Application of the MHVSR method for determining the location of landslide areas before geotechnical project proposal: a case study of Tortum Lake, Turkey

Abstract

Tortum Lake, in Turkey, which is a natural feature and a large landslide barrier lake, was formed due to a natural landslide disaster. In this context, areas with the potential to create landslides in Tortum Lake and the waterfall region are identified and displaced with zoning. Microtremor horizontal-to-vertical spectral ratio method and seismic refraction studies were used, and by considering the results, the areas with high landslide potential were determined. It aims to choose an effective study area by determining the areas with high landslide capability and revealing the boundaries of the geotechnical project. Areas with high landslide potential were compared with those where landslides have happened, and it showed that this method can be used for determining sliding risk before it happens. Results showed that regions with low VS30, combined with the slope, create the potential for landslides. Afterward, when the map of ground amplification values obtained from the microtremor data was reviewed, it was found that the physical properties of areas with high ground amplification values would be the same as those of areas with low VS30 values. When these two maps are reviewed, it is observed that areas with low VS30 values and high ground amplification values are in the same locations as those with high sliding potential. The correct determination of the geotechnical project work area is important both to draw attention to the right area to be designed and to avoid wasting unnecessary time and money on unnecessary areas.

Traces of collisional and transtensional processes between the Carpathia and the European platform in the geoelectric image (NE Slovakia and SE Poland)

Abstract

We present the latest magnetotelluric models on profiles in the northeastern part of Slovakia and the southeastern part of Poland. These models are focused on deciphering the tectonic structures at the contact of the Inner Carpathians with the European Platform in this area. For the Inner Carpathian block, we propose the term Carpathia. Profile SA-01 shows shallower structures and the parallel MT-05 profile shows deeper structures. These models are also correlated with the seismic profile CEL-05. All results are compatible and show an original subduction-collisional structure, which was later replaced by a transpressive-transtensional one. The most striking structures are thick highly conductive subhorizontal zones in the middle crust and a tectonically controlled deep vertical conductive structure—the Carpathian conductive zone. Other significant structures, which also appear in the seismic section, are back thrusting of Flysch Belt and the Klippen Belt basement (Penninic crust) uplift.

Are impacts of the invasive alien plant Crassula helmsii mediated by detritus? A litter experiment in a temperate pond

Abstract

Because of the high growth rates often achieved by invasive alien macrophytes, their establishment in recipient ecosystems may alter the abundance and composition of litter entering detrital pathways, representing a significant—but often overlooked—ecological effect of these invasions. Crassula helmsii (Kirk) Cockayne (New Zealand pygmyweed) is an invasive alien macrophyte, notorious for its profuse growth in invaded waterbodies. C. helmsii is perennial and often forms dense stands, producing abundant detritus. To investigate whether some of C. helmsii’s impacts are mediated by this detritus, we conducted an 85-day litterbag experiment comparing decomposition of C. helmsii with that of Callitriche stagnalis Scop. (water-starwort), a commonly co-occurring native macrophyte. Macroinvertebrate assemblage composition was comparable between macrophyte species throughout the experiment, but shifted as plants decayed. Litterbags were initially dominated by the invasive shredder Crangonyx pseudogracilis Bousfield, 1958 and later by Euglesa casertana (Poli, 1791), an interstitial suspension feeder. C. helmsii litter decomposed more slowly, with proportionally less invertebrate-mediated breakdown, but was ultimately colonised by more abundant macroinvertebrates, including more C. pseudogracilis. Decomposition may be slowed by C. helmsii’s high carbon: nitrogen ratio. These results suggest that C. helmsii invasion may impact macroinvertebrate assemblages via the production of long-lasting and relatively unpalatable detritus.

NASH triggers cardiometabolic HFpEF in aging mice

Abstract

Both heart failure with preserved ejection fraction (HFpEF) and non-alcoholic fatty liver disease (NAFLD) develop due to metabolic dysregulation, has similar risk factors (e.g., insulin resistance, systemic inflammation) and are unresolved clinical challenges. Therefore, the potential link between the two disease is important to study. We aimed to evaluate whether NASH is an independent factor of cardiac dysfunction and to investigate the age dependent effects of NASH on cardiac function. C57Bl/6 J middle aged (10 months old) and aged mice (24 months old) were fed either control or choline deficient (CDAA) diet for 8 weeks. Before termination, echocardiography was performed. Upon termination, organ samples were isolated for histological and molecular analysis. CDAA diet led to the development of NASH in both age groups, without inducing weight gain, allowing to study the direct effect of NASH on cardiac function. Mice with NASH developed hepatomegaly, fibrosis, and inflammation. Aged animals had increased heart weight. Conventional echocardiography revealed normal systolic function in all cohorts, while increased left ventricular volumes in aged mice. Two-dimensional speckle tracking echocardiography showed subtle systolic and diastolic deterioration in aged mice with NASH. Histologic analyses of cardiac samples showed increased cross-sectional area, pronounced fibrosis and Col1a1 gene expression, and elevated intracardiac CD68+ macrophage count with increased Il1b expression. Conventional echocardiography failed to reveal subtle change in myocardial function; however, 2D speckle tracking echocardiography was able to identify diastolic deterioration. NASH had greater impact on aged animals resulting in cardiac hypertrophy, fibrosis, and inflammation.