Starting from a concept of the land surface, its definition and subdivision from Digital Elevation Models (DEMs) is considered. High-resolution DEMs from active remote sensing form a new basis for ...geomorphological work, which is moving on from consideration of whether data are accurate enough to how the surface of interest can be defined from an overabundance of data. Discussion of the operational definition and delimitation of specific landforms of varying degrees of difficulty, from craters to mountains, is followed by the applicability of ‘fuzzy’ boundaries. Scaling, usually allometric, is shown to be compatible with the scale-specificity of many landforms: this is exemplified by glacial cirques and drumlins. Classification of a whole land surface is more difficult than extraction of specific landforms from it. Well-dissected fluvial landscapes pose great challenges for areal analyses. These are tackled by the delimitation of homogeneous elementary forms and/or land elements in which slope position is considered. The boundaries are mainly breaks in gradient or aspect, but may also be in some type of curvature: breaks in altitude are rare. Elementary forms or land elements are grouped together into functional regions (landforms) such as ‘hill sheds’. It may often be useful to recognise fuzziness of membership, or core and periphery of a surface object.
Plains and etched or scoured surfaces defy most of these approaches, and general geomorphometry remains the most widely applicable technique. It has been applied mainly within arbitrary areas, and to some extent to drainage basins, but more experimentation with mountain ranges and other landforms or landform regions is needed. Geomorphological mapping is becoming more specialised, and its legends are being simplified. Its incorporation into geographical information systems (GIS) has required greater precision with definitions, and the separation of thematic layers, so that it is converging with specific geomorphometry and becoming more flexible and more applicable, with a broader range of visualisation techniques.
► Geomorphological mapping and specific geomorphometry share a need to define landforms objectively and reproducibly. ► This is easier for some landforms than others: for many landscapes, general geomorphometry is more appropriate. ► In addition to map sheets, drainage basins and mountain ranges (bounded by valleys and low passes) can be used as study areas for general geomorphometry. ► Many landforms are scale-specific and develop allometrically.
Arthur W. Staats (1924-2021) Evans, Ian M.
The American psychologist,
04/2022, Letnik:
77, Številka:
3
Journal Article
Recenzirano
Memorializes Arthur W. Staats (1924-2021). Arthur Wilbur Staats was arguably one of the most expansive proponents of behavioral psychology in the second half of the 20th century. He went to Arizona ...State University and helped make it a dynamic center for applied behavior analysis, then moved to the University of Hawai'i at Mānoa in 1966 until his retirement in 1997. In his early theoretical work, he espoused three integrating principles, unique at the time. First, his A-R-D theory articulated how internal stimuli-symbols, thoughts, and mental images- performed three simultaneous functions: eliciting affect, reinforcing, and as discriminative stimuli. Second, he posited that responses prompt chains of further actions. The third unifying principle was that all basic responses involves a combination of instrumental and classical conditioning-of seminal importance to clinical behavior therapy methods as well as theory. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
p130Cas: A key signalling node in health and disease Barrett, Angela; Pellet-Many, Caroline; Zachary, Ian C. ...
Cellular signalling,
April 2013, 2013-Apr, 2013-04-00, 20130401, Letnik:
25, Številka:
4
Journal Article
Recenzirano
p130Cas/breast cancer anti-oestrogen resistance 1 (BCAR1) is a member of the Cas (Crk-associated substrate) family of adaptor proteins, which have emerged as key signalling nodes capable of ...interactions with multiple proteins, with important regulatory roles in normal and pathological cell function. The Cas family of proteins is characterised by the presence of multiple conserved motifs for protein–protein interactions, and by extensive tyrosine and serine phosphorylations. Recent studies show that p130Cas contributes to migration, cell cycle control and apoptosis. p130Cas is essential during early embryogenesis, with a critical role in cardiovascular development. Furthermore, p130Cas has been reported to be involved in the development and progression of several human cancers. p130Cas is able to perform roles in multiple processes due to its capacity to regulate a diverse array of signalling pathways, transducing signals from growth factor receptor tyrosine kinases, non-receptor tyrosine kinases, and integrins. In this review we summarise the current understanding of the structure, function, and regulation of p130Cas, and discuss the importance of p130Cas in both physiological and pathophysiological settings, with a focus on the cardiovascular system and cancer.
► p130Cas is a ubiquitously expressed adaptor protein. ► p130Cas is phosphorylated in response to integrin, RTK and GPCR signalling. ► p130Cas-mediated recruitment and activation of GEFs is critical for cell motility. ► Expression of p130Cas is essential for the development of the cardiovascular system. ► Aberrant p130Cas signalling contributes to the development of several human cancers.
