Relevant bibliographies by topics / Polymorphic systems

Academic literature on the topic 'Polymorphic systems'

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Published: 10 December 2022
Last updated: 28 January 2023

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Journal articles on the topic "Polymorphic systems"

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Du, Dan, Guo-Bin Ren, Ming-Hui Qi, Zhong Li, and Xiao-Yong Xu. "Solvent-Mediated Polymorphic Transformation of Famoxadone from Form II to Form I in Several Mixed Solvent Systems." Crystals 9, no. 3 (March 20, 2019): 161. http://dx.doi.org/10.3390/cryst9030161.

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This paper discloses six polymorphs of famoxadone obtained from polymorph screening, which were characterized by XRPD, DSC, and SEM. A study of solvent-mediated polymorphic transformation (SMPT) of famoxadone from the metastable Form II to the stable Form I in several mixed solvent systems at the temperature of 30 °C was also conducted. The transformation process was monitored by Process Analytical Technologies. It was confirmed that the Form II to Form I polymorphic transformation is controlled by the Form I growth process. The transformation rate constants depended linearly on the solubility difference value between Form I and Form II. Furthermore, the hydrogen-bond-donation/acceptance ability and dipolar polarizability also had an effect on the rate of solvent-mediated polymorphic transformation.
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DELGADO, G., M. GUILLEN, and A. J. MORA. "4-METHYL HYPPURIC ACID: A CASE OF POLYMORPHISM AND SOLVATOMORPHISM." Periódico Tchê Química 16, no. 32 (August 20, 2019): 812–19. http://dx.doi.org/10.52571/ptq.v16.n32.2019.830_periodico32_pgs_812_819.pdf.

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Polymorphism is known as the ability of a solid material to exist in more than one form or crystal structure, with important applications in the preparation of active pharmaceutical ingredients. Characterization of different polymorphs of the specific metabolite of 4-xylene can contribute to the chemical and pharmaceutical industry. Polymorphism is of particular importance in industrial processes, where different physical properties of polymorphic forms can substantially alter the viability and quality of a manufactured product. This is particularly so for the design and production of drugs in the pharmaceutical industry, as varying physical properties between different polymorphs can affect shelf life and durability, solubility, as well as bioavailability and manufacturing of the drug. The crystallization, spectroscopic and X-ray diffraction characterization of two polymorph and one solvatomorph of 4-methylhippuric acid are presented. These compounds crystallizes in different crystalline systems. Polymorph I (4mH-I) crystalize in an orthorhombic cell with space group P212121. Polymorph II (4mHII) crystallizes in a monoclinic space group P21/c. Solvatomorph (4mH-S) crystallizes in a triclinic P-1 cell. All polymorphs crystallize in neutral form. The crystal packing of the three compounds are governed by hydrogen bonds intermolecular interactions of the type N--H···O and O--H···O forming tridimensional networks.
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Labine-Romain, Mackenzie, Sabrina Beckmann, Mohan Bhadbhade, Saroj Bhattacharyya, Michael Manefield, Christopher E. Marjo, and Anne M. Rich. "Polymorphs of Neutral Red, a Redox-Mediating Phenazine in Biological Systems." Australian Journal of Chemistry 70, no. 9 (2017): 1032. http://dx.doi.org/10.1071/ch17141.

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Neutral red 1 is a heterocyclic phenazine that, as a crystalline solid, has been observed to accelerate microbial methane generation from coal. Scale-up to an industrial process will require large quantities of neutral red crystals, hence an understanding of any polymorphic behaviour is essential for careful control of this process. A room-temperature structure of 1 (Form I) has been reported previously, and this study describes a new polymorph (Form II) crystallising from aqueous solution at 50°C, or transforming from Form I over an incubation time of one week at 70°C. Single-crystal X-ray diffraction has been used to study the molecular arrangements and intermolecular interactions in the new polymorph, and compared with those found in the room temperature form. Both polymorphs have been characterised using Raman and infrared spectroscopy, and a synthetic mixture of polymorphs successfully imaged using Raman spectroscopy. Raman imaging is proposed as a quality control method for small quantities of sample to ensure the correct polymorph is produced as a feedstock for this new methanogenesis process.
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Mnguni, Malitsatsi J., Joseph P. Michael, and Andreas Lemmerer. "Binary polymorphic cocrystals: an update on the available literature in the Cambridge Structural Database, including a new polymorph of the pharmaceutical 1:1 cocrystal theophylline–3,4-dihydroxybenzoic acid." Acta Crystallographica Section C Structural Chemistry 74, no. 6 (May 23, 2018): 715–20. http://dx.doi.org/10.1107/s2053229618006861.

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An analysis and classification of the 2925 neutral binary organic cocrystals in the Cambridge Structural Database is reported, focusing specifically on those both showing polymorphism and containing an active pharmaceutical ingredient (API). The search was confined to molecules having only C, H, N, O, S and halogens atoms. It was found that 400 out of 2925 cocrystals can be classified as pharmaceutical cocrystals, containing at least one API, and that of those, 56 can be classified as being polymorphic cocrystals. In general, the total number of polymorphic cocrystal systems of any type stands at 125. In addition, a new polymorph of the pharmaceutical cocrystal theophylline–3,4-dihydroxybenzoic acid (1/1), C7H8N4O2·C7H6O4, is reported.
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van den Ende, Joost, and Herma Cuppen. "Solid-to-solid polymorphic transitions in amino acid crystals." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1627. http://dx.doi.org/10.1107/s2053273314083727.

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The properties of crystals are related to their structure and therefore they can be different for different polymorphs. For example, the pharmaceutical characteristics bioavailability and shelf life can depend on the formed polymorph and its stability. We aim to understand transitions between polymorphs that occur in the solid phase, with the ultimate goal to induce or inhibit these transitions. We apply Molecular Dynamics (MD) simulations as a computational microscope to study these processes at the molecular level. Our used model systems for polymorphic behavior of molecular crystals in a pharmaceutical context are amino-acid crystals, in particular DL-norleucine. The polymorphs of DL-norleucine consist of tightly packed hydrogen-bonded bilayers with straight side chains that are weakly bound through Van-der-Waals interactions. When DL-norleucine undergoes a polymorphic transition, the bilayers shift with respect to each other. In the simulations of the enantiotropically-related beta and alpha polymorph, we observe that the transformed lattice parameters and molecular properties behave identically with temperature for both polymorphs. Consequently, the polymorphs only differ in the orientation of the molecular bilayers in the a'c' and the b'c'-plane, which explains the ease of transitions between them. Moreover, in simulations of the beta polymorph at 350 K we observe partial phase transitions which we could follow with the help of specifically designed order parameters. The transitions are exclusively occurring in the b'c'-plane. This indicates a possible transformation mechanism in which first shifts of bilayers occur in this plane, followed by shifts in the a'c'-plane. Interestingly, the region of highest flexibility of the molecule shifts from the middle to the end of the carbon chain at the highest studied temperature.
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Gordon, Colin S. "Polymorphic Iterable Sequential Effect Systems." ACM Transactions on Programming Languages and Systems 43, no. 1 (April 2021): 1–79. http://dx.doi.org/10.1145/3450272.

