Nasıl Algılıyor, Yorumluyor ve Öneriyorlar?

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    Öğretmenlerin mesleki gelişimi, kariyerleri boyunca devam etmesi gereken ve hem kendi öğretim stratejilerini gözden geçirme imkânı buldukları hem de öğrencilerin ihtiyaçlarını nasıl karşılayabileceklerini öğrendikleri bir süreçtir. Başarılı bir kariyer gelişimi, öğretmenlerin kendilerini bu sürecin içerisinde nasıl konumlandırdıklarına bağlıdır. Çalışmada, öğretmenlik kariyer basamaklarına ve 19 Kasım 2022 tarihinde uygulanan yazılı sınavına ilişkin Türkçe öğretmenlerinin görüşlerine başvurulmuştur. Görüşler doğrultusunda sınavın tutarlılığı, niteliği, kapsayıcılığı, işlevselliği ve güvenilirliği ile Türkçe öğretmenlerinin uzmanlık ve başöğretmenlik kariyer basamaklarına ilişkin değerlendirmeler yapılmıştır. Temel nitel araştırma ile desenlenen bu araştırmanın çalışma grubunu, uzman öğretmenlik ve başöğretmenlik yazılı sınavına girmiş 71 Türkçe öğretmeni oluşturmaktadır. Görüşme aracılığıyla çalışma grubundan yazılı yolla veri toplanmış, toplanan veriler içerik analizine tabi tutularak tema ve alt temalar belirlenmiştir. Elde edilen bulgulardan hareketle öğretmenlerin kariyer basamaklarına yönelik yeterliklerini ölçmek için uygulanan sınava ilişkin görüşleri; uzman öğretmen ve başöğretmen olmanın yeterlikleri, sınavın kariyer basamaklarına yönelik beklentileri karşılayıp karşılamama durumu, uzman öğretmen ve başöğretmen ayrımı, sınavın kapsadığı konuların kariyer basamaklarını belirleme ve kılavuzda belirtilen konuları ölçme yeterliği olmak üzere beş ana tema etrafında analiz edilmiştir

    Dietary Acrylamide Exposure and Cancer Risk: A Systematic Approach to Human Epidemiological Studies

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    Acrylamide, identified by the International Cancer Research Center as a possible carcinogenic compound to humans, is a contaminant formed as a result of the thermal process in many foods, such as coffee, French fries, biscuits and bread, which are frequently consumed by individuals in their daily lives. The biggest concern about acrylamide is that the health risks have not yet been fully elucidated. For this reason, many studies have been carried out on acrylamide in the food, nutrition and health equation. This study focused on epidemiological studies examining the associations between dietary acrylamide exposure and cancer risk. For this purpose, articles published in PubMed, Isı Web of Knowledge, Scopus and Science Direct databases between January 2002 and April 2022 were systematically examined using various keywords, and a total of 63 articles were included in the study. Although some studies on reproductive, urinary, gastrointestinal, respiratory and other systems and organs stated that there is a positive relationship between dietary acrylamide exposure and cancer risk, many publications did not disclose a relationship in this direction. Studies examining the relationship between dietary acrylamide exposure and cancer should be planned to include more people and foods in order to obtain more reliable results. Making research plans in this way is very important in terms of guiding health policies to be formed in the future

    Expanding the clinical and immunological phenotypes of PAX1-deficient SCID and CID patients

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    Paired box 1 (PAX1) deficiency has been reported in a small number of patients diagnosed with otofaciocervical syndrome type 2 (OFCS2). We described six new patients who demonstrated variable clinical penetrance. Reduced transcriptional activity of pathogenic variants confirmed partial or complete PAX1 deficiency. Thymic aplasia and hypoplasia were associated with impaired T cell immunity. Corrective treatment was required in 4/6 patients. Hematopoietic stem cell transplantation resulted in poor immune reconstitution with absent naïve T cells, contrasting with the superior recovery of T cell immunity after thymus transplantation. Normal ex vivo differentiation of PAX1-deficient CD34+ cells into mature T cells demonstrated the absence of a hematopoietic cell-intrinsic defect. New overlapping features with DiGeorge syndrome included primary hypoparathyroidism (n = 5) and congenital heart defects (n = 2), in line with PAX1 expression during early embryogenesis. Our results highlight new features of PAX1 deficiency, which are relevant to improving early diagnosis and identifying patients requiring corrective treatment
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