scholarly journals The morphological variability of Maltese ‘cart ruts’ and its implications

2021 ◽  
Author(s):  
Huw Groucutt
Keyword(s):  
Morphological Variability ◽  
Formation Processes ◽  
Interesting Aspect ◽  
Central Mediterranean ◽  
Functional Association ◽  
Limestone Dissolution ◽  
Railway Tracks ◽  
Geomorphological Processes ◽  
And Function ◽  
Shape Changes

Hundreds of ‘cart ruts’ – pairs of incised parallel grooves in the bedrock – are found across the Maltese archipelago in the central Mediterranean. The age, functional association, formation processes, and taphonomic alteration of these ruts, which occur here with a globally unrivalled frequency, has been much debated. Generally seen as being created by erosion from vehicles such as wheeled carts, or alternatively being cut into the rock to facilitate movement of such vehicles, specific models range from the use of carts to move soil in the Neolithic to them reflecting classical era stone quarrying, and many other possibilities. One interesting aspect concerns the morphological variability of the cart ruts, such as the notion that they have a standard gauge (width between ruts), and that this gauge is very similar to that of modern railway tracks. Evaluating the morphological variability of the cart ruts contributes to an understanding of the phenomenon, as, for instance, we might expect that if they date to different periods, with different functions, and/or were extensively modified by geomorphological processes this will be reflected in the character of their morphological variability. The analysis suggests that cart ruts are fairly standardised in terms of basic measurements such as widths and depth, perhaps suggesting that they are of a consistent age and function. This study identified a need for definitional clarity as the commonly cited gauge measurements are not taken in the same way as gauge is defined for railway tracks. There are hints of rut shape changes reflecting extensive use and or processes such as limestone dissolution, which give insights into their formation histories.

scholarly journals Overview on the distribution of gorgonian species in Tunisian marine coastal waters (central Mediterranean)

2018 ◽  
Vol 82 (1) ◽  
pp. 55 ◽  
Author(s):  
Raouia Ghanem ◽  
Emna Soufi Kechaou ◽  
Jamila Ben Souissi ◽  
Joaquim Garrabou
Keyword(s):  
Coastal Waters ◽  
Local Ecological Knowledge ◽  
Conservation Status ◽  
Ecological Knowledge ◽  
Central Mediterranean ◽  
Management Actions ◽  
Conservation Actions ◽  
Gorgonian Species ◽  
Species Richness And Abundance ◽  
And Function

Gorgonian species play an important ecological role in the structure and function of marine communities. Human activities are negatively affecting the conservation status of gorgonian populations in the Mediterranean. Acquiring knowledge of gorgonian distribution is therefore a key step required to promote efficient management and conservation actions. However, information on the distribution of gorgonian species is lacking in many Mediterranean areas. This study aimed to provide an overview of the geographic and bathymetric distributions of gorgonians in the coastal waters of the Tunisian coast (1136 km). The sampling design encompassed three sectors, 27 localities and 87 sites. Information was collected from scuba diving (26 sites) and local ecological knowledge surveys of fishermen and divers (132 interviews), as well as from a literature review. Overall, the occurrence of eight gorgonians was confirmed at 54 out of the 87 sites surveyed in Tunisian coastal waters (7-120 m depth). The species that were found were Eunicella singularis, Eunicella cavolini, Paramuricea clavata, Paramuricea macrospina, Leptogorgia sarmentosa, Eunicella verrucosa, Corallium rubrum and Ellisella paraplexauroides. The highest gorgonian species richness and abundance was recorded in northern, followed by eastern Tunisian waters. In the southern areas only one species was recorded. This pattern was related to the rocky substrate that characterizes the northern and eastern coasts of Tunisia. This study is the first to report the occurrence of E. singularis, E. cavolini, E. verrucosa and Leptogorgia sarmentosa in northern and eastern Tunisian waters. The results are discussed in the hope of guiding future conservation and management actions for gorgonian assemblages in Tunisia.

scholarly journals Extensive morphological variability in asexually produced planktic foraminifera

