Tomasz Zieliński

Vegetation-controlled modern anastomosing system of the upper Narew River (NE Poland) and its sediments

Abstract The anastomosing system of the upper Narew River consists of a network of interconnected channels. The channels are relatively deep (width/depth ratio 2–10), straight to sinuous, and they lack natural levees. They are characterised by a low water slope and very low stream power. The river is distinctly bedload-dominated and the transport of suspended clastic fines is minimal. Channel deposits consist almost exclusively of medium- to coarse-grained sand. Laterally extensive interchannel areas are flat and covered with peat-forming vegetation. These stable wetlands are flooded for many weeks during high water stages. Except for the channels, the valley fill consists of peat layer reaching 4 m in thickness. The rate of vertical aggradation of the peat deposit is estimated at 1–1.5 mm/year. The radiocarbon dating indicates that the peat layer is predominantly late Holocene in age. The impact of vegetation on the system is overwhelming. Vegetation produces an erosion-resistant peat layer, stabilizes channel banks and slows down the water flow. Vegetation also stimulates aggradation of bedload material on the channel bottom, and contributes to avulsion by blocking the channels. The channel network owes its origin to repeated though infrequent avulsion. Avulsion in the studied system is a small-scale, gradational and slow process. New channels evolve very slowly because of unfavourable hydrologic conditions and the presence of a resistant peat substratum. A new channel eventually intercepts only a part of the flow, while the old channel is still active, though to a limited extent. Although newly formed channels might subsequently be abandoned, long-lasting ones predominate within the system.

The Pleistocene end moraine fans: controls on their sedimentation and location

Abstract This paper presents a model of end moraine sedimentation based on data from Pleistocene ice sheet margins. According to this model, end moraines quite often constitute alluvial fans (or coalesced fans) formed at the ice margin by redeposition of supraglacial material. Three types of end moraine fan have been recognized: those composed mainly of mass-flow deposits (type A—equivalent to “dry” alluvial fan in nonglacial settings), those containing both mass-flow and waterlain sediments (type B) and those that contain mainly sorted waterlain material (type C—equivalent to “wet” alluvial fan in nonglacial settings). For each type of fan, several sedimentary subenvironments, differentiated by distance from the ice front, are identified. The diagnostic processes on the end moraine fans are: cohesive and cohesionless debris flows or grain flows (types A and B) or hyperconcentrated flows and sheetflows (types B and C). The type B fan seems to represent the most typical sequence in the end moraine zones, but the type C fan is also quite common at the Pleistocene ice sheet margins. Our studies also suggest that the terminal supraglacial drainage controls the type of end moraine fan sedimentary subenvironment (moraine types A, B, C), whereas subglacial hydrology and ice stream regime, which determine the mobility of the ice front and larger scale conditions of sediment supply to the ice margin, control the location and size of the end moraine fan.

Characteristics and genesis of moraine-derived flowtill varieties

Abstract Field studies in NE Poland of end moraines and the alluvial fans derived from them provided an excellent opportunity to compare the textural variability of flowtills with that of the parent material. It was found that the flowtills largely inherit the texture of the parent material but that the specific mass-transport mechanism plays an even larger part in determining their texture. This finding implies that the genesis of flowtills can be reconstructed, at least in most cases, on the basis of their textural characteristics. The field data from 26 sites indicate that all flowtills fit in a spectrum characterised by a gradual change of textural and structural properties, ranging from the “classical”, often clay-rich glacial diamicton to diamictic sands and gravels characteristic of glaciofluvial deposits. They can be grouped, however, into three categories, one of them with three varieties. The resulting spectrum of six major textural/ structural groups of flowtills reflects the various types of mass flow, from highly viscous debris flow to hyperconcentrated stream flow.