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Effect systems are lightweight extensions to type systems that can verify a wide range of important properties with modest developer burden. But our general understanding of effect systems is limited primarily to systems where the order of effects is irrelevant. Understanding such systems in terms of a semilattice of effects grounds understanding of the essential issues and provides guidance when designing new effect systems. By contrast, sequential effect systems—where the order of effects is important—lack an established algebraic structure on effects. We present an abstract polymorphic effect system parameterized by an effect quantale—an algebraic structure with well-defined properties that can model the effects of a range of existing sequential effect systems. We define effect quantales, derive useful properties, and show how they cleanly model a variety of known sequential effect systems. We show that for most effect quantales, there is an induced notion of iterating a sequential effect; that for systems we consider the derived iteration agrees with the manually designed iteration operators in prior work; and that this induced notion of iteration is as precise as possible when defined. We also position effect quantales with respect to work on categorical semantics for sequential effect systems, clarifying the distinctions between these systems and our own in the course of giving a thorough survey of these frameworks. Our derived iteration construct should generalize to these semantic structures, addressing limitations of that work. Finally, we consider the relationship between sequential effects and Kleene Algebras, where the latter may be used as instances of the former.
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Liu, Jie, and Wenfei Fan. "Polymorphic queries for P2P systems." Information Systems 36, no. 5 (July 2011): 825–42. http://dx.doi.org/10.1016/j.is.2011.01.001.

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GOTO, MATTHEW, RADHA JAGADEESAN, ALAN JEFFREY, CORIN PITCHER, and JAMES RIELY. "An extensible approach to session polymorphism." Mathematical Structures in Computer Science 26, no. 3 (February 23, 2015): 465–509. http://dx.doi.org/10.1017/s0960129514000231.

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Session types describe and constrain the input/output behaviour of systems. Existing session typing systems have limited support for polymorphism. For example, existing systems cannot provide the most general type for a generic proxy process that forwards messages between two channels. We provide a polymorphic session typing system for the π calculus, and demonstrate the utility of session-type-level functions in combination with polymorphic session typing. The type system guarantees subject reduction and safety properties, but not deadlock freedom. We describe a formalization of the type system in Coq. The proofs of subject reduction and safety properties, as well as typing of example processes, have been mechanically verified.
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Hoshizaki, Sugihiko. "Detection of isozyme polymorphism and estimation of geographic variation in the brown planthopper, Nilaparvata lugens (Homoptera: Delphacidae)." Bulletin of Entomological Research 84, no. 4 (December 1994): 503–8. http://dx.doi.org/10.1017/s0007485300032739.

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AbstractIsozyme polymorphism in the brown planthopper, Nilaparvata lugens (Stål) was investigated using isoelectric focusing. Four of the 18 enzyme systems assayed were polymorphic. Allelic designations could be made for two enzyme systems (PGM and AK), but not for GPI and IDH, and GPI seemed to be sex-linked. Using the two highly polymorphic enzyme systems, GPI and PGM, geographic variation was estimated among several Asian (except Japanese) laboratory populations and several Japanese wild populations. Significant variation was observed among the Asian (except Japanese) populations, but the genetic structures of Japanese populations were very similar to each other. These results are suggestive of substantial differentiation among Asian populations and large panmictic structure of the migrant population.
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Chauhan, Ravi, Ulya Sabeel, Alireza Izaddoost, and Shahram Shah Heydari. "Polymorphic Adversarial Cyberattacks Using WGAN." Journal of Cybersecurity and Privacy 1, no. 4 (December 12, 2021): 767–92. http://dx.doi.org/10.3390/jcp1040037.

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Intrusion Detection Systems (IDS) are essential components in preventing malicious traffic from penetrating networks and systems. Recently, these systems have been enhancing their detection ability using machine learning algorithms. This development also forces attackers to look for new methods for evading these advanced Intrusion Detection Systemss. Polymorphic attacks are among potential candidates that can bypass the pattern matching detection systems. To alleviate the danger of polymorphic attacks, the IDS must be trained with datasets that include these attacks. Generative Adversarial Network (GAN) is a method proven in generating adversarial data in the domain of multimedia processing, text, and voice, and can produce a high volume of test data that is indistinguishable from the original training data. In this paper, we propose a model to generate adversarial attacks using Wasserstein GAN (WGAN). The attack data synthesized using the proposed model can be used to train an IDS. To evaluate the trained IDS, we study several techniques for updating the attack feature profile for the generation of polymorphic data. Our results show that by continuously changing the attack profiles, defensive systems that use incremental learning will still be vulnerable to new attacks; meanwhile, their detection rates improve incrementally until the polymorphic attack exhausts its profile variables.
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Dissertations / Theses on the topic "Polymorphic systems"

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Towler, Christopher. "Nucleation in polymorphic systems." Thesis, University of Manchester, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520283.

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Mathieson, John T. J. "Towards Polymorphic Systems Engineering." Thesis, The George Washington University, 2021. http://pqdtopen.proquest.com/#viewpdf?dispub=28257912.

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Systems engineering is widely regarded as a full life cycle discipline and provides methodologies and processes to support the design, development, verification, sustainment, and disposal of systems. While this cradle-to-grave concept is well documented throughout literature, there has been recent and ever-increasing emphasis on evolving and digitally transforming systems engineering methodologies, practices, and tools to a model-based discipline, not only for advancing system development, but perhaps more importantly for extending agility and adaptability through the later stages of system life cycles – through system operations and sustainment. This research adopts principles from the software engineering domain DevOps concept (a collaborative merger of system development and system operations) into a Systems Engineering DevOps Lemniscate life cycle model. This progression on traditional life cycle models lays a foundation for the continuum of model-based systems engineering artifacts during the life of a system and promotes the coexistence and symbiosis of variants throughout. This is done by facilitating a merger of model-based systems engineering processes, tools, and products into a surrogate and common modeling environment in which the operations and sustainment of a system is tied closely to the curation of a descriptive system model. This model-based approach using descriptive system models, traditionally leveraged for system development, is now expanded to include the operational support elements necessary to operate and sustain the system (i.e. executable procedures, command scripts, maintenance manuals, etc. modeled as part of the core system). This evolution on traditional systems engineering implementation, focused on digitally transforming and enhancing system operations and sustainment, capitalizes on the ability of model-based systems engineering to embrace change to improve agility in the later life cycle stages and emphasizes the existence of polymorphic systems engineering (performing a variety of systems engineering roles in simultaneously occurring life cycle stages to increase system agility). A model-based framework for applying the Systems Engineering DevOps life cycle model is introduced as a new Systems Modeling Language profile. A use-case leveraging this “Model-Based System Operations” framework demonstrates how merging operational support elements into a spacecraft system model improves adaptability of support elements in response to faults, failures, and evolving environments during system operations, exemplifying elements of a DevOps approach to cyber-physical system sustainment.
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Lopes, Joao Antonio Correia. "An architecture for the compilation of persistent polymorphic reflective higher-order languages." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360127.