2020 ◽  
Vol 6 (28) ◽  
pp. eabb8930 ◽  
Author(s):  
Catherine V. Davis ◽  
Caitlin M. Livsey ◽  
Hannah M. Palmer ◽  
Pincelli M. Hull ◽  
Ellen Thomas ◽  
...  
Keyword(s):  
Morphological Variability ◽  
Laboratory Culture ◽  
Structure And Function ◽  
Optimal Conditions ◽  
Temporal Response ◽  
Planktic Foraminifera ◽  
Neogloboquadrina Pachyderma ◽  
Marine Protists ◽  
And Function ◽  
Pelagic Ecosystems

Marine protists are integral to the structure and function of pelagic ecosystems and marine carbon cycling, with rhizarian biomass alone accounting for more than half of all mesozooplankton in the oligotrophic oceans. Yet, understanding how their environment shapes diversity within species and across taxa is limited by a paucity of observations of heritability and life history. Here, we present observations of asexual reproduction, morphologic plasticity, and ontogeny in the planktic foraminifer Neogloboquadrina pachyderma in laboratory culture. Our results demonstrate that planktic foraminifera reproduce both sexually and asexually and demonstrate extensive phenotypic plasticity in response to nonheritable factors. These two processes fundamentally explain the rapid spatial and temporal response of even imperceptibly low populations of planktic foraminifera to optimal conditions and the diversity and ubiquity of these species across the range of environmental conditions that occur in the ocean.

scholarly journals Accessing Ancestral Origin and Diversity Evolution by Net Divergence of an Ongoing Domestication Mediterranean Olive Tree Variety

2021 ◽  
Vol 12 ◽  
Author(s):  
Hélia Sales ◽  
Zlatko Šatović ◽  
Mara Lisa Alves ◽  
Pedro Fevereiro ◽  
João Nunes ◽  
...  
Keyword(s):  
Minimum Spanning Tree ◽  
Genetic Relationships ◽  
Morphological Variability ◽  
Age Groups ◽  
Genetic Erosion ◽  
Olive Tree ◽  
Gene Pools ◽  
Central Mediterranean ◽  
Ancestral Origin ◽  
Olive Variety

Olea europaea ‘Galega vulgar’ variety is a blend of West and Central Mediterranean germplasm with cultivated-wild admixture characteristics. ‘Galega vulgar’ is known for its high rusticity and superior-quality olive oil, being the main Portuguese variety with high impact for bioeconomy. Nevertheless, it has been replaced by higher-yielding and more adapted to intensive production foreign varieties. To clarify the potential ancestral origin, genetic diversity evolution, and existing genetic relationships within the national heritage of ‘Galega vulgar’, 595 trees, belonging to ancient and centenary age groups and prospected among ten traditional production regions, were characterized using 14 SSR markers after variety validation by endocarp measurements. Ninety-five distinguishable genets were identified, revealing the presence of a reasonable amount of intra-genetic and morphological variability. A minimum spanning tree, depicting the complete genealogy of all identified genets, represented the ‘Galega vulgar’ intra-varietal diversity, with 94% of the trees showing only a two-allele difference from the most frequent genet (C001). Strong correlations between the number of differentiating alleles from C001, the clonal size, and their net divergence suggested an ancestral monoclonal origin of the ‘Galega vulgar’, with the most frequent genet identified as the most likely origin of all the genets and phenotypic diversification occurring through somatic mutations. Genetic erosion was detected through the loss of some allele combinations across time. This work highlights the need to recover the lost diversity in this traditional olive variety by including ancient private genets (associated with potential adaptation traits) in future breeding programs and investing in the protection of these valuable resources in situ by safeguarding the defined region of origin and dispersion of ‘Galega vulgar’. Furthermore, this approach proved useful on a highly diverse olive variety and thus applicable to other diverse varieties due either to their intermediate nature between different gene pools or to the presence of a mixture of cultivated and wild traits (as is the case of ‘Galega vulgar’).

scholarly journals Cytoskeleton Dynamics in Peripheral T Cell Lymphomas: An Intricate Network Sustaining Lymphomagenesis

2021 ◽  
Vol 11 ◽  
Author(s):  
Valentina Fragliasso ◽  
Annalisa Tameni ◽  
Giorgio Inghirami ◽  
Valentina Mularoni ◽  
Alessia Ciarrocchi
Keyword(s):  
T Cell ◽  
Cell Shape ◽  
Aurora Kinase ◽  
T Cell Lymphomas ◽  
Molecular Landscape ◽  
And Function ◽  
Cytoskeleton Dynamics ◽  
Shape Changes ◽  
Peripheral T Cell Lymphomas

