scholarly journals Modeling Fruit Tree Architectural Growth, Source–Sink Interactions, and Physiology with L-PEACH

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1010D-1010
Author(s):  
Ted M. DeJong ◽  
Romeo Favreau ◽  
Mitch Allen ◽  
Przemyslaw Prusinkiewicz
Keyword(s):  
Tree Growth ◽  
Carbon Allocation ◽  
Carbon Partitioning ◽  
Detailed Model ◽  
Graphical Simulation ◽  
L System ◽  
Architectural Development ◽  
The Individual ◽  
And Function ◽  
Source Sink

Modeling source–sink interactions and carbohydrate partitioning in plants requires a detailed model of plant architectural development, in which growth and function of each organ is modeled individually and carbohydrate transport among organs is modeled dynamically. L-PEACH is an L-system-based graphical simulation model that combines supply/demand concepts of carbon partitioning with an L-system model of tree architecture to create a distributed supply/demand system of carbon allocation within a growing tree. The whole plant is modeled as a branching network of sources and sinks, connected by conductive elements. An analogy to an electric network is used to calculate the flow and partitioning of carbohydrates between the individual components. The model can simulate multiple years of tree growth and be used to demonstrate effects of irrigation, crop load, and pruning on architectural development, tree growth, and carbon partitioning. Qualitative model outputs are viewed graphically as the tree “grows” on the computer screen while quantitative output data can be evaluated individually for each organ or collectively for an organ type using the MatLab software.

Narrow is the Gate to Utopia

Moreana ◽  
2012 ◽  
Vol 49 (Number 187- (1-2) ◽  
pp. 207-226
Author(s):  
Marie-Claire Phélippeau
Keyword(s):  
Social Construction ◽  
Free Will ◽  
Religious Toleration ◽  
Individual Liberty ◽  
The Reformation ◽  
The Individual ◽  
And Function

This study examines the notions of pleasure, individual liberty and consensus in Thomas More’s Utopia. The paradox inherent in Utopia, written before the Reformation, is especially visible in the affirmation of religious toleration coexisting with the need for a strict supervision of the citizens. The dream of an ideal republic is based on a Pauline vision of man which defines the individual mainly as a sinner. Consequently, it is the duty of the republic’s rulers to guide the citizens and establish a consensus. This study tries to determine the part left to the individual’s free will and examines the nature and function of the structures that are supposed to ensure the happiness of each one and of the whole community. The notion of moral hierarchy is asserted as the linchpin of the Utopian social construction.

scholarly journals Adolescent and adult laryngotracheal stenosis: a review

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Gerhard Johan Klopper ◽  
Oladele Vincent Adeniyi ◽  
Kate Stephenson
Keyword(s):  
Intensive Care ◽  
Past Century ◽  
Main Body ◽  
Laryngotracheal Stenosis ◽  
Airway Protection ◽  
Interventional Pulmonology ◽  
The Past ◽  
Airway Emergency ◽  
The Individual ◽  
And Function

Abstract Background The larynx has multiple composite functions which include phonation, airway protection, and sensory control of respiration. Stenosis of the larynx and trachea were first recorded by O’Dwyer in 1885 and by Colles in 1886, respectively. Initially, the aetiology of laryngotracheal stenosis was predominantly infective. Currently, the leading cause is iatrogenic injury to the laryngotracheal complex secondary to prolonged ventilation in an intensive care unit. Main body Laryngotracheal stenosis is a complex and diverse disease. It poses a major challenge to the surgeon and can present as an airway emergency. Management typically demands the combined involvement of various disciplines including otorhinolaryngology, cardiothoracic surgery, anaesthesiology, interventional pulmonology, and radiology. Both the disease and its management can impact upon respiration, voice, and swallowing. The incidence of iatrogenic laryngotracheal stenosis has reflected the evolution of airway and intensive care whilst airway surgery has advanced concurrently over the past century. Correction of laryngotracheal stenosis requires expansion of the airway lumen; this is achieved by either endoscopic or open surgery. We review the relevant basic science, aetiopathogenesis, diagnosis, management, and treatment outcomes of LTS. Conclusion The choice of surgical procedure in the management of laryngotracheal stenosis is often dictated by the individual anatomy and function of the larynx and trachea, together with patient factors and available facilities. Regardless of how the surgeon chooses to approach these lesions, prevention of iatrogenic laryngotracheal damage remains of primary importance.