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Petrucciani, Tommaso. "Polymorphic set-theoretic types for functional languages." Thesis, Sorbonne Paris Cité, 2019. http://www.theses.fr/2019USPCC067.

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Cette thèse porte sur l'étude des types ensemblistes : des types qui contiennent des connecteurs d'union, d'intersection et de négation. Les types ensemblistes permettent de typer de manière très précise plusieurs constructions des langages de programmation (comme par exemple les branches conditionnelles, le filtrage par motif et la surcharge des fonctions) lorsqu'ils sont utilisés avec une notion appropriée de sous-typage. Pour définir celle-ci, nous utilisons l'approche du sous-typage sémantique, dans laquelle les types sont interprétés comme des ensembles, et où le sous-typage est défini comme l'inclusion ensembliste. Dans la plupart de cette thèse, les types ensemblistes sont polymorphes, dans le sens où ils contiennent des variables de type pour permettre le polymorphisme paramétrique.La thèse étend les travaux précédents sur les types ensemblistes et le sous-typage sémantique en montrant comment les adapter à de nouveaux contextes et comment les utiliser pour typer plusieurs aspects des langages fonctionnels. Elle se compose de trois parties.La première partie porte sur une étude des langages typés de manière implicite avec polymorphisme du "let" et inférence de types (contrairement aux travaux précédents sur le sous-typage sémantique qui étudiaient des langages typés explicitement). Nous y décrivons un lambda-calcul typé implicitement avec un système de types dont nous démontrons la correction. De même, nous y étudions l'inférence de types dont nous démontrons la correction et la complétude. Enfin, nous montrons comment rendre l'inférence plus précise quand les programmes sont partiellement annotés avec des types.La deuxième partie décrit une nouvelle approche permettant d'étendre un système de types statique avec du typage graduel; l'originalité venant du fait que nous décrivons le système de types de façon déclarative, lorsque les systèmes existants proposent des descriptions algorithmiques. Nous illustrons cette approche en ajoutant le typage graduel à un système de types à la Hindley-Milner sans sous-typage. Nous décrivons pour cela un système de types déclaratif, un processus de compilation vers un langage avec vérifications de type dynamiques (ou "casts"), et nous présentons un système d'inférence de types correct et complet. Ensuite, nous y ajoutons les types ensemblistes, en définissant une relation de sous-typage sur les types graduel ensemblistes, puis en présentant un système d'inférence de types correct pour le système étendu.La troisième partie porte sur l'étude des sémantiques non-strictes. Les systèmes existants qui utilisent le sous-typage sémantique ont été développés pour des langages avec appel par valeur et ne sont pas sûrs pour des sémantiques non-strictes. Nous montrons ici comment les adapter pour garantir leur sûreté en appel par nécessité. Pour faire ça, nous introduisons dans les types une représentation explicite de la divergence, afin que le système des types puisse distinguer les expressions qui ne demandent pas d'évaluation de celles qui la demandent et pourraient ainsi diverger
We study set-theoretic types: types that include union, intersection, and negation connectives. Set-theoretic types, coupled with a suitable subtyping relation, are useful to type several programming language constructs – including conditional branching, pattern matching, and function overloading – very precisely. We define subtyping following the semantic subtyping approach, which interprets types as sets and defines subtyping as set inclusion. Our set-theoretic types are polymorphic, that is, they contain type variables to allow parametric polymorphism.We extend previous work on set-theoretic types and semantic subtyping by showing how to adapt them to new settings and apply them to type various features of functional languages. More precisely, we integrate semantic subtyping with three important language features.In Part I we study implicitly typed languages with let-polymorphism and type inference (previous work on semantic subtyping focused on explicitly typed languages). We describe an implicitly typed lambda-calculus and a declarative type system for which we prove soundness. We study type inference and prove results of soundness and completeness. Then, we show how to make type inference more precise when programs are partially annotated with types.In Part II we study gradual typing. We describe a new approach to add gradual typing to a static type system; the novelty is that we give a declarative presentation of the type system, while previous work considered algorithmic presentations. We first illustrate the approach on a Hindley-Milner type system without subtyping. We describe declarative typing, compilation to a cast language, and sound and complete type inference. Then, we add set-theoretic types, defining a subtyping relation on set-theoretic gradual types, and we describe sound type inference for the extended system.In Part III we consider non-strict semantics. The existing semantic subtyping systems are designed for call-by-value languages and are unsound for non-strict semantics. We adapt them to obtain soundness for call-by-need. To do so, we introduce an explicit representation for divergence in the types, allowing the type system to distinguish the expressions that are already evaluated from those that are computations which might diverge
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Sattler, Christian. "On the complexities of polymorphic stream equation systems, isomorphism of finitary inductive types, and higher homotopies in univalent universes." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/28111/.

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This thesis is composed of three separate parts. The first part deals with definability and productivity issues of equational systems defining polymorphic stream functions. The main result consists of showing such systems composed of only unary stream functions complete with respect to specifying computable unary polymorphic stream functions. The second part deals with syntactic and semantic notions of isomorphism of finitary inductive types and associated decidability issues. We show isomorphism of so-called guarded types decidable in the set and syntactic model, verifying that the answers coincide. The third part deals with homotopy levels of hierarchical univalent universes in homotopy type theory, showing that the n-th universe of n-types has truncation level strictly n+1.
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Simone, Elena. "Application of process analytical technology (PAT) tools for the better understanding and control of the crystallization of polymorphic and impure systems." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/20098.

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This work presents a comprehensive study on the application of PAT tools to study, monitor and control polymorphism during batch cooling crystallization processes. For the first time, the same techniques were used to control and adjust polymorphic purity of the solid phase but also to investigate the relation between chemical equilibrium in solution and polymorphic outcome of cooling crystallization. Crystallization is an important unit operation used as separation and purification technique. It is widely employed in the pharmaceutical, chemical, agrochemical, food and cosmetics industries but also in the electronic, metallurgic and material industries. More than 90% of the APIs on the market are produced by crystallization, therefore, monitoring and control this process is fundamental to ensure the quality of the final product. The implementation of process analytical technology (PAT) tools during the development stage of APIs has largely helped in better understanding and optimizing both batch and, more recently, continuous crystallization. Polymorphism is the capacity of a compound to crystallize in more than one different crystalline structure, which can have different properties such as density, melting point, bioavailability and solubility. The choice of solvent, pH, kinetic conditions and presence of impurities has very strong effect on the polymorphic outcome of a cooling crystallization in solution. Understanding this phenomenon as well as being able to monitor and control it during industrial crystallization is one the biggest challenges for pharmaceutical industries.
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Hogan, J. L. "The polymorphism of headgroup methylated phosphatidylethanolamines." Thesis, University of Southampton, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.235235.

