Heteroblasty in bromeliads - anatomical, morphological and physiological changes in ontogeny are not related to the change from atmospheric to tank form

2013 ◽  
Vol 40 (3) ◽  
pp. 251 ◽  
Author(s):  
Kerstin Meisner ◽  
Uwe Winkler ◽  
Gerhard Zotz
Keyword(s):  
Abrupt Change ◽  
Size Range ◽  
Step Change ◽  
Comparative Approach ◽  
Large Set ◽  
Storage Tissue ◽  
Uptake Rates ◽  
Functional Implications ◽  
Ontogenetic Drift ◽  
Functional Relevance

Heteroblasty is defined as an abrupt change in gross morphology during ontogeny, whereas homoblastic species show no or gradual changes. For Bromeliaceae, there are conflicting reports on a very limited number of species on the functional importance of this step change compared with gradual changes (ontogenetic drift). Studying a large set of species should allow more general conclusions. Seventeen homoblastic and heteroblastic species from Panama were investigated, including the entire size range of most species. Measurements included functionally relevant anatomical (water storage tissue), morphological (stomatal and trichome densities) and physiological parameters (transpiration rates, nutrient uptake rates). Size-related variation in all parameters was common, but evidence for a step change in the studied parameters could not be detected in any of the heteroblastic species. Our results caused us to question the widely held view of the course of the ontogenetic development in heteroblastic bromeliads and their functional implications. These findings suggest that the possible functional relevance of heteroblasty in bromeliads require rethinking and future investigations should employ a comparative approach with both homoblastic and heteroblastic species and including the entire size range to account for ontogenetic drift.

scholarly journals The Significance of Database Size in Modelling the Market of Nonresidential Premises

2016 ◽  
Vol 24 (2) ◽  
pp. 47-56
Author(s):  
Anna Barańska
Keyword(s):  
Housing Market ◽  
Real Estate Market ◽  
Comparative Approach ◽  
Large Set ◽  
Property Market ◽  
Commercial Property ◽  
The Real Estate ◽  
Database Size ◽  
Multidimensional Modelling ◽  
Different Characteristics

Abstract The market of non-residential premises is the subject of analyses less frequently than the housing market. There are two main reasons which probably contribute thereto. First of all, commercial premises are relatively less frequently objects of trade than dwelling units; secondly, they are more diverse due to their various uses. The category includes garages, office premises, commercial premises, as well as warehouses. Such differences in their uses result in significantly different characteristics, such as surface area. The article attempts to analyse a selected non-residential segment of the commercial property market in Krakow based on a large set of data (280 objects), referring to the transactions concluded in the last five years. The size of the data enabled the use of multidimensional modelling of the selected market in different size variants. This made it possible to draw reliable conclusions which undermine the widespread belief regarding very limited possibilities of using the method of market statistical analysis in the comparative approach, especially in this segment of the real estate market, as well as in others, where transactions are concluded less frequently than on the housing market.

Relaxation of the Turbulent Boundary Layer After an Abrupt Change From Rough to Smooth Wall (Data Bank Contribution)

1993 ◽  
Vol 115 (3) ◽  
pp. 379-382 ◽  
Author(s):  
R. P. Taylor ◽  
J. K. Taylor ◽  
M. H. Hosni ◽  
H. W. Coleman
Keyword(s):  
Boundary Layer ◽  
Skin Friction ◽  
Abrupt Change ◽  
Plate Boundary ◽  
Data Bank ◽  
Skin Friction Coefficient ◽  
Step Change ◽  
Test Surface ◽  
Layer Flow ◽  
Flat Plate Boundary Layer

Measurements of velocity and turbulence intensity profiles and skin friction coefficient are presented for turbulent flat-plate boundary layer flow over a test surface with a rough-to-smooth step change in surface roughness. The first 0.9 m length of the test surface is roughened with 1.27 mm diameter hemispheres spaced 2 base diameters apart in a uniform staggered array, and the remaining 1.5 m length is smooth. The profiles are compared with previous data for all-rough cases under closely matched conditions in the same facility. The skin friction data are compared with previous data for both all-rough and all-smooth cases.

scholarly journals Transsynaptic mapping of Drosophila mushroom body output neurons