NRP1 (neuropilin-1) is a co-receptor for members of the VEGF (vascular endothelial growth factor) family in endothelial cells, but is increasingly implicated in signalling induced by other growth ...factors. NRP1 is expressed in VSMCs (vascular smooth muscle cells), but its function and the mechanisms involved are poorly understood. The present study aimed to determine the role of NRP1 in the migratory response of HCASMCs (human coronary artery smooth muscle cells) to PDGF (platelet-derived growth factor), and to identify the signalling mechanisms involved. NRP1 is highly expressed in HAoSMCs (human aortic smooth muscle cells) and HCASMCs, and modified in VSMCs by CS (chondroitin sulfate)-rich O-linked glycosylation at Ser612. HCASMC migration induced by PDGF-BB and PDGF-AA was inhibited by NRP1 siRNA (small interfering RNA), and by adenoviral overexpression of an NRP1 mutant lacking the intracellular domain (Ad.NRP1ΔC). NRP1 co-immunoprecipitated with PDGFRα (PDGF receptor α), and immunofluorescent staining indicated that NRP1 and PDGFRα co-localized in VSMCs. NRP1 siRNA also inhibited PDGF-induced PDGFRα activation. NRP1-specific siRNA, Ad.NRP1ΔC and removal of CS glycans using chondroitinase all inhibited PDGF-BB and -AA stimulation of tyrosine phosphorylation of the adapter protein, p130Cas (Cas is Crk-associated substrate), with little effect on other major signalling pathways, and p130Cas knockdown inhibited HCASMC migration. Chemotaxis and p130Cas phosphorylation induced by PDGF were inhibited by chondroitinase, and, additionally, adenoviral expression of a non-glycosylatable NRP1S612A mutant inhibited chemotaxis, but not p130Cas phosphorylation. These results indicate a role for NRP1 and NRP1 glycosylation in mediating PDGF-induced VSMC migration, possibly by acting as a co-receptor for PDGFRα and via selective mobilization of a novel p130Cas tyrosine phosphorylation pathway.
Neuropilin 1 (NRP1) is a non-tyrosine kinase receptor for vascular endothelial growth factor (VEGF) and class 3 semaphorins, playing a role in angiogenesis and neuronal axon guidance, respectively. ...NRP1 is expressed in smooth muscle cells (SMC) but the functional role of NRP1 in SMC has not been elucidated. We therefore investigated the biological relevance of NRP1 in SMC in vivo by generating mice with SMC-specific Nrp1 deficiency.
Conditional gene targeting generated SMC-specific Nrp1 knockout mice (Nrp1SMKO) in which Cre recombinase is driven by the smooth muscle-specific myosin heavy chain (smMHC) promoter.
SMC-specific Nrp1 deficiency resulted in a significant reduction in intestinal length by 6 months, and, by 18 months, in severe constipation, and enlargement of the intestine consistent with chronic intestinal pseudo-obstruction. These effects were associated with significant thinning of the intestinal smooth muscle, and decreased intestinal contractility. Expression of contractile proteins was reduced in Nrp1SMKO mice, including the smMHC isoform, SMB, whereas we observed a significant increase in the expression of the small-conductance calcium-activated potassium channel 3 (SK3/KCa2.3), implicated in negative regulation of smooth muscle contraction.
Nrp1 deficiency in visceral SMC results in adult-onset defects in gastrointestinal contractility and motility and causes a shift to a less contractile SMC phenotype. These findings indicate a new role for Nrp1 in the maintenance of the visceral SMC contractile phenotype required for normal GI motility in aged mice.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Land surface morphology is fundamental to geomorphological mapping and many GIS applications. Review and comparison of various approaches to segmentation of the land surface reveals common features, ...and permits development of a broad theoretical basis for segmentation and for characterization of segments and their boundaries. Within the context of defining landform units that maximise internal homogeneity and external differences, this paper introduces the concept of elementary forms (segments, units) defined by constant values of fundamental morphometric properties and limited by discontinuities of the properties. The basic system of form-defining properties represents altitude and its derivatives, constant values of which provide elementary forms with various types of homogeneity. Every geometric type of elementary form can be characterized by a defining function, which is a specific case of the general polynomial fitted function. Various types of boundary discontinuity and their connections and transformations into other types of morphological unit boundaries are analysed.
The wealth of types of elementary forms and their boundaries is potentially unbounded and thus is sufficient to cover the real variety of landforms. Elementary forms in the basic set proposed here have clear potential for genetic and dynamic interpretation. A brief worked example documents the possibility of analytical computation of various models of ideal elementary forms for particular segments of landform. Ideal elementary forms can be considered as attractors, to which the affinity of surface segments can be measured by multivariate statistical methods. The use of the concept of elementary forms in landscape segmentation is promising and it could be adapted for elementary segmentation of various other spatial fields.