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Connor, R. C. H. "Types and polymorphism in persistent programming systems." Thesis, University of St Andrews, 1991. http://hdl.handle.net/10023/13487.

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Fonseca, Gutierrez Maria del Carmen. "Genetic polymorphism in systemic sclerosis." Thesis, University College London (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409294.

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Johansson, Börje. "An implementation of Milner's CCS with a polymorphic type system." Licentiate thesis, Luleå tekniska universitet, EISLAB, 1996. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18530.

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Books on the topic "Polymorphic systems"

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Tandem repeat polymorphisms: Genetic plasticity, neural diversity, and disease. New York, N.Y: Springer Science+Business Media, 2012.

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Nakov, Svetlin. Fundamentals of Computer Programming with C#: The Bulgarian C# Book. Sofia, Bulgaria: Svetlin Nakov, 2013.

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Bernstein, Joel. Polymorphism in Molecular Crystals. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780199655441.001.0001.

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First recognized in 1822, polymorphism of crystals is now a widely recognized and observed phenomenon, with both fundamental and commercial ramifications in disciplines and industries that study and utilize solid forms of matter. The purpose of this edition is to summarize and to bring up to date the current knowledge and understanding of polymorphism in molecular crystals, and to concentrate it in one source. The information has been gleaned from a wide variety (~2500) of sources in the open literature; however, because of the increasing commercial importance of the phenomenon, a significant portion of the information is less accessible, we have attempted to include both the information from those sources as well with full details of their citations. An introductory chapter on fundamental concepts, definitions, and historical development is followed by a presentation of the physical and structural bases for crystallization and polymorphism. The exploration of the crystal form landscape is described in detail, including polymorph screens, concomitant polymorphs, and disappearing polymorphs. A survey of analytical methods for studying and characterizing polymorphs is followed by a discussion of rapidly developing computational methods for studying and attempting to predict polymorphic behavior. A chapter with many examples of the utilization of polymorphic systems to investigate structure–property relationships in solids precedes three individual chapters on the role and importance of polymorphism in pharmaceuticals, high energy materials, and pigments. The book closes with a chapter on the role of polymorphism in establishing and protecting intellectual property connected with polymorphs through the patent system.
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Roach, Andrew Kennedy. The bus structure for a polymorphic computer system. 1986.

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Polymorphism in condensed matter model systems: Recent progress via scale-bridging modeling. Courtaboeuf, France: EDP Sciences ; [Berlin], 2007.

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Minelli, Alessandro. Evolvability and Its Evolvability. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780199377176.003.0007.

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No universally accepted notion of evolvability is available, focus being alternatively put onto either genetic or phenotypic change. The heuristic power of this concept is best found when considering the intricacies of the genotype→phenotype map, which is not necessarily predictable, expression of variation depending on the structure of gene networks and especially on the modularity and robustness of developmental systems. We can hardly ignore evolvability whenever studying the role of cryptic variation in evolution, the often pervious boundary between phenotypic plasticity and the expression of a genetic polymorphism, the major phenotypic leaps that the mechanisms of development can produce based on point mutations, or the morphological stasis that reveals how robust a developmental process can be in front of genetic change. Evolvability is subject itself to evolution, but it is still uncertain to what extent there is positive selection for enhanced evolvability, or for evolvability biased in a specific direction.
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Testing for cytochrome P450 polymorphisms in adults with non-psychotic depression treated with selective serotonin reuptake inhibitors (SSRIs). Rockville, MD: AHRQ, 2007.

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B, Matchar David, United States. Agency for Healthcare Research and Quality., and Duke University Evidence-based Practice Center., eds. Testing for cytochrome P450 polymorphisms in adults with non-psychotic depression treated with selective serotonin reuptake inhibitors (SSRIs). Rockville, MD: Agency for Healthcare Research and Quality, 2007.

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Whitworth, Caroline, and Stewart Fleming. Malignant hypertension. Edited by Neil Turner. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199592548.003.0216.

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Malignant hypertension (MH) is recognized clinically by elevated blood pressure together with retinal haemorrhages or exudates with or without papilloedema (grades III or IV hypertensive retinopathy); and may constitute a hypertensive emergency or crisis when complicated by evidence of end-organ damage including microangiopathic haemolysis, encephalopathy, left ventricular failure, and renal failure. Though reversible, it remains a significant cause of end-stage renal failure, and of cardiovascular and cerebrovascular morbidity and mortality in developing countries.MH can complicate pre-existing hypertension arising from diverse aetiologies, but most commonly develops from essential hypertension. The absolute level of blood pressure appears not to be critical to the development of MH, but the rate of rise of blood pressure may well be relevant in the pathogenesis. The pathogenesis of this transformation remains unclear.The pathological hallmark of MH is the presence of fibrinoid necrosis (medial vascular smooth muscle cell necrosis and fibrin deposition within the intima) involving the resistance arterioles in many organs. Fibrinoid necrosis is not specific to MH and this appearance is seen in other conditions causing a thrombotic microangiopathy such as haemolytic uraemic syndrome, scleroderma renal crisis, antiphospholipid syndrome, and acute vascular rejection post transplant. MH can both cause a thrombotic microangiopathy (TMA) but can also complicate underlying conditions associated with TMA.The pathophysiological factors that interact to generate and sustain this condition remain poorly understood. Risk factors include Afro-Caribbean race, smoking history, younger age of onset of hypertension, previous pregnancy, and untreated hypertension associated with non-compliance or cessation of antihypertensive therapy.Evidence from clinical studies and animal models point to a central role for the intrarenal renin–angiotensin system (RAS) in MH; there is good evidence for renal vasoconstriction and activation of the renal paracrine RAS potentiating MH once established; however, there may also be a role in the predisposition of MH suggested by presence of increased risk conferred by an ACE gene polymorphism in humans and polymorphisms for both ACE and AT1 receptor in an animal model of spontaneous MH. Other vasoactive mediators such as the endothelin and the inflammatory response may be important contributing to and increasing endothelial damage. There have been no randomized controlled trials to define the best treatment approach, but progressive lowering of pressures over days is considered safest unless made more urgent by critical clinical state. It seems logical to introduce ACE inhibition cautiously and early, but in view of the risk of rapid pressure lowering some recommend delay.
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Book chapters on the topic "Polymorphic systems"

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Belo, João Filipe, Michael Greenberg, Atsushi Igarashi, and Benjamin C. Pierce. "Polymorphic Contracts." In Programming Languages and Systems, 18–37. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-19718-5_2.

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Alhazov, Artiom, Sergiu Ivanov, and Yurii Rogozhin. "Polymorphic P Systems." In Membrane Computing, 81–94. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-18123-8_9.