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Kristin M Scaplen ◽  
Mustafa Talay ◽  
John D Fisher ◽  
Raphael Cohn ◽  
Altar Sorkaç ◽  
...  
Keyword(s):  
Associative Memory ◽  
Mushroom Body ◽  
Behavioral Responses ◽  
Previous Experience ◽  
Shaped Body ◽  
Functional Implications ◽  
Output Neurons ◽  
Functional Relevance ◽  
The Brain ◽  
Lateral Accessory Lobe

The mushroom body (MB) is a well-characterized associative memory structure within the Drosophila brain. Analyzing MB connectivity using multiple approaches is critical for understanding the functional implications of this structure. Using the genetic anterograde transsynaptic tracing tool, trans-Tango, we identified divergent projections across the brain and convergent downstream targets of the MB output neurons (MBONs). Our analysis revealed at least three separate targets that receive convergent input from MBONs: other MBONs, the fan-shaped body (FSB), and the lateral accessory lobe (LAL). We describe, both anatomically and functionally, a multilayer circuit in which inhibitory and excitatory MBONs converge on the same genetic subset of FSB and LAL neurons. This circuit architecture enables the brain to update and integrate information with previous experience before executing appropriate behavioral responses. Our use of trans-Tango provides a genetically accessible anatomical framework for investigating the functional relevance of components within these complex and interconnected circuits.

scholarly journals The retrocalcarine sulcus maps different retinotopic representations in macaques and humans

2021 ◽  
Author(s):  
Michael J. Arcaro ◽  
Margaret S. Livingstone ◽  
Kendrick N. Kay ◽  
Kevin S. Weiner
Keyword(s):  
Functional Organization ◽  
Careful Consideration ◽  
Primate Species ◽  
Comparative Approach ◽  
Anatomical Landmarks ◽  
Cortical Folding ◽  
Cortex Area ◽  
Functional Relevance ◽  
Multiple Species ◽  
Species Specific

AbstractPrimate cerebral cortex is highly convoluted with much of the cortical surface buried in sulcal folds. The origins of cortical folding and its functional relevance have been a major focus of systems and cognitive neuroscience, especially when considering stereotyped patterns of cortical folding that are shared across individuals within a primate species and across multiple species. However, foundational questions regarding organizing principles shared across species remain unanswered. Taking a cross-species comparative approach with a careful consideration of historical observations, we investigate cortical folding relative to primary visual cortex (area V1). We identify two macroanatomical structures—the retrocalcarine and external calcarine sulci—in 24 humans and 6 macaque monkeys. We show that within species, these sulci are identifiable in all individuals, fall on a similar part of the V1 retinotopic map, and thus, serve as anatomical landmarks predictive of functional organization. Yet, across species, the underlying eccentricity representations corresponding to these macroanatomical structures differ strikingly across humans and macaques. Thus, the correspondence between retinotopic representation and cortical folding for an evolutionarily old structure like V1 is species-specific and suggests potential differences in developmental and experiential constraints across primates.

scholarly journals Why colorectal screening fails to achieve the uptake rates of breast and cervical cancer screening: a comparative qualitative study

2019 ◽  
Vol 29 (6) ◽  
pp. 482-490
Author(s):  
Marie Kotzur ◽  
Colin McCowan ◽  
Sara Macdonald ◽  
Sally Wyke ◽  
Lauren Gatting ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cervical Cancer ◽  
Cancer Screening ◽  
Cervical Screening ◽  
Comparative Approach ◽  
Cancer Treatments ◽  
Breast And Cervical Cancer ◽  
Home Based ◽  
Uptake Rates ◽  
Colorectal Screening

BackgroundIn Scotland, the uptake of clinic-based breast (72%) and cervical (77%) screening is higher than home-based colorectal screening (~60%). To inform new approaches to increase uptake of colorectal screening, we compared the perceptions of colorectal screening among women with different screening histories.MethodsWe purposively sampled women with different screening histories to invite to semistructured interviews: (1) participated in all; (2) participated in breast and cervical but not colorectal (‘colorectal-specific non-participants’); (3) participated in none. To identify the sample we linked the data for all women eligible for all three screening programmes in Glasgow, Scotland (aged 51–64 years; n=68 324). Interviews covered perceptions of cancer, screening and screening decisions. Framework method was used for analysis.ResultsOf the 2924 women invited, 86 expressed an interest, and 59 were interviewed. The three groups’ perceptions differed, with the colorectal-specific non-participants expressing that: (1) treatment for colorectal cancer is more severe than for breast or cervical cancer; (2) colorectal symptoms are easier to self-detect than breast or cervical symptoms; (3) they worried about completing the test incorrectly; and (4) the colorectal test could be more easily delayed or forgotten than breast or cervical screening.ConclusionOur comparative approach suggested targets for future interventions to increase colorectal screening uptake including: (1) reducing fear of colorectal cancer treatments; (2) increasing awareness that screening is for the asymptomatic; (3) increasing confidence to self-complete the test; and (4) providing a suggested deadline and/or additional reminders.