Defects in cytoskeleton functions support tumorigenesis fostering an aberrant proliferation and promoting inappropriate migratory and invasive features. The link between cytoskeleton and tumor features has been extensively investigated in solid tumors. However, the emerging genetic and molecular landscape of peripheral T cell lymphomas (PTCL) has unveiled several alterations targeting structure and function of the cytoskeleton, highlighting its role in cell shape changes and the aberrant cell division of malignant T cells. In this review, we summarize the most recent evidence about the role of cytoskeleton in PTCLs development and progression. We also discuss how aberrant signaling pathways, like JAK/STAT3, NPM-ALK, RhoGTPase, and Aurora Kinase, can contribute to lymphomagenesis by modifying the structure and the signaling properties of cytoskeleton.

scholarly journals Tendon-derived biomimetic surface topographies induce phenotypic maintenance of tenocytes in vitro

2020 ◽  
Author(s):  
Aysegul Dede Eren ◽  
Aliaksei Vasilevich ◽  
E. Deniz Eren ◽  
Phanikrishna Sudarsanam ◽  
Urandelger Tuvshindorj ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Shape ◽  
Flat Surface ◽  
Flat Surfaces ◽  
Tissue Culture Polystyrene ◽  
Surface Topographies ◽  
And Function ◽  
Shape Changes

AbstractThe tenocyte niche contains biochemical and biophysical signals that are needed for tendon homeostasis. The tenocyte phenotype is correlated with cell shape in vivo and in vitro, and shape-modifying cues are needed for tenocyte phenotypical maintenance. Indeed, cell shape changes from elongated to spread when cultured on a flat surface, and rat tenocytes lose the expression of phenotypical markers throughout five passages. We hypothesized that tendon gene expression can be preserved by culturing cells in the native tendon shape. To this end, we reproduced the tendon topographical landscape into tissue culture polystyrene, using imprinting technology. We confirmed that the imprints forced the cells into a more elongated shape, which correlated with the level of Scleraxis expression. When we cultured the tenocytes for seven days on flat surfaces and tendon imprints, we observed a decline in tenogenic marker expression on flat but not on imprints. This research demonstrates that native tendon topography is an important factor contributing to the tenocyte phenotype. Tendon imprints therefore provide a powerful platform to explore the effect of instructive cues originating from native tendon topography on guiding cell shape, phenotype and function of tendon-related cells.

Interaction of the cell surface with the extracellular matrix during epithelial morphogenesis

1983 ◽  
Vol 41 ◽  
pp. 668-671
Author(s):  
Alan C. Rapraeger ◽  
Joy E. Koda ◽  
Merton Bernfield
Keyword(s):  
Extracellular Matrix ◽  
Epithelial Morphogenesis ◽  
Matrix Assembly ◽  
Organizational Role ◽  
Matrix Interactions ◽  
The Matrix ◽  
Rich Information ◽  
Extracellular Molecules ◽  
And Function ◽  
Shape Changes

The shape of adherent cells is the product of two scaffolds: the Intracellular cytoskeleton and the surrounding extracellular matrix. During epithelial morphogenesis, changes In cell shape require modifications in both of these structures. Studies of the components of the cytoskeleton, their Inter-relationships and their response to cell motility and shape changes have provided rich Information about how changes in cytoskeletal organization may take place. Less is known about how extracellular molecules interact with one another, and particularly how the cell regulates these matrix interactions. As an approach to this problem, we are investigating the structure and function of heparan sulfate proteoglycans in mammary eplthellal cells, molecules that are able to bind a variety of matrix molecules, and therefore may have an organizational role in extracellular matrix assembly. Additionally, some are Integrally associated with the plasma membrane, thereby potentially anchoring the cell to the matrix.