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Stoica, Adrian, Ricardo Zebulum, and Didier Keymeulen. "Polymorphic Electronics." In Evolvable Systems: From Biology to Hardware, 291–302. Berlin, Heidelberg: Springer Berlin Heidelberg, 2001. http://dx.doi.org/10.1007/3-540-45443-8_26.

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Bernardy, Jean-Philippe, Patrik Jansson, and Koen Claessen. "Testing Polymorphic Properties." In Programming Languages and Systems, 125–44. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-11957-6_8.

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Pande, Amit, and Joseph Zambreno. "Polymorphic Wavelet Transform." In Embedded Multimedia Security Systems, 33–65. London: Springer London, 2013. http://dx.doi.org/10.1007/978-1-4471-4459-5_4.

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Sekiyama, Taro, and Atsushi Igarashi. "Handling Polymorphic Algebraic Effects." In Programming Languages and Systems, 353–80. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-17184-1_13.

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Craig, Duncan Q. M. "Characterization of Polymorphic Systems Using Thermal Analysis." In Polymorphism, 43–79. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2006. http://dx.doi.org/10.1002/3527607889.ch3.

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Henglein, Fritz, and Christian Mossin. "Polymorphic binding-time analysis." In Programming Languages and Systems — ESOP '94, 287–301. Berlin, Heidelberg: Springer Berlin Heidelberg, 1994. http://dx.doi.org/10.1007/3-540-57880-3_19.

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Toninho, Bernardo, and Nobuko Yoshida. "On Polymorphic Sessions and Functions." In Programming Languages and Systems, 827–55. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-89884-1_29.

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Seco, João Costa, and Luís Caires. "Subtyping First-Class Polymorphic Components." In Programming Languages and Systems, 342–56. Berlin, Heidelberg: Springer Berlin Heidelberg, 2005. http://dx.doi.org/10.1007/978-3-540-31987-0_24.

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Conference papers on the topic "Polymorphic systems"

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Lucassen, J. M., and D. K. Gifford. "Polymorphic effect systems." In the 15th ACM SIGPLAN-SIGACT symposium. New York, New York, USA: ACM Press, 1988. http://dx.doi.org/10.1145/73560.73564.

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Lerner, Sorin, Stephen R. Foster, and William G. Griswold. "Polymorphic Blocks." In CHI '15: CHI Conference on Human Factors in Computing Systems. New York, NY, USA: ACM, 2015. http://dx.doi.org/10.1145/2702123.2702302.

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Mendis, B. S. U., and T. D. Gedeon. "Polymorphic fuzzy signatures." In 2010 IEEE International Conference on Fuzzy Systems (FUZZ-IEEE). IEEE, 2010. http://dx.doi.org/10.1109/fuzzy.2010.5584440.

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Seilert, Julia, and Eckhard Floter. "Relating polymorphic transition and triglyceride composition." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/uiuq2084.

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Structuring fats are complex triglyceride (TAG) mixtures characterized by diverse crystallization events. These range from co- and subsequent crystallization of different fractions determined by the mixture's phase behavior, i.e., solid immiscibility, to polymorphism shaping the overall crystallization kinetics. The kinetics behind polymorphism differ depending on TAG type and fractions, complicating this even more. Several experimental studies have shown that multiple-step crystallization takes place, in which, in most cases, the first step is assigned to the formation of α-crystals followed by melt-mediated β' crystallization - the latter being the so-called polymorphic transition. Both are important in fats processing utilizing a combination of shear with rapid cooling, e.g., in a scraped surface heat exchanger. This obeys highly dynamic conditions often not captured using standard methods, e.g., Differential Scanning Calorimetry, rheology, XRD, leading to even more complex crystallization phenomena unexplored. In search of new techniques, the evaluation of measurements must be undertaken with care with regard to the TAG composition. This contribution presents a first step towards linking the TAG molecular composition to characteristic crystallization events observed using varying techniques in the static and dynamic mode. Using model systems of varying TAG fractions with different melting characteristics, the contributions to the described crystallization kinetics are discussed.
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Veenhuis, Christian, and Mario Koppen. "Differential evolution with polymorphic schemes." In 2009 IEEE International Conference on Systems, Man and Cybernetics. SMC 2009. IEEE, 2009. http://dx.doi.org/10.1109/icsmc.2009.5346652.

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Ciobanu, Catalin, Georgi Gaydadjiev, Christian Pilato, and Donatella Sciuto. "Dataflow computing with Polymorphic Registers." In 2013 International Conference on Embedded Computer Systems: Architectures, Modeling, and Simulation (SAMOS XIII). IEEE, 2013. http://dx.doi.org/10.1109/samos.2013.6621140.

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Abia, Mike, and Irwin Brown. "A Polymorphic Model of Information Systems Success." In the 2015 Annual Research Conference. New York, New York, USA: ACM Press, 2015. http://dx.doi.org/10.1145/2815782.2815814.

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Fiser, Petr, and Vaclav Simek. "Optimum polymorphic circuits synthesis method." In 2018 13th International Conference on Design & Technology of Integrated Systems In Nanoscale Era (DTIS). IEEE, 2018. http://dx.doi.org/10.1109/dtis.2018.8368585.

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Messie, D., and J. C. Oh. "SWARMs of self-organizing polymorphic agents." In Fifth International Conference on Hybrid Intelligent Systems (HIS'05). IEEE, 2005. http://dx.doi.org/10.1109/ichis.2005.101.

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Ruzicka, Richard, Vaclav Simek, and Lukas Sekanina. "Behavior of CMOS polymorphic circuits in high temperature environment." In Systems (DDECS). IEEE, 2011. http://dx.doi.org/10.1109/ddecs.2011.5783134.

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Reports on the topic "Polymorphic systems"

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Levisohn, Sharon, Maricarmen Garcia, David Yogev, and Stanley Kleven. Targeted Molecular Typing of Pathogenic Avian Mycoplasmas. United States Department of Agriculture, January 2006. http://dx.doi.org/10.32747/2006.7695853.bard.