Social communication is fraught with ambiguity. Negotiating the social world requires interpreting the affective signals we receive and often selecting between channels of conflicting affective ...information. The affective face-word Stroop (AFWS) provides an experimental paradigm which may identify cognitive-affective control mechanisms underpinning essential social-affective skills. Initial functional magnetic resonance imaging (fMRI) study of the AFWS identified right amygdala as driving this affective conflict and left rostral anterior cingulate cortex (rACC) as the locus of conflict control. We employed electroencephalogram (EEG) and eLORETA source localization to investigate the timing, location, and sequence of control processes when responding to affective conflict generated during the AFWS. However we designated affective word as the response target and affective face as the distractor to maximize conflict and control effects. Reaction times showed slowed responses in high vs. low control conditions, corresponding to a Rabbitt type control effect rather than the previously observed Grattan effect. Control related activation occurred in right rACC 96-118 ms post-stimulus, corresponding to the resolution of the P1 peak in the Visual Evoked Potential (VEP). Face distractors elicit right hemisphere control, while word distractors elicit left hemisphere control. Low control trials require rapid "booting up" control resources observable through VEPs. Incongruent trial activity in right fusiform face area is suppressed 118-156 ms post stimulus corresponding to onset and development of the N170 VEP component. Results are consistent with a predicted sequence of rapid early amygdala activation by affective conflict, then rACC inhibition of amygdala decreasing facilitation of affective face processing (however, amygdala activity is not observable with EEG).
Concordance among wetland physicochemical conditions, vegetation, and surrounding land cover may result from the influence of land cover on the sources of plant propagules, on physicochemical ...conditions, and their subsequent determination of growing conditions. Alternatively, concordance may result if differences in climate, soils, and species pools are spatially confounded with differences in human population density and land conversion. Further, we expect that land cover within catchment boundaries will be more predictive than land cover in symmetrical buffers if runoff is a major pathway. We measured concordance between land cover, wetland vegetation and physicochemical conditions in 48 prairie pothole wetlands, controlling for inter-wetland distance. We contrasted land-cover data collected over a four-year period by multiple extraction approaches including topographically-delineated catchments and nested 30 m to 5,000 m radius buffers. After factoring out inter-wetland distance, physiochemical conditions were significantly concordant with land cover. Vegetation was not significantly concordant with land cover, though it was strongly and significantly concordant with physicochemical conditions. More, concordance was as strong when land cover was extracted from buffers <500 m in radius as from catchments, indicating the mechanism responsible is not topographically constrained. We conclude that local landscape structure does not directly influence wetland vegetation composition, but rather that vegetation depends on 1) physicochemical conditions in the wetland that are affected by surrounding land cover and on 2) regional factors such as the vegetation species pool and geographic gradients in climate, soil type, and land use.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
OBJECTIVE—NRP1(neuropilin-1) acts as a coreceptor for VEGF (vascular endothelial growth factor) with an essential role in angiogenesis. Recent findings suggest that posttranslational proteolytic ...cleavage of VEGF receptors may be an important mechanism for regulating angiogenesis, but the role of NRP1 proteolysis and the NRP1 species generated by cleavage in endothelial cells is not known. Here, we characterize NRP1 proteolytic cleavage in endothelial cells, determine the mechanism, and investigate the role of NRP1 cleavage in regulation of endothelial cell function.
APPROACH AND RESULTS—NRP1 species comprising the carboxy (C)-terminal and transmembrane NRP1 domains but lacking the ligand-binding A and B regions are constitutively expressed in endothelial cells. Generation of these C-terminal domain NRP1 proteins is upregulated by phorbol ester and Ca ionophore, and reduced by pharmacological inhibition of metalloproteinases, by small interfering RNA-mediated knockdown of 2 members of ADAM (a disintegrin and metalloproteinase) family, ADAMs 9 and 10, and by a specific ADAM10 inhibitor. Furthermore, VEGF upregulates expression of these NRP1 species in an ADAM9/10-dependent manner. Transduction of endothelial cells with adenoviral constructs expressing NRP1 C-terminal domain fragments inhibited VEGF-induced phosphorylation of VEGFR2 (VEGF receptor tyrosine kinase)/KDR (kinase domain insert receptor) and decreased VEGF-stimulated endothelial cell motility and angiogenesis in coculture and aortic ring sprouting assays.
CONCLUSIONS—These findings identify novel NRP1 species in endothelial cells and demonstrate that regulation of NRP1 proteolysis via ADAMs 9 and 10 is a new regulatory pathway able to modulate VEGF angiogenic signaling.
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