scholarly journals CLASP2 interacts with p120-catenin and governs microtubule dynamics at adherens junctions

2013 ◽  
Vol 203 (6) ◽  
pp. 1043-1061 ◽  
Author(s):  
Marta N. Shahbazi ◽  
Diego Megias ◽  
Carolina Epifano ◽  
Anna Akhmanova ◽  
Gregg G. Gundersen ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Adherens Junctions ◽  
Direct Interaction ◽  
P120 Catenin ◽  
Basal Progenitor ◽  
Classical Cadherins ◽  
Functional Implications ◽  
Functional Relevance ◽  
Mouse Keratinocytes ◽  
Cell Cell

Classical cadherins and their connections with microtubules (MTs) are emerging as important determinants of cell adhesion. However, the functional relevance of such interactions and the molecular players that contribute to tissue architecture are still emerging. In this paper, we report that the MT plus end–binding protein CLASP2 localizes to adherens junctions (AJs) via direct interaction with p120-catenin (p120) in primary basal mouse keratinocytes. Reductions in the levels of p120 or CLASP2 decreased the localization of the other protein to cell–cell contacts and altered AJ dynamics and stability. These features were accompanied by decreased MT density and altered MT dynamics at intercellular junction sites. Interestingly, CLASP2 was enriched at the cortex of basal progenitor keratinocytes, in close localization to p120. Our findings suggest the existence of a new mechanism of MT targeting to AJs with potential functional implications in the maintenance of proper cell–cell adhesion in epidermal stem cells.

scholarly journals FaviCoV -a comprehensive manually curated resource for functional genetic variants in SARS-CoV-2

2020 ◽  
Author(s):  
Mercy Rophina ◽  
Kavita Pandhare ◽  
Mohit Mangla ◽  
Afra Shamnath ◽  
Bani Jolly ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Genetic Epidemiology ◽  
Genetic Variants ◽  
Comprehensive Collection ◽  
The World ◽  
Functional Implications ◽  
Functional Consequences ◽  
Rapid Dissemination ◽  
Functional Relevance ◽  
Supporting Functional

The widespread and unprecedented adoption of genome sequencing to understand the genetic epidemiology of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in the ongoing COVID-19 pandemic has provided interesting insights into the evolution and spread of the pathogen. Further research has enabled the understanding of the functional implications of genetic variants. While a compilation of functionally relevant variants in the genome would significantly enhance the interpretation of genomes, there has been a paucity of resources systematically collecting and evaluating evidence on the functionality of genetic variants. To this end, we manually compiled evidence from literature and preprints on variants in SARS-CoV-2 genomes and their functional relevance, including assays used and interpretations. This compilation presently includes 430 unique variants including 79 variants which have experimental evidence supporting their functional consequences. To the best of our knowledge, this is the only resource providing a comprehensive collection of evidence supporting functional consequences of variants in SARS-CoV-2. While researchers across the world work coherently to sequence more genomes and also evaluate functions of genetic variants, we hope this resource would continue to play a central role in rapid dissemination of evidence. The resource is available at https://clingen.igib.res.in/favicov/

scholarly journals The Retrocalcarine Sulcus Is Functionally Distinct Between Macaques and Humans

2021 ◽  
Author(s):  
Michael Arcaro ◽  
Margaret S. Livingstone ◽  
Kendrick N. Kay ◽  
Kevin S. Weiner
Keyword(s):  
Functional Organization ◽  
Careful Consideration ◽  
Primate Species ◽  
Comparative Approach ◽  
Anatomical Landmarks ◽  
Cortical Folding ◽  
Developmental Constraints ◽  
Functional Relevance ◽  
Species Specific ◽  
Primate Cerebral Cortex

