scholarly journals Biogeomorphological effects of leaf accumulations in stepped-bed channels: Exploratory study, Moravskoslezské Beskydy Mountains, Czech Republic

2016 ◽  
Vol 24 (3) ◽  
pp. 13-23 ◽  
Author(s):  
Zdeněk Přibyla ◽  
Tomáš Galia ◽  
Jan Hradecký
Keyword(s):  
Exploratory Study ◽  
Transport Processes ◽  
Small Streams ◽  
Typical Morphology ◽  
Coarse Sediments ◽  
Material Forming ◽  
And Function ◽  
Pool Formation ◽  
Supercritical Flows ◽  
Statistical Results

Abstract The stepped-bed system, with a step-like longitudinal profile, is typical morphology in steep headwater streams. These systems are created by a series of coarse sediments or instream wood (steps with supercritical flows) interspaced with finer material (forming pools with subcritical flows). In the case of well-developed steps and pools, the resulting channel-reach morphology is referred to as “step-pool” morphology. In this study, we identify a previously undescribed type of step-pool formation, the “foliaged step-pool”, in the high-gradient Stoligy Stream of the Moravskoslezské Beskydy Mountains. The defining feature of this formation is the significant presence of leaves in the step structure. The geometry of the steps and pools was measured and the parameters that characterise the distribution, amount and function of leaves acting in these areas were defined. Statistical results showed differences between non-foliaged and foliaged step-pool formations, in which the latter showed a significant increase in storage level, influencing the channel’s hydrodynamics. Particle-size analyses demonstrated that foliaged step-pool formations had finer sediment in the pools, which indicates that there are differences in sediment transport processes between foliaged and non-foliaged formations. These results offer new insights into stepped-bed and step-pool morphology, providing directions for further research on small streams in deciduous forested regions.

scholarly journals Cellular distribution and function of ion channels involved in transport processes in rat tracheal epithelium

2017 ◽  
Vol 5 (12) ◽  
pp. e13290 ◽  
Author(s):  
Anne Hahn ◽  
Johannes Faulhaber ◽  
Lalita Srisawang ◽  
Andreas Stortz ◽  
Johanna J Salomon ◽  
...  
Keyword(s):  
Ion Channels ◽  
Transport Processes ◽  
Tracheal Epithelium ◽  
Cellular Distribution ◽  
And Function

scholarly journals Functional genomics analysis of human colon organoids identifies key transcription factors

2020 ◽  
Vol 52 (6) ◽  
pp. 234-244 ◽  
Author(s):  
Shiyi Yin ◽  
Greeshma Ray ◽  
Jenny L. Kerschner ◽  
Shuyu Hao ◽  
Aura Perez ◽  
...  
Keyword(s):  
Functional Genomics ◽  
Intestinal Epithelium ◽  
Epithelial Transport ◽  
Three Dimensional ◽  
Human Colon ◽  
Transport Processes ◽  
Open Chromatin ◽  
Motif Analysis ◽  
Human Intestinal Epithelium ◽  
And Function

Organoids are a valuable three-dimensional (3D) model to study the differentiated functions of the human intestinal epithelium. They are a particularly powerful tool to measure epithelial transport processes in health and disease. Though biological assays such as organoid swelling and intraluminal pH measurements are well established, their underlying functional genomics are not well characterized. Here we combine genome-wide analysis of open chromatin by ATAC-Seq with transcriptome mapping by RNA-Seq to define the genomic signature of human intestinal organoids (HIOs). These data provide an important tool for investigating key physiological and biochemical processes in the intestinal epithelium. We next compared the transcriptome and open chromatin profiles of HIOs with equivalent data sets from the Caco2 colorectal carcinoma line, which is an important two-dimensional (2D) model of the intestinal epithelium. Our results define common features of the intestinal epithelium in HIO and Caco2 and further illustrate the cancer-associated program of the cell line. Generation of Caco2 cysts enabled interrogation of the molecular divergence of the 2D and 3D cultures. Overrepresented motif analysis of open chromatin peaks identified caudal type homeobox 2 (CDX2) as a key activating transcription factor in HIO, but not in monolayer cultures of Caco2. However, the CDX2 motif becomes overrepresented in open chromatin from Caco2 cysts, reinforcing the importance of this factor in intestinal epithelial differentiation and function. Intersection of the HIO and Caco2 transcriptomes further showed functional overlap in pathways of ion transport and tight junction integrity, among others. These data contribute to understanding human intestinal organoid biology.

