GNSS station design for global climate change monitoring in Antarctica: ınstallation of TUR1 and TUR2 GNSS stations on Horseshoe Island in Antarctica During The 4th Turkish Antarctic Science Expedition

Son yıllarda uzay tabanlı konumlama sistemleri, GNSS Meteorolojisi ve GNSS Reflektometresi teknikleri kullanılarak gözlemlenen atmosferik su buharı, deniz, buz ve kar seviyeleri gibi önemli parametrelerle küresel iklim değişikliğinin izlenmesinde etkili bir destekleyici araç haline gelmiştir. Küresel ölçekte tüm bölgelerden daha hızlı ısınan Antarktika'da iklim değişikliğini incelemek, gelecekteki iklim değişikliğini daha doğru tahmin etmek için çok önemlidir. Dünya'nın iklim değişikliği etkilerinin izlenebilmesi amacıyla, 118Y322 No’lu TÜBİTAK projesi kapsamında GNSS Meteorolojisi ve GNSS Reflektometresi teknikleri ile 24 Şubat 2020 tarihinden itibaren Antarktika’da atmosferik su buharı değişimleri, kar derinliği ve buz kalınlığı değişimleri gözlemlenmektedir. Bu çalışmada, Troposfer ve Deniz Seviyesi Gözlem İstasyonu (TUR1) ile Troposfer ve Kar / Buz Seviyesi Gözlem İstasyonunun (TUR2) tasarım çalışmaları ve 4. Ulusal Antarktika Bilim Seferi’nde Antarktika Horseshoe Adası’na kurulum aşamaları anlatılmıştır. Bu çalışmalar, meteorolojik koşullar, şebekeden bağımsız ve batarya ile bütünleşik enerji sisteminin en sağlıklı şekilde güneş ve rüzgâr enerjisinden beslenmesi ve bölgede oluşabilecek buzul oluşumu ve kayaç parçalanması gibi jeolojik parametreler de göz önüne alınarak yapılmıştır.In recent years, space-based positioning systems have become an effective supporting tool for monitoring global climate change by important parameters such as atmospheric water vapor, sea, ice and snow levels observed by using GNSS Meteorology and GNSS Reflectometry techniques. Studying climate change in Antarctica, which is warming faster than all of the regions on a global scale, is very important to predict future climate change more accurately. In order to monitor climate change effects of the Earth, tropospheric water vapor variations, snow depth and ice thickness changes have been observing in Antarctica since 24 February 2020 by means of GNSS Meteorology and GNSS Reflectometry techniques within the scope of the TUBITAK Project No. 118Y322 In this study, designing studies of Troposphere and Sea Level Observation Station (TUR1) and Troposphere and Snow / Ice Level Observation Station (TUR2) and installation steps to Horseshoe Island in Antarctica during the 4th National Antarctic Science Expedition are explained. These studies was carried out by taking into account the meteorological conditions, the healthiest feeding of the off grid battery integrated energy system from solar and wind energy and geological parameters such as glacial formation and rock fragmentation that may occur in the region

The positioning performance of low-cost GNSS receivers in the Precise Point Positioning method

Satellite-based positioning, which started being developed in the mid-1960s for military purposes, is now used in almost every area. For the studies single and/or double frequency receivers are used. The cost of a receiver and antenna couple that have capable of high coordinate accuracies ranges from $3000 to$15000. With the production of Original Equipment Manufacturer (OEM) receivers, the cost of satellite-based location determination decreases to approximately one in 10 for the civilian user compared to the operations performed with geodetic receivers and antennas. However, although these receivers collect data in multi-Global Navigation Satellite System (GNSS) and frequencies, the accuracy of the coordinate values estimated is not as high as geodetic receivers and antennas. Therefore, it is necessary to carry out an accuracy study to obtain information about which studies can be used in. In this study, measurements were made at the UZEL point located on the roof of the Yıldız Technical University Geomatics Engineering Department by using the ZED-F9P-02B OEM multi GNSS receiver and ANN-MB L1/L2 multi-band GNSS patch antenna. The performance of the test results has been examined by comparing the results from CSRS(Canadian Spatial Reference System)-PPP with the coordinates of the UZEL point. As a result of the comparison, the difference between the coordinate determined with collected 3.5 hr data and the coordinates of the UZEL point has been determined as – 1.4 cm, 2.8 cm, and 9.3 cm in the East, North, and Height directions, respectivel

