Forward modelling of brightness variations in Sun-like stars I. Emergence and surface transport of magnetic flux

The latitudinal distribution of starspots deviates from the solar pattern with increasing rotation rate. Numerical simulations of magnetic flux emergence and transport can help model the observed stellar activity patterns and the associated brightness variations. We set up a composite model for the processes of flux emergence and transport on Sun-like stars, to simulate stellar brightness variations for various levels of magnetic activity and rotation rates. Assuming that the distribution of magnetic flux at the base of the convection zone follows solar scaling relations, we calculate the emergence latitudes and tilt angles of bipolar regions at the surface for various rotation rates, using thin-flux-tube simulations. Taking these two quantities as input to a surface flux transport SFT model, we simulate the diffusive-advective evolution of the radial field at the stellar surface, including effects of active region nesting. As the rotation rate increases, (1) magnetic flux emerges at higher latitudes and an inactive gap opens around the equator, reaching a half-width of $20^\circ$ for $8\Omega_\odot$, (2) the tilt angles of freshly emerged bipolar regions show stronger variations with latitude. Polar spots can form at $8\Omega_\odot$ by accumulation of follower-polarity flux from decaying bipolar regions. From $4\Omega_\odot$ to $8\Omega_\odot$, the maximum spot coverage changes from 3 to 20%, respectively, compared to 0.4% for the solar model. Nesting of activity can lead to strongly non-axisymmetric spot distributions. On Sun-like stars rotating at $8\Omega_\odot$ ($P_{\rm rot}\simeq 3$ days), polar spots can form, owing to higher levels of flux emergence rate and tilt angles. Defining spots by a threshold field strength yields global spot coverages that are roughly consistent with stellar observations.Comment: 16 pages, 13 figures. Astron. & Astrophys. (in press); minor language corrections mad

Teachers’ opinions regarding the symptoms of central auditory processing disorder in children with reading and writing difficulties

Central Auditory Processing Disorder (CAPD) refers to difficulties in perceptual processing of auditory information. It is a difficulty experienced by a person whose pure tone hearing, intelligence, and language abilities are within the appropriate age norms. In children with CAPD, difficulty in spelling and reading loudly can also be observed. Symptom scales (or questionnaires) are required to determine the presence of CAPD-like symptoms. If risks are found in the scales, the children are referred for diagnosis. The study reported on here aimed to investigate whether CAPD symptoms were underlying to reading and writing difficulty. Eight state schools were randomly selected. The questionnaire evaluating the presence of the CAPD symptoms was answered by 32 teachers for 328 children in total. While the children without reading and writing difficulty did not have CAPD indications, the probability of having CAPD was significantly higher in the children with reading and writing difficulties (p < 0.001). When gender effect was examined, a higher CAPD symptom score was found in males. As a result of the 18-item questionnaire, it was detected that children with CAPD symptoms had a significant disadvantage in reading and writing compared to children who did not have these symptoms. Children with CAPD symptoms should be referred for diagnosis if the CAPD indications are identified. Keywords: central auditory processing disorder; initial reading and writing skills; reading and writing difficulties; reading and writing difficulty questionnair

From the Guest Editor

Lung cancer is still a detrimental problem for physicians and surgeons. Because of having no standard treatment and poor survival, enforces us to find new approaches for its eradication. However, we have a so long way to this purpose. Genetic and cell researches to find out its real etiology and pathway are developing. But today, patients with lung cancer are waiting for some treatment methods which ease and give hope themselves immediately. Surgery is the most hopeful way for radical solution of lung cancer. Recently, new anesthetic and surgical technics give us some important advantages that were very frightfully before. In this issue, we aimed to emphasize the new researches, interventions and experimental studies about pulmonary carcinoma. All authors worked hard for this purpose. I appreciate all of them and the editor in chief Prof. Murat Sucu. I hope all articles will help us thinking and researching lung cancer in all ways. Prof. A. Feridun Işı