Sink strength of citrus rootstocks under water deficit

2021 ◽  
Author(s):  
Simone F da Silva ◽  
Marcela T Miranda ◽  
Vladimir E Costa ◽  
Eduardo C Machado ◽  
Rafael V Ribeiro
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Water Deficit ◽  
Carbon Allocation ◽  
Sink Strength ◽  
Rangpur Lime ◽  
Carbon Supply ◽  
Valencia Orange ◽  
Source Sink ◽  
Orange Trees

Abstract Carbon allocation between source and sink organs determines plant growth and is influenced by environmental conditions. Under water deficit, plant growth is inhibited before photosynthesis and shoot growth tends to be more sensitive than root growth. However, the modulation of source-sink relationship by rootstocks remain unsolved in citrus trees under water deficit. Citrus plants grafted on Rangpur lime are drought tolerant, which may be related to a fine coordination of the source-sink relationship for maintaining root growth. Here, we followed 13C allocation and evaluated physiological responses and growth of Valencia orange trees grafted on three citrus rootstocks (Rangpur lime, Swingle citrumelo and Sunki mandarin) under water deficit. As compared to plants on Swingle and Sunki rootstocks, ones grafted on Rangpur lime showed higher stomatal sensitivity to the initial variation of water availability and less accumulation of non-structural carbohydrates in roots under water deficit. High 13C allocation found in Rangpur lime roots indicates this rootstock has high sink demand associated with high root growth under water deficit. Our data suggest that Rangpur lime rootstock used photoassimilates as sources of energy and carbon skeletons for growing under drought, which is likely related to increases in root respiration. Taken together, our data revealed that carbon supply by leaves and delivery to roots are critical for maintaining root growth and improving drought tolerance, with citrus rootstocks showing differential sink strength under water deficit.

Studies on the structure and function of the mammalian testis V. Steroid metabolism by isolated interstitium and seminiferous tubules of the human testis

1974 ◽  
Vol 186 (1083) ◽  
pp. 99-120 ◽  
Keyword(s):  
Metabolic Activity ◽  
General Pattern ◽  
Steroid Metabolism ◽  
Human Testis ◽  
Clinical Aspects ◽  
Seminiferous Tubules ◽  
Bicarbonate Buffer ◽  
The Media ◽  
The Individual ◽  
And Function

Tissue was obtained from the testes of three men, two in the age range 72-75 years (subjects A and B) and one aged 25 years (subject C). Parts of the testes were dissected to obtain samples of interstitium and tubules. The individual components and whole tissue were each incubated with equimolar concentrations of [7 α - 3 H]pregnenolone and [4- 14 C]progesterone in Krebs-Ringer bicarbonate buffer pH 7.4, at 35 °C with the addition of glucose but without cofactors. Some incubations were carried out with the substrates [4- 14 C]androstenedione and [7 α - 3 H]testosterone. The media were extracted both at various time intervals throughout the incubation for a kinetic study of the metabolic activity and after a fixed interval of time at the end of the incubations. In some incubations with whole tissue both media and tissue were extracted. Both the tubules and interstitium displayed steroid metabolic activity. Qualitatively they yielded the same range of metabolites, one series leading to the formation of testosterone (∆ 5 pathway) and the other to a variety of C 21 compounds as represented by 5 α -pregnan-3 β -ol-20-one. With similar amounts of tissue there was little difference in the yields of the main products formed by the tubules as compared with those formed by the interstitium; in incubations with [4- 14 C]androstenedione the rate of conversion to [ 14 C ]testosterone by the tubules greatly exceeded that due to the interstitium. Marked differences were found in the pattern of steroid metabolism by whole tissue as compared to the general pattern presented by the corresponding tubules and interstitium. It is concluded that the seminiferous tubules and interstitium of the human testis are both capable of steroid metabolism and hence that whole tissue incubations alone are of limited value and could give rise to misleading data. Some clinical aspects of the results are briefly discussed.