Relationship between renal resistive index and early target organ damage in patients with never treated essential hypertension

The aim of our study was to evaluate renal resistive index (RI) value in never treated hypertensive patients in relation to ambulatory blood pressure measurement (ABPM) values and early target organ damage. The study included 318 subjects: 223 patients with never treated essential hypertension (mean age 37.1 years) and 95 normotensive healthy subjects (mean age 37.9 years). ABPM, echocardiography and carotid and renal arteries duplex color Doppler examinations were performed. RI values in patients with never treated essential hypertension were no different from the normotensive control group (0.59 ± 0.05 vs 0.59 ± 0.05; NS). In the untreated patients RI correlated significantly with 24‐h pulse pressure (r=0.234; p<0.01) and ambulatory arterial stiffness index (AASI) values (r=0.274; p<0.001), intima‐media thickness (IMT) (r=0.249; p<0.001), E′/A′ (rho= −0.279; p<0.001) and relative wall thickness (RWT; r=0.185; p<0.01). In the multivariate stepwise analysis, RI values correlated independently with carotid IMT (β=0.272; p=0.020) and 24‐h AASI values (β=0.305; p=0.009). In normotensive healthy controls, significant independent correlation between RI and carotid IMT and 24‐h AASI values were also found. Our study may indicate limited value of RI in differentiating patients with uncomplicated hypertension with healthy controls. Renal resistive values were independently correlated with carotid IMT and AASI. These may suggest that renal vascular resistance is related to two markers for cardiovascular events both in the hypertensive and normotensive subjects.

Subaerial terminoglacial fans III: overview of sedimentary characteristics and depositional model

A general model is presented for the small type of fans (not to be confused with sandurs) that develop subaerially in the zone immediately before an ice front. These fans have in common with other fans that a proximal, a middle and a distal subenvironment– with distinctly different sedimentary facies– can be distinguished. The characteristics of these fans differ in several respects, however, from those formed under other conditions, particularly by the high proportion of mass-flow deposits in the proximal part, by the relative scarcity of fine particles in the middle fan, and by the relatively uniform character of the sediments in the distal fan. The special character of this type of fan is ascribed to the interaction of a continuously changing distance between the ice front and the fan (as a result of alternating phases of ice advance and ice retreat), its position that may be surrounded by ice for a large part, and the irregular supply of debris-laden meltwater that comes sometimes even in the form of more or less catastrophic floods. Due to the fact that terminoglacial fans have a good preservation potential only during phases of ice retreat, these fas tend to show a slight fining-upward tendency. The slope of terminoglacial fans tends to be more gentle (rarely over 2–5°) than that of fans formed under different conditions.

Home-based telemonitored Nordic walking training is well accepted, safe, effective and has high adherence among heart failure patients, including those with cardiovascular implantable electronic devices: a randomised controlled study

Background The benefits of rehabilitation in heart failure (HF) patients are well established. Little is known about Nordic walking (NW) training in HF patients especially in those with cardiovascular implantable electronic devices (CIEDs). Purpose The purpose of this study was to assess safety, effectiveness, adherence to and acceptance of home-based telemonitored NW in HF patients, including those with CIEDs (i.e. cardiac resynchronisation therapy, implantable cardioverter-defibrillator). Methods The study design was a single-centre, prospective, parallel-group, randomised (2:1), controlled trial among 111 HF patients, New York Heart Association (NYHA) II–III; left ventricular ejection fraction (EF) ≤ 40%. The intervention was a home-based telemonitored eight-week NW (training group (TG) n = 77) five times weekly vs usual care alone (control group (CG) n = 34). Outcome measures included a primary end point of functional capacity assessed by peak oxygen consumption (VO2peak). Secondary end points included: workload duration (t) in cardiopulmonary exercise test (CPET), six-minute walking test (6-MWT) distance and quality of life (QoL), Medical Outcome Survey Short Form 36 (SF-36); safety; adherence to and acceptance of NW. Measurements were made before and after intervention. Results NW resulted in significant improvement in: VO2peak (16.1 ± 4.0 vs 18.4 ± 4.1(ml/kg/min), p = 0.0001), t (471 ± 141 vs 577 ± 158 (s), p = 0.0001), 6-MWT(428 ± 93 vs 480 ± 87 (m), p = 0.0001) and QoL (79.0 ± 31.3 vs 70.8 ± 30.3 (score), p = 0.0001). We did not observe favourable results in the CG. The differences between the TG and CG were significant in: ΔVO2peak (Δ2.0 ± 2.4 vs Δ−0.2 ± 2.1, p = 0.0004); Δt (Δ108 ± 108 vs Δ0.94 ± 109, p = 0.0031); Δ6-MWT (Δ53.8 ± 63.9 vs Δ22.0 ± 68.7, p = 0.0483). In neither group were there deaths nor necessity for hospitalisation. We did not observe any intervention from CIEDs during NW. All patients in the TG completed rehabilitation and accepted it well. Conclusion In HF patients, including those with CIEDs, home-based telemonitored NW is safe and effective. NW was well accepted by patients and adherence was high and promising.