Large woody debris characteristics and contributions to pool formation in forest streams of the Boreal Shield

2005 ◽  
Vol 35 (5) ◽  
pp. 1213-1223 ◽  
Author(s):  
David P Kreutzweiser ◽  
Kevin P Good ◽  
Trent M Sutton
Keyword(s):  
Woody Debris ◽  
Average Frequency ◽  
Large Woody Debris ◽  
Primary Input ◽  
Clear Cut ◽  
Mixedwood Forests ◽  
Riparian Trees ◽  
Boreal Shield ◽  
And Function ◽  
Pool Formation

The inputs, characteristics, and function of large woody debris (LWD) were assessed in 16 mid-order (average channel widths of 3–7 m), moderate-gradient (approx. 1%–5% channel slopes) streams in mixedwood forests of the Boreal Shield in Ontario. Three of the streams were adjacent to clearcuts, with the remainder in areas that have not been logged or recently (>70 years) burned. The average frequency (19.9 pieces·100 m–1) and size (mean diameter 16.7 cm) of LWD in these streams were less than reported in most other regions and forest types. Averaged across sites, input sources were undetermined for about 50% of the LWD owing to fluvial displacement from the points of origin. Natural mortality (24%) and windthrow (15%) were primary input sources of the remaining LWD. Windthrow was highly variable and mostly associated with nearby clear-cut logging. At the three sites near clearcuts, windthrow contributed 34%–62% of LWD in streams. In study reaches where active beaver colonies were observed, beaver-felled trees accounted for up to 47% of LWD inputs. The average frequency of debris dams (2.4 dams·100 m–1) was less than those reported from studies in other areas and was positively correlated with an index of bottom substrate size (r = 0.72). Less than 15% of the pools in these streams were formed or influenced by LWD. Most wood pieces appeared to be ineffective as pool-forming agents because of their relatively small size and instability. In these Boreal Shield forests, it appears that most riparian trees do not live long enough or grow to sufficient size to contribute functional LWD and influence stream morphology or pool formation.

scholarly journals Exploring the form and function of dissident Irish Republican online discourses

2012 ◽  
Vol 5 (1) ◽  
pp. 71-85 ◽  
Author(s):  
Lorraine Bowman-Grieve ◽  
Maura Conway
Keyword(s):  
Exploratory Study ◽  
Support Function ◽  
The Internet ◽  
Political Extremism ◽  
Face To Face ◽  
Form And Function ◽  
Irish Republicanism ◽  
Use Of The Internet ◽  
And Function ◽  
Significant Support

This article seeks to contribute to broadening the focus of research in the area of violent online political extremism by examining the use of the internet by dissident Irish Republicans and their supporters. The argument here is not that the internet substitutes face-to-face contacts amongst Irish Republicans, including violent dissidents, nor that it currently plays a central role in processes of radicalisation into violent dissident groups, but that it has an important support function in terms of providing an ‘always-on’ space for discussion, consumption, and production of Irish Republicanism and thus a potentially educative role in terms of introducing ‘newbies’ to violent dissident Republicanism while also acting as a ‘maintenance’ space for the already committed. This exploratory study considers the importance of these functions in the context of repeated suggestions that the dissidents have no significant support base or constituency as internet activity certainly gives the appearance of some such support.

Contribution of leucine 85 to the structure and function of Saccharomyces cerevisiae iso-1 cytochrome c

2001 ◽  
Vol 79 (4) ◽  
pp. 517-524 ◽  
Author(s):  
Jonathan C Parrish ◽  
J Guy Guillemette ◽  
Carmichael JA Wallace
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Electron Transfer ◽  
Electron Transport ◽  
Cytochrome C ◽  
Transport Processes ◽  
Complex Iii ◽  
Side Chain ◽  
Inner Mitochondrial Membrane ◽  
And Function ◽  
First Time

Cytochrome c is a small electron-transport protein whose major role is to transfer electrons between complex III (cytochrome reductase) and complex IV (cytochrome c oxidase) in the inner mitochondrial membrane of eukaryotes. Cytochrome c is used as a model for the examination of protein folding and structure and for the study of biological electron-transport processes. Amongst 96 cytochrome c sequences, residue 85 is generally conserved as either isoleucine or leucine. Spatially, the side chain is associated closely with that of the invariant residue Phe82, and this interaction may be important for optimal cytochrome c activity. The functional role of residue 85 has been examined using six site-directed mutants of Saccharomyces cerevisiae iso-1 cytochrome c, including, for the first time, kinetic data for electron transfer with the principle physiological partners. Results indicate two likely roles for the residue: first, heme crevice resistance to ligand exchange, sensitive to both the hydrophobicity and volume of the side chain; second, modulation of electron-transport activity through maintenance of the hydrophobic character of the protein in the vicinity of Phe82 and the exposed heme edge, and possibly of the ability of this region to facilitate redox-linked conformational change.Key words: protein engineering, cytochrome c, structure-function relations, electron transfer, hydrophobic packing.