Characteristics of the Snow Cover in East and West Antarctica and Their 20-Year Trends Retrieved from Satellite Remote Sensing Data

The aim of this study was to make a comparative analysis of the state of the snow surface in East and West Antarctica, including changes in snow cover characteristics during the past two decades. To do so, we used the ASAR (Antarctic Snow Albedo Retriever) algorithm, which processes satellite data and retrieves an effective snow grain size and a fraction of rocks not covered by snow, to process the MODIS data throughout the entire period of its operation (up to now). We have chosen several test areas (approximately 30 × 30 km2) to study the state of the snow cover on Enderby Land (East Antarctica), on the coast of the Ross Sea (the Transantarctic Mountains), and the Antarctic Peninsula (West Antarctica). As a result, we have plotted and analyzed the time series of the effective snow grain size and rock fraction in these areas across the last 20 years. We have found weak negative trends for the effective grain size on the coast of Enderby Land and the Ross Sea. The rock fraction does not demonstrate any trend. The study of snow cover trends on a continental scale can contribute to the investigation of environmental changes in Antarctica

Deep phenotyping of miRNAs in the exercise-induced cardiac hypertrophy and fibrosis

Cardiac hypertrophy (CH) is an adaptational enlargement of the myocardium, in exposure to altered stress conditions or in case of injury which can lead to heart failure and death. MicroRNAs (miRNAs) are non-coding RNAs that play a significant role in modulating gene expression. Here, we aimed to identify new miRNAs effective in an experimental CH model and to find an epigenetic biomarker that could demonstrate therapeutic targets responsible for the pathology of heart tissue and serum. In this study, Sprague–Dawley male rats were divided into the training group (TG, n=9) and the control group (CG, n=6). Systolic and diastolic dimensions of the left ventricle and myocardial wall thickness were measured by echocardiography to assess CH. After the exercise program of the rats, miRNA expression measurements and histological analyses were performed. The 25,000 genes in the rat genome were searched using microarray analysis. A total of 128 miRNAs were selected according to the fold change rates, and nine miRNAs were validated for expression analysis. The terminal deoxynucleotidyl transferase dUTP nick (TUNEL) method was used to detect apoptotic cells. Cell proliferation was evaluated by the proliferative cell nuclear antigen (PCNA) method. Necrosis, bleeding, and intercellular edema were detected in TG. The mean histopathological score was higher in TG (p=0.03). There were rarely positive cells for apoptosis of both groups in cardiomyocytes. In the receiver characteristic curve analysis (ROC), the heart tissue rno-miR-290 had an area under the curve (AUC) of 0.920 with 100% sensitivity and 89.90% specificity (p=0.045), rno-miR-194-5p had AUC of 0.940 with 83.33% sensitivity and 100% specificity (p=0.003), and the serum rno-miR-132-3p AUC was 0.880 with 66.67% sensitivity and 100% specificity (p=0.004) in TG. miR-194-5p was used as a therapeutic target for remodeling the cardiac process. While miR-290 contributes to CH as a negative regulator, miR-132 in serum is effective in the pathological and physiological cardiac remodeling process and is a candidate biomarker

Integrated Ground-Based and Satellite Remote Sensing of the Earth’s Surface and Atmosphere in East and West Antarctica with Lidar and Radiometric Systems

We have developed remote ground-based and satellite methods and hardware and software for studying atmospheric aerosols, clouds, and the underlying surface in Eastern and Western Antarctica. The ground-based equipment includes: (1) a CIMEL solar spectrum photometer, which measures the spectrum of solar radiation transmitted and scattered by the atmosphere, (2) a multi-wavelength Raman lidar, which measures the vertical backscatter profile, (3) an albedometer, which measures the spectral albedo of the surface, primarily snow, and (4) a reflectometer, which measures the directional spectral reflectance of snow. The ground-based measurement data were integrated with data from satellite radiometers MODIS or OLCI and the satellite lidar CALIOP. A synergy of the manifold data results in retrieval of various atmosphere and surface characteristics such as the aerosol optical depth, profiles of concentration of the fine and coarse aerosol fractions, spatial distribution of the effective snow grain size, fraction of outcrops, etc