Shock-induced resuspension deposits from a Pleistocene proglacial lake (Kleszczow Graben, central Poland)

ABSTRACT Several glaciolacustrine successions forming part of the Quaternary fill of the Kleszczow Graben contain massive and widespread fine-grained units that are abnormally thick and homogeneous. Field studies of such a unit indicate that it is the result of rapid settling of particles from a sediment cloud consisting of material that had once settled on the lake bottom but were resuspended. The geological setting makes it likely that the trigger mechanism responsible for the sediment cloud in the lake water was a shock and that this shock (most probably an earthquake) was caused by tectonic activity in the graben.

Subaerial terminoglacial fans I: a semi-quantitative sedimentological analysis of the proximal environment

Fans formed under subaerial terminoglacial (previously called ‘ice-contact’) conditions have several characteristics that differ from those formed under other conditions. Twenty-five such fans in NE Poland were investigated to model the dominant genetic processes involved. These fans show, as do other types, a proximal, a middle and a distal environment. The present study deals with the proximal environment. The fans date from the last, i.e. Weichselian or Vistulian, glacial. The proximal terminoglacial fan comprises abundant gravelly sediments, resembling the glacial deposits from which they were derived. Three facies, each subdivided into two subfacies, can be distinguished; these are dominated by mass flows, unchannelised flows, and stream (= channelised) flows, respectively. The characteristics of the facies are described and illustrated. It is concluded that the irregular supply of water by the nearby ice masses dominates the sedimentary processes.

Subaerial terminoglacial fans II: a semi-quantitative sedimentological analysis of the middle and distal environments

Twenty-five fans in NE Poland, formed under subaerial terminoglacial (previously called ‘ice-contact’) conditions, were investigated to model the dominant genetic processes involved. These fans show, as do other types, a proximal, a middle and a distal subenvironment. It is found, however, that the characteristics of these subenvironments as present in subaerial terminoglacial fans differ in several respects from those in fans formed under other climatic conditions. The present study deals with the middle and distal subenvironments. These appear to be much less complex than the proximal subenvironment in this type of fan. The middle terminoglacial fan comprises two sandy facies, characterized by unchannelized transport (mainly sheet floods) and stream flows. The distal terminoglacial fan is characterized by one (sandy/silty) facies, resulting from unchannelized currents and from settling in ephemeral ponds; braided streams play a secondary part in this fan subenvironment. The characteristics of the middle and distal fan subenvironments are described and illustrated, as is the facies from the distal subenvironment. Their vertical and lateral relationships are presented in a facies model.

Catastrophic flood effects in alpine/foothill fluvial system (a case study from the Sudetes Mts, SW Poland)

Depositional effects of two great floods in the Nysa drainage basin have been studied: the alluvial forms and deposits of channels and floodplains. Three types of bars and one overbank form were found in the mountain streams, and four types of bars and three types of overbank forms have been distinguished in main rivers. A specific spatial succession of depositional forms was recognized along the mountain streams, however, no analogous phenomena were noted within the main river valleys. Several types of bars and alluvial lithofacies have been regarded as characteristic effects of the catastrophic flood. The study indicates that the Nysa river is close to the threshold of metamorphosis to a typical braided fluvial system.