The Use of Potsherds for Interpreting Alluvial Deposits: A Case Study in the Adige River Basin (Italy)

1990 ◽  
Vol 185 ◽  
Author(s):  
C. Balista ◽  
S.T. Levi ◽  
A. Vanzetti ◽  
M. Vidale
Keyword(s):  
River Basin ◽  
Analytical Framework ◽  
Formation Processes ◽  
Alluvial Deposits ◽  
Fluvial Erosion ◽  
Stratigraphic Analysis ◽  
Geomorphological Processes

AbstractThe paper discusses the use of a small assemblage of potsherds as evidence of fluvial erosion and indicators of microstratigraphical and geomorphological processes. The potsherds, sandwiched between 2 alluvial deposits, provide dating criteria for the two stratigraphic units, very important for understanding the geomorphology of the whole region. By integrating evidence of negative interfaces on potsherds by fluvial erosion and sedimentological evidence, it is possible to reconstruct the local stratigraphic formation processes. Furthermore, the paper discusses some theoretical implications of this case study for stratigraphic analysis. Negative interfaces produced by erosion on sediments and ceramics are considered in the same analytical framework; in both cases, they represent cumulative units preserving the record of complex stratigraphic processes. Far from being simple limits marking gaps in sedimentary deposition, erosive interfaces are very particular types of strata to be recorded and studied with geoarchaeological methods and with the same detail of traditional sedimentary units.

scholarly journals Sulcal organization in the medial frontal cortex reveals insights into primate brain evolution

2019 ◽  
Author(s):  
Céline Amiez ◽  
Jérome Sallet ◽  
William D. Hopkins ◽  
Adrien Meguerditchian ◽  
Fadila Hadj-Bouziane ◽  
...  
Keyword(s):  
Frontal Cortex ◽  
World Monkey ◽  
Morphological Variability ◽  
Brain Evolution ◽  
Medial Frontal Cortex ◽  
Old World ◽  
Organizational Principle ◽  
Human Uniqueness ◽  
Higher Cognitive Functions ◽  
And Function

ABSTRACTAlthough the relative expansion of the frontal cortex in primate evolution is generally accepted, the nature of the human uniqueness, if any, and between-species anatomo-functional comparisons of the frontal areas remain controversial. To provide a novel interpretation of the evolution of primate brains, sulcal morphological variability of the medial frontal cortex was assessed in old-world monkeys (macaque, baboon) and Hominoidea (chimpanzee, human). We discovered that both Hominoidea do possess a paracingulate sulcus, which was previously thought to be uniquely human and linked to higher cognitive functions like mentalizing. Also, we revealed systematic sulcal morphological organisations of the medial frontal cortex that can be traced from multiple old-world monkey to Hominoidea species, demonstrating an evolutionary conserved organizational principle. Our data provide a new framework to compare sulcal morphology, cytoarchitectonic areal distribution, connectivity, and function across the primate order, leading to clear predictions on how other primate brains might be anatomo-functionally organized.

scholarly journals Early Contact Stage of Apoptosis: Its Morphological Features and Function

2006 ◽  
Vol 6 ◽  
pp. 1783-1804 ◽  
Author(s):  
Etheri Mikadze ◽  
Teo Mamatsashvili
Keyword(s):  
Apoptotic Cell ◽  
Early Stage ◽  
Close Contact ◽  
Morphological Features ◽  
Contact Stage ◽  
Ultrathin Sections ◽  
Molecular Substances ◽  
And Function ◽  
Distinguishing Features ◽  
Shape Changes

Apoptosis has been a biological phenomenon of intense interest for 20 years, but the earlier morphological features of apoptosis have not been determined hitherto. Using the methods of semi- and ultrathin sections, the livers of intact embryos and young rats have been studied under the effect of cycloheximide to determine morphological features of an early stage of apoptosis. It is discovered that both in hepatoblasts and hepatocytes, apoptosis, besides the well-known stages, also includes an early contact stage, distinguishing features of which are agglutination of bound ribosomes (breaking of translation), elimination of the nucleolus, reduction of free polysomes (and in hepatocytes, reduction of cisterns of rough endoplasmic reticulum), formation of cytoplasmic excrescences, and cell shape changes. The early stage of apoptosis is characterized by close contact with neighboring cells. At a certain phase of the contact stage of apoptosis, the nucleolus reappears in the nucleus and the number of free polysomes in the cytoplasm increases, which suggests the renewal of synthesis of new RNA and proteins. Close contact of differentiating and mitotic hepatoblasts with apoptotic cells indicates a certain functional relationship between these cells that is realized not only by micropinocytosis, but through gap junctions as well. We assume that the apoptotic cell, besides proteolytic products, can contain newly synthesized, low-molecular substances, the relocation of which from apoptotic to neighboring cells may contribute to both functional activity and proliferation of adjacent hepatoblasts and, therefore, the function of apoptosis may not be limited only to the elimination of harmful, damaged, and unwanted cells.

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