196 hasil untuk "Martin Adam"
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Artikel Jurnal Teks lengkap
A Reassessment of Carbon Content in Tropical Trees
Accurate knowledge of carbon (C) content in live wood is essential for quantifying tropical forest C stocks, yet generic assumptions (such as biomass consisting of 50% carbon on a weight/weight basis) remain widely used despite being supported by little chemical analysis. Empirical data from stem…
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Artikel Jurnal Teks lengkap
Modular regulation of Rho family GTPases in development
Rho family GTPase signaling regulates the actin cytoskeleton and is critical for behaviors that range from the cell to tissue-scale. A theme in Rho GTPase biology is that there are many more regulators, such as guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs), than…
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Artikel Jurnal Teks lengkap
Tuning cell shape change with contractile ratchets
Throughout the lifespan of an organism, shape changes are necessary for cells to carry out their essential functions. Nowhere is this more dramatic than embryonic development and gastrulation, when cell shape changes drive large-scale rearrangements in tissue architecture to establish the body plan…
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Artikel Jurnal Teks lengkap
Flow-dependent myosin recruitment during Drosophila cellularization requires zygotic dunk activity
Actomyosin contractility underlies force generation in morphogenesis ranging from cytokinesis to epithelial extension or invagination. In Drosophila, the cleavage of the syncytial blastoderm is initiated by an actomyosin network at the base of membrane furrows that invaginate from the surface of…
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Artikel Jurnal Teks lengkap
Force Transmission in Epithelial Tissues
In epithelial tissues, cells constantly generate and transmit forces between each other. Forces generated by the actomyosin cytoskeleton regulate tissue shape and structure and also provide signals that influence cells’ decisions to divide, die, or differentiate. Forces are transmitted across…
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Artikel Jurnal Teks lengkap
Abl suppresses cell extrusion and intercalation during epithelium folding
Tissue morphogenesis requires control over cell shape changes and rearrangements. In the Drosophila mesoderm, linked epithelial cells apically constrict, without cell extrusion or intercalation, to fold the epithelium into a tube that will then undergo epithelial-to-mesenchymal transition (EMT)…
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Artikel Jurnal Teks lengkap
Apical sarcomere-like actomyosin contracts nonmuscle Drosophila epithelial cells
Actomyosin networks generate contractile force that changes cell and tissue shape. In muscle cells, actin filaments and myosin II appear in a polarized structure called a sarcomere, where myosin II is localized in the center. Nonmuscle cortical actomyosin networks are thought to contract when…
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Artikel Jurnal Teks lengkap
Tension, contraction and tissue morphogenesis
D'Arcy Thompson was a proponent of applying mathematical and physical principles to biological systems, an approach that is becoming increasingly common in developmental biology. Indeed, the recent integration of quantitative experimental data, force measurements and mathematical modeling has…
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Artikel Jurnal Teks lengkap
Does active commuting improve psychological wellbeing? Longitudinal evidence from eighteen waves of the British Household Panel Survey
OBJECTIVE: The aim of this study is to explore the relationship between active travel and psychological wellbeing. METHOD: This study used data on 17,985 adult commuters in eighteen waves of the British Household Panel Survey (1991/2–2008/9). Fixed effects regression models were used to investigate…
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Artikel Jurnal Teks lengkap
Evaluating causal relationships between urban built environment characteristics and obesity: a methodological review of observational studies
BACKGROUND: Existing reviews identify numerous studies of the relationship between urban built environment characteristics and obesity. These reviews do not generally distinguish between cross-sectional observational studies using single equation analytical techniques and other studies that may…
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Artikel Jurnal Teks lengkap
Accumulating crop functional trait data with citizen science
Trait-based ecology is greatly informed by large datasets for the analyses of inter- and intraspecific trait variation (ITV) in plants. This is especially true in trait-based agricultural research where crop ITV is high, yet crop trait data remains limited. Based on farmer-led collections, we…
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Artikel Jurnal Teks lengkap
Quantitative analysis of cell shape and the cytoskeleton in developmental biology
Computational approaches that enable quantification of microscopy data have revolutionized the field of developmental biology. Due to its inherent complexity, elucidating mechanisms of development requires sophisticated analysis of the structure, shape, and kinetics of cellular processes. This need…
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Artikel Jurnal Teks lengkap
EGFR-dependent actomyosin patterning coordinates morphogenetic movements between tissues
The movements that give rise to the body’s structure are powered by cell shape changes and rearrangements that are coordinated at supracellular scales. How such cellular coordination arises and integrates different morphogenetic programs is unclear. Using quantitative imaging, we found a complex…
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Artikel Jurnal Teks lengkap
The leaf economics spectrum’s morning coffee: plant size-dependent changes in leaf traits and reproductive onset in a perennial tree crop
BACKGROUND AND AIMS: Size-dependent changes in plant traits are an important source of intraspecific trait variation. However, there are few studies that have tested if leaf trait co-variation and/or trade-offs follow a within-genotype leaf economics spectrum (LES) related to plant size and…
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Artikel Jurnal Teks lengkap
Roles of the Actin Cytoskeleton and Cell Adhesion in Tissue Morphogenesis
The generation of organismal form (i.e., morphogenesis) arises from forces produced at the cellular level. In animal cells, much of this force is produced by the actin cytoskeleton. Here, we review how mechanisms of actin-based force generation are deployed during animal morphogenesis to sculpt…
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Preprint Teks lengkap
Probing EFT breakdown in the tails of $W^+ W^-$ observables
In this letter, we test clipping effective field theory (EFT) simulations as a method of ensuring EFT validity. The procedure imposes that, at the level of the simulation, the invariant mass of a $W^+W^-$ pair $M_{WW}$ is less than the new physics scale $Λ$. We compare this to two other methods…
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Preprint Teks lengkap
Geometric Amplitudes: A Covariant Functional Approach for Massless Scalar Theories
Functional geometry is a framework using concepts from geometry to understand the invariance of amplitudes in quantum field theory under a large class of field redefinitions, including those involving derivatives. It is inspired by recursion relations among correlation functions, where higher-point…
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Artikel Jurnal Teks lengkap
Morphogenetic forces planar polarize LGN/Pins in the embryonic head during Drosophila gastrulation
Spindle orientation is often achieved by a complex of Partner of Inscuteable (Pins)/LGN, Mushroom Body Defect (Mud)/Nuclear Mitotic Apparatus (NuMa), Gαi, and Dynein, which interacts with astral microtubules to rotate the spindle. Cortical Pins/LGN recruitment serves as a critical step in this…
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Preprint Teks lengkap
Effective Field Theory of Stückelberg Vector Bosons
We explore the effective field theory of a vector field $X^μ$ that has a Stückelberg mass. The absence of a gauge symmetry for $X^μ$ implies Lorentz-invariant operators are constructed directly from $X^μ$. Beyond the kinetic and mass terms, allowed interactions at the renormalizable level include…
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Artikel Jurnal Teks lengkap
Apical domain polarization localizes actin-myosin activity to drive ratchet-like apical constriction
Apical constriction promotes epithelia folding, which changes tissue architecture. During Drosophila gastrulation, mesoderm cells exhibit repeated contractile pulses that are stabilized such that cells apically constrict like a ratchet. The transcription factor Twist is required to stabilize cell…