Evaluation of ovarian reserve and function in female patients treated with oral isotretinoin for severe acne: an exploratory study

2014 ◽  
Vol 34 (1) ◽  
pp. 21-24 ◽  
Author(s):  
Savaş Öztürk ◽  
Tülin Öztürk ◽  
Haydar Ucak ◽  
Ilker Erden ◽  
Betül Demir ◽  
...  
Keyword(s):  
Ovarian Reserve ◽  
Exploratory Study ◽  
Severe Acne ◽  
Female Patients ◽  
Oral Isotretinoin ◽  
And Function

scholarly journals Abdominal fat distribution and its relationship to brain changes: the differential effects of age on cerebellar structure and function: a cross-sectional, exploratory study

BMJ Open ◽  
2013 ◽  
Vol 3 (1) ◽  
pp. e001915 ◽  
Author(s):  
Matthias Raschpichler ◽  
Kees Straatman ◽  
Matthias Leopold Schroeter ◽  
Katrin Arelin ◽  
Haiko Schlögl ◽  
...  
Keyword(s):  
Exploratory Study ◽  
Fat Distribution ◽  
Abdominal Fat ◽  
Structure And Function ◽  
Cross Sectional ◽  
Differential Effects ◽  
Brain Changes ◽  
And Function

Soil and sediment microbial structure and function in intermittent stream corridors after a decade of catchment succession

2020 ◽  
Author(s):  
Jose Schreckinger ◽  
Aline Frossard ◽  
Linda Gerull ◽  
Mark O. Gessner ◽  
Michael Mutz
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Vegetation Cover ◽  
Structure And Function ◽  
Grass Species ◽  
Microbial Structure ◽  
Small Streams ◽  
Northeastern Germany ◽  
And Function ◽  
Soil And Sediment

<p>Large-scale resource exploitation by open-cast mining severely alters landscapes and impairs key ecosystem properties such as soil and sediment structure and function. Understanding the ecological recovery processes starting from an initially bare landscape generated by destructive land-use is extremely limited. Here we took advantage of a 6-ha experimental catchment to assess microbial community structure and function in soils and stream sediments after 3 and 13 years of catchment succession. The catchment (Chicken Creek) was created in 2005 by depositing quaternary sands from a lignite mine forefield in northeastern Germany and has since been left to develop under undisturbed conditions. In the initial stage, 3 years after catchment construction, rills and small streams had formed and the sparse vegetation cover mainly consisted of forbs. Over the next 10 years, the geomorphology, hydrology, and vegetation structure underwent a major transformation. A nearly full vegetation cover established, including various tree, shrub and grass species. Increased evaporation lowered the shallow groundwater table and led to stream intermittency. These changes were accompanied by large modifications in the structure and function of the microbial communities in sediments and soils. Initially, microbial structure and function were strikingly disconnected, whereas linkages had established 10 years later, although some functions still remained disconnected. Potential enzymatic activities increased vastly over the course of 10 years and also became much less variable across seasons. Cyanobacteria, predominant in soils and sediments during the early successional stage, declined to become a minor component of the microbial community. Moreover, despite distinct flow intermittency of the streams, microbial structure and function distinctly differed between sediments and adjacent soils. These results demonstrate a rapid succession of microbial communities during a decade of ecosystem development, suggesting that undisturbed succession is a feasible catchment restoration strategy.</p>

Gender, individualism–collectivism and individuals’ propensity to trust: A comparative exploratory study

2017 ◽  
Vol 26 (4) ◽  
pp. 445-459 ◽  
Author(s):  
Rachid Zeffane
Keyword(s):  
Small Business ◽  
United Arab Emirates ◽  
Exploratory Study ◽  
Management Practice ◽  
Business Owners ◽  
Future Research ◽  
Small Business Owners ◽  
Propensity To Trust ◽  
The Impact ◽  
Statistical Results

AbstractWe explore the impact of gender, individualism–collectivism on individual’s propensity to trust. The study draws on data from three groups of individuals in the United Arab Emirates: students; (n=370); small business owners/operators (n=324), and employed individuals (n=376). Three main hypotheses are tested. We develop and explore three main hypotheses. Statistical results reveal that females are generally more collectivist and less trusting than their males counterparts. Further analysis revealed that small business/operators are generally more trusting than the other cohorts of respondents. Propensity to trust was also found to be strongly associated with collectivist (rather than individualist) aspirations. Implications for future research and management practice are discussed.

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