scholarly journals Postprenylation CAAX Processing Is Required for Proper Localization of Ras but Not Rho GTPases

2005 ◽  
Vol 16 (4) ◽  
pp. 1606-1616 ◽  
Author(s):  
David Michaelson ◽  
Wasif Ali ◽  
Vi K. Chiu ◽  
Martin Bergo ◽  
Joseph Silletti ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Protein Trafficking ◽  
Rho Gtpases ◽  
Ras Proteins ◽  
Rho Proteins ◽  
Carboxyl Methylation ◽  
C Terminus ◽  
Individual Contributions ◽  
The Individual ◽  
And Function

The CAAX motif at the C terminus of most monomeric GTPases is required for membrane targeting because it signals for a series of three posttranslational modifications that include isoprenylation, endoproteolytic release of the C-terminal– AAX amino acids, and carboxyl methylation of the newly exposed isoprenylcysteine. The individual contributions of these modifications to protein trafficking and function are unknown. To address this issue, we performed a series of experiments with mouse embryonic fibroblasts (MEFs) lacking Rce1 (responsible for removal of the –AAX sequence) or Icmt (responsible for carboxyl methylation of the isoprenylcysteine). In MEFs lacking Rce1 or Icmt, farnesylated Ras proteins were mislocalized. In contrast, the intracellular localizations of geranylgeranylated Rho GTPases were not perturbed. Consistent with the latter finding, RhoGDI binding and actin remodeling were normal in Rce1- and Icmt-deficient cells. Swapping geranylgeranylation for farnesylation on Ras proteins or vice versa on Rho proteins reversed the differential sensitivities to Rce1 and Icmt deficiency. These results suggest that postprenylation CAAX processing is required for proper localization of farnesylated Ras but not geranygeranylated Rho proteins.

The Tegument and Associated Structures of Fasciola Hepatica

1963 ◽  
Vol s3-104 (68) ◽  
pp. 505-512
Author(s):  
L. T. THREADGOLD
Keyword(s):  
Electron Microscopy ◽  
Surface Layer ◽  
Light Microscopy ◽  
Fasciola Hepatica ◽  
Golgi Bodies ◽  
New Knowledge ◽  
Pinocytotic Vesicles ◽  
The Individual ◽  
And Function ◽  
Internal Level

The cuticle of light microscopy is shown by electron microscopy to be a surface layer of protoplasm which is an extension of areas of nucleated protoplasm lying deep in the parenchyma. The cuticle therefore exists at two levels. The external level is syncytial, consisting of plateaux separated by branching valleys. This level contains apical pinocytotic vesicles, numerous mitochondria, endoplasmic membranes, large basal and other vacuoles, and dense spines. Tube-like evaginations from the base of the external level connect it to the individual areas of flask-shaped protoplasm which compose the internal level. Each of these areas of protoplasm contains a nucleus, great numbers of mitochondria, some vacuoles and diffuse inclusions, and the Golgi bodies. The histochemistry and function of the cuticle is discussed in the light of this new knowledge of cuticular ultrastructure, and a comparison is made between the cuticle of Cestoda and Trematoda.