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Intraspecies identification (DNA "fingerprinting") of pathogenic avian mycoplasmas is a powerful tool for epidemiological studies and monitoring strain identity. However the only widely method available for Mycoplasma gallisepticum (MG) and M. synoviae (MS)wasrandom amplified polymorphic DNA (RAPD). This project aimed to develop alternative and supplementary typing methods that will overcome the major constraints of RAPD, such as the need for isolation of the organism in pure culture and the lack of reproducibility intrinsic in the method. Our strategy focussed on recognition of molecular markers enabling identification of MG and MS vaccine strains and, by extension, pathogenic potential of field isolates. Our first aim was to develop PCR-based systems which will allow amplification of specific targeted genes directly from clinical material. For this purpose we evaluated the degree of intraspecies heterogeneity in genes encoding variable surface antigens uniquely found in MG all of which are putative pathogenicity factors. Phylogenic analysis of targeted sequences of selected genes (pvpA, gapA, mgc2, and lp) was employed to determine the relationship among MG strains.. This method, designated gene targeted sequencing (GTS), was successfully employed to identify strains and to establish epidemiologically-linked strain clusters. Diagnostic PCR tests were designed and validated for each of the target genes, allowing amplification of specific nucleotide sequences from clinical samples. An mgc2-PCR-RFLP test was designed for rapid differential diagnosis of MG vaccine strains in Israel. Addressing other project goals, we used transposon mutagenesis and in vivo and in vitro models for pathogenicity to correlated specific changes in target genes with biological properties that may impact the course of infection. An innovative method for specific detection and typing of MS strains was based on the hemagglutinin-encoding gene vlhA, uniquely found in this species. In parallel, we evaluated the application of amplified fragment length polymorphism (AFLP) in avian mycoplasmas. AFLP is a highly discriminatory method that scans the entire genome using infrequent restriction site PCR. As a first step the method was found to be highly correlated with other DNA typing methods for MG species and strain differentiation. The method is highly reproducible and relatively rapid, although it is necessary to isolate the strain to be tested. Both AFLP and GTS are readily to amenable to computer-assisted analysis of similarity and construction of a data-base resource. The availability of improved and diverse tools will help realize the full potential of molecular typing of avian mycoplasmas as an integral and essential part of mycoplasma control programs.
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Miller, Andrew C., Barry S. Payne, and Fawn M. Burns. Zebra Mussel Research. Introduction and Spread of Dreissena polymorpha in the U.S. Inland Waterway System, 1992-1993. Fort Belvoir, VA: Defense Technical Information Center, October 1995. http://dx.doi.org/10.21236/ada303351.

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Cao, Xianling, Xuanyou Zhou, Naixin Xu, Songchang Chang, and Chenming Xu. Association of IL-4 and IL-10 Polymorphisms with Preterm Birth Susceptibility: A Systematic Review and Meta-Analysis. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, April 2022. http://dx.doi.org/10.37766/inplasy2022.4.0044.

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Review question / Objective: The aim of our systematic review and meta-analysis was to summarize the effects of IL-4 and IL-10 gene polymorphism and clarify their possible association with PTB. Condition being studied: World Health Organization (WHO) defines preterm birth (PTB) as babies born alive before 37 weeks of pregnancy are completed. The new estimates show that the prevalence of PTB during 2014 ranged from 8.7% to13.4% of all live births, about 15 million preterm babies born each year. Besides, PTB is the leading cause of death worldwide for children below 5 years of age. Babies born preterm are at an increased risk of short-term and long-term complications attributed to immaturity of multiple organ systems, such as cerebral palsy, intellectual disabilities, vision and hearing impairments, and impaired cognitive development. PTB has become a worldwide public health problem, but its etiology remains unclear. Accumulating evidence shows that PTB is a syndrome that can be attributed to a variety of pathological processes(5). Inflammatory diseases and genetic background are known risk factors for PTB, many studies had shown that genetic variations in proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1 α (IL-1 α) are associated with increased risk of PTB, but the relationship between genetic polymorphism in anti-inflammatory cytokines and risk of PTB remains controversial.
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Yuan, Qihang. Circulating Leptin Level, Soluble Leptin Receptor Level and Their Gene Polymorphism in Patients with Systemic Lupus Erythematosus: A Systematic Review and Meta-analysis. INPLASY - International Platform of Registered Systematic Review Protocols, April 2020. http://dx.doi.org/10.37766/inplasy2020.4.0137.

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Huang, Kecheng, Aiyue Luo, Rvnfeng Yang, Wenyu Pei, Chen Zhang, Chuqin Wu, Zhilan Chen, et al. Polymorphism of rs1799782 (c.580C>T) is associated with outcome of NSCLC patients treated with platinum-based chemotherapy: a system review and meta-analysis. INPLASY - International Platform of Registered Systematic Review and Meta-analysis Protocols, September 2021. http://dx.doi.org/10.37766/inplasy2021.9.0052.

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Funkenstein, Bruria, and Shaojun (Jim) Du. Interactions Between the GH-IGF axis and Myostatin in Regulating Muscle Growth in Sparus aurata. United States Department of Agriculture, March 2009. http://dx.doi.org/10.32747/2009.7696530.bard.

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Growth rate of cultured fish from hatching to commercial size is a major factor in the success of aquaculture. The normal stimulus for muscle growth in growing fish is not well understood and understanding the regulation of muscle growth in fish is of particular importance for aquaculture. Fish meat constitutes mostly of skeletal muscles and provides high value proteins in most people's diet. Unlike mammals, fish continue to grow throughout their lives, although the size fish attain, as adults, is species specific. Evidence indicates that muscle growth is regulated positively and negatively by a variety of growth and transcription factors that control both muscle cell proliferation and differentiation. In particular, growth hormone (GH), fibroblast growth factors (FGFs), insulin-like growth factors (IGFs) and transforming growth factor-13 (TGF-13) play critical roles in myogenesis during animal growth. An important advance in our understanding of muscle growth was provided by the recent discovery of the crucial functions of myostatin (MSTN) in controlling muscle growth. MSTN is a member of the TGF-13 superfamily and functions as a negative regulator of skeletal muscle growth in mammals. Studies in mammals also provided evidence for possible interactions between GH, IGFs, MSTN and the musclespecific transcription factor My oD with regards to muscle development and growth. The goal of our project was to try to clarify the role of MSTNs in Sparus aurata muscle growth and in particular determine the possible interaction between the GH-IGFaxis and MSTN in regulating muscle growth in fish. The steps to achieve this goal included: i) Determining possible relationship between changes in the expression of growth-related genes, MSTN and MyoD in muscle from slow and fast growing sea bream progeny of full-sib families and that of growth rate; ii) Testing the possible effect of over-expressing GH, IGF-I and IGF-Il on the expression of MSTN and MyoD in skeletal muscle both in vivo and in vitro; iii) Studying the regulation of the two S. aurata MSTN promoters and investigating the possible role of MyoD in this regulation. The major findings of our research can be summarized as follows: 1) Two MSTN promoters (saMSTN-1 and saMSTN-2) were isolated and characterized from S. aurata and were found to direct reporter gene activity in A204 cells. Studies were initiated to decipher the regulation of fish MSTN expression in vitro using the cloned promoters; 2) The gene coding for saMSTN-2 was cloned. Both the promoter and the first intron were found to be polymorphic. The first intron zygosity appears to be associated with growth rate; 3) Full length cDNA coding for S. aurata growth differentiation factor-l I (GDF-II), a closely related growth factor to MSTN, was cloned from S. aurata brain, and the mature peptide (C-terminal) was found to be highly conserved throughout evolution. GDF-II transcript was detected by RT -PCR analysis throughout development in S. aurata embryos and larvae, suggesting that this mRNA is the product of the embryonic genome. Transcripts for GDF-Il were detected by RT-PCR in brain, eye and spleen with highest level found in brain; 4) A novel member of the TGF-Bsuperfamily was partially cloned from S. aurata. It is highly homologous to an unidentified protein (TGF-B-like) from Tetraodon nigroviridisand is expressed in various tissues, including muscle; 5) Recombinant S. aurata GH was produced in bacteria, refolded and purified and was used in in vitro and in vivo experiments. Generally, the results of gene expression in response to GH administration in vivo depended on the nutritional state (starvation or feeding) and the time at which the fish were sacrificed after GH administration. In vitro, recombinantsaGH activated signal transduction in two fish cell lines: RTHI49 and SAFI; 6) A fibroblastic-like cell line from S. aurata (SAF-I) was characterized for its gene expression and was found to be a suitable experimental system for studies on GH-IGF and MSTN interactions; 7) The gene of the muscle-specific transcription factor Myogenin was cloned from S. aurata, its expression and promoter activity were characterized; 8) Three genes important to myofibrillogenesis were cloned from zebrafish: SmyDl, Hsp90al and skNAC. Our data suggests the existence of an interaction between the GH-IGFaxis and MSTN. This project yielded a great number of experimental tools, both DNA constructs and in vitro systems that will enable further studies on the regulation of MSTN expression and on the interactions between members of the GHIGFaxis and MSTN in regulating muscle growth in S. aurata.
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Funkenstein, Bruria, and Cunming Duan. GH-IGF Axis in Sparus aurata: Possible Applications to Genetic Selection. United States Department of Agriculture, November 2000. http://dx.doi.org/10.32747/2000.7580665.bard.