Consumption, consumer culture and consumer society

This paper mainly deals with the concepts and issues surrounding the contemporary notion of consumption. Consumption is a complex social phenomenon in which people consume goods or services for reasons beyond their basic use-value. Conspicuous Consumption, Symbolic Consumption, Addictive Consumption, Compulsive Consumption and Sacred Consumption are five main categories defining distinctive consumption styles. Basic characteristics of consumer culture can be summarized in the transforming of needs to desires, utilitarian/hedonic needs-values, commodity fetishism, conspicuous leisure and consumption, cultural values, aestheticization, alienation, differentiation and speed. A consumer society is one in which the entire society is organized around the consumption and display of commodities through which individuals gain prestige, identity, and standing. The paper explores the main factors fueling the engine of consumer society that has over the past few decades gained a global perspective

Características y propiedades de los ignimbritos de Bitlis y sus implicaciones ambientales

Bitlis rock is used as a construction material and comes from the lava emitted by volcanoes and their subsequent transformation into ignimbrites. This type of rocks has been characterized physically, chemi­cally, toxicologically and radioactively using different procedures including determination of the coefficient of thermal conductivity, gamma spectrometry, ultrasonic speed test, ICP masses and metal extraction. The results indicate that Bitlis rocks have an ACI greater than 1, although their content of radon is lower than other rocks of volcanic origin. Leaching of metals from these rocks indicates that Pb and Cd can provide an infiltration level in the field higher than the level permitted by TCLP and they have undesired toxicological risks. The percent­ages of extraction of other metals also point to this infiltration problem. Despite this, the material offers good qualities for usage as a building material such as its thermal coefficients.La roca Bitlis se utiliza como material de construcción y proviene de la lava emitida por los volcanes y su posterior transformación en ignimbritas. Este tipo de rocas se ha caracterizado física, química, toxicológica y radioactivamente utilizando diferentes procedimientos, incluida la determinación del coeficiente de conductividad térmica, espectrometría gamma, prueba de velocidad ultrasónica, ICP masas y extracción de metales. Los resultados indican que las rocas Bitlis tienen un ACI mayor que 1, aunque su contenido de radón es más bajo que el de otras rocas de origen volcánico. La lixiviación de metales de estas rocas indica que el Pb y el Cd pueden proporcionar un nivel de infiltración en el campo más alto que el nivel permitido por TCLP y tener riesgos toxicológicos no deseados. Los porcentajes de extracción de otros metales también apuntan a este problema de infiltración. A pesar de esto, el material ofrece buenas cualidades para su uso como material de construcción, como pueden ser sus coeficientes térmicos

Giant germ cell tumor with mediastinal localization: A report of two cases

Germ celled tumors frequently localize in anterior mediastinum.In this study we presented two germ cell tumors with different localization and huge size. We discussed two cases with germ cell tumors operated in our clinic togetherwith literature findings. Chest x-ray, computerized tomography (CT) and transthorasic tru-cut biopsy were used for diagnosis. The huge intratorasic teratomas are rarely seen and surgical full resection is the most importantfactor in survival

Existence and stability results for a coupled system of impulsive fractional differential equations with Hadamard fractional derivatives

The purpose of this study is to give some findings on the existence, uniqueness, and Hyers-Ulam stability of the solution of an implicit coupled system of impulsive fractional differential equations possessing a fractional derivative of the Hadamard type. The existence and uniqueness findings are obtained using a fixed point theorem of the type of Kransnoselskii. In keeping with this, many forms of Hyers-Ulam stability are examined. Ultimately, to support main results, an example is provided.This work was supported in part by the Basque Government under Grant IT1555-22

Fixed point approach to the Mittag-Leffler kernel-related fractional differential equations

The goal of this paper is to present a new class of contraction mappings, so-called -contractions. Also, in the context of partially ordered metric spaces, some coupled fixed-point results for -contraction mappings are introduced. Furthermore, to support our results, two examples are provided. Finally, the theoretical results are applied to obtain the existence of solutions to coupled fractional differential equations with a Mittag-Leffler kernel.This work was supported in part by the Basque Government under Grant IT1555-22