Effect of EPS on biofilm structure and function as revealed by an individual-based model of biofilm growth

2001 ◽  
Vol 43 (6) ◽  
pp. 135-135 ◽  
Author(s):  
J.-U. Kreft ◽  
J. W. Wimpenny
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Structure And Function ◽  
Individual Based Model ◽  
Biofilm Growth ◽  
Rate Dependent ◽  
Binding Forces ◽  
The Individual ◽  
And Function ◽  
Biofilm Structure

We have simulated a nitrifying biofilm with one ammonia and one nitrite oxidising species in order to elucidate the effect of various extracellular polymeric substance (EPS) production scenarios on biofilm structure and function. The individual-based model (IbM) BacSim simulates diffusion of all substrates on a two-dimensional lattice. Each bacterium is individually simulated as a sphere of given size in a continuous, three-dimensional space. EPS production kinetics was described by a growth rate dependent and an independent term (Luedeking-Piret equation). The structure of the biofilm was dramatically influenced by EPS production or capsule formation. EPS production decreased growth of producers and stimulated growth of non-producers because of the energy cost involved. For the same reason, EPS accumulation can fall as its rate of production increases. The patchiness and roughness of the biofilm decreased and the porosity increased due to EPS production. EPS density was maximal in the middle of the vertical profile. Introduction of binding forces between like cells increased clustering.

scholarly journals p38δ genetic ablation protects female mice from anthracycline cardiotoxicity

2020 ◽  
Author(s):  
Sharon A George ◽  
Alexi Kiss ◽  
Sofian N Obaid ◽  
Aileen Venegas ◽  
Trisha Talapatra ◽  
...  
Keyword(s):  
Cardiac Injury ◽  
Mapk Signaling ◽  
Anthracycline Cardiotoxicity ◽  
Genetic Ablation ◽  
Female Mice ◽  
Echocardiographic Parameters ◽  
The Individual ◽  
And Function ◽  
First Time ◽  
Dose Dependent

ABSTRACTBACKGROUNDThe efficacy of an anthracycline antibiotic doxorubicin (DOX) as a chemotherapeutic agent is limited by dose-dependent cardiotoxicity. DOX is associated with activation of intracellular stress signaling pathways including p38 MAPKs. While previous studies have implicated p38 MAPK signaling in DOX-induced cardiac injury, the roles of the individual p38 isoforms, specifically, of the alternative isoforms p38γ and p38δ, remain uncharacterized.OBJECTIVESTo determine the potential cardioprotective effects of p38γ and p38δ genetic deletion in mice subjected to acute DOX treatment.METHODSMale and female wild-type (WT), p38γ-/-, p38δ-/- and p38γ-/-δ-/- mice were injected with 30 mg/kg DOX and their survival was tracked for ten days. During this period cardiac function was assessed by echocardiography and electrocardiography and fibrosis by PicroSirius Red staining. Immunoblotting was performed to assess the expression of signaling proteins and markers linked to autophagy.RESULTSSignificantly improved survival was observed in p38δ-/- female mice post-DOX relative to WT females, but not in p38γ-/- or p38γ-/-δ-/- male or female mice. The improved survival in DOX-treated p38δ-/- females was associated with decreased fibrosis, increased cardiac output and LV diameter relative to DOX-treated WT females, and similar to saline-treated controls. Structural and echocardiographic parameters were either unchanged or worsened in all other groups. Increased autophagy, as evidenced by increased LC3-II level, and decreased mTOR activation was also observed in DOX-treated p38δ-/- females.CONCLUSIONSp38δ plays a crucial role in promoting DOX-induced cardiotoxicity in female mice by inhibiting autophagy. Therefore, p38δ targeting could be a potential cardioprotective strategy in anthracycline chemotherapy.NEW AND NOTEWORTHYThis study for the first time identifies the roles of the alternative p38γ and p38δ MAPK isoforms in promoting DOX-cardiotoxicity in a sex-specific manner. While p38γ systemic deletion did not affect DOX-cardiotoxicity, p38δ systemic deletion was cardioprotective in female but not in male mice. Cardiac structure and function were preserved in DOX-treated p38δ-/- females and autophagy was increased.

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