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Many factors affect growth rate in fish: environmental, nutritional, genetics and endogenous (physiological) factors. Endogenous control of growth is very complex and many hormone systems are involved. Nevertheless, it is well accepted that growth hormone (GH) plays a major role in stimulating somatic growth. Although it is now clear that most, if not all, components of the GH-IGF axis exist in fish, we are still far from understanding how fish grow. In our project we used as the experimental system a marine fish, the gilthead sea bream (Sparus aurata), which inhabits lagoons along the Mediterranean and Atlantic coasts of Europe, and represents one of the most important fish species used in the mariculture industry in the Mediterranean region, including Israel. Production of Sparus is rapidly growing, however, in order for this production to stay competitive, the farming of this fish species has to intensify and become more efficient. One drawback, still, in Sparus extensive culture is that it grows relatively slow. In addition, it is now clear that growth and reproduction are physiological interrelated processes that affect each other. In particular sexual maturation (puberty) is known to be closely related to growth rate in fish as it is in mammals, indicating interactions between the somatotropic and gonadotropic axes. The goal of our project was to try to identify the rate-limiting components(s) in Sparus aurata GH-IGF system which might explain its slow growth by studying the ontogeny of growth-related genes: GH, GH receptor, IGF-I, IGF-II, IGF receptor, IGF-binding proteins (IGFBPs) and Pit-1 during early stages of development of Sparus aurata larvae from slow and fast growing lines. Our project was a continuation of a previous BARD project and could be divided into five major parts: i) obtaining additional tools to those obtained in the previous project that are necessary to carry out the developmental study; ii) the developmental expression of growth-related genes and their cellular localization; iii) tissue-specific expression and effect of GH on expression of growth-related genes; iv) possible relationship between GH gene structure, growth rate and genetic selection; v) the possible role of the IGF system in gonadal development. The major findings of our research can be summarized as follows: 1) The cDNAs (complete or partial) coding for Sparus IGFBP-2, GH receptor and Pit-1 were cloned. Sequence comparison reveals that the primary structure of IGFBP-2 protein is 43-49% identical to that of zebrafish and other vertebrates. Intensive efforts resulted in cloning a fragment of 138 nucleotides, coding for 46 amino acids in the proximal end of the intracellular domain of GH receptor. This is the first fish GH receptor cDNA that had been cloned to date. The cloned fragment will enable us to complete the GH - receptor cloning. 2) IGF-I, IGF-II, IGFBP-2, and IGF receptor transcripts were detected by RT-PCR method throughout development in unfertilized eggs, embryos, and larvae suggesting that these mRNAs are products of both the maternal and the embryonic genomes. Preliminary RT-PCR analysis suggest that GH receptor transcript is present in post-hatching larvae already on day 1. 3) IGF-1R transcripts were detected in all tissues tested by RT-PCR with highest levels in gill cartilage, skin, kidney, heart, pyloric caeca, and brain. Northern blot analysis detected IGF receptor only in gonads, brain and gill cartilage but not in muscle; GH increased slightly brain and gill cartilage IGF-1R mRNA levels. 4) IGFBP-2 transcript were detected only in liver and gonads, when analyzed by Northern blots; RT-PCR analysis revealed expression in all tissues studied, with the highest levels found in liver, skin, gonad and pyloric caeca. 5) Expression of IGF-I, IGF-II, IGF-1R and IGFBP-2 was analyzed during gonadal development. High levels of IGF-I and IGFBP-2 expression were found in bisexual young gonads, which decreased during gonadal development. Regardless of maturational stage, IGF-II levels were higher than those of IGF-L 6) The GH gene was cloned and its structure was characterized. It contains minisatellites of tandem repeats in the first and third introns that result in high level of genetic polymorphism. 7) Analysis of the presence of IGF-I and two types of IGF receptor by immunohistochemistry revealed tissue- and stage-specific expression during larval development. Immunohistochemistry also showed that IGF-I and its receptors are present in both testicular and ovarian cells. Although at this stage we are not able to pinpoint which is the rate-limiting step causing the slow growth of Sparus aurata, our project (together with the previous BARD) yielded a great number of experimental tools both DNA probes and antibodies that will enable further studies on the factors regulating growth in Sparus aurata. Our expression studies and cellular localization shed new light on the tissue and developmental expression of growth-related genes in fish.
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Perl-Treves, Rafael, Rebecca Grumet, Nurit Katzir, and Jack E. Staub. Ethylene Mediated Regulation of Sex Expression in Cucumis. United States Department of Agriculture, January 2005. http://dx.doi.org/10.32747/2005.7586536.bard.