Abstract Primate cerebral cortex is highly convoluted with much of the cortical surface buried in sulcal folds. The origins of cortical folding and its functional relevance has been a major focus of systems and cognitive neuroscience. Stereotyped patterns of cortical folding across individuals and multiple primate species indicate common evolutionary pressures in their development. However, foundational questions regarding organizing principles shared across species remain unanswered. Taking a cross-species comparative approach with a careful consideration of historical observations, we investigate cortical folding within the calcarine sulcus, a primary fold in primates. We identify two macroanatomical structures – the retrocalcarine and external calcarine sulci – in 24 humans and 6 macaque monkeys. We show that within species, these sulci are identifiable in all individuals, fall on a similar part of the V1 retinotopic map, and thus, serve as anatomical landmarks predictive of functional organization. Yet, across species, the actual underlying visual field representations differ strikingly across humans and macaques. Thus, the structure-function correspondence for an evolutionarily old structure like V1 is species-specific and suggests intriguing differences in developmental constraints across primates.

scholarly journals AGO-unbound cytosolic pool of mature miRNAs in plant cells reveals a novel regulatory step at AGO1 loading

2019 ◽  
Vol 47 (18) ◽  
pp. 9803-9817 ◽  
Author(s):  
Ágnes Dalmadi ◽  
Péter Gyula ◽  
Jeannette Bálint ◽  
György Szittya ◽  
Zoltán Havelda
Keyword(s):  
Molecular Weight ◽  
High Throughput Sequencing ◽  
Size Range ◽  
Plant Cells ◽  
Molecular Size ◽  
Mature Mirnas ◽  
Biologically Active ◽  
Limiting Factor ◽  
Low Molecular Weight ◽  
Large Set

Abstract RNA interference (RNAi) is mediated by small, 20-24-nt-long, non-coding regulatory (s)RNAs such as micro (mi) and small interfering (si) RNAs via the action of ARGONAUTE (AGO) proteins. High-throughput sequencing of size-separated sRNA pools of plant crude extracts revealed that the majority of the canonical miRNAs were associated with high molecular weight RNA-induced silencing complexes co-migrating with AGO1 (HMW RISC). In contrast, the majority of 24-nt-long siRNAs were found in association with low molecular weight complexes co-migrating with AGO4 (LMW RISC). Intriguingly, we identified a large set of cytoplasmic sRNAs, including mature miRNA sequences, in the low molecular size range corresponding to protein-unbound sRNAs. By comparing the RISC-loaded and protein-unbound pools of miRNAs, we identified miRNAs with highly different loading efficiencies. Expression of selected miRNAs in transient and transgenic systems validated their altered loading abilities implying that this process is controlled by information associated with the diverse miRNA precursors. We also showed that the availability of AGO proteins is a limiting factor determining the loading efficiency of miRNAs. Our data reveal the existence of a regulatory checkpoint determining the RISC-loading efficiencies of various miRNAs by sorting only a subset of the produced miRNAs into the biologically active RISCs.

Microtomy of spherical Al2O3 powders

1983 ◽  
Vol 41 ◽  
pp. 74-75
Author(s):  
E.J. Jenkins ◽  
D.S. Tucker ◽  
J.J. Hren
Keyword(s):  
Thin Film ◽  
Size Range ◽  
Particle Aggregation ◽  
Ion Milling ◽  
Thin Sections ◽  
Α Phase ◽  
Convenient Means ◽  
Van Der Waals Attraction ◽  
Negative Feature ◽  
Film Substrate

The size range of mineral and ceramic particles of one to a few microns is awkward to prepare for examination by TEM. Electrons can be transmitted through smaller particles directly and larger particles can be thinned by crushing and dispersion onto a substrate or by embedding in a film followed by ion milling. Attempts at dispersion onto a thin film substrate often result in particle aggregation by van der Waals attraction. In the present work we studied 1-10 μm diameter Al2O3 spheres which were transformed from the amprphous state to the stable α phase.After the appropriate heat treatment, the spherical powders were embedded in as high a density as practicable in a hard EPON, and then microtomed into thin sections. There are several advantages to this method. Obviously, this is a rapid and convenient means to study the microstructure of serial slices. EDS, ELS, and diffraction studies are also considerably more informative. Furthermore, confidence in sampling reliability is considerably enhanced. The major negative feature is some distortion of the microstructure inherent to the microtoming operation; however, this appears to have been surprisingly small. The details of the method and some typical results follow.

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