Predictions of Astrometric Jitter for Sun-like Stars. II. Dependence on Inclination, Metallicity, and Active-Region Nesting

Ultra-precise astrometry from the Gaia mission is expected to lead to astrometric detections of more than 20,000 exoplanets in our Galaxy. One of the factors that could hamper such detections is the astrometric jitter caused by the magnetic activity of the planet host stars. In our previous study, we modeled astrometric jitter for the Sun observed equator-on. In this work, we generalize our model and calculate the photocenter jitter as it would be measured by the Gaia and Small-JASMINE missions for stars with solar rotation rate and effective temperature, but with various values of the inclination angle of the stellar rotation axis. In addition, we consider the effect of metallicity and of nesting of active regions (i.e. the tendency of active regions to emerge in the vicinity of each other). We find that, while the jitter of stars observed equator-on does not have any long-term trends and can be easily filtered out, the photocenters of stars observed out of their equatorial planes experience systematic shifts over the course of the activity cycle. Such trends allow the jitter to be detected with continuous measurements, in which case it can interfere with planet detectability. An increase in the metallicity is found to increase the jitter caused by stellar activity. Active-region nesting can further enhance the peak-to-peak amplitude of the photocenter jitter to a level that could be detected by Gaia.Comment: 24 pages, 20 figures in the main body and 4 in the appendix, accepted for publication in Ap

Protective effect of Coriandrum sativum extract against inflammation and apoptosis in liver ischaemia/reperfusion injury

Background: The aim of this study was to investigate the anti-inflammatory and antioxidant effects of Coriandrum sativum extract on liver ischaemia reperfusion injury at light microscopic and biochemical levels. Materials and methods: Sham, ischaemia/reperfusion injury (IRI), IRI + Coriandrum sativum extract and only Coriandrum sativum extract groups were formed. Sixty minutes of ischaemia and 60 minutes of reperfusion were performed. In the treatment group, 300 mg/kg/day Coriandrum sativum was given by gavage. Hepatic tissues were fixed in 4% paraformaldehyde. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) enzymes were measured. Nuclear factor-kappa beta (NF-κB), tumour necrosis factor-alpha (TNF-α) and caspase-3 immunohistochemistry staining was performed. Microscopic scoring was performed in terms of sinusoidal congestion, vacuolisation, and necrosis. Results: Sinusoidal enlargement and diffuse congestion, Kupffer cell increase, neutrophil increase in necrotic areas, vacuolisation in hepatocytes, and bile duct proliferation in the portal triad were observed in ischaemia/reperfusion hepatic tissue. Very rare, necrotic areas were observed in the Coriandrum sativum treatment group, while congestion and vacuolisation and bile duct proliferation were decreased compared to the ischaemic group. The AST and ALT levels were increased in the IRI and IRI + Coriandrum sativum groups. When compared to the IRI group, the AST and ALT levels of the Coriandrum sativum were considerably decreased. The IRI and IRI + Coriandrum sativum groups had statistically significant differences in ALP compared to that of the Coriandrum sativum and Sham groups. There was no significant difference between the ALP levels of the IRI and IRI + Coriandrum sativum groups TNF-α, NF-κB and caspase-3 immune positive stained hepatocytes were numerous and widely observed in the injury group. There were positive TNF-α immunohistochemical staining Kupffer cells in the IRI group. In the group treated with Coriandrum sativum, Kupffer cells were not stained, while TNF-α, NF κB and caspase-3 expressing hepatocytes were found to be decreased compared to the IRI group. When the expression values of the TNF-α, NF-κB and caspase-3 groups were evaluated statistically, it was seen that there was a significant decrease in the group treated with Coriandrum sativum. Conclusions: It was found that Coriandrum sativum extract decreased proinflammatory cytokine TNF-α and apoptotic cell death and liver enzymes in liver ischaemia/reperfusion injury