Effect of sodium chloride on the metabolic activity of halophilic bacteria isolated from the Lake Gardno estuary

The effect of different concentrations of sodium chloride on the metabolic activity of halophilic bacteria derived from the Lake Gardno estuary was studied using respirometric methods. The influence of salt was examined in two ways: the bacteria were preincubated in various concentrations of sodium chloride, and the cells used for respirometric measurements were supplied with substrates dissolved in water amended with various concentrations of the salt. Generally, an increase in the concentration of sodium chloride in the medium used for preincubation resulted in an increase in metabolic activity. Conversely, a decrease was noted when solutions of increasing salt content were employed to dissolve the substrate. The decrease in oxygen uptake noted when increased amounts of salt were added is proposed to be the result of the short period allowed for adaptation of cells to the higher salt concentrations.     

Effect of weather conditions on the incidence of Lophodermium yellow needle blight in the dwarf mountain pine in the Karkonosze and Izerskie Mountains (Poland)

The study aimed to determine, by using a statistical model, the effect of weather conditions on the incidence of Lophodermium yellow needle blight causing by new species for science- Lophodermium corconticum, in the mountain dwarf pine growing in the subalpine Karkonosze Mountains and the Izerskie Mountains(Poland). Needles showed symptoms of yellow spots, gradual discolouration and premature fall in July. The assessment of healthiness of infected mountain dwarf pine needles spanned three years(2011- 2013) and was conducted in several test sites in the Karkonosze and Izerskie Mountains. The results were analyzed by taking into account the meteorological conditions. Field observations seem to indicate that the highest infestation of mountain dwarf pine occurs in June and July, while September and October see a significantly lower disease index in the Karkonosze Mountains. The lower indices of the infestation of mountain dwarf pine are characteristic for the vegetation in the Hala Izerska high mountain pasture; whereas the environmental conditions prevailing in the Kocio? Ma?ego Stawu cirque and above the Samotnia hostel are conducive to the development of Lophodermium yellow needle blight.     

The ice/bed interface mosaic: deforming spots intervening with stable areas under the fringe of the Scandinavian Ice Sheet at Sampława,Poland

The glacial sediment succession exposed close to the southern margin of the Late Weichselian Scandinavian Ice Sheet in Poland reveals a mosaic consisting of isolated patches of heavily deformed deposits separated by areas lacking any visible evidence of deformation. In the studied outcrop, the subglacial deforming spots composed of outwash deposits intercalated with till stringers are about 2–10 m wide and 20–60 cm thick. They rest on outwash sediments and are covered by a basal till. Based on structural and textural characteristics, the deforming spots are interpreted as previous R‐channels filled with meltwater deposits. Lack of deformation in outwash sediment immediately beneath the deforming spots and in the intervening areas between the channels suggests that the ice‐bed was frozen and the deformation of the channel infill was facilitated by high pore‐water pressure arising because water drainage into the bed was impeded by permafrost. Channel infill deposits and the till immediately above were coevally deformed to a strain of less than 9. This study documents the possible co‐existence of deforming and stable areas under an ice sheet, generated by spatially varying thermal and hydrological conditions affecting sediment rheology.     

Topography and melting dynamics of ice‐cored ridges: evidence from the geometry,kinematics and sedimentary evolution of collapse structures within kame deposits,eastern Poland

In earlier studies, the topography and melting dynamics of ice‐cored ridges within marginal zones of the Pleistocene ice sheets were routinely reconstructed based only on conceptual and qualitative models supported by geomorphological, sedimentological and palaeogeographical studies. Here, a novel approach based on detailed structural analysis of two collapse structures affecting Pleistocene kame deposits is presented. The high regularity of the geometry of synclines and related strain fields as well as the patterns of subsidence of the folded strata are all interpreted as evidence of topography of ice‐cored ridges and their melting dynamics. The topography is described in terms of elongation, orientation and cross‐sectional shape of ice‐cored ridges. In turn, the melting dynamics are assessed based on a semi‐quantitative model of different relative rates of backwasting and downwasting. The topography of ice‐cored ridges, derived independently from the morphology of the related supraglacial landforms, is interpreted as an effect of ablation controlled by debris bands within parent ice. The reconstructed ice‐cored ridges are considered to represent the second‐order topographic features within a wide ice‐cored depression. The sedimentary evolution of collapse structures expressed as migration of their hinges/depocentres provides new semi‐quantitative insight into melting dynamics of ice showing the predominance of backwasting over downwasting. This evolution concerns the final stage of de‐icing, which was probably preceded by lowering of the ice‐cored topography and progressive formation of the ice‐cored ridges.     

Evaluation of the thermal conductivity of sandstone solid skeleton using the concept of equivalent microstructure

Acta Geotechnica - We evaluate thermal conductivity of the skeleton of porous sandstone from the measurements of the effective thermal conductivities of dry and saturated specimens provided by...     

HiRISE observations of gas sublimation-driven activity in Mars’ southern polar regions: III. Models of processes involving translucent ice

Enigmatic surface features, known as ‘spiders’, found at high southern martian latitudes, are probably caused by sublimation-driven erosion under the seasonal carbon dioxide ice cap. The Mars Reconnaissance Orbiter (MRO) High Resolution Imaging Science Experiment (HiRISE) has imaged this terrain in unprecedented details throughout southern spring. It has been postulated [Kieffer, H.H., Titus, T.N., Mullins, K.F., Christensen, P.R., 2000. J. Geophys. Res. 105, 9653-9700] that translucent CO₂ slab ice traps gas sublimating at the ice surface boundary. Wherever the pressure is released the escaping gas jet entrains loose surface material and carries it to the top of the ice where it is carried downslope and/or downwind and deposited in a fan shape. Here we model two stages of this scenario: first, the cleaning of CO₂ slab ice from dust, and then, the breaking of the slab ice plate under the pressure built below it by subliming ice. Our modeling results and analysis of HiRISE images support the gas jet hypothesis and show that outbursts happen very early in spring.     

Modeling and monitoring of mine water rebound in an abandoned coal mine complex: Siersza Mine, Upper Silesian Coal Basin, Poland

A variable-volume, head-dependent mine water filling model (MIFIM) has been utilized to simulate the post-abandonment flooding of the Siersza coal mine in the Upper Silesian Coal Basin of southern Poland. It is demonstrated that desaturated pore space in the aquifer adjacent to the mine comprises a significant component of the resaturable mine-related void. The model results are very sensitive to the value of this poorly constrained parameter. Nevertheless, the model successfully predicted the first appearance of mine water in an observation well and its subsequent rise. Despite this apparent success, it is concluded that such modeling approaches generally lack predictive power for mines in permeable, porous host rocks. As real monitoring data accumulate, however, such models can be calibrated and their utility increased.     

The effects of deforestation on slope and channel evolution in the tectonically active Darjeeling Himalaya

The main indicators of Quaternary tectonic uplift are the young mountain slopes of the Darjeeling Himalaya, rising straight above the Ganga–Brahmaputra foredeep, fragments of uplifted river terraces and fresh fault scarps. Evidence for the continuation of the uplift includes downcutting of the Tista and other straight rivers in the bedrock, continuing aggradation in the plains and overriding of the metamorphic rocks on the alluvia. Owing to deforestation and extensive land use, the earlier natural tendency of a dominance of channel incision over slope degradation has changed to prevailing aggradation, even in steep valley reaches, caused by intensive slope mass movements and the overloading of the mountain creeks. Aggradation progresses upstream along the rivers dissecting the mountain front.