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Monoecious species such as melon and cucumber develop separate male and female (or bisexual) flowers on the same plant individual. They display complex genetic and hormonal regulation of sex patterns along the plant. Ethylene is known to play an important role in promoting femaleness and inhibiting male development, but many questions regarding critical sites of ethylene production versus perception, the relationship between ethylene and the sex determining loci, and the possible differences between melon and cucumber in this respect are still open. The general goal of the project was to elucidate the role of ethylene in determining flower sex in Cucumis species, melon and cucumber. The specific Objectives were: 1. Clone and characterize expression patterns of cucumber genes involved in ethylene biosynthesis and perception. 2. Genetic mapping of cloned genes and markers with respect to sex loci in melon and cucumber. 3. Produce and analyze transgenic melons altered in ethylene production or perception. In the course of the project, some modifications/adjustments were made: under Objective 2 (genetic mapping) a set of new mapping populations had to be developed, to allow better detection of polymorphism. Under Objective 3, cucumber transformation systems became available to us and we included this second model species in our plan. The main findings of our study support the pivotal role of ethylene in cucumber and melon sex determination and later stages of reproductive development. Modifying ethylene production resulted in profound alteration of sex patterns in melon: femaleness increased, and also flower maturation and fruit set were enhanced, resulting in earlier, more concentrated fruit yield in the field. Such effect was previously unknown and could have agronomic value. Our results also demonstrate the great importance of ethylene sensitivity in sex expression. Ethylene perception genes are expressed in sex-related patterns, e.g., gynoecious lines express higher levels of receptor-transcripts, and copper treatments that activate the receptor can increase femaleness. Transgenic cucumbers with increased expression of an ethylene receptor showed enhanced femaleness. Melons that expressed a defective receptor produced fewer hermaphrodite flowers and were insensitive to exogenous ethylene. When the expression of defective receptor was restricted to specific floral whorls, we saw that pistils were not inhibited by the blocked perception at the fourth whorl. Such unexpected findings suggest an indirect effect of ethylene on the affected whorl; it also points at interesting differences between melon and cucumber regarding the mode of action of ethylene. Such effects will require further study. Finally, our project also generated and tested a set of novel genetic tools for finer identification of sex determining genes in the two species and for efficient breeding for these characters. Populations that will allow easier linkage analysis of candidate genes with each sex locus were developed. Moreover, effects of modifier genes on the major femaleness trait were resolved. QTL analysis of femaleness and related developmental traits was conducted, and a comprehensive set of Near Isogenic Lines that differ in specific QTLs were prepared and made available for the private and public research. Marker assisted selection (MAS) of femaleness and fruit yield components was directly compared with phenotypic selection in field trials, and the relative efficiency of MAS was demonstrated. Such level of genetic resolution and such advanced tools were not used before to study these traits, that act as primary yield components to determine economic yields of cucurbits. In addition, this project resulted in the establishment of workable transformation procedures in our laboratories and these can be further utilized to study the function of sex-related genes in detail.
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Droby, Samir, Joseph W. Eckert, Shulamit Manulis, and Rajesh K. Mehra. Ecology, Population Dynamics and Genetic Diversity of Epiphytic Yeast Antagonists of Postharvest Diseases of Fruits. United States Department of Agriculture, October 1994. http://dx.doi.org/10.32747/1994.7568777.bard.

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One of the emerging technologies is the use of microbial agents for the control of postharvest diseases of fruits and vegetables. A number of antagonistic microorganisms have been discovered which have the potential to effectively control postharvest diseases. Some of this technology has been patented and commercial products such as AspireTM (Ecogen Corporatin, Langhorne, PA, USA), Biosave 10TM and Biosave 11TM (Ecoscience Inc., Worchester, MA, USA) have been registered for commercial use. The principal investigator of this project was involved in developing the yeast-based biofungicide-AspireTM and testing its efficacy under commercial conditions. This research project was initiated to fill the gap between the knowledge available on development and commercial implementation of yeast biocontrol agents and basic understanding of various aspects related to introducing yeast antagonists to fruit surfaces, along with verification of population genetics. The main objectives of this study were: Study ecology, population dynamics and genetic diversity of the yeast antagonists Candida guilliermondii, C. oleophila, and Debaryomyces hansenii, and study the effect of preharvest application of the yeast antagonist C. oleophila naturally occurring epiphytic microbial population and on the development of postharvest diseases of citrus fruit during storage. Our findings, which were detailed in several publications, have shown that an epiphytic yeast population of grapefruit able to grow under high osmotic conditions and a wide range of temperatures was isolated and characterized for its biocontrol activity against green mold decay caused by Penicillium digitatum. Techniques based on random amplified polymorphic DNA (RAPD) and arbitrary primed polymerase chain reaction (ap-PCR), as well as homologies between sequences of the rDNA internal transcribed spacers (ITS) and 5.8S gene, were used to characterize the composition of the yeast population and to determine the genetic relationship among predominant yeast species. Epiphytic yeasts exhibiting the highest biocontrol activity against P. digitatum on grapefruit were identified as Candida guilliermondii, C. oleophila, C. sake, and Debaryomyces hansenii, while C. guilliermondii was the most predominant species. RAPD and ap-PCR analysis of the osmotolerant yeast population showed two different, major groups. The sequences of the ITS regions and the 5.8S gene of the yeast isolates, previously identified as belonging to different species, were found to be identical. Following the need to develop a genetically marked strain of the yeast C. oleophila, to be used in population dynamics studies, a transformation system for the yeast was developed. Histidine auxotrophy of C. oloephila produced using ethyl methanesulfonate were transformed with plasmids containing HIS3, HIS4 and HIS5 genes from Saccharomyces cerevisiae. In one mutant histidin auxotrophy was complemented by the HIS5 gene of S. cerevisiae is functionally homologous to the HIS5 gene in V. oleophila. Southern blot analysis showed that the plasmid containing the S. cerevisiae HIS5 gene was integrated at a different location every C. oleophila HIS+ transformant. There were no detectable physiological differences between C. oleophila strain I-182 and the transformants. The biological control ability of C. oleophila was not affected by the transformation. A genetically marked (with b-glucuronidase gene) transformant of C. oleophila colonized wounds on orange fruits and its population increased under field conditions. Effect of preharvest application of the yeast C. oleophila on population dynamics of epiphytic microbial population on wounded and unwounded grapefruit surface in the orchard and after harvest was also studied. In addition, the effect of preharvest application of the yeast C. oleophila on the development of postharvest decay was evaluated. Population studies conducted in the orchard showed that in control, non-treated fruit, colonization of wounded and unwounded grapefruit surface by naturally occurring filamentous fungi did not vary throughout the incubation period on the tree. On the other hand, colonization of intact and wounded fruit surface by naturally occurring yeasts was different. Yeasts colonized wounded surface rapidly and increased in numbers to about two orders of magnitude as compared to unwounded surface. On fruit treated with the yeast and kept on the tree, a different picture of fungal and yeast population had emerged. The detected fungal population on the yeast-treated intact surface was dramatically reduced and in treated wounds no fungi was detected. Yeast population on intact surface was relatively high immediately after the application of AspireTM and decreased to than 70% of that detected initially. In wounds, yeast population increased from 2.5 x 104 to about 4x106 after 72 hours of incubation at 20oC. Results of tests conducted to evaluate the effect of preharvest application of AspireTM on the development of postharvest decay indicated the validity of the approach.
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